(335l) Study On Performance of Alkanolamines as Absorbents for CO2 Capture

Because of global warming, CO2 capture and sequestration (CCS) now is looked as the main method to reduce the amount of green house gases released into the atmosphere. For CO2 capture, absorption, adsorption and membrane separations are main methods. In order to decrease the energy consumption for CO2 capture, new absorbents are necessary. In this paper the capture of CO2 by aqueous amine solutions with different molecular structures was studied to determine the relationship between the structure and the performance. The experiments for gas solubility of CO2 were conducted at 313.15K for absorption and 393.15K for regeneration in a stirred reactor. The amines selected were those with substituted chain of 1 to 3 carbon atoms on amino group. Results show that primary amine and secondary amine have the similar absorption performance while secondary amine and tertiary amine have the similar regeneration performance. A further result indicates that an increase in chain length results in an increase in the capacity but the increase of the capacity is more prominent by increasing main chain length rather than the branched chain length. The influence on the capacity by the functional groups was also investigated. The growth of the number of carbon atoms between the hydroxyl group and amino group leads to a higher capacity, and the increase of hydroxyl groups results in the decrease of capacity.