Abstract: A catalytic combuster having a mixing section upstream of a combustion section. The mixing section includes a multi-port injector for injecting a first reactant gas into the mixing section in a plurality of directions perpendicular the direction or flow of a second reactant gas.

Abstract: The present invention relates to a catalytic combustion device comprising a main combustion zone (20, 200) including at least one catalytic section (5, 103) and at least one air/fuel mixing zone (11, 117), said mixing zone comprising at least one pressurized air inlet (1, 101) and injection means (12, 105) for injecting a liquid fuel.

Abstract: Integrated Combustion Reactors (ICRS) and methods of making ICRs are described in which combustion chambers (or channels) are in direct thermal contact to reaction chambers for an endothermic reaction. Particular reactor designs are also described. Processes of conducting reactions in integrated combustion reactors are described and results presented. Some of these processes are characterized by unexpected and superior results, and/or results that can not be achieved with any prior art devices.

Abstract: A catalytic combustor contains multiple sections for catalytically combusting an anode effluent. The anode effluent is divided into a plurality of portions with each portion routed to a different section or stage of the combustor. The proportioning of the anode effluent allows the combustor to be operated so that the flows combusted do not autoignite and various heat loads placed on the different stages of the combustor can be met. Additionally, the proportioning of the anode effluent allows the temperature within the various components of the combustor to be controlled so that a useful life of the combustor can be increased.

Abstract: A process atmosphere incinerator for neutralizing chemical non-innocent gaseous mixtures uses thermally induced neutralization reactions, and does not rely on the use of auxiliary components. In these reactions, chemical non-innocent gaseous mixtures are neutralized to form benign and environmentally friendly products. A plurality of flame breakers is disposed inside of the reaction chamber of the process atmosphere incinerator. The flame breakers introduce variations in gas flow paths and flame patterns, and provide surfaces of elevated temperature inside the reaction chamber. The process atmosphere incinerator is constructed in a way as to support neutralization of a wide range of amounts of non-innocent gaseous mixtures of arbitrary composition.

Abstract: Described is a premix burner arrangement as well as a method for operating the same, comprising a pilot fuel feeding means for operating a combustion chamber of a gas turbine arrangement, a premix burner, wherein at least one fuel addition unit as well as supply air openings have been provided in such a way that gaseous and/or liquid fuel can be mixed with combustion supply air inside the premix burner and form a fuel/air mixture, which exits from the premix burner downstream in the direction towards the combustion chamber positioned after the premix burner arrangement and which can be ignited inside the combustion chamber in the form of a spatially largely stationary flame.

Abstract: The present invention provides a combustor for a fuel processor which integrates a burner and a catalyst. The burner is utilized to quickly heat the catalyst to a light-off temperature to prepare it for normal operation. The heated catalyst is then used to react anode exhaust with air or cathode exhaust under normal operation.

Abstract: A low-cost, high-mass-productivity catalytic combustion apparatus having a construction that permits easy maintenance is realized. There is provided a catalytic combustion apparatus in which, by means of a combustion chamber having a fuel supply portion 1 and a combustion air supply portion on the upstream side thereof and a combustion gas exhaust port on the downstream side thereof and a catalytic combustion portion with an upstream surface and a downstream surface provided in the combustion chamber, the upstream surface and the downstream surface being substantially parallel to each other, a fuel-air mixture supplied to the interior of the combustion chamber is caused to react to liberate heat.

Abstract: The invention relates to a catalyzer for burning at least part of a fuel/oxidant mixture flowing through the catalyzer, in particular for a burner of a power plant installation. The catalyzer comprises several catalytically active channels and several catalytically inactive channels. A longitudinal section of the catalyzer is spaced apart from an inflow side in the main flow direction. In this longitudinal section turbulators are arranged in at least several catalytically active channels. In addition or alternatively, connections that enable a flow between the channels are formed in this longitudinal section between several adjoining channels.

Abstract: An asphalt plant includes a plurality of asphalt processing components including a first set of components producing volatile emissions and a second set of components requiring process heat. A separate central burner assembly is adapted to supply heat energy in the form of heated gas to satisfy the process heat requirements of the second set of components. A first duct system is provided which includes a fan and which is adapted to capture a portion of the volatile emissions produced by the first set of components and to convey the captured emissions into the central burner assembly for mitigation. A second duct system is provided and includes a fan and is adapted to convey heated gas from the central burner assembly to the second set of components.

Abstract: Disclosed is a hybrid high pressure catalytic combustion burner employing catalysts and CST combustion with staged mixing systems, in which a primary combustion gas containing reacted gas of a primary gas mixture, which is formed via catalytic combustion, is subject to a secondary mixing with the primary gas mixture containing fuel and high temperature air, completing stable high temperature CST combustion at ultra lean conditions, thereby achieving high temperature combustion reducing formation of NOx.

Abstract: A premix burner arrangement with catalytic combustion provides a fuel/air mixture to a combustion chamber of a gas turbine arrangement. The premix burner arrangement includes a premix burner, at least one fuel addition unit, and air inlet openings arranged in such a way that at least one of gaseous and liquid fuel can be mixed with combustion inlet air inside the premix burner to form a fuel/air mixture. The fuel/air mixture exits from the premix burner downstream in the direction towards a combustion chamber positioned after the premix burner arrangement and can be ignited inside the combustion chamber. A catalyzer unit is provided before the entrance of the fuel/air mixture into the combustion chamber. Part of the fuel/air mixture can be introduced into and passed through the catalyzer unit before the catalyzed part of the fuel/air mixture flows together with the remaining portion of the fuel/air mixture into the combustion chamber.

Abstract: A catalytic combustor includes a plurality of channels formed by corrugated and flat strips, some of the channels being coated with a catalyst and others being uncoated. In the vicinity of the inlet end of the combustor, the boundary of each coated channel has a thermal barrier, to inhibit the flow of heat from the coated channel to an adjacent uncoated channel. Also in the vicinity of the inlet end, the coated channels may include one or more additional coated members, to enhance catalytic combustion in the light-off zone. The combustor of the present invention lights off at a relatively low temperature, and quickly reaches a stabilized and controlled operating temperature.

Abstract: The invention is a method and apparatus for purging an oxidant or residual fuel by controlled oxidation within a closed loop system. The particular application disclosed can operate to purge oxygen from an anode loop of a fuel cell just prior to startup, and can also operate to consume the remaining hydrogen or fuel at shutdown. The method employs the addition of additional fuel to a feed stream within the anode loop to a level that will through oxidation within the apparatus deplete the desired amount of oxygen. The method also employs the addition of air into a hydrogen feed loop that through oxidation within the apparatus consumes the hydrogen. Oxidation is accomplished first by diffusion burning and then catalysis to accomplish the depletion quickly. The method and apparatus eliminates the need for a separately stored inert gas purge tank and associated systems.

Abstract: A low-cost, high-mass-productivity catalytic combustion apparatus having a construction that permits easy maintenance is realized. There is provided a catalytic combustion apparatus in which, by means of a combustion chamber 200 having a fuel supply portion 1 and a combustion air supply portion 2 on the upstream side thereof and a combustion gas exhaust port 4 on the downstream side thereof and a catalytic combustion portion 5 with an upstream surface and a downstream surface provided in the combustion chamber 200, the upstream surface and the downstream surface being substantially parallel to each other, a fuel-air mixture supplied to the interior of the combustion chamber 200 is caused to react to liberate heat.

Abstract: A burner (2; 2a; 11; 25; 31; 34), comprising a burner body (12; 26; 32; 35), wherein a mixture of fuel and air can be introduced, and a burner head (14; 27; 32; 35a; 41), wherein a plurality of openings (15; 28; 40; 44) is provided, thr ough which said mixture can flow, is associated with shield means (3; 16; 29: 33; 36; 42) shielding said burner head (14; 27; 32; 35a; 41) suitable for limiting the maximum temperature that said burner head (14; 27; 32; 35a; 41) can reach during working of the burner (2; 2a; 11; 25; 31; 34).

Abstract: A system and method of combusting a hydrocarbon fuel is disclosed. The system combines the accuracy and controllability of an air staging system with the ultra-low emissions achieved by catalytic combustion systems without the need for a pre-heater. The result is a system and method that is mechanically simple and offers ultra-low emissions over a wide range of power levels, fuel properties and ambient operating conditions.

Abstract: The present invention provides a combustor for a fuel processor which integrates a burner and a catalyst. The burner is utilized to quickly heat the catalyst to a light-off temperature to prepare it for normal operation. The heated catalyst is then used to react anode exhaust with air or cathode exhaust under normal operation.

Abstract: A catalytic combuster having a mixing section upstream of a combustion section. The mixing section includes a multi-port injector for injecting a first reactant gas into the mixing section in a plurality of directions perpendicular the direction or flow of a second reactant gas.

Abstract: The invention disclosed herein is a method and apparatus for use therewith for creating flow passages of approximately equal cross section whereby a flow of a fluid through any passage will be approximately equal to the flow of a fluid through another passage.

Abstract: A synthetic ember comprising refractory ceramic wool coated with about 0.10 wt. % to about 5.0 wt. % of an oxidation catalyst of Pt, Pd, Rh, Co, Mn and mixtures thereof for use in small pieces as embers in a gas-fired log set or fireplace. The refractory ceramic wool preferably has a surface area of from 20 to 200 square meters per gram and a density of 0.01 to 0.05 grams per cubic centimeter and the catalytic embers are less than one inch square. The synthetic embers increase heat recoverable at a given BTU from a flame, with reduced nitrogen oxides, hydrocarbons and CO emissions and improved aesthetics.

Abstract: The invention is a method and apparatus for purging an oxidant or residual fuel by controlled oxidation within a closed loop system. The particular application disclosed can operate to purge oxygen from an anode loop of a fuel cell just prior to startup, and can also operate to consume the remaining hydrogen or fuel at shutdown. The method employs the addition of additional fuel to a feed stream within the anode loop to a level that will through oxidation within the apparatus deplete the desired amount of oxygen. The method also employs the addition of air into a hydrogen feed loop that through oxidation within the apparatus consumes the hydrogen. Oxidation is accomplished first by diffusion burning and then catalysis to accomplish the depletion quickly. The method and apparatus eliminates the need for a separately stored inert gas purge tank and associated systems.

Abstract: An apparatus for producing hydrogen from hydrocarbons or alcohol, particularly methanol, by feeding a reaction mixture comprising a hydrocarbon or alcohol and water onto a catalyst. The catalyst is formed by compressing at least one catalyst powder into a compressed layer to form a shaped body. The reaction mixture flows under pressure through the catalyst layer while the pressure drops. Furthermore, the apparatus is suitable for a use in a hydrogen shift phases for reducing carbon monoxide, in carbon monoxide oxidizers and catalytic burners. A process for producing the catalyst is also disclosed.

Abstract: A recuperated microturbine system including a low temperature duct burner in the exhaust gas which accommodates significant variations in the exhaust gas flow from the recuperator, which burns the added hydrocarbon fuel, for example natural gas, reasonably efficiently, without generating a significant amount of additional NOx. A wire mesh burner is used to burn the added fuel in part of the exhaust gas from the recuperator. The duct burner is operated either in a more or less radiant combustion mode, or in a blue flame mode. The remainder of the recuperator exhaust gas, which bypasses the afterburner, is heated mainly by radiant heat transfer from the wire mesh burner. The use of the wire mesh burner minimises additional NOx formation. In the duct burner the dynamic pressure of the exhaust gas is used to overcome the inherent static pressure loss of the wire mesh burner.

Abstract: There is provided a flameless catalytic burner system employing a catalytic bed assembly (20) for catalyzing the oxidation of a fuel stream. The catalytic bed assembly (20) includes first and second retaining members (122, 124) which define a compartment therebetween. The catalytic bed assembly (120) also includes a plurality of catalytic members (126) disposed within the compartment. The first retaining member (122) is formed with an upstream face portion (1220) transversely extending relative to the fuel stream to describe a convex peripheral contour about at least a portion of the compartment. The second retaining member (124) is formed with a downstream face portion (1240) transversely extending relative to the fuel stream to describe a concave peripheral contour about at least a portion of the compartment. The upstream face portion (1220) is greater in surface area than the downstream face portion (1240).

Abstract: The invention relates to a catalyzer for burning at least part of a fuel/oxidant mixture flowing through the catalyzer, in particular for a burner of a power plant installation. The catalyzer comprises several catalytically active channels and several catalytically inactive channels. A longitudinal section of the catalyzer is spaced apart from an inflow side in the main flow direction. In this longitudinal section turbulators are arranged in at least several catalytically active channels. In addition or alternatively, connections that enable a flow between the channels are formed in this longitudinal section between several adjoining channels.

Abstract: The present invention is a chemical reactor and method for catalytic chemical reactions having gas phase reactants. The chemical reactor has reactor microchannels for flow of at least one reactant and at least one product, and a catalyst material wherein the at least one reactant contacts the catalyst material and reacts to form the at least one product. The improvement, according to the present invention is: the catalyst material is on a porous material having a porosity that resists bulk flow therethrough and permits molecular diffusion therein. The porous material further has a length, a width and a thickness, the porous material defining at least a portion of one wall of a bulk flow path through which the at least one reactant passes.

Abstract: The invention relates to a catalytic burner (1) of a combuster (2), in particular of a power station installation, comprising

Abstract: A segmented radiant gas burner features wide modulation of thermal output simply by the independent control of fuel gas flow to each burner segment. The burner also features a porous fiber burner face, preferably having dual porosities, and a metal liner positioned to provide a compact combustion zone adjacent the burner face. The segmented radiant burner is ideally suited for use with gas turbines not only because of its compactness and broad thermal modulation but also because only the flow of fuel gas to each burner segment requires control while the flow of compressed air into all segments of the burner remains unchanged.

Abstract: A catalytically operating burner with a catalyzer structure (4), useful in particular for a gas turbine system, has a heat-resistant carrier material (10) that forms the walls of several adjoining channels (13). The channels (13) pervade the catalyzer structure (4) in longitudinal direction and permit that a gaseous reaction mixture flows through the catalyzer structure (4). The walls are coated at least in part with a catalyst. In order to improve the catalytic conversion within the catalyzer structure (4), communicating openings (14) are constructed in the walls between an inlet end and an outlet end of the catalyzer structure (4). Adjoining channels (13) are able to communicate with each other through the communicating openings (14).

Abstract: A more efficient combustion or oxidation device for the formation of nitrogen, phosphorus and/or sulfur oxides from a sample containing these elemental constituents is disclosed. The device uses multi-staged addition of an oxidizing agent to enhance oxidation and liberation of nitrogen, phosphorus and/or sulfur oxides for subsequent detection. The oxidation devices of the present invention allow for the injection of larger samples or, the introduction of a greater amount of sample per unit of time which results in a larger amount of analyte being delivered to the detector per unit of time, thereby improving detection limits and detection efficiency.

Abstract: A miniature heat source capable of being used in a hand-held device for delivering a metered pulse of fuel to a combustion chamber where it is converted into a pulsed amount of heat. For example, the heat source apparatus can be used in a hand-held cigarette smoking system or within a portable device wherein a microturbine generates electricity, as well as any type of environment where a high energy pulse of heat is desired. The heat source includes a valve such as a sliding, rotatable or timed valve which delivers a metered volume of fuel to the combustion chamber. The valve can deliver the fuel, in an expanded gaseous form, to a venturi conduit which increases the velocity of the gas flow, and delivers the fuel to a combustion chamber where the gas is mixed with air. The combustible mixture is then combusted within the combustion chamber by ignition and/or by catalyzed oxidation.

Abstract: A process for a catalytic chemical reaction includes depositing a solid catalyst on a refractory catalytic support. A catalyst includes an active metal phase and a refractory catalytic support of mainly silicon nitride in &agr;-form.

Abstract: An energy generating apparatus using the cyclic combustion of Brown gas is disclosed. The apparatus comprises a heat generating unit, an outer wall, a Brown gas generator, an open-shut valve and a burner. The heat generating unit is positioned on a base. The outer wall surrounds the heat generating unit so as to define a combustion chamber, is provided with a discharge hole at its upper portion, and radiates infrared rays. The Brown gas generator is used to generate Brown gas. The open-shut valve is positioned between supply pipes so as to block the Brown gas discharged from the Brown gas generator. The burner is used to heat the heat generating unit by burning Brown gas supplied through the open-shut valve and the supply pipes.

Abstract: In order to realize a catalytic combustion apparatus capable of effectively utilizing radiation from a surface of a catalytic element, providing a higher efficiency of heat exchange, and characterized in superior characteristics of an exhaust gas, a catalytic combustion apparatus according to the invention comprises a catalytic element 7 in the shape of a plate consisting of multiple through-holes for combusting a mixed gas of a fuel gas and air and a combustion chamber 6 accommodating the catalytic element 7, and incorporating a radiated heat receiving plate 11 that is positioned in opposition to either one of two surfaces of the catalytic element 7 as a part of its side walls.

Abstract: Device (1) for the surface emission of infrared radiation, comprising a combustion chamber (2) having a wall (3) made of refractory material, permeable through its thickness, suitable for the passage of a mixture (4) to be burnt (combustible gas (30) plus oxidizer gas (31), for example air) from its upstream face (3a) to its downstream face (3b), and the internal developed surface of which is coated with a catalytic combustion material, and an upstream chamber (5) supplied on one side with the mixture to be burnt and closed on the other side by the catalytic combustion wall. The combustion chamber (2) includes at least one heat exchange wall (6), placed upstream of and facing the catalytic wall (3), in order to receive via its downstream face (6b) at least most of the heat radiated by the upstream face (3a) of said catalytic combustion wall, said heat exchange wall made of refractory material also being permeable through its thickness and suitable for passage of the mixture (4) to be burnt.

Abstract: A reformation reactor, especially suitable for the reformation of methanol, includes a reaction zone in which a reformation catalyst is located and to which a gas mixture to be reformed can be supplied. The reactor includes an evaporator body that adjoins the reaction zone in a flush manner. The evaporator body has a porous, heat-conducting structure for providing the gas mixture to be reformed by mixing and evaporating the gas mixture components supplied to it and for two-dimensionally distributed supply of the gas mixture thus prepared and into the reaction zone. A starting phase can be provided for the operation of the reactor, in which the evaporator body is wetted by a fuel liquid film and, following the addition of oxygen, a flammable mixture results in the reaction zone that is catalytically oxidized. The evaporator body can be heated to operating temperature by the resultant combustion heat, after which a switch can be made to continuous operation of the reformation reactor.

Abstract: A burner apparatus includes a foraminous burner surface having a multitude of openings through which flames can extend. The burner surface is irregularly shaped so that flames extending from the openings are directed in an irregular pattern whereby eddy currents are generated and effectively disrupt oscillation of the flames to result in reduced noise generation from flame oscillation.

Abstract: A sensor for detecting the flame occurring during a flashback condition in the fuel nozzle of a lean premix combustion system is presented. The sensor comprises an electrically isolated flashback detection electrode and a guard electrode, both of which generate electrical fields extending to the walls of the combustion chamber and to the walls of the fuel nozzle. The sensor is positioned on the fuel nozzle center body at a location proximate the entrance to the combustion chamber of the gas turbine combustion system. The sensor provides 360° detection of a flashback inside the fuel nozzle, by detecting the current conducted by the flame within a time frame that will prevent damage to the gas turbine combustion system caused by the flashback condition.

Abstract: A method of cleansing nitrogen oxide (NOx), hydrocarbon (HC) and carbon monoxide (CO) from waste gases, such as the waste gases or exhaust gases originating from burners and internal combustion engines. The waste gases, or exhaust gases, are passed through a catalyst for catalytic cleansing of the gases. The air-fuel ratio, or the lambda value (L), is reduced to a level below L=1. The gases are passed through a first catalyst and then through a second catalyst, to bring the CO-content of the gas in the first catalyst to a sufficiently high level and to reduce NOx to N2 to an extent such as to bring the NOx content down to a predetermined level. Sufficient oxygen (O2) is delivered to the gases at a point between the first and second catalysts to oxidize both CO and HC to CO2 and H2O to such an extent as to reduce the CO-content of the gas to a predetermined level. A gas burner to carry out the method is also disclosed.

Abstract: A process and product for producing an attractive soot-free fire from a specially formed gas pipe embedded in a bed of broken, specially-formulated, tempered glass pieces is provided. The broken glass pieces are preferably formed from a specifically-formulated, tempered glass which, after formation, is broken and then sifted and washed so as to remove any slivers or debris. The gas pipe is preferably formed with two rows of equally spaced openings offset with respect to each other and spaced approximately 90° apart to burn gas in a cleaner and hotter manner. A number of gas pipes may be used and formed in any desired configuration to add to the attractiveness of the soot-free fire produced thereby.

Abstract: There are provided an evaporative/regenerative incineration system for organic waste water for incinerating organic waste water and volatile organic compounds completely at low expenses and a method therefor. Waste gas is generated by evaporating waste water including organic compounds in an evaporator and the generated waste gas is mixed with air in a regenerative thermal oxidizer (RTO) in flow communication with the evaporator for oxidation. The heat energy generated from the oxidation is collected and supplied to the evaporator.

Abstract: A method serves the purpose of introducing fuel and/or thermal energy into a gas stream flowing to a catalytic reactor. The gas stream flows in part through an exterior chamber and in part through an interior chamber, which is at least partially open in the flow direction and to which fuel is supplied. The partial streams are re-united after flowing through the two chambers and are fed to the catalytic reactor. In a starting phase of the still cold catalytic reactor, the fuel is burned in the interior chamber. During conventional normal operating modes of the warm catalytic reactor, the fuel is vaporized in the interior chamber. In a suitable device, the exterior chamber and the interior chamber are designed as two tube elements that are inserted into one another.

Abstract: The present invention is a method, and an apparatus for practicing the method, that creates a product stream and a heat of reaction from a fuel-rich fuel/air mixture and then contacts the product stream with a sufficient quantity of additional air to completely combust all of the fuel, to which air a portion of the heat of reaction has been transferred.

Abstract: A catalytic combustion apparatus comprises a combustor 11, a fuel tank 12, a valve 13, and an ignition device 14. The combustor 11 further comprises a gas nozzle 16, an air intake/ejector 17, a mixing chamber 18, a firing chamber 19, an ignition plug 20, a combustion chamber 21, a catalyst for combustion 22 housed inside the combustion chamber 21, and an exhaust port 23. The mixing chamber 18 is made into a straight cylindrical passage, a cylindrical firing chamber 19 is provided in parallel to the mixing chamber 18 so that an opening 24 on the side of the firing chamber 19 communicates with the combustion chamber 21, a burner port 25 is disposed on the boundary between the mixing chamber 18 and the firing chamber 19, and the burner 25 is configured with a catalytic net 25a.

Abstract: The present invention is a method, and an apparatus for practicing the method, that creates a product stream and a heat of reaction from a fuel-rich fuel/air mixture and then contacts the product stream with a sufficient quantity of additional air to completely combust all of the fuel, to which air a portion of the heat of reaction has been transferred.

Abstract: The present invention provides a small-sized and lightweight catalytic combustor which can operate stably against variations of members to be heated. The catalytic combustor includes a heat-conductive separator for defining a combustion chamber and conducting heat to a member to be heated, the separator has projections and depressions in at least one part of a surface facing the combustion chamber, and an oxidation catalyst is supported on at least one part of the projections and depressions of the heat-conductive separator. By providing the projections and depressions in the surface of the heat-conductive separator, which faces the combustion chamber, a flow of a mixture of combustible materials and combustion-assisting materials can partly stay around the projections and depressions to enable a stable combustion thereof even at various flow rates.

Abstract: A hybrid combustor, for providing stable high and low levels of operation while minimizing emissions of NOx, CO, and UHCs, includes a casing having a chamber, a catalytic combustor disposed in the chamber, and a non-premixed combustor disposed in the chamber. The hybrid combustor may comprise a fuel nozzle comprising a casing having a chamber, and a body supportable in the chamber to define a passageway between the body and the casing. The passageway has an inlet for receiving a stream of air and an outlet for discharging a stream of fuel and air, and the body includes a tapering downstream portion. Desirably, flow separation of the fuel and air mixture from the body (i.e., recirculation of the fuel and air mixture in the passageway and/or chamber) is inhibited whereby a generally uniform fuel and air mixture is provided.

Abstract: A catalytic combustor burns a fuel-air mixture which is not preheated. The combustor includes a strip or strips of metal which define a plurality of alternating wide and narrow channels. The channels contain corrugated strips which maintain the spacing of the channels. A catalyst coating is deposited only in the wider channels, the narrower channels remaining un-catalyzed. The strip or strips can be heated resistively to start the combustion. Once the combustion is started, the electric current is stopped, and the combustion continues. The combustor is useful in a home heating appliance such as a gas furnace. In another embodiment, in which the combustor is used in a high-temperature environment such as in a gas turbine, the catalyst can be deposited in the small channels only, so as to limit the amount of catalytic combustion.

Abstract: Methods for operating catalytic combustion chambers including first and second catalytic reactors disposed in series with an intermediate chamber therebetween are disclosed, the method including heating the first catalytic reactor to a temperature at least equal to the ignition temperature of the first catalytic reactor, introducing air and fuel mixture to the first catalytic reactor whereby catalytic combustion is initiated in the first catalytic reactor, and increasing the mass flow through the first catalytic reactor whereby combustion of the air and fuel mixture takes place in the gas phase in the intermediate chamber and the end surface of the second catalytic reactor is heated to a temperature at least equal to the ignition temperature of the second catalytic reactor and ignition takes place in the second catalytic reactor.