1547 results about "Partial oxidation" patented technology

A method of removing at least a portion of a silicon oxide material is disclosed. The silicon oxide is removed by exposing a semiconductor structure comprising a substrate and the silicon oxide to an ammonium fluoride chemical treatment and a subsequent plasma treatment, both of which may be effected in the same vacuum chamber of a processing apparatus. The ammonium fluoride chemical treatment converts the silicon oxide to a solid reaction product in a self-limiting reaction, the solid reaction product then being volatilized by the plasma treatment. The plasma treatment includes a plasma having an ion bombardment energy of less than or equal to approximately 20 eV. An ammonium fluoride chemical treatment including an alkylated ammonia derivative and hydrogen fluoride is also disclosed.

The invention forms an epitaxial silicon-containing layer on a silicon germanium, patterned strained silicon, or patterned thin silicon-on-insulator surface and avoids creating a rough surface upon which the epitaxial silicon-containing layer is grown. In order to avoid creating the rough surface, the invention first performs a hydrofluoric acid etching process on the silicon germanium, patterned strained silicon, or patterned thin silicon-on-insulator surface. This etching process removes most of oxide from the surface, and leaves only a sub-monolayer of oxygen (typically 1×10¹³-1×10¹⁵/cm² of oxygen) at the silicon germanium, patterned strained silicon, or patterned thin silicon-on-insulator surface. The invention then performs a hydrogen pre-bake process in a chlorine containing environment which heats the silicon germanium, strained silicon, or thin silicon-on-insulator surface sufficiently to remove the remaining oxygen from the surface. By introducing a small amount of chlorine containing gases, the heating processes avoid changing the roughness of the silicon germanium, patterned strained silicon, or patterned thin silicon-on-insulator surface. Then the process of epitaxially growing the epitaxial silicon-containing layer on the silicon germanium, patterned strained silicon, or patterned silicon-on-insulator surface is performed.

The present invention provides systems and methods to improve the performance and emission control of internal combustion engines equipped with nitrogen oxides storage-reduction (“NSR”) emission control systems. The system generally includes a NSR catalyst, a fuel processor located upstream of the NSR catalyst, and at least one fuel injection port. The fuel processor converts a fuel into a reducing gas mixture comprising CO and H₂. The reducing gas mixture is then fed into the NSR catalyst, where it regenerates the NSR adsorbent, reduces the NO_x to nitrogen, and optionally periodically desulfates the NSR catalyst. The fuel processor generally includes one or more catalysts, which facilitate reactions such as combustion, partial oxidation, and/or reforming and help consume excess oxygen present in an engine exhaust stream. The methods of the present invention provide for NSR catalyst adsorbent regeneration using pulsed fuel flow. Control strategies are also provided.

A catalyst for treating the exhaust gas from internal combustion engines is provided, wherein the catalyst contains two catalytically active layers supported on a support. The first catalytically active layer contains a platinum group metal in close contact with all of the constituents of the first catalytically active layer, wherein the constituents of the first catalytically active layer include particulate aluminum oxide; particulate oxygen storage material, such as cerium oxide, cerium/zirconium and zirconium/cerium mixed oxides, and alkaline earth metal oxides. The second catalytically active layer, which is in direct contact with the exhaust gas, contains particulate aluminum oxide and at least one particulate oxygen storage material, such as cerium oxide, cerium/zirconium and zirconium/cerium mixed oxides. Rhodium is supported on part of the aluminum oxides in the second catalytically active layer or on the particulate oxygen storage material in the second catalytically active layer. By providing the platinum group metal in close contact with all of the constituents of the first catalytically active layer, improved conversion efficiency of the impurities in the exhaust gas can be achieved.

A process for the partial catalytic oxidation of a hydrocarbon containing feed comprising contacting the feed with an oxygen-containing gas in the presence of a catalyst retained within a reaction zone in a fixed arrangement, wherein the catalyst comprises at least one catalytically active metal selected from the group consisting of silver and Group VIII elements supported on a porous ceramic carrier. The porous ceramic carrier has a distribution of total pores wherein about 70% of the total pores (1) have a volume-to-surface area (V/S) ration that is within about 20% of the mean V/S value for the total pores and no pores have a V/S ration that is greater than twice the mean V/S value for the total pores; (2) have a pore-to-pore distance between neighboring pores that is within about 25% of the mean pore-to-pore distance between neighboring pores; and (3) have a pore throat area that is within about 50% of the mean pore throat are for the pores. Additionally, about 50% of the total pores have a coordination number between neighboring pores that is within about 25% of the mean coordination number between neighboring pores. Preferably, the oxidation process comprises a multistage, staged oxygen, catalytic partial oxidation process having fewer than or equal to about five stages and including a first stage preheat temperature of greater than about 550° C., and wherein the temperature of the product mixture in each stage following the first stage is at least about 700° C.

A steam methane reforming method in which a feed stream is treated in a reactor containing a catalyst that is capable of promoting both hydrogenation and partial oxidation reactions. The reactor is either operated in a catalytic hydrogenation mode to convert olefins into saturated hydrocarbons and/or to chemically reduce sulfur species to hydrogen sulfide or a catalytic oxidative mode utilizing oxygen and steam to prereform the feed and thus, increase the hydrogen content of a synthesis gas produced by a steam methane reformer. The method is applicable to the treatment of feed streams containing at least 15% by volume of hydrocarbons with two or more carbon atoms and/or 3% by volume of olefins, such as a refinery off-gas. In such case, the catalytic oxidative mode is conducted with a steam to carbon ratio of less than 0.5, an oxygen to carbon ratio of less than 0.25 and a reaction temperature of between about 500° C. and about 860° C. to limit the feed to the steam methane reformer to volumetric dry concentrations of less than about 0.5% for the olefins and less than about 10% for alkanes with two or more carbon atoms.

The present invention provides several variations for converting biomass, and other carbon-containing feedstocks, into syngas. Some variations include pyrolyzing or torrefying biomass in a devolatilization unit to form a gas stream and char, and gasifying the char. Other variations include introducing biomass into a fluid-bed gasifier to generate a solid stream and a gas stream, followed by a partial-oxidation or reforming reactor to generate additional syngas from either, or both, of the solid or gas stream from the fluid-bed gasifier. Hot syngas is preferably subjected to heat recovery. The syngas produced by the disclosed methods may be used in any desired manner, such as conversion to liquid fuels (e.g., ethanol).

Disclosed is a process for the preparation of superheated of steam by transferring heat from at least a fraction of a high pressure steam to a lower pressure steam to produce a superheated, lower pressure steam. The high pressure steam can be generated by recovering heat from a heat producing chemical process such as, for example, the partial oxidation of carbonaceous materials. The lower pressure steam can be generated by reducing the pressure of a portion of the high pressure steam or by recovering heat from one or more chemical processes. The superheated, lower pressure steam may used to generate electricity in a steam turbine, operate a steam turbine drive, or as a heat source. Also disclosed is a process for driving a steam turbine using superheated steam produced by the process of the invention.

A catalyst has a base catalyst layer containing platinum and barium as precious metal supported by alumina and an over catalyst layer containing platinum and rhodium as precious metal supported by zeolitr. The platinum and rhodium in the over catalyst layer activate NOx and HC so as to make them more reactive in terms of energy, and the barium in the base catalyst layer makes the platinum be more dispersive in the base catalyst layer. Under the existence of dispersive platinum, NOx in exhaust gas is decomposed and purified by reaction with reactive NO2 and partially oxidized HC generated in the over catalyst layer.

The invention discloses a hydro dewaxing catalyst and the preparation method. In the method, compound with hydrogen active component is mixed with aluminum dry gel to prepare adhesive; and then the adhesive is mixed with shape-selective cracked zeolite and is pinched in shape; after drying and roasting, catalyst carrier is yielded; then the catalyst carrier is impregnated in the impregnating solution containing the rest active component and promoter; and after drying and roasting again, the catalyst of the invention is yielded. The invention is capable of taking full advantage of the alumina used as adhesive in the catalyst carrier under low hydrogen active component content conditions to prepare adhesive containing all the molybdenum and tungsten and part of the nickel, thereby keeping a certain amount of nickel oxide in the zeolite. The rest of the active metal component is distributed in the alumina, keeping the zeolite passage unobstructed with good hydro dewaxing effect and effectively improving the hydrogen addition and purification performance of the catalyst. The catalyst is especially suitable for hydro dewaxing of raw material containing wax and with high nitrogen impurity content and suitable for hydrogen addition and purification.

A method and device for the gasification of pulverized fuels from solid fuels such as bituminous coals, lignite coals, and their cokes, petroleum cokes, coke from peat or biomass, in entrained flow, with an oxidizing medium containing free oxygen, by partial oxidation at pressures between atmospheric pressure and 80 bar, and at temperatures between 1,200 and 1,900° C., at high reactor capacities between 1,000 and 1,500 MW. The method uses the following steps: metering of the fuel, gasification reaction in a gasification reactor with cooled reaction chamber contour, quench-cooling, crude gas scrubbing, and partial condensation.

This invention relates to methods for reacting a hydrocarbon, molecular oxygen, and optionally water and/or carbon dioxide, to form synthesis gas. The preferred embodiments are characterized by delivering a substochiometric amount of oxygen to each of a multitude of reaction zones, which allows for optimum design of the catalytic packed bed and the gas distribution system, and for the optimization and control of the temperature profile of the reaction zones. The multitude of reaction zones may include a series of successive fixed beds, or a continuous zone housed within an internal structure having porous, or perforated, walls, through which an oxygen-containing stream can permeate. By controlling the oxygen supply, the temperatures, conversion, and product selectivity of the reaction can be in turn controlled and optimized. Furthermore the potential risks of explosion associated with mixing hydrocarbon and molecular oxygen is minimized with increased feed carbon-to-oxygen molar ratios.

A process for the removal of organosulfur compounds from hydrocarbon materials is disclosed. The process includes contacting an ionic liquid with a hydrocarbon material to extract sulfur-containing compounds into the ionic liquid. The sulfur-containing compounds can be partially oxidized to sulfoxides and/or sulfones prior to or during the extraction step.

Systems and methods for producing syngas are provided. A first hydrocarbon can be partially oxidized in the presence of an oxidant and one or more first catalysts at conditions sufficient to partially combust a portion of the first hydrocarbon to provide carbon dioxide, non-combusted first hydrocarbon, and heat. The non-combusted first hydrocarbon can be reformed in the presence of the heat generated in the partial oxidation step and the one or more first catalysts to provide a first syngas. Heat can be indirectly exchanged from the first syngas to a second hydrocarbon to reform at least a portion of the second hydrocarbon in the presence of steam and one or more second catalysts to provide a second syngas. A syngas, which can include the at least a portion of the first syngas, at least a portion of the second syngas, or a mixture thereof can be converted to provide one or more Fischer-Tropsch products, methanol, derivatives thereof, or combinations thereof.

Method of preparing and introducing fuel into the combustors of a gas turbine in which a hydrocarbon containing feed, oxygen and steam are introduced into a catalytic partial oxidation reactor to produce a product stream. The hydrocarbon containing feed contains no less than about 15 percent by volume on a dry basis of hydrocarbons with at least two carbon atoms and/or at least about 3 percent by volume of olefins. The reactant mixture formed of the hydrocarbon containing feed, oxygen and steam has an oxygen to carbon ratio of between about 0.08 and about 0.25 and a water to carbon ratio of between about 0.05 to about 0.5. The hydrocarbon containing feed is introduced into the reactor alone or with a steam at a temperature no greater than 600° C. and the product stream is produced at a temperature of between about 600° C. and 860° C. and contains less than about 0.5 percent of olefins and less than 10 percent of hydrocarbons with two or more carbon atoms on a dry basis. After cooling the product stream the product stream is introduced into the combustors of the gas turbine to form part or all of the fuel required to support combustion.

A field effect transistor (FET) is formed as follows. A trench is formed in a silicon region. An oxidation barrier layer is formed over a surface of the silicon region adjacent the trench and along the trench sidewalls and bottom. A protective layer is formed over the oxidation barrier layer inside and outside the trench. The protective layer is partially removed such that a portion of the oxidation barrier layer extending at least along the trench bottom becomes exposed and portions of the oxidation barrier layer extending over the surface of the silicon region adjacent the trench remain covered by remaining portions of the protective layer.

The present invention provides several variations for converting biomass, and other carbon-containing feedstocks, into syngas. Some variations include pyrolyzing or torrefying biomass in a devolatilization unit to form a gas stream and char, and gasifying the char. Other variations include introducing biomass into a fluid-bed gasifier to generate a solid stream and a gas stream, followed by a partial-oxidation or reforming reactor to generate additional syngas from either, or both, of the solid or gas stream from the fluid-bed gasifier. Hot syngas is preferably subjected to heat recovery. The syngas produced by the disclosed methods may be used in any desired manner, such as conversion to liquid fuels (e.g., ethanol).