Patent ID: 7128828

Claim:
A process for producing food grade wax from a feedstock selected from the group consisting essentially of de-oiled paraffin waxes, de-oiled microcrystalline waxes, deasphalted residual oils and slack wax which process comprises: (a) contacting the feedstock and hydrogen with a hydrotreating catalyst in a first hydrogenation zone; (b) passing the resulting effluent without cooling from the first hydrogenation zone to an interstage separator operated at the hydrogenation zone outlet pressure to strip hydrogen sulfide, ammonia and non-waxy hydrocarbons by countercurrent contact with a first hydrogen-rich gaseous stream; (c) passing a liquid waxy hydrocarbonaceous stream from the interstage separator and a second hydrogen-rich gaseous stream and contacting the resulting stream with a hydrogenation catalyst comprising platinum or palladium in a second hydrogenation zone to saturate aromatic compounds; (d) passing the resulting effluent from the second hydrogenation zone to a first vapor-liquid separator operated at a temperature from about 149° C. (300° F.) to about 260° C. (500° F.) to maintain the waxy hydrocarbonaceous stream as a liquid; (e) passing the liquid waxy hydrocarbonaceous stream from the first vapor-liquid separator to a fractionation zone; (f) passing a vapor stream comprising hydrogen and non-waxy hydrocarbons from the first vapor-liquid separator to a second vapor-liquid separator operated at a temperature from about 10° C. (50° F.) to about 65° C. (150° F.); (g) passing at least a portion of a third hydrogen-rich gaseous stream recovered from the second vapor-liquid separator to provide at least a portion of the first hydrogen-rich gaseous stream in step (b) and at least a portion of the second hydrogen-rich gaseous stream in step (c); (h) passing a stream comprising non-waxy hydrocarbons from the second vapor-liquid separator to a fractionation zone; and (i) recovering a food grade wax in step (e).