Study On Decarbonization Technology Based On Ionic Liquid-organic Amine Aqueous Solution

In the field of CO₂ capture,the technology of wet decarburization that used ethanolamine after combustion has been widely used and it's relatively mature.However,the energy consumption of the ethanolamine method is too large,easy to be volatiled and degrade.The ionic liquid has the characteristics of nonvolatility,good thermal stability,safety and environmental protection.The combination of traditional ethanolamine process and ionic liquid technology can be combine both advantages.In this paper,firstly,the decarburization process of ionic liquid and ethanolamine?MEA?mixed aqueous solution was studied and optimized,the equilibrium model was used in Aspen plus 8.8 to simulate and check decarbonization processes of[Bmim]bf4-MEA-H₂O solution and[Bpy]bf4-MEA-H₂O solution.Decarbonization processes of Solution with respective mass concentration of 30%wt MEA and 70%wt H₂O was taken as a comparative item for optimizing the decarbonization techniques of[Bmim]bf4-MEA-H₂O solution and[Bpy]bf4-MEA-H₂O solution.The results show that adding ionic liquid to MEA aqueous solution can reduce the energy consumption of decarbonization regeneration under the optimized decarburization process.Further study was made on the decarburization performance of MCA?N-methylcyclohexylamine?and ionic liquids mixed aqueous solution,using semi continuous aborption desorption decarbonization test device to investigate the decarburization performance of certain ratio of MCA-[Bmim]bf4?1-butyl-3-methyl-imidazolate tetraphenyl fluoride?aqueous solution,MCA-[[Bpy]bf4?1-butyl-pyrid-ine borofluoride?aqueous solution,and compare with the same ratio of MCA,MEA?ethanolamine?aqueous solution,get result:30%wt?[Bmim]bf4?-30%wt?MCA?aqueous solution is good decarburizing reagent,under atmospheric pressure,40?remove CO₂,and desorbed at90?,the CO₂ loading rate of unit molar MCA in solution is up to 0.52.then,absorption enthalpy and CO₂ loading rate of MCA aqueous solution,MCA and[[Bpy]bf4mixed aqueous solution were studied by reaction calorimeter RC1,result show:under different conditions,the two decarbonization solutions maintained a high reaction rate within 30min,with the increase of temperature and MCA concentration,the CO₂ loading at per unit mol MCA decreased,but with the pressure increases,the load rate increases.MCA,[Bmim]bf4 concentration and pressure have little effect on the absorption enthalpy of solution,the effect of temperature on the absorption enthalpy of the solution is great,and the absorption enthalpy increases with the increase of temperature,the absorption enthalpy of the unit molar CO₂ absorbed by MCA-[[Bpy]bf4 mixed aqueous solution,MCA aqueous solution is measured between 80-130kJ.Finally,the decarbonization energy consumption of[Bmim]bf4-MCA aqueous solution have obtained by using the post-combustion decarbonization energy consumption calculation model,In view of the optimal desorption temperature of the new absorbent is90?,Designed flue gas extraction energy supply,solar-flue gas-extraction integrated energy supply carbon capture system,and evaluated by economics respectively,get result:The decarburization energy consumption of the new decarburization reagent is 3.47MJ.t^-1,and the overall energy consumption is reduced by 20%compared with the conventional decarburization reagent MEA.For the600MW supercritical unit,the new carbon capture has less impact on the original unit than the traditional MEA carbon capture,ahas better economic performance.