DEFect NETwork Materials Science and Engineering
Marie Sklodowska-Curie European Training Network (MC-ETN)
H2020-MSCA-2014-ITN
http://www.defnet-etn.eu/
Paul Adrian Iacomi, ESR-10
Aix-Marseille Université, France
Gas separation and adsorption on defective metal organic frameworks
Separating compounds is always a challenge, as we are working against entropy, the
natural tendency of the universe towards disorder. It is usually done by exploiting
physical or chemical differences between compounds. The separation of gasses is one of
the most difficult, due to their high mobility and volume. Distillation, the most common
method, requires a high amount of energy and large industrial equipment.
Adsorption is a different method of separating gasses where, instead of using differences
between boiling points, the main factor is the interaction of gasses and solids. The
surfaces of solids attract gas molecules. A thin layer of liquid forms on the solid’s surface when it is immersed in
a gas. While for most solids, this layer is very small in comparison to the mass of the solid, solids with a very high
surface can store a large amount of gas within them. Because the volume of a liquid is much smaller than that of
a gas (air takes up 600-700 times less space when liquid) it means adsorption is also a very good storage method.
The surface of a solid can also have special sites where the attraction towards one type of gas molecule is higher
than to another due to its physical properties. Therefore, by passing a mixture of two gasses over the right kind
of solid, only one of them will adsorb, while the other will pass through unaffected. This is the adsorption method
of gas separation, which depends on the solid material used. Carefully designed materials could be used to make
difficult separations very fast and efficient. Metal organic frameworks, as easily tunable porous materials, are
great candidates for the purpose.
The areas of interest in my PhD are carbon monoxide and paraffin/olefin separations. The defect materials
created by the DEFNET group will be used in adsorption experiments. We hope that the unique properties of
these materials will improve existing gas separations or pave the way to completely new ones.
Carbon monoxide is a very toxic gas produced though incomplete burning of organic substances. Concentrations
as low as 0.05% in the air we breathe can prove fatal. Burning tobacco in cigarettes produces carbon monoxide,
amongst other toxic substances. By including a specific adsorbent in the filter, it could be separated and therefore
reduce the dangerous effects of cigarette smoke.
Paraffin/ olefin separation is the separation of hydrocarbons with a double bond from saturated ones. It is a very
important industrial separation, as it is used in the production of ethylene, the most manufactured chemical in
the world. Improving on current methods could lead to major reductions in the energy used in manufacturing
plants.
Funded by the European Commission;
Call H2020-MSCA-ITN-2014