Abstract: A DPF with an SCR catalyst and a method for selectively reducing nitrogen oxides with ammonia, filtering particulates, and reducing the ignition temperature of soot on a DPF are provided. The catalyst includes a first component of copper, chromium, cobalt, nickel, manganese, iron, niobium, or mixtures thereof, a second component of cerium, a lanthanide, a mixture of lanthanides, or mixtures thereof, and a component characterized by increased surface acidity. The catalyst may also include strontium as an additional second component. The catalyst selectively reduces nitrogen oxides to nitrogen with ammonia and oxidizes soot at low temperatures. The catalyst has high hydrothermal stability.

Abstract: A hydrogen generation system is disclosed that includes a fuel reforming reactor generating a hydrogen-rich reformate gas at a temperature greater than 150 C, a pressure swing adsorption (PSA) hydrogen purification unit that separates the reformate gas into a relatively pure hydrogen stream and an off-gas stream, and a catalytic reactor down stream of the PSA unit that converts carbon monoxide (CO) and hydrogen (H2) contained in the relatively pure hydrogen stream into methane (CH4) and water vapor (H2O). The method of purification involves generating a hydrogen-rich reformate gas at a temperature greater than 150 C in a fuel reforming reactor, separating the reformate gas into a relatively pure hydrogen stream and an off-gas stream in a pressure swing adsorption (PSA) hydrogen purification unit, and converting carbon monoxide (CO) and hydrogen (H2) contained in the relatively pure hydrogen stream into methane (CH4) and water vapor (H2O) in a catalytic reactor down stream of the PSA unit.

Abstract: An exhaust gas purifying apparatus for an internal combustion engine is provided with a NOx removing device and a particulate filter in an exhaust system. A temperature of the exhaust system is detected. A switching control is performed for alternately performing a process for removing sulfur oxide accumulated in said NOx removing device and a regeneration process for burning particulates trapped in said particulate filter, when it is determined to be necessary to perform at least one of the removal of the sulfur oxide in said NOx removing device and the regeneration of the particulate filter. The switching control is performed according to the detected exhaust system temperature.

Abstract: A method for treating fly ash of flue gas exiting a furnace of a fluidized bed boiler. A side flow conveying a first fraction of fly ash is separated from a flow conveying a second fraction of fly ash. After the separation, the side flow conveying the first fraction has a higher solids content than the flow conveying the second fraction. The first fraction of fly ash is separated from the side flow at a separation temperature of at least 400° C., whereafter the first fraction of fly ash is discharged from the process.

Abstract: A small scale, but effective, reactive chemical containment system includes apparatus and methods for reaction of process gases exhausted from reaction furnaces with a reactant gas in a non-combustible manner to produce and contain particulate or powder byproducts, thereby removing the process gas from the exhaust gas flow. The apparatus provides process gas inlet, treatment reactive gas diffusion, process gas and treatment reactive gas pre-mixing, primary containment, secondary containment, and outlet zones.

Abstract: A gaseous component treatment sheet of the present invention has a gas-permeable base film and a particulate remover for removing a predetermined gaseous component, and the particulate remover is dispersed in the base film. A protective layer and/or an adhesive layer can be laminated further on the base film. Since the gaseous component treatment sheet is a sheet-like member including the base film for holding the particulate remover, the size and the shape can be adjusted easily.

Abstract: The invention provides methods and apparatuses for removing aerosols and, in some cases, vapor phase contaminants, such as mercury, from a gas stream. One method is directed to the removal of additional aerosols from a gas stream from which aerosols have previously been removed by using a screen in combination with a primary aerosol collection device. Another method is directed to the removal of both aerosols and vapor phase contaminants by using a sorbent in combination with a screen. Another method is directed to the removal of vapor phase contaminants by using a catalyst to convert the contaminant to a form that is more easily removed from the gas stream and optionally injecting a chemical to increase the rate of conversion. The invention also provides various apparatuses for use in performing the various methods of the invention.

Abstract: A system for removing mercury from combustion gas. The system includes a combustion device, a stack, and a duct system that couples the combustion device to the stack. The system further comprises an injection system that is coupled to the duct system. The injection system injects sorbents including alkali-based sorbents and carbon-based sorbents into the duct system.

Abstract: A purification method excellent in removing particulates or the like from exhaust gas from an internal combustion engine, in particular, a diesel engine or the like. The purification method uses an exhaust gas purification apparatus including an oxidation zone installed with an oxidation catalyst supporting both platinum and palladium, and a filtering zone installed with a particulate filter, along exhaust gas flow at the exhaust gas passage of an internal combustion engine. Hydrocarbon-based liquid is supplied to the inflow side of the exhaust gas of the oxidation zone at the time when 2 to 10 g of particulates per 1 liter of the particulate filter are caught, to raise temperature of the exhaust gas up to equal to or higher than 550° C. by the oxidation catalyst so as to make the residue of the particulate filter combusted.

Abstract: A process for the removal of heavy metals from flue gas deriving from combustion processes comprising the following steps: a) optional removal by filtration of solid particles or of particulate of heavy metals or their compounds, having an average diameter higher than 10 micron; b) flue gas washing performed with an aqueous phase and transfer of the heavy metals or their compounds to the aqueous phase; c) flue gas cooling and partial condensation of the steam contained in the flue gas and separation of a condensed phase; d) discharge of the flue gases substantially free from heavy metals or their compounds into the environment; f) discharge of the aqueous phase substantially free from heavy metals or their compounds into the environment.

Abstract: A system for contaminant removal from a fluid stream comprises a plurality of flow through reactors arranged in stages that are spaced apart from one another, each reactor comprising at least one flow-through monolith configured to react with at least one contaminant in a fluid stream, and a flow control system configured to selectively control through which of the plurality of flow-through reactor stages a fluid stream containing at least one contaminant may pass.

Abstract: A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

Abstract: The invention relates to a device for the, (in particular continuous), oxidation of particulates from the exhaust gases of diesel motors. Said device consists of an open-pored body as a particle filter, on whose surface an oxidation catalyst is finely dispersed. The device is characterized in that from an exhaust gas temperature as low as 150° C., the catalyst causes the oxidation of particulates attached to the filter using the residual oxygen of the exhaust gas, thus keeping the filter body continuously free of particulates during almost all the operating conditions of the motor.

Abstract: A honeycomb structured body includes a plurality of honeycomb members which are bonded to one another by interposing an adhesive layer. Each of the honeycomb members has a number of cells placed in parallel with one another in the longitudinal direction with a cell wall therebetween. When the longitudinal direction is defined as the orientation axis, the degree of orientation ? of the inorganic fibers in the adhesive layer obtained by the Saltykov method is set in the range of about 0.2???about 0.7 or in the range of about ?0.7???about ?0.2 in the adhesive layer.

Abstract: A process for treating flue gas containing fly ash and carbon dioxide is disclosed. In the process, carbon dioxide and fly ash are contacted with an aqueous metal hydroxide solution to convert carbon dioxide into a metal carbonate, and wherein the metal carbonate and the metal hydroxide cause the fly ash to undergo a geopolymerization reaction and form a geopolymerized fly ash. The geopolymerized fly ash is recovered for disposal or for further use, such as a concrete additive.

Abstract: An exhaust treatment system and method for removing particulates and/or gases from exhaust gases and for cooling exhaust gases. The exhaust treatment system may include a venturi nozzle for injecting a mixture of water and air into the exhaust gases to cause particulate matter and/or certain gases present in the exhaust gases to adhere to water droplets in the mixture. The exhaust treatment system may further include a receptacle positioned in proximity to the exhaust outlet and adapted for collecting water and particulate matter exiting the exhaust outlet, a filter adapted to receive water from the receptacle and remove particulate matter from the water, and/or a heat transfer device adapted to receive water from the filter and remove heat from the water.

Abstract: A method for enlarging the particle diameters of sulfuric acid mists in waste gas and collecting the sulfuric acid mists in high efficiency is provided. A process for disposing waste gas containing sulfur oxides that introduces the waste gas in dry type electrostatic precipitator to remove dusts and then introduces the waste gas in a wet desulfurization apparatus to carry out desulfurization, wherein the waste gas temperature of a smoke channel at a more upstream side than the wet desulfurization apparatus is measured, the flow channel length is variable based on the measurement value of the waste gas temperature, the waste gas is flown to a flow channel means that is adjusted at a channel length capable of cooling the waste gas to the dew point of acid by heat release and then, the waste gas is introduced into the wet desulfurization apparatus.

Abstract: One aspect of the invention relates to a method for removing contaminants from a flue gas stream (22). The method includes: removing fly ash from a flue gas stream (22) utilizing a particle collector (24); contacting the flue gas stream with an alkaline reagent in a wet scrubber (26); discharging a purge liquid (30) from the wet scrubber (26); and, combining at least a portion of the purge liquid with at least a portion of fly ash circulating within a dry circulating fluid bed scrubber (48) to form moistened fly ash (60).

Abstract: The invention relates to a method of reforming a gas containing tarry impurities, such as the gasification gas obtained by gasifying a fuel. In the method, oxygen or an oxygenous gas (10) is added to a gas flow (8), after which the gas is brought into contact with a solid catalyst (11, 12) at a high temperature. According to the invention, the reformation takes place in stages so that, in the first pre-reforming stage, the gas is brought into contact with a zirconium-based catalyst (11), such as zirconium oxide, for example, and, in the next stage, with a metal catalyst (12), such as metallic nickel. The two-stage reformation is used for preventing the deactivation of the metal catalyst and the formation of carbon deposits in the reforming reactor. The invention also includes the use of the zirconium compound in pre-reforming the tar-bearing gas to achieve the said goals.

Abstract: A catalyst is provided having higher mercury oxidation performance than a conventional catalyst without increasing catalyst quantity or enhancing SO2 oxidation performance and constitutes an oxidation catalyst for metal mercury, which contains a molybdenum and vanadium complex oxide, for example, MoV2O8, as a main component having a catalytic activity and is formed by placing the molybdenum and vanadium complex oxide in layers only on the surface of a plate-like or honeycomb-like porous carrier. The porous carrier contains Ti and W and has a function of an NOx removal catalyst as a whole.

Abstract: The present invention provides for process for inhibiting the levels of nitrogen oxides in process gas streams from sulfuric acid regeneration and production plants. The process gas stream from the waste heat boiler and the candle mist eliminator is contacted with ozone which will react with nitrogen oxides present in the flue gas.

Abstract: A method to efficiently reduce lead content of cement without exerting influence upon quality of the cement. The method comprises the steps of: controlling O2 concentration of combustion gas in an inlet end of a cement kiln to 5% or lower and/or CO concentration thereof 1000 ppm or more; extracting a part of combustion gas from the cement kiln and collecting dust contained in the combustion gas; and collecting lead from the dust collected. With this, the area where raw material temperature in the cement kiln is between 800° and 1100° can be turned into reducing atmosphere to sharply increase volatilization rate of lead, and collection of lead from the dust allows lead content of cement to efficiently be reduced without exerting influence upon quality of the cement.

Abstract: A promoted carbon and/or non-carbon base sorbent are described that are highly effective for the removal of mercury from flue gas streams. The promoted sorbent comprises a carbon and/or non-carbon base sorbent that has reacted with and contains forms of halogen and halides. Optional components may be added to increase and/or preserve reactivity and mercury capacity. These may be added directly with the base sorbent, or in-flight within a gas stream (air, flue gas, etc.), to enhance base sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The promoted sorbent can be regenerated and reused. Base sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active base sorbent into the mercury contaminated gas stream are described.

Abstract: A process and system for removing sulfur oxide, other gases, and particulate from a flue gas. The process includes treating flue gas with a slurry formed from water, an alkaline reagent, and the purge stream from a wet scrubber in a spray dryer, thereby producing a dry by-product. The process further includes filtering the flue gas to remove at least a portion of the dry by-product, wet scrubbing the flue gas exiting the filter in a wet scrubber, adding a lime or limestone reagent to the wet scrubber, and producing gypsum. Activated carbon may be injected into the flue gas upstream of the filtering step and particulate may be removed from the flue gas upstream of the spray dryer.

Abstract: A method for enlarging the particle diameters of sulfuric acid mists in waste gas and collecting the sulfuric acid mists in high efficiency is provided. A process for disposing waste gas containing sulfur oxides that introduces the waste gas in dry type electrostatic precipitator to remove dusts and then introduces the waste gas in a wet desulfurization apparatus to carry out desulfurization, wherein outside air with a flow rate at which the waste gas introduced in the wet desulfurization apparatus is the dew point of acid is taken in from an introducing tube to mix the outside air in the waste gas.

Abstract: Ammonia and optionally carbon monoxide are injected into the flue gas containing metals such as mercury in a manner so that there are sufficient amounts of these materials in the flue gas when the flue gas is at a temperature of from 900° F. to 1,450° F. to oxidize the metals within the flue gas. The oxidized metals are then attracted to particulates present in the flue gas. Oxidation is facilitated by a reaction zone stabilizer through which the flue gas flows. The stabilizer provides a stable continuous ignition front. These particulates bound with oxidized metals are removed from the flue gas by a particulate removal device such as an electrostatic precipitator or baghouse. After the ammonia is injected, the flue gas can be rapidly cooled to a temperature below 500° F. to minimize decomposition of oxidized metals in the flue gas.

Abstract: A process and device for purifying flue gases in refuse incineration plants during regeneration of a catalyst which serves for reducing nitrogen oxides, by, in a first step, removing acidic pollutant gases from the flue gas in a wet or dry manner, in a second step adding ammonia for reducing nitrogen oxides to the flue gas purified in the first step, in a third step feeding the flue gas admixed with the ammonia to a catalyst, where the catalyst is heated at a controlled heat-up rate for regeneration, which leads to liberation of ammonia, where the amount of ammonia added in the second step and the heat-up rate in the third step are controlled by the amount of a pollutant gas selected from the group of ammonia, and which the purified flue gas contains.

Abstract: An arrangement for removal of particulates in a gas flow includes at least one gas passage that is at least partly surrounded by a porous material. An arrangement for exposing the gas passage to sound that induces gas movements in a direction towards the porous material is provided. A method for removal of particulates in a gas flow is also provided.

Abstract: The removal of particulates and acidic gases from the effluent from a fluid catalytic cracking process regenerator. The effluent is treated in two contacting stages with an effective amount of both a caustic solution as well as ammonia and the composition of the contacting solutions in the two stages is independently controlled.

Abstract: The invention provides a process and system for purification of an exhaust gas stream from a combustion engine containing hydrocarbons, soot, carbon monoxide and sulphur dioxide. The process comprises the steps of oxidising the hydrocarbons and part of the soot in a first reactor in the presence of a first catalyst active in oxidising hydrocarbons and soot without oxidising sulphur dioxide and forming a partly purified exhaust gas stream, of cooling of the partly purified exhaust gas stream, of converting the carbon monoxide of the partly purified exhaust gas stream in a second reactor in presence of a second catalyst active in oxidising carbon monoxide without oxidising sulphur dioxide and of withdrawing a purified exhaust gas stream.

Abstract: A method for reducing the particle and nitrogen oxide proportion in an exhaust gas flow of an internal combustion engine includes supplying a reducing agent to the exhaust gas flow, subjecting the exhaust gas flow containing the reducing agent to particle filtering, and then carrying out a selective catalytic reduction of at least a portion of the nitrogen oxides in the exhaust gas flow. The method and an exhaust gas treatment unit make it possible to simultaneously reduce the proportion of particles and nitrogen oxides in the exhaust gas. Ammonia, in particular, is used as the reducing agent. Regeneration of the particle filter is promoted by leading an ammonia-containing flow of gas through the particle filter. The method and device make it possible to consume less fuel with the same reaction rate and, at the same time to reduce available installation space, in comparison with existing corresponding prior art systems.

Abstract: One aspect of the invention relates to a method for removing contaminants from a flue gas stream (22). The method includes: removing fly ash from a flue gas stream (22) utilizing a particle collector (24); contacting the flue gas stream with an alkaline reagent in a wet scrubber (26); discharging a purge liquid (30) from the wet scrubber (26); and, combining at least a portion of the purge liquid with at least a portion of fly ash circulating within a dry circulating fluid bed scrubber (48) to form moistened fly ash (60).

Abstract: A novel multiple stage separator (MSS) vessel is disclosed wherein the vessel includes at least first and second stages or decks of separation cyclones, the stages arranged for operation in series. Each stage or deck includes an upper and lower tube sheet on which a plurality of cyclones are installed, solid particles in the gas stream being separated from the stream and dispensed between the tube sheets as the stream passes through each stage. The vessel has an inlet to receive a gas stream containing the particulates, and the flow travels typically downwardly, first passing through the first stage, then passing through at least a second stage. When implemented downstream of a fluid catalytic cracking (FCC) unit, the MSS has been found to remove a surprisingly increased amount of particulates over a conventional third stage separator (TSS), which contains a single stage separator.

Abstract: A system is set forth for the exothermic generation of soot depleted syngas comprising (i) reacting a hydrocarbon-containing fuel with an oxygen containing gas in a first reactor to produce the syngas and byproducts comprising CO2, H2O and soot; and (ii) introducing the syngas and byproducts into a second reactor containing a non-carbonaceous material that traps the soot for a sufficient time such that the majority of the byproduct soot is gasified via reaction with the byproduct CO2 and/or H2O to produce a syngas stream that is depleted in the soot. The system is particularly suitable for the practice of heat exchange reforming wherein a portion of the heat is recovered from the soot depleted syngas stream and used as at least a portion of the heat to facilitate the additional production of syngas via the (endothermic) catalytic reforming of natural gas and steam.

Abstract: Problems associated with deposition of contaminants from air streams in transport ducts in the wood products industry and other sources of such contaminants are at least minimized by close coupling a cyclone separator/scrubber to the source of the air stream.

Abstract: One aspect of the invention relates to a method for removing contaminants from a flue gas stream (22). The method includes: removing fly ash from a flue gas stream (22) utilizing a particle collector (24); contacting the flue gas stream with an alkaline reagent in a wet scrubber (26); discharging a purge liquid (30) from the wet scrubber (26); combining at least a portion of the purge liquid (30) with at least a portion of the fly ash (48) to form moistened fly ash (60); and injecting at least a portion of the moistened fly ash (60) into the flue gas stream (22) upstream of the particle collector (24), whereby the moistened fly ash (60) removes at least a portion of contaminants present in the flue gas stream (22).

Abstract: This invention is a novel process for removing volatile mercury from a gas stream to produce a filtered solid. The gas stream is contacted with treating agents which comprise a semivolatile acidic vitrifying compound such as boric acid, water, oxygen-containing gas and a chlorine source. The filtered solids produced in the process have low mercury leachability thereby allowing the solids to be used, for example in flyash-containing concrete.

Abstract: The present invention is directed to an improved apparatus and method of minimizing catalyst poisoning from exhaust gas streams containing inorganic deposits and particulate matter. More specifically, the present invention is directed to an upstream metallic foam trap and a downstream monolithic precious metal catalyst, wherein the trap physically blocks inorganic deposits and particulate matter from poisoning the downstream catalyst. The present invention is also directed to a metallic foam trap containing a coat comprising a first metallic thermal arc sprayed layer and optionally a second refractory metal oxide.

Abstract: A method of reducing at least one atmospheric oxidising pollutant, such as ozone, with a reducing agent comprises contacting the reducing agent with the at least one atmospheric oxidising pollutant, wherein the reducing agent comprises a precious metal-free trap material, such as a zeolite, including at least one trapped atmospheric reducing pollutant, e.g. a hydrocarbon, whereby as the at least one atmospheric oxidising pollutant is reduced the at least one trapped atmospheric reducing pollutant is oxidised.

Abstract: A spray dryer absorber (SDA) system used to reduce the concentration of at least one acid compound in a gas utilizes low or no alkali-containing particulate compounds to prevent cementing during operation. The low or no-alkali-containing compounds may be supplied from external sources and/or from a particulate collection device located downstream of the SDA.

Abstract: A catalyst mainly containing silicon oxide and vanadium oxide and having an Si/V atomic ratio within the range from 99.5/0.5 to 85/15 is obtained by gelatinizing a liquid mixture of a colloidal silica and a vanadium compound in advance, then mixing the thus-obtained slurry by heating, and finally drying and/or firing the resulting mixture. As a catalyst for oxidizing mercury metal, this catalyst is brought into contact with an exhaust gas containing mercury metal, thereby oxidizing mercury metal.

Abstract: A system and method including a radially non-uniformly plugged flow-through honeycomb substrate positioned upstream of a wall-flow particulate filter for controlled thermal regeneration of the wall-flow particulate filter, the flow-through honeycomb substrate having a flow-through region including a first portion of parallel channels and a flow-control region including a second portion of parallel channels, the first portion of the parallel channels including unplugged channels and the second portion of the parallel channels including plugged channels, with the flow-control region adjusting flow distribution through the flow-through honeycomb substrate.

Abstract: A method is provided for reducing the fouling during the removal of sulfur trioxide from a flue gas stream by maintaining the reagent (i. e. sodium sesquicarbonate) in contact with the flue gas for a sufficient time and temperature to react a portion of the reagent with a portion of the sulfur trioxide to substantially avoid formation of liquid phase NaHSO4 reaction product that combines with the fly ash so as to not form a sticky ash residue that adheres to the flue gas duct, wherein the reaction product of the reagent and the sulfur trioxide is selected from the group consisting of Na2SO4, Na2S2O7 and mixtures thereof.

Abstract: A composition comprising a vanadium oxide compound and an alkali metal promoter loaded onto a porous support material is disclosed. Methods of making and using the composition to remove heavy metals or heavy metal containing compounds from a fluid stream are also provided. Such methods are particularly useful in the removal of mercury and mercury compounds from flue gas streams produced from the combustion of hydrocarbon-containing materials such as coal and petroleum fuels.

Abstract: A process by which heat is removed from a reactant fluid to reach the operating temperature of a known pollutant removal method and said heat is recirculated to raise the temperature of the product fluid. The process can be utilized whenever an intermediate step reaction requires a lower reaction temperature than the prior and next steps. The benefits of a heat-recirculating cooler include the ability to use known pollutant removal methods and increased thermal efficiency of the system.

Abstract: Process for removing sulfur oxides, mercury vapor, and fine particulate matters from industrial flue gases that contain such pollutants. Pollutants are removed by modules, which contain microporous adsorbent (i.e., sorbent) material held within a polymer matrix. The composite material that contains the microporous absorbent material held within a polymer matrix removes sulfur oxides by converting them into high concentration sulfuric acids. SULFURIC acid produced inside the composite material is automatically expelled onto the external surfaces of the composite material and is drained into an acid reservoir together with the fine particulate mailers which are washed from the external surfaces of the composite material by the constant dripping of the sulfuric acid along the external surfaces of the composite material.

Abstract: A method for increasing the nitrogen oxide emissions by either removing or modifying fuel rich nitrogen oxide (NOx) reduction processes thereby improving combustion efficiencies especially with low volatile low sulfur coals, and remove unburned carbon, reduce sulfur dioxide and reducing carbon dioxide emissions, while using post-primary combustion urea or ammonia injection with or without a reburn fuel NOx reducing process to restore NOx to regulated emission levels. Furthermore, adding lime or limestone to the urea or ammonia solution to further reduce SO2 and to increase the concentration of the carbon free fly ash to cementitious concentrations. Furthermore, by proper number and disposition of the injectors in the post combustion zone and by further water diluting the mixture, this NOx reduction process is effective at substantially higher gas temperatures than conventional Selective Non-Catalytic NOx Reduction and with no ammonia slip. This method significantly increases the profitability of power plants.

Abstract: A method for continuously removing mercury from a supply of combustion gas is provided. The method includes introducing SO3 into the supply of combustion gas to oxidize at least a portion of elemental mercury within the supply of combustion gas into ionic mercury. A turbulent flow of combustion gas is produced to suspend particulate matter including fly ash contained in the supply of combustion gas. A substantial portion of the mercury is absorbed within the particulate matter. The supply of combustion gas is filtered to remove the particulate matter from the mercury. The introduction of SO3 into the combustion gas is controlled based at least partially on at least one of an oxidation rate of mercury and an absorption rate of mercury.

Abstract: A method and system for removing hydrogen sulfide from gaseous process streams, such as sour gas streams are disclosed and described. A gaseous stream containing hydrogen sulfide can be contacted with an aqueous silicon-containing composition under high shear conditions to form a sweetened gaseous product. The gaseous product has significantly reduced hydrogen sulfide content and recovered liquid and solid filtrates are generally non-toxic.

Abstract: An exhaust cleanup filter which, even if the exhaust temperature is low as during vehicular driving under low load, can trap PM efficiently to prevent clogging by PM buildup and which also is effective in purifying the exhaust from a diesel engine that does not use any burner or heater to remove PM. The cleanup filter is for purifying the exhaust from diesel engines and comprises particulate ceramic porous bodies that have a three-dimensional network structure, as well as artificial pores and communication channels in the interior, with some of the pores being partially exposed on the surfaces of the porous bodies.