Abstract: BF.sub.3, CO.sub.2 or both are removed from a mixture containing these gases with B.sub.2 H.sub.6 by contacting the mixture with an inorganic hydroxide such as LiOH. B.sub.2 H.sub.6 is synthesized by contacting BF.sub.3 with KBH.sub.4.

Abstract: In a method for reducing hydrogen chloride emissions from an asphalt air-blowing process, an asphalt is subjected to an air-blowing process where air is bubbled through hot asphalt to raise the softening point of the asphalt. The fumes from the air-blowing process are bubbled through a liquid seal in a knockout tank before going to an incinerator and finally being emitted to the atmosphere. The knockout tank normally operates to condense oil in the fume stream, and the liquid seal is composed of this oil, as well as some of the water evolved in the air-blowing process. When using ferric chloride or ferrous chloride as a catalyst in the air-blowing process, the fume stream contains significant levels of hydrogen chloride.

Abstract: The present invention relates to a method to catalyze the oxidation of Hg(0) in a flue gas stream prior to standard emissions control equipment. The oxidized mercury has been found to be more condensable than Hg(0) and consequently more easily removed from the gas phase. Accordingly, mercury in its oxidized form can be trapped from a flue gas stream or the like by absorption onto a solid mass or can be more efficiently removed from flue gas streams by wet processes such as a two-stage wet FGD. The gist underlying the inventive concept of the instant invention relates to the use of a porous bed of gold-coated material that is saturated with Hg(0) to the point that the gold in the presence of HCl in the exhaust stream catalyses the oxidation of Hg(0).

Abstract: The present invention provides a catalyst having excellent capability of removing organic halogen compounds such as dioxins, a method for preparing the catalyst, and a method for removing organic halogen compounds using the catalyst. A catalyst for removing organic halogen compounds comprises titanium oxide as a catalyst component and has pores including a group of pores having a pore diameter distribution peak in a range of 0.01 to 0.05 gm and another group of pores having a pore diameter distribution peak in a range of 0.1 to 0.8 .mu.m. Another catalyst for removing organic halogen compounds comprises titanium oxide and a titanium-silicon composite oxide as catalyst components and has pores including a group of pores having a pore diameter distribution peak in a range of 0.01 to 0.05 .mu.m and another group of pores having a pore diameter distribution peak in a range of 0.8 to 4 .mu.m.

Abstract: A process is provided for removing fluorinated compounds, such as perfluorinated or partially fluorinated C1 to C4 hydrocarbons, NF.sub.3 and SF.sub.6, out of a gas by passing this gas through gamma alumina, wherein the temperature of the gamma alumina is between ambient temperature and 600.degree. C. The gas stream and the gamma alumina are anhydrous. The fluorinated compounds chemically react with the gamma alumina to result in a gas containing a diminished quantity of fluorinated compounds and an aluminum fluoride containing composition.

Abstract: A process for destroying NF.sub.3 in a gas containing NF.sub.3 by contacting the gas with a fluidized bed of metal particles capable of reacting with NF.sub.3 wherein the metal particles have a particle size essentially no greater than approximately 300 microns. The process can be conducted in parallel connected switching fluidized beds wherein the beds are switched based upon achieving a predetermined bed height expansion based upon the reaction of the metal particles with the NF.sub.3.

Abstract: This invention is directed to a method for producing UHP tungsten hexafluoride by introducing an amount of crude tungsten hexafluoride to an evaporating process for separation into an amount of tungsten hexafluoride-containing volatile impurities and an amount of non-volatile metallic impurities; passing the amount of tungsten hexafluoride-containing volatile residue to a gas phase adsorption process for separation into an amount of semi-crude tungsten hexafluoride product and an amount of hydrogen fluoride non-volatile residue; and passing the amount of semi-crude tungsten hexafluoride product to a sparging system using UHP helium for separation into a non-volatile UHP tungsten hexafluoride product.

Abstract: Process for purifying a gas flow with respect to at least one of the impurities capable of being oxidized and/or reduced which it contains, in which the gas flow is subjected to at least the following steps:(a) compressing the gas flow to a pressure in excess of atmospheric pressure,(b) bringing the compressed gas flow into contact with at least a first bed of particles of a material containing at least one metal peroxide, and(c) bringing the gas flow resulting from step (b) into contact with at least a second bed of at least one catalyst.

Abstract: A method for scrubbing flue gases of furnaces includes subjecting the flue gases with addition of activated carbon particles to wet scrubbing in a wet scrubbing device. Activated carbon particles are mixed with particles of at least one compound selected from slaked lime and limestone to produce a particle mixture that is introduced into the flue gases upstream of a flue gas heat exchanger that is positioned upstream of the wet scrubbing device.

Abstract: A process for producing chlorine comprises the steps of oxidizing hydrogen chloride in the presence of a catalyst in an oxidation reactor, passing the product gas together with the catalyst removed from the oxidation reactor to a high velocity transporter at a temperature between 150-250.degree. C. to remove the residual HCl from the product gas, removing the catalyst from the product and recycling the removed catatalyst back to the oxidation reactor.

Abstract: The invention relates to a process for removing hydrogen halides from hydrocarbon-containing streams. More particularly, the invention relates to a process and an HCl sorbent for the removal of HCl and other hydrogen halides from hydrocarbon streams to prevent the formation of green oils. The sorbent has an increased capacity for the sorption of HCl and a reduced catalytic activity for the formation of green oils which, surprisingly, results from the pre-loading of water on a sodium promoted alumina adsorbent. The pre-loading of water on the sodium promoted alumina adsorbent in the range of about 5 to about 11 percent of the essentially water-free adsorbent increases the HCl sorption capacities by about 25% with a corresponding decrease in catalytic reactivity.

Abstract: A process for the abatement of a ClF.sub.x containing gas such as exhaust gases from a reactor wherein at least one step of the manufacture of integrated circuit is carried out, wherein the ClF.sub.x containing gas is passed through a bed of adsorbent comprising sodalime having a moisture content of less than 3% by weight, to substantially remove all of the ClF.sub.x compound from the ClF.sub.x containing gas with substantially no generation of byproducts.

Abstract: Nitrogen oxides are removed from an exhaust gas containing nitrogen oxides and oxygen in a proportion larger than its stoichiometric proportion relative to unburned components in the exhaust gas, by (i) disposing an exhaust gas cleaner in a flow path, the exhaust gas cleaner comprising a first catalyst composed of 0.2-20 parts by weight (on a metal basis) of silver or silver oxide supported on a porous inorganic oxide, and a second catalyst composed of 1-50 parts by weight of tungsten and/or vanadium supported on a porous inorganic oxide; (ii) introducing oxygen-containing organic compounds having 2 or more carbon atoms or a fuel containing the oxygen-containing organic compounds into the exhaust gas on the upstream side of the exhaust gas cleaner; and (iii) bringing the exhaust gas into contact with the exhaust gas cleaner at a temperature of 150-650.degree. C., thereby causing a reaction of the nitrogen oxides with the oxygen-containing organic compounds to remove the nitrogen oxides.

Abstract: A catalyst of the present invention is adapted for purifying fumigation exhaust gases, and comprises, as a catalyst component A, a metal oxide containing at least one, or a composite oxide containing two or more metals selected from the group consisting of Ti, Si and Zr; and, as a catalyst component B, an oxide containing at least one selected from the group consisting of V, Cu, W and Cr; and has an average micropore diameter in the range of 0.010 to 0.070 .mu.m, a total micropore volume in the range of 0.30 to 0.60 ml/g, and a specific surface area in the range of 50 to 200 m.sup.2 /g. The use of this catalyst makes it possible to economically and efficiently purify fumigation exhaust gas.

Abstract: A method for adsorbing and oxidizing VOC's in the same bed, thus reducing the size of or even eliminating the need for a catalytic or thermal oxidation unit at the end of the system. In this system, a catalyst is intimately interspersed with the adsorbent material. The catalyst oxidizes VOC's released during desorption when it reaches the `light off temperature,` that is, the catalyst temperature necessary for oxidation to begin. As VOC's are desorbed, they are combusted by the catalyst in the same bed and also by their combustion, heat the bed to aid in the desorption of VOC's elsewhere in the bed.

Abstract: A method for cleaning process gases is provided, in which a sorbent is supplied to the process gases for reaction with gaseous pollutants that are present therein, thereby forming particulate reaction products which are separated in a subsequent particulate separator, and in which the moisture content and temperature of the cleaned process gases are measured to determine the relative humidity of the process gases and the concentration of at least one of the gaseous pollutants in the cleaned process gases is measured, wherein the relative humidity of the process gases is increased from a substantially constant basic level (BL) to an increased level (IL) and the amount of sorbent supplied to the process gases is increased when the concentration of at least one gaseous pollutant in the cleaned process gases exceeds an upper limit value (UL), and wherein the relative humidity is decreased back to said basic level, after a period of time and/or when the concentration of at least one gaseous pollutant in the cleane

Abstract: A process for recovery of fluorocompound gas from an effluent gas stream containing the fluorocompound gas and other gas components, in which at least one of the other gas components is removed, e.g., by oxidation or contacting of the effluent stream with a dry material such as an adsorbent or scrubber medium, to yield a first effluent gas mixture containing the fluorocompound gas. The fluorocompound gas is removed from the first effluent gas mixture and recovered as a concentrated fluorocompound gas, by a process such as cryogenic processing, membrane separation, and/or adsorption.

Abstract: Fluorocarbons including perfluorocarbons and hydrofluorocarbons are highly efficiently decomposed by contacting a gaseous fluorocarbon with a reagent comprising carbon and an alkaline earth metal or carbon, an alkaline earth metal and an alkali metal at an elevated temperature, the decomposed halogen being fixed to the reagent.

Abstract: Disclosed is a process for separating chlorine gas from a mixture of gases. The mixture of gases is cooled to a temperature less than 0.degree. C. and is contacted with ice, which results in the formation of chlorine hydrate on the ice. The ice is separated from the mixture of gases and is heated or the operating pressure reduced to release chlorine.

Abstract: A process is provided for the destruction of organohalogen compounds, such as methyl chloride, chloroform, carbon tetrachloride, etc., by mixing the organohalogen compounds with a heated carrier gas, such as nitrogen, argon or air, and either steam or water to form a mixture; supplying the mixture to a catalyst, such as titanium oxide/tungsten oxide, to decompose the organohalogen compounds into halogens and hydrogen halides, such as chlorine, hydrochloric acid, fluorine and hydrofluoric acid; conducting the halogen and hydrogen halide contaminated gas through a bent path, created by a baffle that prevents the entry of mist or droplets into the catalyst chamber, into a cooling section where the halogen and hydrogen halide contaminated gas is sprayed with water to cool the gas to a temperature low enough to prevent the formation of dioxines. An alkaline agent, such as sodium hydroxide, can be added to the cooling water to neutralize the halides and hydrogen halides.

Abstract: A dioxin preventative includes an adsorbent that sorptively removes dioxin precursors from an exhaust gas stream of an incinerator at a point prior to the exhaust gas stream cooling to below a temperature of 400.degree. C. The dioxin preventative includes a covering agent which coats flyash.

Abstract: A method is disclosed for recovering chlorine-containing species from the outlet gas of a hydrocarbon conversion process with a cyclic regeneration operation. The outlet gas from an off-stream catalyst bed in which regeneration is occurring is passed to another off-stream catalyst bed which contains spent catalyst and which is maintained at sorption conditions. The spent catalyst particles sorb the chlorine-containing species from the outlet gas. This method captures and retains within the hydrocarbon conversion process chlorine-containing species that would otherwise be scrubbed and lost from the process and that would need to be replaced by the injection of make-up chlorine-containing species. This method results in significant savings in operating costs of a cyclic regeneration process. This method is adaptable to many processes for the catalytic conversion of hydrocarbons in which deactivated catalyst are regenerated by a cyclic regeneration operation.

Abstract: Process for removing organic constituents from a high pressure exhaust gas stream in a bromine assisted air oxidation process in which the exhaust gas contains methyl bromide.

Abstract: A process for removing nitrogen oxides and/or sulfur oxides and/or hydrogen chloride out of a gas, for example from the combustion of fuel or the incineration of waste, by injecting a mixture of a peroxide compound such as sodium percarbonate and an alkali metal salt such as alkali metal carbonates, alkali metal bicarbonates and solid solutions of alkali metal carbonate and alkali metal bicarbonate into the gas and filtering the gas in bag filter, cyclone or electrostatic separator.

Abstract: There is disclosed a process for cleaning a harmful gas which comprises bringing a harmful gas containing at least one member selected from the group consisting of nitrogen fluorides, tungsten fluorides, silicon fluorides, hydrogen fluoride and fluorine, especially nitrogen trifluoride into contact with a cleaning agent comprising stannous oxide as an effective ingredient at a temperature of 200.degree. C. at the lowest. The above process makes it possible to clean the harmful gas in a high performance at a relatively low temperature without by-producing a harmful gas or a gas with a fear of causing environmental pollution.

Abstract: Finely divided composite materials are provided comprising a first metal oxide (e.g., MgO) at least partially coated with an extremely thin layer of a second metal oxide selected from the group consisting of the transition metal oxides such as Fe.sub.2 O.sub.3. The composites are very effective for the destructive adsorption of undesirable fluids in gaseous or liquid form, such as chlorocarbons and chlorofluorocarbons. In use, a fluid stream including undesirable fluids are contacted with the composites of the invention, such as through the use of a filter containing the composite as a part of the filter media thereof.

Abstract: A method of treatment of a fleon gas consisting only of carbon and fluorine is provided, wherein the fleon gas is exposed to a plasma to decompose and chemically activate the fleon gas. The fleon gas having been chemically activated is then made into contact with a reactant to form a reaction product.

Abstract: A method for the removal and rapid decomposition of halogenated fumigation agents is described. A fumigation agent, such as methyl bromide, contained in the gas stream exiting a fumigation chamber or structure is captured on activated carbon or other retentive substrate and rapidly decomposed using thiosulfate and water. The method provides an inexpensive, safe, and on-site executable way to remove and detoxify methyl bromide from fumigation discharge gases, thereby reducing or eliminating methyl bromide emissions into the atmosphere.

Abstract: Absorbent granules comprising an intimate mixture of particles of alumina trihydrate, 0.5 to 2 parts by weight of particles of a sodium component selected from the group consisting of sodium carbonate, sodium bicarbonate and mixtures thereof per part by weight of said alumina trihydrate and from 5 to 20% by weight of a binder, said alumina trihydrate, sodium component and binder being present in such proportions that, after ignition of a sample of the granules at 900.degree. C., the sample has a sodium oxide, Na.sub.2 O, content of at least 20% by weight. Processes for manufacturing such absorbent granules and for using such absorbent granules for the removal of acidic gases are also disclosed.

Abstract: Methods and chemical compositions for treating a gas stream comprising non-halogenated and halogenated organic compounds while suppressing halogenation of the non-halogenated organic compounds with the oxidation products of the halogenated organic compounds in the gas stream are disclosed. The gas stream in the presence of oxygen is contacted with the catalyst compositions of the invention to oxidize the non-halogenated and the halogenated compounds to form water, carbon dioxide, and halogen molecules (Cl.sub.2, Br.sub.2, etc.) and/or halogen acids such as HCl, HBr, etc. An advantage of the present compositions and methods is that halogenation or of the treated emissions is suppressed over a process operating temperature range 400 to 550.degree. C.

Abstract: Disclosed and claimed is a process for selectively separating hydrogen halides from sulfur-dioxide-containing gases by using an adsorbent made from a porous ceramic support material which is impregnated with an alkaline earth metal salt solution and, after evaporation of the solvent, the alkaline earth metal salt is pyrolysed at 200.degree. to 800.degree. C. to give alkaline earth metal oxide .Xh.sub.2 O, where x is a number from 0 to 1.

Abstract: The treatment, through a dry adsorption process, of a gas from a hot electrolytic process for aluminum production comprises at least two stages. Particulate aluminum oxide (the adsorbent) passes through the stages of the adsorption process countercurrently to the gas. Thus, the gas is treated with a partly spent adsorbent in a first dry adsorption stage, whereupon the particulate adsorbent is separated from the gas downstream from the first adsorption stage. Part of the separated particulate adsorbent is removed from the adsorption process for recycling adsorbed fluorine-containing substances to the electrolytic process. The remainder of the separated adsorbent is recirculated in the first adsorption stage in order to optimize the adsorption of fluorine-containing substances and the desorption of sulfur dioxide from the aluminum oxide in this stage. Simultaneously, the gas is transferred to a second dry adsorption stage.

Abstract: There are disclosed a cleaning agent for removing a fluorine-compound gas such as hydrogen fluoride, fluorine, tungsten hexafluoride, silicon tetrafluoride and boron trifluoride which agent comprises a molded article produced by using strontium hydroxide as a principal component, an organic binding agent as a molding agent and the hydroxide of an alkaline earth metal other than strontium as a molding aid; and a process for cleaning a harmful gas which comprises feeding a harmful gas containing a fluorine-compound gas into a column packed inside with the above cleaning agent to remove the fluorine-compound gas; and exhausting a gas substantially free from the fluorine-compound gas. The above cleaning agent is capable of removing the fluorine-compound gas in high efficiency without causing any danger, thereby making itself well suited to the cleaning of the gases exhausted, for example, from semiconductor manufacturing industries.

Abstract: A waste gas stream containing toxic NF.sub.3 and optionally other gases, such as acidic fluoride gases, for example, HF, SiF.sub.4, MoF.sub.6 and WF.sub.6 is first treated with particles or ribbons of a Cr-containing Fe alloy at about 300.degree.-600.degree. C. to remove the NF.sub.3 content and, if desired, subsequently with an alkaline neutralizing agent in the form of pellets to remove the acidic fluoride contents, if any; said alloy containing preferably about 16-26% Cr and being used in a form of bed packed with said ribbons.

Abstract: A method for treating a gas flow containing organohalogen compounds including the steps of contacting the gas flow with a catalyst at a temperature below 500.degree. C. in the presence of an effective amount of steam, wherein the catalyst contains titania, tungsten oxide, and silica, the Ti and W are present in the range of 20-95 mol % Ti and 5-80 mol % W based on Ti and W, and the amount of silica is in the range of 0.5-15% by weight silica to 100% by weight titania. Accordingly, the organohalogen compound can be decomposed effectively to carbon monoxide, carbon dioxide, and hydrogen halide.

Abstract: This invention relates to a process for thermally cracking waste polymer(s) comprising chlorinated polymers in a reactor in the presence of a fluidizing gas and a fluidized bed of solid, particulate fluidizable material at a temperature from 350.degree.-600.degree. C. to cracked products comprising a mixed vapor of lower hydrocarbons which have a chlorine content of less than 50 ppm. In the process, the cracked products emerging from the fluidized bed are passed through one or more guard beds comprising calcium oxide or a compound capable of giving rise to calcium oxide under the reaction conditions maintained at a temperature in the range from 400.degree.-600.degree. C. in such a way that the chlorine content of the product is less than 50 ppm.

Abstract: The present invention relates to a method for decomposing any of chlorocarbons, chlorofluorocarbons, perfluorocarbons and SF.sub.6 contained in a gas. This method includes the step of bringing the gas into contact, at a temperature of at least 300.degree. C., with a first mixture consisting essentially of 0.05-40 wt % of potassium hydroxide and at least one compound selected from the group consisting of alkali-earth-metal oxides and alkali-earth-metal hydroxides, for decomposing the at least one halide compound. When the halide compound-containing gas further contains oxygen, this gas may be brought into contact, at a temperature of at least 500.degree. C., with at least one first substance selected from the group consisting of active carbon, iron powder and nickel powder, for removing the oxygen from the gas, prior to the halide compound decomposition. When the halide compound-containing gas still further contains a strong oxidizing gas (e.g.

Abstract: A method for the simultaneous control of SO.sub.2, NO.sub.x, HCl, air toxins, metal fumes, and particulate emissions (ash, soot, metal oxides) from fossil fuel burning combustion processes is provided by injecting a sorbent upstream of a filter in the furnace and collecting sorbent and particulates in the filter. Collecting the sorbent in the filter increases its residence time in the process. The sorbent is injected in the post-flame region of a furnace, where it reacts with the SO.sub.2, the NO.sub.x, the HCl, and the air toxics in the effluent gas. A surface filter that can withstand temperatures of approximately 1000.degree. C. is mounted, either fixedly or rotatably, in the furnace downstream of the sorbent injection region. The gas flows through the filter, and the sorbent and other particulates become embedded in the surface layer of the filter.

Abstract: A process for recovery of halocarbons from a gas mixture containing the halocarbon and acid gas components comprises the steps of contacting the gas mixture with a dry scrubber to remove the acid gas components from the gas mixture and yield a first effluent gas mixture containing the halocarbon. The first effluent gas mixture is contacted with an adsorbent which is selective for the halocarbon component of the first effluent gas mixture to adsorb the halocarbon component and yield a second effluent gas. The adsorbed halocarbon is recovered by desorbing same from the adsorbent. The process of contacting with adsorbent can be carried out in at least two adsorbent beds joined at inlet and outlet ends thereof to gas feed and gas discharge manifolds, respectively.

Abstract: A method for cleaning waste gases containing ozone-depleting and/or climate-active halogenated compounds has a sorption device (S1,S2) having two chambers (1, 2) each containing a solid stationary sorbent (6, 7) for the ozone-depleting and/or climate-active halogenated compounds and communicate with each other via a heating device (4). The two chambers (1, 2) are alternatively connectable with the gas feeding means (8) for the waste gas to be cleaned for reversing the direction of flow of the waste gas to be cleaned.

Abstract: A treating method for decomposing organohalogen compounds such as chlorofluorocarbons (CFC), trichloroethylene, methyl bromide, halon, and the like, effectively, with a high activity of catalyst is provided.Organohalogen compounds are decomposed by contacting at a temperature in a range of 200.degree..about.500.degree. C. with catalyst which comprises titania and tungsten oxide by an atomic ratio of Ti and W in a range from 20 mol % to 95 mol % Ti and from 5 mol % to 80 mol % W, and at least surface of the titania is covered with porous layer of tungsten oxide.In accordance with the present invention, organic compounds containing any of fluorine, chlorine, and bromine can be decomposed with a high efficiency, and the activity of the catalyst can be maintained for a long time.

Abstract: A process for cleaning a harmful gas which comprises bringing a harmful gas containing a halogen gas and/or a halogen compound gas such as hydrogen fluoride, hydrogen chloride, tungsten hexafluoride, silicon tetrafluoride and boron trifluoride into contact with a cleaning agent comprising metal oxides composed principally of copper (II) oxide and manganese (IV) oxide that are spreadingly and adhesively incorporated with sodium formate so as to remove a harmful component from the harmful gas. According to the cleaning process of the present invention, it is possible to remove harmful components from the harmful gas in extremely high efficiency at ordinary temperature, dispensing with heating or cooling irrespective of the concentration of the harmful components. The cleaning capacity of the cleaning agent is favorably maintained without deterioration even when the harmful gas is in a dry state.

Abstract: An apparatus (50) for contacting a gas stream (62) with solid particulate material includes two contacting zones (58, 60). Sets of angled blades (54, 56) cause gas flowing through the contacting zones (58, 60) to have a swirling circumferential velocity. Solid particulate material is fed from hopper (70) via line (72) to the upper contacting zone (56), in which the swirling gas flow causes a turbulent band of particles (60) to form. Contact between the gas and the solid occurs in this band of particles. Overflow of particles from band (74) flows down conduits (76, 77) and into lower contacting zone (58). The swirling gas flow in contacting zone (58) causes a turbulent band of particles (78) to be established. The gas stream enters at conduit (62) and travels through the turbulent band of particles (78) in the lower contacting zone (58). The gas then passes through restriction (66), through the turbulent band of particles (74) in upper contacting zone (60) and then leaves the apparatus (50) via outlet (68).

Abstract: A first reaction/adjustment tank has a lower portion containing a calcium carbonate mineral, an upper portion containing a calcium carbonate mineral and a plastic filler, and an air lift pump for circulating waste water from the lower portion to the upper portion. Exhaust gas is introduced into a space. A second reaction/adjustment tank has a lower portion containing a calcium carbonate mineral and charcoal, and an upper portion containing charcoal and a plastic filler. Waste water circulates sequentially through the lower and upper portions of the first reaction/adjustment tank, and the lower and upper portions of the second reaction/adjustment tank. Exhaust gas circulates sequentially through the upper portion of the first reaction/adjustment tank and the upper portion of the second reaction/adjustment tank.

Abstract: The invention relates to a process for removing hydrogen halides from hydrocarbon containing streams. More particularly, the invention relates to a process and an HCl sorbent for the removal of HCl and other hydrogen halides from hydrocarbon streams to prevent the formation of green acids. The sorbent has a high capacity for sorption of HCl, sufficient physical strength to permit operation in packed bed form, and catalytic inertness to not causing the oligomerization reactive hydrocarbons such as olefins, diolefins. The HCl sorbent comprises an admixture of magnesium hydroxide and a hydrogen halide reactive component such as calcium hydroxide or oxide with at least one or more metal oxide, hydroxide or carbonate wherein the magnesium is present in an amount greater than about 5 mol-% of the total cation content of the sorbent.

Abstract: A cleaning agent for removing acidic gases which are harmful materials from a harmful gas containing such acidic gases, and a cleaning method using the cleaning agent are disclosed. The cleaning agent comprises a molded product of a composition comprising strontium hydroxide and an iron oxide, and the harmful gas is passed through a cleaning column packed with the cleaning agent to contact the harmful gas with the cleaning agent, thereby removing the acidic gases from the harmful gas.

Abstract: The process of purifying oxygen-containing exhaust gases produced by combustion of waste materials including garbage, industrial waste and sewage sludge includes reacting an exhaust gas containing pollutants in a gas-solids suspension at a temperature of 120.degree. to 140.degree. C. and at a gas velocity from 3 to 20 m/s for a reaction time of 0.5 to 10 seconds with a mixture containing naturally occurring zeolites to remove mercury, mercury compounds and polyhalogenated hydrocarbons pollutants from the exhaust gas. The naturally occurring zeolites have a median particle size (d.sub.50) from 5 to 50 micrometers and the gas-solids suspension has a mean suspension density from 0.020 to 10 kg of solids per sm.sup.3 of exhaust gas. The mixture contains from 10 to 20% by weight mordenite, from 60 to 70% by weight clinoptilolite, from 0 to 5% by weight montmorillonite and a remaining balance of SiO.sub.2. The purified gas contains <50 micrograms of mercury per sm.sup.3, <0.1 ng TE per sm.sup.

Abstract: A process for removing a carbon dioxide, HF or sulfur dioxide contaminant from an exhaust gas stream containing that contaminant comprising providing a gas stream to a reaction zone, the gas stream entering the reaction zone from underneath and being caused to flow through the reaction zone with components of velocity in substantially upwards and circumferential directions; contacting the gas stream in the reaction zone with particulate material to adsorb the contaminant on the particulate material, wherein the flow of gas in the reaction zone causes a dispersed toroidal bed of particulate material to be formed in the reaction zone; the slip velocity of the gas stream relative to the particulate material in the toroidal bed is greater than 1 m/s; and entraining a fine fraction of the particulate material in the gas stream whereby the fine fraction is removed from the toroidal bed by the gas stream exiting the bed; and separately recovering a coarse fraction of the particulate material from the reaction zone.

Abstract: A catalyst and process for treating gas streams which contain halogenated organic compounds, non-halogenated organic compounds, carbon monoxide or mixtures thereof, and particularly gas streams which contain organobromides. The catalyst comprises at least one platinum group metal, zirconium oxide and at least one oxide of manganese, cerium or cobalt.

Abstract: A process for decomposing organohalogen compounds which are present in dust-laden gases which have a carbon content of less than 0.6% by weight, by oxidative breakdown with the aid of solid catalysts suitable for this purpose, whereina) the dust is deposited from the gases at 250.degree.-500.degree. C., and the dust-free gas is passed together with oxygen or an oxygen-containing gas over the catalyst, orb) the deposition of the dust takes place at below 250.degree. C., the organohalogen compounds are desorbed from the dust in an oxygen-containing gas stream at 250.degree.-500.degree. C., and the gas stream is passed over the catalyst, orc) the dust-laden gas is passed in the presence of oxygen over the catalyst at 250.degree.-500.degree. C., and the dust is subsequently removed.