Abstract: A desulphurizing composition for the treatment of CLAUS plant tail gases, comprises: an organic solvent A with a boiling point of more than 200° C. at atmospheric pressure; a catalyst composition B of at least one alkali- or alkaline-earth salt (S) of an organic monoacid or an organic polyacid which has at least one dissociation constant value (pK) in the range 2.2 to 8 such as formic acid, acetic acid, ascorbic acid, fumaric acid, maleic acid, malonic acid, oxalic acid, tartaric acid, benzoic acid, salicyclic acid, and sulphosalicyclic acid; at least one complexing agent (C) such as an alkali or alkaline-earth salt or a ferrous or ferric salt of a mono- or poly-aminocarboxylic acid, citric acid, a sulphocyanide ion, a ferrocyanide ion, a ferricyanide ion, a phosphate ion, a pyrophosphate ion, a fluoride ion and/or a thiosulphate ion; and water (W), in the following proportions by weight: S=0.1% to 30%; C=0.001% to 30%; W=balance.

Abstract: A process and an apparatus are described for treatment of a gas containing hydrogen sulphide and sulphur dioxide, for example a Claus plant tail gas, in which the gas is brought into contact with an organic solvent (1) e.g. polyethylene glycol 400, containing a catalyst e.g. sodium salicylate, in at least one gas-liquid reactor-contactor (2) and a gas (20) substantially no longer containing hydrogen sulphide and sulphur dioxide is recovered. A single-phase solution (4) of solvent and sulphur is extracted from the reactor-contactor and a portion is cooled in at least one cooling zone (8) to obtain a suspension of sulphur crystals in the solvent, the crystallised sulphur is separated from the solvent in a separation zone (10), the sulphur-depleted solvent (14, 15) is recovered and recycled at least in part to the reactor-contactor (2), and the sulphur (13) is recovered.

Abstract: An apparatus for treating a gas containing hydrogen sulphide and sulphur dioxide comprising a first gas-liquid reactor-contactor (2), means (3) for supplying a gas to be treated and means (5) for supplying an organic solvent, means (25) for recovering sulphur and means (20) for extracting a gaseous effluent containing sulphur in vapour form, the apparatus being characterized in that it comprises a second reactor-contactor (102) connected to the means for extracting the gaseous effluent, means (105) for supplying an organic solvent which is depleted in sulphur connected to the second reactor-contactor, means (120) for recovering a gaseous effluent which has been cleaned of sulphur connected to the second reactor-contactor, means (104) for extracting a liquid phase containing the organic solvent and sulphur connected to the second reactor-contactor, at least one means for depleting at least a portion of the liquid phase in sulphur connected to the means for extracting the liquid phase, comprising at least one m

Abstract: An apparatus for treating a gas containing hydrogen sulphide and sulphur dioxide, comprising a liquid-gas reactor-contactor (2), means (3) for supplying gas to be treated and means (1) for supplying an organic solvent containing a catalyst, means (25) for recovering sulphur an doutlet means (20) for a gaseous effluent containing sulphur in vapour form, the apparatus being characterized in that it comprises at least one means (7) for contacting and cooling the gaseous effluent, delivering a three-phase effluent, having an inlet connected to the effluent outlet means (20) and to means (6, 13) for recycling a cooling solvent, means (30) for separating said three-phase effluent connected to the cooling means, adapted to separate purified gas from sulphur and comprising means (17) for evacuating purified gas, means (15) for extracting sulphur and means (14) for recovering solvent connected to the means (6, 13) for recycling the cooling solvent.

Abstract: A process is provided for removing hydrogen sulfide out of a gas, such as natural gas. The hydrogen sulfide contaminated gas is contacted with a catalytic aqueous solution containing a polyvalent metal chelating agent under conditions in which the hydrogen sulfide is oxidized into elemental sulfur and the polyvalent metal chelating agent is reduced to a lower oxidation state, and the treated gas is recovered. The solution containing the polyvalent metal chelating agent and the elemental sulfur is filtered at a pressure of at least 1 Mpascals. At least a portion of the filtered solution containing the polyvalent metal chelating agent is degassed and/or depressurized for the removal of components such as light hydrocarbons and carbon dioxide; contacted with an oxidizing agent and recycled back to the hydrogen sulfide removal step. By filtering the sulfur out of the solution at a pressure of at least 1 Mpascal, foam formation and clogging problems can be avoided.

Abstract: The invention is a process for analyzing a fluid sample.

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: 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 the treatment of ventilation air containing malodorous gases, e.g., styrene, involving:1. An adsorption step onto a hydrophobic zeolite containing, for example, platinum and/or palladium,2. A combustion-desorption step wherein hot gases pass over the impregnated zeolite in order to desorb the gas, e.g., styrene and burn it on the zeolite,in which the zeolite is encased in small tetrahedral-shaped containers.

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: 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: Process for separating H.sub.2 S from CO.sub.2, both contained in a treated gas, wherein said gas is contacted with a solution which selectively absorbs H.sub.2 S, wherefrom H.sub.2 S is separated in a regeneration zone, CO.sub.2 being released, said contact step being effected in a contact apparatus comprising 1 to 10 stages each formed of parallel vertical tubes whose bottom portion is provided with injection means of the cyclonic type imparting to the supplied gas and liquid a swirling ascending motion.

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: 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: 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.

Abstract: Process for regenerating brines containing simultaneously sodium sulfites and sulfates so as to produce sulfur dioxide and an alkaline solution usable for absorbing sulfur dioxide, comprising contacting the brine with ammonium bisulfate, sodium bisulfate and ammonium sulfite to produce sulfur dioxide and an enriched solution of sodium sulfate and ammonium sulfate, which is reacted with CO.sub.2 and ammonia to obtain solid sodium bicarbonate which is decomposed to form CO.sub.2 and an enriched solution of ammonium sulfate, containing dissolved ammonium bicarbonate, which is heated with a reducing agent so as to decompose the ammonium sulfate to ammonia and ammonium bisulfate which is partly reduced to gaseous ammonia and sulfur dioxide, said process including several recycling steps.

Abstract: H.sub.2 S and CO.sub.2 from a waste gas are absorbed in an ammoniacal or alkali metal hydroxide solution. The resultant sodium, potassium or ammonium sulfide solution is reacted with pulverized copper oxide and the resultant copper sulfide precipitate is separated and the resultant solution of increased sodium hydroxide, potassium hydroxide or ammonia content is recycled as absorbent for hydrogen sulfide and CO.sub.2. The copper sulfide is roasted to form recyclable copper oxide and product sulfur dioxide.

Abstract: This process avoids the disadvantages of admixing hot molten ammonium bisulfate with ammonium sulfites solutions. Overflowing hot molten ammonium bisulfate is admixed with a stream of aqueous ammonium bisulfate solution, said solution being preferably circulated in a closed loop. A portion of the resulting solution is then used to acidify the ammonium sulfites solution.