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.

Automated summary

CO2 separation using harmful chemicals is damaging to the environment. It is important to explore greener solvents producible from renewable resources, such as biomass. This study investigated the suitability of N-methyl-D-glucamine (MG) as a renewable bio-solvent for capturing CO2.