Fuel production system

Abstract

To provide a fuel production system capable of improving efficiency of the whole system.SOLUTION: A fuel production system 1 comprises: a CO2 recovery device 71, an electrolytic device 60, a liquid fuel production device 4, a steam reformer 74 that performs steam reforming of methane to generate hydrogen, and a control device 10, wherein the control device 10 includes: a heat quantity determination part 116 that determines whether a quantity of heat required to raise a temperature inside a gasification furnace 30 to a level necessary for gasification of a biomass feedstock is less than a predetermined threshold value; a H2 generation amount determination part 115 that determines whether an amount of hydrogen generated by the electrolytic device 60 is equal to or greater than a predetermined threshold value; and a steam reforming control part 118 that, when the heat quantity determination part 116 determines that the quantity of heat in the gasification furnace 30 is equal to or greater than the predetermined threshold value and the H2 generation amount determination part 115 determines that the amount of hydrogen generated is less than the predetermined threshold value, controls the steam reformer 74 to perform steam reforming and introduces the generated hydrogen into the gasification furnace 30.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a fuel production system, and more particularly to a fuel production system that produces liquid fuel based on biomass feedstock and renewable energy. [Background technology]

[0002] 2. Description of the Related Art Electrosynthetic fuels, which are made from raw materials such as hydrogen produced from electricity generated by renewable energy sources and carbon sources such as biomass and carbon dioxide emitted from factories, have traditionally been attracting attention as an alternative to fossil fuels.

[0003] The general procedure for producing liquid fuels such as methanol and gasoline from biomass is as follows: the biomass feedstock that has undergone a certain pretreatment process is gasified together with water and oxygen in a gasifier to produce synthesis gas containing hydrogen and carbon monoxide; the synthesis gas that has been produced is washed and tar is removed in a cleaning process; and the synthesis gas that has undergone the cleaning process is degassed using H2O. 2 Adjust the H / CO ratio to the target ratio according to the liquid fuel to be produced. 2 / CO ratio adjustment process, and 2 Liquid fuel is produced from biomass feedstock through a desulfurization process in which sulfur components are removed from the synthesis gas that has undergone the / CO ratio adjustment process, and a fuel production process in which liquid fuel is produced from the synthesis gas that has undergone the desulfurization process.

[0004] Here, the H of the synthesis gas produced through the gasification process is 2 In many cases, the ratio of hydrogen to CO does not reach the target ratio, resulting in a shortage of hydrogen. Patent Documents 1 and 2 disclose a method for producing hydrogen by electrolysis using renewable energy, which generates hydrogen from water and supplies it to a gasification furnace or a feedstock supply line for biomass feedstock, thereby reducing the amount of H in the synthesis gas discharged from the gasification furnace. 2 According to the techniques described in Patent Documents 1 and 2, it is possible to suppress the amount of carbon dioxide generated in the entire fuel production system. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-147504 [Patent Document 2] Patent Publication No. 2021-147506 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when hydrogen is introduced from outside during gasification of biomass raw materials, the amount of methane produced as a by-product during gasification, for example, tends to increase, leaving room for improvement in terms of effectively utilizing components such as by-products generated during the gasification process.

[0007] An object of the present invention is to provide a fuel production system that can improve the efficiency of the entire system. [Means for solving the problem]

[0008] (1) A fuel production system for producing liquid fuel from a biomass feedstock, comprising: a gasification furnace that gasifies the biomass feedstock and produces a synthesis gas containing hydrogen and carbon monoxide; a methane recovery device that recovers methane by-produced in the gasification furnace; an electrolysis device that generates hydrogen using electricity generated using renewable energy; a liquid fuel production device that produces liquid fuel from the synthesis gas produced in the gasification furnace; a steam reformer that steam reforms the methane recovered by the methane recovery device to produce hydrogen; and a control device that controls the methane recovery device and the steam reformer, The apparatus is a fuel production system having a heat quantity determination unit that determines whether the amount of heat required to raise the temperature inside the gasification furnace to a temperature required for gasifying the biomass feedstock is less than a predetermined threshold value; a hydrogen production amount determination unit that determines whether the amount of hydrogen produced by the electrolysis device is equal to or greater than a predetermined threshold value; and a steam reforming control unit that controls the steam reforming device to perform the steam reforming and introduces the generated hydrogen into the gasification furnace when the heat quantity determination unit determines that the required amount of heat is less than the predetermined threshold value and the hydrogen production amount determination unit determines that the amount of hydrogen produced is less than the predetermined threshold value.

[0009] (2) The fuel production system according to (1), further comprising: a carbon dioxide capture device that captures carbon dioxide generated when a synthesis gas is produced in the gasification furnace; a carbon dioxide tank that stores the carbon dioxide captured by the carbon dioxide capture device; and a dry reforming device that performs dry reforming of methane to produce hydrogen and carbon monoxide, wherein the control device further comprises a carbon dioxide amount determination unit that determines whether an amount of carbon dioxide stored in the carbon dioxide tank is equal to or greater than a predetermined threshold, and a dry reforming control unit that controls the dry reforming device to perform the dry reforming when the heat amount determination unit determines that the required heat amount is less than the predetermined threshold, the hydrogen production amount determination unit determines that the amount of hydrogen produced is equal to or greater than the predetermined threshold, and the carbon dioxide amount determination unit determines that the amount of carbon dioxide stored is equal to or greater than the predetermined threshold, and controls the dry reforming device to introduce the generated hydrogen and carbon monoxide toward the liquid fuel production device and into a synthesis gas discharge area where synthesis gas is discharged from the gasification furnace.

[0010] (3) The fuel production system according to (1) or (2), wherein the control device further includes a heating control unit that uses methane recovered in the methane recovery device as a heat source for the gasification furnace when the heat quantity determination unit determines that the required heat quantity is equal to or greater than a predetermined threshold value. Effect of the Invention

[0011] According to the present invention, it is possible to improve the efficiency of the entire system. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram showing a configuration of a fuel production system according to an embodiment of the present invention. [Diagram 2] 1 is a block diagram showing a hardware configuration including a control device that executes a methane utilization process and a carbon dioxide utilization process in a fuel production system according to an embodiment of the present invention, and a functional configuration of the control device. [Diagram 3]FIG. 4 is a diagram showing the relationship between the temperature inside a gasification furnace and the amount of methane generated during gasification of biomass raw material. [Figure 4] FIG. 1 is a diagram showing the relationship between the temperature inside a gasification furnace with a supply rate of biomass raw material of about 100 g / h and the amount of heat required to heat the inside of the gasification furnace 30 to each temperature. [Diagram 5] FIG. 1 is a diagram showing the relationship between the amount of solar radiation and the amount of hydrogen produced when hydrogen is produced using electricity generated by a solar power generation facility. [Figure 6] FIG. 4 is a diagram showing the relationship between the amount of hydrogen introduced into a gasification furnace and the amount of carbon dioxide generated in the gasification furnace. [Figure 7] FIG. 1 is a diagram showing the relationship between the hydrogen concentration in the gas introduced into a gasification furnace and the carbon dioxide concentration in the synthesis gas generated in the gasification furnace when gasifying biomass feedstock in the gasification furnace at 900° C. [Figure 8] 4 is a flowchart showing an example of the flow of a methane utilization process executed by a control device of a fuel production system according to an embodiment of the present invention. [Figure 9] 4 is a flowchart showing an example of the flow of a carbon dioxide utilization process executed by a control device of a fuel production system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, a fuel production system according to an embodiment of the present invention will be described with reference to the drawings.

[0014] Fig. 1 is a diagram showing the configuration of a fuel production system 1 according to this embodiment. Fig. 2 is a block diagram showing the hardware configuration including a control device 10 that executes a methane utilization process and a carbon dioxide utilization process in the fuel production system 1, and the functional configuration of the control device 10. The fuel production system 1 includes a biomass raw material supplying device 2 that supplies biomass raw material, a gasification device 3 that gasifies the biomass raw material supplied from the biomass raw material supplying device 2 to produce synthetic gas containing hydrogen and carbon monoxide, a liquid fuel production device 4 that produces liquid fuel from the synthetic gas supplied from the gasification device 3, a power generation facility 5 that generates electricity using renewable energy, a hydrogen generation and supply device 6 that generates hydrogen from water using the electricity generated in the power generation facility 5 and supplies the generated hydrogen to the gasification device 3, a methane utilization treatment device 7 that recovers and utilizes methane generated as a by-product during gasification of the biomass raw material by the gasification device 3, a carbon dioxide utilization treatment device 8 that recovers and utilizes carbon dioxide generated during gasification of the biomass raw material, and a control device 10 that controls the gasification device 3, the power generation facility 5, the hydrogen generation and supply device 6, the methane utilization treatment device 7, and the carbon dioxide utilization treatment device 8, and uses these to produce liquid fuel from the biomass raw material.

[0015] The biomass raw material supplying device 2 performs a predetermined pretreatment on biomass raw materials such as rice grains, bagasse, and wood, and supplies the pretreated biomass raw materials to the gasification furnace 30 of the gasification device 3 via a raw material supply path 20. Here, the pretreatment of the biomass raw materials includes, for example, a drying process for drying the raw materials and a crushing process for crushing the raw materials.

[0016] The gasification apparatus 3 includes a gasification furnace 30 that gasifies the biomass raw material supplied through the raw material supply path 20, a pressure sensor (not shown) that detects the pressure inside the gasification furnace 30, a temperature sensor 31, a gas detection unit 37, a water supply device 32 that supplies water into the gasification furnace 30, an oxygen supply device 33 that supplies oxygen or air into the gasification furnace 30, a heating device 34 that heats the gasification furnace 30, a scrubber 35 that cleans the synthesis gas discharged from the gasification furnace 30, and a desulfurization device 36 that removes sulfur components from the synthesis gas cleaned by the scrubber 35 and supplies it to the liquid fuel production apparatus 4.

[0017] The water supply device 32 supplies water stored in a water tank (not shown) into the gasification furnace 30. The oxygen supply device 33 supplies oxygen stored in an oxygen tank (not shown) into the gasification furnace 30. The heating device 34 heats the gasification furnace 30 by consuming fuel supplied from a fuel tank (not shown) or electricity supplied from a power source (not shown). The amount of water supplied from the water supply device 32 to the gasification furnace 30, the amount of oxygen supplied from the oxygen supply device 33 to the gasification furnace 30, and the amount of heat input from the heating device 34 to the gasification furnace 30 are controlled by the control device 10. Note that in the fuel production system 1 according to this embodiment, by supplying hydrogen from the hydrogen generation and supply device 6 described later into the gasification furnace 30 or into the raw material supply path 20, there are cases where it is not necessary to actively supply water from the water supply device 32 to the gasification furnace 30. In this case, the water supply device 32 can be removed from the fuel production system 1.

[0018] When water, oxygen, heat, etc. are fed into the gasification furnace 30 to which the biomass raw material has been charged, using the water supplying device 32, oxygen supplying device 33, and heating device 34 as described above, multiple types of gasification reactions and their reverse reactions, for example as shown in the following formulas (1-1) to (1-5), proceed in the gasification furnace 30, and synthesis gas containing hydrogen and carbon monoxide is produced.

[0019] [ka]

[0020] The temperature sensor 31 detects the temperature inside the gasification furnace 30. The temperature sensor 31 in this embodiment detects, for example, the temperature inside a reaction tube in the gasification furnace 30 where a gasification reaction of the biomass raw material occurs. Information on the temperature detected by the temperature sensor 31 is transmitted to the control device 10.

[0021] The gas detection unit 37 detects information about the synthesis gas generated in the gasification furnace 30. The information about the synthesis gas is, for example, the flow rate of the synthesis gas in the gasification furnace 30, and the amount and concentration of each component. The gas detection unit 37 may be configured, for example, with a plurality of sensors. The plurality of sensors may include, for example, a H 2 Detect H / CO ratio 2 / CO sensor, CO to detect carbon dioxide in the gasifier 30 2 Sensor, CH for detecting methane in gasifier 30 4 Sensor, H to detect hydrogen in gasifier 30 2 For example, the gas detection unit 37 may be disposed near the outlet of the gasification furnace 30 and may include a measuring device such as a gas chromatograph that measures the amount of a specific gas, such as hydrogen, methane, carbon monoxide, or carbon dioxide, contained in the synthesis gas generated in the gasification furnace 30. Detection signals and information detected by these sensors and measuring devices constituting the gas detection unit 37 are transmitted to the control device 10.

[0022] The gasification apparatus 3 mixes the synthesis gas generated by the gasification reactions shown in the above formulas (1-1) to (1-5) and the reverse reaction with hydrogen supplied from the hydrogen generation and supply apparatus 6 described below, thereby converting the H 2 A predetermined target ratio of H / CO depending on the liquid fuel to be produced (for example, when producing methanol, H 2 After adjusting the target F / CO ratio to 2), this synthesis gas is supplied to the liquid fuel production device 4.

[0023] The liquid fuel production device 4 includes a methanol synthesis device, an MTG (Methanol To Gasoline) synthesis device, an FT (Fischer Tropsch) synthesis device, an upgrading device, and the like. By using these devices, a predetermined H 2 Liquid fuels such as methanol and gasoline are produced from synthetic gas with an adjusted / CO ratio.

[0024] The power generation facility 5 is composed of a wind power generation facility that generates electricity using wind power, which is a renewable energy, a solar power generation facility that generates electricity using solar light, which is a renewable energy, etc. The power generation facility 5 is connected to a hydrogen generation and supply device 6, and electricity generated using renewable energy in the wind power generation facility, solar power generation facility, etc. can be supplied to the hydrogen generation and supply device 6. The power generation facility 5 is also connected to a commercial power grid 9. Therefore, some or all of the electricity generated in the power generation facility 5 can be supplied to the commercial power grid 9 and can also be sold to an electric power company.

[0025] The hydrogen generation and supply device 6 includes an electrolysis device 60, a hydrogen filling pump 61, and a H 2 Tank 62 and H 2 The hydrogen supply pump 64 is provided and is used to generate hydrogen using the power supplied from the power generation facility 5 . The generated hydrogen is then supplied to the gasification device 3 .

[0026] The electrolysis device 60 is connected to the power generation facility 5, and generates hydrogen and oxygen by electrolysis of water using power supplied from the power generation facility 5. The electrolysis device 60 is also connected to a commercial power grid 9. This allows the electrolysis device 60 to generate hydrogen and oxygen not only using power supplied from the power generation facility 5, but also using power supplied from the commercial power grid 9 by purchasing power from a power company. The amounts of hydrogen and oxygen generated by the electrolysis device 60 are controlled by the control device 10.

[0027] The hydrogen filling pump 61 compresses the hydrogen produced by the electrolysis device 60 and 2 The amount of hydrogen filled by the hydrogen filling pump 61 is controlled by the control device 10. 2 The tank 62 stores hydrogen compressed by the hydrogen filling pump 61. 2 The amount detection unit 63 is H 2 The amount of hydrogen stored in the tank 62 is detected. 2 The amount detection unit 63 is, for example, H 2 It may be a pressure sensor that detects the internal pressure of the tank 62. 2The amount detection unit 63 is H 2 The internal pressure of the tank 62 is detected and a detection signal is sent to the control device 10. 2 The amount of hydrogen in tank 62 is H 2 The amount is calculated by the control device 10 based on the detection signal from the amount detection unit 63.

[0028] The hydrogen supply pump 64 supplies H 2 The hydrogen stored in the tank 62 is supplied to the gasification furnace 30 of the gasification device 3. The amount of hydrogen supplied from the hydrogen supply pump 64 to the gasification furnace 30 is controlled by the control device 10. 2 A case will be described in which hydrogen stored in the tank 62 is supplied to the gasification furnace 30 by the hydrogen supply pump 64, but the present invention is not limited to this. 2 The hydrogen stored in the tank 62 may be supplied upstream of the gasifier 30, more specifically, into the raw material supply path 20 for the biomass raw material. The hydrogen supply pump 64 also supplies hydrogen to the carbon dioxide utilization treatment device 8 in the carbon dioxide utilization treatment described below.

[0029] The methane utilization treatment device 7 is 4 Recovery device (methane recovery device) 71 and CH 4 Tank 72 and CH 4 The system includes an amount detection unit 73, a steam reforming device 74, and a dry reforming device 75.

[0030] CH 4 The recovery device 71 has a gas separation membrane and recovers methane produced as a by-product in the gasification furnace 30. 4 The recovery device 71 recovers methane by passing the synthesis gas supplied from the gasification furnace 30 through a gas separation membrane to separate the methane contained in the synthesis gas from other components such as carbon dioxide. 4 The methane separated from the synthesis gas by the recovery unit 71 is CH 4 The other components, including carbon dioxide, are sent to the CO 2 Capture device (carbon dioxide capture device) 81 or CO 2 It is sent to tank 82. 4The recovery device 71 is controlled by the control device 10, and recovers methane produced as a by-product in the gasification furnace 30 when predetermined conditions, which will be described later, are satisfied.

[0031] CH 4 Tank 72, CH 4 The methane recovered by the recovery device 71 is stored. 4 The amount detection unit 73 detects 4 The amount of methane stored in the tank 72 is detected. 4 The amount detection unit 73 is, for example, 4 It may be a pressure sensor that detects the internal pressure of the tank 72. 4 The amount detection unit 73 detects 4 The internal pressure of the tank 72 is detected and a detection signal is sent to the control device 10. 4 The amount of methane in tank 72 is CH 4 The amount is calculated by the control device 10 based on the detection signal from the amount detection unit 73.

[0032] The steam reformer 74 reforms methane with steam to generate hydrogen and carbon monoxide. In the steam reformer 74, steam reforming is performed, for example, at a pressure of 1 MPa or less and a temperature of 800° C., and a reaction as shown in the following formula (2) proceeds. As shown in the following formula (2), 3 moles of hydrogen and 1 mole of carbon monoxide can be generated by steam reforming 1 mole of methane. The generated hydrogen and carbon monoxide are introduced from the steam reformer 74 to the gasifier 30. At this time, the hydrogen and carbon monoxide may be directly introduced from the steam reformer 74 into the gasifier 30, or may be introduced into the gasifier 30 upstream of the gasifier 30, more specifically, via the raw material supply path 20. Since a gas containing 3 moles of hydrogen per mole of carbon monoxide is introduced from the steam reformer 74 to the gasifier 30, the hydrogen concentration in the gasifier 30 can be increased. The steam reformer 74 is controlled by the control device 10, and when a predetermined condition described later is satisfied, the CH 4 Hydrogen and carbon monoxide are produced by steam reforming methane supplied from tank 72.

[0033] [ka]

[0034] The dry reforming unit 75 performs dry reforming of methane to produce hydrogen and carbon monoxide. 4 Dry reforming is performed using methane supplied from the tank 72, carbon dioxide supplied from the carbon dioxide utilization treatment device 8, and a predetermined catalyst, etc., and a reaction as shown in the following formula (3) proceeds. As shown in the following formula (3), 2 moles of hydrogen and 2 moles of carbon monoxide can be generated by dry reforming 1 mole of methane. The generated hydrogen and carbon monoxide are introduced into a synthesis gas discharge area where synthesis gas is discharged from the gasifier 30 toward the liquid fuel production device 4, for example. In this specification, the synthesis gas discharge area refers to an area including a flow path of the synthesis gas from the gasifier 30 to the liquid fuel production device 4. Specifically, the synthesis gas discharge area refers to an area including a synthesis gas flow path connecting the gasifier 30 and the scrubber 35, the inside of the scrubber 35, a synthesis gas flow path connecting the scrubber 35 and the desulfurization device 36, the inside of the desulfurization device 36, and a synthesis gas flow path connecting the desulfurization device 36 and the liquid fuel production device 4. In this embodiment, the hydrogen and carbon monoxide generated by the dry reforming device 75 are introduced into a synthesis gas flow path connecting the gasifier 30 and the scrubber 35. This makes it possible to increase the total amount of synthesis gas. The dry reforming device 75 is controlled by the control device 10, and when a predetermined condition described later is satisfied, the dry reforming device 75 is 4 Hydrogen and carbon monoxide are produced by dry reforming methane supplied from tank 72.

[0035] [ka]

[0036] The carbon dioxide utilization processing device 8 is a CO 2 Recovery device 81 and CO 2 Tank 82 and CO 2 Amount detection unit 83 and CO 2It includes a conversion device 84 and a fuel synthesis device 85.

[0037] CO 2 The recovery unit 81 recovers the carbon dioxide generated when the synthesis gas is produced in the gasification furnace 30, and also recovers the carbon dioxide and CH that were not synthesized into fuel in the fuel synthesis unit 85. 4 The carbon dioxide captured by the capture device 71 is recovered. 2 The carbon dioxide captured in the capture device 81 is CO 2 It is supplied to tank 82.

[0038] CO 2 Tank 82 is CO 2 The carbon dioxide captured by the capture device 81 is stored. 2 The carbon dioxide stored in the tank 82 can be converted into CO 2 The converter 84 is supplied with CO 2 The amount detection unit 83 detects 2 The amount of carbon dioxide stored in the tank 82 is detected. 2 The amount detection unit 83 detects, for example, CO 2 It may be a pressure sensor that detects the internal pressure of the tank 82. 2 The amount detection unit 83 detects 2 The internal pressure of the tank 82 is detected and a detection signal is sent to the control device 10. 2 The amount of carbon dioxide in the tank 82 is CO 2 The amount is calculated by the control device 10 based on the detection signal from the amount detection unit 83.

[0039] CO 2 The converter 84 is a 2 The carbon dioxide captured by the capture device 81 is converted to carbon monoxide. 2 The converter 84 is a 2 Carbon monoxide is produced using the carbon dioxide recovered by the recovery device 81 and the hydrogen produced by the electrolysis device 60 as raw materials. 2The carbon monoxide converted by the converter 84 is supplied to the gasifier 3 as a raw material for liquid fuel together with hydrogen produced in the electrolysis device 60 and supplied by the hydrogen supply pump 64. 2 The carbon dioxide that is not converted to carbon monoxide by the converter 84 is supplied to the fuel synthesis unit 85. 2 The converter 84 and the hydrogen supply pump 64 are controlled by the control device 100, and when a predetermined condition described later is satisfied, the converter 84 and the hydrogen supply pump 64 are controlled by the control device 100 to convert the CO 2 Carbon dioxide and H supplied from tank 82 2 Carbon monoxide is produced using hydrogen supplied from a tank 62 as a raw material.

[0040] The fuel synthesis unit 85 is a CO 2 The CO is collected by the collection device 81. 2 The fuel to be used in the gasification furnace 30 is synthesized using the carbon dioxide that was not converted to carbon monoxide in the conversion device 84 and the hydrogen generated by the electrolysis device 60 as raw materials. 2 When carbon dioxide, hydrogen, etc. are input by the converter 84 and the electrolysis device 60, a catalytic reaction such as that shown in the following formula (3) proceeds in the fuel synthesis device 85, and a fuel containing methane and water is synthesized. The fuel synthesized by the fuel synthesis device 85 is supplied to the gasification furnace 30. Carbon dioxide that is not synthesized by the fuel synthesis device 85 is converted into CO 2 It is supplied to a recovery device 81.

[0041] The control device 10 is a computer that controls the amount of water supplied by the water supply device 32, the amount of oxygen supplied by the oxygen supply device 33, the amount of heat input by the heating device 34, and the operation of the hydrogen generation and supply device 6, based on detection signals from the temperature sensor 31, the gas detection unit 37, etc. 2 Amount detection unit 63, CH 4 Amount detection unit 73, CO 2Based on detection signals from the amount detection unit 83, etc., the hydrogen supply pump 64, the methane utilization treatment device 7, the carbon dioxide utilization treatment device 8, etc. are controlled to execute the methane utilization treatment and the carbon dioxide utilization treatment. The methane utilization treatment and the carbon dioxide utilization treatment performed by the control device 10 will be described later.

[0042] Here, the amount of methane generated in the gasification furnace 30 will be described with reference to FIG. 3. FIG. 3 is a diagram showing the relationship between the temperature in the gasification furnace 30 and the amount of methane generated during gasification of the biomass feedstock. The horizontal axis indicates the temperature in the gasification furnace 30, and the vertical axis indicates the amount of methane generated in the gasification furnace 30. As shown in FIG. 3, the higher the temperature in the gasification furnace 30, the smaller the amount of methane generated, and the lower the temperature in the gasification furnace 30, the larger the amount of methane generated. For example, when the temperature drops when the gasification apparatus 3 is stopped, or when synthesis gas flows near the outlet of the reaction tube of the gasification furnace 30 and the temperature of the synthesis gas drops, etc., the amount of methane generated increases. 4 According to the fuel production system 1 of this embodiment, methane, which is a by-product of gasification of biomass feedstock, can be effectively utilized in fuel production.

[0043] Next, a hardware configuration of the control device 10 that executes the methane utilization process and the carbon dioxide utilization process will be described. As shown in FIG.

[0044] The communication unit controls communications with other devices such as the temperature sensor 31, the gas detection unit 37, the water supply device 32, the oxygen supply device 33, the heating device 34, the electrolysis device 60, the hydrogen supply pump 64, the methane utilization treatment device 7, and the carbon dioxide utilization treatment device 8. The communication unit transmits and receives detection signals, control signals, and the like to and from these devices.

[0045] The storage unit 13 is a storage area for various programs for causing the hardware group to function as the control device 10, various data, etc., and can be configured with a ROM, a RAM, a flash memory, a solid-state drive (SSD), or hardware (HDD), etc. Specifically, the storage unit 13 stores a program for causing the processing unit 11 to execute each function of this embodiment, a control program for the methane utilization process and the carbon dioxide utilization process, and a H 2 The target value of the A / CO ratio, the temperature inside the gasification furnace 30 required for gasification of the biomass feedstock, data such as tables and formulas showing the relationship between the amount of heat added to the gasification furnace 30 and the temperature inside the gasification furnace 30 increased by that amount of heat (hereinafter referred to as relationship data between the amount of heat and the temperature rise in the gasification furnace 30), and a first threshold, a second threshold, a third threshold, a first upper limit threshold, a second upper limit threshold, and a third upper limit threshold, which will be described later, are stored. Note that the temperature inside the gasification furnace 30 required for gasification of the biomass feedstock, and the relationship data between the amount of heat added and the temperature rise in the gasification furnace 30 can be appropriately changed by the user depending on the type and supply amount of the biomass feedstock, the size of the gasification furnace 30, etc.

[0046] The processing unit 11 is an arithmetic device configured by a processor, and executes predetermined data processing by reading various programs and data from the storage unit 13. The processor is, for example, a central processing unit (CPU), a micro processing unit (MPU), a system on a chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), a vision processing unit (VPU), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field-programmable gate array (FPGA).

[0047] Next, the functional configuration of the processing unit 11 of the control device 10 for executing the methane utilization process and the carbon dioxide utilization process in the fuel production system 1 will be described with reference to FIGS.

[0048] As shown in FIG. 2, the processing unit 11 4 A storage amount determination unit 111 and a CO 2 A storage amount determination unit 112 and H 2 A storage amount determination unit 113 and a CH 4 A generation amount determination unit 114 and H 2 A generation amount determination unit 115, a heat amount determination unit 116, a heating control unit 117, a steam reforming control unit 118, a dry reforming control unit 119, and a CO 2 The usage control unit 120 is provided.

[0049] CH 4 The storage amount determination unit 111 is 4 It is determined whether the amount of methane stored in the tank 72 is equal to or greater than a predetermined threshold (hereinafter, the first upper limit threshold). 4 The storage amount determination unit 111 receives the CH 4 The result of detection by the storage amount detection unit 73 is acquired, and the CH 4 Determine the amount of methane stored in the tank 72. 4 The storage amount determination unit 111 receives the CH 4 The first upper limit threshold indicating the capacity of the tank 72 is read out. 4 The storage amount determination unit 111 is 4 It is determined whether the amount of methane stored in the tank 72 is equal to or greater than the first upper limit threshold.

[0050] CO 2 The storage amount determination unit 112 determines whether 2 It is determined whether the amount of carbon dioxide stored in the tank 82 is equal to or greater than a predetermined threshold (hereinafter, a second upper limit threshold). 2 The storage amount determination unit 112 receives the CO 2 The result of detection by the amount detection unit 83 is acquired, and based on the acquired detection result, 2A process is performed to determine the amount of carbon dioxide stored in the tank 82. 2 The storage amount determination unit 112 determines whether 2 It is determined whether the amount of carbon dioxide stored in the tank 82 is equal to or greater than the second upper limit threshold.

[0051] H 2 The storage amount determination unit 113 is H 2 It is determined whether the amount of hydrogen stored in the tank 62 is equal to or greater than a predetermined threshold (hereinafter, the third upper limit threshold). 2 The storage amount determination unit 113 receives the H 2 The result of detection by the amount detection unit 63 is obtained, and H 2 A process is performed to determine the amount of hydrogen stored in the tank 62. 2 The storage amount determination unit 113 is H 2 It is determined whether the amount of hydrogen stored in the tank 62 is equal to or greater than the third upper limit threshold. In this embodiment, the first upper limit threshold, the second upper limit threshold, and the third upper limit threshold indicate the capacity that can be stored in each tank.

[0052] CH 4 The generation amount determination unit 114 determines whether the amount of methane generated as a by-product in the gasification furnace 30 is equal to or greater than a predetermined threshold (hereinafter, referred to as a first threshold). 4 The generation amount determination unit 114 acquires information about the amount of methane generated, which is detected by the gas detection unit 37 that detects information about the synthesis gas near the outlet of the gasification furnace 30, and retrieves the first threshold value from the storage unit 12. 4 The generation amount determination unit 114 compares the amount of methane generated detected by the gas detection unit 37 with a first threshold value, and determines whether the amount of methane generated during gasification of the biomass material is equal to or greater than the first threshold value.

[0053] H 2 The production amount determination unit 115 determines whether the production amount of hydrogen produced in the electrolysis device 60 is equal to or greater than a predetermined threshold value (hereinafter, referred to as a second threshold value). 2The H2 generation amount determination unit 115 acquires information on the amount of hydrogen generated from the electrolysis device 60, and retrieves the second threshold value from the storage unit 12. Then, the H2 generation amount determination unit 115 compares the acquired amount of hydrogen generated by the electrolysis device 60 with the second threshold value, and determines whether the amount of hydrogen generated is equal to or greater than a predetermined threshold value.

[0054] The heat quantity determination unit 116 determines whether or not the amount of heat required to heat the inside of the gasifier 30 to a temperature required for gasifying the biomass raw material (hereinafter referred to as the gasification temperature) is less than a predetermined threshold value (hereinafter referred to as the third threshold value). For example, the heat quantity determination unit 116 may calculate the difference between the temperature inside the gasifier 30 acquired from the temperature sensor 31 and the gasification temperature, and may calculate the amount of heat required to heat the inside of the gasifier 30 to the gasification temperature by referring to the relationship data between the amount of heat and the temperature rise of the gasifier 30. The smaller the amount of heat required to heat the calculated gasification temperature, the closer the temperature inside the gasifier 30 is to the gasification temperature, and the larger the amount of heat required, the further away the temperature inside the gasifier 30 is from the gasification temperature and the lower the temperature is. The heat quantity determination unit 116 may compare the calculated amount of heat required to heat the gasifier 30 to the gasification temperature with the third threshold value to determine whether or not the amount of heat required to heat the inside of the gasifier 30 to the gasification temperature is less than the third threshold value.

[0055] FIG. 4 is a diagram showing the relationship between the temperature in the gasifier 30 with a supply rate of 100 g / h of biomass raw material and the amount of heat required to heat the inside of the gasifier 30 to each temperature. The relationship shown in FIG. 4 was confirmed by a laboratory-level verification machine. The horizontal axis indicates the temperature (°C) in the gasifier 30, and the vertical axis indicates the amount of heat (kJ) required to heat the gasifier 30. In FIG. 4, the solid line indicates the correspondence relationship between the amount of heat applied to the gasifier 30 and the temperature in the gasifier 30 when that amount of heat is added, and the dashed line indicates the amount of heat required to heat the gasifier 30 to 800°C. In FIG. 4, for example, in the gasifier 30 with a supply rate of 100 g / h of biomass raw material, the verification result by the laboratory-level verification machine shows that the amount of heat required to heat the inside of the gasifier 30 to 800°C is about 9 kJ.

[0056] When the heat amount determination unit 116 determines that the heat amount required to heat the inside of the gasification furnace 30 to the gasification temperature is equal to or greater than the third threshold, the heating control unit 117 controls the methane utilization treatment device 7 to heat the CH 4 The methane recovered in the recovery device 71 is used as a heat source for the gasification furnace. 4 The outside of the reaction tube of the gasification furnace 30 may be heated using high-temperature methane stored in the tank 72. 4 The gasifier 30 may be heated by flowing the high-temperature methane stored in the tank 72 into the fluidized bed of the gasifier 30 and heating the fluidized material in the fluidized bed. This allows methane to be used as a heat source for gasification, for example, when the amount of heat required for gasification is insufficient. This makes it possible to effectively use methane as a heat source and suppress the generation of methane itself.

[0057] For example, when all of the following conditions (a) to (d) are satisfied, the steam reforming control unit 118 controls the water supply device 32 and the steam reforming device 74 to 4 It was collected by the collection device 71 and CH 4 The steam reforming control unit 118 then controls the steam reforming device 74 to perform steam reforming of the methane stored in the tank 72. 4 Methane from the tank 72 and water from the water supply device 32 are introduced, and steam reforming of the methane is carried out. The generated hydrogen and carbon monoxide are then controlled to be introduced into the gasification furnace 30. (a) The CH4 generation amount determination unit 114 determines that the amount of methane generated is equal to or greater than the first threshold value. (b) The CH4 storage amount determination unit 111 determines whether 4 The amount of methane in the tank 72 is determined to be less than the first upper limit threshold. (c) The heat quantity determination unit 116 determines that the heat quantity required to raise the temperature inside the gasification furnace 30 up to the gasification temperature is less than the third threshold value. (d) The H2 production amount determination unit 115 determines that the amount of hydrogen produced is less than the second threshold value.

[0058] Here, the relationship between the amount of hydrogen produced using renewable energy, the amount of hydrogen introduced during gasification of biomass feedstock, and the amount of carbon dioxide produced will be described with reference to Figs. 5 to 7. Fig. 5 is a diagram showing the relationship between the amount of hydrogen produced by the electrolysis device 60 using electricity generated by the power generation facility 5, which is a solar power generation facility, and the amount of solar radiation. In general, the more the amount of solar radiation, the more hydrogen can be produced by the electrolysis device 60, and the less the amount of solar radiation, the less hydrogen can be produced by the electrolysis device 60. That is, in bad weather, the amount of hydrogen produced by the electrolysis device 60 may be insufficient.

[0059] FIG. 6 is a diagram showing the relationship between the amount of hydrogen introduced into the gasifier 30 (hereinafter referred to as the hydrogen introduction amount) and the amount of carbon dioxide generated in the gasifier 30 (hereinafter referred to as the carbon dioxide generation amount). The horizontal axis shows the hydrogen introduction amount, and the vertical axis shows the carbon dioxide generation amount. FIG. 7 is a diagram showing the relationship between the hydrogen concentration in the gas introduced into the gasifier 30 and the carbon dioxide concentration in the synthesis gas generated in the gasifier 30 when the biomass feedstock is gasified in the gasifier 30 at 900°C. The relationship shown in FIG. 7 was obtained from laboratory-scale test results. The vertical axis shows the molar concentration of carbon dioxide in the synthesis gas, and the horizontal axis shows the hydrogen concentration in the gas introduced into the gasifier 30.

[0060] As shown in Figures 6 and 7, the smaller the amount of hydrogen introduced into the gasifier 30, the greater the amount of carbon dioxide generated, and the greater the amount of hydrogen introduced, the smaller the amount of carbon dioxide generated. From the results shown in Figures 5 to 7, it can be confirmed that when the amount of hydrogen produced using renewable energy decreases and the amount of hydrogen introduced into the gasifier 30 decreases, the amount of carbon dioxide generated during gasification of biomass raw materials increases.

[0061] According to the methane utilization process of this embodiment, when the amount of hydrogen produced is reduced, hydrogen is produced by steam reforming the by-produced methane, and the produced hydrogen is introduced into the gasifier. Therefore, even if the amount of hydrogen produced by renewable energy is insufficient due to bad weather or the like, hydrogen produced from methane, which is a by-product during the gasification of biomass raw materials, can be replenished to the gasifier 30. Therefore, the amount of carbon dioxide produced during the gasification of biomass raw materials can be reduced, and the amount of methane exhausted from the fuel production system 1 can be reduced.

[0062] The dry reforming control unit 119 controls the dry reforming device 75 and the like when all of the above conditions (a) to (c) and the following conditions (e) and (f) are satisfied, for example. 4 It was collected by the collection device 71 and CH 4 The dry reforming control unit 119 controls the dry reforming device 75 to perform dry reforming of the methane stored in the tank 72. 4 Methane and CO from Tank 72 2 Carbon dioxide is introduced from a tank, methane is dry reformed, and the produced hydrogen and carbon monoxide are controlled to be introduced into the synthesis gas discharge area A. (e)H 2 The production amount determination unit 115 determines that the amount of hydrogen produced is equal to or greater than the second threshold value. (f)CO 2 The storage amount determination unit 112 determines whether 2 It is determined that the amount of carbon dioxide in the tank is equal to or greater than the second upper limit threshold.

[0063] CO 2 The usage control unit 120 determines whether or not the CO 2 Recovery device 81, CO 2 The converter 84, the fuel synthesis device 85, the hydrogen supply pump 64, and other components are controlled to perform the carbon dioxide utilization process. 2 The usage control unit 120 2 The recovery device 81 is controlled to recover carbon dioxide from the gasification furnace 30, and the CO 2The CO 2 The usage control unit 120 controls the CO2 conversion device 84 and the hydrogen supply pump 64 to convert carbon dioxide into carbon monoxide, supply the carbon monoxide together with hydrogen to the gasification furnace 30, and supply the unconverted carbon dioxide to the fuel synthesis device 85. 2 The usage control unit 120 controls the fuel synthesis device 85 and the hydrogen supply pump 64 to synthesize fuel containing methane and water from carbon dioxide and hydrogen, and introduce the fuel into the gasification furnace 30. (g) The CO2 storage amount determination unit 112 determines whether or not the CO 2 The amount of carbon dioxide in the tank is determined to be less than a second upper limit threshold. (h)H 2 The storage amount determination unit 113 is H 2 It is determined that the amount of hydrogen in the tank is equal to or greater than a third upper limit threshold.

[0064] According to the carbon dioxide utilization process of the present embodiment, fuel to be used again in gasifying biomass raw materials can be produced from the carbon dioxide generated during the gasification of biomass raw materials, thereby making it possible to improve the efficiency of fuel production.

[0065] Next, an example of a methane utilization process and a carbon dioxide utilization process executed by the processing unit 11 of the control device 10 will be described with reference to Fig. 8 and Fig. 9. Fig. 8 is a flowchart showing an example of the flow of a methane utilization process executed by the processing unit 11 of the control device 10 of the fuel production system 1. Fig. 9 is a flowchart showing an example of the flow of a carbon dioxide utilization process executed by the processing unit 11 of the control device 10 of the fuel production system 1.

[0066] As shown in FIG. 8, in step S1 of the methane utilization process, 4 The generation amount determination unit 114 determines whether the amount of methane generated as a by-product in the gasification furnace 30 is equal to or greater than a first threshold value. 4 When the generation amount determination unit 114 determines that the amount of methane generation is less than the first threshold value (NO in step S1), the processing unit 11 does not perform control to recover methane (step S2). 4When the generation amount determination unit 114 determines that the methane generation amount is equal to or greater than the first threshold value (YES in step S1), the processing unit 11 shifts the process to step S3.

[0067] In step S3, CH 4 The storage amount determination unit 111 is 4 It is determined whether the amount of methane stored in the tank 72 is less than the first upper limit threshold. 4 The storage amount determination unit 111 determines whether 4 When it is determined that the amount of methane stored in the tank 72 is equal to or greater than the first upper limit threshold (NO in step S3), the processing unit 11 does not perform control to recover methane (step S2). 4 The storage amount determination unit 111 determines whether 4 When it is determined that the amount of methane stored in the tank 72 is less than the first threshold value (YES in step S3), the processing unit 11 shifts the process to step S4.

[0068] In step S4, the steam reforming control unit 118 4 The recovery device 71 is controlled to recover the methane by-produced in the gasification furnace 30 .

[0069] In step S5, the heat amount determination unit 116 determines whether the amount of heat required to raise the temperature inside the gasifier 30 to the gasification temperature (hereinafter, referred to as the required heat amount) is less than the third threshold value. If the heat amount determination unit 116 determines that the required heat amount is equal to or greater than the third threshold value (NO in step S5), the heating control unit 117 controls the methane utilization treatment device 7 to heat the CH 4 The methane stored in the tank 72 is used as a heat source for the gasification furnace 30. For example, the heating control unit 117 controls the CH 4 The outside of the reaction tube may be heated by flowing high-temperature methane stored in the tank 72 into the gasifier 30. On the other hand, when the heat amount determination unit 116 determines that the required heat amount of the gasifier 30 is less than the third threshold value (YES in step S5), the processing unit 11 transitions to step S7.

[0070] In step S7, H 2The production amount determination unit 115 determines whether the production amount of hydrogen produced in the electrolysis device 60 is less than a second threshold value. 2 When the generation amount determination unit 115 determines that the hydrogen generation amount is less than the second threshold value (YES in step S7), the steam reforming control unit 118 controls the water supply device 32 and the steam reforming device 74 to generate CH 4 The methane stored in the tank 72 is steam reformed to generate hydrogen and carbon monoxide (step S8). After that, the steam reforming control unit 118 controls the steam reformer 74 to introduce the hydrogen and carbon monoxide generated in step S8 into the gasifier 30 (step S9), and the methane utilization process is terminated. Note that the methane that was not converted to carbon monoxide by the steam reforming in step S8 is converted into CH 4 It may be collected by a collection device 71. 2 When the production amount determination unit 115 determines that the hydrogen production amount is equal to or greater than the second threshold value (NO in step S7), the processing unit 11 shifts the process to step S10.

[0071] In step S10, CO 2 The storage amount determination unit 112 determines whether 2 It is determined whether the amount of carbon dioxide stored in the tank 82 is equal to or greater than the second upper limit threshold. 2 The storage amount determination unit 112 determines whether 2 When it is determined that the amount of carbon dioxide stored in the tank 82 is equal to or greater than the second upper limit threshold (YES in step 10), the dry reforming control unit 119 controls the dry reforming device 75 and the carbon dioxide utilization processing device 8, etc., to 4 Methane and CO stored in Tank 72 2 Dry reforming is performed using the carbon dioxide stored in the tank 82 to generate hydrogen and carbon monoxide (step S11). Then, the dry reforming control unit 119 introduces the hydrogen and carbon monoxide generated in step S11 into the synthesis gas discharge area (step S12), and ends the methane utilization process. 2When the storage amount determination unit 112 determines that the amount of carbon dioxide is less than the second upper limit threshold (NO in step S10), the processing unit 11 shifts the process to carbon dioxide utilization processing in step S20.

[0072] As shown in FIG. 9, in step S21, 2 The usage control unit 120 2 The recovery device 81 is controlled to recover the carbon dioxide generated in the gasification furnace 30 .

[0073] In step S22, H 2 The storage amount determination unit 113 is H 2 It is determined whether the amount of hydrogen stored in the tank 62 is equal to or greater than the third upper limit threshold. 2 The storage amount determination unit 113 2 When it is determined that the amount of hydrogen stored in the tank 62 is less than the third upper limit threshold (NO in step 22), the processing unit 11 ends the carbon dioxide utilization process. 2 The storage amount determination unit 113 determines whether H 2 If it is determined that the amount of hydrogen stored in the tank 62 is equal to or greater than the third upper limit threshold (YES in step S22), the processing unit 11 transitions the process to step S23.

[0074] In step S23, CO 2 The usage control unit 120 2 The converter 84 and the hydrogen supply pump 64 are controlled to convert carbon dioxide into carbon monoxide, and the converted carbon monoxide and the hydrogen generated in the electrolysis device 60 are mixed to produce H 2 Adjust the H / CO ratio to the desired target ratio. 2 The synthesis gas with the adjusted CO / CO ratio is supplied to the synthesis gas discharge area (step S24). Carbon dioxide that was not converted to carbon monoxide in step S23 is synthesized into fuel by the fuel synthesis device 85 (step S25). The fuel synthesized by the fuel synthesis device 85 is supplied to the gasification furnace 30 (step S26), and the carbon dioxide utilization process is completed. Note that the carbon dioxide that was not synthesized by the fuel synthesis device 85 is converted into CO 2It is collected by the collection device 81.

[0075] Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment. The detailed configuration may be appropriately changed within the scope of the spirit of the present invention. [Explanation of symbols]

[0076] 1. Fuel production system 4 Liquid fuel production equipment 30 Gasifier 71 CO 2 Recovery equipment (methane recovery equipment) 60 Electrolyzer 74 Steam reformer 10 Control device 116 Calorific value determination section 115 Hydrogen generation amount determination unit (H 2 generation amount determination section) 118 Steam reforming control unit

Claims

1. A fuel production system for producing liquid fuel from a biomass feedstock, comprising: a gasification furnace for gasifying a biomass feedstock and generating a synthesis gas containing hydrogen and carbon monoxide; a methane recovery device that recovers methane produced as a by-product in the gasification furnace; An electrolysis device that generates hydrogen using electricity generated using renewable energy; a liquid fuel production device for producing liquid fuel from the synthesis gas produced in the gasification furnace; a steam reformer that performs steam reforming of the methane recovered by the methane recovery device to generate hydrogen; A control device for controlling the methane recovery device and the steam reformer, The control device includes: a heat quantity determination unit that determines whether or not a heat quantity required to raise the temperature inside the gasification furnace to a temperature required for gasifying the biomass feedstock is less than a predetermined threshold value; a hydrogen production amount determination unit that determines whether an amount of hydrogen produced by the electrolysis device is equal to or greater than a predetermined threshold; a steam reforming control unit that, when the heat quantity determination unit determines that the required heat quantity is less than a predetermined threshold and the hydrogen production amount determination unit determines that the hydrogen production amount is less than a predetermined threshold, controls the steam reforming device to perform the steam reforming and introduces the generated hydrogen into the gasification furnace.

2. a carbon dioxide recovery device that recovers carbon dioxide generated when generating synthesis gas in the gasification furnace; a carbon dioxide tank for storing the carbon dioxide captured by the carbon dioxide capture device; A dry reforming device for dry reforming methane to produce hydrogen and carbon monoxide. The control device includes: a carbon dioxide amount determination unit that determines whether the amount of carbon dioxide stored in the carbon dioxide tank is equal to or greater than a predetermined threshold; 2. The fuel production system according to claim 1, further comprising a dry reforming control unit that controls the dry reforming apparatus to perform the dry reforming when the heat amount determination unit determines that the required heat amount is less than a predetermined threshold, the hydrogen production amount determination unit determines that the hydrogen production amount is equal to or greater than a predetermined threshold, and the carbon dioxide amount determination unit determines that the stored amount of carbon dioxide is equal to or greater than a predetermined threshold, and introduces the generated hydrogen and carbon monoxide toward the liquid fuel production apparatus into a synthesis gas discharge area where synthesis gas is discharged from the gasification furnace.

3. 3. The fuel production system according to claim 1, wherein the control device further comprises a heating control unit that uses methane recovered in the methane recovery device as a heat source for the gasification furnace when the heat quantity determination unit determines that the required heat quantity is equal to or greater than a predetermined threshold value.

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