Catalyst for the hydroisomerization of contaminated hydrocarbon feedstock

A process for hydroisomerization of a sulfur and nitrogen contaminated hydrocarbon feedstock, comprising the steps of:

• providing a hydrocarbon feedstock having an initial sulfur content of up to about 10,000 ppm and an initial nitrogen content of up to about 200 ppm;
• providing a catalyst system comprising a matrix selected from the group consisting of alumina, silica alumina, titanium alumina and mixtures thereof;
• at least one support medium substantially uniformly distributed through said matrix and comprising a silica alumina molecular sieve material having a composition xSiO.sub.2 :Al.sub.2 O.sub.3 :yP.sub.2 O.sub.5 wherein x is at least about 0.1;
• a first catalytically active metal phase supported on said support medium, said first catalytically active metal phase comprising a first metal and a second metal each selected from group VIII of the Periodic Table of Elements, said first metal being different from said second metal;
• a second catalytically active metal phase supported on said matrix, said second catalytically active metal phase comprising a third metal and a fourth metal each selected from group VIII of the Periodic Table of Elements and a fifth metal selected from group VIb of the Periodic Table of Elements, said third metal being different from said fourth metal;
• and
• contacting said feedstock with said catalyst system under a hydrogen atmosphere and at hydroisomerization conditions so as to provide a final product having a final sulfur content and final nitrogen content which are less than said initial sulfur content and said initial nitrogen content.