Method for adding make-up fluid bed oxidation catalysts for fluid bed oxidation catalysts containing the mixed oxides of vanadium and phosphorus

摘要

A process is provided for activating fluidizable catalysts containing the mixed oxides of vanadium and phosphorus useful for the production of maleic anhydride from 4-carbon atom hydrocarbons and oxygen by subjecting the catalyst to fluidization conditions and contacting the fluidized catalyst with oxygen at a temperature at least 20 DEG C. greater than the temperature required to produce about 85 percent conversion of hydrocarbon. A process is also provided for adding make-up fluid bed catalyst to an equilibrated catalyst by introducing a calcined and unequilibrated make-up catalyst into the fluid bed vessel containing equilibrated catalyst, subjecting the mixture to fluidization conditions and contacting the fluidized catalyst mixture with oxygen at a temperature at least 20 DEG C. greater than the temperature required to produce about 85 percent conversion of the hydrocarbon. The catalysts so activated and a process for producing maleic anhydride from 4-carbon atom hydrocarbons is also provided.