JPH11158476A - Production of fuel from waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently treat waste water produced from a process for producing a fuel from wastes. SOLUTION: A dry waste gas 19 from a drier 27 is subjected to hear exchange by means of a heat exchanger 43 to recover its heat, and the moisture contained in the waste gas 19 is recovered as condensed water 77. The condensed water 77 is sent to a wet-process waste water treatment equipment 71, where it is separated into clean water and contaminants. The clean water is discharged as such, and the separated contaminants (sludge) 74 are dehydrated in a dehydrator 72 to be separated into a dehydrated liquid 76 and a dehydrated cake 75. The dehydrated cake 75 is sent to the drier 27. The dehydrated liquid 76 is returned to the equipment 71. Further, also the waste water 79 in a refuse pit 21 is sent to the equipment 71, where it is treated in a similar manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing fuel from waste, and more particularly, to a process for producing fuel from waste, which is used for deodorizing water and moisture recovered from waste and exhaust gas from a dryer. The present invention relates to a method for effectively processing deteriorated activated carbon and converting it to fuel to improve production efficiency.

[0002]

2. Description of the Related Art Moisture contained in exhaust gas generated when drying waste (general refuse) cannot be released as it is because it is highly contaminated by dirt. The temperature is lowered, the water in the exhaust gas is converted into condensed water, and then the treatment such as combustion is performed. At the same time, sewage discharged from waste such as a garbage pit may be treated by combustion or the like. Further, the exhaust gas after recovering the evaporated water is deodorized by a deodorant such as activated carbon.

[0003]

The conventional treatment of waste water and exhaust gas has the following problems. Combustion equipment is required to perform processing such as combustion,
Further, in the combustion treatment, not only the wastes are burned but also the water is re-evaporated, so that the fuel cost increases, which is economically disadvantageous. It requires treatment of main ash and fly ash generated during combustion, which increases the cost of treatment. Further, equipment for collecting fly ash is also required, which complicates the equipment, increases costs, and is economically disadvantageous. . The odor of the exhaust gas after collecting the evaporated water and the odor of the waste in the plant is deodorized by installing a deodorizing device using activated carbon, but the degraded activated carbon is treated as landfill without being reused. However, there is a problem that it is difficult to secure landfill.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems and to efficiently treat degraded activated carbon used for deodorization and waste in wastewater collected from waste and dried exhaust gas. The present invention provides a method for producing fuel from fuel.

[0005]

According to the first aspect of the present invention,
Primary crushing of waste, then drying the primary crushed waste, then sorting combustibles from the dried waste, compression-molding the sorted combustibles into solid fuel from waste In the fuel production method, the dried exhaust gas of the waste is heat-exchanged for heat recovery, moisture in the exhaust gas is collected as condensed water, pollutants are separated from the condensed water, and the separated pollutants are burned. It is characterized by being reused as a product.

According to a second aspect of the present invention, in the method according to the first aspect, the odor generated from the dried exhaust gas, the waste and the solid fuel is removed using activated carbon, and the deteriorated activated carbon is removed from the flammable carbon. It is characterized by being reused as a product.

[0007]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a flowchart according to an embodiment of the method of the present invention, and FIG. 2 is a process diagram showing a process of separating general waste and converting it into combustible fuel according to an embodiment of the method of the present invention. 1 to 15 in FIGS.
Corresponds to the numbers 1 to 15 in the following steps. The steps enclosed by a dotted frame in FIG. 1 indicate steps that can be deleted.

[0008] 1 From the waste pit 21 to the primary crushing equipment 23
(Garbage) transported to the crusher 23 is primarily crushed. 22 is a garbage crane. The primary crushed waste is conveyed to the dryer 27 by the conveyors 24 and 56. Most of the garbage is collected in bags or the like, and the contents of the garbage are large. Therefore, even if the garbage is put into a sorting machine as it is, flammable materials and incombustible materials cannot be separated. Therefore, the refuse is finely crushed by the primary crushing equipment 23 described above. As the primary crushing equipment 23 used for the primary crushing, for example, a biaxial shearing crusher having a rotary blade is used.

The particle size after the primary crushing is preferably about 50 mm or less, and preferably about 95% or less that can pass through a 50 mm mesh screen. However, since it is difficult to specify the physical properties of the refuse, it is desirable to use the above-described twin-shaft crusher to cope with metal lump and the like. In addition, the twin-shaft crusher uses a rotary blade (screw).
Since the material is sheared between the crushers, there is a characteristic that garbage such as cloth and wire is crushed into strips and becomes long string-like garbage due to its characteristics. . The rotary shaft of the rotary blade of the second (lower) crusher rotates the first rotary blade in order to efficiently crush the trash that has fallen as a string from the first (upper) crusher. It may be arranged at an angle of about 90 degrees to the axis. Furthermore, 1
The blade width of the rotary blade in the first stage is preferably about 50 mm or more and about 25 mm or less in the second and subsequent stages. In addition, it is desirable that refuse to be fed into the crusher be supplied in a fixed amount in order to enhance the crushing ability of the crusher. If hazardous materials are mixed in depending on the quality of the waste, a device to sort dangerous materials before crushing will be installed. Also,
Hand sorting or the like may be used to remove dangerous goods.

2 Immediately after the primary crushing, the refuse is dried by a dryer 27. 49 is a hot blast stove, 46 is a fuel tank,
51 and 69 are pumps, 50 is a fuel service tank, 25
Is an induction fan, and 26 is a dryer cyclone. Drying is performed until the water content becomes about 10% or less in order to prevent RDF from spoiling. By doing so, it is possible to reduce the collection rate due to the accumulation of refuse in the equipment, and it is also effective in suppressing the plant odor. In addition, by drying, garbage is separated, and subsequent separation can be performed with high accuracy. In addition, when the moisture content is about 10% or less from the beginning due to the dust quality, the drying step may be omitted.

3 The dried refuse is conveyed by a conveyor 47 to a vibrating conveyor 28 where it is loosened and uniformly supplied to an oscillating sorter 29. The dried garbage is in a state of being separated and easy to separate, but in order to further improve the accuracy of separation, a dryer 27 is used.
To disperse garbage coming out of
It is desirable to install the vibration conveyor 28 by all means.

Next, the dried waste is separated into a hard and heavy waste 18, a small-sized waste 16 and a soft and light waste 17 by an oscillating sorter 29. The oscillating type sorting device 29 is a device that sorts using a difference in repulsive force of a substance, and an inclined plate (screen) having a sieve hole oscillates, and among the refuse put on the plate, Since the soft and light refuse 17 is hard to repel, the refuse 17 is conveyed upward inclining by the plate. Many are paper, cloth and film plastics. Since the hard and heavy debris 18 is likely to repel, it repels the plate and falls downward. Many are metals, rigid plastics and corrugated paper. Also, due to the sieve holes opened in the plate, the finely crushed small particle dust 16 passes through the sieve holes and falls under the plate. Most of the small particle size refuse 16
Light garbage such as kitchen garbage, paper and plastic, metal such as bolts and nuts, and glass fragments. The rate of falling dust can be changed by changing the inclination angle of the plate or the number of rotations of the swinging motion. The inclination angle is about 0
9 degrees, the rotation speed of the rocking motion is about 103 to 206 rpm, and the size of the sieve hole of the plate is about 20 to 50 mm. In the case where there are few small-sized particles such as kitchen garbage due to the refuse, the plate may not have sieve holes.

5 Most of the refuse sent upward on the slope is soft and light refuse 17, but a small amount of aluminum pieces or the like may be mixed. In order to increase the separation accuracy, it is desirable to remove incombustibles using a wind separator. The wind speed is desirably 10 m / s or more. However, depending on the waste quality,
Alternatively, in the case where the non-combustible material is less mixed, such as when the tilting angle of the oscillating separation device is about 6 degrees or more, the rotation speed is about 150 rpm or less, and the sieve hole size of the plate is about 20 mm or more, the wind separator is used. It is not necessary. 5 is omitted from FIG.

6. Thereafter, when recovering metals such as iron, it is desirable to install a sorter suitable for each. For example, a magnetic separator is used for recovering iron, an aluminum separator is used for recovering aluminum, and a SUS separator is used for recovering stainless steel. 6 is omitted in FIG.

7 The soft and light refuse 17 sorted by the oscillating sorter 29 is secondarily crushed by the secondary crusher 30, passed through the secondary crusher induction fan 31, the secondary crusher cyclone 37, and the conveyor 54. Transported to The soft and light refuse sent upward on the slope can be further crushed to increase granulation, reduce the load on the granulator, and avoid equipment trouble after the sorter due to entanglement of string-like refuse. desirable. It is necessary to set a string removing device to avoid troubles on the downstream side due to entanglement of string-like refuse. The secondary crusher 30
It is desirable to install a single-shaft rotary crusher capable of finely crushing a cord-like cloth.

8 From the small particle size dust 16 dropped through the sieve hole under the plate of the oscillating sorter 29, it is conveyed to the wind separator 34 by the conveyor 53 in order to further improve the sorting accuracy, where the Is removed. The wind speed is desirably 10 m / s or more. However, when there is little incombustibles due to the quality of the refuse, it is not necessary to perform the wind separation. The combustibles are conveyed to the conveyor 54 via the wind separator cyclone 36.

[9] Thereafter, when collecting metals such as iron, it is desirable to install a sorter suitable for each. For example, a magnetic separator is used for recovering iron, an aluminum separator is used for recovering aluminum, and a SUS separator is used for recovering stainless steel. 9 is omitted from FIG.

10 Most of the refuse falling down the plate of the oscillating sorter 29 is hard and heavy refuse 18 which is likely to repel, but is a composite of incombustible material such as metal and combustible material such as hard plastic. It is. Then, in order to further increase the separation accuracy, the hard and heavy refuse 18 is returned to the primary crushing equipment (double-shaft crusher) 23 by a conveyor 61 or the like,
The crushing particle size can be reduced again by the primary crushing equipment 23.
By repeating this step once or a plurality of times, almost all of the refuse is converted into a material having a small particle size. The hard and easily repelled refuse thus reduced in particle size is conveyed to the wind separator 34 by the conveyor 53 together with the small-particle waste 16 described above, where the combustibles are separated by wind and separated from the residue. It is conveyed to the conveyor 54 via the selection cyclone 36. 3
3 is a bag filter, 32 is an induction fan, and 64 is a container. On the other hand, the incombustibles sorted by the wind sorter 34 are collected in the container 65.

Before re-input to the primary crushing equipment 23, a wind separator, a magnetic separator for recovering iron, an aluminum separator for recovering aluminum, and a SUS separator for recovering stainless steel. May be installed to collect incombustibles such as metals. Further, in the case of a wind separator, the adjustment of the waste quality and the amount of circulated waste is desirably adjustable by a mechanism for adjusting the air flow and the like.

11 The refuse of the above steps 7 and 8 is collected in the hopper 62 by the conveyor 54 after being subjected to the wind separation and the secondary crushing, thereby suppressing harmful gas during RDF combustion,
Slaked lime supplied from the slaked lime feeder 39 is added to prevent DF decay, and is uniformly mixed by the mixer 40. In the case where no harmful gas is generated due to the quality of the refuse or the refuse does not rot, it is not necessary to add an additive and mix.

12 Next, in order to improve the transportability and the storage property, the solid fuel (R
DF). Then, the RDF is transported by the conveyor 55 to be packed 66.

13 Since the solid fuel is discharged at a high temperature of about 50 ° C. or more, if the solid fuel is packed as it is, the RD
Since water adheres to F, molds are generated, and RDF decays, it is desirable to cool at room temperature using a cooling device. In the case of garbage that does not decay due to the quality of the garbage, a cooling device may not be necessary. 13 is omitted in FIG.

14 The dried exhaust gas 19 of the dryer 27 exchanges heat with the heat exchanger 43 to recover heat, and at the same time, the moisture contained in the exhaust gas 19 is recovered as condensed water 77. 44 is a cooling tower, and 82 is a pump. The condensed water 7
Numeral 7 is sent to a wet wastewater treatment facility 71, where biological treatment such as activated sludge method or rotating plate contact method, or chemical treatment such as acid value / reduction with chemicals, oxidation with ozone or ultraviolet light, etc. The purified water is separated into pollutants and purified water, and the purified water is discharged (see reference numeral 78, and 81 is a discharge pump). Separated pollutants (sludge) 74
Is dried again and turned into a solid fuel as combustible material. At this time, in order to reduce the load on the dryer 27, the sludge 74 is dehydrated by the dehydrator 72 to form a dewatered cake 75, and then sent to the dryer 27. The dewatering liquid 76 obtained by dewatering the dewatering cake 75 is returned to the wet wastewater treatment equipment 71. In addition, garbage pit 21
Wastewater 79 is also sent to the wet wastewater treatment equipment 71 (80 is a water supply pump) and can be treated similarly. In addition, it is also possible to treat in-plant drainage (not shown) and the like in the same manner.

15 As the deodorization of the gas after recovering the evaporated water from the drying exhaust gas 19 from the dryer 27 in the heat exchanger 43, the odor is removed by a deodorizing device 42 using activated carbon 73 or the like. Device induction fan 52
Is released to the atmosphere. The odor generated from the RDF (see reference numeral 66) packed in the process 12 is removed by the deodorizing device 5.
9 to deodorize. 58 is a bag filter, 67 is a container, and 60 is a fan for inducing the deodorizing device. Deodorizing device 4
The activated carbon 73 adsorbed and degraded by use in 2 and 59 is sent to the process 11 (hopper 62) without being disposed of, and is converted into solid fuel (RDF).

[0025]

As described above, according to the present invention, water (waste) recovered from heat of dried exhaust gas from a dryer after primary crushing of waste (general waste) and waste from waste pits are obtained. Wastewater such as sewage is separated from pollutants by wet effluent treatment equipment, and the separated pollutants (sludge) are converted to solid fuel (RDF) using waste combustible solid fuel (RDF) process.
The activated carbon used for odor removal can also be converted to RDF in the same manner, and effective treatment of waste water and degraded activated carbon generated in the fuel production process from waste can be achieved. The facility used can be installed at low cost and is economically advantageous, thus providing useful effects.

[Brief description of the drawings]

FIG. 1 is a flowchart according to an embodiment of the method of the present invention.

FIG. 2 is a process diagram showing a general waste separation and combustible fuel conversion process according to an embodiment of the method of the present invention.

[Explanation of symbols]

 1 to 15: Process of the present invention 16: Small particle size waste 17: Soft and difficult to repel 18: Hard and heavy waste 19: Exhaust gas 21: Waste pit 22: Waste crane 23: Primary crushing equipment 24: Conveyor 25: Induction fan 26: Dryer cyclone 27: Dryer 28: Vibrating conveyor 29: Oscillating sorter 30: Secondary crushing equipment 31: Secondary crushing equipment induction fan 32: Fan 33: Bag filter 34: Wind separator 36: Wind separator Machine cyclone 37: Secondary crushing equipment cyclone 39: Slaked lime 40: Mixer 41: Compression molding device 42: Deodorizing device 43: Heat exchanger 44: Cooling tower 46: Fuel tank 47: Conveyor 49: Hot air stove 50: Fuel service tank 51: Pump 52: Deodorizing device inducing fan 53-57: Conveyor 58: Bag filter 59: Deodorizing device 60 Deodorizing device induction fan 61: Conveyor 62: Hopper 64, 65: Container 66: RDF packaging 67: Container 69: Pump 71: Wet wastewater treatment equipment 72: Dewatering device 73: Activated carbon 74: Sludge 75: Dewatering cake 76: Dewatering liquid 77 : Condensed water 78: Discharge 79: Garbage pit drainage 80, 81, 82: Pump

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kuniichi Okuyama 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Inside Nihon Kokan Co., Ltd.

Claims (2)

[Claims] The present invention relates to a solid fuel, comprising: firstly crushing waste; drying said firstly crushed waste; selecting a combustible from the dried waste; compressing and molding the selected combustible; In the process of producing fuel from waste
Heat exchange and heat recovery of the dried exhaust gas of the waste, as well as collecting water in the exhaust gas as condensed water, separating pollutants from the condensed water, and reusing the separated pollutants as the combustibles. A method for producing fuel from waste. 2. An odor generated from the dry exhaust gas, the waste and the solid fuel is removed using activated carbon,
The method for producing fuel from waste according to claim 1, wherein the deteriorated activated carbon is reused as the combustible.