JP5118338B2 - Carbonization and gasification method and system - Google Patents

Description

  The present invention relates to a carbonization / gasification method and system. More specifically, the present invention is suitable for use in combination with a technology for generating electricity with a gas engine or the like, and thermally decomposes biomass fuel such as woody biomass, waste biomass such as municipal waste, and mixed biomass thereof. The present invention relates to a carbonization / gasification method and system for biomass that is carbonized and further gasified.

  In this specification, biomass fuel refers to woody biomass such as agricultural and forestry resources and their residues and building waste, livestock and fishery resources and their residues and waste biomass such as food waste and sludge, and mixtures thereof. Used to mean biomass. The carbonization / gasification method and system are used to mean a method and system in which biomass fuel is pyrolyzed and carbonized using a carbonizer and further gasified using a gasifier.

  Examples of techniques related to conventional carbonization and gasification methods applicable to biomass and organic waste include, for example, carbide obtained by carbonizing biomass or organic waste at 300 ° C. to 800 ° C., steam, There is a pyrolysis gasification apparatus in which air is introduced into a pyrolysis gasification furnace to obtain a combustible gas by a water gasification reaction (Patent Document 1).

JP 2004-35837 A

  However, in the pyrolysis gasification apparatus of Patent Document 1, when the carbide is introduced into the gasification furnace in order to partially combust the carbide and obtain a combustible gas by the water gasification reaction, it is obtained by carbonization treatment by the carbonization apparatus. Since the generated carbide is directly put into the gasification furnace, the size of the carbide put into the gasification furnace varies, and the combustion and reaction in the gasification furnace vary. For this reason, it cannot be said that it is guaranteed that the gasification performance of continuously generating a combustible gas having a high quality such as a large gas calorific value is exhibited.

  In addition, when supplying flammable gas to equipment or facilities that require continuous operation, such as power generation equipment using a gas engine, the flammability is maintained at a high level and constant quality such as the amount of heat generated by the gas. It is necessary to supply gas continuously and stably.

  Then, an object of this invention is to provide the carbonization and gasification method and system which can improve gasification performance. Furthermore, an object of the present invention is to provide a carbonization / gasification method and system capable of continuously and stably gasifying biomass.

  In order to achieve this object, the carbonization / gasification method according to claim 1 is a two-stage gas generation method in which a biomass fuel is carbonized to produce a carbide and a combustible pyrolysis gas generated during carbonization of the biomass fuel is generated. It is sent to both the gasification / combustion section and gas reforming section of the gasification furnace, and the carbide is supplied to the gasification / combustion section of the two-stage gasification furnace to perform combustion and gasification and to the gas reforming section. The combustible pyrolysis gas sent in is reformed to generate combustible gas.

Furthermore, the carbonization / gasification system according to claim 8 is a carbonization device that carbonizes biomass fuel to generate carbides, a gasification / combustion unit that performs combustion and gasification of carbides, and carbonization treatment of biomass fuel. A two-stage gasification furnace having a gas reforming section for reforming the generated combustible pyrolysis gas, a gasification / combustion section of the two-stage gasification furnace from the carbonization apparatus for the combustible pyrolysis gas, and And a gas supply pipe provided with a branch pipe to be fed into each of the gas reforming sections.

  Therefore, according to this carbonization / gasification method and system, the combustible pyrolysis gas is supplied not only to the gas reforming section of the two-stage gasification furnace but also to the gasification / combustion section (also called the high-temperature gasification section). As a result, a sufficient amount of heat is introduced into the gasification / combustion section.

  The invention according to claim 2 is the carbonization / gasification method according to claim 1, wherein the carbide is pulverized to produce fine powder carbide, and the fine powder carbide is ejected to form a two-stage gasifier. The gas is supplied to the combustion / combustion section.

The invention according to claim 9 is the carbonization / gasification system according to claim 8 , wherein a pulverizer for pulverizing the carbide to produce fine powder carbide, and a two-stage gasification furnace for jetting the fine powder carbide. It further has a powder injection means for supplying to the gasification / combustion section.

In this case, since the carbide is pulverized into fine powder before being supplied to the gasifier, the carbide may be generated depending on the type of raw material biomass fuel, even if the combustion rate of the generated carbide is slow. There is fully combusted without leaving burning the gasification furnace (gasification and combustion section of the two-stage gasifier in concrete). Furthermore, compared with the case of directly supplied to the gasification furnace carbides discharged from carbonization apparatus, gasifier since the size of the carbides is finely and carbides supplied ejected (concrete in the two-stage gas The carbide is diffused throughout the gasification / combustion section) and the size of the carbide is kept small and constant, so that the carbide is uniformly diffused throughout the gasification furnace.

The invention according to claim 3 is the carbonization / gasification method according to claim 1 or 2 , wherein the carbonization of the biomass fuel is performed using a plurality of carbonization apparatuses, and the carbonization processes by the plurality of carbonization apparatuses are alternately performed. It is going to end.

According to a tenth aspect of the present invention, in the carbonization / gasification system according to the eighth or ninth aspect , a plurality of carbonization apparatuses are set so that the carbonization of the biomass fuel is alternately terminated.

  In this case, since the carbonization treatment is set to be alternately ended at a predetermined interval between the plurality of carbonization apparatuses, the carbide is continuously supplied to the gasifier without interruption. Further, since carbonization of biomass fuel is performed by a plurality of carbonization apparatuses and carbide is supplied from the plurality of carbonization apparatuses to the gasifier, the carbonization after one carbonization process in one carbonization apparatus is performed. The variation in amount is alleviated and a certain amount of carbide is continuously and stably supplied to the gasifier.

The invention according to claim 4 is the carbonization / gasification method according to any one of claims 1 to 3 , wherein the combustible pyrolysis gas generated in the initial stage of the carbonization treatment of the biomass fuel is supplied to the gasifier. I am trying not to supply it.

An eleventh aspect of the present invention is the carbonization / gasification system according to any one of the eighth to tenth aspects, wherein the flare stack for combusting the combustible pyrolysis gas generated at the initial stage of the carbonization processing of the biomass fuel is provided. Furthermore, it has to have.

  In this case, the combustible pyrolysis gas that is generated in the initial stage of the carbonization treatment of the biomass fuel and contains a large amount of moisture and has low combustion performance is prevented from being sent into the gasification furnace.

Further, the invention according to claim 5 is the carbonization / gasification method according to any one of claims 1 to 4 , wherein the biomass fuel is dried before the carbonization treatment.

A twelfth aspect of the present invention is the carbonization / gasification system according to any one of the eighth to eleventh aspects, further comprising a drying mechanism for drying the biomass fuel.

  In this case, since the moisture in the biomass fuel is reduced in advance, the moisture contained in the combustible pyrolysis gas generated during the carbonization treatment of the biomass fuel is reduced.

Further, the inventions according to claims 6 and 13 are the carbonization / gasification method according to any one of claims 1 to 5 and the carbonization / gasification system according to any one of claims 8 to 12 . In addition, air mixed with oxygen is used as a gasifying agent fed into the gasification furnace. In this case, the oxygen enrichment operation is performed in the gasification furnace.

Further, the invention according to claims 7 and 14 is the carbonization / gasification method according to any one of claims 1 to 6 and the carbonization / gasification system according to any one of claims 8 to 13 . The temperature of the gasifying agent fed into the gasification furnace is raised in advance. In this case, it is possible to prevent the temperature in the gasification furnace from decreasing.

According to the carbonization / gasification method and system of claims 1 and 8 , the combustible pyrolysis gas is supplied not only to the gas reforming section of the two-stage gasification furnace but also to the gasification / combustion section. Therefore, it is possible to input a sufficient amount of heat into the gasification / combustion section, and the gasification performance can be improved.

Furthermore, according to carbonization and gasification method and system 9 according to claim 2 parallel beauty, a carbide even when the combustion rate of the produced carbides is slower gasifier (concrete in two-stage gasifier The gasification / combustion section) can be sufficiently combusted, and the gasification performance can be improved. Moreover, (the concrete gasification and combustion section of the two-stage gasifier) gasifier is possible to uniformly diffuse the carbides throughout the gasifier together to spread the carbides throughout the Yes, the gasification performance can be improved.

Furthermore, according to the carbonization / gasification method and system according to claims 3 and 10 , the carbide can be continuously supplied to the gasification furnace without interruption, and the continuous and stable combustible gas can be supplied. Generation can be performed. In addition, a certain amount of carbide can be continuously and stably supplied to the gasification furnace, so that a combustible gas can be continuously and stably generated.

Furthermore, according to the carbonization / gasification method and system of claims 4 and 11, it is possible to prevent combustible pyrolysis gas containing a lot of moisture and having low combustion performance from being sent into the gasification furnace. Yes, because the temperature in the gasification furnace can be maintained at a high temperature, the gasification performance is improved and the moisture in the gasification product gas (combustible gas) is reduced. Can be used.

Furthermore, according to the carbonization / gasification method and system according to claims 5 and 12, it is possible to reduce the moisture contained in the combustible pyrolysis gas generated during the carbonization treatment of the biomass fuel. Since the inside temperature can be maintained at a high temperature, the gasification performance is improved and the moisture in the gasification product gas (combustible gas) is reduced. Also, by removing moisture before charging the carbonizer, the amount of carbides and pyrolysis gas generated in one carbonization process increases, so the temperature in the gasifier can be maintained at a high temperature. The performance is improved and fuel with a high water content can be used.

Furthermore, according to the carbonization / gasification method and system according to claims 6 and 13 , since the oxygen enrichment operation can be performed in the gasifier and the temperature in the gasifier can be kept high, the gasification performance is improved. Improvement can be achieved, thereby enabling the use of a fuel with a low calorific value or a fuel with a high water content, and an increase in the number of fuel types.

Furthermore, according to the carbonization / gasification method and system according to claims 7 and 14 , since the temperature inside the gasification furnace can be prevented from being lowered, the gasification performance can be improved, and thereby the fuel having a low calorific value. In addition, it is possible to use a fuel with a high water content and to expand the fuel type.

  Hereinafter, the configuration of the present invention will be described in detail based on the best mode shown in the drawings.

  1 and 2 show an example of an embodiment of the carbonization / gasification method and system of the present invention. In the present embodiment, a case where a two-stage gasification furnace having a lower gasification / combustion section and an upper gas reforming section is used as the gasification furnace will be described as an example. In this carbonization / gasification method, biomass fuel 1 is carbonized to produce carbide 4 and combustible pyrolysis gas 3 generated during carbonization of biomass fuel 1 is gasified / combusted in a two-stage gasifier 7. Is sent to both the part 8 and the gas reforming part 9, and the carbide 4 is supplied to the gasification / combustion part 8 of the two-stage gasification furnace 7 to perform combustion and gasification, and is sent to the gas reforming part 9. The combustible pyrolysis gas 3 is reformed to generate the combustible gas 11.

  The carbonization / gasification method is apparatusized as the carbonization / gasification system of the present invention. The carbonization / gasification system of the present embodiment includes a carbonization device 2 that carbonizes biomass fuel 1 to generate carbides 4, a pulverizer 6 that pulverizes the carbides 4 to generate fine powdered carbides 4 ', and a fine powdery state. Two-stage gasification having a gasification / combustion unit 8 that performs combustion and gasification of the carbide 4 ′ and a gas reforming unit 9 that reforms the combustible pyrolysis gas 3 generated during carbonization of the biomass fuel 1. A gas supply pipe having a furnace 7 and branch pipes 12a and 12b for feeding the combustible pyrolysis gas 3 from the carbonization device 2 to the gasification / combustion unit 8 and the gas reforming unit 9 of the two-stage gasification furnace 7, respectively. 12.

  The combustible gas 11 generated in the two-stage gasifier (hereinafter simply referred to as a gasifier) 7 is, for example, a gas engine, a gas turbine, a fuel cell or the like (hereinafter referred to as a generated gas utilization device; Omitted) and used for power generation and the like.

  The carbonization apparatus 2 performs carbonization by separating the biomass fuel 1 into a combustible pyrolysis gas 3 containing moisture and volatiles in the biomass fuel 1 and a carbide 4 mainly composed of fixed carbon and ash. is there. Specifically, the biomass fuel 1 is heated, and carbonization is performed by evaporation of moisture and thermal decomposition reaction of organic matter in an oxygen-free state blocked from outside air. The carbonization apparatus used in the present invention is not particularly limited, and any carbonization apparatus may be used as long as the above-described carbonization treatment is possible (for example, a carbonizer manufactured by Okadora Corporation). ). In the present embodiment, a batch type carbonization apparatus is used as the carbonization apparatus 2, but the carbonization apparatus used in the present invention is not limited to a batch type.

  Here, depending on the type of the biomass fuel 1, the moisture content may be high, and in that case, the combustible pyrolysis gas 3 generated during the carbonization treatment contains a large amount of moisture. When the combustible pyrolysis gas 3 containing a large amount of moisture is sent to the gasification furnace 7, the quality of the combustible gas 11 deteriorates, for example, the temperature in the gasification furnace 7 decreases and the amount of heat generation decreases. There is a risk that.

  Therefore, when biomass fuel having a high moisture content is used as a raw material, the biomass fuel 1 may be dried in advance using a dryer (not shown) before being introduced into the carbonization apparatus 2. Specifically, it is preferably dried until it falls below 40 W%, more preferably below 20 W% (hereinafter referred to as a moisture content reference value).

  Here, the carbonization device 2 has a two-layer structure including an inner portion that pyrolyzes and carbonizes the biomass fuel 1 and an outer jacket portion that surrounds the inner portion, and is discharged from the generated gas utilization device, for example. The biomass fuel 1 may be heated by sending high-temperature exhaust gas of about 600 ° C. into the jacket portion. Thus, by setting it as the structure which carbonizes the biomass fuel 1 using the high temperature waste gas discharged | emitted from the generated gas utilization apparatus which operate | moves using the combustible gas 11 produced | generated in the gasification furnace 7 In addition, it is possible to effectively use energy as a whole system including the generated gas utilization device.

The gasification furnace 7 is a two-chamber, two-stage spouted bed type gasification furnace. The gasification furnace 7 burns the carbide produced in the carbonization apparatus 2 in the lower gasification / combustion unit 8 to form a high-temperature gas 10 of about 1500 ° C. and sends it to the upper gas reforming unit 9, and also gas reforming In the part 9, the high-temperature gas 10 is brought into contact with the combustible pyrolysis gas 3 generated by the carbonization treatment in the carbonization apparatus 2. Then, carbon monoxide (CO) and hydrogen (H) are obtained by a reforming reaction mainly based on a shift reaction (specifically, CO + H ₂ O ← → CO ₂ + H ₂ ) and decomposition of tar in the combustible pyrolysis gas 3. ₂ ) is generated as a main component. In order to decompose the tar in the combustible pyrolysis gas 3, the gas in the gas reforming section 9 is sent to the gas reforming section 9 in the upper stage of the gasification furnace 7 and comes into contact with the combustible pyrolysis gas 3. The gas temperature is required to be 1100 ° C. or higher. That is, in order for the gasification furnace 7 to exhibit good gasification performance, it is necessary to input a sufficient amount of heat to the gasification / combustion unit 8.

  The gasification / combustion section 8 of the gasification furnace 7 is fed with the gasification agent 5 by the gasification agent supply means 14 to cause a combustion reaction. As the gasifying agent 5, for example, air or air mixed with an appropriate amount of oxygen is used. When an appropriate amount of oxygen is mixed with air and used as the gasifying agent 5, the amount of oxygen mixed with air is not particularly limited, and the required calories of the flammable gas 11 determined by the generated gas utilization device or the flammable gas 11 It is set as appropriate according to the gas properties inside. Specifically, for example, it can be considered that the oxygen concentration in the gasifying agent 5 is set to 25 to 50 vol%. By mixing an appropriate amount of oxygen into the air as the gasifying agent 5, an oxygen enrichment operation is performed in the gasification / combustion unit 8, and the gasification performance is improved by raising the temperature in the gasification / combustion unit 8. As a result, it is possible to use a fuel with a low calorific value or a fuel with a high water content, and to expand the types of fuel.

  Alternatively, the temperature of the gasifying agent 5 may be raised in advance and then fed into the gasification / combustion unit 8. The temperature of the gasifying agent 5 in this case is not particularly limited, and the higher the temperature within the range of the heat resistance performance of the pipes constituting the carbonization / gasification system, the better. Specifically, for example, it is conceivable to raise the temperature of the gasifying agent 5 to about 300 ° C to 400 ° C. Thereby, the improvement of gasification performance can be aimed at. When the temperature of the gasifying agent 5 is increased, energy can be effectively utilized by using surplus heat in the system including the carbonization / gasification system of the present invention and the generated gas utilization device. There is no particular limitation as to which surplus heat of the entire system is used, but in the case of the present embodiment, the carbonization device 2 is a high-temperature exhaust gas discharged from the generated gas utilization device. The temperature of the gasifying agent 5 is raised using a high-temperature gas used as a heat source for carbonization treatment.

  Specifically, the gasifying agent supply means 14 is composed of an air supply device or piping for sending air or the like.

  A gas supply pipe 12 is provided between the carbonization apparatus 2 and the gasification furnace 7. One end of the gas supply pipe 12 is connected to the upper part of the carbonization apparatus 2, and sends the combustible pyrolysis gas 3 generated during the carbonization process to the gasification furnace 7. In addition, in order to prevent tar from adhering to the inner peripheral surface of the gas supply pipe 12, if necessary, measures such as covering the gas supply pipe 12 with a heat insulating material or heating the heater or surplus heat in the system are used. Appropriately applied.

  In the present invention, the gas supply furnace 12 side of the gas supply pipe 12 branches into a branch pipe 12a and a branch pipe 12b, and the combustible pyrolysis gas 3 is converted into the gasification / combustion section 8 and the gas reformer of the gasification furnace 7. The structure can be supplied to both of the mass parts 9. As described above, the combustible pyrolysis gas 3 that has been supplied only to the gas reforming unit 9 can be supplied to the gasification / combustion unit 8 as compared with the conventional case. The temperature of 8 can be sufficiently raised to completely burn the carbide 4 supplied to the gasification / combustion unit 8, and the gasification performance of the gasification furnace 7 can be improved. Note that the combustible pyrolysis gas 3 may not be supplied to the gasification / combustion unit 8 at all times. For example, in the gasification / combustion unit 8, the supply is performed only to the gas reforming unit 9. In a predetermined case such as when the temperature drops, the gasification / combustion unit 8 may be supplied.

  Here, depending on the type of the biomass fuel 1, a large amount of moisture may be contained in the combustible pyrolysis gas 3 generated in the initial stage of the carbonization treatment by the carbonizer 2. When the combustible pyrolysis gas 3 containing a large amount of moisture is sent to the gasification furnace 7, the quality of the combustible gas 11 deteriorates, for example, the temperature in the gasification furnace 7 decreases and the amount of heat generation decreases. There is a risk that.

  Therefore, the carbonization / gasification system of the present embodiment has a mechanism for separately processing the combustible pyrolysis gas 3 generated in the initial stage of the carbonization process without sending it to the gasification furnace 7. Specifically, the gas supply pipe 12 provided between the carbonization apparatus 2 and the gasification furnace 7 has a valve 26 in the middle, and a conduit 25b including the valve 25a is a carbonization apparatus for the valve 26 of the gas supply pipe 12. A flare stack 25 connected to the two sides is provided.

  The method for determining whether or not to send the combustible pyrolysis gas 3 generated in the carbonization process to the gasification furnace 7 is not particularly limited, and the characteristics of the carbonizer 2 to be used and the characteristics of the biomass fuel 1 to be used. It is set appropriately in consideration of the above. For example, it is conceivable that the combustible pyrolysis gas 3 generated for a certain time from the start of the carbonization treatment by the carbonizer 2 is not sent into the gasifier 7. In this case, the carbonization process is preliminarily performed in a combination of the carbonizer 2 and the biomass fuel 1 that are actually used, and the amount of water contained in the combustible pyrolysis gas 3 discharged is measured over time. Based on this measurement result, a certain time during which the combustible pyrolysis gas 3 is not sent to the gasification furnace 7 may be determined.

  Alternatively, as a method for determining whether or not to send the combustible pyrolysis gas 3 to the gasification furnace 7, the moisture contained in the combustible pyrolysis gas 3 discharged from the carbonization apparatus 2 is continuously measured, If the amount exceeds a certain amount, it is conceivable that the combustible pyrolysis gas 3 is not sent to the gasification furnace 7. Furthermore, when the biomass fuel 1 is introduced, the temperature in the carbonizer 2 rapidly decreases, and thereafter, when the evaporation of moisture is completed, the temperature starts to increase. Therefore, the temperature in the carbonizer 2 increases from the time when the biomass fuel 1 is introduced. It is conceivable that the combustible pyrolysis gas 3 is not sent to the gasification furnace 7 until it turns.

  Further, the carbonization / gasification system of the present embodiment includes a pulverizer 6 that pulverizes the carbide 4 to generate fine powdered carbide 4 ′. The pulverizer 6 pulverizes the carbide 4 introduced from the carbonization apparatus 2 to the micron order. The pulverizer used in the present invention is not particularly limited, and any pulverizer may be used as long as the carbide can be pulverized to the micron order. In the present embodiment, as the pulverizer 6, a pulverizer 6 is used which is composed of a rotating disk on which pin-shaped impact pillars are mounted in a radial pattern of two to three circles and a fixed disk mounted so as to mesh with the rotating disk. The pulverizer 6 takes in the carbide 4 from the central part of the rotating disk and the fixed disk, diffuses it with the air flow, gives an impact by the impact column and the fixed column, and adjusts the size with a screen mounted on the outer periphery. And then discharged as finely divided carbide 4 '.

  A carbide supply means 13 is provided between the carbonization device 2 and the pulverizer 6. One end of the carbide supply means 13 is connected to the bottom of the carbonization apparatus 2, and the carbide 4 generated by the carbonization process and remaining at the bottom of the carbonization apparatus 2 is taken out and conveyed. Specifically, as the carbide supply means 13, for example, a screw feeder is used.

  Here, in FIG. 1, the processing system for supplying the biomass fuel 1 and generating and transporting the carbide 4 and the finely divided carbide 4 ′ is shown as a single system for the sake of simplifying the explanation of the overall system configuration. A system | strain is not restricted to one system | strain, You may comprise by several systems.

  In the present embodiment, as shown in FIG. 2, the supply of biomass fuel 1 and the generation and transportation of carbide 4 and finely divided carbide 4 ′ are performed in a plurality of systems.

  Specifically, first, the raw material take-out means 31 for taking out the biomass fuel 1 charged and stored in the raw material receiving hopper 30 from the raw material receiving hopper 30 and the biomass fuel 1 taken out by the raw material take-out means 31 are distributed into two systems. It has the distribution means 32 and the transfer means 33 which conveys the distributed biomass fuel 1 to the fixed quantity supply hopper 29. As the raw material take-out means 31, for example, a mechanism comprising a screw feeder and a bucket conveyor provided at the bottom of the raw material receiving hopper 30 is used. As the distribution means 32, for example, a distribution screw conveyor is used, and as the transfer means 33, For example, a screw conveyor is used.

  Then, the fixed amount supply hopper 29 discharges the biomass fuel 1 in a predetermined amount based on the processing capacity of the carbonization apparatus 2 and the like while distributing the stored biomass fuel 1 into two systems.

  The carbonization / gasification system of the present embodiment has a fuel supply means 20 for supplying the biomass fuel 1 distributed and discharged from the fixed supply hopper 29 to the carbonizer 2. As the fuel supply means 20, for example, a screw feeder is used.

  As described above, in the present embodiment, the biomass fuel 1 stored in the raw material receiving hopper 30 is first distributed to two systems, and each system is further distributed to two systems. Therefore, a total of four carbonizers 2 are used. Thus, the carbonization treatment is performed.

  In addition, when performing a carbonization process using two or more carbonization apparatuses 2, the gas supply piping 12 is provided in each carbonization apparatus 2, and the valve | bulb 26 is provided in each of this gas supply piping. Thereby, the control of whether the combustible pyrolysis gas 3 is sent to the gasification furnace 7 or the flare stack 25 is controlled for each carbonizer 2. The carbonization process is performed using a plurality of carbonization apparatuses 2 and the destination of the combustible pyrolysis gas 3 is individually controlled, so that the combustible pyrolysis gas 3 continues to the gasifier 7. Sent.

  Furthermore, in this embodiment, the timing of the carbonization process start by these four carbonization apparatuses 2 is shifted, and it is adjusted so that the four carbonization apparatuses 2 end the carbonization process alternately. Specifically, each carbonization apparatus 2 is adjusted such that one carbonization process is completed within one hour, for example, 30 minutes or 40 minutes, by adjusting the processing amount and output per one time. Further, the four carbonization apparatuses 2 are adjusted so that the carbonization process is completed with a 15-minute shift in one hour. Thereby, the carbide | carbonized_material 4 is continuously produced | generated in the whole system, without interrupting at intervals of 15 minutes.

  And the carbide | carbonized_material supply means 13 conveys the carbide | carbonized_material 4 for two carbonization apparatuses 2 collectively to the grinder supply hopper 28 (illustration omitted in FIG. 1). Then, the carbide 4 stored in the pulverizer supply hopper 28 is supplied to the pulverizer 6 by the carbide supply means 13 and processed into fine powdered carbide 4 ′.

  In this way, by setting the carbides 4 for the two carbonization apparatuses 2 to be collectively collected and then supplied to the pulverizer 6, the carbide 4 generated by the carbonization process per time by the single carbonization apparatus 2 can be obtained. Even when there is a variation in the amount, a constant amount of carbide 4 can be continuously and stably supplied to the pulverizer 6. That is, it is possible to continuously supply a certain amount of pulverized carbide 4 ′ to the gasification furnace 7, and continuously and stably gasify the biomass fuel 1, and a stable amount of combustible gas. 11 can be generated.

  The carbonization / gasification system of the present embodiment includes an air flow transport mechanism 21 for air transporting the fine powdered carbide 4 ′ generated by the pulverizer 6. The airflow transport mechanism 21 includes a cyclone 17 and a bag filter 18 and various pipes 22, 23 and 24.

  The cyclone 17 and the bag filter 18 collect fine powdered carbides 4 'that are conveyed by airflow from the airflow.

  The airflow conveyance pipe 22 is provided between the pulverizer 6 and the cyclone 17 and conveys the finely powdered carbide 4 ′ discharged from the pulverizer 6. The finely powdered carbide 4 ′ is conveyed by airflow using nitrogen 19 in order to prevent the oxidation reaction.

  The airflow pipe 23 is provided between the cyclone 17 and the bag filter 18, and feeds the fine powdered carbide 4 ′ that could not be collected by the cyclone 17 into the bag filter 18.

  The nitrogen pipe 24 is provided between the bag filter 18 and the pulverizer 6, and feeds the airflow in which the finely divided carbide 4 ′ is recovered by the cyclone 17 and the bag filter 18 and becomes only nitrogen 19 to the pulverizer 6. It is.

  In the airflow conveyance mechanism 21, the nitrogen 19 circulates between the pulverizer 6, the airflow conveyance pipe 22, the cyclone 17, the airflow pipe 23, the bag filter 18, and the nitrogen pipe 24. Further, the airflow in the airflow conveying pipe 22 and the airflow pipe 23 includes fine powdered carbide 4 ′ and nitrogen 19, and the airflow in the nitrogen pipe 24 is only nitrogen 19.

  Furthermore, the carbonization / gasification system of the present embodiment includes a gasification furnace supply hopper 16 and a powder injection means 15 as a mechanism for supplying fine powdered carbide 4 ′ to the gasification / combustion unit 8 of the gasification furnace 7. Have.

  The gasification furnace supply hopper 16 stores fine powdered carbide 4 ′ recovered by the cyclone 17 and the bag filter 18. The finely divided carbide 4 ′ recovered by the cyclone 17 and the bag filter 18 is dropped by gravity, for example, and collected in the gasifier supply hopper 16 installed immediately below the cyclone 17 and the bag filter 18. Alternatively, the gas may be collected from the cyclone 17 and the bag filter 18 to the gasifier supply hopper 16 by a screw feeder.

  The powder jetting means 15 jets the fine powdered carbide 4 ′ stored in the gasification furnace supply hopper 16 into the gasification / combustion unit 8 of the gasification furnace 7 together with a gas such as a gasifying agent. Specifically, for example, a powder burner is used as the powder ejection means 15. In the powder burner 15 of the present embodiment, an LP gas pilot flame is formed at the center and an LP gas combustion flame is formed around the LP gas pilot flame. When the supply of the fine powdered carbide 4 ′ to the gasification / combustion unit 8 is started, the surrounding LP gas combustion flame is extinguished, and thereafter, the fine powdered carbide 4 ′ is mainly supplied when stably supplied. The pilot flame is also extinguished. The finely powdered carbide 4 ′ is preliminarily mixed with the gasifying agent in the powder burner 15 to form a flame at the tip of the powder burner 15.

  The operation of the carbonization / gasification system of the present embodiment described above will be described below.

  First, when the moisture content of the biomass fuel 1 is high, the biomass fuel 1 is dried by a dryer (not shown) until the moisture content falls below the moisture content reference value. When the drying process is performed, the biomass fuel 1 is stored in the raw material receiving hopper 30 as it is when the drying process is not performed.

  The raw material takeout means 31 takes out the biomass fuel 1 from the raw material receiving hopper 30 and sends it to the distribution means 32, and the distribution means 32 distributes the biomass fuel 1 to the two transfer means 33.

  Subsequently, the transfer means 33 transports the biomass fuel 1 to the quantitative supply hopper 29, and the quantitative supply hopper 29 distributes the biomass fuel 1 to the two fuel supply means 20.

  And the carbonization apparatus 2 spends time sufficiently, for example at the temperature of about 600 degreeC, and performs a carbonization process with the thermal decomposition of the biomass fuel 1 supplied by the fuel supply means 20. FIG.

  The carbonization device 2 discharges the combustible pyrolysis gas 3 generated by the carbonization treatment of the biomass fuel 1 to the gas supply pipe 12.

  When the combustible pyrolysis gas 3 contains a lot of moisture in the initial stage of carbonization treatment by the carbonization apparatus 2, the valve 26 of the gas supply pipe 12 is closed, and the valve 25 a provided in the conduit 25 b of the flare stack 25 is be opened. Thereby, the combustible pyrolysis gas 3 is supplied to the flare stack 25.

  When the carbonization process by the carbonization apparatus 2 proceeds and the moisture contained in the combustible pyrolysis gas 3 decreases, the valve 25a of the flare stack 25 is closed and the valve 26 of the gas supply pipe 12 is opened.

  The combustible pyrolysis gas 3 is sent to the gas reforming section 9 through a branch pipe 12b branched from the gas supply pipe 12. When the temperature in the gasification / combustion unit 8 becomes low, specifically, for example, when the temperature of the gas reforming unit 9 falls below 1100 ° C., which is a standard for the decomposition temperature of tar, through the branch pipe 12a. The combustible pyrolysis gas 3 is also sent to the gasification / combustion unit 8.

  Moreover, the carbonization apparatus 2 produces | generates the carbide | carbonized_material 4 containing fixed carbon, ash, and some volatile matter by carbonization process.

  Then, the carbide supply means 13 takes out the carbide 4 generated by the carbonization apparatus 2 and conveys it to the crusher supply hopper 28.

  Subsequently, the carbide supply means 13 between the pulverizer supply hopper 28 and the pulverizer 6 supplies the carbide 4 once stored in the pulverizer supply hopper 28 to the pulverizer 6.

  The pulverizer 6 pulverizes the supplied carbide 4 to the micron order to produce fine powder carbide 4 '.

  The air flow transport mechanism 21 air-transports the fine powdered carbide 4 ′ generated by the pulverizer 6, and the cyclone 17 and the bag filter 18 of the air flow transport mechanism 21 collect the fine powder carbide 4 ′ from the air flow. The recovered pulverized carbide 4 ′ is collected and stored in the gasifier supply hopper 16.

The powder jetting means 15 jets the fine powdered carbide 4 ′ stored in the gasification furnace supply hopper 16 into the gasification / combustion unit 8 at the lower stage of the gasification furnace 7.

  Further, the gasifying agent supply means 14 feeds air, which is heated to a high temperature and mixed with an appropriate amount of oxygen, into the gasification / combustion unit 8 as the gasifying agent 5.

  The gasification / combustion unit 8 uses the supplied fine powdered carbide 4 ′ as a fuel, and performs combustion and gasification using the gas that has been fed at a high temperature and mixed with an appropriate amount of oxygen as the gasifying agent 5, and is 1500 ° C. A high temperature gas 10 of a degree is generated.

  Then, the gas reforming unit 9 in the upper stage of the gasification furnace 7 uses the high-temperature gas 10 supplied from the gasification / combustion unit 8 as a heat source, and the tar contained in the combustible pyrolysis gas 3 fed from the carbonization device 2. Gas reforming is performed by decomposing the portion.

  At this time, when the flow rate of the combustible pyrolysis gas 3 of about 400 to 600 ° C. sent to the gas reforming unit 9 with respect to the supply amount of the fine powdered carbide 4 ′ is extremely large, the gasification / combustion unit 8 In some cases, the temperature of the high-temperature gas 10 of about 1500 ° C. supplied from the gas suddenly decreases in the gas reforming section 9 and becomes lower than the tar decomposition temperature of 1100 ° C. However, in the present invention, since the combustible pyrolysis gas 3 is also sent to the gasification / combustion unit 8 for combustion, a sufficient amount of heat is input to the gasification / combustion unit 8, and the gas reforming unit 9. Is maintained at 1100 ° C. or higher where tar can be decomposed.

Here, the state of the reaction in the gasification furnace 7 is expressed as follows using a chemical formula. As the combustion reaction in the gasification / combustion unit 8, reactions represented by chemical formulas 1 to 3 occur.
(Chemical Formula 1) C + O ₂ → CO ₂
(Chemical Formula 2) C + 1 / 2O ₂ → CO
(Chemical formula 3) H ₂ + 1 / 2O ₂ → H ₂ O

Furthermore, reactions represented by chemical formulas 4 and 5 occur as gasification reactions.
(Chemical formula 4) C + CO ₂ → 2CO
(Chemical Formula 5) C + H ₂ O → CO + H ₂

After the combustion reaction and the gasification reaction, CO, CO ₂ , H ₂ , H ₂ O, N ₂ , fixed carbon, and ash move from the gasification / combustion unit 8 to the gas reforming unit 9. Thereafter, a shift reaction represented by Chemical Formula 6 occurs in the gas reforming unit 9.
(Chemical formula 6) CO + H ₂ O ← → CO ₂ + H ₂

  The ash generated as a result of the combustion reaction and the gasification reaction in the gasification / combustion unit 8 becomes a molten slag when the melting point of the ash is lower than the temperature in the gasification / combustion unit 8. Removed from the bottom.

  The gasification furnace 7 discharges the generated combustible gas 11 from the gas reforming unit 9.

  In addition, although the above-mentioned form is an example of the suitable form of this invention, it is not limited to this, A various deformation | transformation implementation is possible in the range which does not deviate from the summary of this invention.

  For example, in the present embodiment, the case where the gasification furnace is a two-stage gasification furnace has been mainly described. However, the combustible pyrolysis gas generated during the carbonization treatment of biomass fuel is gasified in the two-stage gasification furnace. -Needless to say, the present invention is not limited to the form of the gasification furnace of the present embodiment except that it is fed to both the combustion section and the gas reforming section.

  In the present embodiment, the case where a two-stage gasification furnace having a lower gasification / combustion section and an upper gas reforming section is used as a two-stage gasification furnace has been described. The type of the gasification furnace is not limited to this, and the gasification / combustion unit and the gas reforming unit may be connected in the horizontal direction, or the gasification / combustion unit and the gas reforming unit. The part may be configured separately from each other.

  Further, in the present embodiment, the carbide 4 is pulverized by using the pulverizer 6 to form the finely divided carbide 4 ′ and then supplied to the gasification furnace 7. However, the present invention is not limited to this, and the pulverizer 6 is not used. It is good also as a structure.

  In the present embodiment, the flammable pyrolysis gas 3 containing a large amount of water is burned using the flare stack 25. However, the present invention is not limited to this, and the flare stack 25 may not be used. For example, when there is no environmental problem, it may be simply released into the atmosphere. Furthermore, it is good also as a structure which does not have the switching mechanism for sending the combustible pyrolysis gas 3 discharged | emitted from the carbonization apparatus 2 to a flare stack, or making it discharge | release to air | atmosphere.

  In this embodiment, when biomass fuel having a high water content is used as a raw material, the biomass fuel 1 is dried in advance using a dryer before being put into the carbonization apparatus 2. The drying mechanism is not limited to this, and the raw material receiving hopper 30 for storing the biomass fuel 1 itself is heated and dried, or the biomass fuel 1 is heated by equipment for transporting the raw material receiving hopper 30 to the carbonization apparatus 2. You may make it dry. Furthermore, it is good also as a structure which does not have a mechanism which dries biomass fuel 1 previously.

  Moreover, in this embodiment, oxygen is mixed with the air as the gasifying agent 5 to be sent to the gasification furnace 7, but it may be sent directly to the gasification furnace 7 without mixing oxygen.

  Further, in the present embodiment, the temperature of the gasifying agent 5 is increased by using a high-temperature gas that is a high-temperature exhaust gas discharged from the generated gas utilization device and is used as a heat source for carbonization treatment by the carbonization device 2. However, the method of raising the temperature of the gasifying agent 5 is not limited to this. For example, the combustible gas 11 at the outlet of the gasification furnace 7 may be used, or the gasification gas is discharged from the gasification furnace 7. You may utilize the heat | fever of the gas production | generation apparatus (illustration omitted) which refine | purifies the combustible gas 11. FIG. Furthermore, it is good also as a structure which does not have a mechanism which raises the temperature of the gasifying agent 5 previously.

  In the present embodiment, the biomass fuel 1 stored in the raw material receiving hopper 30 is first divided into two systems for the supply system of the biomass fuel 1 and the processing system for generating and transporting the carbide 4 and the finely divided carbide 4 ′. This system is further divided into two systems, and the carbonization process is performed by the four carbonization apparatuses 2, but the number of supply systems of the biomass fuel 1 and the processing system for generating and transporting the carbides 4 and finely divided carbides 4 ′ The number is not limited to this, and may be smaller or larger depending on the scale of the carbonization / gasification system.

  Furthermore, in this embodiment, using the four carbonization apparatuses, it is adjusted so that one carbonization process is completed within one hour, and is adjusted so that the carbonization process is completed with a shift of 15 minutes. The entire system continuously generates carbides without interruption, but the number of carbonization apparatuses used, the time of one carbonization treatment, and the interval between carbonization treatments are not limited to these. Specifically, for example, three carbonization apparatuses may be used to adjust the carbonization time for one cycle within 30 minutes and the carbonization end interval may be adjusted to 10 minutes. It is also possible to adjust the time for one carbonization treatment within 2 hours using the apparatus and to adjust the interval for the end of carbonization treatment to 20 minutes.

It is a schematic block diagram which shows an example of embodiment of the carbonization / gasification apparatus at the time of device-izing the carbonization / gasification method of this invention. It is a schematic block diagram of the fuel supply of the carbonization-gasification apparatus of this embodiment, and the production | generation of a carbide | carbonized_material, and a conveyance processing system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Biomass fuel 2 Carbonization apparatus 3 Combustible pyrolysis gas 4 Carbide 4 'Fine powder carbide 6 Crusher 7 Two-stage gasification furnace 8 Gasification / combustion part 9 Gas reforming part 11 Combustible gas

Claims (14)

  Carbonizing biomass fuel to produce carbides and sending combustible pyrolysis gas generated during carbonization of the biomass fuel to both the gasification and combustion section and gas reforming section of a two-stage gasifier, Combustion and gasification are performed by supplying the carbide to the gasification / combustion section of the two-stage gasification furnace, and the combustible pyrolysis gas sent to the gas reforming section is reformed and combustible. A carbonization / gasification method characterized by producing a reactive gas.   The carbonized product according to claim 1, wherein the carbide is pulverized to produce fine powdered carbide, and the fine powdered carbide is ejected and supplied to a gasification / combustion section of the two-stage gasification furnace. Gasification method. 3. The carbonization / gasification method according to claim 1, wherein the biomass fuel is carbonized using a plurality of carbonization apparatuses, and the carbonization processes performed by the plurality of carbonization apparatuses are alternately completed. The carbonization / gasification method according to any one of claims 1 to 3 , wherein the combustible pyrolysis gas generated in the initial stage of carbonization of the biomass fuel is not supplied to the gasification furnace. The carbonization / gasification method according to any one of claims 1 to 4 , wherein the biomass fuel is dried before the carbonization treatment. The carbonization / gasification method according to any one of claims 1 to 5 , wherein air mixed with oxygen is used as a gasifying agent fed into the gasification furnace. The carbonization / gasification method according to any one of claims 1 to 6 , wherein the temperature of the gasifying agent fed into the gasification furnace is increased in advance.   A carbonization device that carbonizes biomass fuel to generate carbide, a gasification / combustion unit that performs combustion and gasification of the carbide, and reforming of combustible pyrolysis gas generated during carbonization of the biomass fuel A two-stage gasification furnace having a gas reforming section, and a branch for feeding the combustible pyrolysis gas from the carbonization device to each of the gasification / combustion section and the gas reforming section of the two-stage gasification furnace A carbonization / gasification system comprising a gas supply pipe provided with a pipe. And further comprising a pulverizer for pulverizing the carbide to produce fine powder carbide, and a powder jetting means for jetting the fine powder carbide and supplying the fine powder carbide to the gasification and combustion section of the two-stage gasification furnace. The carbonization / gasification system according to claim 8 . 10. The carbonization / gasification system according to claim 8 , comprising a plurality of the carbonization apparatuses set so that the carbonization treatment of the biomass fuel is alternately completed. The carbonization / gasification system according to any one of claims 8 to 10 , further comprising a flare stack for performing a combustion treatment on the combustible pyrolysis gas generated in the initial stage of the carbonization treatment of the biomass fuel. The carbonization / gasification system according to any one of claims 8 to 11 , further comprising a drying mechanism for drying the biomass fuel. The carbonization / gasification system according to any one of claims 8 to 12 , wherein air mixed with oxygen is used as a gasifying agent to be fed into the gasification furnace. The carbonization / gasification system according to any one of claims 8 to 13 , wherein the temperature of the gasifying agent fed into the gasification furnace is increased in advance.

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