Hybrid tube as hydrogen burner lance

Abstract

A burner lance (110) is proposed, comprising a conduit configured for transferring a fuel from a first end of the conduit to a second end of the conduit. The fuel at least partially comprises hydrogen-containing gas, wherein the conduit comprises an Oxide Ceramic Matrix Composite (OCMC). The conduit comprises an inner tube (112) of monolithic ceramic with a shell (114) of OCMC.

Description

250060W001Hybrid tube as Hydrogen burner lanceTechnical FieldThe invention relates to a burner lance, a radiant burner system, several uses and a method for providing a fuel gas for generating heat, e.g. for carrying out at least one chemical reaction, and / or for energy conversion. For example, the burner lance can be used for an industrial furnace such as a steam cracker furnace. However, other applications are possible.Background artBurner systems for burning hydrocarbons such as natural gas are well known, e.g. from US 2002 / 0076668 A1 and EP 0 787 947 A2. These burner systems use usually metal-based burner lances. In the future, hydrogen will gradually replace natural gas as burning medium. The change to hydrogen may be performed in a sudden switch or may be gradually be replaced. For example, pipeline networks may first be co-fed with hydrogen, leading to a natural gashydrogen mixture. Burning hydrogen, however, shows different properties from burning natural gas, such as typically shorter flames with higher temperatures at the burner lance tip, or higher gas velocities. Conventional burner lances for burning natural gas do not meet these requirements.Other materials for burner lances for natural gas as fuel gas are known. For example, WO 2024 / 124542 A1 describes a method for carrying out a chemical reaction. A fuel gas, such as natural gas, is combusted by means of at least one burner lance in a combustion chamber in order to heat a reaction fluid. The at least one burner lance is formed at least partially from an oxide ceramic matrix composite. In particular, as described in paragraph

[0008] of WO 2024 / 124542 A1 , it is proposed that at least the section of the burner lance at which combustion takes place is formed from the oxide ceramic matrix composite, e.g., at least a section that is located adjacent to an outlet opening for fuel gas.However, for using of hydrogen as burning gas, there is still a need for burner lances that can withstand these conditions. Pure OCMC as proposed in WO 2024 / 124542 A1 is very porous. In particular in case the system is operated in overpressure, e.g. in case of using small exit openings in order to reach speed of sound, leakages can occur, e.g. the fuel can exit undefined through the OCMC. Diffusion can be significant since H2 is a small molecule in comparison to CH4, CO such that this problem may intensify. This can result in safety problems. Flames can occur at non-wanted locations, e.g. within the brickwork, which can lead to damage and subsequent shutdowns.Problem to be solved250060W001-2 -It is therefore desirable to provide a burner lance, a radiant burner system, several uses and a method for generating heat and / or for energy conversion, which at least partially address above-mentioned technical challenges of known methods and devices. Specifically, burner lances shall be provided which allow for withstanding the higher temperatures and higher gas velocities which come along with using hydrogen containing gas as fuel.SummaryThis problem is addressed by a burner lance, a radiant burner system, several uses and a method for generating heat and / or for energy conversion with the features of the independent claims. Advantageous embodiments which might be realized in an isolated fashion or in any arbitrary combinations are listed in the dependent claims as well as throughout the specification.As used herein, the terms "have”, "comprise” or "include” or any arbitrary grammatical variations thereof are used in a non-exclusive way. Thus, these terms may both refer to a situation in which, besides the feature introduced by these terms, no further features are present in the entity described in this context and to a situation in which one or more further features are present. As an example, the expressions "A has B”, "A comprises B” and "A includes B” may both refer to a situation in which, besides B, no other element is present in A (i.e. a situation in which A solely and exclusively consists of B) and to a situation in which, besides B, one or more further elements are present in entity A, such as element C, elements C and D or even further elements.Further, it shall be noted that the terms "at least one”, "one or more” or similar expressions indicating that a feature or element may be present once or more than once typically are used only once when introducing the respective feature or element. In most cases, when referring to the respective feature or element, the expressions "at least one” or "one or more” are not repeated, notwithstanding the fact that the respective feature or element may be present once or more than once.Further, as used herein, the terms "preferably", "more preferably", "particularly", "more particularly", "specifically", "more specifically" or similar terms are used in conjunction with optional features, without restricting alternative possibilities. Thus, features introduced by these terms are optional features and are not intended to restrict the scope of the claims in any way. The invention may, as the skilled person will recognize, be performed by using alternative features. Similarly, features introduced by "in an embodiment of the invention" or similar expressions are intended to be optional features, without any restriction regarding alternative embodiments of the invention, without any restrictions regarding the scope of the invention and without any restriction regarding the possibility of combining the features introduced in such way with other optional or non-optional features of the invention.In a first aspect of the invention, a burner lance is disclosed. The burner lance comprises a conduit configured for transferring a fuel from a first end of the conduit to a second end of the conduit. The fuel at least partially comprises250060W001- 3 -hydrogen-containing gas. The conduit comprises an Oxide Ceramic Matrix Composite (OCMC). The conduit comprises an inner tube of monolithic ceramic with a shell of OCMC.The term "burner lance” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an element configured for providing and / or distributing a fuel with one or more of: a defined speed, a defined temperature, or a defined angle, to a pre-defined spatial region, in particular into a combustion zone of a combustion chamber. For example, the burner lance may be a component of a burner system of an industrial furnace, e.g. a steam cracker furnace. For example, the burner lance may be a component of a burner system of a power plant. Within the burner system, the burner lance may be used for introducing a secondary fuel into a combustion zone, in particular to enhance the combustion of primary fuel gases.The term "combustion chamber” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a device and / or location in which a mixture of fuel and oxidizer is burned.For example, the combustion chamber may be an element of an industrial burner. The term "industrial furnace” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a device configured for generating heat by combusting fuel with an oxidizer for carrying out at least one chemical reaction. The industrial furnace may comprise a combustion zone in which the combustion takes place, also denoted as radiant section or firebox.For example, the combustion chamber may be an element of a power plant. The term "power plant” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a system configured for converting chemical energy of the fuel into kinetic energy, e.g. for rotating a turbine, thereby generating a power output.The burner lance may have a very low NOx emission. The fuel may be divided into primary and secondary fuel. Air may be guided only through a primary radiation burner. The mixture within the primary fuel may be lean such that the temperature is reduced, resulting in reduced thermal NOx. The secondary fuel may comprise the remaining fuel which mixes with remaining oxygen from the radiation burner. The temperature is reduced, e.g. less power locally, mixing and the like, resulting in reduced NOx.In an embodiment, the burner lance may be part of a radiant burner system of a steam cracker furnace. For example, the steam cracker furnace may comprise a plurality of radiant burners at defined locations such as the floor and / or ceiling and / or sidewalls. For example, the burner lance may be a part of a radiant wall burner. In the following, reference250060W001- 4 -will be made exemplarily to steam cracking. However, other applications, e.g. for other chemical reactions or for energy conversion, are possible.The term "conduit” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an elongated element configured for transferring the fuel from a first end, e.g. an inlet, to a second end, e.g. an outlet or exit, of the element. For example, the conduit may be completely straight. For example, the conduit may comprise a straight part and, e.g. at the second end, a curved part. The conduit may comprise a cylindrical part. The conduit may be a channel and / or tube. The first end and the second end may be opposing ends of the conduit.An outer diameter of the conduit may be from 4 mm to 100 mm, preferably from 8 mm to 55mm. An inner diameter may be from 2 mm to 94 mm, preferably from 4 mm to 50 mm.The conduit may be open on one side. The conduit may be open on the first end and may be configured for receiving the fuel at the first end. The first end may be an inlet of the conduit.The conduit may be closed at the second end. The term "closed” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to the fact that the second end of the conduit is covered, wherein at least one opening configured for providing the fuel to an exterior exists. The conduit may comprise a burner lance tip. The burner lance tip may at least partially close the second end of the conduit.The term "burner lance tip” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a part of the conduit which is configured for delivery of fuel to an exterior and / or which comprises at least one outlet for the fuel.The burner lance tip may comprise the at least one opening, e.g. an outlet bore, configured for providing the fuel to an exterior, in particular to the combustion zone. The term "opening” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an outlet for the fuel. The opening may also be denoted as aperture. The position and number of the openings can define the velocity and direction of the fuel exiting the burner lance into the combustion zone. For example, the fuel can exit from the burner lance at the speed of sound. The burner lance may comprise an axis along a longitudinal extension of the conduit. The opening may be arranged from 0° to ± 90° with respect to said axis. The burner lance tip comprises 1 to 100 openings, preferably 1 to 50 openings, more preferably 1 to 20 openings. At least one of the openings, e.g. of the outlet bores, may be arranged on the axis along the longitudinal extension of the conduit. The openings can be arranged perpendicular to said axis and / or at an arbitrary250060W001- 5-angle in between. The openings may be arranged at different positions at the burner tip. The openings may have identical or different cross sections, e.g. circular cross sections. A cross section of the opening may be from 0.1 mm to 50 mm, preferably from 0.5 mm to 30 mm, more preferably from 1 mm to 20 mm. The openings may have identical shapes or may be embodied differently.The term "fuel” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a substance or a mixture of substances configured for undergoing combustion and / or providing chemical energy which is released during combustion. The fuel at least partially comprises hydrogen-containing gas. The fuel may comprise at least one gas selected from the group consisting of: hydrogen gas (H2); hydrogen containing exhaust gases; hydrocarbon-containing gases; hydrogen nitride containing gas such as NH3 or hydrazine (N2H4); mixtures of the afore-mentioned gases.The fuel in addition may comprise at least one gas selected from the group consisting of: natural gas, synthesis gas; exhaust gas such as CO containing gas, other gas which has a calorific value, an off-gas. Another possibility may be exhaust gases that are subjected to an exhaust gas after treatment to be decomposed, which could then be any gases that are harmful to the environment (N2O, etc.).During use, the fuel may have a proportion of hydrogen from 4% by volume to 100 % by volume.The addition of hydrogen-containing gas, e.g. H2, can allow shortening the flame and increase of heat release. The flame may burn closer to the exit of the burner lance such that the temperature of the material will increase. The present invention proposes that the conduit comprises an Oxide Ceramic Matrix Composite (OCMC), wherein the conduit comprises an inner tube of monolithic ceramic with a shell of OCMC. This so called "hybrid” conduit can allow withstanding the higher temperatures associated with combustion processes using at least partially hydrogen-con-taining gas. Higher flame temperatures can be possible without brittleness of the material. Thus, the hybrid conduit can allow tolerating addition of hydrogen-containing gas without changing the design of the burner lance and / or a burner system comprising the burner lance. For example, in case of using NH3 or in case of using N2H4, the hybrid conduit can prevent problems with nitridation. The hybrid conduit can allow ensuring a gas-tight system even in case of hydrogen-containing fuel. The hybrid conduit can be embodied as gas tight, heat permeable multilayer ceramic composite tube, e.g. as described WO 2016 / 184776 A1.As outlined above, the conduit comprises an OCMC. The conduit comprises an inner tube of monolithic ceramic with a shell of OCMC. In addition, the burner lance tip may comprises an OCMC. The burner lance tip may comprise a core of monolithic ceramic with a shell of OCMC.250060W001- 6 -The term "composite material” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary material being produced from two or more constituent materials. These constituent materials may have notably dissimilar chemical or physical properties and may be merged to create a material with properties unlike the individual materials. Within the composite material, the individual materials may remain separate and distinct.Specifically, the composite material may be a fiber-reinforced composite material. The term "fiber-reinforced composite material (FRC)” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary material generally comprising at least two main components: reinforcing fibers and an embedding matrix which may serve as a filler and / or adhesive between the fibers. Mutual interactions between the two components may give overall material higher-grade properties than either of the two components involved alone. The fiber-reinforced composite (FRC) may specifically comprise the fibers as a discontinuous or dispersed phase, the matrix as a continuous phase and an interphase region, which may also be referred to as interface.The term "Ceramic Matrix Composite (CMC)” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary composite material, specifically to an arbitrary fiber-reinforced composite material, comprising a plurality of ceramic fibers embedded in a ceramic matrix. Thereby, carbon and carbon fibers may also be regarded as a ceramic material.The term "Oxide Ceramic Matrix Composite (OCMC)” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary ceramic matrix composite comprising an oxide ceramic matrix reinforced by oxide ceramic reinforcing fibers. The term "OCMC” may refer to pure OCMC structures and to hybrid OCMC structures comprising in addition to the OCMC at least one further material such as metallic fibers.For example, the OCMC may comprise at least one element selected from the group consisting of: SiC / AhOa, SiC / Mullite, C / AI2O3, C / Mullite, AI2O3 / AI2O3, AhOs / Mullite, Mullite / AI2O3 and / or Mullite / Mullite. The names of the OCMC is based on the notation of Walter E.C. Pritzkow, Frank Wehner, Dietmar Koch, Oxide Fiber Reinforced Oxide Ceramic Matrix Composite - An Alternative to Metallic Alloys at High Temperature, Editor(s): Francisca G. Caballero, Encyclopedia of Materials: Metals and Alloys, Elsevier, 2022, Pages 425-441. In this notation A / B refers to „A“ the fiber composite and „B“ refers to the composition of the matrix.250060W001- 7 -The OCMC may have a plurality of fibers, specifically a plurality of oxide ceramic reinforcing fibers. The term "fiber” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary element having a length and a width, wherein the length of the element exceeds the width of the element such as at least by a factor of 5, preferably at least by a factor of 10 and most preferably at least by a factor of 20. The fiber may specifically be an artificial fiber. The artificial fiber may be a fiber whose chemical composition, structure, and / or properties may be significantly modified during a manufacturing process. Artificial may refer to regenerated fibers and synthetic fibers.The plurality of the oxide ceramic reinforcing fibers may form a fiber fabric. The term "fiber fabric” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a manufacturing of the fibers. The fiber fabric may be manufactured in a sheet, a mat, specifically a continuous mat, or as continuous filaments. The fiber fabric may be manufactured from at least one technique selected from the group consisting of: weaving, knitting, braiding and stitching. The fibers may be manufactured in two-dimensional or three-dimensional orientations. In the two-dimensional orientation the fibers may be essentially only aligned along a plane in x-direction, and in y-direction of the material. In the three-dimensional orientation fibers may be incorporated in the x-direction, y-direction and z-direction. The fiber fabric may also be referred to as fiber preform, fiber backbone, fiber scaffold or fiber framework.The oxide ceramic reinforcing fibers may have a fiber diameter from 1 pm to 50 pm, preferably from 3 pm to 30 pm and most preferably from 5 pm to 20 pm. However, also other dimensions may be possible.The fiber fabric may be a homogeneous fiber fabric or a hybrid fiber fabric.The homogeneous fiber fabric may comprise exclusively one kind of fibers.The hybrid fiber fabric may comprise at least two different kinds of fibers. In one embodiment, the hybrid fiber fabric may comprise fibers of a first ceramic material, e.g. an oxide ceramic material, and a second ceramic material, e.g. of silicon carbide. In one embodiment, the hybrid fiber fabric may comprise fibers of a ceramic material, e.g. an oxide ceramic material, and carbon fibers. In one embodiment, the hybrid fiber fabric may comprise fibers of a ceramic material, e.g. an oxide ceramic material, and metallic fibers, e.g. electrically conductive fibers as described below. The hybrid fiber fabric may comprise fibers of more than two different types, e.g. a combination of the mentioned embodiments.The ceramic fibers may comprise at least one material selected from the group consisting of: a binary oxide (MXOZ), a mixed oxide (M1xM2yOzor M1xM2yM3wOz), mixtures of binary oxides (M1yOzI M2VOW), mixtures of mixed oxides250060W001- 8 -(MxM1yOzI MuM2v0w), non-oxide ceramic (C, MXCW, MXNZ, MxNzCw, ByCw, MxByNzCw). Thereby, 0 may refer to the chemical element oxygen. B may refer to the chemical element boron (B). N may refer to the chemical element nitrogen (N) and C may refer to the chemical element carbon (C).M may specifically be an element selected from the group consisting of: aluminum (Al), zirconium (Zr), silicon (Si), calcium (Ca), magnesium (Mg), beryllium (Be), yttrium (Y), lanthanum (La), iron (Fe), nickel (Ni), chromium (Cr), tungsten (W), hafnium (Hf), strontium (Sr), scandium (Sc), Cerium (Ce), Ytterbium (Yb). Preferably, M may be selected from the group consisting of: aluminum (Al), silicon (Si), strontium (Sr), zirconium (Zr), lanthanum (La), yttrium (Y). M1 may specifically be an element selected from the group consisting of: aluminum (Al), zirconium (Zr), yttrium (Y). Preferably, M1 may be aluminum (Al). M2 specifically be an element selected from the group consisting of: silicon (Si), zirconium (Zr), magnesium (Mg), yttrium (Y). Preferably, M2 may be silicon (Si). M3 may specifically be cobalt (Co), x, y and w may each independently be between 1 and 10, preferably between 1 and 7 and most preferably between 1 and 5. z may specifically be between 1 and 30, preferably between 1 and 20 and most preferably between 1 and 10.The OCMC may have a matrix, specifically an oxide ceramic matrix. The term "matrix” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary constituent of a composite material. Specifically, the matrix may refer to or may comprise at least one material in which other components are embedded. The matrix may specifically serve the following functions. The matrix may be configured for binding a fiber reinforcement. Further, the matrix may be configured for providing a composite component its shape and may direct its surface quality.The matrix may specifically comprise at least one of: a binary oxide (MXOZ); a mixed oxide such as M1xM2yOzand / or M1xM2yM3wOz; a complex matrix comprising a plurality of ceramic particles and / or of metallic particles. Specifically, the OCMC may have a matrix composition selected from the group consisting of: SixMyOz, SixM1yM2wOz, SixByNzCw, AIN, MxOy and mixtures of oxides (M1xOy / M2wOz). For example, the OCMC may have a matrix composition comprising a mixture of oxides such as 85% AI2O3 and 15% ZrO2 (e.g. a matrix available under FW12 from WPS). However, also other kinds of materials may be possible.Thereby, O may refer to the chemical element oxygen. B may refer to the chemical element boron (B). N may refer to the chemical element nitrogen (N) and C may refer to the chemical element carbon (C).M may specifically be an element selected from the group consisting of: aluminum (Al), zirconium (Zr), silicon (Si), calcium (Ca), magnesium (Mg), beryllium (Be), yttrium (Y), lanthanum (La), iron (Fe), nickel (Ni), chromium (Cr), tungsten (W), hafnium (Hf), strontium (Sr). Preferably, M may be an element selected from the group consisting of: aluminum (Al), zirconium (Zr), silicon (Si), strontium (Sr), lanthanum (La), yttrium (Y). M1 may specifically be an element selected from the group consisting of: aluminum (Al), zirconium (Zr), yttrium (Y). Preferably, M1 may be alumi-250060W001-9 -num (Al). M2 may specifically be an element selected from the group consisting of: zirconium (Zr), silicon (Si). Preferably, M2 may silicon (Si). M3 may specifically be cobalt (Co), x, yand w may each independently be between 1 and 10, preferably between 1 and 7 and most preferably between 1 and 5. z may specifically be between 1 and 30, preferably between 1 and 20 and most preferably between 1 and 10.The monolithic ceramic comprises at least one element selected from the group consisting of: a binary oxide (MXOZ); a mixed oxide (M1yM2vOzand / or M1xM2yM3wOz); a metal carbide (M3VCW), a metal nitride (M3VNW); mixtures of binary oxides (M1yOzI M2v0w, MXOZI M1yOzI M2VOW); mixtures of mixed oxides (MxM1yOzI MUM2VOW); mixtures of binary oxides and metal carbides (MXOZI M3VCW) and / or mixtures of binary oxides and metal nitrides (MXOZI M3VNW). O may refer to the chemical element oxygen. B may refer to the chemical element boron (B). N may refer to the chemical element nitrogen (N) and C may refer to the chemical element carbon (C).M is at least one element selected from the group consisting of: aluminum (Al); zirconium (Zr); silicon (Si); calcium (Ca); magnesium (Mg); titanium (Ti); beryllium (Be); yttrium (Y); lanthanum (La); iron (Fe); nickel (Ni); chromium (Cr); tungsten (W); hafnium (Hf); strontium (Sr); Scandium (Sc); Cer (Ce); Ytterbium (Yb). M1 specifically is an element selected from the group consisting of: aluminum (Al); zirconium (Zr); yttrium (Y). M2 specifically is an element selected from the group consisting of: zirconium (Zr); silicon (Si); magnesium (Mg); titanium (Ti); yttrium (Y). M3 specifically is an element selected from the group consisting of: aluminum (Al); silicon (Si); boron (B); tungsten (W). x, y, z, u, v and w are each independently between 1 and 10, preferably between 1 and 7 and most preferably between 1 and 5.The proposed hybrid burner lance, combining a monolith ceramic tube and oxide-ceramic matrix composites, can withstand the conditions of both natural gas burning and hydrogen burning. This can allow for the construction of a burner lance that can be used for natural gas burning and also for the burning of gas mixtures with gradual increase in the hydrogen share up to 100% hydrogen. This can allow for the use of one burner system without having to gradually adapt the geometries of the burner lances and exchanging the burner lances according to the changing burning gas compositions. Thus, the metal burner lances of known burner systems can now be replaced by hybrid tube burner lances of the same geometries and these lances will not have to be replaced when the burning gas is changed to higher hydrogen contents. Installing the burner lance according to the present invention in applications with natural gas burning grants the flexibility to easily adapt to hydrogen-rich or pure hydrogen burning gases in the future. The installation of new burning systems with each change in the burning gas composition is therefore not necessary. For example, the natural gas-burning power plants can then utilize the varying compositions of burner gas.In a further aspect, a radiant burner system is disclosed, comprisinga burner head,a primary fuel conduit configured for transferring a mixture of primary fuel and oxidizer, e.g. air, to from an inlet of the primary fuel conduit to the burner head,a primary fuel supply configured for providing the primary fuel to the primary fuel conduit,250060W001- 10-a primary oxidizer supply configured for providing the oxidizer for a required fuel-to-oxidizer ratio, a burner lance according to the present invention such as according to an embodiment described above or as described in more detail below, wherein the burner lance is configured for providing a secondary fuel, wherein the secondary fuel at least partially comprises hydrogen-containing gas.With respect to definitions and embodiments of the burner lance reference is made to the description of the burner lance given above or as given in more detail below.The term "system" as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary set of interacting or interdependent components parts forming a whole. Specifically, the components may interact with each other in order to fulfill at least one common function. The at least two components may be handled independently or may be coupled or connectable.The term "radiant burner system" as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a combustion system configured for generating heat primarily through radiation. The radiant burner system may be an industrial burner. In an embodiment, the radiant burner system may be a radiant wall burner.The term "burner head” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a component of the radiant burner system configured for delivery and distribution of primary fuel into the combustion zone. The burner head may be configured for distribution of the mixture of primary fuel and oxidizer into a combustion zone. The burner head may comprise at least one nozzle. The nozzle may be configured for distributing the mixture of primary fuel and oxidizer in a radial direction, e.g. into the combustion zone. For example, the burner head may be embodied as nozzle, e.g. as described in US 2002 / 0076668 A1.The primary fuel may comprise at least one fuel gas selected from the group consisting of: natural gas, carbon monoxide CO; hydrogen gas (H2); hydrogen containing exhaust gases; hydrocarbon-containing gases; hydrogen nitride containing gas such as NH3 or hydrazine (N2H4); mixtures of the afore-mentioned gases.The term "primary fuel conduit” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a conduit, e.g. an elongated tube, configured for transferring the mixture of primary fuel and oxidizer from an inlet, or respective inlets of the primary fuel and the oxidizer, to the burner head. For example, the primary fuel conduit may be embodied as elongated burner tube, e.g. as described in US 2002 / 0076668 A1.250060W001- 11 -The burner lance may be arranged within the primary fuel conduit or may be arranged outside the primary fuel conduit, e.g. the conduit of the burner lance extending at least partially parallel to the primary fuel conduit. The burner lance tip and the burner head may be arranged adjacent. The burner lance may be configured for distribution of the secondary fuel into the combustion zone.The term "primary fuel supply” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a device or system providing the primary fuel. The primary fuel supply may be configured for mixing and / or providing the mixture of primary fuel and oxidizer. For example, the primary fuel supply may be embodied as fuel-air mixture supply system, e.g. as described in US 2002 / 0076668 A1.In a further aspect, a use of a burner lance according to the present invention such as according to an embodiment described above or as described in more detail below in a combustion chamber, e.g. of an industrial furnace or a power plant, is disclosed. The industrial furnace is configured for steam cracking or steam reforming. For example, the burner lance may be used for steam cracking, e.g. within a steam cracker furnace. The steam cracker furnace may comprise a plurality of radiant burner systems at defined locations such as the floor and / or ceiling and / or sidewalls, e.g. floor burner and / or wall burner. For example, the burner lance may be used for steam reforming, e.g. within a steam reformer furnace. The steam reformer furnace may comprise a plurality of radiant burner systems at defined locations such as the floor and / or ceiling and / or sidewalls, e.g. floor burner and / or wall burner. For example, the burner lance may be used for combustion within a power plant. The power plant may comprise a plurality of burner systems, e.g. within the combustion chamber of a gas turbine.Exemplarily, a burner lance according to the present invention could particularly be used in reformers like steam methane reformer (SMR), ammonia reformer, partial oxidation (POX) reformer, autothermal reformer (ATR), methanol reformer and catalytic naphtha reformer. Furthermore, a burner lance according to the present invention could particularly be used in crackers like an ammonia cracker or a steam cracker, preferably a naphtha-based steam cracker.SMR is one of the most important large-scale industrial processes for producing hydrogen from carbon-containing energy carriers and water. Natural gas and / or hydrogen is in general the main feedstock, but many aliphatic hydrocarbons such as light gasoline, methanol, biogas, or biomass can serve as energy carriers, too.Examples for possible applications of the burner lance according to the present invention:• Chemical Industry: A burner lance according to the present invention may be used for furnaces, such as in crackers, steam crackers, naphtha-based crackers, ammonia crackers, reformers, steam reformers, steam methane reformers, or ammonia reformers. Furthermore, the burner lance according to the present invention may be used for burners for syngas or thermal afterburning.250060W001- 12 -• Petrochemicals and Refineries: A burner lance according to the present invention may be used for preheating processes, reforming processes, or support during furnace start-up / shutdown.• Power Plants: A burner lance according to the present invention may be used for ignition and support burners in coal or biomass boilers.• Ceramics and Refractory Industry: A burner lance according to the present invention may be used for firing processes in tunnel and roller kilns.• Waste Incineration, Waste and Hazardous Waste Treatment: A burner lance according to the present invention may be used for rotary kilns, in particular for hazardous waste.• Pulp and Paper Industry: A burner lance according to the present invention may be used for in-lime kilns for chemical recovery.• Shipbuilding and Offshore: A burner lance according to the present invention may be used for thermal processes in heavy fuel oil combustion or inerting.• Cement Industry: A burner lance according to the invention may be used for kiln start-up and heating, in particular to quickly bring rotary kilns to operating temperature, to enable additional fuel injection, also for alternative fuels (e.g., liquid fuels, waste materials), directly into the burning zone, and to provide a temperature profile control, especially for a local heat supply to optimize clinker quality.• Metallurgical Industry: A burner lance according to the present invention may be used for steel plants (electric and oxygen converters), in particular for oxygen lances for carbon oxidation and preheating, in melting furnaces to support melting of iron, copper or aluminum, and in 'desulfurization and slag treatment for adirect heat supply for reactions in ladle furnaces.• Glass Industry: A burner lance according to the present invention may be used for furnaces, in particular to provide additional heat for glass melting to ensure temperature uniformity, in boosting systemsfor a local temperature increase for higher melting capacity, and inspecialty glass production to have a precise temperature control for special glass types.In a further aspect, a method for providing a fuel gas for generating heat, e.g. for carrying out at least one chemical reaction and / or for energy conversion is proposed. The method comprises using a burner lance according to the present invention such as according to an embodiment described above or as described in more detail below.Summarizing and without excluding further possible embodiments, the following embodiments may be envisaged:Embodiment 1. A burner lance comprising a conduit configured for transferring a fuel from a first end of the conduit to a second end of the conduit, wherein the fuel at least partially comprises hydrogen-containing gas, wherein the conduit comprises an Oxide Ceramic Matrix Composite (OCMC), wherein the conduit comprises an inner tube of monolithic ceramic with a shell of OCMC.250060W001- 13 -Embodiment 2. The burner lance according to the preceding embodiment, wherein the conduit comprises a burner lance tip, wherein the burner lance tip comprises an OCMC, wherein the burner lance tip comprises a core of monolithic ceramic with a shell of OCMC.Embodiment 3. The burner lance according to the preceding embodiment, wherein the burner lance tip at least partially closes the second end of the conduit, wherein the burner lance tip comprises at least one opening configured for providing the fuel to an exterior.Embodiment 4. The burner lance according to the preceding embodiment, wherein the burner lance comprises an axis along a longitudinal extension of the conduit, wherein the opening is arranged from 0° to ± 90° with respect to said axis.Embodiment 5. The burner lance according to any one of the two preceding embodiments, wherein the burner lance tip comprises 1 to 100 openings, preferably 1 to 50 openings, more preferably 1 to 20 openings.Embodiment 6. The burner lance according to any one of the three preceding embodiments, wherein a cross section of the opening is from 0.1 mm to 50 mm, preferably from 0.5 mm to 30 mm, more preferably from 1 mm to 20 mm.Embodiment 7. The burner lance according to any one of the preceding embodiments, wherein the OCMC comprises at least one element selected from the group consisting of: SiC / AhOa, SiC / Mullite, C / AI2O3, C / Mullite, AI2O3 / AI2O3, AhOs / Mullite, Mullite / AI2O3 and / or Mullite / Mullite.Embodiment 8. The burner lance according to any one of the preceding embodiments, wherein the monolithic ceramic comprises at least one element selected from the group consisting of: a binary oxide (MXOZ); a mixed oxide (M1yM2vOz and / or M1xM2yM3wOz); a metal carbide (M3VCW), a metal nitride (M3VNW); mixtures of binary oxides (M1yOzI M2v0w, MXOZI M1yOzI M2VOW); mixtures of mixed oxides (MxM1yOzI MuM2v0w); mixtures of binary oxides and metal carbides (MXOZI M3VCW) and / or mixtures of binary oxides and metal nitrides (MXOZI M3vNw), wherein M is at least one element selected from the group consisting of: aluminum (Al); zirconium (Zr); silicon (Si); calcium (Ca); magnesium (Mg); titanium (Ti); beryllium (Be); yttrium (Y); lanthanum (La); iron (Fe); nickel (Ni); chromium (Cr); tungsten (W); hafnium (Hf); strontium (Sr), wherein M1 specifically is an element selected from the group consisting of: aluminum (Al); zirconium (Zr); yttrium (Y), wherein M2 specifically is an element selected from the group consisting of: zirconium (Zr); silicon (Si); magnesium (Mg); titanium (Ti); yttrium (Y), wherein M3 specifically is an element selected from the group consisting of: aluminum (Al); silicon (Si); boron (B); tungsten (W), wherein x, y, z, u, v and w are each independently between 1 and 10, preferably between 1 and 7 and most preferably between 1 and 5.250060W001- 14-Embodiment 9. The burner lance according to any one of the preceding embodiments, wherein an outer diameter of the conduit is from 4 mm to 100 mm, preferably from 8 mm to 55mm, wherein an inner diameter is from 2 mm to 94 mm, preferably from 4 mm to 50 mm.Embodiment 10. The burner lance according to any one of the preceding embodiments, wherein the fuel comprises at least one gas selected from the group consisting of: hydrogen gas (H2); hydrogen containing exhaust gases; hydrocarbon-containing gases; hydrogen nitride containing gas such as NH3 or hydrazine (N2H4); mixtures of the afore-mentioned gases, wherein the fuel gas in addition comprises at least one gas selected from the group consisting of: natural gas, synthesis gas; exhaust gas such as CO containing gas, other gas which has a calorific value, an off-gas.Embodiment 11. A radiant burner system comprisinga burner head,a primary fuel conduit configured for transferring a mixture of primary fuel and oxidizer to from an inlet of the primary fuel conduit to the burner head,a primary fuel supply configured for providing the primary fuel to the primary fuel conduit,a primary oxidizer supply configured for providing the oxidizer for a required fuel-to-oxidizer ratio, at least one burner lance according to any one of the preceding embodiments, wherein the burner lance is configured for providing a secondary fuel, wherein the secondary fuel at least partially comprises hy- drogen-containing gas.Embodiment 12. The radiant burner according to the preceding embodiment, wherein the burner head is configured for distribution of the mixture of primary fuel and oxidizer into a combustion zone, wherein the burner lance is configured for distribution of the secondary fuel into the combustion zone.Embodiment 13. The radiant burner according to any one of the preceding embodiments relating to a radiant burner system, wherein the primary fuel comprises at least one fuel gas selected from the group consisting of: natural gas, hydrogen; carbon monoxide CO; hydrogen gas (H2); hydrogen containing exhaust gases; hydro- carbon-containing gases; hydrogen nitride containing gas such as NH3 or hydrazine (N2H4); mixtures of the afore-mentioned gases.Embodiment 14. Use of a burner lance according to any one of the preceding embodiments relating to a burner lance in a combustion chamber configured for steam cracking or steam reforming, or of a power plant.Embodiment 15. A method for providing a fuel gas into a combustion chamber for generating heat and / or for energy conversion, the method comprises using a burner lance according to any one of the preceding embodiments relating to a burner lance.250060W001- 15-Short description of the FiguresFurther optional features and embodiments will be disclosed in more detail in the subsequent description of embodiments, preferably in conjunction with the dependent claims. Therein, the respective optional features may be realized in an isolated fashion as well as in any arbitrary feasible combination, as the skilled person will realize. The scope of the invention is not restricted by the preferred embodiments. The embodiments are schematically depicted in the Figures. Therein, identical reference numbers in these Figures refer to identical or functionally comparable elements.In the Figures:Figure 1 shows an embodiment of a burner lance;Figure 2 shows a further embodiment of a burner lance; andFigure 3 shows an embodiment of a radiant burner.Detailed description of the embodimentsFigures 1 and 2 show embodiments of a burner lance 110. Figure 1 shows an upper part of the burner lance 110, in particular in a cross sectional view. The axis of symmetry is shown as a dashed dotted line in Figure 1. The lower part of the burner lance 110, which is not shown in this Figure, is embodied symmetrically to the upper part with respect to the axis of symmetry. Figure 2 shows an embodiment of the burner lance 110 in cross sectional view.For example, the burner lance 110 may be part of a radiant burner system of a steam cracker. The burner lance 110 may be a part of a radiant burner.The burner lance 110 comprises a conduit configured for transferring a fuel from a first end of the conduit to a second end of the conduit. For example, the conduit may be completely straight, as shown in Figure 2. For example, the conduit may comprise a straight part and, e.g. at the second end, a curved part, as shown in Figure 1. The conduit may be a channel and / or tube.The fuel at least partially comprises hydrogen-containing gas. The fuel may comprise at least one gas selected from the group consisting of: hydrogen gas (H2); hydrogen containing exhaust gases; hydrocarbon-containing gases; hydrogen nitride containing gas such as NH3 or hydrazine (N2H4); mixtures of the afore-mentioned gases. The fuel in addition may comprise at least one gas selected from the group consisting of: natural gas, synthesis gas; exhaust gas such as CO containing gas, other gas which has a calorific value, an off-gas. Another possibility may be exhaust gases250060W001- 16 -that are subjected to an exhaust gas after treatment to be decomposed, which could then be any gases that are harmful to the environment (N2O, etc.).The addition of hydrogen-containing gas, e.g. H2, can allow shortening the flame and increase of heat release. The flame may burn closer to the exit of the burner lance such that the temperature of the material will increase. The present invention proposes that the conduit is a "hybrid” conduit, which comprises an Oxide Ceramic Matrix Composite (OCMC), wherein the conduit comprises an inner tube 112 of monolithic ceramic with a shell 114 of OCMC.An outer diameter of the conduit may be from 4 mm to 100 mm, preferably from 8 mm to 55mm. An inner diameter may be from 2 mm to 94 mm, preferably from 4 mm to 50 mm.The OCMC may comprises at least one element selected from the group consisting of: SIC / AI2O3, SIC / Mullite, C / AI2O3, C / Mullite, AI2O3 / AI2O3, AhOs / Mullite, Mullite / AI2O3 and / or Mullite / Mullite.The monolithic ceramic may comprises at least one element selected from the group consisting of: a binary oxide (MxOz); a mixed oxide (M1yM2vOzand / or M1xM2yM3wOz); a metal carbide (M3VCW), a metal nitride (M3VNW); mixtures of binary oxides (M1yOzI M2VOW, MXOZI M1yOzI M2VOW); mixtures of mixed oxides (MxM1yOzI MuM2v0w); mixtures of binary oxides and metal carbides (MXOZI M3VCW) and / or mixtures of binary oxides and metal nitrides (MXOZI M3VNW), wherein M is at least one element selected from the group consisting of: aluminum (Al); zirconium (Zr); silicon (Si); calcium (Ca); magnesium (Mg); titanium (Ti); beryllium (Be); yttrium (Y); lanthanum (La); iron (Fe); nickel (Ni); chromium (Cr); tungsten (W); hafnium (Hf); strontium (Sr), wherein M1 specifically is an element selected from the group consisting of: aluminum (Al); zirconium (Zr); yttrium (Y), wherein M2 specifically is an element selected from the group consisting of: zirconium (Zr); silicon (Si); magnesium (Mg); titanium (Ti); yttrium (Y), wherein M3 specifically is an element selected from the group consisting of: aluminum (Al); silicon (Si); boron (B); tungsten (W), wherein x, y, z, u, v and w are each independently between 1 and 10, preferably between 1 and 7 and most preferably between 1 and 5.The conduit may be open on one side. The conduit may be open on the first end and may be configured for receiving the fuel at the first end. The first end may be an inlet of the conduit.As best visible in Figure 2, the conduit may be closed at the second end. The conduit may comprise a burner lance tip. The burner lance tip may at least partially close the second end of the conduit. The burner lance tip may comprise the at least one opening 116, e.g. an outlet bore, configured for providing the fuel to an exterior, in particular to the combustion zone. The position and number of the openings 116 can define the velocity and direction of the fuel exiting the burner lance into the combustion zone. For example, the fuel can exit from the burner lance at the speed of sound. The burner lance may comprise an axis along a longitudinal extension of the conduit. The opening may be arranged from 0° to ± 90° with respect to said axis. The burner lance tip comprises 1 to 100 openings, preferably 1 to 50250060W001- 17-openings, more preferably 1 to 20 openings. In the embodiment shown in Figure 2, the burner lance tip may comprise two openings 116. The openings 116 can be arranged at an arbitrary angle in between. The openings 116 may be arranged at different positions at the burner tip. The openings 116 may have identical or different cross sections, e.g. circular cross sections. In Figure 2, an embodiment with different cross sections is shown. A cross section of the opening 116 may be from 0.1 mm to 50 mm, preferably from 0.5 mm to 30 mm, more preferably from 1 mm to 20 mm. The openings 116 may have identical shapes or may be embodied differently.Figure 3 shows an embodiment of a radiant burner system, in this embodiment of a radiant wall burner. The radiant burner system comprises a burner head 120, a primary fuel conduit configured for transferring a mixture of primary fuel and oxidizer to from an inlet of the primary fuel conduit to the burner head, a primary fuel supply 122 configured for providing the primary fuel to the primary fuel conduit, and a primary oxidizer supply 124 configured for providing the oxidizer for a required fuel-to-oxidizer ratio. The radiant burner system further comprises at least one burner lance 110, e.g. a burner lance as described with respect to Figures 1 and 2, configured for providing a secondary fuel. The secondary fuel at least partially comprises hydrogen-containing gas. The burner lance 110 may comprise a secondary fuel supply 118 configured for providing the secondary fuel.The radiant wall burner may be arranged at a wall of a combustion chamber of a furnace, e.g. may extend through an outer wall of an outer furnace wall 130. Suitable furnace insulation 132 may be used.250060W001- 18 -List of reference numbers110 Burner lance112 inner tube114 shell116 opening118 secondary fuel supply 120 burner head122 primary fuel supply 124 primary oxidizer supply 130 outer furnace wall 132 furnace insulation

Claims

250060W001- 19 -Claims1. A burner lance (110) comprising a conduit configured for transferring a fuel from a first end of the conduit to a second end of the conduit, wherein the fuel at least partially comprises hydrogen-containing gas, wherein the conduit comprises an Oxide Ceramic Matrix Composite (OCMC), wherein the conduit comprises an inner tube (112) of monolithic ceramic with a shell (114) of OCMC.

2. The burner lance (110) according to the preceding claim, wherein the conduit comprises a burner lance tip, wherein the burner lance tip comprises an OCMC, wherein the burner lance tip comprises a core of monolithic ceramic with a shell of OCMC.

3. The burner lance (110) according to the preceding claim, wherein the burner lance tip at least partially closes the second end of the conduit, wherein the burner lance tip comprises at least one opening (116) configured for providing the fuel to an exterior.

4. The burner lance (110) according to the preceding claim, wherein the burner lance comprises an axis along a longitudinal extension of the conduit, wherein the opening (116) is arranged from 0° to ± 90° with respect to said axis.

5. The burner lance (110) according to any one of the two preceding claims, wherein the burner lance tip comprises 1 to 100 openings (116), preferably 1 to 50 openings (116), more preferably 1 to 20 openings (116).

6. The burner lance (110) according to any one of the three preceding claims, wherein a cross section of the opening (116) is from 0.1 mm to 50 mm, preferably from 0.5 mm to 30 mm, more preferably from 1 mm to 20 mm.

7. The burner lance (110) according to any one of the preceding claims, wherein the OCMC comprises at least one element selected from the group consisting of: SiC / AhOa, SiC / Mullite, C / AI2O3, C / Mullite, AI2O3 / AI2O3, AhOs / Mullite, Mullite / AI2O3 and / or Mullite / Mullite.

8. The burner lance (110) according to any one of the preceding claims, wherein the monolithic ceramic comprises at least one element selected from the group consisting of: a binary oxide (MXOZ); a mixed oxide (M1yM2vOz and / or M1xM2yM3wOz); a metal carbide (M3VCW), a metal nitride (M3VNW); mixtures of binary oxides (M1yOzI M2v0w, MxOz I M 1 yOzI M2v0w); mixtures of mixed oxides (MxM1yOzI MuM2v0w); mixtures of binary oxides and metal carbides (MXOZI M3VCW) and / or mixtures of binary oxides and metal nitrides (MXOZI M3VNW),250060W001-20-wherein M is at least one element selected from the group consisting of: aluminum (Al); zirconium (Zr); silicon (Si); calcium (Ca); magnesium (Mg); titanium (Ti); beryllium (Be); yttrium (Y); lanthanum (La); iron (Fe); nickel (Ni); chromium (Cr); tungsten (W); hafnium (Hf); strontium (Sr), wherein M1 specifically is an element selected from the group consisting of: aluminum (Al); zirconium (Zr); yttrium (Y), wherein M2 specifically is an element selected from the group consisting of: zirconium (Zr); silicon (Si); magnesium (Mg); titanium (Ti); yttrium (Y), wherein M3 specifically is an element selected from the group consisting of: aluminum (Al); silicon (Si); boron (B); tungsten (W), wherein x, y, z, u, v and w are each independently between 1 and 10, preferably between 1 and 7 and most preferably between 1 and 5.

9. The burner lance (110) according to any one of the preceding claims, wherein an outer diameter of the conduit is from 4 mm to 100 mm, preferably from 8 mm to 55mm, wherein an inner diameter is from2 mm to 94 mm, preferably from 4 mm to 50 mm.

10. The burner lance (110) according to any one of the preceding claims, wherein the fuel comprises at least one gas selected from the group consisting of: hydrogen gas (H2); hydrogen containing exhaust gases; hydrocar- bon-containing gases; hydrogen nitride containing gas such as NH3 or hydrazine (N2H4); mixtures of the aforementioned gases, wherein the fuel in addition comprises at least one gas selected from the group consisting of: natural gas, synthesis gas; exhaust gas such as CO containing gas, other gas which has a calorific value, an off-gas.

11. A radiant burner system comprisinga burner head (120),a primary fuel conduit configured for transferring a mixture of primary fuel and oxidizer to from an inlet of the primary fuel conduit to the burner head,a primary fuel supply configured for providing the primary fuel to the primary fuel conduit,a primary oxidizer supply configured for providing the oxidizer for a required fuel-to-oxidizer ratio, at least one burner lance (110) according to any one of the preceding claims, wherein the burner lance is configured for providing a secondary fuel, wherein the secondary fuel at least partially comprises hydro- gen-containing gas.

12. The radiant burner according to the preceding claim, wherein the burner head is configured for distribution of the mixture of primary fuel and oxidizer into a combustion zone, wherein the burner lance (110) is configured for distribution of the secondary fuel into the combustion zone.

13. The radiant burner according to any one of the preceding claims relating to a radiant burner system, wherein the primary fuel comprises at least one fuel gas selected from the group consisting of: natural gas, hydrogen; carbon monoxide CO; hydrogen gas (H2); hydrogen containing exhaust gases; hydrocarbon-containing250060W001-21 -gases; hydrogen nitride containing gas such as NH3 or hydrazine (N2H4); mixtures of the afore-mentioned gases.

14. Use of a burner lance (110) according to any one of the preceding claims relating to a burner lance (110) in a combustion chamber configured for steam cracking or steam reforming, or of a power plant.

15. A method for providing a fuel gas into a combustion chamber for generating heat and / or for energy conversion, the method comprises using a burner lance (110) according to any one of the preceding claims relating to a burner lance (110).

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