燃煤电厂氨法脱碳工艺流程仿真及能耗分析

Simulation and Energy Analysis of the Ammonia Based Carbon Capture Process in a Power Plant

冷冻氨法脱碳工艺克服了MEA脱碳强腐蚀性、易降解、能耗大等缺点,但氨气逃逸问题严重阻碍了该工艺的发展。在控制氨气逃逸率满足排放要求的条件下,基于Aspen Plus的Radfrac模型建立了冷冻氨法脱碳工艺的仿真模型,基础案例下碳捕集系统的再生能耗为2.499 GJ/t CO_2,冷冻功为0.181 3 GJ/t CO_2,氨气捕集系统的再生能耗为1.937 GJ/t CO_2,脱碳系统综合能耗为1.144 GJ/t CO_2。随着氨水浓度的增加,脱碳系统综合能耗加速增长趋势,氨水浓度为8%左右时,脱碳系统综合能耗稳定在1 GJ/t CO_2左右。随着贫液负荷的增加,脱碳系统综合能耗逐渐降低。脱碳系统综合能耗随吸收塔入口温度的变动较小,稳定在1.16 GJ/t CO_2。随着再生塔压力的增加,脱碳系统综合能耗呈现先降低后增加的趋势,在2 MPa附近出现最小值1.128 6 GJ/t CO_2。

Chilled Ammonia Process（CAP）overcomes the shortcomings of the MEA based carbon capture process,such as strong corrosive,easily degradable of MEA and high energy consumption of the regeneration process.But the high escape rate of the ammonia based carbon capture process obstructs its further development.Taking the escape of the ammonia into account,a Radfrac model in Aspen Plus was used to simulate the CAP.The result of the baseline case shows that the heat consumption of CO_2 capture system is 2.499 GJ/t CO_2,the cooling power is 0.181 3 GJ/t CO_2,the heat consumption of NH_3 capture system is 1.937 GJ/t CO_2 and the comprehensive energy consumption is 1.144 GJ/t CO_2.With the increase of ammonia concentration,the comprehensive energy consumption of the process increases.When ammonia concentration is approximately 8%,the comprehensive energy consumption could stabilize at 1 GJ/t CO_2.With the increase of the lean solution loading,the comprehensive energy consumption gradually reduces.With the decrease of the inlet temperature of the absorber,the comprehensive energy consumption stabilized at about 1.16 GJ/t CO_2.With the increase of the pressure of the regeneration tower,the comprehensive energy consumption increases at first and then decreases.When it is 2 MPa,the energy consumption is minimum which is about 1.128 6 GJ/t CO_2.