ammonia production industries (IEA, 2004). Traditionally, the CO2
is vented or used for enhanced oil recovery, food manufacturing or
chemicals production (IEA, 2004). The most mature and applied
technology for the capture and release of CO2 is cyclic chemical
absorption/stripping using an aqueous amine solution of 30%
(w/w) monoethanolamine (4.9 M MEA). Aqueous solutions of other
amines that have better performance characteristics than MEA are
also available as proprietary formulations from a number of commercial
suppliers (e.g. Fluor, BASF and MHI). In a packed absorber
column flue gas (entering from the bottom) and amine solution
(entering from the top) are counter-currently contacted at atmospheric
pressure and low temperature (∼40 ◦C). The CO2 rich amine
solution is then circulated to the top of a stripping column which is
at high temperature (∼100–150 ◦C). At this temperature and under
the influence of stripping steam the chemical equilibria are shifted
such that the absorbed CO2 is released and exits at the top of the
column. The regenerated amine solution is then circulated back to
the absorber column.
Currently a great deal of research is being undertaken to develop
aqueous amine absorbents that deliver improved CO2 capture performance.
An ongoing challenge in this development is assessing
the performance of a new absorbent at a process level based on
laboratory data. A critical aspect of describing process performance
is a model to describe the vapour–liquid-equilibria (VLE)
1750-5836/$ – see front matter © 2013 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.ijggc.2013.05.016