Behavior of Reboiler Heat Duty for CO2 Capture Plants Using Regenerable Single and Blended Alkanolamines

The reboiler heat duty for regeneration of aqueous single and blended alkanolamines used in the carbon dioxide (CO2) absorption process was evaluated experimentally in a bench-scale gas stripping and solvent regeneration system under atmospheric pressure. The evaluation was done for a number of alkanolamines, including monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA), and 2-amino-2-methyl-1-propanol (AMP), and the mixtures of MEA-MDEA, DEA-MDEA, and MEA-AMP. The experimental results of heat duty were compared with industrial data available in the literature and subsequently correlated with process parameters. The results indicate that the reboiler heat duty is dependent upon CO2 loading of lean and rich solutions, alkanolamine type and concentration, and composition of blended alkanolamines. MEA requires the highest reboiler heat duty, followed by DEA and MDEA. The reboiler heat duties of blended alkanolamines are between the heat duties of their parent alkanolamines.