Abstract:

In order to address the problems of high energy consumption and corrosive nature that occur in the absorption and desorption of CO₂ with traditional alcoholamine aqueous solvents, [DETAH][HCOO]-MEA-DMSO (diethylene-triamine formate) was fabricated by using ethanolamine (MEA) as the main adsorbent, [DETAH][HCOO] (diethylenetriamine) as the activator and DMSO (dimethyl sulfoxide) as the solvent. Desorption properties, resolving properties and corrosion resistance of the adsorbent were systematically investigated. It was confirmed that at the temperature of 20℃, the ratio of [DETAH][HCOO] and MEA was 1∶1, the total mass fraction of [DETAH][HCOO] and MEA was 20% and the gas-liquid ratio was 2∶1, part of the amino group (—NH₂) in the anhydrous absorbent reacted with CO₂ to form carbamic acid without HCO₃^-/CO₃^2- formation after absorbing CO₂ to produce very low corrosivity. Compared with the mixed absorbent of water system, it was found that the CO₂ absorption capacity of the nonaqueous absorbent was increased by 14.67%, the maximum CO₂ absorption rate was increased by 1.24%, the desorption load was increased by 35.61% and the energy consumption of desorption was reduced by 54.41%. This work provided a novel strategy for the development of CO₂ absorbent, which would strongly promote the steady implementation of the dual carbon strategy in China.

Key words: CO₂ capture, ion liquids, absorption, desorption, corrosion resistance

摘要：

针对传统醇胺水溶剂在吸收和解吸CO₂过程中出现的能耗高和腐蚀性强的问题，本文以乙醇胺（MEA）为主体吸收剂，二乙烯三胺甲酸盐（[DETAH][HCOO]）为活化剂，二甲亚砜（DMSO）为溶剂制备二乙烯三胺甲酸盐复配无水吸收剂（[DETAH][HCOO]-MEA-DMSO），并系统研究吸附剂的吸附性能、解吸性能及耐腐蚀性能。研究表明，在温度20℃、[DETAH][HCOO]与MEA的质量比为1∶1、[DETAH][HCOO]与MEA的总质量分数为20%、气液比为2∶1的条件下，无水吸收剂中部分氨基（—NH₂）与CO₂反应生成氨基甲酸，吸收CO₂后并未产生HCO₃^-/CO₃^2-，腐蚀性极低。无水吸收剂与水体系混合吸收剂相比，CO₂吸收容量提高了14.67%，CO₂最大吸收速率提高了1.24%，解吸负荷提高了35.61%，同时解吸能耗降低了54.41%。该研究为新型CO₂吸收剂的开发提供了新的思路，助力我国“双碳”战略的稳步实施。

关键词: CO₂捕集, 离子液体, 吸收, 解吸, 耐腐蚀性