Abstract: A binderless X-type zeolite is used in a process for the reduction of the level of carbon dioxide and/or N2O in a gaseous mixture, the zeolite being obtained by converting the binder in a bound zeolite to zeolite such that the ratio of the adsorption capacity for carbon dioxide of the binderless zeolite to the adsorption capacity of the bound zeolite is greater than the weight ratio of the level of zeolite in the binderless zeolite to the level of zeolite in the bound zeolite.

Abstract: The present invention provides for a thermal swing adsorption process for the removal of trace impurities such as oxides of nitrogen and hydrocarbons from air prior to its separation by cryogenic distillation. The process may utilize three adsorbent layers, the first primarily removes water; the second primarily removes carbon dioxide; and the third layer is a composite adsorbent layer which removes the oxides of nitrogen and hydrocarbons from the air stream. Another embodiment employs a two layer adsorbent system to remove the impurities. Additionally, a single layer of composite adsorbent may be used to remove water, carbon dioxide, oxides of nitrogen, and hydrocarbons from the air stream.

Abstract: The invention is directed to an adsorbent comprising: a) 20-30% porous carbon with incorporated organic nitrogen species; and b) 70-80% inorganic matter. The invention is directed to a method of making an adsorbent which comprises: a) thermally drying dewatered sewage sludge to form granulated organic fertilizer; and b) pyrolyzing said the organic fertilizer at temperatures between 600 and 1000° C. The invention is additionally directed to the process of removing acidic gases from wet air streams comprising putting an adsorbent in contact with the wet air stream and allowing the adsorbent to adsorb the acidic gases.

Abstract: A process for purifying a gas stream containing at least one impurity chosen from the group formed by propane, nitrogen protoxide and ethylene, in which process: (a) the gas stream to be purified is brought into contact with at least one adsorbent including at least one X zeolite containing barium cations; (b) at least one impurity is adsorbed on the adsorbent. Preferably, the adsorbent includes particles of X zeolite exchanged to at least 70%, preferably at least 89%, with barium cations, it being possible for the adsorbent to furthermore include a bed of activated alumina particles which is located upstream of the bed of barium-exchanged X zeolite.

Abstract: Nitrogen oxides and low molecular weight hydrocarbons are removed from air by subjecting the air to a temperature swing adsorption process using as the adsorbent a composite zeolite product containing both zeolite type A and zeolite type X. The composite zeolite product is prepared by crystallizing a sodium ion- or sodium ion- and potassium ion-containing alumina-silica hydrogel under conditions which result in the production of a zeolitic composite which contains both zeolite type A and zeolite type X crystal domains. In a preferred embodiment, calcium ions constitute a substantial number of the composite's exchangeable cations and the type X portion of the composite zeolite product has a silicon-to-aluminum atomic ratio in the range of 0.9 to less than 1.15. The nitrogen oxide- and hydrocarbon-selective adsorbent can be incorporated into an atmospheric air prepurification plant downstream of a water vapor-selective adsorbent and a carbon dioxide-selective adsorbent.

Abstract: Nitrogen oxides and low molecular weight hydrocarbons are removed from air by subjecting the air to a temperature swing adsorption process using as the adsorbent a composite zeolite product containing both zeolite A and zeolite X. The composite zeolite product is preferably prepared by forming a mixture of an agglomerate of silica and sodium zeolite X having a Si/Al atomic ratio in the range of about 0.9 to less than about 1.2 and a water-soluble sodium aluminate salt; maintaining the mixture at a temperature in the range of about 25 to about 100° C. for a period of time sufficient to convert at least 50% of the silica to sodium zeolite A; and at least partially exchanging the zeolite A-containing product with divalent cations, preferably calcium ions.

Abstract: The regeneration phase of the adsorption cycle includes a depressurization step, a heating/elution step, during which the bed is purged with a hot heating/elution gas, and a cooling/elution step, during which the bed is purged with a cold cooling/elution gas. The cooling/elution step is terminated while the cooling/elution gas leaving the bed is at a temperature markedly higher than the temperature of the gas to be treated and the adsorption phase comprises an initial adsorption step during which the bed is cooled down to the low adsorption temperature due to the effect of the gas to be treated.

Abstract: The present invention provides for a process for purifying atmospheric air prior to its separation by cryogenic distillation. The process utilizes three adsorbent layers, the first primarily removes water; the second primarily removes CO2; and the third layer is designed to remove displaced gas components such as N2O and hydrocarbons which are displaced by the second layer. It has been found that CaX type adsorbents provide the removal of N2O and hydrocarbons in the third layer.

Abstract: A method and composition for the removal of contaminants in a gas stream used in the contamination sensitive processes of photolithography and metrology are described. The synergistic effect of a combination of an electropositive metal component, a high silica zeolite, and a late transition metal compound effects removal or reduction of the contaminates in the gas which interfere with light transmittance to the ppb or ppt levels necessary for the gas to be suitable for these uses. The removal of neutral polar molecules, neutral polar aprotic molecules, protic and aprotic alkaline molecules, acidic polar species, and neutral non-polar aprotic molecules is accomplished with the claimed composition. Depending on the type of contaminant, the composition components are each varied from 10 to 80 parts by volume, with the total composition limited to 100 parts by volume.

Abstract: Provided are a system and method for nitrous oxide purification, wherein the nitrous oxide product for use in semiconductor manufacturing. The system and process involve a first sub-system having a purification tank for holding a liquefied nitrous oxide, therein; a vaporizer in communication with the purification tank to receive, vaporize and convey a nitrous oxide vapor back to the purification tank; a distillation column disposed on a distal end of the purification tank to receive a nitrous oxide vapor; a condenser disposed on the distillation column, wherein light impurities are removed and wherein a nitrous oxide devoid of light impurities is conveyed and converted into vapor in the vaporizer. A second sub-system having a first dry bed vessel is disposed downstream of the vaporizer to receive the vapor and reacting the acid gas therein; a second dry bed vessel downstream of the first dry bed vessel for removing water and ammonia in the vapor.

Abstract: A method for selectively absorbing nitrogen oxides NOx from gaseaous mixtures containing carbon dioxide or carbon dioxide and water and optionally contaminants chosen among CO, SO2, hydrocarbons and mixtures thereof, comprising placing the gaseous mixtures in contact with absorber compounds having formula Ba2Cu3O5+d, where d is a number from 0.6 to 1. New compounds having the above formula are characterized by high resistance to carbonatation and by specific Raman spectra.

Abstract: A process, especially a PSA or TSA process, for purifying a gas containing at least carbon dioxide (CO2) as impurity, in which the carbon dioxide is adsorbed on an adsorbent comprising particles of activated alumina. According to this process, the activated alumina has a specific surface area of between 200 m2/g and 299 m2/g and contains at least 80% aluminum oxide (Al2O3), silicon oxide (SiO2), iron oxide (Fe2O3) and from 0.001% to 7.25% of at least one oxide of at least one alkali or alkaline-earth metal, such as sodium and potassium oxides. According to the invention, the gas stream to be purified is air or a synthesis gas.

Abstract: Novel compositions of molecular sieve adsorbents are provided in which at least 50% of the exchangeable cations are selected from those of Li, Ca, Ag and Cu and which have within their pore system metal oxide, metal oxide precursors or mixtures thereof. These compositions are useful for the separation of gases and, in particular, the separation of nitrogen from air to produce oxygen or oxygen-enriched gas.

Abstract: A process is disclosed for checking the operatability of a nitrogen oxide storage catalyst which is used to remove the nitrogen oxides contained in the exhaust gas stream from a lean burn engine and which contains at least a nitrogen oxide storage material, a catalytically active component and optionally an oxygen storage material. The lean burn engine is operated with cyclic alternation of the air/fuel mixture from lean to rich and the nitrogen oxides contained in the exhaust gas are stored by the nitrogen oxide storage material in the presence of lean burn exhaust gas (storage phase) and is desorbed and converted in the presence of rich exhaust gas (regeneration phase).

Abstract: A method and apparatus for preventing contamination of a substrate or a substrate surface, and particularly relates to prevention of contamination of raw materials, semi-finished products, base materials of products and substrate surface in a high-tech industry such as in the production of semiconductors and liquid crystals. A gas coming into contact with a base material or substrate is purified by dust removing apparatus and adsorption and/or absorption apparatus so that the concentration of fine particles in the gas is below class 1,000 and a non-methane hydrocarbon concentration is below 0.2 ppm. Thereafter, the base material or the substrate surface is exposed to this gas.

Abstract: A process, particularly of the TSA type, for separating impurities of the nitrogen protoxide (N2O) and possibly carbon dioxide (CO2) or ethylene (C2H4) type which are contained in a gas stream, such as air. The impurities of nitrogen protoxide type are removed on a faujasite zeolite having a Si/Al ratio of 1 to 1.5 and containing from 0 to 35% of K+ cations, between 1 and 99% of Na+ cations and between 1 and 99% of Ca2+ cations, preferably at least 50% of Ca2+ cations. The separation is preferably carried out at a temperature of approximately −40° C. to +80° C., preferably at room temperature. Advantageously, the process is employed for prepurifying atmospheric air before cryogenic distillation of the air thus prepurified.

Abstract: The present invention provides a nitrogen dioxide absorbent for the exhaust gas purifying facility designed to remove by absorption or adsorption of NO2 from a gas (such as ventilation gas from road tunnels) containing NOx in low concentrations. The absorbent is composed of a porous carrier and a basic amino acid and/or organic amine compound supported thereon. The absorbent is produced by impregnating a porous carrier sequentially with two aqueous solutions each containing in an amount of, for example, 0.5-3.0 mol/l (preferably 1.0-2.0 mol/l) of basic amino acid and 0.5-3.0 mol/l (preferably 1.0-2.0 mol/l) of organic amine compound, or impregnating a porous carrier with a solution containing 0.5-3.0 mol/l (preferably 1.0-2.0 mol/l) of basic amino acid and/or 0.5-3.0 mol/l (preferably 1.0-2.0 mol/l) of organic amine compound.

Abstract: Carbon dioxide, water, nitrous oxide and optionally ethylene are removed from a feed air stream by a temperature swing adsorption using a first adsorbent such as alumina to adsorb water, a second adsorbent such as 13X zeolite to adsorb carbon dioxide, and a third adsorbent such as binderless calcium exchanged X zeolite to adsorb nitrous oxide and optionally ethylene, prior to cryogenic separation of the purified air stream.

Abstract: A feedstream comprising nitrous oxide is purified by a pressure swing adsorption process employing a copurge with an oxygen-lean stream to produce a high purity nitrous oxide stream. The high purity nitrous oxide stream can be incorporated in a complex for the production of adipic acid to recover nitrous oxide from a dilute waste stream and pass the recovered nitrous oxide to a process for the production of phenol from an aromatic hydrocarbon. Unreacted nitrous oxide from the phenol production step acid can be recovered in a second, or vent PSA step, and combined with the recovery of byproduct nitrous oxide waste streams from the production of adipic for the overall recovery of nitrous oxide, thereby significantly reducing nitrous oxide emissions from the production of adipic acid.

Abstract: Disclosed is a method for separating a vaporous or gaseous contaminant from an air stream contaminated therewith. This method includes the steps of: (a) passing said contaminated air into a contact zone in which is disposed an aerogel material capable of selecting adsorbing said contaminant from air and therein contacting said contaminated air with an aerogel material; and (b) withdrawing from said zone, air depleted of said contaminant. For present purposes, "contaminant" means a material not naturally occurring in ambient air and/or a material naturally occurring in air but present at a concentration above that found in ambient air. Thus, the present invention scrubs (or treats) air for the purpose of returning it to its ambient composition.

Abstract: This invention discloses an adsorbent ideal or the removal of nitrogen oxides (NO.sub.x : nitrogen monoxide and nitrogen dioxide), particularly nitrogen dioxide, from an exhaust gas containing the nitrogen oxides at low concentrations and a method for efficient removal of nitrogen oxides, particularly nitrogen dioxide, from an exhaust gas containing the nitrogen oxides at low concentrations by the use of the adsorbent. The adsorbent either comprises at least one noble metal selected from the group consisting of Pt, Au, Ru, Rh, and Pd and/or a compound thereof supported on a carrier or comprises the noble metal component and an oxide of at least one heavy metal selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn and Pb, which may be supported on the carrier, if necessary.

Abstract: Selective and thermally reversible adsorption of NO.sub.x from a mixture of hot gases is achieved by contact with an adsorbent of active copper in the form of CuO on a support of TiO.sub.2 and SiO.sub.2 and in the form of Cu.sup.+2 on a support of pillared clay.

Abstract: The present invention provides compositions including a salt selected from the group consisting essentially of sodium nitrate, sodium nitrite, ammonium nitrate, lithium nitrate, barium nitrate, cerium nitrate, and mixtures thereof, as flue gas conditioning formulations for use in controlling particulates, hazardous substances, NO.sub.x, and SO.sub.x. For the purpose of obtaining greater yields of particulate and hazardous substance removal, the compositions may further include a polyhydroxy compound, preferably selected from the group consisting essentially of sucrose, fructose, glucose, glycerol, and mixtures thereof. Methods are also provided for adding these compositions to the flue gas stream to control particulate, hazardous substance, NO.sub.x, and SO.sub.x emissions.

Abstract: A nitrogen oxide absorbing material, comprising a hollandite-type complex oxide having main metal elements comprising minimally of aluminum and tin, or zinc and tin, and a method of using that nitrogen oxide absorbing material comprising the steps of contacting the nitrogen oxide absorbing material with a gas containing nitrogen oxides. The method of reducing the adsorbed nitrogen oxides on the nitrogen oxide absorbing material includes the steps of releasing the nitrogen oxides from the nitrogen oxide absorbing material, and of reducing the released nitrogen oxides with a three way catalyst or other nitrogen oxide reducing catalysts.

Abstract: A device for removing at least laughing gas and anesthetic vapor from a gas sample based on a molecular sieve shall be improved such that it possesses good adsorption properties for both gas components. A molecular sieve arrangement is provided, which is flown through from a gas inlet to a gas outlet and comprises a first molecular sieve area with a first pore size between about 0.3 nm and 0.5 nm and a second molecular sieve area with a second pore size between about 0.8 nm and 1 nm.

Abstract: A method and apparatus for preventing contamination of a substrate or a substrate surface, and particularly relates to prevention of contamination of raw materials, semi-finished products, base materials of products and substrate surface in a high-tech industry such as in the production of semiconductors and liquid crystals. A gas coming into contact with a base material or substrate is purified by dust removing apparatus and adsorption and/or absorption apparatus so that the concentration of fine particles in the gas is below class 1,000 and a non-methane hydrocarbon concentration is below 0.2 ppm. Thereafter, the base material or the substrate surface is exposed to this gas.

Abstract: A process for removing nitrogen oxides, as well as water and carbon dioxide, from gas streams containing at least 0.2 ppm by volume of nitrogen oxides by passing the gas stream through an alumina adsorbent and a zeolite adsorbent, preferably 13X-zeolite. The process has utility in front end cleanup of air prior to cryogenic distillation of the air where nitrogen oxides would otherwise freeze under the cryogenic processing.

Abstract: An air prepurification process which includes, as a first step, a pressure swing adsorption process in which the air is passed through a bed of adsorbent which contains activated alumina, thereby effecting removal of substantially all moisture and most carbon dioxide from the feed air and as a second step, a temperature swing adsorption process in which the dried feed air is passed through a bed of carbon dioxide-selective adsorbent, thereby removing substantially all of the carbon dioxide remaining in the feed air. The feed air may be passed through beds of hydrogen oxidation and carbon monoxide oxidation catalysts between the first and second steps to convert any hydrogen and carbon monoxide in the feed air to water vapor and carbon dioxide, respectively, these components being removed from the feed air during the second step.

Abstract: Polyarylene ethers are employed as filter material for removing NO.sub.2 from gases and liquids. In the presence of an oxidizing agent having a redox potential of at least 0.96 V SHE, NO can also be removed. The filter material is used to produce NO.sub.2 -free gases, for example in the medical sector.

Abstract: A process for the adsorption of at least carbon dioxide, water and oxides of nitrogen and preferably acetylene from a feed gas, comprises contacting the feed gas with an adsorbent mixture of a zeolite and an alumina. The process may be operated as a swing adsorption process comprising contacting the gas with the adsorbent at a first temperature and pressure to adsorb at least carbon dioxide, water and oxides of nitrogen therefrom and periodically regenerating the adsorbent by reducing the pressure and or increasing the temperature to which the adsorbent is exposed.

Abstract: The present invention discloses an improved method for filtration of air within enclosed spaces. Improvement is achieved by the use of a high-temperature carbonaceous char that is catalytically active for the removal of certain undesirable constituents from contaminated air under ambient temperature conditions. This carbonaceous char is used as an air filtration medium and incorporated into an air filtration device by any of a number of technologies. Such devices may be used for removal of contaminants such as NO.sub.x, NO.sub.2, SO.sub.x, SO.sub.2, H.sub.2 S, mercaptans, light aliphatic gases such as butane and propane and other compounds such as benzene, hexane, toluene, xylene, amines and the like from enclosed or confined structures such as buildings or vehicles including automobiles, aircraft, trucks, farm equipment, and the like.

Abstract: The present invention discloses an improved method for filtration of air within enclosed spaces. Improvement is achieved by the use of a high-temperature carbonaceous char that is catalytically active for the removal of certain undesirable constituents from contaminated air under ambient temperature conditions. This carbonaceous char is used as an air filtration medium and incorporated into an air filtration device by any of a number of technologies. Such devices may be used for removal of contaminants such as NO.sub.x, NO.sub.2, SO.sub.x, SO.sub.2, H.sub.2 S, mercaptans, light aliphatic gases such as butane and propane and other compounds such as benzene, hexane, toluene, xylene, amines and the like from enclosed or confined structures such as buildings or vehicles including automobiles, aircraft, trucks, farm equipment, and the like.

Abstract: A gas mixture comprised of nitric oxide and, optionally an inert gas, and containing small amounts of nitrogen dioxide, and perhaps moisture and sulfur dioxide, is purified by passing the gas stream through a bed of zeolite having a silica to alumina ratio not greater than about 200. The concentration of nitrogen dioxide, sulfur dioxide and moisture in the gas stream are reduced to about 1 ppm or less as the gas mixture passes through the bed of zeolite.

Abstract: The present invention relates to the separation of one or more components from a multi-component gaseous stream. The component(s) being separated are relatively small molecular diameter gas components. They are separated by sorption techniques wherein the sorbent is a unique class of layered nanostructure materials, such as carbon nanofibers, characterized as having; (i) a surface area from about 0.2 to 3,000 m.sup.2 /g as determined by N.sub.2 adsorption at -196.degree. C., (ii) a crystallinity from about 5% to about 100%, and (iii) interstices from about 0.335 nm to about 0.67 nm.

Abstract: A desulfurizing and denitrating apparatus wherein an inner space of a tower body, which has an introduction port for a gas to be processed and a processed gas discharge port formed respectively in opposite side walls, is partitioned in a direction from the side wall having the processed gas introduction port toward the side wall having the processed gas discharge port by an inlet louver, a perforated plate and an outlet louver all extending vertically parallel to each other, a constant-rate discharging device for setting a moving speed of a carbon-base adsorbent in a small chamber defined between the inlet louver and the perforated plate and a constant-rate discharging device for setting a moving speed of a carbon-base adsorbent in a large chamber defined between the perforated plate and the outlet louver are provided, the moving speed of the carbon-base adsorbent in the small chamber is set to be 2 to 4 times greater than an average moving speed, and the distance from the inlet louver to the perforated plate

Abstract: A gas mixture comprised of nitric oxide and, optionally an inert gas, and containing small amounts of nitrogen dioxide, and perhaps moisture and sulfur dioxide, is purified by passing the gas stream through a bed of metal cation-free silica, alumina, or zeolite. The concentration of nitrogen dioxide, sulfur dioxide and moisture in the gas stream are significantly reduced as the gas mixture passes through the bed of adsorbent.

Abstract: The device for feeding gaseous substances into liquid media comprises a number of hollow membrane bodies which are permeable to gas and contain the liquid media. These membranes are arranged with a distance between them in such a way that they can be reached by the gaseous substances. Such a device lends itself particularly to air purification. Gaseous substances such as nitrogen oxides can be converted with the aid of this device. According to the invention the device can also be used for pure or mixed cultures of various microorganisms whereby, above all, information about the toxicity of individual substances can be obtained.

Abstract: Disclosed is a method of adsorbing and removing NOx, by washing with water a gas discharged by ventilation from highway tunnels in a washing tower as pretreatment, and then adsorbing NOx in the gas with a rotary NOx adsorption unit. The washed gas may be heated by a heater which is placed between the washing tower and the rotary NOx adsorption unit.

Abstract: A gas mixture comprised of nitric oxide and, optionally an inert gas, and containing small amounts of nitrogen dioxide, and perhaps moisture and sulfur dioxide, is purified by passing the gas stream through a bed of metal cation-free alumina-deficient zeolites of types Y or ZSM-5. The concentrations of nitrogen dioxide, sulfur dioxide and moisture in the gas stream are reduced to about 1 ppm or less as the gas mixture passes through the bed of zeolite.

Abstract: Removal NO.sub.x and SO.sub.x from the flue gas utilizing a transport line adsorber through which sorbent is transported by pressurized flue gas to cause the sorbent to absorb NO.sub.x and SO.sub.x from the flue gas while the flue gas is transporting the sorbent particles through the transport line adsorber. A plurality of interconnected cyclones may be utilized to contact sorbent saturated with NO.sub.x and SO.sub.x removed from the flue gas with a heated gas to heat the sorbent and remove the NO.sub.x from the sorbent and separate the sorbent and the heated gas to produce an off stream of heated gas carrying the removed NO.sub.x away; the heated gas and gravity combine to pass the sorbent through the plurality of cyclones and which cyclones are positioned vertically and successively downwardly with respect to each other. A plurality of interconnected cyclones is also utilized to contact heated sorbent having the NO.sub.x and SO.sub.

Abstract: An apparatus and process is provided for the production of hot mix asphalt (HMA) by the treatment of virgin material alone or adding reclaimed or recycled asphalt pavement (RAP) of up to 100% of the HMA comprised of reclaimed asphaltic pavement (RAP). The HMA is first heated in either a parallel or a counter flow rotating drum which is supplied with hot combustion gases generated by a remote low NO.sub.x burner. The temperature of hot gases entering the drum is from about 400.degree. to 2,000.degree. F., and the temperature of gases exiting from the drum is from about 130.degree. to 220.degree. F. The HMA material optionally can be subjected to microwave radiation to raise the material to a final temperature, or optionally to only reorient the dipolar molecules of the material without any measurable heating of the material. The exhaust gas is treated and made environmentally safe.

Abstract: Removal of NO.sub.x and SO.sub.x from flue gas utilizing a transport line adsorber through which sorbent is transported by pressurized flue gas to cause the sorbent to adsorb NO.sub.x and SO.sub.x from the flue gas while the flue gas is transporting the sorbent through the transport line adsorber A plurality of interconnected cyclones is utilized to contact sorbent saturated with NO.sub.x and SO.sub.x removed from the flue gas with a heated gas to heat the sorbent and remove the NO.sub.x from the sorbent and separate the sorbent and the heated gas to produce an off stream of heated gas carrying the removed NO.sub.x away; the heated gas and gravity combine to pass the sorbent through the plurality of cyclones and which cyclones are positioned vertically and successively downwardly with respect to each other. A plurality of interconnected cyclones is also utilized to contact heated sorbent having the NO.sub.x and SO.sub.

Abstract: This invention relates to a production process of formed activated coke for SOx and NOx removal which is employed in treatment systems for various flue gases and the like.The formed activated coke for SOx and NOx removal obtained in accordance with the process of this invention has excellent pressure resistance, abrasion resistance and impact strength and also superb SOx- and NOx-removing ability, so that the coke is suitable for use in moving-bed, SOx and NOx- removing systems.The formed activated coke for SOx and NOx removal can of course show excellent SOx- and NOx-removing effects when employed in conventional SOx- and NOx-removing processes and, moreover, owing to its characteristic high NOx-removing ability, is suited for the removal of NOx from low-SOx flue gas of a fluidized-bed combustion boiler or cogeneration power plant.According to the process of this invention, dried, formed activated coke prepared from coal as a raw material is reacted with SO.sub.3 gas at 100.degree.-300.degree. C.

Abstract: In this method and this apparatus exit gases to be purified from kiln installations are first of all dedusted in a first filter stage and then in at least one further filter stage they are purified of the NH.sub.x compounds and/or volatile pollutant elements and compounds with at least partial reduction of NO.sub.x with the aid of a carbonaceous filter medium. In order that the filter dust precipitated in the first filter stage can without problems either be re-used in a suitable manner of deposited in simple refuse dumps, the proportion of low-boiling pollutants and pollutant compounds in this precipitated filter dust is reduced by successive method steps in which the said pollutants are evaporated out of the filter dust, the quantities of dust are precipitated out of these vapors and the dedusted vapours are passed through a filter unit containing a carbonaceous filter medium.

Abstract: A process of preparing lignite (low rank) coal filter material, suitable for use in lieu of more expensive activated carbon filter materials, is disclosed. The process comprises size reducing Leonardite coal material to a suitable filtering effective size, and thereafter heating the size reduced Leonardite preferably to at least 750.degree. C. in the presence of a flow of an inert gas.

Abstract: A process is provided for removing sulfur oxides from gaseous mixtures such as flue gases or tail gases. The process involves contacting the gaseous mixture with a non-functionalized polymeric sorbent which is essentially hydrophobic, such as styrenic polymers. The process may utilize pressure swing adsorption techniques, and is capable of producing a desorption stream with an SO.sub.2 concentration suitable for immediate conversion to elemental sulfur by the Claus process.