胍类氨基酸离子液体捕集烟气中CO2实验研究

Experimental study on the capture of CO2 in flue gas by guanidine amino acid ionic liquids

关键词:  二氧化碳捕集  离子液体  氨基酸  烟气  吸收机理 

Key words:  CO₂ capture  ionic liquids  guanidine  amino acid  flue gas  absorption mechanism

摘要:

目的 通过开展胍类氨基酸离子液体捕集烟气中CO₂性能研究实验,找到吸收性能好、溶剂损失少和能耗低的新型CO₂吸收剂。方法 以四甲基胍(TMG)为阳离子,赖氨酸(Lys)、丙氨酸(Ala)和天冬氨酸(Asp)为阴离子,制备了、和3种低黏度胍类氨基酸离子液体,并对其脱碳性能进行评价。结果 碱性较大的具有较高CO₂吸收量,在常压、45 ℃、80 mL/min的条件下,吸收量为0.64 mol CO₂/mol IL。水的加入对CO₂的吸收有积极的影响,30%(w)水溶液的吸收量增加到0.99 mol CO₂/mol IL,且经过5次吸收-解吸循环后仍能达到0.81 mol CO₂/mol IL。通过傅里叶红外光谱(FT-IR)、核磁共振氢谱(¹H-NMR)对的脱碳机理进行分析,CO₂主要通过与阴离子上的氨基反应生成氨基甲酸酯,以实现对烟气中CO₂的高效捕集。结论 该研究可为工业CO₂捕集高效低耗吸收剂的开发提供参考。 

Abstract:

Objective In order to find a new absorbent with good absorption performance, low solvent loss, and low energy consumption for CO₂ capture, the preparation and performance of guanidine amino acid ionic liquids to capture CO₂ in flue gas was investigated. Methods Three kinds of guanidine amino acid ionic liquids with low viscosity, namely , , and , were prepared using tetramethylguanidine (TMG) as a cation and lysine (Lys), alanine (Ala), and aspartic acid (Asp) as anions. The effects of anionic types on CO₂ absorption were investigated. Results The alkaline had a higher CO₂ absorption, with a CO₂ absorption capacity of 0.64 mol CO₂/mol IL under the condition of atmospheric pressure, 45 ℃, and 80 mL/min. The addition of water had a positive effect on the absorption of CO₂. The absorption capacity of 30 wt% aqueous solution increased to 0.99 mol CO₂/mol IL and could still keep 0.81 mol CO₂/mol IL after 5 absorption-desorption cycles. The decarbonization mechanism of was analyzed by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance hydrogen spectroscopy (¹H-NMR). CO₂ mainly reacts with the amino group on the anion to form carbamate to achieve efficient capture of CO₂ in the flue gas. Conclusion sIt can provide reference for the development of new absorbents in industrial CO₂ capture.