Abstract: The control of emissions from fossil-fired boilers wherein an injection of substances above the primary combustion zone employs multi-layer feedforward artificial neural networks for modeling static nonlinear relationships between the distribution of injected substances into the upper region of the furnace and the emissions exiting the furnace. Multivariable nonlinear constrained optimization algorithms use the mathematical expressions from the artificial neural networks to provide the optimal substance distribution that minimizes emission levels for a given total substance injection rate.

Abstract: A circulating fluidized bed steam generator 10 and a method for operating the circulating fluidized bed steam generator are provided which offer the flexibility to use carbon dioxide (CO2) both as a desirable end product and as support to the combustion process. The method includes the step of introducing a substantially pure oxygen feed stream into the circulating fluidized bed steam generator 10 and the step of combusting a fuel in the presence of the substantially pure oxygen feed stream to produce a flue gas having carbon dioxide and water vapor as its two largest constituent elements by volume. The method also includes the step of passing the flue gas through an oxygen feed stream pre-heater 144 at which heat from the flue gas is transferred to the oxygen feed stream. Furthermore, the method includes the step of separating the flue gas into an end product portion and a recycling portion.

Abstract: An incineration and melting furnace has a furnace main body that is filled with a conductive heat generation body (for example, graphite). Radioactive combustible materials in contact with the conductive heat generation body are burnt and the radiaoactive incombustible materials are melted. The resultant exhaust gases and the molten products flow downwardly in the conductive heat generation body filled region and flow out of a molten product discharging port. Noxious gases such as dioxins contained in the exhaust gases are thermally decomposed into a non-toxic state in a high temperature portion of the conductive heat generation region.

Abstract: The invention provides a technology to largely decrease generation of dioxin in combustion ashes as well as exhaust gas by use of an ordinary combustion apparatus.

Abstract: An improved method of burning low sulfur coal in order to power gas turbines using unmixed combustion that ensures virtually complete oxidation of the coal, with the sulfur content of the coal being recovered as elemental sulfur for use as recycle in the unmixed combustion process. An unmixed combustion catalyst is circulated between two fluid bed reactors and becomes reduced by low sulfur coal in the first fluid bed reactor and oxidized by air in the second fluid bed reactor. The first reactor produces carbon-containing fly ash which is then separated and contacted with gases containing SO2 from the first fluid bed reactor to produce CO2, CO, H2S, COS, CS2, and elemental sulfur. The elemental sulfur is separated and a portion thereof recycled back to the first fluid bed reactor.

Abstract: Formation of dioxins in flue gases is inhibited by contacting the flue gas with at least one of sodium phosphite, calcium phosphate, sodium hypophosphite, and calcium as reducing agents preferably at a temperature in the range of from 150° C. to 850° C. Hydrogen chlorides are also rendered harmless by the contact with the reducing agent. Also, metal ions contained in the fly ash of the flue gas are reduced to metals to reduce the occurrence of dissolution of the metals in subsequent treatment of the fly ash.

Abstract: The invention provides a boiler provided with low cost means which can reduce a concentration of CO, an unburned matter, an attached ash and the like near a side wall and maintain a combustion state well with a simple structure. In a boiler having a combustion chamber 13 formed by front and rear walls (burner walls) provided with a plural stages of burners 2, 3 and 4 on at least one of them and opposing to each other, and side walls 1a and 1b crossing to said burner walls 14a and 14b, a gas port 6 containing no fuel for making a pressure of a gas near said side walls 1a and 1b within said combustion chamber 13 higher than a pressure of a gas at a center portion of said combustion chamber 13 is provided between an outermost burner and the side walls 1a and 1b within a range of a height of said burner stages 2, 3 and 4. A combustion gas 16 can not come close to the side walls 1a and 1b due to the jet 18 of the gas.

Abstract: The present invention provides a method of operating a solid fuel fired boiler comprising introducing a solid fuel and an iron-bearing material into the boiler. The solid fuel is at least partially combusted in the boiler to produce an ash slag, wherein the ash fusion temperature characteristics (i.e., one or more of the IDT, ST, HT, and FT) of the ash slag are different than the ash fusion temperature characteristics of the ash slag that would result on combustion of the solid fuel alone. The method of the present invention is particularly applicable to slag tap boilers, including cyclone-type boilers. These boilers are, typically, designed to operate with a liquid ash slag.

Abstract: A NOx reduction burner system and process. Fuel modification and fuel rich reactor zone gases are brought together with products from a fuel lean reactor zone in a low temperature burnout and NOx reduction reactor zone. The fuel modification fuel rich reactor stabilizes combustion through recirculation of hot gases to the reactants. Nitrogenous species decay reactions in the fuel rich zone controls the production of NOx. The nitrogenous species from the fuel rich zone and the NOx from the fuel lean zone then react in the burnout zone at an optimal temperature and nitrogenous species mix where NOx is minimized. Temperature in all zones, and in particular the burnout zone, can be controlled by furnace gas entrainment, induced flue gas recirculation, forced flue gas recirculation and active cooling by radiative and/or convective heat transfer. NOx can be even further reduced by introducing ammonia, or a like amine species, into the low temperature burnout zone.

Abstract: This invention discloses the synergistic integration of solid fuel combustion, low NOx control technologies (such as Low NOx Burners, reburning and Advanced Reburning) with partial in-duct gasification of coal or other solid fuels. For partial gasification, the solid fuel can be transported and injected by recycled flue gas stream at 600-800° F. in the reburning zone or in the upper section of the main combustion zone of a boiler. This allows the fuel to be preheated and partially pyrolyzed and gasified in the duct and then injected into the boiler as a mixture of coal, gaseous products, and char. Gasification increases coal reactivity and results in lower carbon-in-ash levels. As an option, the gaseous and solid products can be split using a cyclone separator. Splitting the gasified fuel stream will allow the volatile matter to be used for reburning and the fixed carbon to be injected into the high-temperature main combustion zone.

Abstract: The invention concerns a method for cremating human or animal bodies which consists in generating from a wall (10) of the combustion chamber (3), a turbulence in the form of a vertical displacement above the body (2) and in injecting the air required for combustion into this turbulence. Preferably, the turbulence is generated by rotating means (11) directed inside the chamber (3) and equipped with an inlet air duct (17), provided with a closing valve (18) and the air injection is adjusted by actuating the valve.

Abstract: A method for utilizing ultra-thin catalytic monoliths, internal molding and high concentrations of reactive catalytic species to exploit the unique high surface area of Aerogels in order to achieve catalytic selectivity of the desired gas phase heterogeneous reaction.

Abstract: The present invention provides improved methods of reducing NOx emissions in the flue gases produced by a steam boiler fired by a fluid fuel and combustion air burner and including a steam drum provided with make-up water from which produced steam and blowdown steam are withdrawn. In accordance with the invention at least a portion of the blowdown steam is combined with the fluid fuel or combustion air or both.

Abstract: Nitrogen oxides, NOx, resulting from the excess air combustion of solid fuels in a combustor or burner in a furnace are reduced. By introducing sufficient additional fuel to the combustion gases in the furnace downstream of the primary combustion zone, a fuel rich gas zone is created in a temperature range that favors the conversion of NOx to nitrogen, N2. Further downstream sufficient additional air is added to complete the combustion of any unburned fuel. Alternatively, the fuel rich gas zone can be confined to a central region of the furnace. In that case, final combustion takes place when the fuel rich gas mixes with the untreated gas further downstream in the furnace. The preferred embodiment of this invention is to introduce the additional fuel in said downstream combustion zone as solid particles dispersed in aqueous droplets of varying size that vaporize throughout the furnace gas zone being treated. The dispersed solid fuel particles burn as they evolve from the droplets.

Abstract: A method and apparatus for combustion of a solid carbonaceous material in which the solid carbonaceous material is preheated and at least a portion thereof pyrolyzed on a stoker grate disposed in the lower portion of a combustion chamber to produce pyrolysis products. Overfire oxidant is then introduced into the combustion chamber above the stoker grate to ensure complete combustion of combustibles in the products of combustion generated by combustion of the solid carbonaceous material and the pyrolysis products. Preheating and pyrolysis of the solid carbonaceous material is carried out by the introduction of a pyrolysis agent directly into the bed of solid carbonaceous material.

Abstract: A process for removing vapor phase contaminants from a gas stream includes the step of adding a raw carbonaceous starting material into a gas stream having an activation temperature sufficient to convert the raw carbonaceous starting material into an activated material in-situ. The activated material then adsorbs the vapor phase contaminants, and the activation material containing the vapor phase contaminants is removed from the gas stream using a particulate collection device. The process is particularly suited for the removal of vapor phase air toxics, such as mercury, from the flue gas of a combustion process. An apparatus for the removal of vapor phase contaminants from a gas stream is also described.

Abstract: Materials containing CH polymer chains are treated by a process comprising triggering combustion of the material in an environment insulated from the outside; removing gaseous combustion products from the environment under a vacuum; feeding combustion-supporting gas in a quantity insufficient to create centers of combustion while maintaining the environment under vacuum to favor a process of molecular decomposition of the material; condensing the gases, and collecting the condensate in a non-pressurized environment.

Abstract: A method and apparatus for controlling or removing mercury, mercury compounds and high molecular weight organics, if present, from a resource recovery exhaust stream by separately adding a carbonaceous char to the flue gas while it is still within the unit. The char can be produced in situ by adding a carbonaceous material and allowing it to thermally decompose.

Abstract: An apparatus for pyrolysis of a bituminous paving mix is provided, comprising an oven having a bottom wall, a top wall, and side walls defining a combustion chamber, a sample support within the combustion chamber, an infrared heater mounted within the oven and arranged for emitting infrared radiation towards the sample holder so as to heat a sample of paving mix by means of radiation heat transfer, an air inlet positioned for emitting air into the combustion chamber, and an outlet positioned to provide for the circulation of air and combustion gases through the combustion chamber. The apparatus may further include a blower located on the downstream side of the outlet for inducing flow into the combustion chamber by the inlet and out of the combustion chamber by the outlet. A variable speed blower controller may be used to vary the blower speed during paralysis of the paving mix.

Abstract: A method and apparatus for controlling or removing mercury, mercury compounds and high molecular weight organics, if present, from a waste incineration apparatus exhaust stream by separately adding a carbonaceous char to the flue gas while the flue gas is still within the unit. The char can be produced in situ by adding a carbonaceous material and allowing the carbonaceous material to thermally decompose.

Abstract: A method for decreasing the concentration of a chlorinated aromatic compound in the exhaust gas from a combustion furnace. The exhaust gas from the combustion furnace is passed through a bag filter. The concentration of the chlorinated aromatic compound in the exhaust gas is measured and the operating temperature of the bag filter is adjusted based on the measured concentration of the chlorinated aromatic compound in order to decrease the concentration of the chlorinated aromatic compound in the exhaust gas.

Abstract: A method for operating a boiler using oxygen-enriched oxidants includes introducing oxygen-enriched air, or oxygen and air, in which the oxygen concentration ranges from about 21% to about 100% by volume. Fuel and oxygen-enriched air are introduced into the combustion space within the steam-generating boiler. The fuel and oxygen-enriched air is combusted to generate thermal energy. At least a portion of the flue gases are collected and at least a portion are recirculated through the boiler. In the steam-generating boiler, the oxygen-enriched oxidant is introduced at one or more locations within the radiation zone and the convection zone of the boiler. Additionally, flue gas is collected and recirculated into one or more locations within the radiation zone and/or the convection zone of the boiler.

Abstract: In a combustion installation for burning a fuel, which installation includes a hearth operating as a circulating fluidized bed, and in which installation at least a fraction of the flow of solid particles resulting from the combustion of the fuel in the hearth is returned to the hearth via a heat exchanger operating as a fluidized bed, the method of decreasing nitrogen oxide emissions consisting in the heat exchanger being fed with a fluidization gas which is considerably poorer in oxygen than air.

Abstract: A process is provided for NOx, removal at coal burning power plants, which includes introducing ammonia that is liberated upon drying a mixture of organic waste, coal combustion by-products, and optionally lime, having a pH of at least 9.5, to a coal burner in the power plant. A process is also provided for fueling a coal burner of a power plant with coal and a dried mixture of organic waste and coal combustion by-products. The present invention is further directed to the dried mixture of organic waste and coal combustion by-products made by the processes of the present invention, which may optionally be used as a soil additive or as a supplemental fuel.

Abstract: The invention provides a boiler provided with low cost means which can reduce a concentration of CO, an unburned matter, an attached ash and the like near a side wall and maintain a combustion state well with a simple structure. In a boiler having a combustion chamber 13 formed by front and rear walls (burner walls) provided with a plural stages of burners 2, 3 and 4 on at least one of them and opposing to each other, and side walls 1a and 1b crossing to said burner walls 14a and 14b, a gas port 6 containing no fuel for making a pressure of a gas near said side walls 1a and 1b within said combustion chamber 13 higher than a pressure of a gas at a center portion of said combustion chamber 13 is provided between an outermost burner and the side walls 1a and 1b within a range of a height of said burner stages 2, 3 and 4. A combustion gas 16 can not come close to the side walls 1a and 1b due to the jet 18 of the gas.

Abstract: There are provided an evaporative/regenerative incineration system for organic waste water for incinerating organic waste water and volatile organic compounds completely at low expenses and a method therefor. Waste gas is generated by evaporating waste water including organic compounds in an evaporator and the generated waste gas is mixed with air in a regenerative thermal oxidizer (RTO) in flow communication with the evaporator for oxidation. The heat energy generated from the oxidation is collected and supplied to the evaporator.

Abstract: Methods and apparatus for reducing the content of nitrogen oxides in the flue gases produced by the combustion of fuel gas and combustion air introduced into a burner connected to a furnace are provided. The methods basically comprise the steps of conducting the combustion air to the burner, providing a chamber outside of the burner and furnace for mixing flue gases from the furnace with the fuel gas, discharging the fuel gas in the form of a fuel jet into the mixing chamber so that flue gases from the furnace are drawn into the chamber and mixed with and dilute the fuel gas therein and conducting the resulting mixture of flue gases and fuel gas to the burner wherein the mixture is combined with the combustion air and burned in the furnace.

Abstract: A method and installation for the cremation of bodies in coffins. The coffin is placed in a crematorium furnace in the wall of which at least one burner is disposed. Conbustion occurs in a chamber of the crematorium furnace without naturally-occurring air and with the burning of the coffin supplying energy along with part of the recirculated flue gas in which oxygen has been added. The flue gas fed back to the crematorium furnace is recirculated uncooled. The temperature at the crematorium furnace is maintained by the burning coffins and the oxygen-enriched recirculated flue gas.

Abstract: Methods and apparatus for reducing the content of nitrogen oxides in the flue gases produced by the combustion of fuel gas and combustion air introduced into a burner connected to a furnace are provided. The methods basically comprise the steps of conducting the combustion air to the burner, providing a chamber outside of the burner and furnace for mixing flue gases from the furnace with the fuel gas, discharging the fuel gas in the form of a fuel jet into the mixing chamber so that flue gases from the furnace are drawn into the chamber and mixed with and dilute the fuel gas therein and conducting the resulting mixture of flue gases and fuel gas to the burner wherein the mixture is combined with the combustion air and burned in the furnace.

Abstract: A method for purifyiing flue gas derived form incinerators burning refuse, wood, or sludge, in which the flue gas is cooled in a spray drier. A dust remover removes the dust from the flue gas. The flue gas is filtered through a filter-bed adsorber having filtering surfaces and packed with an adsorbent containing calcium hydroxide. The filter-bed adsorber is cleaned at intervals for removing adsorbate from the filtering surfaces. An aqueous suspension is prepared from at least some of the adsorbate that is removed from the filtering surfaces, and the flue gas is brought into contact with the suspension in at least one location upstream of the filter-bed adsorber for further separation of contaminates. The aqueous suspension is supplied to the spray drier for improving the purification of the flue gas.

Abstract: A process is disclosed for recovering raw materials, in particular heavy metals such as chromium, zinc, copper, lead, or nickel, by separation from waste and residues, wherein a liquid or viscous starting mixture and/or a starting mixture composed of crushed or ground components is first prepared. The invention is characterized in that the raw materials are separated by a thermochemical treatment. The liquid, viscous and/or solid starting mixture is first mixed with additives, depending on its composition, then subjected to a thermal treatment in an oven. The atmosphere in the oven flows through the starting mixture and the suspended materials thus generated as flakes or dust are conveyed out of the oven through a filter installation with several stages in which they are separated from the waste gas. The first filter is designed as a hot filter, after which the waste gas is cooled and after flowing through at least a second filter, pre-heated and then burnt at a high temperature.

Abstract: A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

Abstract: A method of combustion of animal wastes to avoid release of objectionable odors and to obtain useful products from the animal wastes involving the drying of animal waste in a primary heat exchange dryer, mixing the dried animal waste material with a combustible fuel and moving the mix of dried waste and combustible fuel to a burner assembly of a furnace for burning, the exhaust from the primary heat exchange dryer being collected so that gases in the exhaust are used as combustion air for the burner assembly and with exhaust from the burner assembly housing being separated into fly ash and acceptably clean exhaust.

Abstract: A method for reducing acid gas emissions from a carbonaceous fuel burning power plant. An aqueous potassium hydroxide dry scrubber method is used to reduce the formation of nitrogen oxides, sulfur oxides, hydrogen chlorides and hydrogen fluoride from plant flue gases. For those plants utilizing an electrostatic precipitator to remove particulate matter from the flue gas, the performance of this component is also enhanced by the injection of potassium hydroxide upstream of the component. As an added advantage, the final product has beneficial commercial utility as a fertilizer product, rather than having to be disposed in a landfill.

Abstract: A method is provided for controlling the operation of a furnace. A furnace generally includes a boiler having a combustion zone, a plurality of burners burning a mixture of fuel and air in the combustion zone producing a gaseous by-product, and an electrostatic precipitator in fluid communication with the boiler removing particulates from the gaseous by-products. The method includes the steps of monitoring operating conditions of the electrostatic precipitator on a section-by-section basis, and controlling a select one or more of the burners based upon the section-by-section monitored operating conditions.

Abstract: The present invention provides a novel method of controlling the incineration temperature of industrial waste incineration processes such that the incineration emissions products comply with governmental regulations and operating and capital costs are minimal. Modifying the incineration temperature in response to changes in the emission products and the waste streams results in optimal and reliable control of the incineration process and the resultant incineration emissions. Capital and operating costs are reduced significantly as a result.

Abstract: In an improved method for reducing nitrogen oxide emissions from a furnace wherein at least one injector is attached to the furnace above the primary combustion zone a biomass or biowaste and water slurry is injected into the flue gas through the injectors. The biowaste or a biomass material can be supplemented with a fixed nitrogen source.

Abstract: An installation for generating power, comprising a main combustion chamber for burning fossil fuels, having means for generating steam; at least one thermal pre-processing chamber for processing carbonaceous materials; and a guiding duct for guiding the flue gases of at least one thermal pre-processing chamber to the main combustion chamber. The airflow in the thermal pre-processing chamber is toroidal. The thermal pre-processing chamber comprises an annular series of blades, a device for generating an air flow through the series of blades, a burner located under the series of blades, a cone shaped element in the center of the series of blades. The guiding duct has particle removal means, which are arranged to remove particles down to a size wherein the particles do not disturb processes in the main combustion chamber.

Abstract: A boiler has a combustion chamber formed by front and rear walls and a side wall extending between the front and rear walls. Plural stages of burners are placed on at least one of the front and rear walls. In the front and rear walls are opposing gas jets for making a pressure of the gas near the side wall within the combustion chamber higher than the pressure of the gas at a center portion of the combustion chamber. The gas jet ports are disposed at a height within a range of the height of the burner stages. The burner stages supply the pulverized coal, the air for transferring the pulverized coal and the air for burning. A part of the air for transferring the pulverized coal or the air for burning is supplied in a branched manner to the gas jet port and injected into the combustion chamber. Further, the air is preferably injected from the gas jet ports in a direct gas flow, not a swirling flow.

Abstract: In a process for the thermal treatment of solid materials (3), in particular refuse, in which the solid materials (3) are burnt/gasified or pyrolized in a first step (5) with a lack of oxygen, and then, in an afterburning zone (14), the flue gases (6) from the first step (5) are mixed with an oxygen-containing gaseous medium (15) and are burnt with complete burn-off, the flue gases (6) emerging from the first step (5) are firstly actively homogenized in a mixing zone (7) with the addition of a gaseous oxygen-free or low-oxygen medium (8) before they are mixed with the oxygen-containing medium (15). Then, the homogenized flue-gas stream flows through a holding zone (13), in which it stays for at least 0.5 second, before, in an afterburning zone (14), the medium (15) which serves to ensure complete burn-off of the flue gas is added. The process according to the invention is distinguished by simple process steps and by a reduced level of pollutant emissions, in particular NOx, compared to the prior art.

Abstract: A method for reducing NOx emissions from the combustion of carbonaceous fuels using three stages of oxidation and second stage in-situ furnace flue gas recirculation. In the first stage, a partial oxidation combustor is used to partially combust the fuel in the presence of preheated combustion air. The fuel gas produced in the partial oxidation process is passed to a second stage partial oxidation combustor while molten slag is removed and disposed of. Preheated combustion air also is introduced into the second stage of combustion to produce a slightly reducing flue gas and is injected into the furnace in such a way as to create the desired in-situ furnace flue gas recirculation. In the upper part of the furnace a third combustion air is mixed with the flue gas in a third stage of combustion to substantially complete the combustion process. Preheated steam may be added to the first or second stages of combustion.

Abstract: The present invention provides an incinerator for removing toxic substances contained in a flue gas. That is, there is here disclosed an incinerator for removing toxic substances in which a removal section for removing the toxic substances generated from a burning section is connected to the burning section for burning incineration substances, and an air flow of from the burning section to the removal section is prepared by a suction type negative pressure means or by an air duct type negative pressure means, so that a negative pressure condition is always maintained in the burning section.

Abstract: In the method according to the invention for reducing volatile pollutants in the exhaust gases of a heat exchanger system for heating of cement raw meal or the like, partially preheated raw meal is heated to a temperature for release of the pollutants contained therein. In order to be able to achieve this with a reliable mode of operation and with relatively low investment costs, partially preheated raw meal is drawn off from an upper preheater stage and is mixed together in a mixing zone with a fraction of raw meal which is already highly heated and of such a size that the raw meal mixture which is obtained is set to a mixing temperature which releases the pollutants and as a result at least volatile sulphur oxides are incorporated into the raw meal mixture, whilst carbon monoxide formed in the course of this is led off by means of a carrier gas.

Abstract: A method for reducing NOx emissions from the combustion of carbonaceous fuels using two sequential stages of partial oxidation followed by a final oxidation stage. In the first stage, substoichiometric air condition of about 0.55 to 0.75 is used in a plug flow fashion, while second stage combustion is performed at a stoichiometric ratio of about 0.80 to 0.99. As the second stage combustion products are cooled by radiant heat transfer to the boiler furnace walls, overfire air is added to produce an stoichiometric ratio of about 1.05 to 1.25 to complete the combustion process. In this manner, the formation of thermal NOx is reduced.

Abstract: A method of disposing of undesirable chemical compounds in waste dust generated in a first kiln in the manufacture of cement clinker by using the dust and slag as the feedstock material to a second kiln, heating the feedstock material in an oxidizing atmosphere, and raising the heat sufficient to diffuse the waste dust and the slag to form a hydraulic product such as cement clinker and lime but insufficient to volatilize previously precipitated chemical compounds in the feedstock material.

Abstract: A method and apparatus for reducing NOx emissions in a furnace having a main combustion zone with a waterwall and apparatus for supplying main combustion air and fuel to the main combustion zone, also reduces unburned carbon and waterwall corrosion in the furnace. The method involves providing at least one lower overfire air injector at a first level over the main combustion zone of the furnace for supplying overfire air to create a lower overfire air zone in the furnace over the main combustion zone and at least one upper overfire air injector at a second level over the lower overfire zone for supplying overfire air to create an upper overfire air zone in the furnace over the lower overfire zone. The overfire air in the lower and upper overfire air zones are supplied at a rate for reducing the stoichiometry in the main combustion zone which reduces unburned carbon and a corrosive reducing atmosphere in the furnace.

Abstract: In this process the material is passed through a precalcination device equipped with at least one fuel injector at the outlet of which a fuel injection zone is formed, then the at least partially calcined material is passed into the rotary kiln which at its downstream end, is equipped with a primary combustion unit. At least one oxygen rich fluid with an oxygen concentration by volume higher than that of the products of combustion from the rotary kiln is injected near to the injection zone so that the oxygen rich fluid can supply from 1% to 40%, and preferably form 1 to 10% of the stoichiometric amount of oxygen needed for the combustion of the fuel injected by the injector.

Abstract: A method for operating a boiler using oxygen-enriched oxidants includes introducing oxygen-enriched air, or oxygen and air, in which the oxygen concentration ranges from about 21% to about 100% by volume. Fuel and oxygen-enriched air are introduced into the combustion space within the steam-generating boiler. The fuel and oxygen-enriched air is combusted to generate thermal energy. At least a portion of the flue gases are collected and at least a portion are recirculated through the boiler. In the steam-generating boiler, the oxygen-enriched oxidant is introduced at one or more locations within the radiation zone and the convection zone of the boiler. Additionally, flue gas is collected and recirculated into one or more locations within the radiation zone and/or the convection zone of the boiler.

Abstract: A procedure wherein a catalyst pertaining to the family of zeolites is injected into the vessel (1) of the circulating fluidized bed, in powder form. The installation includes a vessel (1) in which the top is connected to a separator (3) in which the bottom is connected to the vessel (1) by a recirculation loop (4), a silo (5), in which the catalyst based on crushed zeolites is stored, and which is connected by a conveyer (6) to the recirculation loop (4).

Abstract: An iron compound catalyst for inhibiting the generation of dioxin of the present invention, comprise iron oxide particles, iron oxide hydroxide particles or mixed particles thereof having a catalytic activity capable of converting not less than 15% of carbon monoxide into carbon dioxide when 2.8×10−4 mol of iron oxide particles obtained by heat-treating said iron compound catalyst in air at a temperature of 800° C. for 15 minutes, are instantaneously contacted with 6.1×10−7 mol of carbon monoxide at a temperature of 250° C. at a space velocity (SV) of 42,400 h−1 in an inert gas atmosphere using a pulse catalytic reactor, said iron oxide particles or said iron oxide hydroxide particles having an average particle size of 0.01 to 2.0 &mgr;m, a BET specific surface area of 0.2 to 200 m2/g, a phosphorus content of not more than 0.02% by weight, a sulfur content of not more than 0.6% by weight and a sodium content of not more than 0.5% by weight.