Experiments And Modeling Of Vapor-liquid Equilibrium Data In DEEA-CO₂-H₂O System

Greenhouse gas,global warming problems and etc.are increasingly critical that caused serious impact on people's lives.Thus how to mitigate greenhouse gas emissions mainly including the high CO2 emissions with the rapid industrial development in recent years has been focused by researchers.This paper aims at the chemical solvent of DEEA,researches and analysis the vapor and liquid equilibrium thermodynamics model in the system of diethylethanol amine solution(DEEA-CO2-H2O).This paper has a deep experimental research with the experimental DEEA concentration of 1M,2M,3M,and 4M,temperature of 293K,313K,333K,353K and CO2 partial pressure of 6.2Kpa-100.8Kpa.Solubility data indicate that DEEA has a relatively high solubility under the condition of low CO2 partial pressure and with the increase of CO2 partial pressure solubility value increases gently.DEEA has a higher capacity than the traditional MEA solution and its absorption capacity is close to the AMP solution which is easy to crystallize in low temperature.Besides DEEA as a tertiary amine has a better absorption effect in low CO2 partial pressure and lower regeneration energy consumption compared with MDEA.By comparing and analyzing among MEA,DEA,MDEA and AMP,DEEA has a strong application prospect and advantage.Moreover,empirical models have been established under different DEEA concentration conditions with the vapor and liquid equilibrium data turns out to have a good prediction effects,regress the model parameters with the experimental data,the average absolute deviations with DEEA concentration of 1M,2M,3M,4M are 1.72%,2.68%,1.32%,10.32%respectively and the deviation increases with the increase of DEEA concentration.This paper has a vapor and liquid equilibrium thermodynamics model comparison among KE,e-NRTL and Uniquac model in the conventional MEA solution which is widely studied.DEEA as a new tertiary amine has a limited physical property parameter.Based on the model prediction results analysis in MEA system,KE model has a good prediction with fewer parameters.Considering no researches have been done in DEEA solution with the model of KE.Thus this work focuses in this area.By regressing of solubility data,the protonation amine dissociation reaction equilibrium constant K10 has been regressed.The results turns out that KE model has a good prediction in DEEA-CO2-H2O system.The KE model prediction AAD in 1M,2M DEEA is 3.28%and 5.10%while the AAD reach 11.43%and 14.73%in 3M,4M DEEA.In additional,simulation has been made with conventional solvent of 30%wt MEA for the later DEEA simulation work which will help when it is adopted in industries.