MgO modified zeolite facilitated low temperature chemisorptive removal of gaseous acetaldehyde into value added intermediate as desorption product.

Abstract

The adsorptive removal of acetaldehyde is more compatible for real-world applications. However, it must be upgraded from simple adsorption to a high efficiency process with value added products. This study develops a modified zeolite with Mg2+ ions that possesses acid-base sites for the removal of acetaldehyde at room temperature. Through a modified procedure, MgO is coated on commercial zeolite (13x), achieving a porosity of 501\xa0m2\xa0g-1 with MgO particles of 100\xa0nm and pore diameter of 2.6\xa0nm, and high breakthrough capacity of 50.00\xa0mg/g. The initial pH and concentration of Mg2+ ion 12.5 and 0.2\xa0M, respectively, with a maximum breakthrough capacity of 12.72\xa0mg/g at 10% humidity. Significant variations in breakthrough capacity with respect to humidity in the presence of H2S and NH3 demonstrate the effects of water and gases on adsorption efficiency. Desorptive oxidation of adsorbed acetaldehyde at 250\xa0°C yielded a high molecular weight intermediate ethylene oxide formation. The oxidation is followed by aldol condensation and hydrogenation. The higher breakthrough capacity and the intermediate product yielded using the developed MgO-zeolite proves the acid-base reaction sites involved in acetaldehyde removal follows chemisorption and possible process scale-up.