JP2000160176A - Treatment of refuse solid fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which treatment can be carried out without requiring a special treatment facility even if the refuse solid fuel is the refuse solid fuel containing noxious materials. SOLUTION: A refuse solid fuel is dry distilled and the resultant dry distilled material is utilized as a raw material for a sintering machine in an iron manufacturing process. Contained combustibles are carbonized by carrying out the dry distillation treatment of the refuse processed fuel and most of volatile organic components and chlorine causing the production of dioxins are removed. As a result, the resultant material can be utilized as a raw material for the sintering machine in the iron manufacturing process. Since equipment for removing noxious materials in a waste gas is installed in a waste gas treatment system of the sintering machine, the noxious materials contained in the gas produced from the dry distilled material of the refuse solid fuel are removed by the equipment. The noxious materials contained in the ash component are fixed in a sintered ore and finally converted into a slag (detoxified) in a blast furnace.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for treating solid fuel waste.

[0002]

2. Description of the Related Art Combustible waste is solidified so that it can be reused as a fuel resource, that is, solid waste (RD)
F) is regarded as a promising alternative to fossil fuels because of its storability, transportability, and property stability, and its use as boiler fuel, cement raw fuel, power generation fuel, and the like is being studied.
For example, Japanese Patent Application Laid-Open No. Hei 9-072521 discloses a system in which RDF can be used as a fuel for power generation and at the same time can be rendered harmless.

[0003]

However, in recent years, its use has been restricted due to impurities contained in solid waste such as chlorine, ash, heavy metals and the like. That is, deterioration of cement quality due to chlorine in refuse solid fuel, deterioration of boiler water pipe corrosion and power generation efficiency due to the presence of HCl (hydrogen chloride) in combustion gas, and dioxin contained in combustion exhaust gas and dust. The problem has been pointed out. In addition, final disposal of ash containing heavy metal as a by-product is also required separately, and additional facilities and processes such as exhaust gas treatment, dust and ash treatment are required separately in order to effectively utilize solid waste fuel.

[0004] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method capable of treating waste solid fuel containing harmful substances without requiring a special treatment facility. Make it an issue.

[0005]

A first means for solving the above-mentioned problems is to solidify refuse solid fuel and to use the obtained dry-distillate as a raw material for a sintering machine in an iron making process. (Claim 1).

[0006] The combustibles contained by carbonization of the waste processing fuel are carbonized, and volatile organic components and chlorine which cause dioxin formation are mostly removed. As a result, it can be used as a raw material for a sintering machine in an iron making process. The exhaust gas treatment system of the sintering machine is equipped with equipment that removes harmful substances from the exhaust gas.Hazardous substances contained in the gas generated from the dry distillate of refuse solid fuel are removed by these equipment. You. Further, the harmful substances contained in the ash component are fixed to the sintered ore, and finally converted into slag (detoxification) in the blast furnace. When used as a raw material for a sintering machine, it can be used as a mixture with at least one of a raw material for coke sintering and coke powder.

[0007] A second means for solving the above-mentioned problems is as follows.
The first means, wherein a combustible gas generated when carbonizing the refuse solid fuel is used as a heat source for carbonization or a process heat source in a steel mill (claim 2).
It is.

[0008] The combustible gas generated during carbonization of refuse solid fuel can be recycled and used as a heat source for carbonization. Since this gas contains harmful substances such as chlorine, a device for removing these harmful substances is necessary for use. Further, a harmful substance removing device for exhaust gas from the carbonization device is also required. If the generated combustible gas is recycled and used as a heat source for carbonization, the harmful substance removing device for combustible gas can be omitted.

Further, this combustible gas can be used as a heat source in various processes (blast furnace, coke oven, sintering oven, etc.). Since these steelmaking processes are provided with high-performance exhaust gas treatment equipment, there is no need to separately provide exhaust gas treatment equipment for removing harmful substances contained in combustible gas.

[0010] A third means for solving the above problems is as follows.
The first means or the second means, wherein after combusting a combustible component in a combustible gas generated when dry solidifying the refuse solid fuel, the exhaust gas is diffused into a sintering machine exhaust gas. (Claim 3).

In the exhaust gas system of the sintering machine, a high-performance harmful substance treatment device and a dust removal device are provided. By discharging the exhaust gas into the exhaust gas flue of the sintering machine, it is possible to treat harmful substances and dust without providing a special exhaust gas treatment facility.

[0012]

Next, an embodiment of the present invention will be described in detail. Waste solid fuel (RDF) is produced by crushing, drying and molding general waste and industrial waste, and is composed of combustibles and non-combustibles. Although this ratio largely depends on the quality of the refuse used as a raw material, combustibles are mainly paper and plastic, and non-combustibles are metals, sand, and the like. When the solid refuse fuel is used as a boiler fuel or a power generation fuel, the calorific value of the combustible component is used.

The most characteristic feature of the present embodiment is that, when using garbage solid fuel as fuel, there is no need for separate processing equipment and associated exhaust gas processing equipment, and expensive processing such as dust and ash processing. It can be processed by simple preprocessing. That is, combustibles contained by carbonization of RDF are carbonized, and volatile organic components and chlorine which cause dioxin formation are mostly removed. As a result, it can be used as a heat source for a sintering machine in an iron making process. In the sintering machine, the ash component is fixed to the sinter and finally converted into slag (detoxification) in the blast furnace. The sintering machine is equipped with exhaust gas treatment equipment, and it can process large quantities. In some cases, harmful substances contained in the carbonized matter can be treated without providing special equipment.

Lignite, pitch, waste plastic, waste paper, etc. may be added as a third component to the refuse solid fuel. The dry distillation is performed in an inert atmosphere. Oxygen may be present, but treatment in an inert atmosphere suppresses carbonaceous combustion. As a result, the yield of the distillate and the ratio of carbonaceous matter in the distillate can be increased, and the generation of dioxin can be suppressed. Further, the carbonization may be performed in the presence of steam.

As the carbonization furnace, a general industrial furnace can be used. For example, a rotary kiln, a fluidized-bed furnace, a coke oven, or the like may be used. The carbonization temperature is 400 ° C or higher and 1000 ° C or lower, preferably 6 ° C.
It is not less than 00 ° C and not more than 800 ° C. If the temperature is lower than 400 ° C., volatile components causing dioxin formation remain. Further, the temperature may be 1000 ° C. or more, but there is no effect on the increase in the amount of heat input. In addition, there is a possibility of operational trouble due to melting of some ash components. The carbonization time is not particularly limited, but it is necessary that the inside of the refuse solid fuel has reached a predetermined temperature.

It is preferable that the obtained dry-distilled product is pulverized if necessary. By pulverizing, improvement in dispersibility at the time of mixing the raw materials and prevention of segregation can be expected. The pulverized particle size is preferably 5 mm or less, particularly preferably 1 mm or less. However, in consideration of the pulverizing treatment, it is generally sufficient that the above-mentioned particle size component is contained in a certain ratio. For example 0.8mm
The pulverization may be such that the following particle size components are contained in an amount of 80% or more by weight. Furthermore, it is also possible to remove ash by specific gravity separation or the like after pulverization.

The carbonized material is put into a sintering bed from a hopper together with a sintering raw material. Thereafter, air is supplied from above, and the carbonized matter is burned by ignition, and powdered iron ore or the like is sintered by the combustion heat, and finally, a sintered ore is generated. The ash contained in the carbonized product is fixed in the sintered ore and fixed in the slag in the blast furnace.

The combustible gas generated at the time of carbonization can be used as a heat source for carbonization or a process heat source in an ironworks, which is preferable. Heat sources in steelworks are used in blast furnaces, coke ovens, metal heating ovens, heat treatment ovens and incinerators.

When the combustible gas produced contains chlorine, dust, tar components and the like and cannot be used effectively, organic compounds which cause dioxin formation, especially oils such as tar, are burnt in advance. By removing the flammable gas, it becomes possible to mix these combustible gases into the sintering flue gas and treat them with an electric dust collector or the like. Since the temperature of the exhaust gas from the sintering machine is high, generation of dioxin does not occur. In addition, high-performance harmful substance treatment equipment and dust removal equipment are provided in the flue gas of the sintering machine. And dust processing can be performed.

As described above, the present invention is a system in which the problem of impurities in the prior art is solved, solid waste fuel can be effectively used as solid fuel, and no expensive treatment is required.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. Waste solid fuel used (RD
Table 1 shows the property values of F).

[0022]

[Table 1]

Example 1 This RDF was carbonized in an electric tubular furnace shown in FIG. In FIG. 1 is a quartz glass tube, 2 is an electric heater, 3 is a thermocouple, 4 is a nitrogen gas, 5
Represents a carbonization exhaust gas, 6 represents an RDF, and 7 represents a temperature controller. Put RDF6 in a quartz glass tube and put nitrogen gas 4 from above
The RDF 6 was heated at a heating rate of 10 ° C./min to 600 ° C. by a heating rate of 10 ° C./min. The yield of the obtained dry distillate was 30%, and the ash content measured by JIS M 8812 was 44%.

Example 2 A carbonized product was obtained in exactly the same manner as in Example 1 except that the carbonization temperature was 800 ° C. The yield of the obtained dry distillate was 25.4%, and the ash content measured by JIS M 8812 was 51.5%.

(Example 3) RDF was carbonized in an externally heated rotary kiln furnace. Nitrogen atmosphere in furnace, 800 temperature
C. was maintained. RDF was introduced at a rate of 10 kg / h from the furnace introduction section, and the residence time was set at 30 minutes to carry out dry distillation. The yield of the obtained dry distillate was 26%, and the ash content measured by JIS M 8812 was 49%.

The sintering test apparatus shown in FIG. 2 was used to evaluate whether the dry distillates obtained in Examples 1 to 3 can be used in place of coke breeze as a heat source in a sintering machine. . In FIG. 2, 8 is an ignition furnace, 9 is an ignition burner, 10 is a pan, 11 is a wind box, and 12 is a blower.
The RDF carbonized matter put together with the ore in the pan 10 is ignited by the ignition burner 9 of the ignition furnace 8, and the air above the pan 10 is sucked into the pan 10 by the blower 12 through the wind box 11. The combustion exhaust gas is sucked from 10 into the wind box 11. Thus, a sintered ore is produced.

The sintering powder coke was replaced with a calorie equivalent. As a result, the product properties of the obtained sintered ore were comparable to those of all the distillates, even when the coke powder for sintering was replaced with almost 100% RDF.

(Comparative Example 1) Using a sintering test apparatus shown in FIG. 2, RDF was not subjected to dry distillation treatment, and was evaluated in place of coke breeze which is a heat source in a sintering machine. Components causing dioxin generation, such as chlorine, tar, chlorobenzene, and chlorophenol, were measured from the exhaust gas.

Comparative Example 2 A carbonized product was obtained in exactly the same manner as in Example 1 except that the carbonization temperature was 400 ° C. The yield of the obtained dry distillate was 47.8%, the ash content measured by JIS M 8812 was 29.0%, and the volatile content was 43%. Almost no chlorine was measured in the exhaust gas, but components causing dioxin production, such as tar, chlorobenzene, and chlorophenol, were measured.

[0030]

As described above, in the invention according to claim 1 of the present invention, the combustibles contained by carbonization are carbonized, and volatile organic components and dioxins are formed. Chlorine is largely removed. As a result, it can be used as a raw material for a sintering machine in an iron making process. The exhaust gas treatment system of the sintering machine is equipped with equipment that removes harmful substances from the exhaust gas.Hazardous substances contained in the gas generated from the dry distillate of refuse solid fuel are removed by these equipment. You. Therefore, the solid waste fuel can be effectively utilized without requiring a special treatment device.

In the invention according to the second aspect, if the generated combustible gas is recycled and used as a heat source for dry distillation, the harmful substance removing device for combustible gas can be omitted. If flammable gas is used as a heat source in various processes (blast furnace, coke oven, sintering oven, etc.),
There is no need to separately provide an exhaust gas treatment facility for removing harmful substances contained in combustible gas.

In the invention according to claim 3, the exhaust gas treatment equipment of the sintering machine can be used, and the ash is made harmless as slag in the blast furnace. Hazardous substances and dust can be treated.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of an electric furnace for carbonizing RDF.

FIG. 2 is a view showing an outline of a test apparatus for evaluating the adsorbent substitute performance of adsorbent in a sintering machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Quartz glass tube 2 ... Electric heater 3 ... Thermocouple 4 ... Nitrogen gas 5 ... Carbonization exhaust gas 6 ... RDF 7 ... Temperature controller 8 ... Ignition furnace 9 ... Ignition burner 10 ... Pan 11 ... Wind box 12 ... Blower

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tatsuro Ariyama 1-2-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 4H012 HA01 KA04 4H015 AA01 AA02 AA17 AB01 BA01 BA08 BA12 BB03 CA03 CB01

Claims (3)

[Claims] 1. A method for treating refuse solid fuel in which refuse solid fuel is carbonized, and the obtained carbonized product is used as a raw material for a sintering machine in an iron making process. 2. The method for treating solid fuel according to claim 1, wherein the combustible gas generated when carbonizing the solid fuel is used as a heat source for carbonization or a process heat source in an ironworks. 3. The sintering machine according to claim 1, wherein after combustible components in the combustible gas generated when the refuse solid fuel is carbonized are burned, the exhaust gas is diffused into the sintering machine exhaust gas. The solid waste fuel treatment method according to the above.