Abstract: A process for removing soot from the exhaust gas of a diesel engine by oxidizing the nitrogen monoxide present in the exhaust gas to nitrogen dioxide, separating the soot from the exhaust gas stream and oxidizing the soot using the nitrogen dioxide produced. The process is performed in at least two consecutive process stages and the soot is separated from the exhaust gas stream with an efficiency W between 0.05 and 0.95 in each process stage, wherein each process stage can be assigned a transmission for soot in accordance with T=1−W and the total transmission of the process for soot is given as the product of the transmissions of all the process stages.

Abstract: Five combustion exhaust gas treatment systems capable of removing dust and selenium (Se) in combustion exhaust gas and making harmless are proposed: (1) combustion exhaust gas is cooled to 350° C. or less, dust is separated, Se is transformed into insoluble compound, and Se is separated; (2) combustion exhaust gas is cooled to 350° C. or less, dust is separated, Se elution preventive agent is added, and dust is formed into scale; (3) dust in combustion exhaust gas is collected by dust collector, dust is formed into slurry by making use of part of circulation liquid in desulfurization apparatus, and tetravalent Se in dust slurry is transformed into insoluble compound, which is separated into solid and liquid; (4) dust is separated from combustion exhaust gas by dust collector, and it is heated to gasify Se, and is led into desulfurization apparatus, etc.

Abstract: The invention provides a process for removing soot particles from exhaust gas from produced by a diesel engine. The process uses a particle filter that collects soot particles with the aid of nitrogen dioxide which is generated by catalytic oxidation of nitrogen monoxide contained in the exhaust gas. The process is characterized in that the particle filter is a deep-bed particle filter, having a filtration efficiency for the soot particles. The particle filter is coated with a catalytic coating for oxidizing nitrogen monoxide to nitrogen dioxide and the exhaust gas leaving the particle filter subsequently filtered through a particle filter serving as a soot barrier. The filter can have a filtration efficiency of over 95%.

Abstract: Thionyl chloride is a hazardous and reactive chemical used as the liquid cathode in commercial primary batteries. Contrary to previous thinking, ASZM-TEDA® carbon (Calgon Corporation) reversibly absorbs thionyl chloride. Thus, several candidate materials were examined as irreversible getters for thionyl chloride. The capacity, rate and effect of temperature were also explored. A wide variety of likely materials were investigated through screening experiments focusing on the degree of heat generated by the reaction as well as the material absorption capacity and irreversibility, in order to help narrow the group of possible getter choices. More thorough, quantitative measurements were performed on promising materials. The best performing getter was a mixture of ZnO and ASZM-TEDA® carbon. In this example, the ZnO reacts with thionyl chloride to form ZnCl2 and SO2. The SO2 is then irreversibly gettered by ASZM-TEDA® carbon.

Abstract: A particulate filter (22) is arranged in an exhaust passage of an engine. When an amount of discharged particulate discharged from a combustion chamber (5) per unit time exceeds an amount of particulate removable by oxidation which can be removed by oxidation on the particulate filter (22) per unit time without emitting a luminous flame, at least one of the amount of discharged particulate and the amount of particulate removable by oxidation is controlled so that the amount of discharged particulate becomes smaller than the amount of particulate removable by oxidation, whereby the particulate in the exhaust gas can be continuously removed by oxidation on the particulate filter (22) without emitting a luminous flame.

Abstract: A method for filtering and cleaning high temperature combustible gases, such as synthetic gas produced by a gasifier. The method involves introducing reactive lime to the hot combustible gas that has been previously cooled to less than approximately thirteen hundred (1,300) degrees Fahrenheit, and then filtering the gas through ceramic fiber filters to remove any particulate matter and the calcium salts resulting from the reaction of the lime with the chemical pollutants present within the gas. Optionally, reactive lime may also be introduced into the biomass feed as it travels to the gasifier.

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: This patent describes technology for generating ammonia from urea. The method is based on the hydrolysis of an aqueous solution of urea and/or biuret by heating under pressure to form a mixture of ammonia, carbon dioxide and water. The gas mixtures produced are useful for supplying ammonia at controlled pressure and rate of flow for many industrial applications without the risks and hazards associated with the transportation and on-site storage of ammonia, thereby providing a significant safety advantage over present industrial practice.

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 column for purifying gases by a dry method contains a horizontal plate fitted at a position above a bed of a purifying agent and below a gas inlet, and an upstanding pipe passing through the center of the horizontal plate for guiding harmful gases from the gas inlet to below the horizontal plate, and inner wall surface of the column, upper surface of the horizontal plate and outer wall surface of the pipe form a space defining a collector for the powdered material. Thus there is provided a purifying means which facilitates the purification of harmful gases discharged from e.g. a semiconductor manufacturing process and containing powdered material without accompanying blocking of a purification apparatus, and, thereby, make the operation for the purification and maintenance of the facilities easy, while allowing a purifying agent to exhibit its purifying ability thoroughly.

Abstract: Constantly high efficiency of a catalytic converter can only be ensured when the configuration is maintained relatively free of particulate matter. A screen is disposed on the inflow side of the catalytic converter, which continuously or discontinuously transports away the flue dust particles collected by the screen. The flue dust collected is transported by the lateral movement of the screen to one side of the catalytic converter where the collected dust is removed. Alternatively or additionally, a vacuum system may be employed to clean the screen.

Abstract: In the reduction of at least one of the quantity of hydrocarbons, and the quantity or size of particulates in the exhaust of a diesel engine, wherein said exhaust is contacted with a catalyst, the improvement wherein the catalyst comprises a combination of a zeolite having acidic properties and at least one noble metal. There may also be present at least one element from the second main group of the periodic system of elements and the rare-earth elements.

Abstract: A method and apparatus for producing clean, sweet, fuel gas for use in a combustion process and for producing other useful products by processing a waste stream from digestion of lignocellulosic material. Essentially, the waste stream is partially oxidized to form hot gases and molten salts. The hot gases and molten salts are then cooled using a quench liquor to form quenched gas and carbonate liquor. Particles are removed from the quenched gas to form a raw fuel gas, preferably by subjecting the quenched gas to a multi-step fume reduction process which includes heat extraction from the quenched gas to reduce particulate load and water content of the quenched gas to form a low fume fuel gas. H2S is removed from the low fume fuel gas using an H2S removal process which is more selective for H2S than it is for CO2, the removing step forming clean, sweet, fuel gas and acid gases.

Abstract: Five combustion exhaust gas treatment systems capable of removing dust and selenium (Se) in combustion exhaust gas and making harmless are proposed: (1) combustion exhaust gas is cooled to 350° C. or less, dust is separated, Se is transformed into insoluble compound, and Se is separated; (2) combustion exhaust gas is cooled to 350° C. or less, dust is separated, Se elution preventive agent is added, and dust is formed into scale; (3) dust in combustion exhaust gas is collected by dust collector, dust is formed into slurry by making use of part of circulation liquid in desulfurization apparatus, and tetravalent Se in dust slurry is transformed into insoluble compound, which is separated into solid and liquid; (4) dust is separated from combustion exhaust gas by dust collector, and it is heated to gasify Se, and is led into desulfurization apparatus, etc.

Abstract: A method for destroying carbon carryover created in high temperature plasma waste treatment systems whereby the carbon carryover is mixed with a wetting agent and returned to the high temperature plasma waste treatment system for further processing. The method may further utilize the carbon carryover to first capture the hydrocarbons produced in a high temperature plasma waste treatment system, and then feed the thus captured hydrocarbons back into the high temperature processing system to be converted into useful products together with the carbon carryover.

Abstract: A process and an apparatus involving a reaction zone loaded with particles for the prolonged continued time of operation time on a dust containing feed stream by arrangement of the particles in a plurality of beds, and in a number of operation time bypassing with main part of the feed stream a number of the particle beds.

Abstract: A system for cleaning the air, such as air in the interior of motor vehicles, airplanes, buildings or shelters, having organic substances such as alcohols, alkanes and aliphatic and aromatic hydrocarbons. The air cleaning system includes a cylindrical adsorber. The cylindrical adsorber has a plurality of circular segments for passing air to be cleaned and for passing desorption air through the adsorber. The adsorber contains adsorption agents, such as a hydrophobic zeolite, that can be regenerated with microwaves. The air cleaning system also includes a microwave unit disposed on adsorber and an oxidation catalyst.

Abstract: A method of binding pollutants, such as sulfur dioxide, hydrochloric acid and/or hydrofluoric acid, in flue gas in one or more combustion plants.

Abstract: A method for removing combustible, metallurgical dust out of the exhaust gas from installations for drawing single silicon crystals is provided. The dust contaminated exhaust gas and a reactive gas, such as air, oxygen or ozone, are fed into a reactor operated at a temperature of 50 to 500° C. where the reactive gas combusts the dust to form solid products. The reactor may be equipped with a catalyst, such as nickel, palladium or platinum, to promote the reaction. The solid products-containing exhaust gas is passed through a filter. By combusting the dust in the reactor, spontaneous explosions can be minimized.

Abstract: An activated carbon catalyst having sulfur dispersed homogeneously thereon, the sulfur being chemically bonded to the activated carbon. A method of making the catalyst involves forming an intimate mixture of a synthetic carbon precursor and a sulfur-containing material, curing the carbon precursor, carbonizing the carbon precursor, activating the carbonized carbon precursor to produce an activated carbon catalyst having sulfur chemically bonded to said activated carbon and uniformly dispersed thereon.

Abstract: The present invention provides a process for disposing of exhaust gases which process enables to effectively inhibit the discharge of the dioxins by low-cost modification of already existing incineration facilities which are formed from an incinerator and an electric dust collector or cyclone. Incinerator exhaust gases are dedusted with an electric dust collector or cyclone, and then treated with a ceramic filter to sufficiently remove dust from the exhaust gases and bought into contact with a catalyst to decompose and thereby remove the dioxins which are contained in the exhaust gases.

Abstract: The particulates, etc. deposited on the trap are burnt in such a manner that the trap is heated so that the temperature of the trap does not exceed 500° C. or the maximum temperature gradient in radial direction of the trap is 20° C./mm or less, preferably 10° C./mm or less.

Abstract: A process and apparatus for the decontamination of gaseous contaminants (especially oxygen, carbon dioxide and water vapor) from hydride gases (including their lower alkyl analogs) down to ≦100 ppb contaminant concentration are described. The critical component is a high surface area metal oxide substrate with reduced metal active sites, which in various physical forms is capable of decontaminating such gases to ≦100 ppb, ≦50 ppb or ≦10 ppb level without being detrimentally affected by the hydride gases. The surface area of the substrate will be ≧100 m2/g, and preferably 200-800 m2/g. Oxides of various metals, especially manganese or molybdenum, can be used, and mixtures of integrated oxides, or one type of oxide coated on another, may be used. The substrate is preferably retained in a hydride-gas-resistant container which is installed in a gas supply line, such as to a gas- or vapor-deposition manufacturing unit.

Abstract: An exhaust gas cleaning system for diesel motors made out of two diesel exhaust catalytic converters, arranged in sequence one behind the other, in the form of honeycomb bodies with parallel flow channels, whose wall surfaces are provided with a catalytically active coating. The first upstream catalytic converter possesses a cell density of less than 40 to 80 flow channels per cross-sectional square centimeter, while the cell density of the second catalytic converter situated downstream is larger than that of the first catalytic converter. Through this arrangement, it is possible to select a high cell density that, without connection in line with the low cell density catalytic converter would very quickly lead to a clogging by diesel particles.

Abstract: A dust collecting apparatus and method for dedusting a Ca-containing gas using a ceramics filter is provided, in which a filter differential pressure elevation rate is suppressed. A desulferizing agent 103 and a mineral 106 containing MgO are supplied via a hopper 13, 15 a valve 14 and a feeder 16 into a pressurized fluidized-bed combustion furnace 1 together with coal 101 and air 102. A combustion gas 201 is dedusted by a cyclone 2 to become a combustion gas 301, the combustion gas 301 enters a filter container 3a, 3b having a ceramics filter 31a, 31b and is further dedusted. A combustion gas 401 which is dedusted is supplied into a gas turbine 4 to generate power, and combustion gas 501 heats a waste heat recovery boiler 5 which in turn drives a steam turbine 7. The mineral 106 containing MgO is added in the combustion gas 301 which flows in the ceramics filter 31a, 31b. Thereby MgO is added to the combustion gas so that the filter differential pressure elevation rate can be suppressed.

Abstract: The process serves for removing carbon monoxide and/or hydrogen from an air stream by catalytic oxidation. Dusts and/or aerosols of a particle size of less than 20 &mgr;m are removed from the air stream upstream of the catalytic oxidation.