Simulation And Optimization Of Capturing High Concentrated CO₂ Gas With Aqueous Amine Solution

Blast furnace tail gas in metallurgical industry and oil field associated gas in oil production industry usually contain high concentration of CO₂.Capturing CO₂in these industrial tail gas is conducive to reducing CO₂emissions and alleviating environmental problems caused by global warming.At the same time,it also meets the major needs of carbon peaking and carbon neutralization in China.However,insufficient attention is still paid to the CO₂capture of medium and high concentration emission source industries,especially the adaptation mechanism between high concentration CO₂and alcohol amine solution absorbent is still unclear.Based on this,this thesis is adopted the chemical process simulation and optimization method,and constructs the process model of alcohol amine solution capturing high concentration CO₂Based on the pilot test platform and operation data.With the goal of reducing energy consumption,improving capture rate and maintaining capture output,this thesis is explored the influence law of process structure and operation parameters on capture purity,capture rate and heat energy consumption,so as to provide theoretical and technical support for optimizing high concentration CO₂capture.When 30 wt%MEA solution was used as solvent,a rate-based model was established in Aspen Plus simulation,which was verified by 11 groups of experimental data of CO₂absorption pilot plant of Hunan University.Through the comparison of the above data,the MEA model constructed in this study is in good agreement with the pilot test,and the model is accurate,true and reliable,which provides reliable initial stage data for the optimization design of subsequent pilot test process and operating parameters.Then,aiming at the capture of high concentration CO₂gas with an annual processing capacity of 50 tons,the process flow and operating parameters were optimized under the conditions of 90%capture rate and 95%product purity.Compared with the highest capture rate and the lowest unit consumption before optimization,the CO₂capture rate increased by 12.37%and the unit consumption decreased by 22.44%.When the total concentration of 5 M MEA-MDEAAMP mixed amine solution was taken as the solvent,the performance of four different ratios of MEA-MDEA-AMP mixed amine solution was compared.The model of compound amine solution capturing high concentration CO₂gas was established by Aspen Plus simulation,which was verified by 14 groups of pilot experimental data.Through the comparison of the above data,the MEA-MDEA-AMP simulation established in this study has been verified in the pilot test,which can accurately describe and predict the study of compound amine capturing high concentration CO₂.Finally,when the total concentration of 5 M MEA-MDEA-AMP mixed amine solution was taken as t he solvent and the capture of high concentration CO₂gas with an annual treatment of 150 tons was taken as the design goal,the process and operating parameters were optimized under the conditions of 90%capture rate and 95%product purity.Compared with the cases before optimization,the unit consumption was reduced by 29.2%.The research results are expected to provide technical feasibility support for MEA method and MEA-MDEA-AMP mixed amine solution CO₂capture process.