JP2003176486A - Integrated circulating fluidized bed gasifying furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact integrated circulating fluidized bed gasifying furnace capable of stably affording a combustible gas having excellent properties without requiring special mechanical handling of a fluid medium between a gasifying chamber and a char combustion chamber, forming a circulating fluidized bed type and thereby reducing the hearth area. <P>SOLUTION: This integrated circulating fluidized bed gasifying furnace is equipped with a gasifying chamber 1 having a concentrated fluidized bed or a high-speed fluidized bed in the lower part and the high-speed fluidized bed in the upper part and capable of converting a raw material (a) into a thermal decomposition gas, a collector 2 provided in the latter stage of the gasifying chamber 1 for collecting scattered particles (e), returning the collected particles (e) into the gasifying chamber 1 and discharging a combustible gas (c) separated from the scattered particles (e) to a process in the latter stage, and a combustion chamber 3 burning at least a part of combustibles such as char in the collected scattered particles (e) and discharging a combustion gas (d). Thereby, the combustion chamber 3 is composed so as to return the scattered particles (e) from the combustion chamber 3 to the gasifying chamber 1. The combustible gas (c) discharged from the collector 2 and the combustion gas (d) discharged from the combustion chamber 3 can individually be recovered without mixing the combustible gas (c) with the combustion gas (d). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated circulating fluidized bed gasifier, and more particularly to a gasifier using various wastes such as RDF and waste plastics and various fuels such as coal and biomass, and the same. Regarding the gasification system used.

[0002]

2. Description of the Related Art An external circulation type fluidized bed gasification furnace is used for discharging chars and tars produced together with a fluidized medium to the outside of the system and for returning the medium particles after the combustion to the inside of the system. Mechanical equipment is required. In particular, in the case of gasifying a raw material having a large fixed carbon content, there is a two-column circulation system in which medium particles and products are circulated through two separate columns for gasification and combustion. As shown in FIG. 7, the two-tower circulation type gasification furnace has two furnaces (tower) of a gasification furnace 101 and a char combustion furnace 102.
And the sensible heat of the fluid medium heated by the combustion heat of the char in the char combustion furnace 102 to circulate the fluid medium and the char between the gasification furnace 101 and the char combustion furnace 102 to heat the amount of heat required for gasification. Therefore, the gasification furnace 101 is to be supplied. Since it is not necessary to burn the generated gas generated in the gasification furnace, there is a feature that the calorific value of the generated gas can be maintained high. With this method, the issues of handling high-temperature particles such as securing a sufficient particle circulation amount between the gasification furnace and the char combustion furnace, controlling the particle circulation amount, and stable operation, and the temperature control of the char combustion furnace are independent from other operations. Due to the operational problem of being unable to do so, it was not possible to construct a large-scale real machine.

On the other hand, in recent years, as shown in FIG. 8, the total amount of the combustion gas of the char combustion furnace 110 is introduced into the gasification furnace 112 through the high temperature dust collector 114, and it is insufficient to supply sensible heat by circulating particles. A system has been proposed that attempts to supplement the heat of gasification that tends to occur. In this system, fuel such as waste is put into the gasification furnace 112 and gasified,
Incombustible substances in the fuel are discharged from the gasification furnace 112. The generated gas generated in the gasification furnace 112 is the gas cooler 113.
After passing through the high temperature dust collector 114, it is supplied to the next step. On the other hand, the char separated from the produced gas in the high-temperature dust collector 114 is supplied to the char combustion furnace 110 described above, and is burned in the presence of a combustion gas such as air, oxygen, or steam, and the char combustion described above is performed. Gas is produced.

However, in the above-mentioned system, since the total amount of the combustion gas discharged from the char combustion furnace is guided to the gasification furnace, a product gas having a high calorific value cannot be obtained.
That is, when the amount of the char combustion gas exceeds the amount required for gasification or fluidization in the gasification furnace, the generated gas is diluted with the extra char combustion gas, so that the calorific value thereof decreases. Moreover, in this system, the temperature control of the char combustion furnace is a method that changes the bed height to change the heat transfer area in the bed, and when the load is low, the combustion gas is cooled by the heat transfer tubes exposed on the bed. As a result, the temperature of the gasification furnace, the fluidization rate, etc. change, which also affects the gasification reaction rate, making it difficult to operate the system stably.

In the field of refuse combustion power generation system,
Pyrolysis of garbage and volatilization of chlorine components along with volatile components,
A proposal has been made to perform high-efficiency power generation by superheating steam with the combustion heat of the remaining char with a significantly reduced chlorine content. However, in general, almost no char is generated in the thermal decomposition of general waste, so there is a high possibility that the char combustion heat required for steam superheating cannot be obtained. Further, the fluidizing medium as a heat medium and the char have to flow from the gasification furnace side to the char combustion furnace side, but in the conventional method, there is no choice but to mechanically convey it by using a conveyor etc., and handling of high temperature particles. Is difficult and there are many problems with sensible heat loss.

In view of these problems, the inventors of the present invention have three gasification chambers, a char combustion chamber and a heat recovery chamber inside one fluidized bed.
We are devising an integrated gasification furnace in which each of them is provided via a partition wall. This integrated gasification furnace was devised to overcome the above-mentioned problems of the two-column circulation system, and enables a large amount of fluidized medium circulation between the char combustion chamber and the gasification chamber. It is a technology that has the possibility of being able to supply a sufficient amount of heat for gasification only with the sensible heat of, and to "obtain a generated gas with the smallest possible amount and high calorific value". However, this technique has a problem that the hearth area becomes large because it is a bubbling fluidized bed type.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and does not require any special mechanical handling of a fluidized medium between the gasification chamber and the char combustion chamber. It is possible to stably obtain excellent combustible gas,
Moreover, it is an object of the present invention to provide a compact integrated circulating fluidized bed gasification furnace having a small furnace floor area by adopting the circulating fluidized bed type.

[0008]

In order to achieve the above object, the integrated circulating fluidized bed gasification furnace of the present invention has a concentrated fluidized bed or a high speed fluidized bed in the lower part and a high speed fluidized bed in the upper part. Having a gasification chamber for pyrolyzing and gasifying the raw material, and collecting the scattered particles in the latter stage of the gasification chamber and returning them to the gasification chamber, the combustible gas separated from the scattered particles is subjected to the subsequent process. The gasification chamber includes a trapping device for discharging and a combustion chamber that burns at least a part of combustible components such as char in the collected scattered particles and discharges combustion gas. The combustible gas discharged from the trap and the combustion gas discharged from the combustion chamber can be individually recovered without being mixed with each other. Is.

The integrated circulating fluidized bed gasification furnace of the present invention has a gasification chamber, a collector, and a combustion chamber, and in the gasification chamber,
The raw material is pyrolyzed and gasified, and the produced gas is decomposed and reformed.The collection device collects the scattered particles and separates and recovers the combustible gas.The combustion chamber burns combustibles such as char in the scattered particles. I do. The combustion gas discharged from the combustion chamber is cooled by a device in the latter stage such as a waste heat recovery unit and discharged to the outside of the system.

In one embodiment of the present invention, the raw material is pyrolyzed and gasified in a concentrated fluidized bed or a high-speed fluidized bed in the lower part of the gasification chamber to form a product gas and char, and then in the upper part of the gasification chamber, a high-speed gas is formed. It is characterized in that the gas is decomposed and reformed in the fluidized bed. In one aspect of the present invention, when the lower part of the gasification chamber is a rich fluidized bed, a gas such as steam or nitrogen is fluidized from the upper part of the rich fluidized bed so that the upper part of the gasification chamber is a high-speed fluidized bed. It is characterized by supplying as.

In one aspect of the present invention, in order to form a high temperature region necessary for decomposing and reforming the gas generated by the pyrolysis gasification of the raw material in the high-speed fluidized bed above the gasification chamber, It is characterized in that a gas containing oxygen is supplied to the gasification chamber as a fluidizing gas. That is, for the purpose of decomposing and reforming the gas generated by pyrolysis gasification, a gas containing oxygen is supplied as a fluidizing gas to the gasification chamber in order to raise the temperature of the high-speed fluidized bed, and the generated gas is Burn some. The gas containing oxygen is supplied to either or both of the lower part and the upper part of the gasification chamber.

In one aspect of the present invention, the combustion chamber has a fluidized bed formed by the collected scattered particles, for burning combustible components such as char contained in the scattered particles in the combustion chamber. Was supplied with a gas containing oxygen, and by returning the scattered particles, which had been heated to a high temperature by burning the combustibles, to the gasification chamber, the heat necessary for the pyrolysis gasification in the gasification chamber was supplied. It is characterized by That is, at least a part of the scattered particles separated by the collector flows into the combustion chamber to form a fluidized bed in the combustion chamber, and combustible components such as char contained are burned in the fluidized bed. By the heat of combustion of this combustible component, the temperature of the scattered particles rises and is returned to the gasification chamber,
It becomes a heat source for pyrolyzing and gasifying the raw material.

In one aspect of the present invention, the combustion chamber has an internal circulation type fluidized bed composed of a plurality of chambers partitioned by partition walls, and the combustion chamber comprises a main combustion chamber and a heat recovery chamber having a heat transfer tube. Therefore, the amount of heat recovered in the heat recovery chamber is controlled by changing the flow rate of the gas containing oxygen supplied to the heat recovery chamber, and the bed temperature of the fluidized bed is adjusted. That is, the combustion chamber is an internal circulating fluidized bed composed of a plurality of chambers partitioned by partition walls. The combustion chamber is composed of a main combustion chamber and a heat recovery chamber, and an in-layer heat transfer tube is installed in the heat recovery chamber. The scattered particles collected by the collector flow into the combustion chamber from the particle supply port, combustible components such as char are burned by the gas containing oxygen, and the combustion exhaust gas is discharged from the gas outlet. Some of the scattered particles that have become hot due to the combustion in the main combustion chamber jump over the partition walls and flow into the heat recovery chamber where they are recovered by the in-layer heat transfer tubes. There is an opening between the lower part of the heat recovery chamber and the main combustion chamber, and the scattered particles of which heat is recovered move to the main combustion chamber. On the other hand, a part of the scattered particles that have become hot in the main combustion chamber are sent to the gasification chamber from the particle outlet. The bed temperature is controlled by changing the flow rate of the gas containing oxygen supplied from the lower part of the heat recovery chamber to adjust the moving amount of the scattered particles and changing the heat recovery amount.

One aspect of the present invention is characterized in that the heat recovery chamber has an oxidizing atmosphere. That is, by increasing the amount of oxygen contained in the gas supplied from the lower part of the heat recovery chamber to be larger than the theoretical combustion oxygen amount of combustible components in the scattered particles, an oxidizing atmosphere is created in the heat recovery chamber so that the internal heat transfer tube Corrosion due to chlorine etc. can be reduced.

In one aspect of the present invention, in order to decompose and reform the gas produced by the thermal decomposition and gasification of the raw material in the gasification chamber, at least the medium particles forming the rich fluidized bed or the fast fluidized bed. It is characterized in that a part thereof is used as catalyst particles.

One aspect of the present invention is characterized in that carbon and the like deposited on the catalyst surface of the catalyst particles are removed and regenerated in the combustion chamber. That is, when at least a part of the medium particles are used as the catalyst particles, the gas generated by the pyrolysis gasification of the raw material is decomposed and reformed in the high-speed fluidized bed portion in the gasification chamber, and in this process, it is deposited on the surface of the catalyst particles. Carbon and the like are burned and removed in the combustion chamber, and the catalyst particles are regenerated.

In one aspect of the present invention, in order to remove impurities such as chlorine compounds and sulfur compounds contained in the combustible gas and to purify the produced gas, a medium for forming the concentrated fluidized bed or the fast fluidized bed. It is characterized in that at least a part of the particles are absorption catalyst particles such as a calcium compound. That is, by absorbing and removing chlorine compounds, sulfur compounds and the like contained in the produced gas, by using an absorption catalyst such as a calcium compound as at least a part of the medium particles in order to purify the produced gas, The harmful component concentration can be reduced.

In one embodiment of the present invention, the raw material is pyrolyzed and gasified in the gasification chamber, the gas obtained is decomposed and reformed, and the flammable particles recovered by separating from the scattered particles by the trapping device. In order to further reform the gas further, a cracking device is provided in the latter stage of the trapping device, and the combustible gas introduced into the cracking device is secondarily reformed. In other words, in order to pyrolyze the raw material in the gasification chamber, decompose and reform the obtained gas, separate the combustible gas separated from the scattered particles by the trapping device, and further reform it. A cracking device can be provided in the latter stage of the trapping device to secondarily reform the combustible gas introduced to the cracking device.

In one aspect of the present invention, auxiliary fuel is supplied to the combustion chamber. That is, if necessary, auxiliary fuel may be supplied to the combustion chamber, and in addition to combustible components such as char contained in the scattered particles, the auxiliary fuel is burned to discharge combustion exhaust gas, and the temperature is raised. By returning the scattered particles to the gasification chamber, it is possible to supply the heat necessary for the pyrolysis gasification in the gasification chamber.

In the integrated gasification method of the present invention, a raw material is pyrolyzed and gasified using a circulating fluidized bed gasification furnace in which a concentrated fluidized bed or a high-speed fluidized bed is formed in the lower portion and a high-speed fluidized bed is formed in the upper portion. A gasification step to collect, a collection step for collecting the scattered particles in the latter stage of the gasification step, and burning at least a part of combustible components such as char in the collected scattered particles to produce a combustion exhaust gas. And a combustion process capable of returning the scattered particles to the gasification process, and mixing the combustible gas generated in the gasification process and separated in the collection process with the combustion exhaust gas in the combustion process. It is characterized in that it can be taken out individually without any need. 1 of the present invention
In the aspect, in order to decompose / reform the gas generated by the thermal decomposition / gasification of the raw material in the gasification step, at least a part of the medium particles are used as catalyst particles, and the catalyst surface of the catalyst particles is used in the combustion step. It is characterized in that the carbon and the like deposited on the surface are removed and regenerated.

The gasification system of the present invention comprises an integrated circulating fluidized bed gasification furnace having the above-mentioned structure, and a combustible gas discharged from the trap of the integrated circulating fluidized bed gasification furnace for power recovery or power generation or It is characterized in that it is used for chemical synthesis and the like, and waste heat is recovered from the combustion exhaust gas discharged from the combustion chamber of the integrated circulating fluidized bed gasification furnace.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows the basic configuration of an integrated circulating fluidized bed gasification furnace.
The integrated circulating fluidized bed gasification furnace has a gasification chamber 1, a collection device 2, and a combustion chamber 3 together. The raw material a is supplied to the gasification chamber 1, and the pyrolysis gasification of the raw material a and the decomposition / reformation of the produced gas are performed in the gasification chamber 1. The char and generated gas generated in the gasification chamber 1 flow into the collector 2 together with the fluidized medium. The collection device 2 collects scattered particles e and separates and recovers the combustible gas c, and the combustion chamber 3 burns combustible components such as char in the scattered particles. In the lower part of the gasification chamber 1, a rich fluidized bed or a high speed fluidized bed is formed. When the lower part of the gasification furnace 1 is a rich fluidized bed, a gas such as steam or nitrogen is supplied as the fluidizing gas b2 from the upper part of the rich fluidized bed to make the upper part of the gasification chamber a fast fluidized bed. In the gasification chamber 1, for the purpose of decomposing and reforming the gas generated by the pyrolysis gasification, a gas containing oxygen may be supplied as the fluidizing gas b1 or b2 to raise the temperature of the fast fluidized bed. Of course, a part of the generated gas may be burned. The gas containing oxygen is supplied to either one or both of b1 and b2.

FIG. 2 is a schematic diagram showing an example of the structure of the gasification chamber in the integrated circulating fluidized bed gasification furnace shown in FIG. As shown in FIG. 2, when the lower part of the gasification chamber 1 is a dense fluidized bed, the superficial velocity of the fluidized gas b1 supplied from the furnace bottom from the peripheral air box 71 is the central air box 70. By making the superficial velocity to be 1.5 times or more higher than the superficial velocity supplied from the inside, a swirling flow 72 of the fluid medium is formed in the rich fluidized bed, which fluidizes and descends in the central portion and rises in the peripheral portion while fluidizing. It may be done. By this swirling flow, it is possible to uniformly disperse the raw material in the layer,
The temperature in the layer is uniform. The fluidized gas b2 is supplied to the upper portion of the rich fluidized bed of the gasification chamber 1. The incombustible material f in the raw material is discharged out of the system through an incombustible material discharge port 69 provided in the furnace bottom of the gasification chamber 1.

The fluidizing gas b1 supplied from the furnace bottom
By making the superficial velocity supplied from the central air box 70 to be 1.5 times or more the superficial velocity supplied from the peripheral air box 71, the fluidized ascending in the central part in the dense fluidized bed. However, a swirling flow of the fluidized medium that fluidizes and descends may be formed in the peripheral portion, and the incombustible substance f in the raw material is discharged by the swirling flow, which is provided in the center of the furnace bottom of the gasification chamber 1. It is discharged from the outlet to the outside of the system. As a result, the number of incombustible material discharge ports can be reduced to one, and the device can be simplified.

As shown in FIG. 1, the gas discharged from the gasification chamber 1 and the scattered particles e flow into the collector 2 and are separated into gas and solids. The collection device 2 shown in FIG. 1 is a cyclone dust collection device using centrifugal force dust collection. The combustible gas c separated here is led out of the furnace. On the other hand, the scattered particles e collected are passed through the loop seal 51 to the combustion chamber 3
Flow into. Due to the material sealing effect of the scattered particles of the loop seal 51, mixing of the combustible gas c and the combustion exhaust gas d can be avoided. Further, the particles scattered in the loop seal portion may be fluidized, and it is preferable to use an inert gas such as steam or nitrogen as the fluidizing gas. A part of the scattered particles e collected by the collecting device 2 may be supplied to the gasification chamber 1 without passing through the combustion chamber 3. In this case, the amount of particles supplied to the combustion chamber 3 can be adjusted by changing the flow rate of the fluidizing gas supplied to the loop seal 51.
The loop seal 51 may be replaced with another mechanism having a sealing property such as an L valve, and it is sufficient that the combustible gas c and the combustion exhaust gas d can be prevented from being mixed by the existence of the mechanism.

When at least a part of the medium particles in the gasification chamber 1 are used as the catalyst particles, the gas generated by the pyrolysis gasification of the raw material is decomposed and reformed in the high-speed fluidized bed portion in the gasification chamber 1, In this process, carbon and the like deposited on the surface of the catalyst particles are burned and removed in the combustion chamber 3 to regenerate the catalyst particles. Further, chlorine compounds and sulfur compounds contained in the gas generated in the gasification chamber 1 are absorbed and removed, and an absorption catalyst such as a calcium compound is used as at least a part of the medium particles in order to purify the generated gas. The concentration of harmful components in the combustible gas c can be reduced.

At least a part of the scattered particles e separated by the trap 2 flows into the combustion chamber 3, and combustible components such as char contained in the scattered particles e flowing into the combustion chamber 3 are burned in the combustion chamber 3. To be done. A gas b3 containing oxygen necessary for combustion is supplied to the combustion chamber 3. This combustion heat raises the temperature of the scattered particles e to return to the gasification chamber 1 and serves as a heat source for pyrolyzing and gasifying the raw material a.

FIG. 3 is a schematic diagram showing an example of the structure of the combustion chamber in the integrated circulating fluidized bed gasification furnace shown in FIG.
As shown in FIG. 3, the combustion chamber 3 is an internal circulating fluidized bed composed of a plurality of chambers partitioned by partition walls. The combustion chamber 3 is composed of a main combustion chamber 52 and a heat recovery chamber 53, and the in-layer heat transfer tube 4 is installed in the heat recovery chamber 53. The scattered particles e collected by the collector 2 flow into the combustion chamber 3 from the particle supply port 55, combustible components such as char are burned by the gas b3 containing oxygen, and the combustion exhaust gas d is discharged from the gas outlet 57. It
A part of the scattered particles, which have been heated to a high temperature by the combustion in the main combustion chamber 52, jump over the partition wall 58 and flow into the heat recovery chamber 53 as indicated by an arrow 61a, and the heat is recovered by the in-layer heat transfer tube 4. An opening 60 is provided below the heat recovery chamber 53 between the heat recovery chamber 53 and the main combustion chamber 52, and the scattered particles of the heat recovered move to the main combustion chamber 52 as indicated by an arrow 61b. On the other hand, the main combustion chamber 5
A part of the scattered particles e whose temperature has been raised in 2 is sent to the gasification chamber 1 from the particle outlet 56. By changing the flow rate of the gas b3 containing oxygen supplied from the heat recovery chamber lower air box 66,
The layer temperature is controlled by adjusting the movement amount of the scattered particles and changing the heat recovery amount. Here, the heat recovery chamber 53 is not always necessary, and when returning the scattered particles e, which have been heated to a high temperature due to the combustion of combustible components in the main combustion chamber 52, to the gasification chamber 1, the scattered particles are used for controlling the layer temperature of the gasification chamber 1. The heat recovery is performed when it is desired to lower the temperature of e before supplying.

Further, the amount of oxygen contained in the gas supplied from the lower air box 66 of the heat recovery chamber is made larger than the theoretical burned oxygen amount of the combustible components in the scattered particles, so that the inside of the heat recovery chamber 53 becomes an oxidizing atmosphere. As a result, it is possible to reduce corrosion of the in-layer heat transfer tube due to chlorine or the like. The fluidized gas b3 containing oxygen supplied to the main combustion chamber 52 in the combustion chamber 3 is supplied to the peripheral air box 65.
The superficial velocity supplied from the central wind box 64 is 1.5 times or more higher than the superficial velocity supplied from the central wind box 64, so that the central combustion chamber 52 fluidizes and descends in the central portion, and the peripheral combustion chamber 52 in the peripheral portion. A swirling flow 62 of the fluidized medium that rises while fluidizing may be formed. This swirling flow makes it possible to uniformly disperse combustible components such as char in the scattered particles in the layer, so that the temperature in the layer becomes uniform.

Further, as shown in FIG. 3, a partition wall 59 is provided, a scattered particle settling chamber 54 is provided between the particle discharge port 56 and the main combustion chamber 52, and a flow supplied to the scattered particle settling chamber wind box 67. By adjusting the flow rate of the atomized gas b3, the particle discharge port 5
It is also possible to control the amount of scattered particles supplied from 6 to the gasification chamber 1. This makes it possible to change the particle concentration of the fast fluidized bed without changing the flow rates of the gases b1 and b2 supplied to the gasification chamber 1 and without discharging the medium particles from the furnace bottom of the gasification chamber 1. It is possible.

FIG. 4 is a diagram showing an example of the flow of a gasification system using the integrated circulating fluidized bed gasification furnace of the present invention. As shown in FIG. 4, an integrated circulating fluidized bed gasifier 10
The combustible gas c collected from the collector 2 at 0 is used for power recovery, power generation, chemical synthesis, etc. in the subsequent process. The combustion gas d discharged from the combustion chamber 3 in the integrated circulating fluidized bed gasification furnace 100 is cooled in the rear waste heat recovery unit 5 and discharged to the outside of the system.

Further, catalyst particles are used as at least a part of the medium particles, and a gas containing oxygen is supplied to the gas obtained by pyrolyzing and gasifying the raw material in the gasification chamber 1 to supply gas containing oxygen in the upper high-speed fluidized bed region. Instead of decomposing / reforming by burning a part of the gas to raise its temperature, it is also possible to decompose / reform the gas in a temperature atmosphere that does not require gas combustion. The catalyst particles used here are CaO, FeSiO ₂ , MgSiO ₂ , A
It may be 1 ₂ O ₃ or the like. Furthermore, carbon and the like deposited on the surface of the catalyst particles in the decomposition / reforming reaction in the gasification chamber 1
In the combustion chamber in the latter stage, the gas containing oxygen is burned and removed, and as a result, the catalyst particles are regenerated.

FIG. 5 is a diagram showing another example of the flow of the gasification system using the integrated circulating fluidized bed gasification furnace of the present invention. As shown in FIG. 5, the raw material a is pyrolyzed and gasified in the gasification chamber 1, the obtained gas is decomposed and reformed, and the flammable gas recovered by separating from the scattered particles e by the trap 2 is collected. It is also possible to provide a cracking device 15 in the subsequent stage of the trapping device 2 in order to further secondary reform the c, and secondarily reform the combustible gas c introduced into the cracking device 15. The cracking device 15 includes a reforming reaction chamber 15a and a catalyst regeneration chamber 15
consists of b and particles circulate between these chambers,
The structure is such that the gases do not mix. It is also possible to use an internal circulation type fluidized bed as an example of such a device. The reforming catalyst regenerated in the catalyst regeneration chamber 15b and the combustible gas c are supplied to the reforming reaction chamber 15a, and the combustible gas c is reformed. On the other hand, in order to remove carbon and the like deposited on the catalyst particles in this reforming step and regenerate the catalyst particles, the catalyst particles are supplied to the catalyst regeneration chamber 15b, discharged from the combustion chamber 3 and supplied to the catalyst regeneration chamber 15b. It reacts with at least a part of the generated combustion exhaust gas d. The product gas c secondarily reformed in this way is used as power recovery or power generation or a raw material for chemical synthesis.

FIG. 6 is a diagram showing still another example of the flow of the gasification system using the integrated circulating fluidized bed gasification furnace of the present invention. Combustible gas c generated in the gasification chamber 1 of the integrated circulating fluidized bed gasification furnace 100 and recovered from the collector 2
Is supplied to the gas scrubber / cooler 6. The gas scrubber / cooler 6 removes harmful acidic gas such as hydrogen chloride contained in the gas and cools the combustible gas c to a temperature at which it can be supplied to the gas engine 7. The cleaned and cooled combustible gas c is guided to the gas engine 7 and used for power generation. Exhaust gas d2 from the gas engine 7 is introduced into the waste heat boiler 9 to recover heat, and then is discharged from the chimney 14 to the outside of the system via the induced blower 13.

The flue gas d1 discharged from the combustion chamber 3 of the integrated circulating fluidized bed gasification furnace 100 is introduced into the waste heat boiler 9 and heat is recovered, and thereafter, from the chimney 14 via the induced blower 13 to the outside of the system. Is discharged to. Canned water is a forced circulation pump 1
2 is supplied to the waste heat boiler 9 to generate combustion exhaust gas d1, d
It heat-exchanges with 2 to become saturated steam, and this saturated steam is guided to the in-layer heat transfer tube 4 of the heat recovery chamber 53 in the combustion chamber 3 of the integrated circulating fluidized bed gasification furnace 100. The can water that has undergone heat exchange in the in-layer heat transfer tube 4 and has become superheated steam is guided to the steam turbine 10 and used for power generation. The condensed can water is condensed in the condenser 11.

By the method and apparatus shown in the above embodiments, it is possible to stably obtain a product gas having excellent properties without requiring special mechanical fluid medium handling between the gasification chamber and the char combustion chamber. Thus, it is possible to provide a gasification system capable of high-efficiency power generation and a compact system having a small hearth area.

[0037]

As described above, according to the integrated circulating fluidized bed gasification furnace of the present invention, it is possible to stably generate a product gas having excellent properties without requiring special mechanical fluidized medium handling. Obtainable. Further, by making the fluidized bed gasification furnace a circulating fluidized bed type, it is possible to make a compact gasification furnace having a small floor area. Furthermore, a gasification system capable of highly efficient power recovery or power generation, a raw material gas production system for various chemical synthesis, and the like can be configured by using the integrated circulating fluidized bed gasification furnace.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of an integrated circulating fluidized bed gasification furnace.

FIG. 2 is a schematic diagram showing an example of the configuration of a gasification chamber in the integrated circulating fluidized bed gasification furnace shown in FIG.

FIG. 3 is a schematic diagram showing an example of a configuration of a combustion chamber in the integrated circulating fluidized bed gasification furnace shown in FIG.

FIG. 4 is a diagram showing an example of a flow of a gasification system using the integrated circulating fluidized bed gasification furnace of the present invention.

FIG. 5 is a diagram showing another example of the flow of the gasification system using the integrated circulating fluidized bed gasification furnace of the present invention.

FIG. 6 is a diagram showing still another example of the flow of the gasification system using the integrated circulating fluidized bed gasification furnace of the present invention.

FIG. 7 is an explanatory diagram of a conventional two-column circulation type gasification furnace.

FIG. 8 is an explanatory diagram of a combined power generation system using a conventional fluidized bed furnace.

[Explanation of symbols]

1 gasification chamber 2 Collection device 3 Combustion chamber 4 layer heat transfer tube 5 Rear waste heat recovery section 6 Gas washer / cooler 7 gas engine 8a Gas engine generator 8b Steam turbine generator 9 Waste heat boiler 10 steam turbine 11 condenser 12 Forced circulation pump 13 Incentive blower 14 chimney 15 Cracking device 15a Reforming reaction chamber 15b Catalyst regeneration room 51 loop seal 52 Main combustion chamber 53 Heat recovery room 54 Scattering particle settling chamber 55 Scattered particle supply port 56 Scattered particle outlet 57 Combustion exhaust gas outlet 58 Partition wall between main combustion chamber and heat recovery chamber 59 Partition wall between main combustion chamber and scattered particle settling chamber 60 Heat recovery chamber-main combustion chamber opening 61a Main combustion chamber-heat recovery chamber Scattered particle circulation flow 61b Heat recovery chamber-Main combustion chamber Scattered particle circulation flow 62 Main combustion chamber swirl flow 63 Main combustion chamber-scattering particles sedimentation chamber Particle circulation flow 64 Main combustion chamber central air box 65 Wind box around the main combustion chamber 66 Heat Recovery Chamber Wind Box 67 Scattered Particle Settling Chamber Wind Box 68 Gasification chamber gas dispersion plate 69 Incombustibles outlet 70 Gasification chamber central air box 71 Wind box around the gasification chamber 72 Concentrated fluidized bed swirling flow in gasification chamber 100 Integrated circulating fluidized bed gasifier a raw material b1 Gasification chamber furnace bottom supply gas b2 Gas supply in upper part of gasification chamber b3 Combustion chamber supply gas c Combustible gas d Combustion exhaust gas d1 Combustion chamber exhaust gas d2 gas engine exhaust gas d3 Waste heat boiler exhaust gas e Scattered particles f Incombustibles

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F23G 5/16 F23G 5/30 B 5/30 E L M 5/46 B 5/46 F23C 11/02 311 (72) Inventor Fumitoshi Nishiura 11-1 Haneda-Asahi-cho, Ota-ku, Tokyo Ebara Corporation (72) Inventor Takahiro Oshita 11-1 Haneda-Asahi-cho, Ota-ku, Tokyo F-term in Ebara Corporation ( (Reference) 3K061 AA11 AB02 AC13 AC17 AC20 BA01 EA03 EA04 EA07 EB01 EB12 EB15 3K064 AA02 AA04 AB03 AC05 AD05 AD08 AE15 AF06 BA03 BA05 BA07 BA09 BA15 BA17 BA22 CA21 CA21 CA21 CA21 CA03 CA21 BA01 BA03 BA01 JA04 BA0 JA01 78

Claims (15)

[Claims] 1. A gasification chamber having a dense fluidized bed or a high-speed fluidized bed in the lower part and a high-speed fluidized bed in the upper part, which pyrolyzes and gasifies a raw material, and a scatter provided in the latter stage of the gasification chamber. A trapping device for trapping the particles and returning them to the gasification chamber and discharging the combustible gas separated from the scattered particles to a subsequent process, and at least a combustible component such as char in the trapped scattered particles. And a combustion chamber configured to return the scattered particles from the combustion chamber to the gasification chamber, the combustion chamber being configured to burn a part of the combustion gas and to discharge the combustion gas, and the combustion chamber. An integrated circulating fluidized bed gasification furnace, characterized in that it can be individually recovered without mixing with the combustion gas discharged from the furnace. 2. In the lower part of the gasification chamber, the raw material is pyrolyzed and gasified in a dense fluidized bed or a high-speed fluidized bed to form a product gas and char, and then in the upper part of the gasification chamber, a gas is formed in the high-speed fluidized bed. The integrated circulating fluidized bed gasification furnace according to claim 1, characterized in that it is decomposed and reformed. 3. When the lower part of the gasification chamber is a rich fluidized bed, a gas such as steam or nitrogen is supplied as a fluidizing gas from the upper part of the rich fluidized bed in order to make the upper part of the gasification chamber a high-speed fluidized bed. The integrated circulating fluidized bed gasification furnace according to claim 1 or 2, characterized in that. 4. Oxygen is provided in the gasification chamber in order to form a high temperature region necessary for decomposing and reforming the gas generated by pyrolysis gasification of the raw material in the high-speed fluidized bed above the gasification chamber. The integrated circulating fluidized bed gasification furnace according to any one of claims 1 to 3, wherein a gas containing the gas is supplied as a fluidized gas. 5. The combustion chamber has a fluidized bed formed by the collected scattered particles, and a gas containing oxygen for burning combustible components such as char contained in the scattered particles in the combustion chamber. Is supplied to the gasification chamber to return the scattered particles that have been heated to a high temperature due to the combustion of the combustible component, thereby supplying the heat necessary for the pyrolysis gasification in the gasification chamber. An integrated circulating fluidized bed gasifier according to any one of claims 1 to 4. 6. The combustion chamber has an internal circulation type fluidized bed composed of a plurality of chambers partitioned by partition walls, and the combustion chamber comprises a main combustion chamber and a heat recovery chamber having a heat transfer tube. The amount of heat recovered in the heat recovery chamber is controlled by changing the flow rate of the gas containing oxygen supplied to the chamber, and the bed temperature of the fluidized bed is adjusted. The integrated circulating fluidized bed gasification furnace according to Item 1. 7. The integrated circulating fluidized bed gasification furnace according to claim 6, wherein the heat recovery chamber has an oxidizing atmosphere. 8. In order to decompose / reform the gas generated by the thermal decomposition / gasification of the raw material in the gasification chamber, at least a part of the medium particles forming the concentrated fluidized bed or the high-speed fluidized bed is used as catalyst particles. The integrated circulating fluidized bed gasification furnace according to any one of claims 1 to 7, wherein 9. The integrated circulating fluidized bed gasification furnace according to claim 8, wherein carbon and the like deposited on the catalyst surface of the catalyst particles are removed and regenerated in the combustion chamber. 10. At least a part of medium particles forming the concentrated fluidized bed or the high-velocity fluidized bed in order to remove impurities such as chlorine compounds and sulfur compounds contained in the combustible gas and to purify the produced gas. 10. The integrated circulating fluidized bed gasification furnace according to any one of claims 1 to 9, wherein is an absorption catalyst particle such as a calcium compound. 11. The raw material is pyrolyzed and gasified in the gasification chamber, the gas obtained is then decomposed and reformed, and the combustible gas recovered by separating from the scattered particles by the trapping device is further secondary. The cracking device is provided in the latter stage of the trapping device for reforming, and the flammable gas introduced to the cracking device is secondarily reformed, and the cracking device is secondarily reformed. Integrated circulating fluidized bed gasifier. 12. The integrated circulating fluidized bed gasification furnace according to claim 1, wherein auxiliary fuel is supplied to the combustion chamber. 13. A gasification step of pyrolyzing and gasifying a raw material by using a circulating fluidized bed gasification furnace in which a dense fluidized bed or a high-speed fluidized bed is formed in a lower portion and a high-speed fluidized bed is formed in an upper portion, and the gas. A collecting step for collecting scattered particles in the latter stage of the liquefaction step, and burning at least a part of combustible components such as char in the collected scattered particles to discharge combustion exhaust gas to remove the scattered particles. A combustion process that can be returned to the gasification process is provided, and the combustible gas generated in the gasification process and separated in the collection process and the combustion exhaust gas in the combustion process can be individually taken out without mixing. An integrated gasification method characterized by the above. 14. In order to decompose / reform the gas generated by the thermal decomposition / gasification of the raw material in the gasification step, at least a part of the medium particles are used as catalyst particles, and the catalyst particles in the combustion step are used. The integrated gasification method according to claim 13, wherein carbon or the like deposited on the catalyst surface is removed and regenerated. 15. The integrated circulating fluidized bed gasification furnace according to claim 1, and the power recovery of the combustible gas discharged from the collecting device of the integrated circulating fluidized bed gasification furnace. Alternatively, an integrated circulating fluidized bed gasification furnace is used, which is used for power generation or chemical synthesis and recovers waste heat from combustion exhaust gas discharged from the combustion chamber of the integrated circulating fluidized bed gasification furnace. Gasification system.