TheCO2 absorption performance of aqueous solvent blendscontaining four imidazoles (2-MeIm, 2-Et-4-MeIm, 2,4,5-MeIm and 1,2,4,5-MeIm)and four promoters (MEA, DEA, PZ, and MAPA) were investigated usinga small-scale screening apparatus. Exceptionally high absorption capacityof 14 and 16 wt % was obtained for 2,4,5-MeIm/PZ and 2,4,5-MeIm/MAPAsolutions, respectively. Cyclic capacities as high as 12 wt % wereobtained for 3 M 2,4,5-MeIm + 1 M PZ solutions between 40 and 80 °Cat 10 kPa CO2. The outstanding performance is the resultof selective precipitation of 2,4,5-MeImH+ bicarbonate,allowing the formation of a highly loaded slurry solution. 2,4,5-MeIm/diaminesolutions are proposed as a novel type of absorption blend for CO2 capture.
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