Improved CO₂ capture method by absorption

A process of CO₂ capture was built based on an existing power plant by ASPEN PLUS for studying CO₂ capture from flue gas of fossil fuel-fired power plant. Eletrolyte-NRTL model was used for the reaction of the process, and the absorber and stripper were built by RADFRAC model. The effect on CO₂ removal by changing the operation parameters was analyzed, and the optimal operation condition was found. In addition, the performance was improved by recycling the interstage thermal energy of the compressors. The optimal operation condition was obtained when monoethanolamine(MEA) mass fraction was 40%, CO₂ removal rate was 99.2%, operation pressure of stripper was 0.2 MPa, and lean solvent loading was 0.131. The results show that by combining the optimal operation condition with recycling interstage energy, the thermal energy requirement of the process is 2.947 GJ/t, the cost of CO₂ removal is 344.0 RMB/t, and the efficiency of power plant decreases from 45% to 32.75%.