Method for preparing zeolite-based catalyst composition

Claim 1

PROCESS FOR PREPARING A CONVERSION CATALYST WHICH COMPRISES: A. PROVIDING A ZEOLITE Y MOLECULAR SIEVE HAVING A SIO2/AL2O3 MOLAR RATIO OF AT LEAST 4.0 AN ALKALI METAL CATION CONTENT OF FROM 10 TO ABOUT 30 EQUIVALENT PERCENT AND COMPLEMENTARILY FROM ABOUT 90 TO ABOUT 70 EQUIVALENT PERCENT NON-METALLIC CATIONS, B. HEATING SAID MOLECULAR SIEVE AT A TEMPERATURE OF FROM 350*C. TO BELOW THE CRYSTALLINE DESTRUCTION TEMPERATURE FOR A PERIOD OF AT LEAST 0.1 HR., SAID HEATING WITHIN THE SAID TEMPERATURE RANGE BEING THE FIRST SUCH HEATING TO WHICH THE MOLECULAR SIEVE IN ITS PRESENT CATION FORM HAS BEEN SUBJECTED, C. COOLING THE MOLECULAR SIEVE TO LESS THAN 300*C. AND CONCONTACTING SAME WITH AN AQUEOUS AMMONIUM ION SOLUTION TO REDUCE THE ALKALI METAL CATION CENTENT BY ION EXCHANGE TO LESS THAN 10 EQUIVALENT PERCENT ALKALI METAL CATIONS, THE PH OF THE SAID AMMONIUM ION SOLUTION IN CONTACT WITH SAID MOLECULAR SIEVE BEING IN THE RANGE OF 4 TO 8, D. THEREAFTER FORMING A COMPOSITION BY INTIMATELY ADMIXING THE RESULTING MOLECULAR SIEVE PRODUCT WITH FINELY DIVIDED ALUMINA, AN ALKALI METAL-FREE WATER SOLUBLE SALT OF AT LEAST ONE NON-NON-NOBLE METAL OF GROUP VIII OF THE PERIODIC SYSTEM AT LEAST ONE WATER SOLUBLE ALKALI METAL-FREE COMPOUND OF A METAL OF GROUP VI-B OF THE PERIODIC SYSTEM AND WATER, SAID GROUP VI-B METAL BEING PRESENT IN AN AMOUNT OF FROM 10 TO 30 WEIGHT PERCENT CALCULATED AS THE METAL OXIDE BASED ON THE TOTAL WEIGHT OF AL2O3PLUS ZEOLITE PRESENT (SOLIDS BASIS), SAID GROUP VIII METAL BEIGN PRESENT IN AN AMOUNT OF FROM 2 TO 10 WEIGHT PERCENT CALCULATED AS THE METAL OXIDE BASED ON THE TOTAL WEIGHT OF AL2O3 PLUS ZEOLITE PRESENT (SOLIDS BASIS), AND SAID WATER BEIGN PRESENT IN AN AMOUNT SUFFICIENT TO RENDER SAID COMPOSITION A THIXOTROPIC EXTRUDABLE MASS, AND E. EXTRUDING THE COMPOSITION THUS FORMED AND AT LEAST PARTIALLY DEHYDRATING THE EXTRUDATE.