Alcohol regulated phase change absorbent for efficient carbon dioxide capture:Mechanism and energy consumption  

作　　者：Chen Wang Weixin Kong Zhangfeng Dong Bihong Lv Guohua Jing Zuoming Zhou 

机构地区：[1]College of Chemical Engineering,Xiamen Key Laboratory of Terrigenous Environmental Pollution Treatmentand Ecological Remediation,Huaqiao University,Xiamen 361021,China

出　　处：《Journal of Environmental Sciences》2025年第4期440-450,共11页环境科学学报(英文版)

基　　金：supported by the National Natural Science Foundation of China(Nos.22278168 and 22276064);the MOE Key Laboratory of Resources and Environmental System Optimization(No.KLRE-KF202205);the Science and Technology Project of Fujian province(No.2022Y3007).

摘　　要：Phase change absorbents based on amine chemical absorption for CO_(2)capture exhibit energy-saving potential,but generally suffer from difficulties in CO_(2)regeneration.Alcohol,characterized as a protic reagent with a low dielectric constant,can provide free protons to the rich phase of the absorbent,thereby facilitating CO_(2)regeneration.In this investigation,N-aminoethylpiperazine(AEP)/sulfolane/H_(2)O was employed as the liquid-liquid phase change absorbent,with alcohol serving as the regulator.First,appropriate ion pair models were constructed to simulate the solvent effect of the CO_(2)products in different alcohol solutions.The results demonstrated that these ion pair products reached the maximum solvation-free energy(△E_(solvation))in the rich phase containing ethanol(EtOH).Desorption experiment results validated that the inclusion of EtOH led to a maximum regeneration rate of 0.00763 mol/min,thus confirming EtOH’s suitability as the preferred regulator.Quantum chemical calculations and^(13)C NMR characterization were performed,revealing that the addition of EtOH resulted in the partial conversion of AEP-carbamate(AEPCOO−)into a new product known as ethyl carbonate(C_(2)H_(5)OCOO−),which enhanced the regeneration reactivity.In addition,the decomposition paths of different CO_(2)products were simulated visually,and every reaction’s activation energy(△E_(act))was calculated.Remarkably,the△E_(act)for the decomposition of C_(2)H_(5)OCOO−(9.465 kJ/mol)was lower than that of the AEPCOO−(26.163 kJ/mol),implying that CO_(2)was more likely to be released.Finally,the regeneration energy consumption of the alcohol-regulated absorbentwas estimated to be only 1.92 GJ/ton CO_(2),which had excellent energy-saving potential.

关 键 词：Biphasic solvent Organic alcohols activator Regenerability Energy consumption 

分 类 号：X703[环境科学与工程—环境工程]