Hydrocarbon conversion process utilizing stabilized zeolite catalysts

Claim 1

IN A HYDROCARBON CONVERSION PROCESS WHEREIN A HYDROCARBON FEEDSTOCK IS CONTACTED WITH A CATALYST UNDER HYDROCARBON CONVERSION CONDITIONS, THE IMPROVEMENT WHICH COMPRISES UTILIZING AS SAID CATALYST A PARTICLE-FORM AGGREGATE OF A STABILIZED CRYSTALLINE ALUMINOSILICATE ZEOLITE COMPONENT AND AN AMORPHOUS REFRACTORY INORGANIC OXIDE COMPONENT SELECTED FROM THE CLASS CONSISTING OF ALUMINA, SILICA, MAGNESIA, BERYLLIA, ZIRCONIA, TITANIA, THORIA, CHROMIA, AND COMBINATIONS THEREOF, SAID CATALYST HAVING BEEN PREPARED BY: A. ION EXCHANGING A CRYSTALLINE ALKALI METAL ALUMINOSILICATE ZEOLITE WITH AMMONIUM IONS UNDER EXCHANGE CONDITIONS ADJUSTED TO REDUCE THE ALKALI METAL CONTENT OF SAID ZEOLITE TO LESS THAN ABOUT 3 WEIGHT PERCENT DETERMINED AS THE METAL AND REPLACE BETWEEN ABOUT 20 AND 95 PERCENT OF THE ORIGINAL ALKALI METAL CONTENT OF SAID ZEOLITE WITH AMMONIUM IONS; B. STEAMING THE RESULTANT EXCHANGED ZEOLITE AT A TEMPERATURE OF ABOUT 800* TO ABOUT 1650*F IN THE PRESENCE OF AT LEAST ABOUT 0.5 PSI WATER VAPOR PARTIAL PRESSURE FOR AT LEAST ABOUT 10 MINUTES, SUFFICIENT TO CONVERT SAID EXCHANGED ZEOLITE TO THE CORRESPONDING HYDROGEN FORM AND STABILIZE SAID ZEOLITE; C. RE-EXCHANGING THE RESULTANT STABILIZED ZEOLITE WITH AMMONIUM IONS UNDER CONDITIONS SUFFICIENT TO FURTHER REDUCE SAID ALKALI METAL CONTENT TO LESS THAN ABOUT 2 WEIGHT PERCENT DETERMINED AS THE CORRESPONDING OXIDE AND TO INTRODUCE INTO SAID ZEOLITE BY EXCHANGE WITH ZEOLITIC ALKALI METAL IONS AN AMOUNT OF AMMONIUM IONS CORRESPONDING TO AT LEAST ABOUT 5 PERCENT OF THE ORIGINAL ION EXCHANGE CAPACITY OF SAID ZEOLITE; AND D. CALCINING THE RE-EXCHANGED ZEOLITE AS A PARTICLE-FORM AGGREGATE CONTAINING SAID REFRACTORY OXIDE INTIMATELY ADMIXED THEREIN AT A TEMPERATURE OF AT LEAST ABOUT 600*F.