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 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least one contact stage, the SO3-containing process gas, after it has passed through at least one contact stage, being withdrawn from the converter and fed to an apparatus for recovering heat, in which steam is generated from feedwater by means of the heat of the process gas, and the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: There are described a process and a plant for producing sulfuric acid by catalytic oxidation of SO2 to SO3 and subsequent absorption of SO3 in sulfuric acid, wherein the SO3 is introduced into a first absorption stage and absorbed there in concentrated sulfuric acid, wherein the sulfuric acid having a higher concentration due to the absorption is passed through a heat exchanger and cooled, and wherein the non-absorbed SO3 is supplied to a second absorption stage for the further absorption in sulfuric acid. Before the first absorption stage a partial stream of SO3 is branched off and supplied directly to the second absorption stage.

Abstract: The present invention is concerned with a process and a plant for the production of sulphuric acid wherein a sulphur dioxide-containing feed gas is converted, at least in part, with oxygen in at least two contact stages of main contacts arranged in series, to generate sulphur trioxide, and wherein generated sulphur trioxide-containing gas is conducted to an absorber and converted therein to sulphuric acid. In order to be able to economically process feed gases of a sulphur dioxide content of between 13 and 66% by volume to sulphuric acid, using conventional catalysts, it is suggested to withdraw from a contact stage connected upstream of the last main contact stage, a partial stream of the sulphur dioxide- and sulphur trioxide-containing gas, to mix the said partial stream with the feed gas to generate a contact gas of a sulphur dioxide content of more than 13% by volume, and to return the same to the first contact stage.

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 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 heat exchanger for use in a sulphuric acid manufacturing plant to effect heat transfer between desired gas streams selected from air, sulphur dioxide and sulphur trioxide. The exchanger provides for hot or cold split flow gas streams through the exchanger shell with either mixing or splitting into two or more streams to provide for reduced condensible material condensation, corrosion, metal thermal differential stress and capital equipment cost. A preferred exchanger is used in combination with a sulphur burning furnace to provide an improved preheater.

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: 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: 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: 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 process for preparing a cordierite, which includes dissolving a silicon compound, an aluminum compound and a magnesium compound in a molar ratio of 1:0.7 to 1:0.3 to 0.5 in a complexing agent represented by the formula R(OCH.sub.2 CH.sub.2).sub.n OH, wherein R is an alkyl group and n is an integer of 1 to 4; heating the resulting solution to bring about a ligand exchange reaction of the silicon compound, aluminum compound and magnesium compound with the complexing agent; conducting hydrolysis to form a gel; drying the gel and sintering the dried gel at 800.degree. to 1450.degree. C.

Abstract: A process is provided by means of acid scrubbing in combination with electrolysis for removing sulfur dioxide from a waste gas stream such as effluent vent of flue gas, for purposes of economy, for achieving a useful by-product, and for minimizing environmental pollution.

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: Sulfuric acid is admixed with a foaming agent to produce a lather which is then mixed with cottonseed to delint the same. The lint is removed in a dry or semi dry condition.

Abstract: The effluent streams from utility stack gases containing nitric oxides and sulfur dioxide are sequentially oxidized, absorbed with effluent spent alkylation acid, the unabsorbed remaining gases contacted with carbon monoxide from alkylation units in refinery cracking and other industrial plants to form sulfur, carbon dioxide and nitrogen, the carbon dioxide and nitrogen being vented, the sulfur oxidized to sulfur trioxide and contacting aqueous sulfuric acid therewith to effect concentration of said acid and suitability for recycle to an alkylation unit; the absorbate containing spent alkylation acid sequentially treated with a burning, oxidation, aqueous dilution and carbon monoxide treatment steps to form sulfuric acid for recycle to an alkylation unit and venting formed carbon dioxide and nitrogen.

Abstract: A process for thermally-degrading the thermally-degradable organic matter contained in spent sulfuric acid by condensing steam in the spent acid for a time sufficient to degrade the thermally-degradable organic matter, the steam being at a pressure exceeding the vapor pressure of said spent acid. Treated sulfuric acid is useful in the production of wet process phosphoric acid by a novel process. Spent sulfuric acid containing non-degradable organic matter can be used in a mixture with the treated sulfuric acid.

Abstract: Process of reducing the bromine content of spent sulfuric acid bromination liquor containing organic impurities by blowing an oxygen containing gas through said sulfuric acid liquor at an elevated temperature at least until substantially all of the organic material in said liquor is oxidized.