Preparation of maleic anhydride and catalyst thereof

Claim 2

A PROCESS FOR THE PREPARATION OF MALEIC ANHYDRIDE WHICH COMPRISES THE PARTIAL OXIDATION OF BENZENE WITH MOLECULAR OXYGEN IN THE PRESENCE OF A CATALYST CONSISTING ESSENTIALLY OF A REFRACTORY SUPPORT IN PARTICULATE FORM OF ABOUT 0.2 TO ABOUT 0.5 INCH AVERAGE DIAMETER, AND HAVING A SURFACE AREA IN THE RANGE OF ABOUT 0.002 TO 10 SQUARE METERS PER GRAM, SAID SUPPORT BEING PREPARED FOR SUBSEQUENT ADDITION THERETO OF CATALYTIC MATERIALS BY CONTACTING THE SUPPORT WITH AN ACID HAVING A DISSOCIATION CONSTANT GREATER THAN ABOUT 10-5 FOR AT LEAST ABOUT 2 HOURS AT A TEMPERATURE OF ABOUT 20 TO 200 DEGREES CENTIGRADE, AND A MIXTURE OF ABOUT 1 PART MOO3, 1.5 TO 8 PARTS V2O5, 0.1 TO 0.01 PART P2O5, 0.1 TO 0.01 PART NA, AND 0.1 TO 0.0001 PART NI, CONTAINING ABOUT 3 TO 15 PARTS PER WEIGHT OF SUPPORT PER PART OF SAID MIXTURE, SAID CATALYST BEING OBTAINED BY PROVIDING THE CATALYST SUPPORT WITH A MIXTURE OF THE PRECURSOR OF THE ABOVE MATERIALS, DRYING AT A TEMPERATURE UP TO ABOUT 175*C., HEATING AT A TEMPERATURE IN THE RANGE OF ABOUT 175 TO 320*C. WITH A LINEAR AIR FLOW THROUGH THE CATALYST IN THE RANGE OF 0 TO 7.7 CM./MIN. AND THEN HEATING AT A TEMPERATURE IN THE RANGE OF 320 TO 400*C. WITH A LINEAR AIR FLOW IN THE RANGE OF 0.58 TO 21.1 CM./MIN. AT A TEMPERATURE IN THE RANGE OF ABOUT 350 TO 550*C., AND RECOVERING MALEIC ANHYDRIDE FROM THE REACTION MIXTURE.