Kinetics of carbon dioxide absorption in aqueous solution of diethylenetriamine (DETA)

A string of discs contactor was used to measure the kinetics CO₂ absorption in unloaded aqueous solution with the diethylenetriamine (DETA) concentrations ranging between 1.0 and 2.9 kmol m⁻³ and at temperatures ranging between 298.1 and 332.3 K. The reaction rates strongly increase as the increasing the concentrations and temperatures. Both the termolecular and the zwitterion models were applied to interpret the experimental data and gave identical results for all practical purposes. The reaction order with respect to the DETA concentration is found to vary slightly with temperature between 1.71 and 1.76 with an average of about 1.73. Both DETA and water contribute as a base in carbamate formation. It was found that fitting of experimental data to the termolecular mechanism gave statistically more robust results than fitting to the zwitterion mechanism.