Nanotechnologies and new materials
Project presentation
THE MOLECULAR SIEVES
FOR
GAS SEPARATING MEMBRANES
R. A. Denissov
A.V.Chernyshev
S.A.Yakushev
Membrane - a partition dividing volume on
two parts.
The membrane.
Last years, in arising of ecological and
energy problems, there has appeared
couple of technologies - «zero emission
fuel combustion» where the central
point takes burning fuel in an
atmosphere of oxygen - complete
combustion. Products of complete
combustion are H2O, CO2 and inert
components, thus the thermal emission
increases that allows to save fuel or use lowcalorie one. There has appeared need of
scale oxygen production
Fig.1. The basic operating diagram of air separating
membrane p1, p2 - pressure. If no nitrogen gathering
there is more simple design, the membrane operates
under rarefaction.
The physical principle of separation is
based on indication of oxygen and nitrogen
structural properties distinguishing. In
particular, because of kinetic diameters
difference (O2 ~ 3,46Å, N2 ~ 3,64Å), being
smaller one oxygen can faster move in a
membrane material, and, hence, has being
collected a lot in the other volume, it’s a
principle of different resistance to motion.
Small diameters difference (~8 %) does air
separating process fine. There is a rule: the
higher separation level the fewer throughput.
Decision searching. The most widespread
cryogenic way of oxygen to produce (air
freezing in -150Cº lower) implies a single
oxygen factory that is expedient for the big
consumers, but is unacceptable for middle
and small ones, in particular, in transport.
There are searching the way in development
membrane technologies air separating as
continuous process to get and use oxygen on
a site (in situ) and with no storage (cylinder).
.
Intensive development of small molecules
membrane separation technologies was in
60th years. Also it has been caused
by necessity of independent lifesupport conditions to create in
underwater and space vehicles (noneconomic reasons). As a membrane
the continuous material has been
used to be thin ~1µm polymeric
film, which surface takes hundreds
square meters in a single module.
With the beginning of ХХ1 century, in
connecting to energy and ecology problems
(economic reasons), there was a big interest
to membrane technologies possibilities and
their new areas application.
The attention had focused on:
- development of new, low sized design
decisions using a polymeric film;
- creation of the new materials to give new
separation quality and capable to operate in
wider range of conditions.
The projects of
prestige
1.Polymer membrane.
Japan, Matsushita polymeric membrane. It is
submitted on the market, as the conditioner
making raised oxygen concentration (~27 %)
in automobiles gas-polluted streets located
apartments. Design: there are frameworks
covered by polymer film united in module.
It’s advanced and market adopted 60th year’s
development. It operates under rarefaction,
takes outside air.
https://industrial.panasonic.com/ww/products_e/product_cat2/AYD0
000_e/AYD0000_e.html
The USA, a polymeric membrane
Transportation Technology R&D Center
of Argonne National Laboratory. There is in
automobile air filter place. Air enriched by
oxygen (have no data it could be accepted
about 1.5 times) is used for a fuel charge
preparation. It allows improve fuel
combustibility and as consequence, "exhaust"
parameters, to increase power. Other
separation component - nitrogen goes to a
spark arrester and further, in plasma mode,
mixes up with exhaust gases, restoring toxic
nitrogen oxides so up to molecular nitrogen
as oxygen. A membrane are been polymeric
pipes walls mounted parallel in cylinder
module, analogue of 60th year’s
development. It operates in excess pressure.
It’s commercialization stage. Project almost
completed, is in test.
http://www.transportation.anl.gov/research/engine/air_separation.ht
ml
2.Composite membrane.
The USA, Praxair Inc composite membrane
has ionic (complex minerals with oxygen
sublattice) and electronic (metal) conductivity
to use in powerful combusting plants. It’s a
commercialization stage. It has no close
analogues. It activates at temperatures 700 1000 °С (arranging in gas burning furnaces
directly), it is made as pipes ~ Ø3 sm in
length of ~3 m. The best concentration of
oxygen is 99,5 %. Basic problem is in
composite gas-resistance.
http://www.gasification.org/Docs/2002_Papers/GTC02037.pdf
http://gcep.stanford.edu/pdfs/RxsY3908kaqwVPacX9DLcQ/kobayas
hi_coal_mar05.pdf
Italy. Politecnico di Milano are being
studyed composite membranes also.
3.Zeolite films.
The USA, some of research groups, a
membrane made as a polycrystalline zeolitic
film. It has no close analogues. The basic idea
is the use of porous zeolite crystals as
molecular sieve. Having a small surface, the
sieve has high throughput and good selection.
It does a membrane universal for the widest
applications and others competitive. The
approaches are: zeolite microcrystals are been
growing on a porous substrate, intervals
between them are filled by polymer or, as the
same the crystallization has been repeating,
all of these is calling a membrane. The basic
problems are in a non-dense, film low
mechanical strength.
http://www.cems.umn.edu/research/tsapatsis/
http
://www.aps.anl.gov/Future/Workshops/Membrane_Science/Presentat
ions/Tsapatsis%20.pdf
http://www.colorado.edu/che/FalcGrp/research/zeolite.html
http://www.cems.umn.edu/research/kokkoli/pubs/Nat%20Mat.pdf
These projects execution will put big
economic and social consequences.
Zeolites and air
separation.
Zeolites are porous strong alumino-silicate
crystals having very complex structure, which
element contains many tens of atoms. Their
correct formed pores, incorporating each
other through "windows", make a through
channels correct network inside crystals
(galleries).
Fig. 2. Pores of synthetic zeolite A forming the
channel. Being attach the same figures to others 8terms "windows" there is come out crossed channels
three-dimensional system -calibrated through
apertures molecular sieve that is favorable for fine
separation.
Quadrupole interaction is features of the
nitrogen molecule structure, indicated zeolite
cavity inside and there is selection strong
factor.
Fig. 3. The Y and NaA zeolites crystals surface in
nanoscale, the area of "windows" makes ~7 % - Y and
~9,5 % - NaA, window diameters according are 7,4Ǻ
and 4,2Ǻ (subnano).
We consider air separation physical
model in zeolite channels. Process of
selection is defined by three
simultaneously acting mechanisms: on
input "windows" (1), at movement inside
zeolite (2) and stronger nitrogen
molecules quadrupole interaction with
zeolite lattices cations (3). All of them
act for the use of oxygen, as permeate
(membrane through gas), that implies a high
separation level of a mix. Changing zeolites
and their structure it is possible these
mechanisms to operate.
Our works with Zhdanov zeolite show the
zeolite complex alumino-silicate framework is
capable to be reconstructed with structure
conservation, i.e. to be in recrystallizating
processes where single grains growth or
reduction is in free space between them filling
and strong couplings forming. Such a
complex systems recrystallizating processes
discovery and their real time activation
possibility is an event in experimental
mineralogy. It means also to have a basic
opportunity to get dense polycrystalline forms
with other zeolites too.
The problem and
proposing decision.
The problem of zeolitic membrane to
create as a homogeneous, dense material to
get is caused by complexity of zeolites
structure, it is a reason them to have no liquid
and gaseous state. Good structure has pure
artificial zeolites only, and they are
synthesized as single microcrystals, the sizes
~1µm, and do not form films. Natural zeolites
are polluted by impurities and other forms.
In the beginning of 80th we had been
developed polycrystalline monoliths
technology producing from Zhdanov zeolite
powders ("window" - 2,2Å) and it deriving
non-stoichiometrical sodalites numbers,
keeping physical properties of initial
microcrystals. Then method and substance
was got the USSR patents and patents of
Japan, the USA, England, Italy, France,
Germany and Sweden also.
Photo. A monolithic polycrystalline Zhdanov zeolite
plate of 0,3 mm thick: it is optical transparent, the
density corresponds to crystal, being much better than
99 %, mechanical properties is close to glass,
vibration-proof, allows mechanical clearing and
washing, all a range of temperatures keep intact.
The proposing decision: having suitable for
air separating channels zeolite powder is
pressed to make glass-like, having initial
microcrystals structure monolithic block.
Further it will be cutting for some plates and
using them as membranes.
Some applications and
markets.
Healthcare. In some estimations to satisfy
superfluous oxygen personal needs the
zeolitic membrane device can be placed in
dimensions of a match box. The membrane
also will protect from a dust, the microbes,
and unpleasant smells, poison gases
(ultrafiltration or deactivation by oxygen
surplus). It can be used not only in single
purposes and conditions, but to become daily
accessory of each person, to change style of
life.
Sports. There’s sportsmen’s organism
rehabilitation after trainings.
Food stuffs. Food stuffs process and store in
nitrogen inert atmosphere. It’s water
saturating by oxygen in fish facilities.
Power and transport. Due complete
combustion it is possible to get about 20 %
addition of energy at toxic emissions absence.
Oxygen concentration increasing the
combustion process is intensified; it opens
abilities to use different new kinds of fuel,
including biofuel and dust, with no any of
essential preparatory transformations.
The industry. Motor industry. There are
industrial wastes deactivating, including
sewage and emissions in atmosphere. There is
creation of new technological processes and
devices in applying of oxidizing reactions,
nitrogen inert atmosphere and atmosphere to
be free of dust, microorganisms and the other
pollution, inaccessible by other ways. There
is separating of other mixes, water
desalinating.
Architecture. Houses heating (boilers,
furnaces, fireplaces). There is apartments
conditioning. Stock-rooms and storehouses:
there are preventing of ignitions and spoilage
at long-term storage in nitrogen atmosphere.
As adsorbents, powder zeolites occupy about
100 application fields. Market emergence of
simple and cheap membranes will create an
opportunity for mass engineering creativity
and will cause a new turning of progress.
Spheres of application variety and extensive
and free markets together will define project
innovative attraction. Consumers of simple
independent devices having membrane
central element can be private persons, small
and middle-sized companies. This
circumstance will allow begin manufacture
and sale of production, being irrespective to
innovation ability level of the large
companies.
“A technology breakthrough in separation
processing is crusial to hydrocarbon
industry…The end effect would be about
75% energy reduction in production and
about 60% capital reduction”
(From Sandia National Laboratories US DOE
Report, 1999)
http://www.ms.ornl.gov/programs/energyeff/aim/annual/98sec34.pdf
Cracking membrane
(project developing
prospects).
Necessary condition of a high-grade ignition
mixture preparing is good fuel vapourability.
This fuel should be made of small molecular
weight hydrocarbons. Therefore oil is treated
by cracking - decomposition of heavy
hydrocarbons on easy ones as a result of
couplings C - C breaking.
Inside a zeolite cavity, in conditions of crystal
field acting, breaking hydrocarbonic
molecules C - C couplings is easier
(operating time 3 seconds less). Therefore
they are used as the catalyst in cracking.
In an existing variant, zeolite
microcrystals, as granules in porous
binding are brought in an oil reactor (550 750 ºС), zeolite pores are sated by
hydrocarbons. Formed as a result of
couplings breaking easy molecules are
leaving zeolite and mixing up with other
mass which further is separated on
fractions.
Application of zeolitic membrane will allow
to carry out cracking and separation in one
process – operation analogue of a «molecular
meat grinder» which processes heavy
hydrocarbons to (CnHm) "forcemeat" of easy
and flying ones.
In operating it will be a boiler with a window
- membrane. Such a 1 litre capacity boiler
taking oil refining function, placed in motor
compartment, will make automobile as
“omnivorous”.
Fig. 4. The combustion diagram where applying
cracking and air separating membranes.
Clusters in zeolites
(project developing
prospects).
Powder zeolites pores inside it is possible to
create and very high dense to place the
structured groups of atoms – clusters (being
impossible zeolite outside) which have
unique optical, electric, magnetic properties.
Then, during the recrystallizating pressing do
these ones "to seal" as optical transparent
dielectric monolithic polycrystalline block.
These are materials for optoelectronics.
We developed this way in Zhdanov zeolite
works (cluster point defects as memory cells).
In result there has been created optical
transparent media series for reversive
recording, storing and displaying information
having screen imaging possibility. ”Dark
trace” recording contrast comes nearer to
black ink writing on a white paper (a history
of matter).
Information recording and storing media (see
a photo also) were exhibited at the Exhibition
of National Economic Achievements of the
USSR. Work is awarded with a medal named
as In achievements of national economy of
the USSR.
Fig. 5 Structure Zhdanov zeolite which some pores
contains alkaline-halogen clusters having various point
defects, Na3Al3Si3O12 (NaHal) х, where 0 <х <1
(from the old publication).
Publications:
Project examining.
The team.
1. Roman Denissov, Sergei Yakushev.
“The molecular sieves for gas separating
membranes”. – Portal: SCIENTIFIC
FRONTLINE , Oklahoma City, Oklahoma
USA 17.01.2007 (Short issue April of 2006).
The project has been submitted to
Competition of Innovating Russian
2007/2008 http://www.inno.ru, carrying out
by supporting by Ministry of Education and
Science (the Minister is the Competition
Council member) and Government of
Moscow City.
The project head:
Denissov Roman Alexeevich
PhD of physics
Speciality: solid state physics
Developed Zhdanov zeolite monoliths to get
technology - the base of the project.
Estonia, Tallinn, hot.ee@romulus1
Personal site: http://www.hot.ee/romulus1
http://www.sflorg.com/abstracts/ab090206_01.html
2. Р.А. Денисов, А.В. Чернышев, С.А.
Якушев. «Молекулярные сита для
газоразделительных мембран». –
Portal: NANO NEWS NET, Russia,
4.10.2007. http://nanonewsnet.ru/articles/2007/molekulyarnyesita-dlya-gazorazdelitelnykh-membran
3. “The molecular sieves for gas separating
membranes”. – R. Denissov personal site :
http://www.hot.ee/romulus1 (RUS, ENG).
4. “The molecular sieves for gas separating
membranes”. – Abstracts of Scientific and
Technological Sections, Nanotechnology
International Forum December of 3-5
Moscow, V.1, p. 583-584 (rus, eng).
"White book” nomination, part:
«Nanotechnologies and new materials».
Competition is accepted projects determining
scientific and technical progress in all spheres
of activity (11 parts, the general competition),
their examination and ranging are carried out,
and a database is made.
The project is in Competition final. There is
a short list of 570 qualified ones.
Chernyshev Andrey Viktorovich
PhD of physics
Speciality: physics of semiconductors and
dielectrics
Russia, S.-Petersburg
anchernyshev@mail.ru
Yakushev Sergei Alexandrovich
The engineer
Speciality: radio electronics
Estonia, Tallinn,
sergei.yakushev@mail.ee
The conclusion.
Our works on creation of monoliths left
behind the time. Till now Zhdanov zeolite
monoliths remain unique. The reason of such
things should be considered not fundamental
problems only, but as the nanotechnology
opportunities interest and new needs have
been arisen with a new millenium beginning
only.
The nearest analogue and, the most
perspective to other materials, being grown as
films molecular sieves have many of
intercrystalline passes and in this reason are
not suitable in fine air separating process.
Even, the technology to get dense films will
be created; the next will follow these ones
operational stability problems.
This weakest point is diverse materials
interfacing (zeolite - substrate) which is
unreliable to have no interpenetration
transitive zone, the last one is been out this
case. This circumstance isn’t intended in
operational condition wide range as: high
temperature, chemical factors, various
mechanical influences, including vibration.
Besides films (thin and fine) always has a
surface clearing problem.
All these shortcomings are not for a monolith.
Recrystallizating pressing - direct
technology to form monolith, eliminating
intergranual cavities and passes. The
proposing decision as zeolite polycrystalline
monolith is novelty, high operational
properties and, probably, - the only way of a
molecular sieve sizing suitable for wide
application to get.
The present project is 4-th big project
membrane air separating and a new breakthrough way to create predetermined
property materials:
Monolithic polycrystalline zeolites having
free and nuclear clusters filled pores.
Membrane researches and developments will
borrow ~10 years or more. There will need to
found target laboratory (the research center),
manufacturing of the unique equipment and
other research groups to draw.
June of 2007, Tallinn-Kuusalu
First issue –november of 2005,
unpublished variant – 1992.