Abstract: A process for isomerising a feed comprising normal paraffins containing 5 to 8 carbon atoms per molecule as a major portion in the presence of hydrogen is characterized in that the sum of the amounts of normal paraffins containing 7 and 8 carbon atoms per molecule contained in the feed is in the range 2% to 90% by weight with respect to the feed, and in that said feed is treated in at least one reaction zone containing at least one catalyst in a fixed bed, said catalyst comprising a support, at least one halogen and at least one group VIII metal, the reaction being carried out at a temperature in the range 30° C. to 150° C.

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 relates to a process for the production of a mixture of compounds that comprises for the most part at least one mono-alkylbenzene that belongs to the group that is formed by the 2-, 3-, 4-, 5- and 6-phenylalkanes by alkylation of benzene with at least one monoolefin that comprises at least two carbon atoms in its molecule, in the presence of a catalyst that comprises 12-tungstophosphoric acid and/or 12-tungstomolybdic acid, deposited on a substrate that develops a large specific surface area and a high pore volume and that comprises a majority proportion of zirconium oxide (ZrO2).

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 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: 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 isomerising a feed comprising normal paraffins containing 5 to 8 carbon atoms per molecule as a major portion in the presence of hydrogen is characterized in that the sum of the amounts of normal paraffins containing 7 and 8 carbon atoms per molecule contained in the feed is in the range 2% to 90% by weight with respect to the feed, and in that said feed is treated in at least one reaction zone containing at least one catalyst in a fixed bed, said catalyst comprising a support, at least one halogen and at least one group VIII metal, the reaction being carried out at a temperature in the range 30° C. to 150° C.

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: 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 is concerned with a catalyst comprising a matrix, a MFI type zeolite and at least one group VIII element, in which the crystals of the MFI type zeolite are desaluminated on their outer surface by at least one treatment with at least one solution of a fluorosilicate of a cation selected from the group formed by NH4+, alkylammoniums, K+, Na+, Li+, Ba2+, Mg2+, Cd2+, Cu+, Cu2+, Ca2+, Cs+, Fe2+, Co2+, Pb2+, Mn2+, Rb+, Ag+, Sr2+, Zn2+, Tl+ and H+, the global desalumination rate of said MFI zeolite thus treated being less than 5 atomic per cent.

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: The invention is concerned with a catalyst comprising a matrix, a MFI type zeolite and at least one group VIII element, in which the crystals of the MFI type zeolite are desaluminated on their outer surface by at least one treatment with at least one solution of a fluorosilicate of a cation selected from the group formed by NH.sub.4.sup.+, alkylammoniums, K.sup.+, Na.sup.+, Li.sup.+, Ba.sup.2+, Mg.sup.2+, Cd.sup.2+, Cu.sup.+, Cu.sup.2+, Ca.sup.2+, Cs.sup.+, Fe.sup.2+, Co.sup.2+, Pb.sup.2+, Mn.sup.2+, Rb.sup.+, Ag.sup.+, Sr.sup.2+, Zn.sup.2+, Tl.sup.+ and H.sup.+, the global desalumination rate of said MFI zeolite thus treated being less than 5 atomic percent.

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 a process for isomerising a feed containing essentially hydrocarbons, preferably paraffins containing principally 4 to 8, preferably princiapply to 6 and more principally 5 and/or 6 carbon atoms per molecule, comprising a fractionation zone and at least two isomersation reaction zones, said process comprising carrying out the following steps:(1) sending the feed to a fractionation zone;(2) drawing off at least a portion of the liquid circulating in said zone, via at least two draw-off levels; and(3) sending the major portion of the liquid drawn off in step (2) to at least two isomerisation zones, each isomerisation zone being associated with a draw-off level.