Abstract: A process for synthesising a zeolite with structure type EUO comprising at least one element X selected from silicon and germanium and at least one element T selected from aluminum, iron, gallium, boron, titanium, vanadium, zirconium, molybdenum, arsenic, antimony, chromium and manganese, comprises reacting an aqueous mixture comprising at least one source of at least one element X, at least one source of at least one element T, and at least one precursor of an organic compound comprising at least one alkylated polymethylene &agr;-&ohgr; diammonium derivative, wherein at least one precursor is selected from monoamines. The zeolite obtained is used as a catalyst in a process for converting hydrocarbon-containing feeds, as an adsorbent to control pollution and as a molecular sieve for separation, and particularly for isomerising aromatic compounds containing 8 carbon atoms.

Abstract: The present invention relates to a process for activating catalysts for isomerizing aromatic compounds containing 8 carbon atoms, the catalysts containing at least one group VIII metal, comprising at least one sulfurization and at least one passivation using ammonia.

Abstract: Process for isomerization of a feedstock that contains aromatic compounds with eight carbon atoms characterized in that it comprises at least one isomerization stage a) that is carried out in the presence of a catalyst that contains at least one metal of group VIII and that is activated according to an activation process that comprises at least one sulfurization stage and at least one stage for passivation with ammonia, and at least one dehydrogenation stage b).

Abstract: This invention relates to a process for synthesis of an EUO-structural-type zeolite that comprises at least one element X that is selected from among silicon and germanium and at least one element T that is selected from among aluminum, iron, gallium, boron, titanium, vanadium, zirconium, molybdenum, arsenic, antimony, chromium and manganese, whereby said process is carried out in the presence of an organic structuring agent that is derived from dibenzyldimethylammonium (DEDMA) or its precursors and in the presence of nuclei of at least one zeolitic material of the same structure as the zeolite that is to be synthesized. The zeolite that is thus obtained has an X/T ratio of between 5 and 50. It is used in particular as a catalyst, for example in a process for isomerization of aromatic compounds with 8 carbon atoms per molecule.

Abstract: The present invention relates to a process for isomerizing aromatic compounds containing 8 carbon atoms, the catalysts containing at least one group VIII metal, comprising at least one sulfurization step and at least one passivation step using ammonia.

Abstract: A process for isomerising a feed comprising aromatic compounds containing 8 carbon atoms is carried out in two steps: an isomerisation step and a dehydrogenation step. In FIG. 1, the feed to be treated is introduced into isomerisation zone R1 via line 1. Substantially pure hydrogen is introduced into line 1 via line 12 and recycled hydrogen is introduced into line 1 via line 13. Hydrogen which circulates in line 13 is purged via line 15. The effluent from isomerisation zone R1 is sent to a separation zone S1 via line 2. In S1, hydrogen contained in the effluent is isolated and recycled to the inlet to isomerisation zone R1 via line 13, the remaining effluent being evacuated from this separation zone S1 via line 3. The fluid contained in line 3 is heated in an oven F1 then evacuated therefrom via line 4. The effluent leaving the oven is enriched in recycled hydrogen via line 14 then it is introduced into dehydrogenation zone R2. The effluent from zone R2 is sent via line 5 to separation zone S2.

Abstract: The invention relates to a catalyst comprising: a matrix consisting of 0 and 100% by weight of &lgr; transition alumina, the complement up to 100% by weight of the matrix being in &ggr; transition alumina, and relative to the total weight of the catalyst, from 0.001 to 2% by weight of silicon, from 0.1 to 15% by weight of at least one halogen chosen from the group formed by fluorine, chlorine, bromine and iodine, from 0.01 to 2% by weight of at least one noble metal from the platinum group, from 0.005 to 10% by weight of at least one promoter metal chosen from the group formed by tin, germanium, indium, gallium, thallium, antimony, lead, rhenium, manganese, chromium, molybdenum and tungsten, and if required from 0.001 to 10% by weight of a doping metal.

Abstract: For isomerising aromatic compounds containing eight carbon atoms in the presence of hydrogen, a mixture containing compounds with a boiling point of about 80° C. to 135° C. comprising at least one paraffin containing eight carbon atoms, at least one naphthene containing eight carbon atoms, at least benzene and at least toluene is added to the feed before introducing it into the isomerisation reactor R via line 1. These additions are made by a recycle via line 6 or by adding fresh compounds via line 11, or be a combination of fresh and recycled compounds via lines 6 and 11. Hydrogen is added via line 15.

Abstract: Paraxylene and ethylbenzene are produced from an aromatic hydrocarbon feedstock by using adsorption zones in a simulated fluid bed. The feedstock is first passed into a first adsorption zone to produce a first paraxylene-rich fraction and a second ethylbenzene-rich fraction. The second fraction is then passed into a second adsorption zone to produce a third fraction containing essentially pure ethylbenzene and a fourth fraction containing a majority of orthoxylene and metaxylene. The fourth stream is then passed into an isomerization zone to produce an isomerate which is then recycled back to the first adsorption zone.

Abstract: The present invention relates to a process for isomerizing aromatic C8 cuts in the presence of a catalyst containing a mordenite which is slightly or not dealuminated and a binder. This mordenite is generally present at least in part in its acid form and its Si/Al atomic ratio is less than 20, preferably in the range 5 to 15, and more preferably in the range 5 to 10. The catalyst also contains at least one metal from group VIII of the periodic table, preferably selected from the group formed by palladium and platinum. Finally, the catalyst further contains at least one metal from group III of the periodic table, namely gallium, indium or thallium, preferably indium, and optionally at least one metal from group IV of the periodic table, namely germanium, tin or lead, preferably tin. The present invention also relates to the catalyst used in the isomerization process and to a process for its preparation.

Abstract: A C.sub.8 aromatic feedstock is isomerized by an isomerization stage conducted at 320-380.degree. C. with a catalyst containing at least one EUO-structure-type zeolite and at least one metal of group VIII, to obtain an effluent containing isomerized alkyl aromatics and about 10-30% by weight of naphthenes. The effluent is then subjected to a dehydrogenation stage so as to convert the naphthenes to additional alkyl aromatics.

Abstract: The invention concerns a catalyst comprising at least one zeolite with structure type EUO for example EU-1, at least partialy in its acid form, at least one matrix, and at least one metal from group VIII of the periodic table. the zeolite comprising silicon and at least one element T selected from the group formed by aluminium, iron, gallium and boron (preferably aluminium and boron), with a global Si/T atomic ratio over 5, the catalyst being characterized in that the dispersion of the group VIII metal is in the range 50% to 100%, limits included, and the macroscopic distribution coefficient of the group VIII metal is in the range 0.7 to 1.3, limits included, the catalyst having a mechanical strength such that the bed crush strength is more than 0.7 MPa. The invention also relates to the preparation of the catalyst and to the use of the catalyst in a process for isomerizing aromatic compounds containing 8 carbon atoms per molecule.

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: The invention concerns the use of a catalyst for the dismutation of alkylaromatic hydrocarbons, and preferably for the dismutation of toluene to produce benzene and xylenes, and/or for the transalkylation of alkylaromatic hydrocarbons, preferably for the transalkylation of toluene and trimethylbenzenes to produce xylenes. The catalyst comprises a zeolite with structure type mazzite, comprising silicon and at least one element T selected from the group formed by gallium and aluminium, preferably aluminium, in which the number of extra-network T atoms is less than 15% of the global number of T atoms present in the zeolite, in which the global Si/T aromatic ratio is in the range 5 to 100, and its preparation by extraction of element T from the zeolitic framework, preferably by dealuminization of the framework by means of at least one hydrothermal treatment followed by at least one acid attack.

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: The invention concerns a catalyst comprising at least one matrix and at least one zeolite of structure type mazzite, preferably omega zeolite, comprising silicon and aluminium, at least partially, preferably practically completely in its acid form, said zeolite having been prepared by dealuminization of the framework, by means of at least one treatment using at least one solution of a fluorosilicate of a cation in a proportion of 0.05 to 5 moles per mole of aluminium contained in the dry zeolite, said catalyst optionally comprising at least one element selected from groups IB and VIII of the periodic classification of the elements. The invention also concerns the use of said catalyst for the dismutation of alkylaromatic hydrocarbons, and preferably for the dismutation of toluene to produce benzene and xylenes, and/or for the transalkylation of alkylaromatic hydrocarbons, preferably for the transalkylation of toluene and trimethylbenzenes to produce xylenes.

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 catalyst for transforming aromatic hydrocarbons, preferably for dismutation of toluene to produce benzene and xylenes and transalkylation of toluene and aromatic compounds containing at least 9 carbon atoms per molecule, preferably trimethylbenzenes, to produce xylenes, contains a mordenite in its acid form in a proportion of 40% to 90% by weight and a binder, which is preferably alumina, and which is generally present in a proportion of 10% to 60% by weight. The mordenite contains less than 0.1% by weight of sodium and has a SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio of over 40-60.

Abstract: The present invention relates to a catalyst comprising :a matrix consisting of a mixture of .eta. transition alumina, .gamma. transition alumina, andat least one doping metal chosen from the group made up of titanium, zirconium, hafnium, cobalt, nickel, zinc, the lanthanides, the alkali metals and alkaline-earth metals,at least one halogen chosen from the group made up of fluorine, chlorine, bromine and iodine,at least one noble metal from the platinum group, andat least one promoter metal chosen from the group made up of tin, germanium, indium, gallium, thallium, antimony, lead, rhenium, manganese, chromium, molybdenum and tungsten.

Abstract: The invention concerns the use of a catalyst for the dismutation of alkylaromatic hydrocarbons, preferably for the dismutation of toluene to produce benzene and xylenes, and/or for the transalkylation of alkylaromatic hydrocarbons, preferably for the transalkylation of toluene and trimethylbenzenes to produce xylenes. The catalyst is a composite comprising at least one zeolite with structure type mazzite, at least partially in its acid form, at least one zeolite with structure type mordenite, at least partially in its acid form, at least one matrix and, optionally, at least one element selected from the group formed by groups IB and VIII of the periodic classification of the elements.