Method and apparatus for producing hydrogen from a carbon-containing raw material

Abstract

A process for producing hydrogen from a carbon-containing raw material, wherein the raw material is introduced into a container (2) and exposed in the container (2) to steam superheated to up to 1200 °C at no pressure, so that carbon-containing components of the raw material are converted into a gaseous state in order to form hydrogen, and wherein, prior to the step of exposure to the superheated steam, the raw material is heated in a first step to 100 °C with low-temperature steam in order to dissolve and / or extract water-soluble and water-insoluble components from the raw material, characterized in that the steam produced in the first step, together with the vapors and / or dissolved and / or extracted components contained therein, is condensed by means of a first condenser, wherein the heat energy contained in the steam produced is transferred to a first evaporator.

Description

[0001] The invention relates to a process for producing hydrogen from a carbon-containing raw material, wherein the raw material is introduced into a container and exposed in the container to a pressureless steam superheated to up to 1200 °C, so that carbon-containing components of the raw material are converted into a gaseous state in order to form hydrogen, and wherein, prior to the step of exposure to the superheated steam, the raw material is heated in a first step to 100 °C with low-temperature steam in order to dissolve and / or extract water-soluble and water-insoluble components from the raw material.

[0002] Furthermore, the present invention relates to an apparatus for carrying out a method for producing hydrogen from a carbon-containing raw material, namely for carrying out the method according to one of claims 1 to 12, with a container, wherein the raw material is introduced into the container and is exposed in the container to a pressureless steam superheated to up to 1200 °C in such a way that carbon-containing components of the raw material are converted into a gaseous state in order to form hydrogen, and wherein, prior to the step of exposure to the superheated steam, the raw material can be heated to 100 °C in a first step with low-temperature steam in order to achieve a dissolution and / or extraction of water-soluble and water-insoluble components from the raw material.

[0003] It should be noted here that the term "carbon-containing raw material" generally refers to materials or substances that have a carbon content suitable for hydrogen production. This includes not only raw materials in the narrow sense, but also compounds and any combinations of raw materials, as well as mixtures of different substances and compounds.

[0004] Processes and devices for converting solid carbon into gaseous carbon, usually mixed gases, have been known since the beginning of the 19th century and are referred to in the scientific community as coal chemistry. The temperatures required for coal gasification are mostly generated by substoichiometric combustion or partial combustion of the coal itself.

[0005] Beginning with the development of artificial fertilizers in the early 20th century, steam reforming was developed and, to some extent, also used in coal chemistry as a non-inert process. To this day, this process remains one of the important large-scale chemical production methods for hydrogen (water-gas shift reaction).

[0006] Photocatalysis is a process that, under the influence of electromagnetic radiation, primarily in the visible wave range, either significantly lowers the application temperature in synthesis processes or results in a reaction with very few byproducts, i.e., with high concentration and high purity of the desired products.

[0007] Furthermore, the Winkler fluidized bed process is described in the literature. This process has proven unfeasible in smaller units and in various projects. Either the process and the associated plant technology are too expensive, or the process is unsuitable, for example, for biomass, which is a significant raw material for hydrogen production. Reference is made to DE 10 149 649 A1 as an example. This process involves pure coal gasification using steam and substoichiometric partial combustion. However, the use of a fluidized bed requires pressurized gas. This precludes highly efficient operation from the outset, as generating pressure usually requires a high energy input. Especially in smaller plants, the need for compression significantly reduces the efficiency of the process.

[0008] Furthermore, US Patent 5,589,599 A discloses a method and an apparatus for producing hydrogen from a carbonaceous raw material, wherein the raw material is placed in a container 14, 16, and 18 and exposed in the container to unpressurized superheated steam, such that carbonaceous components of the raw material are converted into a gaseous state to form hydrogen. This document further discloses the feature whereby, prior to exposure to the superheated steam, the raw material is heated in a first step to 100 °C with low-temperature steam to dissolve and / or extract water-soluble and water-insoluble components from the raw material.

[0009] Furthermore, document US 2001 / 0011457 A1 discloses a method and apparatus for producing hydrogen from a carbon-containing raw material, wherein the raw material is placed in a container and exposed in the container to a pressureless superheated steam, so that carbon-containing components of the raw material are converted into a gaseous state in order to form hydrogen.

[0010] The present invention is therefore based on the objective of providing a method and a device for producing hydrogen from a carbon-containing raw material, whereby particularly efficient hydrogen production is made possible with structurally simple means.

[0011] According to the invention, the foregoing problem is solved by a method having the features of claim 1 and by a device having the features of claim 13.

[0012] According to the invention, it has been demonstrated that hydrogen can be produced safely and easily from a carbon-containing raw material, particularly in smaller, cost-effective plants. Specifically, this is achieved by using non-pressurized superheated steam to treat the raw material. Treating the raw material with non-pressurized steam eliminates the need for complex safety measures for handling a pressurized medium or raw material. This significantly simplifies and reduces the overall plant design, thereby considerably increasing the economic viability of hydrogen production. Non-pressurized superheated steam is entirely sufficient to convert the necessary carbon-containing components of the raw material into a gaseous state required for hydrogen production.Treatment of the raw material with pressurized steam is not necessary.

[0013] In the device according to the invention, the raw material introduced into a suitable container or reactor is exposed to pressureless superheated steam in such a way that carbon-containing components of the raw material are converted into a gaseous state in order to form hydrogen. The steam can be used here as a circulating medium, which, due to its lack of pressure, serves not only as an essential component of the process but also as a safety feature, since the lack of pressure enables inherently safe use of the device with the process according to the invention.

[0014] Consequently, the inventive method and device enable a comparatively simple and safe production of hydrogen even in small plants using structurally simple means.

[0015] The carbon-containing raw material used in the process and device according to the invention can be solid, liquid, or gaseous. Mixed phases can also be used. Particularly advantageously, the carbon-containing raw material can be essentially solid biomass. Such biomass can serve as a renewable raw material in a particularly environmentally friendly way in the production of hydrogen.

[0016] To ensure particularly safe and efficient hydrogen production, the raw material is first heated to 100 °C with low-temperature steam before being exposed to superheated steam. This process dissolves and / or extracts water-soluble and water-insoluble components. These dissolved and / or extracted components can then be advantageously removed from the process or recycled. Removing these potentially valuable components from the raw material is particularly beneficial because further temperature increases would not only destroy them but also lead to the formation of unwanted hydrocarbon compounds.

[0017] Furthermore, in the process according to the invention, the water vapor generated in the first step, along with any vapors and / or dissolved and / or extracted components contained therein, is condensed by means of a first condenser, whereby the heat energy contained in the resulting water vapor is transferred to a first evaporator, preferably with temperature control by means of a first compressor. The temperature level of the water evaporator can be slightly below the vapor temperature of the water vapor within the vessel. By using this first condenser, heat recovery can be provided for the entire process, thereby further increasing the efficiency of hydrogen production.

[0018] Also with a view to achieving particularly high efficiency of the process, a catalyst can be added after the first step to promote hydrogen formation.

[0019] Furthermore, the low-temperature steam, particularly after the removal or extraction of components not required for the subsequent process from the biomass, can be heated using a heating device or heating coil. The required temperature, for example up to 1200 °C, can be achieved through any type of energy transfer. A burner for gas, liquid fuel, or solid fuel can be used. It is particularly advantageous to use a fuel derived from renewable raw materials or from the gaseous phase of the gas produced in the process itself. It is especially beneficial if the steam required for the process is generated from heat recovery within the process and only superheating is necessary to bring the steam to the required superheated state.

[0020] In a further advantageous embodiment of the process, a gas mixture produced when the raw material is exposed to superheated steam can be subjected to a second heat treatment, preferably by interacting with or passing over a catalyst to promote hydrogen formation. This second heat treatment can, in particular, serve to homogenize the crude mixed gas produced in the first heating step.

[0021] Following the second heat treatment, the gas mixture heated by the second heat treatment can be cooled by means of a second condenser, wherein heat energy contained in the gas mixture is preferably transferred to a second evaporator, and furthermore preferably pressure regulation to compensate for a pressure loss is carried out by means of a second compressor. This second condenser can be designed as a water evaporator, whereby excess vapor can be condensed and the heat recovered.

[0022] To maintain a particularly high hydrogen concentration, the components of the raw material, converted into a gaseous state, or the gas mixture, can be exposed to illumination with a predefinable wavelength, preferably between 400 nm and 700 nm, to generate a photocatalytic reaction for increasing the hydrogen concentration. Electrically induced photocatalysis is a particularly simple method of quality assurance, even if the efficiency is not very high.

[0023] Furthermore, to achieve a particularly high hydrogen concentration in a generated gas, a flow aid, a material improving conveying and / or flowability, and / or a catalyst to promote hydrogen formation can be added to the raw material before, during, or after it is introduced into the container. The specific flow aid or catalyst must be selected based on the particular application.

[0024] Regarding an advantageous process extension, after the raw material has been exposed to superheated steam, coal gasification can be carried out by burning the resulting solid coal fraction. Partial combustion of a high-purity and clean coal fraction can be performed to maximize the overall hydrogen yield.

[0025] With a view to energy-efficient heat recovery, a further process step can be the cooling of a formed solid coal fraction by means of non-superheated steam or by means of a mixture of steam and hot water, whereby further heated steam and / or formed steam is used to heat raw material and heat recovery is thereby achieved.

[0026] The following section explains advantageous aspects and details of exemplary embodiments of the method and device according to the invention: Advantageously, steam can be used as a circulating medium in the process, simultaneously serving as a reactant – reducing or oxidizing agent – ​​in chemical synthesis and as a safety device. The process can therefore be called a feedstock steam process or, when biomass is used, a biomass steam process.

[0027] The following explanation describes, as an example, the use of biomass as a raw material. However, this should not be understood as limiting its use to biomass as a raw material. As explained above, any carbon-containing raw material can be used in the same way and with the same advantages. Therefore, in the following explanation, the term "biomass" can always be replaced by the term "raw material" without any restriction of meaning or the advantages described.

[0028] In this process, the proportion of a given biomass is converted into the gaseous state using pressureless superheated steam, which on the one hand corresponds to the maximum mass fraction of CO - carbon monoxide - and CH4 - methane gas - of the initial mass and on the other hand to the proportionate heat capacity of the superheated portion of the steamer corresponding to the heat capacity of the solid biomass in terms of balance or energy.

[0029] The inventive method and device utilize known chemical reactions, which, however, have not previously been applied or practiced in this form. The inventive method is significant in both the aspect of thermal recuperation and heat recovery from waste heat, as well as the possibility of integrating a high-temperature heat pump based on steam compression.

[0030] This process according to the invention, or biomass steam process, is a universal method for producing various products from solid biomass – in the broadest sense, carbon-containing solids of biogenic origin with a high proportion of bound oxygen. These products are liquid products, primarily carbon-containing derivatives, solid carbon – biochar – and gaseous products, primarily hydrogen and carbon dioxide.

[0031] What makes this process special is that the relatively simple fractionation of biomass enables complete yet differentiated utilization – both energetic and material. These fractions can be fed primarily into existing markets, such as energy, biochar, or CO2. For a distillate fraction, the quantity and composition of which depend heavily on the raw materials used, applications in cosmetics and pharmaceuticals are possible in addition to energy recovery. The biomass steam process is ideally suited as a component of a sustainable energy supply that simultaneously enables the material utilization of biomass fractions.

[0032] Due to the use of unpressurized steam with a correspondingly low vapor pressure level in the inventive method, simple integration of existing thermal energy flows - indirect heat recovery - as well as direct heat recovery using a steam heat pump and efficient heat recovery is made possible.

[0033] With the inventive method and the inventive device, it is possible to carry out future energy-intensive processes, especially using renewable raw materials, in a very energy-efficient manner with efficient use of raw materials and essentially CO2-neutral or with extremely low CO2 environmental impact.

[0034] The process according to the invention is preferably carried out at atmospheric pressure. Depending on the raw materials used and the desired end products, the pressure range can be up to 0.5 bar below or above atmospheric pressure. Therefore, a specific process or device is subject to no or only very minor safety requirements, making the process applicable in virtually any environment.

[0035] For example, solid carbon-containing raw materials or components are converted into gas in a closed reactor using superheated but pressureless steam in such a way that the highest possible purity is achieved while simultaneously ensuring high efficiency in the production of hydrogen and carbon dioxide.

[0036] The potential proportion of raw materials or biomass that can be easily converted to gas by heating corresponds to the mass fraction resulting, according to the respective ratios, from carbon monoxide (C) and oxygen (O) to carbon monoxide (C), and from methane (C) and hydrogen (H). Once these components have been converted into the gaseous state, mostly only solid carbon with some minerals remains. This state is almost reached at a final temperature of approximately 850 °C, at which point gas production drops to almost zero. Mineral elemental carbon requires a melting point of 3500 °C, which is why an overlap between the process according to the invention and the coal gasification process can be ruled out. This ensures that, in practice, a clear differentiation between coal gasification and the desired partial gasification is feasible and measurable.

[0037] The process described here demonstrates in practice that partial pressureless raw material steam gasification or biomass steam gasification is clearly distinct from coal gasification and known pyrolysis and partial combustion processes.

[0038] The pressureless steam atmosphere ensures the following important properties and advantages: 1. Inerting of the process space in the container (airtight seal) 2. Identical degassing behavior of the starting materials as in atmospheric combustion 3. Extremely fast and almost ideal direct heat transfer properties due to the reactant in the form of water vapor itself. 4. This enables the safe direct conversion of CO potentials (water-gas shift reaction) to CO2 and H2, which in turn ensures that 5. No significant formation of possible intermediate products, such as tars, PAHs (polycyclic aromatic hydrocarbons), etc., occurs.

[0039] The process ensures a safe, fast and direct binding of the contained oxygen into the stable CO2, without detours or the formation of problematic substances via uncontrollable partial oxidations in allothermal processes, pyrolysis gases in autothermal operation or substoichiometric combustion products as in wood gasification plants.

[0040] Steam in the aforementioned pressure range, i.e., in a virtually pressureless environment, can also be used at temperatures below 100 °C. The steam condenses on the raw material or biomass with extremely high heat transfer, allowing for the rapid and gentle separation of water-soluble and water-insoluble fractions, such as essential oils, waxes, and sugars, in a liquid mixture phase. This separation occurs before the carbon-containing components of the raw material are converted into a gaseous state, i.e., before the actual synthesis process. These fractions can then be used for material purposes.

[0041] Furthermore, due to the low vapor pressure, it is possible to integrate active and passive energy recovery measures into the process in a crucial area of ​​the energy balances.

[0042] The generation of steam requires the highest proportion of energy – approximately 90% – for the phase transition, i.e., the conversion of water into steam. Generating unpressurized steam from waste heat, however, requires relatively little equipment. Pumping energy in a closed loop using a steam compressor is feasible with high COP values ​​– the conversion of electrical energy to pumped thermal energy.

[0043] Only with the application of pressureless steam does the process open up possibilities for indirect or direct heat recovery, which is very difficult, very expensive or technically impossible with high steam pressures.

[0044] The water-gas shift reaction for hydrogen production is primarily used in large-scale industrial plants. In contrast, the process according to the invention focuses on a structurally simple device with maximum efficiency for small power outputs within the context of decentralized energy supply. Implementing large-scale equipment with separate apparatus solutions for each subtask is not suitable for small power outputs. Equipment losses in large-scale plants can be more or less negligible when considering the energy consumption of these plants. However, equipment losses play a significant role in the energy balance of small plants.

[0045] For this reason, it remains advantageous to keep process temperatures as low as possible in the inventive method and device. The technical effort involved in pressurized steam generation plays a crucial role in the implementation of small-scale systems.

[0046] The targeted use of electrical energy is very important for the process according to the invention, since conventional plant technology can become very complex and expensive for small systems and devices. Furthermore, it is not possible to use different pressure levels, as the process according to the invention is a pressureless process.

[0047] Targeted manipulation of the generated gas or syngas using light with wavelengths between 400 nm and 700 nm can significantly improve the quality of the synthesis process, even at low specific efficiencies. Due to its specific properties—penetration in space—light effectively achieves a given volume flow rate without the need for large technical equipment such as heat exchangers. Photo- and potentially photocatalytic effects can also reduce the proportion of CO in the gas stream, effectively creating a second pressure stage.

[0048] The pressureless steam process can utilize various process improvements, such as catalysts and additional synthesis methods. These improvements can include, for example, the following: 1. Use of one or more aids - mixtures - to improve conveying and flowability 2. Use of one or more mixtures or catalysts in these aids 3. Process extensions such as subsequent coal gasification through partial combustion of the high-purity and clean coal fraction to maximize the overall hydrogen yield.

[0049] The described process involves the breakdown of solid hydrocarbon compounds—including synthetically produced carbon compounds such as PE, PP, etc.—by converting them into a gaseous state. This breakdown is primarily achieved through the thermal energy derived from the superheating of essentially unpressurized steam introduced directly into a container or process chamber. A portion of this unpressurized, non-superheated steam is used to recover the thermal energy of the biochar that is necessarily produced, by cooling the biochar with unpressurized steam.

[0050] A key advantage of this process is the removal of atmospheric gases, primarily nitrogen, resulting in pure gas streams of hydrogen and carbon dioxide. The calorific value of these products is present in the form of H₂. Processing in a fuel cell enables a highly efficient, "green" overall process. Due to the energy-efficient nature of the process, pure carbon dioxide gas with a positive energy balance can be supplied for further applications. No nitrogen oxides or particulate matter are produced.

[0051] The method presented here, along with the accompanying example devices, goes far beyond a mere combination of various known methods. Due to the advantages described above, highly efficient operation is possible even with small systems, for example, for decentralized hydrogen production.

[0052] The process enables almost 100% heat recovery from energy flows not required for the chemical endothermic processes. By integrating targeted heat recovery, virtually only the energy required for phase transitions and the energy lost through the equipment itself is needed. This allows thermochemical processes to be implemented safely and efficiently, even in small units.

[0053] There are now various ways to advantageously develop and further refine the teaching of the present invention. Reference is made, on the one hand, to the dependent claims and, on the other hand, to the following explanation of preferred embodiments of the teaching according to the invention with reference to the drawing. In conjunction with the explanation of the preferred embodiments with reference to the drawing, generally preferred embodiments and further developments of the teaching are also explained. The drawing shows Fig. 1 in a schematic representation a first embodiment of the device according to the invention and Fig. 2 in a schematic representation a second embodiment of the device according to the invention.

[0054] The Fig. 1 and Fig. Figure 2 shows two different embodiments of the device according to the invention for producing hydrogen from a carbon-containing raw material. The embodiment shown in Figure 2 features... Fig. 1. A vertically extending elongated container 2 or reactor 2. The embodiment according to Fig. In contrast, Figure 2 features an elongated container 2 or reactor 2 extending in a horizontal direction. In the following text and throughout this document, the terms "container" and "reactor" are used synonymously.

[0055] A key difference between fossil carbon-containing raw materials and biogenic raw materials lies in the oxygen content. Due to its only partial carbonization, lignite occupies an intermediate position with a relatively high oxygen content.

[0056] The composition of renewable biomass consists primarily of carbon, oxygen, and hydrogen. The distribution of these components is approximately: 50% carbon, 43% oxygen, and 6% hydrogen. The ash content typically ranges between 0.5% and 10%. Fluctuations in the ash content primarily affect the carbon content.

[0057] Furthermore, fresh biomass contains, in some cases, very complex compounds that exhibit both water-soluble and water-insoluble components. These products either dissolve or evaporate during prolonged storage.

[0058] The multi-stage process presented here as an example takes special account of this fact of the different components of complex compounds. Stage 1 extraction using low-temperature steam and energy recovery (heat recovery)

[0059] In reactor 2, inerting is carried out using low-temperature steam 4. This means that the low-temperature steam 4 is introduced close to the raw material feed 3. This forces the air back out of the inlet opening into the atmosphere, similar to the outgassing of steam drums. A resulting water phase containing water-soluble components, mostly sugar-like complexes, is washed out in the condensate 5.

[0060] During the heating of the raw material to 100°C, it is simultaneously steamed, and any low-boiling components (essential oils, terpenes, etc.) present are converted into the gas phase. The residual moisture in the raw material is also evaporated through appropriate superheating of the steam.

[0061] The resulting steam, containing hydrocarbon compounds, is condensed in a first condenser 5.1. The energy contained in the steam / vapor mixture is then transferred to a water-based evaporator 20.1. The temperature of the water evaporator is slightly below the steam temperature within reactor 2. Control is achieved by a first compressor 7.1, which is suitable for steam and compensates for the necessary pressure drop. The COP ratio of the required electrical drive work to the pumped thermal energy can be as high as 1:20. Since electrical energy will increasingly be generated from renewable sources in the future, this system will have a nearly 100% CO2 neutral balance.

[0062] It is important that these high-quality components are removed from the raw materials or biomass, as they are not only lost with further temperature increases, but can even generate problems regarding the formation of unwanted hydrocarbon compounds.

[0063] During steam compression, the low-temperature steam undergoes a corresponding superheating in proportion to the electrical energy input. Ideally, this system can be controlled so that only the required energy for vaporizing the hydrocarbons, the equipment losses, and the steam losses need to be supplied as electrical energy (naturally taking the efficiency chain into account). Stage 2: Water-gas shift reaction using highly superheated high-temperature steam and further energy recovery (heat recovery)

[0064] After the complex, high-quality sugars and oils have been removed or extracted from the raw material or biomass, the raw material or biomass can be further heated. This is done using highly superheated, but essentially pressureless, steam. For this purpose, the low-temperature steam is further superheated after the steam compressors using a heating coil 17. The required temperature of up to 1200°C can be achieved by any type of energy transfer. This can be done using a burner for gas, liquid, or solid fuel. Preferably, renewable raw materials, gas produced on-site from the gas phase, self-produced coal, or fuel from the process's own liquid phase can be used as fuel. However, an electric heater can also be used.It should be noted that the steam is generated from heat recovery and only superheating is required to transfer the energy, according to the gas formation, by means of direct steam injection 11 into reactor 2 and thus directly onto the raw material or material without any apparatus.

[0065] An alternative to external steam recovery (heat recovery) could be an external steam source, such as exhaust steam. This would eliminate the need for steam compressors and the associated electrical energy. Cooling would then have to be carried out in the conventional manner (cooling plant with heat dissipation to the environment).

[0066] Selected raw materials, and biomass in particular, are characterized by the fact that, upon sufficient heating, carbon-containing components form in gaseous form, primarily CO and CH4. Once the oxygen and hydrogen contained in the initial raw material or biomass are depleted, the degassing process ceases. This degassing does not occur abruptly but rather over a more or less extended period. The degassing process depends on various parameters, including particle size, the type of raw material or biomass, and the heating curve. Since the process presented here is pressureless, its behavior is comparable to atmospheric degassing.

[0067] When a final temperature of approximately 850 °C is reached, the outgassing process is complete, or the gas volumes approach zero. Highly pure carbon with the bound ash components remains.

[0068] Elemental carbon requires significantly higher temperatures (>3,500 °C) for a phase transition, which is why the separation between coal gasification and, for example, biomass is clear. The remaining carbon is not altered, or only very slowly, by the temperatures of the superheated steam.

[0069] The outgassing of biomass, for example, begins at approximately 180 °C, with CO and CH4 formation occurring at that temperature. However, outgassing within a pressureless water vapor atmosphere is unknown even to recognized experts. In relevant literature, water vapor is only mentioned theoretically as an energy carrier. It can therefore be assumed that corresponding scientific studies are scarce. The only comparable process is scientific research in the field of pyrolysis. No studies have been found on the effect of inerting with pressureless water vapor and its behavior as a reactant in connection with biomass and its outgassing behavior.

[0070] Since no specific apparatus ever provides ideal conditions for a synthesis, a catalyst can be added directly after the extraction phase, see connection 8. This is intended to initiate a water-gas shift reaction as early as possible in order to support the overall process through an exothermic reaction, even if only a weak one. Stage 3: Catalytic water-gas shift reaction, heat recovery and drying of the gas phase

[0071] The syngas flows countercurrently to the feedstock and can only escape from the apparatus at port 9. The water-gas shift reaction with direct heat recovery to the solid feedstock takes place between ports 9 and 11. The gas phase at port 9 has cooled to near the temperature of the vapor extraction stage. This means that the gas mixture originated between a relatively low and a relatively high temperature and is therefore not homogeneous. The gas mixture contains water vapor, CO, H₂, CH₄, and uncondensed vapors from the first stage. To homogenize this raw mixed gas, it must be heated again to a high temperature and passed over a catalyst. For this purpose, a two-stage heat exchanger 10 is located downstream of reactor 2. In a first step, the gas will heat and simultaneously cool itself in countercurrent flow.At the end of this heat exchanger section, the gas is heated to its maximum temperature using a conventional heat exchanger along with the live steam 12. At this maximum temperature, a catalyst—in the simplest case, the heat exchanger itself—is present to carry out the water-gas shift reaction in a second step. At this point, virtually all existing carbon compounds are broken down and subjected to the water-gas shift reaction. The homogenized gas, primarily CO2, hydrogen, and a small proportion of CO, cools down via the counterflow section.

[0072] The gas is cooled and dried by means of a second condenser 5.2, again designed as a water evaporator. The excess vapor is condensed, and the heat is recovered in the vapor phase in a water evaporator. The pressure loss is also compensated for here by a suitable steam compressor. The function here is also that of a heat pump. Step 4 Photocatalytic Synthesis

[0073] After the gas has cooled, a photocatalytic reaction 15 improves its quality with regard to hydrogen concentration, thus ensuring a high to very high hydrogen concentration. Electrically induced photocatalysis is the simplest method of quality assurance, even if its efficiency is low. At this point, generating radicals using light, which further minimize the already low CO concentration, requires only a very small amount of electrical power. The light penetrates the gas stream directly and immediately without the need for complex equipment.

[0074] The gas phase leaves the apparatus in a very high hydrogen concentration 16. The other gases are primarily CO2 and moisture. Stage 5: Heat recovery and cooling of the coal

[0075] At the end of the degassing phase 11, the remaining carbon has heated up to almost the high inlet temperatures of the superheated steam. This energy is to be retained within the process, and the coal must also be cooled and moistened to prevent or eliminate any remaining hot spots within the coal pieces. For this purpose, a two-phase mixture of steam and hot water is sprayed at the end 13 of reactor 2. The liquid component is absorbed by the porous structure of the carbon. The steam component heats up as it passes through the coal, which in turn cools down. The steam is forced towards the high-temperature section and heats up to almost the same temperature as the live steam. The steam then seals the apparatus from the atmosphere at the outlet.

[0076] The 2-phase mixture injection retains the thermal energy in the process without the need for special equipment (heat exchanger).

[0077] The cooled and moistened biochar can be discharged from reactor 2 via a simple discharge 14. Optimizations

[0078] The exemplary embodiment according to Fig.2 features a screw conveyor to transport the solid raw materials or components within this horizontally arranged container 2. To prevent steam losses at the inlet 3 and outlet 14, appropriate airlocks or rotary valve conveyors may be provided. Furthermore, simple heat recovery from the condensates via a heat exchanger may be provided, for example, for potential fresh water heating or raw material drying. In addition, various separation techniques may be provided for separating water, any solids, and liquid hydrocarbons. Specific features

[0079] The process described here uses unpressurized steam as the crucial working, reactant, and recovery medium. Energy recovery measures are only made possible through the use of unpressurized steam.

[0080] Furthermore, a steam extraction process, which is very useful and takes place upstream of the actual synthesis process, can be integrated using pressureless steam.

[0081] This upstream steam extraction is particularly advantageous because, for example, biomass behaves fundamentally differently than coal of fossil origin. Biomass originates from water-based photosynthesis, which can also be described as natural water chemistry. Therefore, biomass must be heated with low-pressure steam to vaporize the components that might transition into a gaseous phase. The steam also acts as an inert gas here, preventing oxygen ingress and driving out any existing atmospheric oxygen. In doing so, it also drives out, to use chemical terminology, the more volatile substances. If the temperature of the steam is increased, the biomass begins to release the bound oxygen along with its carbon compounds in the form of carbon monoxide. This process is fundamentally different from coal gasification.Coal gasification requires thermal energy to produce carbon monoxide. With biomass, carbon monoxide is released solely due to a temperature increase. Therefore, coal gasification, at least with regard to the gaseous fraction, cannot be compared to raw material gasification or biomass gasification. Furthermore, no catalysts are required for this process. Input material

[0082] The input material can be either lumpy or bulk material. It can consist of a mixture of various components or just one component. A loose catalyst and other additives can be added to the raw material or solid biomass. The materials and additives can be homogenized in an upstream mixing section.

[0083] In a further embodiment of the device according to the invention, the first capacitor 5.1 and the second capacitor 5.2 can also be arranged in series, with the component 10 preferably being arranged between the first capacitor 5.1 and the second capacitor 5.2. Following this, the component 15 can be arranged for a photocatalytic synthesis.

[0084] Regarding further advantageous embodiments of the method and device according to the invention, reference is made to the general part of the description and to the attached claims to avoid repetition.

[0085] Finally, it should be expressly pointed out that the exemplary embodiments described above serve only to illustrate the claimed teaching, but do not limit it to these exemplary embodiments. Reference symbol list 1 drive 2 Reactor, container 3. Material feed: Raw material biomass / with / without aids, bulking agents, subsequent mixing section 4. Connection: Steam (unpressurized), slightly superheated, according to the objective of extracting (volatile) materials, inerting and expulsion of air via supply / steam extraction. 5 Condensate outlet of the liquid phase from stage 1 5.1 Condenser 1: The focus here is on the condensation of condensable vapors such as essential oils and hydrocarbon compounds. Cooling is achieved through water evaporation. A compressor generates the necessary pressure difference. 5.2 Condenser 2: The focus here is on the condensation of moisture / water vapor, as this is also produced by the synthesis process. Condensation of higher-boiling hydrocarbon compounds. Cooling is achieved through water evaporation. A compressor generates the necessary pressure difference. 6. Controlled water injection according to mass and energy balance 7.1 Water vapor compressor 1 for heat recovery (The function corresponds to external vapor compression) 7.2 Water vapor compressor 2 for heat recovery (The function corresponds to external vapor compression) 8 Connection aids for synthesis reaction / catalysts 9 Output Synthesis gases / Steam cooled 10 Superheating for the 2nd synthesis step / catalysis by means of 2-stage heating, 1st stage heat recovery, 2nd stage heating to the level of thermal equilibrium according to water-gas shift reaction. 11. Connection for high-temperature steam (unpressurized steam): Superheating according to thermodynamic balance 12 High-temperature steam via heat exchangers to heat synthesis gas 13. Connection for low-temperature steam / hot water injection to cool the coal; the water content is absorbed by the predominantly porous coal. The steam absorbs the heat from the coal, cools it, and is itself superheated for use in synthesis, according to thermodynamic balancing. 14. Removal of ash, cooled / moistened 15 Photocatalytic Synthesis (3rd Synthesis Step) 16 Output hydrogen / synthesis gases 17. Superheater: Superheating of the unpressurized, low-temperature steam. The necessary energy can also be supplied electrically. 18 Connection for the flow pipe of the superheater. The superheater can also be a burner. 19 Connection return superheater. Cooled gas / medium if a physical medium is used. 20.1 Condenser 1 as evaporator for water 20.2 Condenser 2 as evaporator for water

Claims

[1] A process for producing hydrogen from a carbonaceous raw material, wherein the raw material is introduced into a container (2) and is exposed in the container (2) to steam superheated to up to 1200 °C at no pressure, so that carbonaceous components of the raw material are converted into a gaseous state in order to form hydrogen, and wherein, prior to the step of exposure to the superheated steam, the raw material is heated in a first step to 100 °C with low-temperature steam in order to dissolve and / or extract water-soluble and water-insoluble components from the raw material, characterized by , that the water vapor produced in the first step, along with any vapors and / or dissolved and / or extracted components contained therein, is condensed by means of a first condenser, whereby heat energy contained in the resulting water vapor is transferred to a first evaporator. [2] Method according to claim 1, characterized by that the carbon-containing raw material is solid, liquid or gaseous, wherein preferably the carbon-containing raw material is essentially solid biomass. [3] Method according to claim 1 or 2, characterized by , that during the transfer of the heat energy contained in the resulting water vapor to the first evaporator, temperature control is carried out by means of a first compressor. [4] Method according to any one of claims 1 to 3, characterized by that the dissolved and / or extracted components are removed from the process or recycled. [5] Method according to any one of claims 1 to 4, characterized by , that after the first step a catalyst is added to promote hydrogen formation. [6] Method according to any one of claims 1 to 5, characterized bythat the low-temperature steam is heated by means of a heating device or a heating coil. [7] Method according to any one of claims 1 to 6, characterized by , that a gas mixture produced when the raw material is exposed to superheated steam is subjected to a second heat treatment, preferably by interacting with or passing over a catalyst to promote hydrogen formation. [8] Method according to claim 7, characterized by , that the gas mixture heated by the second heat treatment is cooled by means of a second condenser, wherein heat energy contained in the gas mixture is preferably transferred to a second evaporator and further preferably pressure control is carried out to compensate for a pressure loss by means of a second compressor. [9] Method according to any one of claims 1 to 8, characterized bythat the components of the raw material or the gas mixture, converted into a gaseous state, are or will be exposed to illumination with a predefinable wavelength, preferably between 400 nm and 700 nm, to generate a photocatalytic reaction for increasing a hydrogen concentration. [10] Method according to any one of claims 1 to 9, characterized by , that a bulking aid or an agent to improve conveying and / or flowability and / or a catalyst to promote hydrogen formation is added to the raw material before, during or after it is placed in the container (2). [11] Method according to any one of claims 1 to 10, characterized by , that as a further process step after the raw material is exposed to the superheated steam, coal gasification takes place by burning a solid coal fraction that has formed. [12] Method according to any one of claims 1 to 11, characterized by, that a formed solid coal fraction is cooled by means of non-superheated steam or by means of a mixture of steam and hot water, whereby further heated steam and / or formed steam is used to heat raw material and heat recovery is thereby achieved. [13] Apparatus for carrying out a process for producing hydrogen from a carbon-containing raw material, namely for carrying out the process according to any one of claims 1 to 12, comprising a container (2), wherein the raw material is introduced into the container (2) and is exposed in the container (2) to a pressureless steam superheated to up to 1200 °C in such a way that carbon-containing components of the raw material are converted into a gaseous state in order to form hydrogen, and wherein, prior to the step of exposure to the superheated steam, the raw material can be heated to 100 °C in a first step with low-temperature steam in order to achieve the dissolution and / or extraction of water-soluble and water-insoluble components from the raw material, characterized by, that the water vapor produced in the first step, containing vapors and / or dissolved and / or extracted components, can be condensed by means of a first condenser, whereby heat energy contained in the water vapor produced can be transferred to a first evaporator.

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