CO2 separation using composites consisting of 1-butyl-3-methylimidazolium tetrafluoroborate/CdO/1-aminopyridinium iodide

Abstract

1-Aminopyridinium iodide (iodine salt) was used in CO2 separation composites consisting of CdO and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM+BF4−). Using iodine salt, the separation performance was largely improved. The CO2/N2 selectivity was 64.6 and the permeance of CO2 gas was 22.6 GPU, which was about twice that of BMIM+BF4−/CdO composites without addition of iodine salt. These results were due to the both effect of iodine salt on the transport of the N2 molecules by the cyclic ring compound and the promoting transport of CO2 molecules by the amine groups. Moreover, the oxide layer on the surface of the CdO could enhance the CO2 solubility, resulting in the enhancement of separation performance. The mechanical and chemical properties were measured using SEM, Raman, TGA and FT-IR. The cross-section of coated membranes was confirmed by SEM. The coordinative interactions of iodine salts with BMIM+BF4−/CdO composite were observed by Raman.