1D absorption kinetics modeling of CO2–DEAB–H2O system

Abstract

The experimental kinetics data for carbon dioxide (CO2) absorption into aqueous 4-diethylamino-2-butanol (DEAB) solutions were measured by laminar jet absorber at atmospheric pressure over a temperature range of 298–318K, a DEAB concentration range of 1–2M, and a CO2 loading range of 0.001–0.18mol CO2/mol amine. These data were interpreted with the aid of 1 dimension comprehensive numerically solved CO2 absorption rate/kinetics model, which takes into account the coupling between chemical equilibrium, mass transfer, and chemical kinetics of all possible chemical reactions between CO2 and aqueous DEAB solutions. The partial differential–nonlinear algebraic equations of the model were solved by the finite element method (FEM) based on COMSOL software. The results show that CO2 absorption reaction with DEAB is faster than that with MDEA, also comparable with those with AMP and DEA, but slower than those with MEA and PZ, respectively. In addition, the reaction kinetics in terms of enhancement factor was found to increase as DEAB concentration increased, and increase as temperature increased, but decrease as CO2 loading increased.