KR20170103503A - Sintering method and apparatus - Google Patents

Abstract

The present invention provides a sintering method and a sintering apparatus applied to the same. The sintering method comprises: a process of preparing a mixed base material and gaseous fuel; a process of charging the mixed base material in a cart moved in one direction; a process of heat treating the mixed base material by moving the cart to an ignition section and a sintering section in order; and a process of supplying gaseous fuel containing bio gas to at least one of the ignition section and the sintering section. Moreover, while heat energy required to sinter the mixed base material is supplied enough, usage of coal fuel is able to be reduced and the generation of pollutants reduced.

Description

[0001] Sintering method and apparatus [0002]

The present invention relates to a sintering method and apparatus, and more particularly, to a sintering method and apparatus capable of reducing the use of coal-based fuel while sufficiently supplying heat energy required for sintering a blended raw material and reducing pollutant generation.

According to a study on the establishment of standards and ranges of bioenergy (Ministry of Commerce, Industry and Energy, 2013), bioenergy is judged only in Korea if it meets biogenesis, biodegradation, carbon dioxide reduction, renewable and flammable elements. The case is judged as new energy and waste energy.

Conversion technologies of bioenergy include conversion techniques using physical conversion, thermochemical conversion and biochemical conversion. Among them, there are solid fuel conversion technologies using the physical conversion, and switching technologies using thermochemical conversion include direct combustion technology and carbonization technology using solid fuel. The conversion technology using biochemical conversion includes methane fermentation technology and sugar Fermentation technology and starch-based fermentation technology. These conversion technologies are currently in the commercialization or commercialization stage. Conversion technologies other than the above-mentioned conversion techniques are still difficult to apply to industrial fields as research and demonstration stages.

The sintered ores are manufactured by a series of processes in which powdered iron ore, limestone, coke, and anthracite are mixed and sintered in a sintering machine. Then, the sintered ores are crushed and sorted to a predetermined particle size, . At this time, various pollutants including carbon dioxide and oxides are generated.

Meanwhile, in accordance with the green growth and environmental management policy, in order to reduce the amount of coal-based fuel used and the amount of pollutants generated in the steelworks, the bio-energy conversion technology that has been commercialized or put to practical use has been combined with the sintering- And a new method capable of reducing the amount of pollutants generated is required.

The technology to be a background of the present invention is disclosed in Korean Patent Publication No. 10-1462549, Korean Patent Publication No. 10-2015-0076381, Japanese Patent Application Laid-Open No. 2007-238878, and Korean Patent Laid-Open Publication No. 10-2014-0087636 Lt; / RTI >

KR 10-1462549 B1 KR 10-2015-0076381 A JP 2007-238878 A KR 10-2014-0087636 A

The present invention provides a sintering method and apparatus capable of reducing use of coal-based fuel and generation of pollutants by utilizing biomass.

The present invention provides a sintering method and apparatus capable of reducing use of coal-based fuel and generation of pollutants by replacing a part of solid fuel with biochar.

The present invention provides a sintering method and apparatus capable of reducing use of coal-based fuel and generation of pollutants by replacing a part of gaseous fuel with biogas.

A sintering method according to an embodiment of the present invention includes a step of preparing a compounding material; The process of preparing gaseous fuel; Charging the compounding material into a bogie moving in one direction; A step of moving the bogie in the order of an ignition period and a sintering period and heat-treating the blended raw material; And supplying the gaseous fuel to at least one of the ignition section and the sintering section, wherein the gaseous fuel contains biogas.

The process for preparing the compounding raw material includes the steps of preparing a raw material, an additive, and a coal-based solid fuel; The process of preparing woody solid fuel; And a step of preparing the blended raw materials by using the raw materials, additives, coal-based solid fuels and wood-based solid fuels.

The process for preparing the wood-based solid fuel includes the steps of drying and molding wood-based biomass; And carbonizing the biomass to produce a bio-tea.

The compounding raw material may contain 3 to 8% by weight of the woody solid fuel based on the total weight of the solid fuel mixed with the compounding raw material.

The process of preparing the gaseous fuel includes: preparing an organic waste in an oxygen-free atmosphere; Collecting the biogas generated from the organic waste; A process of preparing coal-based gaseous fuel; And mixing the coal-based gaseous fuel and the biogas.

The biogas may contain methane gas.

The gaseous fuel may contain from 3% to 8% by weight of the biogas based on the total weight of the gaseous fuel.

Wherein the step of supplying the gaseous fuel includes the steps of generating the flame by supplying the gaseous fuel to the ignition section; And spraying the flame to the blend material.

Wherein the sintering section includes a plurality of partial sections arranged in the one direction, and the step of supplying the gaseous fuel further comprises a step of supplying the gaseous fuel to at least one or more partial sections that are connected to the ignition section among the plurality of section sections And a process of supplying the product.

The amount of heat required to produce the sintered ores by sintering the compounding materials may be provided by the coal-based solid fuel, the wood-based solid fuel and the gaseous fuel.

A sintering apparatus according to an embodiment of the present invention includes: a plurality of bogies arranged in one direction so as to be movable and provided with a space in which a heat treatment material can be heat-treated; A hopper positioned above the bogie; An ignition spaced in one direction from the hopper above the bogie; And a fuel supply unit having a storage space for gaseous fuel containing biogas therein and connected to at least one of the bogie and the ignition path.

And a hood connected to the fuel supply unit, the fuel supply unit being connected to the bogie through the hood.

Wherein the gaseous fuel includes a coal-based gaseous fuel and the biogas, and the amount of heat required to produce the sintered ore by sintering the blending material is at least one of the coal-based gaseous fuel and the biogas, Solid fuel, wood-based solid fuel and gaseous fuel.

According to embodiments of the present invention, some of the solid fuels and gaseous fuels used as heat sources in the sintering process and equipment of various treatments can be replaced by biomass. Therefore, the use of the coal-based fuel can be reduced, and the generation of pollutants can be reduced.

For example, when applied to a sintering process of a steel mill, a part of the solid fuel and the gaseous fuel for sintering the blended raw materials can be replaced with biochar and bio gas, respectively. Accordingly, the use of coal-based fuel such as coke oven, anthracite coal, blast furnace gas (BFG) and coke oven gas (COG) can be reduced as compared with the prior art, and generation of pollutants such as carbon dioxide and oxides can be reduced.

1 is a view for explaining a sintering method according to an embodiment of the present invention.
2 is a table for illustrating a biomass according to an embodiment of the present invention.
3 is a view for explaining a sintering apparatus according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below, but may be embodied in various forms. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. In the meantime, the drawings may be exaggerated to illustrate embodiments of the present invention, wherein like reference numerals refer to like elements throughout.

Hereinafter, embodiments of the present invention will be described in detail with reference to the sintered-ore-making process and equipment of a steelworks. However, the present invention can be applied to a process and equipment for sintering various kinds of treatments.

FIG. 1 is a flow chart of a sintering method according to an embodiment of the present invention, FIG. 2 is an analysis table of composition of a biomass according to an embodiment of the present invention, and FIG. 3 is a schematic diagram of a sintering apparatus according to an embodiment of the present invention.

A sintering method according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG.

The sintering method according to the embodiment of the present invention includes a process of preparing a blend material, a process of preparing a gaseous fuel containing a biogas, a process of charging a blend material into a bogie moving in one direction, And a step of supplying gaseous fuel to at least one of the ignition section and the sintering section.

First, a blend material is prepared (S100). The process of preparing the raw material mixture may include a process of preparing a raw material, a subsidiary material and a coal-based solid fuel (S110), a process of preparing a wood-based solid fuel (S120), a process of preparing a raw material, an additive, a coal- And a process (S130) of producing a blended raw material.

The raw material may include iron ores and mined iron ores as raw materials containing iron components, and the subordinate may include limestone as an additive containing calcium carbonate. The coal-based solid fuel may comprise fractional coke and anthracite, and the wood-based solid fuel may comprise bio-car made from woody biomass. These solid fuels serve as a binder and as a heat source.

For example, powdered iron ore, limestone, coke, anthracite, and bio char may be prepared, mixed, and humidified, and granulated to a predetermined particle size, for example, 2 mm to 3 mm. The ingredients may be stored in a hopper.

At this time, the blended raw material may be assembled to contain wood based solid fuel in an amount of 3% by weight to 8% by weight based on the total weight of the blended solid fuel. For example, the woody solid fuel may contain 5% by weight based on the total weight of the solid fuel.

When the wood-based solid fuel is contained in an amount of less than 3% by weight, since the coal-based solid fuel as the relatively expensive solid fuel is used in an amount of 97% by weight or more, the cost reduction effect due to the use of the wood-based solid fuel may be insignificant.

In addition, when the wood-based solid fuel is contained in an amount exceeding 8% by weight, the coal-based solid fuel may not be supplied in a sufficient amount as required for sintering the raw material.

Meanwhile, the process of preparing the woody solid fuel may include a process of drying and molding the woody biomass, and a process of carbonizing the woody biomass to produce the bio-tea.

For example, a woody biomass may be prepared, dried and shaped to a predetermined particle size, charged into a carbonization chamber, and then carbonized for a predetermined time at a predetermined temperature range to produce biochips. Here, the woody biomass may include, for example, forest biomass such as forest waste wood, mounting wood chips, wood pellets, sawdust, trees, and waste wood. In this embodiment, as shown in FIG. 2, a wood biomass is exemplified by a first biomass, a second biomass, a third biomass, and a fourth biomass, and each of the wood chips, sawdust, And mixtures of woods, rice hulls. On the other hand, the detailed process for producing bio-tea using woody biomass is not particularly limited in the examples of the present invention.

Then, the gaseous fuel is prepared (S200). The process of preparing gaseous fuel includes a process of preparing organic waste in an anoxic atmosphere S210, a process of collecting biogas generated from organic wastes S220, a process of preparing coal-based gaseous fuel S230, (S240) of mixing the biogas, and may be stored in the fuel supply unit.

Gaseous fuels may include coal-based gaseous fuels and biogas. The coal based gaseous fuel may include blast furnace gas and coke oven gas, and the biogas may include methane gas produced by fermentation of the organic waste.

The gaseous fuel may contain from 3% to 8% by weight of the biogas based on the total weight of the gaseous fuel. For example, the biogas may be contained at 5% by weight based on the total weight of the gaseous fuel.

When the biogas is contained in an amount of less than 3% by weight, since the coal-based gaseous fuel of relatively high production cost is used in an amount of 97% by weight or more, the cost reduction effect due to the use of the biogas may be insignificant.

Further, when the biogas is contained in an amount of more than 8% by weight, the amount of coal-based gaseous fuel may be relatively low, so that the amount of heat required for sintering the raw material may not be sufficiently supplied.

For example, organic wastes (organic biomass) are prepared and fermented in an oxygen-free atmosphere, and biogas generated at this time can be collected and prepared. Organic wastes may include animal wastes and food wastes. The organic waste may also include livestock manure such as cattle, pigs, chickens, and ducks. In this embodiment, as shown in FIG. 2, a fifth biomass is illustrated, and the fifth biomass may include a step. On the other hand, the detailed process for producing bio-tea using woody biomass is not particularly limited in the examples of the present invention.

Meanwhile, the process (S100) for preparing the blend material and the process (S200) for preparing the gaseous fuel are not particularly limited to the above-mentioned order. These processes can be performed simultaneously, and the process of preparing the gaseous fuel may be performed first.

Thereafter, the compounding material is charged into the bogie moving or traveling in one direction of the conveyance path (S300). The process may include a process of charging the top light to a predetermined height to the carriage 100, and a process of filling the material mixture on the top light to form a raw material layer.

At this time, the height of the raw material layer to be formed and the mixing ratio of the raw materials and solid fuels contained in the raw material layer may vary depending on the component characteristics of the raw material of the raw materials and the quality of the desired sintered ores. The present invention is not limited to these examples.

Thereafter, the bogie is moved in the order of the ignition zone and the sintering zone, and the mixed material is heat-treated (S400). At this time, the gaseous fuel containing the biogas may be supplied to at least one of the ignition section and the sintering section (S500) to supply the amount of heat required for sintering the raw material layer.

For example, a flame is injected into a bogie running on an ignition section to ignite the flame on the solid fuel. Subsequently, the flame surface formed on the raw material layer is transferred from the upper part of the raw material layer to the lower part by sucking the inside of the carriage running on the sintering section, and the sintering is performed by heat treatment. At this time, the gaseous fuel containing the biogas may be supplied to the ignition furnace provided in the ignition section and used for forming the flame. That is, it is possible to generate a flame by supplying gaseous fuel to the ignition section during the ignition period, and to spray the produced flame to the mixture material.

Meanwhile, since the combustion zone inside the raw material layer moves from the upper part to the lower part of the raw material layer during the sintering, the temperature of the upper part of the raw material layer may be lower than the desired temperature after the combustion zone passes. In this case, a heat quantity imbalance may occur and the recovery rate and strength of the sintered ores formed on the raw material layer may be lowered.

Therefore, the gaseous fuel provided in the fuel supply section can be supplied to the hood provided above the sintering section, and the gaseous fuel containing the biogas can be smoothly supplied to the upper portion of the raw material layer using the hood. As the methane component of the gaseous fuel reacts with oxygen at least in the upper portion of the raw material layer to generate sufficient heat, the upper portion of the raw material layer can be supplied with a sufficient amount of heat. This makes it possible to uniformly control the amount of heat of the raw material layer and to improve the recovery rate and strength of the sintered ores that are sintered above the raw material layer. That is, the amount of heat required to produce the sintered ores by sintering the compounding materials is provided by coal-based solid fuel, wood-based solid fuel, coal-based gaseous fuel and biogas.

Meanwhile, the period during which the gaseous fuel is supplied may be at least one or more partial sections that are connected to the ignition section among the plurality of partial sections of the sintering section, and these sections may correspond to the heat quantity shortage section. That is, the gaseous fuel is supplied to at least one or more partial sections (in the heat quantity shortage section) which are connected to the ignition section among the partial sections of the sintering section.

after. The sintered ores that have been sintered are shaded to a predetermined particle size and cooled. The cooled sintered ores may be sorted by particle size and then supplied to a blast furnace or re-used as sintered blend material.

A sintering apparatus according to an embodiment of the present invention will be described with reference to FIG.

The sintering apparatus according to an embodiment of the present invention includes a plurality of bogies (100) arranged in one direction to be movable and having a space capable of being heat treated therein, a hopper (100) disposed above the bogie 200), an ignition path (300) spaced from the hopper (200) in one direction above the bogie (100), a storage space for containing gaseous fuel containing biogas is formed therein, And a fuel supply unit 400 connected to at least one of the fuel supply unit 300 and the fuel supply unit 400.

The one direction includes a direction in which the bogie 100 moves or travel in a state in which the bogie material is loaded. The blending raw material can be used as a raw material in a process for producing sintered ores, for example, an sintering process. The blending raw materials may include raw materials, additives, coal-based solid fuels and wood-based solid fuels. The blending raw materials may be prepared by mixing and heating raw materials, additives, coal-based solid fuels and wood-based solid fuels, and they may be assembled to a size of about 2 mm to 3 mm. The compounding material may be charged to a predetermined height inside the carriage 100 to form a raw material layer.

The raw material may include iron ores and mined iron ores as raw materials containing iron components, and the subordinate may include limestone as an additive containing calcium carbonate. The coal-based solid fuel may comprise fractional coke and anthracite, and the wood-based solid fuel may comprise bio-car made from woody biomass. These solid fuels serve as a binder and as a heat source.

The carriage 100 is arranged in one direction so as to be movable in one direction, and a space capable of heat-treating the raw material mixture can be provided therein. The inside of the bogie 100 is opened upward, so that the bogie material can be dropped inside the bogie 100.

A plurality of trucks 100 are connected to each other and connected to each other through an endless structure, for example, to form an upper transport path and a lower transport path. The carriage 100 travels the conveying path in one direction, receives the blending material, enters the conveying path in the conveying path, and distributes the sintered light in the inside thereof to the crushing unit (not shown) And can be returned to the conveying path.

The transfer path may include a plurality of sections arranged in one direction, and may include, for example, a charging section, an ignition section, and a sintering section. These sections may be arranged in the order of charging section, ignition section and sintering section based on one direction.

The charging section is a section where the blend material is loaded on the carriage 100 to form a raw material layer. The ignition section is a section in which the flame is sprayed to the raw material layer. The sintering section moves the flame from the upper part to the lower part of the raw material layer, The sintered body may be sintered. The hopper 200 may be disposed in the charging section, and the ignition furnace 300 may be disposed in the ignition section.

The hopper 200 may be located above the transport path. The mixing material can be stored in the hopper 200. A drum feeder is provided at a lower portion of the hopper 200, and a chute is provided at a lower portion of the drum feeder.

The drum feeder controls the number of revolutions and controls the mixing raw material to be smoothly loaded, and the chute slopes the mixing raw material obliquely so that the raw material is charged into the inside of the carriage 100 in a vertically segregated manner.

An upper light hopper (not shown) may be provided on the upper side of the conveyance path spaced apart from the hopper 200 in the opposite direction. The upper light may include sintered ores having a particle size of 8 mm to 15 mm, for example. The upper light is supplied to the pallet and the grate bar of the bottom 100 of the carriage 100 in advance so as to prevent the blending material from adhering to the pallet and the grate bar of the bottom 100 of the carriage 100, And is charged inside.

The ignition furnace 300 may be located above the transfer path spaced from the hopper 200 in one direction. The ignition furnace 300 may be formed to enable the flame to be injected into the lower conveyance path. The flame is ignited by the coal-based solid fuel and the wood-based solid fuel contained in the raw material layer to form a combustion surface. The combustion surface can be moved in the direction from the upper portion to the lower portion of the raw material layer so that the raw material can be sintered.

The fuel supply unit 400 has a storage space for gaseous fuel containing biogas therein and is connected to at least one of the bogie 100 and the ignition furnace 300 to supply the gaseous fuel. For example, the fuel supply unit 400 may be connected to the bogie 100 and the ignition furnace 300, respectively, to supply the gaseous fuel to each of the bogie 100 and the ignition furnace 300. The gaseous fuel supplied to the ignition furnace 300 can be used for generating flames and the gaseous fuel supplied to the bogie 100 can be directly supplied to the raw material layer and used for reducing the temperature deviation between the upper and lower portions of the raw material layer. That is, the amount of heat required to produce the sintered ores by sintering the compounding materials can be provided by coal-based solid fuel, wood-based solid fuel, coal-based gaseous fuel, and biogas.

Gaseous fuels may include coal-based gaseous fuels and biogas. The coal based gaseous fuel may include blast furnace gas and coke oven gas, and the biogas may include methane gas produced by fermentation of the organic waste.

A hood 500 may be provided on the upper side of the conveyance path spaced from the ignition furnace 300 in one direction. The hood 500 may be connected to the fuel supply unit 400. The fuel supply unit 400 can be connected to the bogie 100 by the hood 500 and can supply the gaseous fuel to the raw material layer. That is, the inside of the hood 500 can be opened so as to face the lower conveying path, and the gaseous fuel can be injected from the fuel supply unit 400 to the side of the vehicle 100 running on the conveying path .

A crushing unit (not shown) may be provided at a position apart from the sintering zone on the opposite side of the ignition zone with respect to the sintering zone. The sintered sintered light which passes through the sintering section in one direction can be supplied to the crushing section by being lighted from the truck 100 while the truck 100 enters the return path from the conveyance path. The crushing part serves to crush the light-distribution sintered ores to a predetermined particle size.

A plurality of windboxes 600 may be disposed in the lower part of the conveying path and may be continuously arranged in one direction. The wind box 600 may be connected to the inside of the carriage 100 and may form a negative pressure to draw in the inside of the carriage 100. A flow toward the lower part of the raw material layer is formed in the inside of the carriage 100 by the windmill 600 so that the flame surface propagates along the raw material layer and the raw material can be sintered.

An exhaust unit 700 is connected to the wind box 600. The exhaust unit 700 may include an exhaust chamber 710, a dust collector 720, a blower 730, and an exhaust port 740. The exhaust unit 700 serves to apply a strong suction force by providing negative pressure to the windbox 600. The exhaust gas generated during sintering by the exhaust part 700 can be exhausted.

The exhaust chamber 710 has a passage through which the exhaust gas passes. The exhaust chamber 710 may be connected to each of the windboxes 600. The dust collector 720 is connected to the end of the exhaust chamber 710 to remove dust mixed in the exhaust gas. The blower 730 is connected to a dust collector 720 to direct the flow of the exhaust gas. The exhaust port 740 exhausts the exhaust gas to the outside air.

In the embodiment of the present invention, the amount of the coal-based solid fuel and the coal-based gaseous fuel can be partially substituted in the production of the sintered ores by using the biocide obtained from the woody biomass and the biogas obtained from the organic biomass . Accordingly, the generation of pollutants generated from coal-based fuels can be reduced, and the amount of carbon dioxide used can be reduced. Particularly, the bio-tea produced from the woody biomass has a calorific value greater than the calorific value (4500 kcal / kg) of the ordinary wood chips and has a considerable energy accumulation effect, and thus can be suitably used as a heat source have.

It should be noted that the above-described embodiments of the present invention are for the purpose of illustrating the present invention and not for the purpose of limitation of the present invention. In addition, it should be noted that the configurations and the methods disclosed in the above embodiments of the present invention may be combined with each other or applied cross-over to form a variety of different forms, and these variations may be regarded as the scope of the present invention. As a result, the present invention may be embodied in various other forms without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents are intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. .

100: Truck 200: Hopper
300: by ignition 400: fuel supply part
600: wind box 700: exhaust part

Claims (13)

A process of preparing a raw material mixture;
The process of preparing gaseous fuel;
Charging the compounding material into a bogie moving in one direction;
A step of moving the bogie in the order of an ignition period and a sintering period and heat-treating the blended raw material;
And supplying the gaseous fuel to at least one of the ignition section and the sintering section,
Wherein the gaseous fuel contains biogas. The method according to claim 1,
The process for preparing the compounding raw material may include:
A process of preparing raw materials, additives and coal-based solid fuels;
The process of preparing woody solid fuel;
And a step of preparing the compounding material by using the raw material, the subordinate material, the coal-based solid fuel, and the woody solid fuel. The method of claim 2,
The process for preparing the wood-based solid fuel includes:
The process of drying and molding the woody biomass;
And carbonizing the biomass to produce a bio-tea. The method of claim 2,
Wherein the blended raw material contains 3 to 8 wt% of the wood based solid fuel based on the total weight of the solid fuel mixed with the blended raw material. The method according to any one of claims 1 to 4,
The step of preparing the gaseous fuel includes:
The process of preparing organic wastes in an anaerobic atmosphere;
Collecting the biogas generated from the organic waste;
A process of preparing coal-based gaseous fuel;
And mixing the coal-based gaseous fuel and the biogas. The method according to any one of claims 1 to 4,
Wherein the biogas contains methane gas. The method according to any one of claims 1 to 4,
Wherein the gaseous fuel contains from 3% to 8% by weight of the biogas based on the total weight of the gaseous fuel. The method according to any one of claims 1 to 4,
The step of supplying the gaseous fuel includes:
Generating a flame by supplying the gaseous fuel to the ignition section;
And spraying the flame to the blend material. The method according to any one of claims 1 to 4,
Wherein the sintering section includes a plurality of partial sections arranged in the one direction,
The step of supplying the gaseous fuel includes:
And supplying the gaseous fuel to at least one or more partial sections of the plurality of partial sections connected to the ignition section. The method of claim 2,
Wherein the amount of heat required to produce the sintered ores by sintering the compounding material is provided by the coal-based solid fuel, the wood-based solid fuel, and the gaseous fuel. A plurality of bogies arranged in one direction so as to be movable and provided with a space for heat-treating the blended raw materials therein;
A hopper positioned above the bogie;
An ignition spaced in one direction from the hopper above the bogie;
And a fuel supply unit having a storage space for gaseous fuel containing biogas therein and connected to at least one of the bogie and the ignition furnace. The method of claim 11,
And a hood connected to the fuel supply unit, the fuel supply unit being spaced apart from the ignition conduit in one direction,
And the fuel supply unit is connected to the carriage through the hood. The method of claim 11,
The blending raw materials include raw materials, additives, coal-based solid fuels and wood-based solid fuels,
Wherein the gaseous fuel comprises a coal-based gaseous fuel and the biogas,
Wherein the amount of heat required to produce the sintered ores by sintering the compounding material is provided by the coal-based solid fuel, the wood-based solid fuel and the gaseous fuel.

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