二氧化碳捕集技术进展

CO2是主要的温室气体之一,据统计,1965~2011年全球CO2年排放量从117×108t增长到340×108t,46年间增长了近2倍,年均增长率2.35%,累计排放量达1×1012t以上。预计到2030年,全球CO2年排放量将达到427×108t。化学吸收法是目前工业上捕集CO2的主要手段,主要包括Econamine FGSM工艺、HICAP+TM工艺、DXMTM工艺、KM-CDR工艺、Cansolv CO2捕集工艺、西门子捕集工艺、可再生溶剂吸收工艺、Hitachi技术、Praxair技术、两步闪蒸工艺、CESAR工程工艺和Toshiba工艺等,化学吸收法的溶剂主要是有机胺。虽然有机胺化学吸收法是最有效、最常用且较为经济的CO2捕集方法,但由于有机胺水溶液具有一定的挥发性,也会导致对CO2的吸收能力下降、排放的胺对环境产生一定危害、有机胺腐蚀设备以及由此产生的维护问题等。其他工艺还有膜分离工艺、熔融碳酸盐电化学分离工艺、生成CO2水合物、酶基吸附工艺以及离子液体捕集工艺等,但这些工艺均处于实验室研究阶段。

The Latest Advances in Carbon Dioxide Capture Technologies

Carbon dioxide is one of the major greenhouse gases.Statistics show that global carbon dioxide emission nearly doubled in 46 years,from ll7×10^8t to 340×10^8t from 1965 to 2011.The annual growth rate reached 2.35% and cumulative emission exceeded 10×10^8t.Global carbon dioxide emission is expected to reach 427×10^8t by 2030.The chemical absorption method is currently the main approach used by the industry to capturing carbon dioxide.The main technologies based on this method include Econamine FGSM,HICAP＋TM, DXMTM, KM -CDR, Cansolv COz capture technology, Siemens capture technology, renewable solvent adsorption technology, Hitachi technology, Praxair technology, two -step flash distillation technology, CESAR engineering technology and Toshiba technology.Organic amine is the main solvent used in the chemical absorption method. Although it is the most effective ,most commonly used and economic carbon dioxide capturing method,the organic amine chemical absorption method has its drawbacks.As the organic amine solution is volatile,the method＇s ability to absorb carbon dioxide will drop over time.In addition,the discharged amine will have certain impact on the environment and organic amine also corrodes equipment,resuhing in maintenance issues. Other carbon dioxide capturing technologies include membrane separation technology,molten carbonate electro- chemical separation technology,carbon dioxide hydrate generation and enzyme-based adsorption technology,and ionic liquid capturing technology.However,all these technologies are still in the stage of laboratory research.