Impact of alpha-D-glucose pentaacetate on the selective separation of CO2 and SO2 in supported ionic liquid membranes

A biocompatible, nontoxic, and nonvolatile compound, alpha-D-glucose pentaacetate (GPA), was impregnated in supported ionic liquid membranes (SILMs) and used for the selective separation of CO2 and SO2. It was found that GPA could cooperate with [Bmim][BF4] to influence the permeability of CO2 and enhance the CO2/N-2 selectivity. Further permeation experiments demonstrated that the addition of GPA could reduce the permeability of N-2 in the SILMs and thereby improve the CO2/N-2 and SO2/N-2 selectivities. The highest CO2/N-2 selectivity obtained in the paper is 79 +/- 0.9 for dry gas and 86 +/- 1.6 for humidified gas, and the highest SO2/N-2 selectivity is 686 +/- 19.8 for dry gas. This environmentally benign separation process with high gas permeability and good selectivity may be expected to have a potential application for the separation of CO2 and SO2 from a flue gas stream.