WO2003068894A1

WO2003068894A1 - Method and device for gasification

Info

Publication number: WO2003068894A1
Application number: PCT/JP2003/001282
Authority: WO
Inventors: Toru Akiyama; Shinji Tanaka; Fumihiko Kiso; Fumihiko Hanayama
Original assignee: Hitachi, Ltd.; Babcock-Hitachi K.K.
Priority date: 2002-02-12
Filing date: 2003-02-06
Publication date: 2003-08-21
Also published as: CN1630701A; JP4085239B2; CN100447221C; AU2003207084A1; JP2003231888A

Abstract

A gasification device and a gasification method for solid fuel capable of lowering the temperature of generated gas discharged from a gasification furnace while increasing a fuel-to-gas conversion efficiency, the gasification device comprising a washer (3) washing with water and collecting soot and dust including unreacted inflammable components accompanying the generated gas flowing through a regenerated gas flow passage (59), a dehydrator (5) generating slurry by regulating the water amount of washing waste including soot and dust collected by the washer (3), and a nozzle (11) installed at a step part where an upper stage burner (25) is installed and feeding the slurry to the gasification furnace (1); the gasification method comprising the steps of allowing the slurry fed from the nozzle (11) into the gasification furnace (1) to be accompanied by a downward flow formed by the upper stage burner (25) and flowing the slurry in a direction opposed to the flow of the regenerated gas in the gasification furnace (1) led to an outlet.

Description

Specification

Gasification method and gasification equipment

The present invention relates to a solid fuel gasification technique, and more particularly, to a solid fuel gasification method and apparatus using a gas-bed gasification furnace. Background art

Gasifiers that pulverize solid fuels, such as solid hydrocarbons such as coal, and partially burn them with oxygen to produce gas are called fixed beds, fluidized beds, and gas or spouted beds. Various methods have been proposed. Among these, the method called the gas layer or spouted bed enables the operation of the gasifier at a relatively high temperature, for example, 150 ° C, and converts the fuel into gas. Efficiency is higher than other methods. In addition, since the gasification furnace can be operated at a relatively high temperature, the ash in solid fuel such as charcoal hydrogen can be melted, so the ash must be collected and reused as slag. Can also.

Here, in a gasifier equipped with such a gas bed type gasifier, the generated gas generated in the gasifier and discharged from the gasifier is an unreacted combustible component, for example, an unreacted component. It is accompanied by dust containing carbon components such as char and tar. For this reason, a gasifier has been proposed that re-supplies the unreacted combustible components entrained in the generated gas to the gasifier, uses the combustible components as much as possible, and improves the conversion efficiency of fuel to gas. ing. See, for example, Japanese Patent Application Laid-Open No. Hei 7-279585

In a gasification apparatus as disclosed in Japanese Patent Application Laid-Open No. 7-278755, a gasification furnace formed in a cylindrical shape is provided with an outlet for product gas at one end, and the other end is provided with a gasification furnace. A configuration with a fuel, oxygen, or air It has a gasifier. Then, soot dust containing unreacted flammable components entrained in the product gas discharged from the outlet of the gasifier is recovered from the product gas, and the collected dust and solid fuel such as finely pulverized coal are collected. Are mixed to form a slurry. Then, this slurry is supplied to the gasifier as fuel by pressurizing it to a pressure higher than the operating pressure of the gasifier using a pump or the like.

In conventional gasifiers, the temperature of the product gas generated in the gasifier is cooled to the temperature required by the facilities and equipment to which the product gas is sent. A cooler with a flow path is provided to cool the product gas discharged from the gasification furnace. For example, when the generated gas is processed by a desulfurization device or the like, the desulfurization process is generally performed at room temperature, so it is necessary to cool the generated gas to a room temperature by the desulfurization device. As a cooler for cooling such a generated gas, a boiler-type cooler for cooling the generated gas by performing heat exchange between a generated gas and a fluid such as water or steam flowing through a flow path. It is used.

At this time, depending on the temperature of the product gas discharged from the gasification furnace, slag may be generated due to melting of ash accompanying the product gas discharged from the gasification furnace. For this reason, if a cooler with a structure in which a plurality of conduits through which the fluid that exchanges heat with the generated gas flows flows is used as the cooler, the gap between the conduits through which the fluid flows In some cases, slag adheres to the gas and blocks the flow path of the generated gas. Therefore, in a gasifier where the temperature of the generated gas discharged from the gasification furnace may reach a temperature at which slag is generated, the flow path of the generated gas is used to prevent the flow path from being blocked by the slag. A structure in which a flow path through which fluid for heat exchange with generated gas flows, such as a water-cooled wall structure or a jacket structure, is connected to the outlet of the gasification furnace.

Coolers with such a water-cooled wall structure / jacket structure have a heat exchange efficiency, that is, a cooling efficiency that is lower than that of a cooler with a structure in which multiple pipes are arranged in the flow path of the generated gas. Since the temperature is lower than that, the size of the cooler increases. For example, a gasifier with a height of several meters may need to be equipped with a cooler with a height of several tens of meters. A cooler such as a water-cooled wall structure or a jacket structure provided in such a gasifier causes an increase in the size of the gasifier and an increase in cost. Therefore, it is desired to reduce the temperature of the generated gas discharged from the gasifier to reduce the size of a cooler such as a water-cooled wall structure or a jacket structure.

On the other hand, the inventors of the present application supplied a slurry generated by dust collected from the generated gas discharged from the gasification furnace to an outlet side of the generated gas of the gasification furnace, and provided the generated gas of the gasification furnace. Is considering reducing the temperature of the product gas discharged from the gasifier by evaporating the moisture of the slurry supplied to the outlet side of the gasifier. However, if the slurry is supplied to the outlet of the gasification furnace, the supplied slurry will be discharged from the gasification furnace with the generated gas. The unreacted combustible component contained in the slurry has a shorter residence time in the gasifier compared to the gasifier that re-supplies the gas to the gasifier, and this unreacted combustible component reacts in the gasifier. And the efficiency of converting fuel to gas cannot be improved. Therefore, it is necessary to lower the temperature of the product gas discharged from the gasifier while improving the efficiency of converting fuel to gas. Disclosure of the invention

An object of the present invention is to provide a gasification method and a gasification apparatus for lowering the temperature of product gas discharged from a gasification furnace while improving the conversion efficiency of fuel to gas.

According to the gasification method of the present invention, an unreacted combustible component entrained in the product gas discharged from the outlet is included in an outlet portion of a product gas of a gasifier that partially burns a solid fuel to generate a gas. Slurry generated by collecting soot and dust is supplied, It is characterized in that the supplied slurry flows in a direction opposite to the flow of the generated gas toward the outlet in the gasification furnace.

With such a configuration, the temperature of the product gas discharged from the gasification furnace can be reduced by the water in the slurry by supplying the slurry to the outlet side of the product gas of the gasification furnace. Furthermore, the unreacted combustible components contained in the slurry are introduced into the gasifier by flowing the slurry supplied into the gasifier in a direction opposite to the flow of product gas in the gasifier toward the outlet. The staying time can be extended, and the amount of unreacted combustible components contained in the slurry can be increased. Therefore, the temperature of the product gas discharged from the gasifier can be reduced while improving the efficiency of converting fuel to gas.

Further, a gasification furnace is provided at a lower burner for supplying solid fuel into the gasification furnace, and at a portion closer to an outlet than the gasification furnace lower combustion furnace. And a slurry for supplying a slurry to a step provided with an upper parner of the gasification furnace, whereby an outlet side of the gasification furnace is provided. The slurry supplied to the portion is entrained by the descending flow formed by the upper stepper, so that the slurry can easily flow in the direction opposite to the flow of the generated gas toward the outlet in the gasification furnace.

In addition, if the slurry is injected into the gasification furnace and a flow is formed in the gasification furnace in the direction opposite to the flow of the generated gas toward the outlet, the flow will be like the descending flow formed by the upper stepper. Even if the flow in the direction opposite to the flow of the generated gas in the gasification furnace is not formed, the slurry can flow in the direction opposite to the flow of the generated gas toward the outlet.

Further, the gasification apparatus of the present invention includes: a gasification furnace for partially burning solid fuel to generate a gas; a product gas flow path through which a product gas generated by the gasification furnace flows; A slurry generating means for recovering soot and dust containing unreacted combustible components entrained in the generated gas provided on the road and generating a slurry from the collected dust; and a slurry generated by the slurry generating means. Pressurize and transport And a nozzle for supplying the slurry conveyed from the slurry generation means into the gasification furnace by the pump, and the nozzle is provided at an outlet side of the generation gas of the gasification furnace. The slurry supplied to the gasifier from the furnace is characterized in that the slurry flows in a direction opposite to the flow of product gas in the gasifier toward the outlet.

With this configuration, the slurry is supplied to the outlet side of the product gas in the gasification furnace, and the temperature of the product gas discharged from the gasification furnace can be reduced by the moisture in the slurry. Furthermore, the slurry supplied from the nozzle into the gasification furnace flows in the direction opposite to the flow of product gas in the gasification furnace toward the outlet, so that unreacted combustible components contained in the slurry are converted into gasification furnace. The amount of unreacted combustible components contained in the slurry can be increased by increasing the time spent in the slurry. Therefore, the temperature of the product gas discharged from the gasifier can be reduced while improving the efficiency of converting fuel into gas.

Further, the gasification furnace is provided at a lower-stage parner for supplying solid fuel into the gasification furnace, and at a portion closer to the outlet side than the lower burner of the gasification furnace, and supplies the solid fuel into the gasification furnace. And a top partner that forms a downward flow in the gasification furnace, and the nozzle is provided in a step part provided with the top partner of the gasification furnace. As described above, if the nozzle is provided in the step portion provided with the upper parner of the two-stage burner type gasifier having the upper parner and the lower parner, the slurry supplied from the nozzle into the gasification furnace becomes: Since the slurry flows along with the downward flow formed by the upper parner, the slurry can be easily flowed in the direction opposite to the flow of the generated gas in the gasifier toward the outlet.

Also, the slurry generating means includes a cleaning device that cleans the generated gas flowing through the generated gas flow path with water or an alkaline solution and removes and collects soot and dust accompanying the generated gas from the generated gas, A dehydrator that adjusts the amount of water in the slurry by removing a part of the water from the cleaning wastewater containing soot and dust collected by the washer _(in such a configuration, Water to the dust when producing a slurry containing This is preferable because there is no need to provide equipment for addition.

Furthermore, a temperature detector for measuring the temperature of the product gas discharged from the gasification furnace is provided, and the slurry generation means adjusts the amount of water contained in the slurry according to the temperature of the product gas detected by the temperature detector. Configuration. Such a configuration is preferable because the temperature of the product gas discharged from the gasifier can be controlled by the amount of water in the slurry.

In addition, a hydrogen production apparatus including any one of the above gasifiers, wherein the solid fuel is a solid hydrocarbon. Further, any one of the above gasifiers, and a catalytic reactor containing a catalyst for a reaction for producing hydrogen from carbon monoxide and water contained in the product gas discharged from the gasifier, The hydrogen production system is configured so that the fuel is solid hydrocarbon. With the hydrogen production apparatus having such a configuration, the hydrogen concentration in the generated gas can be increased, and the hydrogen production apparatus can be downsized. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram showing a schematic configuration and operation of a gasifier of Embodiment 1 to which the present invention is applied, and FIG. 2 is a schematic configuration and operation of a gasifier provided in the gasifier of Embodiment 1. FIG. 3 is a cross-sectional view of a stepped portion provided with a lower stepper showing a schematic configuration and operation of a gasification furnace provided in the gasifier of Example 1, and FIG. Fig. 5 is a cross-sectional view of a step portion provided with an upper-side parner, showing a schematic configuration and operation of a gasification furnace provided in the gasification device of Fig. 5; FIG. 6 is a block diagram showing a schematic configuration and operation of a gasifier according to Embodiment 3 to which the present invention is applied, and FIG. 7 is a block diagram showing a gasifier to which the present invention is applied. FIG. 1 is a block diagram showing a schematic configuration and operation of an embodiment of a hydrogen production apparatus provided with a hydrogen generator. BEST MODE FOR CARRYING OUT THE INVENTION (Example 1)

Hereinafter, a gasifier to which the present invention is applied will be described with reference to FIGS. FIG. 1 is a block diagram showing a schematic configuration and operation of a gasifier to which the present invention is applied. FIG. 2 is a longitudinal sectional view showing a schematic configuration and operation of a gasification furnace provided in a gasification apparatus to which the present invention is applied. FIG. 3 is a cross-sectional view of a stepped portion provided with a lower stepper showing a schematic configuration and operation of a gasification furnace provided in a gasifier to which the present invention is applied. FIG. 4 is a cross-sectional view of a stepped portion provided with an upper-side parner, showing a schematic configuration and operation of a gasification furnace provided in a gasifier to which the present invention is applied. In the present embodiment, a swirling flow type gasifier having two stages of panners, an upper burner forming an ascending swirling flow and an upper burner forming a descending swirling flow, is used in the gasification furnace. It illustrates a gasifier with a furnace.

As shown in FIG. 1, the gasifier of the present embodiment includes a gasifier 1 for gasification using solid or granular solid hydrocarbon as solid fuel, for example, finely pulverized coal as fuel. Gas scrubber that removes soot dust containing carbon, which is unreacted combustible component, in the product gas generated in the gasification furnace 1, such as char, with water or an alkaline solution and removes it from the product gas. 3.A dehydrator 5 for separating a part of the water in the washing wastewater including the channel from the gas scrubber 3.A slurry generated by adjusting the amount of water in the dehydrator 5 is pressurized. Slurry pump 7 for transporting and transferring the water, washing water pump 9 for returning the water separated by the dehydrator 5 to the gas scrubber 3, and supplying the slurry transported by the slurry pump 7 into the gasification furnace 1. And the like.

The gasification furnace 1 is a vertical furnace as shown in FIGS. 1 and 2, and has a gasification chamber 13, a slag recovery chamber 15 provided below the gasification chamber 13, and the like. are doing. Above the gasification chamber 13 of the gasifier 1, a cooler 17 for cooling the gas generated in the gasifier 1 is connected. The gasification chamber 13 is formed in a cylindrical shape, and a refractory material 19 is lined on the inner surface. Moth In the lower part of the gasification chamber 13 of the gasification furnace 1, a lower parner 21 is provided above the lower parner 21 and at a part on the outlet 23 side of the generated gas from the gasification chamber 13. In the gasification furnace 1, a nozzle 11 is provided in a step portion of the gasification chamber 13 where the upper parner 25 is provided.

As shown in Fig. 3, the lower parner 21 directs the direction of injection of fuel and the like from the lower parner 21 into a tangent to a concentric circle 27 with the outer wall of the gasifier 1 which is assumed to be at a position where a swirl flow is formed. It is installed in a state along the direction. By providing the lower burner 21 in this manner, a swirling flow along the concentric circle 27 is formed in the gasification chamber 13 of the gasification furnace 1. In this embodiment, four lower burners 21 are installed at equal intervals. As shown in FIG. 4, the upper burner 25 sets the direction in which fuel or the like is ejected from the upper parner 25 into a concentric circle 2 with the outer wall of the gasification furnace 1 that is assumed to be at a position where a swirling flow is formed. 9 is installed along the tangential direction. By providing the upper burner 25 in this manner, a swirling flow along a concentric circle 29 is formed in the gasification chamber 13 of the gasification furnace 1. In this embodiment, two upper burners 25 are installed at equal intervals.

In the present embodiment, similarly to the upper burner 25, the nozzle .11 is also located at a position where a swirling flow is formed, along a tangential direction of a concentric circle 29 with the outer wall of the gasification furnace 1. It is installed in. In the present embodiment, two nozzles 11 are installed at equal intervals alternately with the upper parner 25 in the step where the upper parner 25 of the gasification furnace 1 is installed. Note that the nozzle 11 may be provided with the slurry supplied from the nozzle 11 into the gasifier 1 along with the swirl flow formed by the upper parner 25. If the stepped portion is provided, it need not be provided at the same height as the position of the upper parner 25, and may be provided at a position higher or lower than the position of the upper parner 25.

Further, in the gasification furnace 1 in which the upper-stage panner 25 of the gasification furnace 1 has the two-stage panner as in this embodiment, the slurry supplied into the gasification furnace 1 from the nozzle 11 is the upper stage The downward swirling flow formed by the Then, the gas flows in the direction opposite to the upward flow, which is the flow of the generated gas in the gasification furnace 1 toward the outlet 23. Therefore, the nozzles 11 are concentric circles as in this embodiment.

It is not necessary to install in a state where a swirling flow along 29 is formed. However, it is preferable to install the sozzle 11 in a state in which the swirl flow is formed along the concentric circle 29 as in the present embodiment, because the descending swirl flow formed by the upper-stage parner 25 is hard to be disturbed. The finely ground coal is connected to a lower burner 21 as shown in FIGS. 1 and 2, and a lower fuel line 31 serving as a flow path for solid fuel and an upper burner 2 are provided. 5 and is divided into an upper fuel line 33 that serves as a flow path for solid fuel, and is passed through a lower burner 21 and an upper burner 25 using incombustible gas such as nitrogen or carbon dioxide. It is supplied into the gasifier 1. Further, the lower-stage parner 21 and the upper-stage parner 25 are provided with a lower-stage oxygen pipe that serves as a flow path for oxygen or air for guiding oxygen serving as a gasifying agent to the lower-stage parner 21 and the upper-stage burner 25. 35 and the upper oxygen line 37 are connected to each other, and oxygen or air flows into the gasifier 1 together with the finely pulverized coal through the lower burner 21 and the upper parner 25. Supplied.

As shown in FIG. 2, the gasification chamber 13 and the slag recovery chamber 15 are slag taps having a diameter smaller than the inner diameter of the gasification chamber 13 and the slag recovery chamber 15.

Connected via 3-9. The slag recovery chamber 15 is provided with an ignition parner 41 and a slag tap burner 43. The ignition parner 41 has an auxiliary fuel pipe 45 serving as a flow path for guiding auxiliary fuel to the ignition parner 41, and an ignition burner serving as a flow path for leading oxygen or air to the ignition parner 41. Oxygen line 47 is connected. As with the ignition parner 41, the slag reservoir 43 has an auxiliary fuel line 49 serving as a flow path for guiding auxiliary fuel to the slag reservoir 43, and oxygen or air. A slag tap burner oxygen pipeline 51 serving as a flow path leading to the slag tap parner 43 is connected to the slag tap burner. The slag tap wrench 43 is not necessarily required.

Above the gasifier 1, as shown in Fig. 2, the gas generated from the gasifier 1 A cooler 17 is provided which has a cooling chamber 53 which communicates with the outlet 23 and which is formed of a product gas flow path extending vertically. The side walls that define the cooling chamber 53 have a water-cooled wall type formed by a conduit through which a cooling medium such as water or a cooling medium such as cooling steam flows, or a flow path 54 through which the cooling medium flows. The cooling medium introduction pipe 55 for introducing the cooling medium to the cooling device 17 is located at the lower part of the cooling device 17, and the upper part of the cooling device 17 is located at the lower part of the cooling device 17. A cooling medium outlet pipe 57 for connecting the cooling medium heated by heat exchange to the cooling medium 17 is connected to the cooling medium outlet pipe 57. Although illustration of the cooler 17 is omitted in FIG. 1, it is determined whether the cooler 17 should be installed according to the temperature of the product gas discharged from the gasifier 1. In the gasifier of the present invention, it is not always necessary.

+ The generated gas generated in the gasification chamber 13 of the gasifier 1 is cooled to the outlet 23 of the gasification chamber 13 of the gasifier 1 if the cooler 17 is not provided. When the cooler 17 is not provided, it is connected to the upper end of the cooler 17 and flows into the generated gas pipe 59 serving as a flow path of the generated gas. As shown in FIG. 1, the generated gas flowing into the generated gas pipe 59 flows through the generated gas pipe 59 and is guided to the gas scrubber 3 to which the generated gas pipe 59 is connected. .

The purified gas, which is the product gas washed by the gas scrubber 3, is connected to the gas scrubber 3 and is disposed downstream of the gasifier through a purified gas pipe 61 serving as a flow path of the purified gas. Guided to facilities and equipment. On the other hand, the washing wastewater from the gas washer 3 containing dust and soot that was entrained in the generated gas was sent to the dehydrator 5 through the washing drainage pipe 63, which is the flow path of the washing wastewater. Be guided. In addition, the purified gas pipe 61 has a temperature of the purified gas flowing through the purified gas pipe 61 and a temperature of the purified gas required by the equipment and devices disposed downstream of the gasifier. Accordingly, a cooler for cooling the purified gas may be provided separately from the cooler 17. As a cooler provided in the purified gas pipe 61, generally, a plurality of pipes through which a cooling medium flows are provided in a flow path through which the purified gas flows. The one having the structure described above is used. The dehydrator 5 separates excess water from the cleaning wastewater guided from the gas cleaning device 3 through the cleaning drainage pipe 63 to generate a slurry including a char. As the dehydrator 5, various types of dehydrators such as a strainer, a filter, a sedimentation layer, and a centrifuge can be used as long as excess water can be separated from the washing wastewater. Thus, the gas scrubber 3 and the dewatering device 5 constitute a slurry generating means.

The water separated by the dehydrator 5 is re-supplied to the gas scrubber 3 through a scrubbing water pipe 65 provided with a scrubbing water pump 9 and used as scrubbing water. On the other hand, the slurry generated by the dehydrator 5 is transferred to a nozzle 11 provided in the gasification furnace 1 via a slurry supply pipe 67 provided with a slurry pump 7. The slurry pump 7 pressurizes the slurry to a pressure higher than the operating pressure of the gasification furnace 1 and transports the slurry to the nozzle 11. '

The operation of the gasifier having such a configuration and the features of the present invention will be described. In the step section provided with the lower burner 21 in the gasifier 1, a part of the combustible component in the solid fuel is gas. It is oxidized by the agent, that is, the combustible components in the solid fuel are partially burned, generating high heat of, for example, about 150 ° C. The ash in the solid fuel is melted by the high heat in the gasification chamber 13 and collected in the slag recovery chamber 15 through the slag type 39.

On the other hand, the remaining combustible components in the solid fuel are converted into combustible gases such as hydrogen and carbon monoxide in the gasification chamber 13. The generated gas, which is a flammable gas generated in the gasification chamber 13, is discharged from the outlet 23 of the gasification furnace 1 to the generated gas pipe 59. The soot dust containing carbon, which is an unreacted combustible component, entrained in the product gas from the gasification furnace 1 flowing through the product gas pipeline 59 is collected by the gas cleaning device 3 with cleaning water. The cleaning wastewater containing the soot and dust collected from the gas cleaning device 3 is slurried at a desired concentration by separating a predetermined amount of water in the dehydrator 5.

The obtained slurry is pressurized to a pressure higher than the operating pressure of gasifier 1 with a slurry pump. The gas is supplied from the nozzle 11 into the gasification furnace 1. The slurry supplied into the gasifier 1 is directed to the outlet 23 of the gasifier 1, which is formed by the upper burner 25, in the direction opposite to the flow of the product gas in the gasifier 1. The gas flows into the gasification furnace 1 at the step where the lower parner 21 is provided, accompanied by the downward flow. Unreacted combustible components re-supplied into the gasifier 1 as slurry descend from the nozzle 11 to the step provided with the lower parner 21, and then from the step provided with the lower parner 21. While ascending to the step where the upper parner 25 is provided, it is again exposed to the opportunity for reaction and gasified. Furthermore, since the slurry containing water is supplied to the step portion provided with the upper burner 25 by the nozzle 11, the heat in the gasification furnace 1 evaporates the water in the slurry, so that the gasification furnace 1 The step provided with the upper burner 25 is cooled, and the temperature of the generated gas discharged from the gasification furnace 1 decreases.

Here, in a gasifier equipped with a swirler type gasifier equipped with a two-stage burner, a conventional gasifier for supplying slurry to a step provided with a lower-stage parner, and the present embodiment Table 1 shows the results of a comparison between the temperature of the gas produced at the gasifier and the outlet temperature of the gasifier from the gasifier and the conversion efficiency of fuel to gas. The conversion efficiency indicates the ratio of the calorific value of the raw material shown below converted to the calorific value of the generated gas.

(Conversion efficiency) = (calorific value of generated gas) / (calorific value of fuel) X 100

丄

As shown in Table 1, in a conventional gasifier, if the oxygen-to-coal weight ratio is 0.8, the temperature in the gasifier becomes about 1300 ° C due to the effect of moisture in the slurry. Therefore, the ash in the raw material cannot be melted. Also, since the temperature inside the gasification furnace is as low as about 1.300 ° C, the conversion efficiency is as low as 55%. Therefore, if the supply amount of oxygen as a gasifying agent is increased and the oxygen / coal weight ratio is set to 1.0, the temperature in the gasifier becomes about 150 ° C., and the ash can be melted. The conversion efficiency also increased to 60%. However, the outlet temperature of the generated gas from the gasifier was about 1200 ° C, and the ash entrained in the generated gas was in a semi-molten state and attached to the outlet of the gasifier.

On the other hand, in the gasifier of the present embodiment, the oxygen / coal weight ratio was 1.0, the gasification furnace temperature could be set at about 1500 ° C, and the ash could be melted. . In addition, the outlet temperature of the generated gas from the gasification furnace could be cooled down to about 900 ° C, and ash deposition at the gasification furnace outlet could be suppressed. The conversion efficiency was 60%, and there was no decrease in the conversion efficiency.

As described above, in the gasifier of the present embodiment, the slurry is supplied to the step portion provided with the upper burner 25 of the gasifier 1, that is, to the outlet 23 side of the generated gas of the gasifier 1. As a result, the heat exchanger paper at the step provided with the upper parner 25 of the gasifier 1 (Rule 26): As the water in the slurry evaporates, the step provided with the upper parner 25 of the gasification furnace 1 is cooled, and the temperature of the product gas discharged from the gasification furnace 1 can be lowered. Further, the slurry supplied from the nozzle 11 into the gasification furnace 1 flows in the direction opposite to the flow of the generated gas in the gasification furnace 1 toward the outlet 23, so that unreacted flammable substances contained in the slurry are The time during which the components remain in the gasifier 1 can be prolonged, and the amount of unreacted combustible components contained in the slurry can be increased. Therefore, the temperature of the product gas discharged from the gasifier can be reduced while improving the efficiency of converting fuel to gas.

Further, in the gasifier of the present embodiment, the required cooling capacity can be reduced by lowering the temperature of the generated gas discharged from the gasifier, so that the gasifier such as the cooler 17 shown in FIG. A cooler provided continuously at the outlet of the gasifier can be downsized. If the temperature of the product gas discharged from the gasification furnace is lower than the temperature at which slag may be generated, the cooler 17 shown in Fig. In addition, the size of the cooler can be further reduced by replacing the cooler with a structure in which a plurality of pipes through which a cooling medium flows in a flow path through which a gas having a high cooling efficiency flows. In addition, although it depends on the temperature of the product gas cooled by the supply of the slurry, it is also possible to eliminate a cooler such as the cooler 17 shown in FIG. 2 which is continuously provided at the outlet of the gasification furnace. In addition, since the cooler provided continuously at the outlet of the gasifier can be reduced in size or eliminated, the size and cost of the gasifier can be reduced.

In particular, the swirling-flow gasifier with a two-stage panner as in this example can achieve gasification with higher efficiency than other gas-bed gasifiers, and has the same throughput. Although the feature is that the furnace volume can be made smaller, the heat load increases, and the temperature of the product gas discharged from the gasifier is higher than that of other gas-bed gasifiers. For this reason, in the gasifier equipped with the swirling flow type gasifier as in this embodiment, the gasifier such as the cooler 17 is located at the outlet of the gasifier such as the cooler 17 in comparison with other gas-bed type gasifiers. The size of the continuous cooler has increased. In many cases, the size and cost of the gasifier increase. Therefore, applying the present invention to a gasifier equipped with a swirling flow gasifier having a two-stage panner as in the present embodiment requires a reduction in the size and cost of the gasifier. The effect of reduction is greater than gasifiers equipped with other gas bed type gasifiers. However, the present invention is not limited to a gasifier having a swirling flow type gasifier, but also a gasifier having two other stages and a gasifier having only one stage burner. The present invention can be applied to gasifiers equipped with various gas-bed gasifiers, such as a gasifier equipped with a gasifier.

Further, in the present embodiment, since the gas scrubber 3 and the dehydrator 5 that collect dust and soot in the generated gas with the washing water are used as the slurry generating means, when the slurry containing soot and dust is generated, the slurry is dried. There is no need to provide equipment for adding water to the dust collected in the above. However, it is also possible to use a cyclone or the like to collect soot and dust in a dry state from the generated gas and add water to this to generate a slurry.

Also, in the gasification apparatus of this embodiment, the soot dust is re-supplied to the gasification furnace by using a suction hopper to pressurize the soot dust as a slurry with a pump and resupply the gasification furnace. This eliminates the need for nitrogen gas for dust transfer, and reduces the concentration in the generated gas of gases other than the desired gas, such as nitrogen gas, which is desired to be obtained, thereby producing the desired gas. The concentration in gas can be increased. For example, when it is desired to obtain hydrogen gas using a hydrocarbon as a solid fuel, the concentration of hydrogen gas in the generated gas can be increased. Further, since the lock hopper is not used, the cost related to the lock hopper can be reduced. Furthermore, as shown in Table 1, the conversion efficiency of solid fuel to product gas can be improved. Further, in the present embodiment, four lower parners 21, two upper parners 25, and two nozzles 11 are provided, but the lower parner 21 and the upper parner 25 rotate. As long as the flow can be formed, the number of the lower and upper parners can be selected as appropriate. The number of tubes can be selected as appropriate according to the flow rate of the nozzles and the like, since the purpose is to supply them to the inside. However, it is desirable that the number and arrangement of the nozzles 11 be such that the downward swirling flow formed by the upper parner 25 is not easily disturbed.

(Example 2)

FIG. 5 is a block diagram showing a schematic configuration and operation of a gasifier to which the present invention is applied. In the present embodiment, the same components and operations as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The configuration and features different from the first embodiment will be described.

The difference between the gasifier of the present embodiment and the first embodiment is that the temperature of the product gas discharged from the gasification furnace is detected and the amount of water in the slurry is adjusted according to the detected temperature. That is, as shown in FIG. 5, the gasification apparatus of the present embodiment flows through the generated gas pipeline 59 to the portion of the generated gas pipeline 59 connected to the outlet of the gasification furnace 1. It has a thermometer 69 for detecting the temperature of the generated gas, a control unit 71 for controlling the operation of the dehydrator 5, and the like. The thermometer 69 and the control unit 71, and the control unit 71 and the dehydrator 5 are electrically connected to each other via a wiring 73.

Here, the temperature of the generated gas cooled by the supply of the slurry and discharged from the gasifier is determined by the ratio of dust and water in the slurry. Therefore, in the gasifier of the present embodiment, the thermometer 69 measures the temperature of the generated gas discharged from the gasifier 1, and transmits a temperature signal corresponding to the measured value to the controller 71. You. The control unit 71, which has received the temperature signal from the thermometer 69, determines the temperature of the product gas discharged from the gasification furnace 1 measured by the thermometer 69, and the temperature or temperature range set in advance. The water concentration in the slurry supplied from the nozzle 11 into the gasifier 1 is calculated, the operation of the dehydrator 5 is controlled, and the amount of water separated by the dehydrator 5 is adjusted. Then, the slurry whose water content has been adjusted is supplied from the nozzle 11 into the gasification furnace 1, thereby cooling the step corresponding to the upper parner 25 in the gasification furnace 1. Control the temperature of the product gas discharged from the It is kept constant.

As described above, in the gasifier of the present embodiment, the slurry in which the amount of moisture is adjusted according to the temperature of the generated gas discharged from the gasifier 1 is supplied to the outlet side of the gasifier 1 so that the gasifier Temperature of the product gas discharged from the fuel cell can be controlled. By the way, as described above, the temperature of the product gas cooled by the slurry supply and discharged from the gasification furnace is determined by the ratio of dust and water in the slurry, and therefore the amount of dust accompanying the product gas If the temperature fluctuates, the temperature of the product gas discharged from the gasifier fluctuates. For this reason, when the variation in the amount of soot and dust generated in the generated gas is within an allowable range, a configuration in which a constant amount of water is always separated from the cleaning water containing soot and dust may be used as in Embodiment 1. When the variation in the amount of dust entrained in the produced gas exceeds an allowable range, it is desirable to use the gasifier having the configuration of the present embodiment.

(Example 3)

FIG. 6 is a block diagram showing a schematic configuration and operation of a gasifier to which the present invention is applied. In this embodiment, the same components and operations as those in Embodiments 1 and 2 are denoted by the same reference numerals, and the description thereof will be omitted. The configuration and features different from those in Embodiments 1 and 2 will be described. Will be described.

The difference between the gasifier of the present embodiment and Embodiments 1 and 2 is that the gasifier is provided with a solid fuel and a gasifying agent at the top of the gasifier, and is produced in the gasifier. The product gas flows downward from above in the gasifier, and the outlet for the product gas is provided with a downflow gasifier provided at the lower part of the gasifier. That is, the gasifier of the present embodiment is provided with a downflow type gasifier 75, and the generated gas pipeline 59 is connected to the outlet located at the lower part of the gasifier 75, A panner 79 is provided at the furnace top of the furnace 75, and a nozzle 11 is provided at a lower side of the gasification furnace 75, that is, at a portion on the outlet side.

Solid fuel, such as finely pulverized coal, is connected to a burner 79, and is supplied to a gasification furnace 75 through a fuel supply pipe 81 and a panner 79 serving as a fuel flow path. Supplied to At the same time, oxygen serving as a gasifying agent is connected to the parner 79 and supplied to the gasification furnace 75 via the oxygen supply pipe 83 serving as a flow path for oxygen or air and the parner 79. In the gasification furnace 75, a part of the combustible components in the solid fuel is oxidized by the gasifying agent to generate high heat, for example, about 150 ° C., and the remainder of the combustible components is hydrogen. It is converted into flammable gas such as carbon monoxide. The generated gas generated is taken out to a generated gas pipe 59 connected to an outlet located at a lower part of the gasification furnace 75.

Slurry formed of dust containing combustible components generated by treating the washing wastewater from the gas scrubber 3 with the dehydrator 5 is applied to the gasification furnace 75 using a slurry pump 7 at a pressure higher than the operating pressure. Is supplied to the lower part of the gasification furnace 75 through the nozzle 11. The nozzle 11 of the present embodiment is installed in a state of squirting slurry upward in the gasification furnace 75, and the slurry ejected from the nozzle 11 is installed in the gasification furnace 75. It is jetted upward of the generated gas. Therefore, the slurry supplied from the nozzle 11 into the gasification furnace 75 flows in the direction opposite to the flow of the generated gas toward the outlet in the gasification furnace 75. As a result, the slurry supplied from the nozzle 11 into the gasification furnace 75 is exposed to the high temperature in the gasification furnace 75 for a longer time, and unreacted combustible components in the slurry react. Generates flammable gases such as carbon monoxide. Further, the moisture of the slurry supplied from the nozzle 11 into the gasification furnace 75 evaporates immediately after being supplied to the gasification furnace 75, and cools the lower part of the gasification furnace 75 to cool the gasification furnace. 75 Reduce the temperature of the product gas exhausted from 5.

As described above, also in the present embodiment, the temperature of the generated gas discharged from the gasifier can be reduced while improving the conversion efficiency of the fuel into the gas. Therefore, the present embodiment is similar to the first and second embodiments except that a swirling flow type gasifier having a two-stage wrench and a gasifier including a gasifier in which generated gas flows upward from below. Not limited to this, by forming a slurry flow in the direction opposite to the flow of product gas toward the outlet of the gasifier in the gasifier with the slurry ejected from the nozzle, A swirling flow gasifier with a two-stage burner--a gas with various gas-bed gasifiers other than a gasifier with a gasifier through which product gas flows upward from below The present invention can be applied to a gasifier.

(Example 4)

FIG. 7 is a block diagram showing a schematic configuration and operation of a hydrogen production apparatus provided with a gasifier to which the present invention is applied. In this embodiment, the same components and operations as those in the first, second and third embodiments are denoted by the same reference numerals, and the description thereof will be omitted. The first, second and third embodiments will be omitted. Configurations and features different from those described above will be described.

In the present embodiment, a hydrogen production apparatus is formed using the gasification apparatus of the first embodiment. The hydrogen production apparatus according to the present embodiment is for producing hydrogen gas from a raw material composed of granular or powdery solid hydrocarbons, for example, pulverized coal, as shown in FIG. Gasifier 1, gas scrubber 3, deicing machine 5, slurry pump 7, washing water pump 9, and nozzle 11 installed in gasifier 1 The lower raw material hopper 85 connected to the upper fuel line 31 via the lower fuel line 31 and the upper raw material hopper 87 connected to the upper burner 25 via the upper fuel line 33. And a shift reactor 89 provided in the purified gas pipeline 61 and containing a catalyst. The finely pulverized coal, which is a raw material for hydrogen production, is divided into a lower raw material hopper 85 and an upper raw material hopper 87, and is stored in the lower raw material hopper 85 and the upper raw material hopper 87. The raw material stored in the lower raw material hopper 85 and the raw material stored in the upper raw material hopper 87 are discharged quantitatively from the lower raw material hopper 85 and the upper raw material hopper 87 respectively, and the lower raw material hopper 85 and the upper raw material The mixture is mixed with carrier nitrogen supplied from a lower-stage raw material transfer nitrogen pipeline 91 and an upper-stage raw material transfer nitrogen pipeline 93 connected to the raw material discharge section of the hopper 87, respectively, and air-fed. The raw material and nitrogen for transport are supplied to the lower burner 21 via the lower fuel line 31 and to the upper parner 25 via the upper fuel line 33, respectively. The gas is supplied into the gasification furnace 1 from the lower burner 21 and the upper parner 25. At this time, oxygen or air is supplied to the lower and upper parners 21 and 25 by the lower and upper oxygen pipes 35 and 37, respectively, so that the lower and upper burners 21 and 25 are supplied with oxygen. The upper parner 25 supplies oxygen or air as a gasifying agent together with the raw material into the gasification furnace 1.

In the gasifier 1, the raw material and oxygen are mixed, and some of the combustible components in the raw material are oxidized to generate high heat. Further, the remaining combustible components are converted into a gas containing hydrogen or carbon monoxide as a main component, and are taken out of the gasification furnace 1 into a product gas pipe 59 as a product gas. The generated gas flowing through the generated gas pipeline 59 is removed by the cleaning water in the gas scrubber 3 to remove soot and dust. At this time, the generated gas is 100 ° C or more. However, part of the washing water is evaporated by this heat and is mixed into the purified gas. The purified gas containing steam obtained in the gas washer 3 flows into the purified gas pipe 61 and is introduced into the shift reactor 89 provided in the purified gas pipe 61. The shift reactor 89 contains a well-known catalyst such as a copper-zinc-based catalyst or an iron-chromium-based catalyst having a catalytic action to promote the shift reaction of the formula (1). ing.

_{CO + H 2 0 → C 0} 2 + H 2 ... Equation (1) Thus, by the purified gas containing the vapor is contacted flows into the shift reactor 8 9 shift reaction catalyst, a shift of the formula (1) A reaction occurs, increasing the hydrogen concentration in the purified gas, and the purified gas is taken out of the shift reactor 89 as a product gas, and equipment and devices that use the product gas via the purified gas line 61 Sent to As described above, the water necessary for the shift reaction in the shift reactor 89 is partly used as the washing water evaporated in the gas washer 3 and mixed with the purified gas as steam.

On the other hand, the dust collected from the generated gas in the gas washer 3 is mixed with the washing water. Then, it is taken out to the washing drain pipe 63 as washing waste water. The washing wastewater taken out from the washing drainage pipe 63 is introduced into the dehydrator 5, where a part of the water is separated and slurried. The slurry purified by the dehydrator 5 is pressurized by a slurry pump 7 to a pressure higher than the operating pressure of the gasification furnace 1, conveyed to a nozzle 11 via a slurry supply pipe 67, and is supplied with gas from the nozzle 11. Furnace 1 is supplied. The unreacted carbon in the slurry supplied into the gasifier 1 is further reacted in the gasifier 1 and is converted into a gas such as carbon monoxide. In addition, the moisture in the slurry supplied to the gasifier 1 cools the step provided with the upper burner 25 in the gasifier 1 and also performs the shift reaction of the equation (1). It is used and converted to hydrogen gas.

As described above, in the hydrogen production apparatus according to the present embodiment, the soot and dust accompanying the purified gas is re-supplied as a slurry to the outlet side in the gasifier, so that an appropriate amount of the slurry supplied to the gasifier is Moisture converts carbon monoxide to hydrogen and increases the hydrogen concentration in the product gas. Further, the size of the cooling device provided continuously at the outlet of the gasification furnace can be reduced or eliminated, so that the hydrogen production apparatus can be reduced in size.

Further, in the hydrogen production apparatus of the present embodiment, a part of the cleaning water is evaporated by cleaning the generated gas with the cleaning water in the gas cleaning device 3, and the evaporated cleaning water is purified gas from the gas cleaning device 3. To accompany. By introducing the purified gas accompanied by the vapor into the shift reactor 89 containing the shift reaction catalyst, carbon monoxide remaining in the purified gas can be converted to hydrogen. Therefore, the hydrogen concentration in the product gas can be further increased. Further, the steam required for these shift reactions can be covered by re-supply of the washing water and evaporation of the washing water, so that it is not necessary to provide a separate boiler or the like to supplement the water. In addition, the generated gas is cooled by the gas washer 3, and at this time, the heat of the generated gas is generated by the steam used for the reaction in the shift reactor 89, that is, by direct contact with the cleaning water. Used for washing water evaporation. Therefore, a separate boiler is required. As compared with the case where steam generated by this boiler is generated by the heat of the generated gas, the decrease in thermal efficiency is small or not.

In addition, the present embodiment is not limited to the gasifiers of Embodiments 1 to 3 and the hydrogen production apparatus of Embodiment 4, but includes gasifiers of various configurations including a gas-bed gasification furnace. And hydrogen production equipment. Industrial applicability

According to the present invention, it is possible to provide a gasification method and a gasification apparatus capable of lowering the temperature of a product gas discharged from a gasification furnace while improving the conversion efficiency of fuel to gas.

Claims

The scope of the claims

1. Collect soot and dust containing unreacted combustible components entrained in the product gas discharged from the outlet at the outlet side of the product gas of the gasifier that partially burns the solid fuel to generate gas. A gasification method comprising: supplying a slurry generated by the above-described method; and flowing the supplied slurry in a direction opposite to a flow of a generated gas toward the outlet in the gasification furnace.

2. The gasification furnace is provided with a lower-stage parner for supplying the solid fuel into the gasification furnace, and provided at the outlet side of the gasification furnace with respect to the lower-stage parner; And an upper stage for supplying a solid fuel and forming a downward flow in the gasification furnace, wherein the slurry is supplied to a step portion of the gasification furnace provided with the upper stage burner. The gasification method according to claim 1, wherein

3. The method according to claim 1, wherein the slurry is jetted into the gasification furnace to form a flow in the gasification furnace in a direction opposite to a flow of the generated gas toward the outlet. Gasification method.

4. A gasifier for partially combusting the solid fuel to generate a gas, a product gas channel through which the product gas generated by the gasifier flows, and A slurry generating means for collecting dust containing unreacted combustible components entrained in the gas and generating a slurry from the collected dust, and a pump for pressurizing and conveying the slurry generated by the slurry generating means. A nozzle for supplying the slurry conveyed from the slurry generating means by the pump into the gasification furnace;

The nozzle is provided at an outlet side of a product gas of the gasification furnace, and the slurry supplied from the nozzle into the gasification furnace is directed to the flow of the product gas in the gasification furnace toward the outlet. A gasifier characterized by flowing in opposite directions.

5. The gasifier is a lower-stage parner that supplies the solid fuel into the gasifier. And an upper stage provided at a portion of the gasification furnace closer to the outlet side than the lower stage parner, and configured to supply the solid fuel into the gasification furnace and form a downward flow in the gasification furnace. 5. The gasifier according to claim 4, wherein the nozzle is provided in a step portion of the gasification furnace provided with the upper-side parner.

6. The nozzle is characterized by ejecting a slurry into the gasification furnace to form a flow in the gasification furnace in a direction opposite to a flow of the generated gas toward the outlet. The gasifier according to claim 4.

7. The above-mentioned slurry generation means, a cleaning device for cleaning the generated gas flowing through the generated gas flow path with water or alkali solution to remove and collect soot and dust accompanying the generated gas from the generated gas, The gasification according to claim 4, further comprising a dehydrator for removing a part of the water from the cleaning wastewater containing soot and dust collected by the cleaning device to adjust the amount of water in the slurry. apparatus.

8. A temperature detector for measuring the temperature of the product gas discharged from the gasifier is provided, and the slurry generating means determines the amount of water in the slurry according to the temperature of the product gas detected by the temperature detector. The gasifier according to claim 4, wherein the gasifier is adjusted.

9. A hydrogen production apparatus comprising the gasifier according to claim 4, wherein the solid fuel is a solid hydrocarbon.

10. The gasifier according to claim 4, and a catalytic reactor having a catalyst for a reaction for generating hydrogen from carbon monoxide and water contained in a product gas discharged from the gasifier, The hydrogen producing apparatus, wherein the solid fuel is a solid hydrocarbon.