Green Synthesis of Solketal from Glycerol Using Metal-Modified ZSM-5 Zeolite Catalysts: Process Optimization

Abstract The production of solketal (2, 2-dimethyl-1, 3-dioxolane-4-methanol) from glycerol via ketalization reaction was facilitated using a metallic zeolite M-ZSM-5 catalyst. The catalyst is prepared using the wet impregnation method, enabling precise control over metal loading and ensuring versatility in catalyst preparation. Various characterization methods, such as XRD, FTIR, TGA, and FESEM-EDX, were utilized to illuminate the properties of the catalyst. Solketal production unfolded in a solvent-free reactor within a rotamantle instrument. Various parameters were studied to understand the impact on the prepared solketal, including temperature, catalyst amount, molar ratio (G:A), reaction time, and stirring speed. The confirmation of solketal formation was achieved through GC-MS analysis. It has been found that the catalyst Cu-ZSM-5 exhibited the highest performance (99% conversion of glycerol and 96% selectivity of solketal) among various M-ZSM-5 catalysts. The Cu-ZSM-5 catalyst has been used for deactivation and reusability. To regenerate the spent catalysts, calcination was used, which also restored their initial activity. The solketal product obtained in this study has significant applications as fuel additives, solvents, and pharmaceuticals. This research promotes developing environment-friendly routes for utilizing glycerol as a renewable feedstock.