A process for preparing butadiene from n-butenes, comprising the steps of: A) providing an input gas stream comprising n-butenes; B) feeding the input gas stream comprising n-butenes and a gas containing at least oxygen into at least one oxidative dehydrogenation zone and oxidatively dehydrogenating n-butenes to butadiene, giving a product gas stream; Ca) cooling the product gas stream by contacting with a circulating cooling medium in at least one cooling zone; Cb) compressing the cooled product gas stream in at least one compression stage, giving at least one aqueous condensate stream c1 and one gas stream c2; D) removing uncondensable and low-boiling gas constituents comprising oxygen and low-boiling hydrocarbons as gas stream d2 from the gas stream c2 by absorbing the C.sub.4 hydrocarbons in an absorbent, giving an absorbent stream laden with C.sub.4 hydrocarbons and the gas stream d2, and then desorbing the C.sub.4 hydrocarbons from the laden absorbent stream, giving a C.sub.4 product gas stream d1; E) separating the C.sub.4 product stream d1 by extractive distillation; F) distilling the stream e1 into a stream f1 consisting essentially of the selective solvent and a stream f2 comprising butadiene; G) removing a portion of the aqueous phase of the cooling medium which circulates in step Ca) as aqueous purge stream g; H) distillatively separating the aqueous purge stream g into a fraction h1 and a fraction h2 depleted of organic constituents.

A process to convert paraffinic feedstocks into renewable poly-alpha-olefins (PAO) basestocks. In a preferred embodiment of the invention, renewable feed comprising triglycerides and/or free fatty acids are hydrotreated producing an intermediate paraffin feedstock. This paraffin feedstock is thermally cracked into a mixture of olefins and paraffins comprising linear alpha olefins. The olefins are separated and the un-reacted paraffins are recycled to the thermal cracker. Light olefins preferably (C2-C6) are oligomerized with a surface deactivated zeolite producing a mixture of slightly branched oligomers comprising internal olefins. The heavier olefins (C6-C16) are oligomerized, preferably with a BF3 catalyst and co-catalyst to produce PAO products. The oligomerized products can be hydrotreated and distilled together or separate to produce finished products that include naphtha, distillate, solvents, and PAO lube basestocks.

The present invention relates to a device and a process for converting aromatic compounds, wherein: methyl-substituted aromatic compounds are extracted from a hydrocarbon feedstock (2) comprising aromatic compounds having at least 8 carbon atoms in an extraction unit (1), to produce at least one effluent enriched in methyl-substituted aromatic compounds (3A, 3B) and an effluent depleted in methyl-substituted aromatic compounds (4); and C2+ alkyl chains of the aromatic compounds of the depleted effluent (4) are converted into methyl groups in a hydrogenolysis unit (5) placed downstream of the extraction unit (1), to produce a hydrogenolysis effluent enriched in methyl-substituted aromatic compounds (7).

In an FCC apparatus in which swirl arms are used to discharge gas and catalyst from a riser, the swirling movement of the catalyst particles is inhibited while impeding the catalyst particles and gaseous products from exiting the disengaging chamber and entering a reactor annulus. The catalyst particles and gaseous products pass through a tunnel comprising a vertical wall to enter the reactor annulus. The vertical wall presents a face that is opposed to the angular direction in which the catalyst particles and gaseous products swirl. A baffle may be located at the intersection between the reactor annulus and the disengaging chamber to deflect catalyst laterally in a stripping section after exiting the reactor annulus. The baffle may be equipped with openings to fluidize the large proportion of catalyst passing over this region to effectively pre-strip this catalyst before it enters a stripping section.

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.

Processes for treating effluent streams in alkylation processes are described. One or more process streams rom HF alkylation processes, H.sub.2SO.sub.4 alkylation processes, or ionic liquid alkylation processes can be thermally oxidized in a thermal oxidation system. The thermal oxidation system can replace at least one of the caustic wash unit, the neutralization unit, and the acid gas treatment unit.

Improved systems and methods for producing propylene from olefins including isobutylene is disclosed. The improvements combine streams containing co-produced 1-butene, 2-butene, butadiene, and heavy olefins (C5+) exiting both a metathesis reactor and a skeletal isomerization reactor in a gasoline fractionation tower to remove the heavy olefins. The C4-containing distillate from the gasoline fractionation tower is then fed to a hydroisomerization unit to form mono-olefins and 2-butene. The resulting 2-butene rich stream can then be utilized in metathesis reactions to increase the production of propylene while increasing the lifetime of the metathesis catalyst.

A propane dehydrogenation and propylene purification process in which a stream comprising propylene, propane, and methyl acetylene and propadiene (MAPD) is mixed with a hydrogen stream then reacted in at least three distinct reaction zones in a hydrogenation reactor system where MAPD is hydrogenated by a high-selectivity hydrogenation catalyst in a first reaction zone, and a second and a third reaction zones each have a low-selectivity hydrogenation catalyst to remove unreacted hydrogen. The outlet stream leaving the hydrogenation reactor system is MAPD-free and can be fed to a splitter column, which now mainly serves to separate propylene from propane. Various embodiments of reaction zone arrangements in a single or multiple reactors are also provided.

A propane dehydrogenation and propylene purification process in which a stream comprising propylene, propane, and methyl acetylene and propadiene (MAPD) is mixed with a hydrogen stream then reacted in at least three distinct reaction zones in a hydrogenation reactor system where MAPD is hydrogenated by a high-selectivity hydrogenation catalyst in a first reaction zone, and a second and a third reaction zones each have a low-selectivity hydrogenation catalyst to remove unreacted hydrogen. The outlet stream leaving the hydrogenation reactor system is MAPD-free and can be fed to a splitter column, which now mainly serves to separate propylene from propane. Various embodiments of reaction zone arrangements in a single or multiple reactors are also provided.

A process for removing light components from an ethylene stream may include providing a dried ethylene stream containing ethylene, ethane, CO, CO.sub.2, H.sub.2, CH.sub.4, and C.sub.3+ hydrocarbons. The process may include sending the dried ethylene stream to a stripper to produce an overhead stream containing ethylene, CO, H.sub.2 and CH.sub.4, and a bottom stream containing ethylene, ethane, CO.sub.2, and C.sub.3+ hydrocarbons. The gaseous phase on top of the stripper may be condensed in a heat exchanger cooled by a refrigerant stream to get a first gaseous phase and a first liquid phase. The first gaseous phase may be condensed in a heat exchanger cooled by liquid ethane or liquid ethylene to get a second gaseous phase containing ethylene CO, H.sub.2 and CH.sub.4 and a second liquid phase. The first and second liquid phases may be the reflux of the stripper.