Systems and methods are provided for performing solvent dewaxing using a dewaxing solvent that is not fully miscible with the feed being dewaxed. It has been unexpectedly discovered that by operating with a ketone solvent mixture that is beyond the miscibility limit by a small amount, the rate of solvent dewaxing can be substantially increased. Additionally, the difference between the filtration temperature during solvent dewaxing and the pour point of the resulting dewaxed product is unexpectedly reduced. The dewaxing solvent beyond the miscibility limit can correspond to, for example, a solvent mixture where the weight percent of methyl ethyl ketone is beyond the miscibility limit by 0.1 vol % to 5.0 vol %.

Systems and methods are provided for modifying or selecting processing conditions for bright stock formation based on compositional characterization of the feedstock and/or bright stock products. In some aspects, the compositional information can include Z-class characterization of the components of a feed and/or bright stock product, optionally in combination with carbon number and/or molecular weight for the components. The compositional information can be used to select processing conditions to allow for removal and/or modification of selected components within a bright stock in order to improve throughput and/or provide desirable cold flow properties.

A catalyst system for dewaxing of a hydrocarbon feedstock comprising at least two catalytic sections, the first section comprising a first dewaxing catalyst and a subsequent section comprising a second dewaxing catalyst, wherein the first dewaxing catalyst is a ZSM-12 zeolite based catalyst and the second dewaxing catalyst is a EU-2 and/or ZSM-48 zeolite based catalyst. The catalyst system displays enhanced performance when compared to systems containing either ony ZSM-12 based catalyst or EU-2/ZSM-48 based catalyst only.

A catalyst system for dewaxing of a hydrocarbon feedstock comprising at least two catalytic sections, the first section comprising a first dewaxing catalyst and a subsequent section comprising a second dewaxing catalyst, wherein the first dewaxing catalyst is a ZSM-12 zeolite based catalyst and the second dewaxing catalyst is a EU-2 and/or ZSM-48 zeolite based catalyst. The catalyst system displays enhanced performance when compared to systems containing either ony ZSM-12 based catalyst or EU-2/ZSM-48 based catalyst only.

Disclosed are methods and apparatuses for separating a wax product from a hydrocarbon feedstream by a) conducting a hydrocarbon feedstream to a membrane separation zone; b) retrieving at least one retentate product stream from the first side of the membrane element; c) retrieving at least one permeate product stream having a wax phase and an oil phase from a second side of the membrane element, wherein a pour point of the wax phase of the permeate product stream is higher than a pour point of the oil phase of permeate product stream; and d) separating a wax product from the wax phase of the permeate product stream.

Disclosed are methods and apparatuses for separating a wax product from a hydrocarbon feedstream by a) conducting a hydrocarbon feedstream to a membrane separation zone; b) retrieving at least one retentate product stream from the first side of the membrane element; c) retrieving at least one permeate product stream having a wax phase and an oil phase from a second side of the membrane element, wherein a pour point of the wax phase of the permeate product stream is higher than a pour point of the oil phase of permeate product stream; and d) separating a wax product from the wax phase of the permeate product stream.

Provided in one embodiment is a continuous process for converting waste plastic into recycle for polyethylene polymerization. The process comprises selecting waste plastics containing polyethylene and/or polypropylene, and passing the waste plastics through a pyrolysis reactor to thermally crack at least a portion of the polyolefin waste and produce a pyrolyzed effluent. The pyrolyzed effluent is separated into offgas, a pyrolysis oil and optionally pyrolysis wax comprising a naphtha/diesel fraction and heavy fraction, and char. The pyrolysis oil and wax is passed to a refinery FCC feed pretreater unit. A heavy fraction is recovered and sent to a refinery FCC unit, from which a C.sub.3 olefin/paraffin mixture fraction is recovered, which is passed to a steam cracker for ethylene production. In another embodiment, a propane fraction (C.sub.3) is recovered from a propane/propylene splitter and passed to the steam cracker.

Provided in one embodiment is a continuous process for converting waste plastic into recycle for polyethylene polymerization. The process comprises selecting waste plastics containing polyethylene and/or polypropylene, and passing the waste plastics through a pyrolysis reactor to thermally crack at least a portion of the polyolefin waste and produce a pyrolyzed effluent. The pyrolyzed effluent is separated into offgas, a pyrolysis oil and optionally pyrolysis wax comprising a naphtha/diesel fraction and heavy fraction, and char. The pyrolysis oil and wax is passed to a refinery FCC feed pretreater unit. A heavy fraction is recovered and sent to a refinery FCC unit, from which a C.sub.3 olefin/paraffin mixture fraction is recovered, which is passed to a steam cracker for ethylene production. In another embodiment, a propane fraction (C.sub.3) is recovered from a propane/propylene splitter and passed to the steam cracker.

Provided in one embodiment is a continuous process for converting waste plastic into recycle for polyethylene polymerization. The process comprises selecting waste plastics containing polyethylene and/or polypropylene, and passing the waste plastics through a pyrolysis reactor to thermally crack at least a portion of the polyolefin waste and produce a pyrolyzed effluent. The pyrolyzed effluent is separated into offgas, a pyrolysis oil and optionally pyrolysis wax comprising a naphtha/diesel fraction and heavy fraction, and char. The pyrolysis oil and wax is passed to a refinery FCC feed pretreater unit. A heavy fraction is recovered and sent to a refinery FCC unit, from which a C.sub.3 olefin/paraffin mixture fraction is recovered, which is passed to a steam cracker for ethylene production. In another embodiment, a propane fraction (C.sub.3) is recovered from a propane/propylene splitter and passed to the steam cracker.

Provided in one embodiment is a continuous process for converting waste plastic into recycle for polyethylene polymerization. The process comprises selecting waste plastics containing polyethylene and/or polypropylene, and passing the waste plastics through a pyrolysis reactor to thermally crack at least a portion of the polyolefin waste and produce a pyrolyzed effluent. The pyrolyzed effluent is separated into offgas, a pyrolysis oil and optionally pyrolysis wax comprising a naphtha/diesel fraction and heavy fraction, and char. The pyrolysis oil and wax is passed to a refinery FCC feed pretreater unit. A heavy fraction is recovered and sent to a refinery FCC unit, from which a C.sub.3 olefin/paraffin mixture fraction is recovered, which is passed to a steam cracker for ethylene production. In another embodiment, a propane fraction (C.sub.3) is recovered from a propane/propylene splitter and passed to the steam cracker.