Abstract: The present invention relates to new crystalline zeolite SSZ-54 prepared using a templating agent comprising N-isopropyl ethylenediamine, or a mixture of 1-N-isopropyl diethylenetriamine and isobutylamine, and processes employing SSZ-54 in a catalyst.

Abstract: Bismuth- and phosphorus-containing catalyst supports, naphtha reforming catalysts made from such supports, methods of making both support and catalyst, and a naphtha reforming process using such catalysts.

Abstract: A process for conversion of hydrocarbon feed by contacting the feed with a catalyst containing heteropoly acid supported on a carrier at reaction conditions being effective in the conversion of the feed, wherein the carrier is selected from substantially inert inorganic amorphous or crystalline material, which retains characteristic structure of the heteropoly acid as evidenced by vibration frequencies around 985 and 1008 cm−1, and which has a surface area larger than 15 m2/g excluding surface area in pores below 15 Å in diameter.

Abstract: A reforming catalyst containing a Group VIII metal, or a Group VII B metal, or tin, or germanium, or copper, or selenium or combinations of any two or more metals or oxides thereof is activated by: a) continuously flowing a reducing gas over the catalyst for contact with the catalyst; (b) during step a), flowing a halogen-containing compound over the catalyst for contact with the catalyst for a first time period, wherein the first time period is greater than about 1 minute, and wherein the first time period is less than about 60 minutes; and (c) following step b), and during step a), substantially discontinuing the flow of the halogen-containing compound over the catalyst for a second time period, wherein the second time period is greater than about 1 minute.

Abstract: There is provided a coated zeolite catalyst in which the accessibility of the acid sites on the external surfaces of the zeolite is controlled and a process for converting hydrocarbons utilizing the coated zeolite catalyst. The zeolite catalyst comprises core crystals of a first zeolite and a discontinuous layer of smaller size second crystals of a second zeolite which cover at least a portion of the external surface of the first crystals The coated zeolite catalyst finds particular application in hydrocarbon conversion processes where catalyst activity in combination with zeolite structure are important for reaction selectivity, e.g., catalytic cracking, alkylation, disproportional of toluene, isomerization, and transalkylation reactions.

Abstract: While a substantially water-free hydrocarbon feed is being charged to a catalytic reformer reactor, an organic chloride is contacted with the reformer catalyst in an amount and for a time period that are effective to restore at least a portion of the activity of the reformer catalyst.

Abstract: A catalyst and a process for using the catalyst are disclosed generally for the conversion of hydrocarbons. By the use of at least one high temperature calcination under dry conditions, a catalyst with a beneficial combination of lowered surface area and excellent piece crush is created. X-ray diffraction pattern information is used to distinguish the resulting product.

Abstract: The invention relates to a homogeneous bed of catalyst particles comprising at least one amorphous matrix, at least one noble metal, at least one additional metal M and at least one halogen, and in which, for a catalyst particle: CPt is the local concentration of noble metal; CM is the local concentration of additional metal M; Cx is the local concentration of halogen; in which catalyst particle bed the local dispersion of the value of CPt/CM or CPt/Cx is termed homogeneous along the diameter of the particle, which corresponds to at least 70% of the values CPt/CM or CPt/Cx deviating by a maximum of 30% from the local average ratio. The invention also relates to a process for transforming hydrocarbons into aromatic compounds with the catalyst, such as a gasoline reforming process and a process for producing aromatic compounds.

Abstract: A novel catalyst and the use thereof in a reforming process is disclosed. The catalyst comprises a refractory inorganic oxide, platinum-group metal, Group IVA(IUPAC 14) metal, indium and lanthanide-series metal. Utilization of this catalyst in the conversion of hydrocarbons, especially in reforming, results in significantly improved selectivity to the desired gasoline or aromatics product.

Abstract: There is provided a process for converting hydrocarbons using a catalyst comprising macrostructures having a three-dimensional network of particles comprised of porous inorganic material. The particles of the macrostructures occupy less than 75% of the total volume of the macrostructures and are joined together to form a three-dimensional interconnected network comprised of pores having diameters greater than about 20 Å. The macrostructures can be made by forming an admixture containing a porous organic ion exchanger and a synthesis mixture capable of forming the porous inorganic material; converting the synthesis mixture to the porous inorganic material; and removing the porous organic ion exchanger from the inorganic material.

Abstract: Deactivation of a reformer catalyst is inhibited by charging a hydrocarbon feed having a concentration of an organic aluminum halide compound to a reformer reactor operating under reforming conditions and containing a reformer catalyst.

Abstract: Catalyst activation of a platinum reforming catalyst system contained in a multiple reactor system by simultaneously reducing the catalyst with hydrogen while introducing a nonmetallic chlorine-containing compound into a reactor of the multiple reactor system in an amount to add from about 0.05 to about 0.3 weight percent chlorine to the catalyst and thereafter purging the system with about 100 to about 50,000 cubic feet of hydrogen per cubic foot of catalyst resulting in a reforming system having increased activity and providing enhanced RON values with reduced cracking of feedstock.

Abstract: A substantially water-free hydrocarbon feed is charged to a multiple-reactor reformer system being operated under reforming conditions and comprising at least two reformer reactors serially connected in fluid-flow communication and each containing a reformer catalyst; and, simultaneously with the charging step, a chloriding agent is sequentially introduced, without simultaneously introducing water, immediately upstream from the inlets of all the reformer reactors in an amount and for a period of time that are effective to inhibit the deactivation of the reformer catalyst.

Abstract: For transforming hydrocarbons into aromatic compounds, the reaction is conducted on a homogeneous bed of catalyst particles, said catalyst comprising at least one amorphous matrix, at least one noble metal, at least two additional metals M1 and M2 and at least one halogen, and in which, for a catalyst particle, Cpt is the local concentration of platinum; CM1 is the local concentration of additional metal M1; CM2 is the local concentration of additional metal M2; in which the standard deviation of the distribution of the local ratios of the concentrations of the additional metals, CM1/CM2, measured along the particle diameter, is better than 25% relative.

Abstract: Catalyst activation of a platinum reforming catalyst system contained in a multiple reactor system by simultaneously reducing the catalyst with a sustained hydrogen flow through the multiple reactor system while introducing a nonmetallic chlorine-containing compound serially into each reactor of the multiple reactor system in an amount to provide from about 0.05 to about 0.3 weight percent chlorine on the catalyst and thereafter purging the system with about 100 to about 50,000 cubic feet of hydrogen per cubic foot of catalyst prior to commencing use of the treated catalyst system for reforming hydrocarbon feed.

Abstract: A method for regenerating a hydrocarbon conversion catalyst wherein at least a portion of a halogen-containing compound is precombusted in a precombustion zone, and the catalyst is regenerated in the presence of the halogen. By precombusting the halogen-containing compound in a precombustion zone rather than in the regeneration zone, this invention decreases the risk of permanent catalyst deactivation and of costly equipment damage in the regeneration zone. This method is adaptable to many processes for the catalyst conversion of hydrocarbons in which deactivated catalyst particles are regenerated in a moving bed.

Abstract: Catalyst activation of a platinum reforming catalyst system contained in a multiple reactor system by simultaneously reducing the catalyst with hydrogen while introducing a nonmetallic chlorine-containing compound into a reactor of the multiple reactor system in an amount to provide from about 0.05 to about 0.3 weight percent chlorine on the catalyst and thereafter purging the system with about 100 to about 50,000 cubic feet of hydrogen per cubic foot of catalyst resulting in a reforming system having increased activity and providing enhanced RON values with reduced cracking of feedstock.

Abstract: Catalyst activation of a platinum reforming catalyst system contained in a multiple reactor system by simultaneously reducing the catalyst with a sustained hydrogen flow through the multiple reactor system while introducing a nonmetallic chlorine-containing compound serially into each reactor of the multiple reactor system in an amount to provide from about 0.05 to about 0.3 weight percent chlorine on the catalyst and thereafter purging the system with about 100 to about 50,000 cubic feet of hydrogen per cubic foot of catalyst prior to commencing use of the treated catalyst system for reforming hydrocarbon feed.

Abstract: A process of hydroreforming in the presence of a catalyst containing at least one refractory inorganic carrier, platinum, possibly at least one metal from Group VIII (palladium, nickel, and ruthenium), a halogen or compound thereof, and at least one additional metal M selected from among germanium, tin, lead, gallium, indium, and thallium, process in which said metal M, in the form of at least one organic compound, is introduced in situ into the reactor where the hydrocarbon charge will then be treated or into a prereactor that is connected to said reactor.

Abstract: A catalytic reforming process comprising the catalytic conversion of hydrocarbons to aromatics, said process comprising treating a halided zeolite catalyst (hiz-cat) containing a Group VIII metal at commercial startup conditions and then reforming hydrocarbons, wherein said catalyst is prepared by washing a bound zeolite catalyst base or a bound zeolite catalyst before halide addition. A preferred hiz-cat is a non-acidic Pt K L-zeolite catalyst prepared by a process that includes the steps of preparing a calcined silica-bound K L-zeolite catalyst base; washing said bound zeolite catalyst base with a liquid comprising water; and incorporating Pt and halogen-containing compound(s) comprising chlorine and fluorine into said washed catalyst base. Ammonium chloride and ammonium fluoride are preferred halide sources.

Abstract: A catalytic reforming process comprising the catalytic conversion of hydrocarbons to aromatics, said process comprising treating a halided zeolite catalyst (hiz-cat) containing a Group VIII metal at commercial startup conditions and then reforming hydrocarbons, wherein said catalyst is prepared by washing a bound zeolite catalyst base or a bound zeolite catalyst before halide addition. A preferred hiz-cat is a non-acidic Pt K L-zeolite catalyst prepared by a process that includes the steps of preparing a calcined silica-bound K L-zeolite catalyst base; washing said bound zeolite catalyst base with a liquid comprising water; and incorporating Pt and halogen-containing compound(s) comprising chlorine and fluorine into said washed catalyst base. Ammonium chloride and ammonium fluoride are preferred halide sources.

Abstract: In a method of removing acidic compounds, color, and polynuclear aromatic hydrocarbons, and for removing or converting hydrocarbons containing heteroatoms from used oil distillate, phase transfer catalysts are employed to facilitate the transfer of inorganic or organic bases to the substrate of the oil distillate. An inorganic or organic base, a phase transfer catalyst selected from the group including quaternary ammonium salts, polyol ethers and crown ethers, and used oil distillate are mixed and heated. Thereafter, contaminants are removed from the used oil distillate through distillation.

Abstract: A hydrocarbon feedstock is catalytically reformed in a sequence comprising a first bifunctional-catalyst reforming zone, a zeolitic-reforming zone containing a catalyst comprising a platinum-group metal and a nonacidic zeolite, and a terminal bifunctional catalyst reforming zone. The first and terminal bifunctional catalysts preferably comprise a lanthanide-series metal component. The process combination permits higher severity, higher aromatics yields and/or increased throughput relative to the known art, and is particularly useful in connection with moving-bed reforming facilities with continuous catalyst regeneration.

Abstract: A composition is prepared by a method which comprises mixing a first solid material comprising a platinum group metal, a rhenium component, a porous carrier material and, optionally, a halogen component and a second solid material comprising silica and bismuth. The thus-obtained composition is employed as a catalyst in the conversion of hydrocarbons to aromatics. In an alternate embodiment, hydrocarbons are converted to aromatics by sequentially contacting the hydrocarbons with the first solid material and then the second solid material.

Abstract: A method is disclosed for decreasing the emissions of chlorine-containing species from a moving bed process for regenerating spent catalyst particles with a recycle gas stream. A recycle gas stream contacts spent catalyst particles at regeneration conditions, thereby producing a flue gas stream. The flue gas stream which contains chlorine-containing species contacts spent catalyst particles at sorption conditions. The spent catalyst particles sorb the chlorine-containing species from the flue gas stream, thereby producing the recycle gas stream. A portion of the recycle gas stream is vented from the process. This method captures and returns to the process the chlorine-containing species that would be lost from the process and that would need to be replaced by the injection of make-up chlorine-containing species. This method results in a significant savings in capital and operating costs of the process.

Abstract: An isomerization process for converting an isomerization feed stream containing alkanes having about 4 carbon atoms to about 10 carbon atoms per molecule and cycloalkanes having about 5 carbon atoms to about 10 carbon atoms per molecule to at least one product hydrocarbon isomer. The isomerization feed stream, which contains at least one feed hydrocarbon and hydrogen, is contacted in an isomerization zone at effective isomerization conditions with a catalyst where deactivation of such catalyst occurs in the isomerization zone. The isomerization process includes the presence of an additive in the isomerization feed stream. The concentration of the additive is sufficient to alleviate or diminish the deactivation of the catalyst and to maintain a substantially constant conversion of the at least one feed hydrocarbon to the at least one product hydrocarbon isomer at effective isomerization conditions.

Abstract: In a process for the dehydrocyclization of a dehydrocyclizable hydrocarbon contained in a dehydrocyclization feed stream which comprises contacting said dehydrocyclizable hydrocarbon in a dehydrocyclization zone under dehydrocyclization conditions in the presence of a dehydrocyclization catalyst, the improvement comprises carrying out said dehydrocyclization process in the presence of a metal chloride additive in said dehydrocyclization feed stream, said metal chloride additive being present in an amount sufficient to inhibit deactivation of such dehydrocyclization catalyst.

Abstract: A reforming process, selective for the dehydrocyclization of paraffins to aromatics, is effected using a catalyst containing a uniformly distributed platinum-group metal component, a surface-layer metal component comprising one or more of the Group IVA metals, indium, Group VIIB (IUPAC 7) metals, iron, zinc, gold and bismuth and a nonacidic large-pore molecular sieve. The use of this bed of catalyst results in greater selectivity of conversion of paraffins to aromatics and in improved catalyst stability.

Abstract: A novel catalyst and the use thereof in a reforming process is disclosed. The catalyst comprises a refractory inorganic oxide, platinum-group metal, Group IVA(IUPAC 14) metal, and lanthanide-series metal in a specified ratio. Utilization of this catalyst in the reforming of hydrocarbons, especially in reforming, results in significantly improved selectivity to the desired gasoline or aromatics product.

Abstract: A novel catalyst and the use thereof in a reforming process is disclosed. The dual-function catalyst comprises a refractory inorganic oxide, indium, Group IVA(IUPAC 14) metal, and a platinum-group metal concentrated in the surface layer of each catalyst particle. Utilization of this catalyst in the conversion of hydrocarbons, especially in reforming, results in significantly improved selectivity to the desired gasoline or aromatics product.

Abstract: A process for converting hydrocarbons into aromatic compounds, which entails contacting a composition containing hydrocarbons with a catalyst under temperature and pressure conditions to produce the aromatic compounds, the catalyst containing a matrix of .eta. transition alumina and/or .gamma. transition alumina. The catalyst contains 0.001 to 2 wt % of silicon, 0.1 to 15 wt % of at least one platinum group metal, and 0.005 to 10 wt % of at least one promoter metal. The promoter metals may be tin, germanium, indium, gallium, thallium, antimony, lead, rhenium, manganese, chromium, molybdenium or tungsten. The catalyst may also contain a doping metal.

Abstract: A catalytic reforming process comprises a prereactor which provides an intermediate stream to 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-bed 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 novel catalyst and the use thereof in a reforming process is disclosed. The catalyst comprises a refractory inorganic oxide, platinum-group metal, Group IVA(IUPAC 14) metal, indium and lanthanide-series metal. Utilization of this catalyst in the conversion of hydrocarbonsaromatics product.

Abstract: Gasolines are reformed and parafin and naphthene hydrocarbons are converted to aromatic compounds by contacting the hydrocarbons with a catalyst comprising a matrix of .eta. transition alumina and .gamma. transition alumina. The catalyst contains at least one doping metal, at least one halogen, at least one noble metal and at least one promoter metal. The doping metals are selected from titanium, zirconium, hafnium, cobalt, nickel, zinc, and the lanthanides and the promoter metals are selected from tin, germanium, indium, gallium, thallium, antimony, lead, rhenium, manganese, chromium, molybdenum and tungsten.

Abstract: A large pore volume catalyst was used for reforming heavy cracked naphtha. The average pore diameter is preferably between about 110 to 150 Angstroms. Improved catalytic stability and improved liquid yield was achieved. As a result of the improvement a 101 RON debutanized naphtha reformate is produced at a reduced catalyst aging rate.

Abstract: A process for the conversion of a hydrocarbon load containing paraffin, naphthene and aromatic hydrocarbons having 5 to 12 carbon atoms into aromatic compounds, which entails contacting the load with a catalyst under temperature and pressure conditions to produce the aromatic compounds, the catalyst containing:a matrix consisting of 0 to 100% by weight of .eta. transition alumina, the remaining weight percentage of the matrix, up to 100%, consisting of .gamma. transition alumina, andat least one doping metal selected from the group consisting of alkali metals and alkaline-earth metals,at least one halogen selected from the group consisting of fluorine, chlorine, bromine and iodine,at least one noble metal selected from the platinum group, andat least one promoter metal selected from the group consisting of tin, germanium, indium, gallium, thallium, antimony, lead, rhenium, manganese chromium, molybdenum and tungsten,the catalyst having previously been hydrothermally treated at a temperature of 300 to 1,000.

Abstract: A method is disclosed for recovering chlorine-containing species from the outlet gas of a hydrocarbon conversion process with a cyclic regeneration operation. The outlet gas from an off-stream catalyst bed in which regeneration is occurring is passed to another off-stream catalyst bed which contains spent catalyst and which is maintained at sorption conditions. The spent catalyst particles sorb the chlorine-containing species from the outlet gas. This method captures and retains within the hydrocarbon conversion process chlorine-containing species that would otherwise be scrubbed and lost from the process and that would need to be replaced by the injection of make-up chlorine-containing species. This method results in significant savings in operating costs of a cyclic regeneration process. This method is adaptable to many processes for the catalytic conversion of hydrocarbons in which deactivated catalyst are regenerated by a cyclic regeneration operation.

Abstract: A hydrocarbon feedstock is catalytically reformed in a sequence comprising a first bifunctional-catalyst reforming zone, a zeolitic-reforming zone containing a catalyst comprising a platinum-group metal and a nonacidic zeolite, and a terminal bifunctional catalyst reforming zone. The first and terminal bifunctional catalysts preferably comprise a lanthanide-series metal component. The process combination permits higher severity, higher aromatics yields and/or increased throughput relative to the known art, and is particularly useful in connection with moving-bed reforming facilities with continuous catalyst regeneration.

Abstract: A catalytic reforming process using a halided zeolite catalyst containing platinum in a metal-coated reactor system where, prior to catalyst loading and reforming, halide acid is removed from the catalyst. The process comprises providing a reforming reactor system having a metal coating; providing a halided zeolite catalyst containing platinum prepared by a method which includes removing volatile halide acid; loading said catalyst into said reactor system; and catalytically reforming hydrocarbons to aromatics, wherein metal from the metal-coated reactor system does not deactivate the catalyst. The coating metal preferably comprises tin and the zeolite catalyst is preferably a platinum L-zeolite catalyst. The invention is also a method for reducing catalyst contamination from a metal which was used to coat a reactor system. The method comprises pretreating a halided catalyst with hydrogen to remove volatile halide acid.

Abstract: A hydrocarbon feedstock is catalytically reformed in a sequence comprising a first bifunctional-catalyst reforming zone, a zeolitic-reforming zone containing a catalyst comprising a platinum-group metal and a nonacidic zeolite, and a terminal bifunctional catalyst reforming zone. The process combination permits higher severity, higher aromatics yields and/or increased throughput relative to the known art, and is particularly useful in connection with moving-bed reforming facilities with continuous catalyst regeneration.

Abstract: A catalytic reforming process is disclosed using a catalyst containing a Group VIII metal, low amounts of bismuth, and a zeolite L. The catalyst is a non-acidic, monofunctional reforming catalyst. Preferably, the catalyst contains one or more halogens. Preferably, the feed includes C.sub.8 hydrocarbons. The addition of small amounts of bismuth increase or substantially maintain catalyst stability. Unexpectedly low dealkylation rates are achieved using the catalyst while reforming to produce aromatics, especially to produce xylenes such as paraxylene.

Abstract: A hydrocarbon conversion process wherein austenitic stainless steel portions that are subject to halide stress-corrosion cracking conditions, such as the colder portions of the process equipment including effluent coolers, knockout drums, accumulation drums, and piping low points, are provided with a protective layer having improved halide stress-corrosion cracking resistance. The method comprises applying a metal cladding, plating, paint or other coating to a stressed portion of austenitic stainless steel hydrocarbon conversion process equipment, optionally curing the coated steel to form intermetallic compounds to protect the steel portions; converting hydrocarbons utilizing a halided catalyst or under conditions where a halogen-containing compound is added or evolved or both; and subjecting the protected steel portion to halide stress-corrosion cracking conditions.

Abstract: A novel catalyst and the use thereof in a reforming process is disclosed. The catalyst comprises a refractory inorganic oxide, platinum-group metal, Group IVA(IUPAC 14) metal, and europium in a specified ratio. Utilization of this catalyst in the reforming of hydrocarbons, especially in reforming, results in significantly improved selectivity to the desired gasoline or aromatics product.

Abstract: Acidic halides, especially chlorides, are removed from liquid hydrocarbons such as catalytic reformate by contact with solid caustic such as a bed of NaOH pellets covered with a thin film of brine. Hydration of reformate improves removal when large amounts of chlorides are present in reformate. Halides in liquid hydrocarbon are recovered as a brine phase, which can be only slightly alkaline. Hydration of reformate can be controlled based on pH of brine removed from the bed.

Abstract: Acidic halides, especially chlorides, are removed from dry process vapor and liquid hydrocarbon streams by contact with solid caustic, such as a bed of NaOH. Salt deposits from form on the solid caustic, which are periodically removed by passing a liquid hydrocarbon continuous phase containing a minor amount of dissolved or entrained water over the solid caustic. Salts may be removed from the liquid hydrocarbon by extraction with water, which also saturates the liquid hydrocarbon so that it may be used to remove additional salt deposits.

Abstract: The invention concerns a process for reducing the benzene content of petrol fractions, in which hydrogenation is carried out on a feed with the following composition by weight: 40% to 80% of paraffins, 0.5% to 7% of cyclic hydrocarbons and 6% to 45% of aromatics, and with a maximum distillation temperature of between 70.degree. C. and 90.degree. C., followed by isomerisation of the effluent from the hydrogenation step, mixing said feed and/or said effluent with a C.sub.5 -C.sub.6 cut; said process being characterised in that an isomerisation catalyst is used which contains chlorine and at least one group VIII metal deposited on a support composed of a mixture of specific proportions of eta alumina and gamma alumina.

Abstract: The present invention is directed to an improved isomerization process employing a catalyst wherein the catalyst comprises a pair of catalyst particles of different acidity utilized either as distinct beds of such discrete particles or as a mixture of such discrete particles. The isomerization process utilizing such a catalyst produces a product which exhibits higher VI as compared to products produced using either catalyst component separately or using a single catalyst having the average acidity of the two discrete catalysts.

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: Reforming is effected with a combination of a primary supported noble-metal catalyst and a catalyst containing one or more medium-pore non-zeolitic molecular sieves (MP-NZMS). The latter reforming and dehydrocyclization catalysts comprise a Group VIII metal and at least one bound MP-NZMS characterized in the calcined form by an adsorption of isobutane of at least 2 percent by weight at a partial pressure of 500 torr and a temperature of 20.degree. C. and characterized by an adsorption of triethylamine less than about 5 percent by weight at a partial pressure of 2.6 torr and a temperature of 22.degree. C. The MP-NZMS catalyst binder preferably is alumina and/or silica, and the Group VIII metal preferably is platinum.

Abstract: The invention concerns a process for reducing the benzene content of petrol fractions and isomerizing paraffins in the presence of an isomerization catalyst comprising 4 to 15% of at least one halogen and at least one metal from group VIII deposited on a support composed of a mixture of specific proportions of eta alumina and gamma alumina, in which isomerization is carried out on a mixture of a) a feed with the following composition by weight: 40% to 80% of paraffins, 0.5% to 7% of cyclic hydrocarbons and 6% to 45% of aromatics, and with a maximum distillation temperature of between 70.degree. C. and 90.degree. C., b) a C.sub.5 -C.sub.6 cut which is generally a straight run cut, and c) a chlorine-containing compound providing a concentration of 50-5000 ppm of chlorine in the mixture.