Abstract: The present invention concerns catalysts which contain at least one zeolite with structure type NES, preferably NU-87, comprising silicon and at least one element T selected from the group formed by aluminium, iron, gallium and boron. Preferably, element T has been extracted so that the overall Si/T atomic ratio is more than 20. This zeolite is at least partially in its acid form. The binder is preferably alumina. The catalyst also contains at least one metal selected from the group formed by group VIIB, group VIB and iridium, preferably molybdenum. Finally, the catalyst optionally also contains at least one metal selected from the group formed by elements from groups IIIA and IVA of the periodic table, preferably indium or tin. The present invention also concerns the use of the catalyst in a process for transalkylating alkylaromatic hydrocarbons such as toluene and alkylaromatic compounds containing at least 9 carbon atoms.

Abstract: The present invention concerns a catalyst which contain at least one zeolite with structure type NES, preferably NU-87, comprising silicon and at least one element T selected from the group formed by aluminium, iron, gallium and boron. Preferably, element T has been extracted so that the overall Si/T atomic ratio is more than 20. This zeolite is at least partially in its acid form. The binder is preferably alumina. The catalyst also contains at least one metal selected from the group formed by group VIIB, group VIB and iridium, preferably rhenium. Finally, the catalyst optionally also contains at least one metal selected from the group formed by elements from groups III and IV of the periodic table, preferably indium or tin. The present invention also concerns the use of the catalyst in a process for transalkylating alkylaromatic hydrocarbons such as toluene and alkylaromatic compounds containing at least 9 carbon atoms.

Abstract: This invention relates to 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. The zeolite of the invention has an X/T ratio of between 5 and 50 and an N/T ratio of between 0.010 and 0.065. This invention also relates to the use of the EUO zeolite as a catalyst in a process for conversion of hydrocarbon feedstocks and more particularly in a process for isomerization of aromatic compounds with 8 carbon atoms per molecule.

Abstract: The present invention concerns a catalyst which contain at least one zeolite with structure type NES, preferably NU-87,, comprising silicon and at least one element T selected from the group formed by aluminium, iron, gallium and boron. Preferably, element T has been extracted so that the overall Si/T atomic ratio is more than 20. This zeolite is at least partially in its acid form. The binder is preferably alumina. The catalyst also contains at least one metal selected from the group formed by group VIIB, group VIB and iridium, preferably rhenium. Finally, the catalyst optionally also contains at least one metal selected from the group formed by elements from groups III and IV of the periodic table, preferably indium or tin. The present invention also concerns the use of the catalyst in a process for transalkylating alkylaromatic hydrocarbons such as toluene and alkylaromatic compounds containing at least 9 carbon atoms.

Abstract: The present invention concerns a process for pretreating a catalyst used in hydrocarbon conversion processes, comprising the following steps: a) pretreating a catalyst containing at least one zeolite with structure type EUO and at least one hydrodehydrogenating metal in the presence of a hydrocarbon feed, at a temperature such that a catalyst comprising carbon is obtained; b) then treating the hydrocarbon feed and the catalyst at a temperature which is lower than the temperature applied in step a). The invention also concerns an activated catalyst and its use in a process for isomerizing aromatic compounds containing 8 carbon atoms.

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 (DBDMA) 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 concerns a catalyst which contain at least one zeolite with structure type NES, preferably NU-87, comprising silicon and at least one element T selected from the group formed by aluminium, iron, gallium and boron. Preferably, element T has been extracted so that the overall Si/T atomic ratio is more than 20. This zeolite is at least partially in its acid form. The binder is preferably alumina. The catalyst also contains at least one metal selected from the group formed by group VIIB, group VIB and iridium, preferably rhenium. Finally, the catalyst optionally also contains at least one metal selected from the group formed by elements from groups III and IV of the periodic table, preferably indium or tin. The present invention also concerns the use of the catalyst in a process for transalkylating alkylaromatic hydrocarbons such as toluene and alkylaromatic compounds containing at least 9 carbon atoms.

Abstract: The invention relates to a process for the production of at least one isomer of xylenes, preferably paraxylene, as well as benzene, starting from a C8-aromatic fraction, whereby said process comprises a zone for separation of xylenes, a zone for isomerization of aromatic compounds with 8 carbon atoms used in the presence of a catalyst that comprises at least one EUO-structural-type zeolite that is selected from among the EU-1, TPZ-3, ZSM-50 zeolites and at least one metal of group VIII of the periodic table, and finally a transalkylation zone of C7- and C9-aromatic compounds. The invention makes it possible to produce paraxylene and benzene with a high yield, starting from a C8-aromatic fraction that comprises a large amount of ethylbenzene with improved performance levels of the isomerization stage and a good conversion of ethylbenzene in the transalkylation stage.

Abstract: The invention concerns a zeolite with structure type EUO comprising EUO zeolite crystals with a size of less than 5 &mgr;m, at least a portion of the EUO zeolite crystals being in the form of EUO zeolite aggregates, characterized in that the granulometry of the aggregates is such that Dv,90 is 500 &mgr;m or less. The invention also concerns the preparation of the zeolite and the use of the zeolite as a catalyst, for example in a process for isomerising aromatic compounds containing 8 carbon atoms per molecule.

Abstract: A process for the production of at least one xylene isomer, paraxylene, metaxylene or orthoxylene from an aromatic feedstock that has 7 to 10 carbon atoms per molecule. The process comprises a stage for transalkylation of C7- and C9-aromatic compounds, a stage for separation of xylenes and a stage for isomerization of xylenes. The isomerization catalyst used in the process comprises at least one EUO zeolite composition whose crystals are grouped in aggregates that have a grain size with a value of Dv,90 less than or equal to 500 microns and at least one element of group VIII.

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 to produce xylenes, contains 40% to 90% by weight of a mordenite in its acid form in a proportion of and 10% to 60% by weight of binders. The mordenite comprises less than 0.1% by weight of sodium and has a Si02/A2O3 molar ratio of over 70. The catalyst also contains at least one metal from groups VI, VII or VIII and optionally an additional metal from groups III or IV.

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 process for the production of paraxilene comprises an adsorption stage (18) using toluene as a desorbent in a simulated moving bed of a feedstock previously depleted in ethylbenzene by distillation (3) or by adsortion, an isomerization stage (26) without hydrogen in liquid phase diluted with toluene from the raffinate produced, a distillation stage (27) of the raffinate that is isomerized to recover the toluene (29) that is recycled. The separated isomerate is introduced into a xylene distillation column (9). The separated ethylbenzene is isomerized separately in gas phase with hydrogen at higher temperature and is distilled (5, 2, 9) in the presence of a catalyst that comprises an EUO-structural-type zeolite, then recycled to adsorption stage (18).

Abstract: The invention concerns a process for producing at least one compound selected from 2-, 3-, 4-, 5- and 6-phenylalkanes by alkylating benzene using at least one olefin containing at least 9 carbon atoms per molecule, in the presence of a catalyst comprising at least one zeolite with structure type EUO, at least partially in its acid form and at least one matrix, said 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 an Si/T atomic ratio of more than 5; said process being carried out at a temperature in the range 30° C. to 400° C., a pressure in the range 0.1 to 10 MPa, with an hourly space velocity of 0.50 to 200 h−1, and a benzene/olefins mole ratio in the range 1:1 to 50:1.

Abstract: A process for the production of paraxylene is described that comprises an adsorption stage (18) that uses toluene as a desorbent in a simulated moving bed of a feedstock whose ethylbenzene was separated by distillation (line 3) or by adsorption, an isomerization stage (26) without hydrogen in liquid phase that is diluted with toluene from the raffinate produced, a distillation stage (27) of the raffinate that is isomerized to recover the toluene (line 29) that is recycled. The separated isomerate is introduced into a xylene distillation column (9) then recycled, in adsorption. The separated ethylbenzene is isomerized separately in gas phase with hydrogen at higher temperature and is distilled (5, 2, 9) in the presence of a catalyst that comprises an EUO-structural-type zeolite, then recycled in adsorption column (18). The pure paraxylene is collected as extract (line 22) then optionally purified by crystallization (17).

Abstract: A process for the production of at least one isomer of xylenes comprising a simulated moving-bed adsorption (8) of a C8-aromatic feedstock (1) that delivers a paraxylene-rich fraction (9) that is optionally purified after a distillation (16) by at least one high-temperature crystallization (5) and a fraction (10) that is low in paraxylene is described. Fraction (10) is distilled and then isomerized (21) in the presence of an EUO-structural-type catalyst. The lightest hydrocarbons are removed from the isomerization effluent in a first distillation (23) then naphthenes in a second distillation (26), and distilled isomerization effluent (2) that results therefrom is recycled at least in part in adsorption (8). A mother liquor (3) that results from the crystallization stage is recycled at least in part in adsorption (8).

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: The present invention concerns a process for preparing 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 iron, aluminium, gallium, boron, titanium, vanadium, zirconium, molybdenum, arsenic, antimony, chromium and manganese, characterized in that seeds of at least one zeolitic material are used comprising at least one element X′ selected from silicon and germanium and at least one element T′ selected from iron, aluminium, gallium, boron, titanium, vanadium, zirconium, molybdenum, arsenic, antimony, chromium and manganese with a ratio X′/T′ of less than 200, said seeds being different from the zeolite with structure type EUO being prepared.

Abstract: A process for isomerising aromatic compounds containing eight carbon atoms is described in which the catalyst used contains at least one zeolite with structure type EUO and a group VIII element. In FIG. 1, the feed to be isomerised is introduced into reactor R via line 1. This fresh feed is enriched via lines 6 and 11 with a mixture containing at least one compound selected from the group formed by paraffins containing eight carbon atoms, benzene, toluene and naphthenes containing eight carbon atoms. Hydrogen is added via line 15.

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.