The Effect Of Alcohols On The Desorption Performance Of CO₂ Alcohol Amine Absorbents

Global warming caused by excessive emissions of greenhouse gases is becoming more and more serious,and efforts to achieve emission reduction of CO2 are a global trend.Chemical absorption method is one of the most mature technologies in carbon capture technology.The energy consumption of regeneration in the application process is relatively high,accounting for 70%-80%of the total energy consumption of capture.The key issue in controlling the cost of CO2 capture by chemical absorption is to reduce the desorption energy of CO2.The phase change adsorbent has the potential to reduce the desorption energy consumption because it can greatly reduce the regenerated liquid phase.The previous research in this laboratory found that the phase change absorbent can be developed through salting out and solubilization effect,and successfully developed.A phase change absorbent consisting of an alcohol amine-alcohol organic-H2O,which has a high absorption rate and a CO2 cycle loading.However,the phase change absorbent contains a small amount of alcohol-based organic solvent in the liquid phase,and the effect on the liquid-phase desorption process of the absorbent is not clear.This is important for the choice of alcohol in the development of phase-change absorbent.Based on this,this paper explores the influence of different alcohols on the desorption process of MDEA,MEA and DEA systems,and obtains the influence of alcohol on the desorption process of absorbent rich liquid,which provides a basis for the selection of alcohol in the development of phase change absorbent in the future;The effects of operating conditions such as alcohol concentration,desorption temperature and stirring speed on the desorption process of MDEA system were optimized,and the operating parameters of desorption process were optimized.The desorption process of MDEA-n-butanol-H2O system phase change absorbent rich liquid phase was further investigated.Studies have shown that the addition of alcohol can change the desorption rate and cyclic loading of the absorbent rich in MEA,DEA and MDEA systems as well as the total energy consumption.The addition of methanol,ethanol and n-propanol inhibited the desorption process of MEA and DEA system absorbents,and promoted the desorption process of MDEA system absorbents.The addition of n-butanol to MEA The desorption process of DEA and MDEA system absorbents has a promoting effect,and the effect of n-butanol on the desorption process of MDEA system absorbent is the most obvious,that is,the initial desorption rate.It is about 1.5 times higher,the cyclic load is increased by about 20%,and the total energy consumption for desorption is reduced by about 11%.It was found that when the desorption temperature was 70?,the n-butanol concentration was 5 wt.%,and the stirring rotation speed was 1600 r·min-1,the addition of n-butanol had a greater effect on desorption.And MDEA-1-butanol-H2O system phase change absorber The presence of a small amount of n-butanol in the rich liquid phase promotes the desorption of the phase change absorbent rich liquid phase.