Formaldehyde production using methanol and heterogeneous solid catalysts: A comprehensive review

Despite formaldehyde's high toxicity, it has widespread demand worldwide due to its applications in the synthesis of a plethora of important chemicals like urea-formaldehyde, paraformaldehyde, polyacetal, and biological reagents amongst others. Currently, silver and iron molybdenum oxide catalysts are mostly utilized industrially due to their excellent efficiency and stability. As the catalyst ages and becomes saturated, selectivity decreases, pressure-drop increases, and the temperature of the heat transfer fluid rises. This review aims to present a comprehensive summary of formaldehyde production, considering the fundamentals of the process with a focus on decreasing methanol consumption and the utilization of natural zeolites as renewable, cost-efficiency, abundant and reusable catalysts.