JP5503485B2 - Biomass carbonization / gasification system and carbonization / gasification method - Google Patents

Description

  The present invention relates to a biomass carbonization / gasification system and a carbonization / gasification method. More specifically, the present invention carbonizes and gasifies biomass with a particularly high water content, such as agricultural / forestry / livestock / fishery resources and residues thereof, building waste, food waste, sludge, etc., and uses the resulting product gas. The present invention relates to improvements in technology for generating electricity with high efficiency using gas engines.

  With regard to the carbonization / gasification method, a technique in which carbide (carbonized char) generated in a carbonization apparatus is introduced into a gasification furnace and gasified with air and water vapor is widely used (see, for example, Patent Document 1). In the case of this carbonization / gasification method, the fuel input to the gasification furnace is carbonized, moisture in the biomass is removed, and the carbide contains an appropriate amount of volatile matter. It has the feature of high gasification efficiency with respect to the input carbide from the carbonizer to the gasifier.

  Moreover, without carbonization, the biomass is directly supplied to the gasifier with a screw feeder or the like for gasification, and air, oxygen, or steam is introduced into the reforming section provided downstream of the gasifier. A system for decomposing tar produced in a gasification furnace has been proposed (for example, see Patent Document 2).

JP 2004-35837 A JP 2003-326241 A

  However, in the above-mentioned conventional example, although the gasification efficiency of the carbide is expected to be high if the moisture of the carbide is removed, it is by-produced in the carbonization apparatus (that is, it is generated as a secondary product). ) Since flammable pyrolysis gas is not used, the gasification efficiency is not so high for the amount of fuel input to the carbonizer.

  In addition, when the biomass is directly put into the gasification furnace without performing carbonization and gasification is performed, the temperature in the gasification furnace is limited to about 600 to 1000 ° C. due to the large amount of moisture contained. Will generate and stick to the piping. Therefore, as one of the means for preventing this, a measure is taken to decompose the tar content by steam activation. However, when various types of biomass are mixed, it is difficult to completely decompose the generated tar with steam at about 400 to 450 ° C. As a result, it becomes necessary to clean the fixed tar content in a separate device, and the carbon and hydrogen contained therein will be discharged out of the system, resulting in a decrease in the total calorific value of the product gas. Connected to. In addition, a method of decomposing the tar content with oxygen may be used, but this method also leads to a decrease in the generated gas heat generation.

  Therefore, an object of the present invention is to provide a biomass carbonization / gasification system and a carbonization / gasification method capable of preventing a decrease in generated gas heat generation and generation of a tar component and increasing gasification efficiency.

In order to achieve this object, the present inventor has conducted various studies. First, gasification performance prediction calculation software was developed (see Example 1), and performance prediction of carbonization / gasification technology was performed using this software, and the following results were obtained. That is, as a method when charging carbide and flammable pyrolysis gas (volatile gas) generated in the carbonization apparatus into the gasification furnace, “single-stage charging method” in which these are collectively charged into the gasification furnace, The “two-stage charging method” is considered, in which each is divided into two-stage gasification furnaces divided into a high-temperature gasification section (combustor) and a gas reforming section (reductor). In the latter two-stage charging method, carbide is introduced into the high-temperature gasification section, combustible pyrolysis gas is introduced into the gas reforming section, and a gasifying agent containing oxygen is introduced only into the high-temperature gasification section. Thus, it became clear that gasification can be performed with a low overall oxygen ratio, high thermal efficiency, and a small amount of gasifying agent.

  However, the two-stage charging method is also characterized in that the temperature at the outlet of the gasification furnace (that is, the outlet of the gas reforming section) varies depending on the amount of combustible pyrolysis gas generated in the carbonization apparatus. For example, when the flow rate of the combustible pyrolysis gas increases, the outlet temperature decreases, which may cause tar generation. From the viewpoint of suppressing the generation of tar in this way, it is desirable that the outlet temperature of the gasifier is maintained at a predetermined value or higher.

Under the circumstances as described above, the present inventor puts the powdery high-grade char (carbide) separated by the carbonization apparatus and the pyrolysis gas into a high-temperature gasification furnace capable of tar decomposition and gas reforming. As a result, we have come up with a technology that can solve the problem of tar generation without impairing the features of the two-stage charging method. Based on the present invention such a finding, the invention of claim 1, wherein, in the biomass carbonizing-gasifying system for further gasification carbonizing biomass fuel by thermal decomposition, woody biomass, wastes such as municipal waste Combustible pyrolysis gas containing carbonized equipment that indirectly heats biomass fuel such as biomass and mixed biomass to produce carbide, high-temperature gasification section that gasifies this carbide, and tar volatilized during carbide production A two-stage gasification furnace comprising a gas reforming section for reforming, a carbide supply means for supplying carbide to the high-temperature gasification section of the gasification furnace, and a combustible pyrolysis gas generated by the carbonization apparatus a pyrolysis gas flow path for feeding the gas reformer of the gasifier, the flow from the normal at the time of high-temperature gasification part supplies a gasifying agent containing oxygen to the hot gasification unit to the gas reforming unit The gas reforming if there is a case or a risk thereof flow of the combustible pyrolysis gas supplied to the gas reforming unit with respect to the flow of hot gas is less than an increase to 1100 ° C. outlet temperature of the gasifier is comprising a gasifying agent supply means for supplying a gasifying agent containing oxygen to the quality unit, and a power generating device with waste heat during operation as well as power generation by utilizing the generated gas supplied from the gasification furnace, power generator The exhaust heat exhausted from the exhaust gas is supplied as a heat source for the carbonization device, and the water in the biomass fuel is sufficiently evaporated in the carbonization device, and the carbonized material in which the moisture is removed is supplied to the high-temperature gasification unit. It is characterized in that the the like.

As a result of repeated examinations as described above, the present inventor has found that the gas reforming section is used when the flow rate of the combustible pyrolysis gas is large in order to effectively prevent tar generation without impairing the features of the two-stage charging method. In addition, it was clarified that a method of preventing gas temperature drop by introducing a gasifying agent and causing a combustion reaction with combustible pyrolysis gas was effective. In such a case, temperature is to be maintained at not lower than 1100 ° C..

Further, from the viewpoint of avoiding the trouble that tar is generated and sticks to the pipe, the constant temperature at the gasification furnace outlet can be set to 1100 ° C. as described in claim 1 .

According to a second aspect of the present invention, in the carbonization / gasification system according to the first aspect, the gasifying agent supply means includes a branch pipe, and a gas containing oxygen in both the high-temperature gasification section and the gas reforming section. It consists of a device capable of supplying the agent. According to this apparatus, the gasifying agent is supplied only to the high-temperature gasification section during normal operation (that is, during normal operation of the carbonization / gasification system), and the outlet temperature of the gasification furnace is less than 1100 ° C. When there is a fear, the supply state of the gasifying agent is selectively switched according to the situation in the furnace, such as supplying the gasifying agent to the gas reforming unit in addition to the high-temperature gasification unit.

The invention described in Claim 3 is the biomass carbonizing-gasifying process for further gasification carbonizing biomass fuel by thermal decomposition, woody biomass, waste-based biomass and mixed biomass such as municipal waste Indirect combustion of biomass fuels such as carbon to produce carbides, and the carbides are supplied to a high-temperature gasification section of a two-stage gasification furnace for gasification, while flammable containing tar volatilized during carbide production The pyrolysis gas is sent to the gas reforming section of the gasification furnace for reforming. In addition, in addition to supplying a gasifying agent containing oxygen to the high-temperature gasification section, gas reforming is performed from the high-temperature gasification section. When the flow rate of the combustible pyrolysis gas supplied to the gas reforming unit increases with respect to the flow rate of the high-temperature gas flowing to the mass part and the outlet temperature of the gasifier becomes less than 1100 ° C. Is gas reforming Oxygen is supplied to the gasifying agent containing the supplies as a heat source for carbonization device exhaust heat discharged from the power generation device with waste heat during operation as well as power generation by utilizing the generated gas supplied from the gasification furnace In this way, the carbonization apparatus is characterized in that the water in the biomass fuel is sufficiently evaporated and the carbide in a state where the water is removed is supplied to the high-temperature gasification section .

In this biomass carbonization / gasification method, the carbide (carbonized char) produced in the carbonizer is fed into the high-temperature gasification section (combustor) of the gasifier as fuel, and at the same time, air or oxygen is used as a gasifying agent. Similarly, gasification is performed by introducing into the high-temperature gasification section (see FIG. 1). In this case, the carbonized carbide is in a state in which moisture in the biomass has been removed, so that a high-temperature gas atmosphere of 1500 ° C. or higher exceeding the tar decomposition temperature of 1100 ° C. is created in the high-temperature gasification section. It is possible. Further, the combustible pyrolysis gas containing water by-produced in the carbonization apparatus is input to the gas reforming unit (reductor), and the gasification efficiency is increased with respect to the total amount of biomass input to the carbonization apparatus, thereby increasing the tar content. high calorific product gas not to be obtained.

Here, some biomass species have a small amount of fixed carbon and a small proportion of carbide obtained in the carbonization apparatus, but a large proportion of pyrolysis gas by-produced. At this time, with respect to the high temperature gas of 1500 ° C. or higher flowing from the high temperature gasification section to the gas reforming section, the flow rate of the 400-600 ° C. pyrolysis gas supplied from the carbonizer to the gas reforming section increases. A sudden temperature drop occurs in the gas reforming section, and the temperature is lower than 1100 ° C. which is the tar decomposition temperature. In such a case, or in the case where there is a possibility that the temperature falls below a certain temperature, a gasifying agent containing oxygen that has been introduced only into the high-temperature gasification unit until then is also introduced into the gas reforming unit (see FIG. 1). Temperature of the combustion occurring in the gas reformer unit thus gas reforming unit is raised to such a case.

According to the biomass carbonization / gasification system according to claim 1, when the temperature at the gasification furnace outlet is less than 1100 ° C. or when there is a risk , the gasifying agent supplied to the gas reforming section is in the gas reforming section. Causes a combustion reaction to raise the temperature in the gas reforming section . According to this, the temperature at the gasification furnace outlet also rises, so that tar generation at the gasification furnace outlet can be effectively suppressed without impairing the features of the two-stage charging method. In addition, there is no need to wash the fixed tar content with a separate device, which also contributes to prevention of a decrease in the amount of generated gas heat. In addition, it is not necessary to employ a decomposition method that causes a decrease in the generated gas heat generation, such as tar decomposition by oxygen. Moreover, because it uses a combustible pyrolysis gas that is by-produced in the carbonization device, compared to conventional carbonization and gasification systems that do not (that is, systems that do not use combustible pyrolysis gas) High gasification efficiency can be achieved.

Further , it is possible to prevent the gasification outlet from becoming a temperature lower than 1100 ° C. which is the tar decomposition temperature, and to avoid the trouble that tar is generated and adheres to the pipe.

According to the biomass carbonization / gasification system according to claim 2, it is possible to supply the gasifying agent to both the high-temperature gasification unit and the gas reforming unit with a single gasifying agent supply device and a branch pipe. This is advantageous in terms of downsizing the system and reducing costs.

Further, according to the biomass carbonization / gasification method according to claim 3, when the temperature at the gasifier outlet becomes less than 1100 ° C. or when there is a risk , gas is supplied by supplying a gasifying agent to the gas reforming section. A combustion reaction is caused in the reforming section, and the temperature in the gas reforming section can be raised. According to this, the temperature at the gasification furnace outlet also rises, so that tar generation at the gasification furnace outlet can be effectively suppressed without impairing the features of the two-stage charging method. Further, it is not necessary to clean the fixed tar content with a separate device or decompose it with oxygen, which contributes to the prevention of a decrease in the amount of generated gas heat. In addition, since combustible pyrolysis gas by-produced in the carbonizer is used, it is compared with other conventional carbonization and gasification methods (that is, carbonization and gasification methods that do not use combustible pyrolysis gas). Thus, high gasification efficiency can be achieved.

It is a conceptual diagram which shows the structure of the biomass carbonization and gasification system which concerns on this invention. It is a graph which shows the experimental value and calculated value at the time of performing a comparison (oxygen ratio 0.40) with the result of an oral gasification test. It is a graph which shows the gasification performance prediction (gasification agent injection | throwing-in temperature of 50 degreeC) of an oxygen blowing 1 step entrained bed furnace, and represents the change of the carbon conversion rate and gasifier exit temperature when oxygen ratio changes. It is a graph which shows the gasification performance prediction (gasification agent injection | throwing-in temperature of 50 degreeC) of an oxygen blowing 1 stage entrained bed furnace, and represents the change of the product gas ratio and cold gas efficiency when an oxygen ratio changes. It is a graph which shows the gasification performance prediction (air injection temperature 250 degreeC) of an air blowing 1 stage entrained bed furnace, and represents the change of the carbon conversion rate and gasifier exit temperature when an oxygen ratio changes. It is a graph which shows the gasification performance prediction of an oxygen blowing 1 step | paragraph injection | throwing-in system, and represents the change of the carbon conversion rate and gasification furnace exit temperature when an oxygen ratio changes. It is a graph which shows the gasification performance prediction of an oxygen blowing 1 step | paragraph injection | throwing-in system, and represents the change of the product gas ratio and cold gas efficiency when an oxygen ratio changes. It is a graph which shows the gasification performance prediction of the air blowing 1 step | paragraph injection | throwing-in system, and represents the change of the carbon conversion rate and gasification furnace exit temperature when an oxygen ratio changes. It is a graph which shows the gasification performance prediction of an air blowing 1 step | paragraph injection | throwing-in system, and represents the change of the product gas ratio and cold gas efficiency when an oxygen ratio changes. It is a graph which shows the gasification performance prediction of an air blowing 2 step | paragraph injection | throwing-in system, and represents the change of the carbon conversion rate, combustor exit temperature, and gasification furnace exit temperature when an oxygen ratio changes. It is a graph which shows the gasification performance prediction of an air blowing 2 step | paragraph injection | throwing-in system, and represents the change of the production gas ratio and cold gas efficiency when an oxygen ratio changes. This graph shows the gasification performance prediction (combustor oxygen ratio: 0.64) of the air injection system to the gas reforming section. The graph shows the changes in carbon conversion rate, combustor outlet temperature, and gasifier outlet temperature when the oxygen ratio changes. Represents. This graph shows the effect of combustor oxygen ratio on gasification performance (overall oxygen ratio: 0.20), and shows changes in carbon conversion rate, combustor outlet temperature, and gasifier outlet temperature when the combustor oxygen ratio changes. . A graph showing the influence of the combustor oxygen ratio on the gasification performance (overall oxygen ratio: 0.20), showing changes in the ratio of produced gas and cold gas efficiency when the combustor oxygen ratio changes. It is a graph showing the gasification performance prediction of the two-stage charging method of waste, and shows changes in carbon conversion rate, combustor outlet temperature, and gasifier outlet temperature when the oxygen ratio changes. It is a graph showing the gasification performance prediction of the two-stage charging method of waste, and shows the change in the product gas ratio and the cold gas efficiency when the oxygen ratio changes.

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

  FIG. 1 shows an embodiment of the present invention. The biomass carbonization / gasification system according to the present invention is a system for pyrolyzing and carbonizing and further gasifying biomass fuel 1 such as woody biomass, waste biomass such as municipal waste, and mixed biomass thereof. . The biomass carbonization / gasification system of the present embodiment includes a carbonization device 2 that generates biomass 4 by heating the biomass fuel 1, a high-temperature gasification unit 8 that gasifies the carbide 4, and tar volatilized during the generation of the carbide. A two-stage gasification furnace 7 composed of a gas reforming section 9 for reforming the combustible pyrolysis gas 3 and a carbide 4 generated by the carbonization apparatus 2 are supplied to a high-temperature gasification section 8 of the gasification furnace 7. Carbide supply means 13 for carrying out, a pyrolysis gas flow path 12 for sending the combustible pyrolysis gas 3 generated by the carbonization apparatus 2 to the gas reforming section 9 of the gasification furnace 7, and a high-temperature gasification section in normal times A gas for supplying the gasifying agent 6 containing oxygen to the gas reforming section 9 when the gasifying agent 5 is supplied to 8 and the outlet temperature of the gasification furnace 7 becomes lower than or equal to a certain temperature. It has the composition provided with agent supply means 14 See Figure 1).

  Since the biomass fuel 1 has a high water content in the fuel and is not pulverizable, introduction of an effective pretreatment method is indispensable for gasification using the spouted bed gasification furnace 7. Therefore, in the present embodiment, in the carbonization apparatus 2, the combustible pyrolysis gas (volatile gas) 3 containing moisture and volatile matter in the biomass fuel 1 and the carbide 4 mainly composed of fixed carbon and ash are used. A carbonization / gasification method is adopted in which the gasification furnace 7 is charged after separation (see FIG. 1). In the case of the system in which the carbonization process and the gasification process are separated in this way, a device after the gasification furnace 7 (not shown in particular, for example, a supplied gas such as a gas engine, a gas turbine, or a fuel cell) (Shown by reference numeral 10 in FIG. 1) can be used by receiving the supply of system waste heat that is generated by a device that generates power using waste heat during operation and that is exhausted. The carbonization apparatus 2 in the present embodiment has a two-layer structure including an inner portion that pyrolyzes and carbonizes the biomass fuel 1 and a jacket portion (outer portion) 2a that surrounds the inner portion (see FIG. 1). This exhaust heat is utilized by sending high-temperature exhaust gas 11 having a temperature of about 600 ° C. to the jacket portion 2a, and the biomass fuel 1 is indirectly heated from the outside, and moisture is removed in an oxygen-free state blocked from the outside air. Carbonization is performed by evaporation and thermal decomposition of organic matter. Moisture and combustible pyrolysis gas 3 are continuously discharged out of the apparatus, and carbide 4 remains at the bottom (see FIG. 1).

  The moisture and combustible pyrolysis gas 3 generated in the carbonization apparatus 2 are continuously discharged out of the apparatus and sent to the gas reforming section 9 through the pyrolysis gas flow path 12 (see FIG. 1). Further, the carbide 4 remaining at the bottom of the carbonization apparatus 2 is sent to the high-temperature gasification section 8 of the gasification furnace 7 by the carbide supply means 13. Although not shown in detail, the carbide supply means 13 is constituted by, for example, a screw feeder or a flow path for sending out the carbide 4 (see FIG. 1).

The gasification furnace 7 gasifies and reacts the carbide 4 supplied from the carbonization apparatus 2 and the combustible pyrolysis gas 3 containing moisture and volatile components, and CO (carbon monoxide) and H ₂ which are combustible gases. (Hydrogen) is produced.

The gasification agent supply means 14 can selectively switch the gasification agent supply state to the high temperature gasification unit 8 or the gasification agent supply state to both the high temperature gasification unit 8 and the gas reforming unit 9. Means. In the biomass carbonization / gasification system of the present embodiment, air or oxygen is supplied by the gasifying agent supply means 14, and in the high-temperature gasification unit 8, depending on circumstances, the high-temperature gasification unit 8 and the gas reforming unit 9 may be used. Both are supposed to cause a combustion reaction (see FIG. 1). The actual gasifying agent supply means 14 is composed of, for example, a device for feeding air or piping. In FIG. 1, a gasifying agent supplying means 14 for supplying the gasifying agent 5 to the high temperature gasifying section 8 and a gasifying agent supplying means for supplying the gasifying agent 6 containing oxygen to the gas reforming section 9. 14 is divided for convenience, and the gasifying agent is also denoted by reference numeral 5 for the one supplied to the high-temperature gasification section 8 and denoted by reference numeral 6 for the one supplied to the gas reforming section 9. Although shown, the gasifying agent supply means 14 actually installed is not limited to this. That is, the gasifying agent supply means 14 may be installed in each of the high temperature gasification unit 8 and the gas reforming unit 9 as shown in the figure, or may be a mode in which only one apparatus is installed. In short, it is sufficient that the gasifying agent 5 is supplied to the high-temperature gasification unit 8 at normal times and the gasifying agent 6 containing oxygen is supplied to the gas reforming unit 9 when necessary. For example, when only one apparatus is installed as in the latter case, a branch pipe is provided, although not shown, to supply a gasifying agent to the high-temperature gasification unit 8, or the high-temperature gasification unit 8 and the gas reformer. What is necessary is just to enable it to selectively switch the gasification agent supply state to both of the mass parts 9. FIG. In this way, when the supply pipe is branched or the like so that it can be charged to both the high-temperature gasification unit 8 and the gas reforming unit 9, the gasification agent can be charged by a single device. There are advantages such as downsizing and low cost.

  In such a biomass carbonization / gasification system, first, the biomass fuel 1 supplied to the carbonization apparatus 2 is indirectly thermally decomposed at a temperature of, for example, about 600 ° C. sufficiently in the apparatus. Carbonized. In this case, the amount of heat necessary for carbonization can be provided by utilizing the system exhaust heat of the high-temperature exhaust gas 11 of the power generation device (gas engine or the like) at the subsequent stage of the gasification furnace 7. In such a case, not only can the water contained in the biomass fuel 1 be sufficiently removed using high exhaust heat, but also the energy generation system using the biomass fuel 1 as a whole can be used efficiently and efficiently. It becomes possible to construct a system. When the biomass fuel 1 is carbonized, moisture and volatile components are discharged from the upper part of the carbonization apparatus 2 to the outside of the apparatus and sent to the gas reforming unit 9 through the pyrolysis gas flow path 12. Here, the time required for pyrolyzing the biomass fuel 1 depends on the type of raw material and the water content. For example, when the temperature is about 600 ° C., carbonization can be performed in about 30 minutes to about 1 hour. Is possible. In the carbonization apparatus 2 after sufficient carbonization, the carbide 4 containing fixed carbon, ash, and some volatile matter remains. Thus, in the carbonization apparatus 2, the carbide 4 and the volatile gas are supplied from different systems to the subsequent gasification furnace 7 (see FIG. 1).

In the high-temperature gasification section 8 corresponding to the lower part of the gasification furnace 7, the supplied carbide 4 is used as fuel, and the gasification agent 5 is further introduced to perform combustion and gasification. Since the carbide 4 in this case is in a state in which moisture in the biomass is removed, it is possible to generate a high-temperature gas at 1500 ° C. or higher. Further, in the gas reforming section 9 corresponding to the upper portion of the gasification furnace 7, the high-temperature gas is used as a heat source to decompose the tar content contained in the pyrolysis gas 3 fed from the carbonization apparatus 2 and perform gas reforming. At this time, when the flow rate of the combustible pyrolysis gas (approximately 400 to 600 ° C.) 3 is extremely large relative to the flow rate of the carbide 4 in the system, the high temperature gas of 1500 ° C. or higher in the high temperature gasification unit 8 is the gas reforming unit. In 9, the temperature is suddenly decreased and the temperature may be lower than the tar decomposition temperature of 1100 ° C. Therefore, in such a case or when there is such a possibility , the gasifying agent 6 containing oxygen is introduced into the gas reforming unit 9 together with the combustible pyrolysis gas 3 and a part of the pyrolysis gas 3 is introduced. Is heated to 1100 ° C. or higher where tar can be decomposed (see FIG. 1).

Here, the state of the reaction in the gasification furnace 7 is simply expressed as follows using a chemical formula. That is, as a combustion reaction in the high-temperature gasification section 8, [Chemical 1]
CO + 1 / 2O ₂ → CO ₂
[Chemical formula 2]
H ₂ + 1 / 2O ₂ → H ₂ O
As a gasification reaction [Chemical 3]
C + CO ₂ → 2CO
[Chemical formula 4]
C + H ₂ O → CO + H ₂
It reacts. After such a reaction, CO, CO ₂ , H ₂ , H ₂ O, N ₂ , fixed carbon, and ash move from the high-temperature gasification unit 8 to the gas reforming unit 9. Thereafter, in the gas reforming section 9, [Chemical Formula 5]
CO + H ₂ O ← → CO ₂ + H ₂
A shift reaction occurs.

  Ash produced as a result of the combustion reaction and the gasification reaction being performed in the high-temperature gasification section 8 is taken out from the bottom of the gasification furnace 7 as molten slag (see FIG. 1).

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, in the above-described embodiment, the carbonization / gasification system including a single carbonization device 2 has been described, but actually, a plurality (or a plurality of systems) of carbonization devices 2 are arranged according to the time required for carbonization. In addition, it is also preferable that the operation cycle of each carbonization apparatus 2 is provided with a time difference and is operated by rotation so that the carbide 4 and the combustible pyrolysis gas 3 are continuously supplied to the gasification furnace 7. The carbonization process in the carbonization apparatus 2 involves a certain amount of variation in the amount of vaporization and the like, but this variation can be mitigated by forming a rotation with a plurality of apparatuses.

  In addition, the gasification furnace 7 in this embodiment is a two-stage type consisting of a high-temperature gasification part 8 and a gas reforming part 9, but the “two-stage type” in this specification is like this The high temperature gasification section (combustor) 8 and the gas reforming section (reductor) 9 are divided into two stages, and the carbide 4 and the combustible pyrolysis gas 3 are separately charged, and the high temperature gasification section It is not necessary that both the gas reforming unit 8 and the gas reforming unit 9 are partitioned into two chambers. Therefore, for example, even in a gasification furnace 7 in which both are provided in one chamber, or in a gasification furnace 7 in which a constriction is provided near the boundary between the two but the partition is not clear, the application of the present invention. Will not be disturbed.

  The present inventor examined the gasification method of woody biomass and waste biomass (hereinafter sometimes simply referred to as “waste”), from the fuel properties and the measured gasification reaction rate. A method for easily predicting gasification performance was established, and gasification methods for various fuels and target operating condition ranges for high efficiency and stable operation were investigated. The contents will be described below as examples.

1. Study method 1.1 Basic concept of study High-precision numerical values for coal gasifier and super heavy oil gasifier developed by the Central Research Institute of Electric Power (hereinafter referred to as our office), the applicant of this application The analysis technology takes time to create a calculation grid to derive detailed results of various performances in the gasification furnace 7 such as particle behavior, gas properties, and gas temperature distribution in the gasification furnace. It takes several hours to calculate. Therefore, in order to make it possible to easily study gasification methods and optimum operating conditions, we have selected carbon conversion rate, cold gas efficiency, gas from the properties of the target fuel type and gasification reaction rate. We have established a calculation method that can easily predict various gasification performances such as temperature. This calculation does not take into account the irradiation of the furnace wall, particle behavior, furnace shape, etc. Based on the gasification and gas phase reaction rates, the fuel that has been fed into the gasification furnace 7 It is possible to grasp whether the reaction is progressing to some extent.

1.2 Gasification performance prediction calculation method The outline of the established calculation method is described below. The fuel to be introduced into the gasification furnace 7 is coke, which is the target of the gasification reaction, with the fixed carbon obtained from the property analysis values, and the volatile matter is instantaneously gasified by pyrolysis after being introduced into the gasification furnace 7. ). Moisture was supplied as it was to the gasification furnace 7 as H ₂ O and involved in the water gas reaction and shift reaction.

Volatile components such as C, H, and O are introduced as gases, and a shift equilibrium state (CO + H ₂ O = CO ₂ + H ₂ ) based on the equilibrium constant (shift equilibrium constant Ks) shown in Chemical Formula 6 is assumed. Basically, when trying to determine the ratio of CO, CO ₂ , H ₂ , and H ₂ O based on the ratio of C, H, and O in the fuel, O is almost insufficient. Thus, when shift equilibrium was not feasible, all O was combined with C to CO, and when O was insufficient with respect to C, O in the gasifying agent was used. In this case, it was all for the H H _2.

The initial temperature was determined based on the sensible heat of the fuel and the gasifying agent (air, oxygen) and the calorific value when the volatile component was converted to CO or the like. The average constant pressure specific heat Cpi of various gases was calculated by approximating with a sixth-order polynomial of gas temperature (the following chemical formula 7).
[Chemical 6]
Ks = ([CO ₂ ] × [H ₂ ]) ÷ ([CO] × [H ₂ O])
= 0.0265 × exp (3956 ÷ (T + 273)) (T: [℃])
[Chemical 7]
^{Cpi = Ai + BiT + CiT 2} + DiT 3 + EiT 4 + FiT 5 + GiT 6

In the gasification furnace 7, the following four gas phase reactions represented by chemical formulas 8 to 11 are considered, and reactions relating to methane, sulfur, and other trace components are not considered. Table 1 shows reaction rate constants used for calculation of each gas phase reaction.
[Chemical 8]
CO + 1 / 2O ₂ → CO ₂
[Chemical 9]
H ₂ + 1 / 2O ₂ → H ₂ O
[Chemical Formula 10]
CO + H ₂ O → CO ₂ + H ₂
[Chemical 11]
CO ₂ + H ₂ → CO + H ₂ O

The coke gasification reaction considered three reactions of the following chemical formulas 13-15. As the gasification reaction rate constant, a value measured using our thermobalance and PDTF (Ultra High Temperature / Pressurized Fuel Reaction Experimental Facility) was adopted. For the coke gasification reaction rate model, an Arrhenius-type nth-order reaction rate equation shown in Chemical Formula 12 in consideration of the effects of temperature and pressure was adopted. Table 2 shows cedar bark values as an example of gasification reaction rate constants. Previous studies at our laboratory have shown that the gasification reaction is rate limiting in the high temperature range above about 1100 ° C. Therefore, in the gasification reaction with CO ₂ of Chemical Formula 14, as shown in Table 2, the gasification reaction rates in the low temperature region and the high temperature region are compared, and the lower value is adopted. In addition, the gasification reaction with H ₂ O of Formula 15 has been found to be faster than the gasification reaction with CO ₂ according to previous studies at this site, and here it was assumed to be 1.5 times faster.
[Chemical 12]
dx / dt = A ₀ P _i ⁿ exp (−E _Ai / RT)
[Chemical 13]
C + 1 / 2O ₂ → CO
[Chemical 14]
C + CO ₂ → 2CO
[Chemical 15]
C + H ₂ O → CO + H ₂

The gasification furnace 7 has a refractory material structure, and the rate of heat loss to the furnace wall of the gasification furnace 7 was obtained when conducting gasification tests on the oil and residual oil in our new liquid fuel gasification research reactor. It calculated | required using the relationship between the exit gas temperature of the gasification furnace 7 shown to Numerical formula 1, 2, and the heat loss ratio with respect to the amount of heat inputs. At 1370 ° C. or lower, Formula 1 obtained based on the oral gasification test was used, and at 1370 ° C. or higher, Formula 2 obtained in the residual oil gasification test was used. From these equations, the heat loss ratio was determined based on the outlet temperature of the gasification furnace 7, and further, correction was performed in consideration of the ratio of the wall surface area of the gasification furnace 7 to the input heat amount. Thereby, it is possible to consider the influence of the scale-up of the gasification furnace 7.
[Equation 1]
1370 ℃ or less: Heat loss rate (%)
= 3.7666 × 10 ^-34 × gasifier outlet temperature (℃) ^10.836
[Equation 2]
1370 ℃ or higher: Heat loss ratio (%)
= -2.97 × 10 ^-5 × gasifier outlet temperature (° C) ²
+ 9.545 × 10 ^-2 × gasifier outlet temperature (° C) −71.35

1.3 Accuracy of calculation results In order to confirm the accuracy of this calculation method, the results were compared with the results of the oral gasification test conducted at this site. FIG. 2 shows a comparison between the experimental value and the calculated value at an oxygen ratio (λ) of 0.40 when the residence time in the furnace at which the gasification reaction was judged to be almost completed in the experiment was about 5 seconds. As the gasification reaction rate constant, the value measured with our DTF was adopted.

In Fig. 2, various gasification performances of the generated gas heating value (HHV), carbon conversion rate (CCE), and cold gas efficiency (CGE) are almost the same. It was. Although there are slight differences in various gas properties, the concentration of the combustible components CO and H ₂ is almost the same as the experimental value, so the cold gas efficiency is almost the same. . This seems to be because the CO concentration is calculated to be slightly higher because most of the C in the fuel is converted to CO immediately after being introduced into the gasifier 7.

  In this way, the CO concentration is calculated to be slightly higher and the other components are calculated to be slightly lower, but the carbon conversion rate indicating the gasification efficiency and the cold gas efficiency are satisfactory values for predicting the gasification performance. I found out that

2. Examination results Using a well-established calculation method, we examined a method for gasifying cedar chips as an example of biomass with high efficiency. The following points were noted in the study.
-Outlet gas temperature of the high-temperature gasifier (combustor) 8 (in the case of a two-stage gasifier)
... Considered from the viewpoint of heat resistance of combustor wall (2000 ° C or lower) and ash melting and discharging (1600 ° C or higher) · Outlet gas temperature of gasifier 7… Considered from the viewpoint of tar generation (1100 ° C or higher) · Carbon conversion rate ... Considering from the viewpoint of highly efficient use of fuel without recycling facilities (over 99.5%: cold gas efficiency over 75%)

  Table 3 shows the properties of the cedar chips used for the study. Since the ash content in the cedar chip is as small as 0.09%, the ash is not slagged in the gasification furnace 7 and melted and discharged, but is flown as it is to the downstream as it is. As the gasification reaction rate, the value of cedar bark shown in Table 2 was used.

2.1 First-stage spouted bed method First, in the one-stage spouted bed method with a simple structure, the optimum operating conditions were examined for each of oxygen blowing and air blowing. In order to suppress the generation of tar, the conditions for a gasifier outlet temperature of 1100 ° C. or higher and a carbon conversion rate of 99.5% or higher were obtained from the viewpoint of gasification efficiency. The examination was performed under the following conditions.
・ Gas furnace internal pressure is atmospheric pressure, gasifier capacity is 100t / d.
-The residence time in the gasifier is 5 seconds when the gasification reaction is judged to be almost complete.

2.1.1 Oxygen-blown single-stage spouted bed system The results of the examination with oxygen-blown are shown in Figs. Since the oxygen concentration from the oxygen production apparatus is generally 95%, the oxygen concentration in the gasifying agent was set to 95%, and the remaining 5% impurities were nitrogen. The gasifying agent charging temperature was 50 ° C. From the calculation results, it was predicted that high-efficiency operation with a carbon conversion rate of 99.5% or more is possible within an oxygen ratio exceeding 0.58. In general, biomass has a high proportion of O in the fuel, and its calorific value is lower than that of fossil fuel. Therefore, in order to perform the operation for sufficiently raising the temperature in the gasification furnace 7, it was calculated that the operation at a high oxygen ratio exceeding 0.5 was required despite the oxygen blowing. At this time, the cold gas efficiency, which is another index for high-efficiency operation, is 58.9%, and the calorific value of the product gas is as low as about 1000 kcal / m ³ N.

2.1.2 Air blown one-stage spouted bed method Fig. 5 shows the calculation results of the carbon conversion rate and the gasifier outlet temperature when air blowing is studied. The input temperature of air was 250 ° C. Compared with oxygen blowing, the amount of nitrogen input is about 70 times higher in the same oxygen ratio operation (5% to 79% nitrogen in the gasifying agent), so both the carbon conversion rate and gas temperature are reduced in the same oxygen ratio operation. To do. For this reason, a carbon conversion rate exceeding 99% could not be achieved even at an oxygen ratio of 0.80, and it was considered difficult to perform gasification by air blowing in the single-stage spouted bed system.

2.2 Carbonization / Gasification Method In order to gasify biomass containing a lot of water with high efficiency, the carbonization of fuel, called a carbonizer as a pre-treatment method, is based on fixed carbon. A system that decomposes into carbide 4 and pyrolysis gas (volatile gas) 3 containing moisture and volatile matter in the fuel and puts it into gasification furnace 7 was examined (see FIG. 1). Since this method is a gasification method in which the carbonization apparatus 2 and the gasification furnace 7 are combined, this is called a carbonization / gasification method in this specification.

  Fuel such as biomass is supplied to the carbonization apparatus 2 and carbonized at 600 ° C. over a sufficient amount of time. As the high-temperature gas required at that time, it is possible to use a high-temperature exhaust gas downstream of the gasification furnace 7. At the time of carbonization, moisture and volatile matter are discharged out of the machine from the top of the carbonization device 2, and after being sufficiently carbonized, the carbonization device 2 contains fixed carbon, ash, and a carbide containing some volatile matter. 4 remains. Thus, in the carbonization apparatus 2, since the carbide 4 and the pyrolysis gas (volatile gas) 3 are supplied from different systems to the downstream gasification furnace 7, the optimum operating conditions for gasification are examined. Needs to consider how the carbide 4 and the pyrolysis gas 3 are supplied to the gasifier 7.

  In examining the optimum method, in order to determine how much the volatile matter in the cedar chip to be examined in the carbonization apparatus 2 is volatilized, the volatilization characteristics were measured with a thermobalance at this site. As a result, it was found that 92.6% of the volatile components volatilized at 600 ° C. Accordingly, the carbide 4 is assumed to contain 7.4% of each composition in the volatile matter in addition to the fixed carbon and ash.

2.2.1 Single-stage charging method First, a single-stage charging method in which the carbide 4 separated by the carbonizer 2 and the pyrolysis gas (volatile gas) 3 are charged only into the high-temperature gasification unit (combustor) 8 will be studied. went. Here, the efficiency of the gasifier alone excluding the carbonization apparatus 2 will be examined. As in the case of the single-stage spouted bed method, the gasifier pressure was atmospheric pressure, the gasifier capacity was 100 t / d, the residence time was 5 seconds, and the oxygen concentration in the gasifier was 95%. The calculation results are shown in FIGS.

  In this case, the biomass fuel 1 is pre-treated in the carbonizer 2 as compared with the one-stage spouted bed method (see FIGS. 3 and 4), so that the charging temperature rises to 600 ° C., and moisture is converted into steam. Since the latent heat disappears because it is supplied, the gas temperature in the gasification furnace 7 rises, and when compared with the same oxygen ratio, the gasification performance such as the carbon conversion rate and the cold gas efficiency rises. From the calculation, the carbon conversion rate was over 99.5% when the oxygen ratio exceeded 0.27, and the cold gas efficiency at that time was a high value exceeding 85%.

Next, air blowing was examined. For comparison with the single-stage spouted bed method, the air input temperature was 250 ° C. The results are shown in FIGS. Compared with the single-stage spouted bed system as with oxygen blowing, the carbon conversion rate and cold gas efficiency increase with the increase in gasification furnace gas temperature in the same oxygen ratio operation, and high efficiency operation is possible even with air blowing. Become. From the calculation, it was found that high efficiency operation with an oxygen ratio of 0.43 or more and a carbon conversion rate of 99.5% or more is possible. However, at this time, the cold gas efficiency is 67.8%, and the generated gas heating value is as low as about 840 kcal / m ³ N.

2.2.2 Two-stage charging method Next, a two-stage charging method in which the carbide 4 separated by the carbonization apparatus 2 is charged into the high-temperature gasification unit (combustor) 8 and the pyrolysis gas 3 is charged into the gas reforming unit 9. Study was carried out. At this time, the gasifying agent 5 is supplied only to the high-temperature gasification unit 8, and in the high-temperature gasification unit 8, a high-temperature combustion field is formed by the reaction between the carbide 4 and the gasifying agent 5, and the gas reforming unit In No. 9, a gas reforming reaction mainly including a shift reaction is performed by supplying moisture and volatile components. The calculation results are shown in FIGS. The residence time was 3 seconds for the high temperature gasification section 8 and 1 second for the gas reforming section 9. Here, it is considered that the operation with oxygen blowing is difficult for the following reasons, so the examination was performed only with air blowing.
-The high temperature gasification part 8 becomes a high temperature combustion field exceeding 3000 degreeC.
-Since the amount of volatile gas supplied from the carbonization apparatus 2 is larger than the gas flow rate from the high-temperature gasification unit 8 to the gas reforming unit 9, the temperature of the gas reforming unit 9 rapidly decreases, and the gasifier exit temperature Cannot be kept above 1100 ℃.

  10 and 11, it was predicted that high-efficiency operation with a carbon conversion rate exceeding 99.5% could already be realized in ultra-low oxygen ratio operation with an oxygen ratio of 0.14. At this time, the oxygen ratio of the high-temperature gasification unit alone is 0.56. However, the gasifier outlet temperature is about 900 ° C., which is a temperature at which tar formation is a concern. On the other hand, the oxygen ratio at which the gasifier outlet temperature becomes 1100 ° C is 0.20. At this time, the outlet temperature of the high-temperature gasifier 8 is calculated to be 2200 ° C or higher. It is considered a condition.

From the calculation, it is expected that the outlet temperature of the high-temperature gasifier 8 will exceed 2000 ° C at an oxygen ratio of 0.17, and the outlet temperature of the gasifier at this time is 1030 ° C, which is less than 1100 ° C, which is a standard for stable operation. . This is because the gas flow rate at the outlet of the high-temperature gasification unit is about 2300 m ³ N / h, whereas the gas flow rate supplied to the gas reforming unit 9 (volatile gas from the carbonizer 2) is about 2.5 times. This is because the gas temperature from the high-temperature gasification section 8 at about 2000 ° C. is drastically lowered at 5400 m ³ N / h. Therefore, realization of stable operation in consideration of the high temperature gasification unit 8 and the gasification furnace 7 outlet temperature was considered difficult in this method.

2.2.3 Air input method to gas reforming section (reductor) In the two-stage input method, a high carbon conversion rate can be obtained with a low oxygen ratio operation compared to the one-stage spouted bed method and the one-stage input method. Therefore, it is considered that this is an effective system when realizing high-efficiency operation. Therefore, in order to increase the outlet temperature of the gasification furnace 7 to 1100 ° C. or higher while keeping the outlet temperature of the high-temperature gasification unit 8 at 2000 ° C. or lower, the air 6 is introduced into the gas reforming unit 9 to A method for increasing the gas temperature of the gas reforming unit 9 by burning the combustible gas CO and H ₂ from the gasification unit 8 was studied. As shown in FIG. 10, in order to set the outlet temperature of the high-temperature gasifier (combustor) to 2000 ° C. or lower, it is necessary to operate at an oxygen ratio of 0.16 or less (combustor oxygen ratio of 0.64 or less). It was decided to increase the overall oxygen ratio. The carbon conversion rate and the calculation result of the gas temperature are shown in FIG.

  From the calculation, it was found that the gasifier outlet temperature could be 1100 ° C or higher with an overall oxygen ratio of 0.20 or higher. As compared with the one-stage charging method shown in FIGS. 6 and 7, it has been clarified that high-efficiency operation is possible at a lower oxygen ratio. At this time, the carbon conversion rate was 99.8% and the cold gas efficiency was higher than 85%.

  In order to use the cedar chips in the carbonization / gasification method, the carbide 4 from the carbonization apparatus 2 is introduced into the high-temperature gasification unit 8 and the pyrolysis gas (volatile gas) 3 is introduced into the gas reforming unit 9 to obtain the high-temperature gasification unit. The combustor oxygen ratio is set low in order to make the heat load on the furnace wall of 8 as low as possible, and the gas reformer 9 is supplied with air 6 so that the outlet temperature of the gasification furnace 7 becomes an appropriate temperature (1100 ° C. or higher). It was found that the input method is suitable.

  Next, in order to examine the influence of the combustor oxygen ratio, the change in gasification performance was determined with the overall oxygen ratio kept constant at 0.20. The results are shown in FIGS. When the combustor oxygen ratio is lowered without changing the overall oxygen ratio, there is little change in the gasifier outlet temperature, while the combustor outlet temperature and the carbon conversion rate tend to decrease. Considering the heat load on the furnace wall, it is desirable that the combustor oxygen ratio is as low as possible. From FIGS. 13 and 14, the gas having a combustor oxygen ratio of 0.56 or more and a carbon conversion rate of 99.5% or more, which is a standard for high-efficiency operation. It is expected that the performance will be improved.

  From the above results, when using cedar chips as fuel, the optimal operating conditions are the combustor oxygen ratio of 0.56 and the overall oxygen ratio of 0.20. Expected to be.

2.3 Examination of waste gasification method As a fuel other than cedar chips, we investigated a highly efficient gasification method of waste. The studied waste is typical municipal waste, and the properties are shown in Table 4. Unlike cedar chips that have been studied so far, the waste contains several percent of ash, so the ash is melted in the gasification furnace 7 and is examined on the assumption that it is discharged as slag. The melting point of ash was assumed to be 1600 ° C because there was no measurement data.

  From the study at the cedar chip, it is said that the method in which the carbide 4 is introduced into the high-temperature gasification unit 8 and the pyrolysis gas (volatile gas) 3 is introduced into the gas reforming unit 9 by the carbonization / gasification method is capable of high-efficiency operation. Therefore, first, the case where the air that is the gasifying agent 5 was introduced only into the high-temperature gasification unit 8 was examined. 15 and 16 show the calculation results. The fuel throughput was set at 100 t / d, as in the case of cedar chips. However, as for the volatilization ratio in the carbonization apparatus 2, the actual ratio when the carbonization was actually performed at Okadora Co., Ltd., a carbonization apparatus manufacturer, was used, and the weight ratio of the carbide 4 and the pyrolysis gas 3 was 40:60. It was.

  Compared to the case of cedar chips (see FIGS. 10 and 11), the volatilization rate in the carbonization apparatus 2 is reduced, and therefore, a rapid decrease in gas temperature in the gas reforming unit 9 is not observed. Further, since the amount of the carbide 4 introduced into the high-temperature gasification section (combustor) 8 increased, the combustor oxygen ratio with respect to the overall oxygen ratio was lowered. From these facts, the high temperature gasification section 8 does not form an ultra-high temperature region, and there is a result that there is an oxygen ratio condition in which the combustor temperature is 2000 ° C. or lower and the gasifier outlet temperature is 1100 ° C. or higher as the stable operation range. Obtained. From the calculations, it was predicted that the carbon conversion would be 99.5% or higher at an overall oxygen ratio of 0.32 or higher. At this time, the value of the cold gas efficiency exceeding the target value of 75% was obtained.

  In addition, when the oxygen ratio is 0.32 or more, the outlet temperature of the high-temperature gasification unit 8 is 1600 ° C. or more, so that the waste ash used in this example is melted and discharged from the high-temperature gasification unit 8. It is considered possible.

3. Summary Established a calculation method for predicting gasification performance based on fuel properties, our thermal balance, and gasification reaction rate obtained using PDTF. Biomass (cedar chip with 40% moisture), waste (typical municipal waste) The gasification method suitable for the properties) and the high-efficiency and stable operation conditions were examined, and the following results were obtained.
-Cedar chips are difficult to achieve high-efficiency operation with single-stage gas blowing with fuel directly injected into the gasification furnace 7, but are decomposed into carbide 4 and pyrolysis gas 3 containing moisture using the carbonizer 2. If the carbonization / gasification method in which the gasification furnace 7 is charged in two stages is used, high-efficiency and stable operation is possible.
-In the carbonization / gasification method, when the volatilization rate is high like cedar chips, the air temperature to the gas reforming section 9 Input of oxygen 6 is essential.
・ Since waste contains a lot of ash, it is necessary to melt and discharge (slag) ash from the environmental aspect. Since waste has a low volatilization ratio, high efficiency and ash melting and discharging operation can be performed by supplying air only to the high-temperature gasification unit 8 in a two-stage gasification furnace.

1 biomass fuels 2 carbide 3 (containing water combustible) pyrolysis gas 4 carbides 5 gasifying agent 6 oxygen laden gas agent 7 gasifier 8 hot gasification unit 9 the gas reforming unit 12 thermally Decomposition gas flow path 13 Carbide supply means 14 Gasifying agent supply means

Claims (3)

In the biomass carbonizing-gasifying system for further gasification carbonizing biomass fuel by thermal decomposition, woody biomass, biomass fuels such as waste biomass and mixed biomass such as municipal waste indirectly heated A two-stage gasification furnace comprising a carbonization apparatus for generating carbide, a high-temperature gasification section for gasifying the carbide, and a gas reforming section for reforming combustible pyrolysis gas containing tar volatilized when the carbide is generated When the heat for feeding the carbide and carbide supply means for supplying the hot gas section of said gasification furnace, the combustible pyrolysis gas generated in the carbonization device to the gas reformer of the gasifier and decomposing the gas flow path, normal for the flow rate of the hot gas flowing from the high-temperature gasification part supplies a gasifying agent containing oxygen to the hot gas section into the gas reforming unit Oxygen to the gas reformer in a case where serial outlet temperature of the gasification furnace flow is increased in the combustible pyrolysis gas supplied to the gas reformer is sometimes or risk thereof is less than 1100 ° C. A gasifying agent supplying means for supplying a gasifying agent containing gas, and a power generation device that generates power using the generated gas supplied from the gasification furnace and generates exhaust heat during operation, and is discharged from the power generation device. The exhaust heat is supplied as a heat source of the carbonization apparatus, and the carbonized carbon in the carbonized apparatus is sufficiently evaporated of the moisture in the biomass fuel, and the carbide in a state where the moisture is removed is converted into the high-temperature gasification. Biomass carbonization and gasification system characterized by being supplied to the section . 2. The biomass carbonization / gasification according to claim 1, wherein the gasifying agent supply means includes a branch pipe, and comprises an apparatus capable of supplying the gasifying agent of the high-temperature gasification section and the gas reforming section. system. In the biomass carbonization / gasification method, where biomass fuel is pyrolyzed by pyrolysis and further gasified, wood biomass, waste biomass such as municipal waste, and biomass fuel such as mixed biomass are indirectly heated to form carbide Gas is supplied to a high-temperature gasification section of a two-stage gasifier and gasified while the combustible pyrolysis gas containing tar volatilized when the carbide is generated is gas reformed in the gasifier In addition to supplying a gasifying agent containing oxygen to the high-temperature gasification unit, the flow rate of the high-temperature gas flowing from the high-temperature gasification unit to the gas reforming unit is normal. On the other hand, when the flow rate of the combustible pyrolysis gas supplied to the gas reforming unit increases and the outlet temperature of the gasification furnace becomes less than 1100 ° C. or when there is a risk, the gas reforming unit A gasifying agent containing oxygen is supplied, and the generated gas supplied from the gasification furnace is used to generate electric power, and the exhaust heat discharged from the power generation apparatus with exhaust heat during operation is used as a heat source of the carbonization apparatus. The biomass characterized in that, in the carbonization apparatus, moisture in the biomass fuel is sufficiently evaporated, and the carbide in a state where the moisture is removed is supplied to the high-temperature gasification unit. Carbonization and gasification method.

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