SELECTIVE OXIDATION OF NORMAL-BUTANE TO MALEIC-ANHYDRIDE .1. OPTIMIZATION STUDIES

Optimization studies have been carried out for the selective oxidation of n-butane to maleic anhydride (MA) over vanadium-phosphorus oxide (VPO) catalysts promoted with Mo and Ce. It is known that Mo increases the selectivity to MA while Ce increases the conversion of n-butane. Response surface methodoloy has been used for finding out the optimum catalyst composition and optimum values for the process variables, viz., inlet feed composition, reaction temperature, and contact time for the reaction. It is observed that a catalyst having a P/V atomic ratio equal to 1.08, Mo/V weight ratio of 0.06, and Ce/V weight ratio of 0.022 gave the maximum yield of MA (49.5%) at a temperature of 423-degrees-C and an inlet n-butane concentration 1.75% of air and n-butane mixture.