The invention provides a unique, efficient and cost-effective process for the recovery of acid from acid-rich solutions. The process of the invention utilizes a strong oxidizer, such as Caro's acid, to disintegrate or render insoluble organic or inorganic materials such as carbohydrates and complexes thereof contained in acid-rich solutions, to make efficient and simple the separation and recovery of the acid solution. The acid recovered thus obtained is free of organic matter, and containing nearly all of the acid originally contained in the acid-rich solution.

Methods for producing cyclododecasulfur are disclosed, that include the steps of: oxidizing a bromide in aqueous solution to produce a mixture of molecular bromine, tribromide, and bromide; reducing water to produce hydrogen and a hydroxide; and reacting a metallasulfur derivative with the molecular bromine, to produce cyclododecasulfur and a metallabromide derivative.

Methods for producing cyclododecasulfur are disclosed, that include the steps of: oxidizing a bromide in aqueous solution to produce a mixture of molecular bromine, tribromide, and bromide; reducing water to produce hydrogen and a hydroxide; and reacting a metallasulfur derivative with the molecular bromine, to produce cyclododecasulfur and a metallabromide derivative.

In a process for workup of mixed acid and wastewater from the nitration of aromatics in which the nitric acid present is converted by reaction with an aromatic under adiabatic conditions, a. at least one waste stream component selected from waste acid (mixed acid) generated in the nitration, acidic washing water from the workup of crude nitroaromatics and dilute nitric acid generated in an off-gas treatment in the course of the nitration is provided, b. the at least one waste stream component is mixed with re-concentrated sulfuric acid, c. an aromatic is added to the mixture in stoichiometric excess based on the nitric acid, d. the obtained reaction mixture is reacted in an adiabatically operated reactor, e. the obtained organic phase is separated from the sulfuric-acid-containing phase in a separator, f. the sulfuric-acid-containing phase is concentrated under vacuum and g. at least one substream of the re-concentrated sulfuric acid from step g) is employed in step b).

A method of removing hydrogen peroxide from sulfuric acid includes the following steps: First step of pouring the sulfuric acid having 0.1 wt % to 10 wt % of hydrogen peroxide into a vessel. Second step of adding a catalyst containing copper and a copper compound to the vessel to undergo a reaction with the sulfuric acid to remove the hydrogen peroxide from the sulfuric acid, to generate heat, and to generate metal ions in the sulfuric acid. Third step of activating a cooling device to cool the vessel to a predetermined temperature range. Fourth step of adding hydrogen sulfide to the vessel to undergo a reaction with the metal ions to generate metallic sulfide and metal free sulfuric acid. Fifth step of purifying the metallic sulfide and the metal free sulfuric acid to obtain purified metallic sulfide and purified sulfuric acid as products.

A method of removing hydrogen peroxide from sulfuric acid includes the following steps: First step of pouring the sulfuric acid having 0.1 wt % to 10 wt % of hydrogen peroxide into a vessel. Second step of adding a catalyst containing copper and a copper compound to the vessel to undergo a reaction with the sulfuric acid to remove the hydrogen peroxide from the sulfuric acid, to generate heat, and to generate metal ions in the sulfuric acid. Third step of activating a cooling device to cool the vessel to a predetermined temperature range. Fourth step of adding hydrogen sulfide to the vessel to undergo a reaction with the metal ions to generate metallic sulfide and metal free sulfuric acid. Fifth step of purifying the metallic sulfide and the metal free sulfuric acid to obtain purified metallic sulfide and purified sulfuric acid as products.

The present invention concerns a process for the reduction of content of carboxylic acids and derivatives thereof in oleum, disulfuric acid or concentrated sulfuric acid. The invention further concerns a process for the manufacture of carboxylic acid anhydrides comprising the process for the reduction of content of carboxylic acids and derivatives thereof from oleum, disulfuric acid or concentrated sulfuric acid.

Disclosed are porous membranes including a porous support and a coating comprising a copolymer having monomeric units A and B, and optionally monomeric units C; wherein A is a halogenated vinyl monomer other than tetrafluoroethylene, a halogenated alkyl vinyl ether, or an alkene of the formula C.sub.nH.sub.2n, wherein n is 1-6; B is a perfluoro (alkyl vinyl)ether compound, a perfluoroalkyl vinyl compound, or a perfluoro alkoxyalkyl vinyl ether compound, each compound having one or more sulfonic acid groups or a salt thereof, one or more sulfonyl fluoride groups, one or more sulfonamide groups, or one or more sulfonate ester groups, and C is vinylidene fluoride. Also disclosed are methods of preparing such porous membranes and methods of treating fluids by the use of these membranes.

Disclosed are porous membranes including a porous support and a coating comprising a copolymer having monomeric units A and B, and optionally monomeric units C; wherein A is a halogenated vinyl monomer other than tetrafluoroethylene, a halogenated alkyl vinyl ether, or an alkene of the formula C.sub.nH.sub.2n, wherein n is 1-6; B is a perfluoro (alkyl vinyl)ether compound, a perfluoroalkyl vinyl compound, or a perfluoro alkoxyalkyl vinyl ether compound, each compound having one or more sulfonic acid groups or a salt thereof, one or more sulfonyl fluoride groups, one or more sulfonamide groups, or one or more sulfonate ester groups, and C is vinylidene fluoride. Also disclosed are methods of preparing such porous membranes and methods of treating fluids by the use of these membranes.

A method of managing sulfur in a sulfur-containing stream may include steps of providing a sulfur-containing stream; converting sulfur within the sulfur-containing stream to elemental sulfur; transporting the elemental sulfur to a location at or near a sulfur oxide injection location; converting the elemental sulfur to sulfur oxides; recovering electrical energy from said step of converting the elemental sulfur to sulfur oxides; injecting the sulfur oxides into the sulfur oxide injection location. The method may include steps of screening a plurality of injection locations and selecting, from the screened plurality of injection locations, a particular sulfur dioxide injection location with specific reservoir characteristics for the sulfur oxides.