Circular economy of waste plastics into polyethylene and lubricating oil via crude and isomerized dewaxing units

Abstract

Provided is a continuous process for converting waste plastics into polyethylene for recycling. In one embodiment, the process includes selecting waste plastics containing polyethylene and / or polypropylene and passing the waste plastic through a pyrolysis reactor to thermally decompose at least a portion of the polyolefin waste and produce a pyrolyzed effluent. The pyrolyzed effluent is separated into off-gas, a naphtha / diesel fraction, a heavy fraction, and char. The naphtha / diesel fraction is passed to a refinery crude unit distillation column, from which a straight-run naphtha (C5-C8) fraction or a propane / butane (C3-C4) fraction is recovered. The straight-run naphtha fraction (C5-C8) or a propane / butane (C3-C4) fraction is passed to a steam cracker for ethylene production. The heavy fraction from the pyrolysis unit can also be passed to an isomerization dewaxing unit to produce base oil.

Description

[Technical Field]

[0001] (background) The world has witnessed extremely rapid growth in plastic production. According to PlasticsEurope Market Research Group, global plastic production was 335 million tons in 2016, 348 million tons in 2017, and 359 million tons in 2018. According to McKinsey & Company, global plastic waste was estimated at approximately 260 million tons per year in 2016, and is projected to reach 460 million tons per year by 2030 if current trends continue. [Background technology]

[0002] Single-use plastic waste is becoming an increasingly significant environmental problem. Currently, there appear to be few options for recycling polyethylene and polypropylene waste plastics into value-added chemical or fuel products. Only small amounts of polyethylene and polypropylene are currently recycled through chemical recycling, and these recycled and purified polymer pellets are pyrolysis units to produce fuels (naphtha, diesel), steam cracker feedstock, or slack wax.

[0003] Processes for converting waste plastics into hydrocarbon lubricants are known. For example, U.S. Patent No. 3,845,157 discloses the decomposition of waste polyolefins or unused polyolefins to form gaseous products such as ethylene / olefin copolymers, which are then further processed to produce synthetic hydrocarbon lubricants. U.S. Patent No. 4,642,401 discloses the production of liquid hydrocarbons by heating crushed polyolefin waste at temperatures of 150-500°C and pressures of 20-300 bar. U.S. Patent No. 5,849,964 discloses a process for depolymerizing waste plastic materials into volatile and liquid phases. The volatile phase is separated into a gas phase and a condensate. The liquid phase, condensate, and gas phase are purified into liquid fuel components using standard refining techniques. U.S. Patent No. 6,143,940 discloses a procedure for converting waste plastics into a heavy wax composition. U.S. Patent No. 6,150,577 discloses a process for converting waste plastics into lubricating oil. European Patent Application Publication No. 0620264 discloses a process for producing lubricating oil from waste polyolefins or unused polyolefins, comprising thermally decomposing the waste in a fluidized bed to form a waxy product, optionally using a hydrogenation treatment, and then recovering the lubricating oil by catalytic isomerization and fractional distillation.

[0004] Other documents relating to processes for converting waste plastics into lubricants include U.S. Patents 6,288,296, 6,774,272, 6,822,126, 7,834,226, 8,088,961, 8,404,912, and 8,696,994, as well as U.S. Patent Application Publications 2019 / 0161683, 2016 / 0362609, and 2016 / 0264885. The aforementioned patent documents are incorporated herein by reference in their entirety.

[0005] Current methods of chemical recycling via pyrolysis cannot have a significant impact on the plastics industry. Current pyrolysis operations produce low-quality fuel components (products in the naphtha and diesel ranges), but these are produced in sufficiently small quantities to be blended into fuel feed. However, to address environmental concerns and recycle the very large quantities of waste polyethylene and waste polypropylene, such simple blending cannot be sustained. The products directly from the pyrolysis unit are too poor in quality to be blended in large quantities (e.g., 5-20 vol%) into transport fuel.

[0006] To reduce the environmental impact of industrially recycling single-use plastics on a large scale, more robust processes are needed. These improved processes should establish a "circular economy" for waste polyethylene and polypropylene plastics, ensuring that used plastics are effectively recycled as starting materials for polymers and high-value by-products. [Overview of the Initiative]

[0007] The provided process is a continuous process for converting waste plastics into recycled polyethylene polymers. This process involves selecting waste plastics, including polyethylene and / or polypropylene, and passing the waste plastics through a pyrolysis reactor to thermally crack at least a portion of the polyolefin waste, producing a pyrolyzed effluent. The pyrolyzed effluent is separated into off-gas, naphtha / diesel fraction, heavy fraction, and char.

[0008] Integrating this process into an oil refinery is a key aspect of this process, enabling a circular economy using disposable waste plastics such as polyethylene. Thus, the naphtha / diesel fraction is passed through the crude unit of the refinery. The straight-run naphtha (C5-C8) fraction is recovered from the crude unit's distillation column and passed through a steam cracker for ethylene production. The heavy fraction from the pyrolysis unit can be passed through an isomerization dewaxing unit to produce base oil.

[0009] In another embodiment, a continuous process is provided for converting waste plastics containing polyethylene into recycled materials for polyethylene polymerization. This process involves selecting waste plastics containing polyethylene and polypropylene, passing the waste plastics through a pyrolysis reactor to thermally decompose at least a portion of the polyolefin waste and produce a pyrolysis effluent. The pyrolysis effluent is separated into off-gas, naphtha / diesel fraction, heavy fraction, and char. The naphtha / diesel fraction is passed through a crude unit in a refinery from which propane and butane (C3-C4) fractions are recovered. The (C3-C4) fraction is passed through a steam cracker for ethylene production. The heavy fraction from the pyrolysis unit can be passed through an isomerization dewaxing unit to produce lubricating base oil.

[0010] A refinery generally has its own supply of hydrocarbons flowing through its refinery units. The volume of the naphtha / diesel or waxy heavy fraction flow, produced from the thermal decomposition of waste plastics and flowing into the refinery units, can constitute any practical or sufficient volume % (vol%) of the total flow to the refinery units. Generally, for practical reasons, the flow rate of the fraction produced from the thermal decomposition of waste plastics can be up to about 50 vol% of the total flow rate (i.e., refinery flow rate and fraction flow rate). In one embodiment, the naphtha / diesel flow rate is up to about 20 vol% of the total flow rate.

[0011] In particular, among other factors, it has been found that adding a refinery operation can upgrade waste pyrolysis oil and waste pyrolysis wax into high-value products such as gasoline, jet, diesel, and base oils. Furthermore, it has been shown that adding a refinery operation allows for the efficient and effective production of clean naphtha (C5-C8) or C3-C4 from waste pyrolysis oil, enabling the production of ultimate polyethylene polymers. Positive economic benefits are realized throughout the entire process, from recycled plastics to polyethylene products with product quality equivalent to unused polymers. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 illustrates current practices for generating fuel or wax by pyrolysis of waste plastics (basic case).

[0013] [Figure 2] Figure 2 illustrates the process for establishing a circular economy for waste plastics.

[0014] [Figure 3] Figure 3 shows the classification of plastic types for recycling waste plastics. [Modes for carrying out the invention]

[0015] This process provides a method for recycling waste polyethylene and / or waste polypropylene into virgin polyethylene, establishing a circular economy by combining separate industrial processes. The majority of polyethylene and polypropylene polymers are used in single-use plastics, which are then discarded. This single-use plastic waste is becoming an increasingly significant environmental problem. Currently, there appear to be few options for recycling waste polyethylene and polypropylene plastics into value-added chemical or fuel products. Currently, only small amounts of polyethylene / polypropylene are recycled through chemical recycling, and these recycled and purified polymer pellets are pyrolytically decomposed in pyrolysis units to produce fuels (naphtha, diesel), steam cracker feedstock, or slack wax.

[0016] Ethylene is the most widely produced building block of petrochemicals. Hundreds of millions of tons of ethylene are produced annually through steam cracking. Steam crackers use either gaseous feedstocks (ethane, propane, and / or butane) or liquid feedstocks (naphtha or gaseous oil). Steam cracking is a non-catalytic decomposition process carried out at extremely high temperatures, up to 850°C.

[0017] Polyethylene is widely used in a variety of consumer and industrial products. It is the most common plastic, with over 100 million tons of polyethylene resin produced annually. Its primary use is in packaging (plastic bags, plastic films, geomembranes, bottles, and other containers). Polyethylene is produced in three main forms, all sharing the same chemical formula (C2H4). n However, their molecular structures are different: high-density polyethylene (HDPE, approximately 0.940-0.965 g / m²) -3 ), linear low-density polyethylene (LLDPE, approximately 0.915~0.940 g / cm³) -3 ), low-density polyethylene (LDPE, <0.930 g / cm³)-3 )。HDPE has a low degree of branching and short side chains, while LDPE has a very high degree of branching and long side chains. LLDPE is a substantially linear polymer with a significant number of short branches and is typically made by copolymerizing ethylene with short-chain alpha-olefins.

[0018] Low-density polyethylene (LDPE) is produced by radical polymerization at very high pressures of 150 - 300 °C and 1,000 - 3,000 atmospheres. In this process, a small amount of oxygen and / or an organic peroxide initiator is used to produce a polymer having about 4,000 - 40,000 carbon atoms per average polymer molecule and having many branches. High-density polyethylene (HDPE) is produced in the presence of a catalyst at relatively low pressures (10 - 80 atmospheres) and temperatures of 80 - 150 °C. Ziegler-Natta organometallic catalysts (titanium(III) chloride with an alkyl aluminum) and Phillips-type catalysts (chromium(IV) oxide supported on silica) are typically used, and this production is carried out via a slurry process using a loop reactor or a gas-phase process using a fluidized-bed reactor. Hydrogen is mixed with ethylene to control the chain length of the polymer. The production conditions for linear low-density polyethylene (LLDPE) are the same as those for HDPE, except for the copolymerization of ethylene with short-chain alpha-olefins (1-butene or 1-hexene).

[0019] Today, only a very small portion of used polyethylene products are collected for recycling. This is due to the inefficiency and ineffectiveness of the recycling efforts described above.

[0020] Figure 1 shows a diagram of the pyrolysis of waste plastic fuel or wax being carried out in today's industry. As described above, generally, polyethylene and polypropylene waste are sorted together (1). The washed polyethylene / polypropylene waste 2 is converted in the pyrolysis unit 3 into off-gas 4 and pyrolysis oil (liquid product). The off-gas 4 from the pyrolysis unit is used as fuel to operate the pyrolysis unit 3, and only the pyrolysis unit is used for commercial purposes. An on-site distillation unit (not shown) separates the pyrolysis oil to produce naphtha and diesel 5 products, which are sold on the fuel market. The heavy pyrolysis oil fraction 6 is recycled to the pyrolysis unit 3 to maximize the fuel yield. The char 7 is removed from the pyrolysis unit 3. The heavy fraction 6 is rich in long-chain straight-chain hydrocarbons and is very waxy (i.e., it forms paraffinic wax when cooled to ambient temperature). The wax can be separated from the heavy fraction 6 and sold on the wax market.

[0021] This process converts large amounts of waste plastic of pyrolyzed polyethylene and / or polypropylene by integrating the pyrolysis product stream of waste polymers into an oil refinery operation. The resulting process produces polymer feedstocks (naphtha or C3-C4 for an ethylene cracker), as well as high-quality gasoline and diesel fuels, and / or high-quality base oils.

[0022] Generally, this process provides a circular economy for a polyethylene plant. Polyethylene is produced through the polymerization of pure ethylene. Clean ethylene can be produced using a steam cracker. Either a naphtha or C3-C4 stream can be fed to the steam cracker. Then, the ethylene is polymerized to produce polyethylene.

[0023] By adding refining operations to upgrade waste pyrolysis oil into high-value products (gasoline and diesel, base oils), and to produce clean LPG and naphtha for steam crackers for the ultimate polyethylene polymer production, positive economic benefits can be generated throughout the entire process, from recycled plastics to polyethylene products with the same quality as unused polymers.

[0024] The pyrolysis unit produces low-quality products containing contaminants such as calcium, magnesium, chloride, nitrogen, sulfur, dienes, and heavy components, which cannot be used in large quantities for blending transport fuels. It has been found that by passing these products through a refining unit, contaminants can be captured in the pretreatment unit, mitigating their adverse effects. Fuel components can be further upgraded in a suitable refining unit with a chemical conversion process, and the final transport fuel produced by the integrated process can be of higher quality and meet fuel quality requirements. This process also upgrades waxes into valuable lubricating base oils. The integrated process generates a much cleaner naphtha flow for steam cracker feedstock for ethylene production and polyethylene manufacturing. Mass production of these specified materials enables a viable circular economy for recycled plastics.

[0025] The carbon entering and leaving the refining process is "transparent," meaning that not all molecules from waste plastics will necessarily recirculate back to the polyolefin plant and become the exact olefin product. Nevertheless, the net "green" carbon entering and leaving the refinery is positive and therefore considered "credit." These integrated processes will significantly reduce the amount of unused raw material required for polypropylene plants.

[0026] Figure 2 shows this integrated process, which combines refining operations with recycling for effective polyethylene production. In Figure 2, mixed waste plastics are sorted together (21). The washed waste plastics 22 are converted in a pyrolysis unit 23 into off-gas 24, pyrolysis oil (liquid product), and optionally wax (solid product at ambient temperature). The off-gas 24 from the pyrolysis unit can be used as fuel to operate the pyrolysis unit 23. The pyrolysis oil is generally separated into naphtha / diesel fraction 25 and heavy fraction 26 by an on-site distillation unit. After the completion of the pyrolysis process, char 27 is removed from the pyrolysis unit 23.

[0027] The pyrolysis unit can be located near a waste plastic collection site, which may be located away from, near, or within the refinery. If the pyrolysis unit is located away from the refinery, the pyrolysis oil (naphtha / diesel and heavy oil) can be transported to the refinery by truck, barge, railcar, or pipeline. However, it is preferable that the pyrolysis unit be located within the waste plastic collection site or within the refinery.

[0028] The preferred starting material for this process is sorted waste plastics, mainly polyethylene and polypropylene (plastic recycling classification types 2, 4, and 5). The pre-sorted waste plastics are washed, shredded or pelletized, and fed into a pyrolysis unit for pyrolysis. Figure 3 shows the classification of plastic types for waste plastic recycling. Classification types 2, 4, and 5 are high-density polyethylene, low-density polyethylene, and polypropylene, respectively. Polyethylene and polypropylene waste plastics can be used in any combination. It is preferable to use at least some polyethylene waste plastics in this process.

[0029] Proper sorting of waste plastics is crucial to minimize contaminants such as N, Cl, and S. Plastic waste containing polyethylene terephthalate (plastic recycling classification type 1), polyvinyl chloride (plastic recycling classification type 3), and other polymers (plastic recycling classification type 7) needs to be sorted to less than 5%, preferably less than 1%, and most preferably less than 0.1%. This process can tolerate a moderate amount of polystyrene (plastic recycling classification type 6). Waste polystyrene needs to be sorted to less than 30%, preferably less than 20%, and most preferably less than 5%.

[0030] Washing waste plastics removes metallic contaminants such as sodium, calcium, magnesium, and aluminum, as well as non-metallic contaminants from other waste sources. Non-metallic contaminants include contaminants from Group IV of the periodic table, such as silica; contaminants from Group V, such as phosphorus and nitrogen compounds; contaminants from Group VI, such as sulfur compounds; and halogenated contaminants from Group VII, such as fluorides, chlorides, and iodides. Residual metals, non-metallic contaminants, and halides should be removed to less than 50 ppm, preferably less than 30 ppm, and most preferably less than 5 ppm.

[0031] If metal, non-metallic contaminants, and halide impurities are not adequately removed by cleaning, a separate guard floor can be used to remove the metal and non-metallic contaminants.

[0032] Pyrolysis is carried out by contacting the plastic material raw material with pyrolysis conditions in a pyrolysis zone, where at least a portion of the feed material is decomposed, thereby forming a pyrolysis zone effluent containing 1-olefins and n-paraffins. The pyrolysis conditions include temperatures of about 400°C to about 700°C, preferably about 450°C to about 650°C. Conventional pyrolysis techniques teach operating conditions at pressures above atmospheric pressure (see, for example, U.S. Patent No. 4,642,401). Furthermore, it has been found that the yield of the desired product can be controlled by adjusting the pressure downward (see, for example, U.S. Patent No. 6,150,577). Therefore, in some embodiments where such control is desired, the pyrolysis pressure is below atmospheric pressure.

[0033] Figure 2 shows the integrated process, where only the naphtha / diesel fraction 25 from the pyrolysis unit 23 is sent to the crude unit desalination unit 28 to produce C5-C8 naphtha (29), preferably C5-C7 naphtha, and most preferably C5-C6 naphtha, for use as feedstock for the steam cracker 30. The steam cracker 30 produces ethylene 36. The ethylene is passed through the polymerization unit 40 to produce polyethylene. The polyethylene is used for polyethylene consumer products 41.

[0034] A refinery generally has its own supply of hydrocarbons flowing through its refining units. The volume of the naphtha / diesel flow produced from the pyrolysis of waste plastics and flowing into the refining units (in this case, the crude units) can constitute any practical or tolerable volume % (vol%) of the total flow to the refining units. Generally, for practical reasons, the flow rate of the naphtha / diesel fraction produced from the pyrolysis of waste plastics can be up to about 50 vol% of the total flow rate (i.e., the refining flow rate and the naphtha / diesel flow rate). In one embodiment, the naphtha / diesel flow rate is up to about 20 vol% of the total flow rate. In another embodiment, the naphtha / diesel flow rate is up to about 10 vol% of the total flow rate. About 20 vol% has been found to be a very practical amount in terms of impact on the refinery, while also providing excellent results and being tolerable. Of course, the amount of naphtha / diesel produced from pyrolysis can be controlled so that the fraction passing through the refining units provides a desired volume % of the flow rate. The flow rate of heavy fractions to the dewaxing unit can also be controlled and / or adjusted in a similar manner.

[0035] A refinery crude unit separates crude oil into multiple fractions such as liquefied petroleum gas (LPG), naphtha, kerosene, diesel, and gas oil, and then processes them further to produce useful petroleum products. A refinery crude unit includes a crude oil processing section, commonly known as a desalination unit, and a crude oil distillation section or crude oil fractionation section. The distillation section typically includes atmospheric distillation units and vacuum distillation units.

[0036] The naphtha / diesel fraction from the pyrolysis unit is fed into a desalination unit to remove salts and solids from the oil, protecting downstream equipment from the harmful effects of contaminants. To remove the salts, water is mixed with the oil and heated to a temperature typically of about 215°F to 280°F for separation within the desalination unit.

[0037] The desalted oil is sent to an atmospheric distillation unit heated to approximately 340-372°C (644-700°F) at the bottom of the distillation column, where the liquid is removed at various points in the fractional distillation column to produce various fuels. The fuel from the crude unit is sent to various upgrade units in the refinery to remove impurities (nitrogen, sulfur) and catalytically convert the fraction to improve product properties such as octane and cetane numbers. The bottom residue from the atmospheric distillation column (also known as atmospheric residue) is sent to a vacuum distillation column to produce vacuum diesel (650-1050°F) and vacuum residue. Vacuum diesel can be used to produce lubricating base oil or further broken down to produce gasoline, jet, and diesel fuels.

[0038] Steam crackers and ethylene polymerization units are preferably located near the refinery so that raw materials (propane, butane, naphtha) can be transported via pipeline. In the case of petrochemical plants located far from the refinery, raw materials can be delivered by truck, barge, railcar, or pipeline.

[0039] Heavy naphtha / diesel from pyrolysis oil can be combined with hydrocarbons from crude unit distillation and sent to a suitable refining unit 32 to be upgraded to clean gasoline and diesel 33 as heavy naphtha, diesel, atmospheric diesel stream 31.

[0040] The heavy, waxy pyrolysis oil 26 from the pyrolysis unit is sent to a base oil dewaxing unit 34 equipped with a precious metal-containing zeolite catalyst for isomerization dewaxing or hydroisomerization to produce a lubricating base oil 35 having excellent viscosity index and pour point. The flow rate of the heavy, waxy fraction can be controlled and adjusted as needed based on the amount to be contained.

[0041] An isomerization dewaxing unit converts paraffinic, waxy heavy hydrocarbon materials (typically with a boiling point of approximately 650°F) into high viscosity index (VI) lubricating oils. This unit typically includes a feed hydrogenation section, an isomerization dewaxing section, and a distillation section.

[0042] The feed to the dewaxing unit is preferably subjected to hydrogenation first in a hydrogenation process. This hydrogenation is carried out as part of the dewaxing unit. The feed to the hydrogenation process removes most of the nitrogen-containing, sulfur-containing, and / or oxygen-containing contaminants. The hydrogenation process also saturates some of the olefins, dienes, and aromatic compounds to improve the quality of the feed to the dewaxing unit. Typical hydrogenation conditions used to remove contaminants while avoiding decomposition include a temperature in the range of about 190°C (374°F) to about 340°C (644°F), a pressure in the range of about 400 psig to about 3000 psig, and about 0.1 hours. -1 ~approximately 20 hours -1 This includes a space velocity (LHSV) in the range of approximately 400 to 15,000 SCF / B and a hydrogen recycling rate in the range of approximately 400 to 15,000 SCF / B. Hydrogenation catalysts include those conventionally used in hydrogenation units and include metals such as Ni, Mo, Co, and W, and porous carriers such as alumina, silica, or silica-alumina.

[0043] Hydrogenated heavy hydrocarbons are sent to a dewaxing reactor equipped with an isomerized dewaxing catalyst containing a noble metal, molecular sieves of intermediate pore size, and a binder. This catalyst preferably contains molecular sieves of intermediate pore size (10-membered rings) such as ZSM-23, ZSM-35, ZSM-48, ZSM-5, SSZ-32, SSZ-91, SAPO-11, SAPO-31, and SAPO-41. Examples of noble metals include group VIII metals such as Pt, Pd, or mixtures of Pt and Pd. Typically, porous alumina or silica is used to bind the materials and produce catalyst pellets for fixed-bed reactors. Typical reaction conditions for a dewaxing reactor include a temperature range of 200°C (392°F) to about 475°C (887°F), a pressure range of about 200 psig to about 3000 psig, and a reaction time of about 0.2 hours. -1 ~approximately 10 hours -1 This includes a space velocity (LHSV) in the range of 400 to 15,000 SCF / B and a hydrogen recycling rate in the range of approximately 400 to 15,000 SCF / B. The isomerization dewaxing catalyst converts n-paraffins to isoparaffins, thereby lowering the pour point of the resulting oil and forming a high VI lubricant.

[0044] The hydrocarbon effluent from the isomerization dewaxing section is sent to the distillation unit, where it is separated into various oil fractions, such as a base oil fraction that boils at approximately 650°F or higher, a diesel fraction that boils at approximately 300–700°F, and a gasoline fraction that boils at approximately 80–400°F. The boiling points of the gasoline, jet, and diesel fractions are adjusted according to seasonal and regional specifications.

[0045] In another embodiment, the C3-C4 fraction 37 is recovered from the refinery / crude unit 28. This stream can also be fed to a steam cracker 30 for the production of ethylene 36. The ethylene can then be polymerized (40) to produce a consumer product 41.

[0046] The benefits of a circular economy and effective and efficient recycling campaigns will be realized through this integrated process.

[0047] The following examples are provided to further illustrate this process and its benefits. These examples are illustrative and not intended to be limiting. [Examples]

[0048] [Example 1] Characteristics of pyrolysis oils and waxes from commercial sources

[0049] Samples of pyrolysis oil and wax were obtained from commercial sources. Their properties are summarized in Table 1. These pyrolysis samples were prepared from waste plastics, mainly polyethylene and polypropylene, via pyrolysis in a pyrolysis reactor at approximately 400–600°C and near atmospheric pressure, without the addition of gases or catalysts. Pyrolysis units typically produce gas, liquid oil products, optionally wax products, and char. The overhead gas stream containing thermally decomposed hydrocarbons from the pyrolysis unit was cooled, and the condensates were collected as pyrolysis oil (liquid at ambient temperature) and / or pyrolysis wax (solid at ambient temperature). Pyrolysis oil is the main product of the pyrolysis unit. Some pyrolysis units produce pyrolysis wax as a separate product in addition to pyrolysis oil. [Table 1]

[0050] Specific gravity was measured using the ASTM D4052 method. The simulated boiling point distribution curve was obtained using the ASTM D2887 method. Carlo-Erba analysis of carbon and hydrogen was performed according to the ASTM D5291 method. Bromine number was measured according to the ASTM D1159 method. Hydrocarbon type analysis was performed using a high-resolution magnetic mass spectrometer, scanning the magnet from 40 to 500 Daltons. Total sulfur was determined using XRF according to the ASTM D2622 method. Nitrogen was determined using chemiluminescence detection according to the modified ASTM D5762 method. Total chloride content was measured using a combustion ion chromatography instrument according to the modified ASTM 7359 method. Oxygen content in the boiling range of naphtha and distillates was estimated using GC by GC / MS measurement with an electron ionization detector in the m / Z range of 29 to 500. Trace metal and nonmetal elements in the oil were determined using inductively coupled plasma atomic emission spectrometry (ICP-AES).

[0051] In industrial pyrolysis processes for sorted plastics, primarily supplied from polyethylene and polypropylene waste, high-quality hydrocarbon streams with a specific gravity in the range of 0.7–0.9 and a boiling point range of 18–1100°F were produced, similar to pyrolysis oils or pyrolysis waxes.

[0052] The pyrolysis products are fairly pure hydrocarbons mainly composed of carbon and hydrogen. The molar ratio of hydrogen to carbon varies up to nearly 1.7 - 2.0. The bromine number ranges from 14 to 60, indicating various degrees of unsaturation due to olefins and aromatic compounds. The aromatic content ranges from 5 to 23% by volume, and units with more severe pyrolysis conditions produce more aromatic compounds. Depending on the process conditions of the pyrolysis unit, the pyrolysis products show a paraffin content in the range of mid - 20 vol% to mid - 50 vol%. The pyrolysis products contain a significant amount of olefins. Sample A and Sample B are pyrolysis oils produced under more severe conditions such as higher pyrolysis temperature and / or longer residence time, with more aromatic components and fewer paraffin components. As a result, the H / C molar ratio is about 1.7 and the bromine number is as high as 50 - 60. Sample C and Sample D are produced under less severe conditions, and their pyrolysis oils are more paraffinic. As a result, the H / C molar ratio is close to 2.0 and the bromine number is about 40. Sample E (pyrolysis wax) is mostly paraffinic saturated hydrocarbons, containing a significant amount of straight - chain hydrocarbons (in contrast to branched hydrocarbons), and the bromine number is only 14.

[0053] Examples 2 to 5 below show the evaluation of waste plastic pyrolysis oil as a transportation fuel.

[0054] [Example 2] Fractionation of pyrolysis oil for evaluation as a transportation fuel

[0055] Sample D was distilled to produce multiple fractions of hydrocarbons, namely, gasoline (350°F - ) fraction, jet (350 - 572°F) fraction, diesel (572 - 700°F) fraction, and heavy (700°F + ) fraction. Table 2 summarizes the boiling point distribution and impurity distribution of each fraction of the distillation product.

Table 2

[0056] [Example 3] Evaluation of fractions of pyrolysis oil for gasoline fuel

[0057] The potential for use as gasoline fuel was evaluated for sample F (a fraction of pyrolysis oil within the boiling point range of gasoline fuel). The carbon number range of sample F is C5 to C12, which is typical for gasoline fuel.

[0058] Because the pyrolysis oil is olefinic, oxidation stability (ASTM D525) and gum formation tendency (ASTM D381) were identified as the most important properties to investigate. Research octane number (RON) and motor octane number (MON) are also important properties for engine performance. The RON and MON values ​​were estimated from detailed GC analysis of hydrocarbons. [Table 3]

[0059] Sample F (a fraction of pyrolysis oil within the boiling point range of gasoline fuel) is of poor quality and cannot be used alone as automotive gasoline fuel. The gasoline fraction from the pyrolysis oil showed very low oxidation stability, with Sample F failing after only 90 minutes compared to the target stability of over 1440 minutes. The pyrolysis gasoline exceeded the target wash gum of 4 mg / 100 mL, indicating a strong tendency for gum formation. The pyrolysis gasoline had a lower octane rating compared to the reference gasoline. Premium unleaded gasoline was used as the reference gasoline.

[0060] We also investigated the possibility of blending a limited amount of pyrolytic gasoline fraction with reference gasoline. Our study showed that it may be possible to blend up to 15 volume% of sample F with refined gasoline while achieving the target fuel properties. Integrating pyrolytic gasoline products with refined fuels can maintain the overall quality of the product.

[0061] These results indicate that the gasoline fraction produced from pyrolysis oil has limited utility as a gasoline fuel. To convert this gasoline fraction from pyrolysis oil into hydrocarbons that meet the target gasoline fuel properties, an upgrade in the refining unit is preferable.

[0062] [Example 4] Evaluation of fractions of pyrolysis oil for jet fuel

[0063] The usability of sample G (a fraction of pyrolysis oil within the boiling point range of jet fuel) as jet fuel was evaluated. The carbon number range of sample G is C9 to C18, which is typical for jet fuel.

[0064] Because the pyrolysis oil is olefinic, the thermal oxidation test of the jet fuel (D3241) was considered the most important test. Sample G, which was the pure jet fraction of the pyrolysis oil, had an oxidation stability of only 36 minutes, indicating that the pure pyrolysis jet fraction is unsuitable for use as jet fuel.

[0065] We prepared a blend of pyrolysis jet fraction (sample G) at 5% by volume with jet fuel produced at a refinery. This blend still failed the oxidation test of the jet fuel, as shown in Table 4. [Table 4]

[0066] These results indicate that the jet fraction produced from pyrolysis oil is completely unsuitable for jet fuel, and that an upgrade in the refining unit is necessary to convert this jet fraction of pyrolysis oil into hydrocarbons that meet the characteristic targets of jet fuel.

[0067] [Example 5] Evaluation of fractions of pyrolysis oil for diesel fuel

[0068] The usability of sample H (a fraction of pyrolysis oil within the boiling point range of diesel fuel) as diesel fuel was evaluated. The carbon number range of sample H is C14 to C24, which is typical for diesel fuel.

[0069] Sample H contains a considerable amount of straight-chain hydrocarbons. Because straight-chain hydrocarbons tend to exhibit waxy properties, low-temperature flow characteristics such as the pour point (ASTM D5950-14) and cloud point (ASTM D5773) were considered the most important tests.

[0070] We prepared two blends of sample H by blending it with refined diesel fuel at 10% and 20% volume. However, both of these blends still failed to meet the target pour point of -17.8°C (0°F). [Table 5]

[0071] These results indicate that pyrolysis oil, in its raw form, is completely unsuitable for diesel fuel, and that an upgrade in the refining unit is necessary to convert the diesel fraction of the pyrolysis oil into hydrocarbons that meet the characteristic targets of diesel fuel.

[0072] [Example 6] Co-treatment of pyrolysis oil into a crude unit or desalination unit

[0073] The results in Table 1 show that the industrial pyrolysis process of sorted plastics, primarily supplied from polyethylene and polypropylene waste, produces high-quality pyrolysis oil composed mainly of carbon and hydrogen. Good sorting and efficient operation of the pyrolysis unit result in sufficiently low levels of nitrogen and sulfur impurities, allowing modern refineries to handle cofeeding of pyrolysis raw materials to processing units without harmful effects.

[0074] However, some pyrolysis oils may still contain large amounts of metals (Ca, Fe, Mg) and other nonmetals (N, S, P, Si, Cl, O), which can negatively affect the performance of the refinery's conversion units. In the case of pyrolysis oils, products with high levels of impurities are preferentially fed to the desalination unit before the crude unit, where the majority of the impurities are effectively removed.

[0075] By supplying the pyrolysis raw materials to a crude unit, or to a desalination unit prior to the crude unit, the pyrolysis oil is fractionated into multiple components and then further converted in subsequent conversion units, including a paraffin isomerization unit, a jet hydrotreatment unit, a diesel hydrotreatment unit, a fluid catalytic cracking (FCC) unit, an alkylation unit, a hydrocracking unit, and / or a coker unit, to produce gasoline, jet, and diesel fuels with satisfactory product characteristics. The conversion units (FCC or hydrocracking unit) also convert the heavy fraction (corresponding to sample I) into high-quality transport fuels.

[0076] After the crude unit, the pyrolysis oil is further converted in a subsequent crude unit. Example 7 below demonstrates the conversion of waste plastic pyrolysis oil into high-quality transport fuel in a refinement conversion unit (using an FCC unit as an example).

[0077] [Example 7] Conversion of pyrolytic oil in FCC

[0078] To study the effects of coprocessing waste plastic pyrolysis oil into FCC, a series of laboratory tests were conducted using samples A and C. Vacuum gasoline (VGO) is a typical feedstock for FCC. The FCC performance of a 20% blend of pyrolysis oil using VGO and pure pyrolysis oil was compared to that of pure VGO feedstock.

[0079] FCC experiments were performed using a Model C ACE (advanced cracking evaluation) unit from Kayser Technology Inc., employing regenerated equilibrium catalyst (Ecat) from a refinery. The reactor was a fixed fluid reactor using N2 as the fluidizing gas. Catalytic cracking experiments were conducted at atmospheric pressure and a reactor temperature of 900°F. The catalyst / oil ratio was varied between 5 and 8 by changing the amount of catalyst. Gas products were collected and analyzed using a refined gas analysis unit (RGA) equipped with a GC with an FID detector. In-situ regeneration of spent catalyst was performed in the presence of air at 1300°F, and the regenerated flue gas was passed through a LECO to determine the coke yield. Liquid products were weighed and analyzed by GC for simulated distillation (D2887) and C5 - A compositional analysis was performed. Based on the mass balance, the components were identified as coke, dry gas components, LPG components, gasoline (C5, ~430°F), light cycle oil (LCO, 430~650°F), and heavy cycle oil (HCO, 650°F). + The yield of ) was determined. The results are summarized in Table 6 below. [Table 6]

[0080] The results in Table 6 show that co-feeding up to 20% by volume of pyrolysis oil results in only a slight change in the performance of the FCC unit, indicating that co-feeding up to 20% pyrolysis oil is easily feasible. Blending 20% ​​by volume of sample A or sample C resulted in a slight decrease in coke and dry gas yields, a slight increase in gasoline yields, and a slight decrease in LCO and HCO. These are acceptable in most situations. Because pyrolysis oil is paraffinic, blending 20% ​​of sample A or sample C resulted in an octane rating decrease of approximately 3–5. Due to refinery operational flexibility, these octane ratings can be compensated for by blending or adjusting the feeding position.

[0081] The FCC unit decomposes the pyrolysis oil into hydrocarbons within the fuel range, reduces impurities, and isomerizes n-paraffins to isoparaffins. All of these chemical properties improve the fuel properties of the pyrolysis oil and wax. By co-supplying the pyrolysis oil with a zeolite catalyst through the FCC process unit, oxygen and nitrogen impurities within the fuel range were significantly reduced: nitrogen (N) from approximately 300-1400 ppm to approximately 30 ppm, and oxygen (O) from approximately 250-540 ppm to approximately 60-80 ppm. The hydrocarbon composition of all these co-supply products falls well within the range of typical FCC gasoline.

[0082] In the FCC operation using 100% pyrolysis oil, a significant decrease in octane rating (approximately 13-14) was observed. This indicates that co-treatment with pyrolysis oil is preferable to treatment with pure 100% pyrolysis oil.

[0083] [Example 8] Production of C3-C4 and naphtha raw materials for chemical production via co-supply of waste plastic pyrolysis products to refinery and crude unit

[0084] By supplying the pyrolysis oil to the crude unit, or to a desalination unit prior to the crude unit, the pyrolysis oil is fractionated into multiple components. The co-supply of pyrolysis oil generates a considerable amount of clean propane, butane, and naphtha streams containing recyclable components that can be supplied to the steam cracker. At least some (if not all) of these streams are supplied to the steam cracker.

[0085] [Example 9] Supply of recycled C3-C4 and / or naphtha to a steam cracker for ethylene production, and subsequent production of recycled polyethylene resin and polyethylene consumer products.

[0086] Propane, butane, and naphtha flows are generated by co-feeding the pyrolysis products to a crude unit (Example 8). These flows are suitable raw materials for co-feeding to a steam cracker to produce ethylene containing recycled components. The ethylene is then processed in a polymerization unit to produce polyethylene resin containing recycled polyethylene / polypropylene-derived materials. The quality of the newly produced polyethylene is indistinguishable from unused polyethylene made from entirely unused petroleum resources. This polyethylene resin containing recycled materials is further processed to produce a variety of polyethylene products to meet consumer product needs. These polyethylene consumer products contain chemically recycled, circular polymers, but their quality is indistinguishable from those made from entirely unused polyethylene polymers. These chemically recycled polymer products are different from mechanically recycled polymer products, which are of lower quality than polymer products made from unused polymers.

[0087] [Example 10] Co-treatment of pyrolysis wax into an isomerization dewaxing unit for the production of lubricating base oil

[0088] The results in Table 1 show that the industrial pyrolysis process of sorted plastics, primarily supplied from polyethylene and polypropylene waste, produces pyrolysis waxes composed mainly of carbon and hydrogen. Various process options were investigated to produce lubricating base oils from this pyrolysis wax via a hydrogenation-isomerization dewaxing process.

[0089] Pyrolytic waxes still contain large amounts of nitrogen and sulfur impurities, metals (Ca, Fe, Mg), and other nonmetals (P, Si, Cl, O), which adversely affect the performance of hydrogenation isomerization dewaxing catalysts containing noble metals (Pt, Pd, or combinations of Pt and Pd) and zeolites such as ZSM-11, ZSM-23, ZSM-48, SSZ-32, SSZ-91, SAPO-11, SAPO-31, and SAPO-41.

[0090] As shown in Example 11 below, attempts to produce high-quality lubricating base oil by directly supplying pure pyrolysis oil with a dewaxing catalyst were unsuccessful. Because the pyrolysis wax is supplied directly to the hydroisomerization dewaxing unit, the co-supply level must be limited to less than 10 vol%, preferably less than 5 vol%, to maintain catalytic activity. This volume percentage limitation may be due to nitrogen impurities that are detrimental to the zeolite's activity. The nitrogen level of the combined feedstock should be maintained at less than 5 ppm, preferably less than 1 ppm.

[0091] Alternatively, the pyrolysis wax is co-supplied to a hydrocracking unit to remove S, N, and other impurities. The hydrocracking unit hydrogenates the pyrolysis wax and removes impurities. The harsh conditions of the hydrocracking unit can be adjusted to maximize the base oil yield of the combined feedstock. The co-supply level to the hydrocracking unit can be 50 vol%, preferably 20 vol%. In this case, the volume percentage limitation may be due to metallic impurities or N or P impurities, depending on the unit configuration and catalyst selection. The bottom fraction containing the hydrocracking pyrolysis wax is then processed (650°F). + The wax is supplied to a hydrogenation-isomerization-dewaxing unit to produce a lubricating base oil. Alternatively, the pyrolysis wax is supplied to a dedicated hydrogenation unit to remove S, N, and other impurities, and then supplied to a hydrogenation-isomerization-dewaxing unit to produce a base oil. As shown in Example 12 below, the hydrogenation process removes impurities very easily. The hydrogenated wax can be co-supplied to the hydrogenation-isomerization-dewaxing unit in any volume percentage.

[0092] Examples 11 and 12 below demonstrate unsuccessful and successful process routes for producing high-quality base oil using pyrolysis wax from waste plastics as a raw material in refinery conversion units.

[0093] [Example 11] Production of base oil from recycled pyrolysis wax via only a hydrogenation isomerization dewaxing process

[0094] To evaluate the potential for base oil production from recycled wax, sample E (crude pyrolysis wax) was vacuum distilled at 690°F. + A fraction (sample J) was prepared. 100% sample J was hydrogenated overnight in a batch autoclave unit using a Pt / SSZ-32 / alumina catalyst at a weight ratio of oil to catalyst of 10:1, 650°F, and an H2 pressure of 800 psig. The resulting hydrogenation product was subjected to vacuum distillation, and the boiling point was 690°F. + A transparent oil (sample K) was produced. The properties of these samples are summarized in the table. [Table 7]

[0095] Sample J (690°F from the thermal decomposition of waste plastic) + The slack wax fraction is a low-viscosity wax with approximately 4.3 cSt at 100°C and has an excellent viscosity index of 169. However, the slack wax contains significant amounts of N (180 ppm) and P (32.5 ppm), which passivate the activity of the zeolite catalyst in the hydrogenation-isomerization dewaxing process. Sample K, a dewaxing and distilled oil, exhibited a viscosity index of 162 and a pour point of 12°C. While this pour point is significantly lower than that of sample E (42°C), a pour point of 12°C is still very poor compared to the industry target of below -15°C. This oil loses its fluidity / oiliness below ambient temperature of 12°C, becoming thick or solid-like, and therefore cannot be used in high-performance, modern lubricants.

[0096] This study demonstrates that in order to produce an acceptable base oil from waste plastic pyrolysis wax, the pyrolysis wax needs to be hydrotreated or hydrocracking to reduce nitrogen impurities and other impurities.

[0097] [Example 12] Production of high-quality base oil containing recycled components by hydrogenation treatment and subsequent hydrogen isomerization dewaxing process.

[0098] Sample E (crude pyrolysis wax) was hydrogenated in a continuous fixed-bed unit containing a NiMo / alumina catalyst at a reactor temperature of 625°F and a pressure of 1200 psig. The hydrogenation period was 1.5 hours relative to the catalyst bed volume. -1 Using a liquid feed flow rate and an H2 / hydrocarbon flow rate of 2500 scf / bbl, a hydrogenation product consisting mostly of wax was produced. This hydrogenation product was vacuum distilled and obtained as hydrothermally pyrolyzed paraffin wax (sample L) at 650°F. + A fraction was generated.

[0099] Sample L (hydrogenated wax produced from the thermal decomposition of waste plastics) was subjected to hydrogenation, isomerization, and dewaxing in a continuous fixed-bed unit containing a Pt / ZZS-91 / alumina catalyst at a reactor temperature of 625°F and a pressure of 400 psig. The reaction time was 1.0 hr relative to the catalyst bed volume. -1 Using a liquid supply flow rate and an H2 / hydrocarbon flow rate of 2500 scf / bbl, dewaxed oil was produced. This dewaxed oil was vacuum distilled to obtain the final dewaxed base oil product (sample M) at 690°F. + The fraction was generated. The results are summarized in Table 8. [Table 8]

[0100] High-quality hydrogenated wax (Sample L) was produced by hydrogenation of pyrolysis wax (Sample E). Since Sample L contains no measurable impurities that could harm the dewaxing catalyst, all trace impurities are completely removed during hydrogenation. This example demonstrates that high-quality, pure paraffinic wax can be effectively produced from waste plastics, mainly polyethylene and polypropylene, and that mild hydrogenation is a very effective method for purifying waxes derived from waste plastics.

[0101] Hydrogenated isomerization dewaxing of hydrogenated wax (Sample L) produced a 4cSt base oil of excellent quality with a viscosity index of 135, a pour point of -35°C, and a cloud point of -17°C (Sample M). In terms of quality, this base oil, produced from the thermal decomposition of waste plastics, is classified as a Group III base oil category. These positive results were quite surprising considering the poor properties observed in Sample K. Low viscosity (4cSt) base oils are highly desirable because they are widely used as components in automotive lubricants.

[0102] Examples 11 and 12 clearly demonstrate that by carefully selecting the co-supply process configuration and process conditions, a base oil of excellent quality can be produced from waxes obtained from the pyrolysis of polyethylene and polypropylene waste. This result clearly indicates that the preferred method for producing base oil from pyrolysis waxes of waste plastics is by hydrogenation and subsequent hydrogen isomerization dewaxing processes. The final base oil produced contains recycled components, and its quality is equivalent to or better than base oil produced by conventional refining processes using unused virgin crude oil.

[0103] The aforementioned examples clearly demonstrate a new and effective method for recycling large quantities of polyethylene and polypropylene-derived waste plastics through chemical recycling via pyrolysis and subsequent efficient integration, which leads to the co-supply of pyrolysis products at refineries. This integration enables the production of high-quality fuels, lubricating base oils, and recyclable polymers.

[0104] Where used in this disclosure, the words “comprises” or “comprising” are intended as open-ended transitional terms meaning to include the indicated elements, but not necessarily to exclude other unindicated elements. The phrases “consists essentially of” or “consisting essentially of” are intended to mean to exclude other elements that are essentially important to the composition. The phrases “consisting of” or “consists of” are intended as transitional terms meaning to exclude everything other than the elements described, except for trace amounts of impurities.

[0105] All patents and publications referenced herein are incorporated herein by reference to the extent that they do not conflict with this specification. It will be understood that the specific structures, functions, and operations of the above embodiments are not necessary for carrying out the invention and are included in the description merely to complete the exemplary embodiments or multiple embodiments. Furthermore, it will be understood that while specific structures, functions, and operations described in the above-referenced patents and publications can be carried out in combination with the invention, they are not essential for its implementation. Therefore, it should be understood that the invention can be carried out as specifically described without actually departing from the spirit and scope of the invention as defined by the appended claims. The invention described in the original claims of this application is as follows: [Section 1] A continuous process for converting waste plastic into recycled polyethylene polymer, (a) A step of selecting waste plastics including polyethylene and / or polypropylene, (b) A step of passing the waste plastic from (a) through a pyrolysis reactor to thermally decompose at least a portion of the polyolefin waste and produce a pyrolysis effluent, (c) A step of separating the pyrolysis effluent into off-gas, naphtha / diesel fraction, heavy fraction, and char. (d) The process of passing the naphtha / diesel fraction through the crude unit of the refinery, (e) From the crude unit, straight-run naphtha (C 5 -C 8 ) The process of recovering the fraction, (f) The straight-run naphtha fraction (C 5 -C 8 ) is passed through a steam cracker for ethylene production. (g) A step of passing the heavy fraction through an isomerization dewaxing unit to produce a base oil, The above process, including. [Section 2] The process described in item 1, wherein the naphtha / diesel fraction of (c) is passed directly through the refinery / crude unit, and contaminants are removed in the crude unit desalination unit. [Section 3] The process described in Section 1, wherein the contaminants are removed at a pyrolysis site. [Section 4] The process described in item 1, wherein the ethylene produced in (f) is subsequently polymerized. [Section 5] The process according to item 4, wherein a consumer polyethylene product is prepared from polymerized ethylene. [Section 6] The process described in item 1, wherein the waste plastic selected in (a) is from plastic classification groups 2, 4, and / or 5. [Section 7] The process described in item 1, wherein heavy naphtha / diesel / atmospheric diesel fuel is recovered from a crude unit and further processed at a refinery into clean gasoline, diesel, or jet fuel. [Section 8] The process according to item 7, wherein the amount of unused crude oil processed by the crude oil processing unit is reduced by recycled pyrolysis oil. [Section 9] The process according to item 1, wherein the amount of base oil produced by the isomerization dewaxing unit is increased by recycled pyrolysis oil. [Section 10] The process according to item 1, wherein the heavy fraction in (g) is hydrogenated and then isomerized with a dewaxing unit. [Section 11] The process described in item 1, wherein the volumetric flow rate of the naphtha / diesel fraction flowing into the crude unit of the refinery constitutes up to approximately 50 volume percent of the total flow rate of hydrocarbons flowing into the crude oil. [Section 12] The process according to item 11, wherein the flow rate of naphtha / diesel constitutes a maximum of 20 volume percent. [Section 13] A continuous process for converting waste plastic into recycled polyethylene polymer, (a) A step of selecting waste plastics including polyethylene and / or polypropylene, (b) A step of passing the waste plastic from (a) through a pyrolysis reactor to thermally decompose at least a portion of the polyolefin waste and produce a pyrolysis effluent, (c) A step of separating the pyrolysis effluent into off-gas, naphtha / diesel fraction, heavy fraction, and char. (d) The process of passing the naphtha / diesel fraction through the crude unit of the refinery, (e) From the crude unit, propane and butane (C 3 -C 4 )) Process of recovering the fraction, (f) Above (C 3 -C 4 ) The process of passing the fraction through a steam cracker for ethylene production, (g) A step of passing the heavy fraction through an isomerization dewaxing unit to produce a base oil, The above process, including. [Section 14] The process according to Section 13, wherein the naphtha / diesel fraction of (c) is passed directly through the refinery / crude unit, and contaminants are removed in the crude unit desalination unit. [Section 15] The process described in Section 13, wherein the contaminants are removed at a pyrolysis site. [Section 16] The process according to item 13, wherein the ethylene produced in (f) is subsequently polymerized. [Section 17] The process according to item 16, wherein a consumer polyethylene product is prepared from polymerized ethylene. [Section 18] The process described in Section 13, wherein the waste plastic selected in (a) is from plastic classification groups 2, 4, and / or 5. [Section 19] The process described in Section 13, wherein heavy naphtha / diesel / atmospheric diesel fuel is recovered from a crude unit and further processed at a refinery into clean gasoline, diesel, or jet fuel. [Section 20] The process according to item 19, wherein the amount of unused crude oil processed by the crude unit is reduced by recycled pyrolysis oil. [Section 21] The process according to item 13, wherein the amount of base oil produced by the isomerization dewaxing unit is increased by recycled pyrolysis oil. [Section 22] The process according to item 13, wherein the heavy fraction in (g) is hydrogenated and then isomerized with a dewaxing unit. [Section 23] The process described in Section 13, wherein the volumetric flow rate of naphtha / diesel fractions flowing into the crude unit of the refinery constitutes up to approximately 50 volume percent of the total flow rate of hydrocarbons flowing into the crude oil. [Section 24] The process according to item 23, wherein the flow rate of naphtha / diesel constitutes a maximum of 20 volume percent. [Section 25] A process for converting waste plastics into chemicals useful for the preparation of polyethylene and lubricating oils, (a) A step of selecting waste plastics including polyethylene and / or polypropylene, (b) A step of thermally decomposing the waste plastic and recovering naphtha / diesel fraction and heavy fraction, (c) The process of passing the naphtha / diesel fraction through the crude unit of the refinery, (d) A step of passing the heavy fraction through an isomerization dewaxing unit, The above process, including.

Claims

1. A continuous process for converting waste plastic into recycled polyethylene polymer, (a) A step of selecting waste plastics including polyethylene and / or polypropylene, (b) A step of passing the waste plastic from (a) through a pyrolysis reactor to thermally decompose at least a portion of the polyolefin waste and produce a pyrolysis effluent, (c) A step of separating the pyrolysis effluent into off-gas, naphtha / diesel fraction, heavy fraction, and char. (d) A step of passing the naphtha / diesel fraction through a crude unit of a refinery, wherein the volumetric flow rate of the naphtha / diesel fraction flowing into the crude unit constitutes a maximum of 50 volume percent of the total flow rate of hydrocarbons flowing into the crude unit. (e) From the crude unit, straight-run naphtha (C ５ -C ８ ) The process of recovering the fraction, (f) The straight-run naphtha fraction (C ５ -C ８ ) is passed through a steam cracker for ethylene production, (g) A step of passing the heavy fraction through an isomerization dewaxing unit to produce a base oil, (h) A step of recovering the heavy naphtha / diesel fraction from the crude unit and sending it to a refining unit to upgrade it to gasoline and diesel, The above process, including.

2. The process according to claim 1, wherein the naphtha / diesel fraction of (c) is passed directly through the crude unit and contaminants are removed by the crude unit desalination unit.

3. The process according to claim 1, wherein the ethylene produced in (f) is subsequently polymerized, and a consumer polyethylene product is prepared from the polymerized ethylene.

4. The process according to claim 1, wherein heavy naphtha / diesel / atmospheric diesel fuel is recovered from the crude unit and further processed in a refinery into clean gasoline, diesel, or jet fuel.

5. The process according to claim 1, wherein the heavy fraction in (g) is subjected to hydrogenation and then isomerized with a dewaxing unit.

6. The process according to claim 1, wherein the volumetric flow rate of the naphtha / diesel fraction flowing to the crude unit of the refinery constitutes up to 20 volume percent of the total flow rate of hydrocarbons flowing to the crude unit.

7. A continuous process for converting waste plastic into recycled polyethylene polymer, (a) A step of selecting waste plastics including polyethylene and / or polypropylene, (b) A step of passing the waste plastic from (a) through a pyrolysis reactor to thermally decompose at least a portion of the polyolefin waste and produce a pyrolysis effluent, (c) A step of separating the pyrolysis effluent into off-gas, naphtha / diesel fraction, heavy fraction, and char. (d) A step of passing the naphtha / diesel fraction through a crude unit of a refinery, wherein the volumetric flow rate of the naphtha / diesel fraction flowing into the crude unit constitutes a maximum of 50 volume percent of the total flow rate of hydrocarbons flowing into the crude unit. (e) From the crude unit, propane and butane (C ３ -C ４ )) Process of recovering the fraction, (f) The above (C ３ -C ４ ) The process of passing the fraction through a steam cracker for ethylene production, (g) A step of passing the heavy fraction through an isomerization dewaxing unit to produce a base oil, (h) A step of recovering the heavy naphtha / diesel fraction from the crude unit and sending it to a refining unit to upgrade it to gasoline and diesel, The above process, including.

8. The process according to claim 7, wherein the naphtha / diesel fraction of (c) is passed directly through the crude unit and contaminants are removed by the crude unit desalination unit.

9. The process according to claim 7, wherein the ethylene produced in (f) is subsequently polymerized, and a consumer polyethylene product is prepared from the polymerized ethylene.

10. The process according to claim 7, wherein heavy naphtha / diesel / atmospheric diesel fuel is recovered from the crude unit and further processed in a refinery into clean gasoline, diesel, or jet fuel.

11. The process according to claim 7, wherein the heavy fraction in (g) is subjected to hydrogenation and then isomerized with a dewaxing unit.

12. The process according to claim 7, wherein the volumetric flow rate of the naphtha / diesel fraction flowing to the crude unit of the refinery constitutes up to 20 volume percent of the total flow rate of hydrocarbons flowing to the crude unit.

13. The process according to claim 1 or 7, wherein the waste plastic selected in (a) is from plastic classification groups 2, 4, and / or 5.

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