JP5166000B2 - Biomass gasification system - Google Patents

Description

  The present invention relates to a biomass gasification system that uses, for example, a pyrolysis gas generated by pyrolyzing a biomass raw material as a fuel gas.

  In recent years, biomass gasification power generation systems that heat and gasify biomass raw materials (thermally decomposed products) such as wood chips and generate electricity using the generated gas as fuel gas have come into practical use ( For example, Patent Document 1). In such a biomass gasification power generation system, when a raw material biomass is heated and pyrolyzed under low oxygen in a gasification furnace (gasification means), a pyrolysis gas mainly composed of carbon monoxide, hydrogen and hydrocarbons. Will occur. The pyrolysis gas is cooled and purified to be used as fuel gas by supplying it to various power generation facilities such as dual fuel engine power generation, gas engine power generation, gas turbine power generation, or fuel cell.

In such a biomass gasification power generation system, dust such as soot is contained in the pyrolysis gas generated in the gasification furnace, so that the soot and the like are cooled in the gasification furnace and a cooler (cooling means) for cooling the pyrolysis gas. Dust accumulates. For this reason, it is necessary to regularly or irregularly remove dust such as soot accumulated in the gasification furnace or the cooler.
JP 2002-121571 A

  By the way, in the biomass gasification power generation system like patent document 1, since an operator removes dusts, such as soot collected in a gasification furnace or a cooler, manually with a scoop etc., work efficiency is very high. It was bad.

  The present invention has been made paying attention to such problems. The object is to provide a biomass gasification system capable of efficiently removing dust in the pyrolysis gas accumulated in at least one of the gasification means and the cooling means.

  In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that a gasification means for heating a biomass raw material to generate pyrolysis gas, and the gasification means are connected to the gasification means through a flow path. A cooling means for cooling the pyrolysis gas, a dust removal means for removing dust in the cooled pyrolysis gas that is connected to the cooling means through the flow path, and a connection to the dust removal means via the flow path And a power generation device that generates electricity using the pyrolyzed gas removed from the dust as fuel gas, the downstream side of the dust removing means in the flow path of the pyrolyzed gas from the upstream side Suction means for sucking the pyrolysis gas toward the downstream side is provided, and between the dust removal means and the cooling means in the pyrolysis gas flow path, at least of the gasification means and the cooling means It is summarized as that accumulated the suction tube which can lead to dust dumping member by utilizing the suction force of the sucking unit dust of the pyrolysis gas in a square are connected.

  According to this configuration, the dust in the pyrolysis gas accumulated in at least one of the gasification means and the cooling means can be guided to the dust removal means by the suction pipe using the suction force of the suction means. Dust can be efficiently and easily removed.

The gist of the invention described in claim 2 is that, in the invention described in claim 1, the suction tube can be flexibly bent.
According to this configuration, even in a place where the gasification means and the cooling means are intricate, the suction pipe can be easily arranged so that the end of the suction pipe on the side for sucking dust reaches the gasification means or the cooling means. It can be routed.

The invention according to claim 3 is summarized in that, in the invention according to claim 1 or 2, the suction pipe is provided with a pipe opening / closing valve for opening and closing the suction pipe.
According to this configuration, by closing the pipe opening / closing valve during the operation of the biomass gasification system, it is possible to efficiently suck the pyrolysis gas from the upstream side toward the downstream side by the suction means.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the flow path is opened and closed between a portion of the pyrolysis gas flow path where the suction pipe is connected and the cooling means. The gist of the invention is that a flow path opening / closing valve is provided.

  According to this configuration, by closing the flow path opening / closing valve, it becomes possible to efficiently suck dust through the suction pipe by the suction means.

  ADVANTAGE OF THE INVENTION According to this invention, the biomass gasification system which can remove efficiently the dust in the pyrolysis gas collected in at least one among a gasification means and a cooling means can be provided.

Hereinafter, an embodiment in which the present invention is embodied in a biomass gasification power generation system will be described with reference to the drawings.
As shown in FIG. 1, a biomass gasification power generation system 11 as a biomass gasification system includes an input hopper 12 for inputting woody biomass material such as sawdust, and a pyrolysis gas by heating the input biomass material. And a retention tank 14 for temporarily retaining the generated pyrolysis gas and decomposing and removing tar and the like contained in the pyrolysis gas. In this embodiment, the gasification means 13 and the retention tank 14 constitute gasification means.

  A cooling device 15 as a cooling means for cooling the pyrolysis gas is provided on the downstream side of the retention tank 14, and a bag filter 19 as a dust removal means for removing dust from the pyrolysis gas is provided on the downstream side of the cooling device 15. Is provided.

  The cooling device 15 includes a water-cooled cyclone 16 that cools the pyrolysis gas while removing some dust and the like in the pyrolysis gas, a primary cooler 17 and a secondary cooler 18 that cool the pyrolysis gas, and It has. The pyrolysis gas generated in the gasification furnace 13 is at a high temperature of about 800 to 900 ° C., for example, about 600 ° C. in the water-cooled cyclone 16, about 400 to 500 ° C. in the primary cooler 17, and about 50 to about 50 to 50 in the secondary cooler 18. Sequentially cooled to about 80 ° C. The cooling water W (see FIG. 2) used in the water-cooled cyclone 16, the primary cooler 17 and the secondary cooler 18 is routed through each part by the pump 21 by lowering the water temperature by taking the heat of vaporization in the cooling tower 20. It is circulated in.

  The bag filter 19 performs final dust removal of the pyrolysis gas after being cooled by the cooling device 15 to obtain fuel gas, and a blower 22 as a suction means is provided downstream of the bag filter 19. It has been. Therefore, when the blower 22 blows air downstream, a negative pressure is generated on the upstream side of the blower 22 so as to draw the gas downstream. In other words, the blower 22 sucks the pyrolysis gas (fuel gas) from the upstream side toward the downstream side by blowing air downstream.

  The blower 22 draws the fuel gas removed by the bag filter 19 by the suction force of the blower 22 and sends it to the power generation device 23. For example, when the operation of the power generation device 23 is stopped, the fuel gas is sent to the flare stack 24. It comes to send. The fuel gas sent to the flare stack 24 is combusted and then exhausted. Of course, a configuration in which extra fuel gas that is not used in the power generation device 23 is temporarily stored in the gas tank can also be employed.

  The power generator 23 includes an engine 25 that is driven by combustion of fuel gas, and a generator 26 that generates electric power using the rotational output of the engine 25. The biomass gasification power generation system 11 can obtain electricity generated by the generator 26, hot water using waste heat of exhaust gas from the engine 25, and the like. Note that the power generation device 23 in this embodiment employs a dual fuel engine power generation system.

  As shown in FIG. 2, the water-cooled cyclone 16 includes a lower case 30 having a rectangular parallelepiped shape, a substantially cylindrical inner case 31 provided on the upper side of the lower case 30 and closed on the upper side, A cylindrical outer case 32 that covers the outer peripheral surface of the case 31 and is closed on both upper and lower sides is provided. A portion of the inner case 31 from the substantially central portion to the lower end in the vertical direction has a tapered shape whose diameter gradually decreases downward, and the lower end portion of the inner case 31 covers the upper wall of the lower case 30. It penetrates and reaches the lower case 30. That is, since the lower end portion of the inner case 31 opens in the lower case 30, the inner case 31 and the lower case 30 communicate with each other.

  The outer case 32 is adjacent to the lower case 30 and is isolated from the inside of the outer case 32 and the lower case 30. A space is formed between the outer case 32 and the inner case 31, and the space is a cooling water storage chamber 33 filled with the cooling water W. The cooling water W in the cooling water storage chamber 33 is continuously circulated through a path passing through the cooling tower 20.

  A pipe 34 that extends from the retention tank 14 and forms a pyrolysis gas flow path is connected to the upper end of the peripheral wall of the inner case 31 in a state of penetrating the peripheral wall of the outer case 32. That is, the inside of the pipe 34 communicates with the inside of the inner case 31 and does not communicate with the cooling water storage chamber 33. A pipe 35 that extends to the primary cooler 17 and forms a flow path for the pyrolysis gas is connected to the upper wall of the inner case 31, and the inner case 31 and the pipe 35 communicate with each other. An opening 30a is provided in the peripheral wall of the lower case 30, and the opening 30a is closed by a lid 36 so as to be freely opened and closed.

  When the pyrolysis gas flows into the inner case 31 from the pipe 34, the pyrolysis gas swirls along the inner peripheral wall of the inner case 31, and the centrifugal force at this time causes some dust such as soot from the pyrolysis gas. Minutes are removed. The pyrolysis gas from which some dust has been removed flows into the pipe 35 while being cooled by the cooling water W through the peripheral wall of the inner case 31, while the dust that has been somewhat removed from the pyrolysis gas falls within the inner case 31. In the lower case 30.

  As shown in FIG. 2, the bag filter 19 includes a substantially cylindrical main body case 40 whose upper side is closed. A partition plate 43 that partitions the interior of the main body case 40 into an upper compartment 41 and a lower compartment 42 is provided at the upper end of the main body case 40. The lower part of the main body case 40 has a tapered shape whose diameter gradually decreases downward, and an opening 44 is provided at the lower end of the main body case 40. Further, a rotary valve 52 is provided in the opening 44 of the main body case 40, and an opening 45 a of a flexible container bag (flexible container bag) 45 disposed under the main body case 40 is attached to and detached from the rotary valve 52. Connected freely. The rotary valve 52 allows the dust in the main body case 40 to be discharged into the flexible container bag 45 while ensuring airtightness in the main body case 40.

  In the main body case 40, a plurality of (three in the present embodiment) filter cloths 46 each having a bottomed cylindrical shape extending vertically are arranged on the partition plate 43 at predetermined intervals in the horizontal direction. That is, each filter cloth 46 is provided so as to hang from the partition plate 43 in the lower compartment 42, and the upper end of each filter cloth 46 is opened to face the upper compartment 41. Each filter cloth 46 is held in a cylindrical shape by a retainer (not shown) supported by the partition plate 43 so as to allow permeation of pyrolysis gas and restrict permeation of dust such as soot in the pyrolysis gas. It has become.

  A pipe 47 that extends from the secondary cooler 18 and forms a flow path for pyrolysis gas is connected to a position corresponding to the upper end portion of the lower compartment 42 on the peripheral wall of the main body case 40. On the other hand, a pipe 48 extending to the blower 22 and forming a flow path for pyrolysis gas is connected to a position corresponding to the upper compartment 41 on the peripheral wall of the main body case 40. That is, the inside of the lower compartment 42 and the inside of the pipe 47 are in communication, and the inside of the upper compartment 41 and the inside of the pipe 48 are in communication.

  When the pyrolysis gas flows into the lower compartment 42 from the pipe 47, the pyrolysis gas is filtered by the filter cloths 46. That is, the pyrolysis gas passes through each filter cloth 46 and flows into the pipe 48 through each filter cloth 46 and the upper compartment 41. On the other hand, dust such as soot contained in the pyrolysis gas cannot permeate each filter cloth 46, and therefore adheres to the outer surface of each filter cloth 46 or falls in the lower compartment 42. And collected in the flexible container bag 45. Therefore, the pyrolysis gas (fuel gas) flowing into the pipe 48 is in a clean state containing almost no dust such as soot.

  In addition, when the dust layer adhering to the outer surface of each filter cloth 46 becomes thick and the passage resistance of the pyrolysis gas with respect to each filter cloth 46 becomes large, the air injector (not shown) provided in the upper compartment 41 is provided. Thus, air is injected into each filter cloth 46. As a result, the dust layered on the outer surface of each filter cloth 46 is blown off and collected in the flexible container bag 45.

  As shown in FIG. 2, a proximal end of a suction pipe 49 constituted by a long bellows pipe is connected to a midway position of a pipe 47 connecting the secondary cooler 18 and the bag filter 19 in a communicating state. The length of the suction pipe 49 is set so that the opening 49 a at the tip of the suction pipe 49 can reach the gasification furnace 13, the retention tank 14, and the water-cooled cyclone 16 sufficiently. In addition, since the suction tube 49 is configured by a bellows tube, it can be flexibly bent.

  In addition, a pipe opening / closing valve 50 for opening and closing the inside of the suction pipe 49 is provided at the base end portion of the suction pipe 49, and a portion of the pipe 47 to which the suction pipe 49 is connected and the secondary cooler 18 are provided. A flow path opening / closing valve 51 for opening and closing the inside of the pipe 47 is provided therebetween.

Next, an operation when dust such as soot accumulated in the lower case 30 of the water-cooled cyclone 16 is removed will be described with reference to FIG.
First, the operation of the biomass gasification power generation system 11 is stopped, and then the flow path opening / closing valve 51 is closed and the pipe opening / closing valve 50 is opened. Then, after the dust such as soot accumulated in the lower case 30 of the water-cooled cyclone 16 is sufficiently naturally cooled, the lid 36 of the lower case 30 is removed. Subsequently, the distal end portion of the suction tube 49 is inserted from the opening 30 a of the lower case 30. When the air blower 22 is driven in this state and the air is blown downstream, the dust accumulated in the lower case 30 by the suction force of the air blower 22 is sucked together with the air from the opening 49 a of the suction pipe 49.

  Dust sucked together with air from the opening 49 a of the suction pipe 49 is introduced into the lower compartment 42 of the bag filter 19 through the suction pipe 49 and the pipe 47. At this time, air can pass through each filter cloth 46, but dust cannot pass through each filter cloth 46, so that only the dust is on the outer surface of each filter cloth 46 as in the operation of the biomass gasification power generation system 11. Or is dropped in the lower compartment 42 and collected in the flexible container bag 45. In this case, since the suction pipe 49 is set to a sufficient length and can be flexibly bent, the dust accumulated in the lower case 30 can be reliably and easily sucked and removed to every corner. .

  In this way, by connecting the suction pipe 49 to the pipe 47, the bag filter 19 and the blower 22 which are existing facilities in the biomass gasification power generation system 11 can function as a vacuum cleaner for sucking and removing dust. It can be very reasonable.

  After the dust in the lower case 30 is removed, the suction pipe 49 is extracted from the opening 30 a of the lower case 30 and the opening 30 a is closed by the lid 36. Thereafter, the operation of the biomass gasification power generation system 11 is started again with the flow path opening / closing valve 51 opened and the pipe opening / closing valve 50 closed.

  Note that dust such as soot collected in the gasification furnace 13 and the retention tank 14 can be removed in the same manner as the dust collected in the lower case 30 of the water-cooled cyclone 16 described above.

According to the embodiment detailed above, the following effects can be obtained.
(1) Dust such as soot in the pyrolysis gas accumulated in at least one of the gasification furnace 13, the residence tank 14, and the water-cooled cyclone 16 uses the suction force of the blower 22 to draw the bag filter 19 through the suction pipe 49. Therefore, the dust can be sucked and removed efficiently and easily. Therefore, unlike the conventional case where dust is manually removed, an operation of carrying the collected dust to the flexible container bag 45 becomes unnecessary.

  (2) Since the suction pipe 49 can be bent flexibly and has a sufficient length, the suction pipe 49 is provided even in a place where the gasification furnace 13, the retention tank 14, and the water-cooled cyclone 16 are intricate. The suction pipe 49 can be easily routed so that the openings 49a of 49 reach the gasification furnace 13, the retention tank 14, and the water-cooled cyclone 16, respectively.

  (3) Since the pipe opening / closing valve 50 is provided in the suction pipe 49, the pyrolysis gas is caused to flow downstream from the upstream side by the blower 22 by closing the pipe opening / closing valve 50 during operation of the biomass gasification power generation system 11. It can be efficiently sucked toward the side.

  (4) Since the secondary cooler 18 is provided between the portion of the piping 47 connecting the secondary cooler 18 and the bag filter 19 where the suction pipe 49 is connected and the secondary cooler 18, By closing the flow path opening / closing valve 51, dust such as soot collected in the gasification furnace 13, the retention tank 14, and the water-cooled cyclone 16 can be efficiently sucked and removed by the blower 22 through the suction pipe 49. .

(Example of change)
In addition, the said embodiment can also be changed and actualized as follows.
-At least one of the pipe opening / closing valve 50 and the flow path opening / closing valve 51 may be omitted.

-Instead of the pipe opening / closing valve 50 and the flow path opening / closing valve 51, a three-way valve may be provided at a portion of the pipe 47 to which the suction pipe 49 is connected.
-The suction pipe 49 does not need to be bent flexibly. In this case, the suction tube 49 needs to be fixed in a state where the opening 49 a at the tip thereof is inserted into the lower case 30 of the water-cooled cyclone 16.

  -The suction pipe 49 does not necessarily have to be bent flexibly as a whole. That is, the suction tube 49 may be configured such that only a part thereof is configured by a bellows tube, and only a portion configured by the bellows tube is flexibly bent.

-Biomass raw material is not limited to woody biomass raw material. Any biomass material that generates pyrolysis gas by heating in the gasification furnace 13 may be used.
・ Dust includes not only soot, but also ash or deposits of oxides, carbides, nitrides, and the like.

  The power generation device 23 of the biomass gasification power generation system 11 is not limited to the dual fuel engine power generation method, and may be, for example, a gas engine power generation method, a turbine power generation method, or a fuel cell power generation method.

The technical idea grasped from the above embodiment will be described below.
(B) The biomass gasification system according to any one of claims 1 to 4, wherein the suction pipe is a bellows pipe.

  According to this configuration, since the suction tube is a bellows tube, the suction tube can be easily obtained or manufactured.

The block diagram which shows schematic structure of the biomass gasification electric power generation system of embodiment. The principal part expanded sectional view of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Biomass gasification power generation system as biomass gasification system, 13 ... Gasification furnace as gasification means, 14 ... Residence tank as gasification means, 15 ... Cooling device as cooling means, 19 ... Dust removal means Bag filter, 22 ... Blower as suction means, 23 ... Power generation device, 49 ... Suction pipe, 50 ... Pipe open / close valve, 51 ... Flow path open / close valve.

Claims (4)

Gasification means for heating the biomass raw material to generate pyrolysis gas, cooling means connected to the gasification means via the flow path and cooling the pyrolysis gas, and via the cooling means and flow path The dust removing means for removing dust in the pyrolysis gas that is connected and cooled, and the power generation apparatus that is connected to the dust removal means via the flow path and generates electricity using the pyrolysis gas that has been dust removed as fuel gas A biomass gasification system comprising
A suction means for sucking the pyrolysis gas from the upstream side toward the downstream side is provided on the downstream side of the dust removal means in the pyrolysis gas flow path,
Between the dust removing means and the cooling means in the pyrolysis gas flow path, the dust in the pyrolysis gas accumulated in at least one of the gasification means and the cooling means is sucked by the suction means. A biomass gasification system, characterized in that a suction pipe capable of being guided to the dust removing means by using a gas is connected. The biomass gasification system according to claim 1, wherein the suction pipe can be flexibly bent. The biomass gasification system according to claim 1 or 2, wherein the suction pipe is provided with a pipe opening / closing valve for opening and closing the suction pipe. The flow path opening / closing valve for opening and closing the flow path is provided between a portion of the pyrolysis gas flow path to which the suction pipe is connected and the cooling means. 3. The biomass gasification system according to 3.

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