Construction Method And Energy Efficiency Analysis Of Thermodynamic Cycle For Chemical Absorption Carbon Capture

As the increase emission of greenhouse gases in the atmosphere,the global average temperature is rising,which aggravates a series of problems caused by the greenhouse effect.Carbon capture technology is an important technology to reduce the greenhouse gas emissions.However,due to the drawbacks of its high energy consumption,it cannot be widely applied.Therefore,this paper focuses on the theoretical analysis of energy efficiency and combined with experiments and simulation work to study the energy efficiency of carbon capture with chemical absorption.Taking a typical ethanolamine（MEA）benchmark solution as an example,the thermodynamic cycle is developed,and combined with COP_CO2,a new energy efficiency index parameter for the carbon capture system to analysis the energy efficiency with chemical absorption.Through the analysis of key parameters,the impact of its energy efficiency on the system and the upper limit of energy efficiency under the ideal cycle are explored.At the same time,combined with the efficiency of regeneration heat and the second law of thermodynamics,the energy efficiency evaluation system of the carbon capture system is improved.The energy consumption of the MEA absorption method was studied by experimental methods under steady-state operating conditions.By changing the different cycle operating parameters,such as the inlet flue gas concentration,the lean flow rate and the reboiler temperature,the energy consumption of the carbon capture system is investigated,and the CO₂ loading of the solution is analyzed.At the maximum CO₂ concentration of flue gas,the heat consumption was 7.90 GJ/t.Aspen Plus is used to simulate the steady-state process.By comparing the simulation of the original program with the improvement program with condensate reflux,which brought longer continuous-running time,the desorption performance didn’t decrease and the energy consumption was in the same level.Under the base case,the unit capture energy consumption of the 30%wt MEA solution was 4.01 GJ/t.In order to further reduce the energy consumption of carbon capture,the original system was simulated by using 10%wt MDEA+20%wt MEA mixed absorption solution,and the unit absorption capacity of the solution was enhanced.The lowest regeneration energy consumption was 3.44 GJ/t,which brought 14.2%reduction compared with the 30%MEA solution,the energy saving effect is ideal.