JP7584783B2 - Apparatus and method for pyrolysis of organic waste - Google Patents

Description

The present invention relates to a pyrolysis device and a pyrolysis method for pyrolyzing organic waste and recovering pyrolyzed charcoal from the organic waste.

Patent Document 1 describes a conventional pyrolysis device that pyrolyzes organic waste and recovers pyrolyzed carbonized material from the organic waste. The pyrolysis device includes an inner container for pyrolyzing the organic waste contained therein, and an outer container for heating the inner container, and is heated while being rotated around the axis of the inner container to perform pyrolysis.

JP 2005-255841 A

However, the pyrolysis device described in Patent Document 1 had a problem in that air (oxygen) was mixed in when the organic waste was put into the inner container, causing the carbonized material to be recovered to become oxidized.

In view of the above, the present invention aims to provide a pyrolysis device that can suppress the oxidation of the recovered carbonized material.

The pyrolysis apparatus according to the present invention is a pyrolysis apparatus including a dry distillation tank for dry distilling organic waste, an input device for inputting the organic waste into the dry distillation tank, a heating furnace for heating the dry distillation tank in order to dry distill the organic waste, and a recovery device for recovering a carbonized material produced by the dry distillation of the organic waste,
The feeding device is characterized in that it is a screw pump.

According to the pyrolysis device of the present invention, organic waste fed into the dry distillation tank is heated by a heating furnace that heats the dry distillation tank, and is dry distilled (pyrolyzed) by heating to produce carbonized material. The carbonized material can be reused as fuel, a soil conditioner, or a water purifier. The organic waste to be dry distilled is fed into the dry distillation tank by pumping with a screw pump. The organic waste is degassed by pumping with the screw pump, and is dry distilled in a state where air (oxygen) has been removed. Therefore, the carbonized material produced by the dry distillation of the organic waste can be one in which oxidation has been suppressed.

Here, in the above pyrolysis apparatus, the device that supplies the organic waste to the screw pump (hereinafter referred to as the "first screw pump") that feeds the organic waste into the dry distillation tank can be configured as a screw pump (hereinafter referred to as the "second screw pump").

By this, the organic waste is degassed by the pumping of the second screw pump, so that the air (oxygen) is removed, and is further degassed by the pumping of the first screw pump, so that the waste is dry-distilled in a state in which the air (oxygen) has been further removed. As a result, the carbonized material produced by the dry distillation of the organic waste can be made to be one in which oxidation is further suppressed.

In the pyrolysis apparatus, a supply port through which the organic waste is supplied to the first screw pump and a delivery port of the second screw pump that delivers the organic waste to the supply port are connected by a connecting pipe;
a gate valve for regulating the movement of the organic waste is provided on the supply port side and the delivery port side of the connecting pipe,
The connecting pipe may be provided with a degassing device.

According to this, a gate valve that regulates the movement of organic waste is provided on the supply inlet side and the discharge outlet side of the connecting pipe, and a degassing device is provided in the connecting pipe, so that the organic waste inside the connecting pipe can be isolated and degassed by closing the gate valve and operating the degassing device. Therefore, the carbonized material produced by the dry distillation of the organic waste can be more inhibited in oxidation.

The pyrolysis device may also be configured so that the connecting pipe is provided with an inlet for injecting nitrogen gas.

This allows nitrogen gas to be filled into the degassed organic waste inside the connecting pipe. This makes it possible to further suppress oxidation of the carbonized material produced by dry distillation of the organic waste.

The pyrolysis device may also be configured to include an air guide tube that guides the dry distillation gas produced by dry distillation of the organic waste to the heating furnace, and an aspirator that draws the dry distillation gas from the air guide tube and guides it to the air guide port provided in the heating furnace.

This allows the dry distillation gas to be introduced into a heating furnace, where it can be decomposed or combusted.

In addition, in the above pyrolysis device, the air guide pipe can be configured to be disposed inside the heating furnace.

This allows the dry distillation gas to be maintained at a high temperature, preventing the tar, which has a high melting point and is contained in the dry distillation gas, from cooling and adhering to the air guide tube.

In the pyrolysis method using the pyrolysis device, biomass fuel can be used as the fuel for combustion in the heating furnace.

By doing this, since biomass fuel absorbs carbon dioxide during the growth process, it is possible to carry out pyrolysis processing while minimizing environmental destruction.

The pyrolysis device of the present invention can suppress oxidation of the carbonized material produced by dry distillation of organic waste.

1 is a conceptual diagram of a pyrolysis apparatus according to a first embodiment of the present invention. FIG. 2 is a left side view of the dry distillation tank and the heating furnace of the thermal decomposition apparatus. 3 is a horizontal cross-sectional view of the dry distillation tank and the heating furnace, taken along line III-III in FIG. 2. 4 is a vertical cross-sectional view of the dry distillation tank, taken along line IV-IV in FIG. 2. 3 is a vertical cross-sectional view of the dry distillation tank and the heating furnace, taken along line V-V in FIG. 2. FIG. 4 is a conceptual diagram of a pyrolysis device according to a second embodiment. 7 is a horizontal cross-sectional view of the dry distillation tank and the heating furnace of the thermal decomposition apparatus, taken along line VII-VII in FIG. 6. FIG. 11 is a conceptual diagram of a pyrolysis apparatus according to a third embodiment. 9 is a vertical cross-sectional view of the dry distillation tank and hot air duct of the pyrolysis apparatus, taken along line IX-IX of FIG. 8.

First Embodiment
Hereinafter, a first embodiment of the pyrolysis apparatus of the present invention will be described. As shown in FIG. 1 and FIG. 2, the pyrolysis apparatus A of the first embodiment includes a cylindrical dry distillation tank 1 that continuously dry distills waste plastic WP as organic waste while moving it, an input device 3 that inputs the waste plastic WP into the dry distillation tank 1, a heating furnace 2 that covers the dry distillation tank 1 and heats the dry distillation tank 1 by combustion, and a recovery device 4 that recovers charcoal CB and dry distillation gas DG generated by the pyrolysis of the waste plastic WP by heating. As described later, the dry distillation tank 1 is configured to be rotatable around the central axis (rotation axis RA) of the cylindrical shape. In this specification, the orientation of the pyrolysis apparatus A is, as shown in FIG. 1 to FIG. 3, the side having the input device 3 is the front, and the side having the recovery device 4 is the rear. Up, down, left, and right refer to the up, down, left, and right when the pyrolysis apparatus A is viewed from the front side, and F, B, rear, U, up, D, down, L, and R, respectively, are used in the drawings. In addition, the circumferential direction of the rotation of the dry distillation tank 1 is the direction when the thermal decomposition apparatus A is viewed from the front side (e.g., clockwise direction).

As shown in FIG. 1, the dry distillation tank 1 is a cylinder that continuously dry distills waste plastic WP as organic waste while moving it, and the cylindrical dry distillation tank body 11 is arranged so that the axial direction of the cylinder is the horizontal front-rear direction. A rotating gear 15 is provided endlessly in the circumferential direction on the outer circumferential surface of the front end side of the dry distillation tank body 11, and a rotating gear 17 that meshes with the rotating gear 15 and a motor 17a that rotates the rotating gear 17 are provided below the rotating gear 15, and the dry distillation tank body 11 is configured to be rotatable in the circumferential direction around the central axis (rotation axis RA) of the cylinder by the rotation of the motor 17a. As shown in FIG. 4, the dry distillation tank 1 is rotatably installed on a stand 18 via a rotating roller 18a.

3 and 4, the dry distillation tank 1 has eight rows of stirring blades, each row consisting of eight stirring blades 14 arranged in a row along the axial direction (front-back direction) of the inner peripheral surface of the dry distillation tank body 11. The stirring blade rows are protruding from the inner peripheral surface of the dry distillation tank body 11 so as to divide the inner peripheral surface of the dry distillation tank body 11 into eight equal parts along the circumferential direction. Therefore, by rotating the dry distillation tank 1, the waste plastic WP can be easily stirred and rolled, suppressing uneven heating of the waste plastic WP. The stirring blades 14 are arranged so that the rear end of each of them is shifted 5° counterclockwise (relative to the rotation axis RA when viewed from the front) compared to the front end. Therefore, when the dry distillation tank 1 is rotated clockwise, the waste plastic WP as the contained material is stirred and rolled so as to move backward, and when the dry distillation tank 1 is rotated counterclockwise, the waste plastic WP is stirred and rolled so as to move forward. By changing the rotation direction of the dry distillation tank 1, the waste plastic moves back and forth, making it possible to adjust the time for dry distilling the waste plastic WP.

The dry distillation tank 1 has the front wall 11b connected to the input device 3 described below, and the rear wall 11c covered by the recovery device 4 described below, and is closed off from the outside. The input device 3 removes the air (oxygen) that flows into the dry distillation tank 1, and the recovery device 4 suppresses the air (oxygen) that flows into the dry distillation tank 1, so the waste plastic WP can be dry distilled while being prevented from oxidizing.

As shown in FIG. 1, an outlet 31d (described later) of the input device 3 that inputs waste plastic WP as organic waste into the dry distillation tank 1 is disposed on the rotation axis RA of the front wall portion 11b of the dry distillation tank 1. The input device 3 is configured with a first screw pump 31 that inputs waste plastic WP into the dry distillation tank 1, and a second screw pump 32 that supplies waste plastic WP to the first screw pump 31.

The first screw pump 31 is provided with a screw 31b that rotates to pump waste plastic WP inside a pump outer cylinder 31c that serves as a housing, and a motor 31a that rotates the screw 31b in front of the pump outer cylinder 31c. The pump outer cylinder 31c has a supply port 31e at the front upper part to which waste plastic WP is supplied from the second screw pump 32, and the waste plastic WP supplied from the supply port 31e is pumped rearward by the rotation of the screw 31b and is fed into the dry distillation tank 1 from the delivery port 31d at the rear end of the pump outer cylinder 31c. The front wall 11b of the dry distillation tank 1 is provided with an inlet 12 through which waste plastic WP is fed, and the inlet 12 rotatably supports the front end portion having the delivery port 31d of the pump outer cylinder 31c. A gland packing 16 is provided on the inner circumference of the inlet 12, and is structured to prevent air (oxygen) from flowing into the dry distillation tank 1 while allowing the inlet 12 of the dry distillation tank 1 to rotate relative to the delivery port 31d of the pump outer cylinder 31c. As shown in the enlarged view of FIG. 2, the gland packing 16 is structured such that an annular packing 16a covering the outer circumference of the pump outer cylinder 31c is housed in a packing case 16b as a container whose rear is integrated with the inlet 12, and is pressed from the front by a packing gland 16c. In this way, the gland packing 16 prevents air from flowing into the inlet 12 (dry distillation tank 1) while allowing the inlet 12 to rotate relative to the pump outer cylinder 31c.

The second screw pump 32 is a pump that supplies waste plastic WP to the first screw pump 31, and has the same basic configuration as the first screw pump 31. The second screw pump 32 is equipped with a screw 32b that pressurizes the waste plastic WP by rotating inside a pump outer cylinder 32c that serves as a housing, and a motor 32a that rotates the screw 32b in front of the pump outer cylinder 32c. The second screw pump 32 is equipped with a hopper container 33 that stores waste plastic WP in the front upper part of the pump outer cylinder 32c, and is equipped with a supply port 32e at the connection part between the hopper container 33 and the pump outer cylinder 32c through which the waste plastic WP is supplied from the hopper container 33. The waste plastic WP supplied from the supply port 32e is pressurized backward by the rotation of the screw 32b and transferred to the first screw pump 31 from the delivery port 32d at the lower rear end of the pump outer cylinder 32c.

In these first screw pump 31 and second screw pump 32, the waste plastic WP is pumped backward by the rotation of the screws 31b, 32b, and is degassed by the pressure of the rotation of the screws 31b, 32b. It is then transported backward inside the pump outer cylinders 31c, 32c so that the air (oxygen) is removed, and it is then transported to the first screw pump 31 and fed into the dry distillation tank 1.

As shown in FIG. 1, the pump outer cylinders 31c, 32c of the first screw pump 31 and the second screw pump 32 are each arranged facing rearward at an angle α of 5° upward from the horizontal. As the weight of the waste plastic WP is applied to the supply source side, the waste plastic WP is degassed by the pressure of its own weight, and is transported rearward inside the pump outer cylinders 31c, 32c so that the air (oxygen) is removed.

As shown in FIG. 1, the screws 31b, 32b of the first screw pump 31 and the second screw pump 32 are formed so that the pitch P per revolution becomes shorter toward the rear. Therefore, the waste plastic WP is compressed toward the rear and transported toward the rear inside the pump outer cylinders 31c, 32c so that the air (oxygen) is removed.

The supply port 31e of the first screw pump 31 and the delivery port 32d of the second screw pump 32 are connected by a connecting pipe 34 arranged in the vertical direction. A first gate valve 35 that closes the inside of the connecting pipe 34 is provided on the lower side of the connecting pipe 34 (the supply port 31e side of the first screw pump 31), and a second gate valve 36 that closes the inside of the connecting pipe 34 is provided on the upper side of the connecting pipe 34 (the delivery port 32d side of the second screw pump 32). By closing the first gate valve 35 and the second gate valve 36, the inside of the connecting pipe 34 becomes a flow path that is closed from the first screw pump 31 and the second screw pump 32.

The connecting pipe 34 is provided with a degassing port 34a for degassing gas and an inlet 34b for injecting nitrogen gas. A suction blower 34c is connected to the degassing port 34a as a degassing device for sucking air from the connecting pipe 34, and a nitrogen cylinder 34d is connected to the inlet 34b for injecting nitrogen gas into the connecting pipe 34. The first and second gate valves 35 and 36 of the connecting pipe 34 are closed to enclose the waste plastic WP in the connecting pipe 34, and the waste plastic WP is degassed through the degassing port 34a, thereby removing air (oxygen contained in the air). In addition, by injecting nitrogen gas through the inlet 34b after or during degassing, the oxygen contained in the air can be further removed.

The heating furnace 2 covers the dry distillation tank 1 except for the front end and the rear end, burns the biomass fuel BF, and heats the dry distillation tank 1 using the hot air generated by the combustion. As shown in FIG. 2, the heating furnace 2 has a substantially cylindrical shape that covers the dry distillation tank 1, and is arranged in the front-rear direction with the axial direction of the cylindrical heating furnace housing 21 overlapping with the axial direction of the dry distillation tank 1. The front wall portion 21a of the heating furnace housing 21 is formed with a front shaft hole 21c that supports the dry distillation tank 1 that rotates in the circumferential direction, and the rear wall portion 21b is formed with a rear shaft hole 21d that similarly supports the dry distillation tank 1 that rotates in the circumferential direction. The inner circumference of the front shaft hole 21c and the rear shaft hole 21d that contact the dry distillation tank 1 is provided with a gland packing 16, and the dry distillation tank 1 can be rotated relative to the front shaft hole 21c and the rear shaft hole 21d, while the heat of the heating furnace 2 does not leak to the outside. Temperature sensors 27 that measure the temperature inside the heating furnace 2 are installed at multiple appropriate locations in the heating furnace 2.

A combustion device 24 is installed at the top of the front end of the heating furnace 2, and a hot air duct 23 formed in the heating furnace 2 covers the dry distillation tank body 11 from the installation position of the combustion device 24 to the rear, and the dry distillation tank 1 is heated by hot air generated by combustion in the combustion device 24. A chimney 26 that releases hot air into the atmosphere is provided at the top of the rear end of the heating furnace 2, and exhausts the hot air. Between the front wall 21a and the rear wall 21b of the heating furnace housing 21, three partition plates 22 that divide the hot air duct 23 are arranged so as to divide the hot air duct 23 into four in the front-to-rear direction, and the hot air duct 23 is divided into four partitions. The partition plates 22 also serve as supports that support the dry distillation tank body 11.

The four partitions are, from the front, the first partition 23a, the second partition 23b, the third partition 23c, and the fourth partition 23d. A combustion device 24 is installed at the top of the first partition 23a, and a chimney 26 that releases hot air into the atmosphere is provided at the top of the fourth partition 23d. As shown in Figure 2, the first partition plate 22 from the front has an air passage 22a formed on the bottom, the second partition plate 22 has an air passage 22a formed on the top (Figure 5), and the third partition plate 22 has an air passage 22a formed on the bottom. Except for the air passage 22a of the partition plate 22, the hot air passage 23 is separated from the front and rear to form partitions. The hot air generated by the combustion of the combustion device 24 flows down the first partition 23a, through the ventilation passage 22a on the lower side of the first partition plate 22 to the second partition 23b, flows up the second partition 23b, flows from the ventilation passage 22a on the upper side of the second partition plate 22 to the third partition 23c, flows down the third partition 23c, flows from the ventilation passage 22a on the lower side of the third partition plate 22 to the fourth partition 23d, and flows up the fourth partition 23d. In other words, the hot air generated by the combustion of the combustion device 24 flows backward while moving up and down inside the heating furnace housing 21, and flows into the chimney 26 at the top of the rear end side of the heating furnace 2. Inside the chimney 26, a damper 26a that regulates or adjusts the flow rate of the hot air is provided, and by adjusting the flow rate of the hot air, the temperature inside the heating furnace 2 can be adjusted.

The pyrolysis device A uses biomass fuel BF as the fuel for combustion in the heating furnace 2, allowing it to carry out pyrolysis while minimizing environmental damage. This is because biomass fuel BF absorbs carbon dioxide during the growth process of its raw materials, making it possible to reduce total carbon dioxide emissions.

The recovery device 4 is a device that recovers the charcoal CB and dry distillation gas DG generated by the thermal decomposition of waste plastic WP. The recovery device 4 has an inlet 46 at the front for carrying the charcoal CB and dry distillation gas DG, and the inlet 46 is connected to cover the rear end of the dry distillation tank body 11 of the dry distillation tank 1. The inlet 46 rotatably supports the rear end of the dry distillation tank body 11, and the inner periphery of the inlet 46 is provided with a gland packing 16, which is structured to prevent the inflow of air (oxygen). The granular charcoal CB and gaseous dry distillation gas DG generated in the dry distillation tank 1 flow into the recovery device 4, and the charcoal CB with a high specific gravity accumulates in the solid reservoir 42 at the bottom of the recovery device 4, and the dry distillation gas DG with a low specific gravity accumulates in the gas reservoir 41 at the top of the recovery device 4. A rotary valve 44 is provided below the solid reservoir 42 to block outside air and discharge granular solids to the bottom, and the carbonized material CB is discharged to the bottom and collected. A check valve 43 is provided above the gas reservoir 41 to prevent the inflow of outside air and discharge the gas, and the dry distillation gas DG is transferred to the condensation device 5 described next. In the collection device 4, the rotary valve 44 blocks outside air and the check valve 43 prevents the inflow of outside air, thereby suppressing the inflow of air (oxygen) into the dry distillation tank 1.

The condensation device 5 is a device that cools the dry distillation gas DG transferred from the recovery device 4 and recovers the cooled and liquefied liquid droplets LD. The condensation device 5 includes a radiator 51 as a cooler that cools the dry distillation gas DG, and an oil-water separation tank 55 that separates the liquefied liquid droplets LD, obtained by cooling the dry distillation gas DG, into oil droplets OD and water droplets WD.

The radiator 51 of the condensation device 5 cools the dry distillation gas DG introduced from the inlet 52, and the cooled and liquefied liquid droplets LD flow out from the liquid outlet 53 to the oil-water separation tank 55, and the volatile oil VO that does not condense even when cooled is transferred to the heating furnace 2 from the gas outlet 54, thereby separating the liquid and the gas. The liquid outlet 53 is provided below the radiator 51 and discharges the liquid droplets LD that have accumulated below. The gas outlet 54 is provided above the liquid outlet 53 of the radiator 51 and discharges the volatile oil VO that has accumulated above. The radiator 51 is cooled by the cooling water that flows in from the cooling water inlet 51a, circulates inside the radiator 51, and is discharged from the cooling water outlet 51b, thereby cooling the dry distillation gas DG. The radiator 51 is provided with a pressure gauge 51c that measures the pressure of the gas (volatile oil VO) above. The volatile oil VO is sucked under reduced pressure by the aspirator 62 of the air guide device 6, which will be described later, and is ultimately transported from the air guide port 25 to the heating furnace 2, where it is decomposed or combusted.

The oil-water separation tank 55 separates the liquid droplets LD liquefied by the radiator 51 into oil droplets OD and water droplets WD. Because oil droplets OD and water droplets WD are not compatible, the liquid droplets LD are separated into oil droplets OD and water droplets WD due to the difference in specific gravity. The oil droplets OD floating on the top of the oil-water separation tank 55 are collected in the oil recovery tank 56 and can be used as recycled oil, such as fuel. The water droplets WD that accumulate at the bottom of the oil-water separation tank 55 are collected in the moisture recovery tank 57 and, after confirming that they do not contain any harmful components, can be disposed of as sewage.

The air guide device 6 is installed behind the combustion device 24 and is a device that transfers the volatile oil VO from the dry distillation gas DG that was not condensed even after being cooled in the condensation device 5 to the heating furnace 2 through the air guide port 25. By being transferred to the heating furnace 2, the volatile oil VO is exposed to the high heat of the heating furnace 2 and is decomposed or combusted. The air guide device 6 draws in the volatile oil VO in the condensation device 5 using the suction capacity of the aspirator 62, and further reduces the pressure inside the dry distillation tank 1 that is connected via the condensation device 5. The aspirator 62 exerts suction force using the blowing force of the blower 61, draws in the volatile oil VO in the condensation device 5, and guides the volatile oil VO from the air guide port 25 to the heating furnace 2 together with the air blown by the blower 61.

Next, the operation of the pyrolysis device A of the first embodiment will be described. In the first embodiment, waste plastic WP was used as the organic waste to be dry distilled, and biomass fuel BF was used as the fuel for the combustion device 24 of the heating furnace 2.

Waste plastic WP as organic waste is fed into the dry distillation tank 1 by the feeding device 3 in which the second screw pump 32 and the first screw pump 31 are arranged in series. The feeding is performed by repeatedly transferring the waste plastic WP and stopping the transfer to degass (nitrogen purging) the waste plastic WP. When transferring the waste plastic WP, the second screw pump 32 and the first screw pump 31 are started, and the second gate valve 36 and the first gate valve 35 on the upper and lower sides of the connecting pipe 34 between the second screw pump 32 and the first screw pump 31 are opened, respectively, and the waste plastic WP is fed into the dry distillation tank 1 via the second screw pump 32 and the first screw pump 31. When degassing and purging the waste plastic WP with nitrogen, the second screw pump 32 and the first screw pump 31 are stopped, the second gate valve 36 and the first gate valve 35 are closed, respectively, and the waste plastic WP is degassed from the degassing port 34a, and after degassing, nitrogen gas is injected from the injection port 34b. By repeatedly degassing (purging with nitrogen) the waste plastic WP and transferring it, the surrounding air is removed from the waste plastic WP, it is purged with nitrogen, and the oxygen contained in the air is removed. By pumping it to the second screw pump 32 and the first screw pump 31, it is degassed by the pressure of the rotation of the screws 32b and 31b, and is transferred inside the pump outer cylinders 32c and 31c, and then is fed into the dry distillation tank 1.

The waste plastic WP fed into the dry distillation tank 1 is heated and dry-distilled by the combustion of biomass fuel BF in the combustion device 24 of the heating furnace 2, which is physically isolated from the dry distillation tank 1, while being stirred by the rotation of the dry distillation tank 1 and the stirring blades 14 on the inner surface of the dry distillation tank body 11.

In the heating furnace 2, hot air generated by combustion in the combustion device 24 flows backward while moving up and down inside the heating furnace housing 21, and the dry distillation tank body 11 rotates around the rotation axis RA, so that the dry distillation tank body 11 is heated evenly. The hot air that heated the dry distillation tank body 11 flows into the chimney 26 at the top of the rear end side of the heating furnace 2. Inside the chimney 26, a damper 26a is provided to regulate or adjust the flow rate of the hot air, and the temperature inside the heating furnace 2 is adjusted by adjusting the flow rate of the hot air. The temperature inside the heating furnace 2 is adjusted to be about 10°C above 800°C. This is to prevent the generation of dioxins. In this case, the temperature inside the dry distillation tank 1 is around 300°C.

The dry distillation tank 1 is equipped with stirring blades 14 on the inner peripheral surface of the roughly cylindrical dry distillation tank body 11, and the dry distillation tank body 11 itself rotates in the circumferential direction around the rotation axis RA. As a result, the waste plastic WP is heated while being stirred, uneven heating is suppressed, it is heated evenly, and the thermal efficiency of heating is excellent. The waste plastic WP is put into the dry distillation tank 1 in a degassed and nitrogen purged state, and is heated in that state, so oxidation is suppressed and thermal decomposition proceeds. The waste plastic WP is dry distilled for about 90 minutes. The waste plastic WP generates dry distillation gas DG and charcoal CB by thermal decomposition. The dry distillation gas DG and charcoal CB generated from the waste plastic WP are less deteriorated (oxidized) because oxidation is suppressed.

The carbonized material CB generated from the distilled waste plastic WP rolls inside the distillation tank 1, falls from the outlet 13 into the recovery device 4, and accumulates in the solid reservoir 42. The carbonized material CB is discharged and recovered by a rotary valve 44 installed below the solid reservoir 42. The recovered carbonized material CB contains a large amount of charcoal (carbon) and can be reused as fuel, a soil conditioner, a water purification agent, etc.

The dry distillation gas DG generated from the dry distilled waste plastic WP is introduced into the condensation device 5 through the recovery device 4 by suction with the aspirator 62 of the air guide device 6. The dry distillation gas DG introduced into the condensation device 5 is cooled by the radiator 51 and separated into condensed liquid droplets LD and volatile oil VO that does not condense even when cooled. The volatile oil VO is sucked by the aspirator 62 of the air guide device 6 and transferred from the air guide port 25 to the heating furnace 2 together with the air blown from the blower 61, where it is decomposed or burned. The liquid droplets LD are discharged into the oil-water separation tank 55 and separated into oil droplets OD and water droplets WD. The oil droplets OD are collected in the oil recovery tank 56 and can be used as recycled oil for fuel, etc. The water droplets WD are collected in the moisture recovery tank 57 and can be discharged as sewage after confirming that they do not contain harmful components.

Second Embodiment
Next, the second embodiment of the present invention will be described. As shown in FIG. 6, the pyrolysis apparatus B of the second embodiment is different from the pyrolysis apparatus A of the first embodiment in the configuration of the recovery device 204. Specifically, eight discharge holes 246 are provided at equal intervals in the circumferential direction of the rear end side of the cylindrical dry distillation tank 201, and the dry distillation tank 201 rotates in the circumferential direction around the rotation axis RA, so that the carbide CB is discharged from the lower discharge hole 246 and the dry distillation gas DG is discharged from the upper discharge hole 246. In addition, the pyrolysis apparatus B of the second embodiment does not include a condenser, and is configured to guide all of the generated dry distillation gas DG to the heating furnace 202 to decompose or combust the dry distillation gas DG. The rest is almost the same as the pyrolysis apparatus A of the first embodiment, and in the second embodiment, the elements common to the first embodiment will be referred to by the same reference numerals and their description will be omitted (similar to the third embodiment).

As shown in FIG. 6, the dry distillation tank 201 is arranged so that the cylindrical dry distillation tank body 211 has a horizontal axial direction. A chain wheel 217a for rotating the dry distillation tank body 211 is provided at the rear end of the cylindrical dry distillation tank body 211, and a chain ring 217b that meshes with the chain wheel 217a via a chain 217 and a motor 217c that rotates the chain ring 217b are provided below the chain wheel 217a. The rotation of the motor 217c causes the cylindrical dry distillation tank body 211 to rotate circumferentially around the central axis of the cylinder (rotation axis RA) via the chain ring 217b, the chain 217, and the chain wheel 217a.

As shown in FIG. 7, the dry distillation tank 201 has four rows of stirring blades, each row consisting of seven stirring blades 214 arranged in a row along the axial direction on the inner peripheral surface side of the dry distillation tank body 211. The stirring blade rows protrude from the inner peripheral surface of the dry distillation tank 201 so as to divide the inner peripheral surface of the dry distillation tank 201 into four equal parts along the circumferential direction. The rear end of each stirring blade 214 is shifted 20° counterclockwise (relative to the rotation axis RA when viewed from the front) compared to the front end, and is arranged in an arc on the forward side.

Eight discharge holes 246 are provided at equal intervals around the rear end of the dry distillation tank body 211, and as the dry distillation tank body 211 rotates, carbonized material CB is discharged from the discharge holes 246 located on the lower side, and dry distillation gas DG is discharged from the discharge holes 246 located on the upper side. The dry distillation gas DG discharged from the discharge holes 246 located on the upper side is sucked into the aspirator 62, passes through the air guide tube 45 located in the heating furnace 202, and is sent to the heating furnace 202 from the air guide port 25, where it is decomposed or combusted. Since the air guide tube 45 is located in the heating furnace 202, it is possible to prevent the adhesion of high melting point solvents such as tar to the air guide tube 45, even if the dry distillation gas DG contains high melting point solvents.

Third Embodiment
Next, a third embodiment of the present invention will be described. As shown in FIG. 8, the pyrolysis apparatus C of the third embodiment is different from the pyrolysis apparatus A of the first embodiment in the configuration of the heating furnace 302. Specifically, in the first embodiment, the pyrolysis tank 1 rotates relative to the heating furnace 2 fixed at the installation location of the pyrolysis apparatus C, but in the third embodiment, the hot air duct 323 of the heating furnace 302 is joined to the pyrolysis tank 301, and both the pyrolysis tank 301 and the heating furnace 302 rotate. The combustion device 324 of the heating furnace 302 is fixed at the installation location of the pyrolysis apparatus C, and the heating furnace 302 and the pyrolysis tank 301 rotate relative to the combustion device 324.

Since the hot air passage 323 is joined to the dry distillation tank 301 and rotates together with it, the hot air is circulated in the circumferential direction of the dry distillation tank 301. Therefore, unlike the first embodiment, it is not necessary to divide the hot air passage 23 into partitions to circulate the air up and down (Figure 2). Therefore, as shown in Figure 9, the partition plate 322 of the third embodiment has 12 ventilation passages 322a arranged at equal intervals around the entire circumference.

Example 1
In Example 1, continuous pyrolysis was carried out using the pyrolysis apparatus A of the first embodiment under the following conditions.

Heating furnace 2 adjusted to 810°C Biomass fuel BF: Crushed construction waste wood 80 kg/h
Dry distillation tank 1 φ500mm (outer diameter 500mm) x L900mm Capacity 160L Rotation speed 1rpm Organic waste passing time approx. 70 minutes Dry distillation tank temperature approx. 300℃
First screw pump 31 and second screw pump 32: Transfer rate 20 kg/h. Repeat 6 minutes of transfer, 6 minutes of stop (during degassing and nitrogen purging). Degassing and nitrogen purging: Repeat 6 minutes of transfer, 5 minutes of degassing, 1 minute of nitrogen purging. Radiator 51 (condenser 5): 25A (inner diameter 25 mm) x L 300 mm x 12 units. Cooling water pump: 40 L/min.
Aspirator 62 (air guide device 6) 65A (air inlet) x 50A (suction port) x 50A (outlet)
Air blower 61 (air guide device 6) 6m ³ /min
Organic waste: crushed used polyethylene containers 10kg/h

In Example 1, under steady-state operation, 4 kg/h of kerosene/diesel class oil was obtained as oil droplets OD (recycled oil). No water droplets WD were observed. 1 kg/h of charcoal-based particles with a maximum size of about 10 mm were obtained as charcoal CB.

Example 2
In Example 2, continuous pyrolysis was carried out using the pyrolysis apparatus B of the second embodiment under the following conditions.

Heating furnace 2 adjusted to 810°C Biomass fuel BF: Crushed construction waste wood 80 kg/h
Dry distillation tank 1 φ500mm (outer diameter 500mm) x L900mm Capacity 160L Rotation speed 1rpm Organic waste passing time approx. 70 minutes Dry distillation tank temperature approx. 300℃
First screw pump 31 and second screw pump 32: Transfer rate 20 kg/h. Repeat 6 minutes of transfer, 6 minutes of stop (during degassing and nitrogen purging). Degassing and nitrogen purging: Repeat 6 minutes of transfer, 5 minutes of degassing, 1 minute of nitrogen purging. Aspirator 62 (air guide device 6): 65A (air inlet) x 50A (suction port) x 50A (outlet)
Air blower 61 (air guide device 6) 6m ³ /min
Organic waste Automobile shredder dust 10kg/h

In Example 2, under steady-state operation, 1.5 kg/h of charcoal-based particles with a maximum size of approximately 10 mm were obtained as carbide CB.

Example 3
In Example 3, continuous pyrolysis was carried out under the following conditions using the pyrolysis apparatus C of the third embodiment.

Heating furnace 2 adjusted to 810°C Biomass fuel BF: wood processing waste 80 kg/h
Dry distillation tank 1 φ500mm (outer diameter 500mm) x L900mm Capacity 160L Rotation speed 0.5rpm Organic waste passing time approx. 140 minutes Dry distillation tank temperature approx. 300°C
First screw pump 31 and second screw pump 32: Transfer rate 10 kg/h. Repeat 6 minutes of transfer and 6 minutes of stop (during degassing). Degassing: Repeat 6 minutes of transfer and 6 minutes of degassing. Radiator 51 (condenser 5): 25A (inner diameter 25 mm) x L 300 mm x 12 units. Cooling water pump: 40 L/min.
Aspirator 62 (air guide device 6) 65A (air inlet) x 50A (suction port) x 50A (outlet)
Air blower 61 (air guide device 6) 6m ³ /min
Organic waste Wood processing waste 10kg/h

In Example 3, no oil droplets OD were observed during steady-state operation. Wood vinegar was obtained at 4 kg/h as water droplets WD. Particles mainly composed of charcoal up to about 1 mm in size were obtained at 0.5 kg/h as carbonized matter CB.

Comparative Example 1
In Comparative Example 1, a pyrolysis apparatus was used in which the charging device 3 of the pyrolysis apparatus A was removed. Waste plastics WP were charged manually using a shovel.

Dry distillation tank 1 φ500mm (outer diameter 500mm) x L900mm Capacity 160L Rotation speed 1rpm
Heating furnace 2 adjusted to 810°C Biomass fuel BF: Crushed construction waste wood 80 kg/h
Radiator 51 (condenser 5) 25A (inner diameter 25mm) x L300mm x 12 Cooling water pump 40L/min
Aspirator 62 (air guide device 6) 65A (air inlet) x 50A (suction port) x 50A (outlet)
Air blower 61 (air guide device 6) 6m ³ /min
Waste plastic WP Used polyethylene container crushed material 10kg/h

In Example 1, under steady-state operating conditions, 1 kg/h of kerosene/diesel class oil was obtained as oil droplets OD (recycled oil). No water droplets WD were observed. 0.1 kg/h of particles mainly composed of charcoal with a maximum size of approximately 10 mm was obtained as charcoal CB. Compared to Example 1, the amount of oil droplets OD and charcoal CB recovered was small, and it is believed that most of the oil droplets OD and charcoal CB were combusted because oxygen was not removed.

(Other embodiments)
The pyrolysis device of the embodiment can be implemented in the following forms.

In the pyrolysis device of the embodiment, crushed construction waste wood and wood processing waste are used as the biomass fuel BF, but edible oil waste, grain oil, etc. can also be used as the biomass fuel BF. In addition, the fuel used to heat the dry distillation tank 1 is not limited to biomass fuel BF, and general-purpose fuels (city gas, propane gas, etc.) can also be used.

In the pyrolysis device of the embodiment, crushed used polyethylene containers, automobile shredder dust, and wood processing waste were used as organic waste, but there are no particular limitations on the organic waste that can be used, and food waste, feces, and other materials can also be used.

1... dry distillation tank, 2... heating furnace, 3... charging device, 4... recovery device, 5... condensation device, 6... air guide device, 11... dry distillation tank body, 11b... front wall, 11c... rear wall, 12... charging port, 13... outlet, 14... stirring blade, 15... rotating gear, 16... gland packing, 16a... packing, 16b... packing case, 16c... packing retainer, 17... rotating gear, 17a... motor, 18... stand, 18a... rotating roller, 21... heating furnace housing, 21a... front wall, 21b... rear wall, 21c... front shaft hole, 21d... rear shaft hole, 22... partition plate, 22a... ventilation passage, 23... Hot air duct, 23a...first partition, 23b...second partition, 23c...third partition, 23d...fourth partition, 24...combustion device, 25...air inlet, 26...chimney, 26a...damper, 27...temperature sensor, 31...first screw pump, 31a...motor, 31b...screw, 31c...pump outer cylinder, 31d...delivery port, 31e...supply port, 32...second screw pump, 32a...motor, 32b...screw, 32c...pump outer cylinder, 32d...delivery port, 32e...supply port, 33...hopper container, 34...connecting pipe, 34a...ventilation port, 34b ...inlet, 34c...suction blower, 34d...nitrogen cylinder, 35...first gate valve, 36...second gate valve, 41...gas reservoir, 42...solid reservoir, 43...check valve, 44...rotary valve, 45...air guide pipe, 46...delivery port, 51...radiator, 51a...cooling water inlet, 51b...cooling water outlet, 51c...pressure gauge, 52...inlet, 53...liquid outlet, 54...gas outlet, 55...oil-water separation tank, 56...oil recovery tank, 57...moisture recovery tank, 61...blower, 62...aspirator, 201...dry distillation tank, 202...heating furnace, 204...recovery device, 211...dry distillation tank body, 214 ...Agitator blade, 217...Chain, 217a...Chain wheel, 217b...Chain ring, 217c...Motor, 246...Discharge hole, 301...Dry distillation tank, 302...Heating furnace, 311...Dry distillation tank body, 321...Heating furnace housing, 322...Partition plate, 322a...Ventilation duct, 323...Hot air duct, 324...Combustion device, A...Pyrolysis device, B...Pyrolysis device, C...Pyrolysis device, BF...Biomass fuel, CB...Carbonized material, DG...Dry distillation gas, LD...Liquid droplets, OD...Oil droplets, P...Pitch, RA...Pivoting shaft, VO...Volatile oil, WD...Water droplets, WP...Waste plastic, α...Angle.

Claims (5)

A pyrolysis apparatus comprising: a dry distillation tank for dry distilling organic waste; an input device for inputting the organic waste into the dry distillation tank; a heating furnace for heating the dry distillation tank in order to dry distill the organic waste; and a recovery device for recovering a carbonized material produced by the dry distillation of the organic waste,
the introduction device is configured to include a first screw pump that introduces the organic waste into the dry distillation tank, and a second screw pump that supplies the organic waste to the first screw pump;
a supply port through which the organic waste is supplied to the first screw pump and a delivery port of the second screw pump which delivers the organic waste to the supply port are connected by a connecting pipe;
a gate valve for regulating the movement of the organic waste is provided on the supply port side and the delivery port side of the connecting pipe,
A pyrolysis apparatus for organic waste , characterized in that a degassing device is provided in the connecting pipe . The organic waste pyrolysis apparatus according to claim 1, characterized in that the connecting pipe is provided with an inlet for injecting nitrogen gas. 3. The organic waste pyrolysis apparatus according to claim 1, further comprising an air guide tube for directing the dry distillation gas produced by the dry distillation of the organic waste to the heating furnace, and an aspirator for sucking the dry distillation gas from the air guide tube and directing it to the air guide port provided in the heating furnace for directing the dry distillation gas. 4. The thermal decomposition apparatus for organic waste according to claim 3 , wherein the air guide pipe is disposed within the heating furnace. 2. A method for pyrolyzing organic waste, comprising using biomass fuel as a fuel for combustion in the heating furnace of the pyrolysis apparatus for organic waste according to claim 1.

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