Determination of the mechanism of the reaction between CO2 and alkanolamines.

Abstract

Emission control of greenhouse gases especially CO2 has become an environmental challenge. CO2 capture by absorption in amine is so far the only CCS technique that has been industrially acknowledged. Chemical absorption of CO2 in amine solution is a complex process and needs investigation for better understanding.An experimental study has been conducted to understand the kinetics of CO2 absorption in non-aqueous DEA solution at 293K in a stirred cell reactor with a smooth and flat gas liquid interface. Experiments were repeated to ensure the reproducibility of data and the results were compared with literature to ensure the validity of this work. Physio-chemical properties of all chemicals like density, diffusivity and viscosity were taken from literature whereas solubility data was generated by experimentation. Solubility data was also validated by comparison with literature.Experimental data for reaction kinetics was treated with both zwitterion and termolecular mechanism. Based on the findings from this work, the order of reaction is 1.78 with respect to amine. Furthermore, Parity plot between calculated and experimental CO2 fluxes have been generated to elaborate the argument and it could be concluded that for non-aqueous system both studied mechanisms shows less than 10% deviation and hence can give satisfactory results. It is recommended to continue this work at different temperatures for better understanding.