MEA溶液捕集CO2工艺优化及能耗分析

在对单乙醇胺(MEA)溶液捕集CO2解吸能耗分析的基础上,进一步探讨了液气比、MEA溶液浓度及MEA溶液吸收温度对CO2吸收效率和解吸能耗的影响。在模拟计算工况条件下,根据系统中能耗计算公式,可求得最佳液气比为5.6 L/m3。提高液气比有利于CO2的捕集,但当液气比大于5.6 L/m3时,CO2捕集系统中的单位能耗将增加;在吸收液浓度小于40%时,提高吸收剂溶液的质量浓度可以降低单位解吸能耗,但吸收剂质量浓度并不是越高越好,本工况条件下的适宜浓度范围为35%～40%;同时,MEA溶液在吸收-解吸过程中存在氧化和腐蚀问题。因此,CO2捕集系统工艺参数的优化是降低MEA溶液捕集CO2操作费用的关键。

Optimization of process of capturing CO2 by MEA solution and energy consumption analysis

Based upon analysis of desorption energy of capturing CO2 by MEA solution,the impacts of solution to gas ratio,MEA solution concentration and absorption temperature of MEA solution on CO2 absorption efficiency and desorption energy requirement are studied.Under simulation conditions,the study results indicate that the optimal solution to gas ratio is 5.6 L/m3.Increasing solution to gas ratio is favorable for CO2 capture.When solution to gas ratio is greater than 5.6 L/m3,the unit energy requirement of CO2 capture system will rise.When the concentration of absorption liquid is lower than 40%,raising the mass concentration of absorption liquid can reduce unit desorption energy requirement.But the concentration of absorption liquid is not the higher the better.In the operating conditions of the unit,the appropriate concentration is 35%-40%.The oxidation and corrosion of MEA solution are the problems in absorption-desorption process.Therefore,optimization of process parameters is critical for reduction of operation costs of process of capturing CO2 by MEA solution.