Gasification apparatus and gasification method

Abstract

To provide a gasification apparatus and a gasification method capable of stably gasifying wood chips.SOLUTION: A gas power generation system 1 for heating and gasifying semi-carbonized wood chips S, which are chips of woody biomass, includes a reactor column 11 that heats and gasifies the semi-carbonized wood chips S; an outlet pipe 12 that discharges generated gas Go gasified in the reactor column 11; and a cooling tank 41 that cools the generated gas Go (high-temperature gas Gh) that has flowed through the outlet pipe 12 on the downstream side of the outlet pipe 12. In addition, on the upstream side of the cooling tank 41, a high-temperature gas branching pipe 33, a linking pipe 61, and an introduction pipe 62 are provided to introduce at least part of the high-temperature gas Gh discharged from the reactor column 11 into the reactor column 11 as a gasifying agent H that promotes gasification in the reactor column 11.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gasification apparatus and a gasification method for gasifying wood chips. [Background technology]

[0002] In recent years, as environmental issues have come to the forefront, research is being conducted into power generation devices that use combustion materials generated from biomass fuels, such as naturally occurring wood chips and wood chips that have been dried or semi-carbonized, instead of using fossil fuels such as oil and coal for power generation.

[0003] As an example of a gasification apparatus that generates such combustion substances from biomass fuel, Patent Document 1 discloses a gasification apparatus in which a gasification agent such as air, carbon dioxide, or steam is supplied from a gasification agent supply port provided at the bottom of the reaction tower while biomass fuel is introduced from an inlet provided at the top of the reaction tower and heated to gasify the biomass fuel.

[0004] This gasification system is a so-called updraft type gasification system, with an outlet for discharging the product gas generated from the biomass fuel on the upper side of the reaction tower, and an ash discharge section for removing the ash of the biomass that was not gasified at the bottom. Therefore, it is said that the biomass fuel fed from the top is gasified inside the reaction tower, and the ash and biomass fuel that has not been completely gasified and has fallen down (combustion residue) can be stably removed.

[0005] However, the size and moisture content of the biomass fuel fed into the reaction tower are not uniform, and therefore the amount of heat required to gasify the biomass fuel into the desired components inside the reaction tower varies, causing fluctuations in the temperature inside the reaction tower, which may make it difficult to stably gasify the biomass fuel. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2008-101215 A Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a gasification apparatus and a gasification method capable of stably gasifying wood chips. [Means for solving the problem]

[0008] This invention is a gasification device that heats and gasifies wood chips, and is characterized in that it is provided with a reaction tower that heats and gasifies the wood chips, a discharge pipe that discharges high-temperature gas gasified in the reaction tower, and a cooling section downstream of the discharge pipe that cools the high-temperature gas that has flowed through the discharge pipe, and an introduction passage upstream of the cooling section that introduces at least a portion of the high-temperature gas discharged from the reaction tower into the reaction tower as a gasification agent that promotes gasification in the reaction tower.

[0009] The present invention also relates to a gasification method for heat-treating and gasifying wood chips, which is characterized in that, depending on the gasification conditions in a reaction tower where the wood chips are heat-treated, the high-temperature gas before being gasified in the reaction tower and released before being cooled is introduced into the reaction tower as a gasifying agent.

[0010] The wood chips include naturally occurring wood chips, dried wood chips, semi-carbonized wood chips, and the like. The semi-carbonization process refers to a carbonization process in which wood chips and other materials are heated at a specified temperature (approximately 250 to 350°C) in an oxygen-blocked state to produce a carbonized material with a high carbon content and reduced oxygen content, thereby producing a solid fuel with high energy density.

[0011] "Depending on the gasification conditions in the reaction tower in which the wood chips are heat-treated" as mentioned above includes cases in which it depends on the temperature changes inside the reaction tower and on the component ratios of the gas gasified in the reaction tower.

[0012] According to this invention, since high-temperature gas can be introduced into the reaction tower, the temperature change inside the reaction tower caused by the unevenness of the size of the wood chips fed into the reaction tower can be suppressed. Also, the temperature drop inside the reaction tower can be suppressed compared to the case where a room temperature gasification agent such as air is introduced into the reaction tower. Therefore, the temperature inside the reaction tower can be stabilized, and the wood chips can be gasified stably.

[0013] In addition, since high-temperature gas can be introduced into the reaction tower, the inside of the reaction tower can be maintained at a high temperature. This makes it possible to prevent the temperature inside the reaction tower from dropping below the thermal decomposition temperature of tar, etc., thereby making it possible to prevent clogging of the reaction tower and generation of wood chip residues.

[0014] Furthermore, the high-temperature gas introduced into the reaction tower is the gas generated inside the reaction tower. That is, the high-temperature gas is a gas whose component ratio is not significantly different from that of the gas generated inside the reaction tower. Therefore, it is possible to prevent the high-temperature gas generated inside the reaction tower from being diluted by the gasifying agent. Therefore, it is possible to suppress a decrease in the power generation efficiency of the gas generated in the reaction tower.

[0015] As an aspect of this invention, in the process of gasifying the wood chips, a plurality of reaction zones in which the gasification reactions of the wood chips are different are formed inside the reaction tower, and a plurality of inlets that communicate with the inlet passage and can introduce the high-temperature gas may be provided at locations in the reaction tower corresponding to the reaction zones.

[0016] According to the present invention, since a plurality of inlets for introducing the high-temperature gas are provided, the high-temperature gas can be introduced into the reaction tower from an inlet corresponding to the state of the reaction zone. This allows the high-temperature gas to be introduced from a desired location depending on, for example, the temperature state of each reaction zone inside the reaction tower, the state of the gasification reaction, and the component ratio of the gasified gas. This makes it possible to efficiently stabilize the temperature inside the reaction tower.

[0017] As another aspect of the present invention, a collection passage for collecting product gas obtained by cooling the high-temperature gas discharged from the discharge pipe in the cooling section, and a product gas inlet passage for introducing the product gas into the reaction tower as a gasifying agent may be provided downstream of the cooling section.

[0018] The above-mentioned introduction of the product gas into the reaction tower as a gasification agent includes the case where the product gas that has been cooled and stored from the high-temperature gas generated in the reaction tower is introduced, and the case where the product gas that has been cooled from the high-temperature gas generated in the reaction tower is circulated.

[0019] According to this invention, the product gas can be used as a gasifying agent, and therefore gasification can be performed inside the reaction tower without diluting the component concentration of the gas generated in the reaction tower, as compared to the case where other gases are used as gasifying agents. Therefore, the gasification device configured in this way can generate product gas that can generate electricity efficiently.

[0020] In addition, by using the product gas as a gasification agent, it is possible to stably generate product gas with a component ratio that is favorable for power generation efficiency inside the reaction tower. Furthermore, by generating a stable product gas, it is possible to efficiently gasify wood chips.

[0021] As another aspect of the present invention, the product gas inlet passage and the inlet passage may be connected so as to be insertable, and a flow rate adjustment unit may be provided for adjusting the flow rate of the product gas flowing through the product gas inlet passage and the high-temperature gas flowing through the inlet passage.

[0022] In another aspect of the present invention, the high-temperature gas gasified and released in the reaction tower is cooled and used as a product gas, and at least one of the high-temperature gas and the product gas may be introduced into the reaction tower as a gasifying agent depending on the gasification status of the reaction tower.

[0023] The flow rate adjusting unit not only changes the ratio of the product gas to the high-temperature gas, but also changes the flow rates of the high-temperature gas and the product gas according to the component ratio of the gas generated, i.e., changes the blending ratio of the high-temperature gas and the product gas, including adjusting so that only one of the high-temperature gas and the product gas is introduced into the reaction tower, and increases or decreases the total amount of the high-temperature gas or the product gas, or the mixed gas obtained by mixing the high-temperature gas and the product gas.

[0024] This invention allows the mixing ratio of high-temperature gas and product gas to be adjusted according to the gasification reaction in the reaction tower, so that the high-temperature gas can suppress the drop in the internal temperature of the reaction tower, and the product gas can be used as a gasification agent. Therefore, the gasification reaction in the reaction tower can be stabilized, wood chips can be efficiently gasified, and the product gas generated inside the reaction tower can have a component ratio that is efficient for power generation.

[0025] In another embodiment of the present invention, at least a portion of the product gas produced by cooling the high-temperature gas may be circulated to the reaction tower. According to the present invention, the product gas can be circulated and introduced into the reaction tower, so that the product gas can be stably produced with a simple structure.

[0026] In a further aspect of the present invention, the wood chips may be introduced into the reaction tower from below, and the high-temperature gas may be discharged from above. According to this invention, high-temperature gas can be discharged with a simple structure. Also, since wood chips are charged from below, the high-temperature gas can be reduced in the upper part of the reaction tower near the discharge pipe of the high-temperature gas. Effect of the Invention

[0027] According to the present invention, it is possible to provide a gasification apparatus and a gasification method capable of improving the gasification efficiency of wood chips. [Brief description of the drawings]

[0028] [Figure 1] Schematic diagram of a gasification system. [Diagram 2] 1 is a schematic diagram of a gasification reactor and a cyclone. [Diagram 3] 1 is a schematic diagram of a cyclone, a gas cooler, and a power generation device. [Figure 4] FIG. [Diagram 5] Schematic diagram of an electric heater tubular pyrolysis gasification furnace. [Figure 6] 1 is a correlation diagram between the temperature inside the quartz tube and the gas components generated from semi-carbonized wood chips inside the quartz tube. [Figure 7] Correlation diagram of the ratio of hydrogen to carbon monoxide against the temperature inside the quartz tube. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] An embodiment of the present invention will now be described with reference to the drawings. Fig. 1 shows a schematic diagram of the gas power generation system 1, Fig. 2 shows an enlarged schematic diagram of the gasification reaction device 10 and the cyclone 30, Fig. 3 shows an enlarged schematic diagram of the cyclone 30, the gas cooler 40 and the power generation device 50, and Fig. 4 shows a block diagram of the control unit 70. Fig. 5 shows a schematic diagram of an electric heater tubular pyrolysis gasification furnace 80, and Figs. 6 and 7 are graphs showing the correlation of the components of the lab-generated gas Gs generated from semi-carbonized wood chips S against the temperature of the quartz tube 81.

[0030] 1, the gas power generation system 1 is a gas power generation system that generates electricity in a power generation device 50 using product gas Gp obtained by gasifying semi-carbonized wood chips (hereinafter referred to as "semi-carbonized wood chips S"). Note that the gas power generation system 1 may use dried wood chips or naturally derived wood chips instead of semi-carbonized wood chips.

[0031] More specifically, in the gas power generation system 1, the semi-carbonized wood chips S are transported upward from the bottom of a reaction tower 11, which is a substantially cylindrical vertical container, and then the semi-carbonized wood chips S are gasified in the reaction tower 11, which has an increased internal temperature. The product gas Go (carbon monoxide, hydrogen, etc.) generated by this gasification is sent from a discharge pipe 12 provided above the reaction tower 11 to a cyclone 30 and a gas cooler 40, and is generated as product gas Gp. The product gas Gp generated in this manner is used as fuel for power generation in a power generation device 50.

[0032] The structure of the gas power generation system 1 and gasification of semi-carbonized wood chips S using the gas power generation system 1 will be described below. As shown in FIG. 1, the gas power generation system 1 is composed of a gasification reaction apparatus 10 that gasifies semi-carbonized wood chips S, a transport device 20 that transports the semi-carbonized wood chips S, which are the raw material for gasification, to the gasification reaction apparatus 10, a cyclone 30 that refines the generated gas Go generated in the gasification reaction apparatus 10, a gas cooler 40 that cools the high-temperature gas Gh refined in the cyclone 30, a power generation apparatus 50 that generates power using the product gas Gp cooled in the gas cooler 40, an air supply section 60 that supplies a gasifying agent H to the gasification reaction apparatus 10, and a control section 70 that controls the generation of the generated gas Go in the gasification reaction apparatus 10.

[0033] The gasification reaction device 10 is of the so-called updraft type, which gasifies the semi-carbonized wood chips S by pyrolysis, combustion, and reduction, and collects the generated gas Go from above. Such a gasification reaction apparatus 10 includes a reaction tower 11 for gasifying the semi-carbonized wood chips S, and a discharge pipe 12 for discharging the product gas Go generated in the reaction tower 11. The reaction tower 11 is provided at its bottom and side with a gasification agent supply port 13 for supplying a gasification agent H. The reaction tower 11 is also provided inside with a heater 14 for increasing the internal temperature of the reaction tower 11, a temperature sensor 15 for detecting the internal temperature of the reaction tower 11, and a storage amount detection sensor 16 for detecting the amount of semi-carbonized wood chips S stored inside the reaction tower 11.

[0034] The reaction tower 11 is a vertical vessel having a substantially cylindrical shape, and the bottom portion is configured in a conical shape tapering downward. The apex of the cone is provided with an insertion hole for connecting to a vertical transport pipe 231, which will be described later. In addition, an ash discharge section (not shown) is provided at the bottom of the reaction tower 11 for scraping out the residue and ash that remain from the semi-carbonized wood chips S that have not been completely gasified to the outside.

[0035] The inside of the reaction tower 11 can be heated by using the heater 14. The inside of the reaction tower 11 heated by the heater 14 in this manner has a plurality of reaction zones T for gasifying the semi-carbonized wood chips S. More specifically, the inside of the reaction tower 11 has three reaction zones T formed in this order from bottom to top: a pyrolysis zone T1 for pyrolyzing the semi-carbonized wood chips S, a combustion zone T2 for causing a combustion reaction, and a reduction zone T3 for causing a reduction reaction (see FIG. 2).

[0036] The discharge pipe 12 is a pipe for discharging the product gas Go generated inside the reaction tower 11 to the outside, and is provided at the top of the reaction tower 11. A cyclone 30 for removing foreign matter from the generated gas Go is connected to the tip of the discharge pipe 12. A part of the discharge pipe 12 is branched off, and a gas analyzer (not shown) for analyzing the components of the generated gas Go is attached to it. If the generated gas Go does not have the desired component ratio, the generated gas Go is not sent to the cyclone 30 and is discharged.

[0037] The gasifying agent supply inlet 13 is an opening for supplying the gasifying agent H from the outside into the inside of the reaction tower 11, and as shown in FIG. 2, has a first supply inlet 131 provided at a position corresponding to the pyrolysis zone T1 in the reaction tower 11, a second supply inlet 132 provided at a position corresponding to the combustion zone T2 in the reaction tower 11, a third supply inlet 133 provided at a position corresponding to the reduction zone T3 in the reaction tower 11, and a fourth supply inlet 134 provided at the bottom of the reaction tower 11.

[0038] The heater 14 is a heating device for increasing the temperature inside the reaction tower 11. The heater 14 may also be used to increase the internal temperature of the reaction tower 11 when generating the product gas Go, based on the temperature detection result by the temperature sensor 15. The temperature sensor 15 detects the internal temperature of the reaction tower 11. The detection result detected by the temperature sensor 15 is transmitted to a temperature control unit 71 described later.

[0039] The storage amount detection sensor 16 detects the amount of semi-carbonized wood chips S accumulated inside the reaction tower 11. Specifically, inside the reaction tower 11, it detects whether the accumulated semi-carbonized wood chips S are lower or higher than a desired height, specifically the height corresponding to the combustion zone T2 in the reaction tower 11.

[0040] The conveying device 20 is composed of a surge tank 21 that stores the semi-carbonized wood chips S to be conveyed to the gasification reactor 10, an upstream conveying path 22 that conveys the semi-carbonized wood chips S from the surge tank 21 to the gasification reactor 10, and a vertical conveying path 23 that conveys the semi-carbonized wood chips S to the reaction tower 11.

[0041] The surge tank 21 is composed of a surge tank body 211 that stores the semi-carbonized wood chips S, a supply pipe 212 connected to the lower end of the surge tank body 211, and a rotary valve 213 attached between the surge tank body 211 and the supply pipe 212 (see Figure 1).

[0042] The supply pipe 212 is a tubular conveying path. One end is connected to the fuel inlet provided at the lower end of the tapered surge tank body 211 via the rotary valve 213, and the other end is connected to the upstream conveying path 22.

[0043] Note that the semi-carbonized wood chips S stored in the surge tank body 211 are carbides with a high carbon content obtained by thermally decomposing woody biomass such as cedar at a high temperature of 200°C to 350°C under an oxygen-free condition. These semi-carbonized wood chips S have a high energy density per unit weight and good pulverization performance.

[0044] As shown in Figures 1 and 2, the upstream conveying path 22 is composed of an upstream conveying pipe 221 configured in a tubular shape, an upstream screw blade 222 installed inside the upstream conveying pipe 221, and an upstream rotation motor 223 that rotationally drives the upstream screw blade 222.

[0045] The upstream conveying pipe 221 is a tubular body that is erected in the vertical direction and has a curved tip toward the reaction tower 11. An inlet that is connected to the tip of the supply pipe 212 is provided on the side of the upstream conveying pipe 221, and the semi-carbonized wood chips S are fed from the supply pipe 212. The tip of the upstream conveying pipe 221 is connected to a vertical conveying pipe 231 that constitutes the vertical conveying path 23, and the semi-carbonized wood chips S can be fed to the tip side. An upstream rotary motor 223 that rotates the upstream screw blade 222 is provided at the upper end of the upstream conveying pipe 221.

[0046] The upstream screw blade 222 is a blade used in a so-called spring conveyor that is formed in a spiral shape and can rotate while bending, and extends along the upstream conveying pipe 221 from the upper end to the center of the upstream conveying pipe 221.

[0047] The vertical conveying path 23 is composed of a tubular vertical conveying pipe 231, a vertical screw blade 232 installed inside the vertical conveying pipe 231, and a downstream rotary motor 233 that drives the vertical screw blade 232 to rotate. The vertical transport pipe 231 is a tubular body that stands upright along the vertical direction, and is disposed below the reaction tower 11. The vertical transport pipe 231 is connected to the side of the central part so as to be perpendicular to the tip of the upstream transport pipe 221.

[0048] The vertical screw blade 232 installed inside the vertical conveying pipe 231 is a so-called screw feeder that is formed in a spiral shape along the vertical direction and rotates around an axis along the vertical direction. The lower end of this vertical screw blade 232 is connected to a downstream rotation motor 233 provided at the lower end of the vertical conveying pipe 231, and can freely rotate inside the vertical conveying pipe 231.

[0049] The vertical conveying path 23 thus constructed is disposed below the reaction tower 11, and the upper end of the vertical conveying pipe 231 is connected to the insertion hole of the reaction tower 11, so that the semi-carbonized wood chips S stored in the surge tank 21 can be conveyed into the reaction tower 11. The upper end of the vertical screw blade 232 installed inside the vertical conveying pipe 231 is exposed so as to protrude upward from the bottom of the reaction tower 11.

[0050] The cyclone 30 is composed of a cyclone tank 31 connected to the discharge pipe 12, a first gas supply pipe 32 that sends the high-temperature gas Gh crudely refined in the cyclone tank 31 to the gas cooler 40, and a high-temperature gas branch pipe 33 branched off from the first gas supply pipe 32. In addition, at the branch point between the first gas supply pipe 32 and the high-temperature gas branch pipe 33, a first switching unit 34 is provided to adjust the amount of high-temperature gas Gh flowing through the first gas supply pipe 32 and the high-temperature gas branch pipe 33.

[0051] The cyclone tank 31 can use centrifugal force to remove impurities such as dust from the generated gas Go sent from the discharge pipe 12, and can roughly refine the generated gas Go into high-temperature gas Gh. The temperature of the high-temperature gas Gh crudely refined in the cyclone tank 31 is about 300°C.

[0052] The first gas supply pipe 32 is a hollow discharge pipe extending from the upper part of the cyclone vessel 31 and serves to supply the high-temperature gas Gh produced in the cyclone vessel 31 toward the gas cooler 40. The high temperature gas branch pipe 33 is a pipe branched off from the first gas supply pipe 32 and has a tip connected to the gas supply section 60, and supplies high temperature gas Gh to the gas supply section 60. At the branch point between the first gas supply pipe 32 and the high temperature gas branch pipe 33, a first switching unit 34, which is an adjustment valve for adjusting the flow rate of the high temperature gas Gh supplied to the first gas supply pipe 32 and the high temperature gas branch pipe 33, is provided. The first switching unit 34 is configured to be able to freely open and close the flow path between the first gas supply pipe 32 and the high temperature gas branch pipe 33.

[0053] 3, the gas cooler 40 is composed of a cooling tank 41 that cools the high-temperature gas Gh sent through the first gas supply pipe 32 to generate product gas Gp, a product gas supply pipe 42 for sending the product gas Gp generated in the cooling tank 41 to the power generation device 50, and a product gas branch pipe 43 branched off from the product gas supply pipe 42. In addition, at the branch point between the product gas supply pipe 42 and the product gas branch pipe 43, a second switch unit 44 for adjusting the amount of high-temperature gas Gh flowing through the product gas supply pipe 42 and the product gas branch pipe 43 is provided.

[0054] The cooling tank 41 is a cooling tank for cooling the high-temperature gas Gh crudely produced in the cyclone tank 31. By cooling, tar and the like are removed from the high-temperature gas Gh, and the high-temperature gas Gh is converted into product gas Gp. The product gas supply pipe 42 is a pipe for supplying the product gas Gp cooled inside the cooling tank 41 toward the power generation device 50, and extends from the bottom of the cooling tank 41. In addition, a product gas analyzer 45 for analyzing the components of the product gas Gp is ​​attached to the product gas supply pipe 42.

[0055] The product gas branch pipe 43 is a pipe that branches off from the product gas supply pipe 42 and supplies the product gas Gp towards the supply section 60, and its tip is connected to the supply section 60. At the branch point between the product gas supply pipe 42 and the product gas branch pipe 43, a second switching unit 44 is provided which is an adjustment valve that adjusts the flow rate of the product gas Gp supplied to the product gas supply pipe 42 and the product gas branch pipe 43. The second switching unit 44 is configured to be able to freely open and close the flow path between the product gas delivery pipe 42 and the product gas branch pipe 43 .

[0056] The gas supply section 60 is composed of a connecting pipe 61 connected to the ends of the high-temperature gas branch pipe 33 and the product gas branch pipe 43, an introduction pipe 62 that supplies the gas flowing into the connecting pipe 61 to the inside of the reaction tower 11, and a third switching section 63 that adjusts the flow rate of the high-temperature gas Gh and product gas Gp flowing into the connecting pipe 61.

[0057] The connecting pipe 61 is a pipe that is insertably connected to the first air supply pipe 32 and the product gas supply pipe 42, and extends toward the reaction tower 11. That is, the high-temperature gas branch pipe 33 branched off from the first air supply pipe 32 and the product gas branch pipe 43 branched off from the product gas supply pipe 42 join at the base end of the connecting pipe 61. In addition, a third switching section 63 is provided at the base end of the connecting pipe 61.

[0058] The third switching unit 63 is an adjustment valve that adjusts the flow rate of the high temperature gas Gh flowing through the high temperature gas branch pipe 33 and the product gas Gp flowing through the product gas branch pipe 43, and is configured to freely open and close the flow path between the high temperature gas branch pipe 33 and the product gas branch pipe 43 and the connecting pipe 61. This third switching unit 63 not only changes the ratio of the high temperature gas Gh flowing through the high temperature gas branch pipe 33 and the product gas Gp flowing through the product gas branch pipe 43, but can also increase or decrease the flow rates of the high temperature gas Gh and the product gas Gp by, for example, changing the cross-sectional areas of the high temperature gas branch pipe 33 and the product gas branch pipe 43 through which the high temperature gas Gh and the product gas Gp flow.

[0059] The introduction pipe 62 is an air supply pipe branched off from the connecting pipe 61 and communicates with the reaction tower 11. Specifically, the introduction pipe 62 is a pipe connected from the tip of the connecting pipe 61 to a desired location in the reaction tower 11. More specifically, the introduction pipe 62 is composed of a first insertion pipe 621 connected to the first supply port 131, a second insertion pipe 622 connected to the second supply port 132, a third insertion pipe 623 connected to the third supply port 133, and a bottom insertion pipe 624 connected to the fourth supply port 134.

[0060] The first insertion pipe 621 is an insertion pipe that is insertably connected to the first supply port 131 provided at a position corresponding to the pyrolysis zone T1 in the reaction tower 11. The first insertion pipe 621 configured in this manner can introduce the high-temperature gas Gh and the product gas Gp flowing through the connecting pipe 61 as the gasifying agent H to the pyrolysis zone T1 in the reaction tower 11 via the first supply port 131.

[0061] The second insertion pipe 622 is an insertion pipe that is insertably connected to the second supply port 132 provided at a position corresponding to the combustion zone T2 in the reaction tower 11. The second insertion pipe 622 can introduce the high-temperature gas Gh and the product gas Gp flowing through the connecting pipe 61 as a gasifying agent H to the combustion zone T2 in the reaction tower 11 via the second supply port 132.

[0062] The third insertion pipe 623 is an insertion pipe that is insertably connected to the third supply port 133 provided at a position corresponding to the reduction zone T3 in the reaction tower 11. The third insertion pipe 623 configured in this manner can introduce the high-temperature gas Gh and the product gas Gp flowing through the connecting pipe 61 as the gasifying agent H to the reduction zone T3 in the reaction tower 11 via the third supply port 133.

[0063] The bottom insertion pipe 624 is an insertion pipe that is insertably connected to the fourth supply port 134 provided at the bottom of the reaction tower 11, and the high-temperature gas Gh and product gas Gp flowing through the connecting pipe 61 via the fourth supply port 134 can be introduced as gasification agent H from the bottom of the reaction tower 11.

[0064] The introduction pipe 62 from which the first insertion pipe 621, the second insertion pipe 622, the third insertion pipe 623 and the bottom insertion pipe 624 branch off is provided with a gasifying agent regulating valve 625 at each branch point. The gasifying agent regulating valve 625 is a regulating valve for regulating the location and amount of the high temperature gas Gh and the product gas Gp flowing through the connecting pipe 61 to a predetermined location in the reaction tower 11. In other words, the location and flow rate of the high temperature gas Gh and the product gas Gp flowing through the connecting pipe 61 to be introduced are controlled by the gasifying agent regulating valve 625.

[0065] As shown in FIG. 4, the control unit 70 includes a temperature control unit 71 that controls the heater 14, a high-temperature gas control unit 72 that controls the first switching unit 34, a circulation control unit 73 that controls the second switching unit 44, a flow rate adjustment control unit 74 that controls the third switching unit 63, and a flow path control unit 75 that controls the gasifying agent regulating valve 625.

[0066] The temperature control unit 71 controls the heater 14 based on, for example, the set temperature inside the reaction tower 11 or a temperature change inside the reaction tower 11 detected by the temperature sensor 15. This allows the internal temperature of the reaction tower 11 to be adjusted to a temperature suitable for gasifying the semi-carbonized wood chips S.

[0067] The high-temperature gas control unit 72 controls the opening and closing of the first switching unit 34 based on, for example, the internal temperature of the reaction tower 11 detected by the temperature sensor 15, and switches the flow rate of the high-temperature gas Gh sent to the first gas supply pipe 32 and the high-temperature gas branch pipe 33. Specifically, when the internal temperature of the reaction tower 11 drops from a desired temperature, the first switching unit 34 is adjusted so that a part of the high-temperature gas Gh flowing in the first gas supply pipe 32 flows into the high-temperature gas branch pipe 33.

[0068] The circulation control unit 73 controls the opening and closing of the second switching unit 44 based on the components of the product gas Gp analyzed by the product gas analyzer 45, and switches the flow rate of the product gas Gp sent to the product gas delivery pipe 42 and the product gas branch pipe 43. For example, when the ratio of hydrogen to carbon monoxide in the product gas Gp analyzed by the product gas analyzer 45 has decreased from a desired ratio, the first switching unit 34 is adjusted to increase the flow rate of the product gas Gp flowing through the product gas branch pipe 43.

[0069] In this embodiment, the circulation control unit 73 controls the opening and closing of the second switching unit 44 based on the components of the product gas Gp analyzed by the product gas analyzer 45, but the second switching unit 44 may also be controlled to open and close based on the power generation efficiency of the power generation device 50. For example, when the power generation efficiency of the power generation device 50 decreases, the second switching unit 44 may be controlled so that more product gas Gp flows into the product gas branch pipe 43.

[0070] The flow rate adjustment control unit 74 controls the opening and closing of the third switching unit 63 based on the internal temperature of the reaction tower 11 detected by the temperature sensor 15 and the components of the product gas Gp analyzed by the product gas analyzer 45. In this way, the flow rate adjustment control unit 74 controls the flow rates of the high-temperature gas Gh and the product gas Gp sent to the connecting pipe 61. For example, when the ratio of hydrogen to carbon monoxide in the product gas Gp analyzed by the product gas analyzer 45 is decreasing, the third switching unit 63 is adjusted so that the flow rate of the product gas Gp flowing through the connecting pipe 61 is increased. On the other hand, when the internal temperature of the reaction tower 11 is lower than the desired temperature, the third switching unit 63 is adjusted so that the flow rate of the high-temperature gas Gh flowing through the connecting pipe 61 is increased.

[0071] The flow path control unit 75 selects multiple gasifying agent supply ports 13 (first supply port 131 to fourth supply port 134) for introducing the product gas Gp, which is the gasifying agent H, and the high-temperature gas Gh, based on the internal temperature of the reaction tower 11 detected by the temperature sensor 15 and the components of the product gas Gp analyzed by the product gas analyzer 45, and controls the opening and closing of the gasifying agent adjustment valve 625 so as to introduce the gasifying agent H from the desired gasifying agent supply port 13.

[0072] Next, a method for generating product gas Gp using the gas power generation system 1 configured as described above will be briefly described. First, the semi-carbonized wood chips S crushed to a predetermined size are stored in the surge tank 21. Next, the internal temperature of the reaction tower 11 is raised to a desired temperature (800°C), and then the upstream screw blade 222 installed in the upstream conveying pipe 221 and the upstream rotary motor 223 installed in the vertical conveying pipe 231 are rotated. As a result, the semi-carbonized wood chips S introduced from the surge tank body 211 into the upstream conveying pipe 221 are introduced into the reaction tower 11 from the bottom of the reaction tower 11 while being crushed inside the upstream conveying pipe 221 and the vertical conveying pipe 231.

[0073] In this way, the semi-carbonized wood chips S fed from the conveying device 20 into the reaction tower 11 are gasified in the heated reaction tower 11. In detail, by feeding the semi-carbonized wood chips S from the bottom of the reaction tower 11, a pyrolysis reaction occurs in the pyrolysis zone T1 and a combustion reaction occurs in the combustion zone T2. Also, a reduction reaction occurs in the reduction zone T3, and a high-temperature product gas Go containing mainly low hydrocarbons such as carbon monoxide, carbon dioxide, hydrogen, and methane is produced from the semi-carbonized wood chips S (see FIG. 2).

[0074] The product gas Go generated inside the reaction tower 11 is sent to the cyclone 30 through the discharge pipe 12 provided above the reaction tower 11, and becomes high-temperature gas Gh from which foreign matter has been removed in the cyclone tank 31 (see FIG. 2). The high-temperature gas Gh thus produced is a high-temperature gas of approximately 300°C. The generated gas Go flowing out from the discharge pipe 12 is analyzed for its components by a gas analyzer installed in the discharge pipe 12, and when the components of the generated gas Go do not have the desired ratio, such as in the early stages of the reaction, the generated gas Go is exhausted to the outside.

[0075] Next, the high-temperature gas Gh crudely refined in the cyclone tank 31 is sent to the gas cooler 40 via the first gas supply pipe 32, and is cooled in the cooling tank 41 to become a product gas Gp from which foreign matter such as tar has been removed (see FIG. 3). The product gas Gp thus generated in the cooling tank 41 is sent to the power generation device 50 via the product gas supply pipe 42, and is used as power generation gas in the power generation device 50.

[0076] At this time, a part of the product gas Gp sent to the power generation device 50 through the product gas sending pipe 42 is sent to the connecting pipe 61 through the product gas branch pipe 43, and is introduced as a gasifying agent H from the fourth supply port 134 through the introduction pipe 62 into the reaction tower 11. By circulating the product gas Gp as the gasifying agent H and introducing it into the reaction tower 11 in this way, it is possible to generate a generated gas Go with higher power generation efficiency inside the reaction tower 11.

[0077] Hereinafter, the fact that the generated gas Go can be generated with higher power generation efficiency inside the reaction tower 11 will be described using the results of laboratory tests. The laboratory experiment was carried out using an electric heater tubular pyrolysis gasifier 80, as shown in Fig. 5. The electric heater tubular pyrolysis gasifier 80 is composed of a hollow quartz tube 81, an electric heating unit 82 that adjusts the internal temperature of the quartz tube 81, a gasifying agent supply unit 83 that supplies a laboratory gasifying agent to the inside of the quartz tube 81, a gas pack 84 that collects the laboratory generated gas Gs generated in the quartz tube 81 for analysis, and a laboratory gas analyzer 85 that analyzes the components of the laboratory generated gas Gs collected in the gas pack 84.

[0078] The quartz tube 81 is a tubular body made of quartz, and is configured to store approximately 100 mg of semi-carbonized wood chips S. One end of the quartz tube 81 is connected to a tube that can be connected to a gasifying agent supply unit 83, and the other end of the quartz tube 81 is connected to a tube that sends gas generated inside the quartz tube 81 to a gas pack 84. The electric heating unit 82 is an electric heater for raising the temperature of the quartz tube 81 from the outside of the quartz tube 81, and is controlled so that the temperature inside the quartz tube 81 can be raised at 400° C. / hour.

[0079] The gasifying agent supply unit 83 is a cylinder filled with gas to be introduced into the quartz tube 81 as a lab gasifying agent, and is provided with an air cylinder 831 filled with air and a gas cylinder 832 filled with product gas Gp. The flow rate of the lab gasifying agent introduced from the gasifying agent supply unit 83 into the quartz tube 81 is controlled to be constant.

[0080] Using the electric heater tubular pyrolysis gasification furnace 80 configured in this manner, the components of the lab-generated gas Gs generated from the semi-carbonized wood chips S in the quartz tube 81 were analyzed. Below, the method for generating the laboratory-generated gas Gs from the semi-carbonized wood chips S and the component analysis of the laboratory-generated gas Gs will be described in detail.

[0081] First, semi-carbonized wood chips S were finely pulverized to a particle size of 100 μm or less using a Wonder Blender grinder, and 100 mg ± 10 mg was filled into a quartz tube 81. In addition, a gasifying agent supply unit 83 filled with a laboratory gasifying agent to be introduced into the quartz tube 81 was connected to the quartz tube 81, and the flow rate of the laboratory gasifying agent to be introduced into the quartz tube 81 was set.

[0082] Next, the electric heating unit 82 is controlled to raise the temperature inside the quartz tube 81. The temperature raising rate of the quartz tube 81 is set to 400° C. / Hr. By raising the internal temperature of the quartz tube 81 in this manner, the lab generated gas Gs is generated in the quartz tube 81. The lab generated gas Gs generated in the quartz tube 81 is air-cooled in the furnace core tube and tube (not shown) and collected in a strainer (not shown) as a fly ash component, and then collected in a gas pack 84.

[0083] The lab-produced gas Gs collected in the gas pack 84 is then directly injected into the injector of the lab gas analyzer 85 to analyze hydrogen (H 2 ), methane (CH 4 ), and carbon monoxide (CO) were quantitatively measured. Sampling was performed 13 times in total, with the lab-generated gas Gs collected in gas packs at intervals of 50°C from when the internal temperature of the quartz tube 81 exceeded 100°C and 200°C up to 750°C.

[0084] FIG. 6 shows the component ratio of the lab generated gas Gs when the air cylinder 831 and the gas cylinder 832 are connected to the quartz tube 81, that is, when air and the product gas Gp are used as the lab gasifying agents.

[0085] FIG. 6 is a graph showing the component ratio of the lab generated gas Gs versus the internal temperature of the quartz tube 81. More specifically, it shows the component ratio of the lab generated gas Gs generated in the quartz tube 81 when air and product gas Gp are used as the lab gasifying agent. In FIG. 6, when air is used as the lab gasifying agent, hydrogen is represented by a circle, methane is represented by a triangle, and carbon monoxide is represented by a diamond. Similarly, when product gas Gp is ​​used as the lab gasifying agent, hydrogen is represented by a circle, methane is represented by a triangle, and carbon monoxide is represented by a diamond.

[0086] When the product gas Gp was used as a laboratory gasification agent, the sum of each component was set to "1" and the component ratios were calculated.

[0087] It can be seen that by using the product gas Gp as the lab gasifying agent, the amount of lab-produced gas Gs collected in the gas pack 84 is increased compared to the case where air is used as the lab gasifying agent, as shown in Fig. 6. In other words, it is suggested that the semi-carbonized wood chips S can be gasified efficiently.

[0088] In addition, when the product gas Gp is ​​used as a gasification agent for the laboratory, the internal temperature of the quartz tube 81 is raised to nearly 800°C, and the gas components (hydrogen (H 2 ), methane (CH 4 Specifically, by setting the internal temperature of the quartz tube 81 to 650 degrees or higher, the ratio of carbon monoxide (CO) can be reduced and hydrogen (H 2 ) and methane (CH 4 In other words, it is possible to generate lab-generated gas Gs having a high ratio of hydrogen to carbon monoxide.

[0089] More specifically, when the product gas Gp is ​​used as the lab gasifying agent, the ratio of hydrogen to carbon monoxide is more than five times as high as that when air is used as the lab gasifying agent, as shown in Figure 7. Also, the ratio of hydrogen to carbon monoxide is more than twice as high as that when air is used as the lab gasifying agent (see Figure 7).

[0090] Therefore, it is suggested that by using product gas Gp as the gasification agent H for gasifying semi-carbonized wood chips S, it is possible to generate product gas Gp with higher power generation efficiency than when air is used as the gasification agent H.

[0091] As described above, the gas power generation system 1 having the product gas branch pipe 43 and the inlet pipe 62 can use the product gas Gp as the gasifying agent H for gasifying the semi-carbonized wood chips S. Therefore, by using the product gas Gp as the gasifying agent H in the gas power generation system 1, the semi-carbonized wood chips S can be efficiently gasified inside the reaction tower 11, and the product gas Gp, which has a component ratio that provides good power generation efficiency, can be stably generated.

[0092] The gas power generation system 1 also includes a high-temperature gas branch pipe 33 branching off from the first gas supply pipe 32, and a connecting pipe 61 and an introduction pipe 62 to which the tip of the high-temperature gas branch pipe 33 is connected. Therefore, the high-temperature gas Gh sent from the cyclone 30 can be introduced into the reaction tower 11 via the high-temperature gas branch pipe 33, the connecting pipe 61, and the introduction pipe 62.

[0093] As a result, for example, when the internal temperature of the reaction tower 11 is decreased due to variations in the semi-carbonized wood chips S or the use of the product gas Gp at room temperature as the gasification agent H, the temperature decrease can be detected by the temperature sensor 15. Then, based on the temperature detection by the temperature sensor 15, the high-temperature gas control unit 72 controls the first switching unit 34 to allow a part of the high-temperature gas Gh sent from the cyclone 30 to the gas cooler 40 to flow to the high-temperature gas branch pipe 33. In addition, the flow rate adjustment control unit 74 controls the third switching unit 63 to adjust so that the high-temperature gas Gh is sent to the connecting pipe 61 and the introduction pipe 62. As a result, the high-temperature gas Gh can be introduced into the reaction tower 11 as the gasification agent H instead of the product gas Gp, and the decrease in the internal temperature of the reaction tower 11 can be suppressed.

[0094] More specifically, when the internal temperature of the combustion zone T2 in the reaction tower 11 becomes lower than 650°C, the high-temperature gas control unit 72, the flow rate adjustment control unit 74, and the flow path control unit 75 respectively control the first switching unit 34, the third switching unit 63, and the gasifying agent adjustment valve 625. As a result, the high-temperature gas Gh is sent to the second insertion pipe 622 connected to the second supply port 132, and the high-temperature gas Gh can be introduced into the reaction tower 11 from the second supply port 132 instead of the product gas Gp at room temperature. Therefore, the gas power generation system 1 can suppress a temperature drop inside the reaction tower 11.

[0095] Similarly, even when the temperature of the pyrolysis zone T1 or the reduction zone T3 becomes lower than 650° C., the high-temperature gas control unit 72, the flow rate adjustment control unit 74, and the flow path control unit 75 respectively control the first switching unit 34, the third switching unit 63, and the gasifying agent adjustment valve 625. This allows the high-temperature gas Gh to be sent to the first insertion pipe 621 and the third insertion pipe 623 connected to the first supply port 131 and the third supply port 133.

[0096] In this way, since the high-temperature gas Gh can be introduced into the reaction tower 11, it is possible to suppress temperature changes inside the reaction tower 11 caused by non-uniformity in the size and moisture content of the semi-carbonized wood chips S fed into the reaction tower 11. In addition, it is possible to suppress temperature changes inside the reaction tower 11 caused by introducing the product gas Gp as the gasifying agent H. Therefore, it is possible to stabilize the temperature inside the reaction tower 11, and it is possible to stably gasify the semi-carbonized wood chips S.

[0097] In addition, since the high-temperature gas Gh can be introduced into the reaction tower 11, it is possible to suppress a decrease in the internal temperature of the reaction tower 11. As a result, the internal temperature of the reaction tower 11 can be maintained at or above the thermal decomposition temperature of tar, etc., so that clogging of the reaction tower 11 and residue of the semi-carbonized wood chips S can be suppressed.

[0098] In this way, the gas power generation system 1, which heat-treats and gasifies the semi-carbonized wood chips S, which are chips of semi-carbonized wood biomass, is provided with a reaction tower 11 that heat-treats and gasifies the semi-carbonized wood chips S, a discharge pipe 12 that discharges the generated gas Go gasified in the reaction tower 11, and a cooling tank 41 downstream of the discharge pipe 12 that cools the generated gas Go (high-temperature gas Gh) that has flowed through the discharge pipe 12. Furthermore, upstream of the cooling tank 41, a high-temperature gas branch pipe 33, a connecting pipe 61, and an introduction pipe 62 are provided that introduce at least a portion of the high-temperature gas Gh discharged from the reaction tower 11 into the reaction tower 11 as a gasifying agent H that promotes gasification in the reaction tower 11.

[0099] In addition, in the gasification method of heat-treating and gasifying semi-carbonized wood chips S, depending on the gasification conditions in the reaction tower 11 where the semi-carbonized wood chips S are heat-treated, the high-temperature gas Gh before being gasified and released in the reaction tower 11 is introduced into the reaction tower 11 as a gasification agent H.

[0100] This gas power generation system 1 and gasification method can introduce high-temperature gas Gh into the reaction tower 11, thereby suppressing temperature changes inside the reaction tower 11 caused by non-uniform sizes of the semi-carbonized wood chips S fed into the reaction tower 11. Also, compared to the case where a room temperature gasification agent H such as air is introduced into the reaction tower 11, a decrease in temperature inside the reaction tower 11 can be suppressed. Therefore, the temperature inside the reaction tower 11 can be stabilized, and the semi-carbonized wood chips S can be stably gasified.

[0101] In addition, since the high-temperature gas Gh can be introduced into the reaction tower 11, the inside of the reaction tower 11 can be maintained at a high temperature. This makes it possible to prevent the temperature inside the reaction tower 11 from dropping below the thermal decomposition temperature of tar, etc., and therefore makes it possible to prevent the reaction tower 11 from being blocked and the residue of the semi-carbonized wood chips S from being generated.

[0102] Furthermore, the high-temperature gas Gh introduced into the reaction tower 11 is a crude product of the gas (produced gas Go) generated inside the reaction tower 11. That is, the component ratio of the product gas Gp is ​​not significantly different from the component ratio of the produced gas Go generated inside the reaction tower 11. Therefore, it is possible to prevent the produced gas Go generated inside the reaction tower 11 from being diluted by the gasifying agent H. Therefore, it is possible to suppress a decrease in the power generation efficiency of the gas generated in the reaction tower 11.

[0103] In addition, in the process of gasifying the semi-carbonized wood chips S, multiple reaction zones T (pyrolysis zone T1, combustion zone T2 and reduction zone T3) in which the gasification reactions of the semi-carbonized wood chips S are different are formed inside the reaction tower 11, and a first supply port 131, a second supply port 132 and a third supply port 133 are provided at locations corresponding to the reaction zones T in the reaction tower 11, which are connected to the high-temperature gas branch pipe 33, the connecting pipe 61 and the introduction pipe 62, and can introduce high-temperature gas Gh.

[0104] As a result, since the first supply port 131, the second supply port 132, and the third supply port 133 that can introduce the high-temperature gas Gh into the reaction tower 11 are provided, the high-temperature gas Gh can be introduced into the reaction tower 11 from the first supply port 131, the second supply port 132, and the third supply port 133 corresponding to the state of the reaction zone T. As a result, the high-temperature gas Gh can be introduced from a desired location depending on, for example, the temperature state of the reaction zone T inside the reaction tower 11, the state of the gasification reaction, and the component ratio of the gasified product gas Gp. Therefore, the temperature inside the reaction tower 11 can be efficiently stabilized.

[0105] Furthermore, downstream of the cooling tank 41, there are provided a product gas supply pipe 42 for collecting product gas Gp obtained by cooling the high-temperature gas Gh discharged from the discharge pipe 12 in the cooling tank 41, and a product gas branch pipe 43, a connecting pipe 61 and an introduction pipe 62 for introducing the product gas Gp into the reaction tower 11 as a gasifying agent H.

[0106] This allows the product gas Gp to be used as the gasifying agent H, so that the product gas Gp can be gasified inside the reaction tower 11 without diluting the component concentration of the product gas Gp compared to when other gases are used as the gasifying agent H. Therefore, the gas power generation system 1 and the above-mentioned method can generate the product gas Gp that can efficiently generate power.

[0107] In addition, by using the product gas Gp as the gasifying agent H, the product gas Gp having a component ratio that provides good power generation efficiency can be stably generated inside the reaction tower 11. Furthermore, by generating a stable product gas Gp, the semi-carbonized wood chips S can be efficiently gasified.

[0108] In addition, in the gas power generation system 1, the product gas branch pipe 43 and the high-temperature gas branch pipe 33 are connected so that they can be inserted into a connecting pipe 61, and a third switching section 63 is provided to adjust the flow rate of the product gas Gp flowing through the product gas branch pipe 43 and the high-temperature gas Gh flowing through the high-temperature gas branch pipe 33.

[0109] Furthermore, in the above-mentioned gasification method, the high-temperature gas Gh gasified and released in the reaction tower 11 is cooled to produce product gas Gp, and at least one of the high-temperature gas Gh and the product gas Gp may be introduced into the reaction tower 11 as a gasifying agent H depending on the gasification status of the reaction tower 11.

[0110] This allows the blending ratio of the high-temperature gas Gh and the product gas Gp to be adjusted according to the gasification reaction in the reaction tower 11. Therefore, the high-temperature gas Gh can suppress a decrease in the internal temperature in the reaction tower 11, and the product gas Gp can be used as a gasifying agent H. Therefore, the gasification reaction in the reaction tower 11 can be stabilized, the semi-carbonized wood chips S can be efficiently gasified, and the gas generated inside the reaction tower 11 can have a component ratio that is efficient for power generation.

[0111] Furthermore, the gas power generation system 1 circulates at least a portion of the product gas Gp generated by cooling the high-temperature gas Gh to the reaction tower 11. This allows the product gas Gp to be circulated and introduced into the reaction tower 11, making it possible to stably produce the product gas Gp with a simple structure.

[0112] The reaction tower 11 receives the semi-carbonized wood chips S from below and discharges the generated gas Go from above. This allows the generated gas Go to be discharged with a simple structure. Since the semi-carbonized wood chips S are fed from below, the generated gas Go can be reduced in the upper part of the reaction tower 11 near the discharge pipe 12 for the generated gas Go.

[0113] In the configuration of this invention and the above-mentioned embodiment, the wood chip of this invention corresponds to the semi-carbonized wood chip S, and similarly, The gasifier corresponds to the gas power generation system 1, The reaction tower corresponds to reaction tower 11, The high temperature gas corresponds to the high temperature gas Gh, The discharge tube corresponds to discharge tube 12; The cooling section corresponds to the cooling tank 41. The gasification agent corresponds to gasification agent H. The inlet passage corresponds to the high-temperature gas branch pipe 33, the connecting pipe 61 and the inlet pipe 62. The reaction zone corresponds to reaction zone T, The inlets correspond to a first supply port 131, a second supply port 132, and a third supply port 133. The product gas corresponds to the product gas Gp, The collection path corresponds to the product gas pipe 42; The product gas introduction path corresponds to the product gas branch pipe 43, the connecting pipe 61, and the introduction pipe 62. The flow rate adjusting section corresponds to the third switching section 63, but the present invention is not limited to the configuration of the above-mentioned embodiment, and many embodiments can be obtained.

[0114] For example, in this embodiment, the product gas Gp circulated as the gasification agent H is introduced into the reaction tower 11, but for example, the product gas Gp that has been cooled and stored from the product gas Go (high-temperature gas Gh) generated in the reaction tower 11 may be introduced into the reaction tower 11.

[0115] In addition, in this embodiment, the product gas Gp is ​​used as the gasifying agent H, but the gasifying agent H introduced into the reaction tower 11 does not necessarily have to be completely identical to the components of the product gas Gp. For example, the components of the product gas Gp are not limited to this, and it is sufficient if the component ratio is the same as that of the product gas Gp. In other words, the product gas Gp may be one that can obtain a desired power generation efficiency.

[0116] In addition, in this embodiment, the first switching unit 34 and the third switching unit 63 are controlled in response to temperature changes inside the reaction tower 11, but not only the second switching unit 44 but also the first switching unit 34 and the third switching unit 63 may be controlled in response to the component ratio of the product gas Gp.

[0117] Furthermore, in this embodiment, the first switching unit 34, the third switching unit 63, etc. are controlled based on the detection results of the temperature sensor 15, but the first switching unit 34, the third switching unit 63, and also the second switching unit 44 may be controlled based on the component analysis results of the product gas analyzer 45.

[0118] In addition, in this embodiment, the bottom insertion pipe 624 constitutes a part of the introduction pipe 62 connected to the connecting pipe 61, but it does not necessarily have to be connected to the connecting pipe 61. That is, the product gas branch pipe 43 may be branched, one of which may be directly connected to the fourth supply port 134 and the other of which may be connected to the connecting pipe 61. This allows the product gas Gp to be steadily introduced into the reaction tower 11 from the fourth supply port 134. The fourth supply port 134 may be provided in the vertical conveying pipe 231, and the gasifying agent H may be introduced into the reaction tower 11 from the center of the vertical conveying pipe 231, or a gasifying agent introduction port directly connected to the product gas branch pipe 43 may be provided separately in the vertical conveying pipe 231. [Explanation of symbols]

[0119] 1. Gas power generation system 11…Reaction tower 12...Emission tube 33...Hot gas branch pipe 41...Cooling tank 42...Product gas pipe 43...Product gas branch pipe 61…Connecting pipe 62...Introduction pipe 63…Third switching section 131…First supply port 132…Second supply port 133…Third supply port H: Gasifier T: Reaction zone T1: Pyrolysis zone T2: Combustion zone T3: Reduction zone S...Semi-carbonized wood chips Go…Produced gas Gh: High temperature gas Gp: Product gas

Claims

1. A gasification apparatus for gasifying wood chips by heat treatment, a reaction tower for heat-treating and gasifying the wood chips; A discharge pipe for discharging high-temperature gas gasified in the reaction tower; a cooling section that cools the high-temperature gas that has flowed through the discharge pipe is provided downstream of the discharge pipe; An introduction passage is provided upstream of the cooling section to introduce at least a portion of the high-temperature gas discharged from the reaction tower into the reaction tower as a gasification agent for promoting gasification in the reaction tower. Gasifier.

2. In the step of gasifying the wood chips, a plurality of reaction zones in which different gasification reactions of the wood chips are performed are formed inside the reaction tower, A plurality of inlets that communicate with the inlet passage and can introduce the high-temperature gas are provided at locations in the reaction tower corresponding to the reaction zone. The gasifier of claim 1 .

3. a collection path downstream of the cooling section for collecting product gas obtained by cooling the high-temperature gas discharged from the discharge pipe in the cooling section; A product gas inlet passage for introducing the product gas into the reaction tower as a gasifying agent is provided. The gasifier of claim 2.

4. the product gas inlet passage and the inlet passage are connected to each other so as to be insertable therethrough; A flow rate adjusting unit is provided to adjust the flow rate of the product gas flowing through the product gas inlet passage and the high-temperature gas flowing through the inlet passage. The gasifier of claim 3.

5. The reaction tower is configured such that the wood chips are introduced from below and the high-temperature gas is discharged from above. A gasification apparatus according to any one of claims 1 to 4.

6. A gasification method for gasifying wood chips by heat treatment, comprising the steps of: Depending on the gasification status in the reaction tower where the wood chips are heat-treated, the high-temperature gas that has been gasified in the reaction tower and released before being cooled is introduced into the reaction tower as a gasifying agent. Gasification method.

7. The high-temperature gas that has been gasified and released in the reaction tower is cooled to produce a product gas. Depending on the gasification status of the reaction tower, at least one of the high-temperature gas and the product gas is introduced into the reaction tower as a gasification agent. The gasification method according to claim 6.

8. At least a portion of the product gas produced by cooling the high-temperature gas is circulated to the reaction tower. The gasification method according to claim 7.

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