THE
ROLE
OF
LIGNIN
IN
COAL
GENESIS
By
IRVING
A. BREGER
B.S., Worcester Polytechnic Institute
(1941)
Massachusetts Institute of Technology
S.M.,
(1947)
SUBMITTED IN PARTIAL FULFILLMENT OF THE
REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
at the
MASSACHUSETTS
INSTITUTE OF TECHNOLOGY
(1950)
Signature
of Author.
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Department of Geolo y, May 12, 1950
Certified by .
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Thesis Supervisor
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Chairman, Department Committee on Graduate Students
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TABLE OF CONTENTS
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FIGURES .
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ABSTRACT .
INTRODUCTION .
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Problems
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Historical .
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ACKNOWLEDGEMENTS.
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TABLES
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LIGNIN - REVIEW OF THE LITERATUR:E ............
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Introduction .
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Relationship of Lignin and Cellulose in .
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Plant Structure
Isolation
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LIGNIN
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Summary
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Lignin
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EXPERIMENTAL WORK.
Introduction .
Brauns'
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Periodate Lignin ..........
Russell Lignin .
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LIGNIN
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CHEMICAL AND STRUCTURAL RELATIONSHIP TO HUMUS
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Introduction
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Microbial Decomposition of Plant Components
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LIGNIN
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Vacuum Differential Thermal Analysis . .
Discussion of Thermograms .
Summary and Conclusions
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HIGH PRESSURE STUDIES . ...
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Analytical
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Experimental
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Summary of Results
CONCLUSIONS
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Techniques
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AND PROPOSED WORE . .
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Proposed Work .
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APPENDIX -
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Punched Card Bibliography
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BIOGRAPHICAL SKETCH
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Introduction and Review of the Literature
Description of Equipment
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BASIC STRUCTURES IN THE COAL SERIES . . .
Introduction
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FIGURES
No.
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Title
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Infrared Absorption Curves for Humic
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Acid and Lignin
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Furnace for Vacuum Differential Thermal
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Analysis
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Details of Furnace Construction.........
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Details of Furnace Construction .
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Sample Block for Vacuum Differential
Thermal Analysis
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Photographs of Thermographic Equipment
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Photographs of Thermographic Equipment .
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Thermograms for Wood, Cellulose, and Lignin
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Thermographic Comparison of Various Lignins
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Thermograms of Peats .
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Thermograms of Peats . . . . . . . . . . . . .
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Thermograms of Lignites.
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Thermograms of Bituminous Coals o........
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Thermograms of Bituminous Coals .
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Thermograms of Anthracite Coals .
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Thermograms of Vitrain, Durain, Clarain,
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Coals
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Thermograms of Unclassified Coals
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Thermograms of Pyritized Coal and Pyrite .
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Thermograms of Shales . .
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Details of Construction of Bomb and Piston . .
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for High Pressure Studies
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Photograph of Equipment for High Pressure
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Apparatus for the Determination of Methoxyl . .
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Groups
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Photograph of Golden-Brown Component and
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Radial Fractures in Compressed Lignin
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SubdIvision of Subject Matter and Code for .
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Samole Pumched Card .
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TABLES
Page
Title
No.
Treatment of Spruce Chips with Alcohol.
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to Obtain Native Lignin
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Comparative Data for Various Isolated.
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Correlation of Infrared Absorption,. .....
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Spruce Lignins
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Peaks for Humic Acid and
Brauns' Native Lignin
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Summary of Pressure Experiments and.
Blanks
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112a
ACKNOWLEDGEMENTS
The studies described in this thesis serve
,s
an excellent example of research which can be done in
borderline fields.
In this particular instance the
geological advice, suggestions, and inspiration of
Professor Walter L. Whitehead deserve infinitely more
appreciation than words could possibly convey.
Without the unlimited assistance and coo-eration of Professor Harold Fairbairn, the high pressure
studies would have been difficult to carry out.
Professor
Fairbairn has been extremely generous with his time and
equipment.
The author wishes to acknowledge the
inspirational comments of Professor Robert R. Shrock
who has demonstrated keen insight, along with Professor
Whitehead, in the problems of organic geochemistry.
To
Profs. Clark Goodman and Ernest H. Huntress, who also
served on the committee governing the graduate activities
of the author,
Mr.
are extended gratitude and appreciation.
B. C. Parks of the U. S. Bureau of Mines
was extremely helpful in
used in
this work.
supplying many of the coal samples
Dr. E. E. Harris of the U. S.
Forest
Product Laboratory supplied a large quantity of sulphuricacid lignin, and Dr.
C. A.
Sankey of the Ontario Paper Company
vii.
assisted the author in
obtaining spruce wood chips for
the isolation of periodate lignin.
Particular acknowledgement is
made of the
cooperation of Miss Virginia Burton and Miss Geraldine
Sullivan who assisted the author in every possible
manner.
The reference librarians of the Massachusetts
Institute of Technology Libraries were particularly
helpful during the bibliographic phase of this work.
To my wife,
Ruth,
and my parents and
friends who encouraged me at every possible opportunity,
I dedicate this work.
viii.
ABSTRACT
Many theories have been proposed in the past to
account for the formation of coal from plant materials.
present it
At
is generally accepted that two distinct stages are
recognizable in the coal-forming process: (1) the biochemical
stage, and (2) the dynamochemical stage.
In the first of these
two steps plant components are biochemically degraded to humic
substances, and in the second step the humic materials are
metamorphosed into high grade coals.
Considerable controversy has raged on the proposals
on one hand that cellulose is the chief progenitor of coal,
and on the other hand that lignin is the most probable source
naterial for coal formation.
A very thorough and critical
survey of the literature has been made and the evidence in
favor of and against these proposals has been weighed.
On
the basis of numerous biochemical studies it appears likely
that cellulose is rapidly degraded and removed from organic
sediments leaving behind the lignin which is microbially
transformed but not completely decomposed.
Degradation of the
lignin molecule appears to result in a complex mixture of
products which is collectively called humus.
On the basis of
a study of the structure of lignin, a proposal has been
made for the chemical changes which take place in the lignin
molecule during its conversion to humic materials.
ix.
Apparatus has been designed and constructed for the
differential thermal analysis of complex organic substances
under vacuum.
Using this equipment, a study of several
plant components and of various members of the coal series
has been carried'out.
The decomposition pattern of lignin
appears in the lignite and bituminous members of the coal
series, and suggestions are made for the reasons for its
absence in peats and anthracite coals.
The thermogram for
cellulose is distinctive and aoes not appear in bituminous
or anthracite coals.
Thermographic analyses of peats and
lignites, however, provide evidence for the presence in
some of these materials of small quantities of residual
cellulose.
The thermographic evidence points strongly
towards lignin as the progenitor of coal.
A number of preliminary studies have been carried
out to test the possibility that shear stresses are of
importance in the dynamochemical devolatilization of humic
materials into high grade coals.
Lignin, humic acid
isolated from peat, and peat have been sheared while under
pressures of up to 2280 atmospheres.
These experiments
have been carried out at temperatures as high as 1500 C.
and for durations as long as 32 days.
humic acid appears to undergo
Under these conditions
a definite change in structure
that has not yet been explained.
Lignin, which contains
11.09% of methoxyl groups, is demethylated only to the
extent of 0.4% under these conditions.
These preliminary results, although not
conclusive,
do appear to indicate that a piezochemical
devolatilization of coal-forming materials is possible
under the proper conditions.
Geological evidence points
to shear forces as being important in the coalification
process, but further studies will be required before this
fact can be confirmed on a laboratory scale.
CHAPTER I
INTRODUCTION
HISTORICAL
Theories concerning the origin of coal have been
many and varied.
As early as 1778, Franz von Beroldingen
(278) proposed the well known peat-lignite-bituminous-anthracite
series which has
withstood the test of nearly two centuries
of continuous study.
The apparent simplicity of this
coalification scheme was perhaps responsible for attracting
many early workers to the study of naturally-occurring solid
fuels.
Microscopic examinationsof coal were first carried
out by Witham in 1833 (307).
Improvements in both instruments
and technique, especially within the last fifty years, have
made it possible to distinguish between and to identify the
plant components which have contributed to the various types
of coals.
As a result of these studies, carried out by such
eminent microscopists as David White (300,303), Reinhardt
Thiessen (259, 260), Marie Stopes (245, 246, 248, 249),C. E.
Marshall (127, 128, 129, 179, 180, 209), and others (125, 126,
143, 144, 205, 206, 232-5, 253), it is now agreed by geologists
that most coals originate from woody materials.
2.
Although microscopic examination has demonstrated the
plant origin of coal, the chemical nature of the material has
not yet been clearly established,
Extraction studies were carried
out prior to 1909 (66), but critical work was not reported until
1911 when Pictet and his collaborators undertook the isolation
and identification of low molecular weight components of coal
using procedures familiar in organic chemistry (194-8).
Low
temperature extractions of large quantities (5.5 tons) of various
coals led to the separation of toluene, m-xylene, mesitylene and
other identifiable organic compounds.
Vacuum distillation of
the original coal to 4500 C. led to a mixture of hydrocarbons
which was found to be somewhat optically active.
Upon heating
the distillate to 350 0C., the optically active components were
destroyed and an upper limit was established for the temperature
to which the coal had been exposed during its formation.
The purely chemical studies which had been carried
out by Pictet were amplified in England where Marie C. Stopew,
a petrologist, and R. V. Wheeler, a chemist, together engaged
in a study of coal (247, 250, 251, 263).
Wheeler's early work
eventually led to a series of studies in which various coals
were fractionated empirically by means of solvent extraction
procedures (11, 60, 61).
These investigations gave rise to the
conclusion (297) that coal is primarily a mixture of three
principal types of materials: (a) extractable resins and hydrocarbons,
(b) resistant plant skins, and (c)
the ulmins, produced
by decay and subject to progressive alteration.
In coals of
similar rank, as well as in the banded constituents of coal,
differences were thought to exist as a result of varying
proportions of the three major components.
Although coal chemistry had made rapid progress
between 1900 and 1920, the geochemical aspects of coal genesis
had been comparatively neglected.'-In 1907, H. Potonie (203)
summarized his earlier work with the conclusion that coal
formation is a multifold process having the following steps:
(a) Decay of plants under aerobic conditions to
produce gaseous products.
(b) Mouldering to yield a small amount of solid
organic residue.
(c) Conversion to peat.
With thickening of the
peat bed the lower strata become devoid of oxygen.
(d) Faulnis,
In this step the lower peat strata
undergo anaerobic decomposition.
(e) Incoalation,.
Conversion of the product from
(d) into coal without the formation of free carbon.
Although this scheme still
serves to describe the
general process of peat formation, no effort was made by
Potoni6 to establish the relative contributions of the various
plant constituents to the peat.
In 1912 Bergius, in the course of experiments on the
origin of coal, heated wood,
cellulose,
and peat in water under
high pressure to a temperature of 3500 C. and reported that under
these conditions peat led to a product which was "precisely
4.
similar to natural bituminous coal" (12).
In later papers
Bergius reported that by heating peat in water at 34000 ,f or
24 hours a product was obtained which closely resembled
anthracite and which was composed of 84% carbon, 10.4% oxygen,
4.6% hydrogen, and 0.96% nitrogen (13, 14).
This analysis must
be compared with that for an everage anthracite coal containing
96% carbon, 2% hydrogen, and a total of 2% of oxygen, nitrogen,
and sulphur (154). When cellulose wassimilarly heated in water
to 340?0. for 64 hours,
4
was again reported (13).
a product similar to anthr&cite coal
The experiments with cellulose
marked an early critical point in geochemical studies of the
origin of coal since Bergius soon became convinced that all
coals originated from the same parent, namely, cellulose.
To explain variations in naturally-occurring coals, it was
postulated that peats are generated at the surface of the
earth whereas carbonization takes place only under the influence
of the "enormous pressure of overlying strata" (15).
With the
continuation of these studies, sufficient evidence in the new
and exciting field of coal geochemistry was presented to
cause wide international adherence to the cellulose theory
of coal formation.
Among the proponents of this theory were
Donath (67), Schwalbe (226-8), Marcusson (170, 172, 173, 175,
176, 178), Berl (16-30), and many others (31-3, 52, 109, 111,
167, 204, 211, 239, 256, 257, 296). When these studies are
carefully considered, it becomes evident that the geological
limitations of hydrogen ion concentration and temperature were
4
neglected during most of the experimental work.
Although a
number of early investigators in the field of coal chemistry
had suggested approximately 2500C. as a maximum temperature for
the formation of coal, the advocates of the cellulose theory
consistently employed temperatures of 3000 to 35000.
Reactions
were admittedly carried out at elevated temperatures in an
effort to speed up geological processes which normally proceed
slowly with less heat, but the important fact was completely
neglected that most complex organic compounds will decompose
rapidly above 3000C. to yield carbonized residues.
In recent
years conclusive evidence for the low-temperature origin of
coal (lower than 20000.) has been published by Treibs (265-8)
who isolated acid porphyrins from many coals.
Bearing this
major consideration in mind, the conclusions developed from
laboratory experiments with cellulose lose their importance
and the entire theory of the cellulosic origin of coals, as
proposed, appears to rest on an unstable foundation.
In 1921 Fischer and Schrader (79,
80) critically
examined the theories of coal genesis and concluded that
lignin, not cellulose, was the parent material from which coal
had been formed.
Their reasons were as follows:
1. Lignin has an aromatic structure with acetyl
and methoxyl groups.
2.
Cellulose is largely destroyed by bacterial
activity in the early stages of peat formation.
3.
The methoxyl content of peat increases and the
portion soluble in concentrated hydrochloric acid decreases
with increasing age.
4.
The methoxyl content eventually decreases owing
to saponification, reduction, or replacement by hydroxyl; but,
in any case, a phenol results which is taken to be identical
with humic acid.
5.
Oxidation or polymerization of humic acid forms
alkali-insoluble humin.
6. Further splitting off of water and carbon
dioxide, and perhaps methane, at ordinary temperature leads
to the formation of lignite and coal.
The six points presented by Fischer and Schrader were
intended to show an extension of the basic aromatic structure
of lignin into coal.
Fischer and his collaborators have supported
this theory with a large number of studies dealing with the
oxidation, reduction, and decomposition characteristics of a
variety of substances as lignin, cellulose, coals, etc. (73-8,
81-8, 222).
The conclusions of Fischer and Schrader with regard
to the extensive and rapid biochemical decomposition of cellulose
in the early stages of coal formation have also been substantiated
by numerous workers during the past thirty years (44, 218, 221,
261, ?79-83, 286-8, 293).
Similarities in chemical structure
between lignin and various coals have, moreover, been established
by X-ray studies (120, 186, 229, 230).
In recent years (since 1935), disclosures bearing
directly on the origin of coal have been relatively few.
Waksman, who contributed greatly to knowledge regarding peat
formation and soil organic matter (284),
has concentrated his
efforts on the development of antibiotics, while Fischer, prior
to his death in 1949, was concerned chiefly with the FischerTropsch Process for the synthesis of liquid fuels.
For modern
evidence for or against the lignin theory of coal formation
it has been necessary to resort to an extensive literature
survey of publications in the field of microbiology, high
pressure physics,
analytical chemistry, and geology.
The
entire bibliography for this thesis consists of the abstracts
of approximately 2000 papers dating mainly from 1907 to the
present.
Since any effort to summarize all or even most of
these articles in this dissertation would lead to an improperly
balanced product, only the most important references will be
cited.
The entire bibliography, which is assembled on McBee
Keysort Punched Cards, will be deposited in the Headquarters
Office of the M.I.T. Department of Geology, and the Appendix
to this work will include a description of the code and procedures for its use.
STATEMENT OF PROBLEMS
Having reached the conclusion from a critical survey
of the literature that lignin is the most probable progenitor
of the principal components of coal,
several questions remained
I
I,=-- -- Z_
to be answered when the studies described in the following
chapters were undertaken.
At the very first stage of coal formation, plant
components apparently undergo severe biochemical decomposition
resulting in the concentration of an organic sediment which
has been extensively studied under the name "humus" (284).
This substance has been fractionated on the basis of solvent
extraction and chemical properties (102, 106, 159, 171, 174,
212,
241, 242,
258, 264, 274, 275),
and other studies have
led to the isolation of degradation products which are similar
to those obtained from lignin (100, 103).
Although the
chemical evidence for the structural similarities between
lignin and humus (also humic acids, ulmic, acids, ulmin,
hymatomelanic acid, etc.) (9, 99) has been good, the colloidal
characteristics of the humus (89, 148, 187, 310) have made a
complementary physical correlation impossible.
For this and
other reasons, there exists nowhere in the literature today
a satisfactory explanation of the changes which occur in the
basic lignin structure during its conversion to humus.
To interpret the chemical changes which take place
in lignin between the death of the contributing plant and the
peat stage, it is necessary to know the structure of lignin.
Continuous and concerted studies by lignin chemists for 75
years have failed to produce a non-controversial structural
formula for the material.
A review of the most reliable
information in this field was,
therefore, considered to be of
9.
fundamental importance in order to establish points of general
agreement with respect to the structure of lignin.
With this
background, a theoretical interpretation of the lignin-humus
conversion was thought possible.
Regardless of its origin, there is a general agreement
among chemists and geologists that the principal constituents
of most coals are derived from humus or humic acids.
This
opinion is based on the well-known fact that peats and lignites
contain large percentages of acidic organic complexes which
are easily soluble in dilute aqueous alkaline solutions.
With
bituminous coals this type of extraction yields no significant
quantity of extract, and the humic acids are considered to be
in a "coalified stage" (156).
A number of investigators have
reported the regeneration of humic acids from bituminous coals
by careful oxidation in air or with mineral acids (65,
105,
149, 238, 309) thus providing further evidence for the
humic acid-bituminous coal relationship.
Many theories have been developed to account for the
manner in which humic substances have been converted into hard
coals.
Among the various causal factors which have been cited
to account for the formation of different kinds of coals are
the following (181, 254):
1.
Different types of vegetation and differences in
2.
Duration of exposure of vegetation before burial
climates.
by sediments.
10.
3.
Duration since burial of sediments.
4.
Depth of burial of vegetation.
5. Action of heat from compression or from
intrusions of igneous rocks.
6.
Possibility of escape of volatile constituents
after burial beneath sediments because of fractures or pores
in the overlying rocks and jointage in the coal seams.
7. Pressure resulting from compression of the seam
during dynamic changes in the enclosing rocks.
Although different types of vegetation and different
modes of accumulation have undoubtedly led to variations among
coals, these factors can hardly be considered as having
contributed to the energy necessary to devolatilize humus
material during coalification.
This same argument is applicable
to most of the above suggestions, and in the final analysis heat
and pressure must be considered as two of the most reasonable
sources of energy for the coal-forming process.
Bacteria
cannot be considered effective agents for coalification in
the post-peat stage since lignin, upon which bacteria do not
thrive, has been shown to accumulate in the peat bog (255).
Moreover, radioactivity, which has recently been found to
convert naturally-occurring organic acids into hydrocarbons,
(45, 46, 236, 237) is almost completely absent in coals (53,
54, 72, 182).
11.
Petrascheck (191) has recently shown conclusively
that igneous activity affects coal seams only locally and
that depth of burial and accompanying temperature effects are
hardly important in the coalification process (147,
272).
This work, coupled with that of Treibs (265-8) has effectively
eliminated temperature and hydrostatic pressure as sources of
energy for the formation of hard coals.
It has long been recognized that bituminous and
anthracite coals are common in areas where geological folding
has taken place.
David White realized this relationship early
in this century (298, 299, 301, 302, 304) and his opinions
have been substantiated by the observations of other investigators (155,
252).
To investigate the possibility that shear
forces might be effective in the coal-forming process, a
literature survey was proposed to review the effects of high
pressure and shear on organic compounds, and an experimental
program was initiated to study the effects of high pressure
and shear on lignin and related materials.
To summarize, the major sections of this study are
as follows:
1.
A survey of the literature on lignin, its
structure and its relationship to the origin of coal.
2.
An interpretation of the chemical and structural
relationships between lignin and humic material.
3.
An investigation of the basic structures of
lignin and coals.
12.
4.
A survey of the literature on the effects of
high pressures on organic compounds.
5.
Studies of the effect of high pressure and
shear on lignin and related materials.
13.
CHAPTER II
LIGNIN
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REVIEW OF THE LITERATURE
INTRODUCTION
Lignin, which was considered a botanical curiosity
for many years after its discovery by Payen in 1838 (190),
has become within the last fifty years a subject of widespread chemical investigation.
With the development of the
paper pulp industry, lignin has become a major problem, both
as to its removal from wood and as to means for its disposal.
In recent years, especially the last two decades, these
problems have been reflected in an enormous growth of the
technical literature on lignin.
It is almost unbelievable
that all of the studies since 1838 have failed to establish
with absolute certainty either the manner of formation of
lignin in wood or the exact structure of the isolated material.
As outlined in Chapter I, a survey of the literature
was considered necessary for a theoretical interpretation of
the lignin-humus relationship.
The literature on many phases
of lignin research has been examined, and the major contributions are summarized in the following pages.
14.
RELATIONSHIP OF LIGNIN AND CELLULOSE IN
PLANT STRUCTURE
Wood is composed of ash-forming minerals (1.0%),
lignin (18-27%), and holocellulose (70-80%).
These three
components make up the wood structure which is infiltrated
with water-soluble materials and ether-soluble resins and
The lignin and cellulose are so uniformly
waxes (189).
dispersed throughout the tree that either one alone forms a
complete structural pattern of the wood.
this effect is
Recent evidence to
conclusive (3, 107, 161, 189) and refutes with
finality the older view that lignin is not an original wood
component but rather a material produced during isolation
procedures (130-4, 224).
The exact association between the cellulose and
the lignin is unknown.
Centola (57) recently suggested that
some rings of the macromolecule of cellulose may,
a.lteration,
by chemical
take part in the formation of the lignin molecule
in the plant cell.
The view that lignin and cellulose are
chemically united in wood by primary valence forces has been
presented by Staudinger (244), and by Freudenberg and Ploetz
( 94, 199-202).
As further evidence of chemical union between
the two major constituents of wood,
it
should be pointed out
that the greater portion of the lignin (about 90%) can be
isolated only by chemical destruction of the cellulose or
15.
alteration of the lignin itself.
and Yirak (43)
In a recent paper, Brauns
proposed twelve possible lignin-cellulose
linkages which may exist in spruce wood.
As is often the
case with studies in this field, their efforts to establish
the actual bond type led to inconclusive evidence.
Evidence against the theory of chemical combination
between lignin and cellulose in wood has been presented by
Bailey (4) who assumed that his isolation procedures, carried
out in buffered solutions, would prevent hydrolysis of any
existing bonds.
The results of this study appear to be
controversial (40).
wood by thermophilia
Experiments on the fermentability of
bacteria have also been interpreted to
indicate the absence of a chemical bond between lignin and
cellulose in wood (277).
ISOLATION OF LIGNIN
It should be well understood that there is no such
material as pure lignin.
The substance called lignin is
known
to vary in amount in different parts of the plant, being
concentrated in the middle lamella of the cell (162,
216).
The constitution of lignin is known to vary with the seasons
in a particular species, and the isolated product from
coniferous trees differs from that of deciduous trees.
These
peculiarities alone would be sufficient to render the isolation
of a pure substance improbable.
To add to these difficulties,
however, the previously-described intergrowth of cellulose and
16.
lignin is such as to require drastic chemical treatment for
the separation of these two components.
Consequently, it is
hardly to be expected that a product isolated from a material
of variable composition by vigorous chemical procedures can
This point cannot be stressed
be called chemically pure.
too strongly.
Many procedures have been developed for the
isolation of lignin from wood, but most methods follow two
general approaches: (1) Isolation of lignin by destruction
of the cellulose, or (2) Isolation of lignin by extraction
with or without chemical alteration.
The most important
procedures falling in these two categories are described below.
One of the earliest procedures for the isolation
of lignin from wood was that developed by Willstatter and
In this method 40 - 42% hydro-
Zechmeister (306) in 1913.
chloric acid, that is, concentrated hydrochloric acid
saturated with hydrogen chloride gas, is used to hydrolyze
Willst~tter and Zechmeister
and dissolve the cellulose.
demonstrated that pine wood is rapidly attacked by 42% acid
to leave a residue of lignin.
It
appearsthat the cellulose
is actually dissolved first and then, on standing, is hydrolyzed to glucose which leads to the formation of a dark yellow
solution.
The obvious disadvantage in this procedure lies in
the use of strong acid and its effect on the residual lignin.
Brauns (39) has shown that the acid leads to partial
demethylation of the lignin:
R - 0 - CH
+
HC1 ----->
R - OH
R = lignin structure
+
CH 3 01.
17.
The Willst~tter isolation procedure is summarized
below (68,
157):
Wood shavings are extracted with a 1:1 benzene-
alcohol mixture to remove fats, resins, and waxes.
The
shavings are then dried and treated with ten parts by weight
of 40% hydrochloric acid (d. 1.42) which is prepared by
passing hydrogen chloride gas into ordinary concentrated
hydrochloric acid maintained at 00 C.
for fifteen minutes,
After being shaken
the mixture is poured into an excess of
hot water and then rapidly diluted with a large excess of
cold water.
The lignin settles out first and the lighter
cellulose precipitate is removed by decantation.
The lignin
is filtered and then subjected to two further ten-minute
fuming hydrochloric acid treatments, first with five parts
of acid and finally with two and one-half parts of acid.
The product is thoroughly washed with water and dried,
The lignin obtained by this procedure still
contains approximately 8% of pentosans.
The product is
insoluble in most solvents and only slightly soluble in
boiling phenol.
It dissolves readily in trichloroacetic acid,
;iving a violet-brown solution, and on addition of water
the lignin is reprecipitated in a form soluble in alkalies
and acetone.
Sulphite solutions do not dissolve this lignin
readily, but ferric chloride is reduced and Schiff's reagent
is colored.
Fehling's solution is not affected by the lignin
which contains several per cent of chlorine.
18.
A second common acid hydrolysis procedure for the
isolation of lignin is one which employs 72% sulphuric acid
(153).
As is the case with other procedures, so here also
the isolation technique has certain disadvantages and leads
to a degree of conversion of the lignin (69).
Since 72%
sulphuric acid acts both as a hydrolyzing agent and a
condensing agent, insoluble products are formed from pentosans,
hexosans, proteins, and tannins. Theseproducts are isolated
with the lignin.
Demethylation of lignin produces phenolic
hydroxyl groups which are able to react with furfuralsformed
by the action of the sulphuric acid on the pentosans of the
wood.
The insoluble products from these reactions are also
isolated with the lignin.
To minimize these and other
difficulties inherent in this procedure, a method employing
low reaction temperature and a short period of exposure to the
acid reagent has been developed (217).
given below, is
This procedure, as
for the estimation of lignin in wood,
but can
serve as well for the isolation of lignin.
Two grams of wood (80 mesh) are dried at 10500.
and then Soxhlet-extracted with a 2:1 alcohol-benzene mixture
to remove fats, waxes,
and resins.
The dried wood is
then
slowly mixed, at room temperature, with 25 ml. of 72% sulphuric
acid by weight.
Care must be taken that the temperature does
not rise during this step.
At the end of two hours sufficient
water is slowly added to decrease the acidity to 3% and the
mixture is then boiled under reflux for three hours to complete
19.
the hydrolysis of the cellulose.
The solution is filtered and
the lignin, after thorough washing, is dried under vacuum.
Several modifications of this procedure have been
published (153, 169, 220, 225) as well as a series of investigations with regard to the difficulties and limitations of
the method (56,
62, 108, 183,
184).
In recent years a number of attempts have been made
to isolate lignin from wood by the oxidative degradation of the
cellulose.
Purves and his collaborators have reported the use
of sodium paraperiodate as an oxidant (214, 294), and Leavitt
has reported the unsuccessful use of lead tetraacetate (163).
Since periodate lignin was isolated in the course of studies
related to this thesis, a description of the isolation
procedure will be reserved for Chapter III.
Extensive studies have been carried out on the effects
of enzymes on wood and on the possibility of enzymatic
destruction of cellulose for the isolation of lignin (94, 164,
199-202, 243, 277).
Since all results in this field appear to
be inconclusive and point to a fairly extensive conversion of
lignin, it does not seem necessary to describe pertinent
isolation procedures.
Extractive procedures for the isolation of lignin
are of three types: (a) Partial extraction of lignin by organic
solvents with no chemical interaction;
(b) Chemical reaction of
inorganic salt and lignin to form a water-soluble compound;
or (0) Acetal formation between lignin and an alcohol under
acidic conditions to produce a soluble product.
20
Brauns has reported the isolation of approximately
3% of the total lignin in spruce wood by means of extraction,
under neutral conditions,
with alcohol (35,
37).
The light
brown product, called "native lignin", has been isolated in
the course of the present studies and discussion of this
procedure will, therefore, be reserved for Chapter III.
In commercial paper pulp preparation, wood chips
are digested at elevated temperatures with calcium bisulphite
which reacts with the lignin to form a water-soluble lignosulphonic acid.
The reaction involved in the formation of
the soluble product has been thought to proceed by means of
the addition of sulphurous acid to an enolic double bond in
the lignin molecule (36, 41, 116).
H
R - C = 0 - R
OH
H
OH
+
H2 S03 ---- R -
-
RI
IH
H
S03 H
Lignin
Lignosulphonic Acid
The lignosulphonic acid becomes soluble only with increase in
the digestion temperature.
Brauns and Brown (41) have suggested
that this solubility results from the reaction of the lignosulphonic acid with excess calcium bisulphite:
21.
2
R
-
H
OH
H
.-
- Rt
+
Ca (HSO 3 ) 2 ---
R -
OH
- R'
.---
I
H-
Ca + 2H2so3
H-
S@H
SO H
_02
Lignosulphonic acid is unstable and can be handled only-:in the
form of a salt.
The acid contains approximately 3.5% sulphur
or approximately one sulphonic acid unit per building block
(assuming a molecular weight of 840) of lignin (36).
Other commercial processes for the extraction and
isolation of lignin from wood by means of soluble salt
formation yield highly converted products of more or less
unknown constitution.
For this reason it seems unnecessary
to discuss the sulphate or soda processes with respect to
the present work.
The isolation of lignin from wood by means of acid
catalysts and compounds containing hydroxyl groups has long
As early as 1920, Grutss demonstrated the isolation
been known.
of lignin from wood by means of ethyl alcohol and hydrochloric
acid (112,
113).
Since that time studies have been carried
out using methanol (42,
117),
ethanol (47,
97,
98, 118,
135,
138, 139, 140, 168, 208), butanol (4-7, 58, 188), isobutanol
(118, 119), amyl alcohol (118, 119), ethylene glycol (110, 213),
and many other solvents (101, 104, 107, 110, 123).
lignin has been studied extensively,
preparation,
Butanol-
and a procedure for its
taken from Charbonnier (58) is
given below.
w J9
22.
Air-dry wood meal (107.5g.),
corresponding to 100g.
of moisture-free material, is covered with 1200 ml. of anhydrous butanol.
Four hundred ml. of the butanol are distilled
off under reduced pressure to remove the moisture in the wood
meal.
Then 90 ml.
of dry butanol containing 5.1%hydrogen
chloride by weight are added to make the total 0.5% in hydrochloric acid.
The butanol-hydrochloric acid solution is
prepared by passing hyarogen chloride gas (dried over phosphorous pentoxide) into a flask containing anhydrous butanol.
After the acid-alcohol solution is thoroughly mixed with the
wood meal, the mixture is refluxed for two hours and then allowed to stand overnight.
The following day, 90 ml.
of the
5.1% acid-alcohol solution are added, the mixture is thoroughly
stirred and again refluxed for two hours.
When the material
has cooled to room temperature, 200 ml. of butanol are distilled
off under reduced pressure to remove the hydrochloric acid,
the butanol solution is separated by filtration on a BUchner
funnel, and the residue is washed twice with 500-mi. portions
of purified dioxane.
filtrate.
The wash liquors are added to the original
Several portions of ethyl alcohol are then used for
washing the residue until no color appears in the filtrate,
after which the extracted wood meal is spread out to dry for
several days.
it
When the residue (pulp) has become air-dried,
is weighed and sampled for moisture and lignin determinations.
The residue from the butanol treatment is reported to contain
12.9% lignin.
23.
The butanol-lignin is recovered from its dioxane
solution by precipitation with anhydrous ethyl ether.
To
accomplish this step, 4-ml. portions of the dioxane solution
are added dropwise to 80-ml. portions of ether with vigorous
stirring.
After centrifugation, the supernatant liquid is
replaced with fresh ether, and the preoipitat ion cycle is
Following precipitation, the lignin ip
repeated.
washed twice in ethyl ether and twice in petroleum ether and
then allowed to stand overnight in the latter solvent.
Finally
the product is centrifuged, decanted, and dried in a vacuum
desicocator over sulphuric acid.
is
The purification procedure
repeated until the methoxyl content becomes constant.
Since Charbonnier has been able to isolate hydro-
lytically and to identify butanol from the butanol-lignin
product, there can be no question regarding the existence of
a chemical bond between the alcohol and the lignin.
Chemical
evidence points to the formation of acetal-type linkages by
which carbonyl groups in the lignin are converted to hydroxyl
groups.
This has been proved by the fact that methanol-lignin
can be methylated with diazomethane (42).
(Lig)
C= 0
(Lig)
C
+
CH OH - - -)
3OOCH
OH + CH N
00H
2 2
------
(Lig) NC ,OH
(Lig)
C ,OCH3 3 + N
OCH
2
24.
The preparation of methanol-lignin and similar
products can be carried out by using modifications, where
necessary, of the general procedure outlined above.
Formic and acetic acids have been known for several
years to extract lignin from wood.
In a paper on the isolation
and structure of formic acid lignin (308), Wright and Hibbert
indicated that the product has lost methyl groups.
In spite
of some loss of methyl groups, however, the ease of preparation
makes the procedure extremely valuable.
There can be no doubt
that the native lignin has been changed chemically and/or
physically by formic acid treatment,
is soluble in many organic solvents.
since the final product
A procedure for the
preparation of formic acid lignin, as taken from the literature,
is given below.
A suspension of 40 g. of spruce wood meal (75 mesh)
(previously extracted with 1:1 alcohol-benzene,
then with water,
and dried at 550 C. under a pressure of 30 mm.) in 300 ml. of
95% formic acid is refluxed for six hours.
After cooling, the
mixture is filtered by suction and washed with 100 ml. of
cold 90% formic acid.
During the reaction period, the reflux
condenser is maintained at 400 C. to allow methyl formate
(b. p. 31.50 C.) to boil off.
The formic acid solution is evaporated almost to
dryness at 25 mm. pressure, and the residue is then thoroughly
washed with water to remove soluble carbohydrates.
After
filtering by suction the final lignin is dried under vacuum
(25 mm.).
25.
THE STRUCTURE OF LIGNIN
The structure of lignin has been extensively studied
by means of the chemical compounds which are formed when the
lignin is destructively decomposed.
Attempts to produce small
fragments by drastic oxidative procedures have led only to
the formation of oxalic, formic, and acetic acids, and carbon
dioxide (95).
For this reason, it has been necessary to
employ rather mild conditions during the process of decomposition.
Phillips and Goss (192) have reported the use of
ozone for a structural study of lignin.
From among the products
of their decompositions of methylated alkali lignin obtained
from corn cobs, these authors have reported the isolation of
anisic acid (I). Similarly, vanillin (II) has been obtained
In studies of
from ozotized'birch formic acid lignin (70).
the action of selenium on alkali lignin from corn cobs,
guaiacol (III) and 1 - propyl - 3 - methoxy
-
4 - hydroxy-
benzene (IV) have been isolated (193).
Alkali fusion of spruce lignin has led to the formation
of pyrocatechol (V)
26,
014
CHO
Anisic Acid
Vanillin
(II)
(I)
/
ocH
o
04C.
/;0
Guaiacol
1-propyl-3 -met hoxy-4hydroxybenzene
(IV)
(III)
00'
onI
01
go
COOH
Pyrocat echol
(V)
oc
Pyrocatechuic acid
(VI)
(VII)
14
HOOC
Veratric acid
0C i I
OC14 3
Coo1
(VIII)
Gallic acid
Isohempinic Acid
(IX)
C. Ko
Syringaldehyde
(X)
27.
and pyrocatechuic acid (VI) (91, 122).
Beech lignin, under the
same conditions, decomposed to yield pyrocatechuic (VI). and
Treatment of spruce wood with sodium
gallic (VII) acids (96).
hydroxide at 165-1700C., methylation with dimethylsuiphate,
and oxidation by potassium permanganate has led to the formation
of veratric (VIII) and isohempinic acids (IX).
The oxidation
of lignin in the presence of nitrobenzene is used to produce
commercial quantities of vanillin.
With beech lignin this
type of treatment produces syringaldehyde (X) (63, 93).
The catalytic reduction of lignin at 250 atmospheres
and 25000. has led to the isolation of a large number of
similar compounds of which only three are shown (XI, XII, XIII)
(1,
121, 124)0.
H OH
H
OH
OH
H
SS
H CH
2
H CH2 CH2CH
(XII)
(XI)
0
H
H
-
CH
4-n-Propyl-1,2-cyclohexa~diol
4-n.-Propy.1--l-cyclohexanol
4
2
OH
CH2CH2H OH
(0-Hydroxy-n-propyl)
1-cyclohexanol
(XIII).
-
28.
The characteristic building block derived from the
hydrogenation and degradation studies is the phenylpropane
nucleus upon which many structural interpretations of lignin
have been based.
Evidence for the aromaticity of lignin, as
90
CH2CH 2CH3
Phenylpropane
(XIV)
indicated from the derived benzene products, is confirmed by
the ultraviolet data previously cited (3, 161) and also by
the knowledge that aromatically bound methoxyl groups are
present in the original material (90).
Acetyl groups, which
were originally thought to be a part of the lignin structure
(79, 80), are now definitely known to be absent (160).
On the basis of further chemical evidence,
it
has
been estimated that each building block unit of lignin, with
a molecular weight of 840 (35), contains four hydroxyl and
four methoxyl groups.
The presence of a carbonyl group in
lignin has been demonstrated by acetal formation, and carboxyl
groups are known to be absent (115).
Attempts to incorporate the various data regarding
the composition of lignin into a molecular structure have
led to fair agreement among chemists only within the last
decade.
Earlier efforts in this direction resulted in the
formulation of a compound by Schrauth (223) which may today
29.
be regarded as nothing more than a curiosity (XV).
0
"1
0$i
"
' 0
0
Schrauth's Lignin Structure
(XV)
In 1917 Klason, the father of modern lignin chemistry, proposed
a structure made up of one molecule of coniferyl alcohol (XVI)
and three molecules of hydroxyconiferyl alcohol (XVII) (151).
Color reagents tests,
OH
OCH
CH
HO
CHCH 2 OH
Coniferyl alcohol
(XVI)
0
OCH
CH = CHCH20H
Hydroxyconiferyl alcohol
(XVII)
when applied to lignin, usually indicate the presence of
coniferyl alcohol and this information undoubtedly played an
important role in Klason's reasoning (64).
By 1922, Klason
was able to propose a structural formula for lignin (XVIII)
(152).
30.
OCC.
cii
cHCH8N
Klason Lignin (1922,)
(XVIII)
As more information was obtained with regard to the
structural components of lignin, this formula underwent
considerable revision.
In 1948 Brauns proposed a possible
structure composed of five phenylpropane building blocks (38).
These units are condensed in the formula to demonstrate the
"known" presence in lignin of simple ether linkages (A), furan
rings (B), pyran rings (C), and a carbonyl group (D).
Under-
neath the proposed structure (XIX) are shown various isolated
degradation products from lignin and their relationship to
the parent molecule.
Since 1947 several interesting papers have been
published in which lignin has been pictured as a molecule
composed of repeating 8-methoxydihydrobenzopyrone units (XX).
(215, 219).
31.
Lignin Structure Proposed by Brauns
(XIX)
CO-CH 3
B
C
?3 (N
C
A
CM
CH
13
H(C
2H 5 )
E
COOH
COO
003
C==0,
Vanillin
Cyclohemyl,
propane
derivatives
CHO0
OCH
0H)
ON09)
0
OH
Aceto
guaiacone
le
-vanilloyl
ethyl alcohol
Figure
OR
Acetyl
vanilloyl,
OR
p-hydroiy
benzoic acid
OCH3
Isoher ipinic
acid
-- I
32.
The late Alfred Russell pictured
CA3
I
I
0
8-4ethoxydihydrobenzopyrone
(XX)
gymnosperm lignin as ply-8methoxydihydrobenzopyrone (XXI).
Ritter and his associates, working independently, derived
the same formula and indicated the reaction between this
lignin and sulphite solution (XXII).
Although these formulae
0 CR 1
C.
C
H
c. t~
0
C.,
0
0oe6ti 3
Poly-8-methoxydihydrobenzopyrone
(XXI)
U
0
'Ii
~
33.
Ritter's Sulphite Lignin
(XXII)
have been subjected to rather harsh criticism by many lignin
chemists, they do have a number of attractive features.
In
agreement with formula (XIX), it is obvious that Russell's
lignin has the same basic flavanone structure.
Moreover,
Russell's lignin is made up from a simple repeating structure,
whereas Brauns' lignin formula (XIX) is heterogeneousin its
parts.
It has long been known by those chemists working
on natural products that natural synthetic processes lead
to simple rather than to complex polymeric structures.
Undoubtedly the work of Russell and Ritter will open the
entire question of lignin structure to further and more
careful scrutiny, and it
seems probable at this time, that
a generally acceptable structure may be proposed in the
near future.
is
In any case, the polyflavanone structure
simple and easy to discuss and can be used for illus-
trative demonstrations.
A sample of Russell lignin was
synthesized in the course of the studies reported in the
following Chapters.
in Chapter III.
Details of the synthesis are given
34.
SUMMARY
The historical background of lignin has been
reviewed and its association with cellulose in plants
discussed.
Several laboratory procedures have been cited
for the separation and isolation of lignin from wood.
A
short account has been given of the most reliable -information regarding the structure of lignin.
35.
CHAPTER III
LIGNIN - EXPERIMENTAL WORK
INTRODUCTION
To examine the effects produced when lignin is sheared
while under pressure (Chapter VI), it was necessary to have
available a fairly large supply of a relatively unaltered
lignin.
After an examination of the literature on preparative
procedures, those methods of isolation were considered best
which led to light-colored products.
For this reason the
lignins isolated from wood by the acid hydrolysis of cellulose were eliminated from consideration.
Butanol-lignin and
similar materials are chemically converted into new compounds
and, therefore, could not be used for the proposed studies.
The two best lignins for high pressure studies were
thought to be periodate lignin(?1 4 , 294) and Braunb' native
lignin (35).
Braunb' native lignin is extremely difficult
to isolate in quantity because of the large volumes of wood
and solvents which must be used.
For this reason only a
small quantity of the native lignin was isolated, whereas
the periodate lignin was prepared in an amount sufficient
for the pressure studies.
A small quantity of Russell's
lignin was synthesized (219) for comparison with the naturallyoccurring material (Chapter V).
36.
BRAUNS' NATIVE LIGNIN
It had been known for some years before Braunst work
that treatment of wood with neutral alcohol or hot alcoholbenzene led to the extraction of minute quantities of a ligninlike substance (92, 150).
It remained for Brauns, however,
to apply this information on a sufficiently large scale to
isolate enough lignin to characterize.
The procedure for the
isolation of native lignin that was used in the present research
is
given below and is followed by a discussion of differences
between this and the procedure recommended by Brauns.
Canadian spruce wood (27 board feet) was obtained
from a local lumber company.
After some experimentation, it
was found that small chips could be obtained by running the
wood through a joiner.
The air-dried chips were treated in
three batches with 95% ethyl alcohol (see Table I).
Table I
Treatment of Spruce Chips with Alcohol
to Obtain Native Lignin
Batch
Bottle or
Flask capacity
Chips
Alcohol
Liters
Liters
No.
Grams
1
1200
12
11.25
2
1410
12
11.25
3
1850
22
19.
37.
Each batch was set aside for at least a week after
which the alcohol was recovered by decantation.
The alcohol
was removed under vacuum at room temperature to leave a dark
brown oil.
This oil was washed several times with benzene
to remove terpenes and resins, and then was repeatedly washed
with ether.
After several ether treatments the oil finally
solidified into a light yellow flocculent precipitate which
was washed further with ether and then centrifuged.
The
precipitate was then dissolved in anhydrous dioxane and this
solution was poured into water.
The precipitate from this
step was again centrifuged and redissolved in dioxane, the
final solution being poured dropwise into anhydrous ether
with vigorous stirring.
There was a tendency at this point
for the lignin to oil out but, with care, the oil could be
made to solidify to a light yellow powder.
Precipitation of
the lignin from the dioxane solution was carried out three
more times, and the final product was washed with petroleum
ether and dried under vacuum below 500 C.
Yield, 3.8 g. (0.08%).
In Brauns' procedure for the isolation of native
lignin, the spruce wood is
first treated with cold water and
ether before it is subjected to digestion with alcohol.
Since
large scale ether treatment involves certain hazards, this
step and the water washing were reserved for the end phase of
the revised isolation procedure.
Benzene was used in the
washing of the final lignin, a step which Brauns did not
report.
The native lignin was not purified as carefully as
38.
that reported in the literature,
since with only a small
quantity desired for thermographic studies (Chapter V), it
was felt that extreme purity was not necessary.
One of the most unusual properties of native lignin
is its ability to dissolve in dioxane, methanol, ethanol,
4% sodium hydroxide solution, and pyridine.
In this respect
the material differs so greatly from other lignins that
questions were originally raised regarding the identity of
this lignin and the natural product in the wood.
At present
there is no dispute, however, and it has generally been agreed
that the product of this type of alcohol extraction represents
a low molecular weight form or an uncombined form of lignin
in wood.
The great advantage of native lignin preparations
over other isolated lignins is the fact that the product has
not been allowed to react with the solvent and has not suffered
the degradation which is caused by strong acids.
For these
reasons, native lignin has been particularly useful for
structural studies.
On the basis of empirical analyses of
various ligning,Brauns concluded that the fundamental building
block of lignin has a molecular weight of 840.
This infor-
mation, and data derived from acetylation, methylation, and
other experiments led Brauns to propose the following formula
for lignin (XXII):
39.
CH3O
CH
30
CH O
OH
0
H
C
4
n
CH O
OH
6
OH
CH30
0
H
__CH3*C
OH
CH3 0
OH
CH3O
:3
41
3L.
OH
OH
OH
:3
Keto form
Enol form
Brauns' Lignin Formula
(XXII)
Braunstcame to the conclusion that the enolic form of this
formula is already present in wood or that the keto form is
slowly enolized during isolation procedures.
with a molecular weight of 838.3,
The formula,
corresponds remarkably
well with that derived from empirical analyses (840).
PERIODATE LIGNIN
In 1947 Ritchie and Purves (214,
294) reported a novel
procedure for the isolation of lignin from wood.
Their
procedure, utilizing sodium paraperiodate as a celluloseoxidant, was reported to lead to a light-colored product
(golden brown) in good yield and was,
therefore,
chosen for
the isolation of the lignin necessary for the studies described
in Chapter VI of this report.
The paraperiodate procedure is based on the well-known
fact that periodic acid causes the oxidation of cellulose with
its conversion into water-soluble products (142) (XXIII).
40
0
-C0
-C
1
I..co
C-C=0
Ia
o-C-
Periodic
acid
Soluble
t
=.
*
Pro duct
Periodic Acid Degradation of Cellulose
(XXIII)
In the course of studies reported in the literature it was
demonstrated that xylans, starch, and other plant polysaccharides are also oxidized to soluble products,
of side reactions, at pH 4 and 200C.
It
with a minimum
was, therefore,
considered possible to isolate lignin from the carbohydrate
components of wood by selectively oxidizing the polysaccharides to compounds soluble in boiling water.
Through the
kind cooperation of Prof. Purves, an unpublished procedure
was obtained for the large scale isolation of periodate
lignin.
It was this communication which made the following
work possible.
Approximately 25 pounds of black spruce wood chips were
obtained from the
Ontario Paper Company through the courtesy
of Dr. C. A. Sankey.
After passing the wood through a hammer
mill slowly to prevent the chips from overheating, the
resultant meal was spread out on paper to dry overnight.
The
air-dried meal was screened with a Tyler Ro-Tap sieve shaker
and the (-80 + 100) fraction was collected and treated, in a
41.
specially built Soxhlet extractor, with a 2'.1 alcohol-benzene
mixture.
The terpene- and resin-free meal was air-dried,
vacuum-dried at 600C.
until constant weight was attained, and
bottled.
To prepare trisodium paraperiodate (Na3H2I0 6 ), 198.
(1 mol) of sodium iodate was dissolved in the smallest
necessary volume of water and the solution was vigorously
stirred while 200g. (5 mols) of sodium hydroxide was slowly
added.
Chlorine gas was passed into the solution until the
first odor of hypochlorite was observed.
flow of chlorine was stopped and
4 0g.
At this point the
(2 mols) of sodium
hydroxide was added followed by vigorous stirring for three
hours.
The temperature of the solution was maintained at 10000.
throughout the preparation.
When cool, the solution was
filtered through a fritted glass funnel and the crystals were
washed with cold water and dried at 11000.
crystals was 235g. (80%).
The yield of white
Analysis of the product by the
arsenate procedure recommended by Purves (214) showed the
trisodium paraperiodate to be 95-99% pure.
For the oxidation of the spruce meal, a trisodium
paraperiodate solution was prepared by dissolving 20 4 g.
of the
crystals in 5.5 liters of water containing 250 ml. of glacial
acetic acid.
The mixture was adjusted to pH 4.1 with glacial
acetic acid and, after being left overnight, was filtered
through a fritted glass funnel to yield six liters of a 3.4%
paraperiodate solution.
42.
Oxidation of the spruce wood was carried out by adding
510g. of the meal (-80 + 100) to the six liters of 3.4%
paraperiodate solution.
for 24 hours at 2000.
The mixture was stirred vigorously
after which the supernatant liquid was
siphoned off and the remaining suspension was filtered through
a Buchner funnel,
This procedure was necessary in order to
effect the best recovery of unused oxidant. .The oxidized wood
meal was thoroughly washed with water until the washings were
free of iodate ions.
The washing was carried out for 24 hours
in a continuous liquid-solid extractor built, with minor
modifications, according to the suggestions of Ritchie and
Purves.
Upon completion of the washing, the wood meal was
suspended in 10 liters of distilled water and refluxed at
10000. for three hours to hydrolyze and dissolve oxycelluloses.
The meal was next filtered on a Buchner funnel, washed with
water, and reoxidized as before in a 3.4% solution of trisodium paraperiodate.
By the end of three oxidation-extraction
cycles the volume of wood meal had markedly decreased; after
five cycles, the wood particles showed almost imperceptible
birefringence in polarized light indicating that most of the
cellulose had been removed.
The final product was air-dried,
washed with methanal and benzene, and dried to constant weight
under vacuum at 6000.
The yield of lignin was 125g.
having
a composition of 61.82% C., 6.07%H, 0.92% ash, and 10.88% 00H .
Literature:
62.1%C.,
5.8%H, and 10.7% OCH 3 '
430
To recover the unused oxidant from the decantate
following each oxidation, sufficient sodium hydroxide was
dissolved in the solution to cause precipitation of the trisodium paraperiodate.
After filtration, 40 g. of sodium
hydroxide was added to the filtrate (containing sodium iodate),
chlorine was passed into the solution at 1000 C.,
arid the
preparation of paraperiodate was carried out as before.
There can be no doubt that the periodate spruce
lignin underwent some degradation during the isolation
process since the methoxyl content dropped from the normal
14.9 - 15.4% to approximately 10.9%.
With this exception,
periodate lignin has properties which are comparable to those
of lignin in situ in wood.
Both native lignin and periodate lignin are isolated
only by the use of long, tedious procedures.
however,
lead to light-colored products,
These procedures,
indicating that the
lie nin undergoes minimum degradation during isolation.
Comparative elementary data for the two lignins are shown in
Table II.
Table 1I
Comparative Data for Various Isolated Spruce Lignins
(294)
Lignin
72% H204
C
65.7-67.4
H
5.4-5.8
OCH
--
Brauns native
63.9
6.15
14.9
Peri odat e
62.1
5.8
10.7
44.0
RUSSELL
LIGNIN
As discussed in Chapter II, Alfred Russell in 1947
proposed that lignin might be a variant of 8-methoxydihydrobenzopyrone
Because the analytical and chemical data
(XXI).
for this material match closely those for other lignins, it
was considered of interest to synthesize a small quantity of
Russell lignin and to obtain a thermographic curve for the
material (Chapter V).
The synthesis was carried out as
recommended by Russell (219) using 4X quantities.
Vanillin (6 0.8g., 4 mols) was dissolved in 160 ml.
of dry pyridine and acetyl chloride (4 0g., 5 mols) was added
The hot
dropwise over a period of approximately 20 minutes.
orange-colored mixture was heated on a steam bath for 30
minutes and, after cooling, the solution was poured into a
mixture of ice and water.
The precipitate was washed with
water, recrystallized from alcohol to which charcoal had been
added, and dried.
(XXIV)
The final product of vanillin monoacetate
melted at 78-79.5 0 C. on a microscope hot stage
(literature, 7?-78 0 C.), and weighed 35.2g. (45.5% theoretical).
o+rH
f~jocHy
CAo
Vanillin
ooc-c
C
1
-I
?few
/ji
~I:JoCCIAO
Acetyl Chloride
Vanillin
Monoacetate
Preparation of Vanillin Monoacetate
(XXIV)
13
+' MCI
45.
A Fries rearrangement was carried out on the vanillin
monoacetate (XXV)
by dissolving 30g. of that material in 127
ml. of dry, redistilled nitrobenzene and slowly adding
of aluminum chloride.
4 1.2g.
With the addition of the aluminum
chloride the solution became very dark and viscous and the
temperature rose steadily.
When the addition was complete,
the mixture was heated at 1000C. for two hours, cooled,
acidified with dilute hydrochloric acid, and steam distilled
to remove the nitrobenzene.
The residue, a black, tarry mass,
was filtered and dissolved in alcohol from which it was
precipitated by the addition of 1:5 hydrochloric acid.
This
purification was repeated twice, and the final material was
The brittle, black, amorphous
dried under vacuum for two days.
product was highly electrostatic (yield, 8.8g).
ooC--CH 3
ocM3
g
oI+
e
screo
cI4o
oH
0C4
o
C
oil
0
OC043
0
0I
Preparation of Russell Lignin by Fries Rearrangement
of Vanillin Monoacetate
(XXV)
Wk
A
A major objection to this synthesis has been that
the condensation of acetyl vanillin with itself is the type
of reaction which may lead to a mixture of materials rather
than to a single product.
At the time of his death, Russell
was investigating new synthetic routes by which to eliminate
this difficulty,
SUMMARY
Brauns' native spruce lignin and periodate lignin
were isolated for the work described in later chapters of
this report.
Procedures for the isolation of these two
products have been outlined.
Details are given for the
synthesis of Russell's hypothetical lignin structure.
CHAPTER IV
LIGNIN
-
CHEMICAL AND STRUCTURAL RELATIONSHIP
TO HUMUS
INTRODUCTION
As outlined in Chapter I, the origin and nature of
humus and related materials is still open to discussion.
Several disputed theories have been evolved to account for
the conversion of cellulose into humic substances (10, 52,
71, 103,
145,
174, 177),
and several possible structures for
these products have been proposed.
Since the principal
constituents of most coals are of humic origin, it was felt
necessary to examine carefully the fate of cellulose, lignin
and other plant substances in the formation of soil humus
or- peat.
From this study it was considered possible to relate
humus to its parent material and, perhaps, to propose a
skeletal structure for humus and its associated substances.
48.
MICROBIAL DECOMPOSITION OF PLANT COMPONENTS
Sedimentologists examine rocks to establish the
mineral components and then attempt to explain how various
weathering processes affect the disposition of these particles.
By analogous reasoning an attempt was made to determine the
history of the organic components of sediment.~
The preliminary exposure of plants is to atmospheric
gases.
In temperate and sub-tropical areas of average humidity
and rainfall, the combination of moisture and oxidizing
conditions may lead to destruction of the plant by presenting
favorable conditions for microbial growth.
Fungi are particu-
larly active in the destruction and conversion of organic
material under damp, aerobic conditions.
These organisms,
which are devoid of chlorophyll, cannot synthesize a significant
amount of cell matter from atmospheric carbon but must depend
upon their enzymatic processes for the production of assimilable
food.
The presence of fungi, therefore, indicates that a
process is taking place in which the host material is being
modified with the elimination of energy required for the
growth of the organism.
As previously noted, cellulose is
of plant materials.
the major constituent
Cellulose is hardly ever found in the free
state, but is generally associated with lignin in complexes of
unknown character which have been termed "lignocelluloses".
49.
Deposition of leaves, bark, needles, and wood exposes the
"lignocelluloses" to extensive decomposition by a large variety
of fungi that normally inhabit the soil and are capable of
destroying cellulose (158, 295).
The development of fungi in
the upper few centimeters of forest soil is so great that,
even under careful microscopic examination, it has been reported
difficult to determine whether the residues from plants or the
fungi predominate (290).
Fungi require nitrogen for growth in the ratio of
one part of nitrogen for every thirty to fifty parts of cellulose decomposed.
Waksman and Starkey (289) have demonstrated
that addition of sodium nitrate and 1% of cellulose to a raw
soil will raise the fungus count per gram from 160,000 to
4,800,000.
In an area covered by substantial vegetation, this
nitrogen demand can undoubtedly be met by the proteins of
previous generations of plants, bacteria, and other soil
microbes.
Relatively little
is known concerning the metabolic
products which are formed during the destruction of cellulose
by funi.
It has generally been assumed that the poly-
saccharides are hydrolyzed to component sugar units which are
destroyed so rapidly by other soil microorganisms as to be
undetectable (285).
Besides being cellulose-destroyers, several species
of fungi are able to attack the lignin of plants to produce
50.
"white rot".
This "corrosion", as the process is termed, has
not been studied in sufficient detail to lead to information
regarding the transformation products.
It should be emphasized,
however, that the lignin-destroyers are of far less abundance
and importance than are the cellulose-destroyers.
Many species of bacteria are capable of attacking
and destroying cellulose under aerobic conditions.
A number
of these organisms employ cellulose as their exclusive source
of energy and are unable to multiply on simple sugars such
as glucose.
Aerobic bacteria decompose cellulose to yield
a "mucilaginous mass of bacterial cells imbedded in gum-like
compounds".
also formed.
can exist in
Small amounts of organic acids and pigments are
It
is
particularly important to note that fungi
soil media which are acid to a pH of 4.0 or less,
while bacteria will multiply only if the medium has a pH between 6.0 and 8.5 (291).
During the process of plant growth, needles, leaves,
twigs, bark, and pieces of wood are shed and buried beneath
successive layers of organic and inorganic sediments.
Should
this burial become sufficiently deep or complete so that
atmospheric oxygen is
excluded from the organic material,
then
anaerobic bacteria must be considered as agents of decomposition.
Fungi can no longer attack the organic debris.
Anaerobic bacteria decompose sulphates or nitrates
and remove the oxygen for their metabolic processes.
Many
51.
species of anaerobes are found in places where fresh organic
matter is abundant,
that is,
rivers, and marsh soils.
in peat bogs, manure piles,
Of particular importance are the
anaerobic thermophilic bacteria which grow best at temperatures to be present between 550 and 650 0.
These organisms,
which have been reported to be present in the uppermost strata
of a peat bog (262), are known to decompose cellulose very
rapidly with the production of organic acids, ethyl alcohol,
carbon dioxide, methane, and hydrogen.
In this respect it
has been reported that 3.3 g. of cellulose can be decomposed
to produce 2.2 g. of fatty acids, 1.0 g. of carbon dioxide,
and 0.014 g. of hydrogen.
In a different experiment 42 g,
of cellulose yielded 21.6 g of acetic acid, 10.3 g. of ethyl
alcohol, and 11.9 g. of carbon dioxide, in addition to
considerable hydrogen (292).
CONCLUSIONS
In summing up this discussion several points
stand out clearly.
Most important,
it
appears that cellulose
can be destroyed rapidly by soil organisms under a fairly wide
range of hydrogen ion concentrations and temperatures (34, 55).
Secondly, with the exception of a few relatively unimportant
fungi, no organisms are known which can directly destroy
lignin (158,
295).
It is well known that a considerable portion of the
humus complex is acidic and can be extracted with alkalies,
A chemical degradation of the extractable humic acids has been
reported to lead to the isolation of fragments identical with
or similar to those obtained by the decomposition of lignin.
On the basis of biochemical and chemical evidence,
therefore,
it appears probable that lignin, during its accumulation in
the soil or in a peat bog, undergoes chemical transformations
which lead to the series of products known collectively as
humus.
The interpretation of the lignin-humus relationship
has been attempted using, as an example,
for Russell lignin (XXV).
the simple formula
The major difference between this
Cc.14 3
M3
Russell Lignin
(XXV)
compound and a substancesuch as cellulose (XXVI) is that
cellulose can be hydrolytically split to simple structural
units (glucose molecules) while the former cannot.
In the
case of lignin, however, it may be possible, at the proper pH,
53.
-C
C
C
ct
H0-c-
w-C-
-c-oNo
HO
C
-0o
I
I.
I II4-
M
0'16
Vt
C H4,0o
Ik
~
CH1 OH
Hydrolysis of Cellulose to Glucose
(XXVI)
to open the heterocyclic ring and thus to produce a compound
having a structure similar to that of (XXVII) .
This new
OC0
3
~~CN
..
C
~CH
0
oH
0
G-C4UcSR
r~t:K%~y0H
C-'cH:~H
OR
II
0
*W
Cc- " CH= CJ40
0)4
Possible Degradation of Russell Lignin
(XXVII)
54.
structure, it will be noted, has phenyl rings, acidic phenolic
hydroxyl groups, double bonds, and a structure based on
phenylpropane.
These chemical features have all been reported
in studies of the structure of lignin.
The demethylation of
organic residues under natural conditions has also been
reported, and peat is known to have a methoxyl content of only
about 1%.
This conversion has been attributed in the literature
to the biochemical removal of methyl groups from lignin, a
process which probably leads to phenolic hydroxyl groups (XXVII).
It is obvious that the lignin molecule, even
if it does not possess a structure as simple as that proposed
by Russell, has groupings which are rather easily changed
without complete molecular destruction.
Only one transformation
in a single building block of the lignln molecule need occur
to produce acidic properties.
Multiple conversions along the
molecular chain, coupled, perhaps, with occasional chain
cleavage through the formation of carboxyl groups,
which are
known to exist in humic materials (103, 273), may lead to
products called humic acid, hymatomelanic acid, ulmic acid,
apocenic acid, melanin, fulvic acid, etc.
Waxes and resins account for only a small percentage of material of vegetable origin and are highly resistant
to decomposition.
These materials are concentrated into
particular types of deposits or finely distributed throughout
a sediment such as peat.
The resinous components of plants
55.
apparently play no important part in the formation of humus.
To examine experimentally the structural
relationship between lignin and humic acid, specimens of
these two substances were submitted for infrared absorption
analysis performed with a Baird Spectrophotometer owned by
the Massachusetts Institute of Technology Department of
Chemistry.
The spectra are shown in Fig. 1 and are discussed
below.
Following the recommendations of Puri (207), the
humic acid for this work was isolated from peat collected
in Wisconsin by Reinhardt Thiessen in 1937.
The peat (405 g.)
was crushed in a porcelain mortar and then refluxed for two
hours with three liters of 0.1 N hydrochloric acid.
After
standing overnight, the mixture was filtered to yield a darkbrown (almost opaque) filtrate which was discarded.
The
precipitate was thoroughly washed with water and then divided
into two equal portions.
Each portion of the material was
placed in a 5-liter flask along with 4 liters of a solution
0.2 N in sodium carbonate (10.6 g./liter) and 0.2 N in sodium
hydroxide (8.0 g./liter).
The suspensions were heated to 700 C.,
stirred very vigorously for two hours, and then allowed to cool
overnight.
The cool solutions, smelling faintly of ammonia,
were filtered and then adjusted to a pH of 1.0 by the slow
addition, with vigorous stirring, of 175 ml. of concentrated
hydrochloric acid.
The humic acid precipitate was centrifuged
free of supernatant liquid, mixed with fresh water, and
56.
recentrifuged.
As the pH of the suspension rose, centrifugation
became progressively difficult making it necessary to complete
the washing procedure on a Buchner funnel.
The washed material
was a dark brown gel which was dried in a vacuum desiccator
over calcium chloride for 48 hours.
During the drying process
the gel contracted enormously in volume.
The final humic
acid was pitch black when massive, showed concoidal fracture,
and was dark brown when powdered.
A small quantity of the
material was finely ground and redried under vacuum at 550C.
Analysis: C, 52.34%; H, 4.93%; N, 2.09%; Ash, 9.80%.
On an
ash-free basis the analysis becomes: C, 58.02%; H, 5.46%; and
N, 2.32%.
A small quantity of the dry humic acid was
pulverized as well as possible in a mortar and the powder
was then suspended in Nujol for infrared absorption analysis.
The center and top curves of Fig. 1 refer to mulls having high
("20 mg./80 mg. Nujol) and low (~20 mg./150 mg. Nujol) concentrations of powder in the oil.
The bottom curve is
mull of native spruce lignin in Nujol.
for a
The peaks which appear
on all three curves at 3.4, 6.8, 7.25, and 13.8 microns arise
from the absorption of the infrared radiation by the Nujol.
Other peaks, some of which are very weak and subject to
reconsideration with further work, are listed in Table III.
By analyzing the humic acid and lignin curves
according to published data on infrared spectra-structure
Figure 1
Infrared Absorption Curves for Humic Acid
and Lignin
Top curve:
Low concentration mull of humic acid
(-20 mg. sample/150 mg. Nujol).
Center curve:
High concentration mull of humic acid
(~20 mg. sample/80 mg. Nujol) .
Bottom curve:
Nujol mull of Brauns' native spruce lignin.
Wave Numbers in cm
soo
4000
3000
2 00
2000
40
50
1500
1400
1300
1200
1000
1100
900
B00
NO.g
DATE
INDEX
SAMPLE H,
Fro-m'8 me r
Semp.CON:
MmT
ems
Comp. Coil:
mm
ems
mg
Vol.
F.S.
mg
cc
c.c
Sd
Gas
mm
BAIRD ASSOCIATES
20
30
80
70
60
NA CL Pism
I1:0
91
130
120
Wave Length in Microns
Wave Numbers in cm
5000
BAIRD ASSOCIATES
NAIR ASSOCIES
NA CL
4000
3000
30
20
200
2000
40
50
1500
60
1300
1400
70
1200
1000
90
80
PossM
11001
00
800
900
11 0
120
Wave Numbers in cm
5000
to00__
4000
3000
200
2000
1500
1400
1300
_
_-
1200
'
1000
1100
--
8oo
900
.
9
a
770
a
I
120O
SPECTROPNOTMETER
L
NA cL P...M
130
Wave Length in Microns
Wave Length in Microns
58.
Table III
Correlation of Infrared Absorption Peaks for Humic
Acid and Brauns Native Lignin
Humic Acid
(Low conc.)microns
Humic Acid
(High conc.)
microns
Brauns
Lignin
microns
3.0
3.0
3.8
4.3
4.3
*5-9
5.8
4.9
5.3
*5 .9
6.1
*6.2
*6.2
*6.25
*6.6
*7.9
8.1
8.2
8.8
8.8
9.1
9.2
9.7
9.7
9.7
10.3
10.8
11.7
*Large peaks
59.
correlations (2,
8), it
has been possible to obtain infor-
mation regarding the structural components of these two
substances.
The absorption maxima at 3.0, 7.9, 8.1, and
microns appear to be caused, in part at least, by the presence
of phenolic hydroxyl groups.
The 5.9-micron peak indicates a
carbonyl stretching frequency.
Maxima at 8.1 or 8.2 microns
may be caused by aromatic ketone groups, and those at 8.8
microns can be correlated with aliphatic ketone groups.
The
absorption peaks at 6.2 microns may indicate an amide
linkage in the humic acid.
This point in particular requires
further clarification for it may be extremely important in
understanding the manner by which nitrogen is combined in coal.
Other peaks in the curves of Fig. 1, especially those at 9.7
microns, may indicate the presence of multiple substitutions
on benzene rings.
The exact type of substitution cannot be
established with certainty from these spectra.
A procedure which is occasionally used in attempting the identification of complex organic compounds from their
infrared spectra, is to superimpose the curve of an unknown
substance upon that of a known material.
When this is done
with the humic acid and lignin curves of Fig. 1, a clear
correlation of peaks is evident.
With further experimentation
on methods of preparation of humic acid for analysis, it may
be possible to show more conclusively that the skeletal
structures of humic acid and lignin are related or even
identical.
6o.
SUMMARY
A critical analysis of the literature has
shown that cellulose is probably removed from sediments by
biochemical processes soon after deposition of plant
fragments.
Lignin, on the other hand, is apparently not
destroyed completely, but is instead transformed into humus
by microbial action.
Using the structure for Russell lignin
as a model, proposals have been advanced for the chemical
changes which may occur in the lignin molecule to convert it
to a series of related compounds known as humic acid, fulvic
acid, melanin, etc.
Infrared absorption spectra have been obtained
for humic acid and for native spruce lignin.
Structural
simularities between these two substances are indicated by
their spectra.
It is proposed that further infrared studies
may completely clarify the lignin-humus relationship,
61.
CHAPTER V
LIGNIN
-
BASIC STRUCTURES IN THE COAL SERIES
INTRODUCTION
The formation of coal is generally thought to
take place in two distinct stages.
In the first or biochemical
phase, the plant components are degraded and concentrated to
produce the humic substances of peat and lignite.
In the
dynamochemical or metamorphic stage, the components of the
low grade coals are devolatilized to produce fuels having
higher percentages of fixed carbon (166).
Following the
second phase of coalification, the humic components have lost
their identity and can only be recovered by oxidative
degradation of the coal.
For this reason it has been difficult
to relate the structure of coal to that of lignin by chemical
processes.
Because of its physical and chemical properties,
coal can be compared to a three-dimensional polymer which
probably formed by the condensation of humic molecules.
If
this is true, then the basic structure of coal would be
expected to be similar to that of humic substances and probably
similar to that of lignin.
To examine this relationship,
differential thermal analysis has been used as a basic technique
for the determination and comparison of the decomposition
characteristics of lignin, cellulose, and coals.
62.
VACUUM DIFFERENTIAL THERMAL ANALYSIS
Differential thermal analysis is carried out by
heating a material under investigation at a constant rate to
about 100000.
and recording the temperatures at which
exothermic and endothermic reactions occur.
In practice this
is most readily accomplished by employing a metallic block
with two holes, one of which is packed with the unknown
substance, while the other is packed with an inert powder such
as gamma alumina.
A two-headed thermocouple, one head of
which is imbedded in each powder, is then used to determine
the direction and extent of the differential changes as the
block is heated at a constant rate in a furnace.
During recent years, differential thermal analysis
has become a standard analytical procedure for the study of
complex mixtures of minerals when resolution is difficult by
conventional microscopic techniques or X-ray methods.
It has
been especially useful in the analysis of clays and other
colloidal materials.
The use of differential thermal analyses for the
study of complex organic substances and shales has been
reported (231, 271, 305).
Conventional equipment, however,
leads to the combustion of the specimen and makes it difficult
to obtain reproduceable results with certain materials (271).
For this reason a new instrument for differential thermal
63.
analysis has been designed to operate under vacuum or inert
atmosphere.
Previous differential thermal analytical studies
have been carried out with magnesia-packed furnaces, but the
high thermal capacity of the packing made it difficult to
attain heating rates exceeding 100 or 120 C. per minute.
For
this reason, and because of the impracticability of attempting to evacuate a packed furnace, a vertical heating unit
was designed with radiation shielding rather than with
conventional packing.
The furnace (Figs. 2, 3, and 4) is constructed
with a specially-cast alundum core 9" long, 20 1. d., and
having an 1/8" wall.
Sufficient 16 gauge Chromel-A wire is wound onto
the core to make the power input approximately 2 kilowatts at
110 Volts A.C.
The core is shielded by four cylinders
constructed of 0.01811 sheet nickel.
On top and bottom
shielding is by four discs made of the same material.
Elec-
trical connections within the furnace are made with stainless
steel lugs and 1 mm. platinum wire.
For electrical insulation
ceramic fish-spine beads are strung over the leads.
All steel parts of the furnace were machined from
material obtained from the Rustless Iron and Steel Corporation,
Baltimore,
Maryland.
Steel type 446,
containing 23.00 to
30.00% chromium and a maximum of 1% nickel, and type 309,
containing 22.00 to 26.00% chromium and 12.00 to 14.00% nickel,
64.
Figure 2
Furnace for Vacuum Differential
Thermal Analysis
STAND-OFF INSULATOR
-
-PLATE
C
-
ALUNDUM INSULATOR
-
PLATE
D
NICKEL SHIELDS 0.018" T
-
D. 3"
-
D. 3.5"
D. 5.75
-
-D.
6.5"
- SUPPORT RODS I/4" O.D.
SIX, EQUALLY SPACED
ALUNDUM CORE
2" I.D. 1/8" WALL
-PLATE B
ALUNDUM SPACERS
NICKEL BAFFLES 0.018"T
BEARING
-PLATE A
BEARINGS FOR
SUPPORT OF FURNACE
THREE, EQUALLY SPACED
65.
Figure 3
Details of Furnace Design
D. 1/2"
THREE HOLES
*D.1/4"
SIX HOLES
D.
PLAT E A
1/4'"
-D. 1/4"
I
THREE HOLES
I4
1I/4"
A
8 I/4"
1
I 1/4"
PLATE B
THREE HOLES
4111
I 5 1/2"1
-- l"
21/A"
V"8-
66.
Figure 4
Details of Furnace Design
1/4"
PLATE C
1/4
SIX
HOLES
THREE HOLES
PLATE D
THREE HOLES
67.
Figure 5
Sample Block for Vacuum Differential
Thermal Analysis
31 DRILL
41
~ 1I
1/16-
SAMPLE BLOCK
1/16
68.
are used interchangeably depending upon availability.
These
steels were chosen because of their resistance to scaling
and to sulphur at high temperatures.
The furnace is mounted on three posts,
18" long,
which are screwed into an 18" x 18" x 1/2" brass plate.
A
groove 3/16" deep and of width to accomodate an inverted 12" x
24" Pyrex jar is machined into the plate.
To prevent failure
of the glass jar, its flat bottom is rounded and then the
entire jar is carefully annealed.
By setting the plate on
2" adjustable legs and screwing and silver soldering a brass
line into a hole through the plate, a means is afforded for
complete evacuation of jar and furnace or for replacement of
the air by an inert atmosphere such as helium.
Electrical
leads to the furnace and all thermocouple leads are insulated
from the base p'ate by means of Kovar-to-glass seals
obtained from the Stupakoff Ceramics and Manufacturing
Company, Latrobe,
Penn.
The block (Fig. 5) in which analysis is carried
out is machined from type 446 or type 309 steel, has a diameter
of 1
and has a length.of 3/40.
Its lower end has a groove
1/32" deep to enable the block to set firmly in place on a
ceramic 1" o.d. x 12" furnace core which serves as a support
post.
This post is firmly fixed onto the base plate by
means of a tightly fitting brass sleeve.
The furnace bearings
are of such length that when they rest on the brass plate,
the heating block is
exactly centered in the furnace.
69.
The heating rate of the furnace is controlled
from a Chromel-Alumel thermocouple junction placed between
the center two windings of the spiral heating element.
The
output of the thermocouple is fed into a Leeds and Northrop
Micromax controller equipped with an auxiliary device which
enables variation of the heating rate of the furnace from 10
to 500 C. per minute.
A heating rate of 120 C. per minute
was chosen for all comparative work.
Additional control
devices make possible a constant cooling rate and "soak" of
a specimen at a predetermined temperature.
Block temperature is measured by means of a
Chromel-Alumel junction placed in the center hole of the block.
The output of the thermocouple is recorded on a Brown recorder.
The differential thermocouple is made from two
leads of a 28 gauge Chromel wire connected by a short length
of 28 gauge Alumel wire.
The fine wire is used in order to
eliminate conduction of heat away from the specimen and the
short length of connecting Alumel is used for the same reason.
The output of the differential thermocouple is
fed through a
resistance box into a galvanometer having a short time constant.
The position of a light beam reflected from the mirror of
the galvanometer suspension is recorded on a Beckman Photocell
Recorder (National Technical Laboratories, Pasadena, California).
For automatic operation of the installation, the
control unit, recorders, and galvanometer light are wired
70.
through a Type T-27 General Electric time switch which may
be adjusted to start the run and then to turn off the installation after a pre-set time interval.
Samples of 100 mgs. of material ground to pass a
200 gauge screen are used for the analysis.
For maximum
effectiveness the samples are packed immediately around the
thermocouple junction.
Using specially-designed tools, it is
possible to pack the material consistently into the sample
hole at 530 pounds per square inch, while at the same time
assuring horizontal and vertical centering of the thermocouple
junction.
The sensitivity of the differential recording
installation is approximately ± 0.15 millivolt.
During
operation with organic materials, the bell jar is evacuated
to a pressure of less than 1 mm. of Hg and pump operation is
continued throughout the experiment.
Figs. 6*and ?*are photographs showing the general
arrangement of the installation.
To distinguish the vacuum instrument from
conventional installations, the former has been named a
thermograph and its differential records are called thermograms.
DISCUSSION OF THERMOGRAMS
Figures 8 to 20 show the thermograms obtained
from a number of substances ranging from wood and lignin to
coals and shales.
The small peak at 5750 0, in each curve
71.
Figure 6
Photographs of Thermographic Equipment
Upper photograph:
Furnace in raised position
for loading of specimen.
Lower photograph:
Close-up of interior of
furnace.
*Note:
The apparatus illustrated and described
was constructed under joint sponsorship
of the Nova Scotia Research Foundation
and the American Petroleum Institute,
Research Project 43C, to whom acknowledgement is made for its use in this research.
Furnace in Raised Position for
Loading of Specimen
Close-Up of Interior of Furnace
72.
Figure 7
Photographs of Thermographic Equipment
Upper photograph:
Apparatus for thermographic
(vacuum differential thermal)
analysis showing furnace,
controller, recorders,
galvanometer, time-switch,
vacuum gauge, and pump.
Lower photograph:
Close-up of furnace showing
vacuum leads through base
plate.
Apparatus for Thermographic Analysis showing Furnace, Controller,
Recorders, Galvanometer, Time-Switch, Vacuum Gige and Pump.
Close-Up of Furnace Showing Vacuum
Leads Through Base Plate
73.
arises from the quartz which is added to the inert material
in the sample block to serve as an internal standard.
Not
only does the low-to-high endothermic quartz transformation
at 575
0.- serve as a temperature standard, but the peak also
points in an exothermic direction because the material is in
the thermocouple recess opposed to that which contains the
material under study.
The temperature coordinates of all the curves
of Figs.
8 to 20 vary slightly from linearity over their
heating ranges.
For this reason an average scale for the
absdissahas been adopted.
The discrepancy between actual
and scale temperatures above 6000 C. in no case exceeds 150 C.
In Fig. 8 thermograms are shown for A, finelyground spruce wood extracted with a mixture of benzene and
alcohol; B, highly purified spruce cellulose obtained from
the Brown Company of New Hampshire; and C, Brauns' native
spruce lignin.
The spruce lignin undergoes a very large
exothermic decomposition at about 4400 C., while the
cellulose decomposes endothermally at about 4000 C. The
thermal differences arising from lignin and cellulose are
unmistakably reflected in the thermogram for the spruce wood.
The low temperature peaks in the spruce wood curve at about
1500 and 2800 C. may be caused by the decomposition of
compounds such as hemicelluloses or pentosans.
740
Lebeau (165) in a series of careful studies on the
gases evolved on pyrolysis of various substances, showed that
the maximum formation of gas from cellulose takes place at 4000.
At this temperature,
carbon dioxide and carbon monoxide are
The formation of hydrogen from cellulose is
produced.
negligible at 4000 C., but becomes large at 7000 C.
Dehy-
drogenation of many of the substances shown in Figs. 8 to 20
may cause the broad exothermic reaction which occurs between .
6800 and 7100 C.
From the sharpness of the endothermic peak shown by
cellulose at 4000 C., it is probable that this material,
if
present in any appreeiable quantity in organic sediments, is
detectable by the thermographic technique.
The curves of Fig. 9 are for various lignins as
follows: D
Brauns' native spruce lignin (same as curve _);
E, periodate lignin; _F, Russell's synthetic lignin; and G,
lignin obtained from the Forest
Wisconsin.
Products Laboratory, Madison,
This material was prepared by the treatment of
wood with 72% sulphuric acid.
The most important feature of the curves of Fig. 9
is that they all have large
4400 C.
exothermic peaks between 4000 and
The curve for the Russell lignin is very similar to
the other thermograms indicating a relationship of fundamental
structures between the synthetic and natural material.
The
periodate lignin curve has a small shoulder at about 3800 C.
which probably indicates the presence of a small amount of
75.
residual cellulose in the material.
obtained with 50 mg.
These records were all
specimens.
From Lebeau's data (165) it appears likely that the
large peak at 4000 - 4500 C. shown by all the lignins of
Fig. 9 is caused by an exothermic decomposition of the material
during which carbon dioxide and carbon monoxide are released.
As before,
the peaks at about 7000 C. may be caused by
decompositions during which hydrogen is evolved.
In Fig. 10 the thermograms for five peat specimens
are shown.
The maximum exothermic decompositions appear at
about 3000 C. on these curves.
Shoulders close to 4000 0. on
curves I and K and on curve N of Fig. 11 may indicate the
presence of residual cellulose in these peats.
Below 5000 C.,
each specimen appears to have a decomposition curve which
varies from those of the other samples.
Endothermic decom-
positions of unknown origin appear in curve H at 675* C. and
in curve I at 7?50 C.
Curves M and P are for specimens of
Wisconsin peat taken from the same swamp.
Minor differences
between the curves may reflect variations in plant components
and sedimentation, but in general the plots below 5000 C. are
characteristic for this particular material.
Curve 0 was
obtained from a small quantity of lustrous black material
which was picked by hand from the Wisconsin peat.
This
material, which still retained its original woody structure,
led to a thermogram having the characteristics of neither
fusain nor vitrain (see Fig. 16).
From a consideration of
76.
Figs. 10 and 11 and those which follow, it
appears that peats
are mixtures of plant components in intermediary stages of
decomposition.
The variety of partially decomposed substances
results in a number of minor peaks below 4000 C.
The thermograms of lignites, shown in Fig. 12, all
have exothermic maxima between 4000 and 4500 0.
correspond extremely well to those for lignin.
These peaks
In the case of
Gurve T, a shoulder at 3500 0. may indicate a small amount of
residual cellulose in the sample.
The similarity between lignin
A
and lignite curves below 6000 C. cannot be overlooked.
Lignites
do not show broad exothermic peaks at about 7000 C. as do the
lignins.
On the other hand, two of the lignites do have strong
exothermic peaks at about 9000 C. as in the case of the peats
shown in Fig. 11.
The reappearance of strong exothermic peaks at about
4000 C. in the thermograms for the lignites may indicate that
plant products that probably mask this portion of the curve in
peat, have been completely degraded and removed.
The thermograms of Figs. 13 and 14 are for a number of
bituminous coals ranging from those with high volatile content,
Ourve .U., to those with low volatile content, Curve BB.
In all
specimens, with the exception of BB, strong exothermic peaks
appear between 4000 and 4500 C.
In Curve B,
the related
exothermic peak appears to have been displaced to about 5250 C.
The exothermic peaks of Curves W, X, and AA at about 900* 0.
cannot be explained at this time.
77.
Thermograms for anthracite coals (Curves CC and DD
of Fig. 15)
show no clear decomposition peaks below 6000 C.
On the other hand, semi-anthracite coal, Curve EE, still
exhibits a small exothermic peak at about 5000 C.
From an examination of Figs. 8 through 15 it appears
that the low temperature characteristics of the lignin thermogram (below 6000 C.) disappear or are masked in peat and then
reappear strongly and unmistakably in lignite.
With increasing
rank of coal, the important exothermic peak at about 4000 C.
becomes smaller and is displaced to higher temperatures.
By
the time anthracite coal is formed, the devolatilization
process is complete in the coal and there is no significant
peak in the thermogram below 6000 C.
There is some evidence
that small cellulose residues may be present in peat and lignite.
In Fig. 16 thermograms are shown for vitrain, FF;
durain, GG; clarain, HH; and fusain, II.
Of these particular
curves, which were obtained by Mr. Charles Welby using Nova
Scotian coals, those for vitrain, clarain, and durain show
exothermic peaks at about 4750 C.
If the thermograms are
representative, then the coals of the area would appear to be
of a rather high grade bituminous variety.
Since fusain is
mineral charcoal, the Curve II would not be expected to show
the same characteristics as do the other curves.
Low
temperature endothermic peaks on the fusain thermogram may
indicate the removal of adsorbed gases from the material.
A
broad but exothermic peak of low intensity at about 5000 C.
78.
may indicate incomplete devolatilization or carbonization of
the fusain.
The two top curves of Fig. 17 are for a gas coal,
JJ, and a bright block coal,
BK.
oth specimens exhibit thermal
characteristics similar to those of bituminous coals at 4000
to 4500 C. Curve LL was obtained with a cannel coal from
Indiana and has decomposition characteristics which differ
from those of the gas and bright block coals.
It
is difficult
to establish whether the curve LL is truly exothermic at about
4250
If this were the case, then the thermogram might
point to the origin of the coal from mixed humic and, perhaps,
algal materials.
Petrographic study of the coal could very
well clarify this point.
Curves MM and NN of Fig. 18 were obtained with
metamorphosed and weathered coals.
It is apparent that the
coal material has undergone considerable change- in the process
of decomposition (see Curves KK and LL, Fig. 17).
The sharp
endothermic peak at 7250 C. in Curve MM may be caused by the
presence of a mineral (carbonate?) component of the coal.
Thermogram 00 was obtained with an unclassified coal from
Oklahoma.
From the position of the exothermic peak at 4250 C.,
the coal would appear to be a bituminous coal with a fairly
high volatile content.
In Fig. 19 the top Curve, PP, is for a pyritiferous coal from Indiana (100 mg.) and the bottom curve is for
a small specimen of pyrite (25 mg.).
The pyrite in the coal
79.
can easily be identified by the large endothermic peak at
about 6500 C.
In Fig. 20, Curve RR is the thermal decomposition pattern for a marine shale, and Curve
record for the Green River shale.
SS is the
Both materials have small
exothermic peaks between 4000 and 4500 C. indicating the
presence of organic components which probably formed from
lignin.
The sharp endothermic peak at about 5250 C. in
the marine shale.thermogram is distinctive and has appeared
in
other shales.
The Green.River shale is distinguished by
its enormous endothermic decomposition at 8000 C.
SUMMARY AND CONCLUSIONS
Vacuum differential thermal analytical apparatus
has been designed and constructed for the study of the
structural relationships existing between cellulose,
coals, and other substances.
lignins,
Thermographic analyses obtained
by this technique indicate a sharp exothermic peak for
lignin at about 4250 C. and a sharp endothermic peak for
cellulose at 400* C.
peat, where it
is
The lignin peak can be traced through
thought to be masked by a large variety
of partially degraded plant components, into lignite where
it
shows up strongly again.
The humic acid component of
peat shows a very strong exothermic decomposition at 4350 C.
The thermogram for this material has not been included in this
80.
report because the large evolution of heat from humic acid
causes a severe distortion of the heating rate of the sample.
Low percentages of cellulose may be present in some peats
and lignites, but not in any coals of higher rank.
The lignin curve is visible in bituminous
coals where the 4250 C. peak is somewhat smaller and is
displaced to a slightly higher temperature.
These two
effects probably result from the devolatilization of the
humic materials and from their polymerization into a more
stable structure which decomposes at a higher temperature.
Although a semi-anthracite coal shows a small exothermic
decomposition at 5250 0., two anthracite coals which were
examined had no significant decomposition peaks below 6000 C.
The curves for the anthracite coals are interpreted to
indicate that devolatilization is nearly complete at this
stage of ~Ghe coalification process.
The difference in constitution of a cannel
coal from other coals is clearly demonstrated as are the
changes in coal structure upon weathering or metamorphosis.
81.
Figure 8
Thermograms for Wood, Cellulose, and Lignin
Curve A:
Spruce wood, 50 mg.
alcohol and benzene.
Curve B:
Pretreated with
Record No. 248.
Spruce cellulose, 50 mg.
Highly purified
material obtained from the Brown Co.,
New Hampshire.
Curve C:
Record No. 240.
Brauns' native spruce lignin, 50 mg.
Record No. 229.
-------------
I
O
LUJ
x
LUI
0
OLUI
0
I
1
200
I1
1I
I
400
600
TEMPERATURE, C.
1
800
82.
Figure 9
Thermographic Comparison of Various Lignins
Curve D:
Brauns'
native spruce lignin, 50 mg.
Record No. 229.
Curve E:
Spruce periodate lignin, 50 mg.
Record No. 226.
Curve F:
Russell's synthetic lignin, 50 mg.
Record No. 230
Curve G:
Sulphuric acid lignin obtained from
the Forest Products Laboratory, Madison,
Wisconsin, 50 mg.
Record No. 233.
(U)
0
x
D
E
2
F
Zw
G
0
0
200
400
600
TEMPERATURE,
-
-- --
-
Ii1I1III11
iii1111
IIII11111111
III1111
1, ,,
.
'C.
800
83.
Figure 10
Thermograms of Peats
Curve H:
Peat from Gresshartmanndorf, 100 mg.
M.I.T. Sedimentology Collection No.
814 - 100;
Curve I:
Record No.
LT - 76.
Peat (recent) from South Boston, 100 mg.
M.I.T. Sedimentology Collection No. 814 - 34;
Record No. 258.
Curve J:
Bog peat (recent) from New Jersey, 50 mg.
M.I.T. Sedimentology Collection No. 814 - 34;
Record No. 254.
Curve K:
Peat from Boston, 50 mg. M.I.T. Sedimentology
Collection No. 314 - 26;
Curve L:
Record No. 253.
Peat fuel from Sweden, 50 mg.
Collection No.
S14 - 32:
Sedimentology
Record No.
265.
LLJ
0
x
L16
K
o
L
0
200
400
TEMPERATURE,
600
'C.
800
84.
Figure 11
Thermograms of Peats
Curve X:
Peat from Hawk Island Swamp, Manitowoc County,
Wisconsin, 50 mg.
M.I.T. Sedimentology
Collection No. 314-22;
Curve N:
Record No. 264.
Sphagnum moss peat obtained from the U. S.
Bureau of Mines, 50 mg.
Curve 0:
Record No.
235.
Hand-picked lustrous black component of
Peat from Hawk Island Swamp, Manitowoc
County, Wisconsin, 50 mg.
This sample of
peat is described in Chapter IV.
Record
No. 249.
Curve P:
Peat from Hawk Island Swamp, Manitowoc
County, Wisconsin, 50 mg.
This specimen
was collected by Reinhardt Thiessen in
1937 and was obtained from the U. S.
of Mines.
Record No. 237.
Bureau
UA
LU~
0
x
M
U
z
Lii
0
200
400
600
TEMPERATURES ,C.
800
85.
Figure 12
Thermograms of Lignites
Curve Q:
Lignite from Yukon, 100 mg. M.I.T. Sedimentology
Record No. LT - 84.
Collection No. 814 - 96;
Curve R:
Lignite from Noonan Bed, Divide County, North
Dakota, 100 mg.
Specimen obtained from
U. S. Bureau of Mines.
15250;
Curve S:
Record No.
Bur. of Mines. No. D -
LT - 129.
Lignite (Eocene) from Flathead River Area,
British Columbia, 100 mg.
M.I.T.
tology Collection No. 814-31;
Curve T:
Sedimen-
Record No. LT - 85.
Lignite (Miocene) from Queen Charlotte area,
British Columbia, 100 mg.
Collection No.
814 - 28;
M.I.T. Sedimentology
Record No.
LT-86.
cf.
w
x
S
uR
w
z
0
I
200
|
400
600
TEMPERATURE)
I
800
C.
|
1000
86.
Figure 13
Thermograms of Bituminous Coals
Curve U:
High volatile C bituminous coal from Sweetwater
County, Wyoming, 50 mg. U. S. Bureau of Mines
No. D-15782; Record No.
Curve V:
Subbituminous A coal from Moffat County,
Colorado,
No.
Curve W:
LT-131.
100 mg.
D - 11551;
U. S. Bureau of Mines
Record No.
Subbituminous coal, 100 mg.
LT - 132.
M.I.T. Sedimen-
tology Collection No. S14 - 50; Record No.
LT - 107.
Curve X:
Subbituminous C coal from El Paso County,
Colorado,
100 mg.
U. S. Bureau of Mines
No. C-89738; Record No. LT - 149.
UU
c.
0
w
xW
m
z
0
200
400
600
TEMPERATURE,
800
'C.
1000
87.
Figure 14
Thermograms of Bituminous Coals
Curve Y:
Low bituminous coal from Stanton, Mo.,
100 mg.
No.
Curve Z:
M.I.T. Sedimentology Collection
S14 - 33;
Record No.
LT - 103.
Bituminous coal from the mines of the
Colorado Fuel and Iron Company, Colorado,
100 Mg.
No.
Curve AA:
M.I.T.
Sedimentology Collection
314 - 107; Record No. LT-38.
Bituminous coal from the mines of the
Colorado Fuel and Iron Company, Colorado,
100 Mg.
No.
Curve BB:
M.I.T. Sedimentology Collection
S14 - 129;
Record No.
LT - 82.
Low volatile bituminous coal from Somerset
County, Pennsylvania, 100 mg.
Bureau of Mines No.
No. LT - 144.
D-15855;
U. S.
Record
x
xwi
Lii
BB
I
I -III
400
20uu
600
TEMPERATURE,
ii I
I
I
.. Ial
-
I
11
1 ---- -
--
I
800
I
1000
*C.
-- ,, -
--
-
-
- -
-
88.
Figure 15
Thermograms of Anthracite Coals
Curve CC:
Anthracite from Scranton, Penna., 100 mg.
Record No. LT - 39.
Curve DD:
Anthracite from Wales, 100 mg.
M.I.T.
Sedimentology Collection No. S14 - 131;
Record No. LT - 81.
Curve EE:
Semianthracite from Kayak District,
Alaska, 100 mg.
Collection No.
No.
LT - 83.
M.I.T. Sedimentology
Sl4 - 69;
Record
x
acc
TEPRTUEwc
di'
0
EE
200
400
600
800
1C0
89.
Figure 16
Thermograms of Vitrain, Durain, Clarain, and Fusain
Curve FF:
Vitrain isolated from coal from Sydney
Coal block
area, Nova Scotia, 100 mg.
IV-6, B 19;
Curve GG:
Record No. 238.
Durain isolated from coal from Sydney
area, Nova Scotia, 50 mg.
IV-4-36;
Curve HH:
Record No.
280.
Clarain isolated from coal from Sydney
area, Nova Scotia, 50 mg.
IV-5-6;
Curve II:
Coal block
Coal block
Record No. 267.
Fusain isolated from coal from Sydney
area, Nova Scotia, 100 mg.
Record No. 203.
0
x
III
GG
HH
II
200
400
600
TEMPERATURE,
800
'C.
1000
90.
Figure 17
Thermograms of Unclassified Coals
Curve JJ:
Gas coal from Pennsylvania, 100 mg.
M.I.T. Sedimentology Collection
No. S14-47;
Curve KK:
Record No. LT - 93.
Bright block coal from Greene County,
Indiana, 100 mg.
M.I.T. Sedimentology
Collection No. Sl4 - 88;
Curve LL:
Record No. LT - 79.
Cannel coal from Greene County, Indiana,
100 mg.
No.
M.I.T. Sedimentology Collection
14 - 90;
Record No. LT - 80.
K
O
z
L
y
(-
200
400
600
TEMPERATURE)
800
C
10-0
91.
Figure 18
Thermograms of Unclassified Coals
Curve MM:
Metamorphosed fossiliferous coal
(Carboniferous) from Portsmouth,
Rhode Island, 100 mg.
M.I.T. Sedi-
mentology Collection No. S14 - 64;
Record No. LT - 92.
Curve NN:
Weathered coal from Greene County,
Indiana, 100 mg.
M.I.T. Sedimentology
Collection No. S14 - 79;
Record No.
LT - 99.
Curve 00:
Coal (Pennsylvanian) from Henryetta,
Oklahoma, 100 mg.
M.I.T. Sedimentology
Collection No. S14 - 40;
LT - 100.
Record No.
O
0
x
Li
NN
0
Li
I-
00
200
400
800
600
TEMPERATURE)
'C.
1000
92.
Figure 19
Thermograms of Pyritized Coal and Pyrite
Curve PP:
Pyritized coal from Greene County,
Indiana, 100 mg.
Collection No.
M.I.T. Sedimentology
S14 - 86;
Record No.
LT - 90.
Cur ve QQ:
Pyrite, 25 mg.
Record No. LT - 128.
LI
200
400
600
TEMPERATURE)
800
'C.
1000
93.
Figure 20
Thermograms of Shales
Curve RR:
Miocene marine nodular shale from
California (Inglewood oil field),
100 mg.
Curve SS:
Record No. LT - 44.
Green River shale from Fossil, Wyoming,
100 mg.
M.I.T.
No. S14 - 62;
Sedimentology Collection
Record No. LT - 105.
Lii
RR
0
0
ISS
z
Lii
0
200
400
600
TEMPERATURE,
800
*C.
1000
94,
CHAPTER VI
HIGH
PRESSURE
STUDIES
INTRODUCTION AND REVIEW OF THE LITERATURE
Relatively few studies have been reported on the
effects of high pressure on organic substances.
Fortunately,
the most significant work in this field has been carried out
by outstanding investigators leaving no doubt as to the
reliability of their results.
As early as 1914 Bridgman reported that egg albumin
is coagulated by the application of a pressure of 5000 to
7000 atmospheres for thirty minutes (48).
It was not until
1929 that Bridgman and Conant (51) extended the original
study with a series of investigations using many types of
organic compounds.
A pressure of 10,000 atmospheres exerted
over a period of 24 hours was found to have no effect on
amylene, pinacone, tertiary amyl alcohol, diacetone alcohol,
and other substances; but almost the same conditions led to
the partial polymerization of isoprene, 2, 3-dimethyl-1,
3-butadiene, styrene, and indene, Isobutyraldehyde and
n-butyraldehyde were converted to soft, waxy solids by the
action of 12,000 atmospheres for 40 hours.
In this and a
later paper (50) polymerization was attributed to the presence
of peroxides in the compounds under investigation.
These
are the first reported examples of irreversible chemical
95.
transformations caused by hydrostatic pressure.
In 1939,
Raistrick and coworkers (210) found that
cyclopentadiene polymerizes in three stages under pressures
up to 5000 atmospheres and at temperatures of 00 to 400C.
It was specifically found that dimerization takes place first
and is then followed by the production of higher polymers.
Within definite pressure limits at each temperature, an
explosive disruptive reaction takes place resulting in the
formation of a carbonaceous residue and much gas (92% methane
and 81 hydrogen).
An important observation by Raistrick was
that the carbonaceous residue has an X-ray structure similar
to that of low-temperature coke obtained from coal at 5500 -
6000 c.
Further polymerization studies were carried out in
1945 by Vereschlagin and cowerkers (276) who found that cyclohexadiene polymerizes at 3000 to 3600 under 4000 atmospheres,
but that the polymerization is independent of pressure.
The
polymers which were produced were found to be identical with
those formed thermally.
The polymerization of vinylcyclohexene
is reported to be pressure-dependent at 2500 C.
It
is interesting to note the results of experiments
by Johnson and Lewin (146) in which B. escherichia coli were
subjected to pressures up to 8000 pounds per square inch.
These
investigators found that a pressure of 1000 pounds per square
inch retards the growth of the bacterium, while 5000 pounds
96.
per square inch causes disinfection or bacteriostasis.
At
temperatures above the optimum for the growth of the bacteria,
a pressure of 1000 pounds per square inch has an opposite
effect and actually accelerates growth.
This work may offer
a clue as to the importance of bacteria in compressed
sediments..
Much work has been reported with respect to the
effects of high pressures on proteins and enzymes (50).
The results of these experiments are difficult to interpret.
Several Bulgarian workers recently described
experiments in which they subjected coal samples to hydrostatic pressures in the range of 10,000 atmospheres (269,
270).
Analysis of coke yields and of tar fractions before
and after the application of pressure indicated that a small
but significant structural change in the coal material must
have taken place as a result of the compression.
A very significant series of experiments was reported
by Bridgman in 1935 (49).
In this work samples of organic and
inorganic materials were compressed to pressures up to
approximately 50,000 atmospheres and then sheared to the point
of plastic flow.
Many substances such as graphite, sugar,
rosaniline, or Rochelle s4lt underwent no change as a result
of this treatment.
Rubber, Neoprene, wood, paper, and linen
cloth, however, were changed to horn-like substances which
were,
in some cases, translucent.
When celluloid or iodoform
97.
was placed under a hydrostatic load of up to 50,000 atmospheres, no chemical changes were observed.
When sheared
under this pressure, however, both substances decomposed
explosively.
These experiments emphasize the fact that it may
be possible by shearing complex substances, under the proper
conditions, to cause the cleavage and re-formation of chemical
bonds thereby producing a new type of compound without the
use of high temperatures.
This observation is extremely
important to an analysis of the factors influencing the
formation of high rank coals from humic substances under
conditions of geological folding (see Chapter I).
A series of experiments was carried out in which
periodate lignin, sulphuric acid lignin, and humic acid were
subjected to shear under high pressures.
The results of
these experiments are described below.
DESCRIPTION OF EQUIPMENT
The equipment for this work was simple, consisting
only of a small bomb to hold the specimen (Fig. 21),a piston
to bear on the specimen, a yoke to bear on the piston, and a
lever arm with a 30 to 1 ratio to bear on the yoke.
lead weights were hung onto the end of the lever.
Suitable
For
experiments in which the piston was rotated, a small motor,
geared to produce one revolution in 48 hours, was used.
98.
To heat the specimen, a small furnace was constructed to fit
snugly around the bomb.
Before it was used., the furnace
was calibrated to determine the voltage necessary to produce
any desired temperature up to 2500 0. in the sample recess
of the bomb.
equipment,
This calibration was carried out with the
including the lever arm, assembled as if
for a run.
In preliminary experiments, the surface of the piston
bearing on the sample was flat.
In later work, this surface
was ground to the shape of a 450 cone pointing into the
sample (Fig. 21).
This construction was chosen in order to
obtain maximum shear stress in the material being compressed.
The bomb and piston were constructed from No. 309 stainless
steel.
With the rotating piston arrangment, weights totaling
more than 70 pounds on the end of the lever arm caused the
motor gears to slip.
Consequently, an upper limit was set
for the pressure in these experiments using the available
equipment.
An experimental set-up with 150 pounds on the lever
arm is
shown in the photograph of Fig. 22.
99.
Figure 21
Details of 6onstruction of Bomb and
Piston for High Pressure Studies
7WORM-
0.253"
GEAR
7/8"
45
D. 3/16"
I 1/211
0
~
I I
I I
ii
hA'
F~i
11/16"
I I
i
7/16"
THREADS
4'
I I
I!
1 1/2"
i
Figure 22
Phot ograph of Equipment for High
Pressure Studies
101.
ANALYTICAL TECHNIQUES
It was considered possible to follow piezochemical
changes in the lignin molecule by the determination of the
methoxyl content before and after compression of the material.
Since the methoxyl content of coals is
low (about 1%),
it
seemed reasonable to expect demethylation of the lignin as
a possible effect induced by shear stresses.
The best features of several procedures which have
been suggested for the determination of methoxyl groups in
organic substances have been incorporated in the method
In this technique, the organic
proposed by Clark (59).
compound is dissolved in boiling phenol and treated with 48%
hydriodic acid in order to split the methoxyl groups:
+
R -OCH
HI
--- >
R
OH
+
CH1.
The methyl iodide which is formed is swept through
the apparatus by a slow current of carbon dioxide and is
collected in an acetic acid solution off potassium acetate
Under these conditions the methyl
containing bromine.
iodide is oxidized to iodate:
CH 1
IBr
+
2 Br2
+
Br 2
+
--- *
3H2 0 ---
CHRBr
HIO
+
IBr
+
5H Br.
102.
The iodate is determined as follows:
The reaction mixture is
diluted with water, a sodium acetate buffer is added, and the
excess bromine is destroyed with formic acid.
The liquid is
then acidified with sulphuric acid, potassium iodide is added,
and the liberated iodine is titrated with standard sodium
thiosulphate solution.
Addition of the equations for all the
reactions of this procedure leads to the following overall
equation:
ROCH
ROH
+
+
3 Br
+
CH3 Br +
6 Na2S203 +
5HBr
From this equation it
% Methoxyl
is
=
+
6 KI
+
3H2O
3 Na2S40 6
+
6 Nal
---
+
3 K2 S04
easy to show that
(31) (Vol. Na2 S 2 03 ) (Norm. Na2S20 3 )
(60)
(Sample in grams)
Many attempts were made to analyze a carefully
purified standard sample of vanillin by the procedure recommended by Clark.
In each instance very poor precision and
accuracy were obtained.
After much experimentation a number
of improvements were made in the method for determining
methoxyl content.
The revised procedure is outlined below
and a photograph of the apparatus is shown in Fig. 23.
(1)
mg.
Samples of 10 to 13 mg. are weighed to 0.01
on a Berman torsion microbalance.
The weighing is best
103,
accomplished in a piece of cigarette paper folded into the
form of a small boat and suspended on the balance arm by
the shortest necessary length of the finest platinum wire
available.
(2) The sample and paper are very carefully
transferred into the 100-ml. flask with side-arm shown at
the bottom of Fig. 23.
Approximately 2 to 3 ml. of molten
pheno.l are then added to the flask along with a small wad of
glass wool to prevent bumping.
Hydriodic acid (2 ml.) of the
highest available grade is added to the flask which is
quickly connected with the air condenser, trap, and collection
tubes.
The dimensions of these parts follow those recommended
by Clark.
The arrangement, however, which proved to be very
satisfactory, evolved from discussions with Leavitt (163).
A Glas-Col heating element is turned on (optimum boiling at
28 volts) and the flow of sulphuric-acid washed carbon dioxide
is started immediately after the sample flask is connected to
the air condenser.
(Silicone grease proved to be the best
lubricant for the stopcock and joints).
(3) To assure complete demethylation the sample
is allowed to boil for two hours, contrary to the
4 5-minute
period suggested by Clark.
(4) After two hours the bromine solution is
thoroughly washed from the collection tubes into a 250 ml.
1o4.
Figure 23
Apparatus for the Determination
of Methoxyl Groups
I
105.
flask, excess bromine is decolorized with 3 to 5 drops of
formic acid, 5 ml. of 10% sulphuric acid and a pinch of
potassium iodide crystals are added,
and the iodine thus
released is titrated to a sterch end-point with standard
0. 01 N sodium thiosulphate solution.
The thiosulphate
solution is standardized on alternate days against a solution
of approximately 0.6000 g. of potassium iodate in one liter
of aqueous solution.
(6)
Na2 2 20
a 3
(Grams K103/liter)
(214.02) (Vol.
(Vol. KIO
Sol.)
Na2 S2 03 Sol.)
The procedure was at first standardized with vanillin
(20.39% OCH3 ), but anisic acid was later chosen as a more
J
desirable standard (20.39% OCH3 ).
The anisic acid was re-
crystallized from alcohol and then dried at 1050 C. for
three days.
In a series of twelve analyses by two operators
the methoxyl content of anisic acid was found to be 20.09 ±
0.21%.
The precision of the method was + 0.2%.
Carbon and
hydrogen analyses which are reported were obtained by the
conventional dry combustion technique.
The analyses were
made by the Massachusetts Institute of Technology Department
of Chemistry on 5-mg.
samples.
1o6.
EXPERIMENTAL
Several preliminary experiments were carried out
in which the sulphuric-acid lignin obtained from the Forest
Products Laboratory was compressed.
Using a Buehler hand
pump and temperature of 1150 C., an estimated pressure
varying from 11,000 to 14,000 atmospheres caused the material
to turn black and to shatter into flaky fragments upon
removal from the bomb.
In similar experiments which were
carried out at 2000 to 6000 atmospheres under more carefully
controlled conditions, the lignin was recovered in the form
of a solid cylinder, dark at the center and still
retaining
the brown color of the original material around the sides.
Most studies were carried out with the piston
having a conical end.
The results of the most significant
of these experiments are described below.
Experiment L 33-1:
Periodate lignin was packed into the
bomb and compressed to 1655 atmospheres by hanging 49.25
pounds on the end of the lever arm.
After two days at 1000 C.
(one revolution of the piston) the bomb was allowed to cool
and the pellet of lignin was removed.
Maximum shearing stress
was probably applied to the lignin on that surface of the
pellet which was in contact with the rotating piston.
For
this reason the pellet was carefully centered in a lathe,
107.
with a specially-constructed chuck, and a layer of material
0.050" thick was ground from its upper surface.
Extreme
care was taken to prevent contamination of the pellet or
powder by grease.
The collected powder was analyzed and was
found to have a methoxyl content of 10.30 + 0.2%.
The
periodate lignin used for this experiment had a methoxyl
value of 11.09 ± 0.2%.
Experiment L 41-1:
To establish the effect of temperature
on the decomposition of periodate lignin by pressure, a
sample of the lignin was compressed as in Experiment L 33-1,
but at 150* C. instead of 1000 C.
After onerevolution of
the piston,the pellet was removed from the bomb and a layer
of material 0.050" thick was ground from its upper surface
for analysis.
The methoxyl content of this material was
found to be 11.07 i 0.2%; the original lignin, 11.09 + 0.2%.
A powdered specimen of the residual pellet was thermographically
analyzed (Record LT-152).
Experiment L 42-1:
To determine the effect of increased
pressure on the piezochemical decomposition of periodate
lignin, a sample of the material was compressed at 2280
atmospheres and 1500 C. After one revolution of the piston
(48 hours), the pellet was removed from the bomb and a sample
was ground from it
on the lathe as in previous experiments.
The powder thus obtained had a methoxyl content of 10.67 +
0.2%; original lignin, 11.09
+
0.2%.
The residual lignin
108.
pellet was struck a sharp blow and split longitudinally into
two equivalent fragments.
One fragment was ground to a brown
powder which was thermographically analyzed (Record LT-153).
Experiment L 43-1:
Using the conditions of experiment L 42-1
(2280 atmospheres and 1500 C.), a sample of periodate lignin
was compressed for four days (two revolutions of the piston)
to establish the effects of increased piston rotation.
When
the base of the bomb was unscrewed, a small amount of material
was found to be very tightly compressed in the conicallyshaped cavity.
Microscopic examination of this material showed
it to be nearly pitch black and to have a pattern of radial
shear cracks.
The material in each crack was golden-brown in
color and had a resinous appearance.
When an attempt was
made to force the remainder of the sample out of the upper
section of the bomb, the material shattered.
The shattered
material (50 mg.) was thermographically analyzed.
The entire experiment was repeated (Experiment
L 44-1) with the same results.
When the shattered fragments
of the pellet were analyzed, a methoxyl content of 10.91 + 0.2%
was found; original periodate lignin, 11.09 + 0.2%.
Experiment L 46-1:
The conditions employed in experiments
L 43-1 and L 44-1 (2280 atmospheres and 1500
C.) were main-
tained, but the duration of the experiment was extended to
32 days (16 revolutions of the piston).
As in the two
109.
previously-described experiments, a small segment of the
lignin pellet broke off and remained in the base secion of
the bomb.
The cross-section of the pellet which was exposed
by the break (Fig. 24) showed a radial fracture pattern with
golden-brown resinous material following each fracture as in
other experiments.
Careful microscopic examination of the
surface of the cross-section showedthe structure of the black
material to be pitted and to resemble charcoal.
A small flake of the golden..brown resinous substance
was removed from the broken pellet and was transferred to a
microscope slide.
The material was heated slowly on a micro-
scope hot stage and was found to darken at about 2500 C.
At 2900 C. the materialhad become opaque, and by 3500 C. it
appeared to be completely charred.
No signs of softening or
melting were observed.
The main portion of the sample pellet was removed
from the upper section of the bomb and was found to have a
methoxyl content of 11.36 + 0.2%; original periodate lignin,
11.09 + 0.2%.
Experiment L 48-1:
To determine the effects of temperature
on the periodate lignin during the course of the pressure
studies, a small amount of the material was placed in a thermostatically-controlled oven at 1500 C. At the end of 21 days
the lignin had turned quite dark, had lost 27.5% of its original
weight, and had a methoxyl content of only 9.01 + 0.2%;
110.
Figure 24
Photograph of Golden-Brown Component
and Radial Fractures in Compressed Lignin.
---
+-
-
--
anew
-r',,------- ---
----------
-------
-
--
----
-
-
-
-
original lignin, 11.09 ± 0,2%.
By the end of four days the
lignin had already lost approximately 10% of its weight but
still had a methoxyl content of 11.01 + 0.2% (Experiment
L 54-2).
Experiment L 53-1:
A sample of peat (Hawk Island Swamp,
Manitowoc County, Wisconsin - see Fig. 11) was packed into
the bomb as before and compressed at 1500 C. and 2280
atmospheres for four days (two revolutions of the piston).
The sample pellet was removed from the bomb intact and
specimens were ground from off its upper surface on a lathe.
The first layer removed from the pellet was 0.005" thick and
had a methoxyl content of 1.32%.
The second layer (0.100")
had a methoxyl content of 1.32%, and the third layer (0.050"),
1.16 + 0.02%.
When the original peat was heated for five days
at 1500 C., the final material had a methoxyl content of
1.18 + 0.09%.
Experiment L 60-1:
Humic acid which had been isolated from
the Wisconsin peat (Chapter IV) was packed into a bomb and
compressed at 1000 C. and 2280 atmospheres for three days (1.5
revolutions of the piston).
At the end of this time the sample
pellet was removed from the bomb and a layer of humic material
0.025" thick was stripped from the top surface of the pellet.
Analysis of the powder gave the following data: C, 48.27%;
H, 4.04%; Ash, 14.03%.
On an ash-free basis: C, 56.10%; H, 4.70%.
112.
A sample of original humic acid was heated for three
days at 1000 C. At the end of this period the material had
the following composition: C, 53.43%; H, 4.06%; Ash, 8.48%.
On an ash-free basis: 0, 58.2%; H, 4.43%.
The humic acid
lost 3.5% of its weight during the period it was heated.
SUMMARY OF RESULTS
Table IV is a tabulation of the results of all the
pressure experiments that have been cited.
It
is
interesting
that compression of the lignin at only 1655 atmospheres and
at 1000 C. for only two days has produced the largest decrease
in the methoxyl content of the material.
Taking the precision
of the analytical procedure into account, these relatively
mild conditions appear to have caused a decrease of 0.4% of
the methoxyl content of the lignin.
All other experiments
which were carried out at 1500 0. and 2280 atmospheres led to
no appreciable change in the methoxyl content of- the lignin
with the exception of an experiment which lasted only two days.
In this case a decrease of 0.2% in the methoxyl content of
the lignin was indicated.
When lignin was heated for 21 days at 1500 C., the
methoxyl content of the material dropped from 11.09% to 9.01%.
After 32 days at 1500 C. and under a pressure of 2280 atmospheres, the lignin still had a methoxyl content of 11.36%.
This might indicate that, whereas thermal decomposition alone
Table IV
Summary of Pressure Experiments and Blanks
Material
Temp.. 0C.
Pressure, Atmos.
Time or a
Revolutions
Analytical Data
11.09 + 0.2% OCH 3
Periodate lignin
Periodate lignin
100
655
1 Rev.
Periodat e lignin
150
1655
1 Rev.
Periodate lignin
150
2280
1 Rev.
10.30 + 0.2% OCR
3
11.07 + 0.2% OCH3
10.67 + 0.2% OCH3
Periodate lignin
150
2280
2 Rev.
10.91 + 0.2% OCH 3
Periodate lignin
150
2280
16 Rev.
11.36 + 0.2% OCH 3
Periodate lignin
150
21 Days
9.01 + 0.2% OCH
3
Periodate lignin
150
4 Days
11.02 + 0.2% OCH3
Wisconsin peat
150
2280
2 Rev.
1.32% OCH3
1.32% 0CO
1.16 + -0.o2% OCH
Wisconsin peat
150
Humic acid
Humic acid
100
2280
100
aOne revolution = 2 days
bTop layer, 0.005" thick
cMiddle layer, 0.100" thick
5 Days
1.18 + 0.09% OCH
3
1.5 Rev.
3 Days
56.10% C, 4.70% He
58.2% C, 4.43% He
dLower layer, 0
.050" thick
eAsh-free basis
113.
causes demethylation, heat treatment under pressure results
in other structural degradations in the lignin molecule.
This point should be checked in future studies by means of
carbon-hydrogen ratios.
Thermographic analyses of sheared products proved
to be of little value in determining structural changes in
lignin.
In future studies, however, the use of micro
thermographic equipment now under construction may make it
possible to examine specimens of as little as 5 mg. taken from
the top surface of the sample pellet.
When peat was sheared under a compression of 2280
atmospheres, little or no change was observed in the methoxyl
content of the material.
The most highly sheared peat may
have a slightly higher methoxyl content than the original
material.
This might again indicate structural degradations
in the peat molecules.
When humic acid is heated at 1000 C. for three days
the carbon-hydrogen ratio of the final material is 13.15.
When heated to 1000 C. for three days at 2280 atmospheres,
however, the carbon-hydrogen ratio of the final material drops
to 11.95.
This result is difficult to explain and the experi-
ment warrants careful repetition.
In most studies, the material being compressed underwent continuous decrease in volume throughout the duration of
the experiment.
The decrease in volume was rather rapid at first
and then quickly settled down to a gradual change.
In the case
114.
of the humic acid, repeat experiments indicated the usual
gradual decrease in volume during the first part of the run,
By the end of the first half revolution of the piston, however, a sharp increase in the volume of the material was
noted.
Following this sudden change, there was a gradual
increase in the volume of the sample.
This observation may
indicate a structural decomposition of the humic material.
Further work should be carried out to determine the changes
taking place in the humic material.
115.
CHAPTER VII
CONCLUSIONS AND PROPOSED WORK
CONCLUSIONS
It was the stated purpose of these studies to obtain
further information regarding:
lignin and humic materials,
(a) the relationship between
(b) the possibility that the
basic structure of lignin occurs in the various members of
the coal series, and (c),
the possible effects of high
pressure and shear on the conversion of lignin and other
materials into high grade coals.
On the basis of a critical analysis of the literature
it appears that cellulose is probably removed from sediments
by biochemical processes soon af-ter deposition of plant
fragments.
Lignin, on the other hand,
is resistant to
microbial decomposition, but is degraded into humic substances.
Using several structural models for the lignin molecule,
suggestions have been made for the chemical or biochemical
changes which lead to the transformation of lignin into
humic compounds.
Preliminary infrared absorption studies
appear to indicate similar basic structures in lignin and
in a sample of humic acid isolated from peat.
116.
The study of several plant components and of various
members of the coal series by vacuum differential thermal
analysis seems to indicate that the fundamental structure of
lignin occurs in lignites and bituminous coals.
The large
number of possible incompletely degraded plant materials is
thought to mask the appearance of the -major thermographic
peak for lignin in peats.
By the time anthracite coal is
formed, the lignin structure has probably been devolatilized
to the point where the thermographic peak for lignin can
no longer be recognized.
There is no evidence from the
thermographic studies that cellulose structure is present
in any high grade coals.
In some peats and lignites the
thermographic studies do indicate the possible presence of
small percentages of residual cellulose.
.
Several preliminary studies have indicated that
pressures up to 2280 atmospheres,
temperatures to 1500 C.,
and the application of shear stress produce only slight
changes in the chemical structure of lignin, peat, and humic
acid.
Further experiments at lower, as well as higher,
temperatures and pressures appear to be warranted from an
examination of the experimental data.
An effort was made to apply the model theory developed
by M. King Hubbert (136, 137) to a solution of the
dynamochemical phase of coalification.
On calculation, it
was found that a hydrostatic pressure of over 1020
atmospheres would be required to produce coal under
laboratory conditions.
This result could indicate that
hydrostatic pressure plays little or no part in the
formation of coal,
or that the equations used for the
calculation are not adaptable to this type of problem.
Dr. Hubbert, who was consulted on this matter, felt that
the latter conclusion was correct and suggested that
attempts to investigate the problem from the scale-model
point of view be abandoned.
PROPOSED WORK
It
is proposed that the thermographic studies
of coals be continued and amplified using specimens carefully selected from a number of seams on the basis of field
data.
In a small section of a single seam it may be possible
to demonstrate thermally the heterogeneity or homogeneity of
a petrographically homogeneous substance such as vitrain.
If petrographic components can be recognized across lateral
distances in the same seam, then it may be possible to carry
out stratigraphic correlation studies.
A particular advantage
of thermographic analysis is that, if successful, it may
supplant long and tedious microscopic studies based on thin
or polished sections.
118.
Studies should be carried out in which the thermal
behaviour of the macro or micro constituents of the major
petrographic subdivisions of coal are separated and thermographically analyzed.
This work will require the development
of procedures for the isolation of significant components.
Thermal analyses may be made using a newly designed micro
furnace which is under construction.
This phase of the work
should make it possible to establish the sources of certain
characteristic thermal peaks which occur on the thermograms.
Thermal decomposition studies of coal should be
carried out in which each characteristic peak of the thermogram is correlated with the composition and quantity of the
evolved gas.
This study of gases evolved on heating coals
should be based on the exact data furnished by the thermographic analyses.
The results of this work will provide
information regarding the type of chemical degradation taking
place in the organic structure of the coal, and can be a
part of the fundamental evidence used to determine chemical
structure of the constituents of coal.
Infrared analysis has become one of the most powerful tools for the study of organic substances.
This method
should now be extended to the study of coals and related
materials.
There is good evidence that coal has been formed from
lignin.
Infrared studies of the following series will be of
primary importance in understanding the nature of the organic
119.
components in coal:
1.
Lignins isolated by various procedures.
2.
Humic materials.
These substances can be
isolated from peat by certain procedures of extraction
reported in the literature for the separation of humic acid,
ulmic acid, hymatomelanic acid, etc.
Infrared studies should
indicate the similarities and differences among these materials and help to eliminate existing confusion regarding
these substances.
3.
Peats of various types.
4.
Lignites.
5.
Bituminous coals.
Petrographic entities and
macro and micro constituents should be separately examined.
It will be necessary to develop new, and undoubtedly
novel, techniques for some of this work.
Since coals are probably aromatic in structure,
ultraviolet absorption studies should prove helpful in the
determination of structural characteristics.
Emission
spectroscopy should be applied to the study of the inorganic
constituents of coals.
Metallic elements such as vanadium,
nickel, or silver may provide clues to the origin of the
coal, its structure, and possible catalytic activity during
the coalification process.
Since lignin appears to be considerably altered soon
after it is deposited in sediments, the piezochemical
120.
studies should be repeated using peat, lignite, or humic
materials.
Studies at pressures and temperatures both
below and above those already used are indicated from the
work already carried out.
Thermographic analysis and
ultraviolet or infrared spectroscopy should be useful for
analysis of the products and to establish any increase in
rank during the experiments.
121.
APPENDIX
PUNCHED-CARD BIBLIOGRAPHY
Punched-card bibliographies have been used for
some time to answer specific questions in limitedfields.
In such cases this method is an excellent aid to the
literature and to identification procedures (114, 141).
In the course of the research covered by this
thesis, it has been necessary to compile an extensive
bibliography on the origin of coal.
A complete survey of
this subject requires an understanding of the following
fields:
I.
Wood chemistry
A.
Cellulose chemistry
1. Physical properties
2. Chemical properties
3.
B.
C.
Analytical techniques
Lignin chemistry
1.
Physical properties
2.
Chemical properties
3.
Analytical techniques
4.
Isolation procedures
Chtemistry of wood resins and waxes, tannins,
proteins, polysacchorideB other than cellulose,
etc.
122.
II.
Biological agents for the destruction or
alteration of wood components.
A.
Fungi
1.
Physical and chemical effects
B. Actinomyces
1.
Physical and chemical effects
C. Bacteria
1. Aerobic
a.
Physical and chemical effects
2. Anaerobic
a.
III.
IV.
Humus,
Physical and chemical effects.
Humic Acids, Humates.
A.
Origin
B.
Analytical and physical chemistry
C.
Isolation
Coal
A.
B.
C.
Peat
1.
Origin
2.
Chemical analysis and physical properties
Lignite
1.
Origin
2.
Chemical analysis and physidal properties
Bituminous Coal
1.
Origin
2.
Chemical analysis and physical properties
123.
D.
Anthracite
1.
Origin
2. Chemical analysis and physical properties
V.
VI.
VII.
VIII.
General Geological Data of Importance
Petrography of Coal
Inorganic Constituents of Coal
Colloidal Chemistry of Humus,
Coal, and
IX.
Associated Materials.
IX,
Temperature and High Pressure Effects.
Only a casual glance at this outline is
sufficient
to indicate a number of fields in which sub-classifications
overlap.
For instance, analytical chemistry shows up under
cellulose, lignin, humus, peat, lignite, bituminous coal,
and anthracite.
If It
is once understood that analytical
chemistry covers manifold procedures ranging from electron
microscopy to dialysis, then the futility of classifying
analytical chemistry under each of the above major headings
quickly becomes evident.
Not only would such aprocedure
require the use of all the holes on a card, but the duplication of recorded information would be such as to almost
degrade the punched card index to the status of a conventional card file.
For these reasons, only a single section
of the punched card has been used to cover the field of
analysis.
Inasmuch as analysis presented a major interest
in the study of the origin of coal, a major portion of the
card was allotted to this subject (Fig. 25).
124.
Figure 25
Subdivision of Subject Matter and
Code for Punched Cards
O
0
z
B
0
0
I.I
0
g0
z
00
w
AND DIFFRACTIONN
ELECTRONMICROSCOPY
VISIBLE LIGHT-
,,,REVIEW
'BOOK
-- OWN WORK
EMISSION-
00
W
0
INFARAREDR AMAN--'
ULTRAVIOLETOR FLUORESCENCEOPTICAL ACTIVITY-/
EROBIC
*5
ANAEROBIC
O
BACTERIA
.-
UNGI
SPORESOR ENZYMES
0 @INERT_
THERMOGRAM\
VACUUM
ENDOTHERMIC'
-----
EXOTHERMIC
GAS ANALYSIS-
is--
YS
COLOR ANAL
0-
/GEOLOGY
BOILING POINT-
PETROLOGY
OSSILS
MELTINGPOINT-0
CHROMATOGRAPHY
OR ADSORPTION-
GEOCHEMISTRY
REFRACTIVE INDEX---FRACTIONAlION.
*
CRYSTALLIZATIONMOLECULAR WEIGHT--"
EXTRACTION+
MICROSC
OP
Y
COKE-.
TAR- '
@0
@
PYROLYSISSOXYGEN
@
ISOLATION
'--...NITROGEN
NADIUM
SULPHUR
ST:UCTUREN
GENERAL ANALYSIS
,,ICKEL
"-
STRONTIUM
,,-POTASSIUM
-HYDRO
GEN
LOW TEMPERATURE
100-199
0 - 99-
200 -299\
300-399
4 00 - 499.BG0-599-\
700 000-099
-79
-SYNTHESIS
900 -99
1000 - 1099i
00089
OVER
200
11
00
-1199\
HIGH TEMPERATUREI
0
0
QV
2
12 5.
In using this decentralization procedure, several
points become obvious.
First, it becomes necessary to
employ two passes of the needle to establish the results of
a study such as the chromatographic analysis of peat; and
second, the single grouping under analysis saves space which
in turn makes possible a more complete classification and
allows more room for future expansion in original procedures
which might be developed and incorporated into the cards
during the course of the research.
Once the break-down of subject matter has been
decided upon, the process of codification is greatly simplified.
With the easily available McBee Keysort card used
in this work, the sides of the card were reserved for major
subjects and the top and bottom were used for the entry of
information pertaining to the major subjects.
By employing
this system, a single pass of the needle produces a set of
cards referring to a single unambiguous topic.
It is
particularly important to eliminate the extraction of undesired cards at this point since later operations generally
lead to the selection of a proportion of rejects as shown
below.
By eliminating unwanted categories at the very
beginning, the number of unwanted cards which are isolated
at the end of a series of passes is very greatly reduced.
The code for the punched cards used in the present
work is
shown in Fig. 25.
Where lettering extends to the
edge of the diagram, an outside punch is indicated.
Similarly,
lettering in an intermediate position represents a center
126.
punch, and deep lettering represents a deep punch.
These
three punches are represented on the sample card of Fig. 26.
When entering information on the cards, it is of great
assistance to know or to be able to predict the relative
frequency with which the various subjects will occur.
Since
center punches do not automatically separate the required
cards but necessitate manual isolation, it
is
especially
desirable to use center punches only for those topics which
occur infrequently.
Similarly, the use of deep punches is
permissible only where the subjects so coded occur rarely.
It must be remembered that each time a card with a deep
punch is removed, those cards with margin or center punches
on the same two-hole series also are removed.
Deep punches
are mainly valuable where an undesignated category is to be
indicated as illustrated in the case of the "bacteria" punch.
(Fig. 25).
As the accompanying figures show, information is
dispersed on a card and considerable space is allowed
between subjects.
This room is available for later expansion
or for the introduction of new fields which may become of
interest to the research.
The use of the cards and the extraction of particular
information from them offers no problem if
it
is remembered
that fundamentals rather than specific ideas have been coded.
As an example, if all the cards bearing information on peat
127.
Figure 26
Sample Punched Card
1
7
4
2
1
7
4
2
1
7-SF
4-0
2-SF
1-0
7
4
2
1
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
Lieser,
12
4
2
1
7-SF
4-0
2-SF
1-0
7
4
2
1
11
10
9
8
7
6
5
4
3
2
1
C. A., 21, 8213 (1927)
Cellulosechemie, 1, 15676o (1926)
.
N
Proposes isolation of lignin by cellulose-decomposing
bacteria, fungi, etc.
possibilities.
Thermophilic bacteria offer good
-4
A summary of important observations with
N
references.
N
FORMI
MCBEE KEYSORT U. S. PAT. NO. 2,213,607
-KS-152
U
128.
are removed from the file, then a second pass of the needle
can yield cards with information on peat and ultra-violet
light.
Since the ultra-violet entry is under the broad
heading of analytical chemistry, it
is to be expected that
all the cards will be removed which bear upon ultra-violet
light as a tool in the analysis of peat.
Since this light
is a source of energy for certain reactions, however, it
should be understood that cards bearing on the effects of
ultra-violet light on peat will also be separated.
This
explanation is intended to show both how an unusual entry
can be made, and how the desired cards can be removed.
Where broad interests are to be coded, maximum use must
be made of every item on a card to eliminate the necessity
for repetition under specific headings,
Taking a more difficult search for information as
an example,
it
is proposed that the index be used to
determine the role that anaerobic bacteria play in the
origin of humus, peat, and lignite.
Since peat, lignite,
and humus are major interests in this file, it is only
natural that all cards pertaining to these subjects be
removed first.
Having isolated and stacked these cards, a
new file of diminished proportions is presented for further
separations.
The next major item in the request for infor-
mation centers about the word "origin".
It will be noted
-
129.
in Fig. 25 that this word is the turning point of the whole
file and has been accorded the place of honor on the code.
By removing all cards dealing with "origin", the following
subjects have now been isolated:
1.
Origin of peat
2.
Origin of lignite
3.
Origin of humus
If the reverse procedure had been used and all cards
dealing with "origin" were removed first, then an unnecesarily
large group of cards would have been separated to form a bulky
and only partially useful sub-file.
In the third step of this
illustrative search, the needle is passed through the hole
reserved for anaerobic bacteria.
it
Since this is a center punch,
is necessary to remove the displaced cards manually.
During this pass of the needle,
cards dealing with both
aerobic and anaerobic bacteria will drop out along with
references to undesignated bacteria.
The series of three
passes has, therefore, isolated all references to the effects
of anaerobic bacteria on the origin of peat,
lignite, and
humus along with a small number of undesired cards.
To emphasize a difficulty which may be encountered
with the use of center punches, consider a possible search for
information regarding the use of color reactions for the
determination of the structure of lignin.
By successively
isolating those cards pertaining first to lignin and then to
structure, only one further step remains.
When the needle is
U ~
130.
passed through the color analysis hole a number of cards drop
out and a number are displaced.
unambiguous,
The displaced cards are
and those which drop are concerned not only
with "color reactions",
but also with "gas analysis".
If
there were a deep punch designation on this two-hole series,
then a number of those cards which fell during this operation
might have no relation to the desired subject.
This would
be an example of an over-extended code where a large number
of items were placed on the card at the expense of lost time
in manual separations during the isolation procedure.
It is helpful on occasion to be able to subdivide the
zotal index and to remove a particular section for further
study.
purpose.
Thus the "coal" punch in this index serves dual
On one hand, it offers a means of entering infor-
mation on experimental work on coal where the type of coal is
not designated.
On the other hand, by punching the "coal"
code each time peat, brown coal, lignite, bituminous, or
anthracite is entered, it later becomes possible to isolate
all the cards of the index which are related to coal.
In this
fashion only a limited number of cards need be handled instead
of the entire file.
A similar procedure has been applied in
the case of "lignin", "cellulose", and "other wood constituents", all of which have been reentered under the general
"wood" punch.
131.
To conserve space in a number of instances, several
minor related subjects have been simultaneously designated
Thus the "brown coal" entry also contains
on the cards.
references to cannel coal, boghead coal, Torbanites, etc.
Similarly, hydrogen, hydrogenation and dehydrogenat ion, and
oxygen and oxidation are entered under the same code designations.
The entry of highly specialized information in an index of this type can be accomplished with relatively little
difficulty.
As an example,
the results from differential
thermal analyses can be entered on the cards under the
following code headings:
I.
II.
Thermographic analysis
A.
Vacuum
B.
Inert atmosphere
Results
A.
Exothermic reaction
1.
B.
Temperature
Endothermic reaction
1. Temperature
In a typical analysis two significant decompositions
take place when an organic substance is heated at 12 degrees
per minute under vacuum.
The fir-st, an endothermic reaction,
reaches its peak at 2250,
and the second, an exothermic
132.
decomposition, attains its maximum at 4450 C.
this information on the card, it
To enter
is necessary to designate
a vacuum thermogram by the proper deep punch, and then to
employ both edge and center punches (which add up to a
deep punch) in the adjacent two-hole series to indicate that
both exothermic and endothermic reactions have taken place.
Proper entries would next be made on the temperature scale
to indicate that reactions had taken place between 2000
and 3000, and between 4000 and 5000 C.
It will be noted
that deep punches have been used in the temperature code.
In this case, there is
a definite need for contraction of
space and there is no fear of loss of information through
the overlapping of data.
The thermographic analysis entries pre-sent a
difficulty since it is not possible to directly determine
from the code which temperature corresponds to the exothermic
or endothermic reaction.
This is a relatively minor point,
however, since in actual use there would be no loss of information through incomplete coding, but rather, a number of
extra and undesired cards would fall during a search for
information.
Convenience is therefore sacrificed in order
to have e highly useful sub-code which will enable the
identification of unknown substances by comparing their
thermal decomposition peaks.
U ~
133.
BIBLIOGRAPHY
1. Adkins, H., Frank, R. L., and Bloom, E. S., "The Products
of the Hydrogenation of Lignin", J. Am. Chem.
Soc., ..
,
549-55 (1941).
2.
American Cyanamid Co., Stamford Research Laboratories,
"Spectra-Structure Correlations", a chart
obtained through R. C. Gore and dated
Feb. 1, 1950.
3.
Aulin-Erdtman, G., "Ultraviolet Spectroscopy of
Lignin and Lignin Derivaties", Tappi,
160-6 (1949).
4.
Bailey, A. J., "Chemistry of Lignin. I.
2,
The Existence
of a Chemical Bond Between Lignin and Cellulose",
Paper Trade J., 110, No. 1, 29-34 (1940).
5.
Bailey, A. J., "The Preparation and Properties of ButanolLignin",
Paper Trade J., 111, No. 6, 27-30
(1940).
6.
Bailey, A. J., "The Heterogeneity of Lignin",
J., 111, No. 7, 27-30 (1940).
7.
Bailey, A. J., "The Chemistry of Butanol-Lignin", Paper
Trade J., 111, No. 9, 86-9 (1940).
8.
Barnes, R. B.,
Paper Trade
Gore, R. C., Stafford, R. W., and Williams,
V. Z., "Qualitative Organic Analysis and
Infrared Spectrometry", Anal. Chem.,
402-10
9.
Beckley, V. A.,
20,
(1948).
"The Preparation and Fractionation of
Humic Acid", J. Agri. Sci., ll, 66-8 (1921).
10.
Beckley, V. A., "The Formation of Humus", J. Agri. Sci., 11,
69-77 (1921).
11.
Belcher, R., and Wheeler, R. V., "Composition of Coal:
Extraction with Quinoline", J. Chem. Soc.
866-9 (1940).
12.
Bergius, F., "Artifical Formation of Coal", J. Gas.
Lighting, 119, 571 (1912).
134,
13.
Bergius,
F.,
"The Use of High Pressures in Chemical
and Technical Chemical Processes",
Z.
Elektrochem.,
18,
660-2 (1912).
14.
Bergius, F., "High Temperature High Pressure Reactions",
Engineering, 96, 262-3 (1913).
15.
Bergius, F., "Formation of Anthracite",
12, 858-60 (1913).
16.
Berl, E., "Formation of Bituminous Coal", Colliery Guardian,
144, 914.-6, 961-2 (1932).
17.
Berl, E., et al., "The Origin of Petroleum, Asphalt, and
Coal", Naturwiss., 20, 652-5 (1932).
18.
Berl, E., "The Origin of Coal, Oil, and Asphalt", Montan.
Rundschau, 24, No. 19, 1-10 (1932).
19.
Berl, E.,
"The Artificial Formation of Substances Similar
to Bituminous Coal and Petroleum", Prod. 3rd
Intern.
20.
Z. Elektrochem.,
Conf.
Bituminous Coal, 1,
820-30
(1932).
Berl, E., "Cellulose as the Precursor of Coal and
Petroleum", Papier-Fabr., 31, Tech.-wiss.
Teil, 141-9 (1933).
21.
Berl, E., "Thg Origin of Coal, Asphalt, and Mineral Oil",
Osterr. Chem.-Ztg., _4, 385-7 (1937).
22.
Berl, E., "Role of Carbohydrates in Formation of Oil
and Bituminous Coals", Bull. Am. Assoc.
Pet. Geologists, 24, 1865-90 (1940).
23.
Berl, E.,
24.
Berl, E., and Koerber, W., "Fermentation of Cellulose
and Cellulose Humic Acid and Lignin and
Lignin Humic Acid", J. Am. Chem. Soc., 60,
1596-8 (1938).
25.
Berl, E., and Koerber, W., "Partly Aromatic Constitution
of Artificial Carbohydrate Coals", Ind. Eng.
and Keller, H., "Petrographical and Chemical
Researches on the Formation of Coals",
Ann., 501, 84-106 (1933).
Chem.,
26.
2,
676-7 (19
Berl, E., and Schmidt, A., "Behavior of Cellulose on
Heating under Pressure with Water", Ann.,
461, 192-220 (1928) .
135.
27.
Berl,
E.,
II.
"Genesis of Coals.
Coalification of Cellulose and Lignin
and Schmidt, A.,
in Neutral Medium", Ann., 493, 97-123
(1932).
28.
Berl, E., and Schmidt, A., "Genesis of Coals. IV.
Carbonization of Artificial Coals",
91, 135-52 (1932).
Ann.,
29.
Berl, E., and Schmidt, A., "Genesis of Coals. V.
Coalification of Cellulose and Lignin
in Alkaline Medium", Ann., 426., 283-303
(1932).
30.
Berl, E., Schmidt, A., and Koch, H., "The Origin of
Coal"
Z. angew. Chem., 4,
(1930$; 44, 329-30 (1931);
(1932).
31.
Binaghi, R.,
"Present Knowledge of the Phenomena of
Huminization of Fossil Fuels", Atti V.
cong. nazl. chim. pura. applicata, Rome,
1932i, P . 1, 231-51 (1936); Chem. Abst.,
22, 327
32.
(1938).
Bode, H., "Cellulose in Brown Coal and its Bearing on
the Origin of Coal",
(5),
33.
1018-9
517-9
4.,
Bone, W. A.,
Z.
prakt.
Geol.,
38,
70-74 (1930).
et al., "Researches on Coal. II. The
Resinic Constituents and Coking Propensities
of Coals", Proc. Roy. Soc. (London), 100A,
582-98 (1922).
34.
Brandl, A., "Examination of Decayed Oak. Remarks on the
Fischer-Schrader Coalification Theory",
Brennstoff-Chem.,
F.
89-94 (1928).
Isolation and
E., "Native Lignin. I.
Methylation" J. Am. Chem. Soc., 61,
2120-7 (1939 .
35.
Brauns,
36.
Brauns, F. E.,
37.
Brauns,
F.
2,
E.,
"Recent Advances in the Chemistry of
Lignin", Paper Trade J., 111, 33-39
Oct. 3, (1940).
"The Nature of Lignin from Western
Hemlock (Tsuga heterophylla)". J. Org.
Chem., 1, 211-15 (1945).
136.
38.
Brauns, F. E., "The Proven Chemistry of Lignin", Lignin
Chemistry and Utilization, Report on
Conference at New Haven, Conn., September
10, 1947, Northeastern Wood Utilization
Council, P. 0. Box 1577, New Haven.
39.
Brauns, F.
40.
Brauns,
41.
Brauns, F. E.,
E.,
"The Proven Chemistry of Lignin", "Lignin
Chemistry and Utilization", Bull. 19,
Northeastern Wood Utilization Council, F. 0.
Box 1577, New Haven, Conn., page 8
(January, 1948).
F. E., "Lignin", in Progress in the Chemistry
of Organic Natural Products, Vol. V,
L. Zechmeister, Ed., Springer Press,
Vienna, 1948.
and Brown, D.8., "Sulphite Cooking Process.Effect of Pretreatment of Spruce Wood on
the Reaction", Ind. Eng. Chem., 30, 779-81
(1938).
42.
Brauns, F. E., and Hibbert, H., "Studies on Lignin and
Related Compounds. XII. Methanol Lignin",
Can. J. Research, l3B, 28-34 (1935).
43.
Brauns, F. E., and Yirak, J. J., "The Decompostion of
Methylated Spruce Wood", Paper Trade J.,
125,
No. 24, 55-60 (Sept. 18, 1947).
44.
Bray, M. W., and Andrews, T. M., "Chemical Changes of
Ground Wood During Decay", Ind. Eng. Chem.,
16, 137-9 (1923).
45.
Breger, I. A., and Burton, V. L., "The Effects of Radioactivity on a Naphthenic Acid", J. Am.
Chem. Soc., 68, 1639-42 (1946),
46.
Breger, I. A.,
"Transformation of Organic Substances by
Alpha Particles and Deuterons", J. Phys.
& Colloid Chem., .. 2,
47.
Brickman, L., Pyle, J. J., McCarthy, J. L., and Hibbert, H.,
"Studies on Lignin and Related Compounds.
The Ethanolysis of Spruce and Maple
XXXIX.
Woods",
48.
551-63 (1948).
J. Am. Chem. Soc.,
61, 868-9 (1939)
Bridgman, P. W., "The Coagulation of Albumen by Pressure",
J. Biol. Chem., 13, 511-12 (1914).
- -
-
137.
49.
Bridgman, P. W.,
"Effects of High Shearing Strees
Combined with With Hydrostatic Pressurb",
Phys. Rev., 48, 825-47 (1935).
50.
Bridgman, P. W., "Recent Work in the Field of High
Pressures: Addendum", Rev. Mod. Phys., 18,
1-93 (1946).
51.
Bridgman, P.
W., and Conant, J. B., "Irreversible
Transformations of Organic Compounds under
High Pressures", Proc. Nat. Acad. Sci., 15,
680-3 (1929).
52.
Burian, 0., "The Constitution of Natural Humic Acids",
Brennstoff.-Chem., 6, 52-4 (1925).
53.
Bursker, E. S., et al., "Radioactivity of the Coal and
Anthracite of the Doneta Basin", Biochem.
Z., gZ, 276-81 (1931).
54.
Bursker, E. S., et al.,
"Radioactivity of Kuznetgk Coal",
Ukrain. Khem. Zhur., ., 441-5 (1934):
Chem. Abst., ?.,
6138 (1935).
55.
Buswell, A.M., and Boruff, C.S., "Decomposition of
Cellulose and Cellulose Material by Bacteria.
II.", Cellulose, 1, 162-5 (1930): Chem.
Ast., ?I, 49042 (1931),
56.
The DeterCampbell, W. G., and Bamford, K. F., "LXVII.
mination of Lignin in the Analysis of Woods",
Biochem. J., l0, 419-28 (1936).
57.
Centola, G.,
"Transverse Bonds Between Macromolecules of
Cellulose", Chimica e industria, 27, 1-4
(1945).
H. Y., "Lignins Isolated in the Presence of
Butanol", Paper Trade J., 114, No. 11, 31-36
(1942).
58.
Charbonnier,
59.
Clark, E. P., "Semimicro Quantitative Organic Analysis",
Academic Press, N. Y., pp. 68-72 (1943).
60.
Cockram, C., and Wheeler, R. V., "Studies in the Composition
of Coal. The Resolution of Coal by Means of
Solvents". J. Chem. Soc., 700-18 (1927).
138.
61.
Cockram, C., and Wheeler, R. V., "Studies in the
Composition of Coal. The Soluble
Constituents of Coal and their Degree
of Coalification", J. Chem. Soc.,
854-60 (1931).
62.
Cohen, W. E., and Harris, E., "Pretreatment of Wood With
Hot Dilute Acid. Effect on Lignin Values",
Ind. Eng. Chem., Anal. Ed., 2, 234-5 (1937).
63.
Creighton, R. H. J., McCarthy, J. L., and Hibbert, H.,
"Aromatic Aldehydes from Spruce and Maple
Woods", J. Am.
64.
Chem. Soc., 6,
312 (1941).
Crocker, E. C., "Significance of 'Lignint Color Reactions",
Ind. Eng. Chem., 12, 625-7 (1921).
65.
Dennstedt, M., and Schaper, L., "Dangerous Aspects of
Hard Coals", Z. angew. Chem., 25, 2625-29
(1912).
66.
Donath, E., "Contribution to the Knowledge of Fossil
Coals", Chem. Ztg., )2, 1271 (1909).
67.
Donath, E.,
68.
Dore, Charles, "The Methods of Cellulose Chemistry",
"Petroleum and Coal", Chem. Ztg.,
(1919).
Chapman and Hall,
Ltd.,
London,
43, 497-9
p. 494 (1947).
69.
Ibid., p. 370.
70.
Dorland, R. M., Hawkins, W. L., and Hibbert, H., "Studies
on Lignin and Related Compounds. XLVI.
Action of Ozone on Isolated Lignins".
The
J.
Am. Chem. Soc., 61, 2698-2701 (1939).
71.
Enders, C., and Sigurdsson, S., "The Chemistry of Humic
Acid Formation under Physiological Conditions.
V. The Early Phase of Humic Acid Formation:
An Aldol Condensation of Methylglyoxal", Ber.,
76B, 560-3 (1943).
72.
Evans, R. B., and Goodman, C., "Radioactivity of Rocks",
Geol. Soc. Am., Bull., 2, 459-90 (1941).
73.
Fischer, F.,
"Formation and Chemical Structure of Coal",
Naturwiss., 2, 958-65 (1921); J. Soc. Chem.
Ind., 41, 207A.
139.
74.
Fischer, F., "The Decay of Cellulose and Lignin",
Brennstoff -Chem., 3, 132-3 (1924).
75.
Fischer, F., "Origin of Coal" Z. deut.
77A. 534-50 (19251.
76.
Fischer, F., "Defense of the Lignin Theory of Coal
geol. Ges.,
Formation", Brennstoff-Chem., 14, 147-9
(1933).
77.
Fischer, F., and Horn, O., "Formation of Mineral
Coal" Qes. Abhandl.
682-4' (1934).
Kenntn. Kohle,
11,
78.
Fischer, F., and Lieske, R., "Studies on the Behavior
of Lignin in the Natural Decomiposition of
Plants", Biochem. Z., 203, 351-62 (1928).
79.
Fischer, F., and Schrader, H., "The Origin and
Chemical Structure of Coal",
Chem.,
Brennstoff-
2, 37-45 (1921).
80.
Fischer, F., and Schrader, H., "The Origin and Chemical
Structure of Coal", Brennstoff-Chem., 2,
213-19 (1921).
81.
Fisher, F.,
82.
Fischer, F., and Schrader, H., "New Contributions to
the Origin and Chemical Constitutianof
Coal", Brennstof'f-Chem., 2, 65-72 (1922).
83.
Fischer, F., and Schrader, H., "Notes on the Lignin
Origin of Coal", Brennstoff -Chem., 2,
341-3 (1922).
84.
Fischer, F.,
85.
Fischer, F., Schrader, H., and Treibs, W., "Chemical
Breakdown of Cellulose by Pressure
Oxidation", Ges. Abhandl. Kenntn. Kohle, 3,
211-20 (1921).
and Schrader, H., "Effect of Heating
Cellulose and Lignin under Pressure in
the Presence of Water and Aqueous Alkalies",
Ges. Abhandl.
Kenntn. Kohle, 1, 332-59
(1921).
and Schrader, H., "The Constitution of
Coal", Festschrift Kaiser Wilhelm Ges.
Forderung Wiss. Zehnjnhrigen Jubilaum,
59-63 (1921); Chem. Abst., 16, 4792 (1922)
-
-
140.
86.
Fischer, F., Schrader, H., and Treibs, W. "Effect of
Heating Under Pressure the Alkaline
Solutions obtained in the Pressure Oxidation
of Cellulose and Lignin", Ges. Abhandl.
Kenntn.
Kohle,
3,
311-18 (1921).
and Tropsch, H., "Comparative Investigations
2418-28
on Lignin and Cellulose", Ber. 56B,
(1923).
87.
Fischer, F.,
88.
Fischer, F., and Tropsch, H., "The Comparative Vacuum
Distilation of Cellulose, Lignin, and
Deresinated Wood.", Chem. Zentr., 1923, II,
1400-1.
89.
Fischer, G.,
"Acids and Colloids of Humus", Ku*hn-Archiv.,
4,
1-136 (1914); Chem. Abst., 2,
2119 (1915).
90.
Freudenberg, K., Belz, W., and Niemann, C., "The
Aromatic Nature of Lignin. X", Ber., 62B,
1554-61 (1929).
91.
Freudenberg, K., Harder, M., and Markert, L., "Observations on the Chemistry of Lignin ,Ber.,
61B, 1760-65 (1928).
92.
Freudenberg, K., Janson, A., Knopf, E., and Hoag A.,"
B 1415-25 (1936).
Lignin. XV", Ber.,
93.
Freudenberg,
94.
Freudenberg, K., and Ploetz, T.," Research on the
Enzymatic Decomposition of Wood", Holz Rohu. Werkstoff, 1, 105-9 (1940).
95.
Freudenberg, K., and Sohns, F.,
96.
Freudenberg, K., Zocher, H., and DUrr, W., "Further
Researches on Lignin.XI", Ber., 62B.,
1814-23 (1929).
97.
Friedrich, A., and BrUda, B., "Lignin. II. The
Structure of Primary Lignin", Monatsh.,
K., Lautsch, W., and Engler, K., "The
Preparation of Vanillin from Spruce Lignin",
Ber., 12B, 167-71 (1940).
66B, 262-9 (1933).
46, 600-10 (1925).
"Lignin. XXI", Ber.,
141.
98.
Friedrich, A., and Diwald,
J.,
"Lignin. I. Spruce
Lignin", Monatsch., 46, 31-46 (1925).
99.
Fr'mel, W., "Fulvic Acid. II.", Bodenkunde u.
Pflanzenernhr., 27, 247-55 (1942).
100.
Fuchs, W., "The Relation Between Humic Acids and
Lignin", Brennstoff-Chem., 2, 298-302 (1928).
101.
Fuchs, W.,
"Extraction of Lignin with Hydrochloric
Acid in Methylglycol", Ber., 62B, 2125-32
(1929).
102.
Fuchs, W.,
"Our Present Knowledge of the Chemical
Nature of Humic Acid, the Chief Constituent
of Lignite", Ges. Abhandl. Kenntn.
Kohle, 9,
176-81 (1930).
103.
Fuchs, W., and Daur, R., "New Investigations Regarding
the Constitution of the Pine Lignins,
Humic Acids, and Humins", Brennstoff-Chem.,
12, 266-8 (1931).
104.
Fuchs, W., and Daur, R., "Methylglycol Lignin",
Cellulosechem., 12, 103-10 (1931).
105.
Fuchs,
W., Polansky, T. S., and Sandhoff, A. G.,
"Coal Oxidation", Ind. Eng. Chem., 3,
343-5 (1943).
106.
Fuchs, W., and Stengel, W., "Hydroxyl and Carboxyl
Groups in Humic Acids", Brennstoff-Chem.,
10, 303-7 (1929).
107.
Fuller, W. H., and Norman, A. G., "Cellulose Decomposition by Aerobic Mesophilic Bacteria
from Soil. III. The Effect of Lignin",
J. Bact., 46, 291-7 (1943).
108.
Goss, M. J., and Phillips, M., "Studies on the Quantitative Estimation of Lignin. I. Factors
Influencing the Determination by the
Fuming Hydrochloric Acid Method", J. Assoc.
Official Agric. Chem., 19, 341-50 (1936).
109.
Gothan, W., "New Methods of Investigation of Brown
, Coal", Braunkohle, 21, 400-1 (1922).
, ilg!911110
ANZQ
__ ___
142.
110.
Gray, K. R., King, E. G., Brauns, F. E., and Hibbert,
H., "Studies on Lignin and Related Compounds.
XII. The structure and Properties of Glycol
Lignin" Car.J.Research,
B 35-47 (1935).
111.
Gropp, W., and Bode, H., "The Metamorphosis of Coals
and the Problem of Synthetic Coalification",
Braunkohle, 3l, 277-84, 299-302, 309-13
(1932).
112.
Gruss, J."Lignin"
(923),
113.
GrUss,
114.
Guy, A.
115.
Hagglund, E., "Holzchemie", Akademische Verlagsgesellschaft m. b. H., Leipzig, 200 (1939).
116.
Hggglund, E., and Carlsson, G. E., "Sulphonation
of Spruce Li nin. II.", Biochem. Z., 212,
467-77 (1933).
117.
Hagglund, E., and Rosenquist
Ber. dent,
botan Ges.,
41, 48-52
J. "A New Reagent for Wood and Vanillin",
dent. botan. Ges., 38, 361-68 (1920).
Ber.
G., "A Punch Card Filing System for Metallurgical Literature", Metal Progress, 993-1000
(December, 1947).
Biochem. Z., !.2,
T
"Spruce Lignin",
376-83't1926)
118.
Hagglund
119.
Hagglund, E., and Urban, H.", Lignin Acetals. II",
Cellulosechem., 9, 49-53 (1928).
120.
Hamdi, H., "The Colloidal Chemical Properties of
Humus. Dispersoid Chemical Observations
with Graphite-Oxide", Kolloid-Beihefte,
54, 554-634 (1943).
121.
Harris, E. E., D'Ianni, J., and Adkins, H., "Reaction
of Hardwood Lignin with Hydrogen", J. Am.
Chem. Soc., 60, 1467-70 (1938).
122.
Heuser, E., and Winsvold A., "Formation of Oxalic
Acid From Lignin, Cellulosechem., 2, 113
(1921); Ber., 56B, 902-9 (1923).
123.
Hibbert, H., and Phillips, J. B., "Lignin and Related
Compounds. III. Glycerol-Chlorohydrin-Lignin",
Can. J. Research, 2, 65-9 (1930).
6
E., and Urban, H., "Lignin Acetals. I,"
ellulosechem. ,
69-71 (1927).
143.
124.
Hibbert, H., et al., "Studies on Lignin and Related
Compounds. LX, LXI LXII", J. Am. Chem. Soc.,
62, 3052-56, 3056-61, 3061-66 (1941).
125.
Hickling, H. G. A., "The Microscopic Constitution of
J.
Coal"
Soc.
Dyers and Colourists,
2,
9-11
(1916 .
126.
Hickling, H. G. A., "Properties of Coals as Determined
by their Mode of Origin", Colliery Guardian,
_4 401-4 (1932).
127.
Hickling, H. G. A., and Marshall, C. E., "The Microstructure of the Coal in Certain Fossil Trees",
Trans. Inst. Min.'Eng., 84 (2), 13-23 (1932).
128.
Hickling, H. G. A., and Marshall, C. E., "The Microstructure of Coal in Certain Fossil Tree
Barks", Trans. Inst. Min. Eng., 86 (2), 56-75
(1933).
129.
Hickling, H. G. A., and Marshall, C. E., "The Origin
of Vitrain, Chemical Constitution and Further
Iron and Coal Trades Rev., 127,
Research",
637 (Oct.
27,
1933).
130.
Hilpert, R. S., and Pfutsenreuter, J., "The Influence
of Ethylenediamine Copper Oxide Solution on
Wood and Straw", Ber., 72B, 607-10 (1939).
131.
Hilpert, R. S., and Hellwage, H., "Beech-Wood Lignin,
a Reaction Product of Carbohydrates in Lignin
Determination", Ber., 68B 380-3 (1935).
132.
Hilpert,
R. S., Kruger, W., and Hechler, G., "Chemistry
of Lignin. The Action of Nitric Acid on
Woods",
Ber.,
a2,
1075-82
(1939).
133.
Hilpert, R. S., and Meybier, H., "Relationships Between
the Determinations of Pentosans and Lignins",
Ber., 71B, 1962-5 (1938).
134.
Hilpert, R. S., and Pfutzenreuter, J., "Characterization of the Plant Cell Wall by Treatment with
Copper Oxide-Ammonia Solution", Ber., 71B,
2120-2 (1938).
135.
Holmberg, B.
Woodi,
and Runius, S.,
Svensk Kem.
"Alcoholate Digestion of
Tid.,
E,
189-97
(1925).
144.
M. K., "Theory of Scale Models as Applied
to the Study of Geologic Structures", Bull.
Geol. Soc. Am., 48, 1459-1520 (1937).
136.
Hubber,
137.
Hubbert, M. K., "Strength of the Earth", Bull. Am.
Assoc. Pet. Geologists, 29, 1630-53 (1945).
138.
Hunter,
M. J.,
Cramer, A. B.,
"Structure of Lignin",
60, 2815-6 (1938).
and Hibbert, H.,
J. Am.
Chem.
Soc.,
139.
Hunter, M. J., Cramer, A. B., and Hibbert, ,H. "Studies
on Lignin and Related Compounds. XXXVI.
Ethanolysis of Maple Wood", J. Am. Chem. Soc.,
61, 516-20 (1939).
140.
Hunter,
141.
Hurlbut, C. S.,
M. J., and Hibber, H., "Studies on Lignin and
Related Compounds. XLIII. The Absence of the
Piperonyl Group in the Lignin Structure", J. Am.
Chem. Soc., 61, 2196-8 (1939).
"Mineral Determination by Means of
Mineralogist, ll, 508-12
Punched Cards", Am.
(1948).
142.
Jackson, E. L., and Hudson, C. S., Application of the
Cleavage Type of Oxidation by Periodic Acid
to Starch and Cellulose", J. Am. Chem. Soc.,
52,
2049-50
(1937).
143.
Jeffrey, E. C., "Nature of Some Supposed Algal Coals",
Proc. Am. Acad., 46, 273-90 (1910),
144.
Jeffrey, E. C., "The Mode of Origin of Coal", J. Geol.,
29,
145.
218-31 (1915).
Jodl, R., "Carbohydrate Humic Acids and their Relations
to Natural and Phenol Humic Acids", BrennstoffChem., 22,
217-20 (1941).
146.
Johnson, F. H., and Lewin, I., "The Influence of Pressure,
Temperature, and Quinine on the Rates of Growth
and Disinfection of Escherichia Coli in the
Logarithmic Growth Phase" J. Cellular Comp.
Physiol., 28, 77-97 (1946S.
147.
Jones, 0. T., "Hilt's Law and the Volatile Contents of
Coal Seams", Geol. Mag., 86, 303-312, 346-364
(1949).
145.
148.
Junker, E., "Colloid Chemical Properties of Humus.
Dispersion Chemistry of Lignin", Kolloid(1941).
213-50
Z., 2,
149.
Kinney, C. R., Polansky, T. S., and Gauger, A. W.
"Preparation of Humic Acids from
Bituminous Coals and Their Separation
from Mineral Matter and Fusain by Solvent
Treatment", Penna. State College Min.
Ind. Exp. Station, Bull. 44 (1946)
150.
Klason, P.
151.
Klason, P.,"The Chemical Structure of Pine-Wood
Lignin", Svensk, Kem. Tidskrift, 5-16,
47-52 (1917).
152.
Klason, P., "Constitution of Pine-Wood Lignin. II.",
Ber.,
B 448-55 (1922).
153.
Klason, F., "Lignin Content of Spruce Wood", Cellulosechem., 4 81-4 (1923).
154.
Kreulen
155.
Ibid, 38-41.
156.
Ibid
157.
KUrschner, K.
158.
"Beitr~dge Zur Kenntnis der Chemische
usammensetzung des Fichtenholzes",
B8erlin, 34-36 (1911).
D. J. W., "Elements of Coal Chemistry
Nijgh & van Ditmar, Rotterdam, p. 16 (1948).
47.
Brennetoff-Chem.,
158162 177-80, 188-94 208, 304-11 (1925).
Kti*rschner, K., "The Humification of Wood by Merulius
Lacrymans", Z angew. Chem. 40O, 224-32 (1927).
"Lignins",
159.
Ktrschner, K., "Humic Acid from Cassel Brown Coal.
Ni/2"h, Cellulosechem., e, 59-67 (1941).
16o.
Kurth, E. F., and Ritter, G. J., "Spruce Holocellulose
and the Composition ofits Easily Hydrolyzable
Fraction",
J.
Am.
Chem.
Soc.,
16,
2720-23
(1934).
161.
Lange, P. W., "Nature and Distribution of Lignin in
262-5
Spruce Wood", Svensk Papperstidn., 4',
(1944).
146.
162.
Lange, P. W., "Ultraviolet Absorption of Solid Lignin",
Svensk. Papperstidn., 48, 241-5 (1945).
163.
Leavitt, W. Z., "A Study of the Possibility of Isolating
Lignin by the Selective Oxidation of Cellulose
in Black Spruce Wood with Lead Tetracetate",
S.B. Thesis, Dept. of Chemistry, Mass. Inst.
of Tech., 1949.
164.
Lieser, T., "Lignin", Cellulosechem., Z, 156-60 (1926).
165.
Lebeau, P., "The Gaseous Products of Carbonization",
Chimie et industrie, -1, Spec. No., 73-90
(April, 1928).
166.
Lowry, H. H., "Chemistry of Coal Utilization", John
Wiley and Sons, New York, Vol. I (1945).
167.
Luft, F., "The Fiber Structure of Lignite", PapierFabr., Tech.-Wiss. Teil, 28, 787-91 (1930).
168.
MacInnes, A. S., West, E., McCarthy J. L,, and
Hibbert, H., "Studies on Lignin and Related
Compounds XLIX. Occurrence of the Guaiacyl
and~Syringyl Groupings in the Ethanolysis
Products from Various Plants", J. Am. Chem.
Soc.,
62,
2803-2806
(1940).
S.A., and Cable, D.E., "The Chemistry of
Wood. IV. The Analysis of the Wood of
Eucalyptus Globulus and Pinus monticola",
Ind. Eng. Chem., 14, 933-4 (1922).
169.
Mahood,
170.
Marcusson, J., "Petroleum Oil and Coal", Chem. Z+g.,
42, 437-9 (1918).
171
MacusonJ.,"Humic
Acids",
Z. angew. Chem.,
l
I, 237-8 (1919).
172.
Marcusson, J., "Origin of Asphalt and Coal", Chem.
Z+g.
44, 43-4 (1920).
173.
Marcusson, J., "The Structure and Formation of Humic
Acids and Coals", Z. angew. Chem., 21.,
C.A.16, 21228 (1922).
165-6 (1922).
174.
Marcusson, J., "Structure of the Humic Acids and Coals"
Ber., .8B, 869-72 (1925).
147.
175.
Marcusson, J., "The Composition of Peat and the Lignin
Theory", Z.
angew.
Chem.,
38, 339-41 (1925).
176.
Marcusson, J., "Lignin and the Oxycellulose Theory of
the Origin of Coal", Z. angew. Chem., 12,
898-900 (1926); 40, 48-50 (1927); 40, 1233.-4
(1927).
177.
Marcusson, J., "Chemical Constituents of Lignites",
Z. angew. Chem., 40, 1104-6 (1927).
178.
Marcusson, J., and Wisbar, G., "The Composition of
Lignite", Z. angew. Chem.,
179.
ll,
917-8 (1924).
Marshall, C. E., "Contribution to the Comparative
Petrology of British and American Coals of
Carboniferous Age", Fuel, 20 (3), 52-59
(1941); 2Q (4), 89-91 (1941).
180.
Marshall, C. E., "The Constitution of Anthraxylon
(Vitrain or Vitrainite) and its Relation
to Type and Rank Variation in Coal Seams"
Fuel, 22,
140-55
(1943).
181.
Moore, E. S., "Coal", John Wiley and Sons, New York
(1922).
182.
Moureau, C., and Lepape, A., "Helium from Five-Damp
and Radioactivity of Coals, Compt. rend.,
158, 598-603 (1914).
183.
Norman, A. G., and Jenkins, S. H., "The Determination
of Lignin. I.
Errors Introduced by the
Presence of Certain Carbohydrates", Biochem.
J., 28, 2147-59 (1934).
184.
Norman, A. G., "CXCVI. The Determination of Lignin.
III. Acid Pretreatment and the Effect
of the Presence of Nitrogenous Substances",
Biochem, J., 21, 1567-74 (1937).
185.
Norton, F. H., "A Critical Study of the Differential
Thermal Method for the Identification of
the Clay Minerals", J. Am. Ceram. Soc., 22,
54-63
186.
(1939).
Odintsov, P. N., "The Effect of Methods of Preparation
of Lignin on its Chemical Nature", Lesokhim.
Prom
No 1, 10-17 (1939); Chem. Abst., l4,
54176 (1940).
148.
187.
Ostwald, Wo., and Steiner, A., "Colloid Chemistry of
Humus and Peat", Kolloid-Chem. Beihefte,
21, 97-170 (1925).
188.
Ott, E., "Cellulose and Cellulose Derivatives",
Interscience, New York, 103 (1946).
189.
Ibid., p. 287-8.
190.
Payen, M., "Memoir on the Composition of Plant Tissue
and of Lignins", Compt. rend., 7, 1052 (1838).
191.
Petrascheck, W., "The Metamorphosis of Coal and its
;nfluence on the Visible Components", Sitz.
Osterr. Akad. Wissen., Mathem.-naturw.
Kl. Abt I, 156, Nos. 7 and 8, 375-444
(1947).
192.
Phillips, M., and Goss, M. J., "Chemistry of Lignin.
VIII. The Oxidation of Alkali Lignin",
J. Am. Chem. Soc., jj, 3466-70 (1933).
193.
Phillips, M., and Goss, M.J., "The Dehydration of
Alkali Lignin From Corn Cobs with Selenium",
J. Assoc. Off. Agr. Chem., 21, 632-5 (1938).
194.
Pictet,
195.
Pictet, A.,
196.
Pictet, A., and Ramseyer, L., "Constituents of Coal",
Ber. 44 2486-97 (1911).
197.
Pictet, A.,
198.
Pictet, A., Rayseyer, L., and Kaiser, O., "Hydrocarbons
358-61
Present in Coal", Compt. rend., 16
(1916).
199.
Ploetz, T., "The Enzymatic Decomposition of Polymerized
Carbohydrates. IV. Comparative Enzymatic
Decompositions of Several Isolated Wood
Components by means of Snail Enzyme", Ber.,
A.
"The Chemistry of Coal", Gas J., 142,
(1918).
333
"Researches on Coal (Certain Constituents
of Coal)", Ann. Chim. (9), 10, 249-330 (1918).
ardRamseyer,
L.,
"Hydrocarbon from Coal",
Arch. sci. phys. nat.,
lis,
57-60 (1940).
4,
234-49 (1913).
149
200.
Ploetz, T., "The Enzymatic Decomposition of Polymerized
Carbohydrates. V. Enzymatic Decomposition of
of some native Lignin-Containing Materials",
Ber.,
73.B, 61-73 (1940).
"The Enzymatic Decomposition of Polymerized
Carbohydrates. VI. The State of Combination
of Lignin in Wood," Ber., 72B, 74-8 (1940).
201.
Ploetz, T.,
202.
Ploetz, T., "The Enzymatic Decomposition of Polymerized
Carbohydrates. VII. Further Fractionation
Research on Linden Wood and Enzymatic
Decomposition of the Fractions", Ber., 73B,
790-4 (1940).
203.
Potonie,
H., "The Origin of Coal and Related Products
Including Petroleum", Ber. deut. pharm.
Ges., 12,
204.
Potonie,
180-223
(1907).
R., "The Lignin Origin of Coal, A Geologic
and Paleontologic Impossibility", Braunkohle,
21, 365-9 (1922).
205.
Potonie, R., "Microscopy of Brown Coals.
Pollen Forms", Braunkohle, 30,
Tertiary
325-33 (1931).
206.
Potonie, R., and Bosenick, G., "On the Origin of Coal:
Results of A Petrographic-Microchemical
Comparison of the Physical Constituents of
Low and Medium-Rank Bituminous Coal", Preuss.
Geol. Landesanst. Laborat., Mitt. 12, 75-110
(1933); Abst. Brennetoff-Chem., 15, 195-6
(May 15, 1934S.
207.
Puri, A.
208.
Pyle, J. J., Brickman, L., and Hibbert, H., "Studies
on Lignin and Related Compounds. XLIV. The
Ethanolysis of Maple Wood; Separation and
Identification of the Water-Soluble Aldehyde
Constituents," J. Am. Chem. Soc., 61, 21982203 (1939).
209.
Raistrick, A., and Marshall, C. E., "The Nature and
Origin of Coal and Coal Seams", English
Universities Press, London (1939).
N., "Soils, Their Physics and Chemistry,
"Reinhold Publishing Corp., New York,
pp. 222-25 (1949).
150.
210.
Raistrick, B., Shapiro, R. H., and Newitt, D. M.,
"Liquid-Phase Reactions at High Pressures.
V. The Polymerization of Cyclopentadiene
and (-Dicyclopentadiene", J. Chem. Soc.,
1761-69 (1939).
211.
Rakovskl4,E. V., "The Formation of Humus Substances
and Li gnin" Khim. Tverdogo Topliva
1
13-22 (1936; Chem. Abst., 31, 15844 T1937).
212.
Randall, R. B., et al., "The Alkaline Permanganate
Oxidation of Organic Substances Selected
for their Bearing on the Chemical
Constitution of Coal", Proc. Roy. Soc.
(London), A165, 432-52 (1938).
213.
Rassow, B., and Gabriel, H.," Pinewood Lignin",
Cellulosechem., 12,
227-35, 290-95, 318-20
(1931).
214.
Ritchie, P. F., and Purves, C. B., "Periodate Lignins;
Their Preparation and Properties", Pulp
Paper Mag. Canada, 48, No. 12, 74-82 (1947).
215.
Ritter,
216.
Ritter, G. J.,
D. M., et al., "Constitution of Gymnosperm
Lignin," Science, 107, No. 2766, 20-22 (1948).
"Distribution of Lignin in Wood",
Ind. Eng.
Chem.,
12,
1194-7
(1925).
"Factors
of
Method",
(1932).
217.
Ritter, G. J., Seborg, R. M., Mitchell, R. L.,
Affecting Quantitative Determination
Lignin by 72 Per Cent Sulphuric Acid
Ind. Eng. Chem., Anal. Ed., 4, 202-4
218.
Rose,
219.
Russell, A., "Interpretation of Lignin. I. The Synthesis
of Gymnosperm Lignin", J. Am. Chern. Soc., 20,
1o60-64 (1948).
220.
Schorger, A. W., "Chemistry of Cellulose and Wood",
McGraw-Hill, New York, p. 524 (1926).
221.
Schrader, H., "The Behavior of Cellulose, Lignin, Wood,
and Peat Toward Bacteria", Ges. Abhandl.
Kenntn. Kohle, 6, 173-6 (1921).
"The Chemistry of Wood
R. E., and Lisse, X. W.,
Decay. I. Introductory", Ind. Eng. Chem., 2,
284-7 (1917).
151.
222.
Schrader, H., "Recent English Work on the Constitution
of Coal", Brennstoff-Chem., 1, 155-7 (1926).
223.
Schrauth, W.,
"Lignin", Z. angew.
Chem., 36,
149-52
(1922).
224.
Schuitz, F.
and Sarten, P., "Wood Chemistry. The
Pormation of Lignin from Wood and Wood
Extracts and the Oxidation of Sugars,
Cellulose, Wood, and Wood Extracts with
Diazo Compounds to the Acids of the Sugar
Group", Cellulosechem., 21,
225.
35-48 (1943).
Schwalbe, C. G., "A New Method for the Determination of
Lignin", Tech.-Wiss. Teil, Papierfabr., 2,
174-7 (1925); Chem. Abst., 12,
2127 (1925).
226.
Schwalbe, C. G., and Schepp, R., "Transformation of
Ligneous Plant Substances into Coal. I.
Production of Coal-Like Products from
Cellulose", Ber. 57B, 319-22 (1924).
227.
Schwalbe, C. G.., and Schepp, R., "Transformation of
Ligneous Plant Substances into Coal. II.
Chemical Composition of Coaly Substances
from Cellulose", Ber. 57B, 881-3 (1924).
228.
Schwalbe, C. G., and Schepp, R., "Conversion of Lignified
Plant Matter into Coal. III. Sugar Formation
as an Intermediate Stage of Coal Formation",
Ber. 58B, 2500-2 (1925).
229.
Sedletskj4, I. D., and Brunooski., B., "The Structure
of Humic Acid and Its Relation to Lignin
and Coal", Kolloid-Z+g, 12, 90-1 (1935)
230.
Sedletskil,I. D.,
"X-Ray Investigations of Coals",
Soviet Geol., 26 No. 6
Abst.,
4,
6793
48-63 (1939); Chem.
(1940S.
231.
Sedletski$, I. D., and Shmakova, G. V., "Thermal
Characteristics of Humic Acid" Compt. rend.
acad. sci. URSS, )1, 255-7 (1942).
232.
Seyler, C. A., "The Microstructure and Banded Constituents of Anthracite", Fuel, 2, 217-8 (1923).
233.
Seyler, C. A., "The Microstructure of Coal", Fuel in
Science and Practice, 4, 56-66 (1925).
152.
C. A.,
"The Nomenclature of the Banded
Constituents of Coal", J. Roy. Soc. Arts,
14, 609-10 (1926).
234.
Seyler,
235.
Seyler, C. A., "Microstructure of Coal", Gas J. 173,
419-20 (1926).
236.
Sheppard, C. W., and Burton, V. L., "The Effects of
Radioactivity on Fatty Acids", J. Am. Chem.
Soc.,
237.
68,
1636-39
(1946).
Sheppard, C. W., and Whitehead, W. L., "Formation
of Hydrocarbons from Fatty Acids by AlphaParticle Bombardment", Bull. Am. Assoc. Pet.
Geologists, 30, 32-51 (1946).
238.
Smith, R. C., and Howard, H. C., "Equivalent and
Molecular Weights of Humic Acids from a
Bituminous Coal", J. Am. Chem. Soc., 52,
512-16 (1935).
239.
Smith, R. C., and Howard, H. C.,
Cellulose by Heat", J.
234-6 (1937).
240.
Spiel, S., Berkhamer,: L. H., Pask, J. A., and Davis, B.,
"Differential Thermal Analysis" U. S. Bur.
of Mines, Tech. Paper 664 (1945 .
241.
Stach, H.,
242.
Stach, H., "Moscow Brown Coals. IV. Humic Coalsu,
Braunkohle, 22, 617-21 (1933).
243.
Staudinger
244.
Staudinger, M.,
"The Constitution and Chemical Structure of
Bright Brown Coals. III.
Humus Coals",
Brennstoff-Chem,
14, 201-7 (1933).
H., Staudinger, M., and Schmidt, H.,
Macromolecular Compounds. CCXXXVII. The
Destruction of Cellulose by Microorganisms"
Zellwolle, Kunstseide, Seide, 4J, 2-4 (19404.
"Chemical Anatomy of Wood", Holz Roh-u.
Werkstoff,
245.
"Aromatization of
Am. Chem. Soc., 3-,
, 193-201 (1942).
Stopes, M. C., "Studies on the Composition of Coal. I.
The Four Visible Ingredients in Banded
Bituminous Coal", Proc. Roy. Soc. London,
90B, 470-87 (1919).
153.
M. C., and Wheeler, R. V., "The Structure of
(1916).
4641
Coal", Colliery Guardian,
246.
Stopes,
247.
Stopes, M. C., and Wheeler, R. V., "The Constitution of
Coal", Dept. Sci. Ind. Research, 1-58 (1918);
J. Chem. Soc. 114A II, 270-1 (1918); Chem.
Abs., 12, 2426 (1918).
248.
Stopes,
M. C., and Wheeler, R.V., "The Constitution
of Coal. III.", Fuel in Science and Practice,
2, 196-204 (1924),
249.
Stopes,
M. C., and Wheeler, R. V., "The Constitution
of Coal. IV., "Fuel in Science and Practice,
-, 254-61 (1924).
250.
Stopes,
M. C., and Wheeler, R. V., "The Constitution
Fuel in
of Coal. VII. Artificial Coal"
Science and Practice,
251.
2,
Stopes, M. C., and Wheeler, R. V
Thories;,
of Coal. VIII.
and Practice, 2,
393-5
(1924).
"The Constitution
Fuel in Science
395-9 (1924).
252.
Strahan, A., and Pollard., W., "The Coals of South Wales
With Special Reference to the Origin and
Distribution of Anthracite", Mem. Geol. Survey,
England and Wales, 2nd Ed., pp. 73-74 (1915).
253.
Stutzer, 0., "Microscopic Coal Examination", Mikrokosmos,
132-4 (1919-1920).
254.
Stutzer, 0., and Nob, A. C., "Geology of Coal" University of Chicago Press, Chicago (1940 .
255.
Tenney, F. G., and Waksman, S. A., "Composition of
Natural Organic Materials and their
Decomposition in the Soil. IV. The Nature
and Rapidity of the Decomposition of the
Various Organic Complexes in Different Plant
Materials Under Aerobic Conditions", Soil
Sci.,
256.
28,
55-84
(1929).
Thaysen, A., C., et al., "Studies on the Bacterial
Decomposition of Textile Fibers. III. The
Occurrence of Humus Compounds in Deteriorated
Fabrics and the Bearing of Their #ormation on
bie Origin of Peat and Coal", Biochem. J., 20,
210-16 (1926),
~ir
154.
257.
Thaysen, A. C., "The Microbiological Aspect of Peat
Formation", Fuel in Science and Practice,
2, 560-3 (1930).
258.
Thiessen, G., and Engelder, C. J., "Isolation of the
Humic Acids", Ind. Eng. Chem., 22, 1131-33
(1930).
259.
Thiessen, R., "Structure in Paleozoic Bituminous Coals",
U. S. Bureau of Mines Bull, 117, 292 pp. (1920).
260.
Thiessen, R., "What is Coal?", U. S. Bureau of Mines
Information CirculaRr 7397, 53 pp. (1947).
261.
Thiessen, R., and Strickler, H. S., "Distribution of
Microorganisms in Four Peat Deposits",
Mining and Met. Investigations, U. S. Bureau
of Mines, Carnegie Inst., Tech. and Mining
and Met. Advisory Boards, Coop. Bugl., 61
1-18 (1934); Chem. Abst., 34, 7398 (193M.
262.
Thiessen, R., and Strickler, H. S., "Distribution of
Microorganisms in Four Peat Deposits",
Mining and Met. Investigations, U. S. Bur.
Mines, Carnegie Inst., Tech. and Mining and
Met. Advisory Boards, Coop. Bull., 61, 1-18
(1934).
F. V., and Wheeler, R. V., "Studies on the
Composition of Coal. II.
A Chemical
Investigation of Banded bituminous Coal",
J. Chem. Soc., 115, 619-36 (1919).
263.
Tideswell
264.
Tideswell, V., and Wheeler, R. V., "Dopplerite. The
Composition of Coal", J. Chem. Soc., 121,
2345-62 (1922).
265.
Treibs, A., "Organic Minerals. III. Chlorophyll and
Hemin Derivatives in Bituminous Rocks,
Petroleum, Mineral Waxes, and Asphalts.
Origin of Petroleum", Ann., 5j0, 42-62 (1934).
266.
Treibs, A., "Organic Mineral Substances. TV. Chlorophyll
and Hemin Derivatives in Bituminous Rocks,
Petroleums, Coals, and Phosphorites", Ann.,
11, 172-96 (1935).
155.
267.
Treibs, A., "Organic Mineral Substances V. Porphyrins
inCoals", Ann., 32, 144-50 (1935).
268.
Treibs, A., "Chlorophyll and Hemin Derivatives in
Organic Mineral Substances", Angew. Chem.,
42, 682-6 (1936).
269.
Trifonow, I., and Toschew, G, "Alteration of the
Properties of Coals by Compression under
High Pressures, Brennstoff-Chem., 20, 128
(1939); 21, 85-7 (1940).
270.
Trifonow, I., and Phillipow, A., "Changes in Coals
upon Compression at Very High Pressures",
Brennstoff-Chem.,
22,
193-5
(1941).
271.
Tripp, R. M., "Classification of Organic Shales Based
gThermographic Analysis" D. Sc. Thesis,
Dept. of Geology, M.I.T. (1948).
272.
Trotter, F. M., "The Devolatilization of Coal Seams in
South Wales", Quart. J. Geol. Soc., 104, 387-
437 (1949).
273.
Ubaldini, I., "Humic Acids", Brennstoff-Chem., 18,
273-9 (1937).
274.
Ubaldini, I., and Magaldi, F., "The Constitution of
Italian Fuels. II." Ann. chim. epplicata,
27, 146-56 (1937).
275.
"Humic Acids. III..
Ubaldini, I., and Siniramed C
Thermal Decompositionf , Ann. chim. applicata,
27, 94-102 (1937).
276.
Vereshchlagin, L. F., and Polyakova, A.M., "The Explosive
Decomposition of Cyclopentadiene at High
Pressure", Compt. rend. acad. sci. U.R.S.S.,
47, No.
3,
197-8 (1945).
277.
Virtanen, A. I., "The Fermentation of Native Cellulose
in Wood", Rept. Proc. 3rd Intern. Congr.
Micr biol., 747-8 (1939); Chem. Abst., .4,
5246' (1940).
278.
von Beroldingen, F., "Beobachtungen, Zweiful, and Fragen,
die Mineralogie uilberhaupt, and inbesondere
ein natUrliches Mineral-System betreffend",
Hannover, First Edition, 1778; Second Edition,
1792, Volume 1.
156.
279.
Waksman, S. A., "Cellulose and its Decomposition in
the Soil by Microorganisms", Proc. Intern.
Soc. Soil Sci., (N.S.), 2, 293-304 (1926);
Chem. Abst., 21, 3099 (1927).
280.
Waksman,
281.
Waksman, S. A. "The Chemical Composition of Peat and
the Aole of Microorganisms in its Formation",
Am. J. Sci., (5), 12, 32-54 (1930).
282.
Waksman, S. A., "The Chemical Composition and Methods
of Analysis of Peat-Forming Plants and Peats",
S. A., "The Origin and Nature of Soil Organic
Matter or Soil "Humus", III. Nature of
Substances Contributing to the Formation of
Humus", Soil Science, 22, 323-33 (1926).
Brennstoff-Chem.,
11,
277-81
(1930).
283.
Waksman, S A., "Decomposition of the Various Chemical
Constituents of Complex Plant Materials by
Pure Cultures of Fungi and Bacteria", Arch.
Mikrobiol., 2, 136-54 (1931).
284.
Waksman,
285.
Ibid.., p. 96.
286.
Waksman, S. A., and Dubos, R. J., "The Nature of
Organisms which Decompose Cellulose in Arable
Soils", Compt, rend., 185, 1226-8 (1927)
287.
Waksman, S. A., and Gerretsen, F. C., "Influence of
Temperature and Moisture on the Nature and
Extent of Decomposition of Plant Residues by
Microorganisms", Ecology, 12, 33-60 (1931).
288.
Waksman, S. A., and Purves, E. R., "The Microbiological
S. A., "Humus", Williams and Wilkins Co.,
Baltimore (1936).
Population of Peat", Soil Science, 34, 95-113
(1932).
289.
Waksman, S.A., and Starkey, R. L., "Microbiological
Analysis of Soil as an Index of Soil Fertility.
VII. Carbon Dioxide Evolution", Soil Sci., 17,
141-61 (1924).
290.
Waksman, S.A., and Starkey, R. L., "Soil and the Microbe",
John Wiley and Sons, New York, p. 82 (1931).
157.
85-6.
291.
Ibid.,
pp.
292.
Ibid.,
pp. 86-7.
293.
Waksman,
S. A., and Stevens, K. R., "Decomposition of
Wood with Reference to the Chemical Composition of Fossilized Wood", J. Am. Chem.
Soc.,
j1,
1187-96
(1929).
294.
Wald, W. J., Ritchie, P. F., and Purves, C. B.,
"The Elementary Composition of Lignin in
Northern Pine and Black Spruce Woods and of
the Isolated Klason and Periodate Lignins",
J. Am. Chem. Soc., 12, 1371-7 (1947).
295.
Wehmer, C., "Experiments on the Conversion of Cellulose,
Lignin, and Wood into Humins by Fungi",
Brennstoff-Chem., 6, 101-6 (1925).
296.
Weyland, H., "Chemical Processes in the Formation of Coal",
Naturwiss.,
.,
327-35 (1927).
297.
Wheeler, R.V., "The Composition of Coal" Chemistry
and Industry, 10, 335-44 (19315.
298.
White,
299.
White, D.,
D., "Some Problems in the Formation of Coal",
Econ. Geol., 2, 293-318 (1908).
"The Origin of Coal", U. S. Bureau of Mines,
Bull.
300.
38,
1-4 (1913).
White, D., "Analyses of Coal Samples Studied under the
Microscope" U. S. Bureau of Mines Bull., 38,
46-51 (19135.
D.,
"Some Relations in Origin Between Coal and
Petroleum", J. Wash. Acad. Sci., 5, 189-212
(1915).
301.
White,
302.
White, D., "Progressive Regional Carbonization of Coals",
Trans. Am. Inst. Mining Met. Engrs., -1,
253-81 (1925).
303.
White,
D.,
"The Role of Water Conditions in the Formation
and Differentiation of Common Banded Coals",
Econ. Geol., 28, 556-70 (1933).
158.
304.
White, D.,
"Metamorphism of Organic Sediments and
Derived Oils", Bull. Am. Assoc. Pet.
Geologists,
2.,
589-617 (1935).
305.
Widell, T., "Thermal Analysis of Peat", IVA, 18,
178-80 (1947).
306.
Willstatter, R., and Zechmeister, L., "Hydrolysis
of Cellulose. I.".Ber., 46, 2401-12 (1913).
307.
Witham, H., "On the Internal Structure of Fossil
Vegetables found in the Carboniferous and
Oolitic Deposits of Great Britain, 1833;
Thiessen, R., U. S. Mines Bureau, Bull. 38,
p. 189 (1913).
308.
Wright, G. F., and Hibbert, H., "Studies on Lignin and
Related Compounds. XXVI. The Properties of
Spruce Lignin Extracted with Formic Acid",
J. Am. Chem. Soc., 32, 125-130 (1937).
309.
Yohe, G. R., and Blodgett, E. 0., "Reaction of Coal
with Oxygen in the Presence of Aqueous
Sodium Hydroxide. Effect of Methylation
with Dimethyl Sulfate", J. Am. Chem. Soc.,
69, 2644-48 (1947).
310.
Zadmard,
H., "The Colloid Chemical Properties of Humus",
Koll6id-Belhefte,. 42, 315-64 (1939).
159.
BIOGRAPHICAL SKETCH OF AUTHOR
BORN:
January 28,
1920 in Boston, Mass.
ELEMENTARY EDUCATION:
Frank V. Thompson Junior High School, Boston, Mass,
Boston Public Latin School, Boston, Mass.
COLLEGES ATTENDED:
Worcester Polytechnic Institute, Worcester, Mass.,
1937-1941, B.S. in Chemistry.
Boston University, Boston, Mass.
1942.
Massachusetts Institute of Technology, Cambridge,
Mass., 1945-1950, S.M. in Chemistry, 1947
EMPLOYMENT:
Inspector of Powder and Explosives, Boston
Ordnance District, War Department, 1941-1942.
Assistant Senior Chemist Kop ers United Co.,
Kobuta, Penna., 1942-1943.
Research Chemist, Publicker Commercial Alcohol
Co., Philadelphia, Penna., 1943-1945.
Research Assistant in Physics, Mass. Inst.
Tech., Cambridge, Mass., 1945-1946.
of
Research Assistant in Geology, Mass. Inst. of
Tech., Cambridge, Mass., 1946-1947.
Research Associate in Geology, Mass. Inst. of
Tech., Cambridge, Mass., 1947 to present.
160.
PUBLICATIONS:
Breger, I. A., and Burton, V. L., "The
Effects of Radioactivity on a Naphthenic
Acid", J. Am. Chem. Soc., 68, 1639-42
(1946).
Breger, I. A., "Transformation of Organic
Substances by Alpha Particles and Deutrons",
J. Phys. Colloid Chem., E_, 551-63 (1948)
Breger, I. A., "Semimicro Molecular Still",
Anal. Chem., 20, 980-2 (1948).
Breger, I. A., "Effects of Electrical
Discharge and Radiation on Organic
Compounds", Report of Progress - Funda-
mental Research on Occurrence and
Recovery of Petroleum, 1946-1947,
American Petroleum Institute, N.Y.,
214-
33 (1949).
Whitehead, W. L., and Breger, I. A.,
"Vacuum Differential Thermal Analysis",
Science, 1ll, 279-81 (1950).
Whitehead, W. L., and Breger, I. A.,
"The Origin of Petroleum: Effects of
Low Temperature Pyrolysis on the Organic
Extract of A Recent Marine Sediment",
Science, 1ll, 335,- 7,
(1950)
Breger, I. A., "Simple Applications of
Punched Card Techniquesi, a chapter in
a book entitled "Punched Cards --
Their
Application to Science and Industry",
Reinhold Publishing Corp., in press.
SCIENTIFIC SOCIETIES:
American Chemical Society
Society of the Sigma Xi