一种交联型聚离子液体的合成及其对CO2的变压吸收分离

Synthesis of a crosslinked polymeric ionic liquid and pressure swing absorption for CO2 separation

针对目前聚离子液体存在的对CO2的吸收量低且吸收和解吸速率慢等问题,采用交联剂并分别结合不同干燥方法(冷冻干燥、超临界CO2干燥、普通干燥)合成了一种交联型季铵盐类聚离子液体,进而采用高压石英弹簧法测定其对CO2的吸收能力.研究结果表明,采用冷冻干燥法制得的聚离子液体相对结晶度低,具有较高的CO2吸收量,在298.2K、0.21MPa下对CO2的吸收量最高达0.024g/g,而在5.0MPa下高达0.127g/g.在298.2K下5.0MPa的高压合成气(H2/CO/CO2)中对CO2的变压吸收分离结果显示,该聚离子液体具有性能稳定、吸收和解吸速率快及对CO2选择性高等优点.

Carbon dioxide (CO 2 ) capture has attracted extensive attention in recent years.Among the various capture media, polymeric ionic liquids (PILs) have caused concern for its better CO 2 absorption and desorption capacity.However,the CO 2 absorption in PILs is still relatively low in the literature reported.In this work,a quaternary ammonium based crosslinked PIL was synthesized and dried by different drying methods,and the high-pressure quartz spring method was employed to study its absorption of CO 2 .Results showed that the crosslinked PIL from freeze drying had low crystallinity and high CO 2 absorption, and its CO 2 absorption was 0.024 g/g at 298.2 K and 0.21 MPa,while it was up to 0.127 g/g at 298.2 K and 5.0 MPa.At 298.2 K and 5.0 MPa,the pressure swing absorption process was implemented for separation of CO 2 from the high-pressure syngas system,revealing efficient separation of CO 2 from H 2 /CO/CO 2 .And the crosslinked PIL also showed its excellent stability,fast absorption and desorption rate and high selectivity for CO 2.