KR100473525B1 - Apparatus and Method for Controlling Pressurized and Vacuum Conditions for the Pyrolysis of Waste Polymer - Google Patents

Abstract

In the polymer waste pyrolysis apparatus and method thereof, the pressure state inside the pyrolysis apparatus is selectively changed to set decomposition conditions according to the pyrolysis characteristics of each type of waste polymer material, thereby maintaining the oil quality of the produced oil or obtaining a desired product. It is an object of the present invention to provide a polymer waste pyrolysis apparatus having a pressure converting system and a method thereof.

According to the present invention, a melter 21 for melting polymer waste, a reactor 22 for pyrolyzing the molten waste, a quench tank 23 for cooling the gas generated in the reactor 22, and a quench tank ( 23. A pyrolysis apparatus for polymer waste, comprising a condenser 25 for condensing a product in 23, wherein the melter 21, the reactor 22, the quench tank 23, and the condenser 25 communicate with each other. 25 is connected to the first gas discharge pipe 61 and the first control valve 41 is connected to the condenser 25 to discharge the gas located inside the condenser 25 to control the discharge of the gas, the condenser (25) The second gas discharge pipe 62 and the second gas discharge pipe 62 are installed in the second gas discharge pipe 62 and the second control valve 42 for discharging the gas located inside the 25 and controls the discharge of the gas inside the condenser 25 There is provided a polymer waste pyrolysis apparatus including a suction pump (50) for sucking gas.

Description

Apparatus and Method for Controlling Pressurized and Vacuum Conditions for the Pyrolysis of Waste Polymer}

The present invention relates to a polymer waste pyrolysis apparatus for decomposing a polymer waste to recover the produced oil, and in particular, to change the pressure state inside the system according to the type of waste, so that the oil quality of the generated oil can be kept constant or a desired product can be obtained. It relates to a polymer waste pyrolysis apparatus and a pyrolysis method having a pressure conversion system.

Representative polymer wastes include waste plastics and waste tires. It takes a long time for these waste plastics and waste tires to decompose naturally. When such waste plastics and waste tires are left in their natural state, they act as a source of contamination. Therefore, a pyrolysis apparatus has been developed for artificially decomposing such waste plastics and waste tires to remove contaminants and at the same time recovering and reusing the generated oil generated in the decomposition process.

Among polymer wastes, rubbers such as waste tires can be thermally decomposed under reduced pressure and atmospheric pressure because the thermal decomposition reaction conditions are not as difficult as that of general waste plastics.However, in the case of waste plastics, especially thermosetting resins, they are carbonized and not carbonized. If not maintained, it is difficult to pyrolyze, and even in the case of thermoplastic waste plastics containing mostly olefins, there is a disadvantage that oilification is difficult without catalysis. Therefore, pyrolysis under pressure is required to obtain an oil phase of a desired level or to obtain a desired product for pyrolysis of such waste plastics.

On the other hand, plastics have 5 general purpose PVC (Polyvinyl Chloride), PE (Polyethylene), PP (polypropylene), PS (Polystyrene), and ABS.The thermal decomposition temperature of plastics is different depending on the type of plastic. Conditions may also vary depending on the mixed component content of each plastic. In order to pyrolyze waste plastics having various mixed components as described above, the pressure inside the pyrolysis apparatus must be changed according to each condition. However, the conventional pyrolysis apparatus has not been developed a device and technology for changing the pressure in accordance with the decomposition conditions of the plastic, there is a disadvantage that the recovery rate of the product oil due to pyrolysis decreases as the pyrolysis operation proceeds to a constant atmospheric pressure. .

The present invention is provided to solve the problems of the prior art as described above, by changing the pressure state inside the system according to the type of polymer waste to maintain the oil quality of the produced oil to a desired level, as well as to increase the recovery rate It is an object of the present invention to provide a pyrolysis device and pyrolysis method having a system.

According to the present invention for achieving the object as described above, a melter for melting the polymer waste, a reactor for pyrolyzing the molten waste, a quench tank for cooling the gas generated in the reactor, and condensation of the product in the quench tank And a condenser, wherein the melter, the reactor, the quench tank, and the condenser are in a pyrolysis device for polymer waste, the condenser connected to the condenser to discharge the gas located inside the condenser and discharge the gas. A first gas discharge pipe installed with a first control valve to adjust; a second gas discharge pipe connected with the condenser to discharge a gas located inside the condenser; and a second control valve installed to control the discharge of the gas; 2 is installed in the gas discharge pipe to suck the gas inside the condenser There is provided a polymer waste pyrolysis device comprising.

In addition, the second gas discharge pipe of the present invention is communicated between the first control valve of the first gas discharge pipe and the condenser.

In addition, according to the present invention, in the pyrolysis method for pyrolyzing the polymer waste by depressurizing the internal pressure of the melter, the reactor, the quench tank and the condenser in the polymer waste pyrolysis apparatus, closing the first control valve. And a step of opening the second control valve and operating the suction pump to discharge the gas of the condenser through the second gas discharge pipe.

In addition, according to the present invention, in the pyrolysis method for pyrolyzing polymer waste by pressurizing the internal pressure of the melter, the reactor, the quench tank and the condenser in the polymer waste pyrolysis apparatus, the first and second control valves A method of thermally decomposing a polymer waste is provided, the method comprising: closing a pressure of the internal pressure of the condenser, opening the first control valve, and maintaining the internal pressure of the condenser at a constant pressure.

In general, one of the polymer waste plastics is represented by five general-purpose PVC, PE, PP, PS, ABS and PET, and the processing temperatures of these plastics are different. PVC which is a thermoplastic plastic is 230 degreeC, PS is 390 degreeC, ABS is 400 degreeC, PP which is an olefinic plastic is 430 degreeC, and PE is 450 degreeC.

These plastics are thermally decomposed through a pyrolysis device, and in the process of pyrolysis, the polymerized hydrocarbon chain is unwound and converted into low molecular hydrocarbons, which are condensed and recovered as product oils.

In general, in the case of heat treatment at a high temperature, the hydrocarbon chain is broken by the rapid pyrolysis, and high viscosity wax powder is produced. However, when pyrolysis at low temperature for a long time, low molecular weight hydrocarbon is formed and low boiling point pyrolysis generating oil such as light oil is produced. Therefore, in order to obtain a compatible pyrolysis-producing oil having a constant carbon size, a technique for controlling decomposition conditions by changing the pressure of the reactor in addition to a technique using a catalyst while maintaining an appropriate reaction temperature is required.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the polymer waste pyrolysis apparatus and the pyrolysis method having a pressure conversion system according to the present invention will be described in detail.

1 is a schematic diagram of a polymer waste pyrolysis apparatus having a pressure converting system according to an embodiment of the present invention.

As shown in FIG. 1, the waste plastic is stored in the hopper 20, and the waste plastic discharged to the lower portion of the hopper 20 is transferred to the melter 21 by a conveying means and melted. Then, the molten waste plastic is injected into the reactor 22 through the first tube 11, the gas generated in the reactor 22 is led to the quench tank 23 through the second tube 12, the quench tank The high boiling wax powder produced in (23) is recovered to the reactor 22 through the third pipe 13 again.

On the other hand, the pyrolysis product cooled in the quench tank 23 is introduced into the catalyst tower 24, the gas phase catalytic reaction in the catalyst tower 24 improves the properties of the product. The catalytically cracked pyrolysis product flows into the condenser 25, and the condensed product oil is discharged to the reservoir 26 while being indirectly cooled in the condenser 25.

On the other hand, the condenser 25 is provided with a pressure conversion system according to an embodiment of the present invention. The first control valve 41 is installed in the gas discharge pipe 61 connected to the condenser 25, and the branch pipe 62 is connected between the first control valve 41 and the condenser 25, and the branch pipe ( 62, a vacuum pump 50 is installed. The branch pipe 62 is provided with a second control valve 42 in front of the vacuum pump 50.

The function of each component of the polymer waste pyrolysis apparatus having the pressure conversion system configured as described above will be described in detail.

The hopper 20 is a tank for storing waste plastic, and a screw feeder 27 serving as a transfer means is provided at the lower portion of the hopper 20. The waste plastic dropped from the bottom of the hopper 20 is transferred in the direction of the melter 21 by the screw rotation of the screw feeder 27, and dropped into the inside of the melter 21.

Melter 21 is a device for melting the dropped waste plastic, the internal temperature is maintained at about 350 ℃, inside the stirrer 29 is installed inside the melter 21 to stir the waste plastic melted do. On the other hand, the first discharge pipe 31 is connected to the lower portion of the melter 21, the foreign matter deposited on the lower portion of the melter 21 in the state in which the operation of the melter 21 is stopped. Meanwhile, the melter 21 and the reactor 22 are connected by the first tube 11, and the waste plastic melted inside the melter 21 is introduced into the reactor 22 through the first tube 11. do.

The reactor 22 is a device for pyrolyzing the molten waste plastic introduced through the first pipe 11, and the temperature of the reactor 22 is maintained at about 430 ~ 450 ℃. An agitator 29 is installed inside the reactor 22, and a second discharge pipe 32 is connected to a lower end of the reactor 22. The second discharge pipe 32 discharges residues generated by the use of a catalyst during melted waste plastic pyrolysis or by mixing ABS resin or other thermosetting resin.

Meanwhile, the generated gas generated in the reactor 22 flows to the quench tank 23 through the second pipe 12 connected to the upper end of the reactor 22. The quench tank 23 is a device for separating high boiling wax powder from pyrolysis product and re-entering the pyrolysis reactor 22. The product gas introduced from the reactor 22 is separated into high boiling wax powder and pyrolysis product while cooling. The wax powder is reintroduced into the reactor 22 through the third tube 13 connected to the lower part of the quench tank 23, and the pyrolysis product is introduced into the catalyst tower 24 through the fourth tube 14. .

The catalyst tower 24 changes the properties of the pyrolysis product by gas phase catalytic reaction of the pyrolysis product. The product is introduced into the condenser 25 through the fifth tube 15 connected to the lower portion of the catalyst tower 24. The product material is cooled in the condenser 25 by indirect cooling and condensed into the product oil. The condensed product oil flows into the lower reservoir 26 through the third discharge pipe 33. Then, the product oil is discharged through the fourth discharge pipe 34 connected to the reservoir 26. The fourth discharge pipe 34 is provided with a third control valve 43 to control the discharge of the product oil.

On the other hand, from the melter 21 to the reactor 22, the quenching tank 23, the catalyst tower 24, and the condenser 25 are communicated with each other and the pressure therein is the same. Therefore, the internal pressures of the reactor 22, the quench tank 23, and the condenser 25 should be adjusted according to the type of waste plastic to be melted. In this case, the first control valve 41 connected to the condenser 25 and The internal pressure is adjusted by opening and closing the second control valve 42 and operating the vacuum pump 50.

First, when the internal pressure of the melter 21, the reactor 22, the quench tank 23, the catalyst tower 24, and the condenser 25 should be operated higher than the normal pressure, the first control valve 41 and The second control valve 42 is closed. Then, the internal pressure increases while the internal vapor pressure increases due to the temperatures of the melter 21, the reactor 22, the quench tank 23, the catalyst tower 24, and the condenser 25. As such, when the internal pressure increases and is higher than the target pressure, the first control valve 41 is adjusted to discharge some of the steam, thereby maintaining the internal pressure in a pressurized state.

On the contrary, when the inside of the melter 21, the reactor 22, the quench tank 23, the catalyst tower 24, and the condenser 25 should be operated in a vacuum state, the first control valve 41 is closed. do. After the second control valve 42 is opened, the vacuum pump 50 is operated to discharge steam therein through the gas discharge pipe 61. As such, the internal pressures of the melter 21, the reactor 22, the quench tank 23, the catalyst tower 24, and the condenser 25 are maintained in a vacuum state using the vacuum pump 50.

The polymer waste pyrolysis method having the pressure conversion system configured as described above will be described in detail.

The waste plastic stored in the hopper 20 is discharged to the bottom of the hopper 20 and charged into the melter 21 by the screw feeder 27. At this time, the temperature of the melter 21 is about 350 ℃, the charged waste plastic is melted, the stirrer 29 installed inside the melter 21 to prevent local heating on the wall of the melter 21 The molten waste plastic is stirred at a rotational speed of about 30 to 60 rpm to enable uniform heating of the melter 21.

Residual foreign matter generated during the melting process is discharged to the lower screw feeder 27 through the first discharge pipe 31 after the operation is completed. At this time, the discharge valve installed in the first discharge pipe 31 is opened only when the screw is operated.

The waste plastic melted in the melter 21 is introduced into the reactor 22 through the first pipe 11, at which time the temperature of the reactor 22 is maintained at about 430-450 ° C. Like the melter 21 operates the stirrer 29 for uniform heating and the stirring speed is maintained at 30 ~ 60rpm similar to the melter 21.

The product gas discharged from the reactor 22 flows into the quench tank 23 through the second tube 12, and the wax of high boiling point is passed through the third tube 13 installed below the quench tank 23. It is reintroduced into reactor 22.

The generated gas discharged from the quench tank 23 is introduced into the catalyst tower 24 and the catalyst tower 24 containing the assembled catalyst having a constant size of 4 to 5 mm to minimize pressure drop of the generated gas. do. At this time, the operating temperature of the catalyst tower is maintained at the same or slightly lower temperature than the temperature of the reactor 22 to about 400 ~ 450 ℃.

At this time, the pyrolysis product gas (hydrocarbon gas) having a long chain is converted into a constant chain size in contact with the catalyst and moves to the condenser 25 through the fifth tube 15. The condenser 25 is provided with a cooling water circulation system. The cooling gas circulation system indirectly cools the generated gas to recover the generated oil, and the generated oil moves to the storage tank 26 through the third discharge pipe 33 and is stored. At this time, the third control valve 43 is closed, and when the operation for a predetermined time or when a certain amount of the generated oil is recovered and stored in the storage tank 26 is electrically operated to open. The reason why the third control valve 43 is electrically operated and opened in this way is when the third control valve 43 is inadvertently opened and closed in the case of depressurization or pressurization operation rather than the normal pressure operation. This is because an obstacle may occur, and a risk of fire may be caused by inflow of air.

The non-condensable non-condensable gas mainly refers to a gas that is not recovered as the product oil, and passes through the first control valve 41 through the gas discharge pipe 61 or through the second control valve 42 connected to the vibration pump 50. Discharged. The operation when the gas is discharged through the first control valve 41 is a pressurized operation state, and the operation when the gas is discharged through the second control valve 42 indicates a decompression operation state.

In general, the melter 21, the reactor 22, the quench tank 23, and the catalyst tower 24 communicate with each other to maintain a constant pressure. In this state, if the first, second and third control valves 41, 42 and 43 are closed, the pressure is increased by the vapor pressure in the interior, and when the first control valve 41 is opened in such a state, melting occurs. The internal pressure of the vessel 21, the reactor 22, the quench tank 23, and the catalyst tower 24 is reduced. By controlling the opening and closing of the first control valve 41 in this way, the internal pressure in the pressurized state is adjusted.

In the case of depressurization operation, after closing the first control valve 41 and opening the second control valve 42, the vacuum pump 50 is operated to operate the melter 21, the reactor 22, and the quench tank 23. In operation, the internal pressure of the condenser 25 is maintained in a vacuum state, and the second control valve 42 adjusts the opening / closing degree and the rotation speed of the vacuum pump 50 according to the set vacuum degree.

On the other hand, in the above-described embodiment of the present invention, the branch pipe is connected to the gas discharge pipe connected to the condenser, the gas discharge pipe has been described that the first control valve is installed and the second control valve and the vacuum pump is installed in the branch pipe, In one embodiment of the present invention is the best embodiment, even if the second control valve and the branch pipe is installed directly connected to the condenser without branching from the gas discharge pipe pyrolysis process by converting the pressure and pressure reduction state that is the core of the present invention Can be performed.

As described in detail above, the polymer waste pyrolysis apparatus and the pyrolysis method including the pressure conversion system of the present invention are capable of adjusting operating conditions to efficiently decompose waste plastics having different decomposition temperatures or decomposition characteristics. According to the treatment method there is an advantage that the operation can be performed under reduced pressure and pressure.

For example, in order to improve the yield of the produced oil, it is possible to operate by lowering the decomposition temperature by a decompression process, and there is a peak that the pressurization process can be applied when the high temperature treatment is desired while improving the heat transfer rate using the fruit oil.

Although the technical idea of the polymer waste pyrolysis apparatus and the pyrolysis method including the pressure conversion system of the present invention has been described above with the accompanying drawings, this is for illustratively describing the best embodiments of the present invention. no. In addition, it is obvious that any person skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

1 is a schematic diagram of a polymer waste pyrolysis apparatus having a pressure conversion system according to an embodiment of the present invention.

       ♠ Explanation of symbols on the main parts of the drawing ♠

  11 ~ 15: Tube 20: Hopper

  21 melter 22 reactor

  23: quench tank 24: catalyst tower

  25 condenser 26 reservoir

  31 ~ 34: discharge pipe 41 ~ 43: control valve

  50: vacuum pump 61: gas discharge pipe

  62: branch pipe

Claims (4)

delete A device for pyrolyzing polymer waste, A melter for melting the polymer waste, A reactor for pyrolyzing the polymer waste melted in the melter, A quench bath for cooling the gas produced in the reactor, Catalyst tower for promoting the reaction of the pyrolysis product discharged from the quenching tank, A condenser for cooling the reactant discharged from the catalyst tower with a production oil, A first gas discharge pipe through which the gas generated in the condenser is discharged; A first control valve installed in the first gas discharge pipe to control the opening and closing amount of the first gas discharge pipe; A vacuum pump that sucks the gas inside the condenser and lowers the pressure inside the condenser; A second gas discharge pipe branched from the first gas discharge pipe and connecting the condenser and the vacuum pump; And a second control valve installed in the second gas discharge pipe to control the amount of opening and closing of the second gas discharge pipe. A pyrolysis method for thermally decomposing a polymer waste by depressurizing an internal pressure of the melter, the reactor, the quench tank and the condenser in the polymer waste pyrolysis apparatus of claim 2, Closing the first control valve; Opening the second control valve and operating the suction pump to discharge the gas of the condenser through the second gas discharge pipe. A pyrolysis method of pyrolyzing polymer waste in the polymer waste pyrolysis apparatus according to claim 2, wherein the pressure of the melter, the reactor, the quenching tank, and the condenser is pressurized. Closing the first and second control valves to pressurize the internal pressure of the condenser; And opening the first control valve and maintaining the internal pressure of the condenser at a constant pressurized state.