基于SOFC-GT-ST的双塔解吸CO_(2)捕集工艺模拟研究

Simulation Study on CO_(2) Capture Process by Double Tower Desorption based on SOFC-GT-ST

设计并验证了一种新型固体氧化物燃料电池、燃气轮机和蒸汽轮机(SOFC-GT-ST)联合循环动力系统,采用了阳极排气和后燃烧室排气两个再循环回路,研究了气体再循环对系统性能的影响,并对系统发电效率进行优化;针对烟气处理工段设计了闪蒸塔和再生塔结合的双塔解吸CO_(2)捕集工艺,并改进了MDEA溶液补充水的方式,优化了多处余热利用,使用Aspen Plus软件建立了系统模型,研究了贫液温度、烟气温度、贫液流量、吸收塔压力和解吸塔压力等对CO_(2)捕集率的影响。结果表明:阳极排气再循环比最优值为0.28,燃烧室排气再循环比最优值为0.36,CO_(2)的捕集率可达90.82%,碳捕集能耗为3.78 GJ/t。

A new solid oxide fuel cell, gas turbine and steam turbine(SOFC-GT-ST) combined cycle power system was designed and verified. Two recirculation circuits, including anode exhaust and rear combustion chamber exhaust, were adopted to study the influence of gas recirculation on system performance and optimize the electrical efficiency of the system;aiming at the flue gas treatment section, a double tower desorption CO_(2)capture process combining flash tower and regeneration tower was designed, the way of making up water for MDEA solution was improved, and the utilization of multiple waste heat was optimized. The system model was established by using Aspen Plus software, and the effects of lean liquid temperature, flue gas temperature, lean liquid flow, absorption tower pressure and desorption tower pressure on CO_(2)capture rate were studied. The results show that the optimal value of anode exhaust gas recirculation ratio is 0.28,the optimal value of combustion chamber exhaust gas recirculation ratio is 0.36,the CO_(2)capture rate can reach 90.82%,and the carbon capture energy consumption is 3.78 GJ/t.