摘要：CO2 is one of the main greenhouse gases responsible for global warming and is also a major component of biogas. Capturing CO from biogas for CH4 purification has a great economic and environmental value. In this study, C〇2-capture performance of a mixed aqueous solution of l-butyI-3-me-thylimidazolium tetrafluoroborate ([bmim|BF4) and potassium carbonate (K2CO3) was investigated in detail at 25 °C. To investigate the influence of solution composition on CO2 absorption flux, six mixtures of absorbents were prepared by varying the concentrations of 丨bmim]BR» in the range from 0 M to 0.03 M. Moreover, four common amino acid salt absorbents, including potassium glycinate (PG), potassium sarcosine (PS), potassium A-leucine (PLL), and potassium L-serine (PLS), were selected and compared with the mixea ionic liquid (IL) aqueous solutions. The results obtained revealed that the presence of lbmim]BF4 at low concentrations in K2CO3 aqueous solution had a beneficial influence on CO2 absorption flux, and the best absorption performance of CO was obtained when the molar ratio of [bmim]BF4 to K2CO3 was 1:9. In addition, this mixed [bmimjBFa + K2CO; aqueous solution with a molar concentration of 1:9 showed better CO2 absorption performance than PG aqueous solution, which had the best CO2 absorption performance among the four amino acid salt solutions studied under the same conditions.
