Abstract: An exhaust heat recovery boiler in which an exhaust gas discharged from a gas turbine into a boiler duct to recover a heat of the exhaust gas and ammonia is injected to and mixed with the exhaust gas to reduce nitrogen oxide contained in the exhaust gas, the exhaust heat recovery boiler comprising: a boiler duct of a horizontal installation type having an inner hollow portion along which an exhaust gas flows from an upstream side to a downstream side; a superheater; an evaporator; a denitration reactor; and an economizer, which are disposed inside the boiler duct in this order from the upstream side to the downstream side of the exhaust gas flow therein. A drum is disposed outside the boiler duct and connected to the evaporator and a downcomer pipe extending from the drum into the boiler duct.

Abstract: A two-stage method for NO.sub.x reduction in an oxygen-rich engine exhaust comprises a plasma oxidative stage and a storage reduction stage. The first stage employs a non-thermal plasma treatment of NO.sub.x gases in an oxygen-rich exhaust and is intended to convert NO to NO.sub.2 in the presence of O.sub.2 and hydrocarbons. The second stage employs a lean NO.sub.x trap to convert such NO.sub.2 to environmentally benign gases that include N.sub.2, CO.sub.2, and H.sub.2 O. By preconverting NO to NO.sub.2 in the first stage with a plasma, the efficiency of the second stage for NO.sub.x reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber in which a non-thermal plasma converts NO to NO.sub.2 in the presence of O.sub.2 and hydrocarbons, such as propene. A flow of such hydrocarbons (C.sub.x H.sub.y) is input from usually a second pipe into at least a portion of the first chamber. The NO.sub.

Abstract: A Pulp Mill Recovery installation for producing liquors containing different concentrations of recovered process chemicals or combustion gasses containing different concentrations of process chemicals from a spent liquor obtained from the production of pulp.

Abstract: A method and apparatus for heat treating waste materials including pyrolysing the waste materials in a first heating zone to produce pyrolysis gas containing dust and impurities, removing at least 90% of the dust from the pyrolysis gas, and burning the pyrolysis gas to produce flue gas. The flue gas produced is either immediately denitrogenated non-catalytically or first cooled and then catalytically denitrogenated. Following denitrogenation the flue gas is filtered to purify the gas.

Abstract: A method for monitoring the oxidation rate in a flue gas desulfurization system having a slurry comprises locating a monitor in the system for accessing the slurry. A sample is periodically drawn from the slurry by the monitor wherein a titration is performed on each sample. The titration performed on each sample comprises adding a potassium iodate KIO.sub.3 solution, a potassium iodide KI starch solution and an acid solution to the sample in the monitor for causing the sample to exhibit a color corresponding to the oxidation rate.

Abstract: A pollutant removing stack device includes a stack body having a lower reactor section which is divided by a partition into an upper chamber and a lower chamber. A first set of spraying units is disposed in the lower chamber. A second set of spraying units is disposed the upper chamber. A stack gas inlet is connected to the lower chamber of the lower reactor section for entrance of a stack gas. An oxidant supplying unit is connected to the first set of spraying units in order to produce an oxidant mist in the lower chamber for oxidizing a nitrogen compound contained in the stack gas into nitrogen dioxide. An alkaline solution supplying unit is connected to the second set of spraying units in order to produce an alkaline mist in the upper chamber for removing nitrogen dioxide and sulfur dioxide from the stack gas.

Abstract: An ammonia injection device for use in an exhaust gas denitration system comprises ammonia injection pipe units arranged in a multiplicity of stages within an exhaust gas duct and each comprising a horizontal header pipe and a plurality of ammonia injection pipes extending downward from and connected to the header pipe and each having a multiplicity of injection nozzles. The header pipes other than the uppermost header pipe and a guide fixing member disposed horizontally at a bottom portion of the duct are each provided with a plurality of upward tubular guides arranged at a predetermined interval. The injection pipes have their lower ends inserted in the respective guides upwardly and downwardly movably. The injection nozzles have an opening diameter gradually increasing as the injection pipe extends downward.

Abstract: A system and method of injecting an ammonia or urea reactant into a flue gas stream in a steam generating power plant that utilizes Selective Catalytic Reduction (SCR) to lower NO.sub.x emissions and more specifically the injection of the reactant in such a manner that a more uniform mixing of the reactant with the flue gas stream is achieved more rapidly thereby increasing the efficiency of the catalytic reduction process and further a method of increasing the amount of reaction that takes place between the reactant/flue gas mixture and the catalytic material.

Abstract: A hazardous gas mixing apparatus includes a mixing chamber wherein air is mixed with such a gas to render same inert. An air inlet assembly admits an air flow induced into the mixing chamber and includes an air flow sensor having a probe located in a housing of the assembly. Differential air pressures detected by the probe are provided to a signal generating transmitter and signal converter serving a logic controller providing a display correlated to linear feet per minute air flow in the apparatus mixing chamber. A honeycomb air straightener serves to provide a laminar flow of air past the sensor probe. An intake screen on the housing reduces the intake of foreign particles.

Abstract: An effluent gas stream treatment system for treatment of gaseous effluents such as waste gases from semiconductor manufacturing operations. The effluent gas stream treatment system comprises a pre-oxidation treatment unit, which may for example comprise a scrubber, an oxidation unit such an electrothermal oxidizer, and a post-oxidation treatment unit, such as a wet or dry scrubber. The effluent gas stream treatment system of the invention may utilize an integrated oxidizer, quench and wet scrubber assembly, for abatement of hazardous or otherwise undesired components from the effluent gas stream. Gas or liquid shrouding of gas streams in the treatment system may be provided by high efficiency inlet structures.

Abstract: An exhaust catalytic converter for a Diesel engine that provides for enrichment of the Diesel engine exhaust with hydrocarbons that support nitrogen oxide conversion in the catalyst. The system includes a first catalytic converter stage that is designed for NOx conversion in a first temperature range utilizing a first part of the HC enrichment volume in the exhaust and has a suitable first catalyst material charge for the purpose as well as a second catalytic converter stage that follows the first in the exhaust flow direction, the second stage being designed for NOx conversion in a second temperature range higher than the first and utilizing a second part of the HC enrichment volume in the exhaust, and containing a second catalyst material charge suitable for the purpose. By suitably tuning the system with HC enrichment, reduction of emissions of solid and volatile particles in the Diesel exhaust can be achieved.

Abstract: Food grade carbon dioxide is produced from oxyfuel fired glassmaking furnace waste gas by a series of steps including quenching the waste gas with aqueous quench liquid, dry-filtering sulfur salt from the gas, scrubbing the filtered gas with aqueous carbonate to convert the remaining sulfur dioxide to an aqueous sulfite suspension and using the suspension as part or all of the above-mentioned aqueous quench liquid, contacting the sulfur dioxide-free waste gas with ammonia in the presence of a catalyst that selectively converts nitrogen oxides to nitrogen, thereby removing substantially all nitrogen oxides from the waste gas, and distilling the resulting waste gas stream thereby producing high purity liquid carbon dioxide and producing an off-gas, which is recycled to the furnace as fuel.

Abstract: An apparatus and method for reducing NO.sub.x pollution in flue gas produced by a power plant uses heat exchanger elements having extended surfaces which contain a SCR catalyst, with the heat exchanger elements located in the flue gas stream. Coolant is passed through the heat exchanger elements to cool the catalyst, with a temperature control system used to maintain the catalyst at its optimum temperature such that the maximum conversion of NO.sub.x is achieved. Utilizing the present invention, temperature cycling of the catalyst is avoided, prolonging the life of the catalyst, while at the same time optimizing the efficiency of conversion regardless of variations in the flue gas flow or temperature.

Abstract: A method of reducing the nitrogen oxide level in the flue gases issuing from combustion units by introduction of reducing agents into contact with gases containing nitrogen oxides in first and second reducing stages, is provided. The first reducing stage is a non-catalytic stage (e.g. at temperatures over 800.degree. C.), while the second stage is a catalytic stage (e.g. at temperatures of about 300-400.degree. C.). A steam generation boiler with improved nitrogen reduction facilities is also provided. The amount of nitrogen oxides in the hot gases is reduced in the combination of the first and second reducing stages while producing steam in a steam generation boiler system, thus resulting in gases essentially free from nitrogen oxides while eliminating the possibility of NH.sub.3 (or other reducing agent) slip in the exhausted flue gases. Heat transfers in a convection section as used to establish stabilized temperature conditions for catalytic reduction.

Abstract: A diesel exhaust conditioning system removes harmful gaseous and particulate pollutants from the exhaust of a diesel engine, and also lowers the temperature of the emitted exhaust and of the shroud surrounding the pollution control components of the device. The system includes at least one combination catalytic converter and particulate filter, structured to operate at a sufficiently high temperature as to convert potentially harmful gaseous pollutants to innocuous substances, and which also collects and oxidizes carbon and hydrocarbon particles in the diesel exhaust to convert them to innocuous substances as well. The catalytic converter(s) is contained in an insulated canister for containing the heat generated by the catalytic reactions, with the insulation also serving to lower the outside temperature of the canister.

Abstract: An apparatus for purifying waste gases, particularly waste gases from CVD (chemical vapor deposition), plasma etching or similar processes, with at least one combustion space, which is in a vertical arrangement within an outer pipe and is limited at the top by an umbrella-like cover, and an internally or externally mixing burner, the combustion gas nozzles of which protrude into the combustion space, combustion gas, oxygen or air and waste gas being supplied to the burner, as well as to means for supplying and discharging oxidizing agents and/or absorbents to a scrubbing space above the combustion space. By means of the invention, an apparatus is to be provided for purifying waste gases, which can be manufactured cost-effectively and by means of which the disadvantages of the state of the art are avoided.

Abstract: Disclosed is an ammonia adsorption apparatus for removing ammonia contained in a treated gas discharged from a denitrator for decomposing nitrogen oxides present in exhaust gas using ammonia as a reducing agent, comprising at least two adsorption towers into which ammonia-containing exhaust gas is introduced in a vertical direction for removing the ammonia by adsorption, wherein, during regeneration of each adsorption tower, hot gas used for desorption purposes flows from a top toward a bottom of the adsorption tower and cooling gas flows from the bottom toward the top of the adsorption tower.

Abstract: A catalyst for purifying an exhaust gas includes a substrate, a catalyst carrier layer, a catalyst ingredient and a hydrocarbons supplier. The catalyst carrier layer is formed on the substrate. The catalyst ingredient is loaded on the catalyst carrier layer. The hydrocarbons supplier is disposed in the substrate, and supplies supplementary hydrocarbons into the catalyst carrier layer so as to securely react the supplementary hydrocarbons with NO.sub.x included in an exhaust gas. Hence, the catalyst can purify not only CO but also NO.sub.x over a wide temperature range.

Abstract: A two-stage catalyst comprises an oxidative first stage and a reductive second stage. The first stage is intended to convert NO to NO.sub.2 in the presence of O.sub.2. The second stage serves to convert NO.sub.2 to environmentally benign gases that include N2, CO2, and H.sub.2 O. By preconverting NO to NO.sub.2 in the first stage, the efficiency of the second stage for NO.sub.x reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber. An oxidizing first catalyst converts NO to NO.sub.2 in the presence of O.sub.2 and includes platinum/alumina, e.g., Pt/Al.sub.2 O.sub.3 catalyst. A flow of hydrocarbons (C.sub.x H.sub.y) is input from a pipe into a second chamber. For example, propene can be used as a source of hydrocarbons. The NO.sub.2 from the first catalyst mixes with the hydrocarbons in the second chamber. The mixture proceeds to a second reduction catalyst that converts NO.sub.2 to N2, CO2, and H.sub.2 O, and includes a gamma-alumina .gamma.-Al.

Abstract: In a method and apparatus for selective catalytic oxidation of carbon monoxide, the gas mixture and an additionally added oxidizing gas are conducted through a reactor containing the catalyst. Oxidizing gas is added at several points along the mixed gas flow path with a controlled or regulated through flow volume. The mixed gas stream is cooled passively by static mixing structures located in the inlet area of the CO-oxidation reactor. By controlling exothermal CO oxidation along the reactor path, a very variable process guidance is provided, that can be adjusted to individual situations.

Abstract: A catalytic converter assembly for nitrogen oxide reduction in the exhaust gas of an internal combustion engine, in particular a Diesel engine, includes a catalytic converter through which exhaust gas can flow in a given flow direction. The catalytic converter has a catalyst carrier and a catalytically active layer. The catalytic converter has a reducing agent storage capacity per unit of length being increased in the given flow direction.

Abstract: Limestone is dried for grinding to very fine particles e.g., about 8.mu. or less with more than 99% of the particle by weight less than 44.mu., by utilizing waste heat from the flue gas from a large combustor. The finely-divided calcium carbonate is then introduced dry into a scrubbing tower where it mixes with and renews the slurry employed therein for scrubbing SO.sub.x -laden effluent.

Abstract: A plant for the reduction of nitrogen oxide in furnace waste gases includes a furnace, a reactor serving for selective catalytic reduction, and a regenerative heat exchanger to be used for air preheaters as well as for gas preheaters for the treatment of pollutant-containing waste gases which are in a heat exchange with another medium. The regenerative heat exchanger has stationary or revolving storage masses which are composed at least partially of catalytic material. A reduction agent is supplied to the regenerative heat exchanger. The reactor is arranged concentrically above the regenerative heat exchanger. Preferably, the reactor is placed directly onto the housing of the heat exchanger.

Abstract: An exhaust purifier of an internal combustion engine supplies secondary air into an exhaust pipe without cooling nor inactivating an electrically heated catalyst (EHC) that is active. The exhaust purifier includes the EHC 3 disposed in the exhaust pipe 2, a main catalyst 4 disposed in the exhaust pipe 2 downstream from the EHC 3, and a unit for supplying secondary air into the exhaust pipe 2. The secondary air supply unit has a main path 10 for supplying secondary air into a space defined in the exhaust pipe 2 between the EHC 3 and the main catalyst 4 when it is determined that the main catalyst 4 is active. The secondary air supply unit may additionally have a second path 9 for supplying secondary air into the exhaust pipe 2 on the upstream side of the EHC 3 when it is determined that the EHC 3 is active, so that the secondary air may pass through the EHC 3 and reach the main catalyst 4.

Abstract: A device for removal of SO.sub.2 and NO.sub.x from flue gas by high frequency discharge has a chamber having a first inlet opening for entry of flue gas into the chamber and an outlet opening for flue gas to exit from the chamber after removal of SO.sub.2 and NO.sub.x. A generator and electrode produce a high frequency electric field of sufficient strength in the chamber to produce high energy electrons that achieve both excitation and ionization potentials of N.sub.2, O.sub.2 and H.sub.2 O, whereby to produce free radicals of OH., O.sub.2 H., N., O. and H. which react with SO.sub.2 and NO.sub.x molecules in the flue gas. A second inlet opening into the chamber adds ammonia to the SO.sub.2 and NO.sub.x for reaction with the free radicals in neutralization producing ammonium salts from the SO.sub.2 and NO.sub.x in the flue gas exiting from the chamber.

Abstract: An exhaust gas management apparatus including: a first substrate coated with an oxidizing catalyst, wherein the first substrate includes an axial opening and a body portion radially exterior of the axial opening, wherein the axial opening comprises at least part of a bypass passage; an air source located downstream in an exhaust flow path of the axial opening; an air pump unit responsive to a control signal forcing air through the air source wherein, during an activation of the pump unit, the bypass passage is valved shut; and a second substrate coated with an oxidizing catalyst located in the path of exhaust downstream of the first substrate.

Abstract: Apparatus for remediation of particulate matter and gaseous pollutants entrained in flue gases. The flue gases, having a pre-determined moisture content, are mixed with sorbent material and forced through an induct venturi equipped with a mixing impeller. Downstream, the reaction products are removed from the gas stream and collected for use as construction material. The vented gas stream is monitored for specific pollutants and the amount of sorbent material introduced into the system can be automated in response to reading obtained. Additionally, the gas stream can pass through a bag house or cyclone wherein the bags are impregnated with materials specific to the pollutants carried in the stream.

Abstract: A combined furnace limestone injection and dry scrubber flue gas desulfurization (FGD) system collects solids from the flue gas stream in first particulate collection device located downstream of an outlet of a convection pass of the furnace and upstream of the dry scrubber. The collected solids are diverted to the dry scrubber feed slurry preparation system to increase sulfur oxide species removal efficiency and sorbent utilization. The level of lime in the feed slurry provided to the dry scrubber is thus increased, which enhances removal of sulfur oxide species in the dry scrubber. The decreased particulate loading to the dry scrubber helps maintain a desired degree of free moisture in the flue gas stream entering the dry scrubber, which enhances sulfur oxide species removal both in the dry scrubber and downstream particulate collector, normally a baghouse.

Abstract: A waste gas disposal apparatus includes a scraper rotating portion for rotating a scraper configured to simultaneously scrape off fine reactant particles adsorbed to an inner surface of a waste gas collecting unit and a surface of a cone in a collection inducing portion of the collection unit. The scraper is designed to be fixed to a scraper support rod, which is formed coaxially with a cone support rod and rotated through a 360.degree. arc. The fine reactant particle collection efficiency is much higher compared with conventional devices that only rotate through a 180.degree. arc, and must repeatedly reverse directions during scraping operations.

Abstract: An efficient and cost-effective flue gas desulfurization apparatus for removing sulfur dioxide from waste gases is provided. The apparatus employs a substantially solids-free clear liquor scrubbing liquid and an, organic acid additive capable of maintaining a process pH of 4.5 to 6.0 under inhibited oxidation conditions in the absorber to accomplish sulfur dioxide removal while avoiding scale formation and encrustation. Calcium sulfite relative saturation is controlled to a desired low optimum level by maintaining the circulating calcium ion concentration at a corresponding, optimum low level. A smaller thickener unit area is required to produced calcium sulfite crystals with optimum settling and dewatering characteristics. A reactor system that promotes the formation of small, efficiently dewatered calcium sulfite solids is also provided.

Abstract: The present invention relates to a slurry thickening tank comprising a tank body disposed below the surface of a slurry within a slurry tank, a slurry inlet provided in the upper part of the tank body, a thickened slurry outlet provided in the lower part of the tank body, and supernatant liquid withdrawal means provided in the upper part of the tank body, whereby the slurry introduced into the tank body through the slurry inlet is thickened by sedimentation in the tank body and the resulting thickened slurry is discharged from the tank body through the slurry outlet, wherein the surface of the structural member of the tank body extending from the slurry inlet to the thickened slurry outlet has an angle of inclination greater than the angle of repose for the thickened slurry, and to an absorption tower for use in flue gas desulfurization systems which is equipped with such a slurry thickening tank.

Abstract: This invention relates to a waste gas treating apparatus, especially for treating a waste gas containing sulfur dioxide and carbon dioxide. It includes at least one washing tower. At least one fluid inlet is disposed on a lateral wall of the washing tower, so that a fluid is pumped into the washing tower by constant amount and drained out from a draining opening of a base of the washing tower. At least one gas inlet is disposed on the wall of the washing tower below the fluid inlet. The waste gas is injected into the washing tower so as to contact with the fluid and form bubbles which buoy upward to a top of the washing tower and are exhausted from a gas outlet thereof. The fluid serves to react with and absorb the pollutants contained in the waste gas. The products of the reaction are discharged out of the washing tower along with the fluid.

Abstract: For a system having a source of nitrogen oxide-containing gas, an ammonia reduction denitrator, and a leak ammonia recovery unit which adsorbs and removes ammonia escaping from said ammonia reduction denitrator, a method of removing adsorbed ammonia from said leak ammonia recovery unit and reusing the removed ammonia is provided which includes the steps of: introducing hot exhaust gas discharged from said nitrogen oxide-containing gas source into said leak ammonia recovery unit to desorb ammonia therefrom; after desorption of ammonia, cooling said heated leak ammonia recovery unit with cool air; and feeding ammonia carried away by said hot exhaust gas and said cool air to an upstream side of said ammonia reduction denitrator or to the source of nitrogen oxide-containing gas.

Abstract: A flue gas treating system including a gas-gas heater and/or a dust collector, and a wet flue gas desulfurization apparatus, characterized in that the flue gas treating system is equipped with addition means for adding an alkaline agent to an absorbent slurry, a pH detector for detecting the pH of the slurry, gas-gas heater operational state detection means, dust collector operational state detection means, and alkaline agent addition control means for controlling the amount of alkaline agent added in response to signals from the pH detector, the gas-gas heater operational state detection means and the dust collector operational state detection means, so that the pH and calcium compound concentration of the absorbent slurry can be controlled.

Abstract: This invention relates to a wet flue gas desulfurization apparatus including: an absorption tower having defined in the lower part thereof a tank for holding a calcium compound-containing slurry fed thereto; a circulating pump for delivering the slurry within the tank to the upper part of the absorption tower in order to bring it into contact with flue gas; air supply member for supplying air to the tank for purposes of oxidation; a withdrawal pump for withdrawing the slurry within the tank in order to recover gypsum formed as a by-product or discharge waste water; falling slurry withdrawal member for withdrawing part of the slurry delivered to the upper part of the absorption tower by the circulating pump and falling through the absorption tower at a position above the liquid surface of the tank; and mixing member for the slurry withdrawn by the falling slurry withdrawal member with the slurry withdrawn from the tank by the withdrawal pump, whereby oxidizing substances produced in the tank of the absorption

Abstract: A flue gas treatment system is provided for which is capable of easily treating Se contained in flue gas, comprising an extractor 13 for extracting soluble components in the dust removed by a dry-type dust precipitator 5 into water to slurry the dust; insolubilizer supply 16 for supplying an insolubilizer for insolubilizing at least tetravalent Se to the dust slurry which has been slurried from the dust by the extractor 13; adsorbent supply 14 for supplying an adsorbent composed of an organism material for adsorbing at least hexavalent Se in the dust slurry; and separator 15 for solid-liquid separating the dust slurry to which the insolubilizer and the adsorbent have been supplied by said supplies.

Abstract: An apparatus and process for the removal of sulfur, in the form of hydrogen sulfide (H.sub.2 S), from gas, such as natural gas or industrial gas streams, in which the sulfur is removed and separated in the form of particulate elemental sulfur. The apparatus and process are advantageously configured so as to maintain control over the development of undesired concentrations of particulate sulfur in the precipitation catalyst solution with which the sulfur is separated from the gas stream.

Abstract: An exhaust gas cleaner is constituted by a first catalyst carrying an Ag component, a second catalyst carrying an Ni component or two or more of an Ni component, Ag component and Cu component, and optionally a third catalyst carrying a noble metal component alone or in combination with a base metal component. The second and third catalysts may be physically mixed to form a mixed catalyst. Another exhaust gas cleaner is constituted by a mixed catalyst of a first catalyst carrying an Ag component and a second catalyst carrying an Ni component alone or in combination with a Cu component, and a third catalyst carrying a noble metal component alone or in combination with a base metal component. Still another exhaust gas cleaner is constituted by a first catalyst carrying an Ag component, a second catalyst which is a mixture of an Ni catalyst, Ag catalyst and Cu catalyst, and optionally a third catalyst carrying a noble metal component alone or in combination with a base metal component.

Abstract: A plant for generating a nitrogen-based gas is provided. The plant includes a source of impure nitrogen under pressure containing a residual oxygen concentration; a main gas conduit; a catalytic deoxygenation reactor; a secondary gas line connected to a source of a secondary reducing gas at one end thereof and to the main gas conduit at a point situated upstream of the catalytic deoxygenation reactor at another end thereof; and a device for removing water vapor present in a gas. The source of impure nitrogen is connected to the catalytic deoxygenation reactor via the main gas conduit. The main gas conduit between the source of impure nitrogen and the point where the secondary gas line is connected is devoid of any flow control device.

Abstract: A reactor that can be attached to the exhaust manifold of an internal combustion engine to oxidize and burn carbon soot particles, carbon monoxide, and unburned hydrocarbons, and to dissociate nitrogen and sulfur oxides. The reactor has a reaction zone that contains porous heat-retaining foam cells and that is bounded by a porous heat-retaining zone, which in turn is surrounded by ceramic insulation materials to minimize energy losses. Engine exhaust at elevated temperatures and containing some oxygen (air) enters the reaction chamber. By means of impinging heat transfer, thermal radiation enhancement, energy trapping and combustion of engine emissions, temperatures sufficient to oxidize carbon soot particles, carbon monoxide, and unburned hydrocarbons are attained. Steam or atomized water droplets are introduced to improve the efficiency of the reactor through gasification, regasification, water shift reactions, methanation, and hydrocracking reactions. Harmless product of the oxidation reactions, H.sub.

Abstract: An apparatus installed between a fuel economizer and an air preheater for the denitration of exhaust gas from a coal-fired boiler includes at least one vertical flue situated upstream of a reactor containing a denitration catalyst to cause an upward flow of the gas, A hopper is located below the vertical flue for collecting ash separated from the gas, A baffle is preferably provided in the flue to ensure the still more effective separation of ash from a gas.

Abstract: An injection lance for injecting a mixture of air and anhydrous ammonia into a boiler having a flue gas stream moving therethrough to reduce nitrogen oxides therein. The lance includes outer, intermediate and inner tubes. The outer end of the inner tube is in communication with a source of anhydrous ammonia while the outer end of the outer tube is in communication with a source of mixing air. The outer end of the intermediate tube sealably embraces the exterior surface of the inner tube so that air being introduced into the outer tube passes towards the inner end of the lance between the outer and intermediate tubes. The mixing air and the anhydrous ammonia are passed into the space between the inner tube and the intermediate tube and then are discharged from the lance through discharge nozzles or ports which extend from the interior of the intermediate tube to the exterior of the outer tube.

Abstract: A method for a regenerative heat exchanger for the treatment of pollutant-containing waste gases which are in a heat exchange with another medium. The heat exchanger includes stationary or rotating storage masses which are at least partially of catalytic material and to which a reduction agent is supplied from the hot side thereof. A penetration of the reduction agent into the flue gas flow can be prevented by supplying the reduction agent directly to the catalyst separately from the pollutant-containing waste gases and without coming into contact with the remaining heating surfaces. For this purpose, a nozzle arrangement having at least one arm and extending over the entire radius of the heat exchanger may be arranged in both hood sides of the heat exchanger.

Abstract: A system for removing SO.sub.2, NO.sub.2, and other contaminants from flue gases uses hydrogen peroxide (H.sub.2 O.sub.2) as the reagent to convert the oxides of sulfur and some of the oxides of nitrogen (NO, NO.sub.2, etc.) to more stable oxidation states. Acids formed as a result of this conversion, namely sulfuric acid (H.sub.2 SO.sub.4) and nitric acid (HNO.sub.3) can then be neutralized with limestone or, alternatively, the sulfuric and nitric acids can be collected and processed for sale as an industrial product.

Abstract: Activated carbon injection is provided for mercury removal in a flue gas treatment system having an electrostatic precipitator and a wet flue gas desulfurization tower by injecting fresh activated carbon into the flue along with recycled carbon from the exhaust of the precipitator to minimize fresh carbon make up along with an activated carbon bed in the desulfurization tower to maximize mercury and other toxin removal from the flue exhaust.

Abstract: A spray tower for removing acidic gases and particulate matter from flue gases produced by processing operations of the type carried out in utility and industrial facilities. The spray tower is equipped with a tank that serves as a reservoir for an alkaline slurry used to remove acidic gases and particulate matter from the flue gases. The slurry is pumped from the tank to spraying devices located within the tower. The spray tower further includes an internal structure that enables the slurry to be oxidized and gently agitated within a limited region of the tank, and without the requirement for two separate aeration and agitation devices. As a result, the construction, operational and maintenance costs of the spray tower are significantly reduced as compared to prior art spray towers.

Abstract: An exhaust gas purification system includes an adsorbent containing an adsorbent element for adsorbing harmful compounds such as hydrocarbon in an exhaust gas and a catalyst containing a catalyst element for lowering the harmful compounds in the exhaust gas, each disposed in the exhaust gas pipe of an internal combustion engine. When an oxidizing gas is added to the exhaust gas or amounts of combustion gas and fuel are regulated, for a given period, in the process in which the hydrocarbon in the exhaust gas produced at the cold start-up of the internal combustion engine are adsorbed by the adsorbent and desorbed from the adsorbent as a temperature of the adsorbent is increased by the exhaust gas, an exhaust gas composition containing excessive oxygen is provided and the desorbed hydrocarbon are oxidized on the catalyst. With this arrangement, the harmful compounds in the exhaust gas, in particular, the hydrocarbon produced in a large amount at the cold start-up of the engine can be effectively purified.

Abstract: A solid-liquid separator comprising a first roller disposed on one side of a tank containing a slurry subjected to solid-liquid separation at such a height that the lower part thereof is immersed in the slurry, and driven rotationally in a direction which enables the slurry attached to its surface to be lifted up and discharged to the outside of the tank; and a second roller disposed above the first roller facing the first roller so that the second roller comes into pressure contact with the slurry attached to the first roller and lifted up so as to remove the liquid from the slurry; as well as a wet flue gas desulfurization apparatus using this solid-liquid separator.

Abstract: A method and a device for wet desulfurization of flue gas to remove a sulfur dioxide(SO.sub.2) contained in flue gas discharged from thermal power stations and boilers are disclosed. In the method the device with a gas layered sieve plate for wet desulfurization of flue gas, an absorbing liquid improves reacting conditions by effecting it own circulation without using additional power due to the structural characteristics possessed by the device and flue gas is treated very satisfactorily thanks to high gas-liquid contact efficiency. In order to minimize power consumption and the size of the device but promote desulfurization to an unusual degree, an absorber is divided into an upper froth layer and a lower liquid layer by a single-stage gas dispersing plate with a large number of gas ejection holes bored therein.

Abstract: A catalytic converter for accelerating at least one reaction between at least two reactants of a gas mixture includes a catalyst carrier, and a catalytically active substance. The catalytically active substance has a varable chemical composition which is varied along a flow direction of a gas mixture, for suppressing undesired side reactions.