Process for stable blending of waste plastics and petroleum feedstocks for feeding petroleum refinery units and preparation process thereof

Abstract

Provided is a blend of a petroleum feedstock with 1 to 20 wt. % plastic, based on the weight of the blend, where the plastic comprises polyethylene and / or polypropylene, and the plastic in the blend comprises finely dispersed crystalline particles having an average particle size of 10 to less than 100 microns and less than 10 ppm chloride. A process for preparing a plastic and petroleum blend is provided, the process comprising mixing together a petroleum feedstock and a plastic comprising polyethylene and / or polypropylene and heating the mixture to a temperature above the melting point of the plastic but below 500°F. The blended mixture is then hot filtered, and the resulting filtered blended mixture is heated to at least 500°F. The heated mixture can then be treated using a chloride-removing guard bed. The resulting blend can then be cooled and stored or sent directly to a refining and conversion unit.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Application No. 63 / 387,038, filed December 12, 2022, the complete disclosure of which is incorporated herein by reference in its entirety. [Background technology]

[0002] The world has witnessed extremely rapid growth in plastic production. According to PlasticEurope Market Research Group, global plastic production was 335 million tonnes in 2016, 348 million tonnes in 2017, and 359 million tonnes in 2018. According to McKinsey & Company, global plastic waste was estimated to be approximately 260 million tonnes per year in 2016 and is projected to reach 460 million tonnes per year by 2030 if the current trajectory continues.

[0003] Single-use plastic waste is becoming an increasingly significant environmental issue. At present, there appear to be few options for recycling polyethylene and polypropylene waste plastics into value-added chemical and fuel products. Currently, only a small amount of polyethylene / polypropylene is recycled via chemical recycling, and this recycled and cleaned plastic pellets are pyrolyzed in pyrolysis units to produce fuel (naphtha, diesel), steam cracker feedstock, or slack wax. The majority (over 80%) is incinerated, landfilled, or disposed of.

[0004] Current methods of chemical recycling via pyrolysis are not likely to have a significant impact on the plastics industry. Current pyrolysis operations produce poor-quality fuel components (naphtha and diesel-range products), but the quantities are small enough that these products can be blended into the fuel supply. However, if very large quantities of waste polyethylene and waste polypropylene must be recycled to address environmental concerns, such simple blending cannot be sustained. The raw products from pyrolysis units are too poor in quality to be blended in large quantities (e.g., 5-20 vol% blends) into transportation fuels.

[0005] Processes for converting waste plastics into hydrocarbon lubricants are known. For example, U.S. Patent No. 3,845,157 discloses the cracking of waste or virgin polyolefins to form gaseous products, such as ethylene / olefin copolymers, which are further processed to produce synthetic hydrocarbon lubricants. U.S. Patent No. 4,642,401 discloses the heating of pulverized polyolefin waste at temperatures between 150 and 500°C and pressures between 20 and 300 bar to produce liquid hydrocarbons. 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, condensate, and gas phases are refined into liquid fuel components using standard refining techniques. U.S. Patent No. 6,143,940 discloses a procedure for converting waste plastics into heavy wax compositions. U.S. Patent No. 6,150,577 discloses a process for converting waste plastics into lubricating oils. EP 0 620 264 A1 discloses a process for producing lubricating oils from waste or virgin polyolefins by thermally cracking the waste in a fluidized bed to form a waxy product, optionally using hydrotreating, followed by catalytic isomerization and fractionation to recover the lubricating oil.

[0006] U.S. Patent Application Publication No. 2021 / 0130699 discloses a process and system for producing recycle-containing hydrocarbons from recycled waste. The recycled waste is pyrolyzed to form a pyrolysis oil composition, at least a portion of which can be cracked to form a recycled olefin composition.

[0007] Other documents relating to processes for converting waste plastics into lubricating oils include U.S. Patent Nos. 6,288,296, 6,774,272, 6,822,126, 7,834,226, 8,088,961, 8,404,912, and 8,696,994, and U.S. Patent Application Publication Nos. 2019 / 0161683, 2016 / 0362609, and 2016 / 0264885. The foregoing patent documents are incorporated herein by reference in their entireties.

[0008] Globally, recycling and upcycling of plastic waste has attracted significant interest to conserve resources and the environment. Mechanical recycling of plastic waste is significantly limited due to the variations in the types, properties, additives, and contaminants of the collected plastics. Recycled plastics are usually of reduced quality. Chemical recycling into starting materials or value-added chemicals has emerged as a more desirable method.

[0009] However, more robust processes are needed for industrial-scale chemical recycling of single-use plastics to reduce their environmental impact. Such processes may require unique handling and manipulation of the waste plastics. The presence of chlorides is a particular concern when plastics are used to prepare feedstock for refineries. Refinery units have low tolerance for chlorides. Chlorides in the feedstream can cause corrosion of refinery equipment and vessels, potentially resulting in the production of lower-quality fuels and chemicals. Summary of the Invention

[0010] In one embodiment, provided is a composition of a stable blend of waste plastics and petroleum-based feedstocks for direct conversion of the waste plastics in a refinery process unit. In one embodiment, the blend contains less than 100 ppm chloride. In another embodiment, the blend contains less than 10 ppm chloride. In another embodiment, the blend contains less than 5 ppm chloride.

[0011] The stable blend comprises a petroleum-based feedstock and 1-20 wt. % plastic. In one embodiment, the plastic is primarily composed of polyethylene and / or polypropylene. The plastic in the blend is present as finely dispersed, crystalline particles having an average particle size of 10 microns to less than 100 microns, preferably less than 80 microns. The blend may also contain less than 5 ppm chloride.

[0012] Also provided in one embodiment is a process for preparing a plastic-petroleum blend. The process involves mixing a petroleum-based feedstock, or in one embodiment, a bio-based feedstock, and a plastic together and heating the mixture to a temperature above the melting point of the plastic but not exceeding 500°F. In one embodiment, the mixture is heated to a temperature between 250°F and 450°F. In one embodiment, heating can be performed with a residence time of 5 to 240 minutes. The product is then filtered at high temperature to remove contaminants, including glass, metal, PVC, or other plastics with low solubility, such as polystyrene (PS), polyethylene terephthalate (PETE), and other Group 7 plastics. The resulting filtered feedstock-plastic mixture is then heated to 500°F to 800°F (260°C to 427°C), preferably 550°F to 700°F (288°C to 371°C), to decompose any remaining PVC while preserving the polyethylene and polypropylene. The off-gas containing HCl and volatile organic chlorides is treated in a scrubber. A stripping gas, such as nitrogen, hydrogen, steam, or the off-gas from the conversion unit, may be fed to the heater to facilitate removal of the HCl off-gas from the liquid. Optionally, the resulting liquid product is further treated with a chloride-removing guard bed catalyst. The resulting blend contains less than 100 ppm chloride, more preferably less than 10 ppm chloride. The blend can then be fed to a purification unit or cooled to a temperature below the melting point of the plastic and stored for subsequent feed to a refinery and / or transport.

[0013] Among other factors, the present process prepares a blend of plastic and petroleum-based feedstock. The blend contains minimal (if any) chlorides, e.g., in one embodiment, less than 10 ppm or less than 5 ppm chlorides. The blend is nearly, if not essentially chloride-free. The present process also provides a simple process for removing most of the chlorides by filtration. This essentially chloride-free blend of plastic and petroleum-based feedstock provides a means to efficiently and effectively feed waste plastics into a refining process and convert the waste plastics into high-yield, high-volume products. It has been found that preparing the blend and feeding the blend into a refinery operation can efficiently, effectively, and safely recycle waste plastics while complementing the refining operation in the preparation of high-value products such as gasoline, jet fuel, base oil, and diesel fuel. Polyethylene and polypropylene can also be efficiently and effectively produced from waste plastics. In fact, positive economics are realized throughout the recycling process, with product quality comparable to that of virgin polymers. The use of the blend also saves energy, making it more environmentally friendly than traditional recycling processes. The blend contains minimal (if any) chlorides, allowing the blend to be safely passed through a refinery without damaging the equipment and refinery units. This is because the present technology discloses a process to reduce the chloride content to levels below the operational limits of the unit. In one embodiment, the feedstock to be mixed with the plastic can include bio-based feedstocks. Bio-based feedstocks can be used alone or in combination with petroleum-based feedstocks. [Brief explanation of the drawings]

[0014] [Figure 1] The graph shows the results of thermogravimetric analysis (TGA) of pure polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC) plastics and vacuum gas oil (VGO).

[0015] [Figure 2] This shows the classification of plastic types for recycling waste plastics.

[0016] [Figure 3] The present process for preparing a homogeneous liquid blend of plastic and petroleum feedstocks at high temperatures and feeding the blend to a refining and conversion unit is demonstrated.

[0017] [Figure 4] Details of the preparation of a homogeneous blend with minimal chloride and other plastic contaminants and how the homogeneous blend is fed to a purification and conversion unit are provided.

[0018] [Figure 5] The graph shows the results of thermogravimetric analysis (TGA) of recycled waste plastics including PE and PP.

[0019] [Figure 6] The graph shows the results of thermogravimetric analysis (TGA) of household plastics. DETAILED DESCRIPTION OF THE INVENTION

[0020] Disclosed are novel blends of plastics and petroleum-based feedstocks and processes for preparing stable blends of plastics and petroleum-based feedstocks containing minimal (if any) chlorides, metals, and other plastic contaminants for direct conversion of the plastics in a refinery process unit. In one embodiment, the feedstock to be mixed with the plastic can include a bio-based feedstock. The bio-based feedstock can comprise the entire feedstock or can be used in combination with the petroleum-based feedstock.

[0021] In one embodiment, provided is a process for preparing a stable blend of plastics, preferably waste plastics, and petroleum containing minimal chlorides (if present) for storage, transportation, or feeding to a refining unit. By "minimal chlorides" (if present), we mean that the amount of chloride present in the blend is less than 100 ppm chloride, or less than 10 ppm chloride, or even less than 5 ppm chloride. Minimal amounts of metals and other plastic contaminants are also desirable and achieved. The process involves first selecting plastics, preferably waste plastics, including polyethylene and / or polypropylene. These waste plastics are then passed through a blend preparation unit to produce a stable blend of waste plastics and petroleum containing minimal chlorides, metals, and other plastic contaminants (if present). This stable blend can be safely fed to a refining and conversion unit for direct conversion of the waste plastics into value-added chemicals or fuels.

[0022] Stable blends are made by a three- or four-step process. The first step produces a hot, homogeneous liquid blend of the plastic melt and the petroleum feedstock. The preferred range of plastic composition in the blend is about 1-20 wt%. Preferred conditions for preparing the hot liquid blend include vigorously mixing the plastic with the petroleum feedstock while heating it to a temperature above the melting point of the plastic. Preferred process conditions include heating to a temperature of 250°F to 450°F (121°C to 232°C), a residence time at the final heating temperature of 5-240 minutes, and atmospheric pressure of 0-200 psig. This can be done in open air or, preferably, under an oxygen-free inert atmosphere.

[0023] The second step involves hot filtering the blended mixture to remove contaminants, including glass, metal, paper, PVC or other plastics with low solubility (such as PS, PETE, and other Group 7 plastics), and inorganic fillers used in plastic manufacturing. This filtration step removes the majority of the PVC, PS, PETE, and other plastics.

[0024] The third step involves heating the filtered blend of feedstock and plastics to a temperature sufficient to decompose the remaining PVC. Temperatures of approximately 500°F to 800°F (260°C to 427°C) are generally within acceptable limits. The heating time is sufficient to decompose most, if not all, of the remaining PVC without decomposing other plastics. A stripping gas, such as nitrogen, hydrogen, steam, or off-gas from a conversion unit, may be added to facilitate the removal of HCl off-gas from the decomposition of PVC or organic chlorides in the blend. Hydrogen is the preferred stripping gas because it promotes HCl production and minimizes diene production. Preferred conditions include heating to a temperature of 550°F to 700°F (288°C to 371°C), a residence time at the final heating temperature of 5 to 240 minutes, and a pressure of 0 to 200 psig using 100 to 1500 scf / bbl of stripping gas. By maintaining a temperature between approximately 550°F and 700°F, only the polyvinyl chloride decomposes into HCl and hydrocarbons. At this temperature range, the polyethylene and polypropylene remain molten but do not decompose. Minimizing the decomposition of the polyethylene and polypropylene limits the amount of olefins and dienes in the blend, thereby minimizing the formation of organic chlorides produced by the reaction of olefins with HCl.

[0025] Figure 1 shows the thermal stability of polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC) plastics as determined by thermogravimetric analysis (TGA). PVC decomposes via a dehydrochlorination reaction between 450°F and 700°F (232°C and 371°C), producing polyenes and HCl gas. At temperatures above 700°F (371°C), the polyenes further decompose into lower molecular weight compounds. The off-gas from heating contains hydrogen chloride and is therefore treated in a scrubber.

[0026] Polyethylene is stable up to 800°F, and polypropylene is stable up to 700°F. Vacuum gas oil (VGO) is stable over the entire temperature range from ambient to 1200°F (649°C). The weight change of VGO shown in Figure 1 is due to light components evaporating from VGO as light hydrocarbons. To minimize the loss of light hydrocarbons from VGO, it is preferred to operate the chloride stripping process at high pressure, e.g., above 10 psig, and preferably above 50 psig. Alternatively, an overhead condenser can be installed to condense the light hydrocarbon vapors back into a liquid.

[0027] The final, or fourth, step involves optionally treating the liquid product recovered from the third step with a chloride-removing guard bed catalyst. Such catalyst beds are known in the industry to be effective at reducing chlorides to low ppm levels. In one embodiment, the catalyst bed is based on an oxide, such as CaO or MgO, or a hydroxide, such as Fe(OH)2. Such catalyst guard beds are available, for example, from Dorf Ketal, BASF, Evonik, Johnson Matthey, Clariant, and Axens. Preferred conditions include temperatures of 250°F to 700°F (121°C to 371°C), residence times of 5 to 240 minutes, and pressures of 0 to 200 psig. The resulting blend can then be safely fed directly to a refinery or cooled and stored for further use. Further use includes feeding the blend to a refinery or transporting it to a refinery.

[0028] In an alternative embodiment, the third and fourth dechlorination steps described above can be combined into a single third treatment step using a chloride-removing guard bed catalyst. Such catalyst beds are known in the industry to be effective in reducing chlorides to low ppm levels. In one embodiment, the catalyst bed is based on oxides such as CaO or MgO, or hydroxides such as Fe(OH)2. Such catalyst guard beds are available, for example, from Dorf Ketal, BASF, Evonik, Johnson Matthey, Clariant, and Axens. Preferred conditions include temperatures between 250°F and 700°F, residence times between 5 and 240 minutes, and pressures between 0 and 200 psig. Because this is a combination of the third and fourth steps, the temperature used is selected to be suitable for PVC degradation, and therefore temperatures may be closer to 700°F than usual. However, because the catalyst aids the degradation process, the appropriate temperature may not need to be significantly higher than the temperature required without the catalyst. The resulting blend can then be safely fed directly to a refinery or cooled and stored for further use, which may include feeding it to a refinery or transporting it to a refinery.

[0029] For storage, the hot blend is cooled to a temperature below the melting point of the plastic with continuous vigorous mixing, and then further cooled to a lower temperature, preferably ambient temperature, to produce a stable blend. The stable blend is either an oily liquid or a waxy solid at ambient temperature, depending on the content and type of petroleum feedstock and plastic. Because the blend is stable, it can be stored for extended periods of time.

[0030] In one embodiment, the stable blend is made from a petroleum feedstock and 1-20 wt% waste plastic, where the plastic is in the form of finely dispersed micron-sized particles with an average particle size of 10 microns to less than 100 microns. In one embodiment, the feedstock material in the blend can include a bio-based feedstock material.

[0031] There are several advantages realized by the present blends and their use. For example, stable blends of plastics and petroleum feedstocks can be stored for extended periods at ambient temperature and pressure. No agglomeration, settling of polymer particles, or chemical / physical degradation of the blends is observed during storage. This facilitates the handling of waste plastic materials for storage or transportation.

[0032] Stable blends can be easily handled using standard pumps typically used in refineries or warehouses, or by using pumps with transfer tanks. Depending on the blend, it may be necessary to heat the blend above its pour point to pump it for transport or feed to a refinery conversion unit. No polymer agglomeration is observed during heating.

[0033] Another major advantage of the present blend and the process for preparing the blend is that it removes chlorides to levels below 100 ppm, or even 10 ppm or less, so the present blend can be safely delivered to refineries because refining units have a low tolerance for chlorides.

[0034] Another major advantage of the blends and the process for preparing them is that they can be applied to multilayer film plastics that are considered unrecyclable through current recycling processes. These multilayer films contain polyethylene and / or polypropylene layers, but also contain a thin metal layer as a metal barrier. This metal layer often contains aluminum. The polyethylene and polypropylene components in the multilayer film can be selectively dissolved in petroleum feedstocks, and the metal forming the metal layer of the multilayer film can be removed by filtration.

[0035] To feed the refinery unit, the stable blend is further heated to a temperature above the melting point of the plastic, producing a homogeneous liquid blend of oil and plastic. The hot, homogeneous liquid blend is fed directly to the oil refinery process unit for converting waste plastics into high-value products with high yields.

[0036] Refining and conversion units, such as fluid catalytic cracking (FCC) units, hydrocracking units, and hydrotreaters, convert homogeneous liquid blends of plastics and petroleum feedstocks at high temperatures in the presence of a catalyst, using simultaneous conversion of the two. The presence of a catalyst in a conversion unit allows waste plastics to be converted into high-value products at operating temperatures lower than typical pyrolysis temperatures. The yield of undesirable by-products (off-gas, tar, coke, and char) is lower than in typical pyrolysis processes. In hydroprocessing units (hydrocracking and hydrotreaters), hydrogen is added to the unit to improve the conversion of plastics. This blending can produce additional synergistic effects resulting from the interaction of plastics and petroleum feedstocks during the conversion process. Fluid catalytic cracking and hydrocracking processes are the preferred modes of catalytic conversion of stable blends.

[0037] In one embodiment, a stable blend of plastic and petroleum feedstocks can be sent to a coker unit for thermal conversion of waste plastics. In this case, there is no substantial advantage in reactor temperature or product yield compared to a pyrolysis process. The advantage of the coker unit is its feed flexibility, in that it can handle blends with very high nitrogen, sulfur, and metal impurities.

[0038] A stable blend of plastics and petroleum-based feedstocks allows for more efficient recycling of waste plastics. The use of this blend is much more energy efficient than current pyrolysis processes, allowing for recycling with a lower carbon footprint. The improved process could enable the establishment of a circular economy on a much larger scale by efficiently converting waste plastics into virgin-quality polymers or value-added chemicals and fuels.

[0039] Proper sorting of waste plastics is crucial to minimize contaminants such as N, Cl, and S. Plastic waste, including polyethylene terephthalate (Plastic Recycling Classification Type 1), polyvinyl chloride (Plastic Recycling Classification Type 3), and other polymers (Plastic Recycling Classification Type 7), must be sorted to less than 5%, preferably less than 1%, and most preferably less than 0.1%. The process can tolerate moderate amounts of polystyrene (Plastic Recycling Classification Type 6). Waste polystyrene must be sorted to less than 20%, preferably less than 10%, and most preferably less than 5%. Figure 2 shows the plastic type classification for waste plastic recycling.

[0040] Washing waste plastics can remove 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 halide contaminants from Group VII, such as fluoride, chloride, and iodide. Residual metal, non-metallic contaminants, and halides must be removed to less than 50 ppm, preferentially less than 30 ppm, and most preferentially less than 5 ppm.

[0041] The petroleum with which the waste plastics are blended is typically a petroleum feedstock for the refinery. Preferably, the petroleum blend is the same as the petroleum feedstock for the refinery. The petroleum may also include petroleum-derived oils or petroleum-based materials. In one embodiment, the petroleum feedstock may include atmospheric gas oil, vacuum gas oil (VGO), atmospheric residue, or heavies recovered from other refining operations. In one embodiment, the petroleum feedstock with which the waste plastics are blended includes VGO. In one embodiment, the petroleum feedstock with which the waste plastics are blended includes light cycle oil (LCO), heavy cycle oil (HCO), FCC naphtha, gasoline, diesel, toluene, and / or petroleum-derived aromatic solvents.

[0042] In one embodiment, the petroleum feedstock for preparing the blend includes vacuum gas oil, atmospheric gas oil, reformate, light cycle oil, heavy fuel oil, refinery hydrocarbon streams containing toluene; xylene; heptane or benzene, or pure toluene, pure xylene, coker naphtha, C5-C6 isomerized paraffin naphtha, FCC naphtha, hydrocracker bottoms, gasoline, jet fuel, diesel, or mixtures thereof.

[0043] The most preferred petroleum feedstocks are light oils, heavy reformate, or various recycle streams fed to a catalytic conversion unit. The plastic and petroleum feedstocks in the blend are then co-converted via catalytic conversion into high value products.

[0044] Multiple oil feedstocks can be used to optimize blend properties, for example, viscosity and pour point can be reduced by adding lighter oil feedstocks such as light cycle oil, gasoline, or diesel.

[0045] Optionally, a solvent such as benzene, toluene, xylene, or heptane may be added to the blend of plastic and petroleum feedstock to reduce the viscosity or pour point of the blend and make it easier to handle.

[0046] In one embodiment, the feedstock from which the blend is prepared can include a bio-based feedstock, which can include the entire feedstock or can be mixed with a petroleum feedstock.

[0047] In one embodiment, a petroleum feedstock is selected for its preferred dissolution of polyethylene and polypropylene. The petroleum feedstock exhibits high solubility in polyethylene and polypropylene plastics and low solubility in undesirable plastics such as polyvinyl chloride, polystyrene, and other Group 7 plastics, as well as metal barrier films and inorganic impurities. These undesirable materials from waste plastic sources are removed by a filtration step. Examples of suitable petroleum feedstocks include vacuum gas oil (VGO), light cycle gas oil (LCO), and diesel.

[0048] The term "bio" refers to biochemicals and / or natural chemicals found in nature. Thus, bio-feedstocks or bio-oils include such natural chemicals. Preferred starting bio-feedstocks for blend preparation include triglycerides and fatty acids, plant-derived oils (such as palm oil, canola oil, corn oil, and soybean oil), and animal-derived fats and oils (such as tallow, lard, schmaltz (e.g., chicken fat), and fish oil), and mixtures thereof.

[0049] The three- or four-step process for preparing the blend leaves very little chloride residue in the blend, preventing damage to refinery units and equipment. The presence of chlorides can produce HCl acid, which can cause unit degradation. This is important because refineries also prepare chemicals, base oils, and fuel oils, and refinery units and equipment are sensitive to chlorides, as mentioned above. Furthermore, chlorides can affect the quality of catalysts and products used in refineries. The blends prepared by this process can be used to efficiently, effectively, and safely recycle waste plastics while complementing refinery operations in the preparation of high-value products such as gasoline, jet fuel, base oil, diesel fuel, and useful chemicals.

[0050] Without wishing to be bound by theory, the present process prepares a stable blend of minimal chlorides, metals, and other plastic contaminants (if any), which is an intimate physical mixture of plastic and petroleum feedstock for catalytic conversion in a refinery unit. The process produces a stable blend of petroleum feedstock and plastic, with the plastic in a "deagglomerated" state. The plastic remains as "finely dispersed" solid particles in the petroleum feedstock at ambient temperatures. The blend is stable and easy to store and transport. At the refinery, the stable blend is preheated to a temperature above the melting point of the plastic to produce a hot, homogeneous liquid blend of plastic and petroleum, which can then be fed to a conversion unit. Both the petroleum feedstock and plastic are then simultaneously converted in the conversion unit using typical refinery catalysts containing zeolites and other active ingredients such as silica-alumina, alumina, and clay.

[0051] The use of this blend avoids the thermal decomposition of waste plastics. Rather, a stable blend of prepared petroleum feedstock and waste plastics can be fed to the refinery unit. Thus, the thermal decomposition step can be avoided, which results in significant energy savings.

[0052] During blend cooling and storage, the hot, homogeneous liquid blend is cooled to ambient temperature in a controlled manner for easy storage and transport. Using this method, a stable blend can be prepared at a facility away from the refinery and transported to the refining unit. The stable blend is then heated to a temperature above the melting point of the plastic and fed to the refining and conversion unit. The stable blend is a physical mixture of micron-sized plastic particles finely suspended in a petroleum-based oil, with an average particle size of 10 to less than 100 microns. This mixture is stable, and the plastic particles do not settle or agglomerate even when stored for extended periods.

[0053] The significance of heating a blend to a temperature above the melting point of a plastic is clear when using a single plastic. However, when the waste plastic is composed of multiple waste plastics, the melting point of the plastic with the highest melting point will be exceeded. Therefore, the melting points of all plastics must be exceeded. Similarly, when cooling a blend to a temperature below the melting point of a plastic, the temperature must be below the melting points of all plastics that make up the blend.

[0054] Compared to pyrolysis units, these blend preparation units operate at much lower temperatures (approximately 500°C-600°C vs. 120°C-250°C). Therefore, using the blends in conjunction with refineries can provide a much more energy-efficient process than thermal cracking processes such as pyrolysis.

[0055] The use of the waste plastic / petroleum blend of the present invention further increases the overall yield of hydrocarbons obtained from waste plastics. This increase in yield is significant. The hydrocarbon yield using the blend can reach up to 98%. In contrast, pyrolysis produces significant amounts of light products from plastic waste, about 10-30 wt% and about 5-10 wt% char. These light hydrocarbons are used as fuel to run the pyrolysis plant, as previously mentioned. Therefore, the liquid hydrocarbon yield from the pyrolysis plant is up to 70-80%.

[0056] When this blend is passed through a refinery unit, such as an FCC unit, only a small amount of off-gas is produced. The refinery uses a catalytic cracking process, which is different from the thermal cracking process used in thermal cracking. The catalytic process minimizes the production of undesirable light by-products such as methane and ethane. The refinery unit provides efficient product fractionation, allowing all hydrocarbon product streams to be efficiently utilized to produce high-value materials. Refinery co-feeds produce only approximately 2% off-gas (H2, methane, ethane, and ethylene). The C3 and C4 streams can be captured to produce useful products such as cyclic polymers and high-quality fuel products. Therefore, the use of this petroleum / plastic blend not only leads to increased hydrocarbon production from waste plastics, but also provides a more energy-efficient recycling process compared to thermal processing processes such as pyrolysis. The advantages of this blend are significant when considering the recycling of waste plastics.

[0057] FIG. 3 illustrates a method for preparing a high-temperature homogeneous blend of plastics and petroleum feedstocks that can be used for direct injection into a refinery unit. The preferred range of plastic composition in the blend is about 1-20 wt%. If high molecular weight polypropylene (average molecular weight of 250,000 or more) or high density polyethylene (density greater than 0.93 g / cc) is used primarily as the waste plastic, e.g., at least 50 wt%, the amount of waste plastic used in the blend is more preferably about 10 wt% or less, because this increases the pour point and viscosity of the blend. In one embodiment, the plastic has an average molecular weight M in the range of 5,000-150,000. w In another embodiment, the plastic may comprise polypropylene having an average molecular weight M in the range of 150,000 to 400,000. w The polypropylene may include polypropylene having

[0058] Preferred conditions for preparing a hot homogeneous liquid blend include vigorously mixing the plastic with the petroleum feedstock while heating it to a temperature above the melting point of the plastic. Preferred process conditions include heating to a temperature of 250°F to 450°F, a residence time at the final heating temperature of 5 to 240 minutes, and atmospheric pressure of 0 to 200 psig. This can be done in open air or under an oxygen-free inert atmosphere.

[0059] High temperature homogeneous blends of plastic melt and petroleum feedstocks are prepared by mixing the petroleum feedstock and plastic together, then thoroughly mixing while heating the mixture to a temperature above the melting point of the plastic but not exceeding 500°F. Alternatively, they are prepared by melting only the plastic and then adding the plastic melt to the warm or hot petroleum feedstock while thoroughly mixing. Alternatively, they are prepared by heating only the petroleum to a temperature above the melting point of the plastic and then slowly adding the solid plastic to the hot petroleum liquid while thoroughly mixing the mixture and maintaining the temperature above the melting point of the plastic.

[0060] Referring to Figure 3 of the drawings, a step-by-step preparation process for preparing a hot homogenous liquid blend is shown. Mixed waste plastics are sorted to produce post-consumer waste plastics 21 containing polyethylene and / or polypropylene. The waste plastics are cleaned (22) and then mixed with oil 24 in a hot blend preparation unit 23. After mixing in 23, a homogenous blend of plastics and oil is recovered (25). Optionally, a filtration device (not shown) can be added to the hot blend preparation unit 23 to remove undissolved solid contaminants 26, such as undissolved plastic particles (PTFE, PVC, PS, other Group 7 plastics), or solid impurities, such as glass, metal, and paper, present in the hot liquid blend. The hot blend of plastics and oil 25 is then combined with a refinery feedstock, such as vacuum gas oil (VGO) 20, resulting in a mixture of plastic / oil blend and VGO, which can then be passed through a refinery's catalytic conversion unit 27.

[0061] Figure 4 shows a detailed method for preparing a low-chloride, low-impurity homogeneous blend of plastics and oils using this four-step process. The homogeneous blend is produced by a four-step process in the homogeneous blend preparation unit 23. In the first step, a high-temperature, homogeneous liquid blend of plastic melt and petroleum feedstock is produced. This step is identical to the high-temperature blend preparation described in Figure 3. As shown, clean waste 22 is passed through the homogeneous blend preparation unit 23. Selected plastic waste 22 is mixed with hot refinery feedstock 24 in the plastic melting vessel 30, where the plastic waste is heated to a temperature above the melting point of the plastic, melting the plastic. The hot petroleum feedstock 24 is mixed with the molten plastic in 30, maintaining the vessel temperature above the melting points of PE and PP plastics, to produce a homogeneous liquid blend of the melted plastic and VGO. The mixing is often very vigorous. The preferred range of plastic composition in the blend is approximately 1-20 wt%. When high molecular weight polypropylene (average molecular weight of 250,000 or more) waste plastic or high density polyethylene (density greater than 0.93 g / cc) is used primarily as the waste plastic, for example at least 50 wt%, the amount of waste plastic used in the blend is more preferably about 10 wt% or less, because the pour point and viscosity of the blend will be higher.

[0062] Preferred conditions for preparing a hot homogeneous liquid blend at 30 include vigorously mixing the plastic with the petroleum feedstock while heating it to a temperature above the melting point of the plastic. Preferred process conditions include heating to a temperature of 250°F to 450°F, a residence time at the final heating temperature of 5 to 240 minutes, and atmospheric pressure of 0 to 200 psig. This can be done in open air or under an oxygen-free inert atmosphere.

[0063] Any off-gas generated from mixing can be sent to a scrubber (31). Optionally, an optional diluent 32 can be added to the heating and mixing at 30.

[0064] The hot blend of plastic and oil 33 is then collected and sent to a hot filtration unit 35. Contaminants are removed 36, including glass, metal, PVC, or other plastics with low solubility. This filtration step removes most of the PVC.

[0065] The filtered hot liquid blend 37 of plastics and oils is then sent to a dechlorination unit 38. In the dechlorination unit, the blend is heated to a temperature of approximately 500°F to 800°F, preferably 550°F to 700°F. The heating time is sufficient to decompose most, if not all, of the remaining PVC. An optional stripping gas 39 may be added to facilitate the removal of HCl off-gas from the decomposition of PVC or organic chlorides in the blend. Potential sources of stripping gas include nitrogen, hydrogen, steam, or off-gas from the conversion unit 42. Hydrogen is the preferred stripping gas because it promotes HCl production and minimizes diene production. Preferred conditions include heating to a temperature of 550°F to 700°F, a residence time at the final heating temperature of 5 to 240 minutes, and a pressure of 0 to 200 psig using 100 to 1500 scf / bbl of stripping gas. The off-gas from the heating contains hydrogen chloride and is sent to 40 for treatment in a scrubber.

[0066] The dechlorination unit may also include a fourth step (not shown) of treating the heated liquid blend product in a chloride-removing guard bed. Such guard beds typically contain metal oxide or hydroxide adsorbents and are known in the industry to be effective in reducing chlorides. Preferred conditions include treatment at temperatures between 250°F and 700°F, residence times between 5 and 240 minutes, and pressures between 0 and 200 psig.

[0067] The resulting hot, homogeneous, low chloride blend 41 can then be fed directly to a refinery catalytic conversion unit 42. Alternatively, the hot blend of plastics and oils 41 can be combined with a refinery feedstock, such as vacuum gas oil 20 (VGO), to produce a mixture of plastic / oil mixture and VGO, which is then sent to the refinery catalytic conversion unit 42.

[0068] Optionally, the homogenous blend 41 can be cooled to ambient temperature to produce a stable blend. A stable blend is known to be an intimate physical mixture of plastic and petroleum feedstock. The plastic is in a "deagglomerated" state. The plastic maintains a fine dispersion of solid particles in the petroleum feedstock at temperatures below the melting point of the plastic, particularly at ambient temperatures. The blend is stable and easy to store and transport. At the refinery, the stable blend can be heated in a preheater above the melting point of the plastic to produce a hot, homogenous liquid blend of plastic and petroleum. This hot liquid blend can then be fed to a refinery unit as a co-feed along with conventional refinery feedstocks.

[0069] The preferred plastic starting material for use in the present blends is sorted waste plastics containing primarily polyethylene and polypropylene (plastic recycling classification types 2, 4, and 5). The pre-sorted waste plastics are washed, shredded or pelletized, and fed to the blend preparation unit. Figure 2 shows the plastic type classification 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. Polystyrene (class 6) can also be present in limited amounts. [Example]

[0070] [Example 1] Characteristics of unused plastic samples Six commercially available plastic samples were purchased, namely, low-density polyethylene (LDPE, Plastic A), high-density polyethylene (HDPE, Plastic B), two polypropylene samples with average molecular weights of approximately 12,000 (PP, Plastic C) and approximately 250,000 (PP, Plastic D), polystyrene (PS, Plastic E), and polyvinyl chloride (PVC, Plastic F), and their properties are summarized in Table 1. [Table 1]

[0071] Figure 1 shows the thermal stability of polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC) plastics as determined by thermogravimetric analysis (TGA). PVC decomposes via a dehydrochlorination reaction between 450°F and 700°F, producing polyenes and HCl gas. At temperatures above 700°F, the polyenes further decompose into lower molecular weight compounds. Polyethylene is stable up to 800°F, and polypropylene is stable up to 700°F. Vacuum gas oil (VGO) is stable over the entire temperature range from ambient to 1200°F. The weight change of VGO shown in Figure 1 is due to light components evaporating from VGO as light hydrocarbons.

[0072] [Example 2] Characteristics of recycled waste plastic samples Four recycled waste plastic samples were purchased for blend preparation, and their properties are summarized in Table 2.

[0073] FT-IR was used to identify the general properties of the plastics. In addition to identifying the main polymer species, FT-IR data also revealed that all of these recycled plastics contained varying amounts of calcium carbonate and talc. To estimate the amount of potentially recoverable hydrocarbons, each sample was calcined at 1000°F for 3 hours under N2. The recoverable hydrocarbons were assumed to be equal to the loss-on-ignition (LOI) percentage. The inorganic residue after calcination was analyzed by ICP elemental analysis. Using the LOI values ​​and ICP analysis, the impurities in each household plastic sample were estimated and reported in Table 2 below. The most common impurities found in waste plastics were Ca, Mg, Si, Ti, and Al, which may originate from the manufacturing of plastic consumer products, where calcium carbonate, silica, and talc are commonly used as fillers. Fe, Na, P, and Zn were also present in varying amounts. [Table 2]

[0074] Thermogravimetric analysis (TGA) was performed on the waste plastic samples to confirm that the plastic material was thermally stable at temperatures well above the melt preparation temperature. The TGA results, shown in Figure 5, indicate that the waste plastic samples were stable up to 700°F. From the TGA results, the weight percent residual weight at 950°F (510°C) is reported in Table 2. The residual weight from the TGA analysis is in good agreement with the LOI measured by calcination.

[0075] [Example 3] Characteristics of household waste plastic samples Five household plastic (HHP) samples were collected for blend preparation, and their properties are summarized in Table 3. HHP#1 was a collection of semi-rigid plastic poly bubble shipping envelopes. HHP#2 was a collection of lightweight poly shipping bags made from 50% recycled content. HHP#3 was a collection of takeout food packaging labeled as recyclable plastic Group 6 (polystyrene, PS). HHP#4 was clear fruit and vegetable packaging labeled as recyclable plastic Group 1 (polyethylene terephthalate, PETE). HHP#5 was potato chip packaging labeled as non-recyclable.

[0076] As described in Example 2, LOI values ​​and ICP elemental analysis were used to estimate impurities in household plastic samples and are reported in Table 3 below. The most common impurities found in waste plastics are Ti, Ca, Si, and Al, which can originate from the manufacturing of plastic consumer products where talc, calcium carbonate, and silica are commonly used as fillers. The high Ti impurity content in HH Plastic #2 is likely due to the addition of titanium dioxide during the recycling process. [Table 3]

[0077] Thermogravimetric analysis (TGA) was performed on the waste plastic samples to confirm that the plastic materials were thermally stable at temperatures well above the melt preparation temperature. The TGA results, shown in Figure 6, indicate that the waste plastic samples were stable up to 700°F. The weight percent residual weight at 950°F from the TGA results is reported in Table 3. The residual weights from the TGA analysis are in good agreement with the LOIs measured by firing HH Plastics #1, #2, and #5. The TGA analysis of HH Plastic #3 (PS) indicates that the material is very pure and contains very little inorganic filler. The TGA analysis of HH Plastic #4 (PETE) indicates that it contains 15.6% residue, which could be either inorganic filler or carbonaceous residue.

[0078] [Example 4] Characteristics of petroleum feedstocks for blend preparation Petroleum feedstocks that can be used to prepare stable blends with plastics include hydrotreated vacuum gas oil (VGO), Aromatic 100 solvent, light cycle oil (LCO), and diesel, the properties of which are shown in Table 4. Aromatic 100 is a commercially available aromatic solvent produced from petroleum-based materials and contains primarily C9-C10 di- and tri-alkylbenzenes. [Table 4]

[0079] [Example 5] Blending recycled waste plastic with VGO and reducing impurities through filtration Several blends made from vacuum gas oil (VGO) and recycled waste plastic samples (Plastics G-J in Table 2) were prepared by adding plastic pellets to hydrotreated vacuum gas oil (oil feedstock #1 in Table 4) using an autoclave.

[0080] The following procedure was used: At ambient temperature, pre-weighed plastic pellets (solids) and VGO feed (waxy solids) were added to a batch autoclave unit. The autoclave was purged with N2 gas to remove air from the vessel, after which the inlet and outlet valves were closed. The mixture was stirred at 1500 RPM using an impeller while the temperature set point was increased by 50°F (28°C) increments or every 10 minutes via an external heating jacket to a target temperature of 400°F. The temperature was then held at the target temperature for 1 hour. The pressure was monitored throughout the entire time period; typically, the pressure rose to less than 10 psig. For most blend preparations, the hot blend was filtered in a high-temperature oven at 400°F using a cellulose filter with a well-defined pore size (either 0.7µ or 20µ filters were used). In some cases, the blends were not filtered to examine the effect of filtration on impurity removal.

[0081] After dissolving 10 wt% plastic, precipitation of solids was observed, likely from the filler, and the blends generally exhibited very high viscosities (probably due to the presence of solids). At 5 wt% plastic, the blends were easily filtered, and the sticky solid material was removed by filtration. The filtered blend product was cooled to ambient temperature, and the resulting stable blend showed no visible plastic residue and was completely homogeneous upon visual inspection. The plastic / VGO blends exhibited the appearance of a waxy solid VGO. The plastic / VGO blends were stable, with no changes observed over the three-month observation period.

[0082] To assess the need for material handling, the pour point (per ASTM D5950-14) and viscosity (per ASTM D445) of the blends were measured. Additionally, the hot heptane insolubles content was measured according to the procedure in ASTM D3279. The hot heptane insolubles method measures the weight percent of material in an oil that is insoluble in hot heptane at 80°C. This method uses a 0.8 micron membrane filter to separate the insoluble material. The heptane insolubles content provides information about the undissolved plastic in the blend. The chloride content of the blends was measured using combustion ion chromatography (per ASTM D7359). Table 5 below summarizes the list of samples prepared and their properties. [Table 5]

[0083] The heptane insoluble content in Table 5 above correlates with the amount of plastic in the blend. The heptane insoluble content indicates that the plastic is a physical mixture of solid particles dispersed in the VGO in the blend at 80°C, and that the majority of the plastic particles can be effectively separated with a 0.8-micron filter. The slight difference between the heptane insoluble content and the amount of plastic added may be due to very small particles (less than 0.8 microns) not captured by the filter during the heptane insoluble measurement, or to residual impurities filtered from the waste plastic trapping some of the VGO in the filter cake, resulting in a slightly higher weight percentage. For the blends made with waste plastics #1 and #3, the heptane insoluble content was slightly lower than the amount of plastic added to prepare the blend, suggesting that some of the particles may be smaller than the 0.8-micron filter opening. For the blends made with waste plastics #2 and #4, the heptane insoluble content was slightly higher than the amount of plastic added to prepare the blend. Possibly, residual impurities such as cellulose from the paper may trap some of the VGO in the filter cake, causing the weight percentage to be slightly higher.

[0084] Without filtration, blends prepared using recycled plastics containing a high content of impurities (such as fillers and paper fibers) exhibited very high viscosities, making them difficult to pump to the conversion unit (Examples 5-2, 5-6, and 5-8). Filtration through 0.7 or 20 micron filters was effective in removing solids and significantly reducing viscosity. Filtration also reduced the chloride content of the blends.

[0085] This example clearly demonstrates that filtration is a critical step in preparing plastic / petroleum feedstock blends made from waste plastics. The process is effective in preparing stable blends with minimal chlorides and other plastic contaminants, which are intimate physical mixtures of plastic and petroleum feedstock for catalytic conversion in refinery units.

[0086] [Example 6] Blending household waste plastic with VGO and reducing other plastic pollutants through filtration Several blends made from vacuum gas oil (VGO, Petroleum Feedstock #1 in Table 4) and household plastic samples (Plastics K-O in Table 3) were prepared using a procedure similar to that in Example 5. Dissolution was performed in a 1 L glass beaker equipped with an overhead stirrer. VGO was first heated to 400°F, and then finely chopped plastic pieces were placed in the beaker to create a blend of the plastic and VGO. In some cases, not all of the plastic dissolved. The hot blends were filtered using cellulose filter paper with 20-micron pore openings in a high-temperature oven at 400°F. Similar analyses were performed, and the results are summarized in Table 6. [Table 6]

[0087] The heptane insoluble test results in Table 6 above provide a rough indication of the amount of polyethylene and polypropylene dissolved in the blends. For Household Plastics #1 and #2, the heptane insoluble content is equal to or slightly higher than the amount of plastic added to prepare the blends. The slight difference between the heptane insoluble content and the amount of plastic added (5.3-5.6 wt% vs. 5.0 wt%) may be due to experimental error or to residual impurities trapping some of the VGO in the filter cake during the heptane insoluble measurement, resulting in a slightly higher weight percent.

[0088] Household plastic #3, made with polystyrene (PS, Group 6 plastic), has very low solubility in VGO, as indicated by a heptane insolubility test of 0.7 wt%. The viscosity and pour point of the blend (Example 6-3) are comparable to the VGO-only base case (Example 5-1), because much of the added PS did not dissolve in the blend and most of the PS was filtered out. Household plastic #4, made with polyethylene terephthalate (PETE, Group 1 plastic), has even lower solubility in VGO, as indicated by a heptane insolubility test of 0.1 wt%. The viscosity and pour point of the blend (Example 6-4) are again comparable to the VGO-only base case (Example 5-1), because most of the PETE did not dissolve in the blend and all of the PETE was removed by filtration. These results clearly demonstrate that proper selection of petroleum feedstocks can prevent undesirable plastic materials from dissolving in the blend and subsequently being removed by filtration. These results clearly demonstrate that VGO is an excellent petroleum feedstock that selectively dissolves polyethylene (HDPE and LDPE, Groups 2 and 4) and polypropylene (PP, Group 5).

[0089] Household Plastic #5 was a collection of potato chip bags. These bags are made of multilayer film with a thin aluminum metal barrier layer to prevent moisture and air from penetrating the contents of the bag. Recycling of this type of plastic material has been considered nearly impossible because there is no good way to separate the metal layer from the multilayer plastic layer. These bags are labeled "not recyclable." Using our dissolution method, we were able to selectively dissolve polyethylene (HDPE and LDPE, Groups 2 and 4) and polypropylene (PP, Group 5) from Household Plastic #5, as shown by a heptane insolubility test of 4.8 wt%. A novel and effective method for recycling multilayer film containing an aluminum metal barrier layer appears to have been discovered.

[0090] The impurity levels of the final blends were measured by ICP testing and are reported in Table 7. The overall impurity levels are low enough that these blends can be fed to a purification conversion unit for catalytic conversion processes. [Table 7]

[0091] The results in Table 7 clearly demonstrate that with proper selection of petroleum feedstock and filtration, this process can produce stable blends with minimal chlorides, unwanted metals (Na, P, Fe), and other plastic contaminants. The blends are essentially metal-free, except for trace amounts of Al, Ca, Si, and Ti, which arise from typical fillers used in the production of plastic materials. These fillers are in the form of inert oxides and are not expected to affect the catalytic performance of the conversion unit.

[0092] Example 7: Removal of PVC contaminants by solubility and filtration To investigate the impact of PVC contamination from waste plastic sources, a blend was prepared containing 5 wt% recycled waste plastic #3 and 0.5 wt% pure PVC (Plastic F in Table 1). This simulates a 10% PVC contamination of the plastic, which may be far worse than commercial recycling of PE and PP. The blend was prepared using an autoclave and then filtered through a 0.7 micron filter according to the procedure in Example 5. The results, along with some reference cases, are summarized in Table 8. [Table 8]

[0093] These pure VGOs contain chlorides below the detection level of 1 ppm (Example 5-1). The blend prepared using waste plastic #3 contains 12 ppm chloride after filtering through a 0.7 micron filter (Example 5-7). It was found that when 0.5 wt% PVC was added, the PVC did not dissolve in the VGO and remained mostly solid. After filtration, the chloride content of the final blend was 26 ppm, only a slight increase from the reference case of Example 5-7, where the chloride content was 12 ppm. This clearly demonstrates that filtration is a very effective method for reducing PVC contamination during blend preparation.

[0094] These examples clearly demonstrate that the proper selection of petroleum feedstocks (e.g., VGO) can prevent unwanted PVC from dissolving in the blend, allowing the PVC to be subsequently filtered out.

[0095] [Example 8] Further reduction of chloride impurities by heat treatment The blend of Example 7-1 was processed to further reduce the chloride content. Stable Blend 7.1 was autoclaved via three different methods. The first treatment was a heat treatment at 650°F for 1 hour without purge gas (Example 8-1). The second treatment was a heat treatment at 650°F for 1 hour with N2 purge gas (Example 8-2). The third treatment was a heat treatment at 650°F for 1 hour with H2 purge gas (Example 8-3). The purge gas flow rate was 10 sccm per gram of blend. The results are summarized in Table 9. [Table 9]

[0096] The results in Table 9 clearly demonstrate that by selecting the appropriate temperature for blend preparation, PVC can be selectively decomposed while PE and PP remain intact. Simply treating at a high temperature of 650°F reduced the chloride content from 26 ppm to 10 ppm (Example 8-1). By using purge gases such as N2 and H2, the chloride content was further reduced to 4.8 ppm and 3.6 ppm (Examples 8-2 and 8-3). To facilitate the removal of HCl off-gas from the decomposition of PVC or organic chlorides in the blend, a stripping gas such as nitrogen, hydrogen, steam, or off-gas from a conversion unit may be added. Hydrogen may be the preferred stripping gas because it promotes the formation of HCl and minimizes the formation of dienes.

[0097] As used in this disclosure, the words "comprises" or "comprising" are intended as open-ended transitional phrases, meaning the inclusion of the indicated elements, but not necessarily the exclusion of other unspecified elements. The phrase "consists essentially of" or "consisting essentially of" is intended to mean excluding other elements of essential importance to the composition. The phrase "consisting of" or "consists of" is intended as a transitional phrase meaning the exclusion of all other than the stated elements, excepting only trace impurities.

[0098] All patents and publications referenced herein are incorporated by reference to the extent not inconsistent herewith. It will be understood that the specific structures, functions, and operations of the above-described embodiments are not necessary to practice the present invention, but are included in the description merely to complete an exemplary embodiment or embodiments. It will further be understood that the specific structures, functions, and operations described in the above-referenced patents and publications can be practiced in combination with the present invention, but are not essential to its practice. It will therefore be understood that the present invention can be practiced as specifically described without actually departing from the spirit and scope of the present invention, as defined by the appended claims.

Claims

1. 1. A blend of a petroleum feedstock and 1 to 20 wt % plastic, based on the weight of the blend, wherein the plastic comprises polyethylene and / or polypropylene, the plastic in the blend comprising finely dispersed micron-sized particles having an average particle size of 10 microns to less than 100 microns, and the blend containing less than 100 ppm chloride.

2. (a) heating a mixture of petroleum-based feedstock and plastic at a temperature above the melting point of the plastic but below 500°F; (b) recovering the product from step (a) and hot filtering the product to remove contaminants to produce a filtered blend; (c) heating the filtered blend to a temperature of 550-700°F (288-371°C) to decompose the PVC and produce a liquid product; (d) optionally treating the liquid product with a chloride removal guard bed catalyst; 10. The blend of claim 1 prepared by a process comprising:

3. 3. The blend of claim 2, wherein the amount of plastic in the blend comprises 1 to 10 wt% of the blend.

4. 3. The blend of claim 2, wherein the plastic comprises low density polyethylene.

5. 3. The blend of claim 2, wherein the plastic comprises high density polyethylene.

6. 3. The blend of claim 2, wherein the plastic comprises a multilayer film comprising a metal barrier layer, polyethylene and / or polypropylene.

7. 7. The blend of claim 6, wherein the metallic barrier layer is comprised of aluminum.

8. 6. The blend of claim 5, wherein the blend comprises 1 to 10 wt% high density polyethylene.

9. The plastic has an average molecular weight M in the range of 5,000 to 150,000. ｗ 3. The blend of claim 2, comprising a polypropylene having

10. The plastic has an average molecular weight M in the range of 150,000 to 400,000. ｗ 3. The blend of claim 2, comprising a polypropylene having

11. The blend of claim 10, wherein the blend comprises 1 to 10 wt% polypropylene.

12. 3. The blend of claim 2, wherein the plastic comprises a mixture of polyethylene and polypropylene.

13. 3. The blend of claim 2, wherein the heating is carried out while stripping the liquid using a gas such as nitrogen, hydrogen, steam, or light off-gas from a conversion unit.

14. 3. The blend of claim 2 wherein the finely dispersed particles have an average particle size in the range of 10 to 50 microns.

15. 3. The blend of claim 2 wherein the finely dispersed particles have an average particle size in the range of 10 to less than 100 microns.

16. The petroleum feedstock in the blend is selected from the group consisting of vacuum gas oil, atmospheric gas oil, reformate, light cycle oil, heavy fuel oil, refinery hydrocarbon streams containing toluene, xylene, heptane or benzene, coker naphtha, C ５ -C ６ 3. The blend of claim 2 comprising isomerized paraffin naphtha, FCC naphtha, hydrocracker bottoms, gasoline, jet fuel, diesel, or mixtures thereof.

17. 3. The blend of claim 2, wherein the petroleum feedstock is selected for preferred dissolution of polyethylene and polypropylene.

18. 18. The blend of claim 17, wherein the selected petroleum feedstock is VGO.

19. 3. The blend of claim 2, wherein the petroleum feedstock in the blend comprises a light oil or a heavy reformate.

20. 17. The blend of claim 16, wherein the blend comprises light cycle oil, gasoline, or diesel.

21. 20. The blend of claim 19, wherein the blend comprises light cycle oil, gasoline, or diesel.

22. 17. The blend of claim 16, wherein the blend comprises benzene, toluene, xylene, or heptane.

23. 20. The blend of claim 19, wherein the blend comprises benzene, toluene, xylene, or heptane.

24. 3. The blend of claim 2, wherein the blend is at a temperature above the melting point of the plastic and is a homogeneous liquid blend at elevated temperature.

25. 25. The blend of claim 24, further comprising a petroleum feedstock added to the blend.

26. 1. A process for preparing a blend of plastic and petroleum, comprising: (a) mixing together a petroleum feedstock and a plastic comprising polyethylene and / or polypropylene, and while mixing, heating the mixture to a temperature above the melting point of the plastic but below 500°F; (b) recovering the product from step (a) and hot filtering the product to remove contaminants to produce a filtered blend; (c) heating the filtered blend to a temperature of 550-700°F (288-371°C) to decompose the PVC and produce a liquid product; (d) optionally treating the liquid product with a chloride removal guard bed catalyst; The above process, comprising:

27. 27. The process of claim 26, wherein the heating is at a temperature of 550°F to 700°F (288°C to 371°C) with a residence time of 5 to 240 minutes at the final heating temperature.

28. 27. The process of claim 26, wherein the heating is performed while stripping the liquid using a gas such as nitrogen, hydrogen, steam, or light off-gas from a conversion unit.

29. 1. A process for preparing a blend of plastic and petroleum, comprising: (a) mixing together a petroleum feedstock and a plastic comprising polyethylene and / or polypropylene, and while mixing, heating the mixture to a temperature above the melting point of the plastic but below 500°F; (b) recovering the product from step (a) and hot filtering the product to remove contaminants to produce a filtered blend; (c) treating the liquid product with a chloride-removing guard bed catalyst at a temperature of 250°F to 700°F (121°C to 371°C) to decompose the PVC and produce a liquid product; The above process, comprising:

30. 30. The process of claim 29, wherein the treatment is carried out at a temperature of 250°F to 700°F (121°C to 371°C) with a residence time of 5 to 240 minutes at the final heating temperature.

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