Abstract: This invention relates to the recovery of energy in the manufacture of sulfuric acid, and more particularly to enhanced recovery of energy from the absorption of wet SO3 in sulfuric acid. The invention is further directed to control of mist formation during SO3 absorption, and of the sulfuric acid mist content of the gas stream leaving the SO3 absorption step in a process wherein SO3 absorption energy is recovered from absorption acid in useful form.

Abstract: This invention relates to the recovery of energy in the manufacture of sulfuric acid, and more particularly to enhanced recovery of energy from the absorption of wet SO3 in sulfuric acid. The invention is further directed to control of mist formation during SO3 absorption, and of the sulfuric acid mist content of the gas stream leaving the SO3 absorption step in a process wherein SO3 absorption energy is recovered from absorption acid in useful form.

Abstract: A contact process for manufacture of sulfuric acid is disclosed in which the vapor phase heat of formation of sulfuric acid in the sulfur trioxide conversion gas and the heat of absorption of SO3 in sulfuric acid is recovered by transfer of heat from the absorption acid to high pressure boiler feed water that is fed to a waste heat boiler where steam is generated by transfer of heat from sulfur dioxide combustion gas. Heat is transferred from the absorption acid to a boiler feed water stream in an array of heat exchangers that are in series with respect to the flow of both the boiler feed water stream and the absorption acid stream, and with respect to which array the absorption acid stream and the boiler feed water stream flow countercurrently. Boiler feed water is allowed to flash in a reduced pressure zone in the boiler feed water path, thus preserving a ?t throughout the array of heat exchangers for recovering heat from the absorption acid in water fed to the high pressure boiler.

Abstract: This invention relates to the recovery of energy in the manufacture of sulfuric acid, and more particularly to enhanced recovery of energy from the absorption of wet SO3 in sulfuric acid. The invention is further directed to control of mist formation during SO3 absorption, and of the sulfuric acid mist content of the gas stream leaving the SO3 absorption step in a process wherein SO3 absorption energy is recovered from absorption acid in useful form.

Abstract: Described is a method of increasing the sulfuric acid concentration of a first aqueous sulfuric acid solution with a sulfuric acid concentration of 82-89% to a concentrated sulfuric acid solution with a sulfuric acid concentration of at least 90%, including evaporating water from the first aqueous sulfuric acid solution in an evaporator vessel to the concentrated sulfuric acid solution, pumping around a mixture of the first aqueous sulfuric acid solution, part of the concentrated sulfuric acid solution, a second aqueous sulfuric acid solution, and hydrogen peroxide through an enameled piping system comprising the evaporator vessel and one or more heaters and pumps, wherein the piping system is operating at a temperature of at least 180° C., and the sulfuric acid concentration of the second aqueous sulfuric acid solution is at least 90%.

Abstract: This invention relates to the recovery of energy in the manufacture of sulfuric acid, and more particularly to enhanced recovery of energy from the absorption of wet SO3 in sulfuric acid. The invention is further directed to control of mist formation during SO3 absorption, and of the sulfuric acid mist content of the gas stream leaving the SO3 absorption step in a process wherein SO3 absorption energy is recovered from absorption acid in useful form.

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 reactor system for the transformation of solid, liquid, gaseous, and related hydrocarbon feedstocks into high-purity, high-pressure gas streams capable of withstanding high temperatures and high pressures. The system comprises a plurality of reactor housings and a plurality of molten-metal bath vessels within the housings, the bath vessels in fluid communication with each other via conduits, with communication facilitated by gravity and temperature/pressure differentials.

Abstract: A method of manufacturing ultra-pure sulfuric acid is described. Industrial sulfur trioxide is used as the raw material, gasifying it in a round gasifier, getting it gasified for the second time after condensation, sulfur trioxide gas has been purified. Absorbing the sulfur trioxide gas with the dilute sulfuric acid circularly, collect the target product of ultra-pure sulfuric acid. The main content of the ultra-pure sulfuric acid obtained by the method of the present invention can reach more than 96 wt %, the content of the impurities of metal ions, is in conformity with the SEMI C12 standard.

Abstract: The present invention provides a method of manufacturing ultra-pure sulfuric acid. Industrial sulfur trioxide is used as the raw material, gasifying it in a round gasifier, getting it gasified for the second time after condensation, sulfur trioxide gas has been purified. Absorbing the sulfur trioxide gas with the dilute sulfuric acid circularly, collect the target product of ultra-pure sulfuric acid. The main content of the ultra-pure sulfuric acid obtained by the method of the present invention can reach more than 96 wt %, the content of the impurities of metal ions is in conformity with the SEMI C12 standard.

Abstract: Methods and systems for generating sulfuric acid are disclosed. In some embodiments, the method includes combusting a sulfur-containing material with a gas including oxygen to produce a first stream of sulfur dioxide, mixing water with the first stream of sulfur dioxide to produce a mixed stream, using an energy, electrolytically converting the mixed stream of sulfur dioxide and water into sulfuric acid and hydrogen, generating a source of energy from the hydrogen, and providing the source of energy as at least a portion of the energy for electrolytically converting the first stream of sulfur dioxide and water into sulfuric acid and hydrogen. In some embodiments, the system includes a first chamber for combusting a sulfur-containing material to produce a first stream of sulfur dioxide, an electrolytic cell for converting the first stream into sulfuric acid and hydrogen, and a fuel cell for generating an energy source from the hydrogen.

Abstract: Methods and systems for generating sulfuric acid (102) are disclosed. In some embodiments, the method includes combusting a sulfur-containing material (114) with a gas including oxygen (116) to produce a first stream of sulfur dioxide (118), mixing water with the first stream of sulfur dioxide to produce a mixed stream, using an energy, electrolytically converting (108) the mixed stream of sulfur dioxide and water into sulfuric acid (102) and hydrogen (122), generating a source of energy (126) from the hydrogen, and providing the source of energy as at least a portion of the energy for electrolytically converting the first stream of sulfur dioxide and water into sulfuric acid and hydrogen. In some embodiments, the system includes a first chamber for combusting a sulfur-containing material to produce a first stream of sulfur dioxide, an electrolytic cell (108) for converting the first stream into sulfuric acid and hydrogen, and a fuel cell (112) for generating an energy source from the hydrogen.

Abstract: The invention relates to a process and plant for producing sulphuric acid by catalytic oxidation of SO2 to form SO3 in a converter with at least one contact stage, the SO3-containing process gas, after it has passed through at least one contact stage, being withdrawn from the converter and fed to an apparatus for recovering heat, in which steam is generated from feedwater by means of the heat of the process gas, and the process gas then being fed to an absorber, in which the SO3 is absorbed in sulphuric acid. To improve the utilization of heat during the production of sulphuric acid, the feedwater is fed to the heat recovery apparatus at a higher temperature than the process gas fed to the absorber.

Abstract: Process for the recovery of sulfuric acid comprising: (a) contacting a stream containing sulfuric acid vapor and/or sulfur trioxide in an absorption stage with a ionic liquid absorbent, (b) withdrawing a gas substantially free of sulfuric acid vapor and/or sulfur trioxide from said absorption stage, (c) withdrawing a stream comprising the ionic liquid absorbent from said absorption stage, in which said ionic liquid absorbent contains sulfuric acid, (d) recovering sulfuric acid from said ionic liquid absorbent by passing the stream of step (c) through a separation stage, (e) withdrawing from the separation stage (d) a stream rich in sulfuric acid, (f) withdrawing from the separating step (d) a ionic liquid absorbent stream in which said ionic liquid absorbent contains sulfuric acid and returning said stream to the absorption step (a).

Abstract: An economically viable and environmentally sound process is described for the transformation of solid, liquid, gaseous and related hydrocarbon feedstocks into high purity, high pressure gas streams that may be further processed in conjoined multiple metal bath reactors.

Abstract: A process of producing sulfuric acid from feed gases containing 0.1-30% SO2. The process produces concentrated sulfuric acid from a feed gas containing 0.1 vol % to 30 vol % SO2, in particular a strong feed gas containing 6 vol % to 30 vol % SO2, that enables the gas entering the final wet condensing stage to have an acid dew point of below 260° C., while at the same time achieving current requirements of acid mist emissions of about 20 ppmv without resorting to substantial air dilution of the strong feed gas.

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 production of sulphuric acid comprising condensing sulphuric acid vapour from a gas mixture containing 0.01 to 10 vol. % of H2SO4 vapour calculated at complete hydration of SO3 in the gas to H2SO4 and 0 to 50 vol. % of water vapour by cooling of the gas in a sulphuric acid tower, wherein a stream containing NH3 is added upstream of the tower in an amount corresponding to 0.01-100 ppm NH3 by vol. in the gas stream at the entry of the tower.

Abstract: A process is provided for increasing the concentration of sulfuric acid in a waste solution of sulfuric acid previously used to produce titanium dioxide. The waste solution of sulfuric acid is fed into a first heat exchanger/evaporator stage that operates at a sulfuric acid concentration of less than 30%. A portion of the solution discharged from the first heat exchanger/evaporator is fed into a heat exchanger/evaporator that uses waste heat and operates at a sulfuric acid concentration that is greater than 40%, while the remainder of the solution discharged from the first heat exchanger/evaporator and the solution discharged from the heat exchanger/evaporator using waste heat is fed into a second heat exchanger/evaporator that operates at a sulfuric acid concentration that is greater than 50%.

Abstract: A process is provided for the purification of sulfuric acid contaminated with impurities, such as nitric acid, nitrosylsulfuric acid, dinitrotoluenes and mononitrotoluenes, wherein this contaminated sulfuric acid was obtained from the production of nitrated toluene using toluene and nitric acid. The contaminated sulfuric acid is preheated to a temperature in the range of 50 to 180.degree. C. in a heat exchanger. The heated, contaminated sulfuric acid is freed from steam-volatile impurities, such as dinitrotoluenes and mononitrotoluenes, and the nitrogen-containing compounds within the sulfuric acid are decomposed by counter currently contacting the contaminated sulfuric acid with steam and vapors from a downstream concentration step in a steam stripper, which is operated at a pressure ranging from 300 to 1,000 mbars. The steam-stripped sulfuric acid is fed into a first concentration stage, which is operated at the same pressure used in the steam stripper.

Abstract: A process is provided for manufacturing sulfuric acid from a gas containing sulfur dioxide and steam. The sulfur dioxide and steam containing gas is subjected to a catalytic oxidation to convert the sulfur dioxide into sulfur trioxide so as to produce a gas having a sulfur trioxide to steam mole ratio of at least 1:1 at a temperature of 400 to 600.degree. C. This sulfur trioxide and steam containing gas is injected into an indirect heat exchanger where it is indirectly cooled with a cooling fluid so that at least 80 percent of the theoretically possible sulfuric acid is formed and condensed in this heat exchanger. The cooling fluid exiting the heat exchanger is fed into a turbine for the generation of electricity. The gas mixture exiting the heat exchanger is contacted with sulfuric acid in a separate contact vessel to form additional, concentrated sulfuric acid. The sulfuric acid formed in the heat exchanger is discharged.

Abstract: A process for desulfurization of a gaseous substrate containing O.sub.2, SO.sub.2, SO.sub.3, H.sub.2 SO.sub.4, H.sub.2 S, CS.sub.2, COS and/or organic sulfur-containing components. The combustible components are oxidized catalytically into H.sub.2 O, CO.sub.2, and SO.sub.2. The SO.sub.2 is further oxidized catalytically into SO.sub.3, which in the presence in the substrate of at least an equivalent amount of H.sub.2 O in the gas, is further hydrated and condensed as sulfuric acid. The process is conducted in two towers that are connected in series, each tower being loaded with a layer of inert material below a layer of oxidization catalyst preferably consisting of an acid resistant material with parallel, vertical channels. A preferred catalyst includes vanadium oxide supported on a silica carrier material and promoted with alkali metals. The process includes reversing a direction of gas flow in the towers after periods of about 1-40 minutes.

Abstract: Sulfuric acid which contains dilute organic phosphorus compounds and other impurities and is obtained, for example, during preparation of sulfonated arylphosphines, is purified by extraction with an amine which is sparingly soluble or insoluble in water.

Abstract: A method for manufacturing sulfuric acid from a gas containing sulfur oxides, water and oxygen comprising subjecting the sulfur oxides rich gas to either an adiabatic compressor or a flame impinger to rapidly increase the temperature so that the sulfur dioxide in the gas is converted into sulfur trioxide and cooling the sulfur trioxide rich gas to produce sulfuric acid.

Abstract: The process of concentrating a dilute sulfuric acid in a three-stage vacuum evaporation plant includes feeding an entry dilute sulfuric acid to a first evaporation stage of a vacuum evaporation plant to form an overhead vapor (6), withdrawing a finally concentrated sulfuric acid from the third evaporation stage (3), using steam or the overhead vapor (6) of the first evaporation stage as a heating fluid in the three-stage vacuum evaporation plant, maintaining the entry dilute sulfuric acid under a pressure of 0.4 to 0.7 bar and at a temperature of 80.degree. to 120.degree. C. in the first evaporation stage (1), maintaining the partially concentrated sulfuric acid under a pressure of 0.02 to 0.06 bar and at a temperature of 50.degree. to 90.degree. C. in the second evaporation stage (2), maintaining the further concentrated sulfuric acid under a pressure of 0.02 to 0.06 bar and at a temperature of 80.degree. to 120.degree. C.

Abstract: When condensing sulfuric acid from gases containing sulfuric acid vapor and steam in excess, e.g. originating from a power station, a substantial decrease of the amount minute droplets of sulfuric acid (the so-called acid mist) escaping to the surroundings is obtained, even in cases where the sulfuric acid plant is equipped with an aerosol filter, if minute nucleation cores are incorporated into the gas in an amount of 10.sup.9 to 10.sup.12 solid particles per Nm.sup.3 per 0.1 % H.sub.2 SO.sub.4 -vapor in the gas. The nucelation cores may, e.g., be generated by combusting hydrocarbons with>2 carbon atoms or silicones, or added as smoke from an electric arc or welding.

Abstract: A noncatalytic process for producing sulfur trioxide and sulfuric acid in which sulfur is combusted with an oxygen-rich gas in the presence of recycled sulfur dioxide-rich gas to form sulfur trioxide which is absorbed in sulfuric acid and yield a sulfur dioxide rich gas which is compressed to form the recycled sulfur dioxide rich gas.

Abstract: To produce a high-temperature superconductor of the composition Bi.sub.(2+a) (Sr.sub.(1-b) Ca.sub.b).sub.(3-a) Cu.sub.(2+c) O.sub.(8+x), where a is from 0 to 0.3, b is from 0.1 to 0.9 and c is from 0 to 2, and x has a value which depends on the oxidation state of the metals contained, oxides and/or carbonates of bismuth, strontium, calcium and copper are thoroughly mixed. In this process, the copper compound is used as a mixture of copper(I) oxide and copper(II) oxide. Then the mixture of oxides and/or carbonates is first allowed to react mutually in an inert gas atmosphere at temperatures from 700.degree. to 800.degree. C. for 0.5 to 36 hours before subsequently treating the mixture in an oxygen-containing atmosphere at temperatures from 700.degree. to 875.degree. C. for 3 to 60 hours.

Abstract: Flue gases etc. may contain SO.sub.2 which should be prevented from admission to the atmosphere. SO.sub.2 is oxidized to SO.sub.3 and condensed with steam to H.sub.2 SO.sub.4 -vapors which are condensed in vertical glass tubes cooled from the outside. In principle the condensate is collected near the bottom of the tubes. In the cooling process a mist of very small H.sub.2 SO.sub.4 droplets is formed and tends to escape to the atmosphere. Environmental regulations continually increase the demands on reducing the amount of acid mist escaping. According to the invention an important method to achieve a reduction of the escape of acid mist is to pass the gas leaving each tube through an aerosol filter in gastight connection with the tube top. Such a filter may consist of acid resistant fibres or filaments having a thickness of 0.04-0.7 mm and may be arranged in specified manners to ensure a drop of pressure through below 20 mbar.

Abstract: A mixture of sulfuric acid and hydrochloric acid essentially free from dissolved sulfur dioxide to be used in a chlorine dioxide reactor is produced by reacting chlorine and sulfur dioxide in at least two reaction zones. In the bottom of a primary reaction zone the total amount of sulfur dioxide needed for the mixed acid production is introduced in an aqueous mixture of sulfuric and hydrochloric acid containing dissolved chlorine and gaseous chlorine. The sulfur dioxide reacts with chlorine in the aqueous phase to produce sulfuric acid and hydrochloric acid. The mixed acid produced in the primary reaction zone contains dissolved quantities of sulfur dioxide and is forwarded to a secondary reaction zone. Chlorine is introduced into the lower part of the secondary reaction zone. The amount introduced can be the total amount of chlorine to be used in the production of the mixed acid for the chlorine dioxide reactor, or it can be a part of that amount, the balance being introduced in the primary reaction zone.

Abstract: A process for production of chlorine dioxide and chlorine by reacting sodium chlorate with chloride ions and sulfuric acid where the chlorine ions partly are obtained from hydrochloric acid is described. In the process chlorine obtained as a by-product is reacted with sulfur dioxide in a reactor equipped with a condenser. The heat of reaction is removed by keeping the reactor at or above the boiling point of the reaction medium and the vapors are condensed in the condenser and brought back to the reactor. The obtained mixed acid comprising sulfuric acid and hydrochloric acid is returned to the chlorine dioxide reactor.

Abstract: A feed gas mixture with SO.sub.2 partial pressure of at least about 0.5 atmosphere and an O.sub.2 :SO.sub.2 mole ratio of between about 0.7:1 and about 1:1 is passed in plug flow through a packed bed of conversion catalyst. The catalyst bed is cooled to produce a temperature profile including a first zone of increasing temperature, a second zone of substantially constant temperature and a third zone of declining temperature. The exit temperature is sufficiently low for high equilibrium conversion values. The effluent is cooled to condense liquid sulfur trioxide, while the sulfur trioxide remaining in the gas stream can be absorbed into oleum and/or sulfuric acid. Enriched oleum can be prepared by blending condensed sulfur trioxide into oleum or sulfuric acid.

Abstract: Apparatus and process for the manufacture of sulphuric acid by the contact process of the type comprising at least one gas-concentrated sulphuric acid contacting unit and a sulphuric acid heat exchanger characterized in that the contacting unit and/or heat exchanger is formed of high silicon content austenitic steel. The steel is also of use in sulphuric acid concentrators. Reduced corrosion rates are provided.

Abstract: A process for removing hydrogen sulfide from geothermal steam comprising adding free oxygen to the steam and contacting the steam with an oxidation catalyst at a pressure of at least 30 psig and a temperature not greater than the saturation temperature of the steam. The catalyst may comprise activated carbon, a refractory inorganic oxide or a metal phthalocyanine and is wetted with an aqueous solution of thiosulfates, sulfates or polysulfides. The hydrogen sulfide is converted and steam of reduced hydrogen sulfide content is obtained.

Abstract: Stack gases derived from combustion of hydrocarbons are scrubbed by direct contact with an inert liquid capable of taking sulphur compounds into solution. The inert liquid pregnant with sulphur compounds is injected into a reactor where the sulphur compounds are converted into sulphurous acid or in the presence of a catalyst wet oxidized into sulphuric acid. Product acid is withdrawn from the reactor and the stripped inert liquid is returned to the scrubber to repeat the process. Waste heat is captured for further useful work.

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: Dilute solutions of corrosive products, such as sulphuric or phosphoric acid, are concentrated by pre-concentrating the dilute solution and then introducing the pre-concentrated solution into a tunnel in which it flows in a thin layer over successive cascades while being heated, preferably by indirect radiant heating. An installation for carrying out the process is also described.

Abstract: A method of obtaining hydrogen from water in a multi-stage circulatory process avoids the need to use solid inorganic salts as auxiliary products by using only gases and liquids in the reaction stages. Carbon monoxide is reacted catalytically with steam producing carbon dioxide and hydrogen; the carbon dioxide is reacted with steam and sulphur dioxide to give sulphuric acid and carbon monoxide; the sulphuric acid is split into sulphur trioxide and steam; the sulphur trioxide is dissociated into oxygen and sulphur dixoide. The CO and SO.sub.2 are fed back into the process, and hydrogen and oxygen obtained as end products.