Coal
Coke
Tar
Coal Gas
Synergistic Industries (p.391)
• Coal and coal products were essential for
– Fuel for heating and cooking
– Fuel for industrial processes (coke for lime,
bricks)
– Iron production
– Ship building
– Steam engine power
– Production of textiles, explosives, drugs,
chemicals, glass, ceramics, brewing, etc
Some Products of Coal Distillation
(p 389)
•
•
•
•
•
Coke (:charcoal from wood)
Tar (earlier from wood *) @ 1750
Pitch (*) same
Coal gas for lighting and cooking @1800
Fuel  Coal  Coke (s) + Tar (viscous
liquid) + coal gas (g)
• Other products such as rosin and oils for
varnish (p 413, *)
More Products of Coal Distillation
• Cinders or soot for NH4Cl (p 420-21)
– for tinning cast iron, brass and copper
– also used by pharmacists
– boiling salt
– drying malt
• Patents for coal products describe variety
(Clow p 396-7 ) and processes
Coal
• Fossil fuel formed millions of years ago by
the anaerobic decay of living plants.
• Complex mixture of many compounds.
• The chemical formula of coal has been
approximated as C135H96O9NS
• This translates to a material with 85% C
(which is the energy producing
component)
Coal Formation
• Decaying plants + pressure of rocks 
varying degrees of removal of impurities,
nitrogen, water + Si, Na, Ca, Al, Ni, Cu,
Zn, As, Pb, Hg leaving carbon content.
• Some examples of coal
– Peat and lignite – high moisture content; like
plant material, soft
– Bituminous or soft coal – most abundant
– Anthracite – very hard, very high C content
Coal vs Wood
• Recall, IR is associated with the transition
from wood and water-based, homecentered, agrarian economy to coal and
iron-based, manufacturing -centered,
industrial economy.
• Decay products = a mixture of many
hydrocarbons (H and C cmps) which have
considerable energy stored in the
chemical bonds.
Energy Content
• Fuels are rated by energy content; i.e. kJ/g
of energy produced.
Combustible
Material (%C)
kJ/g
US source
Wood
10.4.14.1
Various
Peat
13.0
Mississippi
Lignite (71%)
16.2
North Dakota
Subbituminous
(77%)
24.0
Washington
Bituminous (80%)
30.7
Maryland
Anthracite (92%)
Coke
30.5
~30
Pennsylvania
Coke
• Coal + oven temps of 2000 C without
oxygen  high carbon content coke, with
water, coal gas, ammonia, phenol,
naphthalene, sulfur and other volatile
impurities driven off. (Today, the impurities
are collected and processed).
• Used as fuel and reducing material for
smelting.
Coal Tar
• Black, viscous liquid that is a by-product of
coking (19th c.) and coal gas purification
(20th c.) processes.
• Early uses: Essential in shipbuilding as
sealant, preservative for ship timber,
varnish. Also for roofs and roads.
18th c. Coal Tar Industry
• By variety, methods of production and
products, the coal tar industry is
sometimes called the precursor to the
modern chemical industry and more
specifically, the modern petrochemical
industry.
Sources of Tar and Pitch
• 1667 – first mention of non-timber sources
of tar
• 1700 – Royal Society treatise on using
coal and shale as source of tar and pitch
• P 392 on process
• 1719-1779 – Britain offered bounties for
timber-based tar from the New World esp
for ship building.
British Tar Company
• 1781: patent issued to Earl of Dundonald
for the development and production of coal
distillation by-products. (Clow p 396)
• Clow p 397-98 describes details of patent
• Clow p 410 lists some of coal-based
products.
• Dundonald enjoyed financial success in
extracting tar from coal.
British Tar Company (2)
• Although an Earl, he was always on the
financial edge, but was curious, educated
and ambitious.
• What was his mother’s role in Dundonald’s
business development and successes?
• 1782: Dundonald formed the British Tar
Company (with 3 other co-investors).
British Tar Company (3)
• Prior to establishing the British Tar
Company, Dundonald was in a vulnerable
financial situation and not without
competitors and men (esp Cuthbert) he
owed money.
• In 1785, he emerged victorious with a
patent extension until 1806 and a rapidly
growing tar and pitch industry across
Britain.
British Tar Company (4)
• But this required
– Validation of Dundonald’s chemical processes
by Dr. Joseph Black, professor of chemistry at
Edinburgh University.
– Validation of Dundonald’s chemical products
by related industries.
– Act of Parliament regarding patent.
– Dundonald also collaborated with coke
producers to secure coal and coke for stock
materials.
British Tar Company (5)
• But by early 1800’s, Dundonald’s fortunes
changed. For example, contracts for ship
preservatives disappeared as ship building
materials improved (e.g. copper
sheathing).
British Tar Company (6)
• But the seeds of his success and his
failure were deeply rooted in his personal
and professional attributes. Discuss.
– What were Dundonald’s Achilles’ heels
leading to this downfall?
– What other industrial processes did he
pursue?
Tar Tunnel of Coalbrookdale
• A 1000 foot horizontal tunnel leading from
the Coalport Canal (then to the River
Severn) to the coal deposits of
Coalbrookdale.
• It was dug as a shortcut to transportation.
• A thick syrup of bitumen (polycyclic
aromatic hydrocarbons) oozing from the
tunnel walls and forming pools was
discovered in the tunnel 1787.
Tar Tunnel at Coalbrookdale
• Products included waterproofing pitch and
caulk, lamp black, rheumatism and scurvy
medicine
• Oozing bitumen from the tunnel walls is
still observed today.
• http://www.virtual-shropshire.co.uk/vsgallery2/v/visitor-attractions/tar-tunnel/
Separating the Components of
Coal Tar
• Coal tar has numerous organic (C and H
based) compounds and some inorganic
compounds.
• Fractional distillation is a method of
separating them.
• This method depends on the different
volatilities or boiling points of each
component.
Fractional Distillation
• Apparatus: distillation flask, source of
heat, cooling column and collection flask.
• Distillation is basically boiling a liquid at a
controlled T and P, and then cooling the
“fraction” that boils in order to collect it
separately from other compounds in the
flask.
Fractional Distillation followed by
Purification
• As each fraction comes off, it is collected
in separate containers and then furthered
purified.
• First, the T is set at the lowest level
resulting in the component with the lowest
BP boiling off and then collected.
• The T is then raised for the next distillation
to capture the second lowest BP
component.
http://www.tiscali.co.uk/referenc
e/encyclopaedia/hutchinson/m0
020819.html
Example
• Major products of the petrochemical
industry are benzene (+80.1 C = BP),
ethylene (-103.7 C) and propylene (-47.6
C).
• Which is a gas at room T?
• Which component distills first?
Coal Gas
• Coal + O2 + steam  CO + H2
• Coal  CH4
• These and other gases comprise coal gas
or syn gas
• For energy production. Products?
• Late 18th c., for artificial lighting. Note
Soho House was lit up in 1802 with
artificial lighting for celebrate the Peace of
Amiens.
Petrochemical Industry
• The petrochemical industry of the 20th
century (post World War II) is the modern
day coal tar industry.
• Both industries were/are based on the
decayed products of living matter that
occurred millions of years ago.
• http://www.petrochemistry.net/what-ispetrochemistry.html
Petrochemicals
• These are chemical derived from oil and
natural gas. In both cases, chemicals are
distilled, separated and purified from the
raw material.
• These chemical products
– Are used directly
– Are used to produce other petrochemicals
Petroleum or oil Products
•
•
•
•
•
•
•
Plastic or Petrochemicals
Asphalt
Diesel fuels
Gasoline
Paraffin
Tar
Kerosenes
Three Top Petrochemicals
• Ethylene
110E+6 tons annually
• Propylene 65E+6 tons
• Aromatics (e.g. benzene); PAHs 70E+6
tons
Natural Gas (often found with
petroleum)
• Methane; also ethane, butane, propane
• Inorganic gases: N2, H2S, CO2, He
http://en.wikipedia.org/wiki/Image:N
atGasProcessing.png
References
• Eubanks, L. P. et. al, Chemistry in Context
(5th Edition); McGraw Hill: Boston, 2006.
• http://www.coaleducation.org/lessons/sec/
properties/coalderiv/coalder.pdf
• http://en.wikipedia.org/wiki/Image:NatGas
Processing.png
References
• http://www.tiscali.co.uk/reference/encyclop
aedia/hutchinson/m0020819.html
• http://www.petrochemistry.net/what-ispetrochemistry.html