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JP-7855176-B2 - Gasification device

JP7855176B2JP 7855176 B2JP7855176 B2JP 7855176B2JP-7855176-B2

Inventors

  • 佐々木 和也
  • 徐 思豪
  • 藤原 稔
  • 松本 秀行
  • 鈴木 茂雄
  • 皆川 豊

Assignees

  • ＤＯＷＡサーモテック株式会社
  • 国立大学法人東京科学大学
  • 鉄建建設株式会社

Dates

Publication Date
20260508
Application Date
20220128

Claims (11)

  1. A gasification device that gasifies wood chips, A reaction vessel in which the wood chips are subjected to gasification treatment, A raw material supply passage located at the bottom of the reaction vessel, A tapered vessel provided inside the reaction vessel, The system includes a gas supply mechanism that supplies a combustion-promoting gas to accelerate the combustion of the wood chips, The gasification apparatus is configured such that a pyrolysis zone, a combustion zone, and a reduction zone are formed during the gasification process of the wood chips. The lower end of the tapered container is connected to the upper end of the raw material supply path. The aforementioned tapered container is The aforementioned wood chips are stored in a frustoconical or truncated pyramidal tapered section, A hollow, annular gas storage section is provided in the region corresponding to the combustion zone, The gas storage section has a plurality of openings formed therein , The tapered portion has an increasing cross-sectional area from the lower end to the upper end. The gas supply mechanism is configured to supply the combustion-promoting gas supplied from the outside of the tapered container to the internal space of the gas storage section and then to the inside of the tapered container through the opening, in a gasification device.
  2. A gasification device that gasifies wood chips, A reaction vessel in which the wood chips are subjected to gasification treatment, A raw material supply passage located at the bottom of the reaction vessel, A tapered vessel provided inside the reaction vessel, The system includes a gas supply mechanism that supplies a combustion-promoting gas to accelerate the combustion of the wood chips, The gasification apparatus is configured such that a pyrolysis zone, a combustion zone, and a reduction zone are formed during the gasification process of the wood chips. The lower end of the tapered container is connected to the upper end of the raw material supply path. The aforementioned tapered container is The aforementioned wood chips are stored in a frustoconical or truncated pyramidal tapered section, When the height from the bottom to the top of the reaction vessel is H, a hollow, annular gas storage section is provided within the range of 0.25H to 0.60H, The gas storage section has a plurality of openings formed therein, The tapered portion has an increasing cross-sectional area from the lower end to the upper end. The gas supply mechanism is configured to supply the combustion-promoting gas supplied from the outside of the tapered container to the internal space of the gas storage section and then to the inside of the tapered container through the opening, in a gasification device.
  3. The tapered container has an annular flat portion at the upper end of the tapered portion, The gasification apparatus according to claim 1 or 2 , wherein the gas storage section is arranged on the annular planar section.
  4. The gasification apparatus according to any one of claims 1 to 3 , wherein the opening angle of the tapered portion is 30 to 90°.
  5. The tapered portion is formed in the shape of a frustocone, The aforementioned opening is a slit, The gasification apparatus according to any one of claims 1 to 4 , wherein the slits, when viewed from above, extend in the radial direction of the tapered portion and are formed at intervals along the circumferential direction of the tapered portion.
  6. The gasification apparatus according to claim 5 , wherein the angle between the centerlines of two adjacent slits in the circumferential direction of the tapered portion is 5 to 90°.
  7. The group of openings is formed by arranging the plurality of openings in a straight line, The tapered portion is formed in the shape of a frustocone, The gasification apparatus according to any one of claims 1 to 4, wherein the group of openings extends radially in the tapered portion and is formed at intervals along the circumferential direction of the tapered portion when viewed from above .
  8. The gasification apparatus according to claim 7 , wherein the angle between the centerlines of two adjacent groups of openings in the circumferential direction of the tapered portion is 5 to 90°.
  9. The system includes a control unit that controls the gas supply mechanism, The aforementioned combustion-accelerating gas is air. The gasification apparatus according to any one of claims 1 to 8 , wherein the control unit is configured to perform control of supplying the combustion-accelerating gas such that the air ratio ( A1 / A0 ) of the amount of air A1 supplied to oxidize the wood chips in the reaction vessel and the theoretical amount of air A0 required to completely oxidize the wood chips in the reaction vessel is 0.40 to 0.90 .
  10. A gas treatment method for gasifying wood chips, A reaction vessel in which the wood chips are subjected to gasification treatment, Using a gasification apparatus equipped with a tapered vessel provided inside the reaction vessel, A thermal decomposition zone that causes the thermal decomposition reaction of the wood chips supplied from below the reaction vessel to the lower end of the tapered vessel, A combustion zone that causes an oxidation reaction of the gas generated from the aforementioned wood chips, When gasifying the wood chips by forming a reduction zone that causes a reduction reaction of the gas generated from the wood chips, A gasification treatment method comprising supplying a combustion-accelerating gas to the internal space of a hollow, annularly formed gas storage section provided in a region corresponding to the combustion zone , and gasifying the wood chips while supplying the combustion-accelerating gas to the combustion zone through a plurality of openings formed in the gas storage section.
  11. The aforementioned combustion-accelerating gas is air. The gasification treatment method according to claim 10 , wherein the combustion accelerating gas is supplied such that the air ratio ( A1 / A0 ) of the amount of air A1 supplied to oxidize the wood chips in the reaction vessel and the theoretical amount of air A0 required to completely oxidize the wood chips in the reaction vessel is 0.40 to 0.90.

Description

This invention relates to a gasification apparatus for gasifying wood chips. In recent years, the use of natural and renewable energy sources has been advancing globally to address issues such as the depletion of fossil fuels, global warming, and the risks of dependence on foreign energy sources. Among renewable energy sources is woody biomass energy, which is produced using wood such as thinned timber. It is attracting attention as a new energy source in forested areas such as Japan. Furthermore, woody biomass energy offers many advantages from the perspective of energy self-sufficiency and its ability to provide a stable supply even during emergencies. As a method for efficiently utilizing such woody biomass energy, woody biomass power generation is known, which involves burning wood chips, such as thinned timber, as biomass raw material and using the resulting combustible gas as fuel for power generation. Regarding biomass gasification furnaces that burn and gasify biomass raw materials, Patent Documents 1 and 2 disclose a furnace in which raw materials supplied from the bottom of the furnace are burned and combustible gas is extracted from the top of the furnace. Patent Document 1 discloses a gasification apparatus for wood chips, comprising an input mechanism for introducing semi-carbonized wood chips and a reaction tower for gasifying the wood chips. In this gasification apparatus, three layers are formed from the bottom to the top of the reaction tower: a pyrolysis zone T1, a combustion zone T2, and a reduction zone T3. The pyrolysis zone T1 is the layer where the semi-carbonized wood chips are pyrolyzed; the combustion zone T2 is the layer where the gas produced by pyrolysis is oxidized; and the reduction zone T3 is the layer where the gas produced by pyrolysis is reduced to generate product gases (carbon monoxide and hydrogen) used for power generation. During the gasification process of semi-carbonized wood chips, the heat of combustion generated in the combustion zone T2 is transferred to the pyrolysis zone T1 and the reduction zone T3, thereby promoting the pyrolysis, oxidation, and reduction reactions of the wood chips inside the reaction tower. Patent Document 2 discloses a reactor in which a turntable is provided at the bottom of the first gasification stage, and a container for receiving raw materials from below is provided directly above it. Japanese Patent Publication No. 2021-109907Special Publication No. 6-031341 This is an explanatory diagram showing the schematic configuration of a gasification apparatus according to the first embodiment.This is a schematic perspective view showing the shape of a tapered container.This is a top view of a tapered container.This figure shows the section A-A in Figure 3.This is a top view of a tapered container to illustrate an example of the arrangement of openings.This figure shows examples of opening shapes.This is a top view of a tapered container used to illustrate the group of openings.This figure shows an example of the arrangement of openings in a group of openings.This is a diagram illustrating the opening angle of a tapered container.This figure shows examples of tapered container shapes.This is an explanatory diagram showing the schematic configuration of a gasification apparatus according to the second embodiment.This is a top view of a tapered container.This is a diagram showing the B-B cross-section in Figure 12.This is a schematic diagram of a gasification apparatus used in a combustion experiment. The embodiments of the present invention will be described below with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, thus omitting redundant explanations. The white arrows in the figures indicate the flow of the combustion-accelerating gas, which will be discussed later. <First Embodiment> Figure 1 is an explanatory diagram showing the schematic configuration of a gasification apparatus according to the first embodiment. The gasification apparatus 1 according to this embodiment uses wood chips as biomass raw material, and is an updraft type apparatus that gasifies the wood chips by causing thermal decomposition, oxidation, and reduction reactions, and recovers the generated product gas (for example, carbon monoxide or hydrogen) from above. The following is a general description of the configuration of the gasification apparatus 1, but the description of the apparatus configuration may be omitted for parts where the configuration of a known updraft type apparatus can be applied. Furthermore, from the viewpoint of increasing the production efficiency of the generated gas obtained by the gasification process, it is preferable that the wood chips are semi-carbonized. Semi-carbonization of wood chips is a process in which the wood chips are heated at a predetermined temperature (200-350°C) in an atmosphere where water vapor i