Abstract: Systems and a method for manufacturing a base stock from a hydrocarbon stream are provided. An example method includes cracking the hydrocarbon stream to form a raw hydrocarbon stream, separating an ethylene stream from the raw hydrocarbon stream and oligomerizing the ethylene stream to form a raw oligomer stream. A light olefinic stream is distilled from the raw oligomer stream and linear alpha olefins are recovered from the light olefinic stream. A heavy olefinic stream is distilled from the raw oligomer stream. The heavy olefinic stream is hydro-processed to form a hydro-processed stream. The hydro-processed stream is distilled to form the base stock.

Abstract: Systems and a method for manufacturing a base stock from a light gas stream are provided. An example method includes oxidizing the light gas stream to form a raw ethylene stream. Water is removed from the raw ethylene stream, and carbon monoxide in the raw ethylene stream is oxidized. Carbon dioxide is separated from the raw ethylene stream, and the raw ethylene stream is oligomerized to form a raw oligomer stream. A light olefinic stream is distilled from the raw oligomer stream and a light alpha olefin is recovered from the light olefinic stream. A heavy olefinic stream is distilled from the raw oligomer stream. The heavy olefinic stream is hydro-processed to form a hydro-processed stream. the hydro-processed stream is distilled to form the base stock.

Abstract: This invention relates to a polyolefin comprising one or more aromatic moieties according to the following formulae: wherein the PO is the residual portion of a vinyl terminated macromonomer (VTM) having had a terminal unsaturated carbon of an allylic chain and a vinyl carbon adjacent to the terminal unsaturated carbon; Ar is attached to the terminal portion of the VTM to provide PO—Ar or at the vinylidene carbon of the VTM to provide PO—CH(Ar)CH3; and Ar is a substituted or unsubstituted aromatic group.

Abstract: A hydrocarbon conversion process is described. The process includes contacting a hydrocarbon feed with an acidic catalyst under hydrocarbon conversion conditions in a hydrocarbon conversion zone. The hydrocarbon feed reacts to form a mixture comprising reaction products, the acidic catalyst, and deactivated acidic catalyst containing conjunct polymer. The mixture is separated into at least two streams, a first stream comprising the reaction products and a second stream comprising the deactivated acidic catalyst. The reaction products are recovered. The deactivated acidic catalyst is contacted with at least one silane or borane compound in a regeneration zone under regeneration conditions, the conjunct polymer reacting with the at least one silane or borane compound resulting in a catalyst phase and an organic phase containing the conjunct polymer and at least one silyl or boryl compound.

Abstract: A method of crystallizing a crystalline molecular sieve having a pore size in the range of from about 2 to about 19 ?, said method comprising the steps of (a) providing a mixture comprising at least one source of ions of tetravalent element (Y), at least one hydroxide source (OH?), and water, said mixture having a solid-content in the range of from about 15 wt. % to about 50 wt. %; and (b) treating said mixture to form the desired crystalline molecular sieve with stirring at crystallization conditions sufficient to obtain a weight hourly throughput from about 0.005 to about 1 hr?1, wherein said crystallization conditions comprise a temperature in the range of from about 200° C. to about 500° C. and a crystallization time less than 100 hr.

Abstract: A process for alkylating an aromatic compound comprising reacting at least one aromatic compound with a mixture of olefins selected from olefins having from about 8 to about 100 carbon atoms, in the presence of an acidic ionic liquid catalyst, wherein the resulting product comprises at least about 50 weight percent of a 1, 2, 4 tri-substituted aromatic compound or a 1, 2, 3 tri-substituted aromatic compound or mixtures thereof.

Abstract: An alkylated hydroxyaromatic compound is disclosed which is prepared by reacting at least one hydroxyaromatic compound with at least one branched olefinic propylene oligomer having from about 20 to about 80 carbon atoms in the presence of an acid catalyst, wherein the at least one branched olefinic propylene oligomer is substantially free of any vinylidene content. The alkylated hydroxyaromatic compound has been determined to be substantially free of endocrine disruptive chemicals when the effects were quantified on pubertal development and thyroid function in the intact juvenile female rat.

Abstract: A method of producing a linear alkylbenzene that includes introducing an olefin into an aromatic stream to form a mixture; processing the mixture in a shear device at a shear rate greater than about 20,000 s?1 to form a dispersion; and reacting the dispersion in the presence of a catalyst in a reactor vessel to form a linear alkylbenzene product stream, wherein the reactor vessel is maintained at a bulk reaction temperature in the range of about 0° C. to about 60° C.

Abstract: Methods and systems for the production of linear alkylbenzenes are described herein. The methods and systems incorporate the novel use of a high shear device to promote dispersion and mixing of one or more olefins (e.g. propylene) with an aromatic. The high shear device may allow for lower reaction temperatures and pressures and may also reduce reaction time with existing catalysts.

Abstract: A process for alkylating an aromatic compound comprising reacting at least one aromatic compound with a mixture of olefins having from about 8 to about 100 carbon atoms, in the presence of a strong acid catalyst wherein the resulting product comprises at least about 60 weight percent of a 1,2,4 tri-alkylsubstituted aromatic compound.

Abstract: A process for alkylating an aromatic compound containing no hydroxyl groups comprising reacting at least one non-hydroxyl containing aromatic compound with at least one olefinic oligomer in the presence of an acidic ionic liquid catalyst, wherein the olefinic oligomer has a carbon range of from about C12 to about C70 and is synthesized by oligomerizing at least one monoolefin monomer in the presence of an acidic ionic liquid catalyst.

Abstract: In a process for preparing alkylaryl compounds by reacting a C10-14-monoolefin mixture with an aromatic hydrocarbon in the presence of an alkylation catalyst to form alkyl aromatic compounds and if appropriate subsequently sulfonating and neutralizing the resulting alkylaryl compounds, in the C10-14-monoolefins, on average, more than 0% and up to 100% of methyl branches are present in the longest carbon chain and fewer than 50% of the methyl branches are in the 2-, 3- and 4-position, calculated starting from the chain ends of the longest carbon chain.

Abstract: The preparation of alkylaryl compounds takes place, inter alia, by a1) preparation of a C4 -olefin mixture from LPG, LNG or MTO streams, b 1) reaction of the C4-olefin mixture obtained in this way over a metathesis catalyst for the preparation of an olefin mixture comprising 2-pentene and/or 3-hexene, and optional removal of 2-pentene and/or 3-hexene, c1) dimerization of the 2-pentane and/or 3-hexene obtained in stage b1) over a dimerization catalyst to give a mixture comprising C10-12-olefins, and optional removal of the C10-12- olefins, d1) reaction of the C10-12-olefin mixtures obtained in stage a1) with an aromatic hydrocarbon in the presence of an alkylation catalyst to form alkylaromatic compounds, it being possible to add additional linear olefins prior to the reaction.

Abstract: A process for desulphurizing a gasoline cut containing olefins, sulphur-containing compounds and optionally molecules belonging to C3 and C4 cuts comprises at least a first step A for contacting said gasoline cut with an acidic resin having an acid capacity of more than 4.7 equivalents per kg and a specific surface area of less than 55 m2/g, and a second step B for fractionation of the mixture from the first step.

Abstract: A process for alkylating an aromatic compound containing no hydroxyl groups comprising reacting at least one non-hydroxyl containing aromatic compound with at least one olefinic oligomer in the presence of an acidic ionic liquid catalyst, wherein the olefinic oligomer has a carbon range of from about C12 to about C70 and is synthesized by oligomerizing at least one monoolefin monomer in the presence of an acidic ionic liquid catalyst.

Abstract: A method of alkylating aliphatic or aromatic hydrocarbons with olefins using solid hydrogen fluoride-equivalent catalysts is described. Preferred catalysts comprise solid polymeric onium polyhydrogen fluoride complexes.

Abstract: A side-chain of a substituted aromatic compound is alkylated by reacting the aromatic compound with an alkylating agent in the presence of a catalyst. The catalyst comprises a restructured smectite clay to which basic ions are incorporated by ion-exchange. The restructuring of the smectite clay is carried out by acid-treating the clay prior to ion-exchange.

Abstract: This invention is directed to a fluorine-containing mordenite catalyst and use thereof in the manufacture of alkylbenzene (LAB) by alkylation of benzene with an olefin. The olefin may have from about 10 to 14 carbons. The fluorine-containing mordenite is prepared typically by treatment with an aqueous hydrogen fluoride solution. The benzene alkylation may be conducted using reactive distillation. This invention is also directed to a process for production of LAB having a high 2-phenyl isomer content by use of the fluorine-containing mordenite in conjunction with a conventional solid LAB alkylation catalyst. The two catalysts may be used in a mixed catalyst bed or may be packed in series, with the relative proportions being adjusted to provide a desired 2-phenyl isomer content of in the final product.

Abstract: The present invention is a process for producing phenyl-alkanes by paraffin adsorptive separation followed by paraffin dehydrogenation and then by alkylation of a phenyl compound by a lightly branched olefin. The adsorptive separation step employs a silicalite adsorbent and, as the desorbent, a C5-C8 linear paraffin, a C5-C8 cycloparaffin, a branched paraffin such as isooctane, or mixtures thereof. The effluent of the alkylation zone comprises paraffins that are recycled to the adsorptive separation step or to the dehydrogenation step. This invention is also a process that sulfonates phenyl-alkanes having lightly branched aliphatic alkyl groups that to produce modified alkylbenzene sulfonates. In addition, this invention is the compositions produced by these processes, which can be used as detergents having improved cleaning effectiveness in hard and/or cold water while also having biodegradability comparable to that of linear alkylbenzene sulfonates, as lubricants, and as lubricant additives.

Abstract: A process for the preparation of at least one spherically shaped porous microcomposite is provided which microcomposite comprises a perfluorinated ion-exchange polymer containing pendant sulfonic and/or carboxylic acid groups entrapped within and highly dispersed throughout a network of inorganic oxide, wherein the weight percentage of the perfluorinated ion-exchange polymer in the microcomposite is from about 0.1 to about 90 percent, and wherein the size of the pores in the microcomposite is about 0.

Abstract: A process for the preparation of at least one spherically shaped porous microcomposite is provided which microcomposite comprises a perfluorinated ion-exchange polymer containing pendant sulfonic and/or carboxylic acid groups entrapped within and highly dispersed throughout a network of inorganic oxide, wherein the weight percentage of the perfluorinated ion-exchange polymer in the microcomposite is from about 0.1 to about 90 percent, and wherein the size of the pores in the microcomposite is about 0.

Abstract: A fraction of low bromine number mainly containing a styrenic compound/aromatic compound adduct can be attained, by feeding reaction materials of a styrenic compound and an aromatic compound to a fixed-bed flow reactor packed with a solid acid catalyst in a liquid phase at a temperature in the range of 40 to 350° C. to form a styrenic compound/aromatic compound adduct, in which (1) the feed of reaction materials is stopped when the bromine number of the above fraction is increased up to a predetermined value, (2) a saturated aromatic hydrocarbon having a mean value of the proportion of aromatic ring carbons in a molecule of 55% or more is fed to the reactor in a liquid phase at a temperature higher by 5 to 150° C. than that of the reaction mixture just before the above stopping, and (3) the feed of reaction materials is then restarted to obtain the fraction.

Abstract: This invention concerns fluorine-modified perfluorinated ion-exchange microcomposites, comprising a perfluorinated ion-exchange polymer containing pendant sulphonic acid groups and/or carboxylic acid groups, entrapped within and highly dispersed throughout a network of inorganic oxide, said network having a plurality of fluoride groups bonded thereto; processes for their preparation and their use as catalysts in chemical processes such as alkylation of aromatic compounds.

Abstract: Detergent-quality linear alkylaromatics are recovered from an alkylation reactor effluent containing polymeric byproducts, such as dimers and trimers of the olefinic feedstock. The effluent stream passes to another reactor operating at a higher temperature than the first reactor. Heavy alkylate is separated from the detergent-quality linear alkylaromatics by conventional separation methods such as distillation. This invention decreases the concentration of polymeric byproducts in the linear alkylaromatics. The benefits of this invention include a higher linearity and/or a lower bromine index in the detergent-quality linear alkylaromatic product, as well as a lower color after sulfonation of the linear alkylbenzene sulfonate.

Abstract: This invention is directed to a fluorine-containing mordenite catalyst and use thereof in the manufacture of linear alkylbenzene (LAB) by alkylation of benzene with an olefin. The paraffin may have from about 10 to 14 carbons. The fluorine-containing mordenite is prepared typically by treatment with an aqueous hydrogen fluoride solution. The benzene alkylation may be conducted using reactive distillation. This invention is also directed to a process for production of LAB having a high 2-phenyl isomer content by combining LAB product from the fluorine-containing mordenite product from a conventional LAB alkylation catalyst such as hydrogen fluoride.

Abstract: This invention is directed to a fluorine-containing mordenite catalyst and use thereof in the manufacture of linear alkylbenzene (LAB) by alkylation of benzene with an olefin. The olefin may have from about 10 to 14 carbons. The fluorine-containing mordenite is prepared typically by treatment with an aqueous hydrogen fluoride solution. The benzene alkylation may be conducted using reactive distillation. This invention is also directed to a process for production of LAB having a high 2-phenyl isomer content by use of the fluorine-containing mordenite in conjunction with a conventional solid LAB alkylation catalyst. The two catalysts may be used in a mixed catalyst bed or may be packed in series, with the relative proportions being adjusted to provide a desired 2-phenyl isomer content of in the final product.

Abstract: This invention relates to a process for the alkylation of aromatics by reacting an aromatic hydrocarbon with an olefin in the presence of an ionic liquid comprising (a) a compound of the formula R.sub.n MX.sub.3-n wherein R is a C1-C6 alkyl radical, M is aluminium or gallium, X is a halogen atom and n is 0, 1 or 2 and, (b) a hydrocarbyl substituted imidazolium halide or a hydrocarbyl substituted pyridinium halide wherein at least one of the said hydrocarbyl substituents in the imidazolium halide is an alkyl group having 1-18 carbon atoms. The process allows ready separation of reaction products from the ionic liquid and improves selectivity to alkylated products.

Abstract: A low temperature molten ionic liquid composition comprising a mixture of a metal halide and an alkyl-containing amine hydrohalide salt can be used in linear alkylbenzene formation. The metal halide is a covalently bonded metal halide which can contain a metal selected from the group comprised of aluminum, gallium, iron, copper, zinc, and indium, and is most preferably aluminum trichloride. The alkyl-containing amine hydrohalide salt may contain up to three alkyl groups, which are preferably lower alkyl, such as methyl and ethyl.

Abstract: A process is disclosed for the production of alkylaromatic compounds employing olefinic liquid from thermally or catalytically cracked plastics as alkylating agent. The process comprises contacting a feedstream comprising alkylatable aromatics and the olefinic liquid with acidic alkylation catalyst under alkylation conditions in an alkylation zone; and recovering an effluent stream comprising alkylaromatic compounds. The alkylation can be performed with the product of plastics pyrolysis or with non-degraded plastic feedstock in-situ with thermal/catalytic degradation of the plastic.

Abstract: A process for reducing the mutagenicity of a polynuclear aromatic containing material containing from three to seven fused aromatic rings, especially a hydrocarbon refinery stream. The process reduces the initial mutagenicity index to a lower value by alkylating the compound with an alkylating agent which introduces an alkyl substituent having from three to five carbon atoms into the aromatic compound in the presence of an acid catalyst under alkylation conditions.

Abstract: A zeolite, designated NU-85, is an intergrowth of zeolites EU-1 and NU-87. The zeolite is a useful catalyst in a wide variety of hydrocarbon conversion reactions including isomerisation and alkylation.

Abstract: Process for the preparation of linear alkylbenzenes, wherein the benzene is reacted, in the presence of aluminum chloride or aluminum in powder form, with a mixture composed of C.sub.7 -C.sub.20 n-olefins and C.sub.7 -C.sub.20 chloroparaffins, with a molar ratio n-olefins/chloroparaffins between 70:30 and 99:1.

Abstract: A fluorided silica-alumina catalyst, particularly one with a silica:alumina ratio in the range of 1:1-9:1 containing from 1 to 6 weight percent fluoride, is particularly effective in the liquid phase alkylation of benzene by linear olefins to produce linear alkyl benzenes at temperatures no greater than 140.degree. C. These catalysts also are effective in the liquid phase alkylation of alkylatable aromatics generally with a variety of alkylating agents, including olefins, alcohols, and alkyl halides.

Abstract: Silica-aluminas having a sodium content less than about 0.1 weight percent show increased stability when used as a catalyst for the alkylation of aromatic compounds. Where such silica-aluminas are used as the catalyst in detergent alkylation their increased stability permits continuous alkylation to be performed at lower temperatures, as a result of which the detergent alkylate product shows an incrementally higher linearity. Fluorided silica-aluminas having a sodium content of under 0.05 weight percent are particularly advantageous.

Abstract: A fluorided silca-alumina catalyst, particularly one with a silica:alumina ratio in the range of 1:1-9:1 containing from 1 to 6 weight percent fluoride, is particularly effective in the liquid phase alkylation of benzene to produce linear alkyl benzenes at temperatures no greater than 140.degree. C. Conversions in excess of 98% with selectivity exceeding 85% and linearity exceeding 90% may be achieved readily.

Abstract: It is disclosed that aromatic compounds can be alkylated with mono-olefinic HVI-PAO dimer in contact with an acidic catalyst to produce novel alkylated aromatic compositions. It has been found that the novel HVI-PAO dimer alkylated aromatic compositions exhibit an extraordinary combination of properties relating to low viscosity with high viscosity index and low pour point which renders them very useful as lubricant basestock. Further, it has been found that the novel alkylaromatic compositions of the present invention show improved oxidative stability. Depending upon the substituent groups on the aromatic nucleus, useful lubricant additives can be prepared for improved antiwear, antioxidant and other properties. HVI-PAO dimer is prepared as a product or by-product from 1-alkene oligomerization using reduced chromium oxide on solid support.

Abstract: Aromatic hydrocarbons are alkylated with relatively long chain alkylating agents, e.g., C.sub.8 + olefins, at mole ratio of aromatic to alkylating agent of not greater than about 5 in the presence of, as catalyst, a Lewis acid-promoted amorphous, porous inorganic oxide such as silica to provide long chain alkyl aromatic products which are useful, inter alia, as lubricating oil stocks.

Abstract: A method for preparation of aryl-substituted aliphatic hydrocarbons is disclosed. The method comprises reacting in the presence of a solid superacid resin catalyst an unsaturated aliphatic hydrocarbon in liquid form with an aromatic hydrocarbon that is susceptible to Friedel-Crafts reaction. The reaction between the liquid unsaturated aliphatic hydrocarbon and the aromatic hydrocarbon produces a reaction product comprising an aryl-substituted aliphatic hydrocarbon.

Abstract: Aromatic hydrocarbons are alkylated with relatively long chain alkylating agents, e.g., C.sub.6 + olefins, in the presence of, as catalyst, certain Lewis acid-promoted zeolites to provide long chain aromatic products which are useful, inter alia, as lubricating oil stocks.

Abstract: A process for the production of hydrocarbon white oil by means of hydrogenating a heavy aromatic alkylate is disclosed. The process is characterized in that its feedstock is a previously undesired heavy hydrocarbon byproduct of aromatic alkylation. A white oil derived from such a process has good color and odor properties and results in a superior white oil lubricant.

Abstract: An improved process for the production of alkylaromatic hydrocarbons is disclosed. Paraffinic hydrocarbons are dehydrogenated to yield an olefin-containing stream, which is later charged to an alkylation zone for reaction with an aromatic hydrocarbon in the presence of a solid alkylation catalyst. The olefin-containing stream is first passed through a selective hydrogenation zone in which diolefins are converted to monoolefins by contact with a selective catalyst. This increases the yield and the quality of the product alkylate by greatly reducing the production of biphenyl compounds and oligomers in the alkylation zone. Process efficiency is improved by passing unconverted paraffinic and monoolefinic hydrocarbons from the alkylation zone through another hydrogenation zone for the saturation of monoolefinic hydrocarbons and recycling the saturated stream to the dehydrogenation zone.

Abstract: A process for the production of 2,6-diisopropylnaphthalene is disclosed wherein an isopropylation reaction mixture containing isopropylated naphthalenes is subjected to transalkylation with a triisopropylnaphthalene-containing mixture to obtain a mixture containing mono-, di- and tri-isopropylnaphthalenes which is then separated into a first fraction containing monisopropylnaphthalenes, a second fraction containing diisopropylnaphthalenes and a third fraction containing triisopropylnaphthalenes. The first and third fractions are recycled to the above system, while the second fraction is subjected to separation treatments for the recovery of 2,6-diisopropylnaphthalene. The second fraction from which 2,6-diisopropylnaphthalene has been removed is subjected to transalkylation with naphthalene to obtain a monoisopropylnaphthalene-rich mixture which is to be fed to the isopropylation step.

Abstract: A process for producing an alkylated aromatic product having high selectivity to the thermodynamically preferred isomer by contacting meta-xylene and a C.sub.13 to C.sub.20 alpha-olefinic compound at a reaction temperature of about 40.degree. to about 80.degree. C. in the presence of a catalyst comprising an aluminum halide and elemental iodine.

Abstract: This invention relates to a catalyst composition prepared by reacting in a hydrocarbon solvent a molybdenum or tungsten halide with diethylaluminumtriethylsilaneolate. Preferably the halide is tungsten hexachloride. The instant compositions are particularly useful for the alkylation of benzene and lower-alkyl benzenes with detergent range olefins.

Abstract: A method for producing arylethylene comprising four steps of: (I) bringing 1,1-diarylethane into contact with an acid catalyst in the presence of an inert gas to crack said compound into arylethylenes and alkylbenzenes; (II) separating the reaction mixture obtained in the above cracking step (I) into at least a fraction mainly containing 1,1-diarylethane; (III) bringing said fraction mainly containing 1,1-diarylethane into contact with hydrogen gas in the presence of a hydrogenation catalyst; and (IV) re-cracking hydrogenated fraction obtained in the preceding hydrogenation step (III) by bringing it into said cracking step (I).Particularly, this method is useful for producing p-isobutylstyrene which is a starting material for preparing a valuable medicine of ibuprofen.

Abstract: A method for producing p-alkylstyrene which is characterized in that side reaction scarcely occurs, catalyst and unreacted material are easily recovered for the reuse, the p-position selectivity is excellent and yield of aimed product is high. In the method, monoalkylbenzene having an alkyl group with 3 or more carbon atoms is reacted with acetaldehyde in the presence of hydrogen fluoride catalyst under the conditions of a temperature of 0.degree. C. or lower, a molar ratio of 2 to 100 in "alkylbenzene/acetaldehyde", the other molar ratio of 1.7 to 300 in "hydrogen fluoride/acetaldehyde", the proportion of hydrogen fluoride to the sum of hydrogen fluoride and water in the reaction system of 65% by weight or higher, and the concentration of acetaldehyde in the reaction system of 1.0% by weight or lower to obtain 1,1-bis(p-alkylphenyl)ethane, and then subjecting it to catalytic cracking at a temperature in the range of 200.degree. to 650.degree. C. in the presence of an acid catalyst.

Abstract: An improved process for producing a mono alkyl aromatic by reacting a mono nuclear aromatic compound and an alkylating agent under alkylation conditions to produce the reaction product comprising unreacted mono nuclear aromatic compound, alkane, mono alkyl aromatic, dialkyl aromatic and by-products, treating the reaction product to remove unreacted mono nuclear aromatic compound, free paraffin, and produce a crude product stream containing mono alkyl aromatic, dialkyl aromatic and by-products, separating the majority of the mono alkyl aromatic from the crude product stream to produce a higher boiling fraction containing a minor amount of mono alkyl aromatic, dialkyl aromatic and by-products, and separating the higher boiling fraction into a recycle stream containing mono alkyl aromatic and a by-product stream substantially free of mono alkyl aromatic, and introducing the recycle stream into the alkylation reaction.

Abstract: A thermal medium oil comprising at least one monosubstituted naphthalene derivative such as .beta.-(1,1-dimethyloctyl) naphthalene, .beta.-(1,1-dimethylhexyl) naphthalene and 2-t.-amylnaphthalene.

Abstract: This invention provides a catalyst product for hydrocarbon conversion reactions and a method for reacting hydrocarbons employing such catalyst product. The catalyst product is a composite of a perfluorinated polymersulfonic acid and an ion-stabilizing agent such as hexafluoroisopropanol or trifluoroacetic acid. The composite catalyst has a significantly higher Bronsted acidity than the perfluorinated polymersulfonic acid. When the catalyst composite is used to catalyze the alkylation of toluene with 1-hexene, for example, the rate of alkylation is from about 20 to 30 times greater than using the perfluorinated polymersulfonic acid alone.

Abstract: An improved process for the production of alkylaromatic hydrocarbons is disclosed. Paraffinic hydrocarbons are dehydrogenated to yield an olefin-containing stream, which is later charged to an alkylation zone for reaction with an aromatic hydrocarbon. The olefin-containing stream is first passed through a selective hydrogenation zone in which diolefins are converted to monoolefins by contact with a selective catalyst. This increases the yield and the quality of the product alkylate by greatly reducing the production of biphenyl compounds and oligomers in the alkylation zone. The selective hydrogenation zone is located between the vapor-liquid separator and stripper column of the dehydrogenation zone.