Device and method for gasifying biomass

Abstract

The invention relates to a device (1) for gasifying biomass, comprising - a gas generator (2) having a fuel supply (8), an air supply (4), an ash and coal discharge (30), and a reaction chamber (3) for generating product gas, - a starter (11), which can be coupled at least temporarily to the gas generator (2), for providing starting energy during a gas generator starting process, - a product gas filter (18) fluidically connected to the gas generator (2) via a product gas line (13), and optionally a starting line (14) fluidically connected to the product gas line (13). The device is characterized in that - at least one heat source (12) for at least temporarily treating gas is provided in the gasification device (1). The invention further relates to two methods for heating the gasification device (1) during a cold start.

Description

[0001] Device and method for gasifying biomass

[0002] The invention relates to a device and a method for gasifying biomass such as wood, as well as a method for heating the gasification device in accordance with the introductory part of claim 1.

[0003] State of the art

[0004] Devices and processes for gasifying biomass, such as wood, have been known for a long time. The biomass is pyrolyzed with a defined oxygen deficiency, producing a combustible gas (also known as synthesis gas, pyrolysis gas, product gas, or wood gas). In addition to the combustible components, primarily carbon monoxide (CO), hydrogen (H2), and methane (CH4), this gas also contains non-combustible components such as nitrogen (N2), water vapor (H2O), and carbon dioxide (CO2). Due to the significant proportion of non-combustible components, product gas from biomass is considered a low-calorie gas and is a lean gas with a typical calorific value of 3.5 to 5.5 MJ / m3. 3 .

[0005] Furthermore, the product gas may contain tar and other undesirable components such as ash or unburned biomass particles and condensate-forming components. The product gas can be used, for example, to operate a gas engine (also called an internal combustion engine and subsequently abbreviated to ICE), for example, to power a vehicle or a generator in a combined heat and power (CHP) plant. EP 3067407 B1 discloses a device for gasifying wood. Wood gas is generated in a gas generator and subsequently passed through a hot gas filter for purification.

[0006] The start-up process of biomass gasification systems often takes place as follows: the gasification system is filled with fuel. The fuel is heated using, for example, an external heat source such as a heater fan and with a sufficient supply of air. The oxidation reaction begins slowly and, depending on the fuel and temperature, product gas is formed, which is, however, still of inferior quality. The calorific value is low, and the tar content is high. However, tar contained in the gas is particularly disadvantageous, as it can condense and deposit in parts of the system, causing the affected parts to become tarred. In particular, tar deposition on the filter surfaces of the product gas filters is detrimental, as this can cause blockages and, as a result, stable operation of the system is no longer possible. Furthermore, tar deposits, for example,in the pipes, walls, or in the gas engine and product gas heat exchangers, impairing their function. Other condensate-forming substances also lead to such undesirable deposits. For example, condensing water in combination with other contaminants such as ash, coal, and unburned biomass can form such deposits, which can lead to, for example, clogging of filter surfaces.

[0007] This effect is particularly detrimental when starting up such systems, in particularly cold temperatures and when the gasification device is operated outdoors or in poorly insulated buildings.

[0008] Generally speaking, deposits of tar and condensate lead to unstable operating conditions, considerable maintenance costs, plant downtime and repairs, and thus have a negative impact on the economic management of plants.

[0009] A known counter-strategy in the state of the art is, for example, to burn off the tar deposits. For this purpose, the filter elements or filter candles are heated with an external propane gas burner until the tar deposits burn off and the filter is clear again. To do this, an operator directs the flame of a portable propane gas burner to the filter elements, which are accessible from the outside, for example, through a maintenance hatch.

[0010] This process is particularly common in smaller gas generation systems, but it requires manual manipulation that must be performed frequently and is correspondingly labor-intensive. Furthermore, this burn-off is always performed afterward and is equivalent to treating the symptoms, but does not prevent the formation of deposits. However, it is also known to heat the filter elements, which are particularly susceptible to tar and condensate deposits, with an external propane burner before starting the gasification system in order to prevent condensation, for example, of tar. This process is similar to the tar burn-off described above and is again common in smaller gas generation systems.

[0011] However, this also involves manual manipulation and is correspondingly laborious. Furthermore, the operator has a significant influence on this process and the achieved preheating effect. For example, the preheating process can be terminated even if the temperature is insufficient. It is also possible that only some of the filter elements have been sufficiently preheated, while others have not been sufficiently heated due to a lack of homogeneous temperature distribution.

[0012] The heating of filter elements is also known in the prior art in electrical form; for example, DE102010028476B4 discloses a hot gas filter for pyrolysis gas with filter candles that can be heated by means of an internal electrical heating device.

[0013] KR101872805B1 also describes an electrically operated heating element arranged in a ring around a filter candle. However, the disadvantage of such systems is that only the filter candles are heated, while the surrounding filter housing and other components of the gasification system remain cold. Furthermore, the power supply required for the heating process, e.g., from the grid, and the considerable power consumption are also disadvantageous in electrically heated systems.

[0014] US 10981097 B2 discloses a hot gas filter for a coal gasification plant. This filter is equipped with a recirculation line for the hot and filtered gases to preheat the filter and better utilize the heat. This recirculation line, the so-called "circulation pipe," may contain a combustion chamber.

[0015] The filter candles can also be regenerated by burning off impurities on the filter candles. Impurities such as carbon particles and tar are deposited on the filter candles because, even during preheating, tar-containing gas is first passed through the filter candles before being returned to the filter via the return line.

[0016] Multiple filters can also be connected to such a return line. This system is suitable for large coal-fired plants with filters longer than 100 m. 3 The disadvantages of this solution are the tar contamination of the filter cartridges, even during preheating, as well as the large installation space required, which makes this concept unsuitable for small biomass plants.

[0017] US 2019127649 A1, on the other hand, describes a gasification plant with a flare for flaring off tar-containing gases generated during the start-up process. The tar-containing gases are discharged from the gasification plant via the flare and thus do not come into contact with the filter at all. This can prevent tarring of the filter, but the disadvantages are the complex structure and the resulting energy and product gas losses due to flaring without further use, as well as emissions escaping into the environment.

[0018] Task and solution to the task

[0019] The object of the present invention is therefore to overcome the disadvantages of the prior art and to provide a device and method for gasifying biomass with improved starting characteristics, particularly with regard to rapid and dynamic startup, as well as improved cold-start characteristics. A cold start is understood to mean the start of a new gasification device or a device that has not been operated for a long time and is therefore cold and adjusted to the ambient temperature.

[0020] A further object can be seen in providing a gasification device and method which prevents the condensation of gas components such as tar and water.

[0021] A further object can be seen in providing an improved method for heating a gasification device, in particular a product gas filter. A further object of the invention can be seen in a device and method for minimizing environmentally harmful emissions while simultaneously optimizing the utilization of process heat, enabling more stable process control, and thus enabling the use of different raw material qualities with regard to volatile components and moisture content in the start-up process, such as softwood / hardwood or pellets / wood chips, etc.

[0022] The object is achieved by a device and a method according to the claims.

[0023] The invention relates to a gasification device for gasifying biomass. The gasification device comprises a gas generator with a fuel supply, air supply, ash and coal discharge, and a reaction chamber for generating product gas. A starter that can be at least temporarily coupled to the gas generator to provide starting energy for the gas generator start-up process.

[0024] Furthermore, the gasification device comprises a product gas filter fluidically connected to the gas generator via a product gas line and optionally a start line fluidically connected to the product gas line, wherein at least one heat source is arranged in the gasification device at least temporarily for the treatment of gas.

[0025] The gasification device according to the invention is advantageous because the starter provides starting energy during the gas generator start-up process and for starting the production of product gas. Gas can be discharged from the gasification device via the starter line if necessary.

[0026] Particularly advantageous is the inclusion of a heat source in the gasification system, which can be used to treat gas. Depending on requirements, gas can be heated in the heat source, for example, allowing the heating of downstream plant components. The tar content of the gas can also be reduced in the heat source, preventing tar condensation in subsequent plant components.

[0027] The gasification device may further comprise a heat source which is arranged in or on the product gas line between the gas generator and the product gas filter, or is guided in a bypass with the product gas line between the gas generator and the product gas filter, or is arranged on or at least partially in the product gas filter.

[0028] This arrangement of the heat source is particularly advantageous because gas from the gas generator, for example, product gas, can be heated and / or its tar content reduced directly before entering the product gas filter. This allows for particularly efficient heating of the product gas filter and other system components.

[0029] The gasification device may further comprise a heat source which can be coupled to the product gas line between the gas generator and the product gas filter and / or the product gas filter.

[0030] This arrangement is particularly advantageous because the heat source can be connected or disconnected as needed. This allows for particularly efficient heating of the product gas filter and other system components.

[0031] The gasification device may further comprise a heat source arranged in the gas generator.

[0032] It is particularly advantageous that in such an embodiment the gas is treated, e.g. heated, before being introduced into the product gas filter, for example in the reaction chamber of the gas generator. This allows the product gas filter and the other system components to be heated particularly efficiently.

[0033] Furthermore, the product gas filter of the gasification system can be fluidically separated from the exhaust line via a hot gas discharge line. This design is particularly advantageous for discharging treated gas from the product gas filter via a hot gas discharge line and the exhaust line during the product gas filter warm-up phase or during unforeseen operational disruptions. This makes it possible to prevent gas from entering other system components and thus prevent potential contamination of system components.

[0034] Furthermore, the gasification device can comprise a product gas heat exchanger that is fluidically separably connected to the product gas filter and an ICE that is fluidically separably connected to the product gas heat exchanger and is optionally coupled to an electric generator.

[0035] This embodiment of the invention is particularly advantageous because gas treated in the heat source, e.g., heated gas, can be passed through the product gas filter into the product gas heat exchanger and the ICE. This also allows the system components connected downstream of the product gas filter to be heated with the residual heat available after flowing through the product gas filter.

[0036] In addition, the gasification device may comprise a heat source which comprises a gas mixer and / or gas burner and / or a combustion chamber or is designed as an electrical heating element.

[0037] It has proven advantageous that the gas can be mixed with another gas in a gas mixer and burned for heating. It is particularly advantageous that gas can be heated and / or chemically converted as it passes through the hot coal bed. Furthermore, it is advantageous to heat gas by means of an electrical heating element, such as a heating fan, which can optionally be temporarily coupled to the product gas line or the product gas filter. This design allows for particularly small installation space. Furthermore, such an arrangement means that when several systems are operated in a network, only one electrical heating element, such as a heating fan, is necessary. The heat source of the gasification device can comprise a Venturi nozzle, whereby a particularly homogeneous mixture of gases can be achieved. Another advantage is the very simple design of such a gas mixer.

[0038] The heat source of the gasification device can further comprise an ignition source and / or a supporting flame and / or a catalyst. The advantage of this design is that gas can be ignited at the ignition source as needed and / or gas or gas components can be converted into desired gas components by a catalyst.

[0039] In addition, one or more of the product gas line, start line, and hot gas discharge lines can be designed to be fluidically separable using a slide valve, valve, flap, or three-way cock. This offers advantages such as ease of operation and low maintenance requirements.

[0040] The gasification device can further include a gas storage unit for product gas. This is particularly advantageous because it allows product gas to be stored and used to operate the heat source even when the gas generator is not in operation, for example, before the gas generator is started. This allows the product gas filter and all other system components to be heated before the gas generator is started.

[0041] The gasification device can further comprise at least one temperature sensor in a coal bed or in the region of the gas generator's outlet into the product gas line or in the product gas filter, which is preferably arranged on the raw gas side and is designed as a ceramic sensor, metal sensor, or Type-K or Type-N sheathed thermocouple. This design is particularly suitable for measuring the temperature in the coal bed, at the gas outlet from the gas generator, and in the product gas filter.

[0042] The gasification device can further comprise an exhaust line (15) that is fluidically separably connected to the gas generator (2) via a start line (14). This is particularly advantageous for discharging gases from the gasification device after the gas generator. Contamination of the product gas filter and downstream system components can thus be prevented. For example, resulting product gas that is of inferior quality can be discharged via an exhaust line.

[0043] The gasification device may further comprise an exhaust fan in the exhaust line. This is particularly advantageous for creating negative pressure in the gasification device and for conveying gas through the gasification system.

[0044] The heat source can also be designed as a glowing coal bed.

[0045] The gasification device can further comprise a product gas filter, which is fluidically separably connected to the ICE via a hot gas line. Advantageously, the treated gas from the product gas filter can be fed directly into the ICE via the hot gas line, and the ICE is heated by the treated gas. This allows the ICE to be heated particularly quickly and to a particularly high temperature.

[0046] Furthermore, the gasification device can comprise a product gas heat exchanger, which is fluidically separably connected to the ICE via a cold gas line. Advantageously, the treated gas from the product gas heat exchanger can be fed directly into the ICE via the cold gas line, and the ICE is heated by the treated gas. The ICE can thus be heated directly after the product gas heat exchanger, bypassing the one safety filter.

[0047] The heat source can also be designed to convert tar-containing gas into gas with a reduced tar content. A particular advantage of this is that the treated gas has a reduced tar content, thus preventing the potential for condensation of tar in the product gas filter.

[0048] The gasification device can further comprise a safety filter that is fluidically separably connected to the product gas heat exchanger and the ICE. It is particularly advantageous that the safety filter removes any possible contaminants (e.g., dust particles, tar residues) before gas enters the ICE. This ensures that only purified gas is introduced into the ICE, and any possible "slippage" of contaminants is captured by the previously flowed-through components, particularly the product gas filter.

[0049] Furthermore, the safety filter of the gasification device can be designed as an RME filter. Impurities can be separated particularly effectively using an RME filter.

[0050] The invention further relates to a method for heating a biomass gasification device comprising the steps:

[0051] - Treating a gas with a heat source to provide treated gas

[0052] - Introducing the treated gas into a product gas filter and discharging the treated gas from the product gas filter to heat the product gas filter until a product gas filter target temperature is reached.

[0053] It is particularly advantageous to treat a gas before introducing it into the product gas filter, for example, by heating it and / or reducing its tar content. This can be used to heat a product gas filter. This allows the product gas filter to be brought to a target temperature before normal operation, preventing deposits in the product gas filter and extending maintenance intervals.

[0054] The invention further relates to a method for heating a biomass gasification device comprising the steps:

[0055] - Filling the gas generator with starting fuel, in particular biomass or coal, and heating the starting fuel until a coal bed target temperature is reached using a starter and optionally discharging the resulting gas via a starting line and an exhaust line

[0056] - at the latest when the carbon bed target temperature is reached, optional closing of the start line and start of the treatment of the gas with a heat source into treated gas and introduction of the treated gas into the product gas filter to heat the product gas filter and discharge the treated gas from the product gas filter until a product gas filter target temperature is reached.

[0057] Particularly advantageous is the treatment of a gas from the gas generator before introducing it into the product gas filter, which, for example, heats it and / or reduces its tar content. This can be used to heat a product gas filter. The product gas filter can thus be brought to a target temperature before normal operation, preventing deposits in the product gas filter and extending maintenance intervals.

[0058] Furthermore, the gas can contain combustible components, and the treatment of the gas with the heat source can involve chemical conversion and / or combustion of the combustible components. It is particularly advantageous that heat is generated through the chemical conversion and / or combustion. Furthermore, undesirable gas components, such as tar, can be converted into acceptable gas components, such as CO2.

[0059] Furthermore, the gas can be treated and heated using an electric heating element, particularly a fan heater. The rapid heating process and small space requirement are particularly advantageous.

[0060] The process can also be carried out by treating the gas by passing it through a glowing bed of coal in a reaction chamber of the gasification device. The gas can be heated and chemically converted.

[0061] The gas may further comprise at least one or a combination of several from the group air, carbon monoxide, product gas, low-grade product gas, methane, ethane, propane, butane, natural gas or hydrogen.

[0062] Furthermore, the tar content of the gas can be reduced during the treatment and / or the tar content of the gas after the treatment can be max. 500mg / m 3 , preferably max. 100mg / m 3 The gas with reduced tar content is particularly advantageous for introduction into the product gas filter, as it prevents condensation of substances such as tar.

[0063] Furthermore, the product gas filter target temperature can be in the range of 200 to 600°C, preferably in the range of 300 to 500°C, particularly preferably in the range of 370 to 430°C, which has the advantage that tar does not condense at this temperature and remains in the gas phase. Furthermore, the treated gas from the product gas filter can be introduced into a VKM via a product gas heat exchanger, optionally a safety filter, and discharged from the VKM until a VKM target temperature is reached. This has the advantage that all of the aforementioned system components can be preheated simultaneously, thus minimizing heat losses.

[0064] The treated gas can also be discharged from the product gas filter via a hot gas discharge line and the exhaust line. This has the advantage of preventing unwanted condensation of substances such as water or tar in the downstream system components as the gas cools.

[0065] Furthermore, when the product gas filter target temperature is reached, the hot gas discharge can be closed and the treated gas can be introduced into the ICE via the product gas heat exchanger until the ICE target temperature is reached.

[0066] The ICE target temperature can be in the range of 50 to 90°C, preferably 60 to 80°C, and can be measured in the intake area. This has the advantage that the ICE, and optionally the product gas heat exchanger, can be warmed up before normal operation begins, which has a positive impact on both operation and maintenance intervals.

[0067] It is particularly advantageous if the gas is introduced into the ICE by means of generator operation of the ICE. This creates a vacuum in the ICE and in the gasification device, causing gas to flow through the gasification device to the ICE. At the same time, the ICE is heated by friction. The ICE is also heated by heated gas, and can thus be brought up to temperature more quickly.

[0068] It is particularly advantageous if the normal operation of the gasification device is started by the following steps:

[0069] - Terminating the treatment of the gas in the heat source, and

[0070] - optional closing of the hot gas discharge, and - introduction of the product gas through the product gas filter, through the product gas heat exchanger, optionally through a safety filter, into the VKM and

[0071] - Starting the combustion of the product gas in the ICE to operate a generator.

[0072] In this way, the gasification device can return to normal operation after the system components have warmed up, thus preventing contamination and deposits.

[0073] Furthermore, it is advantageous to initiate a gas generator start-up process when the product gas filter target temperature is reached. This allows the product gas filter to be preheated before the gas generator starts.

[0074] Furthermore, it may be advantageous if the coal bed target temperature is in the range of 200 to 30°C, preferably 235 to 265°C.

[0075] Alternatively, when the product gas filter target temperature is reached, the hot gas discharge can be closed and the treated gas can be introduced into the ICE via a hot gas line or via the product gas heat exchanger and a cold gas line until the ICE target temperature is reached.

[0076] In addition, upon reaching the VKM target temperature, the hot gas line 22 can be closed and the treated gas can be introduced from the product gas filter into the product gas heat exchanger and via the cold gas line into the VKM until the target temperature, called the product gas heat exchanger target temperature, is reached, wherein the product gas heat exchanger target temperature can be in the range of 50 to 150°C, preferably 75 to 125°C, particularly preferably 90 to 110°C. With such a process, the product gas heat exchanger can be heated downstream of the VKM.

[0077] Furthermore, upon reaching the product gas filter target temperature, the ICE target temperature, or the product gas heat exchanger target temperature, the gas treatment and / or the production of gas with reduced tar content can be terminated and normal CHP operation can be started. Furthermore, normal CHP operation can be initiated by optionally closing the hot gas discharge, hot gas line, or cold gas line, introducing the synthesis gas through the HGF, through the product gas heat exchanger, optionally through a safety filter, into the ICE, and combusting the synthesis gas in the ICE to operate a generator.

[0078] It is particularly advantageous to heat the above-mentioned system components before starting normal operation, as this can prevent start-up problems and condensation of tar or water in the system components.

[0079] General definitions

[0080] Gas is to be understood in the usual physical sense and refers to gaseous substances in the aggregate state, for example air, product gas, product gas of inferior quality, hydrogen, etc.

[0081] For the purposes of the present invention, the treatment of gas may comprise one or a combination of several from the following group:

[0082] Warming or heating e.g. of product gas or air Chemical and / or catalytic conversion of gas or gas components Combustion of gas or gas components e.g. product gas

[0083] Mixing of gas with another gas e.g. product gas with combustion air Reduction of the gas tar content

[0084] For the purposes of the invention, gas which is treated may comprise one or a combination of several from the following group:

[0085] Air (also called supply air or combustion air)

[0086] Oxygen (O2)

[0087] Nitrogen (N2)

[0088] Carbon dioxide (CO2)

[0089] Water (H2O)

[0090] Methane (CH4)

[0091] Ethane (C2H6)

[0092] Propane (C3HQ

[0093] Butane (C4H10) Carbon monoxide (CO)

[0094] Hydrogen (H2)

[0095] natural gas

[0096] Product gas (synthesis gas e.g. wood gas, etc.)

[0097] Inferior product gas (from the gas generator start-up process)

[0098] Product gas in mixture with propane, butane, natural gas, other hydrocarbons

[0099] Gas that is treated may also contain the following (undesirable, possibly condensable) components, e.g.

[0100] tar

[0101] BTEX (benzene, ethylbenzene, toluenes, xylenes)

[0102] Dust

[0103] ash

[0104] Money

[0105] Unburned biomass particles

[0106] Water (H2O)

[0107] Product gas (or synthesis gas, pyrolysis gas) is a combustible gas from the gasification process, which can include one or a mixture of several gases from the group consisting of CO, CO2, H2, H2O, N2, CH4, ethane, propane, and ethylene. Product gas is suitable for operating an internal combustion engine.

[0108] For example, product gas from a wood gasification plant is referred to as wood gas. The composition of wood gas depends on the gasification device used for production. The following table shows typical values ​​of wood gas compositions from two different cocurrent fixed-bed gasification devices, measured downstream of the product gas filter:

[0109] The typical tar content of wood gas from a gas generator based on the direct current and fixed bed principle is 100 to 5000 mg / m 3 .

[0110] A low-grade product gas is a combustible or non-combustible gas from the start-up of the gasification process, which can include one or a mixture of several from the group of CO2, CO, H2, H2O, N2, CH4.

[0111] Typically, the tar content can be >500mg / m 3 and up to 5000mg / m 3 , possibly even higher, and this gas is not suitable for operating a gas engine.

[0112] Flammable gas is a gas with one or more combustible components which can be mixed with an oxygen-containing gas such as air to form an ignitable mixture.

[0113] The combustible components are e.g.: CO, H2, hydrocarbons, e.g. and not limited to alkanes (CH4, C2H6, C3H8, C4H10, etc.), alkenes (ethylene, propene, etc.), alkynes (ethyne or acetylene, propyne, etc.) etc.

[0114] Fuel gas is a combustible gas suitable for operating the heat source or a supporting flame of the heat source. It is used in parallel with or instead of product gas produced in the gas generator and supplied directly from the gas generator. Fuel gas can be, for example, natural gas, propane, butane, etc. Fuel gas can also be a purified product gas from a gas storage facility. Tar is a mixture of long-chain hydrocarbons produced during the pyrolysis of biomass, for example. Below the condensation temperature, tar is a viscous, sticky to solid substance.

[0115] Tar deposits are viscous, sticky to solid contaminants formed by the condensation of tar and other hydrocarbons. In the following, deposits formed by the condensation of water and the resulting soot and ash, which also form viscous, sticky to solid contaminants, are also included.

[0116] The start-up process refers to the steps necessary to bring the gasification device from standstill to normal operation.

[0117] Normal operation is the condition in which product gas is continuously produced in the gasification device at a quality that allows the operation of a VMK. The tar content of the product gas should be kept at a maximum of 500 mg / m 3 , preferably max. 100mg / m 3 The tar content is measured in accordance with DIN CEN / TS 15439:2006 "Biomass gasification - Tar and dust in product gases - Sampling and analytical determination"

[0118] The internal combustion engine, also abbreviated to ICE or gas engine, is designed to operate with product gas. During normal operation, the product gas is combusted with air in the gas engine, and the energy released is converted into rotational energy.

[0119] During normal operation, the generator or power generator is coupled to the ICE and converts the rotational energy of the ICE into electrical energy.

[0120] In generator mode, the generator reverses its function as a power generator and operates as an electric motor, driving the ICE coupled to it. The ICE creates a vacuum in the engine compartment through the forced movement and accordingly draws gas from the gasification device. The invention is explained in more detail with the help of the following figures and schematic representations:

[0121] Fig.l shows a schematic representation of a gasification device known in the prior art using the example of a wood gas CHP plant.

[0122] Fig. 2 shows a schematic representation of a gasification device according to the invention using the example of a wood gas CHP plant.

[0123] Fig. 3 is a schematic detailed representation of a gasification device with gas generator and product gas filter.

[0124] Different arrangements of the heat source are shown in Fig. 4a-e.

[0125] Fig. 5 shows a further embodiment of the gasification device according to the invention.

[0126] An embodiment of the heat source is shown in Fig. 6.

[0127] Further embodiments of the heat source are shown in Figs. 7A and 7B.

[0128] Detailed description

[0129] The present invention is described below using the example of a cocurrent fixed-bed gas generator. However, the invention can easily be applied by a person skilled in the art to other gas generator types, such as fluidized-bed gasifiers, countercurrent gasifiers, etc.

[0130] The simplified flow diagrams shown in the figures with gas lines and branches are to be interpreted, as is common practice in process engineering, as appropriate selection devices are provided for selecting the material flow direction at the branches. These selection devices can be implemented, for example, as slide valves, valves, flaps, three-way cocks, etc.

[0131] Gasification devices 1 according to the cocurrent fixed bed principle, as shown in Fig. 1, are known in the art and comprise a gas generator 2 with a reaction chamber 3. The gas generator 2 comprises a fuel supply 8 and at least one air supply 4 and can be tubular and have a constriction 9 or tapered tube diameter in the region of the reaction chamber 3. An agitator 32 and a grate 10 can be arranged below the constriction 9. An ash and coal discharge 30 can be arranged below the grate 10, for example by means of a screw conveyor. Furthermore, a starter 11 can be arranged on the gas generator to provide starting energy.

[0132] The fuel supply 8, shown as an arrow, is located in the upper area of ​​the gas generator 2, and the material slowly flows downward through the gas generator 2 due to gravity. At least one air supply 4 is arranged in the reaction chamber 3. For example, the air can be supplied via air nozzles in the area of ​​a constriction 9 of the gas generator 2. Like the material flow, the gas flow essentially occurs from top to bottom, or from the air supply 4 toward the grate 10.

[0133] The gas generator 2 is fluidically connected to a product gas filter 18 by means of a product gas line 13, and can be fluidically separated if necessary.

[0134] The gasification device 1 further comprises a start line 14 for conducting gas from the gas generator 2 into an exhaust line 15 and enables the discharge of gas from the gasification device 1, optionally via a chimney 17. The start line 14 can, for example, be connected to the product gas line 13. The discharge of gas from the gasification device 1 occurs in particular during the start-up process of the gas generator. The start line 14 is provided with means for opening and interrupting the gas flow, for example a slide valve, valve, flap, or three-way cock. This allows the flow of gas into the start line 14 to be enabled or disabled. In particular, for the start of gas generation in the gasification device 1 described below, hereinafter also referred to as the gas generator start-up process for short, low-quality product gas can be conducted out of the gasification device via the start line 14 and the exhaust line 15.

[0135] The product gas line 13 can be arranged, for example, in the lower or upper area of ​​the gas generator 2 and connected to the product gas filter 18. Gas can thus flow from the gas generator 2 via the product gas line 13 into the product gas filter 18. However, a means for opening and interrupting the gas flow into the product gas filter 18, e.g., a slide valve, flap, or three-way cock, can also be arranged on the product gas line 13.

[0136] The product gas filter 18 comprises at least one filter element 19, e.g., filter candles. Contaminants such as ash, coal, and dust particles are separated at the filter element 19.

[0137] When the product gas enters the product gas filter 18, it is not yet purified of impurities and can therefore also be referred to as raw gas. After passing through the filter element 19 and separating impurities, the product gas can also be referred to as clean gas.

[0138] On the clean gas side, the product gas filter 18 is fluidly connected to a product gas heat exchanger 21 via a clean gas line 29, and the product gas heat exchanger is fluidly connected to a gas engine or internal combustion engine, abbreviated to VKM 25. A safety filter 23, such as a rapeseed oil methyl ester filter, can be arranged between the product gas heat exchanger 21 and VKM 25 and fluidly connected to the product gas heat exchanger 21 and VKM 25 via the clean gas line 29. An exhaust line is arranged at the VKM 25 to discharge the exhaust gas from the VKM 25, if necessary, via chimney 17, and discharge it from the gasification device 1.

[0139] Gasification device according to the invention

[0140] The gasification device 1 according to the invention comprises a gas generator 2 with a fuel supply 8, an air supply 4, and an ash and coal discharge 30. Furthermore, the gasification device 1 according to the invention comprises a product gas filter 18, wherein the gas generator 2 is connected to the product gas filter 18 via a product gas line 13. The gasification device 1 according to the invention further comprises a heat source 12 for gas treatment.

[0141] The gasification device 1 can further comprise a product gas heat exchanger 21, a safety filter 23, a VKM 25, and a generator 26. Fig. 2 shows an embodiment of the gasification device 1 according to the invention. The gasification device 1 comprises a gas generator 2 with a reaction chamber 3. The gas generator 2 comprises a fuel supply 8 and at least one air supply 4 and can be tubular and have a constriction 9 or a tapered tube diameter in the region of the reaction chamber 3. An agitator 32 and a grate 10 can be arranged below the constriction 9. An ash and coal discharge 30, e.g., by means of a screw conveyor, can be arranged below the grate 10. The ash and coal discharge can also be carried out via the product gas line into the product gas filter, where they can be discharged from the gasification device. Versions of the gas generator without a grate are also possible.

[0142] The fuel supply 8, as already described in Fig. 1, is from above. At least one air supply 4 is arranged in the reaction chamber 3. For example, the air can be supplied via air nozzles in the region of a constriction 9 of the gas generator 2. The gas flow and material flow in the gas generator 2, as already described in Fig. 1, occurs essentially from top to bottom. Furthermore, a starter 11 is arranged at least temporarily on the gas generator 2 to provide starting energy; for example, the starter 11 can be coupled to the air supply 4.

[0143] The gas generator 2 is fluidly connected to a product gas filter 18 by means of a product gas line 13, optionally separably connected. The arrangement of the product gas line 13 is described in detail below. Furthermore, a heat source 12 is arranged in the gasification device 1 according to the invention. Details on the arrangement and function of the heat source 12 are described below; see also Fig. 4.

[0144] The gasification device 1 further comprises a start line 14, as already described above in Fig. 1, for discharging gas from the gasification device 1. The start line 14 can, for example, be fluidically separably connected to the product gas line 13 and be provided with means for opening and interrupting the gas flow, for example a slide valve, valve, flap, or three-way cock. This allows the gas flow into the start line 14 to be enabled or blocked as needed. In particular, for the gas generator start-up process described below, inferior product gas can be passed via the start line 14 and exhaust line 15 and, if appropriate, chimney 17 and discharged from the gasification device 1.

[0145] In addition, in the event of operational malfunctions, e.g. when overpressure occurs or when introducing gas into the product gas filter 18 is undesirable, product gas can be discharged via start line 14 and the exhaust line 15.

[0146] The discharge of gas from the gasification device 1 can occur in particular during the start-up process of the gas generator. In Fig. 2 and Fig. 3, in a preferred arrangement, the start line 14 "downstream" of the heat source 12 is fluidly separably connected to the product gas line 13. Gas from the gas generator 2 can be conducted via the product gas line 13 through the heat source 12 into the start line 14 and then discharged from the gasification device 1. However, gas from the gas generator 2 can also be conducted via the product gas line 13 without flowing through the heat source 12 into the start line 14 and then discharged from the gasification device 1.

[0147] Furthermore, gas from the gas generator 2 can be passed into the product gas filter 18 either through the heat source 12 or without flowing through the heat source 12.

[0148] For example, the starting line 14 can also be arranged "upstream" of the heat source 12, see Fig. 5. In other words, the branch from the product gas line to the starting line 14 is arranged such that the gas can flow through the starting line 14 to the exhaust line 15 and be discharged from the gasification device 1 via chimney 17 without first flowing through the heat source 12. Gas from the gas generator 2 can also be passed either via the heat source 12 or directly into the product gas filter 18, as shown in Fig. 5.

[0149] If necessary, two starting lines can be arranged, one "before" and one "after" the heat source 12, as shown in Fig. 4a. If necessary, the starting line 14 can also be omitted (see, for example, Figs. 4b-e). The exact arrangement of the starting line 14 can be easily determined by a person skilled in the art, depending, for example, on space constraints.

[0150] As already described, the gas generator 2 is fluidically connected, if necessary separably, to the product gas filter via a product gas line 13. The product gas line 13 can, for example, be arranged in the lower or upper area of ​​the gas generator 2 and connected to the product gas filter 18. Gas, e.g., product gas or low-quality product gas, can thus flow from the gas generator 2 via the product gas line 13 into the product gas filter 18. A means for opening and interrupting the gas flow into the product gas filter 18, e.g., a slide valve, flap, or three-way cock, can also be arranged on the product gas line 13.

[0151] The exact position of the product gas line 13 can easily be determined by a specialist depending on the reactor type, space conditions, etc.

[0152] As already described above with reference to Fig. 1, the product gas filter 18 comprises at least one filter element 19 for separating contaminants such as ash, coal, and dust particles. The filter element 19 can, for example, comprise one or more filter candles; the filter candles can, for example, be made of metal or ceramic.

[0153] On the clean gas side, the product gas filter 18 can be fluidically separably connected to a product gas heat exchanger 21, e.g., by means of a clean gas line 29. The product gas heat exchanger 21 can be fluidically separably connected to a gas engine or internal combustion engine, abbreviated to VKM 25, e.g., by means of a clean gas line 29. A safety filter 23 can be arranged between the product gas heat exchanger 21 and VKM 25. The safety filter (23) can be fluidically separably connected to the product gas heat exchanger (21) and the VKM (25), e.g., by means of a clean gas line 29. The safety filter 23 can, for example, be designed as a rapeseed oil methyl ester filter, or RME filter for short.

[0154] An exhaust line 15 is arranged on the VKM 25 to divert gas, such as exhaust gas from the VKM 25, via the chimney 17 if necessary, and to discharge it from the gasification device 1. An exhaust fan 16 can be arranged in the exhaust line 15, which can create a vacuum in the upstream system components in order to extract gases from them. The exhaust fan 16 can, for example, be operated together with the starter 11 and / or the heat source 12 and can serve as a safety device with regard to explosion protection (explosion-proof atmospheres).

[0155] Fig. 3 shows a detailed view of an embodiment of the gasification device 1. The gas generator 2 has a fuel supply 8 on the top. At least one air supply 4, e.g. air nozzles, is arranged in the area of ​​the constriction 9. During normal operation, oxygen-containing gas such as air is introduced into the reaction chamber 3 by means of the air supply, and the oxidation zone 6, in which fuel is oxidized, forms around the air supply. The temperatures in the oxidation zone are typically at least 800°C during normal operation. Above the oxidation zone, a pyrolysis zone 5 forms in the supplied fuel, namely the supplied biomass such as wood chips or wood chips, due to the high temperatures. Biomass is already partially converted into gas.

[0156] As already described, the gas flow in the reaction chamber 3 of the gas generator 2 occurs from top to bottom, i.e., from the pyrolysis zone 5 to the reduction zone 7, and is represented by a wavy arrow. It should be noted here that the gas flow can also flow upwards again after passing through the reduction zone 7. To discharge the product gas from the gas generator 2, the product gas line 13 can therefore be arranged in the lower or upper region of the gas generator 2.

[0157] The material flow also occurs from top to bottom. During normal operation, a coal bed 28 is formed above the grate 10 down to the oxidation zone 6, which can also be referred to as a glowing coal bed due to the high temperatures of at least 500°C. In the glowing coal bed 28 below the oxidation zone 6, the reduction zone 7 forms, in which gas is reduced and product gas is formed. In a preferred embodiment, the gas generator 2 has an agitator 32 that can move and homogenize the coal bed 28. This allows more homogeneous conditions and the associated product gas of consistent quality to be produced. The gas generator also contains a temperature sensor 27 in the coal bed 28 for measuring the coal bed temperature and a temperature sensor 27 in the area of ​​the opening into the product gas line 13 for measuring the outlet temperature.

[0158] As already described, the gas generator 2 is fluidically connected, optionally fluidically separable, to a product gas filter 18 via a product gas line 13. Figure 3 also shows the heat source 12 and the start line 14, as already described. At least one temperature sensor 27 is arranged in the product gas filter to measure the temperature of the product gas filter. The temperature sensor can preferably be arranged on the raw gas side, i.e., upstream of the filter element 19 as viewed in the direction of gas flow, or on the clean gas side downstream of the filter element, e.g., in the region of the opening to the clean gas line 29.

[0159] The temperature sensor 27 can be designed, for example, as a ceramic sensor, metal sensor, sheath thermocouple such as type K or other sensors suitable for the correspondingly high temperatures.

[0160] Figs. 4a to 4e show exemplary and schematic designs of the arrangement of the heat source 12 with the gas generator 2 and the product gas filter 18. For clarity, other system components are not shown. For example, the start line 14 is shown only in Fig. 4a in a special design before and after the heat source 12, but is not shown in the remaining Figs. 4b-e.

[0161] Fig. 4a shows a preferred embodiment with a heat source 12, which is routed in a bypass with the product gas line 13. If necessary, the gas flow is routed over the heat source 12 and the gas is treated.

[0162] Fig. 4b shows an arrangement in which an additional unit 31 is connected upstream of the heat source 12. This additional unit 31 can, for example, be designed as a heat exchanger which extracts heat from the gas before it enters the heat source. The additional unit 31 can, for example, also be a pre-filter, e.g. a cyclone or dust filter for separating large particles. Fig. 4c shows a preferred embodiment in which the heat source 12 is arranged in the product gas line 13; Fig. 4d shows a further preferred embodiment in which the heat source 12 is arranged directly on the product gas filter 18 and / or protrudes at least partially into the product gas filter 18.

[0163] Fig. 4e, in turn, shows a further preferred embodiment in which the heat source 12 is guided in a product gas line, parallel to another product gas line 13.

[0164] As shown in Fig. 5, the product gas filter 18 can be fluidly and separably connected to the exhaust line by means of a hot gas discharge line 20. In this way, gas can be discharged directly from the product gas filter 18 out of the gasification device 1.

[0165] Furthermore, the product gas filter 18 can be fluidically separated from the VKM 25 by means of a hot gas line 22. In this design, gas can be fed directly from the product gas filter 18 into the VKM 25.

[0166] Furthermore, in a design with a safety filter 23, the product gas heat exchanger 21 can be fluidly separated from the VKM 25 by means of a cold gas line 24. In such a design, gas from the product gas heat exchanger 21 can be fed into the VKM 25 either directly or via the safety filter 23.

[0167] Normal operation

[0168] Normal operation is the state in which product gas is continuously produced in the gasification device 1 at a quality that allows a VKM 25 to operate. The gasification device 1 is at operating temperature. In the gas generator 2, fuel is converted into product gas using oxygen. The product gas is subsequently purified and fed for further use, e.g., to a VKM 25 coupled to a generator 26 for generating electricity.

[0169] Normal operation is described in detail below

[0170] During normal operation, biomass is introduced into the reaction chamber 3 via fuel supply 8. An oxygen-containing gas, such as air, is fed into the gas generator 2 via the air supply 4, whereby fuel is oxidized in the area around the air supply 4. This area is therefore called the oxidation zone 6. Above the oxidation zone 6, in the pyrolysis zone 5, the pyrolysis of fuel takes place due to the high temperatures. Starting with the oxidation zone 6 and extending downwards to the grate 10 is a coal bed 28, which is schematically shown in Fig. 3 as a dashed triangle. Due to the high temperature during normal operation, a reduction zone 7 forms in the hot or glowing coal bed 28, in which the gas produced from the pyrolysis zone 5 and oxidation zone 6 is reduced and product gas is formed. The product gas is subsequently purified, e.g. freed of dust particles in a filter, and is then used for further processing, e.g.a gas engine. Further details are provided below. As already described, the material flow is from top to bottom. Unburned coal and ash can be removed from the gas generator 2 via the ash and coal discharge 30. The gas flow also occurs from the top, from the pyrolysis zone 5 downwards to the reduction zone 7. The product gas is discharged from the gas generator 2 after flowing through the reduction zone 7.

[0171] During normal operation, the product gas from the gas generator 2 is fed via the product gas line 13 on the raw gas side into the product gas filter 18. In the product gas filter 18, the product gas is purified by separating, for example, dust, ash and coal particles or unburned material. Filter candles or other suitable filtration media such as fabric filters, etc. can be arranged in the product gas filter 18. Furthermore, the product gas filter can also be designed as a cyclone, electrostatic precipitator, impactor, etc. or a combination of the above. After purification, the gas can flow from the product gas filter 18 on the clean gas side via the clean gas line 29 into the product gas heat exchanger 21. In the product gas heat exchanger 21, for example, heat can be extracted from the product gas stream in order to realize a combined heat and power generation. The product gas heat exchanger 21 can be designed such that possible condensation products (such as water, tar) can be discharged.The product gas now flows from the product gas heat exchanger 21 in the clean gas line 29 via an optional safety filter 23 into the VKM 25, where it is combusted to operate the VKM 25. The resulting exhaust gases can be discharged via the exhaust line 15 and led out of the gasification device 1 via the chimney 17. The VKM 25 can be coupled to a generator 26 to generate electricity. The VKM 25 can be speed-controlled or operated at a constant speed.

[0172] However, designs that include a gas storage unit for product gas are also possible. The storage unit can be located, for example, downstream of the product gas filter or downstream of the product gas heat exchanger. Product gas from the gas storage unit can, for example, be used for short-term operation of the VKM or for operating the heat source. Designs that do not have a product gas heat exchanger 21 or a safety filter 23 are also possible. Furthermore, it is also possible to use the VKM 25 to operate another non-power-generating unit.

[0173] Gas generator start-up process and start-up line

[0174] The gas generator start-up process refers to the steps necessary to bring the gasification device 1 from standstill to normal operation. For this purpose, the starting fuel provided in the gas generator 2 is heated by a starter 11, and an oxygen-containing gas is introduced. The oxygen reacts with the starting fuel, forming a product gas of inferior quality, which, according to the prior art, can be discharged from the gasification device 1 via exhaust line 15. The start-up process is described in detail below.

[0175] At least temporarily, a starter 11 can be arranged on the gas generator 2 or coupled to the gas generator 2. The starter 11 can, for example, be an electrically operated heating fan. The starter can also be designed as a heating rod, glow plug, propane gas burner, etc. To start the gasification device 1 or the gasification process, the empty gas generator 2 (e.g., brand new or completely emptied due to maintenance) can be filled with starting fuel. Coal or biomass, or a mixture thereof, can be used as the starting fuel. Analogously, a gas generator 2 can also have a filling of coal and / or biomass from a gasification process stopped during normal operation. If necessary, this filling can be adjusted to an optimal filling level by removal or refilling. By means of the starter 11, heat and corresponding starting energy are introduced into the gas generator 2 and into the starting fuel. In addition, oxygen-containing gas, e.g.Air is introduced. A common design of this starter 11 can be, for example, an electric heater fan, which can introduce air and heat simultaneously. If necessary, the heater fan can be designed such that the heater and the fan can be operated independently of each other; for example, the heater can be switched off while the fan continues to run.

[0176] The starting fuel is heated accordingly and begins to burn and / or glow. Initially, a small ember nest forms in the coal bed 28, which then grows and spreads. The first product gas is produced, however, this is still of inferior quality.

[0177] The starting fuel subsequently heats up more and more and the embers become larger and larger until a glowing coal bed 28 is formed above the grate 10 in the reaction chamber 3, which has a temperature of at least 500°C.

[0178] The product gas is of inferior quality during the start-up process, typically with high tar values ​​and a low calorific value. An ignitable mixture cannot yet be formed, but it can be burned, for example, using a supporting flame. This inferior product gas is therefore unsuitable for operation of the VKM 25. Furthermore, there is a risk of tar condensation when the inferior product gas is introduced into the product gas filter 18 and other system components.

[0179] According to the state of the art, the low-quality product gas from the gas generator start-up process is discharged from the gasification device 1 via start line 14 and exhaust line 15 and, if necessary, via a chimney 17, see Fig. 1. Environmental post-treatment such as flaring, filtration, catalytic conversion, etc. can be carried out.

[0180] According to the present invention and as described further below, the low-grade product gas can be treated in a heat source 12. The treatment in the heat source 12 can be started when a target coal bed temperature is reached; the discharge of the low-grade product gas via start line 14 and exhaust line 15, as known in the prior art, is terminated for this purpose.

[0181] Alternatively, the treatment of low-quality product gas in heat source 12 can also take place simultaneously with the start of the gas generator startup process, which is advantageous both from an environmental and energy-efficient perspective. In this case, no low-quality product gas is discharged via start line 14 and exhaust line 15, and these lines can even be omitted.

[0182] There is a relationship between coal bed temperature, gas outlet temperature and the quality of the product gas, which is summarized in the following table.

[0183] The temperature of the coal bed 28 can be measured by means of at least one temperature sensor 27, see Fig. 3. Preferably, the temperature is measured by means of several concentrically arranged sensors, whereby the homogeneity of the temperature in the coal bed can also be evaluated.

[0184] If the product gas quality is sufficiently high, product gas can be introduced into the VKM 25 and normal operation can begin. The arrangement of a temperature sensor 27 for measuring the gas outlet temperature is shown as an example in Fig. 3 and is located in the area of ​​the inlet to the product gas line 13.

[0185] The temperature measurement is carried out as already described, e.g. with ceramic sensors, metal sensors, sheath thermocouples such as type-K, etc. Heating of the product gas filter - heat source

[0186] The following describes the heating of the product gas filter 18 using gas that is treated in a heat source 12. As described above, the gas that is treated can include, for example, air, product gas, low-grade product gas, hydrocarbons such as methane, ethane, propane, butane, etc. In particular, product gas and low-grade product gas can contain undesirable and condensate-forming components such as tar, BTEX, dust, ash, unburned particles, water, etc.

[0187] The treatment of gas can be carried out, for example, by warming or heating, by chemical and / or catalytic conversion of gas or gas components, by combustion of gas or gas components, by mixing gas with another gas, e.g. product gas with combustion air, or by reducing the gas tar content, or a combination thereof.

[0188] The treatment increases the temperature of the gas and / or reduces the tar content. The treated gas is introduced into the product gas filter 18 and heats the product gas filter 18 and its filter elements 19. Surprisingly, it has been found that when treated gas is introduced into the product gas filter 18, very little or no condensation of tar and other gas components occurs during the heating of the product gas filter, and no measurable tar deposits occur.

[0189] A product gas filter 18 heated to a product gas filter target temperature is less susceptible to the above-described condensation of tar or other gas components such as water. The product gas filter target temperature is accordingly higher than the condensation temperature of tar and is typically at least 200°C.

[0190] The product gas filter target temperature is measured as already described in Fig. 3, for example preferably on the raw gas side before the filter element 19 or on the clean gas side after the filter element, e.g. in the area of ​​the mouth to the clean gas line 29.

[0191] The heating of the product gas filter 18 can take place after the gas generator start-up process described above or simultaneously with the gas generator start-up process. Alternatively, the heating of the product gas filter 18 can also take place before the gas generator start-up process; for example, the gas generator start-up process can follow directly after the heating of the product gas filter.

[0192] The gasification device 1 according to the invention comprises a heat source 12 in which gas can be treated. The heat source 12 can be arranged at least temporarily in the gasification device 1. In a preferred embodiment, the heat source 12 can be arranged in the product gas line 13 between the gas generator 2 and the product gas filter 18 or can be seen as part of the product gas line 13. In a further embodiment, the heat source 12 can, for example, also be arranged in the product gas line 13 such that part of the cross-section of the product gas line 13 remains free and the gas flow flows selectively through the gas mixer or the free cross-section of the product gas line 13 by means of a slide valve, valve, flap, or three-way cock. In another embodiment, the heat source 12 can also be designed so that it can be coupled to the product gas line 13 and / or the product gas filter 18.The heat source 12 can also be arranged in the product gas line 13 and partially extend into the product gas filter 18. It is also possible to arrange the heat source 12 at the transition from the product gas line 13 to the product gas filter 18 and / or entirely in the product gas filter 18.

[0193] The heat source 12 can also be routed in a bypass with the product gas line 13, wherein the heat source 12 is fluidically separably connected to the product gas line 13, so that gas can be optionally routed either solely via the product gas line 13 or via the product gas line 13 and heat source 12. It is also conceivable to arrange the heat source 12 in a product gas line 13 that connects the gas generator 2 and the product gas filter 18 and is routed, so to speak, "parallel" to another product gas line 13. It is also possible for the heat source 12 to be arranged in the gas generator 2.

[0194] Possible arrangements of the heat source have already been described above in Fig. 4a-e. The exact arrangement is easy for a person skilled in the art to determine based on various constraints, such as installation space, etc. It is essential that the heat source 12 is arranged such that the treated gas enters the product gas filter 18 and comes into contact with the filter elements 19, such as filter candles, only after treatment in the heat source 12.

[0195] The heat source 12 can, for example, comprise a gas mixer and / or gas burner. The gas mixer can be designed to mix oxygen-containing gas and gas with combustible components, hereinafter referred to as combustible gas. For example, air can be supplied to the gas mixer and mixed with a combustible gas to form an ignitable gas mixture. The combustible gas can, for example, comprise product gas, low-grade product gas, ethane, methane, propane, butane, or mixtures thereof. Furthermore, the combustible gas can comprise hydrogen and / or natural gas. The combustible gas can be supplied by means of a buffer container, gas tank, or gas cylinder (hereinafter referred to as gas storage for short), or a gas line.

[0196] In a particular embodiment, the combustible gas can comprise product gas or low-grade product gas from the gas generator 2 or a gas storage unit. In a particularly preferred embodiment, the combustible gas can comprise a mixture of low-grade product gas and another combustible gas such as propane and / or butane. This embodiment is particularly advantageous because low-grade product gas can be mixed with another combustible gas and oxygen to form an ignitable mixture. In this way, low-grade product gas, which on its own cannot form an ignitable mixture, can be "enriched" and burned at the beginning of the gas generator start-up process, optionally with a supporting flame. The heat is subsequently used to heat the product gas filter and other system components, and environmental post-treatment can be omitted.It is also possible to treat the low-quality product gas without prior “enrichment” by simply using a supporting flame in the heat source.

[0197] The gas burner can be designed to burn the ignitable gas mixture.

[0198] In a special design, the heat source can include a Venturi nozzle. This allows air to be supplied and / or gas to be mixed with air to form an ignitable mixture. In this way, product gas can be mixed with air in a mixing zone of the Venturi nozzle, for example, to form a highly homogeneous, flammable gas mixture. However, low-quality product gas from the start-up process can also be mixed with air and another flammable gas (e.g., propane gas) to form a flammable gas mixture. This ignitable gas mixture can then be burned, for example, in a combustion chamber.

[0199] In a particular embodiment, the heat source 12 may comprise a combustion chamber in which the ignitable gas mixture is burned.

[0200] The heat source 12 may further comprise an ignition source. This allows the resulting combustible mixture to be ignited. The ignition causes the combustible components to burn, generating heat. Furthermore, unwanted components of the gas, such as tar, can be burned off, resulting in a low-tar, reduced-tar gas. This low-tar, heated gas has a maximum tar content of 500 mg / m³. 3 , preferably max. 100mg / m 3and is particularly suitable for preheating other system components, especially the product gas filter 18. The ignition source can be designed, for example, as a spark plug, glow plugs, piezo ignition, plasma source, or a supporting flame. The ignition source can be located, for example, at the gas outlet of the Venturi nozzle. The ignition source can also be designed in combination with or as a catalyst.

[0201] To stop combustion, for example, the air supply to the heat source 12 can be interrupted or the heat source 12 can be bypassed.

[0202] The low-tar gas can also be discharged from the gasification device 1 via the starting line 14, the exhaust line 15, and, if necessary, the chimney 17. This is advantageous because no further environmental post-treatment is required.

[0203] In another preferred embodiment, the heat source 12 can comprise a catalyst. A particularly preferred embodiment is one with a catalyst suitable for converting tar-containing components. Such catalysts contain, for example, nickel, iron, or precious metals and can be applied, for example, to a ceramic honeycomb body or to a pre-filter. In such an embodiment, the tar content of the gas can be reduced to a desired level by means of catalytic conversion. This ensures that gas with a very low tar content is used to heat the subsequent plant components, such as the product gas filter 18, which prevents the undesirable condensation of, for example, tar in the plant components.

[0204] Heat source example 1

[0205] Figure 6 shows a preferred embodiment of the heat source 12. The heat source 12 comprises at least one supply air line 34, a fuel gas line 33, a gas mixer 35 with a gas burner, and a combustion chamber 38, and is arranged at least partially in the product gas line.

[0206] The heat source 12 comprises at least one supply air line 34 for supplying air (or supply air, combustion air), a fuel gas line 33 with a control valve for regulating the fuel gas and a check valve, and a gas mixer 35. Fig. 6 shows an optional pump 36 designed as an air pump (or supply air blower) and a compressor 37. Supply air (or combustion air) is pumped from pump 36 into the compressor and further into the gas mixer 35. Fuel gas is pumped into the gas mixer via the compressor 37. In the gas mixer, the fuel gas and supply air are mixed to form an ignitable mixture. A combustion chamber 38 is arranged following the gas flow directly downstream of the gas mixer 35 and includes an ignition source. For example, the combustion chamber 38 is arranged in the product gas line 13. The ignition source is advantageously designed as a spark plug and ignites the ignitable mixture. In the combustion chamber 38, the ignitable mixture burns with a flame 40.

[0207] Alternative designs to the check valve include: check valve, safety valve, etc. Alternative designs to the pump include compressed air reservoir, compressor, side channel compressor, radial compressor, etc.

[0208] In other words, fuel gas and air are mixed and burned in a flame 40. The generated heat can then be used to heat the product gas filter and other system components. Flame 40 can also be considered a supporting flame 40, whose purpose is to ignite product gas and / or burn low-quality product gas, or to support the combustion of low-quality product gas, as explained further below.

[0209] The gas mixer 35 is further connected to the product gas line 13 and to a further supply air line 34 which is supplied with air, e.g. compressed air. Product gas is pumped into the gas mixer 35 due to the negative pressure caused by the generator operation. Accordingly, in the gas mixer 35, product gas is mixed with supply air, e.g. in the form of compressed air, to form a mixture, possibly an ignitable mixture. The ignitability of this mixture depends on the quality of the product gas. For example, at the beginning of the start-up process of the gas generator, the product gas is of inferior quality and a non-ignitable mixture is formed. If the product gas is of sufficient quality, an ignitable mixture is formed. The supply air can be regulated according to the product gas flow using a control valve, for example, and can be provided, for example, as compressed air.

[0210] As an alternative to generator operation, the gas flow through the heat source 12 toward the product gas filter 18 can also be generated by means of overpressure, e.g., by an active supply air fan directly in front of the heat source 12 or by the switched-on fan of the starter 11 with the heating element switched on or off. The gas can be discharged, for example, via the starter line 14 or the hot gas discharge line 20. However, a combination of negative pressure through generator operation and overpressure through a supply air fan is also possible and advantageous.

[0211] The mixture of product gas and air is ignited and burns in the combustion chamber 38 by the ignition source and / or the supporting flame 40. The following situations can occur: a) At the beginning of the gas generator start-up process, if the quality of the product gas is inferior, the inferior product gas or its mixture with air burns in the supporting flame 40, which is fed by the fuel gas / air mixture. b) If the quality of the product gas is sufficient, its mixture with air is ignitable and is ignited and burns by the ignition source. This can occur with or without the supporting flame 40, which is fed by the fuel gas / air mixture. The ignition source can also be designed as a supporting flame 40.

[0212] Depending on the product gas quality, the gas flow of the fuel / air mixture can be increased, reduced, or stopped entirely. The support flame, for example, can be controlled with constant parameters, independent of the product gas flow. In another variant, the support flame can be regulated and / or stopped depending on the product gas quality. If the product gas quality is low, sufficient fuel gas ensures combustion of the inferior product gas. As the product gas quality increases, the fuel gas supply can be gradually reduced. If the product gas quality is sufficient, the fuel gas supply can be stopped; a support flame is no longer necessary for combustion.

[0213] The product gas quality can be determined via the coal bed temperature, as described above. The relationship between product gas quality and coal bed temperature can be easily determined by a person skilled in the art.

[0214] The control of the supporting flame or flame 40 and the respective supply of fuel gas and / or air can be carried out, for example, via the flame temperature of the supporting flame or flame 40, for example by means of a viewing window or by means of optical detection.

[0215] In the present example, the gas mixer 35 is tubular, with concentrically arranged outer and inner mixing areas 41, 42. The ignitable mixture of fuel gas and air is mixed in the inner mixing area 42, and the potentially ignitable mixture of product gas and air is mixed in the outer mixing area 41. An enlarged detailed view of the corresponding area is indicated by the dashed rectangle D.

[0216] At the transition from the gas mixer to the combustion chamber, the two mixtures can be mixed. The gas mixer can, for example, incorporate flow-breaking features such as baffles. Of course, other gas mixer designs are also possible, as a modification of this example; for example, fuel gas, supply air, and product gas can be mixed in a single mixer. The exact design is easy for a specialist to determine, depending on the system's specifications.

[0217] In the example shown, the combustion chamber 38 is tubular and extends directly into the product gas line 13. The combustion chamber can also be part of the product gas line 13.

[0218] The supplied air must be regulated depending on the fuel gas and / or product gas volume flow. To regulate the supply air, a lambda probe 39 is arranged downstream of the combustion chamber 38, by means of which the oxygen content of the fuel gas is determined. With complete combustion, the lambda value is equal to or greater than 1; this serves as a controlled variable and combustion occurs at least stoichiometrically or with excess air. If necessary, the air supply can be increased or decreased to ensure combustion under optimal conditions. The lambda probe is particularly advantageously arranged in the area of ​​the ICE and can also be used to regulate the ICE.

[0219] In a variation of this example, it is also possible to carry out combustion with a constant excess of air, and in this case, control with a lambda probe can be dispensed with entirely.

[0220] In this example, the ignition source is a spark plug. However, it is also possible to implement the ignition source as a piezo ignition, glow plug, etc.

[0221] In the example shown, the gas burner is designed as a gas blower burner, for example as a pellet burner or self-cleaning pellet burner.

[0222] The ignitable mixture burns in the combustion chamber and flows toward the product gas filter 18. Combustion further heats the gas, allowing for effective heating of the product gas filter 18. A particular advantage is that low-quality product gas is burned throughout the entire start-up phase, thus preventing emissions of environmentally harmful substances.

[0223] Heat source example 2

[0224] The heat source 12 comprises at least one supply air line 34, a fuel gas line 33, a gas mixer 35 with gas burner and a combustion chamber 38 and is arranged at least partially in the product gas line, see Fig. 6.

[0225] The fuel gas line 33 includes a control valve for regulating the fuel gas and a check valve. Furthermore, the heat source 12, as shown in Fig. 6, includes an optional pump 36 designed as an air pump (or supply air fan) and a compressor 37. Supply air (or combustion air) is pumped by pump 36 into the compressor and then into the gas mixer 35. Fuel gas is pumped into the gas mixer via the compressor 37. Furthermore, product gas is pumped into the gas mixer 35 due to the negative pressure caused by the generator's operation.

[0226] In a common gas mixer 35, the fuel gas, supply air, and product gas are mixed to form an ignitable mixture. A combustion chamber 38 is arranged directly downstream of the gas mixer 35, following the gas flow, and includes an ignition source. For example, the combustion chamber 38 is arranged in the product gas line 13. The ignition source is advantageously designed as a spark plug and ignites the ignitable mixture. A flame 40 forms in the combustion chamber 38, in which the ignitable mixture burns.

[0227] As already described in Example 1, it is possible to regulate or stop the supply of fuel gas depending on the product gas quality. As already described above, with optimal control, harmful emissions are prevented.

[0228] The supply of intake air is controlled by a lambda sensor, as described above. The design of the combustion chamber and ignition sources has also been described above.

[0229] Heat Source Example 3 Furthermore, the following modification of Example 1 describes an advantageous embodiment of the heat source 12. As already described in Example 1, fuel gas is mixed with supply air in the gas mixer 35. However, the product gas and supply air are mixed in a separate gas mixer 35. This mixture is subsequently added to the mixture of air and fuel gas in the area of ​​the combustion chamber 38.

[0230] The separate gas mixer 35 for mixing product gas and supply air is designed, for example, as a Venturi nozzle.

[0231] Heat source example 4

[0232] In a further embodiment shown in Fig. 7A, the heat source 12 is arranged entirely within the product gas line 13. Product gas flows in the product gas line 13 from the gas generator 2 toward the product gas filter 18; the flow direction is indicated by four arrows arranged parallel to one another.

[0233] The heat source 12 is designed as a Venturi nozzle arranged in the product gas line 13. The fuel gas line 33 and the supply air line 34 open into the product gas line 13 in the area where the Venturi nozzle tapers. This area acts as a gas mixer 35, in which the ignitable mixture of product gas and / or fuel gas and air is formed. Following the gas flow is a section of the product gas line that serves as a combustion chamber 38 and in which an ignition source, e.g., a spark plug, is arranged. The stability of the flame 40 can be improved by means of a flame holder, indicated by a vertical dashed line.

[0234] Heat source example 5

[0235] As shown in a further embodiment, in Fig. 7B, the heat source 12 is arranged at least partially outside the product gas line 13 or the product gas filter 18. Fuel gas and supply air are mixed in a gas mixer 35 still outside the product gas line 13. The ignitable mixture flows into the product gas line 13 or the product gas filter 18 in an opening region. The combustion chamber 38 itself is located at least partially in the product gas line 13 or in the product gas filter 18. The ignitable mixture is ignited by means of an ignition source; the flames in any case protrude into the product gas line or the product gas filter.

[0236] From a flow perspective, the product gas is mixed with supply air in a gas mixer 35 upstream of the combustion chamber 38 to form an ignitable mixture. This mixture then flows into the combustion chamber 38, where it burns.

[0237] In other words, the flame "looks into the product gas line or product gas filter." In such a design, it is also possible to operate the flame as a plasma flame.

[0238] Heat source example 6

[0239] In a further embodiment, the heat source is arranged in the product gas line as a ceramic honeycomb body. The ceramic honeycomb body is designed as a catalyst. A gas mixer is arranged upstream of the ceramic honeycomb body in the direction of flow. In this gas mixer, product gas is mixed with air. The mixing area of ​​the gas mixer can be heated to ensure that the gas mixture has a temperature of >400°C. Particularly during the gas generator start-up process, the product gas can have temperatures that can be <400°C.

[0240] The gas mixture then flows through the catalyst, where it undergoes catalytic conversion, particularly the conversion of tar-containing components into non-tar-containing components. After passing through the catalyst, the gas mixture's tar content is reduced.

[0241] Heat source example 7

[0242] In a further embodiment, a portion of the product gas line 13 can be electrically heated, for example. Viewed in the direction of flow, a gas mixer 35 for mixing product gas with air is arranged upstream of the heated portion of the product gas line 13. The ignitable mixture then flows into the heated portion of the product gas line 13, where it undergoes combustion-like conversion due to the high temperatures; in particular, tar-containing components are converted into non-tar-containing components.

[0243] The heating is carried out, for example, by means of a heating coil inductively or resistance.

[0244] Of course, combinations of the above examples are also possible. In particular, the heat source 12 can comprise a combination of a gas mixer, combustion chamber, ignition source, and / or supporting flame. Furthermore, such a combination can include a catalyst.

[0245] The gas mixer can be designed as a Venturi nozzle, as already described, or as a static mixer with baffles. Furthermore, the gas mixer can be designed as a mixing valve.

[0246] In a particularly preferred embodiment, the heat source comprises a gas mixer, combustion chamber, and supporting flame. In the gas mixer, low-grade product gas and / or product gas is mixed with air and then burned in the combustion chamber. The supporting flame ensures that the combustible components are burned even in non-ignitable gas mixtures.

[0247] The heat source 12 may further comprise an electric heating element. For example, the heat source 12 may be an electric heating element, such as an electric fan heater.

[0248] In a particularly preferred embodiment, the heat source comprises an electric heating element as a heating fan, a gas mixer, combustion chamber and supporting flame. In the gas mixer, low-quality product gas and / or product gas is mixed with air and banished in the combustion chamber. The supporting flame ensures that the combustible components are burned even in gas mixtures that are not ignitable. The heating fan ensures that additional heat can be introduced, e.g., to preheat air for the gas mixer or to preheat the product gas filter. In a further special embodiment, the heat source 12 can be arranged in the gas generator 2. For example, the heat source 12 can be designed as a glowing coal bed and have a temperature of more than 500°C. Gas can thus flow through the coal bed 28 and be treated, e.g., heated and / or chemically converted.The gas treated in this way is particularly suitable for introduction into and preheating of the subsequent plant components such as the product gas filter 18.

[0249] The treated gas can be fed from the product gas filter 18 via the clean gas line 29 and via the product gas heat exchanger 21, and if necessary, the safety filter 23, into the VKM 25. For this purpose, the VKM 25 can be driven by the generator 26 in reversal of its actual function as a power generator and, due to the negative pressure created in the VKM 25, generate a gas flow to the VKM 25. This mode of operation is subsequently referred to as generator operation. The treated gas is sucked from the heat source 12 into the product gas filter 18, into the product gas heat exchanger 21, if necessary, into the safety filter 23, into the VKM 25, and then discharged from the gasification plant via the exhaust line 15 and, if necessary, chimney 17. This allows the entire gas path from the product gas filter 18 to the VKM 25 to be heated particularly well and efficiently. Furthermore, heat is generated in the VKM 25 through friction during generator operation.The VKM 25 is therefore heated by the treated gas and by friction, which means that heating takes place more quickly and the VKM target temperature is reached more quickly.

[0250] It was surprisingly found that in generator operation and when treated gas is passed into the gas path from the product gas filter 18 to the VKM 25 during heating of the gas path and the VKM 25, there is very little or no condensation of tar and other gas components and no measurable tar deposits.

[0251] The gasification device 1 according to the invention can comprise a hot gas discharge line 20. This hot gas discharge line 20 can be connected to the product gas filter and the exhaust gas line 15, thereby enabling a gas flow from the product gas filter 18 into the exhaust gas line 15. The hot gas discharge line 20 can, for example, be connected to the product gas filter 18 downstream of the filter element 19, following the gas flow. Treated gas can accordingly flow through, for example, filter candles and then into the hot gas discharge line 20 and the exhaust gas line 15. However, the hot gas discharge line 20 can also be arranged on the product gas filter 18 such that the gas coming from the product gas filter 18 flows into the hot gas discharge line 20 without flowing through the filter element 19, such as filter candles (on the raw gas side, following the gas flow upstream of the filter element 19).This is particularly advantageous for the slow warming of the product gas filter 18 and can prevent the condensation of tar and / or water in the filter element 19. This is especially important because even gas with a reduced tar content can contain water vapor. Condensed water in the filter candles, for example, can more easily lead to deposits of dust, ash, coal, and unburned particles, which can stick together due to the condensed water and form a difficult-to-remove coating.

[0252] The hot gas discharge line 20 can be connected to the exhaust line 15 in such a way that the exhaust fan 16 is arranged following the gas flow after the hot gas discharge line 20 joins the exhaust line 15. Treated gas can thus be extracted by the exhaust fan 16 through the product gas filter 18 and the hot gas discharge line 20.

[0253] The hot gas discharge line 20 can be provided with means for opening and interrupting the gas flow, for example, a slide valve, a flap valve, or a three-way cock. This allows the gas flow into the hot gas discharge line 20 and the exhaust line 15 to be enabled or blocked as needed.

[0254] Heating of the product gas filter 18 can be terminated upon reaching a target product gas filter temperature by closing the hot gas discharge line 20. The target product gas filter temperature can be in the range of 200 to 600°C, preferably 300 to 500°C, and particularly preferably 370 to 430°C. The treated gas can then be fed into the other system components, for example, analogously to normal operation. It is also possible to restart normal operation after reaching the target product gas filter temperature.

[0255] Furthermore, the gasification device 1 according to the invention can comprise a hot gas line 22, which connects the product gas filter 18 to the VKM 25 in a fluidically separable manner. The hot gas line 22 can be connected to the product gas filter 18 upstream or downstream of the filter element 19, following the gas flow. Treated gas can thus flow from the product gas filter 18 directly into the VKM 25 and simultaneously heat the product gas filter 18 and the VKM 25. The VKM 25 can be operated in generator mode for this purpose. Upon reaching the VKM target temperature, the hot gas line (22) can be closed and the treated gas can be introduced from the product gas filter (18) into the product gas heat exchanger (21), e.g., via a cold gas line (24), and into the VKM (25) until the product gas heat exchanger target temperature is reached. The product gas heat exchanger target temperature can be measured, e.g.,when the gas exits the product gas heat exchanger and is preferably in the range 50 to 150°C, preferably 75 to 125°C, particularly preferably 90 to 110°C.

[0256] It is also possible to first heat only the product gas filter 18 as described above and to direct the treated gas via the hot gas discharge line 20 and the exhaust gas line 15 from the gasification device 1 and only as a next step to direct the treated gas into the VKM 25 and to heat it to the target temperature of the VKM 25, hereinafter also referred to as the VKM target temperature.

[0257] The hot gas line 22 can be provided with means for opening and interrupting the gas flow, for example, a slide valve, a flap valve, or a three-way cock. This allows the gas flow into the hot gas line 22 and the VKM 25 to be enabled or blocked as needed.

[0258] Heating of the VKM 25 can be stopped when the VKM target temperature is reached by closing the hot gas line 22. The VKM target temperature is in the range of 50 to 90°C, preferably 60 to 88°C, and is measured in the intake area. The treated gas can then be fed into other system components, such as the product gas heat exchanger 21, in the same way as normal operation. It is also possible to restart normal operation after the VKM target temperature has been reached.

[0259] Furthermore, the gasification device 1 can comprise a cold gas line 24, which fluidically separably connects the product gas heat exchanger 21 to the VKM 25. The cold gas line 24 can be connected to the VKM 25 following the gas flow after the heat exchange elements, i.e., on the "cold side" of the product gas heat exchanger 21. Treated gas can thus flow from the product gas heat exchanger 21 directly into the VKM 25 and simultaneously heat the product gas heat exchanger 21 and the VKM 25. The VKM 25 can be operated as a generator for this purpose.

[0260] The cold gas line 24 can be provided with means for opening and interrupting the gas flow, for example, a slide valve, valve, flap, or three-way cock. This allows the gas flow into the cold gas line 24 and the VKM 25 to be enabled or blocked as needed.

[0261] Heating of the product gas heat exchanger 21 and the VKM 25 can be terminated upon reaching the product gas heat exchanger 21 and / or VKM target temperature by closing the cold gas line 24. The product gas heat exchanger target temperature is in the range of 50 to 150°C, preferably 75 to 125°C, particularly preferably 90 to 110°C. The treated gas can then be fed into the other system components, e.g., the safety filter 23, analogously to normal operation. It is possible to start normal operation after reaching the product gas heat exchanger and / or VKM target temperature.

[0262] To start normal operation, the gas treatment in the heat source 12 is terminated. As required, the start line 14 and / or hot gas discharge 20 and / or hot gas line 22 and / or cold gas line 24 are closed. Product gas is fed via the product gas line 13 from the gas generator 2 into the product gas filter 18, the product gas heat exchanger 21, optionally into the safety filter 23, and the VKM 25. By igniting and starting the combustion of the product gas in the VKM 25, the generator operation is terminated. The VKM 25 now drives the generator to generate electrical power.

[0263] The invention is not limited to the examples described / illustrated.

[0264] In the description and claims, the terms "front," "rear," "top," "bottom," and so on are used in their common sense and with reference to the object in its usual position of use. Transverse to a direction essentially means a direction rotated by 90° to it. During normal operation, unless otherwise defined, the gas flow proceeds from the gas generator toward the product gas filter and on to the ICE. The terms "before" and "after" refer, unless otherwise defined, to the gas flow during normal operation. Accordingly, the gas generator is arranged upstream of the product gas filter, and the ICE is arranged downstream of the product gas filter.

[0265] It should be noted that in the description and claims, terms such as "lower region" of an object mean the lower half and, in particular, the lower quarter of the total height; "lowest region" means the lowest quarter and, in particular, an even smaller part; while "middle region" means the middle third of the total height (width - length). All of these terms have their common meaning, applied to the intended position of the object in question.

[0266] In the description and claims, "substantially" means a deviation of up to 10% of the stated value, if physically possible, both upwards and downwards, otherwise only in the reasonable direction; for degrees (angle and temperature) this means ± 10°.

[0267] All quantities and proportions, especially those used to define the invention, unless they relate to specific examples, are to be understood with a tolerance of ± 10%. For example, 400°C means from 360°C to 440°C. In terms such as "a filter element," the word "a" is not to be considered a numeral, but rather an indefinite article or pronoun, unless the context indicates otherwise. Percentages of gas flows or gas quantities are, unless otherwise stated, percentages by volume; for liquids and solids, percentages by mass. The term "combination" or "combinations," unless otherwise stated, refers to all types of combinations, from two to a plurality or all of such combinations.

[0268] The features and variants specified in the individual embodiments and examples can be freely combined with those of the other examples and embodiments and, in particular, can be used to characterize the invention in the claims without necessarily including the other details of the respective other embodiment or example. List of reference symbols with common English translation

[0269] 1 gasification device - gasifier

[0270] 2 gas producers - gas producer

[0271] 3 Reaction space

[0272] 4 Air supply

[0273] 5 Pyrolysis zone - pyrolysis zone

[0274] 6 Oxidation zone - oxidation zone

[0275] 7 Reduction zone

[0276] 8 Fuel supply

[0277] 9 narrowing

[0278] 10 rust - grate

[0279] 11 Starters (WQ1) - starter

[0280] 12 Heat source (WQ2) - heat source

[0281] 13 Product gas line (PGL) - product gas line

[0282] 14 Start line (BP 1 ) - starting line

[0283] 15 exhaust line

[0284] 16 exhaust blower

[0285] 17 Chimney

[0286] 18 Product gas filter (PGF) - product gas filter

[0287] 19 filter element - filter element

[0288] 20 Hot gas exhaust (BP2) - hot gas exhaust (line)

[0289] 21 Product gas heat exchanger - product gas heat exchanger

[0290] 22 Hot gas line (BP3) - hot gas line

[0291] 23 safety filters

[0292] 24 cold gas line (BP4) - cold gas line

[0293] 25 Internal combustion engine (ICE) - combustion engine

[0294] 26 Generator - (electric) generator

[0295] 27 Temperature sensor - temperature sensor

[0296] 28 coal bed

[0297] 29 Clean gas line

[0298] 30 Ash and coal discharge

[0299] 31 Additional device

[0300] 32 agitator

[0301] 33 fuel gas duct

[0302] 34 supply air duct

[0303] 35 Gas mixer - gas blender

[0304] 36 pump

[0305] 37 compressors

[0306] 38 combustion chamber - burning chamber

[0307] 39 Lambda probe - lambda sensor

[0308] 40 flame, supporting flame - flame

[0309] 41 Outer blending zone

[0310] 42 Inner blending zone

Claims

Patent claims:

1. Gasification device (1) for gasifying biomass, comprising - a gas generator (2) with fuel supply (8), air supply (4), ash and coal discharge (30), reaction chamber (3) for producing product gas, - a starter (11) which can be coupled to the gas generator (2) at least temporarily, for providing starting energy during a gas generator starting process - a product gas filter (18) fluidically connected to the gas generator (2) via a product gas line (13) and optionally a start line (14) fluidically connected to the product gas line (13), characterized in that - at least one heat source (12) is arranged in the gasification device (1) at least temporarily for the treatment of gas.

2. Gasification device (1) according to claim 1, characterized in that the heat source (12) - is arranged in or on the product gas line (13) between the gas generator (2) and the product gas filter (18), or - is routed in bypass with the product gas line (13) between the gas generator (2) and the product gas filter (18), or - is arranged on or at least partially in the product gas filter (18).

3. Gasification device (1) according to claim 1, characterized in that the heat source (12) can be coupled to the product gas line (13) between the gas generator (2) and the product gas filter (18) and / or the product gas filter (18) 4. Gasification device (1) according to claim 1, characterized in that the heat source (12) is arranged in the gas generator (2).

5. Gasification device (1) according to one of the preceding claims, characterized in that the product gas filter (18) is fluidically separably connected to an exhaust gas line (15) via a hot gas discharge line (20).

6. Gasification device (1) according to one of the preceding claims, characterized in that the gasification device (1) - a product gas heat exchanger (21) fluidly separably connected to the product gas filter (18) and - a VKM (25) which is fluidically separably connected to the product gas heat exchanger (21) and which is optionally coupled to an electric generator (26).

7. Gasification device (1) according to one of the preceding claims, characterized in that the heat source (12) comprises a gas mixer and / or gas burner and / or a combustion chamber or is designed as an electrical heating element.

8. Gasification device (1) according to one of the preceding claims, characterized in that the heat source (12) comprises a Venturi nozzle.

9. Gasification device (1) according to one of the preceding claims, characterized in that the heat source (12) comprises an ignition source and / or a supporting flame and / or a catalyst.

10. Gasification device (1) according to one of the preceding claims, characterized in that it comprises at least one line from the group of product gas line (13), start line (14), hot gas discharge line (20) and at least one line is designed to be fluidically separable by means of a slide valve, valve, flap, or three-way valve.

11. Gasification device (1) according to one of the preceding claims, characterized in that the gasification device comprises a gas storage for product gas.

12. Gasification device (1) according to one of the preceding claims, characterized in that the gasification device (1) comprises at least one temperature sensor (27) which is arranged in a coal bed (28) or in the region of the mouth of the gas generator (2) into the product gas line (13) or in the product gas filter (18), preferably on the raw gas side, and wherein the temperature sensor (27) is designed as a ceramic sensor, metal sensor, sheath thermocouple of type K or type N.

13. Gasification device (1) according to one of the preceding claims, characterized in that the gasification device (1) has a gas generator (2) comprises an exhaust line (15) which is fluidically separable via a starting line (14).

14. Gasification device (1) according to one of the preceding claims, characterized in that the exhaust gas line (15) comprises an exhaust gas blower (16).

15. Gasification device (1) according to one of claims 4 to 14, characterized in that the heat source (12) is designed as a glowing coal bed.

16. A method for heating a biomass gasification device (1) comprising the steps: - Treating a gas with a heat source to provide treated gas - introducing the treated gas into a product gas filter (18) and discharging the treated gas from the product gas filter (18) to heat the product gas filter (18) until a product gas filter target temperature is reached.

17. A method for heating a biomass gasification device (1) comprising the steps: - filling the gas generator (2) with starting fuel, in particular biomass or coal, and heating the starting fuel until a coal bed target temperature is reached by means of a starter (11) and optionally discharging the resulting gas via a starting line (14) and an exhaust line (15) - at the latest when the carbon bed target temperature is reached, optional closing of the start line (14) and starting the treatment of the gas with a heat source (12) into treated gas and introducing the treated gas into the product gas filter (18) to heat the product gas filter (18) and discharging the treated gas from the product gas filter (18) until a product gas filter target temperature is reached.

18. A method according to claim 16 or 17, characterized in that the gas comprises combustible components and the treatment of the gas with the heat source comprises the chemical conversion and / or combustion of the combustible components.

19. Method according to claim 16 or 17, characterized in that the gas is treated and heated with an electric heating element, in particular a heating fan 20. A method according to claim 16 or 17, characterized in that the gas is treated and heated by passing it through a glowing coal bed formed in the reaction chamber (3) of a gas generator (2) of the gasification device (1).

21. A process according to any one of claims 16 to 20, characterized in that the gas comprises at least one or a combination of several from the group of air, carbon monoxide, product gas, low-grade product gas, methane, ethane, propane, butane, natural gas or hydrogen.

22. Method according to one of claims 16 to 21, characterized in that the tar content of the gas is reduced during the treatment and / or that the tar content of the treated gas is max. 500 mg / m 3 , preferably max. 100mg / m 3 is.

23. Process according to one of claims 16 to 22, characterized in that the product gas filter target temperature is in the range from 200 to 600°C, preferably from 300 to 500°C and particularly preferably from 370 to 430°C.

24. Method according to one of claims 16 to 23, characterized in that the treated gas from the product gas filter (18) is introduced into a VKM (25) via a product gas heat exchanger (21), optionally via a safety filter (23), and is discharged from the VKM (25) until a VKM target temperature is reached.

25. A method according to claim 16 to 23, characterized in that the treated gas is discharged from the product gas filter (18) via a hot gas discharge line (20) and the exhaust gas line (15).

26. Method according to claim 25, characterized in that when the product gas filter target temperature is reached, the hot gas discharge line (20) is closed and the treated gas is introduced via the product gas heat exchanger (21) into the VKM (25) until the VKM target temperature is reached.

27. Method according to one of claims 24 to 26, characterized in that the VKM target temperature is in the range from 50 to 90°C, preferably from 60 to 80°C.

28. Method according to one of claims 24 to 27, characterized in that the introduction of the gas into the VKM (25) takes place by means of generator operation of the VKM (25).

29. Method according to one of claims 16 to 28; characterized in that the normal operation of the gasification device (1) is started by the following steps: - Terminating the treatment of the gas in the heat source (12), and - Optionally closing the hot gas discharge (20), and - Introducing the product gas through the product gas filter (18), through the product gas heat exchanger (21), optionally through a safety filter (23), into the VKM (25) and - Starting the combustion of the product gas in the ICE (25) to operate a generator (26).

30. Method according to one of claims 16 to 29, characterized in that a gas generator start-up process is initiated when the product gas filter target temperature is reached.

31. Process according to claims 17 to 29, characterized in that the target temperature of the cabbage bed is in the range of 200 to 300 °C, preferably 235 to 265 °C.

Images