Abstract: The invention concerns a process for deodorizing malodorous gaseous effluents from cooking equipment, particularly in restaurants and in the food industry, by washing with an aqueous solution comprising an alkaline or alkaline-earth salt of a dicarboxylic acid or a polycarboxylic acid, optionally associated with a surfactant and a diholoside.

Abstract: The invention involves a process for the isomerization of C.sub.5 /C.sub.6 n-paraffins into isoparaffins comprising:a stage (1) of isomerizing a charge constituted by a light naphtha and recycling a flow rich in methyl-pentanes and n-paraffins,an adsorption stage (2) performed by passing the isomerization effluent onto an adsorbent retaining the n-paraffins and alternating with the adsorpotion stage (2), a desorption stage (3) performed by lowering the pressure and stripping by means of a gas flow rich in methyl-pentanes from the deisohexanization stage (4) anda deisohexanization stage (4) for the adsorption effluent.The isomerate freed from the n-paraffins in stage (2) and distilled in stage (4) is a high octane number product.

Abstract: Disclosed is a gas separation membrane, comprising a film with a thickness ranging from 0.05.10.sup.-6 to 20.10.sup.-6 m, at least 90% by mole of which is at least one aromatic polyimide or copolyimide, the recurrent unit of which corresponds to the following formula (I): ##STR1## where A represents a tetravalent aromatic radical at least 50% by mole of which are represented by the following formula (II): ##STR2## and B represents a bivalent aromatic radical or a mixture of bivalent aromatic radicals.

Abstract: The invention concerns, on one hand, a new zeolitic catalytic composition which comprises a small-pore mordenite present in the form of needles, exchanged with at least one metal chosen from the group consisting of cooper, vanadium, tungsten, iron, colbalt and molybdenum, and on the other hand, use of this catalytic composition as a catalyst for the reduction of nitrogen oxides by ammonia.

Abstract: A mixture of at least two constituents A and B is submitted to selective separation across a selective membrane.The membrane comprises an active layer comprising particles of a selective solid (5) dispersed in a continuous non-porous and non-elastomeric polymer phase (4) and a porous support (6). The thickness of the active layer is less than 100 micrometers, advantageously less than 20 micrometers.

Abstract: The invention relates to a process for removing sulfur oxides, particularly sulfur dioxide, contained in gases such as industrial fumes, characterized in that the gas is contacted with a solid absorbent containing magnesium oxide, in such conditions that sulfur oxides are fixed mainly as magnesium sulfate and then the used solid absorbent is contacted with a gas stream containing elemental sulfur in such conditions that magnesium oxide is regenerated with the production of an effluent of sulfur dioxide containing gas.

Abstract: The invention relates to a process for removing sulfur oxides, particularly sulfur dioxide, contained in gases such as industrial fumes, characterized in that the gas is contacted with a solid absorbent containing magnesium oxide, in such conditions that sulfur oxides are fixed mainly as magnesium sulfate and then the used solid absorbent is contacted with a gas stream containing elemental sulfur in such conditions that magnesium oxide is regenerated with the production of an effluent of sulfur dioxide-containing gas.

Abstract: The invention concerns a process for removing sulfur oxides and particularly sulfur dioxide contained in such gases as industrial fumes, wherein said gas is contacted with a solid absorbent containing magnesium oxide and at least one group VIII noble metal, in such conditions that the sulfur oxides are mainly fixed as magnesium sulfate, and then the used solid absorbent is regenerated by contact with a hydrogen sulfide-containing reducing gas.

Abstract: The invention concerns a process for converting heavy petroleum residues to hydrogen and to gaseous and distillable hydrocarbons, comprising the association of a step of hydropyrolysis (inside tube 3) with a step of catalytic steam-gasification of the formed coke (outside tube 3), characterized in that the hydropyrolysis step is performed in the presence of a solid supporting a carbon gasification catalyst circulating between the hydropyrolysis zone and the coke steam-gasification zone, said steam-gasification being performed in the absence of oxygen.The petroleum residue, hydrogen and steam are introduced respectively through lines 5, 6 and 7.The products are withdrawn through line 10. Heat may be supplied by the radiating tube 4.

Abstract: A carbonaceous material is subjected, in admixture with a hydrogenated recycle oil, to hydrogenation in two successive steps at respective temperature ranges of 350.degree.-470.degree. C. and 600.degree.-1000.degree. C., under a pressure of at least 20 bars, the resulting product being separated into a carbonaceous solid residue, which is subsequently treated with oxygen and steam so as to obtain a hydrogen-containing reducing gas to be used in the second of the two hydrogenation steps, a fraction distilling in major part above 150.degree. C. which, after hydrogenation, forms the recycle oil admixed with the starting carbonaceous material, and a fraction containing the desired lower paraffinic hydrocarbons and monocyclic aromatic hydrocarbons, distilling in major part below 150.degree. C.

Abstract: Process for hydrodesulfurizing and deoxygenating a gas (A) comprising methane, oxygen and at least one organic sulfur compound, said process comprising contacting a mixture of said gas (A) with a hydrogen-containing gas (B) first with a palladium-containing catalyst, at a temperature of 300.degree.-450.degree. C., and then with a second catalyst comprising molybdenum and at least one of nickel and cobalt, at a temperature of 300.degree.-450.degree. C.

Abstract: Process for hydrodesulfurizing a gas comprising together methane, at least one organic sulfur compound and oxygen, characterized by the step of passing a mixture of said gas with a hydrogen containing gas on a palladium catalyst at a temperature of 300.degree. to 450.degree. C.The gas usually comprises at least 2 mg/Nm.sup.3 of sulfur as organic sulfur and 0.05 to 2% by volume of oxygen.

Abstract: This process for converting a charge of heavy oils or petroleum residues to gaseous and distillable hydrocarbons comprises the steps of (a) admixing said charge with a first hydrogenated recycle oil obtained in a subsequent step of the process, heating the mixture to 350.degree.-450.degree. C., admixing it with a reducing gas at a temperature of at least 800.degree. C. and maintaining a temperature of 530.degree.-850.degree. C. and a pressure of at least 20 bars for 0.1 to 60 seconds (b) admixing the resultant product with a second hydrogenated recycle oil whose temperature is lower than 300.degree. C., thereby decreasing the temperature of the resultant mixture to less than 450.degree. C., then contacting it with a steam-hydrogen stream, thereby vaporizing at least 80% of the liquid to a gaseous phase (c) treating the unvaporized remaining fraction with oxygen and steam to form a reducing gas at a temperature of at least 800.degree. C.

Abstract: A process for purifying a gas containing hydrogen sulfide, wherein said gas is admixed with oxygen and contacted with a carbon mass of specific surface higher than 50 m2/g and containing at least one oxide and/or sulfate of iron and/or copper, at a temperature from 20.degree. to 170.degree. C., the operating conditions being so selected as to avoid a substantial oxidation of said mass and said mass being periodically regenerated by heating to 200.degree.-300.degree. C. in the presence of oxygen, the regenerating conditions being such as to avoid a substantial oxidation of the carbon mass.

Abstract: A gas containing carbon oxysulfide or carbon disulfide is passed in admixture with oxygen through a catalyst formed of a carrier, vanadium oxide and silver, the proportion of iron oxide, if any, being lower than 1% by weight. The amount of vanadium oxide may be 0.5 to 10% by weight and that of silver 0.05 to 4% by weight.

Abstract: Process for purifying a gas containing hydrogen sulfide, optionally with carbon dioxide, particularly adapted to the purification of gases of relatively low hydrogen sulfide content, e.g. not in excess of 1% of H.sub.2 S by volume, comprising contacting the gas with an absorption mass containing copper, at a temperature of from 250.degree. to 550.degree. C., to absorb the hydrogen sulfide and form copper sulfide; wherein the absorption mass is regenerated by interrupting the contact of the gas with the mass when the mass is at least partially saturated, contacting the mass with an oxidizing gas containing from 0.5 to 5% by volume of oxygen, at a temperature of from 250.degree. to 345.degree. C., to convert the copper sulfide substantially to copper sulfate, and then contacting the mass with a reducing gas containing from 5 to 20% by volume of hydrogen, at a temperature of from 300.degree. to 450.degree. C.

Abstract: Ammonium imidodisulfate and ammonium sulfamate may be converted to sulfur dioxide and ammonia by heating them with a reducing agent or a catalyst in a bath of molten ammonium sulfate and ammonium bisulfate. The reducing agent is sulfur or a sulfur compound and the catalyst is selected from Mo, W, Cu, Fe, Co, Cr, Mn and Ni.

Abstract: Sulfur and sulfur compounds contained in a gas are oxidized in contact with a catalyst comprising vanadium oxide, iron oxide and alumina, said catalyst having a surface higher than 30 m.sup.2 /g and being obtained by impregnation of aluminum with soluble vanadium and iron compounds.

Abstract: Process for purifying a sulfur dioxide containing gas, by washing with an ammonia aqueous solution, comprising the following steps:(a) contacting a sulfur dioxide containing gas with ammonia and/or ammonium sulfite in the presence of water, to form a solution containing ammonium bisulfite and/or sulfite;(b) reacting at least a portion of the solution obtained in step (a) with ammonium bisulfate, so as to decompose the ammonium bisulfite and sulfite and to obtain ammonium sulfate as an aqueous solution and gaseous sulfur dioxide;(c) recovering the sulfur dioxide;(d) heating the aqueous solution obtained in step (b) for vaporizing at least a portion of the water;(e) heating the product from step (d) to convert the ammonium sulfate to ammonium bisulfate and gaseous ammonia;(f) separating the gaseous ammonia obtained in step (e) and feeding it to step (a) either as such or as ammonium sulfite and,(g) feeding to step (b) the ammonium bisulfate obtained in step (e) either as such or after dissolution in water, wher

Abstract: Process for purifying SO.sub.2 -containing gas comprising a first step of contacting said gas with an aqueous solution of an ammonium sulfite or an ammonium thiosulfate also containing ammonium sulfate, a second step of contacting the resulting solution with a H.sub.2 S-containing gas at 20.degree.-90.degree. C. to produce sulfur which is separated from the remaining solution, a third step of recyling 90 to 99.99% by volume of said remaining solution to the first step, and a fourth step of introducing 0.01 to 10% by volume of said remaining solution into a molten salt formed of ammonium sulfate and/or bisulfate so as to produce a gas containing SO.sub.2, ammonia, sulfur and steam, which is recycled to the first step.