Study On Absorption Of Carbon Dioxide Using Organic Amine And Its Performance

As the profound recognizing of global warming and the necessary of low concentration of CO2 for avoiding poisoning of catalyzer in synthetic ammonia, the study on absorption of CO2 has been attached more importance to. Absorption into alkanolamine solvents is the most suitable process for high volumes of synthesis gas stream for such advantages as high absorption rate, maximum loading, low regeneration energy, low corrosion, and so on. To get a better activator, the method of organic amine has been used in this study. The variation of absorption rate with absorption time and concentration of activator by carrying out absorption and regeneration synchronously was studied, too. Tetraethylenetetramine(TEPA) was firstly adopted as activator in absorption of CO2.Activator has been filtrated under static absorption using MDEA as major absorbent at first, the result indicated that the activity of diethylenetriamine(DETA) and triethylenetetramine(TETA) are much better than that of monoethanolamine(MEA) and piperazine (PZ). The absorption of TETA+MDEA has been focused on subsequently. Higher concentration of TETA was propitious to absorption, the favorite temperature was 30℃.Secondly, the concentration of tail gas has been studied when using different activators under cyclic capture. 1.38 mol/L MDEA+0.12 mol/L TETA was best amond all of the absorbents, the outlet concentration of CO2 could be decreased to 0.05 mol% and the removal efficiency could be increased to 98.62%. Effect of concentration of activator, pressure, temperature, gas and liquid flow rate on outlet concentration of CO2 were also studied, the result indicated that heightening concentration of activator, pressure and liquid flow rate were favorite to decrease concentration of tail gas, removal efficiency could be 100% when liquid flow rate was large enough; and heightening temperature and gas flow rate were opposite. The variation of absorption rate(N) with absorption time(t) and concentration of activator(CMEA) under cyclic capture was established when using MEA+MDEA as absorbent. The equation was: N=A1exp(−t/30.28)+y0. Both A1 and y0 had valuable significance and were under the control of CMEA and t.Finally, after summarizing the function of functional groups of activators, TEPA was firstly adopted as activator. The absorption of TEPA+MDEA has been studied subsequently. In comparison with TETA and DETA, the activities of TEPA were discussed, the results indicated that TEPA was better than TETA and DETA when using as activator. The favorite temperature for TEPA+MDEA was 30℃.