Aspen Plus基于不同吸收体系对高含CO_2天然气净化流程模拟

Aspen Plus process simulation based on different absorption system of purification of natural gas with high CO_2 content

采用哌嗪-甲基二乙醇胺(PZ-MDEA)混合溶液对高含CO2天然气进行脱碳处理。基于Aspen Plus流程模拟软件建立了PZ-MDEA法脱除天然气中CO2的模拟流程,分别采用纯物理吸收、纯MDEA吸收、活化MDEA吸收等3种不同模型进行模拟,将模拟数据与实际生产过程中的相关操作参数进行比较,以寻找出最佳吸收体系模型。模拟结果表明:活化MDEA吸收体系模型的计算结果符合生产实际数据,能够达到生产要求;其中烃类回收率为99.66%(实际要求大于或等于99.5%),CO2回收率为92.7%(实际要求大于或等于90%)。该体系可以用作模拟高含CO2天然气脱碳净化流程的模型。

The natural gas with high content of carbon dioxide is treated by piperazine-methyldiethanolamine （PZ-MDEA） mixed solution absorption to remove carbon dioxide. The simulating process of removing carbon dioxide by PZ-MDEA absorption is established based on Aspen Plus software. Three different models, that is pure physical absorption, pure MDEA absorption and activated MDEA absorption, are applied to simulate the carbon dioxide removal process, and the simulated data are compared with those of practical production process, so that the optimum absorption model is found out. The simulating results show that the calculated results by the activated MDEA absorption system model are in line with the actual production data and can meet the requirements of the manufacture. The hydrocarbon recovery rate is 99.66 % （ the requirement of actual recovery rate is higher than 99.5% ）. The CO2 recovery is 92.7% （the requirement of actual recovery rate is higher than 90% ）. The activated MDEA absorption model can be used to simulate the carbon dioxide removing process in natural gas with high content CO2 purification.