Abstract: Process for adsorbing undesirable constituents from a waste gas by feeding the waste gas through at least one reaction chamber filled with lumpy or granular adsorbent, and through at least one adsorption layer. The adsorbent is introduced into the reaction chamber and discharged therefrom through several separate feed and discharge hoppers in a grid-like distribution. The waste gas is guided in part from the side transversely to the adsorption layer and in part vertically through the reaction chamber by introducing the waste gas between the separate feed hoppers from above to flow downward through an exposed upper surface of the adsorbent in such a manner that the adsorbent in all zones of the reaction chamber participates practically uniformly in the adsorption.

Abstract: The present invention relates to a process for generating reactive species for destroying toxic chemicals. This process first contacts air or oxygen with aqueous emulsions of molten yellow phosphorus. This contact results in rapid production of abundant reactive species such as O, O.sub.3, PO, PO.sub.2, etc. A gaseous or liquid aqueous solution organic or inorganic chemicals is next contacted by these reactive species to reduce the concentration of toxic chemical and result in a non-toxic product. The final oxidation product of yellow phosphorus is phosphoric acid of a quality which can be recovered for commercial use. A process is developed such that the byproduct, phosphoric acid, is obtained without contamination of toxic species in liquids treated. A gas stream containing ozone without contamination of phosphorus containing species is also obtained in a simple and cost-effective manner.

Abstract: A combustion gas is cooled a first time to about 110.degree. C. in a first cooling chamber (3), up to 90% of the ashes is removed in a first precipitator (9) then the gas is cooled again in a second cooling chamber (10), to about 80.degree. C.; in a reaction chamber (13), by energization by means of electrons the sulphur dioxide and nitrogen oxides are converted into sulphuric acid and nitric acid and, with the addition of dry ammonia (15) the two said acids are converted to salts of ammonia, the latter are retained in a second precipitator (21) and sent to a chimney; characteristics of the method and the plant are that, from the instant of the injection of the ammonia into the reaction chamber (13), the temperature of the gas is maintained at above 80.degree. C.

Abstract: A dual-phase zeolite having a transition metal-containing zeolite phase and a transition metal-containing oxide phase. The catalytic material may be an intimate mixture of a phase-layered structure of a first phase constituted preferably of a copper-containing high silica zeolite and a second phase constituted of copper-containing zirconia.Methods are also disclosed for making a single-stage catalyst for removing NO.sub.x and HC at high efficiency in an oxygen-rich automotive exhaust gas, and for treating the exhaust gas with the dual-phase catalyst above.

Abstract: A process for removing NO.sub.x oxides and SO.sub.x oxides from gaseous streams contacts the gaseous stream with an aqueous solution of chloric acid. The process of the invention removes sulfur oxides and nitrogen oxides from waste gas streams without producing inorganic salts. In addition, the use of chloric acid provides improved oxidation of NO and SO.sub.2. The process can be operated to treat "dirty" gas streams containing particulates and compounds which may poison or contaminate NO.sub.x removal systems employing catalysts.

Abstract: Process for desulfurizing combustion gas wherein the gas is fractionated into at least two flows which pass through distinct passageways (4 and 5) and receive particles of a solid desulfurizing agent coming from distinct injectors (7 and 8) . The two particle-charged flows meet (9) , are separated again (10 and 11) and meet again thereafter (12). The process can be repeated several times. The final mixture is carried off and fractionated into desulfurized gas and recovered solid particles.

Abstract: A method of reducing a nitrogen oxide content in gas is disclosed. In this method, subject gas containing nitrogen oxide is supplied to a gas passage of a surface discharger to decompose the nitrogen oxide content in the gas into nitrogen gas.

Abstract: A method for cleaning an exhaust gas containing ammonia and at least one silicon-containing compound selected from the group consisting of silane and chlorosilanes, which comprises contacting the exhaust gas with a scavenger comprising a metal salt which forms tight complexes with ammonia. This ammine-forming metal salt may be immobilized on a porous solid support. Suitable ammine-forming metal salts include the sulfates, nitrates, chlorides, bromides, iodides, and hydroxides of copper, cobalt, iron, and nickel. Suitable supports include materials which are compatible with the gas mixtures being cleaned and the reaction products of the sorption process and which are stable under the conditions of use. Useful support materials include zeolites, aluminosilicates, alumina, silica, silica gel, kieselguhr, and activated carbon.

Abstract: A deoxo unit is operated with excess oxygen to produce high purity nitrogen from a partially purified stream passing from a membrane or pressure swing adsorption unit. Essentially complete fuel utilization is achieved in applications in which essentially oxygen-free nitrogen product is not required.

Abstract: Generation, use, and treatment of new and unique process waters in or for wet-process phosphoric acid manufacturing to substantially eliminate discharge of contaminants to the environment. Acid pond water from conventional wet-process phosphoric acid manufacturing, contaminated with compositions containing fluorine, heavy metals, and radioactive elements such as radium-226, plus residual P.sub.2 O.sub.5, is superseded. Substantially all contaminants from the wet-process are insolubilized and removed, whereas P.sub.2 O.sub.5 normally lost is recovered. Decontaminated gypsum stack water with a mildly acidic pH results from stepwise raising of wastewater pH, with clarification, and subsequent re-acidification, to provide a decontaminated process water with slightly acidic pH adapted to match the pH of environmental ground water. The process is made more economical, while enhancing protection of surrounding air, soil, and water from contaminants.

Abstract: A process for the conversion of nitrous oxide (N.sub.2 O) to nitrogen and oxygen by treating the gas with a catalyst of cobalt oxide and nickel oxide on a zirconia support at a temperature of at least about 280 degrees C.

Abstract: A method is provided for removing sulfur dioxide from a hot gaseous stream while directly producing .alpha.-hemihydrate gypsum from a scrubber effluent. A portion of an aqueous scrubbing medium containing calcium and magnesium sulfite is removed from a scrubbing unit and passed to a pressurized oxidation vessel where the sulfites are contacted with an oxidizing gas at an elevated temperature to convert calcium sulfite directly to .alpha.-hemihydrate gypsum and magnesium sulfite to magnesium sulfate. The .alpha.-hemihydrate is separated from the aqueous medium removed from the pressurized oxidation vessel.

Abstract: An enhanced calcium hydroxide, a process for its manufacture and a process for its use in the removal of volatile heavy metals from a gas is disclosed.

Abstract: The invention refers to a method in cleaning flue gas in a PFBC plant including a gas turbine driven thereby, wherein the reduction of the NO.sub.x content in the flue gas is accomplished by thermal reduction by injecting ammonia into the flue gas flow to the gas turbine and then accomplished catalytically entailed reduction in the presence of ammonia in the flue gas flow from the gas turbine.

Abstract: A catalyst for decomposing dinitrogen monoxide which is pure or present in gas mixtures comprises metallic silver applied to an alumina carrier with a BET surface area of from 5 to 25 m.sup.2 /g.

Abstract: A hot-side electrostatic precipitator removes particulate matter from a NOX-containing flue gas stream passing therethrough, the exit flue gas stream having a temperature of no less than about 450F. The precipitator contains a plurality of collecting surfaces arranged in a series of fields. At least some of the collecting surfaces carry a catalyst which promotes a reaction between NOX in the flue gas passing therethrough and a nitrogeneous compound. Preferably, a nitrogeneous compound such as ammonia is electrically charged and injected into the flue gas stream prior to its passing over the collecting surfaces coated with catalyst. The hot-side electrostatic precipitator may have catalyst coated onto fixed surfaces near its exit end.

Abstract: A process for the reduction of nitrogen oxides in the effluent of a gas turbine is presented. This process comprises forming an emulsion which comprises water and fuel oil and combusting the emulsion in the combustion can of a gas turbine to form an effluent; and contacting the effluent with a catalyst effective for the reduction of nitrogen oxides therein.

Abstract: A method of vaporizing aqueous reducing agent for reducing NO.sub.x in flue gas in a combustion system. A heat exchanger is disposed in the flue gas path so that heat from the flue gas heats a heat transfer medium, preferably ambient air. The heated air is passed to a vaporizer vessel where it vaporizes an aqueous reducing agent, preferably aqueous ammonia. The vaporized ammonia is injected into the flue gas path where it is effective to reduce NO.sub.x. Some aspects of an automatic control system are disclosed.

Abstract: A stable processing of a waste gas containing halogen-containing materials is rendered possible without fear of increase of the pressure loss or clogging of a louver unit near the waste gas inlet in a second moving bed due to accumulation of the halogen components. This can be accomplished by a process for the desulfurization and denitrification of a waste gas containing halogen-containing materials in addition to SO.sub.x and NO.sub.

Abstract: A method for removing nitrogen oxides and organic chlorine compounds from a combustion waste gas, which comprises the steps of: adding ammonia (NH.sub.3) as a reducing agent to a combustion waste gas containing nitrogen oxides and organic chlorine compounds; causing the combustion waste gas added with ammonia to contact with, while keeping the temperature of the combustion waste gas within a prescribed range, with a catalyst comprising at least one selected from the group consisting of platinum (Pt), palladium (Pd), ruthenium (Ru), manganese (Mn), copper (Cu), chromium (Cr) and iron (Fe) and oxides thereof, supported on the surface of a carrier comprising at least one selected from the group consisting of titanium oxide (TiO.sub.2), silicon oxide (SiO.sub.2), aluminum oxide (Al.sub.2 O.sub.3) and zirconium oxide (ZrO.sub.2), thereby removing nitrogen oxides and organic chlorine compounds from the combustion waste gas.