SELECTIVE VAPOR-PHASE OXIDATION OF NORMAL BUTANE INTO MALEIC ANHYDRIDE AND CALCINING OF V/P/O CATALYST

摘要

PROBLEM TO BE SOLVED: To provide a method for selective vapor-phase oxidation of n-butane useful in preparation of a V/P/O catalyst having enhanced activities in oxidizing the n-butane into maleic anhydride and a method for calcining the V/P/O catalyst. ;SOLUTION: This improved method for calcining and activating a catalyst containing a mixed oxide of vanadium and phosphorus (V/P/O) comprises adding a spray-dried catalyst precursor to a fluidized oxygen containing gas at a rate controlled so as to maintain the temperature within the range of 370-410°C (preferably 39±5°C). The dehydrating/calcining treatments of the catalyst precursor are carried out at an elevated temperature in addition to a sudden increase in temperature in a fluidized state in air under ≥3.5atm pressure in about 4hr average residence time or up to 20hr at the maximum in air under 1atm pressure while being simultaneously and continuously maintaining the average Vox at ≤4.55.;COPYRIGHT: (C)1998,JPO