CHEMICAL-KINETICS OF THE REACTION OF CARBON-DIOXIDE WITH ETHANOLAMINES IN NONAQUEOUS SOLVENTS

The kinetics of the reaction of carbon dioxide with mono- and diethanolamine in such nonaqueous solvents as methanol, ethanol, and 2-propanol and in water were studied using a stirred tank absorber with a plane gas-liquid interface at 303 K. The reaction was found to be of first order with respect to carbon dioxide for every solvent. The order of reaction with respect to ethanolamine was found to be unity only for an aqueous solution of monoethanolamine and for the other solutions, ranged from 1. 4 to 2, depending on the solvent species. The reaction order was increased in the order of water, methanol, ethanol, and 2-propanol. The variation of the reaction order with the solvent species could be explained in terms of a reaction scheme via a zwitterion. Almost linear dependence of the logarithm of the reaction rate constant on the solubility parameter of the solvent was derived.