Isomerization of normal paraffins

Claim 1

IN A PROCESS FOR THE ISOMERIZATION OF N-C5-C8 PARAFFIN HYDROCARBONS WHICH COMPRISES CONTACTING A MIXTURE OF HYDROGEN AND N-C5-C8 PARAFFIN HYDROCARBON FEED AT AN ELEVATED PRESSURE, A H2/HYDROCARBON FEED MOL RATIO IN THE RANGE FROM ABOUT 1:1 TO 10:1, AT A TEMPERATURE OF ABOUT 600*-750* F., WITH A CATALYST CONSISTING ESSENTIALLY OF AN ACIDIC REFRACTORY MIXED-OXIDES SUPPORT AND 0.5-20% WT. OF AT LEAST ONE HYDROGENATION AGENT SELECTED FROM THE GROUP CONSISTING OF IRON GROUP METALS, GROUP V, VI, AND VII METAL OXIDES, AND IRON GROUP METAL SALTS OF OXYACIDS OF GROUP V, VI, AND VII METALS, A METHOD OF MITIGATING HYDROCRACKING DURING START-UP OF THE PROCESS WHICH COMPRISES INITIATING THE FLOW OF HYDROGEN AND HYDROCARBON FEED UNDER ISOMERIZATION CONDITIONS OF TEMPERATURE AND PRESSURE, AT A H2/HYDROCARBON FEED MOL RATIO OF SUBSTANTIALLY LESS THAN THE OPTIMUM RATIO FOR A TIME SUFFICIENT TO DEGENERATE THE CATALYST ACTIVITY BY A SMALL AMOUNT NOT IN EXCESS OF 5 CONVERSION UNITS, AND THEREAFTER SLOWLY INCREASING THE H2/HYDROCARBON FEED MOL RATIO UNTIL THE DESIRED OPTIMUM RATIO IN THE RANGE FROM ABOUT 1:1 TO 10:1 IS REACHED FOR THE SELECTED PROCESS CONDITIONS OF TEMPERATURE AND PRESSURE.