Screening And Performance Study Of Organic Amine Absorbents For Absorption And Desorption Of CO₂

The generation of large amounts of CO2 by industrial activities such as power generation and heating is the main cause of the greenhouse effect.At present,the chemical absorption method is the most important technical means in the actual industrial capture of CO2.It has several advantages of strong separation ability,fast absorption rate and easy operation and etc.However,the problems of low circulation capacity,low removal efficiency and high desorption energy consumption of traditional organic amine absorbents have not been well solved.In this paper,through the absorption and desorption of CO2 experiment on single-component organic amine absorbents,comparedthe absorption capacity,absorption speed,desorption capacity,desorption rate and desorption rate of different absorbents of CO2,compounding and combining according to the characteristics of different absorbent to explore the CO2 capture performance of multi-component compound absorbents,the main conclusions are as follows:(1)Carrying out experiments on single-component absorbents on absorption and desorption of CO2,and it was found that thecirculation capacity of primary/secondary amine absorbents' of CO2 from large to small are triethylenetetramine(TETA),diethylenetriamine(DETA),tetraethylene-pentamine(TEPA),N-aminoethyl-piperazine(AEP),?-hydroxyethylene-diamine(AEEA),piperazine(PZ),2-amino-2-methyl-1-propanol(AMP),diethanolamine(DEA)and ethanolamine(MEA).And tertiary amine absorbents from large to small are N,N-diethylethanolamine(DEEA),1-(2-Hydroxyethyl)piperidine(HEP),N-methyldiethanolamine(MDEA)and triethanolamine(TEOA).(2)Adding MDEA,AMP and AEP to the MEA solution can improve the desorption amount,average desorption rate and desorption rate of the solution to CO2,which shows that the multi-component compound absorbent can improve the CO2 desorption of the single component absorbent in some aspects capturing performance.Among them,the 30 wt%MEA+10 wt%MDEA solution has the highest CO2 desorption rate and the average CO2 desorption rate,respectively 67.73%and 5.62×10-5 mol/s,which is an increase of 6.99 percentage points compared to the 40 wt%MEA solution And 7.87%,30 wt%MEA+10 wt%AEP solution has the highest CO2 desorption amount,which is 2.17 mol CO2/kg solution,which is 8.50%higher than 40 wt%MEA solution.(3)MDEA was mixed with AEEA,TEPA,AEP and PZ,respectively,to conduct experiments on absorption and desorption of CO2.It was found that in this group of experiments,25 wt%MDEA+25 wt%PZ solution has highest rate of loading,average absorption rate,desorption capacity and average desorption rate of CO2.They are 3.26 mol CO2/kg solution,1.28×10-4 mol/s,2.65 mol CO2/kg solution and 8.16×10-5 mol/s.DETA was mixed with MDEA,AMP,AEP and PZ respectively to conduct experiments on absorption and desorption of CO2.It was found that in this group of experiments,20 wt%DETA+20 wt%AEP solution has the highest rate of loading,average absorption rate desorption capacity and average desorption rate of CO2.They are 4.61 mol CO2/kg solution,1.54×10-4 mol/s and 2.81 mol CO2/kg solution,20 wt%DETA+20 wt%MDEA solution has the highest average CO2 desorption rate,and it is 6.04×10-5 mol/s.(4)DEEA can improve the CO2 capture performance of the compound system of PZ+AEEA and DETA+AMP,and the effect of some aspects is better than MDEA.In the PZ+AEEA compounding system,the average absorption rate and desorption amount of CO2 of 15 wt%PZ+10 wt%AEEA+10 wt%DEEA solution are higher than 15 wt%PZ+10 wt%AEEA+10 wt%MDEA solution increased by 18.18%and 6.45%.In the DETA+AMP compounding system,15 wt%DETA+10 wt%AMP+10 wt%DEEA solution has higher CO2 loading,average absorption rate,desorption amount and average desorption rate than 15 wt%DETA+10 wt%AMP+10 wt%MDEA solution increased by 6.38%,2.65%,3.23%and 8.21%.