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

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 m² g⁻¹ with MgO particles of 100 nm and pore diameter of 2.6 nm, and high breakthrough capacity of 50.00 mg/g. The initial pH and concentration of Mg²⁺ ion 12.5 and 0.2 M, respectively, with a maximum breakthrough capacity of 12.72 mg/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 °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.