Abstract: A C3 hydrocarbon fractionation system includes: a) a unit for providing a feed containing mainly propane and propylene, b) a C3 fractionation column for separating the feed to provide a top product richer in propylene than the feed and a bottom product leaner in propylene than the feed, wherein the bottom product comprises at least 50 wt % of propylene and c) a cumene production unit comprising an alkylation reactor for producing cumene from a propylene feed and a benzene feed, wherein the propylene feed comprises the bottom product of the C3 fractionation column.

Abstract: A process for reducing the benzene content of gasoline stream, such as a reformate or light naphtha, comprises alkylating the gasoline stream in a reaction zone with an olefin alkylating agent. A paraffinic stream comprising C5 to ClO paraffins is fed to the inlet of the alkylation reaction zone.

Abstract: In a method for cleaning an absorptive polyester, the polymer is dissolved in a first solvent (12) and subsequently the polymer solution is brought into tight contact with a second solvent (41) in a turbulent shear field under the influence of strong shear forces. Here, the second solvent (41) represents a non-solvent for the absorptive polyester and is mixable with the first solvent (12) to an unlimited extent. Subsequently, the polymer suspension resulting from the addition of the second solvent (41) is conveyed onto or into a rotating, cylindrical screen body (71) of a drum shear screen (70) and then the moist polymer mass is removed from the screen body (71) and subsequently dried. The method is suitable for the production of absorptive polyester with a high degree of quality and may be performed in a cost-effective fashion on an industrial scale as well.

Abstract: We provide a process comprising: a. feeding a chlorinated-hydrocarbon and an ionic liquid catalyst to a treatment unit; b. operating the treatment unit at an elevated temperature to produce dechlorinated-hydrocarbon and HCl; and c. collecting the dechlorinated-hydrocarbon, wherein at least 90 wt % of the chlorides are removed. A second process comprises: a. creating an ionic liquid catalyst-rich zone in a distillation unit; b. passing chlorinated-hydrocarbon to the distillation unit; c. operating the unit under conditions causing removal of alkyl chloride to produce dechlorinated-hydrocarbon having a final boiling point close to a first final boiling point. A third process comprises: a. feeding alkylate gasoline blending component and ionic liquid catalyst to a treatment unit; b. operating the treatment unit; and c. collecting a dechlorinated-hydrocarbon, wherein at least 90 wt % of the chlorides have been removed and the dechlorinated-hydrocarbon has a second RON that is close to a first RON.

Abstract: Systems and methods for producing aromatic products are provided. An aromatic stream is provided with aromatic compounds and olefins. The olefins are reacted with aromatic compounds to form colored bodies, and the aromatic stream is distilled to produce an overhead stream and reboiler stream. The colored bodies are in the reboiler stream, and the reboiler stream is passed through an absorbent to remove the colored bodies.

Abstract: The process of producing an alkylbenzene compound from the alkylation of an aromatic compound with an acyclic monoolefin is an exothermic process. A process for maintaining a relatively constant temperature improves the process and allows for controlling the yields. The process includes recycling a compound through the reactor that is relatively inert, but will moderate the exotherm, while maintaining the 2-phenyl content of the final alkylbenzene product.

Abstract: A method of making alkylaromatics is described. The process includes recycling a portion of the alkylation reaction zone effluent back to the alkylation zone to maintain the product quality while reducing energy usage.

Abstract: The present invention relates to a method and system for recovering aromatics from a naphtha feedstock obtained from a crude petroleum, natural gas condensate, or petrochemical feedstock. The method and system comprise the steps of recovering an aromatics fraction from the feedstock prior to reforming.

Abstract: The invention relates to a process for recovering monoalkylbenzene from a gas stream comprising oxygen and monoalkylbenzene, —wherein the gas stream comprising oxygen and monoalkylbenzene is contacted with a liquid stream comprising polyalkylbenzene, a compound comprising two phenyl groups connected to each other via a C1-C3 alkylene bridge or a mixture thereof. Further, the present invention relates to a process for preparing alkyl phenyl hydroperoxide incorporating said monoalkylbenzene recovery.

Abstract: A method for producing an alkylated aromatic compound includes a step (i) of producing a reaction product (a1) containing the alkylated aromatic compound and water by the reaction of an aromatic compound, a ketone, and hydrogen using a metal component containing at least one metallic element of copper, nickel, cobalt, and rhenium and a solid acid substance; a step (ii) of forming a dehydrated product (a2) from at least a portion of the reaction product (a1) by removing at least a portion of the water in the reaction product (a1); and a step (iii) of producing a reaction product (a3) containing the alkylated aromatic compound by bringing at least a portion of the dehydrated product (a2) into contact with a solid acid substance.

Abstract: The proposed process uses crystallization technology to purify paraxylene simultaneously of large concentrations of C8 aromatics and also small concentrations of oxygenated species.

Abstract: A process for the preparation of an aromatic product comprising xylene, which process comprises the steps of: a) converting an oxygenate feedstock in an oxygenate-to-olefins conversion system, comprising a reaction zone in which an oxygenate feedstock is contacted with an oxygenate conversion catalyst under oxygenate conversion conditions, to obtain a conversion effluent comprising benzene, toluene, xylene and olefins; b) separating at least a portion of the benzene and toluene from the conversion effluent to form an aromatics containing stream; c) separating the olefins from the conversion effluent; d) separating xylene from the conversion effluent to produce a xylene product stream; and e) recycling at least a portion of the aromatics containing stream to step a).

Abstract: The inventive method is directed to the production of xylenes by methylation of aromatic compounds with methanol. The process uses fixed bed reactors, operates at lower pressure, and without the need for hydrogen or other gas recycle.

Abstract: The invention is a process for producing paraxylene, benzene and/or toluene is alkylated with methanol in the presence of a catalyst under conditions effective to convert said benzene and/or toluene to xylene and produce a product stream containing water, xylene and one or more phenolic impurities. The said product stream is separated into a water-rich stream and a xylene-rich stream containing one or more phenolic impurities and at least a portion of the xylene-rich stream is contacted with an aqueous solution of a base under conditions to remove at least some of the phenolic impurities from the xylene-rich stream portion.

Abstract: The proposed process uses crystallization technology to purify paraxylene simultaneously of large concentrations of C8 aromatics and also small concentrations of oxygenated species.

Abstract: One exemplary embodiment can be a method for processing polyisopropylbenzene for producing cumene. The method can include passing a transalkylation feed stream to a transalkylation zone, and passing a reaction product to a separation zone. Typically, the separation zone produces a stream including di-isopropylbenzene, tri-isopropylbenzene, and one or more heavy compounds. Moreover, the stream may include at least about 0.7%, by weight, of the one or more heavy compounds based on the weight of the di-isopropylbenzene, tri-isopropylbenzene, and the one or more heavy compounds in the stream, and at least a portion of the stream is recycled to the transalkylation zone.

Abstract: Processing schemes and arrangements are provided for obtaining propylene and propane via the catalytic cracking of a heavy hydrocarbon feedstock and converting the propylene into cumene without separating the propane from the propane/propylene feed stream. The disclosed processing schemes and arrangements advantageously eliminate any separation of propylene from propane produced by a FCC process prior to using the combined propane/propane stream as a feed for a cumene alkylation process. A bottoms stream from the cumene column of the cumene alkylation process can be used and an absorption solvent in the FCC process thereby eliminating the need for a transalkylation reactor and a DIPB/TIPB column.

Abstract: The present invention provides a catalyst comprising metallic Pt and/or Pd supported on a binder-free zeolite for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock, wherein the amount of metallic Pt and/or Pd is of 0.01-0.8 wt %, preferably 0.01-0.5 wt % on the basis of the total weight of the catalyst, and the binder-free zeolite is selected from the group consisting of mordenite, beta zeolite, Y zeolite, ZSM-5, ZSM-11 and composite or cocrystal zeolite thereof. The present invention also provides a process for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock using said catalyst.

Abstract: Continuous processes for monoalkylating aromatic compound with an aliphatic feedstock comprising aliphatic olefin of 8 to 18 carbon atoms per molecule are effected using at least 3 reaction zones in series, each containing solid alkylation catalyst with effluent cooling between reaction zones, each of which reaction zones is supplied a portion of the fresh aliphatic feedstock, such that the Reaction Zone Delta T in each reaction zone is less than about 15° C. The overall aromatic compound to olefin molar ratio is less than about 20:1. The alkylation product has desirable linearity and low amounts of dimers, dealkylated compounds and diaryl compounds even though a low aromatic compound to olefin molar ratio is used.

Abstract: The present invention relates to a new zeolite having a beta-type crystalline structure, characterized by a distribution of the Lewis acid sites and Brønsted acid sites corresponding to a molar ratio [Lewis sites] [Brønsted sites] equal to or higher than 1.5. This new zeolite is useful in preparation processes of alkylated aromatic hydrocarbons through the alkylation and/or transalkylation of aromatic compounds. The preparation method of the new zeolite is also object of the present invention.

Abstract: Processing schemes and arrangements are provided for obtaining ethylene and ethane via the catalytic cracking of a heavy hydrocarbon feedstock and converting the ethylene into ethyl benzene without separating the ethane from the feed stream. The disclosed processing schemes and arrangements advantageously eliminate any separation of ethylene from ethane produced by a FCC process prior to using the combined ethylene/ethane stream as a feed for an ethyl benzene process. Further, heat from the alkylation reactor is used for one of the strippers of the FCC process and at least one bottoms stream from alkylation process is used as an absorption solvent in the FCC process.

Abstract: Processing schemes and arrangements are provided for obtaining ethylene and ethane via the catalytic cracking of a heavy hydrocarbon feedstock and converting the ethylene into ethyl benzene without separating the ethane from the feed stream. The disclosed processing schemes and arrangements advantageously eliminate any separation of ethylene from ethane produced by a FCC process prior to using the combined ethylene/ethane stream as a feed for an ethyl benzene process. Further, heat from the alkylation reactor is used for one of the strippers of the FCC process and at least one bottoms stream from alkylation process is used as an absorption solvent in the FCC process.

Abstract: Processing schemes and arrangements are provided for obtaining propylene and propane via the catalytic cracking of a heavy hydrocarbon feedstock and converting the propylene into cumene without separating the propane from the propane/propylene feed stream. The disclosed processing schemes and arrangements advantageously eliminate any separation of propylene from propane produced by a FCC process prior to using the combined propane/propane stream as a feed for a cumene alkylation process. A bottoms stream from the cumene column of the cumene alkylation process can be used and an absorption solvent in the FCC process thereby eliminating the need for a transalkylation reactor and a DIPB/TIPB column.

Abstract: A process for reformate benzene reduction, the process including: feeding a light reformate fraction, an olefin feed, and an alkylation catalyst to an alkylation reaction zone; contacting the light reformate fraction and the olefin feed in the presence of the alkylation catalyst in the alkylation reaction zone to convert at least a portion of the benzene and the olefin to a monoalkylate; recovering a catalyst fraction from an alkylation reaction zone effluent; and recovering a light reformate product having a reduced benzene content.

Abstract: An improved alkylation reactor design is disclosed. The design uses reactor effluent recycle to reduce the difference in temperature across the reaction zone improving selectivity and insuring the maintenance of a liquid phase in the reactor.

Abstract: Integrated, energy efficient process for making detergent range alkylbenzenes, heavies coproduced during the alkylation of benzene with olefin using a solid, acidic catalyst are transalkylated. Spent benzene from regeneration of the solid, acidic catalyst used for alkylation provides at least about 50 percent of the benzene provided for the transalkylation. The integrated processes thus reduce the load on the benzene distillation assembly used in the alkylbenzene refining system.

Abstract: Integrated, energy efficient process for making detergent range alkylbenzenes use a combination of a low benzene to olefin feed ratio for alkylation, alkylbenzene refining system operation and a transalkylation of dialkylbenzene co-produced during alkylation is used to reduce energy costs per unit of alkylbenzene product.

Abstract: Processes and apparatus for the alkylation of aromatic compound with mono-olefin aliphatic compound in the presence of solid alkylation catalyst use a lights distillation for obtaining desired selectivities to arylalkane in a energy efficient manner. The processes and apparatus offer the potential for debottlenecking existing arylalkane production facilities and reducing the size and energy requirements for a new arylalkane production facility.

Abstract: Spent benzene from a regeneration of a catalyst or solid sorbent in an alkylbenzene complex is subjected to a rough distillation and the benzene fraction from the rough distillation is used a at least a portion of the benzene for a unit operation in the alkylbenzene complex or is passed to a benzene distillation column in the crude alkylbenzene refining section. The processes of this invention can enhance the purity of the alkylbenzene product and can reduce energy consumption per unit of alkylbenzene product or can assist in debottlenecking the crude alkylbenzene refining section of the alkylbenzene complex.

Abstract: The process as described herein produces a moderately aromatic isoparaffinic base oil from a distillate range product. This process comprises: (a) providing a distillate range paraffin feed comprising paraffins and cycloparaffins; (b) mildly reforming the distillate range paraffin feed to convert at least a portion of the cycloparaffins to alkylaromatics and provide a mildly reformed distillate range stream; (c) treating a stream comprising the mildly reformed distillate range stream in a molecular redistribution reactor to provide a distributed stream; (d) dewaxing at least a portion of the distributed stream to provide a dewaxed stream; (e) combining at least a portion of the dewaxed stream with the stream to be processed in the molecular redistribution reactor to provide the distributed stream; and (f) isolating a moderately aromatic isoparaffinic base oil from the dewaxed stream.

Abstract: This cumene process involves contacting, in an alkylation zone, a first benzene recycle stream and a propylene feed stream with an alkylation catalyst to form cumene. In a transalkylation zone, a polyisopropylbenzene recycle stream and a second benzene recycle stream are contacted with a transalkylation catalyst to form additional cumene. The effluents are passed into a benzene distillation column. From the benzene distillation column, a first benzene recycle stream is removed as overhead; a second benzene recycle stream is removed as a side draw; and a bottoms stream comprising polyisopropylbenzene, cumene, and heavy aromatics is removed from an end. The bottoms stream is passed to a dividing wall distillation column where the polyisopropylbenzene recycle stream is removed from an intermediate point; a cumene product stream is removed from a first end, and a heavy aromatic stream is removed from a second end.

Abstract: This cumene process involves contacting, in an alkylation zone, a first benzene recycle stream and a propylene feed stream with an alkylation catalyst to form cumene. In a transalkylation zone, a polyisopropyl benzene recycle stream and a second benzene recycle stream are contacted with a transalkylation catalyst to form additional cumene. The effluents are passed into a dividing wall distillation column. A cumene stream is removed from an intermediate point of the dividing wall fractionation column; a first benzene recycle stream is removed from a first end and a heavy aromatics stream is removed from a second end. A second benzene recycle stream is removed from an intermediate point located between the first end and the cumene stream. A polyisopropyl benzene stream is removed from an intermediate point of located between the second end and the cumene stream.

Abstract: This ethylbenzene process involves contacting, in an alkylation zone, a first benzene recycle stream and an ethylene feed stream with an alkylation catalyst to form ethylbenzene. In a transalkylation zone, a polyethylbenzene recycle stream and a second benzene recycle stream are contacted with a transalkylation catalyst to form additional ethylbenzene. The effluents are passed into a benzene distillation column. From the benzene distillation column, a first benzene recycle stream is removed as overhead; a second benzene recycle stream is removed as a side draw; and a bottoms stream comprising polyethylbenzene, ethylbenzene, and flux oil is removed from an end. The bottoms stream is passed to a dividing wall distillation column where the polyethylbenzene recycle stream is removed from an intermediate point; an ethylbenzene product stream is removed from a first end, and a heavy oil stream is removed from a second end.

Abstract: This ethylbenzene process involves contacting, in an alkylation zone, a first benzene recycle stream and an ethylene feed stream with an alkylation catalyst to form ethylbenzene. In a transalkylation zone, a polyethylbenzene recycle stream and a second benzene recycle stream are contacted with a transalkylation catalyst to form additional ethylbenzene. The effluents are passed into a dividing wall distillation column where a benzene overhead and a benzene side draw are removed and recycled. An ethylbenzene stream product stream is also removed. The remainder, largely polyethylbenzene and tar, is passed to a polyethylbenzene column for separation. The separated polyethylbenzene is recycled to the transalkylation reactor.

Abstract: This ethylbenzene process involves contacting, in an alkylation zone, a first benzene recycle stream and an ethylene feed stream with an alkylation catalyst to form ethylbenzene. In a transalkylation zone, a polyethylbenzene recycle stream and a second benzene recycle stream are contacted with a transalkylation catalyst to form additional ethylbenzene. The effluents are passed into a dividing wall distillation column. An ethylbenzene stream is removed from an intermediate point of the dividing wall fractionation column; a first benzene recycle stream is removed from a first end and a flux oil stream is removed from a second end. A second benzene recycle stream is removed from an intermediate point located between the first end and the ethylbenzene stream. A polyethylbenzene stream is removed from an intermediate point of located between the second end and the ethylbenzene stream.

Abstract: In an alkylation zone, a benzene recycle stream and a propylene feed stream are contacted with an alkylation catalyst to convert the propylene and benzene into cumene. In a transalkylation zone, a polyisopropylbenzene stream and a benzene recycle stream are contacted with a transalkylation catalyst to convert the polyisopropylbenzene and benzene into cumene. The alkylation and transalkylation zone effluents are passed into a dividing wall fractionation column. A cumene product stream is removed from an intermediate point of the dividing wall fractionation column. A benzene recycle stream is removed from a first end, and another benzene recycle stream is removed from an intermediate point of the dividing wall fractionation column. A polyisopropylbenzene stream is removed from a second end of the dividing wall fractionation column. The polyisopropylbenzene stream is passed to a polyisopropylbenzene fractionation column to separate the polyisopropylbenzene from a heavy ends stream.

Abstract: A process for alkylating an aromatic compound comprising reacting (a) a first amount of at least one aromatic compound with a first amount of a mixture of olefins having from about 8 to about 100 carbon atoms, in the presence of a strong acid catalyst; and reacting the product of (a) with an additional amount of at least one aromatic compound and an additional amount of a strong acid catalyst, and optionally, with an additional amount of a mixture of olefins selected from olefins having from about 8 to about 100 carbon atoms, wherein the resulting product comprises at least about 80 weight percent of a 1,2,4 tri-alkylsubstituted aromatic compound.

Abstract: A process for producing a monoalkylation aromatic product, such as ethylbenzene and cumene, utilizing an alkylation reactor zone and a transalkylation zone in series or a combined alkylation and transkylation reactor zone.

Abstract: Processes and apparatus for the alkylation of aromatic compound with mono-olefin aliphatic compound in the presence of solid alkylation catalyst use a lights distillation for obtaining desired selectivities to arylalkane in a energy efficient manner. The processes and apparatus offer the potential for debottlenecking existing arylalkane production facilities and reducing the size and energy requirements for a new arylalkane production facility.

Abstract: A process for the production of alkylaromatic hydrocarbons by alkylating aromatic hydrocarbons with olefinic hydrocarbons is disclosed. The olefinic hydrocarbons are produced by dehydrogenating paraffinic hydrocarbons. Aromatic byproducts formed in dehydrogenation are removed using an aromatic byproducts removal zone and either a dividing wall distillation column or thermally coupled distillation columns. The process significantly decreases the cost of utilities in producing alkylaromatics, such as precursors for detergent manufacture.

Abstract: A unified process for reactive distillation under pressure for the alkylation of light aromatic hydrocarbons such as benzene and cumene with straight chain C6-C18 olefins using a solid acid alkylation catalyst supported in the reflux zone of the distillation column. The process is continuous, using a reactive distillation configuration such that at least a portion of the olefin is injected below the benzene rectification zone at the top of the column. The aromatic hydrocarbon is injected continuously at a low rate above the rectification zone at the base of the column and above the reboiler. The alkylation reaction takes place primarily in the liquid phase on the solid acid catalyst and is characterized in that the molar ratio of aromatic hydrocarbon to olefin in the liquid phase may be adjusted.

Abstract: A process for manufacturing cumene by reacting propylene with benzene, including treating a vent stream from the reaction zone, to recover propylene for return to the reactor. The process involves using a gas separation membrane to separate propylene from propane in the reactor vent stream. The membrane separation step results in a residue stream typically containing as much as 30%, 40% or more propane, which is vented from the process, and a permeate stream containing 95% or less propylene, which is recirculated to the reactor.

Abstract: Process for the alkylation of aromatic compounds by the reaction of the aromatic compound of interest with isopropanol, alone or mixed with propylene, wherein the reaction is carried out in the presence of a catalytic composition based on zeolite, under mixed gas-liquid phase conditions or under completely liquid phase conditions, at such temperature and pressures that the concentration of water in the reaction liquid phase is not higher than 8,000 ppm w/w, regardless of the total water content present in the reaction mixture.

Abstract: A process for the production of alkylaromatic hydrocarbons by alkylating aromatic hydrocarbons with olefinic hydrocarbons is disclosed. The olefinic hydrocarbons are produced by dehydrogenating paraffinic hydrocarbons. Aromatic byproducts formed in dehydrogenation are removed using an aromatic byproducts removal zone and either a dividing wall distillation column or thermally coupled distillation columns. The process significantly decreases the cost of utilities in producing alkylaromatics, such as precursors for detergent manufacture.

Abstract: A process for producing alkyl aromatics using a transalkylation reaction zone and an alkylation reaction zone is disclosed. One portion of the transalkylation reaction zone effluent passes to an alkylation reaction zone where an aromatic substrate is alkylated to the desired alkyl aromatic. At least a portion of the alkylation reaction zone effluent and another portion of the transalkylation reaction zone effluent pass to a product recovery zone. This process decreases the capital and operating costs of recycling aromatic substrate to the transalkylation and/or alkylation reaction zone while maintaining operational flexibility. This process is well suited for solid transalkylation and alkylation catalysts. Ethylbenzene and cumene may be produced by this process.

Abstract: Process for the production of ethylbenzene by alkylation over a silicalite alkylation catalyst with subsequent transalkylation of diethylbenzene with the alkylation catalyst and conditions selected to retard xylene production and also heavies production. Benzene and ethylene are applied to a multi-stage alkylation reaction zone having a plurality of series-connected catalyst beds containing silicalite of a predominantly monoclinic symmetry having a silica/alumina ratio of at least 275. Gas-phase ethylation of benzene is at a flow rate to provide a space velocity of benzene over the catalyst to produce a xylene concentration of about 600 ppm or less of the ethylbenzene content. Periodically the space velocity may be increased to a value which is greater than the space velocity associated with a minimum concentration of diethylbenzene in the alkylation product such that diethylbenzene production is enhanced while minimizing any attendant transalkylation reactions within the alkylation reaction zone.

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: A process for producing 2,6-dialkylnaphthalene from a hydrocarbon feedstock that contains at least one component selected from the group consisting of dialkylnaphthalene isomers, monoalkylnaphthalene isomers, polyalkylnaphthalenes, and naphthalene, is provided that includes the following steps:I. separating the hydrocarbon feedstock and/or a dealkylation product fed from step III into a naphthalene fraction, a monoalkylnaphthalene fraction, a dialkylnaphthalene fraction and a remaining products fraction;II. separating and purifying 2,6-dialkylnaphthalene from the dialkylnaphthalene fraction of step I;III. dealkylating the hydrocarbon feedstock and/or the remaining products fraction of step I and feeding the dealkylation product to step I; andIV. alkylating the naphthalene and monoalkylnaphthalene fractions of step I;wherein the hydrocarbon feedstock is fed to step I or step III.

Abstract: A process for producing 2,6-dialkylnaphthalene from a hydrocarbon feedstock that contains at least one component selected from the group consisting of dialkylnaphthalene isomers, monoalkylnaphthalene isomers, polyalkylnaphthalenes, and naphthalene, is provided that includes the following steps: I. separating the hydrocarbon feedstock and/or a dealkylation product fed from step III into a naphthalene fraction, a monoalkylnaphthalene fraction, a dialkylnaphthalene fraction and a remaining products fraction; II. separating and purifying 2,6-dialkylnaphthalene from the dialkylnaphthalene fraction of step I; III. dealkylating the hydrocarbon feedstock and/or the remaining products fraction of step I and feeding the dealkylation product to step I; and IV. alkylating the naphthalene and monoalkylnaphthalene fractions of step I; wherein the hydrocarbon feedstock is fed to step I or step III.