Abstract: For co-production of metaxylene and paraxylene from a feedstock (line-4) of hydrocarbons, there is employed a simulated moving bed chromatographic column 5 having at least five zones and which delivers an extract, a raffinate and an intermediate raffinate. The feedstock has an ethylbenzene content of less than 5% by weight, and the chromatographic column comprises at least twenty-five beds, of which at least five beds are in zone 3B. The raffinate is distilled (31) to recover the metaxylene at a purity of at least 99% and orthoxylene. The extract is distilled (7, 10) to recover the paraxylene at a purity of at least 99.6%. The recovered isomers can be synthesized into isophthalic acid and terephthalic acid.

Abstract: The invention concerns a reactive distillation process comprising a distillation zone, associated with a reaction zone which is at least in part internal to said distillation zone and comprises at least one catalytic bed in which the feed is transformed in the presence of a catalyst and at least one gas stream containing hydrogen, characterized in that each catalytic bed in the internal portion of said reaction zone is traversed by said gas stream and liquid in ascending co-current mode. The invention particularly concerns selective hydrogenation processes for light unsaturated hydrocarbons, mainly any olefins and benzene, comprised in a mixture, the major portion of which is constituted by hydrocarbons containing at least five carbon atoms per molecule.

Abstract: A process for the treatment of a feed comprising at least hydrocarbons containing at least 3 to 10 carbon atoms per molecule, including acetylenic and diolefinic hydrocarbons, comprises passing the feed into a distillation zone associated with a selective hydrogenation reaction zone comprising at least one catalytic hydrogenation bed which is internal to or external of the distillation zone, in which hydrogenation of at least a portion of the acetylenic and diolefinic hydrocarbons contained in the feed is carried out in the presence of a gas stream rich in hydrogen. The process is particularly suitable for the treatment of products from catalytic cracking.

Abstract: For the treatment of a feed comprising a major portion of olefinic hydrocarbons containing 4 carbon atoms per molecule, including isobutene, 1-butene and 2-butenes in a ratio which substantially corresponds to the thermodynamic equilibrium, in which the feed is treated in a distillation zone comprising a stripping zone and a rectification zone associated with at least one hydroisomerization reaction zone, the hydroisomerization reaction zone being at least partially internal to the distillation zone and comprising at least one catalytic bed, in which hydroisomerization of at least a portion of 1-butene is carried out in the presence of a hydroisomerization catalyst and at least one gas stream comprising hydrogen, such that an effluent rich in isobutene leaves the distillation zone overhead and an effluent rich in 2-butenes leaves the bottom, the process being characterized in that each catalytic bed in the internal portion of the hydroisomerization zone is traversed by an ascending co-current of the gas strea

Abstract: The invention concerns a reactive distillation apparatus comprising a distillation zone, associated with a reaction zone which is at least in part internal to said distillation zone and comprises at least one catalytic bed in which the feed is transformed in the presence of a catalyst and at least one gas stream containing hydrogen, characterized in that each catalytic bed in the internal portion of said reaction zone is traversed by said gas stream and liquid in ascending co-current mode.