Abstract: In a converter for the catalytic oxidation of SO2 to SO3 in a sulfuric acid plant, which comprises a boiler section for the cooling of process gas between catalytic layers (beds), one or more water tube boilers (inter-bed boilers) having horizontal or slightly sloped tubes are used to cool the process gas between the catalytic layers (beds) in the converter. Each water tube boiler is provided with a process gas side bypass to control the temperature to the downstream catalyst layer.

Abstract: Commercial production of sulfuric acid is almost entirely accomplished nowadays using the contact process. And the trend is to increase conversion efficiency and reduce emissions of unconverted sulfur dioxide. By using a special combination of contact catalyst beds, a single contact single absorption (SCSA) system can be engineered to achieve the conversion and emission capabilities of conventional double contact double absorption systems. Thus, the complexity and cost of incorporating a second absorption tower and associated heat exchanger in the system can be omitted. In the SCSA system, the initial catalyst bed or beds comprise vanadium oxide catalyst and the last catalyst bed or beds comprise platinum catalyst operating at a much lower temperature than the initial beds.

Abstract: The present invention relates to a process plant for the oxidation of SO2 to SO3 in a process gas, said process plant comprising a heat exchanger configured for heating the process gas by heat exchange with an oxidized process gas and/or a further oxidized process gas by providing thermal contact between said process gas and said oxidized process gas and/or said further oxidized process gas, a first zone of material catalytically active in oxidation of SO2 to SO3, and a boiler configured for containing steam being heated by the oxidized process gas and/or the further oxidized process after said oxidized process gas has been cooled in the heat exchanger characterized in the cooled oxidized process gas in the boiler being non-condensing with the benefit of providing the possibility for a smaller heat exchanger which may be made with only moderate corrosion resistant materials, compared to a process plant according to the prior art, as well as a related process.

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: SO3 is formed from a replenished circulating inventory of fresh and recycled SO2. Also, a feed stream of replenished SO2 is heated by indirect heat exchange with a hot stream of SO2 and SO3 whereby the hot stream is cooled for separating the two gases. The heated feed stream of replenished SO2 serves as a hot gaseous feed to a sulfur burner. This SO2 feed is divided into two feed streams, one being oxygenated with pure oxygen and the other remains as an SO2 feed. These feeds plus a feed of molten sulfur are concurrently and separately introduced into the sulfur burner where additional SO2 is formed via continuous exothermic reaction. Although heated, the oxygenated feed(s) of SO2 bring in the needed oxygen for the reaction and the feeds of the oxygenated and non-oxygenated SO2 serve as a heat sink in the sulfur burner to reduce the temperature therein.

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: 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: SO3 is formed from a replenished circulating inventory of fresh and recycled SO2. Also, a feed stream of replenished SO2 is heated by indirect heat exchange with a hot stream of SO2 and SO3 whereby the hot stream is cooled for separating the two gases. The heated feed stream of replenished SO2 serves as a hot gaseous feed to a sulfur burner. This SO2 feed is divided into two feed streams, one being oxygenated with pure oxygen and the other remains as an SO2 feed. These feeds plus a feed of molten sulfur are concurrently and separately introduced into the sulfur burner where additional SO2 is formed via continuous exothermic reaction. Although heated, the oxygenated feed(s) of SO2 bring in the needed oxygen for the reaction and the feeds of the oxygenated and non-oxygenated SO2 serve as a heat sink in the sulfur burner to reduce the temperature therein.

Abstract: A system for enhancing the efficiency of an electrostatic precipitator in a flue gas stream that withdraws a selected amount of combustion gas from a main flue gas stream at a location downstream of the electrostatic precipitator; typically heats the selected amount of combustion gas to a predetermined temperature; passes the selected amount of combustion gas through a catalyst to convert sulfur dioxide to sulfur trioxide producing a mixture of flue gas enriched with sulfur trioxide; and returns the mixture of the flue gas enriched with the sulfur trioxide back into the main flue gas stream at a point upstream of the electrostatic precipitator. A controller can control fans, heaters and dampers as well as make computations as the required amount of sulfur trioxide needed.

Abstract: A process for the conversion of sulphur dioxide contained in a feed gas to sulphur trioxide, comprising the steps of a) alternatingly providing a first feed gas containing a high concentration of sulphur dioxide and a second feed gas containing a low concentration of sulphur dioxide as a process gas, b) preheating the process gas by heat exchange with a heat exchange medium, c) reacting the process gas in the presence of a catalytically active material in a catalytic reaction zone, d) converting at least in part the sulphur dioxide of the process gas into sulphur trioxide contained in a product gas in the catalytic reaction zone, e) cooling the product gas by contact with a heat exchange medium, wherein a thermal buffer zone is provided in relation to one of said process steps, providing thermal energy produced during super-autothermal operation for heating the process gas during sub-autothermal operation.

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: Configurations herein include a novel process and apparatus for generating and maintaining sulfur trioxide gas. The generation system and process operate to provide sulfur trioxide calibration gas for calibrating sulfur trioxide detection devices. The system and process provides a known, concentration of sulfur trioxide gas via a heated catalyst, which enables accurate calibration of measurement equipment. The system functions in part by controlling temperature, amount of moisture, residence time, catalyst selection, diluting generated sulfur trioxide and by locating the sulfur trioxide generator at a point of injection of a sulfur trioxide detection system.

Abstract: Process for the continuous catalytic complete or partial oxidation of a starting gas containing from 0.1 to 66% by volume of sulphur dioxide plus oxygen, in which the catalyst is kept active by means of pseudoisothermal process conditions with introduction or removal of energy; apparatus for the continuous catalytic complete or partial oxidation of a starting gas containing sulphur dioxide and oxygen having at least one tube contact apparatus in the form of an upright heat exchanger composed of at least one double-walled tube whose catalyst-filled inner tube forms a reaction tube, with heat being transferred in cocurrent around the reaction tube and an absorber for separating off SO3 downstream of the tube contact apparatus; the reactivity of the catalyst being preset by mixing with inert material.

Abstract: Configurations herein include a novel process and apparatus for generating and maintaining sulfur trioxide gas. The generation system and process operate to provide sulfur trioxide calibration gas for calibrating sulfur trioxide detection devices. The system and process provides a known, concentration of sulfur trioxide gas via a heated catalyst, which enables accurate calibration of measurement equipment. The system functions in part by controlling temperature, amount of moisture, residence time, catalyst selection, diluting generated sulfur trioxide and by locating the sulfur trioxide generator at a point of injection of a sulfur trioxide detection system.

Abstract: The present invention relates generally to catalysts comprising ruthenium oxide and to processes for catalyzing the oxidation and conversion of sulfur dioxide (SO2) to sulfur trioxide (SO3) using such catalysts. SO2 at low concentrations in process gas streams can be effectively oxidized to SO3 at relatively low temperatures using the ruthenium oxide catalysts of the present invention. In one application, the ruthenium oxide catalysts are used in the final contact stage for conversion of SO2 to SO3 in multiple stage catalytic converters used in sulfuric acid manufacture.

Abstract: Process for the continuous catalytic complete or partial oxidation of a starting gas containing from 0.1 to 66% by volume of sulphur dioxide plus oxygen, in which the catalyst is kept active by means of pseudoisothermal process conditions with introduction or removal of energy; apparatus for the continuous catalytic complete or partial oxidation of a starting gas containing sulphur dioxide and oxygen having at least one tube contact apparatus in the form of an upright heat exchanger composed of at least one double-walled tube whose catalyst-filled inner tube forms a reaction tube, with heat being transferred in cocurrent around the reaction tube and an absorber for separating off SO3 downstream of the tube contact apparatus; the reactivity of the catalyst being preset by mixing with inert material.

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: A converter having an exterior shell with a central axis, at least one gas inlet and at least one gas outlet. The exterior shell includes a base and an interior support structure. A number of vertically stacked catalytic chambers within the exterior shell are each in communication with one or more gas inlets and gas outlets. Each chamber is defined by an inner wall of the external shell, a permeable catalytic bed support platform, a lower division plate spaced below the platform defining a gas retention plenum and an upper division plate above the platform. At least one of: the platform; the upper division plate; and the lower division plate have a toroid surface symmetric about the central axis with an outer periphery supported by the inner wall of the exterior shell and an inner periphery supported by the interior support structure.

Abstract: A hydrocarbon trap comprises an Ag-zeolite which is heated by a unique steaming regimen.

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 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: An apparatus and method for producing sulfur comprises a vessel containing a plurality of spaced-apart channels each having an upstream end communicating with an upstream manifold and a downstream end communicating with a downstream manifold. Each channel comprises a single, continuous, uninterrupted conversion stage terminating at the downstream channel end. A first mixture, of SO2 and air from the sulfur burner, is introduced into the upstream manifold and flows as a stream through each of the channels where the stream is cooled and the SO2 is converted in the conversion stage to SO3 to produce, at the downstream channel end, a second mixture consisting essentially of SO3 and air. The first mixture is not cooled between the sulfur burner and the converter. The stream flowing through the conversion stage is maintained at a temperature which sustains conversion of SO2 to SO3, without diluting the stream with a cooling fluid or diverting the stream outside the channel contained in the converter vessel.

Abstract: A process for the recovery of sulphur trioxide, solutions of sulphuric acid, or organic derivatives thereof, using organic compounds and/or supercritical fluids, and catalyst. The process comprises the steps of passing a mixture of SO2 and an oxygen-containing gas over an activated carbon catalyst at a temperature of at least 15° C. and preferably at a pressure of 1-200 atmospheres, and stripping the activated carbon with either (i) a liquid organic compound selected from the group consisting of ketones, ethers, decalin, tetrahydrofurans, sulpholanes, glymes and formamides and which is non-reactive with sulphur trioxide or sulphuric acid, or (ii) a liquid organic compound capable of forming organic sulphates or sulphonates by reaction with sulphur trioxide or sulphuric acid. The process may be used to obtain sulphuric acid, or organic sulphates or sulphonates.

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: This invention relates to a process for generating recoverable sulfur containing compounds, e.g., sulfur dioxide, from a spent sulfuric acid stream by combusting and/or thermally decomposing the spent sulfuric acid stream in a furnace. The spent sulfuric acid stream is sprayed into the furnace through a spray nozzle designed to minimize the spent sulfuric acid droplet size, e.g., to produce droplets having a Sauter mean diameter of from 200 micrometers to 700 micrometers.

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 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: A flue gas conditioning system (FGC) for conditioning the flue gas flowing in a flue from a boiler to an electrostatic precipitator by injecting sulfur trioxide into the flue gas upstream of the electrostatic precipitator. The FGC has a source (52) of granulated sulfur which is transported by a conveyor (54) to a sulfur furnace (60) where it is combusted in sulfur dioxide. The sulfur dioxide flows from the sulfur furnace (60) into a catalytic converter 62 which generates sulfur trioxide therefrom. The sulfur trioxide flows from the catalytic converter 62 into probes 64 which are mounted in the flue duct. Alternatively, the FGC has a source (70) of emulsoid sulfur which is pumped by a sulfur pump (72) to the inlet of an atomizing spray nozzle (200) which atomizes the emulsoid sulfur and sprays it into sulfur furnace (50).

Abstract: A catalytic reaction apparatus includes a catalytic reaction vessel containing a catalyst for an exothermic reaction. First and second catalyst regions contain a catalyst and have different catalytic performances from one another. At least two raw materials are introduced in the catalytic reaction vessel and passed through the first and second catalyst regions to react to generate heat. The heat is transferred to a heat medium arranged outside and contacting the catalytic reaction vessel so that distribution of temperature is controlled in the catalytic reaction vessel. The difference in catalytic performance is achieved by controlling concentration of the catalyst or by using different catalyst species.

Abstract: A process for removing SO.sub.2 from a gas mixture including SO.sub.3 and SO.sub.2 having a volume ratio of SO.sub.3 to SO.sub.2 greater than 1. The process includes intimately contacting the gas mixture in a contacting zone, removing a stream of purified gas containing less SO.sub.2 than the gas mixture from an upper portion of the contacting zone, and removing a stream of sulfuric acid from a lower portion of the contacting zone. Also provided are processes for manufacturing sulfuric acid utilizing the process for removing SO.sub.2 which allow increasing the production of concentrated sulfuric acid solutions by producing more sulfur trioxide without an increase of sulfur dioxide emissions.

Abstract: The method for the production of sulphur trioxide, operating in a non-stanary regime, intend for sulphuric acid production.The aim of the present invention is to provide a method for the production of SO.sub.3 by catalytic oxidation of SO.sub.2, contained in an inlet gas flow, providing a stable regime of operation of wide limits of variation of the flow rate and the concentration of SO.sub.2 in the input gas.The essence of the invention is in this, that between the two layers of the first step of oxidation in a two-step three-layer contact apparatus, the gas flow is partially cooled in an inner heat-exchanger-mixer and part of the heat of the reaction of oxidation of SO.sub.2 in the first stage of oxidation is passed to the second stage of oxidation by means of the gas flow coming out of the intermediate absorption, containing unoxidized SO.sub.2 from the first stage.

Abstract: The present invention provides a flue gas conditioning system and method for generating conditioning agent used in the removal of entrained particles in a flue gas flow with an electrostatic precipitator. The invention involves a catalytic converter that is operable between an operative position where the flue gas is exposed to the catalyst and converts SO.sub.2 contained in the flue gas to SO.sub.3 when conditioning agent is needed and an inoperative position where the flue gas is not exposed to the catalyst when conditioning agent is no longer needed. The catalytic converter and related assembly may take variable configurations to accommodate various flue gas ductworks and space limitations and may carry one or more SO.sub.2 /SO.sub.3 converters providing a plurality of open and generally parallel flow paths of the flue gas.

Abstract: The concentration of sulfuric acid exiting a countercurrent SO.sub.3 absorber is controlled by controlled addition of water vapor to the SO.sub.3 -containing process gas stream entering the absorber. The novel means of concentration control is useful for control of the acid concentration gradient in an SO.sub.3 absorption process and apparatus for high temperature absorption, so as to achieve high temperature absorption heat recovery while minimizing corrosion and formation of acid mist.

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: A catalytic converter for converting sulfur dioxide to sulfur trioxide comprising an exterior shell of a heat resistant weldable metal; foundations from which the shell vertically extends; an interior tube of same metal vertically disposed within the shell and defining a passage; the interior tube having i. a first inlet aperture through which the passage receives a first portion of a sulfur dioxide-containing gas from a source of such gas; ii. a second inlet aperture through which the passage receives a second portion of the sulfur dioxide-containing gas; and iii.

Abstract: Apparatus and process for the production of gaseous sulphur dioxide mixture for conversion to sulphur trioxide in a catalytic converter in the production of sulphuric acid by the contact process. Apparatus comprises the furnace to produce sulphur dioxide gas from elemental sulphur and a first dry air stream; means for feeding a first portion of the sulphur dioxide gas to a waste heat boiler to cool the gas; the improvement comprising combining a second portion of the sulphur dioxide gas exiting the furnace with a second dry air stream to provide a combined gaseous stream which bypasses the boiler and subsequently is combined with the cooled sulphur dioxide stream. The system provides use of a bypass valve which experiences only cooled sulphur dioxide containing gases with its attendant reduced corrosion. Further, the system may operate at higher temperatures than is common to provide further advantages.

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 converter comprising an exterior shell of a strong, heat resistant weldable metal having an interior core tube formed of such metal and vertically disposed, partway within the shell from an upper part thereof. A foundation is provided from which the shell vertically extends. A plurality of catalyst beds are arranged one above the other within the shell and comprise at least one full catalyst bed having a first full bed extending essentially across a lower part of the shell, and at least one annular catalyst bed having a first annular bed between the shell at an upper part thereof and the core tube. Partitions define with the core tube a plurality of distinct, non-concentric, non-coaxial gas passages within the core tube. Each of the annular beds is in singular, gaseous communication within the shell with at least one of the passages. The converter has minimal axial gaseous flow transfer passages for maximum catalyst bed volume while preserving axial access to the beds.

Abstract: A flue gas conditioning system features a self-contained sulfur burner control loop that operates to maintain a constant desired temperature supply of sulfur dioxide in air by varying the rate of supply of sulfur fuel to the sulfur burner, and the absence of device in the sulfur flow path to measure or monitor sulfur flow rate. In the system, a conditioning agent demand signal operates either a means to supply the sulfur burner with a flow of air, or an air heater in the air flow path upstream of the sulfur burner, or both, to provide conditions that would increase or decrease the temperature of the sulfur burner output absent the self-contained sulfur burner control loop, and as a result of the operation of the self-contained sulfur burner control loop, systems of the invention can provide a demanded flow of sulfur dioxide and air at a substantially constant concentration and a desired temperature to a catalytic converter in response to a conditioning agent demand signal.

Abstract: The present invention provides a flue gas conditioning system and method for generating conditioning agent used in the removal of entrained particles in a flue gas flow with an electrostatic precipitator. The invention involves the use of a catalytic converter movable between an operative position where the flue gas flows through the catalyst and converts SO.sub.2 contained in the flue gas to SO.sub.3 when conditioning agent is needed and an inoperative position where the flue gas does not flow through the catalyst when conditioning agent is no longer needed. The movable catalytic converter and related assembly may take variable configurations to accommodate various flue gas ductworks and space limitations.

Abstract: An improved catalytic converter having a shell, a plurality of horizontal catalyst bed supports upon which catalyst is retained and arranged one bed support above another within the shell, and a plurality of horizontal divider plates, one located between each pair of bed supports; the improvement comprising wherein at least one of the bed supports comprises a first full bed support extending essentially across the diameter of the shell, the full bed support comprising (i) an inner dished plate, centrally and symmetrically disposed within the shell, and (ii) an annular dished plate between the shell and the inner dished plate; a substantially circular gas entry port and a substantially circular gas exit port within the shell in gaseous communication with the first full bed support; and a substantially dished divider plate extending essentially across the diameter of the shell above the first bed support and comprising (i) an inner divider plate, centrally and symmetrically disposed within the shell and (ii) an

Abstract: An improved process for manufacture of sulfuric acid by catalytic oxidation of wet sulfur dioxide gas. Wet conversion gas is contacted with sulfuric acid in a heat recovery stage to effect absorption and generate the heat of absorption. Wet gas having a mole ratio of sulfur trioxide to water vapor of at least 0.95 is introduced into the heat recovery stage at a temperature above the dew point of the gas. Sulfuric acid is introduced into the heat recovery absorption stage at a temperature of at least about 170.degree. C. and a concentration between about 98.5% and about 99.5%. The sulfuric acid stream as discharged from the absorption stage is at a temperature of at least about 190.degree. C. and has a concentration between about 99% and about 100%. The heat of absorption is recovered from the discharge absorption acid stream in useful form by transfer of heat to another fluid in a heat exchanger, the another fluid being heated to a temperature of at least about 140.degree. C.

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: Disclosed is an improved process for the production of a sulfur trioxide conditioning gas, which consists in compensating the faulty "ambient gas temperature" in a simple and effective manner, such that all of the subsequent functions can take place at the established optimum temperature and can no longer be adversely affected by fluctuations in the ambient air temperature.

Abstract: The apparatus receives a source of air and a sulfur-bearing source. The apparatus can condition the gas within an electrostatic precipitator of an industrial plant. The apparatus has a sulfur vessel having an output and an input. The sulfur vessel communicates with the sulfur-bearing source and the source of air, for at least providing gaseous, oxidized sulfur. The apparatus includes a supply of liquid, oxidized sulfur and the sulfur vessel includes an evaporator communicating with the supply of liquid, oxidized sulfur for evaporating it. Also included is a converter having an outlet and having an inlet communicating with the output of the sulfur vessel for converting the gaseous, oxidized sulfur into a conditioning medium. The apparatus also includes a sensor, a modulator and a delivery system. The sensor is connected to the outlet of the converter for providing a converted temperature signal signifying the temperature of the outlet of the converter.

Abstract: The invention relates to a process for eliminating nitrogen oxides and sulphur oxides from a stream of flue gas containing nitrogen oxides and sulphur oxides comprising the steps of(a) adding ammonia to the stream of flue gas and contacting the resulting stream, at a temperature of 250.degree.-450.degree. C., with a reduction catalyst for selective reduction of nitrogen oxides into nitrogen and water, the molar ratio of ammonia to nitrogen oxides being in the range of 0.6-1.8,(b) contacting the stream from step (a), at a temperature of 300.degree.-470.degree. C., with an oxidation catalyst for oxidation of unreacted ammonia into nitrogen and water and simultaneous oxidation of sulphur dioxide into sulphur trioxide, and(c) cooling the stream from step (b) for condensation of sulphur trioxide in the form of sulphuric acid.The products of the process of the invention are steam, nitrogen, and concentrated sulphuric acid of commercial quality giving no waste disposal problems.

Abstract: Apparatus and method for precipitation of fly ash from flue gas of a coal burner wherein liquid sulfur is burned to form SO.sub.2. The SO.sub.2 is converted to SO.sub.3 and injected into the flue gas. The sulfur burning process is modulated and controlled.

Abstract: A process is described for the purification of exhaust gases containing oxides of nitrogen and sulfur obtained from combustion installations and industrial production processes by selective catalytic reduction of the nitric oxides with ammonia, subsequent catalytic oxidation of sulfur dioxide with oxygen and conversion into sulfuric acid of the sulfur trioxide obtained.

Abstract: Process and apparatus for carrying out reactions in gas phase, wherein the gas is passed through a cylindrical catalytic reactor so designed that the catalyst bed is divided into several portions arranged in distinct vertical parallelepipedic compartments which are successively traversed by the reaction gas in a direction perpendicular to the axis of the cylindrical reactor. Fresh gas may be supplied between two compartments to maintain the temperature in a well controlled range.