Syngas Dehydration with Ionic Liquids

This work deals with the feasibility
of ionic liquids (ILs) as
an alternative drying agent to the conventional solvent (methanol)
in the application of syngas dehydration. The screening of ILs by
COSMO-RS model shows that [EMIM]­[Tf2N] is the suitable
absorbent for syngas dehydration among various possible ILs. The gas–liquid
equilibrium (GLE) experiments for the CO (H2)–[EMIM]­[Tf2N] systems were carried out. The experimental data were compared
with the predicted results by the UNIFAC-Lei model. The syngas drying
experiments with [EMIM]­[Tf2N] showed the excellent gas
dehydration performance of ILs. On this basis, the conceptual process
of syngas dehydration with [EMIM]­[Tf2N] was simulated and
optimized with the rigorous equilibrium stage (EQ) model, where the
UNIFAC-Lei model parameters were embedded. It was found that the gas
dehydration process with IL exhibits unique advantages in energy consumption,
equipment cost, and dehydration performance when compared to the conventional
benchmark methanol process. This work confirmed that ILs could be
considered as promising alternatives to conventional solvents for
syngas drying.