Abstract: A catalyst and corresponding methods of using a catalyst are provided that can be beneficial for conversion of paraffins into a product stream enriched in aromatics and/or methane while reducing or minimizing the content of ethane in the product stream. Such catalysts and methods can be useful, for example, for processing a raw gas, associated gas, tail gas, natural gas, or other type of methane-containing feed stream to convert C2+ hydrocarbons in the stream to heavier hydrocarbons and methane while reducing or minimizing content of ethane in the products from the conversion reaction. Such conversion can be useful for upgrading a methane-containing feed stream to have an energy content that is suitable for pipeline transport under one or more specifications for transport of natural gas. The catalyst and corresponding method can also be beneficial when used as a second stage catalyst in a configuration involving multiple conversion stages.

Abstract: Zn-promoted and/or Ga-promoted cracking catalysts, such as cracking catalysts comprising an MSE framework zeolite or an MFI framework zeolite can provide unexpectedly superior conversion of branched paraffins when used as part of a catalyst during reforming of a hydrocarbon fuel stream. The conversion and reforming of the hydrocarbon fuel stream can occur, for example, in an internal combustion engine. The conversion and reforming can allow for formation of higher octane compounds from the branched paraffins.

Abstract: An apparatus for reforming a hydrocarbon stream is presented. The apparatus involves changing the design of reformers and associated equipment to allow for increasing the processing temperatures in the reformers and heaters. The reformers are operated under different conditions to utilize advantages in the equilibriums, but require modifications to prevent increasing thermal cracking and to prevent increases in coking.

Abstract: A process for the conversion of mixed lower alkanes into aromatics which comprises first reacting a mixed lower alkane feed comprising at least propane and ethane in the presence of an aromatization catalyst under reaction conditions which maximize the conversion of propane into first stage aromatic reaction products, separating ethane from the first stage aromatic reaction products, reacting ethane in the presence of an aromatization catalyst under reaction conditions which maximize the conversion of ethane into second stage aromatic reaction products, and optionally separating ethane from the second stage aromatic reaction products.

Abstract: To improve stability of catalytic performance, an aromatizing catalyst for converting lower hydrocarbons into aromatic compounds is regenerated. A regeneration process of the aromatizing catalyst according to the present invention includes the steps of: (a) reacting the aromatizing catalyst with a hydrogen gas in an atmosphere containing the hydrogen gas after using the aromatizing catalyst in an aromatizing reaction for converting lower hydrocarbons into aromatic compounds; (b) decreasing a temperature of the atmosphere containing the hydrogen gas reacted with the aromatizing catalyst, by supplying one of an inert gas and a reducing gas to the atmosphere; (c) reacting the aromatizing catalyst reacted with this inert gas, with an oxidizing gas; and (d) reacting the aromatizing catalyst reacted with the oxidizing gas, with a reducing gas.

Abstract: Process for obtaining aromatic hydrocarbons from a stream containing at least one light hydrocarbon selected from the list comprising methane, ethane, ethylene, propane, propene, propylene, butane, butene or butadiene, which comprises putting said stream into contact with a catalyst, which comprises a catalytic material and a binder, in a fluidized bed reactor. Said reactor may have two reaction zones, an oxidizing zone and a reducing zone.

Abstract: The present invention relates to catalyst composition comprising M1/Ga/zeolite and La/binder, wherein M1/Ga/zeolite is a zeolite comprising 0.01-2 wt-% palladium and/or platinum (M1) with respect to the total M1/Ga/zeolite and 0.2-2 wt-% gallium (Ga) with respect to the total M1/Ga/zeolite; and La/binder is a binder comprising 0.5-2 wt-% lanthanum (La) with respect to the total La/binder. Furthermore, the present invention relates to a method for preparing the catalyst composition of the present invention and a process for producing aromatic hydrocarbons comprising contacting a feedstream comprising lower alkanes with the catalyst composition of the present invention under conditions suitable for alkane aromatization.

Abstract: A process for reforming a hydrocarbon stream is presented. The process involves increasing the processing temperatures in the reformers. The reformers are operated under different conditions to utilize advantages in the equilibriums, but require modifications to prevent increasing thermal cracking and to prevent increases in coking. The process utilizes a common catalyst, and common downstream processes for recovering the desired aromatic compounds generated.

Abstract: The invention relates to a process for producing a particulate, Si-bonded fluidized-bed catalyst having improved abrasion resistance, which comprises the steps I. provision of an aqueous suspension comprising zeolite particles, II. addition of a silicone resin mixture comprising one or more hydrolyzable silicone resin precondensates and mixing of the aqueous suspension and the silicone resin mixture, III. spray drying of the mixture obtained from step II, with the mixture being homogenized before spray drying, and IV. calcination of the spray-dried fluidized-bed catalyst obtained from step III, and an Si-bonded fluidized-bed catalyst which can be produced by this process and also its use for the nonoxidative dehydroaromatization of C1-C4-aliphatics.

Abstract: An aromatic compound, particularly benzene, is stably produced in the presence of a catalyst from a lower hydrocarbon having 2 or more carbon atoms, particularly from an ethane-containing gas composition such as ethane gas and natural gas. Disclosed is a process for producing an aromatic compound by reacting ethane or an ethane-containing raw gas in the presence of a catalyst. The catalyst may comprise molybdenum carried on metallosilicate such as H-type ZSM-5H or H-type MCM-22. In the reaction, the temperature is from 550 to 750° C., preferably not lower than 600° C. and not higher than 680° C. Additionally, the raw gas further contains methane and hydrogen is added thereto, thereby improving the production efficiency and stability.

Abstract: The present invention provides a process for producing aromatic hydrocarbons at a sufficiently high yield, from a light hydrocarbon containing mainly hydrocarbons having 7 or fewer carbon atoms. The process of the present invention comprises bringing a feedstock containing mainly light hydrocarbons having 2 to 7 carbon atoms into contact with a catalyst composition comprising at least a gallium-containing crystalline aluminosilicate wherein a reaction step for converting the feedstock to aromatic hydrocarbons comprises at least two or more reaction layers formed of the catalyst composition, arranged in series and heating means arranged either between or in the reaction layers, the amount of the catalyst in the first stage reaction layer is 30 percent by volume or less of the total catalyst volume, and/or the yield of the aromatics in the product outflowing from the first reaction layer is from 0.5 to 30 percent by mass.

Abstract: Process for obtaining aromatic hydrocarbons from a stream containing at least one light hydrocarbon selected from the list comprising methane, ethane, ethylene, propane, propene, propylene, butane, butene or butadiene, which comprises putting said stream into contact with a catalyst, which comprises a catalytic material and a binder, in a fluidized bed reactor. Said reactor may have two reaction zones, an oxidizing zone and a reducing zone.

Abstract: In a process for converting methane to higher hydrocarbons including aromatic hydrocarbons, a feed containing methane is contacted with a dehydrocyclization catalyst in a reaction zone under conditions effective to convert said methane to aromatic hydrocarbons. A first portion of the catalyst is transferred from the reaction zone to a heating zone, where the first catalyst portion is heated by contacting the catalyst with hot combustion gases generated by burning a supplemental source of fuel. The heated first catalyst portion is then returned to the reaction zone.

Abstract: A process for converting methane to higher hydrocarbon(s) including aromatic hydrocarbon(s) comprises providing a hydrocarbon feedstock containing methane and a catalytic particulate material to a reactor system having at least first and second reaction zones connected in series. Each of the reaction zones is operated under reaction conditions sufficient to convert at least a portion of the methane to said higher hydrocarbon(s) and is maintained in a moving bed fashion, with the bulk of the catalytic particulate material being moved from the first reaction zone to the second reaction zone and with the bulk of the hydrocarbon feedstock being moved from the second reaction zone to the first reaction zone.

Abstract: The invention relates to a method for producing unsaturated hydrocarbons. According to said method, in a first step, a hydrocarbon, especially a mixture which contains alkanes, essentially no water, and can contain water vapour, is continuously guided through a first catalyst bed provided with standard dehydration conditions. Liquid water, water vapour and a gas containing oxygen are then added to the reaction mixture obtained in the first step and, in a second step, the reaction mixture obtained is then continuously guided through another catalyst bed for oxidising hydrogen and for further dehydrating hydrocarbons. The first catalyst bed can be heated and the heating in the first step is then preferably regulated in such a way that an essentially isothermic operating mode is created.

Abstract: A process for converting methane to higher hydrocarbon(s) including aromatic hydrocarbon(s) comprises providing a hydrocarbon feedstock containing methane and a catalytic particulate material to a reactor system having at least first and second reaction zones connected in series. Each of the reaction zones is operated under reaction conditions sufficient to convert at least a portion of the methane to said higher hydrocarbon(s) and is maintained in a moving bed fashion, with the bulk of the catalytic particulate material being moved from the first reaction zone to the second reaction zone and with the bulk of the hydrocarbon feedstock being moved from the second reaction zone to the first reaction zone.

Abstract: A process for converting methane to higher hydrocarbon(s) including aromatic hydrocarbon(s) comprises providing a hydrocarbon feedstock containing methane and a catalytic particulate material to a reactor system having at least first and second reaction zones connected in series. Each of the reaction zones is operated under reaction conditions sufficient to convert at least a portion of the methane to said higher hydrocarbon(s) and is maintained in a moving bed fashion, with the bulk of the catalytic particulate material being moved from the first reaction zone to the second reaction zone and with the bulk of the hydrocarbon feedstock being moved from the second reaction zone to the first reaction zone.

Abstract: A method of preparing a catalyst comprising selecting a zeolite having a mean particle size of equal to or less than about 6 microns, blending the zeolite with a binder and water to form a paste, shaping the paste into a bound zeolite support, adding a metal to the bound zeolite support to form a metalized catalyst support, and adding at least one halide to the metalized catalyst support to form the catalyst. A catalytic reforming process for converting hydrocarbons to aromatics comprising: contacting a catalyst comprising a silica bound zeolite, a Group VIII metal supported thereby, and at least one halide with a hydrocarbon feed in a reaction zone under reforming conditions and recovering aromatics from the reaction zone, wherein the silica bound zeolite comprises a zeolite having a mean particle size of equal to or less than about 6 microns and a median particle size of equal to or less than about 5 microns.

Abstract: In this invention, a new structure for the units using a series of moving beds, characterized by a direct supply of regenerated catalyst from at least two of the reactors of the series, is described. The feedstock and the intermediate effluents continue to circulate in succession relative to the reactors. The invention makes it possible in particular to cross a new threshold in the reduction of the operating pressure of the units.

Abstract: This invention is directed towards an improved process for the selective gas phase oxidation of a organic reactant using a metal oxide redox catalyst, wherein the organic reactant and air feeds are at a substantially continuous level, the improvement comprising adding a fluctuating flow of oxygen at alternating relatively high and relatively low levels. The invention also teaches means by which a gas may be provided to a reaction process on a fluctuating basis.

Abstract: The invention is a novel energy efficient process to produce high purity paraxylene from a feed comprising at least 55 to 60 wt % paraxylene, wherein a first portion of high purity paraxylene product is obtained in a first crystallization step at about 10° F. to about 55° F. without the need for further reslurry and recrystallization, and wherein another portion of the high purity paraxylene product is obtained following a reslurry step which warms crystalline paraxylene obtained from subsequent lower temperature crystallizations to yield a slurry at a temperature of about 10° F. to about 55° F. without the need for further refrigeration.

Abstract: The present invention features a system and method for circulating catalyst between a reactor system and a regenerator system. A circulating catalyst system includes a reactor system, a regenerator system, and a distribution unit. The reactor system and regenerator system are adapted to exchange catalyst. The regeneration system preferably includes a regeneration zone adapted for the contact of catalyst with a regeneration gas. The system and method are adapted so that more than one regeneration gas may contact catalyst. The distribution unit is adapted to control the percentage of catalyst contacting each regeneration gas. Thus, the distribution unit is adapted to select the percentages so as to maintain the reactor system and regeneration system under a heat balance regime. Heat is preferably transferred from the regenerator system to the reactor system by an exchange of catalyst.

Abstract: Process for the production of aromatic compounds, such as reforming, that uses at least one fixed catalyst bed with a base of platinum and 0.08% rhenium. In said process, before moving onto the bed, the feedstock undergoes a heat exchange with the effluent that is obtained from the process, whereby the exchange is carried out with a pressure drop that is less than 1 bar and a temperature difference that is less than 70° C. The beds are preferably radial and those that are located at the top of the reactor are covered by a cloth layer. The process preferably uses at least two fixed catalyst beds, whereby the first bed (in the direction of circulation of the feedstock) has an Re/Pt ratio by weight that is greater than that of the second bed, and whereby the second catalyst preferably contains at least 0.08% of Re.

Abstract: A full boiling hydrocarbon feed is reformed to enhance para-xylene and benzene yields. First, the hydrocarbon feed is separated into a C.sub.5- cut, a C.sub.6 -C.sub.7 cut, and a C.sub.8+ cut. The C.sub.6 -C.sub.7 cut has less than 5 lv. % of C.sub.8+ hydrocarbon, and the C.sub.8+ cut has less than 10 lv. % of C.sub.7- hydrocarbon. The C.sub.6 -C.sub.7 cut is subjected to catalytic aromatization at elevated temperatures in a first reformer in the presence of hydrogen and using a non-acidic catalyst comprising at least one Group VIII metal and a non-acidic zeolite support to produce a first reformate stream; and the C.sub.8+ cut is subjected to catalytic aromatization at elevated temperatures in a second reformer in the presence of hydrogen and using an acidic catalyst comprising at least one Group VIII metal and a metallic oxide support to produce a second reformate stream. Less than 20 wt. % of the total amount of C.sub.

Abstract: A hydrocarbon conversion process comprises: (1) contacting a hydrocarbon feed such as, for example, gasoline, with a catalyst under a sufficient condition to effect the conversion of the hydrocarbon to a product stream comprising aromatic hydrocarbons and olefins; (2) separating the product stream into a lights fraction comprising primarily hydrocarbons less than 6 carbon atoms per molecule, a middle fraction comprising C.sub.6 -C.sub.8 aromatic hydrocarbons and non-aromatic hydrocarbons, and a C.sub.9 + fraction comprising aromatic compounds; (3) separating the C.sub.6 -C.sub.8 aromatic hydrocarbons from the middle fraction; and (4) separating hydrocarbons containing 5 or more carbons per molecule (C.sub.5 + hydrocarbons) from the lights fraction. The C.sub.5 + hydrocarbons can be combined with the hydrocarbon feed. The non-aromatic hydrocarbons can also be converted to olefins by a thermal cracking process. Furthermore, the middle fraction can also be obtained by reforming naphtha.

Abstract: In the present invention, dimethylbutanes are removed from the raffinate component of the feed to a dehydrocyclization process. Thus, according to a preferred embodiment, a process is provided for producing aromatics by the following steps:(a) contacting fresh paraffins rich feed hydrocarbons, containing 0.1 to 20.0 wt. % dimethylbutanes with a highly selective dehydrocyclization catalyst in a reaction zone, under dehydrocyclization reaction conditions, to convert paraffins to aromatics and obtain an aromatics rich effluent;(b) separating aromatics from the effluent to obtain an aromatics lean raffinate;(c) removing dimethyl butanes from the raffinate to obtain a raffinate of reduced dimethylbutane content; and(d) recycling the raffinate of reduced dimethylbutane content to the reaction zone.Preferably, the dehydrocyclization catalyst used is a nonacidic, monofunctional catalyst. Platinum on L zeolite is a particularly preferred highly selective dehydrocyclization catalyst for use in the process.

Abstract: A transalkylation reactor having a plurality of catalyst beds with individual feed points for each bed for converting poly alkylated benzene, typically products from a alkylation process, to mono alkylated benzene. Only so many of the catalyst beds are used to optimize the conversion of poly substituted benzene to mono substituted benzene. As the catalyst ages more of the beds are utilized to maintain conversion.

Abstract: A process for carrying out a chemical equilibrium reaction is disclosed in which, in a first stage, one or more reactants are contacted with a fixed arrangement of a catalyst under conditions such that the reactants and the products of the reaction are gaseous, the unconverted reactants and products of the first stage being passed to a second stage, in which they are contacted with a fixed arrangement of a catalyst and the reaction allowed to proceed in the presence of an absorbent capable of absorbing a product of the reaction.

Abstract: A catalytic reforming process uses a riser reactor with multiple catalyst injection points to obtain high aromatics yields from a naphtha feedstock. Product from the riser reactor typically is discharged into a fluidized-reforming reactor, in which the reforming reaction is completed and catalyst is separated from hydrogen and hydrocarbons. Hydrocarbons from the reactor are separated to recover an aromatized product. Catalyst is regenerated to remove coke and reduced for reuse in the reforming process.

Abstract: A process is disclosed for the conversion of light aliphatic hydrocarbons such as propane into aromatic hydrocarbons and especially high purity benzene. The feed hydrocarbon is converted to aromatic hydrocarbons in a dehydrocyclodimerization zone. The product stream from the dehydrocyclodimerization zone which contains benzene, toluene, xylenes and C.sub.6 -C.sub.10 non-aromatics are separated into an overhead stream which contains the non-aromatic hydrocarbons and a small fraction of the benzene and a bottoms stream which contains the remainder of the benzene and other aromatic components. The overhead stream is then flowed to a conversion zone where the C.sub.6 -C.sub.7 non-aromatic hydrocarbons are cracked and the benzene is combined with the bottoms stream and further separated to give a high purity benzene product stream and a toluene, xylenes and C.sub.9 + product stream. The toluene, xylenes and C.sub.9 + product stream may further be separated into a toluene and xylenes product and a C.sub.

Abstract: A process for the production of gasoline from a light hydrocarbon feed. The feed is catalytically aromatized to produce an effluent containing aromatics and olefins with the aromatics and olefins being subjected to alkylation to produce a gasoline product with a higher octane rating.

Abstract: A compound represented by the formula: ##STR1## and a compound represented by the formula: ##STR2## wherein R is C.sub.1 -C.sub.3 alkyl or C.sub.1 -C.sub.3 alkoxy, which is an intermediate for producing the above compound (1) are disclosed.

Abstract: A fluid bed catalytic paraffin upgrading process is disclosed. By closely controlling catalyst particle size distribution and density, together with feedstock superficial vapor velocity, the fluid bed is maintained in a turbulent flow regime. Surprisingly, maintaining the fluid bed in a turbulent flow regime shifts the product selectivity away from methane and ethane and toward the more valuable products hydrogen, light olefins and C.sub.5 + gasoline. In the most preferred embodiment, the catalyst contains a dehydrogenation metal component such as gallium, zinc, platinum or rhenium to provide a C.sub.5+ gasoline product rich in aromatics. Catalysts useful in the inventive process include zeolites as well as layered siliceous materials.

Abstract: A reactor system contained in a fired heater and a hydrocarbon upgrading process are discosed for the concurrent conversion of a hydrocarbon feedstock and the regeneration of a deactivated catalyst. An effluent product slipstream from a set of operating reactors is used to hydrogen-regenerate deactivated catalyst in another set of reactors. Flue gas withdrawn from the fired heater stack is used as a purge and/or carrier gas during oxygen-regeneration of the catalyst.

Abstract: An integrated reforming/aromatization process is disclosed which improves the octane number and C.sub.5 + liquid yield of a catalytic reforming unit by integrating a catalytic aromatization zone into a catalytic reforming unit gas plant fractionator overhead condenser reflux circuit. The fractionator may be operated as a debutanizer to maximize C.sub.5+ gasoline product volume or a depentanizer to maximize C.sub.5+ gasoline product octane number.

Abstract: A process for the increased production of olefinic gasoline is described incorporating the integration of olefins to gasoline conversion under moderate severity conditions in contact with zeolite type catalyst with oxygenates to olefins conversion. The product of the olefins to gasoline conversion is passed to an olefins to gasoline and distillate (MOGD) conversion zone for distillate production. Liquid recycle requirements, feed throughput and/or the number of MOGD fixed bed stages are reduced for the MOGD process and overall process costs are lowered. The process includes the use of common catalyst handling and regeneration steps for the integrated processes.

Abstract: A staged reactor technique for converting ethene-rich olefinic feedstock to heavier hydrocarbons, particularly gasoline and distillate range products. By employing low temperature and high temperature separators, an economic recycle is provided for each stage.

Abstract: A process for converting a C.sub.2 -C.sub.12 paraffinic hydrocarbon feed to aromatics comprising passing the feed through a first conversion zone wherein the feed contacts a noble metal/low acidity medium pore size zeolite catalyst, and then passing the resulting hydrocarbon mixture through a second conversion zone wherein the resulting hydrocarbon mixture contacts a medium pore size acidic zeolite catalyst.

Abstract: A process is provided for converting a feedstock comprising a preponderant amount of C.sub.2 -C.sub.10 aliphatic compounds to a product having a high proportion of benzene in a two stage process, with the effluent from the first stage passing directly to the second stage, i.e., with no intermediate processing such as purification or separation. In the first stage, the feedstock is contacted under suitable conversion conditions with a catalyst comprising an aluminosilicate zeolite having a Constraint Index in the approximate range of 1 to 12 and a degree of acidity indicated by an alpha value of at least about 3.

Abstract: An improved two-step process for the conversion of lower molecular weight paraffins, the process comprising contacting in a first step a C.sub.2 -C.sub.10 alkane-rich feedstock with a siliceous zeolite catalyst in a primary fluidized bed reaction zone under high temperature dehydrogenation conditions to obtain an intermediate product comprising oligomerizable olefinic hydrocarbons and aromatics; and then contacting in a second step the intermediate product with a siliceous zeolite catalyst in a secondary fluidized bed reaction zone under low temperature oligomerization conditions to obtain a final product comprising gasoline boiling range aliphatic and aromatic hydrocarbons.

Abstract: This invention relates to a process for converting a C.sub.2 -C.sub.6 paraffin feedstock to aromatics over a gallium loaded zeolite catalyst. The feature of the invention is to bring the ethane in the feed with a fresh or freshly regenerated catalyst first and thereafter to bring the residual catalyst from this step into contact with the remainder of the C.sub.3 -C.sub.6 feedstock. The present process has the advantage of maximizing the yields of aromatics from a mixed feedstock using a single reactor and a single charge of catalyst.

Abstract: In a process for dehydrocyclization of C.sub.6 -C.sub.12 alkanes in the presence of steam and a bed of a catalyst containing a Group IIA or IIB metal aluminate and a Group VIII metal, an oxygen containing gas is injected into the catalyst bed. The results of the oxygen injection are the internal generation of heat, a lower required steam to hydrocarbon ratio, and increased yield of aromatics.

Abstract: An improved process for converting an olefinic feedstock containing ethene and C.sub.3 .sup.+ alkenes to produce a heavy hydrocarbon product rich in distillate by contacting the feedstock with an oligomerization catalyst bed, at elevated pressure and temperature conditions in operating mode favorable to formation of heavy distillate product by selective conversion of C.sub.3 .sup.+ alkenes. The improvement comprises providing a distillate mode effluent stream containing substantially unconverted ethene in vapor phase and condensed distillate, and recovering unconverted ethene-rich hydrocarbon vapor from the distillate mode effluent stream and further converting such to olefinic gasoline in a second oligomerization catalyst bed at reduced moderate pressure and elevated temperature conditions in operating mode favorable to formation of C.sub.6 .sup.+ olefinic gasoline. At least a portion of the olefinic gasoline is recycled for conversion with the feedstock in the distillate mode catalyst bed.

Abstract: A process is disclosed for the dealkylation of durene resulting from a methanol to gasoline conversion by contacting a durene-containing fraction with zeolite ZSM-12 at elevated temperatures and pressures.

Abstract: 4-Vinylcyclohexene-1 is converted to ethylbenzene by contacting the vinylcyclohexene at a temperature ranging from about 100.degree. C. to about 450.degree. C. with a catalyst prepared by impregnating an alumina with an oxide or decomposable salt of Na, K, Rb, Cs, Ca, Sr and/or Ba and calcining the impregnated material at a temperature ranging from about 450.degree. C. to about 750.degree. C.

Abstract: This case relates to a process for producing aromatics by contacting a C.sub.3 -C.sub.8 hydrocarbon with a gallium catalyst supported on an aluminosilicate in which the ratio of silica to alumina is between 20:1 and 70:1.

Abstract: Catalytic process for reforming or production of aromatic hydrocarbons at a temperature from 480.degree. to 600.degree. C., wherein a charge of hydrocarbons and hydrogen is passed through two reaction zones, of the moving bed type, whose catalyst continuously flows downwardly and is withdrawn at the bottom thereof, is regenerated, treated with hydrogen and then with a sulfur compound, at respective temperatures lower than the reaction temperature, and thereafter fed back continuously to the reaction zone.

Abstract: An improved two-step process for the conversion of lower molecular weight paraffins, the process comprising contacting in a first step a C.sub.2 -C.sub.10 alkane-rich feedstock with a siliceous zeolite catalyst in a primary fluidized bed reaction zone under high temperature dehydrogenation conditions to obtain an intermediate product comprising oligomerizble olefinic hydrocarbons and aromatics; and then contacting in a second step the intermediate product with a siliceous zeolite catalyst in a secondary fluidized bed reaction zone under low temperature oligomerization conditions to obtain a final product comprising gasoline boiling range aliphatic and aromatic hydrocarbons.