Abstract: Process for absorbing hydrocarbons or organic solvents, particularly in solution or suspension in water at a low concentration, by means of an absorption mass consisting of rubber particles of from 0.1 to 3 mm, subjected to a treatment with an organic or inorganic acid or an aqueous solution or emulsion thereof.

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.

Abstract: Molten ammonium sulfate is converted to ammonia and sulfur dioxide by heating in the presence of at least one molybdenum and/or tungsten compound, preferably at a temperature in the range of 350.degree. to 500.degree. C.

Abstract: This process for purifying a sulfur dioxide containing gas, for example stack gas, comprises the steps of washing the gas with aqueous ammonia or ammonium sulfite, vaporizing sulfur dioxide and ammonia therefrom, reacting vaporized sulfur dioxide with hydrogen sulfide and recycling an ammonia containing stream. To avoid the drawbacks resulting from the presence of hydrogen sulfide in the recycle stream, a further oxidation step is provided to convert hydrogen sulfide to sulfur dioxide.

Abstract: A SO.sub.2 -containing gas is contacted with an ammonia solution, the resulting ammonium sulfite solution is vaporized to SO.sub.2 and NH.sub.3 , SO.sub.2 is partially reduced to H.sub.2 S and the resulting gas containing both SO.sub.2 and H.sub.2 S is first contacted with a catalyst to produce sulfur and then made free of sulfur by solvent washing; recovered NH.sub.3 is used to re-constitute the ammonia solution.

Abstract: Molten ammonium sulfates containing iron sulfate as an impurity may be reduced with sulfur or a sulfur compound over long periods provided a fraction of these impure ammonium sulfates is withdrawn, treated for iron removal and fed back to the reduction zone.

Abstract: A solution of sodium sulfite or sulfide is reacted with ammonium sulfate, so as to produce a gas containing SO.sub.2 or H.sub.2 S, NH.sub.3 and H.sub.2 O, which is thereafter treated for sulfur production and NH.sub.3 recovery, and a liquid outflow containing sodium sulfate which is reacted with CO.sub.2 and NH.sub.3, in order to produce NaHCO.sub.3 and regenerate the ammonium sulfate. NaHCO.sub.3 may be converted to sodium carbonate and CO.sub.2, the latter being re-used in the process.

Abstract: Process for purifying industrial gases containing hydrogen sulfide and for simultaneously producing elemental sulfur, comprising contacting said gases with an aqueous solution of sodium hydroxide and/or sodium carbonate, thereby forming a sodium sulfide solution, contacting said solution with an aqueous solution of ammonium hydrogen carbonate or with a gaseous mixture of CO.sub.2 and NH.sub.3 so as to precipitate sodium hydrogen carbonate, decomposing the latter to CO.sub.2 and neutral sodium carbonate which is recycled, heating the resulting liquid phase to produce NH.sub.3 and H.sub.2 S and producing sulfur by reacting the H.sub.2 S with sulfurous anhydride.

Abstract: Sulfur dioxide and ammonia remaining in waste-gas after partial purification thereof, for example by means of ammonia or ammonium sulfite solutions, are withdrawn from said gas by washing with a diluted aqueous solution of ammonium sulfate; the resulting ammonium sulfite containing solution is oxidized thereafter either by means of air or in an electrochemical cell.