阅读说明：本技术 通过废油的二级热解生产选择性石脑油的方法 (Process for producing selective naphtha by secondary pyrolysis of used oils ) 是由 金佳英 金度京 金希洙 李昌奎 于 2021-06-03 设计创作，主要内容包括：本发明提供了一种由混合塑料生产石脑油的方法,该方法包括：使混合塑料进行热解的步骤(a)；将热解过程中产生的产物分离为沸点低于150℃的第一油和沸点高于第一油的沸点的第二油的步骤(b)；和使第二油进行催化热解的步骤(c)。(The invention provides a method for producing naphtha from mixed plastics, which comprises the following steps: a step (a) of subjecting the mixed plastic to pyrolysis; a step (b) of separating a product produced in the pyrolysis process into a first oil having a boiling point lower than 150 ℃ and a second oil having a boiling point higher than that of the first oil; and a step (c) of subjecting the second oil to catalytic pyrolysis.)

1. A method for producing naphtha from mixed plastics comprising:

a step (a) of subjecting the mixed plastic to pyrolysis;

a step (b) of separating the products produced in the pyrolysis process into a first oil having a boiling point lower than 150 ℃ and a second oil having a boiling point higher than that of the first oil; and

step (c) of subjecting said second oil to catalytic pyrolysis.

2. The process of claim 1 further comprising the step (d) of separating a third oil having a boiling point below 150 ℃ by fractionating the product produced in step (c), and mixing the separated third oil with the first oil to produce a final oil.

3. The method of claim 1, wherein in step (a), the mixed plastic is pyrolyzed at a temperature of 500 ℃ or less.

4. The method of claim 1, wherein in step (b), the first oil and the second oil are separated in a weight ratio of 5:95 to 30: 70.

5. The process according to claim 1, wherein the yield of naphtha in the first oil is from 5 to 30 wt. -%, relative to 100 wt. -% of the pyrolysis oil obtained in step (a).

6. The method according to claim 1, wherein the first oil and the second oil satisfy the following relational expression 1:

[ relational expression 1]

1<A₁/A₂<5

Wherein A is₁Is the content of Cl in the first oil in weight percent, A₂Is the content in weight% of Cl in the second oil.

7. The method according to claim 1, wherein the first oil and the second oil satisfy the following relational expression 2:

[ relational expression 2]

1<B₁/B₂<1.5

Wherein B is₁Is the content in weight percent of olefins in the first oil, B₂Is the content in weight% of olefins in the second oil.

8. The process according to claim 1, wherein the olefinic component is comprised in the second oil in an amount of 20-70 wt.%, relative to the total weight of the second oil.

9. The method of claim 8, wherein an external olefin component is included in the second oil in an amount of 5 to 40 wt.%, relative to the total weight of the second oil.

10. The process of claim 1, wherein the catalyst used in step (c) is a zeolite, clay, silica-alumina-phosphate (SAPO), Aluminophosphate (ALPO), Metal Organic Framework (MOF), silica-alumina, or mixtures thereof.

11. The process according to claim 2, wherein the yield of naphtha in the third oil is from 10 to 50 wt% with respect to 100 wt% of the pyrolysis oil obtained in step (a).

12. The process of claim 1, wherein in step (c), the second oil is subjected to catalytic pyrolysis at a temperature of 500 ℃ or less.

13. The process according to claim 2, wherein the yield of naphtha in the final oil produced is 35 wt.% or more with respect to 100 wt.% of the pyrolysis oil obtained in step (a).

Technical Field

The present invention relates to a process for producing selective naphtha by secondary pyrolysis of used oil.

Background

Various waste plastic pyrolysis oils having different boiling points, such as naphtha (to 150 ℃), kerosene (150 ℃.), (265 ℃.), Light Gas Oil (LGO) (265 ℃.), and Atmospheric Residue (AR) (340 ℃ +) are produced by cracking (cracking) and pyrolysis (pyrolysis) reactions of waste materials (e.g., waste plastics).

As a technology for maximizing the yield of low carbon olefins according to the related art, a technology for increasing the value of waste plastics by introducing a Fluid Catalytic Cracking (FCC) catalyst, ZSM-5 (additive), or the like in a single reactor has been reported.

However, in the technology according to the related art, it is difficult to ensure cost-effectiveness by recycling waste plastics. Therefore, it is necessary to develop a technology to additionally increase the value of waste plastics.

Disclosure of Invention

Embodiments of the present invention aim to maximize the yield of naphtha by secondary pyrolysis (catalytic pyrolysis) of pyrolysis oil produced in primary pyrolysis (thermal pyrolysis).

Another embodiment of the present invention relates to the use of an environmentally friendly catalyst (FCC spent catalyst or FCC equilibrium catalyst (e.cat.)) for existing pyrolysis oil (pyrolysis oil) at relatively low temperatures to maximize the yield of naphtha.

Still another embodiment of the present invention is directed to providing a technology for increasing the value of waste plastics by previously separating specific components in primary pyrolysis oil and selectively reacting unseparated heavy oil before secondary pyrolysis.

In one general aspect, a method of producing naphtha from mixed plastics includes: a step (a) of subjecting the mixed plastic to pyrolysis (thermal pyrolysis); a step (b) of separating products produced in the pyrolysis process into a first oil having a boiling point lower than 150 ℃ and a second oil having a boiling point higher than that of the first oil; and a step (c) of subjecting the second oil to catalytic pyrolysis (catalytic pyrolysis).

The process may further comprise the step (d) of separating a third oil having a boiling point below 150 ℃ by subjecting the product produced in step (c) to fractional distillation, and mixing the separated third oil with the first oil to produce a final oil.

In step (a), the mixed plastic may be pyrolyzed at a temperature of 500 ℃ or less.

In step (b), the first oil and the second oil may be separated in a weight ratio of 5:95 to 30: 70.

The yield of naphtha in the first oil may be in the range of 5 to 30 wt% relative to 100 wt% of the pyrolysis oil obtained in step (a).

The first oil and the second oil may satisfy the following relational expression 1:

[ relational expression 1]

1<A₁/A₂<5

Wherein A is₁As the Cl content (% by weight) in the first oil, A₂As the Cl content (wt%) in the second oil.

The first oil and the second oil may satisfy the following relational expression 2:

[ relational expression 2]

1<B₁/B₂<1.5

Wherein B is₁Is the content of olefins in the first oil (% by weight), B₂Is the content of olefins in the second oil (wt%).

The olefin component may be contained in the second oil in an amount of 20 to 70 wt% with respect to the total weight of the second oil.

The external olefin (external olefin) component may be contained in the second oil in an amount of 5 to 40% by weight, relative to the total weight of the second oil.

The catalyst used in step (c) may be a zeolite, clay, silica-alumina-phosphate (SAPO), Aluminophosphate (ALPO), Metal Organic Framework (MOF), silica-alumina, or a mixture thereof.

The yield of naphtha in the third oil may be in the range of 10 to 50 wt% with respect to 100 wt% of the pyrolysis oil obtained in step (a).

In step (c), the second oil may be subjected to catalytic pyrolysis at a temperature of 500 ℃ or less.

The yield of naphtha in the final oil produced may be 35 wt% or more with respect to 100 wt% of the pyrolysis oil obtained in step (a).

Other features and aspects will become apparent from the following detailed description, the accompanying drawings, and the claims.

Drawings

Fig. 1 is a schematic view illustrating a method for producing naphtha from mixed plastics according to an exemplary embodiment of the present invention.

Detailed Description

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Throughout this specification, unless explicitly described to the contrary, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of further elements but not the exclusion of any other elements. In addition, the singular is also intended to include the plural unless the context clearly dictates otherwise.

In the present specification, unless otherwise defined, the expression "a to B" means "a is above and B is below".

In addition, unless otherwise defined, the expression "a and/or B" means at least one selected from a and B.

In the present specification, unless otherwise defined, the boiling point (bp) of each of the first oil and the second oil is measured at atmospheric pressure (1 atm).

An exemplary embodiment of the present invention is directed to a method of producing naphtha from mixed plastics, the method comprising: a step (a) of subjecting the mixed plastic to pyrolysis; a step (b) of separating products produced in the pyrolysis process into a first oil having a boiling point lower than 150 ℃ and a second oil having a boiling point higher than that of the first oil; and a step (c) of subjecting the second oil to catalytic pyrolysis.

It is an object of the present invention to produce naphtha by subjecting primary pyrolysis oil obtained from mixed plastics to secondary pyrolysis (catalytic pyrolysis). In the production of naphtha, naphtha components in primary pyrolysis oil are separated in advance, and only unseparated heavy oil is selectively catalytically reacted to maximize the yield of naphtha.

The step (a) is a step of subjecting the mixed plastic to pyrolysis. In step (a), the mixed plastic is converted to hydrocarbon products in a pyrolysis unit.

The mixed plastics include waste rubber and/or waste plastics. Specifically, the mixed plastic may include Polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), Polystyrene (PS), and the like.

The hydrocarbon product includes waste rubber and/or waste plastic pyrolysis oil. If desired, biomass pyrolysis oil, recycled lubricating oil, crude oil with a high chlorine content, or a mixture thereof may be further blended.

Pyrolysis (thermal pyrolysis) is designed as a pyrolysis method using a batch reactor (e.g., a rotary kiln batch reactor). After the mixed plastics are uniformly melted, primary pyrolysis (primary pyrolysis) may be performed, but the present invention is not limited thereto. Meanwhile, the pyrolysis may not particularly include a pretreatment step and an additive injection step performed to remove impurities and the like.

The pyrolysis may be carried out at a temperature of 500 ℃ or less, preferably 300 ℃ to 500 ℃, 350 ℃ to 400 ℃ or 400 ℃ to 450 ℃ and a pressure of 0 bar (g) or more and 3 bar (g) or less, preferably 0 bar (g) or more and 0.3 bar (g) or less, but the present invention is not limited thereto.

The pyrolysis may be performed for 30 minutes to 16 hours, preferably 5 hours to 12 hours, but the present invention is not limited thereto.

In the case of pyrolysis under the above-described temperature, pressure and/or time conditions, heavy oil having a high olefin content may be produced, and heavy oil having a high external olefin (external olefin) concentration may also be produced.

The step (b) is a step of separating the product produced during pyrolysis into a first oil having a boiling point lower than 150 ℃ and a second oil having a boiling point higher than that of the first oil. In step (b), the primary pyrolysis oil is separated into a naphtha component (first oil) and an unseparated heavy oil (second oil) before the secondary pyrolysis (catalytic pyrolysis).

The pyrolysis oil produced from the mixed plastic may be separated into oil having a specific boiling point by a conventional fractionation method, but the present invention is not limited thereto.

The boiling point of the first oil is below 150 ℃, for example, may be 120 ℃ to below 150 ℃, and may vary depending on the properties of the synthetic plastic pyrolysis oil. Specifically, the step (b) may be a step of separating the product generated during the pyrolysis into a first oil having a boiling point lower than 140 ℃ and a second oil having a boiling point higher than that of the first oil.

The second oil is unseparated heavy oil remaining after separation of the first oil. The second oil has a boiling point that exceeds the boiling point of the first oil. In the present invention, naphtha components in pyrolysis oil obtained from mixed plastics are previously separated, and only remaining unseparated heavy oil is selectively subjected to secondary pyrolysis (catalytic pyrolysis), thereby remarkably improving the yield of final naphtha. In the catalytic pyrolysis of waste plastic pyrolysis oil according to the prior art, there is a problem in that high content of Cl is generated due to the light naphtha fraction. In contrast, in the present invention, the first oil of the naphtha component is separated and the remaining heavy oil, which is not separated, is subjected to catalytic pyrolysis, so that a high content of naphtha may be generated and problems such as corrosion in a reactor and loss of products in a secondary pyrolysis (catalytic pyrolysis) process may be solved.

Meanwhile, the boiling points of each of the first oil and the second oil may be an average boiling point, and the error range thereof may be ± 10 ℃.

The first oil and the second oil are preferably separated in a weight ratio of 5:95 to 30:70, and may be separated in a weight ratio of 10:90 to 30: 70. In the above weight ratio range, the heavy components in the second oil are relatively increased to reduce the generation of the hydrocarbon gas and increase the generation of naphtha in the catalytic pyrolysis in the step (c).

The yield of naphtha in the first oil may be in the range of 5 to 30 wt. -%, 10 to 30 wt. -%, 20 to 30 wt. -% or 20 to 25 wt. -% with respect to 100 wt. -% of the pyrolysis oil obtained in step (a). Therefore, the above effects can be further improved.

The first oil and the second oil may satisfy the following relational expression 1.

[ relational expression 1]

1<A₁/A₂<5

Wherein A is₁As the Cl content (% by weight) in the first oil, A₂As the Cl content (wt%) in the second oil.

Relational expression 1 can satisfy 1<A₁/A₂<4、1<A₁/A₂<3.5 or 1<A₁/A₂<3。

The first oil and the second oil may satisfy the following relational expression 2.

[ relational expression 2]

1<B₁/B₂<1.5

Wherein B is₁Is the content of olefins in the first oil (% by weight), B₂Is the content of olefins in the second oil (wt%).

Relational expression 2 can satisfy 1<B₁/B₂<1.4、1<B₁/B₂<1.3、1<B₁/B₂<1.2 or 1<B₁/B₂<1.1。

A common phenomenon is that the content of olefins as light components in the first oil is high; however, in the present invention, the olefin content in the second oil is adjusted to a level similar to that in the first oil. Therefore, the oil having a high olefin content is catalytically pyrolyzed, so that the yield of naphtha can be increased. Meanwhile, in the case of performing catalytic pyrolysis in step (c), recombination (recombination) of organic Cl occurs by combining Cl with olefin in the second oil, resulting in a loss of product. However, in the present invention, the Cl content in the second oil is low relative to the Cl content in the first oil, the loss of products is significantly less, and the production of hydrocarbons is reduced even if the olefin content is high. Thus, the production of naphtha can be significantly increased. In addition, from the viewpoint of corrosion of the subsequent catalytic pyrolysis reactor, Cl is mainly removed by separating the first oil in which the Cl content is high, so that chloride stress corrosion cracking (Cl — SCC) can be prevented.

The olefinic component in the second oil may be 20 to 70 wt% relative to the total weight of the second oil, and specifically, may be 30 to 70 wt%, 30 to 60 wt%, or 30 to 50 wt% relative to the total weight of the second oil. In the case where the content of olefins upon catalytic pyrolysis of pyrolysis oil is within the above range, the generation of oil gas is suppressed and the yield of naphtha is improved.

The external olefinic component in the second oil may be from 5 to 40 wt%, relative to the total weight of the second oil, and specifically may be from 10 to 40 wt%, from 10 to 30 wt%, or from 15 to 30 wt%, relative to the total weight of the second oil. In the case of catalytic pyrolysis in step (c), recombination of organic Cl occurs through the combination of external olefins with Cl instead of internal olefins in the oil (internal olefin), which results in product loss. However, in the present invention, the content of Cl is low, although the content of the external olefin in the second oil is high. Thus, the loss of product is very low and the production of oil and gas is reduced. Thus, the production of naphtha can be significantly increased.

Step (c) is a step of subjecting the second oil to catalytic pyrolysis in a catalytic pyrolysis unit and a step of converting the second oil into naphtha. In the step (c), only the unseparated heavy oil may be selectively subjected to catalytic pyrolysis to increase the yield of naphtha.

In catalytic pyrolysis, a second oil may be injected into the catalytic pyrolysis unit, and the second oil may be in N₂The catalytic pyrolysis is carried out in an atmosphere at a temperature below 500 ℃ and preferably at 450-500 ℃ and atmospheric pressure for 1-30 minutes, preferably 1-10 minutes or 1-2 minutes. Under the above catalytic pyrolysis conditions, the yield of naphtha can be increased.

Zeolites, clays, silica-alumina-phosphates (SAPOs), Aluminophosphates (ALPOs), Metal Organic Frameworks (MOFs), silica-aluminas, or mixtures thereof may be used as catalysts. The waste zeolite, waste clay, etc. obtained in the petrochemical process may be directly used, or the waste zeolite, waste clay, etc. may be used by simple treatment to further improve the activity.

Meanwhile, for example, a fluid bed catalyst is used in a Residual Fluidized Catalytic Cracking (RFCC) process in which residual oil is converted into light/middle distillates. In order to keep the overall activity (entity activity) constant in the RFCC process, a certain amount of the catalyst in operation (catalyst in operation) is replaced by fresh catalyst, the catalyst being replaced at this time is called the RFCC equilibrium catalyst (E-Cat), and all of it is considered as waste. RFCC equilibrium catalysts can be used as the catalyst of the present invention and can contain 30-50 wt% zeolite, 40-60 wt% clay and 0-30 wt% other materials (alumina, silica gel, functional materials, etc.). By using such an RFCC equilibrium catalyst as a catalyst, the difference in cracking activity is small compared to a fresh catalyst, and there are advantages such as environmental protection and cost reduction by recovery.

In the process of the present invention, a simple treatment may be required to use waste zeolite, waste clay, or the like as a catalyst. When the active sites of the catalyst are physically blocked by substances such as coke and oil, the catalyst may be used after removing the substances therefrom. Air combustion may be performed to remove coke, and treatment with a solvent may be performed to remove oil. In the case where the metal component affects the active sites of the solid acid material to inactivate the active sites, a DeMet process for removing the metal component by a mild acid or dilute hydrogen peroxide treatment may be employed, if necessary.

Meanwhile, the catalyst may further comprise a carrier or binder including carbon, an alkaline earth metal oxide, an alkali metal oxide, alumina, silica-alumina, zirconia, titania, silicon carbide, niobium oxide (niobia), aluminum phosphate, or a mixture thereof.

The content of the second oil may be 40 to 80 parts by weight, preferably 40 to 60 parts by weight, and more preferably 40 to 50 parts by weight, with respect to 100 parts by weight of the catalyst. When the introduced amount of the catalyst material is increased within the above range, the catalytic pyrolysis effect is improved, and when the amount of the second oil is 40 parts by weight or more, the generation of oil gas may be suppressed due to excessive reaction, which is preferable.

Meanwhile, the weight ratio of the catalyst to the second oil (catalyst/oil ratio) may be 1 to 3, 1 to 2.8, 1 to 2.6, 1 to 2.5, or 1.2 to 2.4.

The catalytic pyrolysis may be carried out under known reactor operating conditions of the second oil from which the naphtha component in the second oil is separated by using a fluidized bed reactor, such as catalytic pyrolysis using a semi-fluidized bed reactor, but the present invention is not limited thereto.

The method for producing naphtha from mixed plastics according to an exemplary embodiment of the present invention may further include the step (d) of separating a third oil having a boiling point of less than 150 ℃ by subjecting the product produced in the step (c) to fractionation, and mixing the separated third oil with the first oil to produce a final oil. Meanwhile, the boiling point of the third oil may be the same as that of the first oil, and in this case, the error range thereof may be ± 10 ℃.

The yield of naphtha in the final oil produced may be 35 wt% or more, 40 wt% or more, 45 wt% or more, 50 wt% or more, 51 wt% or more, or 52 wt% or more with respect to 100 wt% of the pyrolysis oil obtained in step (a). The upper limit of the yield is not particularly limited, but may be 90% by weight or less or 85% by weight or less. By the technique for additionally increasing the value of waste plastics according to the present invention, naphtha can be produced at a high yield, and cost-effectiveness can be ensured by recycling of waste plastics.

Hereinafter, preferred embodiments of the present invention and comparative examples will be described. However, each of the following examples is only a preferred exemplary embodiment of the present invention, and the present invention is not limited to the following examples.

Examples

(example 1)

(a) Primary pyrolysis oil is produced by pyrolysis of waste mixed plastics (PE, PP and PS) in a rotary kiln type reactor (rotary kiln type reactor). The fuel is fed into the lower part of the kiln and heated by burning the fuel so that the temperature in the kiln is 350-400 ℃. A part of the oil gas decomposed by heating is used to heat the kiln, and the remaining pyrolysis oil is cooled and condensed and stored in the primary storage tank. The pyrolysis oil in the primary storage tank is centrifuged to remove solid components, thereby producing primary pyrolysis oil.

(b) The resulting primary pyrolysis oil is separated by conventional fractionation methods into a first oil having a boiling point below 150 ℃ and a second oil having a boiling point above 150 ℃.

(c) The second oil remaining after the separation of the naphtha component (first oil) is injected into a semi-fluidized bed reactor in which a catalyst is loaded and catalytic pyrolysis is performed. (feed rate: 1 cc/min, catalyst/oil ratio: 2.4, temperature: 500 ℃ C.)

In this case, RFCC equilibrium catalyst (comprising 40% by weight of zeolite, 50% by weight of clay and 10% by weight of other materials (silica gel, alumina gel and functional material, average particle diameter: 80 μm) was used as the catalyst.) As the RFCC equilibrium catalyst, the catalyst discarded after being used as a cracking catalyst (RFCC Cat) in the RFCC process was directly used.

(d) The resulting catalytic pyrolysis product is separated into oil having a boiling point of less than 150 ℃ and oil having a boiling point of more than 150 ℃ by a conventional fractionation method, and then the oil having a boiling point of less than 150 ℃ is mixed with the naphtha (first oil) separated in the step (b), thereby producing final naphtha.

Comparative example 1

Comparative example 1 was conducted in the same manner as in example 1 except that: step (b) in example 1 was not performed, and the primary pyrolysis oil obtained in step (a) was added to the semi-fluidized bed reactor in step (c).

Evaluation examples

[ evaluation example 1 ]: evaluation of naphtha yield

The results of treating the waste mixed plastics in example 1 and comparative example 1 are shown in table 1.

[ Table 1]

	bp(℃)	Example 1	Comparative example 1
				1 st naphtha	Initial Boiling Point (IBP) to 150	23.9	-
2 nd naphtha	IBP to 150	28.6	-
				Total naphtha.	IBP to 150	52.5	34.3
Exhaust gas	C1 and C2 boiling points	0.7	1.8
				LPG	C3 and C4 boiling points	27.6	30.1
Kerosene (Kero)	150-265	10.9	19.3
				LGO	265-340	2.8	7.6
AR	340+	1.8	6.8

(in Table 1, 1 st naphtha and 2 nd naphtha are expressed as wt% of naphtha produced in step (b) and step (c), respectively, with respect to 100 wt% of primary pyrolysis oil total naphtha is expressed as yield (%) of final naphtha produced in step (d), yield (%) of final naphtha is obtained by adding 1 st naphtha and 2 nd naphtha.)

Referring to table 1, it can be confirmed that in the case of example 1, only the unseparated heavy oil remaining after previously separating the naphtha component in the primary pyrolysis oil is selectively subjected to the secondary pyrolysis, thereby improving the yield of the final naphtha. On the other hand, it was analyzed that in the case of comparative example 1, since the remaining oil other than the gas component in the pyrolysis oil produced in the primary pyrolysis (thermal pyrolysis) was used as the feed for the secondary pyrolysis (catalytic pyrolysis), the naphtha component contained in the primary pyrolysis oil was converted into the gas component by the secondary pyrolysis, and thus the yield of the final naphtha was decreased.

In addition, it was confirmed that in the case of example 1, the heavy components in the second oil used as a feed in the catalytic pyrolysis were relatively increased as compared to comparative example 1, thereby reducing the oil and gas (exhaust gas and C1 and C2) generated during the catalytic pyrolysis by 41%.

[ evaluation example 2] analysis of Properties of pyrolysis oil

(example 2)

(a) The primary pyrolysis oil is produced by performing a pyrolysis step including a reactive distillation and hydrogenation reaction step using a reactor having two reaction sections. As reaction conditions, the pyrolysis step including reactive distillation is carried out at a temperature of 500 ℃ or less, preferably 360-450 ℃ and the hydrogenation reaction step is carried out. The primary pyrolysis oil produced by reactive distillation has relatively small amounts of external olefins.

(b) The produced primary pyrolysis oil is separated into a first oil having a boiling point below 150 ℃ and a second oil having a boiling point above 150 ℃ by a conventional fractionation method.

(c) and (d) were carried out in the same manner as in example 1.

The olefin content, external olefin content and Cl content in the properties of the pyrolysis oil obtained in (a) of each of example 1 and example 2 are shown in table 2. The weight% of naphtha produced from the catalytic pyrolysis in (c) is shown in table 3.

[ Table 2]

[ Table 3]

	(c) Yield (% by weight) of naphtha in the catalytic pyrolysis product obtained in (1)
		Example 1	37.6
Example 2	32.7

(in Table 3, the yield of naphtha is expressed as wt% of the catalytic pyrolysis product naphtha obtained in (c) relative to 100 wt% of the primary pyrolysis oil obtained in (a))

Referring to table 2, it can be confirmed that the properties of the first oil and the second oil are within the range of relational expression 1 of the present invention in the case of example 1 and example 2. In particular, referring to table 3, it can be confirmed that, in the case of example 1, the properties of the first oil and the second oil are within the preferred range of relation 2, indicating that the naphtha yield during catalytic pyrolysis is significantly increased.

By the technique for additionally increasing the value of waste plastics according to the present invention, naphtha can be produced at a high yield, and cost-effectiveness can be ensured by recycling of waste plastics.

In the foregoing, although the exemplary embodiments of the present invention have been described, the present invention is not limited to the exemplary embodiments and may be made in various forms different from each other. It will be appreciated by those skilled in the art that the present invention can be embodied in another specific form without departing from the technical spirit or essential characteristics thereof. It should therefore be understood that the exemplary embodiments described above are illustrative and not restrictive in all respects.