JP2000283433A - Method and system for treating waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a treatment amount of waste per unit time by eliminating to burn gasified gas of waste by a boiler for commercial use and to improve the energy utilizing efficiency of the waste. SOLUTION: Waste H is carbonized, char (carbide) T and coal C are mixed together and by burning the mixture in a boiler 1 for commercial use of a thermal power generating device. This method described above comprises a gasifying process wherein by partially burning the waste H by a gasifying furnace 6, gasified gas B containing chlorine and char T are generated; a separation process wherein pulverized char T mixed in the gasified gas B is separated, and the char T and the coal C are mixed together; and a chlorine removing process wherein the gasified gas B is burnt after the separation process is burnt and at least a chlorine content is removed from combustion gas G by a chlorine removing device 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a system for treating waste by carbonizing the waste and burning the carbide in a thermal power plant such as a boiler for a coal-fired business or a coal gasification facility. In addition, the present invention relates to a technique of burning in a thermal power generator with part of chlorine contained in waste removed. In this specification, waste is used to include municipal waste such as paper and waste plastic, and biomass-based industrial waste such as straw, wood chips and waste pulp.

[0002]

2. Description of the Related Art In recent years, it has been proposed to reuse municipal waste such as paper and waste plastic, and biomass-based industrial waste such as straw, wood chips and waste pulp as various fuels. It is expected that the energy utilization efficiency of the product will increase. For this reason, boiler power generation using a garbage incinerator has also been proposed, but hydrogen chloride generated during garbage incineration corrodes the boiler tubes, making it impossible to operate the boiler under severe conditions, and the garbage contains a lot of moisture. Therefore, the power generation efficiency is poor due to the low combustion temperature.
Furthermore, disposal of ash generated by garbage incineration requires enormous costs and is not economical.

[0003] Therefore, it is conceivable to use the waste as fuel for a coal-fired business boiler or a coal gasification facility already installed in a thermal power plant, thereby eliminating the need for an incinerator for waste treatment. However, it is difficult to put waste directly into such commercial boilers. This is because commercial boilers and the like are difficult to directly burn waste due to the structure of the burner and the like, and the quality of fuel is strictly controlled to control exhaust gas and prevent corrosion of boiler tubes. The problem is that it is not possible to deal with unstable urban garbage.

Japanese Patent Application Laid-Open No. Hei 10-244176 discloses a technique in which organic waste such as waste plastic is used as fuel for a coal-fired boiler. This is because the organic waste is previously stored in an oxygen-deficient atmosphere for 200 to 50 days.
Heat treatment in a temperature range of 0 ° C., the gas generated by this heat treatment is burned in a boiler, and after the heat treatment, solids (so-called carbides mainly composed of carbon) pulverized by a roller mill are mixed with coal as fuel. And burn it in a boiler.

[0005]

By the way, in the above-mentioned waste, chlorine existing in a high molecular chlorine resin such as vinyl chloride and chlorine existing in sodium chloride and calcium chloride are included. Yes (the former is referred to as organic chlorine and the latter is referred to as inorganic chlorine for the sake of convenience in the present specification), and it can be considered that these organic chlorine and inorganic chlorine are present in a ratio of about half. The pyrolysis gas generated in the process of heat treatment of the waste, that is, carbonization by pyrolysis, contains 80 to 90% of the organic chlorine as hydrogen chloride, and this pyrolysis gas is used for business such as thermal power plants. If a large amount is burned in a boiler or the like, the burner may malfunction or the boiler tube may be corroded, so that only a small amount can be burned.

On the other hand, the carbides obtained after the heat treatment of wastes are similar in properties such as the calorific value, specific moisture, and volatility to coal, so that, for example, a fuel such as an existing coal-fired boiler for a thermal power plant is used. It is possible to mix in and burn. However, most of the inorganic chlorine remains in the carbonized waste, and although the properties such as the calorific value are similar to coal, they differ in that they contain much more chlorine than coal. I have. Therefore, if this carbide is used as fuel for a commercial boiler, the same causes the malfunction of the burner and the corrosion of the boiler tube as described above, so that it can be mixed into the coal little by little.

[0007] As described above, in view of the fact that chlorine has a great effect on fuel whose quality is strictly controlled, such as a boiler for a coal-fired business, waste is subjected to heat treatment, and the heat treatment process is performed. In order to properly burn the pyrolysis gas and carbide generated in the above in a commercial boiler, waste (pyrolysis gas and carbide) should be mixed with coal in order to avoid malfunction of the burner and corrosion of the boiler tube. Just one
%, And the chlorine content in the whole must be made very small. As a result, the amount of waste processed per unit time is reduced, and the above-described improvement in the energy use efficiency of garbage cannot be achieved.

Further, since chlorine is contained in exhaust gas after combustion in a commercial boiler, it is necessary to add a chlorine removal function to an exhaust gas treatment facility in order to satisfy exhaust gas regulations. However, adding a chlorine removal function to a large exhaust gas treatment facility in order to remove a small amount of chlorine contained in the exhaust gas is not preferable in terms of cost. In addition, dust generated in the process of treating flue gas from a coal-fired boiler can be reused on the premise that it can be obtained by burning only coal. Such as the need to remove chlorine from dust,
This will reduce the value of dust recycling.

The present invention solves the above-mentioned problems, and a gasification gas generated by pyrolysis in a process of carbonizing waste is burned in a commercial boiler or a coal gasification facility (or a waste heat recovery boiler). To reduce the amount of chlorine input to commercial boilers, etc., thereby increasing the amount of waste processed per unit time and improving the energy use efficiency of garbage And

[0010]

In order to achieve the above object, the invention according to claim 1 is characterized in that waste is carbonized, the carbide is mixed with coal, and the waste is combusted by a thermal power plant to dispose of the waste. A gasification step of producing gaseous gas containing chlorine and carbide by partially burning waste in a gasification furnace, and a fine powdery state mixed in the gasified gas. A technique including a separation step of separating carbides and mixing the carbides with coal, and a chlorine removal step of burning a gasified gas after the separation step to remove at least chlorine from the combustion gas are employed. In this waste treatment method, the gasified gas is burned and treated not by a commercial boiler or a coal gasification facility of a thermal power plant, but by another device, so that the organic chlorine contained in the gasified gas is reduced. As much carbon is burned in the commercial boiler as it is not put into the commercial boiler, etc., thereby increasing the amount of waste processed per unit time and improving the energy use efficiency of waste. It becomes possible to plan. Further, since the chlorine content in the combustion gas is removed in the chlorine removal step, at least a part of the chlorine content contained in the waste is efficiently removed. In addition, since the gaseous gas is burned after separating the fine powdery carbides mixed in the gasified gas, it is possible to avoid the influence of the carbide at the time of burning the gasified gas and to carry out stable combustion. At the same time, it is possible to reduce the adverse effect on the combustion burner.

According to a second aspect of the present invention, in the waste disposal method of the first aspect, a technique is used in which the combustion gas is used as a heat source of a device requiring a heat source such as a dryer. In this waste treatment method, the combustion gas obtained by burning the gasified gas is used as a heat source for other equipment. Therefore, by replacing the heating equipment required for other equipment with the heating equipment required for other equipment, the cost of the equipment can be reduced and the waste energy can be used. Efficiency can be improved.

The invention according to claim 3 is the invention according to claim 1 or 2
In the waste treatment method described above, a technique is employed in which chlorine is removed by adding slaked lime to the combustion gas in the chlorine removal step. In this waste treatment method, slaked lime is added to the combustion gas to produce organic chlorine (hydrogen chloride) in the combustion gas.
And slaked lime (calcium hydroxide) are reacted with each other to remove the reactant, thereby efficiently removing chlorine from the combustion gas.

According to a fourth aspect of the present invention, there is provided a system for treating waste by carbonizing waste, mixing the carbide with coal, and combusting the coal with a thermal power generator, wherein the waste is partially burned. A gasification furnace that produces a gaseous gas containing chlorine and carbides by doing so, a separation device that separates fine powdery carbides mixed in the gasification gas and mixes the carbides with coal, and a separation device. A technology including a chlorine removing device that burns the gasified gas that has passed to remove at least chlorine from the combustion gas is applied. In this waste treatment system, the gasified gas from the gasification furnace is burned in a facility other than the commercial boiler or coal gasification facility of the thermal power plant, so the organic chlorine contained in the gasified gas is transferred to the commercial boiler, etc. It is possible to increase the amount of waste per unit time and improve the energy use efficiency of waste by increasing the amount of waste that can be burned in a commercial boiler, etc. Become. Further, since the chlorine content in the combustion gas is removed by the chlorine removal device, at least a part of the chlorine content contained in the waste is efficiently removed. In addition, since the fine powdery carbides mixed in the gasified gas are removed by the separation device, it is possible to avoid the influence of the carbides during the combustion of the gasified gas, to carry out stable combustion, and to use a combustion burner or the like. It is possible to reduce the adverse effect on the environment.

According to a fifth aspect of the present invention, in the waste treatment system according to the fourth aspect, when the exhaust gas treatment device provided in the thermal power generation device has a chlorine removal function, the technology using the exhaust gas treatment device as the chlorine removal device is applied. Is done. In this waste treatment system, when an exhaust gas treatment device attached to a commercial boiler or the like of a thermal power plant has a chlorine removal function, chlorine in combustion gas can be removed using the exhaust gas treatment device. In addition, there is no need to separately install a chlorine removing device, and the cost can be reduced by simplifying the present system.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. The waste treatment system shown in FIG.
Municipal waste such as paper and waste plastic, and biomass-based industrial waste (waste in this specification) such as straw, wood chips, and waste pulp are burned by the coal-fired boiler 1 of the thermal power generation device X1. It is to let. FIG. 1 shows a flow chart of the waste treatment, in which the solid arrows indicate the flow of solids, and the dotted arrows indicate the flow of gas. First, a thermal power generation device X1 shown in FIG. 1 is schematically configured by a mill 2, a commercial boiler 1, and an exhaust gas treatment device 3. The coal-fired business boiler 1 provided in the thermal power generation device X1 includes, for example, a pulverized coal-fired boiler, a stoker-fired boiler, and a fluidized-bed boiler, all of which use coal as a fuel.

The pulverized coal-fired boiler employs a method in which coal C taken out of a coal bunker (not shown) is pulverized into fine powder by a mill 2 and blown into the furnace from a burner with primary air to perform floating combustion. As a result, the combustion gas has a long residence time, the unburned portion is low, and high combustion efficiency can be realized.

The stoker-fired boiler employs a method in which coal is sprayed on a grate by a sprayer. By spraying new coal thinly and widely on coal that is drying and burning while floating, it is easy to use. Ignites and burns, and relatively stable combustion is obtained with coal which is difficult to ignite. The stoker-fired boiler does not need to pulverize the coal C into fine powder, so that the mill 2 is unnecessary.

The fluidized-bed boiler forms a fluidized bed by flowing sand (bed material) scorched by air supplied from an air distribution plate installed at the lower part of the combustion furnace in the furnace, and puts the fluidized bed into the fluidized bed. It employs a method that instantaneously dries and ignites the fuel that has been burned, efficiently burning the bed material with a long residence time, and burning all types of coal including low-grade coal. It is not necessary to pulverize the coal C into fine powder even in the fluidized-bed boiler, so the mill 2 is unnecessary.

Then, a steam turbine (not shown) is rotated by steam generated by the commercial boiler 1, and power is generated by a generator (not shown) connected to the steam turbine. The exhaust gas discharged from the commercial boiler 1 is treated by the exhaust gas treatment device 3 and then released to the atmosphere. The exhaust gas treatment device 3 includes, for example, a dust collector such as a gas cooling tower and a cyclone, a denitration device employing a dry ammonia catalytic reduction method, a desulfurization device employing a high temperature dry or wet limestone gypsum method, and the like. The dust (coal ash) separated by the exhaust gas treatment device 3 is reused in various ways.

Next, a description will be given of a system for treating waste using the above-mentioned business boiler 1. Waste H
Is first introduced into the crusher 4 and crushed. At this time,
The waste is crushed to about 150 mm or less in order to increase the thermal efficiency in the gasification furnace 6 described later. Then, the crushed waste H is put into the dryer 5 and efficiently dried (removed of water), and then sent to the gasification furnace 6.

Normally, the waste H has a water content of about 30% to 60%.
This is because the gasification efficiency is likely to be reduced, and the gasification efficiency may be reduced by moisture. However, in the type using a fluidized bed as the gasification furnace 6 as will be described later, the water can be easily evaporated from the input waste H. No improvement in efficiency can be expected. Therefore, whether or not the waste H crushed in the present system is dried by the dryer 5 is optional. However, for example, if the gasification furnace 6 does not use a fluidized bed, the gasification efficiency may be improved by drying the waste H. In this case, the installation of the dryer 5 is effective. When treating the waste H having a relatively small water content, it is needless to say that the waste H can be naturally dried or can be directly charged into the gasification furnace 6.

FIG. 2 is a schematic view showing an example of the gasification furnace 6 and shows a type using a fluidized bed. In the gasification furnace 6, an air distribution plate 62 is installed in a furnace body 61, and a waste input port 63, a bed material input port 64, and a gas exhaust port 65 are provided above the air distribution plate 62. An air supply port 66 is provided below the dispersion plate 62. Then, the bed material such as sand is charged onto the air distribution plate 62 from the bed material input port 64 and the air is supplied from the air supply port 66, so that the air is dispersed and ejected from the air distribution plate 62, and the bed material flows. The fluidized bed 67 is formed in the state.

At the time of normal operation, the fluidized bed 67 is in a burning state. In this state, when the waste H is introduced into the furnace body 61 from the waste inlet 63, the waste H is Combustion is caused by the air fed from the air distribution plate 62 together with the flow of the bed material. At this time, the air distribution plate 62
As an air supply amount from the air, for example, an air ratio of 1.0 to 1.3
By supplying air so that the waste H is partially burned (normal combustion is about 1.7 to 1.8), the waste H is partially burned (incompletely burned), and the combustible gasified gas B such as carbon monoxide is discharged.
And a char (carbide) T (gasification step).
The gasification furnace 6 continuously heats the fluidized bed 67 by the heat of the partial combustion of the waste H, and thus does not require a heat source. Further, the gasification furnace 6 is not limited to a type using a fluidized bed as shown in FIG. 2, but various combustion furnaces capable of partially burning waste H can be applied.

The gasification furnace 6 generates the gasification gas B and the char T by partially burning the waste H as described above, and discharges the gasification gas B from the gas discharge port 65.
At this time, the char T flows together with the bed material in the fluidized bed 67 to be further crushed into a fine powder, and this fine char T is mixed with the gasified gas B in the flow of the gasified gas B. Is discharged from the gas discharge port 65. It has been described above that in the waste H, the organic chlorine such as vinyl chloride and the inorganic chlorine such as sodium chloride are present in approximately half the ratio. Then, about 90% of the organic chlorine is contained in the gasification gas B as hydrogen chloride, and the remaining organic chlorine and inorganic chlorine remain in the char T without being decomposed even after the partial combustion. Has become.

In some cases, non-combustible materials such as aluminum cans, iron cans, rubble, and metal wires are mixed in the waste H.
These incombustibles are crushed by the crusher 5 and then charged into the gasification furnace 6 as they are, stay with the fluidized bed 67 while flowing, and discharged from the furnace body 61 together with the discharge of the bed material. The fluidized bed 67 discharges a new bed material from the furnace body 61 periodically or as appropriate while adding a new bed material to the bed material inlet 6.
It has been replaced by being charged from 4 and non-combustibles are collected by utilizing the discharge of the bed material.

Returning to FIG. 1, the gasification gas B discharged from the gasification furnace 6 is sent to the separation device 7. The separation device 7
For example, a fine powder T mixed in the gasified gas B is separated by a dust collector such as a cyclone.
Is mixed into coal C (separation step). In addition, as the separation device 7, a function of separating and removing an oil component from the gasified gas B can be added. The separated oil component is used as various fuels such as burners.

The char T separated from the gasified gas B by the separator 7 is sent to the storage tank W and stored therein. The char T is taken out therefrom by a predetermined amount and is used as fuel for the thermal power generator X1 (business boiler 1). When mixed with coal C, it is burned together with coal C in the commercial boiler 1. However, whether or not the char T is stored in the storage tank W is optional. For example, the char T from the separation device 7 can be directly mixed into the coal C. When the commercial boiler 1 is a pulverized coal-fired boiler, if the char T is already pulverized, it is not necessary to grind the coal T with the coal C in the mill 2. For example, the char T is mixed into the coal C on the downstream side of the mill 2. You may make it do.

Here, as described above, since most of the inorganic chlorine remains in the char T, it cannot be mixed with the coal C in a large amount. However, as described later, the gasification gas B
Is processed through a different route from Char-T, and the commercial boiler 1
Since the amount of chlorine that can be put into the commercial boiler 1 is determined because it is not burned in
% Of the gas T can be mixed into the coal C as much as the amount of the gasified gas B having no gas is burned in the commercial boiler 1, and as a result, the throughput of the waste H per unit time is approximately doubled. Become.

Further, the dust taken out of the exhaust gas treatment device 3 has little influence on the subsequent treatment because the chlorine in the whole is very small. Therefore,
The existing dust treatment facility can be used as it is, and costs can be reduced, as compared with the case where disposal of ash generated when waste is incinerated in an incinerator is expensive.

Subsequently, the gasified gas B passing through the separation device 7
Is sent to the combustion furnace 8 and burned to generate combustion gas (hot air). The combustion furnace 8 burns the gasified gas B with a burner to generate a combustion gas G. The combustion gas G is used as a heat source of a device requiring a heat source such as the dryer 5 and other auxiliary devices. Can be This eliminates the need for a heat source for the device such as the dryer 5 and can reduce the cost of the system. However, the combustion gas G may not be used as a heat source of the dryer 5 or the like, but may be sent to the downstream chlorine removing device 11 via a bypass. The gasifier 6 does not require a heat source,
The combustion gas G may be supplied to the gasification furnace 6 and used as a heat source for heating the fluidized bed 67.

Subsequently, the combustion gas G is sent to the chlorine removing device 9. Since the combustion gas G contains about 90% of the organic chlorine as hydrogen chloride, it cannot be released to the atmosphere as it is. The chlorine removing device 9 includes a slaked lime charging device 10, a dust collector 11 such as a cyclone, a gas cooling tower (not shown), and the like.
The chlorine content is converted into calcium chloride by adding slaked lime to the wastewater, and this is collected by a dust collector 11 downstream to remove the chlorine content from the combustion gas G (chlorine removal step).

However, the chlorine removing device 9 is not limited to this, and various devices capable of removing chlorine from the combustion gas G are applied. The combustion gas G from which chlorine has been removed by the chlorine removing device 9 is treated as exhaust gas. That is, the exhaust gas is treated by the denitration device 12 or the like so as to comply with the exhaust gas regulations and the like, and is then released into the atmosphere.

FIG. 3 shows another embodiment of the chlorine removing device 9. In FIG. 3, when the exhaust gas treatment device 13 of the commercial boiler 1 has a dechlorination function, the combustion gas G is directly sent to the exhaust gas treatment device 13, where chlorine is removed and then released to the atmosphere. I have to. Thus, when the exhaust gas treatment device 13 of the commercial boiler 1 has a dechlorination function, it is not necessary to use a dedicated chlorine removal device 9 as shown in FIG.
This simplifies the system and reduces costs. The exhaust gas treatment device 13 includes a gas cooling tower, a dust collector, a denitration device, a desulfurization device, and the like, similarly to the exhaust gas treatment device 3 of FIG.

FIG. 4 shows another embodiment of the waste treatment system (flow diagram of waste treatment). FIG.
Also, the solid arrows indicate the flow of solids, and the dotted lines (including the one-dot chain line and the two-dot chain line) indicate the flow of gas. As a difference from FIG. 1, FIG. 1 shows a coal-fired commercial boiler 1
4 is different from the thermal power generator X1 using the coal gasification facility 15 in FIG. The thermal power generator X2 shown in FIG. 4 is a so-called coal gasification combined cycle power generation facility, and includes a mill 14, a coal gasifier 15, a gas purifier 16, a gas turbine 17, a generator 18, a compressor 19, and an air separator 20. , An exhaust heat recovery boiler 21, a steam turbine 22, a condenser 23, and an exhaust gas treatment device 24.

First, coal C, which is a fuel, is pulverized into fine powder by a mill 14 (however, the installation of the mill 14 is optional) and charged into a gasification furnace (not shown) of a coal gasification facility 15. Is done. Then, the coal C is gasified in the coal gasification facility 15, and as the coal C, low-grade coal to anthracite can be gasified in the same furnace.

Meanwhile, gasification of coal C is performed by
By supplying approximately half the amount of oxygen required for complete combustion of the coal C to the gasifier, the coal C is partially burned to produce a high-temperature, high-pressure flammable gas mainly composed of carbon monoxide and hydrogen. This is a process for generating F. At this time, by adding water to the coal C to form a fuel slurry, water in the slurry reacts with carbon to cause a water gasification reaction, thereby promoting gasification. The ash generated in the coal gasification facility is discharged as glassy slag.

The high-temperature and high-pressure combustible gas F generated in the coal gasification facility 15 is sent to a gas purification unit 16. The gas purification device 16 includes a desulfurization device such as a desulfurization tower for collecting sulfur content, a dust removal device such as a filter, and the like.
The flammable gas F is subjected to a high-temperature dry treatment. In the gas purifier 16, the foreign matter removed from the combustible gas F by the dust remover is discharged as dust.

The combustible gas F purified by the gas purifier 16 is supplied to the gas turbine 17 at a high temperature and a high pressure. The gas turbine 17 has a rotating shaft 17 a connected to a generator 18, and drives the generator 18 via the rotating shaft 17 a by receiving combustion gas energy of the combustible gas F to generate power. I do. At the same time, the compressor 1 disposed on the rotating shaft 17a of the gas turbine 17
9 is driven to compress the air and send it to the air separation device 20. The air separation device 20 generates oxygen for partially burning coal in the coal gasification facility 15, and a high-pressure cryogenic separation method of separating compressed air into oxygen and nitrogen using a rectification column is applied. The generated oxygen is supplied to the gasifier of the coal gasifier 15.

The combustible gas F after driving the gas turbine 17 is sent to the exhaust heat recovery boiler 21 and burned by a burner or the like and used as a heat source of the exhaust heat recovery boiler 21. The steam generated in the exhaust heat recovery boiler 21 is sent to a steam turbine 22 disposed on a rotating shaft 17a of the gas turbine 17 to rotate the steam. Therefore, when the steam turbine 22 rotates, the generator 18 is driven via the rotating shaft 17a,
Generate electricity.

The steam after driving the steam turbine 22 is
The heat is exchanged with the cooling water in the condenser 23 to become ascites and returned to the exhaust heat recovery boiler 21. Further, a part of the ascites cooled by the condenser 23 is sent to the coal gasification facility 15 and turns into steam using the coal gasification facility 15 (gasification furnace) as a heat source. The steam is sent to the steam turbine 22. Like that.

As described above, the thermal power generation device X2 generates power by the generator 18 by the rotation of the gas turbine 17 due to the pressure of the flammable gas F and the rotation of the steam turbine 22 due to the steam. The steam obtained by burning the combustible gas F and using the gasifier of the coal gasification facility 15 as a heat source is further used as a steam turbine 22.
, It is possible to generate power with high thermal efficiency and high efficiency.

The exhaust gas discharged from the exhaust heat recovery boiler 21 is treated by an exhaust gas treatment device 24 and then released to the atmosphere. The exhaust gas treatment device 24 includes, for example, a gas cooling tower, a dust collector, a denitration device, a desulfurization device, and the like, like the exhaust gas treatment device 3 shown in FIG. Also, the dust (coal ash) separated by the exhaust gas treatment device 24 is reused in various ways.

As shown in FIG. 4, in the thermal power plant X2 described above, the coal C, which is the fuel of the gasification furnace of the coal gasification facility 15, is separated from the gasification gas B by the separation device 7. The obtained char (carbide) T can be mixed. The steps up to the generation of the char T mixed into the coal C are the same as those shown in FIG. Further, the point that the char T can be mixed into the coal C on the downstream side of the mill 14 is the same as the thermal power generation device X1 shown in FIG.

As described above, although a large part of the inorganic chlorine remains in the char T, the gasified gas B is not burned in the gasification furnace of the coal gasification facility 15 or the exhaust heat recovery boiler 21, so that the coal T Assuming that the amount of chlorine that can be supplied to the gasification furnace of the gasification facility 15 is determined, the amount of the char T (approximately double) is increased by not supplying the gasification gas B having about 90% of organic chlorine. Can be mixed with coal C, so that the throughput of waste H per unit time is approximately doubled.

Further, not only the coal gasification equipment 15 but also the gas purification equipment 16, the gas turbine 17, and the exhaust heat recovery boiler 21 which are downstream equipment are affected by the corrosion by chlorine and the like. Since the gasified gas B is not supplied to the thermal power generation device X2 when the doubled char T is mixed with the coal C, adverse effects such as corrosion by chlorine components on these downstream devices do not increase. Further, dust extracted from the exhaust gas treatment device 24 is shown in FIG.
As in the case of the exhaust gas treatment device 3 shown in (1), since chlorine in the entire ash is very small, there is almost no effect on subsequent treatment. Therefore, the existing dust treatment facility can be used as it is in comparison with the treatment of ash generated from the incinerator,
Costs can be reduced.

It should be noted that the shapes, combinations, and the like of the components shown in the above-described embodiment are merely examples, and various changes can be made based on design requirements without departing from the spirit of the present invention.

[0047]

As described above, in the waste disposal method according to the first aspect, the gasified gas is treated by being burned not by a commercial boiler or a coal gasification facility of a thermal power plant but by another device. As a result, organic chlorine contained in the gasified gas is not injected into the commercial boiler, etc., and as much carbon can be burned in the commercial boiler, etc., thereby reducing waste per unit time. And the efficiency of waste energy utilization can be improved. further,
Since chlorine in the combustion gas is removed in the chlorine removal process,
At least a part of the chlorine contained in the waste is efficiently removed. In addition, since the gaseous gas is burned after separating the fine powdery carbides mixed in the gasified gas, it is possible to avoid the influence of the carbide at the time of burning the gasified gas and to carry out stable combustion. At the same time, adverse effects on the combustion burner can be reduced.

According to the second aspect of the present invention, since the combustion gas obtained by burning the gasified gas is used as a heat source of another device, the cost of the device can be reduced by substituting a heating device required for another device. And the energy use efficiency of the garbage can be improved.

According to a third aspect of the present invention, there is provided a waste disposal method, wherein slaked lime is added to a combustion gas to react organic chlorine (hydrogen chloride) and slaked lime (calcium hydroxide) in the combustion gas. By removing it, the chlorine content can be efficiently removed from the combustion gas.

According to the fourth aspect of the present invention, since the gasification gas from the gasification furnace is combusted by means other than the commercial boiler or the coal gasification equipment of the thermal power generation apparatus, the organic system contained in the gasification gas is burned. Chlorine is not injected into a commercial boiler, etc., and more carbon can be burned in the commercial boiler, etc., thereby increasing the amount of waste processed per unit time and improving the energy use efficiency of garbage. Improvement can be achieved. Further, since the chlorine content in the combustion gas is removed by the chlorine removal device, at least a part of the chlorine content contained in the waste is efficiently removed. In addition, since the fine powdery carbides mixed in the gasified gas are removed by the separation device, it is possible to avoid the influence of the carbides during the combustion of the gasified gas, to carry out stable combustion, and to use a combustion burner or the like. Adverse effects can be reduced.

According to a fifth aspect of the present invention, in the case where an exhaust gas treatment device attached to a commercial boiler or the like of a thermal power generation device has a chlorine removal function, the waste gas treatment system uses the exhaust gas treatment device. Since chlorine in the interior can be removed, there is no need to separately install a chlorine removal apparatus, and the cost can be reduced by simplifying the present system.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an embodiment of a waste treatment system according to the present invention.

FIG. 2 is a perspective view showing an example of a gasification furnace.

FIG. 3 is a flowchart showing another embodiment of the chlorine removing apparatus.

FIG. 4 is a flowchart showing another embodiment of the waste disposal system according to the present invention.

[Explanation of symbols]

 C Coal H Waste T Char (Carbide) X1, X2 Thermal power plant B Gasification gas G Combustion gas 1 Commercial boiler 3, 13, 24 Exhaust gas treatment device 6 Gasification furnace 7 Separation device 9 Chlorine removal device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junya Nishino 1st Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishikawashima-Harima Heavy Industries, Ltd. (72) Inventor Mori Ishino 3-2 Toyosu, Koto-ku, Tokyo No. 16 Ishikawajima Harima Heavy Industries, Ltd.Toyosu General Office (72) Inventor Norio Ayabe 1 Shinnakahara-cho, Isogo-ku, Yokohama, Kanagawa Prefecture Ishikawashima Harima Heavy Industries, Ltd.Technical Research Institute (72) Inventor Kenichi Tahara Yokohama, Kanagawa Prefecture No. 1 Shin-Nakahara-cho, Isogo-ku Ishi Kawashima-Harima Heavy Industries, Ltd. F-term (Reference) 3K061 AA24 AB02 AC01 AC13 BA05 CA08 FA07 3K065 AA24 AB02 AC01 AC13 BA05 CA02 CA04 CA14 DA04 JA05 JA20 3K078 AA05 BA09 BA26 CA22 CA24 CA25

Claims (5)

[Claims] 1. A method of treating waste by carbonizing waste, mixing the carbide with coal, and burning the mixture with a thermal power generator, wherein the waste is partially burned in a gasification furnace. A gasification step of producing a gaseous gas containing chlorine and carbide by the method, a separation step of separating fine powdery carbide mixed in the gasification gas and mixing the carbide with coal, A chlorine removal step of burning the gasified gas after the step to remove at least chlorine from the combustion gas. 2. The waste treatment method according to claim 1, wherein the combustion gas is used as a heat source of equipment requiring a heat source such as a dryer. 3. The waste disposal method according to claim 1, wherein in the chlorine removing step, slaked lime is added to the combustion gas to remove chlorine. 4. A system for treating waste by carbonizing waste, mixing the carbide with coal, and burning the mixture with a thermal power generator, wherein chlorine is reduced by partially burning the waste. A gasification furnace that generates a gasified gas and carbides containing the gas, a separation device that separates fine powdery carbide mixed in the gasification gas and mixes the carbide with coal, and a gas that has passed through the separation device. A waste gas treatment system, comprising: a chlorine removal device that burns a chemical gas to remove at least chlorine from the combustion gas. 5. An exhaust gas treatment device provided in the thermal power generation device having a chlorine removal function, the exhaust gas treatment device is used as the chlorine removal device.
Waste treatment system as described.