氨水溶液联合脱除燃煤烟气中CO_2和SO_2的模拟和经济性分析

Modeling and Economic Analysis on Combined Capture of CO_2 and SO_2 in Flue Gas Using Aqueous Ammonia

采用Aspen Plus速率模型(RateSep module)对氨水溶液联合脱除CO2和SO2的理论可行性、技术可行性进行预测,采用IECM(integrated environment control model)模型对氨水溶液联合脱除CO2和SO2工艺过程进行经济分析。结果表明,该工艺过程可以采用吸收/再生的流程实现CO2和SO2的高效吸收以及氨水溶液中CO2负载的解吸,并在将亚硫酸根氧化为硫酸根的基础上,采用向负载氨水中增加钾离子使得具有较低溶解度的硫酸钾等盐类结晶的方法来实现氨水溶液中SO2负载的清除。氨水溶液联合脱除CO2和SO2具有显著经济性,较传统的湿法脱硫结合氨法脱碳工艺可有效降低总成本约17.4%,这对于解决目前困扰CO2减排的高成本问题具有积极的意义。

An Aspen Plus rate-based model （RateSep Module） was applied to predict the theoretical and technical feasibility of aqueous ammonia based combined capture of CO2 and SO2, and an integrated environment control model （IECM） was used to evaluate the economics of the combined CO2 and SO2 capture process. The results show that the absorption/regeneration process can be used to achieve simultaneous absorption of CO2 and SO2 using aqueous ammonia in the absorber, and efficient desorption of CO2 in the regenerator. Based on the oxidation of sulfite to sulfate and the low solubility ofpotassinm sulfate, adding potassium ion to the loaded aqueous ammonia can be able to separate potassium sulfate solid and reduce the SO2 loading in the ammonia solvent. Combined capture of CO2 and SO2 using aqueous ammonia is obviously more economic than the traditional wet-FGD process and CO2 capture system running in series. The combined process can effectively reduce the total cost by approximately 17.4%, which has very positive effect on solving the high cost problem with CO2 capture.