Abstract: In a process for the removal of soot from a sulfurous gas stream, a process gas containing O2 and more than 500 ppm SO2 and/or SO3 together with soot is brought into contact with a VK type catalyst in a reactor, said catalyst comprising vanadium pentoxide (V2O5), sulfur in the form of sulfate, pyrosulfate, tri- or tetrasulfate and one or more alkali metals, such as Na, K, Rb or Cs, on a porous carrier, preferably a silicon dioxide carrier.

Abstract: The invention relates to shaped catalyst bodies for the oxidation of SO2 to SO3, which comprise vanadium, at least one alkali metal and sulfate on a silicon dioxide support material, wherein the shaped body has the shape of a cylinder having 3 or 4 hollow-cylindrical convexities, obtainable by extrusion of a catalyst precursor composition comprising vanadium, at least one alkali metal and sulfate on a silicon dioxide support material through the opening of an extrusion tool, wherein the opening of the extrusion tool has a cross section formed by 3 or 4 partly overlapping rings whose midpoints lie essentially on a circular line having a diameter of y, wherein the rings are bounded by an outer line lying on a circle having an external diameter x1 and an inner line lying on a circle having an internal diameter x2.

Abstract: A process for sulfonating at least one halobenzene with sulfur trioxide (SO3) comprising the following steps: Step 1. manufacturing a gaseous mixture [mixture (M)] comprising SO3 and at least one additional gas different from SO3 by oxidizing sulfur dioxide in the presence of at least one catalyst, wherein the SO3 content in mixture (M) is from 1 to 95% by volume, relative to the total volume of mixture (M); and step 2 contacting said mixture (M) with said at least one halobenzene.

Abstract: The material proposed for sealing off cavities between structural components formed of materials having different thermal characteristics comprises an intumescent mat completely sealed in a polymeric film and the interior bounded by the polymeric film and containing the intumescent mat is evacuated.

Abstract: Improved catalysts for oxidation of sulfur dioxide which are alkali metal-promoted vanadium catalysts which are further promoted by gold. Improved methods employing such catalyst for oxidation of sulfur dioxide and for manufacture of sulfuric acid. Improved methods for multiple step oxidation of sulfur dioxide in which the last oxidation step is carried out employing improved catalysts of this invention at temperatures lower than 400° C.

Abstract: Improved catalysts for oxidation of sulfur dioxide which are alkali metal-promoted vanadium catalysts which are further promoted by gold. Improved methods employing such catalyst for oxidation of sulfur dioxide and for manufacture of sulfuric acid. Improved methods for multiple step oxidation of sulfur dioxide in which the last oxidation step is carried out employing improved catalysts of this invention at temperatures lower than 400° C.

Abstract: The invention relates to a catalyst for the oxidation of SO2 to SO3. The catalyst contains an active substance which contains vanadium, alkali metal compounds and sulfate applied to a support. The support contains naturally occurring diatomaceous earth, wherein the support contains at least one relatively soft naturally occurring uncalcined diatomaceous earth which has a percentage reduction of at least 35% in its D50 value determined in a particle size determination according to the dry method in comparison with the wet method.

Abstract: The invention relates to a catalyst for the oxidation of SO2 to SO3 and also a process for producing it and its use in a process for the oxidation of SO2 to SO3.

Abstract: The invention relates to a process for the continuous preparation of oleum of a concentration of 10 to 45% by weight of SO3 and/or sulphuric acid of a concentration of 94 to 100% by weight of H2SO4 by combustion of sulphur with atmospheric oxygen according to the principle of superstoichiometric combustion, cooling the resultant sulphur-dioxide-containing gases to 350° C. to 500° C., catalytic conversion of these cooled gases to give sulphur-trioxide-containing gases in the presence of a vanadium-containing catalyst using single or double contact catalysis, absorption of the sulphur-trioxide-containing gases after cooling, if appropriate removal of liquids from the gases after absorption and energy recovery, with liquid sulphur being injected into the hot combustion gas stream perpendicular to the main direction of flow in the form of a fan using one or more bimodal fan-type nozzles.

Abstract: There is provided a process for trapping particulate matter in a gas stream exiting a combustion equipment comprising providing a combustion equipment with one or more exits for exhaust gases, each exit connected to one or more ducts, and placing at least one particulate trap in each duct, wherein the particulate trap is removable and/or replaceable while the combustion equipment is online.

Abstract: A process for treating a dust containing, gaseous or liquid feed stream in a reactor containing a plurality of particle beds, which have the capability, once the pressure drop across a bed has reached a maximum allowable level, to distribute most of the feed stream to a point directly upstream of each of the subsequent beds in a series, stepwise manner. The beds contain particles in the form of pellets, cylinders, granules, rings, or mixtures thereof, and at the end of an operation period, the primary fraction of the feed flow is directed through the downstream-most bed in the reactor. By providing for removal of dust in each of the beds, the process enables the reactor to operate with a conventional pressure drop profile, but for an extended on-stream period of time.

Abstract: A method of preparation and use of lightweight, high-strength gypsum wallboard, as well as a core composition suitable for use therein, are disclosed. The core composition includes a slurry of calcium sulfate hemihydrate (stucco), water, acid-modified starch, and a starch cross-linking agent, having a pH of about 9 to about 11. The composition and method provide a wallboard having a lower density than conventional wallboard, and with equivalent or better strength characteristics than conventional wallboard.

Abstract: The invention relates to a process for the continuous preparation of oleum of a concentration of 10 to 45% by weight of SO3 and/or sulphuric acid of a concentration of 94 to 100% by weight of H2SO4 by combustion of sulphur with atmospheric oxygen according to the principle of superstoichiometric combustion, cooling the resultant sulphur-dioxide-containing gases to 350° C. to 500° C., catalytic conversion of these cooled gases to give sulphur-trioxide-containing gases in the presence of a vanadium-containing catalyst using single or double contact catalysis, absorption of the sulphur-trioxide-containing gases after cooling, if appropriate removal of liquids from the gases after absorption and energy recovery, with liquid sulphur being injected into the hot combustion gas stream perpendicular to the main direction of flow in the form of a fan using one or more bimodal fan-type nozzles.

Abstract: A catalyst for reacting SO2 with molecular oxygen to form SO3 is suited for a continuous operation at temperatures of 700° C. and above, when the same consists of a carrier and an active component connected with the carrier, the active component consists of 10 to 80 wt-% iron, the carrier has a BET surface of 100 to 2000 m2/g and an SiO2 content of at least 90 wt-%, and the weight ratio carrier:active component is 1:1 to 100:1.

Abstract: The use of base/clay composites materials as sorbents for the removal of SO.sub.2 and SO.sub.3 (SO.sub.x) from flue gas and other sulfur containing gas streams is described. The base is either an alkaline earth metal carbonate (eg. CaCO.sub.3) or hydroxide (eg. Ca(OH).sub.2) is incorporated onto the clay by precipitating from corresponding metal oxide (eg. CaO) in an aqueous clay slurry. A second metal oxide or oxide precursor, preferably selected from transition metal ions, capable of promoting the oxidation of sulfur dioxide to sulfur trioxide, is incorporated to the base/clay composite during the synthesis in the form of finely divided metal oxide powder, metal oxide sol, water soluble metal salt or as clay-intercalated metal cation. The use of clay as dispersing agent for both the basic oxide and the second metal oxide component decreases the particle agglomeration of base particles and increases the rate of SO.sub.x uptake compared to the bulk bases in current use.

Abstract: In the continuous production of oleum having a concentration of 10 to 45% by weight SO.sub.3 and/or sulfuric acid having a concentration of 94 to 100% by weight H.sub.2 SO.sub.4 by burning sulfur with atomospheric oxygen on the principle of overstoichiometric or understoichiometric burning, cooling the resulting SO.sub.2 -containing gas to 390.degree.-480.degree. C., catalytically reacting the cooled gas to SO.sub.3 -containing gas on a vanadium-containing catalyst on the principle of single- or double-contact catalysis, absorbing the SO.sub.3 -containing gas after cooling and, optionally, separating liquid from the gas after absorption, followed by recovering energy, the improvement which comprises effecting the burning of the sulfur with atomospheric oxygen in the presence of a dry SO.sub.2 -containing gas which contains up to 5,000 ppm (NO).sub.x expressed as NO.

Abstract: Sulfur compounds poison catalysts, such as the anode catalysts and reformer catalysts within molten carbonate fuel cell systems. This poisoning is eliminated using a sulfur scrubber 29 located prior to the inlet of the cathode chamber 13. Anode exhaust 19 which contains water, carbon dioxide and possibly sulfur impurities, is combined with a cathode exhaust recycle stream 22 and an oxidant stream 25 and burned in a burner 33 to produce water, carbon dioxide. If sulfur compounds are present in either the anode exhaust, cathode exhaust stream, or oxidant stream, sulfur trioxide and sulfur dioxide are produced. The combined oxidant-combustion stream 27 from the burner 33 is then directed through a sulfur scrubber 29 prior to entering the cathode chamber 13. The sulfur scrubber 29 absorbs sulfur compounds from the combined oxidant-combustion stream 27. Removal of the sulfur compounds at this point prevents concentration of the sulfur in the molten carbonate fuel cell system.

Abstract: A catalyst which contains vanadium oxide and alkali compounds and serves to oxidize SO.sub.2 to SO.sub.3 is produced in that prefabricated carrier bodies are impregnated with impregnating solutions which contain vanadium and alkalis, the impregnated carrier bodies are thermally treated at elevated temperature and this is followed by an activation under oxidizing conditions at a temperature from 750.degree. C. to 1000.degree. C. In the production of the impregnating solutions, fine-grained V.sub.2 O.sub.5 is dissolved in an acid aqueous medium with addition of a reducing agent and a reduction to form VO.sup.2+ is effected, acid and reducing agent are used in approximately stoichiometric amounts for the dissolution and reduction of V.sub.2 O.sub.5. The alkalis are used in the form of salts. The solution is adjusted to contain SO.sub.4 in an amount which is sufficient to combine the entire amount of the alkalis in neutral sulfates during the drying and activation.

Abstract: A high-density and mean-porosity catalyst, supported on a siliceous matrix, based on vanadium, iron, oxygen and alkali metals, wherein the V.sub.2 O.sub.5 content ranges from 6 to 9% by weight, the Me.sub.2 O content ranges from 8.5 to 12% by weight (Me being an alkali metal), the particle density ranges from 1.10 to 1.40 g/cm.sup.3 and furthermore:the pore volume ranges from 0.20 to 0.70 cm.sup.3 /g and the surface area ranges from 0.30 to 5 m.sup.2 /g, the average radius of the pores ranging from 600 to 2200 nanometers;the SiO.sub.2 content is lower than 75% by weight and the Fe.sub.2 O.sub.3 content is higher than 0.90% by weight.

Abstract: A process for the removal of sulfur dioxide from gasses produced by processes resulting in off gases at elevated temperatures as in the combustion of sulfur containing fuels such as coal and fuel oil by contacting the gasses with a composition including a source of calcium, and a catalytically effective amount of a molybdenum containing catalyst for the oxidation of sulfur dioxide to sulfur trioxide which then reacts with the calcium compound to form calcium sulfate.

Abstract: A process for the recovery of sulphuric acid from a waste acid stream containing ammonium sulphate comprising vaporizing the waste acid and subsequently converting the ammonia and sulphur dioxide generated to nitrogen and sulphur trioxide, respectively. The process provides an economic method for the regeneration of the waste sulphuric acid from a methyl methacrylate production process.

Abstract: A process for preparing a high-density and, low-silica catalyst, supported on a siliceous matrix, based on vanadium, oxygen and alkali metals, wherein the V.sub.2 O.sub.5 content ranges from 6 to 9% by weight, the K.sub.2 O content ranges from 8.5 to 12% by weight and the particle density ranges from 0.90 to 1.40 g/cm.sup.3 and wherein furthermore:the volume of the pores is from 0.30 to 0.70 cm.sup.3 /g and the surface area is from 0.30 to 3 m.sup.2 /g, the average radius of the pores being from 650 to 2200 nanometers;the SiO.sub.2 content is equal to or lower than 75% by weight and the Fe.sub.2 O.sub.3 content is equal to or greater than 0.90% by weight.

Abstract: Catalysts for the oxidation of sulfur dioxide to sulfur trioxide, consisting of a silica-based carrier and, applied on this, an active substance containing vanadium and alkali metal compounds, are prepared by dissolving vanadium pentoxide in an alkali solution, acidifying the solution with sulfuric acid, mixing the acidified solution with the carrier, molding the mixture and drying and calcining the molding. To obtain mechanically stable catalysts, a dissolved alkali metal silicate and/or silica sol are added to the alkaline solution before acidification, the latter process is carried out at below 35.degree. C. and the solution is then immediately incorporated into the carrier. The resulting moist crumbly material contains from 2 to 6% by weight of V.sub.2 O.sub.5, from 35 to 45% by weight of H.sub.2 O and from 15 to 50% by weight of SiO.sub.2. From 5 to 25% by weight of the total silica content originates from the dissolved alkali metal silicate and/or silica sol.

Abstract: A process for preparing a catalyst for the oxidation of sulfur dioxide comprising:(a) intimately contacting a siliceous support with a mixture of a water-insoluble vanadium (V) compound, a potassium (K) salt so that the K/V molar ratio is maintained between about 2.5 and about 4.0, a source of sulfite anion, a water-insoluble sodium (Na) salt of an acid having a pKa between about 3 and about 7 so that the K/Na molar ratio is between about 4 and about 8, and water to form an intermediate product;(b) drying the intermediate product;(c) calcining the dried intermediate product; and(d) sulfating the calcined intermediate product; thus providing a catalyst with high durability and high catalytic activity with an alpha-cristobalite content between from about 1 to about 30 percent.The wet catalyst may be extruded into shaped forms such as spheres, cylinders, trilobes, or tablets before drying.

Abstract: Catalysts comprising bismuth and vanadium components are highly active and stable, especially in the presence of water vapor, for oxidizing hydrogen sulfide to sulfur or SO.sub.2. Such catalysts have been found to be especially active for the conversion of hydrogen sulfide to sulfur by reaction with oxygen or SO.sub.2.

Abstract: Catalysts comprising bismuth and vanadium components are highly active and stable, especially in the presence of water vapor, for oxidizing hydrogen sulfide to sulfur or SO.sub.2. Such catalysts have been found to be especially active for the conversion of hydrogen sulfide to sulfur by reaction with oxygen or SO.sub.2.

Abstract: Catalysts comprising bismuth and vanadium components are highly active and stable, especially in the presence of water vapor, for oxidizing hydrogen sulfide to sulfur or SO.sub.2. Such catalysts have been found to be especially active for the conversion of hydrogen sulfide to sulfur by reaction with oxygen or SO.sub.2.

Abstract: Catalysts comprising bismuth and vanadium components are highly active and stable, especially in the presence of water vapor, for oxidizing hydrogen sulfide to sulfur or SO.sub.2. Such catalysts have been found to be especially active for the conversion of hydrogen sulfide to sulfur by reaction with oxygen or SO.sub.2.

Abstract: A sulphur dioxide converter and pollution arrester system which involves the treatment of smoke and/or contaminated air emanating from a combustion area by passage through a zone achieving turbulence into a water spray contained first treating chamber. The turbulence zone, into which an atomized catalyst is introduced, serves to create a longer path for cooling as well as increased centrifugal motion to the solid particles in the contaminated air and also the formation of sulphur trioxide. In other words, the arrangement is such that pollution arresting action is provided in the form of "slinging" resulting from tangential directional movement and, when combining with the water spray in the first treating chamber, the ultimate formation of sulphuric acid.

Abstract: Catalytic process for reacting a sulphur-containing material such as elemental sulphur or hydrogen sulphide with an oxygen-containing gas to produce sulphur dioxide. The process and apparatus can be used to remove hydrogen sulphide from a gas. The process and apparatus may also be used to produce sulphur dioxide as a product which may be converted to SO.sub.3 and used, for example, to produce sulphuric acid.

Abstract: A waste gas containing sulfur dioxide is desulfurized by contacting the gas with phosphorus-promoted sodium vanadate disposed upon porous alumina having a phosphorus-to-vanadium atomic ratio in the range 0.2-1.8 to 1.

Abstract: A heat resistant catalyst for the production of sulfuric acid for using a gas containing sulfur dioxide in a high concentration which comprises vanadium pentoxide as a main catalytic component, potassium sulfate as a promotor and at least one carrier selected from the group consisting of silica sol and diatomaceous earth, wherein a ratio of K.sub.2 O(mol)/V.sub.2 O.sub.5 (mol) is 3.8 to 5.5, V.sub.2 O.sub.5 content is 5.5 to 7.5% by weight and sum of a value of said ratio and the V.sub.2 O.sub.5 content (% by weight) is 9.3 to 11.

Abstract: A process for the production of sulfuric acid for using a gas containing sulfur dioxide in a high concentration which comprises using a catalyst consisting of vanadium pentoxide as a main catalytic component, potassium sulfate as a promotor and a diatomaceous earth carrier, wherein a ratio of K.sub.2 O(mol)/V.sub.2 O.sub.5 (mol) is 3.8 to 5.5, V.sub.2 O.sub.5 content is 5.5 to 7.5% by weight and sum of a value of said ratio and the V.sub.2 O.sub.5 content (% by weight) is 9.3 to 11.

Abstract: A catalyst for the oxidation of sulfur dioxide comprising vanadium supported by a microporous carrier is disclosed. The microporous carrier is characterized by a silica content greater than 85 percent, an alumina content greater than 3 but less than 5 percent, an iron content less than 2.0 percent, a surface area greater than 10 m.sup.2 /g, a bulk density more than 0.10 and less than 0.35 g/cc, a mean pore diameter greater than 0.3 and less than 2.5 micrometers, a pore volume greater than 2 ml/g, and a porosity greater than 65 percent. The product containing vanadium is easily extrudable into pellets or other shaped forms to give both a durable and highly active catalyst. Diatomaceous earths of the Actinoptychus class, especially Actinoptychus undulata, and of the Coscinadiscus class meet the criteria stated above, as do some acid-leached montmorillonite clays.

Abstract: A catalytic material for oxidation of sulfur dioxide to sulfur trioxide at any temperature above 300.degree. C., comprising a catalyst which at reaction conditions is a melt including sulfatized vanadium ions as the active catalytic component and two different promoters and which is dispersed in an inert porous carrier.The first promoter comprises cesium ions, optionally in combination with ions of another alkali metal such as sodium, potassium or rubidium, known to promote vanadium catalysts. The second promoter comprises ions of a metal such as aluminum, magnesium, yttrium or lanthanum, which does not promote formation of inactive V.sup.4 species and the oxide of which has a heat of formation greater than 100 kcal per oxygen atom and is at least partly soluble in the heavily sulfatized environment of the melt.

Abstract: A sulfuric acid catalyst is made by passing sulfur dioxide gas into an aqueous mixture of vanadium oxide, sulfuric acid, and a potassium salt compatible with the reducing reaction in situ, until a clear blue solution is obtained, wetting diatomaceous earth with this solution, drying and then calcining to provide an active supported catalyst. The process eliminates the necessity for activating the catalyst prior to use by exposure to a gas-stream containing sulfur dioxide and sulfur trioxide.

Abstract: A catalyst/adsorbent for sulfur dioxide from waste gases, via oxidation thereof to sulfur trioxide, comprising vanadium oxide supported on activated carbon, promoted by nickel sulfate or potassium sulfate, or preferably by both.

Abstract: A sulfuric acid catalyst is made by wetting a silica carrier having an alumina content between about 2.5 and about 5.0 percent by weight with an aqueous solution of potassium vanadate and a potassium salt of an acid having a pK.sub.a between about 3 and about 7, drying the wet carrier and then sulfating the carrier.

Abstract: A process for the oxidation of sulphur dioxide to sulfur trioxide in the presence of elemental nitrogen with minimal oxidation thereof which comprises combining the sulfur dioxide with a predetermined amount of oxygen containing gas to give at least 1% stoichiometric excess of oxygen for the oxidation of sulfur dioxide to sulfur trioxide and passing the resulting mixture over a ceramic catalyst of the following empirical formula at a temperature between about 120.degree. C and about 800.degree.;W.sub.k X.sub.n J(1-k-n).sup.ZO (3.+-.m)whereinW is Zirconium, Tin or Thorium or mixtures thereof;X is an alkaline earth metal or mixture thereof;J is scandium, ytrrium, a rare-earth element or mixture thereof;Z is a metal of the first transition series or a mixture thereof, at least 0.01% of said metal having an oxidation state other than +3;k is a number having a value between 0 and about 0.1;m is a number having a value of from 0 to about 0.26; andn is a number having a value from 0 to about 0.

Abstract: A process for the oxidation of hydrogen sulfide to sulfur trioxide in the presence of elemental nitrogen with minimal oxidation thereof which comprises combining the hydrogen sulfide with a predetermined amount of oxygen containing gas to give at least 1% stoichiometric excess of oxygen for the oxidation of hydrogen sulfide to sulfur trioxide and passing the resulting mixture over a ceramic catalyst of the following empirical formula at a temperature between about 100.degree. C and about 700.degree. C.;w.sub.k X.sub.n J(1-k-n).sup.ZO (3.+-.m)whereinW is Zirconium, Tin or Thorium or mixtures thereof;X is an alkaline earth metal or mixture thereof;J is scandium, yttrium, a rare-earth element or mixture thereof;Z is a metal of the first transition series orA mixture thereof, at least 0.01% of said metalHaving an oxidation state other than +3;k is a number having a value between 0 and about 0.1;m is a number having a value of from 0 to 0.26; andn is a number having a value from 0 to about 0.

Abstract: A system for regenerating waste acid, comprises (1) a concentrator for concentrating the waste liquor, (2) a reactor for reacting the concentrated liquor at a temperature below 1000.degree. F. in the presence of oxygen and hydrocarbon combustion gases and on a recycled moving bed of particles without vibration of the reactor bottom, (3) a separator for separating the iron oxide dust from the other gases from the reactor, (4) the same concentrator cools these gases, (5) an absorber for absorbing the hydrogen chloride cooled gas in an aqueous solution from the following scrubber, (6) a scrubber for scrubbing the unabsorbed gases in water to absorb the hydrogen chloride gas remaining in the gases from the absorber, and (7) a condenser for condensing any liquids and any residual HCl remaining in the exhaust gases before exhausting them as non-polluting gases into the atmosphere and passing the condensate back into the waste acid concentrator.

Abstract: Process for production of SO.sub.3 by catalytic oxidation of SO.sub.2 which comprises carrying out the oxidation in two stages with intermediate absorption. The conversion of SO.sub.2 in the first stage is about 70-80% for a starting gas which is a cooled and cleaned roaster gas and 70-90% for a starting gas which is a sulfur combustion gas. The second stage comprises two catalyst beds, and the gas is cooled intermediate the beds. High overall conversion is obtained with low catalyst requirement.

Abstract: The invention is directed to an integrated process for reducing the SO.sub.2 content of sulfuric acid plant off gases by (1) passing the SO.sub.2 -containing feed gas to the process over a specially defined multistage oxidation catalyst to convert SO.sub.2 to SO.sub.3, (2) absorbing the SO.sub.3 in water to form H.sub.2 SO.sub.4 and (3) scrubbing the off gases with aqueous hydrogen peroxide and/or sulfur-containing peroxy acids. At least the final oxidation stage of the process employs a supported CsVO.sub.3 or RbVO.sub.3 catalyst which is activated with cobalt or nickel sulfate and promoted with alkali metal sulfates, potassium aluminum sulfate or chromium potassium sulfate.

Abstract: A catalyst for oxidation of SO.sub.2 to SO.sub.3, which can be used as a fluidized bed catalyst. An abrasive resistant support is formed by adding silica filler and a clay binder to a silica sol; adding hydrated magnesium oxide to the resulting mixture, to form a gellable composition; dispersing the gellable composition in a liquid to form gel spheres; calcining the spheres; and treating them with an acid to remove acid soluble components. After the acid treatment, the support is impregnated with an alkali metal vanadate solution and calcined.

Abstract: A catalyst for oxidation of SO.sub.2 to SO.sub.3, which can be used as a fluidized bed catalyst. An abrasive resistant support is formed by adding silica filler and a clay binder to a silica sol; adding hydrated magnesium oxide to the resulting mixture, to form a gellable composition; dispersing the gellable composition in a liquid to form gel spheres; calcining the spheres; and treating them with an acid to remove acid soluble components. After the acid treatment, the support is impregnated with an alkali metal vanadate solution and calcined.