Treatment and use of porous contact masses

Claim 1

IN PROCESSES FOR THE CONVERSION OF HYDROCARBONS USING SOLID HYDROCARBON CONVERSION CATALYSTS THAT DECLINE IN CATALYTIC ACTIVITY WHEN SUBJECTED TO REPEATED CYCLES OF CONVERSION AND REGENERATION, THE IMPROVEMENT WHICH COMPRISES EFFECTING CONVERSION OF SAID HYDROCARBONS UNDER CONVERSION CONDITIONS IN THE PRESENCE OF A RELATIVELY MORE CATALYTICALLY ACTIVE FRACTION OF A TOTAL CATALYTIC CONTACT MASS COMPRISING PARTICLES OF SAID SOLID CONVERSION CATALYST PREVIOUSLY SUBJECTED TO TEMPERATURES AT WHICH THE ACTIVITY OF SAID CATALYST DECREASES AND COMPRISING PARTICLES OF SAID CATALYST HAVING THE SAME BASIC COMPOSITION AND DIFFERING IN CATALYTIC ACTIVITY, WHICH RELATIVELY MORE CATALYTICALLY ACTIVE FRACTION HAS BEEN OBTAINED BY IMPREGNATING THE PARTICLES OF SAID TOTAL MASS WITH A SEALING LIQUID TO SEAL SAID PARTICLES TO SUBSEQUENT LIQUID PENETRATION, INTRODUCING SAID MASS INTO A BODY OF LIQUID HAVING A DENSITY ADAPTED TO FLOAT ONLY A FRACTION OF SAID PARTICLES, STRATIFYING SAID MASS INTO TWO FRACTIONS OF DIFFERENT AVERAGE PARTICLES DENSITIES, THE FRACTION HAVING THE LESSER AVERAGE PARTICLE DENSITY BEING MORE CATALYTICALLY ACTIVE THAN THE OTHER OF SAID FRACTIONS, AND SEPARATING SAID MORE CATALYTICALLY ACTIVE FRACTION FROM SAID BODY OF LIQUID APART FROM THE OTHER OF SAID FRACTIONS.