Abstract: A method of producing sulfur dioxide is provided. A feed gas stream comprising at least 5% by volume hydrogen sulfide is provided. The feed gas stream is separated into a hydrogen sulfide stream and a hydrocarbon gas stream. An oxidant stream is provided and is combusted with the hydrogen sulfide stream to produce thermal power and a combustion stream containing sulfur dioxide and steam. Sulfur dioxide is separated from the combustion stream.

Abstract: Provided is a process for directly producing sulfur trioxide and sulfuric acid from gypsum. Sulfur trioxide is directly substituted with silicon dioxide by thermal or light-quantum activation, which is assisted with catalytic activation, while restraining reducing atmosphere and removing the resultant sulfur trioxide in time. The resultant sulfur trioxide is then used as raw material to produce sulfuric acid by a well-known method in prior art. The process has the advantages of simplified operational steps, little investment, low energy consumption and manufacturing cost, and low environmental pollution.

Abstract: A method for recovering diluted waste sulfuric acid by extractive rectification with concentrated sulfuric acid which is re-concentrated for reutilization. Waste sulfuric acid from the nitration process is fed into a first column, optionally together with another waste sulfuric acid in a DNT washing acid, and divided into an overhead product containing nitric acid and nitro-organic compounds and a prepurified sulfuric acid in the bottom product. The prepurified sulfuric acid withdrawn from the bottom of the first column is fed to the top of a second column, into the bottom zone of which another waste sulfuric acid is fed in the form of a diluted sulfuric acid recovered from the nitric acid concentration system so the prepurified sulfuric acid from the first column is further purified in the second column and is preconcentrated along with the diluted sulfuric acid recovered from the extractive rectification of nitric acid.

Abstract: Sulfuric acid contaminated with byproducts of chloromethane scrubbing is regenerated for reuse in the scrubbing process by diluting with water to not lower than about a 55 weight percent concentration, heating the diluted acid to boiling at not more than about 135° C., concentrating the acid to a concentration of minimally 80 weight percent at a temperature of at least 170° C., and reacting the concentrated acid with an oxidizing agent.

Abstract: The invention is directed to a process for the recovery of sulphuric acid from a mixture comprising sulphuric acid and hydrocarbons, in particular carbohydrates. In accordance with the present invention the mixture comprising sulphuric acid and carbohydrates, is contacted with an anion selective membrane, thus producing a sulphuric acid rich filtrate stream and a stream depleted in sulphuric acid.

Abstract: The invention involves a process for production of macrostructures of a microporous material. The process is characterized by the fact that seeds formed in or introduced by ion exchange or adsorption to a porous organic ion exchanger with the desired size, shape and porosity are made to grow and form a continuous structure by further deposition of inorganic material from a synthesis solution under hydrothermal conditions. The organic ion exchanger can be eliminated by chemical destruction or dissolution and, in so doing, leaves behind an inorganic microporous structure with the size and shape of the employed organic ion exchanger.

Abstract: A process for the regeneration of sulfuric acid contaminated with hydrocarbons and water to produce pure concentration acid comprising: contacting sulfuric acid contaminated with hydrocarbons and water with oxygen and elemental sulfur in the presence of a vanadium containing catalyst in a reaction zone, maintaining at least a portion of the acid in the liquid phase, converting hydrocarbon to carbon oxides and water, and converting sulfur and sulfurdioxide to sulfurtrioxide, separating the reactor effluent into a vapor stream and a liquid stream and cooling and partially condensing of the vapor stream to concentrate clean acid.

Abstract: A process for the regeneration of spent sulfuric acid comprises decomposing the spent sulfuric acid to SO2, a reducing agent, such as hydrocarbon and water, preferably in a thin film on a solid surface in the presence of a hydrocarbon reducing agent. The SO2 generated in the decomposition step is converted to SO3 in the presence of water and concentrated sulfuric acid is condensed out.

Abstract: A recycling process is presented to treat spent waste acid solutions whereby useful products are produced. Spent waste acid containing inorganic and organic contaminants is mixed with a magnesium compound containing aluminum and iron compounds that form oxyhydroxide flocs that complex, react, sequester and/or co-precipate the contaminates from the admixture. The magnesium reacts with sulfate ions to form a high quality magnesium sulfate solution.

Abstract: The invention relates to the preparation of BF3 and H2SO4 of commercial grade from boron trifluoride hydrate effluents containing organic impurities. The process consists essentially in reacting the said effluent with oleum, in recovering the gaseous boron trifluoride thereby liberated and in subjecting the sulphuric acid by-product to treatment with hydrogen peroxide and to purging with air.

Abstract: A method to separate ethanol from a solution containing sulfuric acid and ethanol which employs a vessel in which ethanol is humidified from a gas. By adding a gas to a solution containing sulfuric acid and ethanol in the vessel a gas is utilized to form humidified ethanol. Heat is provided to the solution to replace heat of vaporization of the humidified ethanol to maintain a substantially constant thermal equilibrium condition within the vessel to compensate for the energy of ethanol evaporation. The gas humidified with ethanol is then parted from the vessel to remove ethanol from the solution. The sulfuric acid, substantially devoid of ethanol, is likewise removed from the vessel. The ethanol humidified gas is thereupon separated from the ethanol to provide ethanol and a gas containing ethanol.

Abstract: A process for the preparation of an aqueous tar suspoemulsion includes the steps of mixing a mixture including (a) a viscous tar composition formed from a tar, from inorganic solids and, optionally, from water; (b) water (W); (c) a surface-active agent (SA) exhibiting a hydrophilicity/lipophilicity balance (HLB) of at least 10; and, optionally, (d) a thickening water-soluble polymer (TWP) with a molecular mass of greater than 10,000. The relative amounts of constituents (W), (SA) and, optionally, (TWP) are such that the viscosity of the (W)+(SA)+optional (TWP) mixture is preferably equal to or greater than the viscosity of the tar. An optional embodiment of the process provides for dilution of the mixture obtained with water or with an aqueous acidic solution.

Abstract: The invention relates to a method for the treatment of an impure aluminium oxide so that the organic impurities present therein it are converted into an insoluble and easily separable substance. According to the invention, aluminium oxide which contains organic matter as impurities is finely ground, the finely ground aluminium oxide is dissolved at an elevated temperature in sulphuric acid which has a concentration of at minimum 90% by weight, the amount of the sulphuric acid being at least stoichiometric in relation to the amount of aluminium oxide, the organic matter being carbonized into an insoluble and easily separable substance, and, if desired, the obtained mixture is treated further in order to form a solution-form or solid chemical which contains aluminium.

Abstract: In the process, used sulfuric acid which contains, as minor constituents, methylsulfuric acid, dimethyl ether, methanol, aliphatic and olefinic hydrocarbons, chlorinated hydrocarbons and oligomeric siloxanes, in a first step;(1) used sulfuric acid is diluted by introducing steam and optionally by adding liquid water to a concentration of at most 55% by weight sulfuric acid and is heated to boiling at a maximum of 135.degree. C. and in a second step;(2) the sulfuric acid from the first step is reacted with an oxidizing agent at a temperature of from 20.degree. C. to 130.degree. C.

Abstract: A process for the preparation of sulfuric acid by burning the oxidizable components of a feed solution obtained as a byproduct of the preparation of 2-hydroxy-4-(methylthio)butyric acid ("HMBA") by hydrolysis of 2-hydroxy-4-(methylthio)butyronitrile ("HMBN"). A combustion gas containing sulfur dioxide is produced. The combustion gas is cooled to condense water and sulfuric acid, then mixed with a source of oxygen to produce a feed gas containing at least about 0.9 moles oxygen per mole sulfur dioxide. The feed gas is passed over a catalyst for the conversion of sulfur dioxide to sulfur trioxide at a temperature effective for the conversion. Sulfur trioxide may be absorbed in concentrated sulfuric acid to generate additional sulfuric acid which may be recycled and used for hydrolysis of HMBN in the preparation of HMBA.

Abstract: Using generated active intermediates or species simultaneously to remove water and organic compounds from the spent sulfuric acid catalyst of the alkylation of olefins and alkanes is disclosed in this invention. Over 90% water and 95% organic compounds of the spent catalyst can be removed by this invention under mild operating conditions, less than 20 atms and in the temperature range from -50.degree. to 250.degree. C. This invention provides a novel process instead of the traditional or commercial process by combustion and treatment of the spent catalyst at high temperature. It is significant to simplify comparing with the traditional process, and is a safe, simple, clean or pollutionless, and cheap one-stage process.

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 process for the preparation of sulfuric acid by burning the oxidizable components of a feed solution obtained as a byproduct of the preparation of 2-hydroxy-4-(methylthio)butyric acid ("HMBA") by hydrolysis of 2-hydroxy-4-(methylthio)butyronitrile ("HMBN"). A combustion gas containing sulfur dioxide is produced. The combustion gas is cooled to condense water and sulfuric acid, then mixed with a source of oxygen to produce a feed gas containing at least about 0.9 moles oxygen per mole sulfur dioxide. The feed gas is passed over a catalyst for the conversion of sulfur dioxide to sulfur trioxide at a temperature effective for the conversion. Sulfur trioxide may be absorbed in concentrated sulfuric acid to generate additional sulfuric acid which may be recycled and used for hydrolysis of HMBN in the preparation of HMBA.

Abstract: A process, using regenerable adsorption materials, for purifying exhaust gases that have been contaminated with at least SO.sub.2, a heavy metal such as mercury and additional toxic gases such as dioxins and furans is disclosed. The process includes adsorbing the exhaust gases where the gas if freed of SO.sub.2, heavy metal and additional toxic gases, and optionally subjecting the gas from the adsorber to further treatment. The contaminated adsorber material is subjected to an oxygen-free regeneration process and the gas from the regeneration process is scrubbed and subsequently processed into pure sulfuric acid in a nitric oxide-sulphuric acid plant.

Abstract: Process for conditioning waste sulfuric acid which is prone to precipitation of tars or resins, which comprises adding emulsifiers, preferably long-chain polyethers, to the waste sulfuric acid.

Abstract: A process for reprocessing sulfuric acid obtained in the purification of yellow phosphorous, which comprises mixing the contaminated sulfuric acid with hydrogen peroxide and reacting this mixture in a vessel containing hot concentrated sulfuric acid at 110.degree. to 210.degree. C. in the presence of FeSO.sub.4, MnSO.sub.4 or NiSO.sub.4 as a catalyst is described.

Abstract: An improved process for treating spent alkylation acid to recover a sulfuric acid product suitable for use in wet process phosphoric plants particularly those which recover uranium as a byproduct. The process utilizes heat and agitation to polymerize the liquid, soluble organic impurities normally contained in spent alkylation acid to insoluble, carbonaceous solids. The carbonaceous solids formed are relatively inert in acidic environments, easy to handle and have valuable cation exchange and impurity scavenging properties.

Abstract: The present invention relates to a method for decoloring sulphuric acid produced in accordance with the contact method, comprising one or more absorption circuits. The produced sulphuric acid is decolored by adding hydrogen peroxide to the system. The method is characterized by adding the hydrogen peroxide to the sulphuric acid in the final absorption circuit, and by maintaining the temperature in this circuit above about 70.degree. C.

Abstract: Process for regenerating spent acid is improved by using oxygen-enriched air for combustion, recycling stack gases, and preheating spent acid and air fed to the furnace.

Abstract: A gas phase process for the regeneration and concentration of spent sulfuric acid containing oxidizable impurities, which minimizes decomposition of sulfur trioxide to sulfur dioxide comprising: providing one or more reactor vessels containing hot turbulent combustion products; providing a supply of oxygen to the reactor; atomizing into the reactor vessel or vessels the spent sulfuric acid in droplets capable of evaporating in less than several milliseconds whether or not electromagnetic or ultrasonic energy sources are used to augment evaporation, having a particle size smaller than 50 microns, thereby vaporizing the droplets, almost instantaneously, dissociating the spent sulfuric acid into sulfur trioxide and water, and oxidizing the hydrocarbons; maintaining the temperature in the reactor vessel below 1000.degree. C.

Abstract: Disclosed are a process and apparatus useful for reclaiming sulfur-containing waste materials such as waste or spent sulfuric acid and acid tars.The sulfur-containing waste material is burned in a multi-stage combustion furnace having, in sequence, a rotary furnace containing heated coke, an intermediate combustion chamber and a secondary combustion chamber. The temperatures, gas flow rates and amount of added air are carefully controlled.A separation gas is produced having a high sulfur dioxide content which can be used in the sulfuric acid contact process. The separation gas is free of nitrous oxides, hydrocarbons and sulfur trioxide.

Abstract: In a process for thermally cracking waste sulphuric acid, a combustible material is mixed with such acid and the mixture is supplied to a burner to which a flow of atomizing air is also supplied. A flow of secondary air which is enriched to about 23-40% by volume of oxygen is injected into a flame generated by burning said waste sulphuric acid-combustible material mixture to thereby thermally crack such acid while reducing the production of by-product sulphur trioxide.

Abstract: The invention provides a process for the regeneration of dilute sulfuric acid containing organic impurities and possibly also inorganic salt in several steps. In the first step, the dilute acid is concentrated by indirect heat exchange with the vapors of the second step, and in the second step it is concentrated by direct heat exchange with a countercurrent mixture of steam and acid vapors coming from a third step. In this third step, the acid discharged from the second step is mixed in direct heat exchange with superheated steam. The regenerated sulfuric acid is separated from this mixture and the remaining steam/vapor mixture is forwarded to the second step. In the case where the dilute acid contains organic substances, an oxidant is added in at least one of these process steps.

Abstract: The foam formation arising when aqueous waste sulfuric acid is concentrated can be suppressed by adding aromatic nitro compounds such as nitrobenzene to the acid.

Abstract: In a process for manufacturing a lactam which includes rearranging a cycloalkanone-oxime with sulfuric acid to form the lactam, neutralizing the rearrangement mixture with ammonia to form ammonium sulfate, and separating the lactam and the ammonium sulfate, the improvement which comprises:A. heating at least a portion of the ammonium sulfate to a temperature of 240.degree. - 460.degree. C to form ammonia and ammonium bisulfate;B. separating the ammonia from the ammonium bisulfate;C. recycling the ammonia to neutralize the rearrangement mixture;D. burning the ammonium bisulfate at a temperature of 850.degree. - 1250.degree. C to form an SO.sub.2 -containing gas;E. oxidizing the SO.sub.2 -containing gas to form sulfuric acid; andF. recycling the sulfuric acid to the rearrangement stage.

Abstract: Improvement in the method for recovering sulfur values in the form of sulfur dioxide from spent sulfuric acid by decomposing the spent sulfuric acid at elevated temperature in the presence of elemental sulfur to generate a sulfur dioxide-containing gas stream, which involves: (a) introducing the spent sulfuric acid into a pool of molten sulfur maintained at temperature of at least about 250.degree. C. to thereby generate a gaseous stream comprising sulfur dioxide, vaporous elemental sulfur, and water; (b) cooling said gaseous stream to temperature above the melting point of the sulfur but below about 160.degree. C. to condense elemental sulfur therefrom, separating the condensed elemental sulfur and returning it to the pool of molten sulfur; followed by (c) further cooling the gaseous stream from which elemental sulfur has been condensed to condense water therefrom, and separating the condensed water from the gaseous stream.

Abstract: In a process for manufacturing a lactam which includes rearranging a cycloalkanone-oxime with sulfuric acid to form said lactam, neutralizing the rearrangement mixture with ammonia to form ammonium sulfate, and separating said lactam and said ammonium sulfate, the improvement which comprises:A. forming the ammonium sulfate into finely divided particles;B. burning the particles at a temperature of 850.degree. - 1250.degree. C. to form an SO.sub.2 -containing gas;C. oxidizing the SO.sub.2 -containing gas to form sulfuric acid; andD. recycling at least a portion of the sulfuric acid to the cycloalkanone-oxime rearrangement step.No external source of sulfuric acid is required. A portion of the SO.sub.2 -containing gas can be used for the manufacture of hydroxylamine sulfate, in which case no external source of SO.sub.2 need be required.

Abstract: A process for removal of fluoride compounds from spent alkylation catalyst containing fluorosulfonic acid and sulfuric acid wherein said spent catalyst is hydrolyzed in the presence of water, at subatmospheric pressure in a vacuum digestion zone for conversion of a major portion of fluorosulfonic acid to hydrogen fluoride, wherein said hydrogen fluoride is removed from the vacuum digestion zone as a vapor, and wherein the remaining sulfuric acid rich liquid fraction of the spent catalyst is treated with silica-alumina cracking catalyst for removal of most of the remaining residual fluoride compounds for providing a sulfuric acid effluent substantially free of fluoride compounds. The hydrogen fluoride recovered is reacted with sulfur trioxide to form fresh fluorosulfonic acid which is combined with sulfuric acid to provide fresh alkylation catalyst.

Abstract: Contaminated sulfuric acid which may contain water, organic compounds and inorganic salts is converted to almost pure concentrated sulfuric acid by passing the acid through a Pauling plant and distilling the concentrated contaminated acid.Addition of nitric acid improves the decomposition of organic compounds and ammonium salts of the contaminated acid.