煤制氢装置二氧化碳捕集流程模拟与对比

Simulation and comparison of carbon dioxide capture processes in coal-to-hydrogen units

煤化工是中国碳排放的重要来源之一。对煤化工装置进行碳减排,是实现煤化工产业健康可持续发展的必要途径。基于Aspen Plus流程模拟软件,对煤制氢装置中两种二氧化碳(CO_(2))捕集流程(尾气低温分离、改造原低温甲醇洗)进行了模拟计算;探究了主要操作参数对CO_(2)回收率、产品中CO_(2)物质的量分数及运行成本的影响,获得了各流程优选的操作参数;同时,以年捕集CO_(2)能力为100×10^(4) t规模为基准,对两种流程的模拟结果进行了对比。结果表明,尾气低温分离流程的CO_(2)回收率比改造原低温甲醇洗流程高19.18%,从而可以回收更多的CO_(2)。但是,改造原低温甲醇洗流程的捕集成本较低,仅为尾气低温分离流程的54.31%,因此在经济性上更有优势。

Coal chemical industry is one of the significant sources of carbon emissions in China.Implementing carbon reduction in coal chemical units is a necessary approach to achieve healthy and sustainable development of the coal chemical industry.Based on Aspen Plus process simulation software,the carbon dioxide(CO_(2))capture processes(low-temperature tail gas separation,revamped rectisol wash)in the coal-to-hydrogen unit were simulated and calculated.The effects of main operating parameters on CO_(2) recovery rate,CO_(2) mole fraction in the product and operating costs were explored,and the optimal operating parameters for each process were obtained.Meanwhile,taking the annual CO_(2) capture capability of one million tons as a basis,the simulation results of the two processes were compared.The results show that the CO_(2) recovery rate of the low-temperature tail gas separation process is 19.18%higher than the revamped rectisol wash process,thus it can recover more CO_(2).However,the capture cost of the revamped rectisol wash process is lower,only 54.31%of the low-temperature tail gas separation,so it has economic advantages.