Laboratory Investigation of Carbon Dioxide Separation by Aqeous Methyl Diethanolamine-Piperazine Solvent in a Microreactor Using Response Surface Methodology

Carbon dioxide absorption is one of the ways to reduce greenhouse gases. This study investigates carbon dioxide absorption by methyldiethanolamine-piperazine aqueous solution using a microchannel. The Design Expert software was used to check and analyze the results. The effect of the parameters of amine concentration (30-50 wt.%), temperature (20-40°C), solvent flow entering the microreactor (3-9 ml/min) and carbon dioxide concentration (5-15 vol.%) on the overall mass transfer coefficient was evaluated. The importance of the input variables for this response is in the order of liquid flow > amine concentration > temperature. Liquid flow intensity is the most effective input variable because there is a direct relationship between liquid flow intensity and the succession of absorption sites. The highest value of the overall mass transfer coefficient was reported as 202.50 kmol/m3.h.kPa. This value was obtained in operating conditions: concentration of 40 wt.% of solvent, flow intensity of 9 ml/min of solvent, operating temperature of 40 degrees Celsius and input concentration of 10 vol.% of carbon dioxide gas.