JP7689486B2 - Waste pyrolysis apparatus and waste pyrolysis method - Google Patents

Description

The present invention relates to a waste pyrolysis device and a waste pyrolysis method.

A method is known in which waste is pyrolyzed to obtain pyrolysates such as carbonized materials and oils, and then the pyrolysates are reused (see, for example, Patent Document 1).

JP 2014-237764 A

In conventional technology, waste is put into a heated pressure vessel for thermal decomposition, but to increase the efficiency of the process, it is necessary to cut and crush the waste before putting it into the heated pressure vessel. The cutting and crushing process is time-consuming for large tires and unvulcanized rubber parts, etc., and there is room for improvement.

In consideration of the above, the present invention aims to provide a waste pyrolysis device and a waste pyrolysis method that can simplify the decomposition process of waste containing inorganic materials.

The waste pyrolysis device according to claim 1 includes a heating pressure vessel capable of storing waste containing inorganic materials in a sealed state, a heating device for heating the waste containing inorganic materials, a gas supply device for supplying gas to the heating pressure vessel to increase the pressure inside the heating pressure vessel, a liquid component recovery device connected to the heating pressure vessel via a first opening/closing valve and recovering condensed liquid components by cooling the pyrolysis gas generated in the heating pressure vessel, an exhaust section connected to the liquid component recovery device, having a second opening/closing valve, and exhausting the pyrolysis gas after the liquid components are recovered by the liquid component recovery device to the outside of the liquid component recovery device, and a control device for controlling the operation of the heating device, the gas supply device, the first opening/closing valve, and the second opening/closing valve.

In the waste pyrolysis device described in claim 1, the heating pressure vessel can contain waste containing inorganic materials in a sealed state.

The heating device can heat waste containing inorganic materials contained in a heating pressure vessel.

The gas supply device can supply gas to the heating pressure vessel to increase the pressure within the heating pressure vessel.

In the waste pyrolysis apparatus according to the first aspect of the present invention, waste can be pyrolyzed as follows, for example.
The heating pressure vessel is sealed and filled with gas to heat the waste containing inorganic materials. The heating temperature is set to a temperature equal to or higher than the temperature at which liquid components are released from the waste under atmospheric pressure, and the pressure is set to a pressure at which the liquid components do not volatilize under heating.

This allows the liquid component to be trapped inside the non-inorganic material, and the non-inorganic material to be degraded by heat and become brittle.

After achieving this state, the pressure in the heating pressure vessel is suddenly reduced, causing the liquid components in the non-inorganic materials to rapidly volatilize, and the brittle non-inorganic materials are crushed by the volatilization expansion force, allowing the inorganic materials to be efficiently separated from the non-inorganic materials.

The liquid component recovery device can recover the condensed liquid components by cooling the pyrolysis gas generated in the heated pressure vessel.

To send the pyrolysis gas generated in the heating pressure vessel to the liquid component recovery device, gas is supplied from the gas supply device to the heating pressure vessel and the first opening/closing valve is opened, so that the pyrolysis gas in the heating pressure vessel is pushed to the liquid component recovery device by the gas supplied from the gas supply device. This makes it possible to send the pyrolysis gas generated in the heating pressure vessel to the liquid component recovery device without using a pump or the like. Note that when gas is supplied to the heating pressure vessel to increase the pressure inside the heating pressure vessel, the first opening/closing valve is closed.

The exhaust section can exhaust the pyrolysis gas after the liquid components have been recovered by the liquid component recovery device to the outside of the liquid component recovery device.

Here, to send pyrolysis gas from the liquid component recovery device to the exhaust section, gas is supplied from the gas supply device to the heated pressure vessel and the first opening/closing valve and the second opening/closing valve are opened, so that the pyrolysis gas after the liquid components in the liquid component recovery device have been recovered can be exhausted to the outside of the liquid component recovery device using the gas supplied from the gas supply device.
Examples of the liquid component include oil and water, but the liquid component may be a liquid other than oil and water.

The invention described in claim 2 is the waste pyrolysis device described in claim 1, in which the heating pressure vessel is provided with a pressure sensor that detects the internal pressure and a temperature sensor that detects the temperature inside the heating pressure vessel, and the control device controls the operation of the heating device, the gas supply device, the first opening/closing valve, and the second opening/closing valve based on pressure detection data from the pressure sensor and temperature detection data from the temperature sensor.

In the waste pyrolysis device described in claim 2, the pressure sensor can detect the pressure inside the heating pressure vessel, and the temperature sensor can detect the temperature inside the heating pressure vessel.

The control device can control the operation of the heating device, the gas supply device, the first opening/closing valve, and the second opening/closing valve based on pressure detection data from the pressure sensor and temperature detection data from the temperature sensor. This makes it possible to process waste containing inorganic materials at the optimum temperature and pressure for pyrolyzing the waste containing inorganic materials.

The invention described in claim 3 is the waste pyrolysis device described in claim 1 or claim 2, in which the waste containing inorganic materials is a tire composed of rubber and steel cord.

The waste pyrolysis device described in claim 3 can pyrolyze tires, which are waste containing inorganic materials, and separate the tires into rubber and steel cords.

The waste pyrolysis method described in claim 4 includes a heating and pressurizing treatment process in which waste containing inorganic materials is heated and pressurized, and a separation process in which the pressure is reduced after the heating and pressurizing treatment process, liquid components contained in the waste are volatilized, the waste is pulverized, and the inorganic materials are separated from materials other than the inorganic materials.

In the waste pyrolysis method described in claim 4, waste containing inorganic materials is treated under heat and pressure in a heating and pressure treatment process.

In the separation process, the waste is pulverized by the volatilization expansion force generated when the liquid components contained in the waste evaporate and expand by reducing the pressure after the heating and pressurizing treatment process, and the waste containing inorganic materials is separated into inorganic materials and non-inorganic materials.

The invention described in claim 5 is the waste pyrolysis method described in claim 4, in which the temperature at which the waste containing inorganic materials is heated in the heating and pressurizing process is set to a temperature equal to or higher than the temperature at which liquid components are released from the waste under atmospheric pressure, and the pressure at which the waste containing inorganic materials is pressurized in the heating and pressurizing process is set to a pressure that does not volatilize the liquid components under the heating.

In the waste pyrolysis method described in claim 5, the temperature at which the waste containing inorganic materials is heated in the heating and pressurizing process is set to a temperature equal to or higher than the temperature at which liquid components are released from the waste under atmospheric pressure, and the pressure at which the waste containing inorganic materials is pressurized in the heating and pressurizing process is set to a pressure at which the liquid components do not volatilize under heating.

Before the separation process, therefore, the liquid components can be trapped inside the materials other than the inorganic materials, and the materials other than the inorganic materials can be heated and deteriorated to make them brittle.

In the separation process of waste containing inorganic materials in this state, the liquid components in the materials other than the inorganic materials rapidly evaporate, and the brittle materials other than the inorganic materials are crushed by the volatilization expansion force, allowing the inorganic materials and the materials other than the inorganic materials to be efficiently separated in the separation process.

The invention described in claim 6 is the waste pyrolysis method described in claim 5, in which the temperature when heating the waste is set within the range of 350°C or more and 500°C or less, and the pressure when pressurizing the waste is set within the range of 0.15 MPa or more and 2.0 MPa or less.

By setting the temperature when heating the waste containing inorganic materials within the range of 350°C or more and 500°C or less, and setting the pressure when pressurizing within the range of 0.15 MPa or more and 2.0 MPa or less, it is possible to thermally deteriorate materials other than inorganic materials during the heating and pressurizing treatment process, and to confine liquid components contained in the materials other than inorganic materials within the materials other than inorganic materials.

The invention described in claim 7 is the waste pyrolysis method described in any one of claims 4 to 6, in which after the separation step, a step of crushing the lumps of material that do not contain the inorganic material is provided.

In the waste pyrolysis method described in claim 7, a process for crushing lumps of material that do not contain inorganic materials is provided after the separation process, so that materials other than inorganic materials that are free of lumps can be obtained.

The invention described in claim 8 is the method for pyrolysis of waste described in any one of claims 4 to 7, in which the waste containing inorganic materials is a tire composed of rubber and steel cords.

The waste pyrolysis method described in claim 8 allows tires to be pyrolyzed to separate rubber and steel cords.

As described above, the waste pyrolysis device and waste pyrolysis method of the present invention can simplify the decomposition process of waste containing inorganic materials.

FIG. 1 is a piping diagram showing a configuration of a pyrolysis device according to one embodiment of the present invention.

A thermal decomposition apparatus 10 according to one embodiment of the present invention will be described with reference to FIG.
As shown in Fig. 1, the pyrolysis device 10 includes a heating pressure vessel 14 capable of storing, in a sealed state, tires 12 as an example of waste containing inorganic materials. The heating pressure vessel 14 includes a vessel body 14A capable of storing a plurality of undecomposed tires 12, and an openable and closable lid 14B that closes the opening of the vessel body 14A. The vessel body 14A includes a heater 16 as an example of a heating device that heats the stored tires 12. The heating pressure vessel 14 is equipped with a pressure sensor 18 that detects the pressure inside the vessel, and a temperature sensor 20 that detects the temperature inside the vessel.

Here, tires 12 are given as an example of waste containing inorganic materials, but waste containing inorganic materials is composed of inorganic materials and materials other than inorganic materials, for example polymer compounds.
The polymer compound can be rephrased as a polymer-based compound. One example of the polymer compound is an organic material containing carbon.
An example of an inorganic material is a metal material such as steel.

A pipe 23 is connected to the vessel body 14A of the heated pressure vessel 14 for introducing gas from a gas supply device 22 into the heated pressure vessel 14. The gas supply device 22 is configured to include a gas tank 24, a pressure adjustment valve 26, an opening/closing valve 28, etc. In this embodiment, the gas tank 24 is filled with nitrogen gas at high pressure (>atmospheric pressure).

The heating pressure vessel 14 is connected to the vacuum vessel 36 via piping 30, a first cyclone 32, and piping 34. An opening/closing valve 38 is provided midway along the piping 30.

When the oil-containing pyrolysis gas discharged from the heating pressure vessel 14 is introduced into the first cyclone 32, the oil is separated and removed from the pyrolysis gas. The pyrolysis gas that has passed through the first cyclone 32 is sent to the vacuum vessel 36 via a pipe 34, and the oil separated in the first cyclone 32 is sent to an oil recovery vessel 44 via a pipe 42. An opening/closing valve 40 is provided in the middle of the pipe 34, and an opening/closing valve 46 is provided in the middle of the pipe 42.
The on-off valve 38 and the on-off valve 40 are examples of the first on-off valve of the present invention.

The vacuum vessel 36 is provided with a cooling device 48, which is capable of cooling the pyrolysis gas introduced into the vacuum vessel 36. The vacuum vessel 36 and the cooling device 48 are an example of the liquid component recovery device of the present invention.
A pipe 50 is connected to the bottom of the vacuum vessel 36 for discharging the oil condensed in the vessel to an oil recovery vessel 44. An opening/closing valve 52 is provided midway along the pipe 50.

The vacuum container 36 is connected to a vacuum pump 56 via a pipe 54, and to a second cyclone 60 via a pipe 58. An opening/closing valve 62 is provided midway through the pipe 54, and an opening/closing valve 64 is provided midway through the pipe 58.

The second cyclone 60 separates the oil contained in the pyrolysis gas discharged from the vacuum vessel 36, and the pyrolysis gas from which the oil has been removed is sent to the incinerator 68 via piping 66, and the oil is sent to the oil recovery vessel 44 via piping 70. A drain cock 44A is attached to the bottom of the oil recovery vessel 44, and the oil accumulated in the oil recovery vessel 44 can be discharged by opening the drain cock 44A.

The incinerator 68 is provided with an ignition burner 72 as an ignition device, and is capable of burning flammable gas inside the incinerator 68. Exhaust gas generated by the combustion of the flammable gas can be discharged into the atmosphere.
The piping 58, the second cyclone 60, the on-off valve 64, the piping 66, and the incinerator 68 are an example of an exhaust unit of the present invention. The on-off valve 64 is an example of a second on-off valve of the present invention.

The pyrolysis device 10 is equipped with a control device 74 that can control each part of the device, such as the heater 16, the pressure adjustment valve 26, the on-off valve 28, the on-off valve 38, the on-off valve 40, the on-off valve 46, the cooling device 48, the on-off valve 52, the vacuum pump 56, the on-off valve 62, the on-off valve 64, and the ignition burner 72.

The control device 74 is also connected to a pressure sensor 18 and a temperature sensor 20, and is capable of controlling each part of the device based on pressure measurement data from the pressure sensor 18, temperature measurement data from the temperature sensor 20, and a preset control flow.

(Tire pyrolysis treatment)
Next, an example of a procedure for pyrolysis treatment of the tire 12 using the pyrolysis device 10 of this embodiment will be described.

(1) Step of Loading Tires The lid 14B of the heating and pressure vessel 14 is opened, and the tires 12 are loaded into the vessel. The tires 12 may be loaded into the vessel without being cut into pieces, or the tires 12 may be cut into 2 or 3 pieces and loaded into the vessel as necessary.
The tire 12 to be subjected to the pyrolysis treatment is a tire that includes at least rubber and steel, and the type of tire is not important. Examples of the steel used in the tire 12 include a bead core, a steel belt, etc.

(2) Nitrogen Gas Filling Process The lid 14B of the heating pressure vessel 14 is closed to seal the inside, and the on-off valve 38, on-off valve 40, and on-off valve 64 are opened while nitrogen gas is supplied from the gas supply device 22 to replace the air in the heating pressure vessel 14 with nitrogen gas. The air in the heating pressure vessel 14 is pushed out by the supplied nitrogen gas, and the air is released into the atmosphere via the piping 30, the first cyclone 32, the piping 34, the vacuum vessel 36, the piping 58, the second cyclone 60, the piping 66, and the incinerator 68.
The air in the heating pressure vessel 14 is replaced with nitrogen gas in order to remove oxygen from the heating pressure vessel 14 and to prevent oxidization (including combustion) of combustible materials inside the vessel in the subsequent process.

After a predetermined time has elapsed and the air inside the heating pressure vessel 14 has been replaced with nitrogen gas, the downstream open/close valve 38 is closed and high-pressure nitrogen gas is supplied from the gas supply device 22 to increase the pressure inside the heating pressure vessel 14 to a predetermined pressure higher than atmospheric pressure.
Here, the predetermined pressure is 2.0 MPa in this embodiment.

The control device 74 detects the pressure inside the heating pressure vessel 14 using the pressure sensor 18, and when it determines that the internal pressure has reached a predetermined pressure, it closes the opening/closing valve 28 of the gas supply device 22, sealing the inside of the heating pressure vessel 14.

(3) Tire Heating and Pressurizing Process After the heating pressure vessel 14 has been sealed, the control device 74 energizes the heater 16 to heat the tire 12 inside the vessel. The control device 74 measures the temperature inside the vessel with the temperature sensor 20, and controls the energization of the heater 16 so that the temperature inside the vessel becomes a predetermined temperature.
Here, the predetermined temperature is 500° C. in this embodiment.

In this way, by heating the tire 12 under the above-mentioned high pressure and high temperature conditions, the rubber of the tire 12 can be thermally deteriorated and made brittle. In addition, under the above-mentioned high pressure and high temperature conditions, the oil in the rubber is heated, but the oil is trapped inside the brittle rubber without volatilizing.

(4) While the tire 12 is being heated, the control device 74 closes the on-off valve 40, the on-off valve 46, the on-off valve 52, and the on-off valve 64 to seal the vacuum container 36, then opens the on-off valve 62 and operates the vacuum pump 56 to create a negative pressure (< atmospheric pressure) inside the vacuum container 36.

Then, after the inside of the vacuum vessel 36 is made negative pressure (<atmospheric pressure), the vacuum pump 56 is stopped and the open/close valve 62 is closed to maintain the negative pressure state of the vacuum vessel 36. At the same time, the cooling device 48 cools the vacuum vessel 36 to a predetermined temperature.
The predetermined temperature is a temperature at which the oil content of the gas introduced into the vacuum vessel 36 can be condensed.

(5) After a preset time has elapsed and heating of the tire 12 has been completed, the control device 74 stops the supply of electricity to the heating heater 16, opens the on-off valve 38 and the on-off valve 40, releases the pyrolysis gas in the heating pressure vessel 14 into the vacuum vessel 36 at once, and reduces the pressure in the heating pressure vessel 14 at once.
This causes the oil in the brittle rubber to rapidly volatilize and expand, and the brittle rubber can be easily crushed by the force of volatilization and expansion, allowing the steel and rubber to be separated simply and efficiently.
Thereafter, the on-off valve 64 is opened and high-pressure nitrogen gas is supplied from the gas supply device 22 to the heating pressure vessel 14, thereby pushing out the gas containing oil remaining inside the heating pressure vessel 14 towards the vacuum vessel 36.

(6) Oil removal (part 1)
The oil-containing pyrolysis gas discharged from the heating pressure vessel 14 has some of the oil removed in the first cyclone 32 before reaching the vacuum vessel 36, and the pyrolysis gas from which the oil has been removed to some extent is introduced into the vacuum vessel 36.
The oil removed by the first cyclone 32 can be discharged into an oil recovery container 44 by opening an on-off valve 46 .

(7) Oil removal (part 2)
Since the vacuum vessel 36 is cooled by a cooling device 48, when the pyrolysis gas passes through the inside of the vacuum vessel 36, the pyrolysis gas is cooled and the oil in the pyrolysis gas is condensed, thereby further removing the oil from the pyrolysis gas.
The oil removed in the vacuum vessel 36 can be discharged into the oil recovery vessel 44 by opening the on-off valve 52 .

(8) Oil removal (part 3)
The pyrolysis gas that has passed through the vacuum vessel 36 then passes through a second cyclone 60 where the oil component is further separated.
The oil removed by the second cyclone 60 can be discharged to the oil recovery container 44 via a pipe 70 .

(9) Gas Combustion Exhaust The pyrolysis gas discharged from the second cyclone 60 may contain flammable gas. In this case, it is preferable to ignite the flammable gas by the ignition burner 72 when the gas passes through the incinerator 68, and to combust (burn) the flammable gas in the incinerator 68.
The exhaust gas remaining after burning the combustible gas can be discharged from the incinerator 68 into the atmosphere.

(10) Once the heated pressure vessel 14 has cooled, the supply of nitrogen gas from the gas supply device 22 to the heated pressure vessel 14 can be stopped, the lid 14B can be opened, and the steel and rubber that have been separated from each other can be removed from the heated pressure vessel 14.

If any lumps remain in the rubber after the steel has been removed, a crushing process may be added to finely crush the lumps.

In this embodiment, the tire 12 to be treated is placed in the heating pressure vessel 14 without being cut, so there is no need to disassemble the tire 12 to be treated before placing it in the heating pressure vessel 14.

In addition, after the rubber is crushed and separated inside the heating pressure vessel 14, it is possible to continue heating the rubber to carbonize it. Also, organic fibers contained in the tire 12 can be carbonized together with the rubber.

The charcoal, steel, and oil recovered from the gas thus separated can be recycled as appropriate. The charcoal and steel can be used as raw materials for tires and other purposes.

In addition, the rubber and steel are separated inside the heating and pressure vessel 14, and the tire 12 is placed into the heating and pressure vessel 14 without being cut, so the mesh steel belt and steel bead core retain their annular shape. Therefore, they can be easily scooped up by hooking them onto a crane hook or the like.

In addition, steel belts and steel bead cores can also be removed using a magnet.

In addition, because the tire 12 is not cut, no steel dust is generated, and no finely shredded steel or iron powder remains in the heating and pressure vessel 14.

[Other embodiments]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms without departing from the spirit and scope of the present invention.

In the above embodiment, the tire 12 was pyrolyzed using the pyrolysis device 10, but the pyrolysis device 10 can also pyrolyze any polymeric compound containing inorganic materials in the same manner as the tire 12.

Examples of waste containing inorganic materials (polymer compounds) include rubber crawlers containing metal cores, rubber belts containing steel cords, rubber hoses containing steel cords, and rubber-coated electric wires, but other materials may also be used.
The inorganic material is not limited to steel, but may be a metal material other than steel, such as copper or brass.
Examples of polymeric compounds other than rubber include synthetic resins such as polyester and nylon.

In the above embodiment, the tire 12 was treated with a pressure of 2.0 MPa inside the heating pressure vessel 14 and a temperature of 500°C inside the vessel, but the pressure and temperature are not limited to these. Conditions for thermally deteriorating the rubber can be a pressure in the range of 0.15 MPa or more and 2.0 MPa or less, and a temperature in the range of 350°C or more and 500°C or less.

10... Pyrolysis device, 14... Heating and pressurizing container, 16... Heater (heating device), 18... Pressure sensor, 20... Temperature sensor, 22... Gas supply device, 36... Vacuum container (liquid component recovery device), 38... Opening and closing valve (first opening and closing valve), 40... Opening and closing valve (first opening and closing valve), 48... Cooling device (liquid component recovery device), 58... Pipe (exhaust section), 60... Second cyclone (exhaust section), 64... Opening and closing valve (second opening and closing valve, exhaust section), 66... Pipe (exhaust section), 68... Combustion furnace (exhaust section), 74... Control device

Claims (4)

a heating and pressure vessel capable of containing waste containing inorganic materials in a sealed state, the vessel being provided with a pressure sensor for detecting an internal pressure and a temperature sensor for detecting an internal temperature ;
a heating device for heating the waste material containing the inorganic material;
a gas supply device that supplies gas to the heating pressure vessel to increase the pressure in the heating pressure vessel;
a liquid component recovery device connected to the heating pressure vessel via a first opening/closing valve and configured to recover a condensed liquid component by cooling the pyrolysis gas generated in the heating pressure vessel;
an exhaust section connected to the liquid component recovery device, having a second opening and closing valve, and sending the pyrolysis gas from the liquid component recovery device to an incinerator, combusting the gas in the incinerator, and then exhausting the gas to the outside;
a control device that controls the operation of the heating device, the gas supply device, the first opening/closing valve, and the second opening/closing valve ,
The control device, based on the detection data from the pressure sensor and the temperature sensor,
a step of closing the first opening/closing valve to seal the heating pressure vessel, and then operating the gas supply device to pressurize the inside of the heating pressure vessel to a predetermined pressure;
activating the heating device to heat the waste material in the heating pressure vessel to a predetermined temperature;
After the pressure in the heating pressure vessel reaches the predetermined pressure, the first opening/closing valve is opened to send the pyrolysis gas to the liquid component recovery device;
After recovering the liquid component with the liquid component recovery device, the second opening and closing valve of the exhaust section is opened to send the pyrolysis gas to the incinerator, and the pyrolysis gas is combusted in the incinerator and then exhausted to the outside;
A waste pyrolysis device that sequentially controls the above . The heating pressure vessel is provided with a pressure sensor for detecting an internal pressure and a temperature sensor for detecting a temperature inside the heating pressure vessel,
the control device controls the operation of the heating device, the gas supply device, the first opening/closing valve, and the second opening/closing valve based on pressure detection data from the pressure sensor and temperature detection data from the temperature sensor.
2. The waste pyrolysis apparatus according to claim 1. The waste material containing inorganic materials is a tire comprising rubber and steel cords.
3. The waste pyrolysis apparatus according to claim 1 or 2. The exhaust unit sends the pyrolysis gas after the liquid component is recovered by the liquid component recovery device from the liquid component recovery device to a cyclone, separates the oil contained in the pyrolysis gas in the cyclone, and sends the pyrolysis gas from which the oil has been removed to the incinerator.
The pyrolysis apparatus according to claim 1 .