(571p) Dopant Modification to Vanadium Phosphorus Oxide Redox Carrier for Chemical Looping Methanol to Formaldehyde Conversion

Formaldehyde is the key intermediate for numerous high-demand products like resins, polymers, adhesives, and paints, making it one of the most valuable chemicals in the world. Current industrial facilities produce formaldehyde from methanol via the silver catalyst process and the Formox process which involve the passage of methanol and air over a catalyst bed. Despite the widespread adoption of these commercial processes, significant challenges persist. The hazardous methanol-air mixture involved in these processes limits the throughput of the product, and the continuous exposure to reactant gases leads to catalytic deactivation. Hence, with an increase in demand for these formaldehyde-derived chemicals, several studies have been conducted to develop processes for efficient production of formaldehyde. A recent study employed a 2-reactor chemical looping scheme where the molecular oxygen of the redox carrier (vanadium phosphorus oxide) selectively oxidizes methanol to formaldehyde. The reported 85% conversion of methanol and the 45% selectivity towards formaldehyde is significantly less than the commercial processes, impacting its financial viability. Hence, the present study investigates dopant modifications aimed at enhancing carrier performance for methanol conversion to formaldehyde. Metal dopants were shortlisted by comparing their effectiveness in reducing the carriers under methanol over multiple redox cycles. A subsequent analysis was performed to assess the impact of dopant concentration on oxygen carrier performance. Furthermore, this research explores the influence of dopant modification on the oxygen carrier phase using X-ray diffraction analysis. A near 15% enhancement in redox carrier performance has been observed over 10 redox cycles for iron-doped vanadium phosphorus oxide. Further analysis will be carried out to improve the carrier performance and stability over multiple redox cycles. Fixed bed studies will be conducted over the doped oxygen carrier to assess the improvement in methanol conversion and selectivity for formaldehyde. Overall, this study assesses the dopant modification strategy to enhance the performance of the chemical looping scheme for selective methanol oxidation to formaldehyde.