(461b) Tunable Reversible Ionic Liquids for CO2 Capture

Authors: 
Verma, M., Georgia Institute of Technology


Regulation of CO2 emissions is likely in
the near future.  The technology for CO2 capture from large
point-source CO2 generators, such as coal-fired power plants, needs
to be developed before CO2 emission regulation is mandated. 
Effective CO2 capture systems must produce pure CO2
streams without becoming an overly parasitic burden to the energy production
process.  Monoethanol amine (MEA) and other
aqueous-based systems have a record of high CO2 capture capacities
but also high regenerative energies resulting in an increased parasitic load to
the plant.  Our research uses tunable reversible ionic liquids (RevILs) as the CO2 capture system.  Here,
we maintain the benefit of high CO2 capture capacities through
chemisorptions of CO2 without the water excesses resulting in the
possibility of a less parasitic regeneration of the absorption system.

The RevILs that will be discussed here are
one-component silylamines.  Before CO2 capture they are silylamine molecular liquids.  Upon reaction with CO2,
the ionic form of the silylamine is produced
reversibly. The silyl group was incorporated with a
reactive primary amine to form the RevILs with
reduced viscosities. The structure of these silylamines
can be tuned to examine and ultimately enhance the desired properties of the
absorption system.  The impact of these structure modifications on the
properties of the silylamines have been studied with
two objectives in mind.  The first objective is to establish an
understanding of what the structural modifications do to the overall behavior
of the RevILs, including CO2 capture
capacity, energy of regeneration and viscosity.  Once these
structure-property relationships are developed, the second objective is to use
these structure-property relationships to design a commercially viable RevIL system.  Additional factors that are considered
in this second objective include ease of synthesis of the silylamine
and stability of the silylamine during CO2
capture and release cycling.  Promising RevILs
identified will be compared to conventional CO2 capture systems.