Improved wax hydroisomerization process

摘要

Waxy feeds are treated under hydroisomerization conditions to produce good yields of an isomerate product of high VI by using a silica-alumina based catalyst in which the silica-alumina has a pore volume less of 0.99 ml/gm (H2O), an alumina content in the range of 35 to 55 wt % and an isoelectric point in the range of 4.5 to 6.5. A lube fraction of the isomerate is dewaxed to provide a lube basestock of high VI. The silica-alumina may be modified with a rare earth oxide or yttria or boria or magnesia in which instance the modified catalyst has an isoelectric point greater than but no more than 2 points greater than base the silica-alumina.