液-液相变CO2吸收剂研究进展

Research status of CO2 capture by phase change absorbents

摘要:

迄今为止，化学吸收是碳捕集技术中应用最广泛、最成熟的方法之一，但是其能耗较高，所用吸收剂腐蚀性较强、易挥发等缺点制约了其工业应用。有鉴于此，可有效降低捕集能耗的液-液相变吸收剂成为新型吸收剂的主要研究方向之一。本文综述了目前液-液相变吸收剂的工艺流程、常见分类及其优缺点，并对液-液相变吸收剂和传统乙醇胺（MEA）吸收剂的再生能耗进行了对比分析，探究了其相变机理，分析了其组分浓度配比、气量与CO2负荷、黏度和温度等关键工艺参数对相变吸收剂吸收性能的影响。阐述了新型液-液相变吸收剂（离子液体相变吸收剂及纳米流体相变吸收剂）的研究现状。旨在为液-液相变吸收剂的进一步研究提供方向，以期加速该技术的工业应用。

Abstract:

Currently, the capture of CO2 in coal-fired flue gas with traditional organic amine absorption is commonly employed. However, its industrial application is limited by high energy consumption of traditional-absorption-regeneration process and strong corrosiveness and being volatile of amine absorption solution. Liquid-liquid phase-change absorbents, which with the lower regeneration energy consumption than that of the traditional amine absorption, is one of the primary research directions as novel absorbents. In this work, the process, types, advantages and disadvantages of existing liquid-liquid phase-change absorbents are systematically summarized. An analysis was conducted on the regeneration energy consumption of conventional liquid-liquid phase-change absorbents in comparison with traditional MEA-based absorbents, their reaction and phase-change mechanisms are confirmed, and the key influencing factors such as concentrations, gas flow rate, CO2 loading, viscosity and temperature on the long-term operational stability of phase-change absorbents were analyzed. The research on new phase-change absorbents such as ionic liquid phase-change absorbents and nanofluid phase-change absorbents are systematically summarized. Recommendations for further research are provided regarding the industrial applications of liquid-liquid phase-change absorbents.