Treatment of hydrocarbon streams, and in one non-limiting embodiment refinery distillates, with high pH aqueous reducing agents, such as borohydride, results in reduction of the sulfur compounds such as disulfides, mercaptans and thioethers that are present to give easily removed sulfides. The treatment converts the original sulfur compounds into hydrogen sulfide or low molecular weight mercaptans that can be extracted from the distillate with caustic solutions, hydrogen sulfide or mercaptan scavengers, solid absorbents such as clay or activated carbon or liquid absorbents such as amine-aldehyde condensates and/or aqueous aldehydes.

A method for washing an oligomerization reactor using by-product solvent recovered from the reactor can include: catalytically converting a monomer in a reactor section in a reaction mode in the presence of a catalyst to form a product stream comprising an oligomer, a by-product solvent, and a polymeric by-product; separating the product stream into a first fraction comprising the oligomer and a second fraction comprising a mixture of the by-product solvent and the polymeric by-product; and separating, in a thin film evaporator, the second fraction into a third fraction comprising the by-product solvent and a fourth fraction comprising the polymeric by-product.

Embodiments of the invention provide processes for catalytically converting oxygenates to hydrocarbon products having an increased C.sub.6-C.sub.8 aromatics content therein. Particular processes include (a) providing a first mixture comprising ≧10.0 wt. % of at least one oxygenate, based on the weight of the first mixture; (b) contacting the first mixture with a catalyst to convert the first mixture to a product stream including water, one or more hydrocarbons, hydrogen, and one or more oxygenates, wherein the catalyst comprises at least one molecular sieve and at least one element selected from Groups 2-14 of the Periodic Table and the hydrocarbons comprise ≧30.0 wt. % of aromatics, based on the weight of the hydrocarbons in the product stream; and (c) separating from the product stream at least one water-rich stream, at least one aromatic-rich hydrocarbon stream, and at least one aromatic-depleted hydrocarbon stream.

A method of producing aromatic hydrocarbons including: supplying a raw material stream to a C6 separation column, supplying an upper discharge stream from the C6 separation column to a first gasoline hydrogenation unit, and supplying a lower discharge stream from the C6 separation column to a C7 separation column; supplying an upper discharge stream from the C7 separation column to the first gasoline hydrogenation unit and supplying a lower discharge stream from the C7 separation column to a C8 separation column; separating benzene and toluene from a discharge stream from the first gasoline hydrogenation unit; removing a lower discharge stream from the C8 separation column and supplying an upper discharge stream from the C8 separation column to a second extractive distillation column; and separating styrene from a lower discharge stream from the second extractive distillation column and separating xylene from an upper discharge stream from the second extractive distillation column.

A process and system for separating butenes and butanes by extractive distillation using a polar solvent is disclosed. The process may include: contacting a hydrocarbon mixture including butanes and butenes with a lean solvent mixture in an extractive distillation column to form an enriched solvent fraction comprising butenes; recovering an overheads fraction comprising butanes and a bottoms fraction from the extractive distillation column; feeding the bottoms fraction to a stripper including a stripping section and a wash section; recovering the lean solvent mixture as a bottoms fraction and a stripper overheads fraction comprising butenes and water from the stripper; condensing the overheads fraction to form a water fraction and a product butenes fraction; feeding water as reflux to a top of the stripper wash section; feeding at least a portion of the condensed water fraction intermediate the top and bottom of the stripper wash section as a second reflux.

A process for treating effluent streams in a naphtha complex is described. One or more of the sour water stripping unit for the NHT sour water from the NHT, the amine treatment unit and the caustic treatment unit for the NHT stripper off-gas, the caustic scrubber unit or other chloride treatment unit for the off-gas from the C.sub.5-C.sub.6 isomerization zone and the C.sub.4 isomerization zone, and the caustic scrubber unit or other chloride treatment unit for the regenerator off-gas are replaced with a thermal oxidation system.

The present invention describes a process for obtaining para-xylene from a feedstock containing xylenes, ethylbenzene and C9+ hydrocarbons, said process comprising a single stage A of separation in a simulated moving bed carried out with a zeolite as adsorbent and a desorbent and making it possible to obtain at least three fractions, a fraction A1 comprising a mixture of para-xylene and of desorbent and two fractions A21, A22 comprising ethylbenzene (EB), ortho-xylene (OX) and meta-xylene (MX) and desorbent, said stage is carried out at a temperature between 20° C. and 250° C., under a pressure between the bubble pressure of the xylenes at the operating temperature and 2.0 MPa, and with a ratio by volume of the desorbent to the feedstock in the unit for separation 2 in a simulated moving bed is between 0.4 and 2.5, a stage B of fractionation by distillation in a 2-cut distillation column of the fractions A21 and A22 resulting from stage A, in which said fractions are introduced separately at distinct injection points, and makes it possible to obtain a fraction B2 containing ethylbenzene, ortho-xylene and meta-xylene, and a fraction B42 devoid of aromatic compounds having 8 carbon atoms and containing desorbent.

The present disclosure relates generally to processes and systems for the hydrodeoxygenation of an oxygenate feedstock that increases the conversion of oxygenates to hydrocarbons while avoiding detrimental effects resulting from increasing the severity of the hydrodeoxygenation reaction.

An apparatus for producing ethylene includes: a reactor; a first separation column, connected to the reactor; a second separation column, the upper part of the second separation column being connected to the bottom of the first separation column, and the top of the second separation column being connected to the lower part of the first separation column; a first condenser, an inlet of the first condenser being connected to the top of the first separation column, and an outlet of the first condenser being connected to the upper part of the first separation column; and a third separation column, used for receiving a second part of a first condensate from the condenser and separating the received part. A method for producing ethylene using the aforementioned apparatus is also described.

A substantially zero-carbon-emission (ZCE) process for making propylene polymers and copolymers including: converting alkanes to the olefin monomers ethylene, propylene, and butene or combinations thereof, using renewable electric power and scrubbing the stack gases from any fired heaters or boilers to remove carbon dioxide, in an oxidative-coupling of methane plant including the steps of passing alkanes through an ethylene plant while adding oxygen, passing a portion of the polymerization grade ethylene through a 2-butene plant, and passing the 2-butene stream and a portion of the polymerization grade ethylene stream through a propylene plant. The polymerization grade propylene is polymerized to produce isotactic homopolymer polypropylene, or ethylene-propylene random copolymer, or impact grade polypropylene containing ethylene-propylene rubber.