JPH08151581A - Apparatus for producing cracked oil by pyrolysis of synthetic polymer and production of cracked oil - Google Patents

Abstract

PURPOSE: To provide a system capable of carrying out separation of solid material from a decomposed material in a state in which operation is continued while carrying out melting and pyrolysis of a raw material in a single tank. CONSTITUTION: In this apparatus for producing cracked oil, reaction liquid flow discharged from melting and thermally decomposing tank 1 is made to flow into a main circulating passage 2 and the main circulating passage 2 is branched into a main circulating passage 2 equipped with a valve A and an outside circulating passage 21 equipped with a valve B and the outside circulating passage 21 is provided with a solid material removing unit 3 for removing at least one part of the solid material which exists in the reaction liquid flow and then made to re-join to the main circulating passage 2 which is equipped with a heating unit 7.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an apparatus for producing oil by pyrolyzing a synthetic polymer. Specifically, it relates to an industrially useful apparatus for producing useful cracked oil such as fuel oil or raw material oil by thermally decomposing it as a measure for treating and reusing plastic waste that has started to be emphasized in environmental issues. . The present invention also relates to a production method for producing a useful cracked oil.

[0002]

2. Description of the Related Art It is conventionally known that when a synthetic polymer is heated to around 400 ° C., it is thermally decomposed to produce oil, tar-like substances or pitch-like substances. However, in the conventional technology, a device for melting the resin, that is, a melting tank and a reaction tank for thermally decomposing the resin are required, and as a result, the equipment cost inevitably becomes high. It was On the other hand, in a processing device that melts and thermally decomposes resin in a single tank, in order to remove non-thermally decomposable substances and solid substances generated by thermal decomposition, the device is stopped when they reach a predetermined amount. Had to do.

[0003]

The object of the present invention is a treatment capable of removing non-pyrolyzable substances and solid substances produced by pyrolysis without stopping a decomposition apparatus for melting and pyrolyzing a resin in a single tank. To provide a device. Therefore, an object of the present invention is to provide a manufacturing method which can effectively achieve the purpose by establishing advantageous operating conditions of the processing apparatus.

[0004]

The inventors of the present invention can perform melting and thermal decomposition of a resin in a single tank by using the processing apparatus illustrated in FIG. It has been found that solid matter generated by decomposition (both solid matter may be collectively referred to as "solid matter") can be removed without stopping the melting tank and the thermal decomposition tank. The processing apparatus of the present invention will be described below with reference to the drawings.

<Solid Material Removal System> FIG. 1 shows a processing apparatus of the present invention. In the figure, the reaction liquid flow that flows out from the melting tank / pyrolysis tank 1 flows into the main circulation path 2, and the main circulation path 2 is normally located as close as possible to the outflow point and is connected to the main circulation path 2 and the external circulation path 21. Branch to. The main circulation path 2 is a circulation path constituted by a forced circulation means P via a valve A, usually via a circulation pump, and a pipeline 2 which is recirculated to a melting tank / pyrolysis tank 1 by a heating unit 7.

On the other hand, the external circulation path 21 is equipped with a solid substance removing unit 3 for filtering out, for example, a non-pyrolyzable substance existing in the reaction liquid flow through the valve B and a part of the solid substance produced by the pyrolysis. It is composed of a pipeline and joins the main circulation path 2 again. In addition to this, as described above, the heating unit 7
May be incorporated. The purpose of mounting the heating unit 7 is to supply the heat required for the thermal decomposition reaction.

The solids removing unit 3 may be any of the commonly known solid / liquid separation means, and the means may be, for example,
A filter, a sedimentation tank, or a continuous centrifugal sedimentation separation means, for example, an apparatus marketed under the trade name "Super Decanter", etc., among which the preferred one is a continuous centrifugal sedimentation separation means. The reason is, as the name implies, that this solids removal unit can separate solid / liquid continuously.

The heating unit 7 is a double tube provided with a heating jacket, or a heating furnace type in which a flexible tube or a straight tube is accommodated in the heating furnace. The melting tank / pyrolysis tank 1 may be equipped with a stirrer (not shown), if necessary, in addition to stirring by the flow velocity of the charging liquid flow itself by the forced circulation means. This is particularly beneficial when a large amount of new cracking material is introduced.

Not only when carbon solids are added to the decomposition raw material but also when carbon solids are not added, instead of filtering off the total amount of solids in the reaction liquid flow, only a part of the reaction liquid flow is valve B. Is separated into an external circulation path 21 in which is incorporated and filtered to remove solids therein, and then the separated liquid stream is normally combined with the main circulation path 2, and the reaction liquid flow in the undivided portion is melted. It is also possible to recirculate to the pyrolysis tank 1. As a result, only a portion of the solids contained in the reaction stream will be removed.

<Operating conditions of the processing apparatus of the present invention> It is sufficient to set the thermal decomposition temperature when operating the processing apparatus of the present invention to the thermal decomposition temperature of the synthetic polymer which is the raw material for thermal decomposition or not. Usually 420 for resin-based raw materials
To 480 ° C., for polypropylene-based raw materials, the temperature is usually set to 390-450 ° C., and for raw materials mainly containing a mixture of approximately the same amount, the temperature that requires a higher decomposition temperature is set. .

The thermal decomposition time in the treatment apparatus of the present invention can be appropriately set according to the type of raw material and its thermal decomposition temperature. For example, when the thermal decomposition temperature is 400 ° C., the thermal decomposition time is set to 3 min to 3 h. To do. In that case, of course, while observing the thermal decomposition state of the synthetic polymer which is the thermal decomposition raw material, the setting conditions can be changed to a preferable side for realizing the desired thermal decomposition treatment.

The waste gas generated by the thermal decomposition treatment in the treatment apparatus of the present invention can be used as a fuel gas as a heat source for melting and thermally decomposing the waste plastic. An operation example of the processing apparatus of the present invention will be described with reference to FIG. The waste plastic is loaded into the processing apparatus 1 which is a melting tank and a thermal decomposition tank from the container S containing the waste plastic as a thermal decomposition raw material through the pipe Sc. When the processing device 1 is operated for the first time, the processing device 1 is empty, and therefore, a small amount of oily substance or a substance that can be easily turned into oil (abbreviation “auxiliary oil”) is used to facilitate the melting of the resin. It is preferable to charge the same in advance and / or at the same time as the start of operation.

As the auxiliary oil, kerosene, light oil, heavy oil,
Waxes, greases, atactic polypropylene, (waste) lubricating oils or waste oils, which are low melting point polymers, can be mentioned. As the above auxiliary oil, decomposed oil of waste plastic can also be used. Raw material waste plastic to be decomposed is put into the charged auxiliary oil, and heated to act to melt the raw material.

The valve B is closed while the raw material resin to be melted is in the solid state, and the valve A is opened while the raw resin is melted. After the raw material resin is melted, the valve A is closed and the valve B is opened to allow the reaction liquid flow to flow into the external circulation path 21, and the removal unit 3 removes solids and the like that hinder the stable operation of the processing apparatus 1. You can

Further, heating of the processing apparatus 1 is continued, and when the internal temperature reaches the thermal decomposition temperature of the raw material resin, a decomposition gas is generated and distilled out from the pipe line 4. When this decomposed gas is cooled by a cooler, a gas that is not liquefied even by cooling is obtained together with the decomposed oil and is discharged from the pipe 5. This gas can also be used as fuel for the heating device. What is liquefied by cooling is discharged from the pipe line 6 as decomposed oil.

When the decomposition of the waste resin as the raw material progresses and the content of the processing apparatus 1 decreases, and the amount of waste plastic becomes suitable for the next injection and melting of the next time, the valve B is closed and the valve A is opened. Put in waste plastic. From the second time, the molten resin of the previous time remains in the processing apparatus, so there is no need to use auxiliary oil for melting the resin such as kerosene used for the first time. The first operation is repeated for melting and thermal decomposition of waste plastic. By repeating this operation, the processing device 1
It is possible to carry out melting and thermal decomposition without stopping.

<Thermolysis Raw Material of the Method of the Present Invention> The synthetic polymer which is a raw material to be treated by the thermal decomposition of the method of the present invention includes both thermoplastic resin and thermosetting resin, and is polyethylene which is a thermoplastic resin. Polyolefin (PO) such as polypropylene, polystyrene (PS), high impact polystyrene (HIPS), ABS resin, ethylene-vinyl acetate copolymer resin (EVA), polyvinyl chloride (PV)
C), polyvinylidene chloride (PVDC), polycarbonate (PC) and the like, and thermosetting resins such as phenol resin, melamine resin, urea resin, alkyd resin and polyurethane (PU), which are independent of each other,
Alternatively, it may be a mixture of two or more kinds. However, the preferred decomposition raw materials are polyolefins, and especially preferred are polyethylene and polypropylene.

The synthetic polymer, which is a raw material for thermal decomposition in the method of the present invention, is not limited to a synthetic resin in a strict sense, but includes soft polymers, copolymers and compositions of two or more kinds thereof. Well, it is a concept that broadly includes wax-like substances, grease-like substances, etc. in addition to those distributed as "resin" in the plastic molding industry, and typical examples thereof are as follows: -Ethylene type Wax polymer or grease polymer, propylene wax polymer or grease polymer such as atactic polypropylene or synthetic rubber such as ethylene-propylene copolymer rubber (EPM), ethylene-propylene-non-conjugated diene copolymer Rubber (EPDM), styrene-butadiene copolymer rubber (SBR), butadiene-acrylonitrile copolymer rubber (NBR), Loroprene rubber (CR), polyisoprene rubber (IR), butyl rubber (IIR), polybutadiene rubber (BR) and their crosslinked products (vulcanized products), thermoplastic elastomers such as ethylene-propylene-non-conjugated diene copolymer rubber / polyethylene composition Partially cross-linked products, styrene-butadiene copolymer hydrides and synthetic "hydrocarbon resins" such as commonly known as "petroleum resins" are also included.

In particular, the coexistence of a low-melting-point polymer such as atactic polypropylene in the pyrolysis raw material in a certain amount is preferable for the practice of the method of the present invention. That is, in the treatment apparatus of the present invention, the low melting point polymer melts first, and serves to assist the melting or subdivision of the pyrolysis raw material polymer, which is a change that should occur prior to pyrolysis. For more information,
As a result of the molten low melting point polymer adhering to the surface of the synthetic polymer, which is the favorite thermal decomposition raw material, and effectively transmitting heat energy, the energy required for melting the favorite polymer is efficiently Can be expected to utilize.

In order to prevent coking on the wall surface of the processing apparatus 1, it is effective to add a carbon solid such as carbon black to the decomposition raw material. Non-pyrolysis products in these solid additives and solid products that can be produced by the pyrolysis from the additives need to be removed from the processing apparatus 1 after the pyrolysis is completed. In the treatment apparatus 1 of the present invention, in addition to the above solid additives, non-pyrolyzable substances and internal solid substances generated by thermal decomposition can be collectively removed by the solid substance removing unit 3.

[0021]

EFFECTS OF THE INVENTION The treatment apparatus of the present invention can achieve the following various effects in combination: (1) Continuous melting, pyrolysis and removal of non-pyrolysable substances and solids of a raw material synthetic polymer. The operation can be performed easily and efficiently by the contribution of not having to stop the processing device at that time. (2) As a result of the fact that the melting tank / pyrolysis tank, which is a means of pyrolyzing the raw material synthetic polymer to produce oil, can perform pyrolysis while melting the resin, the equipment cost of the means is high. Can be reached. (3) The processing apparatus of the present invention can be used by modifying the conventional thermal decomposition apparatus with some design changes.

[Brief description of drawings]

FIG. 1 is a process diagram showing an outline of a processing apparatus of the present invention.

[Explanation of symbols]

1 Melting tank / pyrolysis tank that constitutes the treatment apparatus of the present invention 2 Main circulation path for flowing out a reaction liquid stream from a melting tank / pyrolysis tank 3 Solids removal unit for separating solids from a reaction liquid stream 4 Produced by reaction Discharged pipeline of cracked gas 5 Discharged pipeline of non-liquefied cracked gas produced by reaction 6 Discharged pipeline of oil liquefied by cooling the cracked gas produced by reaction 7 Heating unit 21 Solid matter is separated from the reaction liquid stream External circulation path equipped with a solids removal unit for separation S Container for raw material synthetic polymer Sc Means for feeding raw material synthetic polymer to melting tank / pyrolysis tank

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukishige Shigemura 3-25 Kasumigaseki, Chiyoda-ku, Tokyo Mitsui Petrochemical Industry Co., Ltd. Address Mitsui Sekiyu Kagaku Kogyo Co., Ltd. (72) Inventor Shigeru Hara 2-6 Nakase, Mihama-ku, Chiba, Chiba Mitsui Petrochemical Engineering Co., Ltd.

Claims (7)

[Claims] 1. A main circulation passage that flows out of a tank-type melting device and thermal decomposition device, and an external circulation passage that splits from the main circulation passage but joins again later. The main circulation passage is melted via its valve A. After refluxing to the device / pyrolysis device, at least a part of the reaction liquid flow flowing in the main circulation path is branched to the external circulation path by opening the valve B, and the solid matter is removed in the external circulation path by the solid matter removal unit. Is an oil production apparatus for re-joining the reaction liquid flow of 1 to the main circulation path, and further diverts the diversion flow from the main circulation path to the external circulation path by closing valve B and opening valve A as required. A device for producing cracked oil of selective external circulation type that is organized as possible. 2. The selective external circulation type cracked oil production apparatus according to claim 1, wherein the solid matter removal unit is a continuous centrifugal sedimentation separation means. 3. The selective unit according to claim 1 or 2, wherein a heating unit is mounted in the pipe after the external circulation has joined the main circulation again or in the external circulation just before the merge with the main circulation. External circulation type cracked oil manufacturing equipment. 4. The selective external circulation type cracked oil according to claim 3, wherein the heating unit is a double tube provided with a heating jacket or a heating furnace type in which a serpentine tube or a 99 straight tube passes through the heating furnace. Manufacturing equipment. 5. A method for producing cracked oil for melting and pyrolyzing a synthetic polymer as a pyrolysis raw material, wherein at least a part of a reaction liquid flow flowing through a main circulation path connected to the melting device and the pyrolysis device is valved. A method for producing cracked oil, in which B is opened and branched to an external circulation path, and the reaction liquid stream after the solid matter is removed by the solid matter removal unit in the external circulation path is joined again to the main circulation path. 6. The method for producing cracked oil according to claim 5, wherein the split flow from the main circulation route to the external circulation route is further bypassed by closing valve B and opening valve A as required. 7. A solid synthetic polymer is intermittently charged into a melting device / pyrolysis device without melting and the valve B is closed until the synthetic polymer is completely melted in the device. The thermal decomposition is performed while removing solids from the liquid stream by opening the valve B as necessary to divert the reaction fluid stream to the external circulation path after the polymer has completed melting. A method for producing a cracked oil as described.