Abstract: The invention concerns a process for moderate pressure hydrocracking (i.e., at a hydrogen partial pressure of more than 70 bars and at most 100 bars) with a conversion of at least 80% by volume, of a feed with a T5 temperature in the range 250° C. to 400° C. and a T95 temperature of at most 470° C. (T5 and T95 measured in accordance with ASTM-D2887), to produce a diesel with a 95% distillation point of less than 360° C., a sulphur content of at most 50 ppm and a cetane number of more than 51. The process operates with or without a recycle of the liquid effluent. Highly advantageously, it can be integrated into a refinery layout comprising catalytic cracking.

Abstract: The present invention concerns a process for the conversion of an olefinic C4 cut to polyisobutene and to propylene by metathesis. The process comprises three successive steps: (1) selective hydrogenation of diolefins with simultaneous isomerisation of 1-butene to 2-butenes, (2) polymerisation of the isobutene, including optional prior extraction of the isobutene, (3) metathesis of 2-butene with ethylene. Part or all of the C4 cut may originate from the metathesis of an olefinic C5 cut with ethylene after hydroisomerisation of the C5 cut. Application to C4 and C5 steam cracking cuts.

Abstract: A process for converting a hydrocarbon fraction includes a step a) for treating a hydrocarbon feed in the presence of hydrogen in at least on three-phase reactor, containing at least one hydroconversion catalyst in an ebullated bed, operating in riser mode of liquid and of gas, the reactor including at least one means located close to the bottom of the reactor for extracting catalyst from the reactor and at least one means located close to the top of the reactor for adding fresh catalyst to the reactor, a step b) for treating at least a portion of the effluent from step a) in the presence of hydrogen in at least one reactor containing at least one hydrotreatment catalyst in a fixed bed under conditions for producing an effluent with a reduced sulphur content, and a step c) in which at least a portion of the product from step b) is sent to a distillation zone from which a gaseous fraction, a gasoline type engine fuel fraction, a diesel type engine fuel fraction and a liquid fraction which is heavier than the d

Abstract: The specification describes a method and a fixed bed apparatus for producing olefinic hydrocarbons from a charge of saturated aliphatic hydrocarbons with 2 to 20 carbon atoms and hydrogen in a chamber 1 comprising a plurality of parallel tubes 3 filled with a catalyst and arranged in rows. A so-called reaction phase and a catalyst-regenerating phase are carried out in the tubes of the chamber. The tubes are heated by appropriate radiant heating means 6, arranged in layers substantially perpendicular to the tubes. These layers heat a first part of the tubes (at the feed side) with a heat flux greater than the mean heat flux of the chamber and a second, subsequent part with a mean flux no more than equal to the mean heat flux, so that the isothermicity of the catalyst is substantially maintained, using appropriate control means.

Abstract: The present invention concerns a plant for the conversion of an olefinic C.sub.4 or C.sub.5 cut to an alkyl-tertiobutylether or alkyl-tertioamylether and to propylene, by metathesis. The plant comprises four successive stages: (1) selective hydrogenation of the diolefins with simultaneous isomerisation of the alpha olefins to internal olefins; (2) etherification of the isoolefins; (3) elimination of oxygen-containing impurities; (4) metathesis of internal olefins with ethylene. Application to C.sub.4 and C.sub.5 steam cracking units.

Abstract: For the conversion of an olefinic C.sub.4 or C.sub.5 cut to an alkyl-tertiobutylether or alkyl-tertioamylether and to propylene, by metathesis, the process comprises four successive steps: (1) selective hydrogenation of the diolefins with simultaneous isomerisation of the alpha olefins to internal olefins; (2) etherification of the isoolefins; (3) elimination of oxygen-containing impurities; (4) metathesis of internal olefins with ethylene. The process has application, e.g., to C.sub.4 and C.sub.5 steam cracking cuts.

Abstract: The present invention concerns a process for the conversion of an olefinic C.sub.4 cut to polyisobutene and to propylene by metathesis. The process comprises three successive steps: (1) selective hydrogenation of diolefins with simultaneous isomerisation of 1-butene to 2-butenes, (2) polymerisation of the isobutene, including optional prior extraction of the isobutene, (3) metathesis of 2-butene with ethylene. Part or all of the C.sub.4 cut may originate from the metathesis of an olefinic C.sub.5 cut with ethylene after hydroisomerisation of the C.sub.5 cut. Application to C.sub.4 and C.sub.5 steam cracking cuts.

Abstract: Continuous process for the skeletal isomerization of n-olefins containing at the most 20 carbon atoms, in the presence of a catalyst essentially constituted by alumina and titanium, in which a charge containing the said n-olefins is made to flow through at least one fluidized bed reaction zone, the catalyst flowing into each reaction zone. The catalyst drawn off from the final reaction zone is passed into a regeneration zone, at the outlet of which it is passed into a zone where it undergoes a steam treatment prior to its reintroduction into the first reaction zone. The process is performed in the presence of steam, so that the catalyst is in contact with 3 to 85 wt. % (based on the catalyst weight) of steam. The water/olefin charge molar ratio in the reaction zone is between 0.1 and 3.

Abstract: Process for producing methyl tert-butyl ether (MTBE) by reacting methanol with the isobutene present in a C.sub.4 cut in a proportion from 10 to 60%, wherein said cut, admixed with methanol is contacted, in a first reaction zone, with an acid catalyst in the conditions of etherification of isobutene by methanol unit 93 to 98% of the isobutene has been converted, the reaction product is fractionated under at least 10 bars to a bottom fraction consisting essentially of MTBE and a top fraction which is contacted, in a second reaction zone, with an acid catalyst, under the conditions of etherification of isobutene by methanol, until at least 99% of the initial isobutene has been converted, the resulting product is washed with water and separated into a residual C.sub.4 cut which is discharged and an aqueous phase wherefrom methanol is recovered by distillation.