燃煤电厂烟气CO_(2)捕集化学吸收剂研发进展

Development progress of chemical absorbents for carbon dioxide chemical absorption from flue gas of coal-fired power plants

按照化学吸收剂的研究发展历程,综述了单一胺吸收剂、混合胺吸收剂、双相吸收剂、少水吸收剂和离子液体等化学吸收剂的技术特点和性能差异,并结合具体案例介绍了燃烧后化学吸收法捕集技术的进展情况。由于传统单一胺吸收剂再生能耗高,固体酸催化剂、部分氨基酸及衍生物或部分金属离子常用来辅助再生过程从而降低能耗。混合胺吸收剂将具有不同优势性能的伯胺、仲胺、叔胺或位阻胺等按照不同比例复配来提升吸收剂性能,双相吸收剂吸收后仅对富液相再生可以有效降低再生能耗。工业应用中常用2-氨基-2-甲基-1-丙醇(AMP)降低黏度,聚乙二醇二甲醚(NHD)或亚砜促进分相。少水吸收剂使用物理溶剂代替传统的水,降低含水量从而减少再生能耗。常用物理溶剂主要是醇类及其衍生物。此外,通过在传统离子液体中引入伯胺基团等制成CO_(2)吸收性能更好的功能化离子液体,乙二醇(EG)、正丙醇、单乙醇胺(MEA)、甲基二乙醇胺(MDEA)等与部分功能性离子液体复配可降低黏度和再生热。然而,目前吸收剂还存在能耗高、易降解及吸收剂胺逃逸等问题,亟待开发能耗低、损耗低、成本低、吸收性能良好的化学吸收剂以实现烟气CO_(2)捕集技术规模化应用。

According to the sequence of research and development of chemical absorbers,the technical characteristics and performance differences of single amine absorbers,mixed amine absorbers,biphasic absorbers,non-aqueous absorbers and ionic liquids are summarized,and the progress of post-combustion chemical absorption capture technology is introduced with specific cases.To address the problem of high energy consumption in the regeneration of traditional single amine absorbers,solid acid catalysts,some amino acids and derivatives or some metal ions are often used to assist the regeneration process to reduce energy consumption.Mixed amine absorbents combine different ratios of primary,secondary,tertiary or site-resistant amines with different advantages to enhance the performance.Biphasic absorbents reduce regeneration energy by regenerating only the rich liquid phase after absorption.In industrial applications,2-amino-2-methyl-1-propanol(AMP)is commonly used to reduce viscosity,and polyethylene glycol dimethyl ether(NHD)or sulfoxide is used to promote phase separation.Non-aqueous absorbers use physical solvents instead of traditional water to reduce the water content and thus the regeneration energy consumption.Commonly used physical solvents are mainly alcohols and their derivatives.In addition,functionalized ionic liquids with better CO_(2) absorption performance are made by introducing primary amine groups into conventional ionic liquids.Ethylene glycol(EG),n-propanol,Monoethanolamine(MEA),N-methyl diethanolamine(MDEA),etc.and some functional ionic liquids can reduce viscosity and regeneration heat.However,the current absorbers also have problems such as high energy consumption,easy degradation and escape of absorber amine.There is an urgent need to develop chemical absorbents with low energy consumption,low loss,low cost and good absorption performance to realize the large-scale application of flue gas CO_(2) capture technology.