A method for preparing ethylene, including: passing a feed stream containing C1 and C2 hydrocarbon compounds through a first heat exchanger and feeding the feed stream passed through the first heat exchanger to a second gas-liquid separator; feeding a part of a bottom discharge stream of the second gas-liquid separator to a demethanizer, passing an overhead discharge stream of the second gas-liquid separator through a second heat exchanger, feeding the overhead discharge stream of the second gas-liquid separator passed through the second heat exchanger to a third gas-liquid separator; feeding a bottom discharge stream of the third gas-liquid separator to the demethanizer; feeding a bottom discharge stream of the demethanizer to a C2 separator; feeding an overhead discharge stream of the C2 separator to a second compressor; passing a part of a compressed discharge stream of the second compressor through the first heat exchanger and feeding the part of the compressed discharge stream of the second compressor passed through the first heat exchanger to the second compressor as a first circulation flow; passing a part of the compressed discharge stream of the second compressor through the second heat exchanger and feeding the part of the compressed discharge stream of the second compressor passed through the second heat exchanger to a first compressor as a second circulation flow; and feeding a compressed discharge stream of the first compressor to the second compressor, and an apparatus for preparing ethylene for implementing the same.

An integrated refinery process for removing mercaptans from a hydrocarbon stream containing mercaptans and converting by-product disulfide oil to useful products. The process includes introducing the hydrocarbon stream containing mercaptans into an extraction vessel containing an alkaline solution and passing the hydrocarbon stream through an extraction section of the extraction vessel which includes one or more liquid-liquid contacting decks for reaction to convert the mercaptans to alkali metal alkanethiolates. Further, the process includes withdrawing a hydrocarbon product stream free of mercaptans from the extraction vessel and recovering spent caustic containing alkali metal alkanethiolates from the extraction vessel. Additionally, the process includes subjecting the spent caustic containing alkali metal alkanethiolates to air oxidation to produce a by-product stream containing disulfide oils (DSO) and sulfides and processing the by-product stream in a steam cracking unit to produce a DSO free product stream.

According to one or more embodiments, presently disclosed are processes for producing petrochemical products from a hydrocarbon material. The process may include separating the crude oil into at least a lesser boiling point fraction and a greater boiling point fraction. At least 90 wt. % of the crude oil may be present in the combination of the greater boiling point fraction and the lesser boiling point fraction. The process may further include hydroprocessing the lesser boiling point fraction to form a first hydroprocessed effluent and hydroprocessing the greater boiling point fraction to form a second hydroprocessed effluent. The hydroprocessing of the lesser boiling point fraction may occur at a first pressure, the hydroprocessing of the lesser boiling point fraction may occur at a second pressure, and the second pressure may be at least 25 bar greater than the first pressure. The method may further include cracking at least a portion of the first hydroprocessed effluent and at least a portion of the second hydroprocessed effluent to form cracking reaction products.

Method for the simulated moving bed (SMB) separation of a feedstock (F), in which: at least one zone (1, 2, 3, 4) contains fewer than three beds, if the stream (D, E, F, R) delimiting said zone and situated upstream of said zone is injected or withdrawn at the plate P.sub.i via the bypass line L.sub.i/i+1, then the stream delimiting said zone and situated downstream of said zone is injected/withdrawn at the plate P.sub.j via the bypass line L.sub.j/j+1, and if the stream delimiting said zone and situated downstream of said zone is injected or withdrawn at the plate P.sub.i via the bypass line L.sub.i−1/i, then the stream delimiting said zone and situated upstream of said zone is injected/withdrawn at the plate P.sub.j via the bypass line L.sub.j−1/j.

Relatively low value disulfide oil (DSO) compounds produced as by-products of the mercaptan oxidation (MEROX) processing of refinery hydrocarbon streams, and oxidized disulfide oils (ODSO), are economically converted to value-added BTX by introducing the DSO and/or ODSO compounds as the feed to a fluidized catalytic cracking (FCC) unit and recovering the liquid products. The liquid FCC products are introduced as the feedstream to a selective naphtha hydrogenation and hydrotreating process for desulfurization and are then further separated in an aromatics extraction process for the recovery of BTX.

A system for scrubbing and monitoring H2S includes: a sample inlet valve that controls an input stream of the hydrocarbon gas from the gas canister; a first scrubber that removes a first portion of H2S from the input stream and that outputs a first stream with less H2S than the input stream; a second scrubber that removes a second portion of H2S from the first stream and that outputs a second stream with less H2S than the first stream; a H2S converter that converts all remaining H2S in the second stream into a di-ketone and that outputs an output stream with a concentration of the di-ketone; an optical detector that measures the concentration of the di-ketone in the output stream; and a processor that determines a concentration of H2S in the second stream based on the concentration of the di-ketone in the output stream.

Various illustrative embodiments of a system and process for recovering high-quality biomethane and carbon dioxide product streams from biogas sources and utilizing or sequestering the product streams are provided. The system and process synergistically yield a biomethane product which meets gas pipeline quality specifications and a carbon dioxide product of a quality and form that allows for its transport and sequestration or utilization and reduction in greenhouse gas emissions. The system and process result in improved access to gas pipelines for products, an improvement in the carbon intensity rating of the methane fuel, and improvements in generation of credits related to reductions in emissions of greenhouse gases.

A method and system for separating light hydrocarbons are disclosed, wherein the method comprises compression, cooling, absorption, desorption, rectification, cracking, and recycling cracked gas to the compression step.

Linear alpha olefins (LAOS) may be formed by oligomerization of ethylene in the presence of a Ziegler-type catalyst. The presence of trace water during oligomerization can result in unwanted formation of insoluble higher oligomers or polymer. Methods for limiting the presence of water during ethylene oligomerization reactions may include separating residual ethylene and 1-butene from an LAO product stream to form a higher LAO-enriched stream comprising C.sub.6+ LAOs, separating 1-hexene as an overhead stream from the higher-LAO enriched stream using a first distillation column, obtaining separated solvent as a side stream from the first distillation column or as a side stream from a first of one or more downstream distillation columns, and returning the separated solvent to a reactor in a recycled solvent stream. The recycled solvent stream passes through one or more driers before returning to the reactor.

A method for producing butenes by the dehydrogenation of n-butane includes dehydrogenating the n-butane in a dehydrogenation zone and contacting material from the dehydrogenation zone with a solvent that is more selective to dissolve n-butane than butenes. The resulting fluid from the contacting is subjected to extractive distillation to produce (1) a stream comprising a solution of the n-butane and solvent and (2) a stream comprising the butenes.