Comparison of Carbon Dioxide Absorption in Aqueous MEA, DEA, TEA, and AMP Solutions

Abstract

The separation and capture process of carbon dioxide from power plants is garnering interest as a method to reduce greenhouse gas emissions. In this study, aqueous alkanolamine solutions were studied as absorbents for <TEX>$CO_2$</TEX> capture. The solubility of <TEX>$CO_2$</TEX> in aqueous alkanolamine solutions was investigated with a continuous stirred reactor at 313, 333 and 353 K. Also, the heat of absorption (<TEX>$-{\Delta}H_{abs}$</TEX>) between the absorbent and <TEX>$CO_2$</TEX> molecules was measured with a differential reaction calorimeter (DRC) at 298 K. The solubility and heat of absorption were determined at slightly higher than atmospheric pressure. The enthalpies of <TEX>$CO_2$</TEX> absorption in monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), and 2-amino-2-methyl-1-propanol (AMP) were 88.91, 70.44, 44.72, and 63.95, respectively. This investigation showed that the heat of absorption is directly related to the quantity of heat for absorbent regeneration, and is dependent on amine type and <TEX>$CO_2$</TEX> loading.