Method for stable blends of waste plastics and petroleum feedstocks fed to refinery units and method of making same

Abstract

There is provided a blend of a petroleum feedstock and 1-20% by weight of a 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 microcrystalline particles having an average particle size from 10 microns to less than 100 microns and less than 100 ppm of chloride. There is provided a method of preparing a blend of plastic and petroleum, comprising mixing together a petroleum feed and a plastic comprising polyethylene and / or polypropylene, and heating the mixture to 550 DEG F to 700 DEG F. The blend mixture is then thermally filtered and then optionally treated with a chloride removal guard bed. The resulting blend may then be cooled and stored or sent directly to a refinery conversion unit.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application Serial No. 63 / 387041, filed on December 12, 2022, the entire disclosure of which is incorporated herein by reference in its entirety. Background Art

[0003] World plastic production is growing extremely rapidly. According to PlasticEurope Market Research Group, world 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 volume was estimated at about 260 million tons per year in 2016 and is expected to reach 460 million tons per year by 2030 if the current trajectory continues.

[0004] Disposable plastic waste has become an increasingly important environmental problem. At present, the selection of polyethylene and polypropylene waste plastic recycling into value-added chemicals and fuel products seems to be rare. At present, only a small amount of polyethylene / polypropylene is recycled via chemical recycling, wherein the recycled and clean plastic pellets are pyrolyzed in a pyrolysis unit to make fuel (naphtha, diesel), steam cracker feed or slack wax. Most (more than 80%) are incinerated, landfilled or discarded.

[0005] The chemical recycling method that currently carries out via pyrolysis cannot produce big impact to plastic industry.Current pyrolysis operation produces fuel component (product of naphtha and diesel distillation range) of poor quality, but the amount is small enough so that these products can be blended into fuel supply.However, if very large volume of waste polyethylene and polypropylene must be recycled to solve environmental problems, then this simple blending is unsustainable.The product produced by pyrolysis unit cannot be blended (for example, blended with 5-20 volume %) into transportation fuel in large quantities because quality is too poor.

[0006] Methods for converting waste plastics into hydrocarbon lubricants are known. For example, U.S. Pat. No. 3,845,157 discloses the cracking of waste polyolefins or virgin polyolefins such as ethylene / olefin copolymers to form gaseous products, which are further processed to produce synthetic hydrocarbon lubricants. U.S. Pat. No. 4,642,401 discloses the production of liquid hydrocarbons by heating pulverized polyolefin waste at a temperature of 150-500° C. and a pressure of 20-300 bar. U.S. Pat. No. 5,849,964 discloses a method in which waste plastic materials are depolymerized into a volatile phase and a liquid phase. The volatile phase is separated into a gas phase and a condensate. The liquid phase, condensate and gas phase are refined into liquid fuel components using conventional refining techniques. U.S. Pat. No. 6,143,940 discloses a process for converting waste plastics into heavy wax compositions. U.S. Pat. No. 6,150,577 discloses a method for converting waste plastics into lubricating oils. EP0620264 discloses a process for producing lubricating oil from waste or virgin polyolefins by thermally cracking the waste in a fluidized bed to form a waxy product, optionally using hydrotreatment, followed by catalytic isomerization and fractionation to recover the lubricating oil.

[0007] U.S. Publication No. 2021 / 0130699 discloses a method and system for producing recycled content hydrocarbons from recycled waste. The recycled waste is pyrolyzed to form a pyrolysis oil composition, at least a portion of which can then be cracked to form a recycled olefin composition.

[0008] Other documents related to methods for converting waste plastics into lubricating oils include U.S. Patent Nos. 6288296; 6774272; 6822126; 7834226; 8088961; 8404912 and 8696994; and U.S. Patent Application Publication Nos. 2019 / 0161683; 2016 / 0362609; and 2016 / 0264885. The aforementioned patent documents are incorporated herein by reference in their entirety.

[0009] Globally, recycling or upgrading of plastic waste has attracted great interest, aiming to save resources and the environment. Mechanical recycling of plastic waste is quite limited due to the different types, properties, additives and contaminants in the collected plastics. Usually, the quality of recycled plastics decreases. Chemical recycling into starting materials or value-added chemicals has become a more desired approach.

[0010] However, in order to achieve chemical recycling of large quantities of disposable plastics in industry to reduce their environmental impact, a more robust method is needed. This method may require unique handling and manipulation of waste plastics. If plastics are intended to be used in the preparation of feed for refineries, the presence of chlorides is of particular concern. Refinery units have low chloride tolerance. Chlorides in feed streams can cause corrosion of refinery equipment and containers, and can produce fuels and chemicals of poor quality. Summary of the invention

[0011] In one embodiment, a composition of a stable blend of waste plastic and a petroleum-based feedstock is provided for direct conversion of waste plastic in a refinery process unit. In one embodiment, the blend comprises less than 100 ppm of chloride. In another embodiment, the blend comprises less than 10 ppm of chloride. In another embodiment, the blend comprises less than 5 ppm of chloride.

[0012] The stable blend comprises a petroleum-based feedstock and 1-20% by weight of plastic. In one embodiment, the plastic comprises primarily polyethylene and / or polypropylene. The plastic in the blend exists as finely dispersed microcrystalline particles with 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 of chloride.

[0013] In one embodiment, a method for preparing a blend of plastic and petroleum is also provided. The method includes mixing a petroleum-based feed (or in one embodiment, a biofeed) with plastic, and heating the mixture to a temperature of about 600 to 800°F (206 to 427°C), preferably a temperature of 550 to 700°F (288 to 371°C), for a residence time of 5-240 minutes. The resulting blend is then hot filtered to remove any contaminants, including glass, metal, PVC or other plastics. The filtered liquid product is optionally further treated with a chloride-free guard bed catalyst. The resulting blend comprises less than 100 ppm of chloride and more preferably less than 10 ppm of chloride. The blend can then be fed to a refinery unit or cooled for storage.

[0014] Among other factors, the process of the present invention produces a blend of plastic and petroleum-based feedstock that contains minimal, if any, chlorides, e.g., in one embodiment, less than 10 ppm of chlorides, or even less than 5 ppm of chlorides. The blend is close to being chloride-free, if not essentially chloride-free. The process of the present invention also performs chloride removal in a minimal number of steps.

[0015] This substantially chloride-free blend of plastic and petroleum-based raw materials provides efficient and effective feeding of waste plastics into refinery processes to convert the waste plastics into carriers of large-volume products with good yields. It has been found that by preparing the blend of the present invention and feeding the blend into refinery operations, plastic waste can be efficiently, effectively and safely recycled, while also supplementing the operations of refineries in preparing more valuable 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, the overall recycling process achieves positive economics, and the product quality is the same as the original polymer. Energy is also saved using the blend of the present invention, and it is more environmentally friendly than existing recycling methods. The blend contains the least (if any) chloride allowing the blend to pass safely through the refinery without damaging the device and refinery units, because the art discloses methods for reducing the chloride content to a level below the unit operating limit. In one embodiment, the raw material mixed with plastics may include biofeed. Biofeed can be used alone or in combination with petroleum-based raw materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Shown are the results of thermogravimetric analysis (TGA) of pure polyethylene (PE), polypropylene (PP) and polyvinyl chloride (PVC) plastics and vacuum gas oil (VGO).

[0017] Figure 2 Depicts the classification of plastic types for waste plastic recycling.

[0018] Figure 3 Depicted is the process of the present invention for preparing a hot, intimate liquid blend of plastic and petroleum feedstock, and how that blend can be fed to a refinery conversion unit.

[0019] Figure 4 The preparation of a homogenous blend with minimal chlorides and other plastic contaminants, and how the homogenous blend can be fed to a refinery conversion unit, is described in detail.

[0020] Figure 5 Thermogravimetric analysis (TGA) results of recycled waste plastics containing PE and PP are shown.

[0021] Figure 6 Shown are the results of thermogravimetric analysis (TGA) of household plastics. DETAILED DESCRIPTION

[0022] Disclosed are novel blends of plastics and petroleum-based feedstocks, and methods of making stable blends of plastics and petroleum-based feedstocks containing minimal, if any, chlorides, metals, and other plastic contaminants for direct conversion of plastics in refinery process units. In one embodiment, the feedstock blended with the plastic may comprise a biofeed feedstock. The biofeed may be used as the entire feedstock, or may be used in combination with a petroleum-based feedstock.

[0023] In one embodiment, a method for preparing a stable blend of plastics (preferably waste plastics) and oil is provided, the stable blend is used for storage, transportation or feeding to a refinery unit, wherein the blend comprises a minimum chloride (if any). The minimum chloride (if any) means that the amount of the chloride present in the blend is less than 100 ppm chloride or even less than 10 ppm chloride and less than 5 ppm chloride. Minimum metals and other plastic pollutants are also desired and achieved. The method comprises first selecting plastics, preferably waste plastics containing polyethylene and / or polypropylene. These waste plastics are then sent through a blend preparation unit, to manufacture a stable blend of waste plastics and oil, the blend comprising a minimum chloride (if any), metals and other plastic pollutants. The stable blend can then be safely fed to a refinery conversion unit, to convert waste plastics directly into value-added chemicals and fuels.

[0024] Stable blends are made by two-step or three-step methods. The first step produces a uniform liquid blend of plastic melt and petroleum raw materials. The preferred range of plastic composition in the blend is about 1-20 weight %. The preferred conditions for the preparation of hot liquid blends include heating plastics to a melting point higher than the plastics while vigorously mixing with petroleum raw materials. Preferred process conditions include heating to a temperature of about 500-800°F, preferably about 550-700°F, a residence time of 5-240 minutes at the final heating temperature, and an atmospheric pressure of 0-20 psig. The temperature used is a temperature that will decompose PVC without substantially decomposing any other plastics. By maintaining the temperature at about 550 to 700°F, only polyvinyl chloride is decomposed into HCl and hydrocarbons. At this temperature range, polyethylene and polypropylene remain molten but do not decompose. By minimizing the decomposition of polyethylene and polypropylene, the amount of olefins and dienes in the blend is limited, and this will minimize the formation of organic chlorides that can be manufactured by the reaction of olefins and HCl, stripping gases such as nitrogen, hydrogen, steam or waste gas from a conversion unit can be added to promote the purging of HCl waste gases from the decomposition of PVC or organic chlorides in the blend. Hydrogen can be a preferred stripping gas because it promotes the formation of HCl and minimizes the formation of dienes. Preferred conditions include a temperature of 550 to 700°F, a residence time of 5-240 minutes at the final heating temperature, and a pressure of 0-200 psig and a stripping gas of 100-1500 scf / bbl. By maintaining the temperature at about 550 to 700°F, only polyvinyl chloride is decomposed into HCl and hydrocarbons. At this temperature range, polyethylene and polypropylene remain molten but do not decompose. By minimizing the decomposition of polyethylene and polypropylene, the amount of olefins and dienes in the blend is limited, and this will minimize the formation of organic chlorides that can be produced by the reaction of olefins and HCl.

[0025] Figure 1 The thermal stability of polyethylene (PE), polypropylene (PP) and polyvinyl chloride (PVC) plastics as determined by thermogravimetric analysis (TGA) is shown. PVC decomposes via dehydrochlorination to form polyenes and HCl gas in the temperature range of 450-700°F. At temperatures above 700°F, the polyenes further decompose into low molecular weight compounds. Any exhaust gas from the heating (which will contain hydrogen chloride) is treated with a scrubber. This can be done in an open atmosphere and preferably under an oxygen-free inert atmosphere.

[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. Figure 1The weight change of VGO shown is due to the boiling out of light components from the VGO in the form of light hydrocarbons. In order to minimize the loss of light hydrocarbons in the VGO, it is preferred to operate the chloride stripping process at an elevated pressure, such as above 10 psig, preferably above 50 psig. Alternatively, an overhead condenser may be installed to condense the light hydrocarbon vapors back into liquids.

[0027] The second step involves hot filtering the blend mixture to remove any contaminants. Contaminants may include glass, metal, paper, PVC or other plastics with low solubility such as PS and PETE and other Group 7 plastics, as well as inorganic filler materials used in plastic manufacturing. This filtration step allows the removal of most PVC, PETE, other plastics and most inorganic impurities.

[0028] The last step or the third step includes optionally treating the filtered liquid product recovered from the second step with a chloride removal guard bed catalyst. Such catalyst beds are known in the industry to effectively reduce chlorides to low ppm levels. In one embodiment, the catalyst bed is based on oxides such as CaO or MgO, or based on hydroxides such as Fe(OH)2. Such catalyst guard beds can be obtained, for example, from Dorf Ketal, BASF, Evonik, Johnson Matthey, Clariant and Axens. Preferred conditions include treating at a temperature of 250 to 700°F, a residence time of 5-240 minutes and a pressure of 0-200 psig. If any further decomposition of PVC is required, a suitable temperature can be selected. Now, the resulting blend can be safely fed directly to a refinery, or cooled and stored for subsequent use. This subsequent use can include feeding to a refinery, or transporting and feeding to a refinery.

[0029] For storage, the hot blend is cooled to below the melting point of the plastic while continuing intensive mixing, and then further cooled to a lower temperature, preferably ambient temperature, to produce a stable blend. Depending on the petroleum feedstock and plastic content and type, the stable blend is an oily liquid or waxy solid state at ambient temperature. Because the blend is stable, it can be stored for a long time.

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

[0031] Several advantages are achieved by the blends of the present invention and their use. For example, the stable blends of plastics and petroleum feedstocks can be stored for long periods of time at ambient temperature and pressure. During storage, no agglomeration, sedimentation of the polymer particles, and chemical / physical degradation of the blends are observed. This allows for easier handling of waste plastic materials for storage or transportation.

[0032] The stable blend can be easily handled by using conventional pumps commonly used in refineries or warehouses or by using a pump equipped with a transport tank. Depending on the blend, some heating of the blend above its pour point is required to pump the blend for transfer or feeding to a conversion unit in a refinery. During heating, no agglomeration of the polymer was observed.

[0033] Another major advantage of the blend of the present invention and the process for making the blend is the removal of chlorides to levels of less than 100 ppm, or even 10 ppm and less.The blend of the present invention can be safely supplied to refineries as refinery units have low chloride tolerance.

[0034] Another major advantage of the blends of the present invention and the methods for preparing the blends is that they can be applied to multilayer film plastics, which are considered non-recyclable via current recycling methods. These multilayer films contain polyethylene and / or polypropylene layers and also contain a thin metal layer as a metal barrier layer. The metal layer typically contains aluminum as the metal. The polyethylene and polypropylene components of the multilayer film can be selectively dissolved in petroleum feedstocks, and the metal forming the metal layer of the multilayer film can be removed via filtration.

[0035] To feed the refinery unit, the stable blend is further heated above the melting point of the plastic to produce a homogenous liquid blend of petroleum and plastic. The hot homogenous liquid blend is directly fed to the refinery process unit to convert the waste plastic into high value products with good yields.

[0036] Refinery conversion units such as fluid catalytic cracking (FCC) units, hydrocracking units and hydrotreating units convert the heat of plastics and petroleum feedstocks in the presence of catalysts. The presence of catalysts in the conversion units allows waste plastics to be converted into products of higher value at operating temperatures lower than the usual pyrolysis temperatures. The yield of undesirable byproducts (waste gas, tar, coke, char) is lower than the usual pyrolysis process. For hydroprocessing units (hydrocracking and hydrotreating units), hydrogen is added to the unit to improve the conversion of plastics. The blend can produce additional synergistic benefits from the interaction of plastics and petroleum feedstocks during the conversion process. Fluid catalytic cracking and hydrocracking methods are preferred modes for catalytic conversion of stable blends.

[0037] In one embodiment, the stable blend of plastic and petroleum feedstock can be sent to a coking unit to thermally convert the waste plastic. In this case, there is no significant advantage in reactor temperature or product yield compared to the pyrolysis process. The advantage of the coking unit is its feed flexibility, which is reflected in the fact that the unit can process blends with very high nitrogen, sulfur and metal impurities.

[0038] Stable blends of plastics and petroleum feedstocks allow for more efficient recycling of waste plastics. Use of the blends of the invention is much more energy efficient than current pyrolysis methods and allows for recycling with a lower carbon footprint. The improved process allows for the establishment of a circular economy on a significantly larger scale by efficiently converting waste plastics back into virgin quality polymers or value-added chemicals and fuels.

[0039] In order to minimize pollutants such as N, Cl and S, proper sorting of waste plastics is very important. 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%. The method of the present invention can tolerate moderate amounts of polystyrene (plastic recycling classification type 6). Waste polystyrene needs to be sorted to less than 20%, preferably less than 10% and most preferably less than 5%. Figure 2 Depicts the classification of plastic types for waste plastic recycling.

[0040] Washing waste plastics can remove metal pollutants such as sodium, calcium, magnesium, aluminum and non-metallic pollutants from other waste sources. Non-metallic pollutants include pollutants such as silicon dioxide from Group IV of the periodic table, pollutants such as phosphorus and nitrogen compounds from Group V, pollutants such as sulfur compounds from Group VI, and halide pollutants such as fluoride, chloride and iodide from Group VII. Residual metals, non-metallic pollutants and halides need to be removed to less than 50 ppm, preferably less than 30 ppm and most preferably less than 5 ppm.

[0041] The petroleum blended with waste plastics is generally a petroleum feedstock for a refinery. Preferably, the petroleum blended oil is identical to the petroleum feedstock of a refinery. Petroleum may also include any oil derived from petroleum or a material based on petroleum. In one embodiment, the petroleum feedstock oil may include atmospheric gas oil, vacuum gas oil (VGO), atmospheric residue or a heavy feedstock recovered from other refinery operations. In one embodiment, the petroleum feedstock oil blended with waste plastics includes VGO. In one embodiment, the petroleum feedstock oil blended with waste plastics includes light cycle oil (LCO), heavy cycle oil (HCO), FCC naphtha, gasoline, diesel, toluene and / or an aromatic solvent from petroleum.

[0042] In one embodiment, the petroleum feedstock used for the preparation of the blend includes vacuum gas oil, atmospheric gas oil, reformate, light cycle oil, heavy fuel oil, a refinery hydrocarbon stream containing toluene, xylenes, heptane or benzene, or pure toluene, pure xylenes, coker naphtha, C5-C6 isomerized paraffinic naphtha, FCC naphtha, hydrocracker bottoms, gasoline, jet fuel, diesel or a mixture of some of these.

[0043] The most preferred petroleum feedstock is gas oil, heavy reformate or various recycle streams to be fed to a catalytic conversion unit. The plastic and petroleum feedstock in the blend are then converted together into higher value products via catalytic conversion.

[0044] More than one petroleum feedstock can be used to optimize the blend properties. For example, viscosity and pour point can be lowered by adding lighter petroleum 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 to reduce the viscosity or pour point of the blend of plastic and petroleum feedstock for easier handling.

[0046] In one embodiment, the raw material for preparing the blend may include a bio-feed. The bio-feed may be the entire feedstock, or may be mixed with a petroleum feedstock.

[0047] In one embodiment, the petroleum feedstock is selected to preferentially dissolve polyethylene and polypropylene. The petroleum feedstock exhibits high solubility for polyethylene and polypropylene plastics, and exhibits low solubility for 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 the waste plastic source are removed by a filtration step. Examples of such suitable 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, a biomaterial or bio-oil will contain these natural chemicals. Preferred starting biomaterials for blend preparation include triglycerides and fatty acids, oils of plant origin such as palm oil, rapeseed oil, corn oil and soybean oil, and fats and oils of animal origin such as tallow, lard, schmaltz (e.g., chicken fat) and fish oil, and mixtures of these.

[0049] The method of the present invention with two or three steps for preparing the blend of the present invention ensures that the amount of chloride remaining in the blend is extremely small, and will not cause damage to refinery units and equipment. The presence of chloride can produce HCl acid, which will cause the deterioration of the unit. This is very important because the refinery also has the purpose of preparing chemicals, base oils and fuel oils, and the units and devices in the refinery are sensitive to chlorides, as described above. In addition, chlorides can also affect the catalyst and product quality used in the refinery. By using the blend of the present invention prepared by the method of the present invention, waste plastics can be effectively, efficiently and safely recycled, while also supplementing the refinery in the preparation of more valuable products such as gasoline, jet fuel, base oil, diesel fuel and the operation of useful chemicals.

[0050] Although not wishing to be bound by theory, the method of the present invention prepares a stable blend containing minimal (if any) chlorides, metals and other plastic contaminants, which is an intimate physical mixture of plastics and petroleum feedstocks for catalytic conversion in refinery units. The method of the present invention produces a stable blend of petroleum feedstocks and plastics, wherein the plastics are in a "deagglomerated" state. The plastics retain their state as "finely dispersed" solid particles in the petroleum feedstock at ambient temperature. The blend is stable and allows easy storage and transportation. In a refinery, the stable blend can be preheated to a temperature higher than the melting point of the plastic to produce a hot, uniform liquid blend of plastics and petroleum, and the hot liquid blend is then fed to a conversion unit. Then, both the petroleum feed and the plastic are simultaneously converted in a conversion unit using a typical refinery catalyst containing zeolite and other active components such as silica-alumina, alumina and clay.

[0051] The use of the blend of the present invention avoids pyrolysis of waste plastics. Instead, the prepared stable blend of petroleum feedstock and waste plastics can be fed to a refinery unit. Thus, the pyrolysis step can be avoided, which is a significant energy saving.

[0052] Stable blends are made by a two-step or three-step process. The first step produces a hot, uniform liquid blend of a plastic melt and a petroleum feedstock. The preferred range of plastic in the blend is about 1-20% by weight. The blend of feedstock and plastic is heated to a temperature sufficient to decompose the residual PVC. The temperature may be about 500°F or higher, although temperatures of about 550-700°F are generally found to be acceptable. The duration of heating is sufficient to achieve decomposition of most, if not all, of the remaining PVC. Any waste gases from the heating (which will contain hydrogen chloride) are treated with a scrubber.

[0053] The second step involves hot filtering the blend mixture to remove any contaminants. Hot filtering means filtering the homogenous blend from the previous step while it is still hot. Contaminants may include glass, metal, PVC or other plastics with low solubility such as PS and PET. This filtration step allows the removal of most PVC.

[0054] The final step is to optionally treat the liquid product recovered from the second step with a chloride-removing guard bed catalyst. Such catalyst beds are known in the industry to effectively reduce chloride to low ppm levels. In one embodiment, the catalyst bed is based on oxides such as CaO and MgO, or on hydroxides such as Fe(OH) 2. Now, the resulting blend can be fed directly to a refinery, or cooled and stored for subsequent use. This subsequent use can include feeding to a refinery, or transporting and feeding to a refinery.

[0055] In the cooling and storage of the blend, the hot homogeneous liquid blend is cooled to ambient temperature in a controlled manner to allow easy storage and transportation. By using this method, a stable blend can be prepared in a facility away from a refinery and can be transported to a refinery unit. Then, the stable blend is heated to a melting point higher than that of plastic to feed a refinery conversion unit. The stable blend is a physical mixture of micron-sized plastic particles finely suspended in petroleum-based oil, wherein the average particle size of the plastic particles is 10 microns to less than 100 microns. The mixture is stable, and the plastic particles will not settle or agglomerate when stored for a long time.

[0056] When a single plastic is used, the meaning of heating the blend to a temperature above the melting point of the plastic is clear. However, if the waste plastic contains more than one waste plastic, the melting point of the plastic with the highest melting point is exceeded. Therefore, the melting points of all plastics must be exceeded. Similarly, if the blend is cooled to below the melting point of the plastic, the temperature must be cooled to below the melting points of all plastics contained in the blend.

[0057] Compared to pyrolysis units, these blend preparation units operate at lower temperatures (~500-600°C vs. 288-371°C). Thus, employing the blends of the present invention in conjunction with a refinery can provide a much more energy efficient process than thermal cracking processes such as pyrolysis.

[0058] The use of the waste plastics / petroleum blend of the present invention has also improved the total hydrocarbon yield obtained by the waste plastics. The increase in this yield is significant. The hydrocarbon yield using the blend of the present invention provides a hydrocarbon yield of up to 98%. On the contrary, a large amount of (about 10-30% by weight) light products and about 5-10% by weight of char are produced by the pyrolysis of plastic waste. As mentioned above, these light hydrocarbons are used as the fuel for running the pyrolysis device. Therefore, the liquid hydrocarbon yield from the pyrolysis device is at most 70-80%.

[0059] When the blend of the present invention is sent to a refinery unit such as an FCC unit, only a small amount of waste gas is produced. The catalytic cracking method used in the refinery unit is different from the thermal cracking method used in the pyrolysis. Utilizing a catalytic method, the generation of undesirable light fraction by-products such as methane and ethane is minimized. The refinery unit has an effective product fractionation, and all hydrocarbon product streams can be effectively utilized to produce high-value materials. The refinery co-feed will only produce about 2% of waste gas (H2, methane, ethane, ethylene). C3 and C4 streams are captured to produce useful products, such as cyclic polymers and / or high-quality fuel products. Therefore, the use of the oil / plastic blend of the present invention provides an increased hydrocarbon from plastic waste, and a more energy-efficient recycling method compared to thermal methods such as pyrolysis. When considering recycling waste plastics, the benefits of the blend of the present invention are significant.

[0060] Figure 3 A method for preparing a hot, homogeneous blend of plastic and petroleum feedstock is shown, which can be used for direct injection into a refinery unit. The preferred range of plastic composition in the blend is about 1-20 weight %. If high molecular weight polypropylene (average molecular weight of 250,000 or greater) waste plastic or high density polyethylene (density greater than 0.93 g / cc) is used as the main (e.g., at least 50 weight %) waste plastic, the amount of waste plastic used in the blend is more preferably about 10 weight % or less. The reason is that the pour point and viscosity of the blend will be high. In one embodiment, the plastic may contain an average molecular weight M w In another embodiment, the plastic may include a polypropylene with an average molecular weight M of 5000 to 150000. w Polypropylene of 150,000 to 400,000.

[0061] With reference to the attached drawings Figure 3 , shows a step-by-step preparation method for preparing a hot homogeneous liquid blend. The 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 uniform blend 25 of plastics and oil is recovered. Optionally, a filtering device (not shown) can be added to the hot blend preparation unit 23 to remove any undissolved solid contaminants 26, such as undissolved plastic particles (PTFE, PVC, PS, other plastics of Group 7) or any solid impurities such as glass, metal, paper present in the hot liquid blend. The hot blend 25 of plastics and oil can then be combined with a refinery feedstock such as vacuum gas oil 20 (VGO) and become a mixture of plastic / oil blend and VGO, which can then be sent to a catalytic conversion unit 27 in a refinery.

[0062] Figure 4 A detailed method for preparing a low chloride, low impurity homogeneous blend of plastic and oil is shown. The blend is made in a homogeneous blend preparation unit 23 by a two-step process or a three-step process. The first step produces a hot homogeneous liquid blend of the plastic melt and the petroleum feedstock. This step is similar to Figure 3 The hot blend preparation described in . As shown, the cleaned waste material 22 is sent to the uniform blend preparation unit 23. The selected waste material 22 is heated and mixed with the hot refinery feedstock oil 24 at the plastic dissolving container 30. The mixing is usually strong. The preferred range of plastic composition in the blend is about 1-20 weight %. If high molecular weight polypropylene (average molecular weight is 250000 or more) waste plastic or high density polyethylene (density is greater than 0.93 g / cc) is used as the main (e.g., at least 50 weight %) waste plastic, the amount of waste plastic used in the blend is more preferably about 10 weight % or less. The reason is that the pour point and viscosity of the blend will be high.

[0063] The blend of feedstock and plastic is heated at the plastic dissolving vessel 30 to a temperature sufficient to decompose the residual PVC while keeping the decomposition of polyethylene and polypropylene to a minimum. The temperature can range from about 500-800°F, and temperatures of about 550-700°F (288-371°C) are generally found to be acceptable. The duration of heating is sufficient to achieve decomposition of most, if not all, of the remaining PVC. Any off-gas from the heating, which will contain hydrogen chloride, is treated with a scrubber. Optionally, a small amount of stripping gas 39 such as nitrogen, hydrogen, or off-gas from a catalytic conversion unit may be fed to the dechlorination unit to promote HCl formation and minimize diene formation.

[0064] Any waste gases from the mixing may be sent to a scrubber 31. An optional diluent 32 may be added to aid in heating and mixing at the plastic dissolving vessel 30, if desired.

[0065] The hot blend mixture of plastic and oil is then recovered 33 and sent to a hot filtration unit 35. Contaminants, which may include glass, metal, PVC or other plastics with low solubility, are removed 36. This filtration step allows the removal of most of the remaining PVC.

[0066] The blend preparation unit 23 may also include a third step (not shown) which includes treating the heated and filtered liquid blend product with a chloride removal guard bed. Such guard beds typically contain metal oxide or metal hydroxide adsorbents and are known in the industry to be effective in reducing chlorides. Preferred conditions include treating at a temperature of 250 to 700°F, a residence time of 5-240 minutes, and a pressure of 0-200 psig. If desired, the appropriately selected temperature may also provide additional PVC decomposition.

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

[0068] Optionally, the homogeneous blend 41 can be cooled to ambient temperature to produce a stable blend. It has been found that the stable blend is a close physical mixture of plastic and petroleum raw materials. The plastic is in a "deagglomerated" state. The plastic maintains a fine dispersion of solid particles in the petroleum raw materials at temperatures below the melting point of the plastic and particularly at ambient temperature. The blend is stable and allows easy storage and transportation. In a refinery, the stable blend can be heated in a preheater to a temperature above the melting point of the plastic to produce a hot, homogeneous liquid blend of plastic and petroleum. The hot liquid blend can then be fed to a refinery unit as a co-feed of a conventional refinery feed.

[0069] The preferred plastic starting material for the blend of the present invention is sorted waste plastics containing mainly polyethylene and polypropylene (plastic recycling classification types 2, 4 and 5). The pre-sorted waste plastics are cleaned and shredded or pelletized to feed the blend preparation unit. Figure 2 Depicted are the classifications of plastic types used for waste plastic recycling. Classification types 2, 4, and 5 are high density polyethylene, low density polyethylene, and polypropylene, respectively. Any combination of polyethylene and polypropylene waste plastics may be used. Classification 6 polystyrene may also be present in limited amounts.

[0070] Example

[0071] Example 1: Properties of original plastic samples

[0072] Six commercially available plastic samples were purchased: low-density polyethylene (LDPE, plastic A), high-density polyethylene (HDPE, plastic B), two polypropylene samples with average molecular weights of ~12000 (PP, plastic C) and ~250000 (PP, plastic D), polystyrene (PS, plastic E) and polyvinyl chloride (PVC, plastic F), and their properties are summarized in Table 1.

[0073] Table 1

[0074] The nature of the plastic used

[0075] *Includes the decomposition temperature of PVC.

[0076] Figure 1The thermal stability of polyethylene (PE), polypropylene (PP) and polyvinyl chloride (PVC) plastics determined by thermogravimetric analysis (TGA) is shown. PVC decomposes via dehydrochlorination to form polyenes and HCl gas in the temperature range of 450-700°F. At temperatures above 700°F, the polyenes further decompose into low 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 temperature to 1200°F. Figure 1 The weight changes of the VGO shown are due to the boiling out of the light components from the VGO as light hydrocarbons.

[0077] Example 2: Properties of recycled waste plastic samples

[0078] Four recycled waste plastic samples were purchased for blend preparation and their properties are summarized in Table 2.

[0079] FT-IR was used to determine the general properties of plastics. In addition to determining the main polymer substances, FT-IR data also revealed that all of these recycled plastics contained different amounts of calcium carbonate and talc. In order to estimate the amount of potentially recyclable hydrocarbons, each sample was calcined at 1000°F for 3 hours under N2. It was assumed that the recyclable hydrocarbons were equal to the loss on ignition % (LOI). Inorganic residues from calcination were analyzed using ICP elemental analysis. The impurities of each household plastic sample were evaluated using LOI values ​​and ICP analysis, and are reported in Table 2 below. The most common impurities in waste plastics are Ca, Mg, Si, Ti and Al, which can come from plastic consumer product manufacturing because calcium carbonate, silica, and talc are commonly used filler materials. Fe, Na, P and Zn are also present in different amounts.

[0080] Table 2

[0081] Properties of recycled waste plastics

[0082] Thermogravimetric analysis (TGA) was performed on the waste plastic samples to verify that the plastic material was thermally stable at temperatures well above the melt preparation temperature. Figure 5 The TGA results shown indicate that the waste plastic sample is stable up to 700° F. From the TGA results, the weight percent of the residue weight at 950° F. (510° C.) is reported in Table 2. The residue weight from the TGA analysis corroborates well with the LOI measured by calcination.

[0083] Example 3: Properties of household waste plastic samples

[0084] Five household plastic (HHP) samples were collected for blend preparation, and their properties are summarized in Table 3. HHP#1 is a batch of semi-rigid plastic polymer foam (poly bubble) shipping envelopes. HHP#2 is a batch of lightweight polymer shipping bags made with 50% recycled material. HHP#3 is a batch of take-out food packaging, which is marked as recyclable plastic Group 6 (polystyrene, PS). HHP#4 is a transparent fruit and vegetable packaging, which is marked as recyclable plastic Group 1 (polyethylene terephthalate, PETE). HHP#5 is a batch of potato chip packaging, and is marked as "non-recyclable".

[0085] Using LOI values ​​and ICP elemental analysis, impurities in household plastic samples were evaluated as described in Example 2 and are reported in Table 3 below. The most common impurities in household waste plastics are Ti, Ca, Si, and Al, which can come from plastic consumer product manufacturing because talc, calcium carbonate, and silica are commonly used filler materials. The high Ti impurity content of HH Plastic #2 may come from titanium dioxide added during the recycling process.

[0086] Table 3

[0087] Properties of household plastics

[0088] Thermogravimetric analysis (TGA) was performed on the waste plastic samples to verify that the plastic material was thermally stable at temperatures well above the melt preparation temperature. Figure 6 The TGA results shown indicate that the waste plastic samples are stable up to 700°F. From the TGA results, the weight percent of the residue weight at 950°F is reported in Table 3. For HH Plastics #1, #2, and #5, the residue weight from the TGA analysis corroborates well with the LOI measured by calcination. The TGA analysis of HH Plastic #3 (PS) shows that the material is very pure, containing very little inorganic filler material. The TGA analysis of HH Plastic #4 (PETE) shows 15.6% residue, which may be inorganic filler material or carbonaceous residue.

[0089] Example 4: Properties of petroleum feedstocks used in blend preparation

[0090] 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. Their properties are shown in Table 4. Aromatic 100 is a commercially available aromatic solvent made from petroleum-based materials, containing mainly C9-C 10 Dialkylbenzenes and trialkylbenzenes.

[0091] Table 4

[0092] Properties of petroleum feedstocks used in blend preparation

[0093] Example 5: Preparation of blends of recycled waste plastic and VGO, and reduction of impurities by filtration

[0094] Several blends, each made from vacuum gas oil (VGO) and a recycled waste plastic sample (Plastics G through J of Table 2), were prepared by adding plastic pellets to hydrotreated vacuum gas oil (Petroleum Feed #1 of Table 4) using an autoclave.

[0095] The following procedure was used. Pre-weighed plastic pellets (solid) and VGO feed (waxy solid) were added to a batch autoclave unit at ambient temperature. The autoclave was purged with N2 gas to remove air from the container, and then the inlet and outlet valves were closed. The mixture was stirred with an impeller at 1500 rpm while the mixture was heated to a target temperature of 204°C (400°F) with an external heating jacket by increasing the temperature set point by 28°C (50°F) every 10 minutes. Then, the target temperature was kept warm for 1 hour. The pressure was monitored for all time. Typically, the pressure was established to less than 10 psig. For most blend preparations (preps), the hot blend was filtered (using 0.7 or 20 micron filter paper) using a cellulose filter with a well-defined pore size in a 400°F hot oven. In a few cases, the blend was not filtered to examine the effect of filtration on impurity removal.

[0096] After 10 wt % of the plastic was dissolved, some solid precipitation, possibly from the filler material, was observed, and the blend generally showed very high viscosity, probably due to the presence of solids. For 5 wt % of the plastic dissolved, the blend was easily filtered, and the colloidal solid material was filtered out. The filtered blend product was cooled to ambient temperature, and the resulting stable blend showed no visible plastic residue and was completely uniform according to visual observation. The blend of plastic and VGO showed the appearance of a waxy solid of VGO. The blend of plastic and VGO was stable, and no changes were observed during the 3 month observation period.

[0097] In order to evaluate the material handling needs, the pour point (according to ASTM D5950-14) and viscosity (according to ASTM D445) of the blends were measured. In addition, the content of hot heptane insoluble materials was measured according to the ASTM D3279 procedure. The hot heptane insoluble method determines the weight percentage of materials in oil that are insoluble in hot heptane at 80°C. This method uses a 0.8 micron membrane filter to separate insoluble materials. The heptane insoluble content provides information about the insoluble plastics in the blend. The chloride content of the blend was measured using combustion ion chromatography (according to ASTM D7359). Table 5 below summarizes the list of prepared samples and their properties.

[0098] Table 5

[0099] Preparation of stable blends of waste plastics and VGO

[0100] The heptane insolubility test in Table 5 above is related to the amount of plastic in the blend. The heptane insolubility test shows that at 80°C, the plastic is a physical mixture of solid particles in the VGO dispersed in the blend, and most of the plastic particles can be effectively separated with a 0.8 micron filter. The slight difference between the heptane insoluble material content and the amount of plastic added may be due to very small particles (less than 0.8 microns) that were not captured by the filter during the heptane insolubility measurement, or due to residual filter impurities from the waste plastic, which captured some of the VGO in the filter cake and provided 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 for the blend preparation, indicating that the size of some 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 for the blend preparation. Perhaps residual impurities such as cellulose from paper (along with recycled waste plastics) may capture some of the VGO in the filter cake and produce a slightly higher weight percentage.

[0101] Without filtering, blends made with recycled plastics with high impurities (such as filler materials and paper fibers) showed very high viscosities that would make pumping to the conversion unit challenging (Examples 5-2, 5-6, and 5-8). Filtration with a 0.7 micron or 20 micron filter was effective in significantly reducing viscosity and removing solid material. Filtration also reduced the chloride content of the blend.

[0102] This example clearly shows that filtration is a critical step in preparing plastic / petroleum feedstock blends made from waste plastics. The process of the present invention is effective in preparing a stable blend with minimal chloride and other plastic contaminants. The stable blend is an intimate physical mixture of plastic and petroleum feedstock that can be easily converted in a catalytic conversion unit.

[0103] Example 6: Preparation of blends of household waste plastics and VGO, and reduction of other plastics by filtration

[0104] Several blends were prepared using a procedure similar to Example 5, each made from vacuum gas oil (VGO, petroleum feed #1 of Table 4) and household plastic samples (Plastics K to O of Table 3). Dissolution was performed in a 1 L glass beaker with an overhead stirrer. The VGO was first heated to 400°F, and then finely cut plastic pieces were added to the beaker to make a blend of plastic and VGO. In some cases, not all of the plastic dissolved. The hot blend was filtered in a 400°F hot oven using cellulose filter paper with 20 micron pore openings. Similar analyses were performed, and the results are summarized in Table 6.

[0105] Table 6

[0106] Preparation of stable blends of household plastics and VGO

[0107] The heptane insoluble test results in Table 6 above roughly show the amount of polyethylene and polypropylene dissolved in the blend. For Household Plastics #1 and #2, the heptane insoluble content is comparable to or slightly higher than the amount of plastic added to the blend formulation. The slight difference in 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 because residual impurities may trap some of the VGO in the filter cake during the heptane insoluble measurement and produce a slightly higher weight percentage.

[0108] Household Plastic #3, made from polystyrene (PS, Group 6 plastics), has very low solubility in VGO, as shown by 0.7 wt% in the heptane insolubility test. The viscosity and pour point of the blend (Example 6-3) are comparable to the VGO-only base case (Example 5-1) because not much of the added PS dissolves in the blend and most of the PS is filtered out. Household Plastic #4, made from polyethylene terephthalate (PETE, Group 1 plastics), has an even lower solubility in VGO, as shown by 0.1 wt% in the heptane insolubility test. The viscosity and pour point of the blend (Example 6-4) are also comparable to the VGO-only base case (Example 5-1) because almost no PETE dissolves in the blend and all of the PETE is filtered out. These results clearly show that by properly selecting petroleum feedstocks, undesirable plastic materials can be prevented from dissolving into the blend and then filtered out. 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).

[0109] Household Plastic #5 is a batch of potato chip bags. These bags are made with a multilayer film with a thin aluminum metal barrier layer to prevent moisture and air from penetrating into the contents of the bag. Recycling of this type of plastic material is considered almost impossible because there is no good way to separate the metal layer and the multiple plastic layers. These bags are labeled "non-recyclable". Using the dissolution method of the present invention, polyethylene (HDPE and LDPE, Groups 2 and 4) and polypropylene (PP, Group 5) can be selectively dissolved from Household Plastic #5, as shown by 4.8 weight percent in the heptane insolubility test. It appears that a new and effective method for recycling multilayer films containing aluminum metal barrier layers has been discovered.

[0110] The impurity levels of the final blends were measured using ICP testing and are reported in Table 7. The overall impurity levels were low enough so these blends could be fed to a refinery conversion unit for use in a catalytic conversion process.

[0111] Table 7

[0112] Composition of stable blends made from household plastics and VGO

[0113] The results of Table 7 clearly show that by the process of the present invention, using appropriately selected petroleum feedstocks and filtration, a stable blend with minimal chlorides, undesirable metals (Na, P, Fe) and other plastic contaminants can be prepared. The blend is essentially free of metals, except for trace amounts of Al, Ca, Si and Ti from typical filler materials used in the manufacture of plastic materials. These filler materials are in the form of inert oxides and are not expected to affect the catalyst performance of the conversion unit.

[0114] Example 7: Removal of PVC contaminants by dissolution and filtration

[0115] To study the impact of PVC contamination in waste plastic sources, in addition to 5 wt % of recycled waste plastic #3, 0.5 wt % of pure PVC (Plastic F in Table 1) was added to prepare blends. This simulation corresponds to 10% of the plastic being contaminated with PVC, which may be much worse than the possible commercial recycling of PE and PP. According to the procedure of Example 5, blends were prepared via dissolution in an autoclave followed by 0.7 micron filtration, and the results are summarized in Table 8 along with several reference examples.

[0116] Table 8

[0117] Preparation of stable blends of waste plastics and VGO with minimal PVC contamination

[0118] Pure VGO has chlorides below 1 ppm detection level (Example 5-1). The blend prepared with waste plastic #3 has 12 ppm chlorides after filtering with a 0.7 micron filter (Example 5-7). When 0.5 wt% PVC was added (Example 7-1), it was found that PVC did not dissolve in VGO and most of it remained as a solid. After filtration, the chloride content of the final blend was 26 ppm, only a very small increase compared to the reference of Example 5-7 with 12 ppm chloride. This clearly shows that filtration is a very effective way to reduce PVC contamination during blend preparation.

[0119] This example clearly shows that by proper selection of a petroleum feedstock such as VGO, undesirable PVC can be prevented from dissolving into the blend and the PVC can then be filtered out.

[0120] Example 8: Further reduction of chloride impurities by heat treatment

[0121] The blend of Example 7-1 was treated to further reduce the chloride content. The stable blend from Example 7-1 was treated in an autoclave in three different ways. The first treatment was a heat treatment at 650°F for 1 hour without a purge gas (Example 8-1). The second treatment was a heat treatment at 650°F for 1 hour with a N2 purge gas (Example 8-2). The third treatment was a heat treatment at 650°F for 1 hour with a H2 purge gas (Example 8-3). The purge gas rate was 10 sccm / g blend. The results are summarized in Table 9.

[0122] Table 9

[0123] Further reduction of chlorides by heat treatment

[0124] The results of Table 9 clearly show that PVC can be selectively decomposed by selecting a suitable temperature for blend preparation to drive PVC decomposition while keeping PE and PP intact. The chloride content was reduced from 26 ppm to 10 ppm (Example 8-1) by simply treating at a high temperature of 650 ° F. The chloride content was further reduced to 4.8 and 3.6 ppm (Examples 8-2 and 8-3) using purge gases such as N2 and H2. Any stripping gas such as nitrogen, hydrogen, steam or waste gas from a conversion unit may be added to facilitate the purge of HCl waste gas from the decomposition of PVC or organic chlorides in the blend. Hydrogen may be a preferred stripping gas because it promotes HCl formation and minimizes diene formation.

[0125] As used herein, the phrases "comprising / containing / including" are intended to be open ended transitions, meaning the inclusion of the recited elements but not necessarily the exclusion of other unrecited elements. The phrase "consisting essentially of" is intended to mean the exclusion of other elements of any essential importance to the composition. The phrase "consisting of" is intended to be transitional, meaning all elements other than the recited elements are excluded, except for only trace amounts of impurities.

[0126] To the extent not inconsistent with this document, all patents and publications mentioned herein are hereby incorporated by reference. It should be understood that some of the above-mentioned structures, functions and operations of the above-mentioned embodiments are not necessary for practicing the present invention, and are included in the specification only for the completeness of one or more exemplary embodiments. In addition, it should be understood that the specific structures, functions and operations set forth in the above-mentioned referenced patents and publications can be practiced in conjunction with the present invention, but they are not necessary for the practice of the present invention. Therefore, it should be understood that the present invention can be practiced in a manner other than the specific description without actually departing from the spirit and scope of the present invention defined by the appended claims.

Claims

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

2. The blend according to claim 1, prepared by the following method: (a) heating a mixture of a petroleum-based feedstock and said plastic together at a temperature of about 550° F. to about 700° F. (288-371° C.); (b) recovering the product of step (a), and filtering the product hot to remove contaminants; and (c) optionally treating the liquid product with a chloride removal guard bed catalyst.

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

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

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

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

7. The blend of claim 6, wherein the metal barrier layer comprises aluminum.

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

9. The blend according to claim 2, wherein the plastic comprises polypropylene having an average molecular weight Mw of 5,000 to 150,000.

10. The blend of claim 2, wherein the plastic comprises polypropylene having an average molecular weight Mw of 150,000 to 400,000.

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

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

13. The blend of claim 2, 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.

14. The blend of claim 2 wherein the treating in (c) is conducted at a temperature of 250-700°F (121 to 371°C) with a residence time at the final heating temperature of 5-240 minutes.

15. The blend of claim 2 wherein the average particle size of the finely divided particles is 10-50 microns.

16. The blend of claim 2 wherein the average particle size of the finely divided particles is from 10 to less than 100 microns.

17. The blend of claim 2, wherein the petroleum feedstock in the blend comprises: vacuum gas oil, atmospheric gas oil, reformate, light cycle oil, heavy fuel oil, refinery hydrocarbon streams containing toluene, xylene, heptane or benzene, coker naphtha, C5-C6 isomerized paraffinic naphtha, FCC naphtha, hydrocracker bottoms, gasoline, jet fuel, diesel or mixtures thereof.

18. The blend of claim 2 wherein the petroleum feedstock is selected to preferentially dissolve polyethylene and polypropylene.

19. The blend of claim 18, wherein the selected petroleum feedstock comprises VGO.

20. The blend of claim 2, wherein the petroleum feedstock in the blend comprises gas oil or heavy reformate.

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

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

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

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

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

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

27. A method for preparing a blend of plastic and petroleum, comprising: (a) heating a mixture of a petroleum-based feed and a plastic comprising polyethylene and / or polypropylene at about 550°F to about 700°F (288-371°C); (b) recovering the product of step (a), and hot filtering said product to remove contaminants and produce a filtered blend; and (d) The product recovered from (a) is then optionally treated with a chloride removal guard bed catalyst.

28. A process according to claim 27, 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. The method of claim 27 wherein the treatment is conducted at a temperature of 250-700°F (121 to 371°C) with a residence time at the final treatment temperature of 5-240 minutes.

Images