JP5463524B2 - Biomass gasification method and biomass gasification system - Google Patents

Description

  The present invention relates to a method for gasifying biomass with supercritical water and a system for gasifying biomass with supercritical water.

  In recent years, energy conversion technologies using biomass such as plants or waste materials thereof, livestock manure, garbage, food waste, and sewage sludge have been developed. As an energy conversion technology using biomass as a raw material, for example, a method of fermenting biomass with microorganisms to generate fuel gas, a method of generating pressurized fuel water using water contained in biomass, and generating fuel gas As the latter improvement method, a method of gasifying wet biomass with supercritical water using a catalyst to generate fuel gas is known (for example, see Patent Documents 1 to 4). .

However, in the supercritical water gasification technology known so far, the reaction system ruptures because the biomass and water contained in the biomass rapidly expand in the vicinity of the critical point, and the generated fuel gas There was a problem with safety, such as the possibility of causing an explosion by igniting.
Japanese National Patent Publication No. 11-502891 JP 2002-105466 A JP 2002-105467 A JP 2006-274013 A

  The present invention regulates the supply amount of biomass and the water contained in the biomass to adjust the supply amount of water contained in the biomass and the biomass, and a method for gasifying the biomass with supercritical water safely and efficiently. It aims at providing the biomass gasification system which can be performed.

  In order to solve the above-mentioned problems, the biomass gasification method according to the present invention is characterized in that the biomass is subjected to a temperature within a range of 100 to 250 ° C. and a pressure within a range of 0.1 to 4 MPa in the presence of a nonmetallic catalyst. A pretreatment process for producing a slurry body of the biomass containing the nonmetallic catalyst by hydrothermal treatment under the conditions of the above, and a slurry body containing the nonmetallic catalyst using a slurry supply device A supply step of supplying to the reactor, and a reaction step of generating gas by hydrothermally treating the slurry body supplied to the reactor under conditions of a temperature of 374 ° C. or higher and a pressure of 22.1 MPa or higher, In the biomass gasification method including the above, in the supply step, the slurry body is adjusted while the supply amount is adjusted by controlling the operating frequency of the slurry supply device. And supplying to the vessel. The hydrothermal treatment here refers to treatment with subcritical water or supercritical water, particularly among treatment with high-temperature and high-pressure water.

  The supplying step further includes one or more of a temperature measuring step for measuring a temperature inside or outside the reactor, or a pressure measuring step for measuring a pressure inside or outside the reactor, and the pressure measurement When any one or more of the pressure measured in the process or the measured temperature exceeds a predetermined value, the operation frequency of the slurry supply device is controlled by reducing the operation frequency. preferable.

  The biomass gasification method according to the present invention may further include a heating step of heating the slurry body supplied to the reactor by using the gas as a fuel.

  In addition, the biomass gasification method according to the present invention may further include a power generation step for generating electricity and exhaust heat by using the gas as a fuel. In this case, a first preheating step of preheating the biomass by using the exhaust heat may be further included, and the slurry body supplied to the reactor is preheated by using the exhaust heat. A second preheating step may be further included.

  On the other hand, in the biomass gasification system according to the present invention, in the presence of a non-metallic catalyst, the biomass is heated under conditions of a temperature in the range of 100 to 250 ° C. and a pressure in the range of 0.1 to 4 MPa. By treating, the pre-processing apparatus which manufactures the slurry body of the said biomass containing the said nonmetallic catalyst, and the slurry body containing the said nonmetallic catalyst are the temperature of 374 degreeC or more, and the pressure of 22.1 MPa or more. In a biomass gasification system comprising: a reactor that generates gas by hydrothermal treatment under conditions; and a slurry supply device that supplies a slurry containing the nonmetallic catalyst from the pretreatment device to the reactor. The supply device includes an operation frequency control device that adjusts the supply amount of the slurry by controlling the operation frequency.

  ADVANTAGE OF THE INVENTION According to this invention, the supply amount of water contained in biomass and biomass, and the method of gasifying biomass with supercritical water safely and efficiently by adjusting the supply amount of water contained in biomass and biomass It is possible to provide a biomass gasification system capable of adjusting

  Hereinafter, preferred embodiments will be described in detail with reference to the accompanying drawings.

== Configuration of biomass gasification system according to the present invention ==
FIG. 1 is a diagram showing an overall configuration of a biomass gasification system described as an embodiment of the present invention. As shown in FIG. 1, a biomass gasification system (hereinafter simply referred to as “system”) 200 according to the present invention includes a regulating tank 100, a crusher 110, a supply pump 120, a first heat exchanger 130, a second Heat exchanger 131, pretreatment device 140, slurry supply device 150, operating frequency control device 151, reactor 160, heater 161, preheater 162, heater 163, preheater 164, cooler 170, decompressor 171, gas-liquid A separator 180, a gas tank 181, a catalyst recovery unit 182, a power generator 190 and the like are provided.

  The pretreatment device 140 is a device that forms a biomass slurry. Formation of a biomass slurry is performed by hydrothermal treatment of biomass in the presence of a non-metallic catalyst at a temperature in the range of 100 to 250 ° C. and a pressure in the range of 0.1 to 4 MPa. Done.

  The adjustment tank 100 is a tank that mixes biomass, water, a nonmetallic catalyst, and the like while adjusting the mixing amount of water and a nonmetallic catalyst according to the type, amount, moisture content, and the like of the biomass.

  The crusher 110 crushes the mixture mixed in the adjustment tank 100 so that the biomass in the mixture has a uniform size in advance (preferably an average particle size of 500 μm or less, more preferably an average particle size of 300 μm or less). It is a device.

  The supply pump 120 is a device that transfers the mixture crushed by the crusher 110 to the pretreatment device 140.

  The reactor 160 is a device that gasifies biomass with supercritical water. Biomass gasification with supercritical water is carried out by using a biomass slurry containing a nonmetallic catalyst that has been hydrothermally treated in the pretreatment device 140 at a temperature of 374 ° C. or higher, using the nonmetallic catalyst. It is performed by hydrothermal treatment under conditions of a pressure of 22.1 MPa or more. In addition, the hydrothermal treatment here refers to treatment with subcritical water or supercritical water, among other treatments with high-temperature and high-pressure water. By treating the slurry body with supercritical water in this way, biomass can be decomposed and fuel gas such as hydrogen gas, methane, ethane, or ethylene can be generated.

  The reactor 160 includes a temperature measurement device that measures the internal temperature, external temperature, or heating temperature of the reactor, and a pressure measurement device that measures the internal temperature, heating temperature, or pressurized pressure of the reactor (see FIG. Not shown).

  The reactor 160 is not particularly limited as long as it is a device capable of hydrothermally treating a biomass slurry in the presence of a nonmetallic catalyst under the above-described conditions. A configured reactor, fluidized bed reactor, or the like can be used. In the present embodiment, the case where the reactor 160 is a fluidized bed reactor capable of continuous operation will be described.

  FIG. 2 shows a schematic configuration of a fluidized bed reactor 160 capable of continuous operation in an embodiment of the present invention. A reactor 160 as shown in FIG. 2 includes an inlet 210 for introducing a biomass slurry containing a nonmetallic catalyst into the reactor 160 from below, and the slurry in the reactor 160 at a temperature of 374 ° C. or higher. Reactor gas and ash containing fuel gas produced by hydrothermal treatment under temperature and pressure conditions of 22.1 MPa or higher, and non-metallic catalyst and water (supercritical water) from outside of reactor 160 from above A discharge port 220 for discharging the fluid, a fluid medium 230 for forming a fluidized bed in the reactor 160 by introduction of the slurry body, and a dispersion unit 240 for dispersing the slurry material introduced from the inlet 210 under the fluidized bed. I have.

  The fluid medium 230 has a shape that is not discharged at the introduction speed of the slurry body. That is, the fluidized bed is formed at a speed at which the slurry body is introduced from the introduction port 210, but has a weight that cannot be discharged from the discharge port 220. In addition, when the mesh-shaped plate is installed in the discharge port 220, the fluid medium 230 may be configured with a size larger than the mesh of the plate. The fluid medium 230 is not particularly limited as long as it does not change the particle size even in a supercritical state, that is, the fluid medium is not easily broken. For example, alumina balls, zirconia balls, silica balls, etc. Can be mentioned.

  The dispersion unit 240 may be, for example, a known dispersion plate (for example, a mesh-like plate) used in a fluidized bed reactor or the like, but in order to prevent an increase in pressure due to clogging of the slurry body, It is a layer formed by stacking spherical media (for example, spherical media such as alumina balls) configured in a shape that does not flow at the speed at which the slurry body is introduced (for example, a weight that cannot flow at the speed at which the slurry body is introduced). Is preferred.

  By using the reactor 160 as described above, it is possible to perform a gasification reaction with supercritical water in the presence of a non-metallic catalyst on the slurry introduced from the inlet 210, and the production generated thereby. Gases (including fuel gas) and ash, as well as non-metallic catalysts and water (supercritical water), such as fluid media 230, can be discharged from the discharge port 220. In addition, such a reactor 160 can suppress accumulation of ash, nonmetallic catalyst, and the like in the reactor 160 with the above-described configuration, and thus a biomass slurry containing a nonmetallic catalyst. It is possible to continuously introduce the body and continuously perform the gasification reaction with supercritical water.

  The slurry supply device 150 is a device that supplies a biomass slurry containing a nonmetallic catalyst obtained by performing the hydrothermal treatment in the pretreatment device 140 to the reactor 160.

  The slurry supply device 150 includes an operation frequency control device 151 that controls the operation frequency of the slurry supply device 150. By using this control device 151, the amount of slurry supplied to the reactor 160 can be adjusted by controlling the operating frequency of the supply device 150. For example, if the amount of slurry supplied to the reactor 160 is reduced by reducing the motion frequency of the supply device 150 using the control device 151 when the internal temperature of the reactor 160 reaches around the critical point, the criticality can be reduced. The rapid volume expansion of the biomass slurry in the vicinity of the point can be reduced, and as a result, a rapid increase in the internal pressure of the reactor 160 can be prevented. Further, after the critical point is exceeded and the internal pressure of the reactor 160 becomes substantially constant, the amount of slurry supplied to the reactor 160 is increased by increasing the motion frequency of the supply device 150 using the control device 151. Then, a large amount of slurry can be reacted without abruptly changing the internal pressure of the reactor 160. Therefore, biomass gasification can be performed safely and efficiently by appropriately controlling the operation frequency of the slurry supply device 150 using the operation frequency control device 151.

  The slurry supply device 150 is not particularly limited as long as it is a device that can be used in combination with the operation frequency control device 151 and can supply a slurry body of biomass containing a nonmetallic catalyst. A high-pressure pump, a Mono pump, or the like can be used, but an apparatus capable of continuously supplying the above-described slurry body that can be easily separated into a solid component and a liquid component as shown in FIG. Is preferred.

  FIG. 3 is a diagram showing a schematic configuration of a slurry supply apparatus 150 described as an embodiment of the present invention. A slurry supply apparatus 150 as shown in FIG. 3 receives a biomass slurry body containing a nonmetallic catalyst obtained by performing hydrothermal treatment in the pretreatment apparatus 140 from the pretreatment apparatus 140, and enters the reactor 160. It is a device to supply. The slurry supply device 150 includes two cylinders 310 and 320, a shaft 330, two pistons 331 and 332, two agitators 340 and 350, a water injection device 360, valves 361, 362, 363, 364, 373, 374, and 375. , 376, three-way valves 371, 372 and the like.

  The water injection device 360 is a device for injecting water into the cylinders 310 and 320 by alternately switching the cylinders 310 and 320 for injecting water. The water injection device 360 is, for example, a pump, a high pressure pump, a back pressure pump, or the like.

  The cylinders 310 and 320 are provided with injection / discharge ports for injecting water from the water injection device 360 and discharging the injected water. Further, the cylinders 310 and 320 are provided with receiving / supplying ports that receive the slurry body from the pretreatment device 140 and supply the received slurry body to the reactor 160.

  Pistons 331 and 332 are disposed in the cylinders 310 and 320 so as to partition water injected from the water injection device 360 and a slurry body received from the pretreatment device 140.

  Pistons 331 and 332 are provided at both ends of the shaft 330. The pistons 331 and 332 move in the cylinders 310 and 320 when water is injected into the cylinders 310 and 320 from the water injection device 360, and the slurry bodies in the cylinders 310 and 320 are pressed to make the slurry into the reactor 160. Supply the body. As the one piston 331, 332 moves, the other piston 332, 331 moves in the same direction as the one piston 331, 332, receives the slurry body from the pretreatment device 140, and in the cylinders 320, 310 Drain the water.

  In order to prevent the water in the cylinders 310 and 320 and the slurry from being mixed, a piston ring may be provided on the pistons 331 and 332 to improve the airtightness between the pistons 331 and 332 and the cylinders 310 and 320.

  In the present embodiment, a stopper 333 is provided at the center of the shaft 330. The stopper 333 is a device that prevents contact between the pistons 331 and 332 and the stirrers 340 and 350. When the stopper 333 comes into contact with the cylinders 310 and 320, the pistons 331 and 332 cannot move toward the stirrers 340 and 350.

  The valves 361, 362, 363, and 364 are devices that switch the water to flow from the water injection device 360 to the cylinders 310 and 320 and switch the water in the cylinders 310 and 320 to discharge. The valves 361, 362, 363, 364 are, for example, electromagnetic valves.

  In the present embodiment, the valves 361, 362, 363, and 364 are switched so that water flows into the cylinders 310 and 320 by the water injection of the water injection device 360. Further, the valves 361, 362, 363, and 364 are switched so that water is discharged by drainage from the cylinders 310 and 320. Such switching can be performed electrically with water injection from the water injection device 360 or drainage from the cylinders 310 and 320, for example. Specifically, when it is detected that the stopper 333 provided on the shaft 330 has come into contact with one of the cylinders 310 and 320, the water injection device 360 changes the water injection destination from the cylinders 310 and 320 to the other cylinders 320 and 310. The valves 363 and 361 are opened so that water flows from the water injection device 360 to the cylinders 320 and 310, and the valves 364 and 362 are not discharged so that water injected from the water injection device 360 to the cylinders 320 and 310 is not discharged. The valves 362 and 364 are opened so that water is discharged from the cylinders 310 and 320, and the valves 361 and 363 are closed so that water discharged from the cylinders 310 and 320 does not flow to the water injection device 360. May be performed respectively.

  In the present embodiment, the slurry supply device 150 is provided with valves 361, 362, 363, 364, but instead of these valves 361, 362, 363, 364, two three-way valves are provided, It may be switched so that water flows into the cylinders 310 and 320 by water injection from the injection device 360, or may be switched so that water is discharged by drainage from the cylinders 320 and 310. Such switching can be mechanically performed by, for example, a valve that prevents backflow, but can also be electrically performed in accordance with water injection from the water injection device 360 or drainage from the cylinders 310 and 320. Specifically, when it is detected that the stopper 333 provided on the shaft 330 has come into contact with one of the cylinders 310 and 320, the water injection device 360 changes the water injection destination from the cylinders 310 and 320 to the other cylinders 320 and 310. One of the three-way valves may be switched so that water flows from the water injection device 360 to the cylinders 320 and 310, and the other three-way valve may be switched so that water is discharged from the cylinders 310 and 320.

  The three-way valves 371 and 372 are switched so that the slurry body flows from the pretreatment device 140 to the cylinders 310 and 320 by the reciprocating motion of the pistons 331 and 332, and the slurry bodies received in the cylinders 310 and 320 are cylinders 310 and 320. To switch to flow into the reactor 160.

  In the present embodiment, when receiving the slurry body from the pretreatment device 140, the three-way valves 371 and 372 are switched so that the slurry body flows from the pretreatment device 140 to the cylinders 310 and 320. The three-way valves 371 and 372 are switched so that the slurry body flows from the cylinders 310 and 320 to the reactor 160 when the slurry body is supplied from the cylinders 310 and 320. Such switching can be mechanically performed by, for example, a valve for preventing backflow, but is electrically performed in accordance with the slurry body supply from the cylinders 310 and 320 and the slurry body supply from the pretreatment device 140. You can also. Specifically, when it is detected that the stopper 333 provided on the shaft 330 contacts one of the cylinders 310 and 320, the three-way valves 371 and 372 cause the slurry body to flow from the pretreatment device 140 to the cylinders 310 and 320. The other three-way valves 372 and 371 may be controlled so that the slurry body flows from the other cylinders 320 and 310 to the reactor 160, respectively.

  Note that the detection of the contact between the stopper 333 and the cylinders 310 and 320 is performed, for example, by providing a switch in a part of the region where the stopper 333 and the cylinder 310 and 320 are in contact and pressing the switch. Also good.

  The valves 373 and 374 are used when the cylinder that supplies the slurry body to the reactor 160 is switched from one cylinder 310 or 320 to the other cylinder 320 or 310, that is, the cylinder 310 or 320 into which the water injection device 360 injects water. Is a device that temporarily shuts off the flow (supply) of the slurry body from the cylinders 310, 320 to the reactor 160 when switching from one cylinder 310, 320 to the other cylinder 320, 310. The valves 375 and 376 are slurries from the pretreatment device 140 to the cylinders 310 and 320 when the water injection device 360 switches the cylinders 310 and 320 into which water is injected from the one cylinder 310 and 320 to the other cylinder 320 and 310. It is a device that temporarily blocks the body from flowing. The valves 373, 374, 375, and 376 are, for example, electromagnetic valves.

  The above-described blocking by the valves 373, 374, 375, and 376 may be performed electrically, for example, with water injection from the water injection device 360 or drainage from the cylinders 310 and 320. Specifically, when it is detected that the stopper 333 provided on the shaft 330 is in contact with one of the cylinders 310 and 320, the valves 373 and 374 flow (supply) the slurry body from the cylinders 310 and 320 to the reactor 160. The valves 376 and 375 are closed so as to block the flow (acceptance) of the slurry body from the pretreatment device 140 to the cylinders 320 and 310, and the water injection device 360 controls the water injection destination. After switching from the cylinder 310, 320 to the other cylinder 320, 310, one of the valves 373, 374, one valve 374, 373 flows the slurry body from the cylinder 320, 310 to the reactor 160 via the three-way valve 372, 371. Of the valves 375 and 376, one of the valves 375 and 376 Control of opening from the processing unit 140 to flow into the cylinder 310 the may be performed, respectively.

  The agitators 340 and 350 are devices that agitate the slurry body received in the cylinders 310 and 320 from the pretreatment device 140 via the valves 375 and 376 and the three-way valves 371 and 372. In this manner, by stirring the slurry body with the stirrers 340 and 350 in the cylinders 310 and 320, precipitation of solid substances such as non-metallic catalyst and biomass particles contained in the slurry body can be prevented. The slurry body having a constant concentration can be supplied to the reactor 160.

  In the present embodiment, between the slurry supply device 150 and the reactor 160, the pressure accumulator 380 that accumulates the slurry body supplied from the slurry supply device 150, and between the pretreatment device 140 and the slurry supply device 150. And a pressure accumulator 381 for accumulating a slurry body received by the slurry supply device 150. By providing these, the pressure in the piping connecting the slurry supply device 150 and the reactor 160 and the pressure in the piping connecting the pretreatment device 140 and the slurry supply device 150 can be kept constant, and pulsation And the occurrence of water hammer (water hammer) can be prevented.

  It should be noted that the switching of the water injection destination performed by the water injection device 360 described above may be performed electrically at the timing when the stopper 333 provided on the shaft 330 contacts the cylinders 310 and 320, or in each cylinder 310 or 320. It may be performed by detecting that the pressure has increased. The water injected by the water injection device 360 into the cylinders 310 and 320 is preferably water having the same temperature as the temperature of the slurry body received in the cylinders 310 and 320. Thereby, the cylinders 310 and 320 are cooled by the water injected into the cylinders 310 and 320, and the temperature of the slurry body received in the cylinders 310 and 320 can be suppressed from decreasing. The water injection into the cylinders 310 and 320 by the water injection device 360 is preferably performed at a constant flow rate so that the slurry body is supplied to the reactor 160 at a constant flow rate.

  In the above description, the stopper 333 is provided on the shaft 330 of the slurry supply device 150 to prevent contact between the pistons 331 and 332 and the stirrers 340 and 350. It is possible to prevent the pistons 331 and 332 from coming into contact with the stirrers 340 and 350 by adjusting the length of the water, or to add water in an amount that does not contact the pistons 331 and 332 and the stirrers 340 and 350. 360 may be alternately injected into each of the cylinders 310 and 320 to prevent the pistons 331 and 332 from coming into contact with the stirrers 340 and 350. Moreover, you may provide the stopper (for example, unevenness | corrugation etc.) which controls the movement of piston 331,332 in cylinder 310,320 so that piston 331,332 and stirrer 340,350 may not contact.

  Further, in the above description, one port (injection / discharge port) for injecting water from the water injection device 360 and discharging the injected water is provided in the cylinders 310 and 320, but water is injected from the water injection device 360. The cylinders 310 and 320 may be provided with two ports, an injection port for discharging and a discharge port for discharging the injected water.

  In the above description, the cylinders 310 and 320 are provided with one port (acceptance / supply port) for receiving the slurry body from the pretreatment device 140 and supplying the received slurry body to the reactor 160. The cylinders 310 and 320 may be provided with two ports, an inlet for receiving the slurry body from 140 and a supply port for supplying the received slurry body to the reactor 160.

  The preheater 162 is an apparatus that preheats a biomass slurry body containing a nonmetallic catalyst, which is supplied from the slurry supply apparatus 150 to the reactor 160. By providing the system 200 with the preheater 162, it becomes possible to supply a slurry body having a predetermined temperature to the reactor 160.

  The cooler 170 is a device that cools the discharge discharged from the reactor 160. The exhaust discharged from the reactor 160 contains a product gas such as highly explosive fuel gas (for example, hydrogen, methane, ethane, ethylene) or water vapor (supercritical water). The cooler 170 is provided in the system 200 of the present invention for the purpose of reducing water vapor or converting water vapor into water. In the present embodiment, the cooler 170 is described as an example of a device for cooling the discharge discharged from the reactor 160, but the device that can cool the discharge discharged from the reactor 160. Any device may be used as long as it is.

  The decompressor 171 is a device that reduces the pressure of the effluent discharged from the reactor 160. As a result, the danger caused by the high-pressure fuel gas can be prevented beforehand.

  The gas-liquid separator 180 converts the exhaust discharged from the reactor 160 into a gas mixture (for example, a product gas such as a fuel gas) and a liquid component (water, water, ash, a non-metallic catalyst, or the like). ). As the gas-liquid separator 180, for example, an existing gas-liquid separator such as a separator can be used.

  The gas tank 181 is a container (preferably a pressure resistant container) that stores the gas component (product gas) separated by the gas-liquid separator 180.

  The heater 161 uses a part of the generated gas (fuel gas) stored in the gas tank 181 as fuel, for example, burns together with a gas containing oxygen (for example, oxygen gas, air, etc.) to heat the reactor 160, An apparatus for heating the slurry body to a predetermined temperature. The heater 163 heats the preheater 162 by burning a part of the generated gas (fuel gas) stored in the gas tank 181 with, for example, a gas containing oxygen (for example, oxygen gas, air, etc.). And the slurry body is heated to a predetermined temperature. The heaters 161 and 163 are existing devices that burn and heat fuel gas, such as a burner, for example.

  The catalyst recovery unit 182 recovers the nonmetallic catalyst from the liquid component when the liquid component separated by the gas-liquid separator 180 contains a nonmetallic catalyst other than water, ash, or the like. An apparatus for separating a metal catalyst from a liquid component. In FIG. 4, the schematic block diagram of the catalyst collection | recovery device 182 which isolate | separates ash in a liquid component, a nonmetallic catalyst, and water each demonstrated as one Embodiment of this invention is shown. In the present embodiment, the case where the nonmetallic catalyst is activated carbon having a lower sedimentation rate (termination rate) than ash will be described.

  As shown in FIG. 4, the catalyst recovery unit 182 includes a mixed liquid injection unit 410, a water tank 420, a circulation pump 430, a supply pipe 440, an ash receiving unit 450, valves 460, 461, and 470.

  The liquid mixture injection unit 410 is a pipe for injecting the liquid component (mixed liquid containing ash, activated carbon, water, etc.) separated by the gas-liquid separator 180. The water tank 420 is a cylindrical container in which water for slowly sinking ash and activated carbon in the mixed liquid injected from the mixed liquid injection unit 410 is placed. The water tank 420 has a discharge port 421 for allowing ash in the liquid mixture injected from the liquid mixture injection unit 410 to settle and discharge the water from the water tank 420, an activated carbon receiving part 422 423 for receiving activated carbon in the liquid mixture, and an ash floating in the water tank 420. And a drain outlet 424 for discharging suspended matter such as activated carbon and water together with water.

  The ash receiving unit 450 is a container that receives the ash that has settled from the discharge port 421. The circulation pump 430 is a pump that circulates the water in the water tank 420. The supply pipe 440 is a pipe that introduces water circulated by the circulation pump 430 into the water tank 420 through the discharge port 421. The water circulated by the circulation pump 430 is supplied from the discharge port 421 to the water tank 420 at a flow rate that is faster than the sedimentation rate of the activated carbon and slower than the sedimentation rate of the ash. Thereby, the ash in the mixed liquid injected from the mixed liquid injection unit 410 settles in the ash receiving unit 450 through the discharge port 421, but the activated carbon in the mixed liquid injected from the mixed liquid injection unit 410 is It moves to the activated carbon receiving part 422,423 without passing through the discharge port 421.

  In the present embodiment, the activated carbon receivers 422 and 423 are provided with ridges 425 and 426 made of finer mesh than the activated carbon particles so that the activated carbon collected in the receivers 422 and 423 can be collected. The ash receiving unit 450 is provided with a ridge 451 made of a mesh finer than ash particles so that the ash collected in the receiving unit 450 can be collected.

  The valves 460 and 461 are valves that discharge water from the water tank 420. After separating the ash and activated carbon in the mixed solution injected from the gas-liquid separator 180, the activated carbon accumulated in the tanks 425 and 426 is recovered by draining the water in the water tank 420 through the valves 460 and 461. Can do. Further, the valve 470 is a valve for draining water from the ash receiving unit 450. After separating the ash and activated carbon in the mixed solution injected from the gas-liquid separator 180, the ash collected in the tub 451 can be recovered by draining the water of the ash receiving portion 450 by the valve 470. .

  By providing the catalyst recovery device 182 as described above in the system 200 of the present invention, the mixed solution can be separated into the nonmetallic catalyst, the ash, and the water, and the nonmetallic catalyst can be recovered. This makes it possible to reuse the recovered nonmetallic catalyst.

  The catalyst recovery unit 182 includes an existing solid-liquid separator that separates the mixed liquid containing the ash, the nonmetallic catalyst, and water separated by the gas-liquid separator 180 into a solid component and a liquid component; It may be a combination with an existing sieve device that separates the ash in the separated solid component and the nonmetallic catalyst by sieving.

  The first heat exchanger 130 is obtained by hydrothermal treatment in the pretreatment device 140, and uses the heat of the biomass slurry containing the nonmetallic catalyst to be hydrothermally treated in the reactor 160. 140 is an apparatus for preheating biomass or the like to be subjected to hot water treatment.

  The second heat exchanger 131 is hydrothermally treated in the reactor 160 using the heat of the effluent discharged from the reactor 160 including the product gas generated by hydrothermal treatment in the reactor 160. An apparatus for preheating a biomass slurry containing a non-metallic catalyst.

  As described above, by providing the heat exchangers 130 and 131 in the system 200 of the present invention, energy can be used effectively, so that fuel gas can be generated from biomass at low energy and low cost. become. Moreover, since the heating time in each apparatus 140,160 is shortened, fuel gas can be efficiently generated from biomass. Therefore, it can be said that the system 200 provided with the heat exchangers 130 and 131 is excellent in economic efficiency.

  The power generation device 190 is a device that generates power using the generated gas (fuel gas) stored in the gas tank 181 as fuel. The power generation device 190 is an existing device such as a gas engine (reciprocating engine or rotary engine), a gas turbine, a Stirling engine, or a fuel cell.

  In the present embodiment, as shown in FIG. 1, biomass is generated using heat (exhaust heat) of exhaust gas discharged from the power generation device 190 when the power generation device 190 generates power using the generated gas as fuel. The pretreatment device 140 includes a heat exchanger for heating, and the system 200 includes a preheater 164 having a heat exchanger for preheating a fuel used in the heaters 161 and 163, for example, a gas containing oxygen. . As described above, since the system 200 of the present invention includes the pretreatment device 140 having the heat exchanger and / or the preheater 164, energy can be efficiently used. In addition to being able to produce fuel gas such as hydrogen, it is also possible to generate electric power and supply electric power with low energy and low cost. Accordingly, it is possible to reduce the amount of heated fuel used, reduce the amount of exhaust gas generated, and the like.

  As described above, the exhaust heat of the power generation device 190 may be used by the pretreatment device 140 and the preheater 164 regardless of the temperature of the exhaust heat of the power generation device 190, but the exhaust heat depends on the exhaust gas temperature of the power generation device 190. You may change how to use heat suitably. Specifically, when the exhaust gas temperature of the power generator 190 is higher than the reaction temperature in the reactor 160, the exhaust heat may be used only by the preheater 164 as shown in FIG. Only the exhaust heat may be used. Further, when the exhaust gas temperature of the power generator 190 is lower than the reaction temperature in the reactor 160 and higher than the treatment temperature in the pretreatment device 140, the exhaust heat is used only by the pretreatment device 140 as shown in FIG. May be. As described above, by appropriately changing the method of using the exhaust heat according to the exhaust gas temperature of the power generation device 190, the exhaust heat of the power generation device 190 can be used more effectively.

  Furthermore, in the present embodiment, as shown in FIGS. 1, 5, and 6, the heat of the exhaust gas obtained by burning the product gas in a fuel, for example, a gas containing oxygen, by the heater 163. The reactor 160 is equipped with a heat exchanger for heating the biomass slurry containing the nonmetallic catalyst. Further, the heat of the exhaust gas used to heat the slurry body in the reactor 160 and / or the exhaust gas obtained by burning in the gas containing oxygen, for example, with the product gas as the fuel by the heater 161 A pre-heater 164 having a heat exchanger for preheating the biomass used for the heaters 161 and 163, for example, a gas containing oxygen, is provided in the pre-processing device 140 using the heat of the biomass. Are provided in the system 200. As described above, the reactor 160, the pretreatment device 140, the preheater 164, and the like are provided with a heat exchanger, and the product gas obtained by the heater 163 is burned in a gas containing oxygen, for example, as a fuel. Heat of exhaust gas, heat of exhaust gas used to heat the slurry body in the reactor 160, heat of exhaust gas obtained by burning in a gas containing oxygen, for example, with the product gas as fuel by the heater 161 By using the above, energy can be used more effectively.

  In the above description, the heat of the exhaust gas obtained by the heater 163 is used in the pretreatment device 140 or the preheater 164 after being used in the reactor 160, but in the pretreatment device 140 or the preheater 164. You may use it directly. Further, in the present embodiment, as shown in FIG. 1, the introduced material (specifically, gas containing biomass or oxygen, etc.) introduced into the pretreatment device 140 or the preheater 164 is discharged from the power generation device 190. After heating with a heat exchanger using heat, the heat of the exhaust gas used to heat the slurry body in the reactor 160 and / or the gas containing oxygen, for example, using the product gas as fuel by the heater 161 Although it heats with the heat exchanger using the heat | fever of the waste gas obtained by burning in, these positions may be changed suitably according to the temperature of each waste gas.

  Furthermore, in the above description, the system 200 of the present invention includes the second heat exchanger 131 that preheats the slurry body using the heat of the exhaust discharged from the reactor 160. A heat exchanger that preheats biomass or the like to be hydrothermally treated in the pretreatment device 140 using the heat of the exhaust discharged from the reactor 160, including the product gas generated by the System 200 may be provided.

  In addition, by providing the system 200 according to the present invention with the pretreatment device 140 that preliminarily treats the biomass with hot water, the biomass can be decomposed from a polymer to a low molecule. In addition, the efficiency of contact with non-metallic catalysts can be increased, char and tar can be prevented, and fuel gas can be efficiently generated from biomass.

  Furthermore, since the biomass slurry body having excellent fluidity can be formed by hydrothermally treating the biomass in the pretreatment device 140, the slurry body can be smoothly supplied to the reactor 160 by the slurry supply device 150. It becomes possible to prevent clogging of equipment and piping due to biomass in the supply to the reactor 160.

  In addition, the non-metallic catalyst used in the hydrothermal treatment in the pretreatment device 140 can be used in the hydrothermal reaction in the reactor 160 by the system 200 according to the present invention. It becomes possible to reduce.

  Further, by providing the system 200 according to the present invention with the reactor 160 as shown in FIG. 2, ash (residue) obtained by gasifying biomass with supercritical water will not accumulate in the reactor 160. In addition, gasification treatment of biomass with supercritical water can be performed continuously, and fuel gas can be generated more efficiently from biomass.

  Further, by providing the system 200 according to the present invention with a slurry supply device 150 as shown in FIG. 3, the above-mentioned slurry body that is easily separated into a solid component and a liquid component can be continuously supplied to the reactor 160 at a constant concentration. Therefore, a slurry body containing a nonmetallic catalyst or biomass can be continuously supplied to the reactor 160 under a concentration condition with the highest gasification efficiency of supercritical water, and fuel gas can be generated more efficiently from biomass. It becomes possible.

  Furthermore, by providing the system 200 according to the present invention with the cooler 170, the pressure reducer 171, the gas-liquid separator 180, etc., the produced gas containing the fuel gas can be safely recovered from the exhaust discharged from the reactor 160. Will be able to.

  Moreover, since the biomass can be crushed beforehand by providing the system 200 according to the present invention with the crusher 110 that crushes the biomass, the efficiency of biomass slurrying and gasification can be increased.

  In the present embodiment, the mixture obtained by mixing the nonmetallic catalyst, biomass and water in the adjustment tank 100 is processed by the crusher 110 and supplied to the pretreatment device 140 by the supply pump 120. The system catalyst may be supplied directly to the pretreatment device 140, or after the mixture of biomass and water is processed by the crusher 110, the nonmetallic catalyst may be mixed and supplied to the pretreatment device 140.

== Biomass gasification method according to the present invention ==
Next, as an embodiment of the present invention, a method for gasifying biomass with supercritical water while adjusting the supply amount of biomass and water contained in biomass will be described.

  First, a mixture in which biomass, a nonmetallic catalyst, and water are mixed in the adjustment tank 100 is prepared. The mass ratio between the nonmetallic catalyst and the biomass (the dried biomass) is preferably in the range of 1: 5 to 20: 1, and the biomass gasification efficiency is high of 1: 2 to 20: 1. It is particularly preferable that it is within the range. Moreover, it is preferable to adjust the quantity of the water to mix so that the moisture content of biomass may be 70-95 wt%. Thereby, the gasification efficiency by the supercritical water of biomass can be improved.

  As described above, the amount of the non-metallic catalyst mixed with the biomass and the amount of water is adjusted, and the mixture obtained by mixing these is crushed by the crusher 110 and is fed by the supply pump 120 via the first heat exchanger 130. It is transferred to the processing device 140. The biomass supplied to the pretreatment device 140 is hydrothermally treated under conditions of a predetermined pressure and a predetermined temperature in the presence of a nonmetallic catalyst supplied together with the biomass.

  The conditions for the hydrothermal treatment are not particularly limited as long as the temperature is in the range of 100 to 250 ° C. and the pressure is in the range of 0.1 to 4 MPa. From the viewpoint of the efficiency of the treatment of decomposing into low molecules, it is preferably the saturation temperature of water under a pressure within these ranges, and from the viewpoint of energy saving, a temperature of 179.8 ° C. and a pressure of 1.0 MPa It is particularly preferred that Here, the reason why the hydrothermal treatment is performed at a temperature within the range of 100 ° C. to 250 ° C. is that the decomposition reaction rate of biomass is low below 100 ° C., and if it exceeds 250 ° C., generation of tar and char is concerned. is there. In addition, the hydrothermal treatment is performed at a pressure within the range of 0.1 to 4 MPa because the biomass decomposition reaction rate is low below 0.1 MPa, and the influence on the decomposition reaction rate is much higher even when a pressure higher than 4 MPa is applied. This is because I thought that it might not be.

  Thus, biomass can be efficiently decomposed from a polymer to a low molecule by hydrothermal treatment of the biomass in the presence of a nonmetallic catalyst.

The biomass slurry containing the nonmetallic catalyst obtained as described above provides heat to the mixture supplied from the supply pump 120 to the pretreatment device 140 by the first heat exchanger 130, and the slurry supply device 150 is transferred to the reactor 160 via the second heat exchanger 131 and the preheater 162. By adjusting the motion frequency of the supply device 150 using the motion frequency control device 151, the amount of slurry transferred from the slurry supply device 150 to the reactor 160 can be easily increased or decreased. For example, in order to avoid a sudden increase in the internal pressure of the reactor 160, when the internal temperature of the reactor 160 becomes close to the critical point, the controller 151 is used to decrease the motion frequency of the supply device 150, From the viewpoint of safety, it is preferable to reduce the amount of slurry supplied to the reactor 160. After the critical point is exceeded and the internal pressure of the reactor 160 becomes substantially constant, the amount of slurry supplied to the reactor 160 is increased by increasing the motion frequency of the supply device 150 using the control device 151. Increasing and reacting a large amount of slurry without changing the internal pressure of the reactor 160 rapidly is preferable from the viewpoint of efficiency.
In addition, the slurry body which passed the preheater 162 is heated to predetermined temperature.

  The biomass slurry supplied to the reactor 160 is introduced into the reactor 160 and hydrothermally treated under the conditions of a predetermined pressure and a predetermined temperature in the presence of the nonmetallic catalyst supplied with the biomass. The conditions for the hydrothermal treatment are not particularly limited as long as the temperature is 374 ° C. or higher and the pressure is 22.1 MPa or higher, but the generation of tar and char is suppressed and the reaction efficiency is increased. It is preferable to carry out under the temperature (600 degreeC) and pressure (within the range of 25-35 MPa) which can be performed, and it is especially preferable to carry out at 600 degreeC and 25 MPa from a viewpoint of the burden of equipment, deterioration prevention, and energy saving. In addition, when it is desired to control the ratio of components in the fuel gas converted from biomass, the temperature and pressure conditions are adjusted, and the fluid density and reaction time (the residence time of biomass in the reactor 160) It becomes possible by controlling the above.

  Thus, by reacting the biomass slurry body with supercritical water, it becomes possible to generate combustion gas from the biomass slurry body. In addition, by reducing the biomass from a polymer in advance, the contact efficiency with water or a non-metallic catalyst can be increased, and furthermore, the gasification reaction time of the biomass can be shortened. Fuel gas such as hydrogen gas, methane, ethane, and ethylene can be generated more efficiently from the slurry body.

  The product gas generated by hydrothermally treating the biomass slurry in the reactor 160 is discharged from the reactor 160. This discharged material is supplied to the reactor 160 by the second heat exchanger 131 from the slurry supply device 150, and then supplies heat to the biomass slurry including the nonmetallic catalyst, and then the cooler 170 and the decompressor 171. It is cooled and decompressed and transferred to the gas-liquid separator 180. The exhaust gas supplied to the gas-liquid separator 180 is separated into product gas (gas component) containing fuel gas and water or a mixed solution (liquid component) containing water, ash, non-metallic catalyst, etc. The generated gas is stored in the gas tank 181. When the mixed liquid separated by the gas-liquid separator 180 contains ash other than water, a nonmetallic catalyst, or the like, the mixed liquid is ashed by the catalyst recovery unit 182, the nonmetallic catalyst, and Each may be separated into water to recover the nonmetallic catalyst. Thereby, it becomes possible to reuse the nonmetallic catalyst.

  The generated gas (fuel gas) stored in the gas tank 181 is supplied to the power generator 190 and the heaters 161 and 163. The power generation device 190 generates power using the supplied generated gas and provides power. Further, the heaters 161 and 163 use the supplied product gas as fuel, for example, burn in oxygen-containing gas to heat the reactor 160 and the preheater 162, and heat the slurry body to a predetermined temperature.

  The exhaust gas discharged from the power generation device 190 when the power generation device 190 generates power using the generated gas as fuel is supplied to the pretreatment device 140 and the preheater 164, and the mixture supplied from the supply pump 120 to the pretreatment device 140 is heated. In the preheater 164, heat is supplied to the fuel used in the heaters 161 and 163, for example, a gas containing oxygen.

  Further, the exhaust gas obtained by burning the produced gas as fuel with the heater 163, for example, in a gas containing oxygen is supplied to the reactor 160 to provide heat to the slurry body. The exhaust gas provided with heat in the reactor 160 and the exhaust gas obtained by burning in the gas containing oxygen, for example, with the product gas as the fuel by the heater 161 are supplied to the pretreatment device 140 and the preheater 164. Then, heat is supplied to the mixture supplied from the supply pump 120 to the pretreatment device 140, and heat is supplied to the fuel, for example, oxygen-containing gas, used in the heaters 161 and 163 in the preheater 164.

  In addition, as a nonmetallic catalyst used in this Embodiment, activated carbon, a zeolite, a mixture thereof etc. can be mentioned, for example. Thus, by using a nonmetallic catalyst instead of an alkali metal catalyst, it is possible to prevent deterioration due to corrosion of equipment or piping caused by the alkali metal catalyst, and the system 200 can be used for a long time. Become. In addition, a processing step for neutralizing the alkali metal catalyst is not required, and the efficiency of workability can be improved. As the non-metallic catalyst, it is preferable to use a powder having an average particle size of 200 μm or less, and more preferably porous. By using such a nonmetallic catalyst, it is possible to increase the surface area and increase the reaction efficiency, and to prevent clogging of equipment, piping, etc. in the system 200 due to the nonmetallic catalyst.

  In addition, when the biomass to be treated in the present embodiment is wastewater sludge or manure containing foreign substances such as sand, before and after hydrothermal treatment of biomass in the pretreatment device 140, a known separation technique (for example, Foreign substances such as sand contained in the biomass may be removed by a separation method using a strainer or a separation method using a sediment layer. As a result, troubles caused by foreign matters such as sand can be prevented.

  Hereinafter, the present invention will be specifically described by way of examples. These examples are for explaining the present invention, and do not limit the scope of the present invention.

[Example 1]
A biomass slurry obtained by stirring and mixing 97.6 parts by mass of water, 2 parts by mass of chicken dung, and 0.4 parts by mass of activated carbon having a particle size of 20 μm and hydrothermally treated at 180 ° C. and 1.1 MPa was used as a high-pressure pump. Was pressed into a tubular reactor, and a reaction with supercritical water was performed under conditions of 600 ° C. and 25 MPa. As a control experiment, a gasification reaction with supercritical water was similarly performed without adding activated carbon. As a result, it is clear that the carbon gasification rate is 73% when no activated carbon is added, whereas the carbon gasification rate increases to 88% when 0.4 parts by mass of activated carbon is added. Became.

[Example 2]
Next, 80 parts by mass of water, 20 parts by mass of cellulose powder, and 20 parts by mass of activated carbon having an average particle size of 100 μm were stirred and mixed to prepare a slurry. Thereafter, 40 ml of the slurry was poured into a 167 ml autoclave equipped with a stirrer, and the temperature was raised to 400 ° C. while stirring at a pressure of 25 MPa and held for 1 hour to perform a gasification reaction with supercritical water. After the reaction, the reaction mixture was cooled to room temperature, and the product gas was recovered to determine the carbon gasification rate. As a control experiment, the same treatment was performed without adding activated carbon. As a result, it was found that the carbon gasification rate was 10% when no activated carbon was added, whereas the carbon gasification rate increased to 30% when activated carbon was added.
From the above, it has become clear that the gasification efficiency can be increased by adding a nonmetallic catalyst.

[Example 3]
As shown in FIG. 2, a dispersion plate (net) is provided below a fluidized bed reactor 160 (φ12.3 mm × 2400 mm) provided with an inlet 210 and an outlet 220, and alumina balls having an average particle diameter of 1 mm are flowed. Installed as a medium. In this fluidized bed reactor 160, a mixture of alumina particles (average particle size of 180 to 250 μm or average particle size of 250 to 300 μm) mixed with water instead of biomass (ash) or non-metallic catalyst is mixed with alumina. The particles were ejected and introduced from the inlet 210 at a flow rate (0.19 m / s to 0.60 m / s) at which the alumina balls as the fluid medium did not eject, and the alumina particles discharged from the outlet 220 were collected.

  As a result, when alumina particles having an average particle diameter of 180 to 250 μm are introduced into the fluidized bed reactor 160, 97.5% alumina particles can be recovered, and alumina particles having an average particle diameter of 250 to 300 μm are recovered. When introduced into the fluidized bed reactor 60, it was found that 98.9% alumina particles could be recovered. From this, a slurry body of biomass (average particle size is 300 μm or less) containing a nonmetallic catalyst is supplied to the fluidized bed reactor 160 as described above at a predetermined flow rate (for example, the maximum at which the fluidized medium does not jump out from the discharge port). The generated product gas and ash as well as the nonmetallic catalyst and water (supercritical water) are obtained by performing a hydrothermal reaction at a predetermined temperature and a predetermined pressure while being introduced from the inlet 210 at a flow rate). It was shown that it can be discharged from the outlet 220.

[Example 4]
The biomass gasification system was started, and the operating frequency of the back pressure pump was set to 44.4 Hz (about 0.8 mL / min with the slurry supply amount). Subsequently, 85% by mass of water, 10% by mass of chicken manure, and 5% by mass of activated carbon having a particle size of 20 to 30 μm were added to the adjustment tank. This time was defined as the device start start time.

  The operating frequency, reactor outlet pressure, cooler outlet pressure, preheater outlet temperature of the preheater 162 and reactor outlet temperature were measured over time after the apparatus was started. The results are shown in FIG.

  33 minutes after the start of the apparatus, the heater 161 provided in the preheater and the heater 163 provided in the reactor were ignited. Thereafter, the reactor outlet temperature reached 175 ° C. at 41 minutes after the start-up of the apparatus, and the reactor internal temperature was approaching the critical point. Therefore, in order to avoid a sudden rise in the reactor internal pressure, The kinetic frequency of the pressure pump was gradually decreased to 20.4 Hz in increments of 1 Hz / min, and the amount of slurry supplied to the reactor was gradually reduced.

  The reaction was continued for 22 minutes while keeping the motion frequency of the back pressure pump at 20.4 Hz. 1 hour and 26 minutes after the start-up of the apparatus, the reactor outlet temperature reached 417 ° C, the state inside the reactor was well above the critical point, and the rise in pressure was thought to have settled. Was increased by 2 Hz / min and returned to 44.4 Hz. In the state where the motion frequency of the back pressure pump was increased to 44.4 Hz, the operation could be continued for about 2 hours from 1 hour and 36 minutes after the start of the apparatus.

  On the other hand, when the same biomass gasification was attempted without changing the motion frequency of the back pressure pump from 44.4 Hz as a control experiment, the reaction system burst.

  From the above, it was shown that biomass gasification can be performed safely and efficiently by adjusting the slurry supply amount to the reactor by controlling the motion frequency of the slurry supply device.

It is a figure showing the whole biomass gasification system composition explained as one embodiment of the present invention. In one Embodiment of this invention, it is a figure which shows schematic structure of the fluidized bed reactor which can be operated continuously. It is a figure which shows schematic structure of the slurry supply apparatus demonstrated as one Embodiment of this invention. It is a figure which shows schematic structure of the catalyst recovery device demonstrated as one Embodiment of this invention. In one Embodiment of this invention, it is a figure which shows the whole biomass gasification system structure in case the waste heat temperature of an electric power generating apparatus is higher than the reaction temperature in a reactor. In one Embodiment of this invention, it is a figure which shows the whole biomass gasification system structure in case the temperature of the waste heat of the electric power generating apparatus 190 is lower than the reaction temperature in the reactor 160, and higher than the processing temperature in the pre-processing apparatus 140. is there. In one Embodiment of this invention, it is a figure which shows a time-dependent change at the time of starting a biomass gasification system, controlling a movement frequency.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Adjustment tank 110 Crusher 120 Supply pump 130 1st heat exchanger 131 2nd heat exchanger 140 Pretreatment apparatus 150 Slurry supply apparatus 151 Operation frequency control apparatus 160 Reactor 161 Heater 162 Preheater 163 Heater 164 Preheater 170 Cooler 171 Pressure reducer 180 Gas-liquid separator 181 Gas tank 182 Catalyst recovery unit 190 Power generation device 200 Biomass gasification system

Claims (7)

In the presence of a nonmetallic catalyst, the biomass is included by hydrothermal treatment under conditions of a temperature in the range of 100 to 250 ° C. and a pressure in the range of 0.1 to 4 MPa. A pretreatment process for producing the biomass slurry;
A supply step of supplying the slurry body containing the nonmetallic catalyst to a reactor using a slurry supply device;
A reaction step of generating gas by hydrothermally treating the slurry supplied to the reactor under conditions of a temperature of 374 ° C. or higher and a pressure of 22.1 MPa or higher;
In a biomass gasification method including
The supplying step further includes a pressure measuring step of measuring the pressure inside or at the outlet of the reactor,
The supply step controls and supplies the operation frequency of the slurry supply device by increasing the operation frequency of the slurry supply device when the pressure measured in the pressure measurement step is stable beyond a critical point. A gasification method, wherein the slurry body is supplied to the reactor in an increased amount. The supplying step further includes a temperature measuring step of measuring the temperature inside or at the outlet of the reactor,
If the measured in the temperature measurement process temperature exceeds a predetermined value, by reducing the operating frequency, characterized in that to reduce the supply amount by controlling the operating frequency of the slurry supply device, The gasification method according to claim 1.   The gasification method according to claim 1, further comprising a heating step of heating the slurry body supplied to the reactor by using the gas as a fuel.   The gasification method according to claim 1, further comprising a power generation step of generating electricity and exhaust heat by using the gas as a fuel.   The gasification method according to claim 4, further comprising a first preheating step of preheating the biomass by using the exhaust heat.   The gasification method according to claim 4, further comprising a second preheating step of preheating the slurry body supplied to the reactor by using the exhaust heat. In the presence of a nonmetallic catalyst, the biomass is included by hydrothermal treatment under conditions of a temperature in the range of 100 to 250 ° C. and a pressure in the range of 0.1 to 4 MPa. A pretreatment device for producing the biomass slurry;
A reactor for generating gas by hydrothermally treating the slurry containing the nonmetallic catalyst under conditions of a temperature of 374 ° C. or higher and a pressure of 22.1 MPa or higher;
A slurry supply device for supplying a slurry body containing the nonmetallic catalyst from the pretreatment device to the reactor;
In a biomass gasification system comprising:
A pressure gauge for measuring the pressure inside or at the outlet of the reactor,
When the pressure measured by the pressure gauge is stable beyond the critical point,
The gasification system further comprising an operation frequency control device that increases the supply amount of the slurry by controlling by increasing an operation frequency of the supply device.

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