KR102660629B1 - Apparatus and method for recycling waste synthetic resin - Google Patents

Abstract

The present invention provides a recycling device and method for recycling waste synthetic resin that can produce recycled oil (oil) from waste synthetic resin. The present invention provides a thermal decomposition furnace for generating oil vapor by thermally decomposing waste synthetic resin; A condenser that condenses the oil vapor generated in the pyrolysis furnace to produce condensate; a main flow line installed between the pyrolysis furnace and the condenser and supplying oil vapor generated in the pyrolysis furnace to the condenser; an oil-water separator that separates recycled oil from the condensate generated in the condenser; a main valve installed on the main flow line; a sub-flow line connected to the main flow line and configured to separate and discharge moisture-containing gas generated in the pyrolysis furnace at the beginning of pyrolysis of the waste synthetic resin; and a waste synthetic resin recycling device including a sub valve installed on the sub flow line, and a waste synthetic resin recycling method using the same. According to the present invention, water is separated and discharged at the beginning of thermal decomposition of waste synthetic resin, so that at least the oil-water separation process is improved and high-purity recycled oil can be separated and produced.

Description

Recycling device and method for recycling waste synthetic resin {APPARATUS AND METHOD FOR RECYCLING WASTE SYNTHETIC RESIN}

The present invention relates to a recycling device and a recycling method for waste synthetic resin that can produce recycled oil (oil) from waste synthetic resin, and according to one embodiment, includes a water separation process conducted at an appropriate temperature during thermal decomposition of waste synthetic resin, At least, it relates to a recycling device and method for waste synthetic resin that can improve the oil-water separation process and separate and produce high-purity recycled oil.

Landfilling or incineration of waste synthetic resin at least causes environmental problems. When waste synthetic resin is landfilled, most of it does not decompose and contaminates the soil. In addition, when incinerating waste synthetic resin, for example, SO _x , NO _x , chlorine gas, and dioxin are generated, polluting the air.

Accordingly, several technologies for recycling waste synthetic resin have been proposed. A representative example is chemical recycling technology using the thermal cracking process. Chemical recycling technology is a recycling technology that produces recycled oil (oil) from waste synthetic resin. This is a technology that generates oil vapor by thermally decomposing waste synthetic resin, and then condenses (cools) the generated oil vapor to convert it into recycled oil. At this time, the recycled oil can be recycled into fuel oil, etc. Chemical recycling technology uses a regeneration device (or emulsification device) including a pyrolysis furnace (or pyrolysis reactor), and such regeneration devices are also presented in several prior patents.

In this regard, Korean Patent No. 10-2029047 proposes a low-temperature pyrolysis oil production device equipped with a wax reprocessing device, and Korean Patent Publication No. 10-2010-0100366 proposes a waste synthetic resin emulsification device, Korean Patent Publication No. 10-2020-0092064 proposes an efficient recycling device for waste synthetic resin from pyrolysis oil. In addition, Japanese Patent Laid-Open No. JP 2007-246685 proposes a method for emulsifying waste, Japanese Patent Laid-Open No. JP 2010-222547 proposes an emulsification treatment plant for polymer waste, and Japanese Patent Laid-Open No. JP 2010-505021 proposes an emulsification treatment plant for polymer waste. A device and method for thermal decomposition and emulsification of plastic waste are presented.

Figure 1 is a configuration diagram showing a recycling device for waste synthetic resin according to the prior art. Referring to FIG. 1, generally, a waste synthetic resin regeneration device includes a pyrolysis furnace (1) that pyrolyzes waste synthetic resin to generate oil vapor, and condenses (cools) the oil vapor generated in the pyrolysis furnace (1) to produce condensate (regeneration). a condenser (2) that generates (including oil and moisture), an oil-water separator (3) that separates recycled oil from the condensate generated in the condenser (2), and a purification of the recycled oil separated in the oil-water separator (3) It includes a purifier (4) for (or rectification). Additionally, non-condensable gas that is not condensed in the condenser 2 is usually burned in the waste gas treatment furnace 5. In addition, the sludge (solid carbon, commonly referred to as “CHAR”) remaining in the pyrolysis furnace 1 is discharged and treated as waste.

However, the regeneration device for waste synthetic resin according to the prior art and the regeneration method using the same have problems in that, for example, it is difficult to remove moisture in an oil-water separation process and the purity of the regenerated oil is low. Generally, waste synthetic resin contains a large amount of moisture (about 10 to 15% by weight). Even if it is pre-dried before charging it into the pyrolysis furnace 1, the waste synthetic resin contains moisture. Accordingly, in the process of increasing the temperature (approximately 100°C) at the beginning of operation of the pyrolysis furnace (1), moisture is first evaporated and supplied to the condenser (2) to be condensed, and then the condensate is mixed with the regenerated oil generated by the condensation of oil vapor to form oil. It is supplied to the separator (3). Recycled oil and moisture (condensate) are separated through the oil-water separator (3), but the oil-water separator (3) has a large amount of moisture, making it very difficult to completely separate and remove the moisture. In addition, the recycled oil separated and recovered in the oil-water separator 3 contains at least the above moisture and has low purity.

Korean Patent No. 10-2029047 (2019.10.07. Registration Notice) Korean Patent Publication No. 10-2010-0100366 (published on September 15, 2010) Korean Patent Publication No. 10-2020-0092064 (published on August 3, 2020) Japanese Published Patent JP 2007-246685 (published on September 27, 2007) Japanese Published Patent JP 2010-222547 (published on October 7, 2010) Japanese Published Patent No. JP 2010-505021 (published on February 18, 2010)

The purpose of the present invention is to provide an improved recycling device and method for waste synthetic resin.

According to one embodiment, the present invention includes a water separation process performed at an appropriate temperature at the beginning of the pyrolysis process, and at least an oil-water separation process is improved and a waste synthetic resin recovery device capable of separating and producing high purity recycled oil; The purpose is to provide a reproduction method.

In order to achieve the above object, the present invention,

A pyrolysis furnace that generates oil vapor by pyrolyzing waste synthetic resin;

A condenser that condenses the oil vapor generated in the pyrolysis furnace to produce condensate;

a main flow line installed between the pyrolysis furnace and the condenser and supplying oil vapor generated in the pyrolysis furnace to the condenser;

an oil-water separator that separates recycled oil from the condensate generated in the condenser;

a main valve installed on the main flow line;

a sub-flow line connected to the main flow line and configured to separate and discharge moisture-containing gas generated in the pyrolysis furnace at the beginning of pyrolysis of the waste synthetic resin; and

Provided is a waste synthetic resin recycling device including a sub valve installed on the sub flow line.

According to an embodiment, the apparatus for recycling waste synthetic resin according to the present invention further includes a sub-condenser connected to a sub-flow line, and the sub-condenser condenses the moisture-containing gas discharged through the sub-flow line. At this time, the moisture-containing gas discharged through the sub-flow line may include moisture and chlorine.

In addition, the present invention,

A pyrolysis process in which waste synthetic resin is pyrolyzed in a pyrolysis furnace to generate oil vapor;

A condensation process of condensing the oil vapor generated in the thermal decomposition process in a condenser to produce condensate; and

An oil-water separation process of supplying the condensate generated in the condensation process to an oil-water separator to separate recycled oil from the condensate,

The thermal decomposition process is,

A moisture separation process for separating and discharging moisture-containing gas generated at the beginning of pyrolysis,

A method for recycling waste synthetic resin is provided, including an oil vapor supply process of separating and discharging the water-containing gas and then supplying oil vapor generated by thermal decomposition to a condenser.

In addition, the present invention,

A method for recycling waste synthetic resin using the waste synthetic resin recycling device of the present invention,

A pyrolysis process in which waste synthetic resin is pyrolyzed in a pyrolysis furnace to generate oil vapor;

A condensation process of condensing the oil vapor generated in the thermal decomposition process in a condenser to produce condensate; and

An oil-water separation process of supplying the condensate generated in the condensation process to an oil-water separator to separate recycled oil from the condensate,

The thermal decomposition process is,

A water separation process in which the main valve is closed and the sub valve is opened until the temperature in the pyrolysis furnace reaches 100°C to 120°C to separate and discharge the moisture-containing gas generated at the beginning of the pyrolysis through the sub-flow line;

When the temperature in the pyrolysis furnace exceeds 100 ℃ ~ 120 ℃, the main valve is opened and the sub valve is closed, and the oil vapor supply process of supplying the oil vapor generated by pyrolysis to the condenser through the main flow line of the waste synthetic resin. Provides a playback method.

The present invention provides an improved waste synthetic resin recycling device and recycling method that can recycle waste synthetic resin into useful resources. According to the present invention, at least the oil-water separation process, including the water separation process, is improved and high-purity recycled oil can be separated and produced.

Figure 1 is a configuration diagram showing a recycling device for waste synthetic resin according to the prior art.
Figure 2 is a configuration diagram showing a recycling device for waste synthetic resin according to an embodiment of the present invention.

The present invention provides a recycling device (or emulsification device) for waste synthetic resin that can separate and produce recycled oil (oil) from waste synthetic resin. Additionally, the present invention provides a recycling method (or emulsification method) for waste synthetic resin that can separate and produce recycled oil (oil) from waste synthetic resin. The method for recycling waste synthetic resin according to the present invention can be implemented, for example, using the recycling device for waste synthetic resin according to the present invention. Recycled oil produced by the present invention can be recycled, for example, into fuel oil, etc.

Hereinafter, the present invention will be described with reference to the attached drawings. The accompanying drawings illustrate exemplary embodiments of the invention, and are provided solely to aid understanding of the invention. In describing the present invention, detailed descriptions of related well-known general functions and/or configurations are omitted. The term “and/or” used in the present invention is used to include at least one of the components listed before and after.

Figure 2 is a configuration diagram showing a recycling device for waste synthetic resin according to an embodiment of the present invention.

Referring to FIG. 2, the waste synthetic resin recycling device (hereinafter, sometimes abbreviated as “recycling device”) according to the present invention includes a pyrolysis furnace 10 that pyrolyzes the waste synthetic resin to generate oil vapor; A condenser (20) that condenses the oil vapor generated in the thermal decomposition furnace (10) to produce condensate; It includes an oil-water separator (30) that separates recycled oil from the condensate generated in the condenser (20). At this time, a main flow line (L1) is installed between the pyrolysis furnace 10 and the condenser 20 to supply oil vapor generated in the pyrolysis furnace 10 to the condenser 20, and the main flow line (L1) The main valve (V1) is installed on the top. In addition, a sub-flow line (L2) is connected to the main flow line (L1) for separating and discharging moisture-containing gas generated at the beginning of thermal decomposition of waste synthetic resin, and a sub-valve (V2) is installed on the sub-flow line (L2). It is installed.

The regeneration device according to the present invention may further include a sub-condenser 22 connected to the sub-flow line L2 according to an embodiment of the present invention. In addition, the regeneration device according to the present invention includes a purifier 40 for refining (or rectifying) the regeneration oil separated in the oil-water separator 30; a waste gas storage/processing tank (50) for storing or processing non-condensable gas that is not condensed in the condenser (20); a wastewater storage/treatment tank (60) for storing or treating water separated from the oil-water separator (30); And/or a waste storage/treatment tank 70 for storing or processing sludge (CHAR as solid carbon, etc.) discharged from the pyrolysis furnace 10 may optionally be further included.

The method for recycling waste synthetic resin according to the present invention (hereinafter abbreviated as "recycling method" in some cases) includes a thermal decomposition process of generating oil vapor by thermally decomposing waste synthetic resin in a thermal decomposition furnace 10; A condensation process of condensing the oil vapor generated in the thermal decomposition process in a condenser (20) to produce condensate; It includes an oil-water separation process in which the condensate generated in the condensation process is supplied to an oil-water separator 30 to separate recycled oil from the condensate. At this time, the pyrolysis process includes a moisture separation process of separating and discharging the moisture-containing gas generated at the initial stage of pyrolysis, and an oil vapor supply process of supplying the oil vapor generated by pyrolysis to the condenser 20 after separating and discharging the moisture-containing gas. Includes.

In addition, the regeneration method according to the present invention includes a moisture condensation process for condensing the moisture-containing gas separated in the moisture separation process according to an embodiment of the present invention; A purification process of refining (or rectifying) the recycled oil separated in the oil-water separation process; and/or a sludge discharge process for discharging sludge (CHAR as solid carbon, etc.) remaining in the pyrolysis furnace 10 after performing the pyrolysis process, may optionally be further included. Hereinafter, a method for recycling waste synthetic resin according to an embodiment of the present invention will be described for each process, and a recycling apparatus for waste synthetic resin according to an embodiment of the present invention will also be described.

[1] Pyrolysis process

The waste synthetic resin is charged into the thermal decomposition furnace (10) and thermally decomposed. In the present invention, the waste synthetic resin is not particularly limited, and may be selected from waste generated at industrial sites or general homes. Waste synthetic resins include, for example, vinyl-based, polyethylene (PE)-based, polypropylene (PP)-based, polyethylene terephthalate (PET)-based, polystyrene (PS)-based, polyacrylic (PA)-based, and polyurethane (PU)-based. and/or polycarbonate (PC)-based, etc.

The waste synthetic resin may be washed and/or dried before being charged into the pyrolysis furnace 10. The waste synthetic resin can be dried, for example, by natural drying or heat drying, and the moisture can be sufficiently removed before being charged into the pyrolysis furnace 10. The waste synthetic resin may be crushed and/or pulverized to a predetermined size and charged into the pyrolysis furnace 10 in the form of particles. In addition, the waste synthetic resin may be charged into the pyrolysis furnace 10 through classification/selection, for example, using one type of the resins listed above or a mixture of two or more types.

The thermal decomposition furnace 10 is not particularly limited as long as it can generate oil vapor by thermally decomposing waste synthetic resin. The thermal decomposition furnace 10 may be, for example, a commonly used type. Oil vapor generated in the pyrolysis furnace 10 is supplied to the condenser 20. A main flow line (L1) is installed between the pyrolysis furnace (10) and the condenser (20). The main flow line (L1) connects the pyrolysis furnace 10 and the condenser 20 and provides a flow passage through which oil vapor generated in the pyrolysis furnace 20 can be supplied to the condenser 30. Additionally, a sub-flow line (L2) is connected to the main flow line (L1). The sub-flow line (L2) may be connected to the main flow line (L1) in a branched form. The sub-flow line (L2) provides a flow path through which water-containing gas generated in the pyrolysis furnace 10 can be separated and discharged during pyrolysis of waste synthetic resin (initial pyrolysis). At this time, a main valve (V1) is installed on the main flow line (L1), and a sub valve (V2) is installed on the sub flow line (L2). The main valve (V1) and sub-valve (V2) are not particularly limited as long as they can be opened and closed.

The pyrolysis process is carried out by charging waste synthetic resin into the pyrolysis furnace 10, blocking oxygen inflow, and heating (elevating the temperature). Conditions such as temperature and pressure of this thermal decomposition process can be carried out under normal conditions. The pyrolysis process may be performed as a low-temperature pyrolysis process in which the temperature in the pyrolysis furnace 10 is raised to, for example, 350°C to 450°C, or more specifically, to about 400°C. Additionally, the thermal decomposition process may be performed at a pressure of, for example, 3 to 7 atmospheres (atm) for, for example, 2 to 24 hours.

According to the present invention, the pyrolysis process includes a moisture separation process of separating and discharging the moisture-containing gas generated at the initial stage of pyrolysis, and an oil vapor supply process of supplying oil vapor generated by actual thermal decomposition of the waste synthetic resin to the condenser 20. . That is, at the beginning of the pyrolysis process, a water separation process is performed, and then at an appropriate point, the process is converted to an oil vapor supply process. The standard (point of time) for converting from the water separation process to the oil vapor supply process is the temperature within the pyrolysis furnace 10, which may be, for example, 100°C to 120°C.

In the present invention, the “initial stage of pyrolysis (or the beginning of the pyrolysis process)” refers to the time after the start of heating (temperature increase) until the temperature in the pyrolysis furnace 10 reaches the range of 100°C to 120°C, which is the time for water separation. This is the point (standard) at which the process is converted to an oil vapor supply process. At this time, if the temperature at the time of conversion is less than 100°C, the amount of water vapor generated is low and moisture separation efficiency is reduced, and if the temperature at the time of conversion is higher than 120°C, oil vapor may be separated and discharged along with moisture during the water separation process. Considering this, the temperature at the time of conversion may be 100°C to 110°C, or 100°C to 105°C, for example, about 105°C.

According to one embodiment, in the pyrolysis process, the temperature of the pyrolysis furnace 10 is raised and the moisture separation process (pyrolysis Initial) is performed, and then, at a temperature exceeding 100°C to 120°C (for example, about 105°C), an oil vapor supply process is performed in which oil vapor generated by actual thermal decomposition of the waste synthetic resin is supplied to the condenser 20. At this time, the oil vapor supply process is a temperature range from a temperature exceeding 100 ℃ to 120 ℃ (for example, about 105 ℃) to the final temperature increase temperature (for example, 350 ℃ to 450 ℃, for example, about 400 ℃) It can be carried out for an appropriate amount of time. Referring to FIG. 2, while the water separation process is in progress, that is, until the temperature in the pyrolysis furnace 10 reaches 100°C to 120°C (for example, about 105°C), the main valve (V1) is closed. Then, the sub-valve (V2) is opened to separate and discharge the moisture-containing gas generated at the beginning of pyrolysis through the sub-flow line (L2). In addition, while the oil vapor supply process is in progress, that is, when the temperature within the pyrolysis furnace 10 exceeds 100°C to 120°C (for example, about 105°C), the main valve (V1) is opened and the sub valve (V2) is opened. is closed to supply oil vapor generated by actual thermal decomposition of the waste synthetic resin to the condenser 20 through the main flow line (L1).

According to a specific embodiment, the water separation process may be performed at a temperature in the pyrolysis furnace 10 ranging from about 90°C to 105°C, and the oil vapor supply process may be performed at a temperature exceeding about 105°C within the pyrolysis furnace 10. That is, the thermal decomposition is carried out by raising the temperature of the thermal decomposition furnace (10), but the moisture-containing gas is separated and discharged in the temperature range of about 90°C to 105°C within the thermal decomposition furnace (10), and then the temperature within the thermal decomposition furnace (10) is about 105°C. In the temperature range exceeding ℃, oil vapor generated by actual thermal decomposition of the waste synthetic resin can be supplied to the condenser 20.

Additionally, in the water separation process, not only water but also chlorine can be separated and discharged. That is, the moisture-containing gas separated and discharged through the sub-flow line (L2) may include moisture and chlorine. The chlorine refers to Cl-containing compounds, which may include, for example, Cl ₂ , HCl, and/or Cl-containing hydrocarbons.

In addition, the oil vapor supplied to the condenser 20 may have a moisture content of 2% by weight or less. Specifically, most of the oil vapor supplied to the condenser 20 through the main flow line (L1) is removed through a moisture separation process, and may contain a trace amount of moisture of up to 2% by weight. According to the experimental study of the present invention, when the moisture separation process is carried out until the temperature reaches about 105°C in the initial stage of pyrolysis, it is found that the oil vapor supplied to the condenser 20 contains a trace amount of moisture of about 2% by weight. there was.

For example, the thermal decomposition process may proceed as follows.

First, finely pulverized waste vinyl is charged into the pyrolysis furnace 10, the inflow of oxygen is blocked (sealing the pyrolysis furnace), and then the pyrolysis furnace 10 is operated to raise the temperature. The main valve (V1) is closed and the sub-valve (V2) is opened until the temperature within the pyrolysis furnace 10 reaches approximately 105°C. At this time, in the process from about 90°C to 105°C (initial stage of pyrolysis), moisture-containing gas including water vapor and chlorine gas is generated, which is separated and discharged through the sub-flow line (L2). When the temperature in the pyrolysis furnace 10 exceeds about 105°C, the main valve (V1) is opened and the sub-valve (V2) is closed. At this time, the oil vapor generated by the pyrolysis temperature of about 105°C or higher is supplied to the condenser 20 along the main flow line (L1). For example, when the temperature of the pyrolysis furnace 10 is raised to about 400°C, the oil vapor generated in the temperature range of 105°C to 400°C is supplied to the condenser 20 along the main flow line (L1). .

As previously mentioned, the waste synthetic resin charged into the pyrolysis furnace 10 contains moisture even if it is pre-dried. This moisture is not completely removed by the oil-water separator 30, thereby lowering the purity of the recycled oil. Accordingly, the present invention is to separate and discharge moisture in advance at the beginning of the pyrolysis process, and then supply oil vapor containing a trace amount of moisture (for example, moisture content of 2% by weight or less) to the condenser 20. It is meaningful.

According to the pyrolysis process of the present invention as described above, the condensate supplied to the oil-water separator 30 through the condenser 20 has a very low moisture content, improving the oil-water separation process and having high purity. That is, the condensate supplied to the oil-water separator 30 contains a trace amount of moisture, so the recycled oil and moisture can be easily separated in the oil-water separator 30 and the moisture removal efficiency is improved. In addition, according to the present invention, not only moisture but also chlorine, etc. are separated and removed in the thermal decomposition process (water separation process), and high purity recycled oil can be efficiently produced.

[2] Condensation process

The oil vapor condensation process is performed by supplying the oil vapor generated in the pyrolysis furnace 10 to the condenser 20 and condensing (cooling) it through the condenser 20. The condenser 20 is not particularly limited as long as it can generate liquid condensate by condensing (cooling) the oil vapor introduced along the main flow line L1. For example, a commonly used condenser can be used. . The condensate generated in the condenser 20 contains recycled oil and a trace amount of moisture, and is supplied to the oil-water separator 30. In addition, the non-condensed gas that is not condensed in the condenser 20 is separated separately, and this follows a normal separation process. The non-condensable gas may be supplied to the waste gas storage/processing tank 50 and stored or processed.

Meanwhile, a moisture condensation process may be performed in which the moisture-containing gas discharged through the sub-flow line L2 is supplied to the sub-condenser 22 and condensed (cooled). That is, the moisture-containing gas may be supplied to the sub-condenser 22 connected to the sub-flow line (L2) and condensed. The sub-condenser 22 is not particularly limited as long as it can condense the moisture-containing gas discharged through the sub-flow line L2, and may be selected from a heat exchange cooler or the like. The condensate condensed through the sub-condenser 22 is wastewater containing moisture and chlorine, and can be supplied to the wastewater storage/treatment tank 60 to be stored or treated.

[3] Oil-water separation process

The condensate generated in the condenser 20 is supplied to the oil-water separator 30 to separate recycled oil from the condensate. That is, the recycled oil is separated and recovered from the condensate containing the recycled oil and moisture. The oil-water separator 30 is not particularly limited as long as it can separate recycled oil from condensate, and a commonly used type may be used. The recycled oil separated in the oil-water separator 30 is supplied to the purifier 40, and wastewater such as moisture is supplied to the wastewater storage/treatment tank 60 to be stored or treated.

[4] Purification process

The recycled oil separated in the oil-water separator 30 is supplied to the purifier 40 and purified. This purification process may include an impurity removal process and/or a rectification process. Through this refining process, high-purity recycled oil with impurities removed can be produced, or high-purity recycled oil separated by grade can be produced. The purifier 40 includes purification equipment (e.g., adsorption tower, etc.) for removing trace impurities contained in the recycled oil, and/or rectification equipment (distillation tower, etc.) for fractionally distilling the recycled oil and separating it into grades. can do.

According to one embodiment, the purifier 40 includes at least a fractional distillation column, and can purify (rectify) the recycled oil flowing in from the oil-water separator 30 by fractionally distilling it according to the boiling point. At this time, the refiner 40 fractionally distills the recycled oil and separates it into fuel oil by grade, for example, petroleum gas grade (methane, ethane, etc.), gasoline grade (naphtha), diesel grade, kerosene grade, and/or bunker oil grade. can do. In addition, the recycled oil (fuel oil by grade) refined (rectified) in the purifier 40 may be liquefied and stored/shipped, for example.

[5] Sludge discharge process

After the pyrolysis process is performed, a sludge discharge process is performed to discharge the sludge remaining in the pyrolysis furnace 10. That is, when the pyrolysis process is completed, sludge remains inside the pyrolysis furnace 10, which is discharged and removed for the subsequent pyrolysis process. Most of the sludge is fine powder containing solid carbon (CHAR), which can easily scatter into the air and contaminate the surroundings. Accordingly, the sludge can be removed by injecting (sprinkling) treated water into the pyrolysis furnace 10 to lower the temperature and have an appropriate water content (for example, about 40% by weight), and then discharging it together with the treated water. You can. This sludge can be discharged from the pyrolysis furnace 10 and then supplied to the waste storage/treatment tank 70 for storage or treatment.

In discharging the sludge, when treated water is injected (sprayed) into the high-temperature pyrolysis furnace 10, the treated water evaporates explosively and flows into the condenser 20 along the main flow line L1 along with solid carbon (CHAR). ), etc. can be introduced. In this case, it may be mixed with the recycled oil produced in the subsequent pyrolysis process and contaminate the recycled oil. To prevent this, when discharging the sludge, treated water is injected into the pyrolysis furnace 10 to discharge the sludge, and the main valve (V1) is closed and the sub valve (V2) is opened to discharge the sub flow. Sludge is discharged through line (L2). At this time, when the temperature of the pyrolysis furnace 10 falls below about 100°C, sludge can be discharged by opening and closing each valve (V1) (V2). In this way, when each valve (V1) (V2) is opened and closed to discharge sludge through the sub-flow line (L2), even if the treated water evaporates explosively, the solid carbon (CHAR) along with the main flow line (L1) and the condenser ( 20), etc., preventing contamination of recycled oil and ensuring quality.

In addition, the sludge can be discharged along with the treated water through the sub-flow line (L2) and then supplied to the waste storage/treatment tank 70 for storage/treatment. In addition, the treated water may be, for example, moisture separated in the oil-water separator 30, moisture condensed in the sub-condenser 22, and/or wastewater stored in the wastewater storage/treatment tank 60. You can. According to one embodiment, the treated water may include moisture separated in the oil-water separator 30.

Meanwhile, in the present invention, each of the lines L1 (L2) is not particularly limited as long as it can provide a passage through which fluid (liquid, gas, etc.) can pass. Each line (L1) (L2) may be made of a pipe made of a material selected from, for example, metal, synthetic resin, and/or ceramic, and may be hard and/or flexible. In addition, the lines (L1) (L2), the devices (10) (20) (22) (30) (40), and each device (10) (20) (22) (30) (40) are connected. Components such as piping may be equipped with valves, pumps, pressure gauges, flow meters, thermometers, level gauges, and/or controllers.

According to the present invention described above, a water separation process is carried out at the beginning of the thermal decomposition of the waste synthetic resin, so that at least the oil-water separation process is improved, and high purity recycled oil can be separated and produced from the waste synthetic resin. In the water separation process, at least water (and chlorine) is separated and removed, so that high purity recycled oil (fuel oil, etc.) can be produced.

10: Pyrolysis furnace 20: Condenser
22: Sub-condenser 30: Oil-water separator
40: Purifier 50: Waste gas storage/processing tank
60: Wastewater storage/treatment tank 70: Waste storage/treatment tank
L1: Main flow line L2: Sub flow line
V1: Main valve V2: Sub valve

Claims (8)

delete delete delete delete In the method of recycling waste synthetic resin, which separates and produces recycled oil from waste synthetic resin using a waste synthetic resin recycling device,
The waste synthetic resin recycling device,
A pyrolysis furnace (10) that generates oil vapor by pyrolyzing waste synthetic resin;
A condenser (20) that condenses the oil vapor generated in the thermal decomposition furnace (10) to produce condensate;
A main flow line (L1) installed between the pyrolysis furnace 10 and the condenser 20 and supplying oil vapor generated in the pyrolysis furnace 10 to the condenser 20;
An oil-water separator (30) that separates recycled oil from the condensate generated in the condenser (20);
A main valve (V1) installed on the main flow line (L1);
A sub-flow line (L2) connected to the main flow line (L1) and for discharging water-containing gas and sludge generated in the pyrolysis furnace (10); and
It includes a sub valve (V2) installed on the sub flow line (L2),
At the beginning of pyrolysis, the main valve (V1) is closed and the sub-valve (V2) is opened, so that the moisture-containing gas generated at the beginning of pyrolysis is separated and discharged through the sub-flow line (L2),
After the water-containing gas is separated and discharged, the main valve (V1) is opened and the sub-valve (V2) is closed, so that the oil vapor generated by pyrolysis is supplied to the condenser 20 through the main flow line (L1). become,
After the pyrolysis proceeds, treated water is injected into the pyrolysis furnace 10 and the sludge remaining in the pyrolysis furnace 10 is discharged, and the main valve (V1) is closed and the sub-valve (V2) is opened, The sludge remaining in the pyrolysis furnace (10) is a recycling device for waste synthetic resin discharged through the sub-flow line (L2),
The method for recycling the waste synthetic resin is,
Using the waste synthetic resin recycling device,
A pyrolysis process of generating oil vapor by pyrolyzing waste synthetic resin in a pyrolysis furnace (10);
A condensation process of condensing the oil vapor generated in the thermal decomposition process in a condenser 20 to produce condensate;
An oil-water separation process of supplying the condensate generated in the condensation process to an oil-water separator (30) to separate recycled oil from the condensate; and
After performing the pyrolysis process, it includes a sludge discharge process of discharging the sludge remaining in the pyrolysis furnace (10),
The thermal decomposition process is,
The main valve (V1) is closed and the sub-valve (V2) is opened until the temperature in the pyrolysis furnace 10 reaches 100°C to 120°C, so that the moisture-containing gas generated at the initial stage of pyrolysis is transferred to the sub-flow. A water separation process for separating and discharging water through the line (L2),
When the temperature in the pyrolysis furnace 10 exceeds 100°C to 120°C, the main valve (V1) opens and the sub-valve (V2) closes, allowing the oil vapor generated by pyrolysis to flow into the main flow line (L1). It includes a process of supplying oil vapor to the condenser 20 through,
In the sludge discharge process, treated water is injected into the pyrolysis furnace 10 to discharge sludge, and the main valve V1 is closed to prevent the sludge from flowing into the condenser 20 along the main flow line L1. A method for recycling waste synthetic resin, characterized in that the sub valve (V2) is opened to discharge the sludge remaining in the pyrolysis furnace (10) together with the treated water through the sub flow line (L2).
According to clause 5,
The method for recycling the waste synthetic resin is,
a moisture condensation process for condensing the moisture-containing gas separated in the moisture separation process; and
It further includes a purification process for purifying the recycled oil separated in the oil-water separation process,
The water separation process is carried out at a temperature of 90°C to 105°C in the pyrolysis furnace 10,
The oil vapor supply process is carried out at a temperature exceeding 105°C in the pyrolysis furnace 10,
The purification process includes a rectification process of fractionally distilling the recycled oil separated in the oil-water separation process according to its boiling point,
A method of recycling waste synthetic resin, characterized in that the treated water contains moisture separated in the oil-water separator (30).
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