Method and equipment for producing chlorine-reduced waste plastic pyrolysis oil

Abstract

The present disclosure provides a method for producing waste plastic pyrolysis oil with reduced chlorine, comprising: a first step of charging a waste plastic raw material and a promoter containing char into a reactor; a second step of pyrolyzing the waste plastic raw material in the reactor to recover pyrolysis oil; and a third step of recovering the promoter from the reactor.

Description

[Technical field]

[0001] The present disclosure relates to a method and apparatus for producing reduced chlorine pyrolysis oil from waste plastics. [Background technology]

[0002] Solid fuel is a material produced by sorting, crushing, drying, chemical treatment, and molding combustible waste, such as waste plastic, waste fiber, waste tires, waste paper, waste wood, oil, and livestock by-products, among industrial and general waste, and in recent years, interest in using waste resources such as solid fuel to generate energy has been increasing. To generate energy from solid fuel, it can be burned, gasified, or pyrolyzed, and char is formed as a by-product during this process.

[0003] On the other hand, among solid fuels, waste plastics are produced using petroleum as a raw material, have a low recycling rate, and are often disposed of as garbage. Such waste takes a long time to decompose in natural conditions, polluting the soil and causing serious environmental pollution. One method used to recycle waste plastics is to thermally decompose them and convert them into oil.

[0004] However, pyrolysis oil obtained by pyrolyzing waste plastics contains a high content of impurities such as chlorine, nitrogen, metals, and solid by-products compared to oil produced from crude oil using conventional methods, and therefore cannot be immediately used as a high-value-added fuel such as gasoline or diesel oil. Instead, it must be used as fuel after the impurities are adsorbed through a refining process.

[0005] The conventional refining process for pyrolysis oil involves hydrotreating it in the presence of a hydrogenation catalyst to convert chlorine into hydrogen chloride and then adsorbing and removing it. However, because waste plastic pyrolysis oil contains a high content of chlorine, excess hydrogen chloride is produced during hydrotreating, which causes problems such as corrosion of the equipment, abnormal reactions, and deterioration of product properties.

[0006] In addition, the method of reducing chlorine, nitrogen, etc. using a desalting agent such as metal hydroxide, metal oxide, or waste FCC catalyst (E-cat) requires the use of an excess amount of the desalting agent (2 to 50 times the amount of the oil to be refined), which results in the problem that the desalting agent remains in the generated pyrolysis oil, making it difficult to obtain high-quality pyrolysis oil. In addition, the desalting agent deteriorates during the process of adsorbing chlorine, nitrogen, etc., reducing its adsorption capacity, and therefore the inactivated adsorbent must be replaced continuously. Therefore, there is a need for technology that can produce waste plastic pyrolysis oil with minimized chlorine content from waste plastic. Summary of the Invention [Problem to be solved by the invention]

[0007] The object of the present disclosure is to provide a method and apparatus for producing waste plastic pyrolysis oil, which can effectively reduce chlorine using char, a by-product produced in the waste plastic pyrolysis process, and can improve economic efficiency by reusing the char.

[0008] Another object of the present disclosure is to provide a method and apparatus for producing waste plastic pyrolysis oil that can effectively reduce chlorine by utilizing the physicochemical properties of char and a desalting agent.

[0009] Another object of the present disclosure is to provide a method and apparatus for producing waste plastic pyrolysis oil having a low chlorine content that allows the oil to be directly introduced into a refining process without a post-treatment process for the pyrolysis oil. [Means for solving the problem]

[0010] The present disclosure provides a method for producing waste plastic pyrolysis oil with reduced chlorine, comprising: a first step of charging a waste plastic raw material and an accelerator containing char into a reactor; a second step of pyrolyzing the waste plastic raw material in the reactor to recover pyrolysis oil; and a third step of recovering the accelerator from the reactor.

[0011] In one embodiment, the accelerator in the first step may be charged into the reactor in an amount of 5 to 30 parts by weight based on 100 parts by weight of the waste plastic raw material. In one embodiment, the promoter further comprises one or more dechlorinating agents selected from the group consisting of metal oxides, metal hydroxides, and metal carbonates, capable of reducing chlorine. In one embodiment, the desalting agent may be a metal oxide.

[0012] In one embodiment, the accelerator may be an agglomerate in which a plurality of first particles containing char are bound and agglomerated by the desalting agent. In one embodiment, the desalting agent may be an adhesive powder further containing moisture, and may bind the plurality of first particles together.

[0013] In one embodiment, the promoter may comprise char in an amount greater than the weight of the desalting agent. In one embodiment, the method may further include a fourth step of resupplying the promoter recovered in the third step to the first step.

[0014] In one embodiment, the fourth step may include the steps of washing the promoter recovered in the third step with alcohol, replenishing the promoter washed with alcohol and a desalting agent to produce a promoter, and resupplying the produced promoter to the first step.

[0015] In one embodiment, the second step may be carried out at a temperature of 300 to 600°C. In one embodiment, the second step may be carried out in a non-oxidizing atmosphere.

[0016] In one embodiment, the method may further include a step of further heating the prepared promoter at 500 to 1000° C. to improve activity before the step of re-supplying the promoter to the first step.

[0017] The present disclosure also provides an apparatus for producing waste plastic pyrolysis oil with reduced chlorine, the apparatus including: a reactor in which a waste plastic raw material and a promoter containing char are charged and a pyrolysis process is carried out; and a storage tank in which pyrolysis oil is recovered from the reactor.

[0018] In one embodiment, the system may further include a recovery tank for recovering the promoter from the reactor, and a recycle line for resupplying the promoter from the recovery tank to the reactor. Effect of the Invention

[0019] According to the present disclosure, by reusing char, a by-product produced during the thermal decomposition process of waste plastics, economic efficiency can be improved by utilizing it as an effective resource, and the excellent chemical resistance and adsorption properties of char can effectively reduce chlorine, thereby improving process efficiency.

[0020] According to the present disclosure, after pyrolysis of waste plastic raw materials, pyrolysis oil having a low impurity content that is applicable to refining processes can be produced without a separate post-treatment process. According to the present disclosure, the energy required can be effectively reduced compared to conventional waste plastic pyrolysis processes. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] As used herein, the singular forms of terms may be construed as including the plural forms as well, unless otherwise indicated. Numerical ranges used herein include lower and upper limits, all values ​​within the range, all values ​​limited therein, and all possible combinations of upper and lower limits of numerical ranges limited in different ways. Unless otherwise specified herein, values ​​outside the numerical range that may occur due to experimental error or rounding of values ​​are included in the defined numerical range.

[0022] As referred to in this specification, "comprising" is an open-ended term having the same meaning as terms such as "comprising," "containing," "having," "characterized," and the like, and does not exclude additional, unrecited elements, materials, or steps.

[0023] In this specification, the unit of % used without special mention means % by weight unless otherwise defined. In this specification, the ppm unit used without special reference means ppm by mass unless otherwise defined.

[0024] Waste plastics include polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), etc., and the waste plastics contain impurities such as organic chlorine and inorganic chlorine. The pyrolysis oil produced by the waste plastic pyrolysis process cannot be used immediately as a high-value-added fuel such as gasoline or diesel oil because of its high impurity content, but can be used as fuel after the impurities are adsorbed by a refining process. However, since the waste plastic pyrolysis oil contains a high content of chlorine, excessive hydrogen chloride is generated during hydrotreating, causing problems such as corrosion of the equipment, abnormal reactions, and deterioration of product properties. Therefore, a technology is needed to produce waste plastic pyrolysis oil with a low level of impurity content that can be directly introduced into the refining process without performing a separate post-treatment process.

[0025] Therefore, one embodiment of the present disclosure provides a method for producing waste plastic pyrolysis oil with reduced chlorine, comprising: a first step of loading waste plastic raw material and an accelerator containing char into a reactor; a second step of pyrolyzing the waste plastic raw material in the reactor to recover pyrolysis oil; and a third step of recovering the accelerator from the reactor.

[0026] The waste plastic raw material may be a domestic waste plastic waste or an industrial waste plastic waste, or a mixture of these waste plastics. The domestic waste plastic waste is a plastic containing PVC, PS, PET, PBT, etc. other than PE and PP, and in the present disclosure, as an example, it may be a waste plastic containing 3% by weight or more of PVC together with PE and PP. The chlorine content may be 5,000 ppm or more, specifically 5,000 to 15,000 ppm, per 100 parts by weight of domestic waste plastic, but this is only an example and is not limited thereto.

[0027] The industrial waste plastic is industrial waste generated during the manufacturing process in the industry, and may be waste plastic containing PE and PP as main components. The industrial waste plastic maintains a relatively clean state and has a low chlorine content compared to household waste plastic. However, it has a high organic chlorine content due to adhesive or dye components, and is characterized by a high ratio of chlorine contained in aromatic rings. The chlorine content may be 100 to 1,000 ppm, specifically 500 to 1,000 ppm, more specifically 700 to 1,000 ppm, per 100 parts by weight of the waste plastic, but this is merely an example and is not limited thereto.

[0028] Since waste plastics have low thermal conductivity, a considerable amount of fuel is consumed in the pyrolysis process, and since the waste plastics are not heated uniformly, local temperature deviations occur, resulting in low reaction efficiency. Therefore, by charging the waste plastic raw material and the promoter containing char into the reactor in the first step and then performing the pyrolysis process in the second step, pyrolysis can be promoted to improve process efficiency and the chlorine content in the generated pyrolysis oil can be effectively reduced. The promoter containing char acts as a heat carrier in the waste plastic pyrolysis process, complementing the low thermal conductivity of the waste plastics and promoting heat transfer between waste plastic particles, thereby reducing fuel consumption and promoting the pyrolysis process to improve process efficiency. Additionally, the char is distributed at low cost as a by-product mainly generated in the energy conversion process of solid fuel, so that the cost of the waste plastic pyrolysis process can be reduced and the economy can be improved.

[0029] In addition, since char has developed pores, it can effectively adsorb organic chlorine and inorganic chlorine originating from waste plastics during the pyrolysis process, and therefore the chlorine content in the generated pyrolysis oil can be effectively reduced. In particular, since char contains calcium carbonate, and the chlorine dissociated from the waste plastics during the pyrolysis process remains in a state of being adsorbed by the char, it is possible to suppress the recombination of the dissociated chlorine with olefins in the pyrolysis product to regenerate organic chlorine. Specifically, the chlorine content in the pyrolysis oil generated by the pyrolysis process can be reduced by 80% or more compared to the chlorine content contained in the waste plastic raw material. More specifically, it can be reduced by 90% or more, but not limited to 90% to 97%.

[0030] In other words, by utilizing a promoter containing char in the waste plastic pyrolysis process, it is possible to effectively reduce the chlorine content of the generated waste plastic pyrolysis oil, while also accelerating the pyrolysis process and improving the process efficiency.

[0031] In one embodiment, the accelerator of the first step may be charged into the reactor in an amount of 5 to 30 parts by weight based on 100 parts by weight of the waste plastic raw material. In the above range, chlorine can be effectively adsorbed, and reaction efficiency can be improved. If the amount of the accelerator containing char is less than 5 parts by weight, the chlorine adsorption effect is insignificant, and if the amount is 30 parts by weight or more, the amount is saturated due to excessive addition, and the purity of the generated pyrolysis oil may decrease. The amount of the accelerator containing char may be specifically 5 to 25 parts by weight, more specifically 5 to 20 parts by weight.

[0032] In one embodiment, the promoter may further include one or more dechlorinating agents selected from the group consisting of metal oxides, metal hydroxides, and metal carbonates. The inclusion of the dechlorinating agent can further improve the chlorine adsorption effect of the promoter. The metal may be an alkali metal or an alkaline earth metal, specifically, sodium, magnesium, potassium, calcium, etc. The dechlorinating agent may specifically be calcium hydroxide, sodium hydroxide, magnesium hydroxide, potassium hydroxide, calcium oxide, magnesium oxide, calcium carbonate, sodium carbonate, potassium carbonate, etc.

[0033] In one embodiment, the dechlorinating agent may be a metal oxide. In particular, by using a metal oxide as a dechlorinating agent, chlorine generated in the waste plastic pyrolysis process can be more effectively adsorbed, and it is preferable to use a metal oxide in terms of agglomeration with a plurality of particles including char, which will be described later. Specifically, the dechlorinating agent may be calcium oxide, magnesium oxide, sodium oxide, or potassium oxide, and preferably calcium oxide.

[0034] In one embodiment, the accelerator may be an aggregate formed by binding a plurality of first particles containing char with a desalting agent. Char is a type of carbide particle, and in this specification, each particle of char is referred to as a first particle as a primary particle. The first char particles may form an aggregate, which is a secondary particle, with the desalting agent acting as a binder and positioned between a plurality of first particles. The accelerator has an aggregate structure, which promotes heat transfer to waste plastics and allows chlorine generated by heat transfer to be effectively captured by the adjacent accelerator. Specifically, physical adsorption by the pores of the char contained in the accelerator and chemical adsorption by the desalting agent are effectively realized, thereby maximizing the chlorine removal effect. In particular, when a metal oxide is used as the desalting agent, it is preferable because it has excellent binding properties with the plurality of first particles and allows agglomeration to occur more stably. Specifically, the desalting agent may be calcium oxide, magnesium oxide, sodium oxide, or potassium oxide, and preferably calcium oxide.

[0035] In one embodiment, the desalting agent may be an adhesive powder further containing moisture, and may bind the plurality of first particles. By using an adhesive powder containing moisture, the cohesive force between the plurality of first particles can be improved to form a stable aggregate. Additionally, the moisture can capture chlorine dissociated from waste plastic, thereby improving the chlorine adsorption effect. Specifically, the moisture may be contained in an amount of 0.1 to 5 parts by weight with respect to 100 parts by weight of the desalting agent. By containing moisture within the appropriate range, the cohesive force of the aggregate can be effectively improved. More specifically, the moisture may be contained in an amount of 0.5 to 2 parts by weight with respect to 100 parts by weight of the desalting agent.

[0036] In one embodiment, the promoter may contain char in a weight ratio greater than that of the desalting agent. By containing char in a weight ratio greater than that of the desalting agent, the chlorine adsorption effect can be further improved. Specifically, the weight ratio of the char to the desalting agent may be 100:10 to 100:40. By containing the char to the desalting agent in the above weight ratio, it is preferable in that the physical adsorption of chlorine through the pores formed on the surface of the char is excellent. The weight ratio may be specifically 100:10 to 100:30, and more specifically 100:10 to 100:25.

[0037] The average size of the char may be 0.1 to 5 mm. When the size is within the above range, agglomeration via the desalting agent can occur effectively. Specifically, the average size may be 0.1 to 3 mm.

[0038] The second step is a step of pyrolyzing the waste plastic raw material to recover pyrolysis oil, and the pyrolysis product may include pyrolysis gas and solid by-products. After the pyrolysis gas is discharged from the reactor, it can be cooled and liquefied to recover liquid pyrolysis oil.

[0039] The pyrolysis gas may contain 5-35% by weight of naphtha (bp-150°C), 10-60% by weight of Kero (bp150-265°C), 20-40% by weight of LGO (bp265-380°C), and 5-40% by weight of UCO-2 / AR (bp380°C or higher) based on the total weight of the waste plastic raw material, and specifically, may contain 5-30% by weight of naphtha (bp-150°C), 15-50% by weight of Kero (bp150-265°C), 20-35% by weight of LGO (bp265-380°C), and 10-40% by weight of UCO-2 / AR (bp380°C or higher). In addition, it may contain residual amounts of low boiling point hydrocarbon compounds such as methane (CH4), ethane (C2H6), and propane (C3H8).

[0040] The third step is a step of recovering the accelerator from the reactor, and the accelerator may be recovered from the solid by-product remaining in the reactor after the pyrolysis gas is discharged. Conventionally, when a desalting agent is added to perform a waste plastic pyrolysis process, the desalting agent remains in the liquid pyrolysis oil recovered at 5 to 10% by weight. In contrast, in the present disclosure, the desalting agent remains in the solid by-product in the form of aggregates aggregated with char, so that high-quality pyrolysis oil can be recovered and a separate post-treatment process for treating the desalting agent remaining in the pyrolysis oil can be omitted. The accelerator can be recovered through a pyrolysis oil refining device described later.

[0041] In one embodiment, the method may further include a fourth step of re-supplying the accelerator recovered in the third step to the first step. By recycling the char and desalting agent, which are by-products of the pyrolysis process, as an accelerator in the form of aggregates, waste resources can be made more useful and the above-mentioned chlorine adsorption effect can be obtained.

[0042] In one embodiment, the fourth step may include washing the accelerator recovered in the third step with alcohol, replenishing the accelerator washed with alcohol and a desalting agent to produce an accelerator, and resupplying the produced accelerator to the first step. Specifically, the recovered accelerator may be in an inactivated state by being converted to a metal chloride by already adsorbing chlorine in the pyrolysis process. By washing the accelerator containing the inactivated metal chloride with alcohol, the metal chloride having a high solubility in alcohol is leached and removed, and an unreacted desalting agent having a relatively low solubility in alcohol, such as calcium oxide, is left behind, and the remaining desalting agent may be bound to a plurality of first particles containing char to form an aggregate. The alcohol may be an aliphatic alcohol, specifically, one or a mixture of two or more selected from methanol, ethanol, propanol, isopropanol, butanol, and 2-ethylhexyl alcohol, but this is merely an example and is not necessarily limited thereto. The recovered promoter is washed, then supplemented with desalting agent to improve the activity of the promoter, and then re-supplied to the first step. Through this series of processes, both the utilization of waste resources and the chlorine adsorption effect can be achieved.

[0043] In one embodiment, the first step may be performed at a temperature of 300 to 600°C. When the pyrolysis process is performed in this temperature range, it is possible to prevent the waste plastic from fusing and improve the agglomeration of the char and the desalting agent, and it is possible to improve the efficiency with which the chlorine dissociated from the waste plastic is adsorbed by the accelerator. The temperature may be specifically 300 to 550°C, and more specifically 350 to 500°C.

[0044] In one embodiment, the first step may be performed in a non-oxidizing atmosphere. The non-oxidizing atmosphere is an atmosphere in which waste plastics do not burn, and in order to agglomerate char, combustion must be prevented by heating without supplying oxygen. For example, the atmosphere may be an atmosphere in which the oxygen concentration is adjusted to 1% by volume or less, or an inert gas atmosphere such as nitrogen, water vapor, carbon dioxide, and argon. In the case of the above atmosphere, the pyrolysis process can be performed stably.

[0045] The first step may be carried out in a non-oxidizing atmosphere for 150 to 350 minutes, and when the maintenance time is satisfied, activation of the non-oxidizing atmosphere composition and sufficient agglomeration of the char and the desalting agent can be achieved. Specifically, the maintenance time may be 170 to 330 minutes, and more specifically, 200 to 300 minutes.

[0046] In one embodiment, the method may further include a step of heat-treating the recovered promoter at 500 to 1000°C. The pretreatment step of heating the promoter at the temperature may activate the promoter and improve its chlorine adsorption activity. The heating may be performed in a non-oxidizing atmosphere, and the temperature may be specifically 500 to 900°C, more specifically 600 to 800°C.

[0047] The first step may further include a step of drying with hot air. In order to improve the efficiency of pyrolysis, a step of drying the waste plastic raw material with hot air may be performed, which may be performed before the pyrolysis step or simultaneously with the pyrolysis step. For example, when hot air is blown while performing the pyrolysis in the first step, the accelerator can be activated at the same time as drying the waste plastic, thereby further improving the chlorine adsorption effect.

[0048] The pyrolysis oil recovered in the third step may include an oil layer and a water layer. Oil-water separation occurs in the liquid pyrolysis oil, forming an oil layer and a water layer in the liquid pyrolysis oil. When the oil layer and the water layer are separated, the oil layer can be immediately recovered, or the water layer can be discharged and the oil layer remaining after adsorption can be recovered, thereby recovering waste plastic pyrolysis oil, which is an oil layer with minimized chlorine.

[0049] The chlorine content in the recovered oil layer (pyrolysis oil) may be 300 ppm or less. As described above, by introducing char into the waste plastic pyrolysis process, the chlorine content of the generated waste plastic pyrolysis oil can be effectively reduced. In particular, when the aggregate of the char and the desalting agent is used as an accelerator, the chlorine adsorption effect is further improved, and the chlorine content in the pyrolysis oil may be 150 ppm or less, more specifically, 100 ppm or less.

[0050] In order to effectively separate the oil layer and the water layer, an electric field may be applied, and the oil layer and the water layer may be separated in a short time by electrostatic adhesion due to the application of an electric field. In addition, in order to increase the efficiency of the oil-water separation, an additive may be added as necessary, and the additive may be a conventional demulsifier well known in the art.

[0051] When the water layer is discharged and adsorbed, by detecting the density using a density profiler, it is possible to prevent the oil layer from being adsorbed together with the water layer, and to effectively adsorb only the water layer.

[0052] In addition, one embodiment of the present disclosure provides an apparatus for producing waste plastic pyrolysis oil with reduced chlorine, the apparatus including: a reactor in which a waste plastic raw material and an accelerator containing char are charged and a pyrolysis process is carried out; and a storage tank in which pyrolysis oil is recovered from the reactor.

[0053] The reactor may be a batch reactor or a continuous reactor. In the case of a batch reactor, any type of batch reactor capable of stirring and temperature control may be used, for example, a rotary kiln type batch reactor. In the case of a continuous reactor, a fixed bed continuous reactor may be used.

[0054] As the pyrolysis proceeds, pyrolysis gas is discharged from a first outlet located at the top of the reactor. The discharged pyrolysis gas may flow into a condenser. The condenser may include a region where cooling water flows, and the pyrolysis gas flowing into the condenser may be liquefied by the cooling water and converted into pyrolysis oil. The cooling temperature may be 80 to 180°C, specifically 100 to 150°C. When the liquid pyrolysis oil generated in the condenser rises to a predetermined water level, it may be transported and collected in a storage tank.

[0055] A heat exchanger may be further provided between the condenser and the storage tank. The pyrolysis gas that is not condensed in the condenser flows into the heat exchanger and is condensed again, and the generated pyrolysis oil can be collected in the storage tank. By collecting the pyrolysis gas that is not condensed again, the reaction yield can be improved.

[0056] In one embodiment, the reactor may further include a recovery tank for recovering the promoter from the reactor, and a recirculation line for resupplying the promoter from the recovery tank to the reactor. A solid by-product containing the promoter may be discharged from a second outlet located at a lower portion of the reactor and flow into the recovery tank.

[0057] The recovery tank may include an alcohol supply section. The solid by-product may include unreacted promoter, promoter containing inactivated metal chloride, and other impurities such as copper impurities, and the solid by-product may be washed through the alcohol supply section to remove impurities other than the unreacted promoter.

[0058] The recovery tank may further include a desalting agent supplying unit, through which a desalting agent is supplied to the washed promoter to improve the activity of the promoter.

[0059] The recovery tank may further include a classifier. By further including a classifier in the recovery area, the accelerator can be classified by particle size. For example, particles having a size of 1 mm or more and particles having a size of less than 1 mm can be classified by a sieving device. In particular, since the accelerator is an agglomeration of char and desalting agent, the accelerator can be recovered in high yield by classifying the accelerator by particle size and selectively recovering large particles. Since fine carbide can cause problems such as clogging of the reactor and reduced process efficiency, it is preferable to selectively recover only large particles excluding fine carbide. The recovered accelerator can be resupplied to the reactor through a recirculation line.

[0060] The removed impurities and finely divided charcoal can be used as a fuel source for a batch reactor, thereby contributing to fuel reduction. For matters not described in the refining apparatus for waste plastic pyrolysis oil, please refer to the refining method for waste plastic pyrolysis oil described above.

[0061] Preferred examples and comparative examples of the present disclosure are described below. However, the following examples are merely preferred examples of the present disclosure, and the present disclosure is not limited to the following examples.

[0062] Example 1 A household waste plastic mixture containing 3% by weight or more of PVC along with PE and PP was extruded at 250°C to produce 400g of household waste plastic pellets. The total chlorine content of the household waste plastic pellets was 4000ppm. The batch reactor was purged with nitrogen gas to create a non-oxidizing atmosphere.

[0063] 400g of the domestic waste plastic pellets and 100g of char were put into the batch reactor, and pyrolysis was carried out for 250 minutes at 400°C while continuously supplying fuel. The pyrolysis product produced was transferred to a classification tank, and pyrolysis gas was recovered from a second outlet located at the top of the classification tank and collected in a condenser. Finally, the waste plastic pyrolysis oil was recovered from a storage tank, and solid by-products were collected in a recovery tank from a second outlet located at the bottom of the reactor.

[0064] The char used was produced by the following process. Waste plastic was cut into uniform pieces of 150-200 mesh size and then placed in a U-shaped reactor. Next, pyrolysis was carried out by continuously flowing nitrogen at a flow rate of 50 ml / min at 600°C for 2 hours using a PID (Proportional-Integral-Derivative) controller. As a result, 100 g of char produced as a solid by-product was collected and used.

[0065] Example 2 A reaction was carried out under the same conditions as in Example 1, except that 110 g of an aggregate of the char and calcium oxide was added instead of using the char alone, and a waste plastic pyrolysis oil was recovered. 100 g of char and 10 g of calcium oxide were used to produce the aggregate.

[0066] Example 3 A reaction was carried out under the same conditions as in Example 1, except that a solid by-product contained in the pyrolysis product of Example 2 was recovered and reused instead of the char in Example 1, and a waste plastic pyrolysis oil was recovered. Specifically, in Example 2, a solid by-product was recovered in a recovery tank from a second outlet located at the bottom of the reactor, and then reused as the char in Example 1.

[0067] Example 4 In Example 3, impurities contained in the solid by-product were removed by supplying ethanol at a flow rate of 50 ml / min for 30 minutes through the ethanol supply unit of the recovery tank, and then only aggregates with a size of 1 mm or more were collected through a sieving device. 10 g of calcium oxide was additionally supplied to the collected aggregates to agglomerate them and improve their activity, and the resulting aggregates were reused as char in Example 1.

[0068] Comparative Example 1 The reaction was carried out under the same conditions as in Example 1, except that the reaction was carried out without adding char, and waste plastic pyrolysis oil was recovered.

[0069] Comparative Example 2 The reaction was carried out under the same conditions as in Example 1, except that in Example 1, char was not added and only calcium oxide was added to carry out the reaction, and waste plastic pyrolysis oil was recovered.

[0070] Evaluation example The chlorine content (ppm) in the recovered waste plastic pyrolysis oil was measured by ICP and XRF analysis. The amount of fuel consumed during the pyrolysis process was measured.

[0071] [Table 1]

[0072] In Example 1, when the pyrolysis process was carried out in the presence of char, it was confirmed that the chlorine content in the pyrolysis oil was significantly reduced to 270 ppm compared to the waste plastic raw material (chlorine content 4000 ppm). In Example 2, it was confirmed that the chlorine content in the pyrolysis oil was further reduced to 160 ppm by using an aggregate of char and calcium oxide.

[0073] In addition, in Example 3, the solid by-product contained in the pyrolysis product of Example 2 was recovered and reused as char, and it was confirmed that the chlorine content in the pyrolysis oil was significantly reduced to 290 ppm compared to the waste plastic feedstock. In particular, in Example 4, the recovered solid by-product was washed with ethanol, and calcium oxide was additionally added to improve activity, and it was reused as char, and it was confirmed that the chlorine content in the pyrolysis oil was reduced to 150 ppm, the most compared to the waste plastic feedstock.

[0074] In contrast, in Comparative Example 1, when the pyrolysis step was carried out without adding char, it was confirmed that the chlorine content in the pyrolysis oil was excessive at 970 ppm, and in Comparative Example 2, when only calcium oxide was added without char, it was confirmed that the chlorine content in the pyrolysis oil was considerable at 370 ppm.

[0075] In addition, in the case of Examples 1 to 4, approximately 51 g or less of fuel was consumed in the pyrolysis process, whereas in the case of Comparative Examples 1 and 2, approximately 60 g of fuel was consumed, confirming the effect of reducing fuel consumption due to the role of char as a heat carrier.

[0076] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and may be implemented in various different forms, and a person having ordinary skill in the art to which the present invention belongs can understand that the present invention can be implemented in other specific forms without changing the technical idea or essential features of the present invention. Therefore, it should be understood that the embodiments described above are illustrative in all respects and are not limiting.

Claims

1. A first step of charging a waste plastic raw material and a promoter containing char into a reactor; A second step of pyrolyzing the waste plastic raw material in a reactor to recover pyrolysis oil; a third step of recovering the promoter from the reactor; The present invention relates to a method for producing a chlorine-reduced waste plastic pyrolysis oil, comprising:

2. The method for producing waste plastic pyrolysis oil with reduced chlorine content according to claim 1, wherein the accelerator in the first step is charged into the reactor in an amount of 5 to 30 parts by weight based on 100 parts by weight of the waste plastic raw material.

3. The method for producing waste plastic pyrolysis oil with reduced chlorine content according to claim 1, wherein the accelerator further comprises one or more desalting agents selected from the group consisting of metal oxides, metal hydroxides, and metal carbonates.

4. The method for producing waste plastic pyrolysis oil with reduced chlorine content according to claim 3, wherein the desalting agent is a metal oxide.

5. The method for producing waste plastic pyrolysis oil with reduced chlorine content described in claim 3, wherein the accelerator is an agglomerate in which a plurality of first particles containing char are bound and agglomerated by the desalting agent.

6. The method for producing waste plastic pyrolysis oil with reduced chlorine content according to claim 5 , wherein the desalting agent is an adhesive powder further containing moisture and binds the plurality of first particles together.

7. The method for producing waste plastic pyrolysis oil with reduced chlorine content according to claim 3, wherein the accelerator contains char in a weight amount greater than that of the desalting agent.

8. The method for producing waste plastic pyrolysis oil with reduced chlorine content according to claim 3, further comprising a fourth step of resupplying the accelerator recovered in the third step to the first step.

9. The fourth step includes the steps of washing the accelerator recovered in the third step with alcohol, replenishing the accelerator washed with alcohol and a desalting agent to produce an accelerator, and resupplying the produced accelerator to the first step. The method for producing waste plastic pyrolysis oil with reduced chlorine content according to claim 8.

10. The method for producing waste plastic pyrolysis oil with reduced chlorine content according to claim 1, wherein the second step is carried out at a temperature of 300 to 600°C.

11. The method for producing waste plastic pyrolysis oil with reduced chlorine content according to claim 1 , wherein the second step is carried out in a non-oxidizing atmosphere.

12. The method for producing a chlorine-reduced waste plastic pyrolysis oil according to claim 9, further comprising a step of further heating the produced accelerator at 500 to 1000 ° C. to improve activity before the step of re-supplying the produced accelerator to the first step.

13. A reactor in which a waste plastic raw material and a promoter containing char are charged and a pyrolysis process is performed; a storage tank in which the pyrolysis oil is collected from the reactor; The present invention relates to an apparatus for producing waste plastic pyrolysis oil having reduced chlorine, the apparatus comprising:

14. The apparatus for producing waste plastic pyrolysis oil with reduced chlorine content according to claim 13, further comprising a recovery tank for recovering the accelerator from the reactor, and a recirculation line for resupplying the accelerator from the recovery tank to the reactor.

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