The Recovery Of Low Concentration Carbon Dioxide By Alkylol Amine Solution In Packed Tower

CO2as a kind of greenhouse gas, which has many negative effects for human existence, but at the same time it is a kind of important resources and industrial gas. Now it can be used in many ways to benefit human, such as the food, chemical, pharmaceutical, oil and other departments. So how to recover and use CO2well has become the emphasis of many countries. Alcohol amine absorption process appeared in the1930s CO2, and it has become a major industrial CO2purification method after its industrialization.In this study, we used Aspen Plus process simulation software to design and build a small pilot-plant to investigate the performance of CO2absorption in different amine solutions. Carbon dioxide absorption and desorption are investigated at ambient pressure in two aqueous amine solutions,20%monoethyamino (MEA)+2%N-methyldiethanolamine (MDEA) and20%2-(aminoethylamino)ethanol (AEE)+2%N-methyldiethanolamine (MDEA). Both solutions were studied using static and the dynamic methods. Results showed that the capacity of CO2absorption and desorption in20%AEE+2%MDEA is higher than20%MEA+2%MDEA at the same absorption temperature with little deterioration. In addition,20%AEE+2%MDEA has lower energy consumption by10%than20%MEA+2%MDEA to achieve the same desorption result. For that reason the AEE shows a great potential of industrial application in the future.Carbon dioxide absorption and desorption are investigated in AEE mixed amine solutions with2-amino-2-methyl-l-propanol (AMP). In the condition of constant total amine concentration, the effect of CO2absorption and desorption were researched about different proportion of the mixed amine solution (AEE+AMP+H2O). The solution was studied using static and the dynamic methods. Results showed that with the increase of the2-amino-2-methyl-l-propanol (AMP) concentration, the CO2desorption quantity increased and absorption quantity declined. On the whole, the effect of CO2absorption and desorption with2-amino-2-methyl-l-propanol (AMP) as absorbed agent is not well with MDEA. At the same time, the total volumetric mass transfer coefficient (KGav) about the absorption of low concentration CO2into AEE+AMP solution was measured, and studied the influencing factors. Results showed that the KGav of AEE+AMP solution is increased with the increasing of raw gas and liquid flow. Due to the alkylol amine solution regeneration temperature above373K, the evaporation of water in water and amine aqueous at regeneration process, leading to most of the energy consumption. Therefore, this study used a relatively high boiling point solvent benzene methanol (BP) to research the absorption of CO2. Experimental results show that the absorption of CO2into the water is better than into the benzene methanol at the same amine concentration. But benzyl alcohol has the rapid rate of regeneration and about333K temperature in regeneration, so it can reduce the renewable energy consumption.