Abstract: The invention relates to a process for producing high purity isobutene from a hydrocarbon cut essentially comprising olefinic hydrocarbons containing 4 carbon atoms per molecule including isobutene, also butene-1 and butene-2 compounds in a ratio which substantially corresponds to the thermodynamic equilibrium.

Abstract: The invention concerns a process for the alkylation of at least one isoaffin selected from the group formed by isobutane and isopentane by at least one olefin containing 2 to 6 carbon atoms per molecule in the presence of a liquid acid catalyst, the process comprising mixing a feed comprising the olefin to be converted with an effluent comprising a major portion of isoparaffin in a first mixing zone, and forming an emulsion of said catalyst in a hydrocarbon effluent comprising a major portion of isoparaffin in an emulsifying zone, said effluent constituting the continuous phase of the emulsion thus formed, then mixing a major portion of the emulsion of acid in hydrocarbon effluent with a major portion of the diluted feed comprising the olefin in a second mixing zone, followed by carrying out the majority of the reaction in a reaction zone which is supplied by the major portion of said mixture.

Abstract: The invention concerns a process for optimal operation of a slurry bubble column containing a suspension of solid particles in a liquid, characterized in that a gas phase containing the reactant(s) required for the production of the desired products is injected in the form of bubbles close to the lower extremity of the reactor and at least a portion of the liquid fraction and optionally of the solid fraction of the suspension is recirculated, drawn off from close to one extremity of the reactor and reintroduced close to the other extremity of the reactor, with a liquid flow rate U.sub.l in the reactor which is at least equal to and preferably greater than the sedimentation rate U.sub.s of the solid particles. The invention also concerns an apparatus for optimal operation of the process. Finally, the invention concerns the use of the process and apparatus in the Fischer-Tropsch synthesis.

Abstract: In a process and apparatus for treating a gas containing hydrogen sulphide and sulphur dioxide, the gas is contacted with an organic solvent (1)for example, a polyalkylene glycol, containing a catalyst for example, an alkaline salt of a week organic acid, in at least one gas-liquid reactor contactor (2) and a gas (20) substantially no longer containing hydrogen sulphide and sulphur dioxide is recovered. The effluent contains sulphur vapor. It is cooled by mixing with a solvent-water mixture (14) or by cooled solvent in a cooling zone (7) to produce a suspension of sulphur crystals in the solvent. The crystallised sulphur is separated from the solvent in a separation zone (30) and the cooled solvent is recycled (13). An effluent (17) which is free of sulphur gas is obtained.

Abstract: In a process for treating a gas containing hydrogen sulphide and sulphur dioxide, such as Claus plant tail gas, to substantially reduce emission of sulphur vapor in the treated gases, the process a characterized in that the gas is brought into contact with a solvent (5) in at least one gas-liquid reactor-contactor (2) and a gas (20) is recovered which is sent to a second reactor (102) where it is brought into contact with solvent (105), the solvent (105) being cooled by suitable means (190), to separate a portion of the sulphur from the solvent. The resultant solvent depleted in sulphur, contacts the gas (20) from the first reactor (2). The gas (120) from the second reactor is highly depleted in sulphur vapor. At least one of the reactors contains a catalyst. The solvent may be insoluble in water, e.g. dodecane, tridecane, naphtha, or soluble in water, e.g. glycerol, thiodiglycol, cyclohexanedimethylethanol, or an acid ester. The catalyst may comprise, e.g.

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.

Abstract: The invention concerns a process for isomerizing a feed containing essentially hydrocarbons, preferably paraffins containing principally 4 to 8, preferably principally 4 to 6 and more preferably principally 5 and/or 6 carbon atoms per molecule, comprising a fractionation zone and at least two isomerization 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;(3) sending the major portion of the liquid drawn off in step (2) to at least two isomerization zones, each isomerization zone being associated with a draw-off level;(4) sending the major portion of the effluents from step (3) to the fractionation zone, substantially adjacent to the draw-off levels;(5) recovering an effluent from the fractionation zone.

Abstract: The invention concerns a reactive distillation process carried out in a reactive distillation zone which includes at least one catalytic zone flanked by two distillation zones, the vapor from the distillation circulating from bottom to top so as to be in practically no contact with the catalyst, and the liquid circulating from the upper distillation zone (5) to a substantially central zone at the bottom of the catalytic zone without contacting the catalyst, then circulating radially below the catalytic zone via at least one means (20) so as to be introduced into a liquid distribution zone (23), then circulating through the catalytic bed (8) in the catalytic zone, following which the liquid is recovered via at least one liquid overflow means (19) in a lower distillation zone (14).The invention also concerns an apparatus for reactive distillation.

Abstract: A process for the extraction of hydrogen sulphide from a gas mixture comprises: a step (a) in which the gas mixture is passed into an aqueous acidic solution of copper sulphate under conditions which lead to the formation of copper sulphide; a gas which is highly depleted in hydrogen sulphide and an aqueous phase containing copper sulphide in suspension are recovered; a step (b) in which the copper sulphide contained in suspension in the aqueous phase from step (a) is oxidised using an oxygen-containing gas under conditions which lead to the formation of solid elemental sulphur and soluble copper sulphate from this liquid phase; and a step (c) in which the solid sulphur and the solid copper sulphide which is not transformed during step (b) are separated and at least a portion of the aqueous acidic phase containing the copper sulphate formed during step (b) is optionally recycled to step (a).The process is used to absorb hydrogen sulphide contained in a variety of industrial gases.

Abstract: The invention concerns a process for purifying sulphuric acid, particularly after it has acted as a catalyst in aliphatic alkylation reactions.It is characterized in that the sulphuric acid is impregnated into a porous organic or inorganic support, for example silica, and is then calcined at least once to eliminate organic hydrocarbon substances which the sulphuric acid may contain.

Abstract: A reaction-distillation method is provided in which a chemical reaction and fractionation are conducted in an apparatus having at least one reaction-distillation zone (A,B) including at least one bed of solid elements disposed on a fluid-permeable support (5) having perforations small enough to retain the elements. The bed of solid elements includes loose solid catalytic particles (2) and at least one receptacle (3), containing at least one distillation packing body (4). The external jacket of the at least one receptacle (3) is permeable to fluids and impermeable to the solid catalytic particles (2) and the packing body (4). The apparatus can be used for carrying out chemical reactions and concomitant fractionation of the reaction mixture, for example, to synthesize ethers from olefins and alcohols.

Abstract: The invention concerns a process for regenerating an impure catalyst comprising sulphuric acid deposited on silica.It is characterized in that the catalyst is calcined at least once to eliminate organic hydrocarbon substances contained in the catalyst, in particular as a result of its use in aliphatic alkylation reactions.

Abstract: A reactive distillation process which makes it possible, in the same enclosure, to carry out a catalytic reaction and isolate by distillation the sought product, in which the liquid phase containing the reagents passes from bottom to top through at least one catalyst bed, without the vapor phase of the distillation traversing said catalyst beds. These operating characteristics occur in a reactive distillation zone (C) including an alternation of distillation cells (D) having one or more trays (5) and reaction cells (R) containing the catalyst beds and designed in such a way that the liquid phase flowing from a distillation tray (5) flows above an overflow ( 7) through a downpipe (6) and approaches the base of the catalyst bed (8), traverses the latter in a downward flow and is then allowed to flow over a distillation tray (5) of the following distillation cell (D), so that the distillation vapor circulating from bottom to top through the distillation trays (5) does not traverse said reaction cells (R).

Abstract: A process for simultaneously exchanging material and for exchanging heat, material change being effected between a gas phase and at least one liquid phase by contact and passage in opposite directions of the gas phase and of the at least one liquid phase and heat exchange being effected between a compartment (I) and another compartment (II). In compartment (I) a plurality of spacer plates defining material exchange passages are arranged and the material exchange is effected by causing the at least one liquid phase to flow over a substantially vertical or inclined wall of a corrugated spacer plate having perforations and by causing at least a fraction of the gas phase to traverse simultaneously said perforations in a substantially ascending direction to contact said at least one liquid phase. The heat exchange is effected by circulating a heat exchange fluid in the compartment (II) which has a common wall with the compartment (I).

Abstract: A reaction-distillation apparatus is provided comprising at least one reaction-distillation zone including at least one bed of solid elements disposed on a fluid-permeable perforated support having perforations small enough to retain the elements wherein the bed of solid elements includes loose solid catalytic particles and at least one receptacle, containing at least one distillation packing body, the external jacket of which is permeable to fluids and the impermeable to the solid catalytic particles and packing body. The apparatus can be used for carrying out chemical reaction and concomitant fractionation of the reaction mixture, for example, to synthesize ethers from olefins and alcohols.

Abstract: A reactor for low pressure catalytic reforming of gasolines with heating by smoke gases comprises: at least one device for introducing and removing the charge; at least one device for introducing and removing the catalyst; at least two elementary reaction cells spaced apart from each other are made of substantially vertical and parallelepipedic enclosures (an individual charge distributor, an individual processed charge collector, a catalytic bed); at least one general charge distributor; and at least one general processed charge collector.

Abstract: The present invention relates to a process and a reactor for low pressure catalytic reforming of gasolines with heating by smoke gases.The reactor of the invention comprises:at least one means for introducing and removing the charge,at least one means for introducing and removing the catalyst,at least two elementary reaction cells not adjacent each other, substantially vertical and parallelepipedic, substantially parallel to each other, each of said cells being formed of three substantially parallelepipedic enclosures (an individual charge distributor, an individual processed charge collector, a catalytic bed),at least one general charge distributor,at least one general processed charge collector.The reforming process of the invention may be used in this reactor, smokes-based heating gases, coming from the combustion in air of a hydrocarbon mixture, flowing between the elementary reaction cells and thus bringing the heat required for the reforming reaction.