Patent ID: 6723229
Filing Date: 2004-04-20
Classification: B01J,C10G

Abstract:
A process for the preparation of pharmaceutical grade white oils from a mineral hydrocarbon oil feedstock having a viscosity ranging from about 60 to about 600 SUS at 37.8Â° C., by a four stage catalytic process, which process comprises: (1) hydrotreating the mineral oil feedstock in a first reaction stage containing a hydrotreating catalyst and a hydrogen-containing treat gas under hydrotreating conditions, thereby resulting in a first stage reaction product which is at least partially hydrogenated and desulfurized; (2) hydrotreating the reaction product of the first reaction stage in a second reaction stage in the presence of: (i) a hydrodesulfurization catalyst comprised of a Group VIII noble metal selected from Pt, Pd, Ir, and mixtures thereof on a bound M41S support, (ii) a hydrogen containing treat gas, wherein the second reaction stage is operated at temperatures from about 150Â° C. to 500Â° C. and pressures from about 500 to 3,000 psig (3549 to 20,786 kPa); (3) treating hydrotreated product from stage 2 with a reduced metal hydrogen sulfide sorbent material in stage 3, and (4) hydrogenating the reaction product from reaction stage 3 in a fourth reaction stage in the presence of a Group VIII metal based catalyst, thereby producing a white oil.