Abstract: A process and system for simultaneously removing from a gaseous mixture, sulfur oxides by a solid sulfur oxide acceptor sorbent on a porous carrier, nitrogen oxides by ammonia gas and particulate matter by filtration and for the regeneration of loaded solid sulfur oxide acceptor sorbent. Finely-divided solid sulfur oxide acceptor sorbent is entrained in a gaseous mixture to deplete sulfur oxides from the gaseous mixture, the finely-divided solid sulfur oxide acceptor sorbent being dispersed on a porous carrier material having a particle size up to about 200 microns. In the process, the gaseous mixture is optionally prefiltered to remove particulate matter and thereafter finely-divided solid sulfur oxide acceptor sorbent is injected into the gaseous mixture to form an entrained bed. Ammonia gas is also injected into the exhaust gas stream. A filter separates spent solid sorbent and particulate matter from clean gas. A classifier is used to separate mixtures of spent sorbent from particulate matter.

Abstract: The present invention relates to an injection noncatalyst denitrogen oxide process control system, in which a reducing agent (such as ammonia), carriers and additional gases are injected into the flue gas of a combustion device. The NO.sub.x in the flue gas will be reduced into nitrogen (N.sub.2) and water (H.sub.2 O). A pressure measurement device and a thermocouple device are installed in an injector for measuring the pressure difference and the temperature of the flue gas respectively, and then be converted into a voltage signal and a thermocouple signal respectively. Both of the signals will be transferred into a controller that is controlled by a computer. The controller can control the flow mass of the reducing agent, carriers and additional gases to the flue gas. Therefore, the reduction reaction of the NO.sub.x can be controlled, thereby maximizing the rate of denitrogen oxide (deNOx) and minimizing the discharge amount of the reducing agent.

Abstract: An apparatus for scrubbing a gas in which a vortical flow of a gas and liquid mixture created by an entrainer is emitted from the entrainer and is introduced into a de-entrainer through a guide/deflector assembly. Particulate is removed from the gas and is picked up by the liquid. The de-entrainer separates the liquid from the gas and delivers the scrubbed gas to an outlet. The guide/deflector assembly guides the vortical liquid/gas flow from the entrainer to the de-entrainer and diverts most of the droplets away from the de-entrainer to significantly reduce the amount of liquid droplets entrained in the gas preparatory to entry into the de-entrainer, significantly reducing the amount of droplets emitted with the scrubbed gas. The vane cages of the entrainer/de-entrainer assemblies are designed so that the height to diameter (H:D) ratio is ##EQU1## to increase the operating range.

Abstract: The method for introducing a treatment medium into the waste gas flow in combustion processes provides that a carrier medium be mixed with a treatment medium, wherein these media are brought to a pressure level necessary for the atomization in a one-component nozzle prior to mixing. The quantitative proportion of treatment medium to carrier medium, which is adjustable as desired, is adjusted as a function of the NO.sub.x gas concentration in the treated gas flow or as a function of the waste gas quantity. The atomization pressure is either predetermined as a fixed value corresponding to the nozzle configuration or adjusted as a function of the waste gas quantity. The atomization pressure can also possibly be regulated as a function of the evaporator load. Water serves as carrier medium, while ammonia, sal ammoniac, urea or calcium cyanamide is used as treatment medium.

Abstract: Techniques and associated systems are provided for removing oxides of nitrogen (NO and NO.sub.2, hereinafter called NO.sub.x) from combustion effluent gases. Such a system includes a nozzle and means for introducing a carrier gas and an injection chemical into the nozzle to be mixed together. The mixture is ejected from the nozzle into a flue gas duct to provide a high degree of cross-sectional coverage and intimate mixing between the injection chemical and the NO.sub.x -containing combustion effluent gas.

Abstract: An integrated jet scrubber and particulate collection device for removing sulfur oxides and other contaminants from combustion flue gas and also for removing particulates from this gas, such operations occurring in a single, integrated unit or assembly. In some instances, this combination device may be located in the lower portion of a chimney or stack.

Abstract: An apparatus for reducing NOx pollution in the flue gas produced by a burner includes a heat exchanger wherein at least some of the heat transfer elements are coated with a catalyst. A plurality of reactive gas injectors are arranged to introduce a nitrogeneous compound, preferably a source of ammonia, across a hot-end face of the heat exchanger. A reactive gas flow distribution system permits the distribution of the nitrogeneous compound flowing through at least some of the gas injectors to be varied responsive to the temperature profile of the heat exchanger. Preferably, the apparatus also determines the total NOx flow in the flue gas, and the reactive gas flow distribution system permits the total amount of reactive gas flowing through at least some of the gas injectors to be varied responsive to the total NOx flow in the flue gas.

Abstract: Nozzles are provided for spraying a wetting medium into the gas flow in an activating reactor. The nozzle comprises a nozzle body having a plurality of nozzles The nozzle body is surrounded by a flexible and/or porous casing and a conduit introduces a gaseous medium into the casing. The gas can be introduced in either pulses or continuously. The gas introduced in pulses causes the casing to change its form and, where a perforated or porous casing is used, the continuous gas flow forms a protective gas film around the casing, thus removing the solid material accumulated on the casing.

Abstract: A treatment equipment of exhaust gas containing organic halogen compounds using a catalytic decomposition unit packed with decomposition catalyst for organic halogen compounds having strong acidic sites and a wash tower for removing hydrogen halide gas generated by the decomposition of the organic halogen compounds.

Abstract: The NOx content in a flow of flue gas is reduced by passing the flue gas through a first treatment zone and a second treatment zone. A nitrogeneous treatment agent is introduced into the first treatment zone for the selective non-catalytic reduction of part of the NOx, and the flue gas is thereafter passed through the second treatment zone which includes a catalyst for further selective catalytic reduction of the NOx. Optionally, a second nitrogeneous treatment agent is added to the flue gas in the second treatment zone. The quantity of NOx in the flue gas is detected intermediate the first and second treatment zones and, optionally, after the flue gas has left the second treatment zone. The quantity of ammonia in the flue gas exiting from the second treatment zone is also detected. The amounts of the treatment agents added to the flue gas are controlled responsive to the variations and absolute levels determined by these measurements.

Abstract: A resistance adjusting type heater including a honeycomb structure with at least two electrodes provided thereon to supply a current to the honeycomb structure and with resistance adjusting elements provided between the electrodes. The resistance adjusting elements are formed such that a cross-section of a heating portion of the heater is substantially the same as that of a main monolithic catalyst. A catalytic converter includes the resistance adjusting heater which is disposed upstream of a main monolithic catalyst or between main monolithic catalysts. Also, the catalytic converter includes a resistance adjusting heater which is disposed downstream of a main monolithic catalyst. This resistance adjusting heater comprises a honeycomb structure with a catalyst carried thereon, with at least two electrodes provided thereon to supply a current to the honeycomb structure and with a resistance adjusting elements provided between the electrodes.

Abstract: A catalyst body having carried in a carrier a three way conversion catalyst is disposed inside an exhaust pipe near an exit to the atmosphere. An internal combustion engine is operated in a rich range of air/fuel ratio. Reducing reaction of the exhaust gas takes place in a front portion of the catalyst body. Oxidizing reaction takes place in a rear portion of the catalyst body by intermittently introducing atmospheric air into the catalyst body through pulsations of the exhaust gas.

Abstract: A combustion method for the simultaneous control of PICs and NO.sub.x wherein the combustion is carried out in two combustion zones. High velocity oxidant is injected into the second combustion zone to aspirate exhaust from the first combustion zone prior to combustion within the second combustion zone. The first combustion zone is preferably operated under pyrolytic conditions.

Abstract: A wet-type exhaust gas desulfurization system comprises a reservoir for trapping an absorbing solution which has absorbed SO.sub.2 from exhaust gas; an absorbing solution circulating tank disposed directly under the reservoir; a plurality of bottom pipes which are installed at the bottom of reservoir and extend downward into the absorbing solution in the circulating tank and whose lower end is open, or drop pipes which depend into the absorbing solution and whose lower ends are open; and air supply pipe at least one end of which is open to the atmosphere; a pipe for discharging the air above the surface of absorbing solution onto the surface of solution in the reservoir; and a pipe for supplying the absorbing solution in the circulating tank to a spray nozzle at the upper part of the absorbing tower.

Abstract: Process for removing sulphur-containing compounds from a residual gas with recovery of said compounds in the form of sulphur, wherein the residual gas is subjected to a treatment comprising a hydrogenation and a hydrolysis phase to provide the sulphur-containing compounds in the unique form of H.sub.2 S, a cooling step with water condensation, a catalytic oxidation of H.sub.2 S in CLAUS stoechiometry and a catalytic CLAUS reaction phase with deposition of sulphur on the CLAUS catalyst and periodic regeneration of the sulphur-laden catalyst and cooling of the regenerated catalyst. The gas used for the regeneration and for the cooling is tapped from the gas effluent supplied to the catalytic oxidation and the gas issued from the regeneration is reintroduced at least in part into said gas effluent after separation of the sulphur containing therein. Application to the purification of residual gases issued from CLAUS sulphur units.

Abstract: A process and apparatus for simultaneously removing NO.sub.X and SO.sub.X from the exhaust of a furnace includes an injection of limestone into a region of the furnace having a temperature of about 2,000.degree.-2,400.degree. F., and an injection of ammonia into a region in the furnace having a temperature of about 1,600.degree.-2,000.degree. F. The limestone absorbs at least some of the SO.sub.X and the ammonia absorbs at least some of the NO.sub.X. The exhaust from the furnace which contains particulate and gases, is supplied to a dry scrubber where further reactions take place between unused ammonia and SO.sub.X, and calcium sorbent and SO.sub.X. Sorbent and ammonia regeneration can also be utilized to further improve the efficiency of the system.

Abstract: A nitric acid producing plant including an absorber and a closed vessel. Nitric acid having nitrous acid in solution is produced in the absorber by reacting to the oxides of nitrogen derived from the decomposition of ammonia with water. There is also an oxygen cylinder which supplies oxygen under pressure differential to the vessel. The pressure of the stagnant oxygen in the vessel exceeds atmospheric pressure. The plant also includes means for passing the nitric acid solution from the absorber to the vessel under positive differential pressure and means for recycling to the absorber the product of the reaction of the nitric acid solution and the oxygen. The liquid which is recycled to the absorber absorbs NO at a higher rate than NO.sub.2.

Abstract: The invention relates to a catalyzer installation for spark-ignition engines which are operated with air/fuel ratios of .lambda.1, particularly for boat engines, the catalyzer being subdivided into a reduction part located upstream in the exhaust gas line and an oxidation part located coaxially downstream after it. An intermediate space is located between the reduction and oxidation parts. Both catalyzer parts are surrounded by a preferably cylindrical, water-cooled casing and the casing has a downstream secondary air inlet to which a secondary air blower can be connected, the secondary air separating the very hot catalyzer from the double-walled, water-cooled casing and, in particular, flowing round the oxidation catalyzer part in counterflow for air preheating so that the air preheated in this manner is passed through the intermediate space into the oxidation part. The catalyzer is accommodated in a cartridge which is supported in wire compression rings in the catalyzer casing.

Abstract: A method and apparatus of scrubbing acid gas from flue gas comprises slats which define a moving bed of scrubbing material which is capable of reacting with the acid gas to form reaction products on particles of the scrubbing material. Flue gas from a boiler or other sources of flue gas is passed through the moving bed of scrubbing material. The scrubbing material is sprayed with water to the saturation point for increasing the rate of reaction between the reaction gas on the scrubbing material. The scrubbing material leaving the bottom of the moving bed is subjected to a separation step which removes the reaction products as fine dust which is disgarded, and returns the now regenerated particles of scrubbing material to the top of the moving bed.

Abstract: After aerating sewage sludge in a composting process, a stream of process air is treated to remove odors therefrom by injecting into the airstream an atomized mixture of dilute sulfuric acid and dilute surfactant to remove ammonia and odorous organic compounds therefrom. The airstream is then oxidized with bleach to remove sulfides and treated with a hydrogen peroxide solution to remove chlorine introduced by the bleach while maintaining the oxidation reaction. A dilution fan is used to further dilute the scrubbed airstream as the airstream is exhausted to the atmosphere.

Abstract: Method for the removal of nitrogen from the exhausts of burners after they are cleaned of dust or sulfur, in which the nitrogen-bearing exhaust gases are reheated by the transfer of heat from the denitrogenated exhaust gases in a regenerative heat exchanger.Before they are finally heated to the temperature level of the reduction reaction, the nitrogen-bearing exhaust gases, and, after their reduction, the denitrogenated exhaust gases, are passed countercurrently to one another in a cyclical alternation, through heat exchanging storage masses in an additional catalytic converter serving as the main converter, whose surfaces are provided with catalytically active compounds.

Abstract: A combustion apparatus for continuously obtaining a sample of a preselected trace element contained in a combustible liquid comprising a combustion chamber having inlets for combustible liquid and oxygen, an outlet for gaseous combustion products and a combustion dish, means for continuously supplying oxygen and combustible liquid to the combustion chamber, and a recovery vessel containing a chemical treating solution formulated to recover the preselected element from the combination products.

Abstract: A process and apparatus for removing flue gas cleaning residues in a combustion system. The combustion system includes a combustion chamber; a hot gas filter located downstream from the combustion chamber; and washers located downstream from the hot gas filter which employ a washing liquid. The hot gas filter includes filter elements and an inlet chamber located below the filter elements. Contaminants present in flue gas are precipitated in the washing liquid. Then, the washing liquid is neutralized, thereby enriching the washing liquid with salts. Next, the enriched washing liquid is injected into the inlet chamber, whereby the washing liquid evaporates and the salts contained in the washing liquid are deposited on the filter elements where they can later be removed and mixed with ashes from the combustion chamber.

Abstract: An apparatus for treating a flue gas provided with a heater and an apparatus for removing NOx on the downstream side of an apparatus for removing SOx, where a heat exchanger for heat exchanging a treated gas from the apparatus for removing NOx with conbustion air is provided on the downstream side of the apparatus for removing NOx, whereby the waste heat of the treated gas can be efficiently utilized and the heat required for heating the flue gas can be reduced.

Abstract: Process and apparatus wherein nitrogen oxides NO.sub.x contained in waste gases produced by combustion of fossil fuels in a firing plant are removed by reacting the waste gases with ammonia NH.sub.3 to reduce the nitrogen oxides to elementary nitrogen N.sub.2 ; subjecting the waste gases after being so reacted to wet waste gas cleaning whereby the washing water removes the unreacted ammonia (slip) from the waste gas to produce slip enriched washing water; raising the pH value of the slip enriched washing water to a value of more than 10, introducing air into the pH raised slip enriched washing water to remove the slip from the water and produce an air-slip mixture and recycling the slip into the furnace to react with waste gases to lower the amount of ammonia discharged into the atmosphere.

Abstract: An exhaust system of an internal-combustion engine is provided with a small catalyst as a starting catalyst and wherein this small catalyst is longitudinally movably or pivotedly movable into or out of the exhaust pipe of an internal-combustion engine. When exhaust gas flow from the engine is strong, the catalyst is moved into a dead space lateral chamber with respect to the flow in the exhaust pipe.

Abstract: A catalytic converter of the automotive type comprising a reduced central oval section that compresses a support mat around a catalyst substrate, the reduced central section comprising radially inwardly biased ribs that are parallel to the longitudinal axis of the converter.The converter can be made by inserting a catalyst substrate and surrounding support mat through the open end and into the central portion of an oval sheet metal tube, after which the reduced section and longitudinal ribs are formed in the central portion of the tube to compress the mat and securely engage the substrate, and the ends of the tube are pinched together to form sealed end closures with gas flow passages therein.

Abstract: A compact cogeneration system in which a catalytic converter is positioned within otherwise unused space in an exhaust gas heat exchanger employed to heat water. Exhaust gases from an internal combustion engine of a packaged cogeneration system are directed through a single- or two-stage catalytic converter in a central cylindrical housing of the heat exchanger, then are diverted to pass in counterflow over a water-containing coil in an annulus surrounding the housing.

Abstract: An odor control system neutralizes odors from any source such as those from a sewage disposal plant. The odor control system recirculates a brine solution containing NaOCl. This recirculated solution contacts the unwanted odors to neutralize them. Sufficient NaOCl is added electrochemically to the solution to neutralize the unwanted odors under normal operating conditions. When there are peak odor conditions the unwanted odors exceed the capacity of the electrochemically produced NaOCl. During such peak conditions, supplemental concentrated NaOCl is added from a storage tank. The concentration of the NaOCl in the soolution is determined by sensing the oxidation reduction potential (ORP) in the solution to produce an ORP signal. The ORP signal controls the concentration of NaOCl in the solution including that supplied electrochemically as well as that supplied from the storage tank.

Abstract: Exhaust gases from a process fired boiler are diverted from a stack prior to emission to the atmosphere through a duct system to a plurality of series connected heat exchangers. The exhaust gases are progressively reduced from an elevated temperature, for example in the range between about 350.degree.-525.degree. F., in stages to an ambient temperature of about 50.degree. F. At each stage heat from the exhaust gases is transferred from the gases to another medium, such as water, which is fed back to the boiler to reduce the energy cost of operating the boiler. At ambient temperature the exhaust gases are subjected to an atomized spray of a reagent solution that absorbs the contaminants in the exhaust gases. Absorption of the contaminants into solution with the atomized reagent spray is promoted by contact of the spray and exhaust gases on the surface of a fibrous batting.

Abstract: An exhaust gas purifying apparatus employing a 3-way catalyst has either a Y-type zeolite or a mordenite as an adsorbent for adsorbing a harmful component in exhaust gas which is disposed at the upstream side of the catalytic converter so that, when the exhaust gas temeprature is not higher than a specific temperature, a harmful component is adsorbed by means of the adsorbent, whereas, when the exhaust gas temperature exceeds the specific temperature, the harmful component desorbed from the adsorbent is introduced into the catalytic converter. Further, an activated carbon trapper and a by-pass are provided in parallel at the upstream side of the adsorbent so that the flow paths of exhaust gas are selectively switched from one to the other in accordance with the level of the exhaust gas temperature.

Abstract: Gas reacting apparatus and method are described for wet mass transfer of solute gases from a gas stream with a liquid or slurry reacting medium capable of chemisorption of solute gases in the gas stream. The apparatus comprises an elongated conduit defining a primary reaction zone in fluid-flow communication with a fan defining both a secondary reaction zone and a spray coalescence zone, and a plurality of dual-fluid spray nozzles coaxially spaced in series within the conduit and countercurrently or cocurrently directed to the gas stream for spraying the liquid or slurry reacting medium into said conduit to form a plurality of spray contact zones of uniformly-distributed fine droplets wherein intimate contact of high interfacial surface area between the sprayed liquid or slurry and the gas stream is effected to remove solute gases from the gas stream.

Abstract: A method and reactor system are described for decomposing organic compounds. A gaseous mixture of organic compounds and water, equal to or in excess of stoichiometry, is passed into a first reaction zone having a temperature range between about 200.degree. C. and 1400.degree. C. The first reaction zone has a labyrinthine path which presents organically adsorbent surfaces to the gaseous mixture to provide a residence time in the first reaction zone sufficient to react substantially all of the gaseous organic compounds and the water at high rate. The effluent from the first reaction zone, still with water equal to or in excess of stoichiometry, is then passed to a second reaction zone having a temperature range between about 750.degree. C. and 1820.degree. C. to decompose the organic compounds remaining in the effluent. The first reaction zone is an annulus which is coaxial with and surrounds the second reaction zone. The labyrinthine path is formed by particulate ceramic material.

Abstract: Gas reacting apparatus and method are described for wet mass transfer of solute gases from a gas stream with a liquid or slurry reacting medium capable of chemisorption of solute gases in the gas stream. The apparatus comprises an elongated conduit means defining a primary reaction zone in fluid-flow communication with a fan means defining both a secondary reaction zone and a spray coalescence zone, and plurality of dual fluid spray means coaxially spaced in series within the conduit means and countercurrently or cocurrently directed to the gas stream for spraying the liquid or slurry reacting medium into said conduit means to form a plurality of spray contact zones of uniformly-distributed fine droplets wherein intimate contact of high interfacial surface area between the sprayed liquid or slurry and the gas stream is effected to remove solute gases from the gas stream.

Abstract: In a process in which ZnO is used to absorb H.sub.2 S and/or SO.sub.2 from Claus Plant tail gas, producing ZnS, and in which ZnS is regenerated using O.sub.2 producing regeneration effluent, the volume of regeneration effluent containing sulfur species which must be further processed is reduced or diminished in quantity by diluting the oxygen containing gas with water prior to regeneration of ZnS to ZNO and thereafter removing at least a portion of the added water.

Abstract: Apparatus for removal of deleterious gaseous components from a flue gas, the flue gas is cooled, optionally subjected to preliminary purification, and optionally depleted of SO.sub.2. It is then heated in at least one heat exchanger and is passed over a catalyst suitable for the conversion of nitrogen oxides, whereupon the purified hot flue gas is conducted over at least one further heat exchanger and is discharged in the cooled state. Ammonia is preferably added to the heated flue gas.

Abstract: A catalystic converter includes an annular catalyst bed containing catalyst beads and defined by inner and outer coaxial perforated tubes. An outer shell coaxial with the catalyst bed defines a passage between the outer shell and the outer perforated tube. The passage is connected to an outlet port. Exhaust gas flows radially outward through the catalyst bed and then through the passage to the outlet port. Air is injected into the passage at a selected axial location and is drawn into the catalyst bed by the reciprocating action of the engine. As a result, the single catalyst bed has an inner zone with a scarcity of oxygen which reduces oxides of nitrogen and an outer zone with oxygen present. Unburned hydrocarbons and carbon monoxide are oxidized in the outer zone.

Abstract: A sulfur dioxide-containing gas, for example, one obtained by an SO.sub.x and NO.sub.x removing process using ammonia is treated by the use of a reaction apparatus comprising a reducing reaction portion and a composition controlling oxidation reaction portion, provided in the same reactor or reactors adjacent to each other, to convert the composition of the gas into one suitable for the Claus reaction.

Abstract: An apparatus for filtration of particles and neutralization of sulfurous anhydride for smoke and gases discharged by a boiler includes a scrubbing train, which in turn includes a heat recovery device that receives on an inlet thereof, the smoke and gases, and lowers the temperature thereof by a heat exchanger to cool the same to a temperature within the range of 10.degree.-25.degree. C.

Abstract: A process provided in accordance with practice of this invention for lowering the molar ratio of NO to NO.sub.2 in flue gas by converting a portion of flue gas nitric oxide (NO) to nitrogen dioxide (NO.sub.2), for removing the associated oxides of sulfur (SO.sub.x) and nitrogen (NO.sub.x) from the flue gas prior of discharge of the flue gas into the atmosphere and an apparatus for practicing the process.

Abstract: A waste gas in treated by the sequence of discharge treatment and catalytic oxidation. A microbe-containing gas is disinfected by first mixing it with ozone, then subjecting the gas to discharge treatment and catalytic reaction successively.

Abstract: A system for removal of oxides of nitrogen from the waste gas produced by various combustion processes discloses thoroughly mixing the waste gas with ammonia by means of a static mixing element and then passing the resultant mixture through a catalytic reactor. The ammonia may be supplied by reacting a portion of the waste gas with natural gas in the presence of a catalyst.

Abstract: The invention relates to a catalyst for the conversion of gases and higher hydrocarbons, which comprises an active metal coating containing lanthanum and cobalt as active metal components on a porous oxidic support substance, wherein the coating is formed by impregnating the support substance with a solution of thermally easily decomposable lanthanum and cobalt salts and subsequently baking, whereby the metal coating contains 1 part cobalt and 1-3 parts, preferably 2 parts, lanthanum, as well as 2 to 20 weight percent of cerium based on the sum of these materials.

Abstract: An apparatus is provided for the elimination of the gaseous pollutants sulfur dioxide and nitric oxide from the emissions of furnaces and smelters, and for the production of two commercial products, liquid sulfur and nitric acid. Two precipitators are operated in series, each containing an annular reaction chamber and a cylindrical separation chamber surrounded by the reaction chamber. The first precipitator combines the furnace or smelter emissions with methane in its reaction chamber in order to reduce the sulfur dioxide in the emissions to sulfur. The emissions are then passed through a tangential duct to the first precipitator's separation chamber where the fine sulfur praticles are converted to liquid sulfur by sending the mixed gases through an involuted spiral baffle and allowing the sulfur particles to coalesce on a trip wire grid. The sulfur particles then melt and fall by gravity to the bottom of the separation chamber, from which point the liquid sulfur is withdrawn.

Abstract: An absorption tower for absorbing sulphur trioxide in sulphuric acid having distinct upper and lower packed absorption zones wherein substantially all of the sulphur trioxide is absorbed by the sulphuric acid in the lower zone, while in the upper zone the depleted gas stream is significantly cooled. The two zones receive feed acids of different temperatures and different acid irrigation rates. The tower allows of improved energy recovery while providing for environmentally acceptable emission standards.

Abstract: A process and apparatus for recovering a high-purity inert gas by removing the impurities in a used inert gas (e.g., Ar), comprising a combustible component reaction step and reaction unit for adding oxygen to a raw gas containing a carbonaceous combustible component to thereby react the combustible component in said raw gas with the oxygen; a carbon dioxide gas removing step and removing unit for removing the carbon dioxide in the raw gas sent from said combustible component reaction unit; an oxygen reaction step and reaction unit for adding hydrogen to the raw gas after the carbon dioxide gas removal to react the oxygen remaining in said raw gas with the hydrogen; a moisture removing step and removing unit for removing the moisture in the raw gas sent from the oxygen reaction unit; and a refining step and refining unit for removing the remaining impurities from the raw gas after the moisture removal to recover a high-purity inert gas.

Abstract: In the method and device for separation of harmful substances from a flue gas, in an absorption-heat exchanger arrangement both washing and also cooling of the flue gas is carried out, the flue gas being cooled below the dew point and this cooling process taking place by means of exterior air in counter flow. The flue gas is divided during its passage through the heat exchanger into at least two parallel part flows of which the first part flow is directed into a first treatment zone and the second part flow is directed into a second treatment zone. The two treatment zones are connected parallel to one another. In the first treatment zone a first absorption liquid is introduced into the flue gas which effects extensive removal of harmful substances from the flue gas, while in the second treatment zone a second absorption liquid is introduced into the flue gas, in which second absorption liquid precipitated harmful substances are soluble, to clean equipment surfaces.

Abstract: Flue gases containing crackable and combustible volatiles e.g. from a wood-burning stove are passed through a catalytic combustor having two spaced catalytic units each having small longitudinally extending catalytic flow passages. Air supplied into a chamber between the two units supports after-combustion of combustible volatiles in the downstream catalytic unit. Some pre-cracking and combustion takes place in the upstream catalytic unit, which serves as a gas collimator and disallows any flow of air from the intermediate chamber into the fire box of the stove, whereby combustion in the fire box can be closely controlled to increase production of combustible volatiles. Each unit may have flow passages which decrease in cross-sectional size and increase in length toward the central portion of the unit, thus encouraging uniformity of flow of the flue gases and of the catalytic reaction over the entire cross section of each unit.

Abstract: Modified Claus furnace containing, in addition to primary reaction chamber, a secondary chamber in heat exchange with said primary reaction chamber wherein H.sub.2 S is cracked to supply hydrogen needed downstream in a clean-up system. This eliminates the need for supplemental hydrogen generator now usually provided for in a sulfur recovery system. A catalyst such as cobalt-molybdenum can be used in the secondary reaction chamber.