Energetic Analysis And Comprehensive Assessment On Post-combustion CO₂ Capture With Chemical Absorption

Carbon Capture and Storage(CCS)play an important role in meeting climate goals while ensuring the energy security in power and industry sector.However,the intensive energy consumption for CO₂separation peocess as well as its associated challenges such as large investment is still a critital barrier for the scale-up development of CCS.Therefore,this paper conducts theoretical and experimental analysis as well as compre-hensive assessment for post combustion carbon capture with chemical absorption fo-cusing on improving its energetic performance.Systematic method for energy-efficient analysis of chemical absorption carbon capture technologies based on thermodynamic cycle analysis is developed in this study.A 4-Step monoethanolamine(MEA)based chemical absorption cycle is established and expressed on the equilibrium isothermals diagram of MEA-CO₂-H₂O mixture.Then the influences of cyclic parameters on the energy efficient performance of the entire process or system are evaluated.By defining partial pressure ratial,the driving force for absorp-tion and descorption process are described and considered for cycle analysis.The steady-state of MEA carbon capture process was investigated by expiremental and flowsheet simulation.Experimental results show that the second law efficiency for30wt%carbon capture process is about 18.39%under optimum liquid to gas ratio with12%CO₂ concentration.The flowsheet simulation was validated based on experimental temperature profile data.Then,the effect of operation pamaters are studied based on flowsheet simulation.It is noted that the reboiler duty and second law efficience showed different sensitivity to different operation paramers.Following above mentioned steady-state analysis,this paper combines pilot plant experiments and dynamic modeling to gain insight into the interation between key pro-cess parameters in inducing the dynamic response of a CO₂ capture process.Three cat-egories of dynamic senarios are investigated including step change in steam flowrate,solvent flowrate and flue gas flowrate,reboiler decoupling as well as plant ramping.The average deviation of absorber temperature profile ranges from 4.37-8.75%.Overall,the dynamic model was in agreement with pilot plant trends.Finally,solar-assisted post-combustion CCS processes are analyzed trough a life cycle approach.The implementation of CCS reduces the life cycle green house gas(GHG)emissions by 67.1%under 90%capture rate.The resilience level for five configurations of coal-fired power plant both with and without solar-field,together with the CCS system is measured,considering five critical characteristics towards resilience:fossil fuel depletion potential,global warming potential,levelized cost of energy,solar to electricity fraction and spare capacity.Results indicate that it is promising to inte-grate solar thermal energy to the post-combustion carbon capture power plant.