JP2003253273A - Method and apparatus for gasification of solid fuel and organic substance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for gasification of solid fuel and organic substance, being capable of generating a gas of high combustion energy with a reduced content of nitrogen gas and of attaining almost complete gasification of the carbon component of the raw material and permits easy treatment of the ash formed. <P>SOLUTION: The rotary kiln 12 is provided with a cylindrical kiln main body 15 that is made of a refractory material and is driven around an axis inclined downward, the inlet hood 20 equipped with a means 13 for feeding the raw material, and the outlet hood 21 equipped with the ash exhauster 33 after treatment and the exhauster 30 for exhausting the gas generated. Low- pressure, high-temperature superheated steam is fed through a steam pipe 35 into the rotary kiln whereby a raw material mainly including the solid fuel and/or organic substance charged in the kiln main body is allowed to cause the water gas reaction to produce fuel gas. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasification method and apparatus for solid fuel or organic matter, which is gasified by exposing a solid fuel such as charcoal or a raw material made of organic matter to high temperature superheated steam in a rotary kiln.

[0002]

2. Description of the Related Art In a conventional gasifier for solid fuel or the like, a raw material is put into a combustion furnace and air is put therein, and a part of it is self-combusted to bring the raw material to a high temperature. It was gasified by causing a water gasification reaction with.

[0003]

However, since air is used when a part of the raw material is burned, a large amount of nitrogen remains in the generated gas, the overall calorie of the gas decreases, and the remaining nitrogen remains. Caused NOx to be generated during combustion. Furthermore, since the structure of the furnace is simple, it is difficult to completely carry out the water gasification reaction on the raw materials, so ungasified charcoal is mixed in the ash, and therefore the ash discharge structure is also It was complicated. The present invention has been made in view of the above circumstances, the generated gas has a small amount of nitrogen gas and high combustion energy, and moreover, it is possible to gasify most of the carbon content of the raw material, and the generated ash. It is an object of the present invention to provide a gasification method and apparatus for solid fuels and organic substances, which can be easily treated.

[0004]

A method for gasifying a solid fuel or an organic matter according to the first aspect of the invention, which meets the above-mentioned object, comprises a raw material mainly composed of a solid fuel and / or an organic matter at 600 ° C. or more (more preferably, (800 ° C. or higher) is put in a rotary kiln to which low-pressure high-temperature superheated steam is supplied to cause a water gasification reaction to obtain a fuel gas. Since a part of the raw material is not burned with air, the generated gas does not actively contain nitrogen. When the organic substance contains nitrogen, it is decomposed into nitrogen gas. Then, since the raw material is put into the rotary kiln for processing, the raw material moves to the downstream side while being stirred, and by adjusting the inclination angle of the kiln body of the rotary kiln so that the water gasification reaction is caused more completely, the raw material kiln The residence time in the body can be adjusted. The water gasification reaction means a reaction represented by the following formula (the same applies to the following sentences). C + H ₂ O → CO + H ₂

The solid fuel or organic substance gasification method according to the second aspect of the present invention is the solid fuel or organic substance gasification method according to the first aspect, wherein the raw material is mainly composed of particles having a particle size of 1 to 2.
It is in the range of 0 mm. Since the raw material has a small particle size, it is actively heated by the superheated steam to promote the water gasification reaction. A method for gasifying a solid fuel or an organic matter according to a third invention is the method for gasifying a solid fuel or an organic matter according to the first or second invention, wherein the raw material is an organic matter having no or little water content, The organic substance is thermally decomposed on the upstream side of the rotary kiln, and a water gasification reaction is caused on the downstream side thereof. Since it is a rotary kiln, the raw materials sequentially flow from the upstream side to the downstream side, and in the case of organic substances, thermal decomposition is first performed, and then a water gasification reaction can be caused.

A method for gasifying a solid fuel or an organic matter according to a fourth aspect of the present invention is the method for gasifying a solid fuel or an organic matter according to the third aspect, wherein the organic matter is dehydrated and / or dried in advance. . This facilitates loading into the rotary kiln and reduces heat consumption in the rotary kiln. A gasification method for a solid fuel or an organic matter according to a fifth aspect is the method for gasifying a solid fuel or an organic matter according to any one of the first to fourth aspects, wherein a heat-resistant material is used for the kiln body of the rotary kiln, and the kiln body is used. The parts except both sides of are heated externally. As a result, the supply amount of superheated steam can be suppressed. In this case, since the kiln body has a high temperature, a material (for example, special stainless steel, Inconel, Hastelloy, ceramics, and composites thereof) that withstands the high temperature is used.

A gasifier for solid fuel or organic matter according to a sixth aspect of the present invention is an apparatus used in the method for gasifying solid fuel or organic matter according to the first aspect of the present invention. Side, a cylindrical kiln main body rotatably arranged at a downward slope, a rotary drive source for driving the kiln main body, an inlet hood provided with a raw material charging means, a discharge outlet for ash after treatment and generation An outlet hood provided with an exhaust port for discharging gas, and a low-pressure high-temperature superheat of 600 ° C or higher (more preferably 800 ° C or higher) provided in the kiln body provided through the inlet-side hood or the outlet-side hood. Steam piping for supplying steam. A solid fuel or organic gasifier according to a seventh aspect of the present invention is the solid fuel or organic gasifier according to the sixth aspect of the present invention, wherein the kiln body is heated from the outside except for both sides thereof. An external heating zone is provided. As a result, the amount of superheated steam supplied to the inside can be reduced, and the water gasification reaction can be completed in a shorter time.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. Here, FIG. 1 is a side view of a gasifier for solid fuel and organic matter according to a first embodiment of the present invention,
FIG. 2 is a side view of a gasifier for solid fuel and organic substances according to a second embodiment of the present invention.

As shown in FIG. 1, a gasifier 10 for solid fuel or organic matter according to a first embodiment of the present invention is a rotary kiln 12 provided on a pedestal 11, and a raw material is gradually fed to the rotary kiln 12. Raw material charging means 13 to be supplied
And a steam supply means 14 for supplying superheated steam of about 900 ° C. in the rotary kiln 12. These will be described in detail below. Rotary kiln 12
Has a cylindrical kiln body 15 which is made of a heat-resistant material and is rotatably arranged at a downward gradient from the upstream side to the downstream side. The kiln main body 15 is provided with tires 15a and 15b on the front and rear sides, is in contact with the tires 15a and 15b, and is disposed on the inclined mount 16 via rollers 17 and 18 disposed on the left and right sides, respectively. The tilt base 16 is arranged on the auxiliary base 19 so as to be tiltable, whereby the kiln body 15 can be adjusted downward in a range of 0.1 to 3 degrees. The tilting means 19a, which is provided on the upstream side of the kiln body 15 and includes a jack or the like (not shown) that tilts the kiln body 15 downward, may be manual, or may be automatic using a motor or the like. Reference numeral 19b denotes a bearing which is provided on both sides of the kiln body 15 on the downstream side and which rotatably attaches the inclined mount 16 to the auxiliary mount 19.

The entire length of the kiln body 15 is about 4 to 10 times the diameter (1 to 2 m in this embodiment), which is relatively long, and the heat-resistant material having sufficient strength on the outside (for example, heat-resistant steel, stainless steel, Made of Inconel, etc., and the inside except both sides is coated with refractory or heat-resistant ceramic. The refractory and refractory ceramic may be omitted, and the whole may be made of refractory metal. One or both of the paired rollers 17, 18 is provided with a rotary drive source (not shown) that is driven to rotate by a motor, and the kiln body 15 is mounted on the four rollers 17, 18 in total.
Is configured to be rotatable at, for example, 0.1 to 20 rpm. Attach an external gear around the kiln body 15,
The kiln body 15 can also be rotationally driven by a reduction motor having a pinion that meshes with the external gear attached to the output shaft. A sprocket is attached to the outside of the kiln body 15, and the output shaft of the reduction motor is connected via a chain that meshes with the sprocket. It can also be driven by a sprocket attached to. The kiln body 15 has a tubular shape, and an inlet side hood 20 is provided on the upstream side thereof, and an outlet side hood 21 is provided on the downstream side thereof. The inlet-side hood 20 and the outlet-side hood 21 are made of a heat-resistant metal (for example, stainless steel), and the outside is kept warm with a refractory material, or the inside is filled or lined with a refractory material. And the kiln body 1
Although 5 rotates, the inlet side hood 20 and the outlet side hood 2
Since 1 is fixed to the pedestal 11 via the support members 22 and 23 respectively, a sealing material such as a gland packing is provided in the sliding portion so that steam and gas can be transferred from the kiln body 15 to the outside as much as possible. It is designed so that it does not leak into the. Also, the tires 15a, 15b of the kiln body 15
The outer part except for is preferably covered with a heat insulating material.

The inlet side hood 20 has a raw material charging means 13
Is provided. The raw material charging means 13 has a hopper 24 for storing the raw material and first and second horizontally arranged screw conveyors 25, 26 for gradually discharging the raw material in the hopper 24. A vertical screw conveyor 27 is provided in the hopper 24, the raw material is dropped into the raw material input port 28 of the first screw conveyor 25, and the first screw conveyor 25 is input into the raw material input port 29 of the second screw conveyor 26. Raw materials are gradually added.
The first screw conveyor 25 may be omitted, and the raw material may be directly fed from the hopper 24 to the second screw conveyor 26, and the raw material may be fed into the kiln body 15 by the second screw conveyor 26 (Fig. 2). On the other hand, the outlet side hood 21 is provided with a gas outlet (exhaust port) 30 that discharges the produced water gas to the outside.
Water gas is sent to a gas pipe 32 connected by a flange connection 31. Further, the bottom of the outlet side hood 21 is provided with a residue discharge port 33, and a rotary valve 34 is provided.
Remains (mainly ash) outside (or damper)
Can be discharged. 34a is a container for containing the residue.

Further, the exit side hood 21 has a kiln body 1
A steam pipe 35 for supplying low-pressure and high-temperature superheated steam is arranged in the inside of the pipe 5. When the steam pipe 35 enters the kiln body 15, it becomes a steam ejecting portion 36 provided with a large number of steam ejecting ports (not shown) around the kiln body 15 and ejects low-pressure high-temperature superheated steam into the kiln body 15. Steam spout part 36
Is substantially 0.8 to 1 of the length of the kiln body 15.
It is about double. In the present embodiment, only one steam pipe 35 is contained in the kiln body 15, but a plurality of steam pipes can be inserted. It is also possible to guide a plurality of steam pipes for flowing low-pressure high-temperature superheated steam having different temperatures into the kiln main body 15 to change the jetting temperature on the upstream side and the downstream side of the kiln main body 15. In this case, the low pressure high temperature superheated steam having a relatively low temperature (for example, 300 to 700 ° C.) is used on the upstream side, and the low pressure high temperature superheated steam having a relatively high temperature (for example, 600 to 1000 ° C.) is used on the downstream side.
More preferably, the temperature is set to 800 to 1000 ° C.), and the upstream side of the kiln body 15 can be used as the pyrolysis region of the raw material and the downstream side can be used as the raw material carbonization region. Further, the steam pipe may be provided so as to penetrate the inlet hood. These low-pressure high-temperature superheated steam is produced by the steam supply means 14 including a boiler and a superheater (super heater), and the steam generated by the boiler is further heated to a high temperature by the superheater.

Therefore, when operating the gasifier 10 of this solid fuel or organic matter, a low pressure and high temperature (for example, 600 to 900) is provided in the kiln body 15 by the steam pipe 35.
The raw material accumulated in the hopper 24 is gradually fed into the kiln body 15 through the first and second screw conveyors 25 and 26 in a state of supplying superheated steam at a temperature of ℃, more preferably 800 to 900 ℃. Supply to. In this case, the main raw material is solid fuel such as charcoal and coke, or an organic matter, the particle size of which is in the range of 1 to 20 mm. More preferably, 10% or less) is dehydrated and dried. When the particle size of the raw material is less than 1 mm, the powder approaches the powder and is inconvenient to handle, and when the particle size exceeds 20 mm, the reaction takes time. When the raw material is solid fuel (charcoal, coke, etc.), it gradually moves to the downstream side as the kiln body 15 rotates, but in the process of movement, touching the low-pressure high-temperature superheated steam filled inside. Causes a water gasification reaction. As a result, water gas (fuel gas) containing hydrogen and carbon monoxide is generated. In this case, since it does not contain nitrogen as compared to conventional water gas,
Fuels with extremely high calories can be obtained.

On the other hand, when the raw material is an organic substance (wood chips, etc.), thermal decomposition occurs on the upstream side of the kiln body 15, and the thermally decomposed gas and carbide are gradually converted into low-pressure high-temperature superheated steam from the middle stream region to the downstream side. The water gasification reaction occurs by touching, and water gas (fuel gas) is generated. In the case of an organic substance, the organic substance is first thermally decomposed and then the water gasification reaction is caused, so that the entire processing time becomes long. However, by changing the inclination angle of the kiln body 15, the kiln body of the raw material is changed. Since the residence time in 15 can be controlled, it can correspond to all kinds of carbides and organic substances. The generated water gas is stored in a gas tank (not shown) from the gas outlet 30 via the gas pipe 32. Further, the ash mainly composed of ash falls from the kiln body 15 to the bottom of the outlet hood 21, and is discharged into the container 34 a via the rotary valve 34. The generated water gas contains a large amount of high-temperature steam, so when heat is absorbed via a heat exchanger (not shown), the water vapor becomes water, and the remaining water gas is only water gas, which is used as an effective fuel source. it can.

Next, the gasifier 40 for solid fuel and organic matter according to the second embodiment of the present invention shown in FIG. 2 will be described. The gasification of solid fuel and organic matter according to the first embodiment will be described. The same components as those of the apparatus 10 are designated by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 2, the gasifier 40 for solid fuel and organic matter according to the second embodiment of the present invention has a rotary kiln 41 mounted on the pedestal 11. Rotary kiln 41
Has a cylindrical kiln body 42 rotatably arranged in a downward gradient from the upstream side to the downstream side. Kiln body 4
2 is tires 43, 44 on the front and rear (that is, on the upstream side and the downstream side).
Is equipped with. The slanted pedestal 16 is abutted on the tires 43 and 44, and via the rollers 17 and 18 arranged on the left and right sides,
It is placed on top. Like the solid fuel and organic matter gasifier 10 according to the first embodiment, the inclined mount 16 is tiltably arranged on the auxiliary mount 19, whereby the kiln main body 42 has a downward slope of 0.1 to 0.1. It can be adjusted within a range of 3 degrees. On the upstream side of the kiln body 42, an inclining means 19a including a jack or the like (not shown) for inclining the kiln body 42 downward is provided. One or both of the paired rollers 17, 18 is provided with a rotary drive source (not shown) that is rotationally driven by a motor, and the kiln body 42 is mounted on the four rollers 17, 18 in total.
Is configured to be rotatable at, for example, 0.1 to 20 rpm. The kiln body 42 can also be driven by gear meshing means, sprockets, and chains.

The overall length of the cylindrical kiln body 42 is about 5 to 10 times the diameter (0.5 to 2 m in this embodiment), which is relatively long, and a heat resistant material that can withstand 800 to 900 ° C. (for example, Inconel, Hastelloy). Then, the kiln body 42 is provided with an external heating zone 45 for heating the portion excluding both side portions thereof from the outside. The external heating zone 45 includes an outer case 46 made of a heat-resistant metal fixed to the pedestal 11, a heating burner 47 provided at the bottom of one side of the outer case 46, and the outer case 4
6 and the exhaust pipe 48 provided on the other side upper part, and by supplying air and LPG to the heating burner 47, the kiln main body 42 is 600-900 degreeC (more preferably 800-900 degreeC). It is heated from the outside.
A heat insulating material 49 is provided inside the outer case 46 to prevent the outer case 46 from overheating and to prevent heat loss from the outer case 46. The inlet side hood 20 is provided with a screw conveyor 50 for feeding the raw material upstream of the kiln body 42, and the raw material from the hopper 24 is directly fed to the raw material feeding port 51 of the screw conveyor 50. In addition, 52 shows the drive motor of the screw conveyor 27, 53 shows the drive motor of the screw conveyor 50, respectively.

The operation of the solid fuel or organic substance gasifier 40 and the method for gasifying the solid fuel or organic substance using this device 40 will be described. The solid fuel and organic substance gasifier according to the first embodiment will be described. The difference from the apparatus 10 is that the kiln body 42 is provided with an external heating zone 45. That is, by providing the external heating zone 45, the inside of the kiln body 42 can be heated not only by the low-pressure high-temperature superheated steam but also by the heating burner 47. Thereby, the steam supply means 14
There is an advantage that the heat load of is reduced and a smaller steam supply means is sufficient. Furthermore, when the solid fuel or organic gasifier 40 is first operated, the rotary kiln 41 can be operated early by the external heating zone 45. The pressure of the low-pressure high-temperature superheated steam is preferably higher than atmospheric pressure by about 20 to 200 torr, but the present invention is not limited to this number.

The present invention is not limited to the above-mentioned embodiment, and may be modified within the scope of the invention. Further, the solid fuel and organic gasifiers 10 and 40 according to the first and second embodiments may be combined to form a solid fuel and organic gasifier. Further, in the above-mentioned embodiment, the raw material is fed using the screw conveyor, but it is also possible to gradually cut out the material from the hopper with, for example, a rotary valve and put it into the kiln body with a chute. Further, in the above embodiments, the inside of the kiln body has a simple cylindrical shape, but it is also possible to provide a plurality of ribs inside, whereby the stirring effect of the raw material is improved, and the kiln body is also improved. The bending strength of is also improved.

[0019]

EFFECTS OF THE INVENTION In the method for gasifying a solid fuel or an organic matter according to any one of claims 1 to 5 and the gasifier for a solid fuel or an organic matter according to any one of claims 6 and 7, a raw material mainly composed of a solid fuel and / or an organic matter. Is placed in a rotary kiln to which low-pressure high-temperature superheated steam of 600 ° C or higher is supplied to cause a water gasification reaction to obtain a fuel gas. Therefore, the generated gas contains little nitrogen gas and has a large calorific value. Gas can be easily obtained. Moreover, since most of the generated residue is ash, the amount is small and the treatment is easy. Particularly, in the method for gasifying solid fuel or organic matter according to claim 2, since the main component of the raw material is in the range of particle size 1 to 20 mm, it is easy to process in the rotary kiln, and further,
It also facilitates transportation and raw material supply.

In the method for gasifying a solid fuel or an organic matter according to claim 3, the raw material is an organic matter having no or little water content, the organic matter is thermally decomposed on the upstream side of the rotary kiln, and the water gas is formed on the downstream side thereof. Since the chemical reaction is caused, it is economical because organic matter can be treated in one rotary kiln. In the method for gasifying solid fuel or organic matter according to claim 4, the organic matter is dehydrated and / or
Alternatively, since the drying process is performed, the heat load on the rotary kiln is reduced. In the method for gasifying solid fuel or organic matter according to claim 5, since the kiln body of the rotary kiln is made of a heat-resistant material, and the parts other than both sides of the kiln body are externally heated, low pressure high temperature superheated steam can be saved. However, these steam generators are small in size, and the response time during initial operation is short. When the temperature of the low-pressure high-temperature superheated steam supplied to the inside is low (for example, 600 to 800
Even if it is ℃), the internal temperature is further increased (for example, 9
0 to 1000 ° C).

The solid fuel and organic gasifiers according to the sixth and seventh aspects include a cylindrical kiln body which is made of a heat-resistant material and is rotatably arranged in a downward gradient from the upstream side to the downstream side, and the kiln body. A rotary drive source for driving, an inlet side hood provided with a raw material charging means, an outlet side hood provided with a treated ash discharge port and an exhaust port for discharging generated gas, and an inlet side hood or an outlet side hood. Since the kiln body has a steam pipe for supplying low-pressure high-temperature superheated steam of 600 ° C. or higher, there is only one rotary kiln and the entire kiln body can be made compact. In particular, in the gasifier for solid fuels and organic substances according to claim 7, the kiln body is provided with an external heating zone for heating the portions excluding both sides thereof from the outside, so that low-pressure high-temperature superheated steam can be saved. However, these steam generators are small in size, and the response time during initial operation is short.

[Brief description of drawings]

FIG. 1 is a side view of a gasifier for solid fuels and organic substances according to a first embodiment of the present invention.

FIG. 2 is a side view of a gasifier for solid fuel and organic substances according to a second embodiment of the present invention.

[Explanation of symbols]

10: Gasifier for solid fuel and organic matter, 11: Stand, 1
2: rotary kiln, 13: raw material feeding means, 14: steam supply means, 15: kiln main body, 15a, 15b: tires, 16: inclined mount, 17, 18: rollers, 19: auxiliary mount, 19a: tilting means, 19b: Bearing, 20: inlet side hood, 21: outlet side hood, 22, 23: support member,
24: hopper, 25: first screw conveyor, 2
6: Second screw conveyor, 27: Screw conveyor, 28, 29: Raw material inlet, 30: Gas outlet, 3
1: flange connection, 32: gas pipe, 33: exhaust port, 3
4: rotary valve, 34a: container, 35: steam pipe, 36: steam jetting part, 40: gasifier for solid fuel or organic matter, 41: rotary kiln, 42: kiln body,
43 and 44: tires, 45: external heating zone, 46: outer case, 47: heating burner, 48: exhaust pipe, 49: heat insulating material, 50: screw conveyor, 51: raw material charging port, 5
2, 53: Drive motor

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C10J 3/46 C10J 3/46 M 3/48 3/48

Claims (7)

[Claims] 1. A raw material mainly composed of solid fuel and / or organic matter is put into a rotary kiln to which low-pressure high-temperature superheated steam of 600 ° C. or higher is supplied to cause a water gasification reaction to obtain a fuel gas. Characterizing solid fuel and organic gasification method. 2. The method for gasifying a solid fuel or an organic matter according to claim 1, wherein the raw material mainly has a particle size of 1 to 20 m.
A method for gasifying a solid fuel or an organic substance, which is in the range of m. 3. The method for gasifying a solid fuel or an organic matter according to claim 1, wherein the raw material is an organic matter having no or little water content, and the organic matter is provided upstream of the rotary kiln. A method for gasifying a solid fuel or an organic substance, characterized in that the water gasification reaction is caused on the downstream side of the thermal decomposition. 4. The method for gasifying a solid fuel or an organic matter according to claim 3, wherein the organic matter has been dehydrated and / or dried in advance. 5. The method for gasifying solid fuel or organic matter according to claim 1, wherein the kiln body of the rotary kiln is made of a heat-resistant material, and a portion except both sides of the kiln body is A method for gasifying solid fuel or organic matter, which is characterized by being externally heated. 6. An apparatus used in the method for gasifying solid fuel or organic matter according to claim 1, wherein the cylindrical kiln is made of a heat-resistant material and is rotatably arranged in a downward gradient from upstream to downstream. A main body, a rotary drive source for driving the kiln main body, an inlet side hood provided with a raw material charging means, an outlet side hood provided with an exhaust port for processing ash and an exhaust port for discharging generated gas; A gasifier for solid fuel or organic matter, comprising: a steam pipe that penetrates through the inlet-side hood or the outlet-side hood and that supplies low-pressure high-temperature superheated steam at 600 ° C. or higher to the kiln body. 7. The gasifier for solid fuel or organic matter according to claim 6, wherein the kiln body is provided with an external heating zone for heating a portion except both side portions thereof from the outside. Gasifier for solid fuel and organic matter.