压缩式热泵回收CO2捕集解吸塔废热节能工艺研究

Study on Energy-saving Technology for Recovering Waste Heat from CO2 Capture and Desorption Tower by Compressed Heat Pump

采用压缩式热泵技术回收有机胺法捕集CO2解吸塔废热,通过改变解吸塔塔底压力、进解吸塔富液温度等参数来降低系统再生能耗。随着进解吸塔富液温度的升高,解吸反应进行的越彻底,系统再生能耗、再沸器负荷与贫液CO2负载均呈逐渐降低趋势,当进塔温度为120℃时,系统再生能耗最低,为3.664GJ/tCO2;随着解吸塔塔底压力的升高,系统再生能耗与再沸器负荷均呈逐渐降低趋势,贫液CO2负载呈上升趋势,为减少吸收液损耗及投资成本当解吸塔压力为140kPa时最合适,此时系统再生能耗值为3.651GJ/tCO2,相比常规工艺降低系统再生能耗13.15%。

Compressed heat pump technology is used to recover the waste heat of CO2 desorption tower by organic amine method.The regeneration energy consumption of the system is reduced by changing the pressure at the bottom of the desorption tower and the temperature of rich liquid in the desorption tower.With the increase of Rich-liquid temperature in the desorption tower and the more thorough desorption reaction,the regeneration energy consumption,reboiler load and lean-liquid CO2 load of the system decrease gradually.When the inlet temperature is 120℃,the regeneration energy consumption of the system is the lowest,which is 3.664 GJ/tCO2.With the increase of the bottom pressure of the desorption tower,the regeneration energy consumption and reboiler load of the system decrease gradually,and the lean-liquid CO2 load.In order to reduce the absorption loss and investment cost,the desorption column pressure is 140 kPa.At this time,the regeneration energy consumption of the system is 3.651 GJ/tCO2,which is 13.15% lower than conventional process.