Dewaxing by a combination centrifuge/catalytic process including solvent deoiling

摘要

A hydrocarbon dewaxing process comprising the steps of: P P(a) chilling the waxy hydrocarbon feed to be dewaxed in the absence of solvent to crystallize a portion of the hard wax;P P(b) introducing the hydrocarbon feed to be dewaxed into a centrifuge;P P(c) centrifuging the solvent free hydrocarbon feed thereby generating two streams, stream (I) comprising a major portion of oil with a minor portion of entrained wax, stream (II) comprising a major portion of wax with a minor portion of entrained oil; PP(d) adding a dewaxing solvent to stream (II) generating a slurry A;PP (e) feeding slurry A to a centrifuge thereby separating slurry A into an oil-solvent stream (III) and a wax- solvent stream (IV);PP (f) passing the oil-solvent stream (III) to a membrane separation unit wherein the stream is separated into a recycle solvent stream and an oil- solvent stream of reduced solvent content (stream V);PP(g) passing oil-solvent stream (V) to an oil recovery unit wherein the stream is separated into a recycle solvent stream and an oil stream (VI); PP(h) passing the wax-solvent stream (IV) of step (e) to a wax recovery unit wherein the stream is separated into a recycle solvent stream and a recovered wax product stream;PP(i) combining wax-oil stream (I) of step (c) with oil stream (VI) of step (g) and passing the combined stream to a catalytic dewaxing unit wherein the combined waxy oil stream, in the presence of hydrogen, is contacted with a catalyst and has its wax content reduced, thereby generating a dewaxed oil product stream.