College of Chemical Engineering, Xiamen Key Laboratory of Terrigenous Environmental Pollution Treatmentand Ecological Remediation, Huaqiao University, Xiamen 361021, China.
College of Chemical Engineering, Xiamen Key Laboratory of Terrigenous Environmental Pollution Treatmentand Ecological Remediation, Huaqiao University, Xiamen 361021, China.
J Environ Sci (China). 2025 Apr;150:440-450. doi: 10.1016/j.jes.2023.09.022. Epub 2023 Sep 22.
Phase change absorbents based on amine chemical absorption for CO capture exhibit energy-saving potential, but generally suffer from difficulties in CO 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 regeneration. In this investigation, N-aminoethylpiperazine (AEP)/sulfolane/HO 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 products in different alcohol solutions. The results demonstrated that these ion pair products reached the maximum solvation-free energy (ΔE) 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 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 (CHOCOO), which enhanced the regeneration reactivity. In addition, the decomposition paths of different CO products were simulated visually, and every reaction's activation energy (ΔE) was calculated. Remarkably, the ΔE for the decomposition of CHOCOO (9.465 kJ/mol) was lower than that of the AEPCOO (26.163 kJ/mol), implying that CO was more likely to be released. Finally, the regeneration energy consumption of the alcohol-regulated absorbent was estimated to be only 1.92 GJ/ton CO, which had excellent energy-saving potential.
基于胺化学吸收的用于 CO 捕获的相变换热吸收剂具有节能潜力，但通常在 CO 再生方面存在困难。醇具有低介电常数的质子供体性质，可为富胺相提供游离质子，从而促进 CO 再生。在这项研究中，采用 N-氨乙基哌嗪（AEP）/环丁砜/H2O 作为液-液相变换热吸收剂，醇作为调节剂。首先，构建了适当的离子对模型来模拟不同醇溶液中 CO 产物的溶剂效应。结果表明，这些离子对产物在富含乙醇（EtOH）的相中达到最大的溶剂化自由能（ΔE）。解吸实验结果验证了 EtOH 的加入导致最大的再生速率为 0.00763 mol/min，从而证实了 EtOH 作为首选调节剂的适宜性。进行了量子化学计算和 C NMR 表征，表明 EtOH 的加入导致 AEP-氨基甲酸酯（AEPCOO）部分转化为新的产物乙基碳酸酯（CHOCOO），从而增强了再生反应性。此外，还可视化模拟了不同 CO 产物的分解路径，并计算了每个反应的活化能（ΔE）。值得注意的是，CHOCOO（9.465 kJ/mol）的分解ΔE 低于 AEPCOO（26.163 kJ/mol）的分解ΔE，这意味着 CO 更有可能被释放。最后，估计醇调节吸收剂的再生能量消耗仅为 1.92 GJ/吨 CO，具有优异的节能潜力。
