Wood biomass gas combustion equipment and wood biomass gas combustion method

Abstract

To realize a configuration capable of curbing an increase in a concentration of carbon monoxide contained in processed gas produced after exhaust gas produced when exhaust gas after combustion of thermal decomposition gas undergoes a process in a woody biomass gas combustion facility in which the thermal decomposition gas generated through thermal decomposition of woody biomass undergoes combustion.SOLUTION: A woody biomass gas combustion facility 1 comprises: a filter 23 which collects particles in thermal decomposition gas obtained from woody biomass; oxidation catalyst reaction device 16 which oxidizes carbon monoxide contained in exhaust gas produced when the thermal decomposition gas undergoes combustion with a gas engine 15; a particle removal mechanism 25 which performs particle removal operation; an oxidation gas supply device 40 which mixes the exhaust gas with oxidation gas; and a control device 30 which controls drive of the oxidation gas supply device 40 so as to mix the exhaust gas with the oxidation gas when the particle removal mechanism 25 performs the particle removal operation.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a woody biomass gas combustion facility and a woody biomass gas combustion method for burning pyrolysis gas obtained by pyrolysis of woody biomass. [Background technology]

[0002] There is known a woody biomass gas combustion facility that burns pyrolysis gas obtained by pyrolysis of woody biomass. For example, a gasification system that gasifies woody biomass is disclosed in Non-Patent Document 1 as an example of such a woody biomass gas combustion facility.

[0003] The gasification system uses chipped or pelletized woody biomass as fuel and gasifies it through pyrolysis and reduction reactions, and the resulting gas is combusted to generate electricity and heat. [Prior art documents] [Patent documents]

[0004] [Non-Patent Document 1] “Gasification System Overview,” Japan Wood Biomass Energy Association, [Retrieved February 1, 2022], Internet (https: / / www.jwba.or.jp / small-woody-biomass-generation-guidebook / 08 / ) Summary of the Invention [Problem to be solved by the invention]

[0005] In the gasification system disclosed in Non-Patent Document 1, pyrolysis gases such as carbon monoxide, methane, and hydrogen are obtained by gasifying the woody biomass. During this process, particles such as dust and tar from the woody biomass flow downstream along with the pyrolysis gas. Therefore, the gasification system has a filter for removing these particles upstream of a combustion device that combusts the pyrolysis gas.

[0006] When the filter becomes clogged with the particles, the filter needs to be replaced or the particles trapped on the filter need to be removed. For example, when the particles trapped on the filter are removed from the filter, the flow rate of the pyrolysis gas to the combustion device may temporarily increase during or after the particles are removed.

[0007] When the flow rate of the pyrolysis gas flowing into the combustion device temporarily increases in this way, the concentration of carbon monoxide in the exhaust gas generated after the combustion of the pyrolysis gas in the combustion device increases, which may cause a temporary shortage of oxygen for oxidizing carbon monoxide in the exhaust gas treatment device that treats the exhaust gas.

[0008] As a result, the concentration of carbon monoxide contained in the treated gas after the exhaust gas is treated by the exhaust gas treatment device may increase.

[0009] The object of the present invention is to realize a configuration in a wood biomass gas combustion facility that burns pyrolysis gas produced by pyrolysis of wood biomass, which can suppress an increase in the concentration of carbon monoxide contained in the treated gas after the exhaust gas generated after combustion of the pyrolysis gas has been treated. [Means for solving the problem]

[0010] A woody biomass gas combustion facility according to one embodiment of the present invention includes a gasifier that generates pyrolysis gas by pyrolysis of woody biomass, a filter that collects particles in the pyrolysis gas, and a combustion device that combusts the pyrolysis gas that has passed through the filter. The woody biomass gas combustion facility also includes an exhaust gas treatment device that oxidizes carbon monoxide contained in exhaust gas generated by combustion of the pyrolysis gas by the combustion device, a particle removal mechanism that performs a particle removal operation to remove the particles collected in the filter, an oxidation gas supply device that mixes an oxygen-containing oxidation gas with the exhaust gas or the pyrolysis gas that has passed through the filter, and a control device that controls operation of the oxidation gas supply device to mix the oxidation gas with the exhaust gas or the pyrolysis gas that has passed through the filter when the particle removal mechanism performs the particle removal operation (first configuration).

[0011] In this way, by supplying an oxidizing gas to the exhaust gas generated by the combustion of the pyrolysis gas in the combustion device or to the pyrolysis gas that has passed through the filter in accordance with the timing of removing particles trapped on the filter, the oxygen concentration in the exhaust gas flowing into the exhaust gas treatment device can be increased. This prevents a shortage of oxygen for oxidizing carbon monoxide in the exhaust gas treatment device. Therefore, an increase in the carbon monoxide concentration in the treated gas obtained after treating the exhaust gas with the exhaust gas treatment device can be suppressed.

[0012] In the first configuration, the oxidation gas supply device is capable of mixing the oxidation gas with the exhaust gas at a position upstream of the exhaust gas treatment device in the direction in which the exhaust gas flows from the combustion device toward the exhaust gas treatment device (second configuration).

[0013] An oxidation gas can be mixed with the exhaust gas before it flows into the exhaust gas treatment device. This allows exhaust gas containing a sufficient amount of oxygen to be supplied to the exhaust gas treatment device. This prevents a shortage of oxygen used to oxidize carbon monoxide in the exhaust gas treatment device. This makes it possible to more reliably suppress an increase in the concentration of carbon monoxide contained in the treated gas obtained after the exhaust gas is treated by the exhaust gas treatment device.

[0014] In the first or second configuration, the particle removal mechanism or the control device outputs a removal signal related to the removal of the particles when removing the particles trapped on the filter. The control device has an oxidation gas supply control unit that, when detecting the removal signal, controls the operation of the oxidation gas supply device so as to mix the oxidation gas with the exhaust gas or the pyrolysis gas that has passed through the filter (third configuration).

[0015] The oxidation gas can be supplied to the exhaust gas generated in the combustion device or the pyrolysis gas that has passed through the filter in accordance with the timing at which the amount of pyrolysis gas supplied to the combustion device temporarily increases due to the removal of particles from the filter, thereby suppressing an increase in the concentration of carbon monoxide in the treated gas obtained after the exhaust gas treatment device treats the exhaust gas.

[0016] In the third configuration, the woody biomass gas combustion facility further includes a clogging detection unit that detects clogging of the filter. When the clogging detection unit detects clogging of the filter, the control device generates the removal signal (fourth configuration).

[0017] When the clogging detector detects clogging of the filter, the control device can generate a removal signal and output it to the particle removal mechanism, which allows particles to be removed from the clogged filter at an appropriate time.

[0018] In the first or second configuration, the woody biomass gas combustion facility further includes a particle removal detection unit that detects the removal of the particles from the filter by the particle removal mechanism. When the particle removal detection unit detects the removal of the particles from the filter by the particle removal mechanism, the control device controls the drive of the oxidation gas supply device so as to mix the oxidation gas with the exhaust gas or the pyrolysis gas that has passed through the filter (fifth configuration).

[0019] When removal of particles from the filter is detected, an oxidizing gas can be supplied to the exhaust gas generated in the combustion device or the pyrolysis gas that has passed through the filter, thereby more reliably suppressing an increase in the concentration of carbon monoxide contained in the treated gas obtained after treating the exhaust gas with the exhaust gas treatment device.

[0020] In any one of the first to fifth configurations, the particle removal mechanism is configured to perform the particle removal operation by deforming the filter in a direction intersecting the direction in which the pyrolysis gas flows toward the combustion device, or by vibrating the filter (sixth configuration).

[0021] When the filter is deformed in a direction crossing the flow direction of the pyrolysis gas or when the filter is vibrated as part of the particle removal operation, the flow rate of the pyrolysis gas passing through the filter increases rapidly. In these cases, the amount of carbon monoxide contained in the pyrolysis gas supplied to the combustion device also increases, causing the combustion device to generate exhaust gas containing a high concentration of carbon monoxide. As a result, the exhaust gas treatment device to which the exhaust gas is supplied temporarily lacks oxygen for oxidizing carbon monoxide. As a result, the concentration of carbon monoxide in the treated gas obtained after the exhaust gas treatment device treats the exhaust gas increases.

[0022] In response to this, as in claim 1, by supplying an oxidation gas to the exhaust gas or the pyrolysis gas that has passed through the filter in accordance with the timing of removing particles trapped on the filter, the concentration of oxygen in the exhaust gas flowing into the exhaust gas treatment device can be increased. This prevents a shortage of oxygen for oxidizing carbon monoxide in the exhaust gas treatment device. Therefore, it is possible to suppress an increase in the concentration of carbon monoxide contained in the treated gas obtained after treating the exhaust gas with the exhaust gas treatment device.

[0023] In any one of the first to sixth configurations, the oxidizing gas is a gas containing oxygen (seventh configuration). Because the oxidizing gas is a gas containing oxygen, it is less expensive than oxygen alone. This reduces the running costs of the woody biomass gas combustion facility.

[0024] A woody biomass gas combustion method according to one embodiment of the present invention is a method for burning pyrolysis gas obtained by pyrolyzing woody biomass in a combustion device. The woody biomass gas combustion method includes an exhaust gas treatment step of oxidizing carbon monoxide contained in exhaust gas produced by combustion of the pyrolysis gas in the combustion device, a particle removal step of removing particles from a filter that collects particles in the pyrolysis gas supplied to the combustion device, and an oxidizing gas supply step of mixing an oxygen-containing oxidizing gas with the exhaust gas or the pyrolysis gas that has passed through the filter when removing the particles from the filter in the particle removal step (first method).

[0025] In this way, by supplying an oxidizing gas to the exhaust gas generated by the combustion of the pyrolysis gas in the combustion device or to the pyrolysis gas that has passed through the filter in accordance with the timing of removing particles trapped on the filter, the oxygen concentration in the exhaust gas flowing into the exhaust gas treatment device can be increased. This prevents a shortage of oxygen for oxidizing carbon monoxide in the exhaust gas treatment device. Therefore, an increase in the carbon monoxide concentration in the treated gas obtained after treating the exhaust gas with the exhaust gas treatment device can be suppressed. [Effects of the Invention]

[0026] A wood biomass gas combustion facility according to one embodiment of the present invention has a control device that controls the operation of an oxidizing gas supply device so that an oxidizing gas is mixed with exhaust gas or pyrolysis gas that has passed through the filter when the particle removal mechanism performs a particle removal operation to remove particles captured in the filter.

[0027] This prevents a shortage of oxygen for oxidizing carbon monoxide in the exhaust gas treatment device, thereby suppressing an increase in the concentration of carbon monoxide contained in the treated gas obtained after the exhaust gas is treated by the exhaust gas treatment device. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a wood biomass gas combustion facility according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing a schematic configuration of a gas filter. [Figure 3] FIG. 3 is a diagram schematically illustrating a state in which the gas filter is contracted in the up-down direction by moving the rod downwards using a driving unit. [Figure 4] FIG. 4 is a diagram schematically illustrating the gas filter in a state where the filter has been returned to its original length. [Figure 5]FIG. 5 is a flowchart showing the combustion operation of the wood biomass gas combustion facility. [Figure 6] FIG. 6 is a flowchart showing the particle removal operation and the oxidizing gas supply operation in a woody biomass gas combustion facility. [Figure 7] FIG. 7 is a diagram showing a schematic configuration of a wood biomass gas combustion facility according to the second embodiment. [Figure 8] FIG. 8 is a diagram showing a schematic configuration of a wood biomass gas combustion facility according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0029] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals and the description thereof will not be repeated.

[0030] [Embodiment 1] (Overall composition) Fig. 1 is a diagram showing a schematic configuration of a woody biomass gas combustion facility 1 according to a first embodiment of the present invention. The woody biomass gas combustion facility 1 combusts pyrolysis gas obtained by pyrolyzing woody biomass using a gas engine 15. In Fig. 1, solid arrows indicate the direction of gas flow, and dashed arrows indicate the direction of signal transmission.

[0031] The wood biomass gas combustion equipment 1 has a storage facility 11, a funnel 12, a reformer 13 (gasification device), a heat exchanger 14, a gas engine 15 (combustion device), an oxidation catalytic reaction device 16 (exhaust gas treatment device), a gas filter 20, a control device 30, and an oxidation gas supply device 40.

[0032] The storage 11 is a tank for storing woody biomass. The funnel 12 supplies woody biomass to a supply port (not shown) of the storage 11. Note that the woody biomass gas combustion facility 1 does not necessarily have to include the funnel 12.

[0033] The reformer 13 generates pyrolysis gas by pyrolyzing the woody biomass supplied from the storage 11. The reformer 13 heats the woody biomass at a high temperature and steams it, thereby generating gases such as carbon monoxide, methane, and hydrogen as the pyrolysis gas.

[0034] The heat exchanger 14 cools the pyrolysis gas generated in the reformer 13 with gas or liquid. The pyrolysis gas cooled by the heat exchanger 14 is supplied to a gas filter 20. The configuration of the heat exchanger 14 is similar to that of a general heat exchanger. Therefore, a detailed description of the configuration of the heat exchanger 14 will be omitted.

[0035] The gas filter 20 collects particles such as dust and tar that flow together with the pyrolysis gas using a filter 23 (see FIG. 2). That is, the gas filter 20 has the filter 23, which can remove the particles, on the flow path of the pyrolysis gas.

[0036] The gas filter 20 also has a particle removal mechanism 25 that removes particles trapped in the filter 23 from the filter 23. The particle removal mechanism 25 removes particles trapped in the filter 23 from the filter 23, for example, by moving the filter 23 of the gas filter 20 and applying an impact or vibration to the filter 23.

[0037] The detailed configuration of the gas filter 20 will be described later.

[0038] The gas engine 15 combusts the pyrolysis gas that has passed through the gas filter 20 to remove the particles. The gas engine 15 is, for example, a diesel engine. The gas engine 15 discharges exhaust gas generated by the combustion of the pyrolysis gas. The configuration of the gas engine 15 is similar to that of a conventional gas engine. Therefore, a detailed description of the configuration of the gas engine 15 will be omitted.

[0039] The oxidation catalyst reaction device 16 purifies the exhaust gas discharged from the gas engine 15 through an oxidation catalyst reaction, and oxidizes the carbon monoxide contained in the exhaust gas with oxygen. The oxidation catalyst reaction device 16 is supplied with the exhaust gas discharged from the gas engine 15 and an oxidation gas containing oxygen delivered from an oxidation gas supply device 40. Carbon dioxide is produced by oxidizing carbon monoxide in the oxidation catalyst reaction device 16. The produced carbon dioxide is discharged from the oxidation catalyst reaction device 16 as part of the treated gas.

[0040] The woody biomass gas combustion facility 1 may have, instead of the oxidation catalyst reaction device 16, another device capable of oxidizing carbon monoxide contained in the exhaust gas discharged from the gas engine 15 to produce carbon dioxide.

[0041] The oxidation gas supply device 40 mixes an oxidation gas, which is a gas containing oxygen, with the exhaust gas discharged from the gas engine 15 and supplied to the oxidation catalyst reaction device 16, based on a supply signal generated and output by the control device 30. In this way, the oxidation gas supply device 40 mixes the oxidation gas with the exhaust gas at a position upstream of the oxidation catalyst reaction device 16 in the direction in which the exhaust gas flows from the gas engine 15 toward the oxidation catalyst reaction device 16.

[0042] The oxidizing gas is a gas containing oxygen. The oxidizing gas may be a gas containing only oxygen, or may be air containing oxygen. By using a gas containing oxygen, such as air, as the oxidizing gas, the oxidizing gas can be procured at low cost.

[0043] The oxidizing gas supply device 40 has a gas tank 41 and a valve 42. It is noted that the oxidizing gas supply device 40 does not necessarily have to have the gas tank 41. The oxidizing gas supply device 40 may be supplied with the oxidizing gas from a cylinder or a gas pipe.

[0044] The gas tank 41 stores an oxidation gas, which is air containing oxygen. The valve 42 is provided on the gas flow path between the gas tank 41 and the oxidation catalytic reaction device 16. The valve 42 opens in response to a supply signal output from the control device 30. When the valve 42 opens, the oxidation gas is supplied from the gas tank 41 to the oxidation catalytic reaction device 16 via the gas flow path. As described above, the oxidation gas supplied from the gas tank 41 to the oxidation catalytic reaction device 16 is used in the oxidation catalytic reaction device 16 to oxidize carbon monoxide contained in the exhaust gas emitted from the gas engine 15.

[0045] The control device 30 causes the particle removal mechanism 25 to perform a particle removal operation to remove particles trapped in the filter 23. That is, when a clogging detection signal is output from the clogging detection unit 28 that detects clogging of the filter 23, the control device 30 causes the particle removal mechanism 25 to perform the particle removal operation.

[0046] Furthermore, when the particle removal mechanism 25 performs a particle removal operation to remove particles trapped on the filter 23, the control device 30 causes the oxidation gas supply device 40 to mix the oxidation gas with the exhaust gas discharged from the gas engine 15. In other words, the control device 30 controls the operation of the oxidation gas supply device 40 so as to mix the oxidation gas containing oxygen with the exhaust gas discharged from the gas engine 15 and supplied to the oxidation catalytic reaction device 16.

[0047] Specifically, the control device 30 has a particle removal control unit 31 and an oxidation gas supply control unit 32. When a clogging detection signal is output from a clogging detection unit 28 that detects clogging of the filter 23, the particle removal control unit 31 generates a removal signal and outputs the generated removal signal to the particle removal mechanism 25. The removal signal is also output to the oxidation gas supply control unit 32. When the oxidation gas supply control unit 32 detects the removal signal generated by the particle removal control unit 31, it generates a supply signal and outputs the generated supply signal to a valve 42 of the oxidation gas supply device 40. The removal signal is a signal related to particle removal.

[0048] The clogging detection unit 28 detects whether or not the filter 23 is clogged based on the difference between the pressure on the upstream side and the pressure on the downstream side of the filter 23. When the clogging detection unit 28 detects clogging of the filter 23, it outputs a clogging detection signal. The clogging detection signal is input to the control device 30.

[0049] (gas filter) Fig. 2 is a diagram showing a schematic configuration of the gas filter 20. As shown in Fig. 2, the gas filter 20 has a filter case 21, a filter 23, and a particle removal mechanism 25. In Fig. 2, solid arrows indicate the flow of pyrolysis gas.

[0050] The filter case 21 has a generally cylindrical outer shape. The filter case 21 has a tapered portion 21a at its bottom that slopes downward. As will be described later, particles removed from the filter 23 by the particle removal operation of the particle removal mechanism 25 accumulate at the lowest end of this tapered portion 21a. The filter case 21 may have a shape other than a cylinder, such as a rectangular parallelepiped shape.

[0051] The filter case 21 has an inlet portion 21b and an outlet portion 21c on its side surface. The inlet portion 21b protrudes radially outward from a lower portion of the side surface of the filter case 21. The pyrolysis gas generated in the reformer 13 passes through the inlet portion 21b and flows into the filter case 21. The outlet portion 21c is located at an upper portion of the side surface of the filter case 21 and at a different position in the circumferential direction of the filter case 21 from the inlet portion 21b. The outlet portion 21c is located, for example, on the opposite side of the filter case 21 from the inlet portion 21b in the radial direction. The outlet portion 21c is, for example, a circular through-hole. The outlet may be a through-hole having a shape other than circular.

[0052] The filter case 21 has a space V therein capable of accommodating the filter 23. The space V is connected to the interior of the inlet portion 21b and the outlet 21c.

[0053] The filter 23 is cylindrical and captures particles contained in the pyrolysis gas. The filter 23 is made of a deformable, flexible material such as fiber. The upper end of the filter 23 is connected to a filter upper connector 26a of the particle removal mechanism 25, which will be described later. A rod 26b, which will be described later and has one end connected to the filter upper connector 26a and extends in the vertical direction, is disposed within the filter 23.

[0054] In the gas filter 20 having the above configuration, the pyrolysis gas that flows into the space V of the filter case 21 from the inlet portion 21b flows through the filter 23 and then passes through the filter 23 in the radial direction. As a result, particles contained in the pyrolysis gas are removed by the filter 23. The pyrolysis gas that has passed through the filter 23 is discharged to the outside of the filter case 21 from the outlet 21c.

[0055] The particle removal mechanism 25 performs a particle removal operation on the filter 23 to remove particles trapped in the filter 23. More specifically, the particle removal mechanism 25 has a filter upper connection part 26a, a rod 26b, and a drive part 27.

[0056] Filter upper connection part 26a is connected to the upper end of filter 23. Filter upper connection part 26a has a shape, for example, a ring shape, that allows it to press downward the upper end surface of filter 23. As a result, by moving filter upper connection part 26a downward, the upper end of filter 23 can be moved downward, causing filter 23 to contract in the up-and-down direction.

[0057] One end of rod 26b is connected to filter upper connection part 26a, and is disposed so as to extend vertically inside filter 23. The other end of rod 26b is connected to drive part 27. Rod 26b is, for example, a columnar member made of metal.

[0058] The drive unit 27 applies a force in the vertical direction to the rod 26b so as to move the rod 26b in the vertical direction. The drive unit 27 is, for example, an air cylinder. When a removal signal generated by the particle removal control unit 31 of the control device 30 is input, the drive unit 27 moves the rod 26b downward. The drive unit 27 is disposed at the bottom of the filter case 21. The drive unit 27 may be housed within the filter case 21 or may be disposed outside the filter case 21. The drive unit 27 may be located above the filter 23. In this case, the rod 26b only needs to extend upward relative to the filter upper connection portion 26a.

[0059] Fig. 3 is a diagram schematically illustrating a state in which the filter 23 of the gas filter 20 has been contracted in the up-down direction by moving the rod 26b downward by the driving unit 27. Fig. 4 is a diagram schematically illustrating a state in which the filter 23 has been restored to its original length by moving the rod 26b upward by the driving unit 27. In Figs. 3 and 4, the outline arrow indicates the direction of movement of the rod 26b.

[0060] As shown in FIG. 3, when the rod 26b is moved downward by the driving unit 27, the filter 23 contracts in the vertical direction.

[0061] The driving unit 27 moves the rod 26b downward to contract the filter 23 in the up-down direction, and then moves the rod 26b upward to return the filter 23 to its original length, as shown in Fig. 4. That is, the driving unit 27 deforms the filter 23 in the direction in which the pyrolysis gas flows, which in this embodiment is a direction intersecting the radial direction of the filter, and then returns the filter 23 to its original state. The impact on the filter 23 at this time removes particles captured by the filter 23 from the filter 23.

[0062] The driving unit 27 may move the rod 26b downward for a predetermined time and then return the rod 26b to its original position, or may return the rod 26b to its original position in response to a signal input from the particle removal control unit 31 to the driving unit 27.

[0063] The particle removal operation by the particle removal mechanism 25 as described above removes particles trapped in the filter 23 from the filter 23. The particles removed from the filter 23 are collected at the lowest end of the filter case 21 by the tapered portion 21a located at the bottom of the filter case 21. This allows the particles to be easily collected from the bottom of the filter case 21.

[0064] In the gas filter 20 having the above-described configuration, when the particles trapped in the filter 23 are removed by the particle removal mechanism 25, the amount of pyrolysis gas passing through the filter 23 temporarily increases. Therefore, immediately after the particles trapped in the filter 23 are removed by the particle removal mechanism 25, the flow rate of the pyrolysis gas supplied from the gas filter 20 to the gas engine 15 temporarily increases.

[0065] The particle removal mechanism is not limited to the above-described configuration. For example, it may be configured to remove particles trapped on the filter by the impact generated when the filter is moved vertically and then returned to its original position. That is, the drive unit may move the rod vertically to move the filter in the direction of pyrolysis gas flow, which in this embodiment is a direction intersecting the radial direction of the filter. In this case, there is a possibility that pyrolysis gas may flow into the outlet 21c through gaps created when the filter is moved. Therefore, the flow rate of pyrolysis gas supplied from the gas filter to the gas engine temporarily increases.

[0066] As described above, when the flow rate of the pyrolysis gas supplied from the gas filter 20 to the gas engine 15 temporarily increases, the concentration of carbon monoxide in the pyrolysis gas supplied to the gas engine 15 rises sharply. This causes a sharp rise in the concentration of carbon monoxide contained in the exhaust gas generated by the combustion of the pyrolysis gas in the gas engine 15. Therefore, there is a possibility that carbon monoxide cannot be sufficiently oxidized in the oxidation catalyst reaction device 16, and a high concentration of carbon monoxide is discharged from the oxidation catalyst reaction device 16.

[0067] In contrast, in this embodiment, the oxidizing gas supply control unit 32 of the control device 30 detects whether the particle removal mechanism 25 is performing a particle removal operation by detecting a removal signal generated and output by the particle removal control unit 31 of the control device 30. By detecting the removal signal, the oxidizing gas supply control unit 32 predicts that the particle removal operation by the particle removal mechanism 25 will cause a sudden rise in the carbon monoxide concentration in the exhaust gas emitted from the gas engine 15, and generates a supply signal instructing the oxidizing gas supply device 40 to supply oxidizing gas. In other words, the woody biomass gas combustion facility 1 performs an oxidizing gas supply operation. The particle removal operation and oxidizing gas supply operation by the woody biomass gas combustion facility 1 will be described in detail below.

[0068] (Combustion operation of wood biomass gas combustion equipment) Next, the combustion operation of the wood biomass gas combustion facility 1 having the above-described configuration will be described with reference to Fig. 5. Fig. 5 is a flowchart showing the combustion operation of the wood biomass gas combustion facility 1.

[0069] 5, first, in the woody biomass gas combustion facility 1, woody biomass is pyrolyzed in the reformer 13 to generate pyrolysis gas (step SA1). Then, in step SA2, particles contained in the pyrolysis gas are collected by the filter 23 of the gas filter 20, and the particles are removed from the pyrolysis gas.

[0070] In the following step SA3, the pyrolysis gas from which the particles have been collected by the filter 23 is combusted by the gas engine 15. In the gas engine 15, exhaust gas is generated by combustion of the pyrolysis gas. Then, in step SA4, exhaust gas treatment is performed in the oxidation catalyst reaction device 16, in which carbon monoxide contained in the exhaust gas is oxidized to generate carbon dioxide. Then, in step SA5, the treated gas obtained by the exhaust gas treatment is discharged from the oxidation catalyst reaction device 16.

[0071] This allows the woody biomass gas combustion facility 1 to combust pyrolysis gas obtained from woody biomass, treat the exhaust gas, and then discharge the treated gas.

[0072] (Particle removal operation and oxidation gas supply operation) Next, the particle removal operation by the particle removal mechanism 25 and the oxidation gas supply operation by the oxidation gas supply device 40 in the wood biomass gas combustion facility 1 will be described with reference to Fig. 6. Fig. 6 is a flowchart showing the particle removal operation and the oxidation gas supply operation in the wood biomass gas combustion facility 1.

[0073] 6, first, when the clogging detection unit 28 of the woody biomass gas combustion facility 1 detects clogging of the filter 23 of the gas filter 20, it outputs a clogging detection signal (step SB1). The clogging detection signal output from the clogging detection unit 28 is input to the particle removal control unit 31 of the control device 30.

[0074] When the particle removal control unit 31 detects the clogging detection signal, it generates a removal signal (step SB2). The generated removal signal is output to the particle removal mechanism 25. As a result, the particle removal mechanism 25 performs a particle removal operation to remove particles trapped in the filter 23 (step SB3).

[0075] The removal signal generated by the particle removal control unit 31 is also input to the oxidation gas supply control unit 32 of the control device 30. When the removal signal is input, the oxidation gas supply control unit 32 generates a supply signal (step SB4). The generated supply signal is output to the valve 42 of the oxidation gas supply device 40. This causes the valve 42 to open. With the valve 42 in this open state, oxidation gas is supplied from the gas tank 41 of the oxidation gas supply device 40 to the exhaust gas discharged from the gas engine 15 (step SB5).

[0076] Thereafter, in step SB6, exhaust gas treatment is performed in which carbon monoxide contained in the exhaust gas is oxidized to produce carbon dioxide in the oxidation catalyst reaction device 16. Then, in step SB7, the treated gas obtained by the exhaust gas treatment is discharged from the oxidation catalyst reaction device 16.

[0077] This allows the exhaust gas mixed with the oxidation gas supplied from the oxidation gas supply device 40 to be oxidized in the oxidation catalyst reaction device 16. Therefore, when the particle removal operation is performed by the particle removal mechanism 25, it is possible to prevent a sudden increase in the concentration of carbon monoxide contained in the treated gas discharged from the oxidation catalyst reaction device 16.

[0078] In the particle removal operation and oxidation gas supply operation described above, step SB6 corresponds to the exhaust gas treatment step, step SB3 corresponds to the particle removal step, and step SB5 corresponds to the oxidation gas supply step.

[0079] Furthermore, in the particle removal operation and oxidation gas supply operation described above, step SB3 in which the particle removal mechanism 25 performs the particle removal operation may be performed at any timing after step SB2 in which the particle removal control unit 31 generates the removal signal.

[0080] As described above, in the configuration of this embodiment, the wood biomass gas combustion equipment 1 includes a reformer 13 that generates pyrolysis gas by pyrolyzing wood biomass, a filter 23 that collects particles in the pyrolysis gas, a gas engine 15 that combusts the pyrolysis gas that has passed through the filter 23, an oxidation catalyst reaction device 16 that oxidizes carbon monoxide contained in the exhaust gas generated by the combustion of the pyrolysis gas by the gas engine 15, a particle removal mechanism 25 that performs a particle removal operation to remove the particles captured in the filter 23, an oxidation gas supply device 40 that mixes an oxidation gas containing oxygen into the exhaust gas, and a control device 30 that controls the operation of the oxidation gas supply device 40 so that the oxidation gas is mixed into the exhaust gas when the particle removal mechanism 25 performs the particle removal operation.

[0081] In addition, the wood biomass gas combustion method performed by the wood biomass gas combustion equipment 1 includes an exhaust gas treatment process SB6 that oxidizes carbon monoxide contained in the exhaust gas generated by the combustion of the pyrolysis gas by the gas engine 15, a particle removal process SB3 that removes the particles from a filter 23 that captures particles in the pyrolysis gas supplied to the gas engine 15, and an oxidation gas supply process SB5 that mixes an oxidation gas containing oxygen into the exhaust gas when removing the particles from the filter 23 in the particle removal process SB3.

[0082] The configuration of the woody biomass gas combustion facility 1 of this embodiment allows the oxidation gas to be mixed into the exhaust gas discharged from the gas engine 15 in accordance with the timing of removing particles trapped in the filter 23, thereby increasing the concentration of oxygen contained in the exhaust gas flowing into the oxidation catalyst reaction device 16. This prevents a shortage of oxygen for oxidizing carbon monoxide in the oxidation catalyst reaction device 16. This prevents an increase in the concentration of carbon monoxide contained in the treated gas obtained after treating the exhaust gas with the oxidation catalyst reaction device 16.

[0083] In addition, in this embodiment, the oxidation gas supply device 40 is capable of mixing the oxidation gas with the exhaust gas at a position upstream of the oxidation catalyst reaction device 16 in the direction in which the exhaust gas flows from the gas engine 15 toward the oxidation catalyst reaction device 16.

[0084] This configuration allows the oxidation gas to be mixed with the exhaust gas before it flows into the oxidation catalyst reaction device 16. This makes it possible to supply exhaust gas containing a sufficient amount of oxygen to the oxidation catalyst reaction device 16. This prevents a shortage of oxygen used to oxidize carbon monoxide in the oxidation catalyst reaction device 16. This makes it possible to more reliably suppress an increase in the concentration of carbon monoxide contained in the exhaust gas treated by the oxidation catalyst reaction device 16.

[0085] In this embodiment, the control device 30 outputs a removal signal related to the removal of particles when removing particles trapped on the filter 23. The control device 30 has an oxidation gas supply control unit 32 that controls the operation of the oxidation gas supply device 40 when the removal signal is detected so as to mix the oxidation gas into the exhaust gas.

[0086] The oxidation gas can be supplied to the exhaust gas generated by the gas engine 15 at the same time as the amount of pyrolysis gas supplied to the gas engine 15 temporarily increases due to the removal of particles trapped on the filter 23. This makes it possible to suppress an increase in the concentration of carbon monoxide contained in the treated gas obtained after the exhaust gas is treated by the oxidation catalyst reaction device 16.

[0087] Moreover, this embodiment further includes a clogging detection unit 28 that detects clogging of the filter 23. When the clogging detection unit 28 detects clogging of the filter 23, the control device 30 generates a removal signal.

[0088] With this configuration, when the clogging detection unit 28 detects clogging of the filter 23, the control device 30 can generate a removal signal and output it to the particle removal mechanism 25. This allows particles to be removed from the clogged filter 23 at an appropriate timing.

[0089] In addition, in this embodiment, the particle removal mechanism 25 is configured to perform particle removal operation by deforming the filter 23 in a direction intersecting the direction in which the pyrolysis gas flows toward the gas engine 15.

[0090] As described above, when the filter 23 is deformed in a direction intersecting the flow direction of the pyrolysis gas as part of the particle removal operation by the particle removal mechanism 25, the flow rate of the pyrolysis gas passing through the filter 23 increases rapidly. In this case, the amount of carbon monoxide contained in the pyrolysis gas supplied to the gas engine 15 also increases, causing the gas engine 15 to generate exhaust gas containing a high concentration of carbon monoxide. As a result, the oxidation catalyst reaction device 16 to which the exhaust gas is supplied temporarily experiences a shortage of oxygen for oxidizing carbon monoxide. As a result, the concentration of carbon monoxide contained in the treated gas obtained after the exhaust gas is treated by the oxidation catalyst reaction device 16 increases.

[0091] In contrast to this, in this embodiment, by mixing an oxidation gas into the exhaust gas in accordance with the timing of removing particles trapped on the filter 23, it is possible to increase the concentration of oxygen contained in the exhaust gas flowing into the oxidation catalyst reaction device 16. This makes it possible to prevent a shortage of oxygen for oxidizing carbon monoxide in the oxidation catalyst reaction device 16. Therefore, it is possible to suppress an increase in the concentration of carbon monoxide contained in the treated gas obtained after the exhaust gas is treated by the oxidation catalyst reaction device 16.

[0092] [Embodiment 2] 7 is a diagram showing a schematic configuration of a woody biomass gas combustion facility 100 according to embodiment 2. The woody biomass gas combustion facility 100 according to this embodiment differs from the configuration of the woody biomass gas combustion facility 1 according to embodiment 1 in that a removal signal is input from the drive unit 27 of the particle removal mechanism 25 to the oxidizing gas supply control unit 32. Below, the same components as those in embodiment 1 are assigned the same reference numerals and their explanations are omitted, and only the differences from the configuration of embodiment 1 will be described.

[0093] As shown in Fig. 7, the control device 130 has an oxidation gas supply control unit 32. The control device 130 does not have a particle removal control unit. That is, a particle removal control unit that generates a removal signal as in the first embodiment is provided separately from the control device 130. The particle removal control unit may be provided integrally with the drive unit 27 of the particle removal mechanism 25, for example, or may be provided in the gas filter 20. Note that Fig. 7 schematically illustrates the configuration of a woody biomass gas combustion facility 100 in which the particle removal control unit is provided integrally with the drive unit 27 of the particle removal mechanism 25.

[0094] In the example shown in FIG. 7 , a clogging detection signal is input from the clogging detection unit 28 to the drive unit 27. Also in the example shown in FIG. 7 , a removal signal generated by the drive unit 27 based on the clogging detection signal is input from the drive unit 27 to the oxidation gas supply control unit 32 of the control device 130. When the oxidation gas supply control unit 32 detects the removal signal, it generates a supply signal and outputs the supply signal to the valve 42 of the oxidation gas supply device 40. When the supply signal is input, the valve 42 opens. Thus, the oxidation gas supply device 40 supplies oxidation gas to the exhaust gas discharged from the gas engine 15 and supplied to the oxidation catalytic reaction device 16. The oxidation gas supply control unit 32 may detect a drive signal output from the drive unit 27 instead of the removal signal and generate the supply signal. The drive signal is a signal for driving the drive unit 27.

[0095] Based on the removal signal, the driving unit 27 moves downward the rod 26b of the particle removal mechanism 25 of the gas filter 20. That is, based on the removal signal, the particle removal mechanism 25 performs a particle removal operation to remove particles trapped in the gas filter 20.

[0096] As described above, in the woody biomass gas combustion facility 100 of this embodiment, when the particle removal mechanism 25 performs the particle removal operation, the oxidation gas supply device 40 can supply oxidation gas to the exhaust gas discharged from the gas engine 15 and supplied to the oxidation catalytic reaction device 16. Therefore, the oxidation catalytic reaction device 16 can oxidize carbon monoxide contained in the exhaust gas by the oxidation gas. Therefore, when the particle removal mechanism 25 removes particles trapped in the filter 23, a sudden increase in the concentration of carbon monoxide contained in the treated gas discharged from the oxidation catalytic reaction device 16 can be prevented.

[0097] Furthermore, with the configuration of this embodiment, the oxidation gas supply control unit 32 can control the supply of oxidation gas to the exhaust gas discharged from the gas engine 15 based on the removal signal output from the particle removal mechanism 25. Therefore, when the particle removal mechanism 25 performs the particle removal operation, the oxidation gas can be more reliably mixed into the exhaust gas.

[0098] [Embodiment 3] 8 is a diagram showing a schematic configuration of a woody biomass gas combustion facility 200 according to embodiment 3. The woody biomass gas combustion facility 200 of this embodiment differs from the configuration of the woody biomass gas combustion facility 1 of embodiment 1 in that the oxidizing gas supply control unit 32 generates a supply signal based on a removal detection signal output from the clogging detection unit 128 and outputs the supply signal to the valve 42 of the oxidizing gas supply device 40. Below, the same components as those of embodiment 1 are assigned the same reference numerals and their description will be omitted, and only the differences from the configuration of embodiment 1 will be described.

[0099] 8, the clogging detection unit 128 generates and outputs a clogging detection signal when it detects clogging of the filter 23 of the gas filter 20, as in the first embodiment, and generates and outputs a removal detection signal when it unclogs the filter 23 of the gas filter 20. The clogging detection unit 128 detects clogging and unclogging of the filter 23, for example, from the difference in pressure between the upstream side and the downstream side of the filter 23. In this way, the clogging detection unit 128 also functions as a particle removal detection unit that detects the removal of particles trapped in the filter 23.

[0100] The removal detection signal output from the clogging detection unit 128 is input to the oxidation gas supply control unit 32 of the control device 130. When the oxidation gas supply control unit 32 detects the removal detection signal, it generates a supply signal and outputs the supply signal to the valve 42 of the oxidation gas supply device 40. When the supply signal is input, the valve 42 opens. Therefore, the oxidation gas supply device 40 mixes the oxidation gas with the exhaust gas discharged from the gas engine 15 and supplied to the oxidation catalytic reaction device 16.

[0101] 8, although not shown, a removal signal is input to the drive unit 27 of the particle removal mechanism 25 when the filter 23 becomes clogged. The removal signal may be generated, for example, by a particle removal control unit (not shown) or by the control device 130.

[0102] With the configuration of this embodiment, the oxidation gas supply control unit 32 can control the supply of oxidation gas to the exhaust gas emitted from the gas engine 15 based on the removal detection signal output from the clogging detection unit 128.

[0103] In this embodiment, the woody biomass gas combustion facility 200 has a clogging detection unit 128 that detects the removal of the particles from the filter 23 by the particle removal mechanism 25. When the clogging detection unit 128 detects the removal of the particles from the filter 23 by the particle removal mechanism 25, the control device 130 controls the operation of the oxidation catalyst reaction device 16 so as to mix the oxidation gas with the exhaust gas.

[0104] When removal of the particles trapped on the filter 23 is detected, an oxidation gas can be mixed with the exhaust gas generated by the gas engine 15. This makes it possible to more reliably suppress an increase in the concentration of carbon monoxide contained in the treated gas obtained after treating the exhaust gas with the oxidation catalyst reaction device 16.

[0105] [Other embodiments] Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiments, and it is possible to appropriately modify the above-described embodiments within the scope of the spirit of the present invention.

[0106] In each of the above embodiments, the oxidation gas supply device 40 supplies an oxidation gas, which is a gas containing oxygen, to the exhaust gas discharged from the gas engine 15 and supplied to the oxidation catalytic reaction device 16. However, the oxidation gas supply device may also supply the oxidation gas to the pyrolysis gas generated in the reformer 13 and passed through the gas filter 20.

[0107] In each of the above embodiments, particle removal mechanism 25 moves rod 26b downward using drive unit 27 to contract filter 23 in the up-down direction, and then moves rod 26b upward using drive unit 27 to return filter 23 to its original length. However, the particle removal mechanism may extend the filter in the up-down direction or vibrate the filter. In other words, the particle removal mechanism may have any configuration as long as it is capable of removing particles trapped in filter 23.

[0108] In each of the above-described embodiments, the particle removal mechanism 25 performs a particle removal operation to remove particles trapped in the filter 23 based on a removal signal generated in response to clogging of the filter 23. However, the particle removal mechanism may perform the particle removal operation based on a removal signal generated at predetermined time intervals.

[0109] In the third embodiment, the clogging detection unit 28 functions as a particle removal detection unit that detects the removal of particles from the filter 23. However, the particle removal detection unit may be a displacement sensor that detects the upward displacement of the filter, or a flow rate sensor that detects the flow rate downstream of the filter. In other words, the particle removal detection unit may have any configuration as long as it is capable of detecting that particles trapped in the filter have been removed by the particle removal mechanism. [Industrial Applicability]

[0110] INDUSTRIAL APPLICABILITY The present invention can be used in woody biomass gas combustion facilities that combust pyrolysis gas obtained by pyrolysis of woody biomass. [Explanation of symbols]

[0111] 1, 100, 200 Wood biomass gas combustion equipment 11 Storage 12 Funnel 13 Reformer (gasifier) 14 Heat exchanger 15 Gas engine (combustion device) 16. Oxidation catalytic reaction device (exhaust gas treatment device) 20 Gas Filter 21 Filter case 21a Tapered section 21b Inlet 21c Outlet 23 Filters 25 Particle removal mechanism 26a Filter upper connection 26b Rod 27 Drive unit 28, 128 Clogging detection unit 30, 130 Control device 31 Particle removal control unit 32 Oxidizing gas supply control unit 40 Oxidizing gas supply device 41 Gas Tank 42 Valves V space

Claims

1. a gasification device that generates pyrolysis gas by pyrolyzing woody biomass; a filter for collecting particles in the pyrolysis gas; a combustion device that combusts the pyrolysis gas that has passed through the filter; A wood biomass gas combustion facility having: an exhaust gas treatment device that oxidizes carbon monoxide contained in exhaust gas generated by combustion of the pyrolysis gas by the combustion device; a particle removal mechanism that performs a particle removal operation to remove the particles trapped in the filter; an oxidation gas supply device that mixes an oxidation gas containing oxygen with the exhaust gas or the pyrolysis gas that has passed through the filter; a control device that controls the operation of the oxidation gas supply device so that the oxidation gas is mixed with the exhaust gas or the pyrolysis gas that has passed through the filter when the particle removal mechanism performs the particle removal operation; and having Wood biomass gas combustion equipment.

2. The wood biomass gas combustion facility according to claim 1, the oxidation gas supply device is capable of mixing the oxidation gas with the exhaust gas at a position upstream of the exhaust gas treatment device in a direction in which the exhaust gas flows from the combustion device toward the exhaust gas treatment device. Wood biomass gas combustion equipment.

3. The wood biomass gas combustion facility according to claim 1 or 2, the particle removal mechanism or the control device outputs a removal signal related to the removal of the particles when removing the particles trapped in the filter; The control device an oxidation gas supply control unit that controls the operation of the oxidation gas supply device so that the oxidation gas is mixed with the exhaust gas or the pyrolysis gas that has passed through the filter when the removal signal is detected; Wood biomass gas combustion equipment.

4. The wood biomass gas combustion facility according to claim 3, The device further includes a clogging detection unit that detects clogging of the filter, the control device generates the removal signal when the clogging detection unit detects clogging of the filter. Wood biomass gas combustion equipment.

5. The wood biomass gas combustion facility according to claim 1 or 2, a particle removal detection unit that detects removal of the particles from the filter by the particle removal mechanism; When the particle removal detection unit detects that the particles have been removed from the filter by the particle removal mechanism, the control device controls the operation of the oxidation gas supply device so as to mix the oxidation gas with the exhaust gas or the pyrolysis gas that has passed through the filter. Wood biomass gas combustion equipment.

6. A woody biomass gas combustion method in which pyrolysis gas obtained by pyrolyzing woody biomass is combusted in a combustion device, an exhaust gas treatment step of oxidizing carbon monoxide contained in exhaust gas generated by combustion of the pyrolysis gas by the combustion device; a particle removal step of removing particles from a filter that collects particles in the pyrolysis gas supplied to the combustion device; an oxidation gas supply step of mixing an oxidation gas containing oxygen with the exhaust gas or the pyrolysis gas that has passed through the filter when the particles are removed from the filter in the particle removal step; having Wood biomass gas combustion method.

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