高效3AP-DMEA-正丁醇-水相分离CO_(2)吸收剂的开发

Development of an efficient 3AP-DMEA-butanol-water phase change absorbent for CO_(2)capture

燃煤电厂、钢铁企业等尾气中低浓度CO_(2)的排放控制是实现“碳中和”目标的关键。目前胺法捕获CO_(2)技术被认为是最有产业化应用前景的技术。为突破现有胺法在降能耗方面的技术瓶颈,旨在开发高效的相分离CO_(2)吸收剂。探究了伯/仲胺结构对与胺-正丁醇-水吸收剂吸收CO_(2)后分相特性的构效关系,研究了叔胺结构对3-氨基丙醇(3AP)-正丁醇(NBA)-水吸收-解吸和分相性能的作用规律。实验结果显示,3AP-NBA-H_(2)O吸收剂在富CO_(2)相黏度、胺分布、体积和相变临界点等方面均具有一定的优势,表明其具有良好的分相特性。添加叔胺可以明显降低富CO_(2)相黏度,同时提高单位体积溶液的CO_(2)循环容量和解吸率。新型20%3AP-10%N,N-二甲基乙醇胺(DMEA)-40%NBA-30%H_(2)O相分离吸收剂的富相体积为61.2%,黏度仅为6.73 mPa·s,富相中胺的占比为91.2%,其解吸率和CO_(2)循环容量分别达72.00%和1.42 mol·L^(-1),分别比30%3AP-40%NBA-30%H_(2)O吸收剂提高了88.6%和86.8%,比30%单乙醇胺(MEA)溶液提高了46.8%和13.6%。

Controlling CO_(2)emissions from low-concentration sources like coal-fired power plants and steel mills is crucial for achieving"carbon neutrality".Amine-based CO_(2)capture technology is a leading contender for industrial application.This study aims to overcome limitations in energy consumption associated with amine-based processes by developing an efficient phase-separating CO_(2)absorbent.The structural effects of primary and secondary amines on the phase separation characteristics of amine-n-butanol-water absorbents after CO_(2)absorption were investigated.The role of tertiary amines in the absorption-desorption and phase separation performance of 3AP-NBA-H_(2)O was also studied.Experimental results showed that the 3-aminopropanol(3AP)-n-butanol(NBA)-water absorbent had certain advantages in terms of rich CO_(2)phase viscosity,amine distribution,volume,and phase transition critical point,indicating good phase separation characteristics.The addition of tertiary amines significantly reduced the viscosity of the rich CO_(2)phase while increasing the CO_(2)cycling capacity and desorption rate per unit volume of the solution.The novel 20%3AP-10%N,N-dimethylethanolamine(DMEA)-40%NBA-30%H_(2)O phase-separating absorbent had a rich phase volume of 61.2%and a viscosity of only 6.73 mPa·s.The proportion of amine in the rich phase was 91.2%,with desorption rate and CO_(2)cycling capacity reaching 72.00%and 1.42 mol·L^(-1),respectively.Compared to the absorbent with 30%3AP-40%NBA-30%H_(2)O,the desorption rate and CO_(2)cycling capacity were improved by 88.6%and 86.8%,respectively,while showing an improvement of 46.8%and 13.6%compared to a 30%monoethanolamine(MEA)solution.