A Study On Carbon Dioxide Absorption Using The Alcohol Amine Solution

Greenhouse effect induced by the emissions of carbon dioxide(CO₂)has been the most serious issue to be solved recently.Fossil fuel-based thermal power plant is a concentrated source of CO₂ emissions,and it contains more than 30 percent of the total amount of CO₂ emissions.If the CO₂ containing fuel gas can be recovered,it would be beneficial both socially and economically.Using alcohol amine solution to absorption CO₂ is a traditional and the most economical method.This article conducted preliminary experiments in order to develop more effective absorbents and accumulate necessary and valuable experimental data.The single component solution of AEE(or AMP)for CO₂ absorption was investigated, and then the relationship between CO₂ concentration and the pH of solution was also studied, finally,the possibility of measuring CO₂ concentration by the method of pH was discussed. Experimental results showed that AEE as a new type of CO₂ absorbers was worth to be studied.It had advantages of fast absorption rate,high absorption capacity and insensitiveness to temperature changes.When the CO₂ concentration within a limitted range in the alcohol amine solution,the pH value of the solution changed linearly with the CO₂ concentration change,which can be expressed by the equation of pH=-IX+J.Absorption rates of gaseous CO₂ with absorption time and absorption capacity were measured in a 40%(wt)alcohol amine concentration aqueous of AEE and MDEA or AEE and AMP.And the absorption rates of the solutions at different temperatures were measured. It was found that both of the two systems showed good absorption properties,they are suitable for industrial applications.The interaction between AEE and MDEA mixed solution in the absorption process.The results show that addition of AEE could effectively improve the CO₂ absorption performance of the MDEA solution.When the tool absorption rate less than 0.5,the factor of E increased by about 20%with the increment of AEE content by 10%.There will be interactions in one certain mol absorptance rate of the AEE+MDEA system,and the interaction coefficient decrease with the mol absorptance rate increase.In order to improve the efficiency of the CO₂ cycling process and to reduce the regeneration energy consumption,it is necessary to investigate the regeneration behavior of the saturated alcohol amine solution.Results showed that saturated solution can be renewed through the method of being heating,the renewed solution could reabsorb CO₂.The 20%AEE+20%MDEA system's desorption rate reached 99%after four absorptions and desorptions cycles.