Apparatus for producing light olefins from waste plastics and method for producing light olefins using same

Abstract

The present invention relates to: an apparatus for producing light olefins from waste plastics, the apparatus comprising a fluidized bed reactor and a circulating fluidized bed reactor that utilizes a catalyst; and a method for producing light olefins using same. The apparatus according to an aspect of the present invention can produce light olefins from waste plastics at a high yield. In addition, the apparatus according to the present invention can produce light olefins from waste plastics in a continuous process, and thus the process is convenient and economical.

Description

Device for producing light olefin from waste plastic and method for producing light olefin using the same

[0001] The present invention relates to an apparatus for producing light olefins from waste plastics, comprising a fluidized bed reactor and a circulating fluidized bed reactor utilizing a catalyst, and a method for producing light olefins using the same.

[0002] Light olefins, such as ethylene, propylene, and C4 olefins, are widely used as raw materials for plastic manufacturing in the chemical industry. Light olefins are primarily produced through the pyrolysis of petroleum-derived naphtha. However, this process, which involves high-temperature reactions exceeding 850°C (°F), consumes significant energy and generates large amounts of greenhouse gases. Therefore, energy-efficient technologies that utilize sustainable materials, such as waste plastics, to produce light olefins are needed. Polyolefin plastics, such as polyethylene (PE) and polypropylene (PP), widely used in packaging materials, have a short lifespan and account for more than 60% of global waste plastic generation. Mechanical recycling of these waste plastics is difficult to widely apply due to impurities from other types of plastics (e.g., polyethylene terephthalate (PET), polystyrene (PS), and polyurethane (PU)), additives, and fillers. Furthermore, landfilling and incineration are unsuitable approaches due to their high environmental pollution potential. Therefore, to reduce the negative environmental impact of existing waste plastic processing methods and transition to a circular economy with lower carbon emissions, the development of new energy-efficient processes to convert waste plastics into valuable light olefins is necessary.

[0003] In this context, a method for producing light olefins by hydrogenating pyrolysis oil produced from the pyrolysis of polyolefin waste plastics and then utilizing it as a feedstock for a conventional naphtha cracking process is being actively developed (JP 6942178). This method is divided into two stages: producing pyrolysis oil from polyolefin waste plastics and hydrogenating the produced pyrolysis oil, then utilizing it as a feedstock for a conventional naphtha cracking process to produce light olefins.

[0004] The first step, the production of pyrolysis oil through the pyrolysis of polyolefin waste plastics, is primarily a discontinuous process utilizing a batch rotary kiln. In this process, waste plastics are pyrolyzed in the absence of oxygen, producing gas, liquid oil, and residues. To utilize the resulting pyrolysis oil as a feedstock for a conventional naphtha cracking process to produce light olefins, it is necessary to produce as much pyrolysis oil as possible, which has a low boiling point in the naphtha range (30–150°C). This requires high-temperature operation at 400–500°C for several hours or more. Consequently, although the pyrolysis yield varies depending on the type of polyolefin waste plastic used as a feedstock, reaction temperature, reaction time, and other operating conditions, the typical pyrolysis oil yield is very low, typically around 40–60 wt%. Furthermore, the discontinuous pyrolysis oil production technology utilizing a batch rotary kiln has the following drawbacks: (1) Low productivity (only one operation per day due to the heating-reaction-cooling process), (2) Large energy loss and shortened equipment life due to repeated heating and cooling, (3) Poor working environment due to frequent opening and closing of the reactor, (4) Difficult scale-up for mass production

[0005] In the second step, the generated pyrolysis oil undergoes hydrogenation to remove impurities and contaminants, and is then converted into light olefins through a conventional naphtha pyrolysis process. However, pyrolysis oil derived from waste plastics has different characteristics from petroleum-derived naphtha, making it difficult to use directly as a feedstock for the naphtha pyrolysis process. First, there is the issue of hydrocarbon composition in the pyrolysis oil. The carbon number of waste plastic pyrolysis oil generally ranges from C5 to several hundred carbon atoms, while naphtha mainly consists of carbon numbers from C5 to C9. Therefore, based on carbon number, only a small portion of the pyrolysis oil can be processed in the conventional naphtha cracking process. Second, during the pyrolysis of waste plastics, approximately 30-50% of the pyrolysis oil is produced as olefins, and because high olefin contents induce coke formation during the cracking reaction, industries operate by limiting the olefin content in naphtha to a maximum of 1-2 wt%. To address this issue, it is essential to remove olefins through hydrogenation before introducing pyrolysis oil into the naphtha cracking process. This additional hydrogenation process negatively impacts the process's economics.

[0006] That is, there is a very high need for a method to efficiently produce light olefins from waste plastics, but satisfactory research results have not yet been reported.

[0007] [Prior Art Literature]

[0008] (Patent Document 1) JP 6942178 B2

[0009] In one aspect, the purpose of the present invention is to produce high value-added light olefins from waste plastics.

[0010] In one aspect, an object of the present invention is to produce light olefins from waste plastics through a continuous process.

[0011] In one aspect, the purpose of the present invention is to provide a device that does not have problems such as a decrease in light olefin production efficiency due to pyrolysis products of waste plastics and device failure.

[0012] In one aspect, an object of the present invention is to provide a highly reliable light olefin production device.

[0013] In one aspect, an object of the present invention is to provide a system capable of economically producing light olefins from waste plastics.

[0014] The problem to be solved in the embodiment is not limited to this, and it can be said that the purpose or effect that can be understood from the solution or embodiment of the problem described below is also included.

[0015] The present invention is intended to solve the above problem, and specifically provides a technology that integrates a pyrolysis technology for continuously and with high yield producing pyrolysis oil from waste plastic and a technology for directly converting the produced high viscosity wax oil into light olefin without hydrogenation post-treatment.

[0016] Specifically, the present invention provides a technology for continuously and with high yield producing pyrolysis oil from waste plastics using a fluidized bed reactor, a technology for directly converting high viscosity total wax oil into light olefins without hydrogenation post-treatment using a circulating fluidized bed reactor utilizing a catalyst, and an apparatus for efficiently producing light olefins from waste plastics through the integration thereof, and a method for producing light olefins using the same.

[0017] In order to achieve the above object, the present invention provides, in one aspect, a device for producing light olefin from waste plastic.

[0018] In the above aspect, the present invention provides a device for producing light olefins from waste plastic, the device (1000) including a fluidized bed reactor (1300) and a circulating fluidized bed reactor (1400) utilizing a catalyst.

[0019] In the above aspect, the present invention provides an apparatus for producing light olefins from waste plastics, wherein the apparatus includes performing pyrolysis in at least one of a fluidized bed reactor and a circulating fluidized bed reactor utilizing a catalyst.

[0020] In the above aspect, the present invention provides an apparatus for producing light olefins from waste plastic, wherein the fluidized bed reactor is operated at a temperature of 450 to 650°C, and the circulating fluidized bed reactor utilizing the catalyst is operated at a temperature of 500 to 800°C.

[0021] In the above aspect, the present invention provides a device for producing light olefins from waste plastic, wherein the fluidized bed reactor includes a cyclone inside the reactor.

[0022] In the above aspect, the present invention provides a device for producing light olefins from waste plastic, wherein the fluidized bed reactor further includes at least one of a pyrolysis product reforming unit (1330) and an impurity removal unit (1340).

[0023] In the above aspect, the present invention provides a device for producing light olefins from waste plastics, the device comprising a zeolite catalyst, the circulating fluidized bed reactor utilizing the catalyst.

[0024] In the above aspect, the present invention provides an apparatus for producing light olefins from waste plastic, wherein the zeolite catalyst comprises at least one selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-48, zeolite X, zeolite Y, zeolite-L, zeolite-β, zeolite-Ω, mordenite, erionite, chabazite, and MFI zeolite.

[0025] In the above aspect, the present invention provides a device for producing light olefins from waste plastic, wherein the zeolite catalyst further includes clay, SAPO (silica-alumina-phosphate), ALPO (aluminum phosphate), MOF (Metal Organic Framework), amorphous silica-alumina, or a mixture thereof.

[0026] In the above aspect, the present invention provides an apparatus for producing light olefins from waste plastic, wherein the zeolite catalyst further comprises a carrier or binder comprising carbon, alkaline earth metal oxide, alkali metal oxide, alumina, silica, silica-alumina, zirconia, titania, silicon carbide, niobia, aluminum phosphate, alumina hydrate or a mixture thereof.

[0027] In the above aspect, the present invention provides an apparatus for producing light olefins from waste plastic, wherein the zeolite catalyst may have phosphorus (P) introduced therein.

[0028] In the above aspect, the present invention provides a device for producing light olefin from waste plastic, wherein the cyclone separates or removes char from the pyrolysis product.

[0029] In the above aspect, the present invention provides a method for producing light olefin from waste plastic, the method comprising the step of supplying waste plastic to the device.

[0030] One aspect of the present invention, the device, can produce light olefins from waste plastics at a high yield. Furthermore, the device can produce light olefins from waste plastics in a continuous process, making the process convenient and economical.

[0031] The various advantageous and beneficial effects of the present invention are not limited to the above-described contents, and will be more easily understood in the course of explaining specific embodiments of the present invention.

[0032] Figure 1 (Figures 1a and 1b) is a schematic diagram of a device for producing light olefins from waste plastic according to one aspect of the present invention. In Figure 1, arrows indicate the movement of feed materials and pyrolysis products.

[0033] FIG. 2 is a diagram of a system including a device for separating wax from a plastic pyrolyzate according to one aspect of the present invention.

[0034] Figure 3 shows the results of GC-FID analysis of waxy oil among the products of pyrolysis of low-density polyethylene (LDPE) in a fluidized bed reactor.

[0035] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated and described in the drawings. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0036] In addition, terms or words used in the specification and claims of the present invention should not be interpreted as limited to their usual or dictionary meanings, and should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0037] Terms including ordinal numbers, such as "second," "first," etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a second component may be referred to as a "first component," and similarly, a first component may also be referred to as a "second component." The term "and / or" includes a combination of multiple related items described herein or any of multiple related items described herein.

[0038] In addition, the terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms “comprise,” “contain,” or “have” are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0039] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0040] Additionally, the numerical ranges used herein include lower and upper limits and all values ​​within that range, increments logically derived from the shape and width of the defined range, all doubly defined values, and all possible combinations of upper and lower limits of numerical ranges defined in different shapes. Unless otherwise specified herein, values ​​outside the defined numerical range that may arise due to experimental error or rounding of values ​​are also included in the defined numerical range.

[0041] Hereinafter, embodiments will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or corresponding components are given the same reference numbers, and redundant descriptions thereof will be omitted.

[0042] In one aspect, the present invention is a device (1000) for producing light olefin from waste plastic.

[0043] In one aspect, the waste plastic may include polyolefin itself, or waste plastic containing polyolefin, such as waste plastic including polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, etc.

[0044] The above polyethylene may include low-density polyethylene (LDPE) and high-density polyethylene (HDPE).

[0045] In one aspect, the device may include a fluidized bed reactor (FBR) (1300) and a circulating fluidized bed reactor (CFBR) (1400) utilizing a catalyst.

[0046] In one aspect, pyrolysis may be performed in one or more of the fluidized bed reactor and the circulating fluidized bed reactor utilizing the catalyst of the above device.

[0047] In one embodiment, pyrolysis of waste plastics can be performed in the fluidized bed reactor of the device. In the fluidized bed reactor, waste plastics can be pyrolyzed to produce pyrolysis oil, which is a pyrolysis product. The pyrolysis oil produced in the fluidized bed reactor can be continuously fed as a feedstock to a circulating fluidized bed reactor utilizing a catalyst. The pyrolysis oil supplied to the circulating fluidized bed reactor utilizing the catalyst can be secondarily decomposed by contacting the catalyst in the circulating fluidized bed reactor utilizing the catalyst.

[0048] In one aspect, the fluidized bed reactor may be operated at a temperature of 450 to 650°C. Specifically, the operating (driving) temperature of the fluidized bed reactor may be 450°C or higher, or 460°C or higher, or 470°C or higher, or 480°C or higher, or 490°C or higher, or 500°C or higher, or 510°C or higher, or 520°C or higher, or 530°C or higher, or 540°C or higher, or 550°C or higher, or 560°C or higher, or 570°C or higher, or 580°C or higher, or 590°C or higher, or 600°C or higher, or 610°C or higher, or 620°C or higher, or 630°C or higher, or 640°C or higher, or 650°C or lower, or 640°C or lower, or 630°C or lower, or 620°C or lower, or 610°C or lower, or 600°C or lower, or 590°C or lower, or 580°C or lower, or It may be 570°C or less, or 560°C or less, or 550°C or less, or 540°C or less, or 530°C or less, or 520°C or less, or 510°C or less, or 500°C or less, or 490°C or less, or 480°C or less, or 470°C or less, or 460°C or less.

[0049] In one aspect, the circulating fluidized bed reactor utilizing the above catalyst may be operated at a temperature of 500 to 800°C. Specifically, the operating temperature of the circulating fluidized bed reactor utilizing the catalyst may be 500°C or higher, or 510°C or higher, or 520°C or higher, or 530°C or higher, or 540°C or higher, or 550°C or higher, or 560°C or higher, or 570°C or higher, or 580°C or higher, or 590°C or higher, or 600°C or higher, or 610°C or higher, or 620°C or higher, or 630°C or higher, or 640°C or higher, or 650°C or higher, or 660°C or higher, or 670°C or higher, or 680°C or higher, or 690°C or higher, or 700°C or higher, or 710°C or higher, or 720°C or higher, or 730°C or higher, or 740°C or higher, or 750°C or higher, or 760°C or higher, or 770℃ or higher, or 780℃ or higher, or 790℃ or higher, or 800℃ or lower, or 790℃ or lower, or 780℃ or lower, or 770℃ or lower, or 760℃ or lower, or 750℃ or lower, or 740℃ or lower, or 730℃ or lower, or 720℃ or lower, or 710℃ or lower, or 700℃ or lower, or 690℃ or lower, or 680℃ or lower, or 670℃ or lower, or 660℃ or lower, or 650℃ or lower, or 640℃ or lower, or 630℃ or lower, or 620℃ or lower, or 610℃ or lower, or 600℃ or lower, or 590℃ or lower, or 580℃ or lower, or 570℃ or lower, or 560℃ or lower, or 550℃ or lower, or 540℃ or lower, or It may be 530℃ or less, or 520℃ or less, or 510℃ or less.

[0050] In one embodiment, the operating temperature of the circulating fluidized bed reactor utilizing the catalyst may be 500 to 800°C, or 550 to 800°C, or 550 to 750°C, or 580 to 750°C, or 580 to 720°C, or 590 to 720°C.

[0051] In one aspect, thermal decomposition of waste plastic can be performed within the above temperature range.

[0052] In one aspect, the circulating fluidized bed reactor utilizing the catalyst may include a configuration included in a circulating fluidized bed reactor utilizing a general catalyst. For example, the circulating fluidized bed reactor utilizing the catalyst may include, but is not limited to, a reactor (not shown), a catalyst regenerator (not shown), a stripper (not shown), a stabilizer (not shown), a distillation column (not shown), a coagulant (not shown), a storage tank (not shown), a reflux drum (not shown), a sidecut stripper (not shown), a pump (not shown), an electrostatic precipitator (not shown), a hopper (not shown), a boiler (not shown), a separator (not shown), a pump (not shown), a connecting means (e.g., a pipe, not shown) for connecting each configuration, and the like.

[0053] In one aspect, the device of one aspect of the present invention utilizes the entire pyrolysis oil produced by pyrolyzing waste plastic raw materials, and simplifies the process by eliminating the removal process of olefins and / or non-hydrocarbon substances contained in the pyrolysis oil. In addition, in one aspect, the circulating fluidized bed reactor utilizing the catalyst has a short residence time of the reaction product within the reactor due to the structural characteristics of the reactor, thereby significantly improving the yield of light olefins and enabling the construction of a process with significantly improved economic feasibility by continuously removing coke on the catalyst.

[0054] In one aspect, a circulating fluidized bed reactor utilizing a catalyst may include a zeolite catalyst.

[0055] In one aspect, the zeolite catalyst may include at least one selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-48, zeolite X, zeolite Y, zeolite-L, zeolite-β, zeolite-Ω, mordenite, erionite, chabazite, and MFI zeolite.

[0056] In the above aspect, the present invention may further include the zeolite catalyst, clay, SAPO (silica-alumina-phosphate), ALPO (aluminum phosphate), MOF (Metal Organic Framework), amorphous silica-alumina, or a mixture thereof.

[0057] In the above aspect, the present invention may further include a carrier or binder including carbon, alkaline earth metal oxide, alkali metal oxide, alumina, silica, silica-alumina, zirconia, titania, silicon carbide, niobia, aluminum phosphate, alumina hydrate or a mixture thereof.

[0058] In the above aspect, the present invention may be one in which phosphorus (P) is introduced into the zeolite catalyst.

[0059] In one embodiment, the light olefin may comprise ethylene, propylene or a C4 olefin.

[0060] In one embodiment, the light olefin yield may be at least 40 wt%, at least 42 wt%, at least 44 wt%, at least 46 wt%, at least 48 wt%, at least 50 wt%, at least 52 wt%, at least 54 wt%, or at least 56 wt%, based on 100 wt% of the oil-containing stream. In addition, the sum of the light olefin yields may be at most 75 wt%, at most 70 wt%, at most 65 wt%, or at most 60 wt%. The sum of the light olefin yields may be from 44 to 60 wt%, from 40 to 70 wt%, or from 44 to 70 wt%, based on 100 wt% of the oil-containing stream.

[0061] In one aspect, the method for producing the zeolite catalyst into which the above-mentioned phosphorus is introduced may be as follows.

[0062] Based on 100 parts by weight of zeolite, 250 to 400 parts by weight of distilled water is added to the zeolite to prepare a slurry, and then 30 to 60 parts by weight (or 30 to 55 parts by weight, or 35 to 50 parts by weight, or 40 to 48 parts by weight) of phosphoric acid of about 80 to 90% (or 82 to 88%, or 84 to 88%, or 84 to 86%) is added, and stirred for about 20 to 50 minutes to produce a slurry. The slurry is mixed with a solution in which 140 to 180 parts by weight of boehmite is dispersed in a 1 to 3% nitric acid solution, and then stirred. Thereafter, about 80 to 120 parts by weight of clay is mixed and stirred again. Afterwards, the slurry with added clay is formed into microspheres with a particle size of approximately 75 to 200 micrometers through spray molding, etc., and then fired at high temperature to manufacture a catalyst.

[0063] In one embodiment, the catalyst may be pre-steamed.

[0064] The above pre-steamed catalyst may include one manufactured by contacting it with steam in a high temperature environment, for example, at about 700 to 800°C, for about 18 to 30 hours.

[0065] In one embodiment, the catalyst may be a spherical or oval shaped body.

[0066] Additionally, in one embodiment, the catalyst may have a diameter of at least 1 μm, at least 5 μm, at least 10 μm, at least 20 μm, at least 30 μm, at least 40 μm, at least 50 μm, at least 60 μm, or at least 70 μm. Additionally, the catalyst may have a diameter of at most 500 μm, at most 400 μm, at most 300 μm, at most 250 μm, at most 200 μm, or at most 150 μm. In one aspect, the catalyst may have a diameter of from 30 μm to 200 μm, or from 50 μm to 150 μm.

[0067] If the catalyst diameter is less than 50 ㎛, the oil-containing stream produced by pyrolyzing waste plastic raw materials may not be sufficiently converted into light olefins due to the short residence time in the reactor, or separation of the catalyst and product after the reaction may be difficult. If the catalyst diameter is greater than 150 ㎛, the catalyst flow in the reactor may not be smooth, or problems of catalyst wear during flow may occur.

[0068] In one aspect, the reaction is carried out at a weight hourly space velocity (WHSV), which is defined as the ratio of the mass flow rate of the pyrolysis products, including pyrolysis oil, entering the circulating fluidized bed reactor utilizing the catalyst to the mass of the catalyst, of 1 to 100 h -1 , 1 to 80 h -1 , 1 to 70 h -1 , 1 to 60 h -1 , 2 to 60 h -1 , 2 to 50 h -1 , 3 to 50 h -1 , 3 to 30 h -1 , 4 to 20 h -1 or 4 to 15 h -1 can be performed.

[0069] Space velocity is 15 h -1If it is exceeded, the pyrolysis oil, including the pyrolysis oil produced by pyrolyzing waste plastic raw materials, is not sufficiently converted into light olefins, and 4 h -1 If it is less than this, the light olefins produced due to the influence of excessive secondary reactions may be converted into aromatic hydrocarbons, which may cause a problem in that the yield of light olefins decreases.

[0070] In one aspect, the fluidized bed reactor may include a cyclone (1310) inside the reactor.

[0071] Specifically, the pyrolysis reactor of the present invention has a cyclone positioned inside the reactor, so that during the process in which the pyrolysis product moves from the inside to the outside of the fluidized bed reactor, the pyrolysis product is exposed to a low-temperature environment compared to the temperature inside the fluidized bed reactor where the pyrolysis is performed, thereby improving the problem of deposition or solidification of substances having relatively low boiling and melting points among the pyrolysis products.

[0072] In this specification, the term “pyrolysis product” or “pyrolysis product” is interpreted broadly to include intermediate products and final products generated when pyrolyzing a feed material or a pyrolysis target material.

[0073] In one aspect, the pyrolysis product generated within the fluidized bed reactor can be introduced into a cyclone.

[0074] Additionally, in one aspect, the cyclone can separate or remove char from the pyrolysis product.

[0075] That is, since the pyrolysis reactor of the present invention has a cyclone positioned inside the reactor, it can not only remove char inside the reactor, but also simultaneously perform pyrolysis of feed and separation of char present in the pyrolysis product.

[0076] After primary pyrolysis is performed inside the fluidized bed reactor, pyrolysis vapor is introduced into the cyclone through the pyrolysis material inlet (1311). Low-specific gravity fluid separated inside the cyclone is discharged through the fluid outlet (1312), and high-specific gravity materials such as sand and char are discharged through the discharge port (1313).

[0077] In the above aspect, the device may further include one or more of a modification unit (1330) and an impurity removal unit (1340).

[0078] In one aspect, the fluid discharged through the fluid outlet of the cyclone may flow into the reforming section through the distribution plate (1320). The distribution plate may be porous.

[0079] In one embodiment, when the feed material is waste plastic, the device includes a reforming unit, thereby enabling the wax contained in the pyrolysis product to be reformed immediately before it condenses.

[0080] In this specification, the “reforming unit” may mean equipment or a device that performs the function of reforming a pyrolysis product by reacting it with a catalyst such as calcium oxide inside a pyrolysis reactor, or may mean equipment or a device that can reduce the molecular weight of wax that is primarily produced in a fluidized bed reactor by re-pyrolyzing it.

[0081] Additionally, in this specification, the “impurity removal unit” may refer to equipment or devices that perform the role of removing impurities generated during the thermal decomposition process inside a fluidized bed reactor.

[0082] In one aspect, when the feed material is waste plastic, the impurities may include hydrogen chloride.

[0083] In one aspect, the reforming unit may include a reforming reactor, and the impurity removal unit may include an impurity removal reactor.

[0084] In one embodiment, at least one of the reforming reactor and the impurity removal reactor may be located inside the fluidized bed reactor, but is not limited thereto.

[0085] That is, at least one of the reforming reactor and the impurity removal reactor may be located outside the fluidized bed reactor, in which case they may be connected to the fluidized bed reactor.

[0086] In one aspect, when the pyrolysis reactor includes both a reforming section and an impurity removal section, the pyrolysis product can pass through a cyclone, pass through the reforming section, and then pass through the impurity removal section.

[0087] In one aspect, the present invention is a method for producing light olefins from waste plastics.

[0088] The method may include a step of supplying waste plastic to the device.

[0089] Additionally, the method may further include a step of pyrolyzing waste plastic in the device.

[0090] Additionally, the method may further include a step of separating and obtaining a pyrolysis product produced in the device.

[0091] The present invention will be described in detail through the following experimental examples. These examples are intended solely to illustrate the present invention, and the scope of the present invention is not limited by these examples.

[0092] Unless otherwise stated in the specification, all temperature units refer to degrees Celsius (℃), and unless otherwise stated, the amount of the composition used refers to the unit of weight percent.

[0093]

[0094] [Manufacturing Example 1] Synthesis of ZSM-5 catalyst

[0095] Solution 1 was prepared by adding 29.51 g of distilled water to 36.83 g of water glass and stirring for 30 minutes. In addition, solution 2 was prepared by mixing 3.95 g of aluminum sulfate, 0.19 g of sulfuric acid, and 29.51 g of distilled water and stirring for 20 minutes. Next, solution 2 was added to solution 1, stirred, placed in a Teflon container, and hydrothermally synthesized at 170°C for 24 hours and then cooled to room temperature. After cooling, 50 g of a 10 wt% ammonium sulfate solution was mixed with 4 g of ZSM-5 zeolite recovered through the filtration and washing processes, stirred for 30 minutes, and then the washing and filtration processes were performed three times in succession to perform ion exchange, thereby producing ZSM-5.

[0096] Phase analysis of the product obtained by the above-described method can be performed by collecting data at 2θ 7-9° and 22-25° corresponding to the characteristic peaks of ZSM-5 using an X-ray diffraction analyzer (e.g., Rigaku Model D / Max III). From the analyzed X-ray diffraction pattern, it was confirmed that the prepared zeolite had a ZSM-5 crystal structure.

[0097]

[0098] [Manufacturing Example 2] Manufacturing of P / ZSM-5 molded catalyst

[0099] In Manufacturing Example 1, 165.25 g of ZSM-5 (Si / Al = 11) synthesized was slowly added to 321.23 g of distilled water while stirring to prepare a slurry, then 71.47 g of 85% phosphoric acid was additionally added and stirred at room temperature for 30 minutes. A solution of 277.54 g of boehmite (Al2O3 content 72 wt%) dispersed in a 2% nitric acid solution was further added to the slurry, stirred for 1 hour, then 166.5 g of clay was added and thoroughly mixed for 2 hours using a high-viscosity slurry mixer. The slurry was spray-molded to obtain microspheres having a particle size of 75-200 μm, and calcined at 650°C for 5 hours. After calcination, a P / ZSM-5 molded catalyst was obtained.

[0100]

[0101] [Manufacturing Example 3] Manufacturing of pre-steamed P / ZSM-5 molded catalyst

[0102] The P / ZSM-5 molded catalyst obtained in Manufacturing Example 2 was placed in a steam treatment reactor, and distilled water was injected at a rate of 5 cc / min using a liquid pump, vaporized, and brought into contact with the sample in the form of steam at 760°C for 24 hours in a 100% steam atmosphere, thereby obtaining a pre-steamed P / ZSM-5 molded catalyst.

[0103]

[0104] [Experimental Example 1] Production of feed to be supplied to a circulating fluidized bed reactor utilizing a catalyst (continuous and high-yield production of feed to be supplied to a circulating fluidized bed reactor utilizing a catalyst through thermal decomposition of waste plastic in a fluidized bed reactor)

[0105]

[0106] Low-density polyethylene (Lotte Chemical Co.) having the characteristics described in Table 1 below was used as a sample, and pyrolysis was performed in a fluidized bed reactor, and the pyrolysis products were analyzed.

[0107] Proximate analysis (wt.%)Ultimate analysis (wt.%)Moisture0.3±0.13Carbon85.1±0.17Volatile matter99.7±0.13OxygenN.D.Fixed carbonN.D.Hydrogen14.7±0.12AshN.D.NitrogenN.D.LHV (MJ / kg)43.3±0.08

[0108] * ND: Not detected

[0109]

[0110] Samples were placed in a fluidized bed reactor with a diameter of 160 mm, a height of 550 mm, and a total reaction zone length of 1,030 mm, and pyrolysis was performed. The fluidized bed reactor mainly consists of a feed section, a thermocouple, and a wax oil collection section, and was equipped with a condenser and an impact separator. 5,000 g of sand was used as the fluidized bed material, and the continuous reaction time was approximately 1 hour.

[0111]

[0112] The operating conditions of the fluidized bed reactor were as described in Table 2 below.

[0113]

[0114] Run 1Run 2Run 3Run 4Run 5Run 6FBR set temperature (℃)550550550600510550FBR actual temperature (℃)537534551596520550Feed rate (g / h)493497491501241492Vapor residence time (s)3.382.872.203.383.383.38Type of fluidizing mediumN2N2N2N2N2P.G.

[0115] * PG: Pyrolysis gas

[0116]

[0117] The waxy oil produced in the fluidized bed reactor was qualitatively analyzed by chromatography-mass spectrometry (GC-MS: 7890A and 5975C, Agilent Instruments) and quantitatively analyzed by gas chromatography-flame ionization detection (GC-FID: 7890A, Agilent Instruments). A 10 wt% waxy oil solution was prepared using toluene as a solvent for GC-FID and GC-MS analyses. For the qualitative analysis of the waxy oil, the Wiley Registry / National Institute of Standards and Technology (NIST) library was used for peak identification, and peaks with low probability (<80%) were discarded. For the qualitative analysis of the waxy oil, the contents of oil components obtained by GC-FID were corrected using the relative response factor (RRF), and the RRF was calculated using the effective carbon number. The column used for GC-FID was an HP-5MS column, and helium was used as the carrier gas. The oven was maintained at 30°C for 17 minutes, then increased at 1°C / min to 120°C, then increased at 1.5°C / min to 320°C, and finally maintained at this temperature for 90 minutes. In addition, gas chromatography-simulated distillation (GC-SIMDIS) analysis was performed to investigate the boiling point distribution of the waxy oil. Since waxy oils were expected to have a high content of high molecular weight compounds, the ASTM D 7169 method, which can analyze hydrocarbons with a boiling point of up to 720°C, was selected for analysis. For the GC-SIMDIS analysis, the waxy oil was diluted with carbon disulfide. The pyrolysis gas was sampled using a Tedlar bag and analyzed by gas chromatography-thermal conductivity detection (GC-TCD: 7890 A, Agilent Instruments) and GC-FID. A Carboxen 1000 column was applied for the GC-TCD analysis, and argon was used as the reference gas and carrier gas. During analysis, the oven temperature was maintained at 40°C for 40 minutes.GC-FID analysis employed an HP-plot aluminum oxide (Al2O3) / potassium chloride (KCl) column. Argon was used as a makeup gas at a flow rate of 25 mL / min. The oven temperature was programmed to be maintained at 40°C for 4 min, then increased at 4°C / min to 160°C, then increased at 2°C / min to 200°C, and finally held at this temperature for 30 min.

[0118]

[0119] The results were as follows.

[0120] Mass balance

[0121] Products (wt.%)Run1Run 2Run 3Run 4Run 5Run 6Gas7.927.916.2119.180.8214.65Waxy oil90.3190.2591.6379.0894.5383.17Char1.771.842.161.744.652.18Sum100100100100100100

[0122]

[0123] As can be seen in Table 3 above, the yield of wax oil was found to be significantly affected by the reaction conditions. Among the reaction conditions, the fluidized bed reactor temperature was found to have a particularly large effect, with the yield of wax oil increasing from 79 to 90 wt% as the temperature decreased from 596°C (Run 4) to 537°C (Run 1).

[0124] Although the effect is not significant compared to the reaction temperature, an increase in the residence time of the pyrolysis vapor in the fluidized bed reactor (Runs 3→2→1) was found to have a negative effect on the production of waxy oil.

[0125] Finally, a comparison between Run 1 (N2) and Run 6 (pyrolysis gas) showed that nitrogen was more advantageous than pyrolysis gas as a fluidizing medium for wax oil production.

[0126]

[0127] [Pyrolysis gas]

[0128] Looking at the contents of gas components analyzed through GC-FDI and GC-TCD, it was found that the main gas components were ethylene at 19-30 wt% and propylene at 17-22 wt%.

[0129]

[0130] Component (wt.%)Run 1Run 2Run 3Run 4Run 5Run 6Hydrogen0.571.980.870.481.110.95Methane7.846.786.778.626.5615.13Ethane8.417.859.147.769.1914.06Ethene2 5.7321.7921.9229.9318.9424.59Propane6.987.8910.004.0110.756.49Propene19.4516.7217.6621.6316.7521.09Other C35.496.367.383.309.023.24Other C425.5230.6326.1924.2727.6814.46HHV (MJ / kg)47.2746.4546.7345.9640.5839.80Sum Gases100100100100100100

[0131]

[0132] [Waxy oil]

[0133] The gas chromatograms of wax oils obtained by GC-FID using toluene as a solvent showed that the wax oils formed a homologous series (Fig. 3(A)), and n-alkanes, n-alkenes, and n-alkadienes were the main components of each group (Fig. 3(B)). Although there were slight differences in the results of each analysis, the group with carbon numbers 8 to 27 had three well-separated peaks, and as the carbon number increased, the three peaks clustered together.

[0134]

[0135] Component (wt.%)Run 1Run 2Run 3Run 4Run 5Run 6Cyclopentene0.000.000.000.0050.000.012-methyl-1-buten-3-yne0.000.000.000.000.000.011-methylcyclopentene0.000.000.000.000.000.02Ethylidene cyclobutane0.000.000.000.000.000.03Ethylcyclopropane0.000.000.000.000.000.01n-C 6,7,8 0.310.100.180.090.000.43n-C 9,10 0.840.420.580.450.471.45n-C 11,12 3.341.311.490.871.162.30n-C 13,14 0.321.441.260.981.432.25n-C 15,16 1.261.441.250.931.392.31n-C 17,18 1.811.181.200.861.202.59n-C 19,20 1.701.191.570.821.332.99n-C 21,22 1.661.201.840.781.163.02n-C 23,24 1.521.141.720.731.143.04n-C 25,26 1.451.081.450.680.943.06n-C 27,28 1.461.071.310.601.063.01n-C 29,30 1.571.121.100.651.222.85n-C 31,32 2.571.921.961.022.362.89n-C 33,34 4.483.663.562.014.113.07n-C 35,36 5.935.284.955.505.103.18n-C 37,38 6.566.265.857.895.853.42n-C 39,40 6.566.736.474.506.574.08n-C 41,42 6.507.056.827.247.745.27n-C 43,446.607.577.127.129.196.81n-C 45,46 7.348.497.576.919.898.57n-C 47,48 7.029.238.747.5810.059.69n-C 49,50 6.739.519.348.178.8311.09n-C 51,52 5.728.589.308.076.3210.63n-C 53,54 3.638.837.3812.510.000.00Not identified13.144.206.0113.0411.501.92Sum100100100100100100

[0136]

[0137] As can be seen in Table 5, GC analysis of waxy oil dissolved in toluene solvent identified compounds having 6 to 34 carbon atoms.

[0138]

[0139] (wt.%)Run 1Run 2Run 3Run 4Run 5Run 6n-alkanes10.249.229.3815.141.146.37n-alkenes64.9064.3866.1668.0165.1164.61n-alkanes24.8626.4024.4616.8433.7529.02

[0140]

[0141] It is important that the feed of a circulating fluidized bed reactor unit utilizing a catalyst obtains wax oil with a high content of n-alkenes and n-alkadienes, which are advantageous for the production of light olefins.

[0142] Meanwhile, as can be confirmed in Table 6, it was confirmed that the pyrolysis oil of the present invention contains 64 to 68 wt% of alkene and 1 to 15 wt% of alkadiene.

[0143] By integrating the yield of wax oil (Table 3) and the composition of wax oil (Table 6) from waste plastic pyrolysis, the yields of n-alkenes and n-alkadies can be predicted (assuming that the components of the produced wax oil are the same as those in Table 6). The resulting calculated yields of n-alkanes, n-alkenes, and n-alkadiesens are as shown in Table 7 below.

[0144]

[0145] (wt.%)Run 1Run 2Run 3Run 4Run 5Run 6Waxy oil90.3190.2591.6379.0894.5383.17Alkadienes9.258.328.5911.981.085.30Alk enes58.6158.1060.6353.7861.5553.74Alkanes22.4523.8322.4113.3231.9024.13

[0146]

[0147] [Experimental Example 2] Determining suitability according to reactor type

[0148] In order to determine the type of reactor capable of producing an appropriate feed to be supplied to a circulating fluidized bed reactor unit utilizing a catalyst, pyrolysis was performed under the same conditions using different reactor types as shown in Table 8.

[0149]

[0150] (wt.%)Fixed-bed reactor(LDPE; 500℃; Reaction time (<3h))Drop-tube reactor(Recycled PE; 402℃; Reaction time (994 s))Fluidized bed reactor(Run 5; LDPE; 520℃)Gas-10.10.8Waxy oil64.58794.5Char-2.9 (residue)4.7

[0151]

[0152] As a result, it was confirmed that the fluidized bed reactor of the present invention is more suitable than the fixed bed reactor and drop tube reactor.

[0153]

[0154] [Experimental Example 3] Technology for converting high-viscosity wax oil into light olefins using a circulating fluidized bed reactor utilizing a catalyst.

[0155]

[0156] Among the wax oils produced in the fluidized bed reactor in Table 2, Run 1 and Run 5 products were fed into a simulated circulating fluidized bed reactor and catalytic cracking was performed. (Feed injection rate 0.8 g / min, reaction temperature 680°C, space velocity (WHSV) 4.8 h -1 , reaction time 90 seconds)

[0157] At this time, the catalyst used was the catalyst manufactured by the above-mentioned Manufacturing Example 3. The reaction product was separated into light olefins through a conventional fractional distillation method, and each was recovered. The recovered ethylene yield, propylene yield, C4 olefin yield, and light olefin sum yield, calculated based on 100 wt% of the injected oil-containing stream, are shown in Table 9.

[0158]

[0159] Feed Run 1 Product Run 5 Product Product Yield Ethylene 18.2 22.3 Propylene 36.4 34.7 C4 Olefins 17.3 15.1 Polycyclic Aromatics 5.3 2.29 Ethylene + Propylene 54.6 57.0 C2~C4 Olefins 71.9 72.1

[0160]

[0161] As a result, it was confirmed that light olefins can be produced in high yields when a circulating fluidized bed reactor utilizing a catalyst is used for the high viscosity wax oil products of Run 1 and Run 5, which were obtained continuously and with high yields of 90.3% and 94.5%, respectively.

[0162]

[0163] Although the above description focuses on examples, these are merely examples and do not limit the present invention. Those skilled in the art will appreciate that various modifications and applications not exemplified above are possible without departing from the essential characteristics of the present invention. For example, each component specifically shown in the examples can be modified and implemented. In addition, differences related to such modifications and applications should be construed as being included within the scope of the present invention defined in the appended claims.

[0164]

[0165] [Explanation of symbols]

[0166] 1000: Device

[0167] 1100: Silo

[0168] 1200: Screw

[0169] 1300: Fluidized bed reactor

[0170] 1310: Cyclone

[0171] 1311: Pyrolysis material inlet

[0172] 1312: Fluid outlet

[0173] 1313: Exhaust

[0174] 1320: Dispersion plate

[0175] 1330: Pyrolysis material reforming section

[0176] 1340: Impurity removal section

[0177] 1400: Circulating fluidized bed reactor unit utilizing catalyst

[0178] 1500: Storage tank

Claims

1. A device (1000) for producing light olefin from waste plastic, The above device, Fluidized bed reactor (1300); and An apparatus for producing light olefins from waste plastics, comprising a circulating fluidized bed reactor (CFBR) (1400) utilizing a catalyst.

2. In paragraph 1, The above device, A device for producing light olefins from waste plastics, comprising: a fluidized bed reactor; and a circulating fluidized bed reactor utilizing a catalyst, wherein pyrolysis is performed in at least one of the following:

3. In paragraph 1, The fluidized bed reactor is operated at a temperature of 450 to 650°C, A device for producing light olefins from waste plastic, comprising a circulating fluidized bed reactor utilizing the above catalyst and operating at a temperature of 500 to 800°C.

4. In paragraph 1, The above fluidized bed reactor (1300) is A device for producing light olefins from waste plastics, comprising a cyclone inside the reactor.

5. In paragraph 1, The fluidized bed reactor (1300) is a device for producing light olefins from waste plastic, further comprising at least one of a pyrolysis product reforming unit (1330) and an impurity removal unit (1340).

6. In paragraph 1, A circulating fluidized bed reactor utilizing the above catalyst (1400) An apparatus for producing light olefins from waste plastics, comprising a reactor, a stripper and a regenerator.

7. In paragraph 1, The circulating fluidized bed reactor utilizing the above catalyst (1400) is A device for producing light olefins from waste plastics, comprising a zeolite catalyst.

8. In paragraph 7, The above zeolite catalyst is, An apparatus for producing light olefins from waste plastics, comprising at least one selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-48, zeolite X, zeolite Y, zeolite-L, zeolite-β, zeolite-Ω, mordenite, erionite, chabazite and MFI zeolite.

9. In paragraph 7, The above zeolite catalyst is, An apparatus for producing light olefins from waste plastics, further comprising clay, SAPO (silica-alumina-phosphate), ALPO (aluminum phosphate), MOF (Metal Organic Framework), amorphous silica-alumina or a mixture thereof.

10. In paragraph 7, The above zeolite catalyst is, An apparatus for producing light olefins from waste plastics, further comprising a carrier or binder comprising carbon, alkaline earth metal oxide, alkali metal oxide, alumina, silica, silica-alumina, zirconia, titania, silicon carbide, niobia, aluminum phosphate, alumina hydrate or a mixture thereof.

11. In paragraph 7, The above zeolite catalyst is a device for producing light olefins from waste plastic into which phosphorus (P) has been introduced.

12. In paragraph 2, The above cyclone, A device for producing light olefins from waste plastics, which separates or removes char from the pyrolysis product.

13. A method for producing light olefin from waste plastic, The above method, A method for producing light olefins from waste plastic, comprising the step of supplying waste plastic to a device according to any one of claims 1 to 12.

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