Abstract: An integrated refining process for the production of high quality gasoline blending components from low value components is disclosed. In addition there is disclosed a method of improving the operating efficiency of a refinery by reducing fuel gas production and simultaneously producing high quality gasoline blending components of low volatility. The processes involve the alkylation of a refinery stream containing pentane with ethylene using an ionic liquid catalyst.

Abstract: A method of operation wherein catalytic reactors which cycle between reaction mode and catalyst regeneration mode have their contents exchanged with each other at the beginning of each cycle in order to increase the yield of the desired product. This exchange increases said yield by minimizing the contact of reactant in reaction mode with regenerant utilized in regeneration mode, thereby reducing/preventing the undesirable alternate reaction between the two, which consumes said reactant making it unavailable for the production of the desired product.

Abstract: A catalyst composition includes an oxygen compound of an element selected from Group IVB or Group IVA of the Periodic Table of the Elements; an oxygen compound of an element selected from Group VIB or Group VIA of the Periodic Table of the Elements; and at least about 1% by weight based upon total catalyst weight of fumed silica particles. The catalyst composition is advantageously employed in hydrocarbon conversion processes such as isomerization.

Abstract: A method of producing hydrogen for a fuel cell from a hydrocarbon fuel composition, by providing a hydrocarbon fuel composition, which is obtained by contacting a liquid hydrocarbon feed comprising an alkylating agent with an acidic catalyst, under conditions effective to alkylate at least a portion of the hydrocarbon feed; converting the hydrocarbon fuel composition into hydrogen; and optionally, introducing the hydrogen produced into a fuel cell. In a preferred embodiment the liquid hydrocarbon feed further comprises sulphur-containing impurities, at least a portion of which are alkylated during the alkylation step.

Abstract: The present invention pertains to a method for manufacturing alkylate oil using a composite ionic liquid as catalyst. A mixture of isobutane and C4 olefins is used as the raw material, and a composite ionic liquid is used as catalyst to carry out an alkylation reaction. The alkane/olefin ratio in the raw material is higher than 1:1. In the composition of the aforementioned composite ionic liquid catalyst, the cations come from a hydrohalide of an alkyl-containing amine or pyridine, while the anions are composite coordinate anions coming from two or more metal compounds. One of the metal compounds is an aluminum compound, while other metal compounds are compounds of Group IB and Group IIB elements of the Periodic Table and the transition metals. The present invention also provides a design of static mixer reaction apparatus that can realize the aforementioned manufacturing method.

Abstract: A process for the alkylation of alkane with olefin or olefin precursor such as an oligomer of tertiary olefin comprising contacting a liquid system comprising acid catalyst, isoparaffin and olefin in concurrent downflow into contact in a reaction zone with a disperser mesh under conditions of temperature and pressure to react said isoparaffin and said olefin to produce an alkylate product is disclosed. Preferably, the liquid system is maintained at about its boiling point in the reaction zone. Unexpectedly, the olefin oligomers have been found to function as olefin precursors and not as olefins in the reaction. Thus, for example, a cold acid alkylation using an oligomer of isobutene (principally dimer and trimer) with isobutane produces isooctane with the isobutane reacting with the constituent isobutene units of the oligomers on a molar basis. The product isooctane is essentially the same as that produced in the conventional cold acid process.

Abstract: Compositions including modified carbide-containing nanorods and/or modified oxycarbide-containing nanorods and/or modified carbon nanotubes bearing carbides and oxycarbides and methods of making the same are provided. Rigid porous structures including modified oxycarbide-containing nanorods and/or modified carbide containing nanorods and/or modified carbon nanotubes bearing modified carbides and oxycarbides and methods of making the same are also provided. The compositions and rigid porous structures of the invention can be used either as catalyst and/or catalyst supports in fluid phase catalytic chemical reactions. Processes for making supported catalyst for selected fluid phase catalytic reactions are also provided.

Abstract: A process is described for the valorization of a charge of hydrocarbons and for reducing the vapour pressure of said charge, comprising three steps: a step a) consisting of separating said charge of hydrocarbons into a fraction (O1) comprising essentially compounds containing 5 carbon atoms, including at least 2% by weight of pentenes, a step b) consisting of placing said fraction (O1) in contact with a cut of hydrocarbons (O2) at least partly comprising hydrocarbons having a number of carbon atoms between 6 and 10, including at least 2% by weight of olefins, and a step c) consisting of separating the effluents originating from step b) into a gasoline cut (?) the upper distillation point of which is less than 100° C. and a kerosene cut (?) having a distillation range between 100° C. and 300° C.

Abstract: Hydrocarbon or oxygenate conversion process in which a feedstock is contacted with a non zeolitic molecular sieve which has been treated to remove most, if not all, of the halogen contained in the catalyst. The halogen may be removed by one of several methods. One method includes heating the catalyst in a low moisture environment, followed by contacting the heated catalyst with air and/or steam. Another method includes steam-treating the catalyst at a temperature from 400° C. to 1000° C. The hydrocarbon or oxygenate conversion processes include the conversion of oxygenates to olefins, the conversion of oxygenates and ammonia to alkylamines, the conversion of oxygenates and aromatic compounds to alkylated aromatic compounds, cracking and dewaxing.

Abstract: An alkylation process in which a recycle stream is cooled by heat exchange with the alkylation reactor effluent is disclosed.

Abstract: This invention provides novel stable metallic mesoporous transition metal oxide molecular sieves and methods for their production. The sieves have high electrical conductivity and may be used as solid electrolyte devices, e.g., in fuel cells, as sorbents, e.g. for hydrogen storage, and as catalysts. The invention also provides room temperature activation of dinitrogen, using the sieves as a catalyst, which permits ammonia production at room temperature.

Abstract: A catalyst and process is disclosed to selectively upgrade a paraffinic feedstock to obtain an isoparaffin-rich product for blending into gasoline. The catalyst comprises a support of a sulfated oxide or hydroxide of a Group IVB (IUPAC 4) metal, a first component comprising at least one Group III A (IUPAC 13) component, and at least one platinum-group metal component which is preferably platinum.

Abstract: A catalyst and process is disclosed to selectively upgrade a paraffinic feedstock to obtain an isoparaffin-rich product for blending into gasoline. The catalyst comprises a support of a tungstated oxide or hydroxide of a Group IVB (IUPAC 4) metal, a first component of at least one lanthanide element, yttrium or mixtures thereof, which is preferably ytterbium or holmium, and at least one platinum-group metal component which is preferably platinum.

Abstract: An alkylation process in which a recycle stream is cooled by heat exchange with the alkylation reactor effluent is disclosed.

Abstract: Process for the recovery of perfluorinated sulphonic acid from a hydrocarbon residue, comprising the steps of (a) treating the residue with an alkyl ammonium salt of the perfluorinated sulphonic acid or a mixture of an alkyl ammonium salt of the perfluorinated sulphonic acid and the perfluorinated sulphonic acid in an amount being effective to liquefy the residue at ambient temperature; (b) contacting the liquefied residue with water at conditions to obtaining an aqueous extract containing the perfluorinated sulphonic acid and/or the alkyl ammonium salt of the perfluorinated acid into water; and (c) separating water from the aqueous extract to recover the perfluorinated sulphonic acid or the mixture of the acid and the ammonium salt.

Abstract: A catalyst for the selective oxidation of hydrogen has been developed. It comprises an inert core such as cordierite and an outer layer comprising a lithium aluminate support. The support has dispersed thereon a platinum group metal and a promoter metal, e.g. platinum and tin respectively. This catalyst is particularly effective in the selective oxidation of hydrogen in a dehydrogenation process.

Abstract: The invention pertains to a process for the alkylation of hydrocarbons wherein a hydrocarbon feedstock and an olefin are contacted with a catalyst at alkylation process conditions. The catalyst comprises a hydrogenation function and a solid acid. The ratio between (i) the volume in catalyst pores with a diameter in the range of about 40-8000 nm and (ii) the specific length of the catalyst particles is in the range of about 0.01-0.90 ml/(g*mm). The catalyst has a total pore volume of at least about 0.20 ml/g and the volume in the catalyst pores with a diameter in the range of about 40-8000 nm is below about 0.30 ml/g.

Abstract: Compositions including carbide-containing nanorods and/or oxycarbide-containing nanorods and/or carbon nanotubes bearing carbides and oxycarbides and methods of making the same are provided. Rigid porous structures including oxycarbide-containing nanorods and/or carbide containing nanorods and/or carbon nanotubes bearing carbides and oxycarbides and methods of making the same are also provided. The compositions and rigid porous structures of the invention can be used either as catalyst and/or catalyst supports in fluid phase catalytic chemical reactions. Processes for making supported catalyst for selected fluid phase catalytic reactions are also provided.

Abstract: A process for alkylation of olefin-containing gases with low molecular weight branched alkanes to generate alkylate. The process involves the use of solid acid catalysts as alkylation catalysts. In a specific embodiment, the process employs a three-phase catalytic reactor where olefins present in the gas are reacted, preferably to extinction, with a large excess of liquid branched alkane.

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: The present invention pertains to a method for manufacturing alkylate oil using a composite ionic liquid as catalyst. A mixture of isobutane and C4 olefins is used as the raw material, and a composite ionic liquid is used as catalyst to carry out an alkylation reaction. The alkane/olefin ratio in the raw material is higher than 1:1. In the composition of the aforementioned composite ionic liquid catalyst, the cations come from a hydrohalide of an alkyl-containing amine or pyridine, while the anions are composite coordinate anions coming from two or more metal compounds. One of the metal compounds is an aluminum compound, while other metal compounds are compounds of Group IB and Group IIB elements of the Periodic Table and the transition metals. The present invention also provides a design of static mixer reaction apparatus that can realize the aforementioned manufacturing method.

Abstract: A process for converting n-butane and ethylene to a product by contact with a catalyst containing a Group VIII metal, a halogen, and a support, in the presence of a Lewis Acid, and optionally in the presence of hydrogen, is disclosed.

Abstract: The acid catalyzed-effluent refrigerated alkylation of hydrocarbons in a shell and bare tube type alkylation reactor is improved by providing the bare tubes with internal inserts capable of increasing turbulence and mixing of refrigerant within the tubes whereby heat transfer in the process is enhanced.

Abstract: Catalyst for the asymmetric (transfer) hydrogenation represented by the formula MLaXbSc, where M is a transition metal, to be chosen from rhodium and ruthenium, and X is a counter ion and S is a ligand, a ranges from 0.5 to 3 and b and c, each independently, range from 0 to 2, and L is a chiral ligand having the formula (1), where Cn together with the two 2 O-atoms and the P-atom forms a substituted or non-substituted ring with 2-4 C-atoms, R1 and R2 each independently represent H, an optionally substituted alkyl, aryl, alkaryl or aralkyl group or may form a (heterocyclic) ring together with the N-atom to which they are bound. And a process for the asymmetric (transfer) hydrogenation of an olefinically unsaturated compound, ketone, imine or oxime derivate in the presence of a hydrogen donor and of a catalyst, use being made of a catalyst represented by formula MLaXbSc, where M is a transition metal, to be chosen from rhodium, iridium and ruthenium, X is a counter ion, S is a ligand, a ranges from 0.

Abstract: A process for treating organic compounds includes providing a composition which includes a substantially mesoporous structure of silica containing at least 97% by volume of pores having a pore size ranging from about 15 Å to about 30 Å and having a micropore volume of at least about 0.01 cc/g, wherein the mesoporous structure has incorporated therewith at least about 0.02% by weight of at least one catalytically and/or chemically active heteroatom selected from the group consisting of Al, Ti, V, Cr, Zn, Fe, Sn, Mo, Ga, Ni, Co, In, Zr, Mn, Cu, Mg, Pd, Pt and W, and the catalyst has an X-ray diffraction pattern with one peak at 0.3° to about 3.5° at 2&thgr;.

Abstract: New catalysts that contain heteropolyanions of the 12-tungstophosphoric acid or the 12-tungstomolybdic acid, and, for some of these, at least one metal of group VIII, and that are deposited on substrates that develop a specific surface area and a high pore volume, such as zirconium oxide (ZrO2), silicas, silica-aluminas or aluminas, are used in particular in isomerization of paraffinic fractions that contain in large part n-paraffins that have, for example, 4 to 8 carbon atoms per molecule and in aliphatic alkylation of isoparaffins (for example isobutane and/or isopentane) by at least one olefin that comprises, for example, 2 to 6 carbon atoms per molecule (C2 to C6).

Abstract: Improved methods for conducting solid acid-catalyzed, near- or supercritical heterogeneous chemical reactions (e.g., alkylation reactions) are provided which give enhanced product yields and permit longer processing runs. The preferred reactions of the invention are carried out in the presence of a solid macroporous catalyst having a surface area of from about 50-400 m2/g and a pore size of from about 70-150 Å. Product selectivity is enhanced by pressure-tuning of the reaction to promote production and separation of desired reaction products. In continuous processing, the chemical reaction may be interrupted before significant catalyst deactivation, followed by increasing reactor pressure and/or reducing reactor temperature to remove the accumulating coke; when the catalyst is regenerated, the original reaction conditions and reactant introduction may be resumed.

Abstract: A catalyst comprising A) a stationary acid component selected from the group consisting of a perfluorinated ion exchange polymer on an inert support, a silane modified perfluorosulfonic acid, and a sulfated metal oxide; and B) a mobile acid component selected from the group consisting of chlorosulfonic acid, fluorosulfonic acid, a fluorinated monosulfonic acid, a fluorinated sulfonimide, a fluorinated disulfonic acid, and an adjunct acid mixture is disclosed.

Abstract: This invention relates to a process for alkylation of an isoparaffin with an olefin over a solid-acid catalyst, wherein at least two parallel reactors are used at the same time. When the solid acid catalyst in one or more reactors need to be regenerated, the catalyst is contacted in-situ in the reactor with a solvent to wash out the macromolecular hydrocarbons deposited on the surface of the catalyst in order to resume the high selectivity of catalyst in alkylation.

Abstract: A method and apparatus for alkylating an alkylation substrate with an alkylating agent in the presence of solid catalyst particles in a transport reactor is disclosed. Solid catalyst particles in the transport reactor effluent recirculate to the inlet of the transport reactor through one or more conduits. The rate through each conduit is regulated by fluid-controlled valves that use the alkylation substrate as the regulating fluid. This method and apparatus help ensure uniform or symmetric flow of catalyst from the effluent of the transport reactor to the bottom of the transport reactor. This method and apparatus also help ensure uniform or symmetric flow of alkylation substrate to the bottom of the transport reactor with minimal bypassing by the alkylating agent around of the transport reactor. This invention finds use in the production of motor fuels by the alkylation of liquid hydrocarbons in the presence of solid catalyst particles.

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: Methods and apparatus that are used in an alkylation reactor system for adding low purity isopentane to alkylation reactor feed to block formation of isopentane, resulting in high incremental isopentane conversion and minimal octane and C5+ yield loss, and low acid consumption from C6+ isoparaffins with superior yields.

Abstract: Ethylene is oligomerized with certain catalysts based on iron and cobalt complexes of 2,6-pyridinecarboxaldehydebis(imine) and 2,6-diacylpyridine-bis(imine) tridentate ligands.

Abstract: The invention pertains to a catalyst comprising catalyst particles comprising a hydrogenation function and a solid acid, wherein the ratio between (i) the volume in catalyst pores with a diameter in the range of 40-8000 nm and (ii) the specific length of the catalyst particles is in the range of 0.01-0.90 ml/(g*mm) and wherein the catalyst has a total pore volume of at least 0.20 ml/g and the volume in the catalyst pores with a diameter in the range of 40-8000 nm is below 0.30 ml/g. The invention further pertains to the use of this catalyst in the alkylation of hydrocarbons.

Abstract: A catalyst for trimerization of ethylene is disclosed which comprises (a) a chromium complex having a neutral multidentate ligand having a tripod structure, represented by the formula, ACrJnQ3-n wherein A is a neutral multidentate ligand having a tripod structure, J is a carbonyl ligand or halogen, n is an integer of 0-3, and Q is at least one member selected from hydrogen, a C1-C10 hydrocarbon group, a C1-C10 carboxylate group, a C3-C10 diketonato group, an amide group, an imide group, an C1-C10 alkoxide group, a C1-C10 thioalkoxide group, an C6-C15 arene ligand, an C2-C10 alkene ligand, an C2-C15 alkyne ligand, an amine ligand, an imine ligand, an isonitrile ligand, a phosphine ligand, a phosphine oxide ligand, a phosphite ligand, an ether ligand, a sulfide ligand, a sulfone ligand and a sulfoxide ligand, and (b) a metal alkyl compound.

Abstract: A process for the alkylation of aromatic substrates under supercritical or near-critical reaction conditions is described. In particular, a method for performing Friedel-Crafts alkylation reactions is disclosed under those conditions. Friedel-Crafts reactions may be effected using a heterogeneous catalyst in a continuous flow reactor containing a supercritical or near-critical reaction medium. Selectivity of product formation can be achieved by varying one or more of temperature, pressure, catalyst, flow rates and also by varying the ratios of aromatic substrate to alkylating agent.

Abstract: A process for alkylation of an isoparaffin with an olefin comprising contacting an isoparaffin containing feed with an olefin-containing feed in the presence of a catalyst, said catalyst is a supported heteropoly acid catalyst, which is represented by the following chemical formula: HkYWmMo12-nO40·nH2O, wherein k is 3 or 4, Y is an atom of P, Si, Ge or As, m is a positive integer between 0-12, n is any number in the range of >0-10; the reaction temperature is at least equal to the critical temperature of isoparaffin and up to 300° C.; the reaction pressure is at least equal to the critical pressure of isoparaffin. The advantages of this process are embodied in high olefin conversion, high alkylate yield, and good retention of catalyst stability at the same time.

Abstract: An alkylation catalyst including a least one porous refractory metal oxide with at least one halogen on the surface thereof. The catalyst contains 0.005-1 wt % of at least one metal from groups IA and IIA of the periodic table of the elements and is particularly useful in an isobutane alkylation method using light olefins.

Abstract: Process for the alkylation of paraffinic and/or aromatic hydrocarbon feedstock with an olefinic alkylating agent by contact with a perfluorinated alkyl sulphonic acid movably adsorbed within a confined area of a fixed bed of particle contact material, wherein the fixed bed of particle contact material is subdivided in a number of elongated channels.

Abstract: Disclosed are various embodiments for alkylating olefins and isoparaffins in the presence of an acid to reduce and/or control acid consumption or maximize and/or control the octane number of the produced alkylate product. One embodiment includes alkylation by controlling the C3/iso-C5 olefin ratio to reduce acid consumption. Another embodiment includes alkylation of C3 and C5 olefins in separate alkylation zones to maximize alkylate octane number. Even another embodiment includes propylene alkylation followed by C4 and/or C5 olefin alkylation, with the spent propylene acid used in the C4 and/or C5 olefin alkylation. Still another embodiment includes alkylation of C3, C4 and C5 olefins in separate alkylation zones, with the spent propylene acid used in the C4 alkylation, and the spent butylene acid used in the C5 alkylation. Yet another embodiment includes alkylation by controlling the C3/C4 olefin ratio to maximize the octane number of the produced alkylate.

Abstract: A solid catalyst alkylation process that wets catalyst particles with the alkylation substrate prior to introducing the catalyst particles to a liquid phase alkylation reactor is disclosed. A vapor stream from the wetting step that comprises the alkylation substrate and a reactor effluent stream comprising product alkylate and excess alkylation substrate are both passed to the product recovery zone, which recovers the alkylate product and recycles the alkylation substrate. Routing the vapor stream and the reactor effluent stream together to the product recovery zone minimizes pressure imbalances, ensures steady catalyst flow, and minimizes equipment costs. This process is applicable to alkylation processes that produce motor fuels.

Abstract: This invention relates to an improved method for the alkylation reaction of isoparaffins with olefins over solid catalysts including contacting a mixture of an isoparaffin, an olefin and a phase-modifying material with a solid acid catalyst member under alkylation conversion conditions at either supercritical fluid, or near-supercritical fluid conditions, at a temperature and a pressure relative to the critical temperature(T.sub.c) and the critical pressure(P.sub.c) of the reaction mixture. The phase-modifying phase-modifying material is employed to promote the reaction's achievement of either a supercritical fluid state or a near-supercritical state while simultaneously allowing for decreased reaction temperature and longer catalyst life.

Abstract: The invention concerns the catalytic alkylation of at least one isoparaffin selected from the group formed by isobutane and isopentane in the presence of at least one olefin containing 3 to 6 carbon atoms per molecule, using a catalyst comprising 40% to 99% by weight of an acid selected from acids with formula R--SO.sub.3 H where R is fluorine or an alkyl group or a fluorinated alkyl group, R preferably being F or CF.sub.3, and more preferably CF.sub.3, and 1% to 60% by weight of a solvent selected from the group formed by sulpholane, dimethylsulphoxide and dioxanes, preferably sulpholane.

Abstract: The invention concerns NU-88 zeolite, characterized by:i) a chemical composition with the following formula, expressed in terms of the mole ratios of the oxides for the anhydrous state:100 XO.sub.2, mY.sub.2 O.sub.3, pR.sub.2/n Owherem is 10 or less;p is 20 or less;R represents one or more cations with valency n;X represents silicon and/or germanium;Y represents one or more of the following elements: aluminium, iron, gallium, boron, titanium, vanadium, zirconium, molybdenum, arsenic, antimony, chromium and manganese; andii) an X ray diffraction diagram, in its as synthesized state, which comprises the results shown in Table 1 of the description.The invention also concerns the preparation of the zeolite, any catalyst containing the zeolite and any catalytic process using such a catalyst.

Abstract: A method is disclosed for producing branched aliphatic ketones in hydrocarbon mixtures from isoalkanes by a superacid catalyzed formylation-rearrangement reaction. The method can be used to simultaneously isomerize, if necessary, and formylate hydrocarbons in complex hydrocarbon mixtures such as refinery streams, alkylate mixtures, and natural gas liquids. Natural gas liquids of low octane number are upgraded and oxygenated by adding to the natural gas liquids or reactively producing in the liquids branched aliphatic ketones.

Abstract: The invention pertains to a process for alkylating hydrocarbons in which an alkylatable organic compound is reacted with an alkylation agent to form an alkylate in the presence of a catalyst comprising a hydrogenating function and a solid acid constituent, with the catalyst being subjected intermittently to a regeneration step by being contacted with a feed containing a saturated hydrocarbon and hydrogen, said regeneration being carried out at 90% or less of the active cycle of the catalyst, with the active cycle of the catalyst being defined as the time from the start of the feeding of the alkylation agent to the moment when 20% of the alkylation agent leaves the catalyst-containing reactor section without being converted, not counting isomerization inside the molecule. The process according to the invention is especially attractive for the alkylation of isobutane with one or more butenes to form an alkylate with a high RON.

Abstract: There is provided catalysts and conversion processes for converting hydrocarbons using the catalysts. The catalysts comprises a first alumino-phosphospho-molecular sieves and a binder comprising a second alumino-phopho-molecular sieves. Exemplary conversion processes include the conversion of oxygenates to olefins, dewaxing, reforming, dealkylation, dehydrogenation, transalkylation, alkylation, and isomerization.

Abstract: An HF-agent complex, such as HF-pyridine complex where the complexing agent is pyridine, is recovered and recycled from a by-product stream containing ASO, and ASO is rejected from the by-product stream, in an alkylation process using the complex.

Abstract: A process for preparing high-octane gasoline components consists in that a feed stock, composed of isobutane and olefins, preferably butylenes, in a molar ratio between 1 and 40, is contacted at temperatures of from about 50 to about 160.degree. C. and at pressures of from about 1 to about 40 atm. with a heterogeneous acid catalyst, whose active component is a metal-complex or metaloxopolymeric compound of the general formula H.sub.k (Me.sup.1); (Me.sup.2).sub.m O.sub.n X.sub.p wherein k=1-6; j=1-3; m=1-5; n=1-10, p=2-10, dispersed in a porous organic or inorganic matrix, followed by the extraction regeneration of the deactivated catalyst with an organic or inorganic solvent.

Abstract: The invention concerns a catalyst comprising a porous organic or inorganic support and at least one active phase comprising at least one acid selected from acids with formula R--SO.sub.3 H, where R is fluorine or an alkyl group or a fluorinated alkyl group, and at least one weakly basic aprotic organic solvent, the support having been impregnated with the active phase, the catalyst being such that it is essentially constituted by particles with an average diameter in the range 0.1 .mu.m to 150 .mu.m, and being such that before impregnation with the active phase, the support has a total pore volume in the range 0.5 cm.sup.3 /g to 6 cm.sup.3 /g. The invention also concerns the use of the catalyst for aliphatic alkylation.