Siemens Aktiengesellschaft

Steag Aktiengesellschaft

Apparatebau Rothemuhle Brandt & Kritzler Gmbh

Eskom Holdings Soc Limited

University of the Western Cape

Erich Hums

Nicolas Vortmeyer

Horst Spielmann

Andreas Klatt

Gunther Spitznagel

Peter Heinz Fischer

Helmut Schmelz

Ronald Neufert

Michael Kotter

Friedrich Weyland

Dietmar Hein

Klaus Huttenhofer

Ralf Gilgen

Norbert Landgraf

Werner Niggeschmidt

Leslie Felicia Petrik

Christoph Brandt

Nicholas Mulei Musyoka

Alexander Khinsky

A method for the preparation of zeolites from non-fused fly ash includes the steps of preparing an aqueous alkali hydroxyl solution and mixing the solution with the non-fused fly ash to create an aqueous alkali hydroxyl fly ash mixture, subjecting the mixture to ultrasonication and recovering the zeolites. The method may include the step of centrifuging the aqueous alkali hydroxyl fly ash mixture and washing the solid synthetic products (zeolites).

Ultrasonic synthesis of zeolites from fly ash

Disclosed is a method for reducing the dioxin content of the off-gas in operating a sintering plant, in which prior to sintering a material catalytically active in decomposing dioxins and in the form of fine grains or dust is admixed. The admixed catalytically active material prevents the fresh formation of dioxins and reduces the content of dioxins in the off-gas flowing through the material for sintering. The catalytically active material) is incorporated in the agglomerate of material for sintering which is forming and can be disposed of reliably and without danger via the slag formed in the following blast-furnace process.

Method for operating a sintering plant

The invention relates to a flue gas pipe ( ) of an incineration plant, comprising a reaction zone ( ) for breaking down harmful substances and a heat exchanger ( ) for cooling the flue gas (R) which is mounted downstream and fitted with a dioxin catalytic converter ( ). The dioxin catalytic converter ( ) in the heat exchanger ( ) makes it possible to prevent the renewed formation of dioxins by de novo synthesis when the temperature drops.

Flue gas pipe and method for treating flue gas

A plate-type catalytic converter includes a stack of first plates and second plates. In operation, a flow medium flows from an inflow side to an outflow side. Leading edges of the second plates are set back in the direction of the outflow side relative to leading edges of the first plates. Catalytic activity can therefore be significantly improved as compared with a plate-type catalytic converter of conventional construction for the same physical volume, since the contribution toward the catalytic activity of the catalyst which is provided by turbulent flow is increased without increasing pressure loss or an additional risk of blockage by ash.

Plate-type catalytic converter

A process for producing a catalyst with a catalytically active composition on a support body by thermal spraying and a catalyst produced thereby. A spraying material including a reactive precursor of at least one component of the catalytically active composition is thermally sprayed onto the support body and the reactive precursor is converted to form the component. A catalyst having a high BET surface area can be produced in this way. At the same time, an inactivation of a thermally sensitive component during the spraying process can be avoided.

Process for producing a catalyst

A method of operating a combustion unit of a coal-fired power plant operating according to a slag tap furnace firing method, which includes supplying a titanium-containing material in addition to coal to a melting chamber for accelerating coal burn-up, burning the titanium-containing material together with the coal in the melting chamber at a temperature above 1500.degree. C., and generating fly ash and molten ash as a result of combustion in the melting chamber. Additionally, a combustion unit for a coal-fired power plant, including a melting chamber that has a combustion zone for receiving coal. The combustion zone produces fly ash. The combustion unit also includes a separate feed line for supplying a titanium-containing material to the combustion zone for accelerating burn-up of the coal and a second separate feed line first to supply a titanium-containing material to the fly ash and then supply the titanium-containing material and fly ash combination to the combustion zone for accelerating burn-up of the coal and fly ash.

Method of operating a combustion unit of a coal-fired power plant with a

An SCR catalyst containing titanium, molybdenum and vanadium has the particular characteristic that its catalytic activity is significantly less than that of a tungsten-containing catalyst. That disadvantage has been compensated for in the past by using a comparatively large volume of catalyst. In contrast to the conventional practice of using a molybdenum oxide proportion of about 10 to 12% by weight, the invention proposes that the molybdenum proportion of the catalyst, in the form of molybdenum trioxide MoO.sub.3, is about 0.01 to 5% by weight, preferably 1.5 to 4% by weight, relative to the weight of the catalyst mass. A catalyst containing this amount of molybdenum thus has an activity comparable to that of a tungsten-containing catalyst. The invention is applicable to all deNO.sub.x catalytic converters which call for the simultaneous presence of a reducing agent, in particular plate-type and honeycomb-type catalytic converters.

Catalyst for reducing the nitrogen oxide concentration in a flowing

A sintering plant includes an apparatus for transporting sinter material along a sintering section through at least one first zone in which the sinter material heats to a low temperature, and through a second zone in which the sinter material heats to a high temperature. Discharge lines are provided along the sintering section. A dioxin catalytic converter for exhaust gas is provided in the discharge lines disposed along the second zone or directly downstream thereof. In this manner, catalytic breakdown of dioxins can be achieved even in the exhaust gas of a sintering plant, which has not been possible heretofore.

Sintering plant

A gas turbine and a burner to be used for all gas turbines for the catalytically induced combustion of a fuel, include a flow duct and a main burner having a fuel outlet. A catalytic supporting burner has a fuel outlet in the flow duct upstream of the fuel outlet of the main burner, as seen in the flow direction of the fuel, for stabilizing the main burner along with catalytic combustion of a pilot fuel stream. A marked reduction in nitrogen oxide emission is achieved by replacing a diffusion pilot flame with a catalytic supporting burner.

Burner, particularly for a gas turbine, with catalytically induced

A burner, particularly for a gas turbine, includes a catalytic combustion chamber and a performer/reformer (24). The combustion chamber has an essentially cylindrical extent in a flow direction of a fuel and a catalytically active coating (12) on a wall facing the fuel for oxidation of the fuel. A particularly low nitrogen oxide content of burner exhaust gas is achieved as a result of the catalytically induced combustion of the fuel. At the same time, in contrast to known primary measures for nitrogen oxide abatement, the flow resistance in the burner is not increased by the coating of the wall. Therefore, when the burner is used in a gas turbine, a particularly high efficiency together with a low nitrogen oxide emission can be achieved.

Catalytic combustion chamber operating on preformed fuel, preferably for

A particularly thermally stable and acid resistant catalyst for reacting organic compounds present in a gas mixture, e.g. hydrocarbons, halogenated hydrocarbons, alcohols and solvents, includes titanium oxide, vanadium oxide and at least one further catalytically active component. The titanium oxide is predominantly present as titanium dioxide TiO.sub.2 of the rutile type having a BET surface area of greater than 40 m.sup.2 /g. The catalyst can be used for purifying combustion waste gases of all types and for purifying industrial waste air.

Catalyst for reacting organic compounds present in a gas mixture

A gas turbine can achieve comparatively low emissions of nitrogen oxide. One disadvantage particularly of a catalytic combustion chamber is that, for example for natural gas, the ignition temperature necessary for combustion is in the region of about 400 .degree. C. The use of an auxiliary burner, which constitutes a disadvantageous source of nitrogen oxide, has therefore been heretofore unavoidable. In order to eliminate that disadvantage, a gas turbine for the combustion of a fuel gas, particularly with catalytic combustion of the fuel gas, includes a conduit system for drawing off part of the fuel gas, guiding it through a catalytic preforming stage to convert a hydrocarbon contained in the fuel gas into an alcohol and/or an aldehyde and subsequently feeding it to the fuel gas again in order to lower its ignition temperature. In this way, the comparatively easily igniting fuels alcohol and/or aldehyde are obtained from the fuel gas in the preforming stage. A fuel gas intermixed with these materials therefore ignites at a considerably lower ignition temperature than a fuel gas without preformed constituents.

Gas turbine for the combustion of reformed fuel gas

In the production of a catalyst containing a catalytically active Mo--V--O phase, the problem exists of keeping the Mo--V--O phase and/or an Mo--V--Ti--O phase substantially free of other catalytically active impurities in order not to catalyze competing reactions at the same time. For this purpose, the invention provides that vanadium oxide and molybdenum oxide are mixed in a ratio of 0.7 to 1% by weight based on V.sub.2 O.sub.5 and MoO.sub.3, the mixture is heated to a temperature above 500.degree. C., the Mo--V--O phase is cooled, ground and then subjected to a reducing treatment, and dispersed on a heated oxidic support, the dispersed material is then ground, and then applied to a suitable macroscopic support, optionally with further additives, and calcined. Alternatively, the material dispersed on the oxidic support can be kneaded with additives to form an extrudable compound, and the compound can be extruded and then calcined so that the honeycomb bodies produced from the compound have crosspiece widths in a range of from 0.1 to 0.6 mm and cell densities of 50 to 1200 cells per square inch.

In order to achieve a high degree of conversion, oxides of nitrogen are contacted with a catalyst containing an aluminum silicate having a three-sheet structure as a catalytically active component at a temperature between 100.degree. C. and 700.degree. C. With this type of catalyst, the decomposition of the oxides of nitrogen proceeds without the presence of a reducing agent. Additionally, the degree of decomposition for the oxides of nitrogen is not adversely affected by the oxygen present in the flue gas. Degrees of decomposition greater than 60% were achieved with this catalyst in the temperature range between 200.degree. C. and 600.degree. C. The catalysts of the invention can replace the previous catalysts, which use a reducing agent, for decreasing the amount of oxides of nitrogen in waste gases, for example in flue gas and exhaust gas purification in power stations and combustion engines, respectively.

Process and catalyst for decomposing oxides of nitrogen

An arsenic-resistant composite oxide catalyst containing oxides of at least the metals vanadium and molybdenum, in particular for reducing nitrogen oxides in flue gases in the presence of a reducing agent, such as ammonia or carbon monoxide, includes at least one composite oxide phase with a general formula V.sub.x Mo.sub.y O.sub.32, where x+y.ltoreq.12 and where x.gtoreq.1 and y.gtoreq.1, and optionally a MoO.sub.3 phase. A method for producing an arsenic-resistant composite oxide catalyst includes mixing vanadium oxide and molybdenum oxide or a precursor thereof with one another to form a mixture, heating the mixture to a temperature at which a mixture of oxides is present, preferably in completely molten form, then cooling down the mixture to form at least one composite oxide phase with a general formula V.sub.x Mo.sub.y O.sub.32, and then subjecting the composite oxide phase to a reducing treatment to prepare a lower-oxygen composite oxide phase with the same structure.

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Hessdorf, Germany

Erich Hums