用于烟气二氧化碳捕集的有机胺挥发性研究进展

Research progress of amine volatility for carbon dioxide capture from flue gas

化学吸收法是现阶段唯一可大规模捕集烟气CO_(2)的技术路线,有机胺是常用的吸收剂,有机胺挥发性对系统运行成本、环境污染等影响较大。本文对比了目前文献中用于测量有机胺气液平衡的静态总压法、改进型沸点仪、在线傅里叶红外等实验装置和方法,介绍了描述有机胺体系的Wilson模型、NRTL模型、UNIQUAC模型等热力学模型,重点综述了影响有机胺吸收剂挥发性的主要影响因素及研究现状。极性基团如羟基、伯氨基等有利于降低胺挥发。温度主要是影响亨利常数和饱和蒸气压,摩尔分数主要影响胺分子活度系数。常规胺基吸收剂的挥发性随CO_(2)负荷增加而减小,弱极性吸收剂的挥发性受到离子强度影响更大。结合烟气CO_(2)捕集特性,提出下一步有机胺吸收剂挥发性研究的主要方向。

Currently,chemical absorption is the only one mature technology for large scale CO_(2) capture from flue gas.Organic amines are commonly used solvents,and the volatility of amines has significant effects on the system operating cost and environmental pollution.The methods and experimental apparatus in literatures for detecting the vapor-liquid equilibrium of organic amine,such as static total pressure method,modified ebulliometer,and online FTIR coupled reactor,are compared.The thermodynamic models including Wilson model,NRTL model,and UNIQUAC model which describing the organic amine system are introduced,and the major factors influncing the volatility of amines as well as the research progress are reviewed in detail.Polar groups such as hydroxyl and bernine are beneficial to reduce amine volatility.Temperature mainly affects Henry’s constant and saturated vapor pressure.Mole fraction mainly affects amine activity.The amine volatility in aqueous solvent decreases with the increased CO_(2) loading,and the volatility of weak polar absorbers is more affected by ionic strength.Combing with the characteristics of CO_(2) capture from flue gas,the main direction for volatility study of amine solvent is proposed.