In this work

ionic liquids (ILs) were proposed for the capture of CO2 over the structured packings. The pressure drop and mass transfer coefficient were investigated using computational fluid dynamics (CFD). The relationship among the structure of ILs

performance of pressure drop and mass transfer coefficient

as well as the relationship among the corrugation angles of structured packings

performance of pressure drop and mass transfer coefficient were identified. The results showed that under the same operating conditions with same anion

the increase of carbon number in the alkyl chain on the cation of ILs leads to the increase of the pressure drop (i.e.

[HMIM][Tf2N] > [BMIM][Tf2N] > [EMIM][Tf2N])

and decrease of the mass transfer coefficient (i.e.

[EMIM][Tf2N] > [BMIM][Tf2N] > [HMIM][Tf2N]). Thus

the cation [EMIM] is the optimum choice with regard to the pressure drop and mass transfer performance. Moreover

for ILs with different anions the pressure drop and mass transfer coefficient show the same trend

i.e.

[EMIM][BF4] > [EMIM][TFA] ≈ [EMIM][TfO] > [EMIM][Tf2N]. There is an inverse relationship between the mass transfer coefficient and solubility of CO2 for different ILs. Thus

there is a tradeoff when choosing IL for the capture of CO2. In addition

four types of structured packings with different corrugation angles (X type

Y type

and two transition types) were compared. From the viewpoint of mass transfer performance the two transition types structured packings are superior to the traditional X or Y types.