Absorption of co₂ into aqueous tertiary amine/mea solutions

Abstract

Abstract Absorption rates for CO 2 into aqueous solutions of TEA, MDEA and blends of MEA with MDEA and TEA were measured in a stirred cell by a method similar to that used by Laddha and Danckwerts (1981). Second order rate constants for CO 2 ‐TEA and CO 2 ‐MDEA were obtained from the single amine data for temperatures in the range of 25‐60°C. A modified pseudo first order model based on the film theory is used to predict the rate of absorption of CO 2 into mixed amine solutions. This model accounts for the variation of amine concentration in the film and assumes a shuttle mechanism for rate enhancement. Bulk liquid concentrations of the various species present are obtained from a simplified thermodynamic model. The model predicts absorption rates that are in agreement with experimental measurements.