Abstract: The N.sub.2 O values in gaseous effluents, notably those produced in various organic syntheses entailing nitric acid oxidation (for example the industrial scale production of adipic acid, of glyoxal and of glyoxylic acid), are catalytically decomposed at elevated temperatures over H-mordenite and ammonium mordenite catalysts, preferably the ammonium mordenites that have been exchanged with iron, cobalt or bismuth.

Abstract: The invention provides a catalyst, and a process for preparing the same, for the catalytic reduction of NO.sub.x and for the oxidation of hydrocarbons. The catalyst contains a copper oxide-zinc oxide-aluminum oxide spinel and a zeolitic support material.

Abstract: An organically modified clay comprises a smectite clay of the type having exchangeable, inorganic, cationic species therein, in which at least a portion of the inorganic cationic species have been substituted by a mixture of organic cations comprising X.sub.2 R.sub.2 N.sup.+ and XYR.sub.2 N.sup.+, wherein X is methyl, Y is benzyl and R is saturated alkyl. Also disclosed is a method for the fabrication of the modified clay.

Abstract: A process for preparing a modified Y-zeolite, in which a NaY-zeolite is first subjected to an ammonium exchange, the resulting ammonium-exchanged zeolite is subjected to an aluminum exchange, the aluminum-exchanged zeolite is subjected to a steam calcination, and a phosphorus component is incorporated into the steam calcined zeolite, is disclosed. The modified Y-zeolite obtained by this process and an FCC catalyst containing the modified Y-zeolite are also disclosed. The FCC catalyst containing the aluminum-exchanged phosphorus-containing Y-zeolite prepared according to the present invention shows less coke make, and an improved selectivity to C.sub.3 olefins compared to FCC catalysts containing zeolites which have either been aluminum exchanged or contain phosphorus.

Abstract: A method for producing chlorine dioxide by moving fluid (such as air) relative to a first bed of zeolite crystals impregnated with sodium chlorine and/or zeolite crystals impregnated with chlorine, and by moving the fluid relative to a second bed of zeolite crystals impregnated with one of the following: phosphoric acid, acetic acid and citric acid. The first and second beds may be physically mixed together. A further aspect of the present invention relates to removing chlorine dioxide from a fluid by moving the fluid relative to a bed of zeolite crystals impregnated with one of the following: potassium hydroxide, sodium sulfite, sodium bisulfate and ferrous sulfate. This method may be used to remove chlorine dioxide produced using the method for producing chlorine dioxide described above.

Abstract: A method for producing chlorine dioxide by moving fluid (such as air) relative to a first bed of zeolite crystals impregnated with sodium chlorite and/or zeolite crystals impregnated with chlorine, and by moving the fluid relative to a second bed of zeolite crystals impregnated with at least one of the following: phosphoric acid, acetic acid and citric acid. The first and second beds may be physically mixed together.

Abstract: There is provided a zeolite catalyst, which is first selectivated with a siliceous material and then treated with an aqueous solution comprising a dealuminizing agent such as an acid or a chelating agent.

Abstract: Low expansion molecular sieves bodies and method of making them which involves forming a mixture of up to about 40 weight parts of a thermal expansion control component which can be at least one of zircon, feldspar, calcium silicate, talc, steatite, forsterite, kyanite sillimanite, nepheline syenite, glasses, about 10 to 30 weight parts of permanent binder, at least 50 weight parts of molecular sieve, and temporary binder which can be cellulose ethers, cellulose ether derivatives, and combinations thereof, in a vehicle. The mixture is shaped into a green body which is then dried and fired to produce the product body. Among the preferred bodies are zeolites which find use in hydrocarbon adsorption, denox, and three-way catalyst applications.

Abstract: The NOx content of FCC regenerator flue gas is reduced using a spinel/perovskite additive which maintains activity during FCC operation in the presence of high levels of sulfur oxides and oxygen. Additionally, a stabilization component may be added to enhance catalytic stability of the additive, and a cracking component may be added under conditions of low reducing agents in the regenerator flue gas.

Abstract: Catalytic decomposition of nitrous oxide in the presence of oxygen is achieved using a solid oxide solution of the formula:La.sub.0.8 Sr.sub.0.2 MO.sub.3.+-..differential.where:M is a transition metal, and is preferably selected from the group consisting of Cr, Mn, Fe, Co and Y; and.differential. is the deviation from stoichiometric balance; or:La.sub.1.8 Sr.sub.0.2 CuO.sub.4.+-..differential.where:.differential. is the deviation from stoichiometric balance. The solid oxide solution catalyst exhibits catalytic activity for nitrous oxide decomposition which rivals or exceeds that of dispersed noble metals on alumina.

Abstract: A process for removing environmental contaminants from an exhaust gas by a semidry method through contact with an absorbent slurry containing alkaline compounds in a reactor, comprising the steps of adding a material containing calcium sulfate and/or calcium sulfite, a material containing aluminum oxide, and a material containing silicon dioxide to a material capable of supplying calcium oxide, mixing the mixture with water, curing the whole mixture in hot water, and then introducing and dispersing the resulting absorbent slurry in the reactor for contact with the environmental contaminants. In a modification the absorbent slurry is obtained by adding a material capable of supplying aluminum oxide, silicon dioxide, and calcium sulfate and/or calcium sulfite to a material capable of supplying calcium oxide, calcining the mixture at 750.degree.-950.degree. C., mixing the calcined product with water, and curing the mixture in hot water.

Abstract: A NO.sub.x removal catalyst resistant to high temperatures, comprising an activated alumina wherein the specific surface area measured by the nitrogen adsorption method is 120 m.sup.2 /g or more, the bulk density measured by the mercury porosimetry is 0.60 g/cm.sup.3 or more, and the skeleton density measured by the mercury porosimetry is 1.80 g/cm.sup.3 or less and silver carried on said activated alumina. When said catalyst or a structure having said catalyst coated on a substrate is brought in contact with exhaust gas from an internal combustion engine that is operated at a lean fuel/air ratio, such as a lean-burn engine, NO.sub.x can be removed efficiently within a quite short contact time.

Abstract: An in situ process for making improved zeolitic fluid cracking catalyst by spray drying a mixture of hydrous kaolin, gibbsite and spinel, essentially free from metakaolin, calcining the resulting microspheres to convert the hydrous kaolin to metakaolin whereby the gibbsite is hydrothermally converted to a transitional alumina, and reacting the microspheres composed of a mixture of spinel, transitional alumina and metakaolin with a seeded alkaline sodium silicate solution.

Abstract: There is presented a specially prepared catalyst and a process for the treatment of exhaust gas with that catalyst, which is useful for the selective catalytic reduction of NO.sub.x contained in the exhaust gas. An embodiment of the process of this invention comprises a catalytic stage to selectively catalytically reduce NO.sub.x over a catalyst composition comprising a metal and an in-situ crystallized zeolite, ZSM-5. The catalyst of this invention may be formed into a desired shape, e.g., by extrusion, and finished in a humidified atmosphere after forming.

Abstract: This invention relates to the preparation of supported gold catalysts for carbon monoxide oxidation. The supported gold catalysts were obtained by cation exchange of gold ion into ion exchangeable supports. After being heated in a stream of humidified inert gas at an elevated temperature, the resultant catalysts possess not only high catalytic activities for carbon monoxide oxidation but also good water-durability.

Abstract: A method of purifying NOx-containing exhaust gases characterized by using ammonium acetate as a reducing agent with a zeolite-based catalyst. NO.sub.x in NO.sub.x -containing exhaust gases can be removed extremely effectively even at a low concentration thereof by using Fe-treated mordenite as a zeolite-based catalyst according to said method, and since it uses ammonium acetate as a reducing agent, an excellent effect free from ammonia leakage can be obtained. Particularly NO.sub.x in NO.sub.x -containing exhaust gases can be removed effectively at and around a discharge temperature of an exhaust gas from a gas engine in the presence of ammonium acetate as a reducing agent by constituting Fe-containing mordenite as a monolithic material. Hence, it makes it possible to obtain an excellent effect of simplifying the whole denitration system without needing temperature control of an exhaust gas and/or a catalyst bed. In addition, the NO.sub.

Abstract: The present invention relates to a process for the use of a urea hydrolysate for nitrogen oxides reductions. More particularly, the process involves forming a urea hydrolysate under conditions of low pressure and introducing the hydrolysate into a combustion effluent under conditions effective for the reduction of nitrogen oxides.

Abstract: A process for efficiently reducing nitrogen oxides in exhaust gases including excess oxygen. The process includes intermittently introducing a reducing agent, such as hydrogen and carbon monoxide, for reducing nitrogen oxides to a reducing catalyst, such as platinum, disposed in an exhaust gas passage while maintaining an oxygen excess condition. The reducing agent is intermittently introduced in a manner to satisfy the following equation:[NO.sub.x ]<[H.sub.2 ]+[CO], wherein [H.sub.2 ], [CO] and [NO.sub.x ] are molar concentrations of hydrogen, carbon monoxide and nitrogen oxides, respectively. The reducing catalyst may include a transition metal, an alkaline metal and/or an alkaline earth metal.

Abstract: Process for cleaning a gas containing sulphur dioxide and nitrogen monoxide, in which a quantity of oxygen is employed in the gas which is at least equal to the stoichiometric quantity required to oxidize the nitrogen monoxide to nitrogen dioxide and the gas is treated with an alkali metal bicarbonate. The process applies to the cleaning of fumes generated by the combustion of sulphur-containing fossil fuels, in electricity-producing power stations.

Abstract: Improved processes and improved compositions reduce the environmental damage caused by large-scale combustion, especially in the field of NO.sub.x reduction by selective noncatalytic reduction (SNCR) in the gas phase. In one aspect, the process improves the reliability of known means, compositions and methods for reducing the concentration of pollutants in a gas stream by: preparing an aqueous solution comprising a pollutant-reducing agent and a water-dispersible polymer, and introducing the solution into the gas stream. Preferred polymers comprise high molecular weight polymers selected from the group consisting of homo and copolymers of acrylic acid and acrylamide with RSV values of at least 10, sodium acrylate acrylamide copolymers with RSV values of at least 10, sulfonmethylated acrylamide/acrylamide/acrylic acid terpolymers of RSV of at least 18, alkylene oxide polymers and copolymers, and mixtures of any of these and like polymers.