Influence of temperature on the kinetics of enzyme catalysed absorption of carbon dioxide in aqueous MDEA solutions

Abstract

In the present work the absorption of carbon dioxide in 1000molm−3 N-methyldiethanolamine (MDEA) solutions with and without enzyme has been studied in a stirred cell reactor in the temperature range 278–343K and enzyme concentrations ranging from 0 to 1600gm−3. During this study a new type of carbonic anhydrase has been tested: the evolved tetrameric enzyme GS6-046. The kinetic data from the new enzyme has been compared to the kinetic data obtained with the thermostable CA mutant 5X and the new enzyme showed a faster kinetics towards the CO2 hydration in combination with MDEA.The experimental kinetic data from the evolved CA at the temperatures 278, 288 and 313K resulted in a temperature dependent equation for the enzymatic rate constant kH2O*. In the temperature range 278–313K, this equation predicts kH2O* within an accuracy of 30%. However, at 343K the measured kH2O* is significantly overestimated.