Detailed experimental study on the performance of Monoethanolamine, Diethanolamine, and Diethylenetriamine at absorption/regeneration conditions

Experiments were carried out in a lab-stripper to investigate the regeneration performance of CO2-loaded solutions of Monoethanolamine (MEA) under various operational conditions (energy input, rich solution flow rate, rich solution loading). To better understand the regeneration process of a rich MEA solution, appropriate evaluation of the absorption and regeneration capacities of an aqueous MEA solution were first determined. Thus, first of all, a bubbling reaction system was employed to assess the absorption and desorption capacities of MEA, and other amines, such as Diethanolamine (DEA) and Diethylenetriamine (DETA), were introduced to compare these capacities in terms of amino group. The influences of the solution temperature and the solution concentration on CO2 absorption and desorption performances were investigated. The results show that these factors significantly affect CO2 absorption and desorption. Moreover, experiments in the bubbling reaction system were conducted to compare the regeneration capacities of the three CO2-loaded solutions (MEA, DEA, DETA) with increasing concentrations under the condition of different sweep gases (100% N2, 14% CO2 and 100% CO2). The data show that under the condition of each type of sweep gas, the regeneration capacity of the three types of amino groups followed the rule: DEA > DETA > MEA. On the basis of these data obtained from the reaction system, regeneration experiments with loaded 2 mol/L MEA solutions in a stripper column were conducted to analyze the relationships between the regeneration ratio and the stripper operating parameters.