On the CO2 absorption kinetics, loading capacity, and catalytic desorption of aqueous solutions of N-methyl-D-glucamine

CO2 separation with harmful chemicals will damage the environment. It is essential to explore greener solvents that are producible from renewable resources such as biomass. The suitability of N-methyl-D-glucamine (MG), also known as meglumine, for capturing CO2, was explored in this work. This nontoxic amino sugar, which is derived from sorbitol, represents a renewable bio-solvent. It was found that MG is especially reactive with CO2. Trials were performed in a stirred cell reactor with a flat gas-liquid interface between 303 and 313 K. The values of the pseudo-first-order reaction rate constant, reaction orders, and activation energy were found. The loading capacity (alpha) of 0.5 M MG solution was measured at T = 308 K. For a typical value of alpha = 0.524 mol CO2/mol MG, the corresponding equilibrium partial pressure of CO2 was 22 kPa. Finally, it was found that the catalyst Al2O3 aided in the desorption of CO2-loaded MG solutions. Desorption efficiency using Al2O3 was higher (74%) than that achieved without this catalyst (45%). It is thus clear that MG represents a potential solvent for improved CO2 separation from gases.