A method for quenching a pyrolysis product, including: supplying a discharge stream from a liquid decomposition furnace to a first quench tower; supplying an upper discharge stream from the first quench tower to a second quench tower; supplying a discharge stream from a first gas decomposition furnace to the second quench tower; and supplying a discharge stream from a second gas decomposition furnace to the second quench tower.

A method for producing a supercritical water (SCW)-treated product is provided. The method comprising the steps of introducing a crude oil stream and a water stream to a supercritical water process, wherein the crude oil stream can undergo conversion reactions to produce the supercritical water (SCW)-treated product, wherein the SCW-treated product includes an increased paraffin concentration as compared to crude oil stream. The method further includes the step of introducing the SCW-treated product to a steam cracking process, wherein the SCW-treated product can undergo conversion reactions to produce furnace effluent.

The present invention relates to a process for the production of ethylene-based polymers from waste plastics feedstocks comprising the steps in this order of: (a) providing a hydrocarbon stream A obtained by hydrotreatment of a pyrolysis oil produced from a waste plastics feedstock; (b) optionally providing a hydrocarbon stream B; (c) supplying a feed C comprising a fraction of the hydrocarbon stream A and optionally a fraction of the hydrocarbon stream B to a thermal cracker furnace comprising cracking coil(s); (d) performing a thermal cracking operation in the presence of steam to obtain a cracked hydrocarbon stream D; (e) supplying the cracked hydrocarbon stream D to a separation unit; (f) performing a separation operation in the separation unit to obtain a product stream E comprising ethylene; (g) supplying the product stream E to a polymerisation reactor; and (h) performing a polymerisation reaction in the polymerisation reactor to obtain an ethylene-based polymer; wherein in step (d): .Math. the coil outlet temperature is 2: 800 and:::; 870 C., preferably 2: 820 and:::; 870 C.; and .Math. the weight ratio of steam to feed C is >0.3 and <0.8.

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.

Processes for producing olefins include integration of steam cracking with a dual catalyst metathesis process. The processes include steam cracking a hydrocarbon feed to form a cracking reaction effluent containing butenes, separating the cracking reaction effluent to produce a cracking C4 effluent including normal butenes, isobutene, and 1,3-butadiene, subjecting the cracking C4 effluent to selective hydrogenation to convert 1,3-butadiene in the cracking C4 effluent to normal butenes, removing isobutene from a hydrogenation effluent to produce a metathesis feed containing normal butenes, and contacting the metathesis feed with a metathesis catalyst and a cracking catalyst directly downstream of the metathesis catalyst to produce a metathesis reaction effluent. Contacting with the metathesis catalyst causes metathesis of normal butenes to produce ethylene, propene, and C5+ olefins, and contacting with the cracking catalyst causes C5+ olefins produced through metathesis to undergo cracking reactions to produce additional propene, ethylene, or both.

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.

The delayed coking method includes directing a heated secondary feedstock, which contains heated primary feedstock and recirculate, from a reaction furnace to a coking chamber. Vapor-liquid coking products formed in the coking chamber are then directed to a fractionation column, which fractionates hydrocarbon gas, gasoline, light and heavy gas oils, and bottom residues. Heavy gas oil from the fractionation column is directed to a thermal cracking furnace, the products of which are cooled by cooled light gas oil and directed to an evaporator for separation. In the evaporator, gases and light boiling products are removed by evaporation and returned to the fractionation column, and the remaining distillate cracking residue is separated and used as a component of the recirculate, along with bottom residues from the fractionation column. The resulting process produces high quality and high yield needle and anode cokes.

Disclosed are methods and modular devices for processing hydrocarbon feedstocks. In particular, the methods and modular devices disclosed herein provide for increasing the amounts of light fractions obtainable from a hydrocarbon feedstock.

Processes and systems for in situ heating of a heavy pitch within a coking drum are disclosed. The in situ heating may provide for processing of neat pitch, improving coking operations and increasing liquid yield.

A method of steam cracking using a steam cracking system includes a first steam cracking furnace unit or a plurality of first steam cracking furnace units and a second steam cracking furnace unit or a plurality of second steam cracking furnace units. The first steam cracking furnace unit or each of the plurality of first steam cracking furnace units comprises one or more fired steam cracking furnaces. The second steam cracking furnace unit or each of the plurality of second steam cracking furnace units comprises one or more electric steam cracking furnaces. The first steam cracking furnace unit or each of the plurality of first steam cracking furnace units further includes means for preheating at least a part of combustion air provided to its fired steam cracking furnace or furnaces to a temperature level of at least 100? C.