JP5444847B2 - Gasifier - Google Patents

Description

  The present invention relates to a gasifier.

  2. Description of the Related Art Conventionally, gasification apparatuses that gasify organic raw materials such as biomass and coal and extract organic gases such as methane have been proposed. An example of the gasifier is disclosed in Patent Document 1. The gasification apparatus of Patent Document 1 includes a gasification furnace and a combustion furnace. In the gasification furnace, for example, powdered organic raw materials, fluid medium particles such as heated sand, catalyst particles for promoting gasification, and the like are supplied. A fluidizing gas for fluidizing the particles is supplied to the gasification furnace. An overflow pipe is attached to the gasification furnace, and the overflow pipe leads to the combustion furnace. An exhaust gas pipe is attached to the combustion furnace, and the exhaust gas pipe passes through a separator to the gasification furnace.

  In such a gasification apparatus, the organic material supplied into the gasification furnace is decomposed into organic gas and char by the heat of the fluidized medium particles. The char and the fluidized medium particles are fluidized by the fluidized gas and conveyed to the combustion furnace via the overflow pipe. The char carried to the combustion furnace is burned, and the fluidized medium particles are heated by the combustion heat. The heated fluid medium particles are conveyed to a gasification furnace through an exhaust gas pipe and a separator.

JP 2007-146036 A

  In the gasifier of Patent Document 1, the organic raw material is efficiently decomposed by the catalytic effect, and the tar generated with the gasification is decomposed by the catalytic effect. Therefore, according to the technique of Patent Document 1, organic gas is obtained with high efficiency, and malfunction due to tar is prevented. On the other hand, such a gasifier has room for improvement from the viewpoint of effectively using catalyst particles as described below.

  In order to sufficiently exhibit the catalytic effect in the gasifier using the catalyst particles, the catalyst particles should be sufficiently flowed in the gasification furnace to increase the probability that the catalyst particles are in contact with the organic material. When the catalyst particles are sufficiently flowed, a part of the catalyst particles overflows from the gasification furnace together with the fluidized medium particles and is carried to the combustion furnace. The catalyst particles carried into the combustion furnace are deteriorated by being heated in an oxygen atmosphere. The catalyst particles return to the gasification furnace from the combustion furnace through the exhaust gas pipe and the separator together with the fluidized medium particles. The catalyst particles are pulverized and refined by a separator such as a cyclone. The refined catalyst particles have higher fluidity in the gasification furnace than before the refinement, and are easily transported to the combustion furnace. When the catalyst particles are repeatedly circulated, a substantial amount of the catalyst particles is reduced due to a decrease in the catalytic ability of the catalyst particles due to deterioration, discharge of the refined catalyst particles together with the exhaust gas, and the like.

  As described above, in the conventional gasifier, there is a problem that the catalyst particles that should not be consumed by the reaction are consumed so much that they cannot be ignored. This invention is made | formed in view of the said situation, Comprising: It aims at providing the gasifier which can reduce the consumption of a catalyst particle markedly.

  The gasifier according to the present invention includes a fluid medium particle, an organic material that is thermally decomposed into an organic gas and char by heat supplied from the fluid medium particle, and a gas that stores catalyst particles that promote the thermal decomposition of the organic material And fluidizing particles stored in the gasification furnace, causing the catalyst particles of the particles to stay in the gasification furnace, and part of the char and the fluidized medium particles to the gas And a fluidizing device that discharges from a discharge port provided in the conversion furnace.

  Further, the fluidizing device includes a gas supply device that supplies a fluidizing gas for fluidizing the particles into the gasification furnace, and the followability of the catalyst particles to the fluidizing gas is such that the fluidizing medium particles The fluidization gas that is set smaller than the followability with respect to the fluidizing gas, and the linear velocity of the fluidizing gas supplied to the vicinity of the discharge port in the gasification furnace is supplied to the gas furnace. It is good to set below the average value of the linear velocity of gas.

  The linear velocity of the fluidizing gas supplied in the vicinity of the discharge port may be set to be lower than the fluidization lower limit velocity of the catalyst particles determined by the particle size and density of the catalyst particles.

  Further, the linear velocity of the fluidized gas supplied to at least a part of the gasification furnace excluding the vicinity of the discharge port is equal to or higher than the fluidization lower limit velocity of the catalyst particles determined by the particle size and density of the catalyst particles. It is preferable to set to.

  Moreover, you may make it the structure which the surface near the said discharge port in the bottom face in the said gasification furnace becomes the inclined surface which goes to the perpendicular direction upwards as it goes to the said discharge port.

  In addition, a configuration may be provided that includes a recovery port provided at the bottom of the gasification furnace in the vicinity of the discharge port, and a circulation device that circulates the catalyst particles flowing into the recovery port into the gasification furnace. Good.

  Further, the average value of the linear velocity of the fluidizing gas supplied into the gasification furnace is not less than 3 times and not more than 12 times the fluidization lower limit velocity of the fluid medium particles determined by the particle size and density of the fluid medium particles. It is preferably set.

  A combustion furnace configured to burn the char discharged from the discharge port to heat the fluidized medium particles; and a transfer device configured to transfer the fluidized medium particles heated in the combustion furnace into the gasification furnace; It is preferable to adopt a configuration having.

  In the gasification apparatus of the present invention, the organic material stored in the gasification furnace is fluidized together with the catalyst particles and mixed with the catalyst particles. The organic material is thermally decomposed by the heat supplied from the fluid medium particles, and organic gas and char are generated. Since the thermal decomposition of the organic material is promoted by the catalyst particles, the organic gas is efficiently generated. Part of the fluid medium particles, the generated char, and the catalyst particles are discharged from the discharge port and taken out. Since the fluidizing device selectively retains the catalyst particles among the particles stored in the gasification furnace in the gasification furnace, the consumption of the catalyst particles can be remarkably reduced.

It is a schematic diagram which shows schematic structure of the gasification apparatus of embodiment which concerns on this invention. (A) of a gasification furnace is a perspective view, (b) is an A-A 'line arrow directional view. It is explanatory drawing of a fluidization minimum speed. (A) of the gasification furnace in the modification 1 is a perspective view, (b) is a top view. (A) of the gasification furnace in the modification 2 is a perspective view, (b) is a B-B 'arrow directional view. (A) of the gasification furnace in the modification 3 is a perspective view, (b) is a top view. It is sectional drawing of the gasification furnace in the modification 4.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the technical scope of the present invention is not limited to the following embodiments. Various modifications are possible without departing from the gist of the present invention. In the drawings used for explanation, in order to show characteristic parts in an easy-to-understand manner, dimensions and scales of structures in the drawings may be different from actual structures. In addition, in the embodiment, the same components are illustrated with the same reference numerals, and detailed description thereof may be omitted.

  FIG. 1 is a schematic diagram showing a schematic configuration of a gasifier 1 according to an embodiment of the present invention. As shown in FIG. 1, the gasifier 1 includes a gasifier 10, a fluidizer 11, and a combustion furnace 12. A fluidizer 11, a raw material supply pipe 13, a fluid medium supply pipe 14, a gas recovery apparatus 15, and an overflow pipe 16 are connected to the gasification furnace 10. The combustion furnace 12 is connected to an overflow pipe 16 and a transfer pipe 17. The transfer pipe 17 is connected to a separator 18, and the separator 18 is connected to the fluid medium supply pipe 14.

  The gasifier 1 generally operates as follows. The organic material P1 is supplied into the gasification furnace 10 through the material supply pipe 13. Heated fluid medium particles P <b> 2 are supplied into the gasification furnace 10 through the fluid medium supply pipe 14. In the gasification furnace 10, catalyst particles that promote thermal decomposition of the organic material P1 are stored. The fluidizing device 11 supplies the fluidizing gas G <b> 1 into the gasification furnace 10. The organic material P1, the fluid medium particles P2, and the catalyst particles in the gasification furnace 10 are fluidized by the fluidizing gas G1 to form a fluidized bed F.

  The organic material P1 is thermally separated into a product gas G2 containing an organic gas and a char P3 by heat received from the fluid medium particles P2. The product gas G2 is recovered by the gas recovery device 15 together with the fluidized gas G1 and taken out to the outside. The char P3 and the fluid medium particles P2 are conveyed to the combustion furnace 12 through the overflow pipe 16. The catalyst particles stay in the gasification furnace 10.

  The char P3 burns in the combustion furnace 12, and the fluidized medium particles P2 are heated by the heat generated by the combustion. The exhaust gas G3, the unburned char P3, and the heated fluid medium particles P2 generated by the combustion are conveyed to the separator 18 through the transfer pipe 17. The unburned char P3 and the fluidized medium particles P2 are separated from the exhaust gas G3 and the like by the separator 18 and are carried into the gasification furnace 10 through the fluidized medium supply pipe 14. As described above, the gasifier 1 circulates the fluid medium particles P2 to thermally decompose the organic material P1 to take out the product gas G2, and reheats the fluid medium particles P2 using the generated char P3. It is like that. Hereinafter, the components of the gasifier 1 will be described.

The raw material supply pipe 13 is configured to include, for example, a screw feeder and the like, and conveys the organic raw material P1 supplied from the outside of the gasifier 1 into the gasifier 10.
The fluid medium supply pipe 14 extends substantially vertically upward of the gasification furnace 10. One end of the fluid medium supply pipe 14 communicates with the gasification furnace 10, and the other end of the fluid medium supply pipe 14 communicates with a separator 18 installed vertically above the gasification furnace 10. The fluid medium particles P <b> 2 and the like separated by the separator 18 are moved down in the fluid medium supply pipe 14 by gravity and carried into the gasification furnace 10.

  The gas recovery device 15 includes an exhaust pipe 151, a recovery separator 152, and a gas extraction pipe 153. One end of the exhaust pipe 151 communicates with the gasification furnace 10, and the other end of the exhaust pipe 151 communicates with the recovery separator 152. The recovery separator 152 separates unnecessary matter P4 such as dust accompanying the generated gas G2 recovered through the exhaust pipe 151 by centrifugation or the like. The organic gas or the like contained in the product gas G2 is taken out of the gasifier 1 through the gas extraction pipe 153 and supplied to, for example, a gas turbine or the like.

  The overflow pipe 16 extends substantially vertically downward of the gasification furnace 10. One end of the overflow pipe 16 communicates with the gasification furnace 10, and the other end of the overflow pipe 16 communicates with the combustion furnace 12. The fluidized medium particles P2 and char P3 constituting the upper layer of the fluidized bed F in the gasification furnace 10 overflow into the overflow pipe 16 and are lowered into the overflow pipe 16 by gravity and carried into the combustion furnace 12.

  The combustion furnace 12 burns the char P3 and heats the fluidized medium particles P2 to, for example, about 800 ° C. using heat generated by the combustion. A wind box 121, an auxiliary fuel supply pipe 122, a heat exchanger 123, and a transfer pipe 17 are connected to the combustion furnace 12. An air supply pipe 124 is connected to the wind box 121. Air G4 is supplied through the air supply pipe 124, and the air G4 is supplied into the combustion furnace 12 through the wind box 121. When the amount of heat generated by the combustion of the char P3 is insufficient with respect to the amount of heat necessary for heating the fluidized medium particles P2 to a predetermined temperature, the auxiliary fuel L1 is supplied to the combustion furnace 12 through the auxiliary fuel supply pipe 122. The Excess heat in the combustion furnace 12 is taken out by the heat exchanger 123 and used, for example, for generating or heating the fluidized gas G1. One end of the transfer pipe 17 communicates with the combustion furnace 12, and the other end of the transfer pipe 17 communicates with the separator 18. The fluidized medium particles P2 and the unburned char P3 heated in the combustion furnace 12 are transferred through the transfer pipe 17 by the air G4 supplied from the air supply pipe 124, the exhaust gas G3 by combustion, etc., and are carried to the separator 18. It is.

  The separator 18 is constituted by a solid separator such as a cyclone, for example, and separates solids such as fluid medium particles P2 and unburned char P3 from the exhaust gas G3 and air G4. The separator 18 includes an outer cylinder 181 and an inner cylinder 182, and the exhaust gas G3 and air G4 are exhausted to the outside of the gasifier 1 through the inner cylinder 182. The outer cylinder 181 communicates with the fluid medium supply pipe 14. The fluid medium particles P <b> 2 and the unburned char P <b> 3 are conveyed from the outer cylinder 181 to the fluid medium supply pipe 14.

  FIG. 2A is a perspective view schematically showing the configuration of the gasification furnace 10, and FIG. 2B is a cross-sectional view of the gasification furnace 10 taken along the line A-A ′. FIG. 2B schematically shows the operating state of the gasification furnace 10.

  As shown in FIG. 2A, the gasification furnace 10 has a substantially box shape. The raw material supply port 101 and the fluid medium supply port 102 are provided on one surface of the wall surfaces of the gasification furnace 10 facing each other in the Y direction in the figure, and the discharge port 104 is provided on the other surface. . A raw material supply pipe 13 is connected to the raw material supply port 101, and a fluid medium supply pipe 14 is connected to the fluid medium supply port 102. An overflow pipe 16 is connected to the discharge port 104. A gas outlet 103 is provided on the ceiling surface of the gasification furnace 10. An exhaust pipe 151 is connected to the gas outlet 103.

  In the present embodiment, the bottom surface 105 of the gasification furnace 10 is inclined with respect to the vertical direction. The bottom surface 105 is an inclined surface that extends vertically upward (Z direction in the drawing) from the material supply port 101 toward the discharge port 104. The bottom portion of the gasification furnace 10 including the bottom surface 105 is composed of a sintered wire mesh, a porous plate, or the like. The bottom surface 105 allows the fluidized gas G1 to pass therethrough and hardly allows particles in the gasification furnace 10 to pass through.

  A fluidizing device 11 is provided at the bottom of the gasification furnace 10. The fluidizing device 11 of this embodiment includes a gas supply device 110, gas chambers 111a to 111d, and gas pipes 112a to 112d. The gas supply device 110 supplies, for example, water vapor as the fluidizing gas G1. The gas chambers 111a to 111d are independent of each other. From the raw material supply port 101 toward the discharge port 104, a gas chamber 111a, a gas chamber 111b, a gas chamber 111c, and a gas chamber 111d are arranged in this order. That is, the gas chamber 111a is disposed closest to the raw material supply port 101, and the gas chamber 111d is disposed closest to the discharge port 104.

  The ceiling surfaces of the gas chambers 111 a to 111 d are common with the bottom of the gasification furnace 10. Gas pipes 112a to 112d are connected to the gas chambers 111a to 111d, respectively. Here, all of the gas pipes 112 a to 112 d are connected to the gas supply device 110. The gas pipes 112a to 112d are provided with electromagnetic valves and the like (not shown), and the gas pressures in the gas pipes 112a to 112d can be adjusted independently of each other. In addition, the gas supply apparatus 110 may be provided in common by gas chamber 111a-111d, and may be provided for every gas chamber 111a-111d.

  By adjusting the gas pressure in the gas pipes 112a to 112d, the linear velocity of the fluidizing gas G1 passing through the gas pipes 112a to 112d can be adjusted for each of the gas pipes 112a to 112d. The linear velocities of the fluidizing gas G1 passing through the gas pipes 112a to 112d are set to Va, Vb, Vc, and Vd, respectively. Among the linear velocities Va to Vd, the linear velocity Va of the fluidizing gas G1 supplied to the gas chamber 111a arranged closest to the raw material supply port 101 is set to be the largest, and thereafter decreases in the order of Vb and Vc. The linear velocity Vd of the fluidizing gas G1 supplied to the gas chamber 111d closest to the discharge port 104 is set to be the smallest. A method for setting the linear velocity of the fluidizing gas G1 will be described later.

  As shown in FIG. 2B, catalyst particles P5 are stored in the gasifier 10. The catalyst particles P5 are of a material appropriately selected according to the material of the organic material P1, and are, for example, calcium catalyst particles such as dolomite and lime, iron oxide catalyst particles, and nickel catalyst particles. The followability of the catalyst particles P5 to the fluidizing gas G1 is set lower than the followability of the fluidizing medium particles P2 to the fluidizing gas G1.

  The followability of various particles to the fluidizing gas can be evaluated by the speed difference (drift velocity) between the fluidizing gas and the particles. The drift velocity for a predetermined gas or particle can be obtained by experiment, numerical simulation, or the like. For fluidized gas ejected from vertically downward to upward, as the force applied to the particle from the fluidized gas increases with respect to the gravity acting on the particle, the velocity of the particle vertically upward increases and the drift velocity decreases. Therefore, the followability of the particles to the fluidized gas is increased. In general, the followability decreases as the density difference between the fluidized gas and the particles increases and as the particle size of the particles increases. Therefore, for example, if the material and particle size of the fluid medium particles are determined and the material of the catalyst particles is determined, the particle size of the catalyst particles can be determined so that the followability of the catalyst particles is lower than that of the fluid medium particles. .

  Next, a method for setting the linear velocity of the fluidizing gas will be described. FIG. 3 is an explanatory diagram showing changes in the state of the powdery layer with respect to changes in the flow rate of the fluidized gas. In the graph shown in FIG. 3, the vertical axis indicates the pressure loss in the powdery layer when the fluidized gas is ejected from the bottom of the container in a state where the powdery layer made of particles is formed in the container, and the horizontal axis indicates the fluidized gas. The linear velocity is shown.

  As shown in FIG. 3, the pressure loss increases as the fluidized gas linear velocity increases from zero. In this state, the particles hardly flow and the powdery layer behaves as a stationary layer. When the fluidized gas linear velocity exceeds the threshold, the pressure loss decreases. This is because the particles are fluidized and the fluidized gas easily passes between the particles. That is, the linear velocity at which the pressure loss changes from rising to lowering is the fluidization lower limit velocity, and if the linear velocity is equal to or higher than the fluidization lower limit velocity, the powdery layer behaves as a fluidized bed. When the linear velocity is increased beyond the fluidization lower limit velocity, the pressure loss becomes substantially constant after decreasing. In this state, the powdery layer behaves like a fluid containing bubbles of fluidized gas, and this state is called bubbling. When the linear velocity is further increased, the behavior of the particles becoming solid and floating inside the container is repeated (slagging). By managing the bubbling state, the pressure loss is less than that in the slagging state and the state is stabilized, so that the fluidized bed can be controlled well.

The fluidization lower limit speed is determined by the linear velocity of the fluidization gas, the particle diameter, the density difference between the fluidization gas and the particles, and the like, and can be obtained by experiment, numerical simulation, or the like. Hereinafter, description will be made using specific numerical examples. When silica sand (particle size 300 μm, density 2700 kg / m ³ ) is employed as the fluid medium particles and water vapor is employed as the fluidizing gas, the fluidization lower limit speed of the fluid medium particles is 0.029 m / s. In order to make bubbling from the viewpoint of stably configuring the fluidized bed as described above, the linear velocity is preferably set to, for example, 3 times to 12 times the fluidization lower limit velocity. On the other hand, when γ-alumina (particle size: 500 μm, density: 3500 kg / m ³ ) is employed as the catalyst particles, the fluidization lower limit speed of the catalyst particles becomes 0.106 m / s.

  In the present embodiment, the linear velocity of the fluidizing gas G1 in the vicinity of the discharge port 104 is set within the range of the fluidization lower limit velocity of the fluidized medium particles P2 and less than the fluidization lower limit of the catalyst particles. Further, the linear velocity of the fluidized gas G1 in the portion excluding the vicinity of the discharge port 104 is set to be equal to or higher than the fluidization lower limit of the catalyst particles. For example, using the above numerical example, the linear velocity of the fluidizing gas G1 in the vicinity of the discharge port 104 is set within a range of 0.029 m / s or more and less than 0.106 m / s, and particularly the fluidized bed is well controlled. In view of this, it is set within the range of 0.087 m / s or more and less than 0.106 m / s. Further, the linear velocity of the portion excluding the vicinity of the discharge port 104 is set to 3 times or more (0.318 m / s or more) of the fluidization lower limit velocity of the catalyst particles P5 from the viewpoint of fluidizing the catalyst particles P5 satisfactorily. . When the particle diameter of γ-alumina is changed to 450 μm, the fluidization lower limit speed of the catalyst particles becomes 0.087 m / s, which is almost equal to three times the fluidization speed of the fluid medium particles. In such a case, select a fluidized medium particle having a smaller particle size, select a fluidized medium particle having a smaller density, select a catalyst particle having a larger particle size, The range of a suitable fluidization lower limit speed can be expanded by selecting a catalyst particle having a higher density.

In the gasification furnace 10 as described above, the stored catalyst particles P5 are fluidized by the fluidizing gas G1 and mixed with the organic material P1 and the fluidized medium particles P2. Therefore, the probability that the organic material P1 comes into contact with the catalyst particles P5 is increased, and the organic material P1 is efficiently thermally decomposed. The fluid medium particles P2, the char P3 generated by thermal decomposition, and the catalyst particles P5 flow from the raw material supply port 101 toward the discharge port 104. Since the linear velocity of the fluidizing gas G1 in the vicinity of the discharge port 104 is equal to or higher than the fluidization lower limit velocity of the fluid medium particles P2, the fluid medium particles P2 and the char P3 reach the discharge port 104 while maintaining fluidity and overflow. It flows into the pipe 16. On the other hand, since the linear velocity of the fluidizing gas G1 in the vicinity of the discharge port 104 is lower than the fluidization lower limit speed of the catalyst particles P5, the fluidity of the catalyst particles P5 decreases in the vicinity of the discharge port 104 and settles. The settled catalyst particles P5 are moved by gravity from the discharge port 104 side toward the raw material supply port 101 along the inclined surface because the bottom surface of the gasification furnace 10 is inclined. The catalyst particles P5 moved to the raw material supply port 101 side are fluidized again by the fluidizing gas G1 and mixed with the organic material raw material P1 and the like.
Thus, in the gasification apparatus 1 of the present embodiment, the flow P5f of the catalyst particles P5 becomes a circulation flow, and the catalyst particles P5 stay in the gasification furnace 10, so that the consumption amount of the catalyst particles P5 is remarkably increased. Reduced.

[Modification]
Next, modifications 1 to 4 in which the gasification furnace and the fluidization device are modified with respect to the gasification device of the above embodiment will be described. Since the configurations of the modified examples 1 to 4 excluding the gasification furnace and the fluidizing device are the same as those in the above embodiment, the description thereof is omitted.

  FIG. 4A is a perspective view schematically showing the gasification furnace 20 and the fluidizing device 21 of the first modification, and FIG. 4B is the gasification furnace 20 and the fluidizing device 21 of the first modification. It is the top view which looked at from the Z direction. As shown in FIGS. 4A and 4B, the gasification furnace 20 is different from the above-described embodiment in that only a part of the bottom surface is an inclined surface.

  A raw material supply port 201, a fluid medium supply port 202, a gas recovery port 203, and a discharge port 204 are provided on the inner wall surface of the gasification furnace 20. The discharge port 204 is provided on the inner wall surface facing the raw material supply port 201 and the fluid medium supply port 202. On the inner wall surface, the discharge port 204 is disposed at a position biased in the X negative direction. The raw material supply port 201 and the fluid medium supply port 202 are disposed at positions that are substantially diagonal to the discharge port 204, that is, in the X positive direction.

  The bottom surface directly below the discharge port 204 is an inclined surface that goes vertically downward (Z negative direction) as it goes in the Y direction. A bottom surface immediately below a portion in the X positive direction of the inner wall surface on which the discharge port 204 is disposed is a horizontal plane. Here, the height in the vertical direction at the end of the inclined surface on the discharge port 204 side (Y negative direction side) is substantially the same as the height in the vertical direction of the horizontal plane. Gas chambers 211a to 211d are provided vertically below the inclined surface. Among the gas chambers 211a to 211d, the gas chamber 211a is disposed at a position close to the raw material supply port 201, and the gas chamber 211b, the gas chamber 211c, and the gas chamber 211d are arranged in this order in the negative Y direction away from the raw material supply port 201. It is out. A gas chamber 211e is disposed vertically below the horizontal plane.

  The gas chambers 211a to 211e are independent of each other. Fluidized gas is supplied into the gas chambers 211a to 211e from the same gas supply apparatus as in the above embodiment. The linear velocity of the fluidizing gas supplied to the gasification furnace 20 through the gas chamber 211d disposed in the vicinity of the discharge port 204 is set within a range of not less than the fluidization lower limit velocity of the fluidized medium particles and less than the fluidization lower limit of the catalyst particles. Has been. Here, among the fluidized gases supplied to the gasification furnace 20, the fluidized gas supplied through the gas chamber 211d has the lowest linear velocity, and then the gas chamber 211c, the gas chamber 211b, and the gas chamber 211a in that order. Is getting bigger.

  As shown in FIG. 4B, the organic raw material P1 supplied from the raw material supply port 201 is mixed with the catalyst particles P5 and the fluidized medium particles P2 supplied from the fluidized medium supply port 202, and flows in the Y negative direction. While pyrolyzing. The fluid medium particles P <b> 2 and the char P <b> 3 generated by thermal decomposition flow into the overflow pipe 16 from the discharge port 204. The catalyst particles P5 that have reached the vicinity of the discharge port 204 are settled due to a decrease in fluidity, and move to the raw material supply port 201 side along the inclined surface. Thus, also in the modification 1, since the catalyst particle P5 stays in the gasification furnace 20, the consumption of the catalyst particle P5 is significantly reduced.

  FIG. 5A is a perspective view schematically showing the gasification furnace 30 and the fluidizing device 31 of Modification 2. FIG. 5B is a view taken along the line BB ′ in FIG. It is sectional drawing. As shown in FIGS. 5A and 5B, the gasification furnace 30 is modified in that only a part of the bottom surface is an inclined surface and the inclined surface extends over the entire width in the X direction. Different from 1.

  A raw material supply port 301, a fluid medium supply port 302, a gas recovery port 303, and a discharge port 304 are provided on the inner wall surface of the gasification furnace 30 in the same arrangement as in the above embodiment. The bottom surface directly below the discharge port 304 is an inclined surface 306 that goes vertically downward (Z negative direction) as it goes in the Y direction. The inclined surface 306 is disposed on the discharge port 304 side in the Y direction, and the Y direction of the inclined surface 306 is a horizontal plane 305.

  A gas chamber 311 a is provided vertically below the horizontal plane 305, and a gas chamber 311 b is provided vertically below the inclined surface 306. The gas chambers 311a and 311b are independent of each other. The fluidizing gas G1 is supplied to the gas chamber 311a through the gas pipe 312a from the same gas supply device 310 as in the above embodiment. The fluidizing gas G1 is supplied to the gas chamber 311b via the gas pipe 312b. The linear velocity of the fluidizing gas G1 supplied to the gasification furnace 30 through the gas chamber 311b disposed in the vicinity of the discharge port 304 is within a range of not less than the fluidization lower limit velocity of the fluidized medium particles and less than the fluidization lower limit of the catalyst particles. Is set. The linear velocity of the fluidizing gas G1 supplied to the gasification furnace 30 through the gas chamber 311a is larger than that of the gas chamber 311b.

  As shown in FIG. 5B, the organic material P1 supplied from the raw material supply port 301 is mixed with the fluid medium particles P2 and catalyst particles P5 supplied from the fluid medium supply port 302, and flows in the negative Y direction. While pyrolyzing. The fluid medium particles P2 and the char P3 generated by the thermal decomposition flow into the overflow pipe 16 from the discharge port 304. The catalyst particles P <b> 5 that have reached the vicinity of the discharge port 304 are sedimented due to a decrease in fluidity, and move to the raw material supply port 301 side through the inclined surface 306. Thus, also in the modified example 2, since the catalyst particles P5 stay in the gasification furnace 30, the consumption of the catalyst particles P5 is significantly reduced.

  FIG. 6A is a perspective view schematically showing the gasification furnace 40 and the fluidization device 41 of the third modification, and FIG. 6B is the gasification furnace 40 and the fluidization device 41 of the third modification. It is the top view which looked at from the Z direction. As shown in FIGS. 6A and 6B, the gasification furnace 40 is modified in that only a part of the bottom surface is an inclined surface, and the inclined surface is inclined in the X direction and the Y direction. Different from 1 and 2.

  On the inner wall surface of the gasification furnace 40, a raw material supply port 401, a fluid medium supply port 402, and a discharge port 404 are provided in the same arrangement as in the second modification. Further, as in the second modification, the gas outlet 403 of the gasification furnace 40 is disposed at substantially the center of the ceiling surface of the gasification furnace 40. The bottom surface directly below the discharge port 304 is an inclined surface 406 that extends vertically downward (Z negative direction) toward each of the X direction and the Y direction. Here, the inclined surfaces 406 are arranged only at the corners of the box-shaped gasifier 40, and the bottom surface of the gasifier 40 excluding the inclined surfaces 406 is a horizontal surface 405.

  A gas chamber 411 a is provided vertically below the horizontal plane 405, and a gas chamber 411 b is provided vertically below the inclined surface 406. The gas chambers 411a and 411b are independent of each other. The fluidizing gas G1 is supplied to the gas chambers 411a and 411b from the same gas supply apparatus as in the above embodiment. The linear velocity of the fluidizing gas G1 supplied to the gasification furnace 40 through the gas chamber 411b disposed in the vicinity of the discharge port 404 is within the range of not less than the fluidization lower limit velocity of the fluidized medium particles and less than the fluidization lower limit of the catalyst particles. Is set. The linear velocity of the fluidizing gas G1 supplied to the gasification furnace 40 through the gas chamber 411a is larger than that of the gas chamber 411b.

  As shown in FIG. 6B, the fluid medium particles P <b> 2 and the char P <b> 3 generated by thermal decomposition flow into the overflow pipe 16 from the discharge port 404. The catalyst particles P5 that have reached the vicinity of the discharge port 404 settle due to a decrease in fluidity, and move to the raw material supply port 401 side along the inclined surface 406. Thus, also in the modification 3, since the catalyst particle P5 stays in the gasification furnace 40, the consumption of the catalyst particle P5 is remarkably reduced.

  FIG. 7 is a cross-sectional view schematically showing a gasification furnace 50 and a fluidizing device 51 of Modification 4. As shown in FIG. 7, the gasification furnace 50 is different from the above-described embodiment and Modifications 1 to 3 in that the bottom surface is a horizontal surface and a recovery port for catalyst particles is provided at the bottom.

  A raw material supply port 501, a fluid medium supply port 502, a gas recovery port 503, and a discharge port 504 are provided on the inner wall surface of the gasification furnace 50 in the same arrangement as in the above embodiment. The bottom surface of the gasification furnace 50 is a horizontal surface 505 except for the vicinity of the discharge port 504. A gas chamber 511 a is provided vertically below the horizontal plane 505. The fluidizing gas G1 is supplied to the gas chamber 511a through the gas pipe 512a from the same gas supply apparatus 510 as in the above embodiment. A recovery port 506 is provided at the bottom of the gasification furnace 50 in the vicinity of the discharge port 504. A gas chamber 511 b is provided vertically below the recovery port 506. The fluidizing gas G1 is supplied to the gas chamber 511b from the gas supply device 510 through the gas pipe 512b independently of the gas chamber 511a. The linear velocity of the fluidizing gas G1 supplied from the gas chamber 511a to the gasification furnace 50 through the recovery port 506 is set in the range of not less than the fluidization lower limit velocity of the fluidized medium particles and less than the fluidization lower limit of the catalyst particles. . The recovery port 506 communicates with the catalyst recovery pipe 513. The fluidizing gas G1 is supplied into the catalyst recovery pipe 513 from the gas chamber 511b. Here, the catalyst recovery pipe 513 is connected to the fluid medium supply pipe 14.

  The organic material P1 supplied from the raw material supply port 501 is mixed with the fluid medium particles P2 and catalyst particles P5 supplied from the fluid medium supply port 502, and thermally decomposes while flowing in the Y negative direction. The flowing medium particles P2 and the char P3 generated by thermal decomposition flow into the overflow pipe 16 from the discharge port 504. The catalyst particles P5 that have reached the vicinity of the discharge port 504 settle in the recovery port 506 due to a decrease in fluidity. The catalyst particles P5 that have settled in the recovery port 506 are fluidized by the fluidizing gas supplied from the gas chamber 511b, and are carried to the fluid medium supply pipe 14 through the catalyst recovery pipe 513. The catalyst particles P <b> 5 are returned to the gasification furnace 10 through the fluid medium supply pipe 14. As described above, in Modification 4, a part of the fluid medium supply pipe 14, the recovery port 506, and the catalyst recovery pipe 513 form a circulation path, and the gas that supplies the fluidizing gas G1 to the circulation path and the circulation path. The chamber 511b and the gas supply device 510 constitute a circulation device. As a result, the flow P5f of the catalyst particles P5 becomes a circulation flow, and the catalyst particles P5 stay in the gasification furnace 50, so that the consumption of the catalyst particles P5 is significantly reduced.

DESCRIPTION OF SYMBOLS 1 ... Gasifier, 10 ... Gasifier, 11 ... Fluidizer, 12 ... Combustion furnace, 13 ... Raw material supply pipe, 14 ... Fluid medium supply pipe, 15 ..Gas recovery device, 16 ... overflow pipe, 17 ... transfer pipe, 18 ... separator, P1 ... organic material raw material, P2 ... fluid medium particles, P5 ... catalyst particles

Claims (8)

A gasification furnace in which fluidized medium particles, an organic material that is thermally decomposed into an organic gas and char by heat supplied from the fluidized medium particles, and catalyst particles that promote thermal decomposition of the organic material are stored;
The particles stored in the gasification furnace are fluidized, and the catalyst particles of the particles are retained in the gasification furnace, and the char and part of the fluidized medium particles are provided in the gasification furnace. And a fluidizing device for discharging from the discharged outlet. The fluidizing device includes a gas supply device for supplying a fluidizing gas for fluidizing the particles into the gasification furnace,
The followability of the catalyst particles with respect to the fluidizing gas is set to be smaller than the followability of the fluidizing medium particles with respect to the fluidizing gas, and the fluid supplied to the vicinity of the discharge port in the gasification furnace. The gasification apparatus according to claim 1, wherein a linear velocity of the gasified gas is set to be less than an average value of the linear velocity of the fluidized gas supplied into the gas furnace.   The linear velocity of the fluidizing gas supplied in the vicinity of the discharge port is set to be less than the fluidization lower limit velocity of the catalyst particles determined by the particle size and density of the catalyst particles. Gasifier.   The linear velocity of the fluidized gas supplied to at least a part of the gasification furnace excluding the vicinity of the discharge port is set to be equal to or higher than the fluidization lower limit velocity of the catalyst particles determined by the particle size and density of the catalyst particles The gasifier according to claim 2, wherein the gasifier is provided.   The surface in the vicinity of the discharge port at least on the bottom surface in the gasification furnace is an inclined surface that extends upward in the vertical direction toward the discharge port. The gasifier described in 1. A recovery port provided at the bottom of the gasifier in the vicinity of the discharge port;
The gasifier according to any one of claims 2 to 4, further comprising a circulation device that circulates the catalyst particles flowing into the recovery port into the gasification furnace.   The average value of the linear velocity of the fluidizing gas supplied into the gasification furnace is set to be not less than 3 times and not more than 12 times the fluidization lower limit velocity of the fluidizing media particles determined by the particle size and density of the fluidizing media particles. The gasifier according to any one of claims 2 to 5, wherein: A combustion furnace for heating the fluidized medium particles by burning the char discharged from the outlet;
The gasifier according to claim 2, further comprising: a transfer device that transfers the fluidized medium particles heated in the combustion furnace into the gasifier.

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