Abstract: A reactor suitable for a reaction containing an exothermic reaction is provided. The reactor includes the following components. A reaction channel has an inlet and an outlet, and has a front-end reaction zone, middle-end reaction zones, and a back-end reaction zone from the inlet to the outlet. A front-end catalyst support and a front-end catalyst are located in the front-end reaction zone, a middle-end catalyst support and a middle-end catalyst are respectively located in the middle-end reaction zones, and a back-end catalyst support and a back-end catalyst are located in the back-end reaction zone. The concentration of the front-end catalyst is less than the concentration of the back-end catalyst, and the concentration of the middle-end catalyst is decided via a computer simulation of reaction parameters. The reaction parameters include size and geometric shape of the reaction channel.

Abstract: Techniques are provided for polymerization. A polymerization method may include polymerizing a monomer in a polymerization reactor to produce a slurry comprising polyolefin particles and a diluent, flowing the slurry out of the polymerization reactor through an outlet of the polymerization reactor, receiving the slurry from the outlet into a slurry handling system, conveying a first mixture from the slurry handling system to a diluent and monomer recovery system, and injecting steam into the first mixture downstream of the slurry handling system using a steam injection system.

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 reactor for carrying out an exothermic reaction in the gas phase, which comprises a vessel having an outer wall (13) composed of a metallic material, wherein an inner shell (17) is accommodated in the interior of the reactor (1) and the inner shell (17) has a spacing of at least 50 mm to the inside of the outer wall (13).

Abstract: The present invention provides a method for removing mercury in exhaust gas, in which mercury in exhaust gas discharged from combustion equipment is removed, characterized by including a mercury oxidation process in which mercury in the exhaust gas is converted to mercury chloride in the presence of a catalyst; a contact process in which the exhaust gas is brought into contact with an absorbing solution in a scrubber to absorb and remove mercury components from the exhaust gas; and a control process in which blowing of air or addition of an oxidizing agent into the scrubber is accomplished, and the amount of blown air or the added amount of oxidizing agent is regulated to control the oxidation-reduction potential of the absorbing agent, and a system for removing mercury in exhaust gas. According to the mercury removing method in accordance with the present invention, a phenomenon that mercury chloride is reduced into metallic mercury by SO2 etc.

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: 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: The invention relates to a reactor for carrying out an exothermic reaction in the gas phase, which comprises a vessel having an outer wall (13) composed of a metallic material, wherein an inner shell (17) is accommodated in the interior of the reactor (1) and the inner shell (17) has a spacing of at least 50 mm to the inside of the outer wall (13).

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 process to use ferric sulphate equilibrium to reduce overall acid consumption and iron extraction, the process comprising the steps of: (i) sulphating; (ii) selective pyrolysis and (iii) selective dissolution.

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 method is disclosed for manufacturing one or more oxygen scavenging particles, wherein the particle(s) comprises an oxidizable metal particle, such as elemental iron; an acidifying electrolyte such as sodium or potassium bisulfate and optionally a water hydrolysable Lewis acid, such as aluminum chloride. The method comprises the step of coating the oxidizable particle with a first compound and then reacting the first compound with a second compound to form a third compound, wherein the third compound promotes the reaction of the oxidizable particle with oxygen.

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: 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 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: Sulphur oxides are generated from a liquid stream of hydrogen sulphide by feeding the liquid stream to a vacuum stripper where the stream is contacted with a stripping gas including steam under reduce pressure. Hydrogen sulphide is transferred to the stripping gas, whereby a loaded stripping gas is obtained. Water in the loaded stripping gas is condensed producing a H2S rich stream. The H2S is then burned in the stream to produce a stream rich in oxides of sulphur.

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: It is an high efficiency and low cost apparatus for simultaneous dry desulfurization and denitration (10), capable of simultaneous oxidation of nitrogen monoxide and sulfur dioxide by chain reaction with OH radical, provided with an OH radical supplying unit (12), a reactor (14), a sulfuric acid recovering unit (16), and a nitric acid recovering unit (18). Exhaust gas at 600-800° C. containing sulfur compounds from a boiler (2) is introduced into the reactor (14), nitric acid is spray-supplied from an OH radical supplying unit (12) into the reactor (14), sulfur dioxide and nitrogen monoxide are simultaneously oxidized with OH radicals generated from pyrolysis of nitric acid as an initiator to form sulfur trioxide and nitrogen dioxide, thereby exhaust gas is treated.

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

Abstract: Generally, the present invention provides a method and apparatus for removing a vapor phase contaminant from a gas stream, thereby reducing the concentration of the vapor phase contaminant in the gas stream. In one embodiment, the present invention provides a method for removing a vapor phase contaminant from a gas stream, comprising contacting a gas stream comprising a vapor phase contaminant with a first side of a membrane; sorbing the vapor phase contaminant using the membrane; reacting the vapor phase contaminant into an reacted form of the vapor phase contaminant; transporting the reacted form of the vapor phase contaminant through the membrane to a second side of the membrane; contacting the second side of the membrane with a liquid; and dissolving the reacted form of the vapor phase contaminant into the liquid. Methods for making a membrane comprising a metal for use in the present invention is also described.

Abstract: The invention relates to a novel method for producing high-purity sulfuric acid for use in the semiconductor industry. The method comprises the addition of a hydrogen peroxide solution to an engineered oelum in order to reduce the SO2 concentration, evaporation of the SO3 and separation of acid traces. The high-purity SO3 is then enriched with inert gas and the SO3 is absorbed into sulfuric acid.

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 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: A method for accelerating the rate of chemical reactions is disclosed consisting of subjecting a gas stream from a flue stream, industrial source, or utility boiler to a high time rate of change of temperature increase so as to convert certain polyatomic components of the gas stream to desired product, separating these oxidized polyatomic molecules from the gas stream, and subjecting the remaining polyatomic molecules to a high time rate of change of temperature decrease to convert the second type of polyatomic molecule to desired product.

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 process is provided for conditioning fly-ash present in flue gas which also contains sulfur dioxide and steam by subjecting the fly-ash containing flue gas to ultraviolet radiation so as to convert steam present in the flue gas into hydroxyl radicals which oxidizes about 5 to 10 percent of the sulfur dioxide in the flue gas into sulfur trioxide. This photo-produced sulfur trioxide conditions the fly-ash and renders it more easily separated in the electrostatic precipitator.

Abstract: A process is disclosed for treating an exhaust gas stream containing COS and CO arising from chlorinating titanium-containing material with a cold plasma wherein oxygen is present and selectively oxidizing COS.

Abstract: An improved method and system for cooling the sulfur dioxide gas stream flowing from a sulfur furnace to a catalytic converter in a sulfur trioxide flue gas conditioning system. Water is injected into the sulfur dioxide gas stream upstream of the catalytic converter as appropriate to maintain the temperature at the inlet of the catalytic converter at a desired level.

Abstract: A process for removing and then capturing noxious sulfur oxides from gas streams, particularly from the flue gases of coal-burning power plants, using Ni-containing heated layered double hydroxide (LDH) as recyclable sorbents. The sorbent compositions contain metal components that form stable metal sulfites and sulfates at one temperature, but are decomposed at a higher temperature to regenerate the sorbent material.

Abstract: The invention is a solid catalyst having acid strength H.sub.o less than -18. Such catalysts are characterized by the ability to react with very weak bases, such as butane, at relatively low temperatures, for example temperatures in the range from 20.degree. to 200.degree. C. The catalysts have exceptionally high activity for various hydrocarbon conversion processes, for example, because of their exceptionally high acid strength.

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: An improved process for the recovery of high grade energy from a contact sulfuric acid manufacturing process. Improvements include: injection of steam between an intermediate catalyst stage and a heat recovery absorption tower and/or a heat exchanger for transfer of heat from conversion gas to high pressure boiler feed water; use of a condensing economizer for recovery of the vapor phase energy of formation of sulfuric acid from a wet conversion gas; and use of heat recovery system absorption acid for preheating air to a sulfur burner, the heat transferred to the combustion air being recovered at high pressure and temperature in a waste heat boiler.

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: 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: In a process such as the preparation of sulphuric acid wherein a wrought or cast material or a welding filler is contacted with hot concentrated sulphuric acid or oleum of up to 10 wt-%, the improvement which comprises forming the contact portion of said wrought or cast material or said filler of an austenitic iron-nickel-chromimum-silicon alloy comprising about15.5 to 17.5 wt-% nickel10 to 12 wt-% chromium5.7 to 6.5 wt-% siliconup to max. 0.06 wt-% carbonup to max. 1.5 wt-% manganeseup to max. 0.03 wt-% phosphorusup to max. 0.03 wt-% sulphurup to max. 0.15 wt-% titaniumup to max. 0.8 wt-% zirconiumup to max. 0.2 wt-% nitrogen andup to max. 0.3 wt-% molybdenumand the remainder iron,together with minimal quantities of normally present impurities, including the deoxidizing elements magnesium, aluminum and calcium.

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: 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: 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 method for endothermically dissociating contaminated acid wherein high velocity oxidant causes a recirculation flow within a combustion zone and combusts with fuel to release heat and wherein the heat is efficiently applied by the internal recirculation to the acid for endothermic dissociation of the acid.

Abstract: A method and apparatus for the recovery of heat from a sulfuric acid process are provided. Sulfur trioxide is absorbed into hot concentrated sulfuric acid, acid having a concentration greater than 98% and less than 101% and a temperature greater than 120.degree. C., in a heat recovery tower and the heat created by the exothermic reaction is recovered in a useful form in a heat exchanger. Gas leaving the primary heat recovery absorption zone is cooled by contact with sulfuric acid in a secondary absorption and cooling zone located above the primary absorption zone in the tower.

Abstract: Sodium sulfate-containing residues are worked up by reducing the sulfate by a process in which the sulfate or a mixture or solution of the sulfate is thermally cleaved by adding oxygen, air or oxygen-enriched air at above 1000.degree. C., in particular above 1200.degree. C., under reducing conditions to give gaseous sulfides and oxides of sulfur as well as alkaline slag. The sulfur compounds contained in the gaseous reaction products can be further processed to sulfur, sulfur dioxide and sulfuric acid.

Abstract: The present invention relates to a process for production of chlorine dioxide by reacting in a reaction vessel an alkali metal chlorate, sulfuric acid and a reducing agent, preferably methanol, in proportions to generate chlorine dioxide in a reaction medium maintained at a temperature from about 50.degree. C. to about 100.degree. C. and an acidity within the interval from 4.8 to 11 N and subjected to a subatmospheric pressure sufficient to effect evaporation of water. A mixture of chlorine dioxide and water vapour is withdrawn from an evaporation region in the reaction vessel and alkali metal sulfate is precipitated in a crystallization region in the reaction vessel. The alkali metal sulfate, which is an alkali metal sesquisulfate, from the crystallization region is heated to the formation of gaseous sulfur trioxide and a neutral alkali metal sulfate. The gaseous sulfur trioxide is absorbed in water to the formation of sulfuric acid.

Abstract: The present invention provides an apparatus for generating a reagent of sulfur trioxide in a carrier which includes a reagent generator. The reagent generator has associated therewith means for introducing a source of sulfur trioxide into the reagent generator, means for introducing a carrier such as a liquid halocarbon or an inert gas into the reagent generator, and means for introducing oleum into the reagent generator. The reagent generator also includes means for contacting the sulfur trioxide, carrier, and oleum to provide a reagent of sulfur trioxide in the carrier. Additionally, the system includes means for removing oleum from the reagent generator, as well as means for removing the reagent from the reagent generator. In a preferred embodiment, the system for generating the reagent also includes, in conjunction with the reagent generator, a treatment chamber for the surface treatment of polymer resins including medical products which have polymeric resin material on exposed surfaces thereof.

Abstract: The present invention provides a process for generating a reagent of sulfur trioxide in a carrier. A source of sulfur trioxide, a carrier, and oleum are introduced into a reagent generator. The sulfur trioxide, carrier, and oleum are then contacted to provide a reagent of sulfur trioxide in the carrier. Separate oleum and sulfur trioxide in carrier phases are formed, and oleum is removed from the reagent generator. The sulfur trioxide in carrier reagent is then ready to be used, preferably in a process to treat the surfaces of polymeric resin material such as medical devices fabricated from a variety of polymeric resins. The carrier may be either a liquid halocarbon solution or an inert gas.

Abstract: Process and apparatus for the generation of sulphur trioxide from oleum using microwave energy for use in the sulphonation and nitration of organic compounds and the fortification of oleum. The process provides improved control of production and concentration of the sulphur trioxide produced and comprises subjecting sulphur trioxide-rich oleum feed to microwave energy for a sufficient period of time to produce sulphur trioxide vapour and spent oleum; isolating said sulphur trioxide vapour and collecting said spent oleum.

Abstract: A method and apparatus for the recovery of heat from a sulfuric acid process are provided. Sulfur trioxide is absorbed into hot concentrated sulfuric acid, acid having a concentration greater than 98% and less than 101% and a temperature greater than 120.degree. C., in a heat recovery tower and the heat created by the exothermic reaction is recovered in a useful form in a heat exchanger.

Abstract: A continuous process for the generation of sulphur trioxide from oleum suitable for use in the sulphonation of organic compounds which comprises continuously introducing oleum feed to a sulphur trioxide desorption tower; continuously introducing a recycled dry feed air stream to said desorption tower, whereby a gaseous mixture of sulphur trioxide in air is produced; collecting spent oleum from said desorption tower; introducing said gaseous mixture to a sulphonation reactor; and recycling spent gaseous mixture from said reactor to said desorption tower as said feed air stream. The process offers reduced environmental pollution and operating costs.

Abstract: A method and apparatus for the recovery of heat from a sulfuric acid process are provided. Sulfuric trioxide is absorbed into hot concentrated sulfuric acid, acid having a concentration greater than 98% and less than 101% and a temperature greater than 120.degree. C., in a heat recovery tower and the heat created by the exothermic reaction is recovered in a useful form in a heat exchanger.

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 system for desulfurization of sulfur-containing coal comprises apparatus for comminuting sulfur-containing coal, a gas/solid reactor having an inlet and an outlet, a connection or conduit for supplying the comminuted sulfur-containing coal to the reactor inlet, and an oxidant gas generator constructed in accordance with U.S. Pat. No. 4,248,681 connected to supply an oxidant gas to the reactor. The oxidant gas produced from concentrated salt solutions contains substantial amounts of chlorine dioxide, while the oxidant gas produced from dilute salt solutions contains other oxygen-containing gases. The oxidant gas is introduced at pressures which may range from sub-atmospheric to super-atomospheric and the comminuted coal is mixed or agitated to insure efficient gas/solid contact. The oxidant gas oxidizes the sulfur contaminants of the coal to gaseous sulfur oxides which are removed from the reactor. The desulfurized comminuted coal may be slurried for pipeline transmission.