离子液体-水复配吸收剂捕获CO_2性能

CO_2 capture with complex absorbent of ionic liquid and water

基于绿色合成方法制备出亲水性离子液体(ILs)[NH2-C3mim][Br],从有效降低CO2吸收-解吸操作成本出发,采用ILs-H2O复配吸收剂,开展了常温加压CO2吸收及吸收剂常温减压解吸再生实验。结果表明,比CO2吸收量(基于复配吸收剂或离子液体组分)随复配吸收剂中ILs组分浓度而变;吸收初期,CO2吸收速率随吸收剂配比变化显著;以CO2高吸收率和吸收剂低成本为目标,优选出新型水基复配吸收剂(离子液体与水质量比为1.38∶1)。分别以水基离子溶液、改良热钾碱液和活化复配醇胺液为吸收剂,在自行搭建的超重力场强化吸收-连续逆流接触(加热或减压)解吸再生台架实验装置上进行了CO2捕获与吸收剂再生连续化实验。结果表明,在超重力场作用下,改良热钾碱液和活化复配醇胺液对CO2有较好的捕获,吸收率分别在98%、96%和90%以上,3种吸收剂经加热或减压解吸再生后均可循环回用,水基离子溶液吸收剂在常温减压下解吸更具有实际可操作性。

A sort of functional hydrophilic ionic liquid （ILs）, [-NH2-C3mim][-Br], was prepared by the green synthesis route. Aiming at reduction of operational costs for CO2 absorption and regeneration and reuse of absorbent, experiments on CO2 capture and absorbent-desorption for regeneration and reuse were carried out. Experimental results showed that specific capacity of CO2 （on the basis of complex absorbent or ILs component） changed with the concentration of ILs in the complex absorbent. In the initial stage, CO2 absorption rates changed obviously with the concentration of ILs, and an appropriate ratio of complex absorbent was obtained （mass ratio of ILs to water was 1.38： 1）. Moreover, continuous CO2 capture and absorbent regeneration experiments were carried out with a pilot scale equipment for absorption enhanced by super gravity field and desorption via counter-current contact under vacuum or by heating with water-based ionic liquid solution, improved hot potassium carbonate and activated complex alcamines as absorbent respectively. The results indicated good absorption for COz capture with water-based ionic liquid solution, improved hot potassium carbonate and activated complex alcamines under super gravity field, and the absorption rates for CO2 were 98%, 96% and 90% respectively. regenerated and reused after CO2 removal under vacuum or by heating. Water-based desorption under vacuum and at normal temperature was more practicable. Adsorbent could be ionic liquid solution