离子液体水溶液-气体水合物对CO_2的双捕获工艺

Double-capture Process of CO_2 by Gas Hydrate and Aqueous Solution of Ionic Liquid

设计了以离子液体[APMIM]Br水溶液吸收-生成水合物捕获CO2工艺流程,并利用CO2在该离子水溶液中的溶解度数据和在其中生成CO2水合物的相平衡实验数据进行物料衡算.考察了水含量、压力和液气流量比对气体吸收-水合物生成的CO2双重捕获效果的影响,对比了气体水合物与离子液体水溶液捕获CO2的能力.结果表明,在较高压力和水含量条件下,水合物捕获CO2的效应强于离子液体溶液;较低压力下离子液体溶液吸收CO2起主要作用.与纯水合物法相比,双捕获工艺具有一定优势,且突破了单纯水合物脱碳的压力和CO2含量要求高的局限性.当原料气中CO2低于65%(?)时,系统的脱碳效率低于40%,对于CO2含量较低的气体,其CO2的脱除性能回归至单纯离子液体溶液体系.

Double-capture process of CO2 with CO2 absorption in aqueous solution of ionic liquid 1-aminopropyl-3-methylimidazolium bromide（[APMIM]Br） and simultaneous formation of CO2 gas hydrate was designed. Based on the experimental data of CO2 solubility and phase equilibrium data of CO2 hydrate formation in [APMIM]Br aqueous solution, the mass balance of this process under various working conditions were calculated, the effects of water concentration, pressure and liquid gas flow ratio on the CO2 capture rate examined, and the comparative performances of CO2 gas hydrate capture and CO2 absorption by the ionic liquid solution in the process also studied. The results show that at high pressure and high water content, the CO2 capture performance by gas hydrate formation is comparatively higher than that of the absorption by ionic liquid solution, while at lower pressure, the absorption of the aqueous solution plays a major role. The CO2 capture performance of the double-effect process with CO2 absorption plus hydrate formation in the aqueous solution is superior to that of CO2 gas formation in pure water system. When molar content of CO2 in feed gas is less than 65%, the CO2capture rate of double-capture process is less than 40%. For the feed gas with lower CO2 content, the process approaches to the pure absorption process with the ionic liquid aqueous solution.