Corning Incorporated

J Paul Day

David L Hickman

Kenneth Chyung

Steven Bolaji Ogunwumi

Willard A Cutler

Louis S Socha, Jr

Anthony R Olszewski

Lawrence S Rajnik

Louis M Holleran

Timothy V Johnson

Shahid G Lakhwani

Ronald D Quinn

A catalyst for purification of exhaust gases including (1) a catalysis-promoting coating comprising a noble metal catalyst and a NOx storage component loaded onto a carrier material, wherein the NOx storage component comprises an alkali metal and, (2) a ceramic substrate for supporting the catalysis-promoting coating, wherein the ceramic substrate exhibits resistance to alkali metal migration below 1000&#xb0; C. and a coefficient of thermal expansion of less than about 25&#xd7;10/&#xb0; C. (25-800&#xb0; C.). A second aspect of, the invention is a process for purifying an exhaust gas from a lean burn engine involving simultaneously removing carbon monoxide, hydrocarbons and nitrogen oxides by bringing the exhaust gas from a lean burn engine into contact with the exhaust gas purifying catalyst of the present invention disclosed above. In this process a majority of the nitrogen oxides in the exhaust gas are adsorbed to the NOx storage component on the porous support under a lean burn atmosphere in which oxidizing concentrations are above a stoichiometric point that is required for oxidizing components to be oxidized in the exhaust gas. Furthermore, when the exhaust gas is temporarily change from lean burn to fuel-rich, the adsorbed nitrogen oxides are released and chemically reduced by a reaction with the hydrocarbons and carbon monoxide in the exhaust gas under a stoichiometric atmosphere or a fuel-rich atmosphere in which oxygen concentrations are below stoichiometric point.

Catalyst for purifying exhaust gases

A preform for a z-flow honeycomb filter is formed by a pressing process wherein a batch charge is shaped in a press into a preform of finished plug-and-channel configuration, the shaped preform comprising opposing overlapping arrays of closed-end inlet and outlet channels wherein the end closures consist of bridging segments of batch material connected in continuous (seamless) or uninterrupted fashion with the adjoining channel walls.

Pressed porous filter bodies

Beta-spodumene bodies and method of preparing the bodies that involves providing a uniform plastic batch of inorganic raw materials, organic binder, and vehicle, wherein the inorganic raw materials are composed of, in percent by weight, about 75% to 95% minerals, and about 5% to 25% glass. The batch is formed into a green body that is fired to produce a body composed substantially of beta-spodumene, and having a thermal expansion coefficient of &lt;10.times.10.sup.-7 /.degree.C.(0-800.degree. C.), and a strength of .gtoreq.4 Ksi.

Method of producing .beta.-spodumene bodies

Honeycomb filters for the filtration of molten metal streams comprise a triangular cell cross-section in combination with specified cell density, cell wall thickness, filter open frontal area and geometric surface area, thereby offering improved filtration performance when compared with similar filters of square or circular cell design.

Triangular cell metal filters

Extruded rectangular-channel ceramic honeycombs wherein the channels have a rectangular cross-section of aspect ratio 1.2:1 or greater and a hydraulic diameter D.sub.h and constant temperature Nusselt Number N.sub..mu. ('shape' heat transfer characteristic) yielding an 'effective' channel surface area factor N.sub..mu. /D.sub.h of at least about 70, provide catalytic substrates for engine exhaust emissions control offering better light-off performance, enhanced conversion efficiency at current converter pressure drops, and/or equivalent efficiency at reduced pressure drops.

Rectangular-channel catalytic converters

Extruded low-expansion ceramic honeycombs comprising beta-spodumene solid solution as the principal crystal phase and with less than 7 weight percent of included mullite are produced by compounding an extrusion batch comprising a lithium aluminosilicate glass powder and a clay additive, extruding a green honeycomb body from the batch, and drying and firing the green extruded cellular honeycomb to crystallize the glass and clay into a low-expansion spodumene ceramic honeycomb body.

Extruded ceramic honeycomb and method

A vapor-phase method for treating a beta-spodumene ceramic article to achieve a substitution of exchangeable hydrogen ions for the lithium present in the beta-spodumene crystals, wherein a barrier between the ceramic article and the source of exchangeable hydrogen ions is maintained in order to prevent lithium contamination of the hydrogen ion source and to generate highly recoverable lithium salts, is provided.

Method for treating beta-spodumene ceramics

An engine exhaust system disclosed which is designed to reduce hydrocarbon emissions caused by the evaporation of fuel from the fuel tank and by the inefficiency of combustion and catalytic conversion during cold engine start-up. This system utilizes molecular sieves, such as high-silica zeolites, which adsorb hydrocarbons evaporating from the fuel tank or emitted during engine start-up, before the catalytic converter has attained an effective operating temperature. This system is designed so that hydrocarbons that would otherwise be emitted to the atmosphere from the fuel tank or by passing through the converter unconverted are held within the system either for combustion in the engine or passage through the converter once it is operating efficiently.

Engine exhaust system for reduction of hydrocarbon emissions

A molten metal filter is disclosed having a carbon or carbon-thermite coating that reduces thermal shock to the filter, and protects the filter from corrosion from the metal or components and impurities in the metal, and prevents metal from freezing in the filter. A molten metal assembly suitable for casting molten metal is disclosed which comprises a filter for molten metal and means for molten metal flow passage leading through the filter. The means have surfaces defining a molten metal path. The filter has a coating of carbon or carbon in intimate contact with a thermite material on the surface of the filter. A process is disclosed for filtering molten metal which comprises passing molten metal through the above described coated filter.

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Big Flats, NY, United States of America

J Paul Day