JP2006052360A - Gasification system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gasification system capable of corresponding with the increase of capacity while keeping the stable dust-collecting performance. <P>SOLUTION: The gasification system 1 has a coal-gasification furnace 3 for gasifying a carbon-containing fuel to form a gas fuel, a cyclone 19 installed in the downstream side of the coal-gasification furnace 3, and separating and removing char in the gas fuel, and the first filter 21 and the second filter 23 installed in the downstream side of the cyclone 19 and collecting the char remaining in the gas fuel, and is characterized by two or more of the first and the second filters 21 and 23 arranged in parallel. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gasification system in which a solid or liquid carbon-containing fuel is gasified and used as a gas fuel.

In such a gasification system, for example, as shown in Patent Document 1, in order to separate char that is unburned in gas fuel generated in a gasification furnace, A dust collection facility is provided. As a dust collection facility, a combination of a cyclone that is a centrifugal solid-gas separator and a filter that is filtered with a cloth or ceramic filter medium is often used. In this method, most of the char is efficiently separated by a cyclone, and the remaining char is reliably separated by a filter.
Recently, with an increase in the size of the gasification system, this dust collection facility is also required to have a large capacity. In order to increase the capacity, a plurality of combinations of cyclones and filters are provided in parallel.

Japanese Patent Laid-Open No. 5-222951 (paragraphs [0016] to [0023] and FIG. 1)

  By the way, in the case where a plurality of combinations (for example, two sets) of a cyclone and a filter are provided in parallel, if one of the filters is clogged for some reason, for example, and the differential pressure increases, the gas flow rate passing through this filter is thereby reduced. Decrease. For this reason, since the gas flow rate which passes the cyclone connected to this filter also decreases, the gas flow velocity in this cyclone decreases, and the centrifugal classification performance deteriorates. When the centrifugal classification performance decreases, the char concentration of the gas flowing into the filter increases, so that the clogging in the filter further increases. Due to this vicious cycle, clogging of one filter suddenly progressed, and in the worst case, there was a problem that the operation was stopped and the clogging was removed.

  An object of this invention is to provide the gasification system which can ensure the stable dust collection performance and respond | correspond to large capacity in view of the said problem.

In order to solve the above problems, the present invention employs the following means.
That is, a gasification system according to the present invention includes a gasification furnace that gasifies carbon-containing fuel to produce gas fuel, and a primary collection that is provided downstream of the gasification furnace and separates and removes char in the gas fuel. In a gasification system comprising: a dust collector; and a precision dust collector provided on the downstream side of the primary dust collector for collecting the char remaining in the gas fuel, the precision dust collector includes a plurality of the dust collectors. And arranged in parallel.

According to the present invention, the gas fuel generated from the carbon-containing fuel by the gasification furnace is separated and removed most of the char by the primary dust collector, and then divided into a plurality of precision dust collectors, The remaining char is recovered by the vessel.
As the primary dust collector, a centrifugal separation system such as a cyclone that can cope with a relatively large size is used, and 80 to 90% of char is efficiently separated and removed.
The precision dust collector uses, for example, a filter that filters with a cloth or ceramic filter medium that collects dust at a low speed in order to reliably collect the remaining char.

As described above, according to the present invention, since a plurality of precision dust collectors that collect dust at low speed are provided downstream of the primary dust collector, the processing capacity of the precision dust collector is increased. For this reason, even if the size of the primary dust collector is increased, processing with a precision dust collector is possible, so that the capacity of gas fuel can be increased.
The number of precision dust collectors is selected according to the capacity of the primary dust collector.
Also, for example, when one of the precision dust collectors is clogged and the differential pressure increases, the gas flow rate passing through this precision dust collector decreases, and the amount of gas passing through the other precision dust collector is reduced. Although it increases by that amount, it does not affect the amount of gas fuel passing through the primary dust collector. For this reason, since the dust collection performance in the primary dust collector does not deteriorate, the char concentration of the gas fuel flowing into each precision dust collector does not increase. Therefore, since clogging in the precision dust collector does not increase rapidly, it can be restored by char recovery means such as backwashing performed at a predetermined timing, and stable dust collection performance can be ensured.

  Further, the gasification system according to the present invention includes an aggregator for collecting the char collected from each of the precision dust collectors, and a char recycling facility for supplying the char collected in the aggregator to the gasification furnace. It is characterized by providing.

  In this way, each precision dust collector is equipped with an aggregator that collects char collected from each precision dust collector and a char recycling facility that supplies the char collected in the collector to the gasifier. The variation in the amount of char collected by the collector is absorbed by the collector. For this reason, since the char recycling facility is a facility with a capacity corresponding to the amount of char at the outlet of the primary dust collector, it can be reduced in size as a whole as compared with that provided for each precision dust collector. In addition, the manufacturing cost can be reduced by reducing piping and the like.

  Furthermore, the gasification system according to the present invention is characterized in that the collector collects the char separated by the primary dust collector.

  In this way, the collector collects the char separated by the primary dust collector, so the char recycling facility has a capacity that matches the amount of char generated without corresponding to the fluctuation of the amount of char separated by each dust collector. Therefore, it can be downsized as a whole compared with the equipment provided for each dust collector. In addition, the manufacturing cost can be further reduced by reducing the number of pipes and the like.

  According to the present invention, a plurality of precision dust collectors that collect dust at low speed are provided in parallel downstream of the primary dust collector, so that it is possible to cope with a large capacity of gas fuel and secure stable dust collection performance. .

Embodiments according to the present invention will be described below with reference to the drawings.
[First embodiment]
Hereinafter, the coal gasification system (gasification system) 1 concerning 1st embodiment of this invention is demonstrated using FIG.
FIG. 1 is a block diagram showing a schematic configuration of a coal gasification system 1.
The coal gasification system 1 includes a coal gasification furnace (gasification furnace) 3, a dust removal equipment 5, a desulfurization device 7, and a gas turbine 9.
The coal gasification furnace 3, the dust removal equipment 5, the desulfurization device 7 and the gas turbine 9 are connected by a main system line 17.

The coal gasifier 3 is supplied with pulverized coal 11, gasifying agent 13 and char 15 under pressure. The pulverized coal 11 is supplied as a pulverized coal of several μm to several hundred μm by pulverizing raw coal in a pre-process (not shown). As the gasifying agent 13, air or oxygen is supplied. The char 15 is an unburned component contained in the gas fuel generated in the coal gasification furnace 3 as will be described later.
In the coal gasification furnace 3, by burning these pulverized coal 11, the gasifying agent 13 and the char 15, the carbon in the pulverized coal 11 and the char 15 reacts with CO ₂ and H ₂ O in the high temperature gas. An endothermic reaction to generate CO and H ₂ is performed. The CO and H ₂ are used as gas fuel for the gas turbine 9.

The gas fuel generated in the coal gasification furnace 3 includes char that is an unburned solid, and is led to the dust removal equipment 5 through the main system line 17.
The dust removal equipment 5 includes a cyclone (primary dust collector) 19, and a first filter (precision dust collector) 21 and a second filter (precision dust collector) 23 arranged in parallel downstream of the cyclone 19. It has been.
The cyclone 19 is a centrifugal solid-gas separator and separates 80 to 90% of the char contained in the gas fuel. The separated char 15 is supplied to the coal gasifier 3 by the first char recycling facility 25.

The gas fuel from which most of the char is separated by the cyclone 19 is branched at the position A of the main system line 17 and flows into the first filter 21 and the second filter 23, respectively.
The first filter 21 and the second filter 23 include a ceramic filter medium, and are configured to filter out char in the gas fuel when the gas fuel passes through the filter medium. The filtered char is dropped and recovered by flowing backwashing gas such as nitrogen (backwashing) in a direction opposite to the flow of gas fuel at a predetermined timing.

The char recovered by the first filter 21 is supplied to the coal gasification furnace 3 by the second char recycling facility 27.
The char recovered by the second filter 23 is supplied to the coal gasification furnace 3 by the third char recycling facility 29.
Chars recovered in the first char recycling facility 25, the second char recycling facility 27, and the third char recycling facility 29 are pressurized to a high pressure from inside the coal gasification furnace 3 by nitrogen gas supplied from a compressor (not shown). And supplied to the coal gasifier 3.

The gas fuel that has passed through the first filter 21 and the second filter 23 merges at the position B and is guided to the desulfurization device 7.
In the desulfurization device 7, for example, sulfide is removed from the gas fuel. The desulfurization apparatus 7 is usually a wet type, and a COS converter that converts COS in gas fuel into H ₂ S using a catalyst, a gas cooling tower, a gas washing tower, and H ₂ S filled with an H ₂ S absorption liquid. It is composed of an absorption tower and a heat exchanger for raising the temperature of the cooled gas fuel.

The gas fuel desulfurized by the desulfurization device 7 is guided to the gas turbine 9 through the main system line 17. In the gas turbine 9, the gas fuel sent from the desulfurization device 7 is combusted by high-pressure air from an air compressor (not shown) and converted into a rotational driving force.
For example, the generator is rotated by this rotational driving force to obtain electric power.

Operation | movement of the coal gasification system 1 concerning this embodiment demonstrated above is demonstrated.
In the coal gasification furnace 3, by burning the pulverized coal 11, the gasifying agent 13 and the char 17 supplied under pressure, the carbon in the pulverized coal 11 and the char 17 is converted to CO ₂ and H ₂ in the high-temperature gas. A gas fuel containing CO or H ₂ as a component is produced by reacting with O.
The gas fuel generated in the coal gasification furnace 3 is guided to the cyclone 19 through the main system line 17, and 80 to 90 percent of the mixed char 15 is recovered by the cyclone 19. The recovered char 15 is collected in the first char recycling facility 25, pressurized by nitrogen gas supplied from a compressor (not shown), returned to the coal gasifier 3, and recycled.

The gas fuel from which most of the char has been recovered by the cyclone 19 is branched at the position A through the main system line 17 and led to the first filter 21 and the second filter 23, respectively.
When the gas fuel guided to the first filter 21 passes through the ceramic filter medium, the char in the gas fuel is filtered out. The filtered char is dropped and recovered by flowing backwashing gas such as nitrogen (backwashing) in a direction opposite to the flow of gas fuel at a predetermined timing. The recovered char 15 is collected in the second char recycling facility 27, pressurized by nitrogen gas supplied from a compressor (not shown), returned to the coal gasifier 3, and recycled.

  When the gas fuel guided to the second filter 23 passes through the ceramic filter medium, the char in the gas fuel is filtered out. The char thus filtered is dropped back by being backwashed at a predetermined timing and collected. The collected char 15 is collected in the third char recycling facility 29, pressurized by nitrogen gas supplied from a compressor (not shown), returned to the coal gasifier 3, and recycled.

Thus, according to this embodiment, since the 1st filter 21 and the 2nd filter 23 are provided in parallel downstream of the cyclone 19, the processing capacity in the 1st filter 21 and the 2nd filter 23 increases. For this reason, even if the size of the cyclone 19 is increased, the first filter 21 and the second filter 23 can be processed accordingly, so that the capacity of gas fuel can be increased.
In addition, if the capacity | capacitance of the cyclone 19 further enlarges, the 1st filter 21 and the 2nd filter 23 can respond by increasing a number further.

  For example, when the first filter 21 is clogged and the differential pressure is increased, the flow rate of the gas fuel passing through the first filter 21 is decreased. In this case, the amount of gas fuel passing through the second filter 23 only increases correspondingly, and the amount of gas fuel passing through the cyclone 19 is not affected. For this reason, since the dust collection performance in the cyclone 19 does not deteriorate, the char concentration of the gas fuel flowing into the first filter 21 and the second filter 23 does not increase. Therefore, since clogging in the first filter 21 does not increase rapidly, it can be restored by backwashing performed at a predetermined timing, and stable dust collection performance can be ensured.

The gas fuel that has passed through the first filter 21 and the second filter 23 merges at the position B and is sent to the desulfurization device 7, for example, sulfide is removed from the gas fuel.
The gas fuel desulfurized by the desulfurization device 7 is guided to the gas turbine 9 by the main system line 17 and burned together with the compressed air sent from the air compressor 27.
As a result, the gas turbine 11 is rotationally driven. For example, a generator connected to the rotational shaft of the gas turbine 9 converts the rotational driving force into electric power.

[Second Embodiment]
Next, the coal gasification system 1 concerning 2nd embodiment of this invention is demonstrated using FIG.
FIG. 2 is a block diagram showing a schematic configuration of the coal gasification system 1.
In this embodiment, the structure which handles the char collect | recovered with the dust removal equipment 5 differs from 1st embodiment. Since other components are the same as those of the first embodiment described above, a duplicate description of these components is omitted here.
In addition, the same code | symbol is attached | subjected to the member same as 1st embodiment mentioned above.

The dust removal equipment 5 is provided with a collector 31. The aggregator 31 is configured to accumulate the char separated and collected by the cyclone 19, the first filter 21, and the second filter 23 together.
The char collected in the collector 31 is supplied to the coal gasification furnace 3 by an aggregate char recycling facility (char recycling facility) 33.
The char supplied to the collective char recycling facility 33 is pressurized to a high pressure from the inside of the coal gasification furnace 3 by nitrogen gas supplied from a compressor (not shown) and supplied to the coal gasification furnace 3.

Operation | movement of the coal gasification system 1 concerning this embodiment demonstrated above is demonstrated.
In the coal gasification furnace 3, by burning the pulverized coal 11, the gasifying agent 13 and the char 17 supplied under pressure, the carbon in the pulverized coal 11 and the char 17 is converted to CO ₂ and H ₂ in the high-temperature gas. A gas fuel containing CO or H ₂ as a component is produced by reacting with O.
The gas fuel generated in the coal gasification furnace 3 is guided to the cyclone 19 through the main system line 17, and 80 to 90 percent of the mixed char 15 is recovered by the cyclone 19. The collected char 15 is collected in the aggregator 31.

The gas fuel from which most of the char has been recovered by the cyclone 19 is branched at the position A through the main system line 17 and led to the first filter 21 and the second filter 23, respectively.
When the gas fuel guided to the first filter 21 passes through the ceramic filter medium, the char in the gas fuel is filtered out. The filtered char is dropped and recovered by flowing backwashing gas such as nitrogen (backwashing) in a direction opposite to the flow of gas fuel at a predetermined timing. The collected char 15 is collected in the aggregator 31.

  When the gas fuel guided to the second filter 23 passes through the ceramic filter medium, the char in the gas fuel is filtered out. The char thus filtered is dropped back by being backwashed at a predetermined timing and collected. The collected char 15 is collected in the aggregator 31.

Thus, according to this embodiment, since the first filter 21 and the second filter 23 are provided in parallel downstream of the cyclone 19, the processing capacity of the first filter 21 and the second filter 23 increases. . For this reason, even if the size of the cyclone 19 is increased, the first filter 21 and the second filter 23 can be processed accordingly, so that the capacity of gas fuel can be increased.
In addition, if the capacity | capacitance of the cyclone 19 further enlarges, the 1st filter 21 and the 2nd filter 23 can respond by increasing a number further.

  For example, when the first filter 21 is clogged and the differential pressure is increased, the flow rate of the gas fuel passing through the first filter 21 is decreased. In this case, the amount of gas fuel passing through the second filter 23 only increases correspondingly, and the amount of gas fuel passing through the cyclone 19 is not affected. For this reason, since the dust collection performance in the cyclone 19 does not deteriorate, the char concentration of the gas fuel flowing into the first filter 21 and the second filter 23 does not increase. Therefore, since clogging in the first filter 21 does not increase rapidly, it can be restored by backwashing performed at a predetermined timing, and stable dust collection performance can be ensured.

  The char accumulated in the collecting device 31 is supplied to the collecting char recycling facility 33. The char supplied to the collective char recycling facility 33 is pressurized by nitrogen gas supplied from a compressor (not shown), returned to the coal gasification furnace 3, and recycled.

  In this way, the char recovered by the cyclone 19, the first filter 21 and the second filter 23 is once collected in the collector 31, and then supplied to the coal gasifier 3 by the aggregate char recycling facility 33. The char recycling facility 33 can be a facility with a capacity corresponding to the amount of char generated. For this reason, when providing a char recycling facility for each of the cyclone 19, the first filter 21 and the second filter 23, it is necessary to provide a margin due to fluctuations in the amount of char collected for each char recycling facility. Then, the overall size can be reduced. In addition, the manufacturing cost can be reduced by reducing piping and the like.

  In the present embodiment, the char collected by the cyclone 19, the first filter 21, and the second filter 23 is accumulated in the aggregator 31, but the present invention is not limited to this. For example, Even if the char collected from the first filter 21 and the second filter 23 is accumulated in the collector 31 and the cyclone 19 is provided with a char recycling facility alone, the production cost can be reduced. is there.

The gas fuel that has passed through the first filter 21 and the second filter 23 merges at the position B and is sent to the desulfurization device 7, for example, sulfide is removed from the gas fuel.
The gas fuel desulfurized by the desulfurization device 7 is guided to the gas turbine 9 by the main system line 17 and burned together with the compressed air sent from the air compressor 27.
As a result, the gas turbine 11 is rotationally driven. For example, a generator connected to the rotational shaft of the gas turbine 9 converts the rotational driving force into electric power.

It is a block diagram showing a schematic structure of a coal gasification system concerning a first embodiment of the present invention. It is a block diagram which shows schematic structure of the coal gasification system concerning 2nd embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coal gasification system 3 Coal gasification furnace 19 Cyclone 21 1st filter 23 2nd filter 31 Aggregator 33 Aggregate char recycling equipment

Claims (3)

A gasification furnace that gasifies carbon-containing fuel to produce gas fuel;
A primary dust collector provided on the downstream side of the gasification furnace for separating and removing char in the gas fuel;
In a gasification system having a precision dust collector that is provided downstream of the primary dust collector and collects char remaining in the gas fuel,
A gasification system comprising a plurality of precision dust collectors arranged in parallel. An aggregator for collecting char collected from each of the precision dust collectors;
A char recycling facility for supplying the char collected in the collector to the gasifier;
The gasification system according to claim 1, comprising: The gasifier system according to claim 2, wherein the collector collects the char separated by the primary dust collector.

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