Use of blends of waste plastics and biological feeds for chemical preparation

Abstract

A continuous process for converting waste plastic into a recycle for chemical production is provided. The method includes selecting a waste plastic containing polyethylene and / or polypropylene and preparing a stable blend of the biological feedstock and the selected plastic. The amount of plastic in the blend comprises no more than 20% by weight of the blend. The blend is sent to a conversion unit. Useful chemicals, including C3 and C4 olefins and aromatics, are recovered.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 359,598, filed on July 8, 2022, the entire disclosure of which is incorporated herein by reference in its entirety. Background Art

[0003] As part of the efforts to reduce global warming, industry is experiencing the rapid growth of producing chemicals and fuels from renewable resources such as biomass raw materials. Along with the increase in demand for liquid transportation fuels, the reduction in reserves of 'easy oil' (crude oil that can be easily obtained and recovered) and the increasing carbon footprint restrictions on this type of fuel, the development of an effective way to produce liquid transportation fuels from alternative sources becomes increasingly important. Raw materials based on biomass such as raw materials containing triglycerides (for example, fats and / or oils from plants, animals and / or microbial sources) are important raw materials for non-fossil fuel-derived energy sources due to their large-scale availability. Biomass provides a renewable carbon source. Although research and development of methods for the manufacture of liquid fuels is being conducted, it is still necessary to provide an improved method to produce low carbon footprint hydrocarbons that can be used as liquid fuels or fuel blending components.

[0004] On the other hand, the world's plastic production is growing extremely rapidly. According to Plastic Europe Market Research Group, the world's plastic production was 335 million tons in 2016, 348 million tons in 2017, 359 million tons in 2018, and 367 million tons in 2020. According to McKinsey & Company, if the current trajectory continues, the global plastic waste volume is estimated to be 460 million tons per year by 2030.

[0005] Single-use plastic waste has become an increasingly important environmental issue. Currently, there appear to be few options for recycling polyethylene and polypropylene waste plastics into value-added chemicals and fuel products. Currently, only a small amount of polyethylene / polypropylene is recycled via chemical recycling, where the recycled and cleaned polymer pellets are pyrolyzed in a pyrolysis unit to make fuels (naphtha, diesel), steam cracker feed or slack wax. Most (over 80%) are incinerated, landfilled or discarded.

[0006] The current chemical recycling method via pyrolysis cannot have a big impact on the plastics industry. Current pyrolysis operations produce fuel components (naphtha and diesel range products) of poor quality, but in small enough quantities that these products can be blended into the fuel supply. However, if very large volumes of waste polyethylene and polypropylene are to be recycled to address environmental issues, this simple blending is unsustainable. The quality of the products produced by the pyrolysis unit is too poor to be blended into transportation fuels in large quantities.

[0007] 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 the recycled plastics decreases. Chemical recycling into starting materials or value-added chemicals has become a more desired approach.

[0008] However, in order to achieve chemical recycling of industrially large quantities of single-use plastics to reduce their environmental impact, more robust methods are needed. This improved method should establish a "circular economy" for waste polyethylene and polypropylene plastics, in which used waste plastics are effectively recycled back into starting materials for polymers or value-added chemicals or fuels. Establishing this circular economy while also employing renewable resources such as bio-based feedstocks will even further enhance the environmental benefits of this recycling method. Summary of the invention

[0009] A method for recycling plastic waste by converting plastic waste into valuable chemicals and fuels is provided. The method includes selecting waste plastics to blend with a biomass feedstock, which may include a mixture of biomass feedstocks. The blend may then be fed to a catalytic conversion unit and converted therein. The conversion process produces clean monomers, fuels, and chemical intermediates, including aromatic hydrocarbons.

[0010] In one embodiment, the blend comprises about 20 wt% or less of the selected waste plastic.In another embodiment, the blend is fed to a refinery conversion unit such as an FCC unit.

[0011] The term "bio" refers to biochemicals and / or natural chemicals found in nature. Thus, biomaterials or bio-oils will include 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.

[0012] Combining this method with an oil refinery is an important aspect of the inventive method, and allows the generation of a circular economy about plastic recycling. Therefore, the blend is sent to a refinery FCC unit. The blend is transported at a temperature higher than its pour point so that the blend can be pumped to a refinery FCC unit. The blend is heated to a melting point higher than plastics and then injected into a reactor. Reclaim the liquefied petroleum gas C3 olefin / paraffin mixture from the FCC unit. The C3 olefin / paraffin mixture can be sent to produce polyethylene and polypropylene. However, other chemical streams can be recovered from the FCC unit to produce important and valuable chemicals.

[0013] A refinery typically has its own hydrocarbon feed that flows through the refinery units. An important aspect of the process of the present invention is that it does not negatively impact the operation of the refinery. The refinery still has to produce valuable chemicals and fuels. Otherwise, integrating the process with a refinery would not be a viable solution. Therefore, the flow volumes must be carefully observed.

[0014] The flow volume of the waste plastic / biomass blend delivered to the refinery unit can account for any actual or adapted volume % of the total flow delivered to the refinery unit. Typically, the flow of the blend can be up to about 100% by volume of the total flow, i.e., the blend flow is all flow, without refinery flow. In one embodiment, the flow of the blend is up to about 50% by volume of the total flow (i.e., refinery flow and blend flow).

[0015] Among other factors, it has been found that a blend of waste plastics and biomass can be prepared, and if desired, the blend manufactured can be sufficiently stable for storage or transportation. In addition, the blend can then be converted into value-added chemicals and fuels in a conversion unit. Biomass is used together with waste plastics to greatly enhance the environmental aspects of the conversion process. By further having a conversion unit part operated by a refinery, plastic waste can be effectively and efficiently recycled, while also supplementing the refinery's operations in preparing higher value products such as gasoline, jet fuel, base oil and diesel. The overall process from recycled plastics to value-added chemicals and fuels has achieved positive economics, while also enhancing the environmental aspects of the recycling process by adopting the blend of biomass and waste plastics. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The current practice of pyrolyzing waste plastics to produce fuels or waxes is depicted (base case).

[0017] Figure 2 The process of the invention is depicted for preparing a hot, homogeneous liquid blend of plastic and biofeedstock, and feeding this blend to a conversion unit.

[0018] Figure 3The stable blend preparation unit process is depicted in detail, and how the stable blend can be fed to the conversion unit.

[0019] Figure 4 Depicts the classification of plastic types for waste plastic recycling.

[0020] Figure 5 The process of the present invention is depicted wherein a plastic / biofeedstock blend is sent to a refinery FCC unit to produce a number of value added chemicals and polymers.

[0021] Figure 6 The process of the present invention is depicted wherein a waste plastic / biofeedstock blend is sent to a refinery hydrocracking unit to produce a number of value-added chemicals.

[0022] Figure 7 Graph depicting thermogravimetric analysis (TGA) of the thermal stability of polyethylene and polypropylene. DETAILED DESCRIPTION

[0023] In the method of the present invention, a method for recycling waste plastics such as polyethylene and / or polypropylene back to value-added chemicals and fuels is provided. Most of polyethylene and polypropylene polymers are used in disposable plastics and are discarded after use. Disposable plastic waste has become an increasingly important environmental issue. At present, the selection of recycling polyethylene and polypropylene waste plastics into value-added chemicals and fuel products seems to be few. At present, only a small amount of polyethylene / polypropylene is recycled via chemical recycling, wherein the recycled and cleaned polymer pellets are pyrolyzed in a pyrolysis unit to make fuel (naphtha, diesel), steam cracker feed or slack wax.

[0024] Ethylene is the largest petrochemical base stock produced. Hundreds of millions of tons of ethylene are produced every year via steam cracking. Steam crackers use either gaseous feedstocks (ethane, propane and / or butane) or liquid feedstocks (naphtha or gas oil). This is a non-catalytic cracking process that operates at very high temperatures (up to 850°C).

[0025] Currently, only a small fraction of spent polyethylene products is collected for recycling due to the inefficiency and ineffectiveness of recycling efforts described above.

[0026] Polypropylene is widely used in a variety of consumer and industrial products. Polypropylene is the second most widely produced commercial plastic after polyethylene and is mechanically strong and highly resistant to chemicals. Polypropylene is widely used in packaging, films, fibers for carpets and clothing, molded articles, and extruded pipes. Currently, only a small portion of used polypropylene products are collected for recycling due to the inefficiency and ineffectiveness of recycling efforts mentioned above.

[0027] A method for recycling plastic waste back to clean monomers is now provided, wherein the waste plastics and biomass are simultaneously converted in a conversion unit. The clean monomers can be used for value-added chemicals, fuels, and aromatic chemical intermediates. The method includes preparing a novel blend of waste plastics and biomass. The blend is converted in a conversion unit such as a catalytic process unit.

[0028] High quality gasoline, jet fuel, diesel fuel and base oils can also be produced from waste plastic / biofeed blends. The fuel components are upgraded via chemical conversion processes in suitable refinery units. The final transportation fuels and base oils produced by the integrated process are of high quality and meet the quality requirements of fuels and base oils.

[0029] Figure 1 A simplified flow chart of a basic example of a waste plastic pyrolysis process commonly operated in the current industry is shown. Typically, waste plastics are sorted together 1. Clean plastic waste 2 is converted into waste gas 4 and pyrolysis oil (liquid product) in a pyrolysis unit 3. The waste gas 4 from the pyrolysis unit 3 is used as fuel to operate the pyrolysis unit. An on-site distillation unit separates the pyrolysis oil to produce naphtha and diesel 5 products, which are sold to the fuel market. The heavy pyrolysis oil fraction 6 is recycled back to the pyrolysis unit 3 to maximize the fuel yield. Char 7 is removed from the pyrolysis unit 3. The heavy fraction 6 is rich in long-chain linear hydrocarbons and is very waxy (i.e., paraffin is formed when cooled to ambient temperature). Wax can be separated from the heavy fraction 6 and sold to the wax market.

[0030] The use of the waste plastic / biofeed blend of the present invention provides many advantages over pyrolysis methods for recycling. The method of the present invention does not pyrolyze the waste plastic. Instead, the blend of biofeed and waste plastic is directly converted in the conversion unit.

[0031] The blend can be prepared in a hot blend preparation unit, where the operating temperature is above the melting point of the plastic (about 120-300° C.) to produce a hot, homogeneous liquid blend of plastic and bio-oil. This hot, homogeneous liquid blend of plastic and bio-feedstock can be fed directly to the conversion unit.

[0032] The preferred range of plastic in the composition blend is about 1-20 weight percent. In one embodiment, the conditions for preparing the hot liquid blend include heating the blend to a melting point above the plastic while vigorously mixing with the biomass. The process conditions may include heating to 250-550°F, a residence time of 5-240 minutes at the final heating temperature, and an atmospheric pressure of 0-10 psig. This can be done in an open atmosphere and preferably in an oxygen-free atmosphere.

[0033] Alternatively, the blend is prepared in a stable blend preparation unit, where 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 remote facility away from a refinery and can be transported to a refinery unit. The stable blend is then heated to a temperature above the melting point of the plastic to feed the refinery conversion unit. The stable blend is a physical mixture of micron-sized plastic particles finely suspended in a petroleum-based oil. The mixture is stable and the plastic particles do not settle or agglomerate when stored for a long time.

[0034] The stable blend of the present invention is manufactured by a two-step process. The first step produces a hot, uniform liquid blend of a plastic melt and a biomass feedstock. The preferred range of plastic composition in the blend is about 1-20% by weight. In one embodiment, the conditions for preparing the hot liquid blend include heating the plastic to a melting point higher than the plastic while vigorously mixing with the biomass feedstock. Preferred process conditions include heating to 250-550°F, a residence time of 5-240 minutes at the final heating temperature, and an atmospheric pressure of 0-10 psig. This can be accomplished in an open atmosphere and preferably in an oxygen-free, inert atmosphere.

[0035] In the second step, the hot blend is cooled to below the melting point of the plastic while continuing to be intensively mixed with the bio-feedstock, and then further cooled to a lower temperature, preferably ambient temperature, to produce a stable blend.

[0036] The resulting composition comprises a stable blend of waste plastic and bio-feedstock for direct conversion of waste plastic in a conversion unit such as a refinery process unit. The resulting composition is novel and provides numerous benefits.

[0037] The stable blend is produced from biomass and 1-20% by weight of plastic waste, wherein the plastic is primarily polyethylene, polypropylene and / or polystyrene, and the plastic is in the form of finely dispersed micron-sized particles.

[0038] The stabilized blend is fed into a catalytic conversion process to simultaneously convert the bio-feedstock and waste plastic into chemical feedstocks.

[0039] When a single plastic is used, the meaning of heating the blend to a temperature above the melting point of that 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 a plastic, the temperature must be cooled to below the melting points of all plastics contained in the blend.

[0040] Several advantages are realized in implementing these concepts.

[0041] The process of the present invention does not pyrolyze waste plastics. Instead, a blend of biomass and waste plastics is prepared. Thus, the pyrolysis step can be avoided, which is a significant energy saving.

[0042] The stable blend of plastic and bio-based materials can be stored for long periods of time at ambient temperature and pressure. During storage, no agglomeration of the polymers and chemical / physical degradation of the blends were observed. This allows for easier manipulation of waste plastic materials for storage or transportation.

[0043] 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.

[0044] To feed the conversion unit, the stable blend is further heated to above the melting point of the plastic to produce a homogenous liquid blend of bio-feedstock and plastic. This hot homogenous liquid blend is directly fed to the refinery process unit to convert waste plastic and bio-feedstock into high-value, sustainable products with good yields.

[0045] Likewise, these blend preparation units operate at much lower temperatures (-500-600°C vs. 120-300°C) compared to pyrolysis units. Thus, the process of the present invention is a much more energy efficient process for preparing refinery feedstocks from waste plastics compared to thermal cracking processes such as pyrolysis.

[0046] The use of the waste plastic / biomass blend of the present invention also increases the total hydrocarbon yield obtained from the waste plastic. 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%. In contrast, a large amount of (about 10-30% by weight) light products and about 5-10% by weight of char are produced by pyrolysis of plastic waste. As mentioned above, these light hydrocarbons are used as fuel to operate the pyrolysis device. Therefore, the liquid hydrocarbon yield from the pyrolysis device is at most 70-80%.

[0047] 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 process, the generation of undesirable light fraction by-products such as methane and ethane is minimized. The refinery unit has an effective product fractionation, and the entire hydrocarbon product stream 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.

[0048] The process of the present invention can convert large amounts of disposable waste plastics by integrating the waste plastics blended with a bio-feedstock stream into refinery operations. The resulting process can produce feedstocks for polymers (naphtha or C3 and C4 for ethylene crackers), but also high-quality gasoline, jet fuel and diesel, and / or high-quality base oils, as well as value-added chemicals, including aromatic intermediates.

[0049] By adding refinery operations to upgrade waste plastics into higher value products, positive economics are achieved for the overall process of recycling plastics. Also, by combining the recycling process of the present invention with refinery operations, a more energy efficient and efficient process is achieved while avoiding any issues with refinery operations.

[0050] On the other hand, the integration of refinery operations becomes quite important. Waste plastics contain pollutants such as calcium, magnesium, chlorides, nitrogen, sulfur, dienes and heavy components, and these products cannot be blended in transportation fuels in large quantities. It has been found that by sending these products through refinery units, pollutants can be captured in pre-treatment units and their negative impacts can be reduced. Chemical conversion methods can be used to further upgrade the fuel components using suitable refinery units, wherein the final transportation fuel produced in the integrated method has a higher quality and meets the fuel quality requirements.

[0051] Figure 2 Shown is a method for preparing a heat homogeneous blend of plastics and biomass raw materials according to the inventive method. The hot blend can be used for direct injection into a conversion unit. The preferred range of plastic composition in the blend is about 1-20 weight %. If high molecular weight polypropylene (average molecular weight is 250,000 or greater) waste plastics or high density polyethylene (density greater than 0.93 g / cc) are used as the main (e.g., at least 50 weight %) waste plastics, the amount of the waste plastics used in the blend is more preferably about 10 weight %. The reason is that the pour point and viscosity of the blend will be high.

[0052] Preferred conditions for blend preparation include heating the plastic to above the melting point of the plastic while vigorously mixing with the biomass. Preferred process conditions include heating to a temperature of 250-550°F with a residence time at the final heating temperature of 5-240 minutes, and an atmospheric pressure of 0-10 psig. This can be done in an open atmosphere and preferably in an oxygen-free inert atmosphere.

[0053] With reference to the attached drawings Figure 2 , a step-by-step preparation method for preparing a blend of plastic and bio-based raw materials is shown. 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 bio-based raw oil 24 in a hot blend preparation unit 23. After mixing in 23, a uniform blend of plastic and bio-oil 25 is recovered. Optionally, a filtering device (not shown) can be added to remove any undissolved plastic particles or any solid impurities present in the liquid blend. The blend of plastic and bio-oil can then be sent to a catalytic conversion unit 27. In the method of the present invention, in one embodiment, the conversion unit is a refinery unit such as an FCC unit. Optionally, the conversion unit can co-process vacuum gas oil 20 or another conventional feedstock for a refinery.

[0054] Figure 3 A method for preparing a stable blend of plastic and oil for use in the process of the present invention is shown. The stable blend is produced in a stable blend preparation unit by a two-step process. The first step produces a hot, homogeneous liquid blend of the plastic melt and the biomass raw material. Figure 2 The hot blends described are prepared the same. 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) waste plastic or high density polyethylene (density greater than 0.93 g / cc) is used as the main (e.g., at least 50 wt %) waste plastic, the amount of waste plastic used in the blend is more preferably about 10 wt %. The reason is that the pour point and viscosity of the blend will be high.

[0055] Preferred conditions for the preparation of a hot, homogeneous liquid blend include heating the plastic to above the melting point of the plastic while vigorously mixing with the biomass. Preferred process conditions include heating to a temperature of 250-550°F with a residence time at the final heating temperature of 5-240 minutes, and an atmospheric pressure of 0-10 psig. This can be accomplished in an open atmosphere and preferably in an oxygen-free, inert atmosphere.

[0056] In the second step, the hot blend is cooled to below the melting point of the plastic while continuing to mix vigorously. An optional diluent may be added during mixing. Further cooling is to a lower temperature, preferably ambient temperature, to produce a stable blend of plastic and oil.

[0057] It has been found that a stable blend is an intimate physical mixture of plastic and bio-material. The plastic is in a "deagglomerated" state. The plastic maintains a fine dispersion of solid particles in the bio-material 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 above the melting point of the plastic to produce a hot, uniform liquid blend of the plastic and the bio-material. The hot liquid blend can then be fed to a refinery unit either alone or as a co-feed with conventional refinery feeds.

[0058] exist Figure 3 , other details of the preparation of a stable blend are shown. The stable blend is manufactured in a two-step process in a stable blend preparation unit 100. As shown, clean waste 22 is sent to a hot blend preparation unit 23. The selected plastic waste 22 is mixed with a bio-raw oil 24 and heated to a temperature above the melting point of the plastic in unit 23. The mixing is usually quite intense. An optional diluent 26 may be added during mixing. The mixing and heating conditions may typically include heating at a temperature of about 250-550°F, with a residence time of 5-240 minutes at the final heating temperature. Heating and mixing may be accomplished in an open atmosphere or in an oxygen-free inert atmosphere. The result is a hot, uniform liquid blend 101 of plastic and oil. Optionally, a filtering device (not shown) may be added to remove any undissolved plastic particles or any solid impurities present in the hot, uniform liquid blend.

[0059] The hot blend 101 is then cooled to below the melting point of the plastic while mixing of the plastic and bio-oil blend continues at unit 102. An optional diluent 103 may be added during mixing and cooling. Cooling typically continues, typically to ambient temperature, to produce a stable blend of plastic and oil 29. At the refinery, the stable blend may be fed to a preheater 130 which heats the blend to above the melting point of the plastic to produce a homogenous mixture of the plastic / oil blend 105 which is then fed to a refinery conversion unit 27.

[0060] The preferred plastic starting material for the process 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 4 Depicted are classifications of plastic types 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 can be used. For the method of the present invention, at least some polyethylene waste plastics are preferred. Polystyrene (classification 6) can also be present in limited amounts.

[0061] Proper sorting of waste plastics is very important in order to minimize contaminants such as N, Cl and S. Plastic waste containing polyethylene terephthalate (plastic recycling classification type 1), polyvinyl chloride (plastic recycling classification type 3) and other polymers (plastic recycling classification type 7) needs to be sorted to less than 5%, preferably less than 1% and most preferably less than 0.1%. 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%.

[0062] 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 and oxygen 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 be less than 50ppm, preferably less than 30ppm and most preferably less than 5ppm.

[0063] The term "bio" refers to biochemicals and / or natural chemicals found in nature. Therefore, biomass raw materials or bio-oils will include these natural chemicals. Preferred starting biomass raw materials 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, chicken fat (e.g., chicken fat) and fish oil, and mixtures of these. In one embodiment, the biomass raw material may include biomass pyrolysis oil prepared by pyrolyzing biomass raw material material.

[0064] The most preferred bio-based materials are palm oil and beef tallow, which have high saturation (i.e., low unsaturation) showing iodine values ​​of 91 or less. The iodine value is a measure of the amount of unsaturation in fats, oils, and waxes. It is determined by measuring the mass (grams) of iodine consumed by 100 g of a substance. A higher value means that the substance is more unsaturated. This is similar to using the bromine value to measure unsaturation in a petroleum sample.

[0065] It has been found that biomass raw materials with polyunsaturated fatty acids of high iodine values, such as soybean oil (iodine value of 130), cannot make stable blends with plastics. However, a mixture of biomass raw materials consisting of low (≤70) and high (>70) iodine value biomass raw materials can make stable blends with plastics. It has been found that a mixture of biomass raw materials with about 95 or lower iodine values ​​makes stable blends with plastics. In one embodiment, the mixture of biomass raw materials exhibits an iodine value of 91 or lower.

[0066] In addition, plastic and biomass blends can be blended with other diluent hydrocarbons such as heptane as needed to change the properties of the blend, such as viscosity or pour point, so as to more easily operate or process.Preferred blended hydrocarbon feedstocks include conventional petroleum-based feedstocks such as vacuum gas oil (VGO), aromatic solvents or light cycle oil (LCO).In one embodiment, the blended hydrocarbon feedstock comprises atmospheric gas oil, VGO or heavy feedstocks recovered from other refinery operations.In another embodiment, the blended hydrocarbon feedstock comprises LCO, heavy cycle oil (HCO), FCC naphtha, gasoline, diesel, toluene or aromatic solvents from petroleum.Also a portion of liquid FCC products (such as naphtha and LCO) can be recycled into the blend to reduce viscosity.In one embodiment, petroleum feedstock is not used, and only biomass feedstock is used to produce the blend and mix with the blend.

[0067] Although not wishing to be bound by theory, the stable blend prepared is a close physical mixture of plastic and bio-feedstock for catalytic conversion unit. The method of the present invention produces a stable blend of bio-feedstock and plastic, wherein the plastic is in a "deagglomerated" state. The blend is stable and allows easy storage and transportation. In the refinery, the stable blend is preheated to a uniform liquid blend of heat above the melting point of the plastic to produce plastic and bio-feedstock, and then the hot liquid blend is fed to the conversion unit. Then, both the bio-feedstock and the plastic are simultaneously converted in the conversion unit with a typical refinery catalyst containing zeolite and other active components such as silica-alumina, alumina and clay.

[0068] Catalytic conversion units such as fluid catalytic cracking (FCC) units, hydrocracking units, and hydroprocessing units convert a hot, homogeneous liquid blend of plastic and biomass in the presence of a catalyst to simultaneously convert plastic and biomass. The presence of a catalyst in the conversion unit allows waste plastics to be converted into higher value products at operating temperatures below typical pyrolysis temperatures. For hydroprocessing units (hydrocracking and hydroprocessing units), hydrogen is added to the unit to improve the conversion of plastics.

[0069] Fluid catalytic cracking is the preferred mode for catalytic conversion of stable blends. The yield of undesirable byproducts (waste gas, tar, coke) is lower than that of typical pyrolysis methods. The blend can produce additional synergistic benefits from the interaction of plastics and bio-feedstock during the conversion process.

[0070] Good catalyst selectivity is crucial for maximizing the conversion of the desired product. It has been found that FCC catalysts based on ZSM-5 are particularly effective in producing LPG olefins and aromatics from plastics and biomass blends. It has also been found that a xylene product rich in p-xylene can be selectively produced in high yield. Utilizing ZSM-5 catalysts, the xylene produced by this method is mainly p-xylene, and wherein the p-xylene selectivity is about 60-70%. P-xylene is the most desired xylene isomer in the manufacture of polyethylene terephthalate polymers. ZSM-5 is a 10-ring medium pore size zeolite. Catalysts containing other medium pore size zeolites such as ZSM-11, ZSM-23, ZSM-25, ZSM-48, SSZ-32, SSZ-91 are also applicable to the conversion of plastics and biomass blends, for LPG olefins and aromatics production.

[0071] The most commonly used FCC catalysts are based on large pore faujasite USY or REY zeolites. Catalysts containing Y zeolite have excellent cracking activity for heavy molecules in traditional petroleum feedstocks such as VGO. FCC catalysts containing USY have been found to produce more LCO from blends of plastics and bio-feedstocks. USY is a large pore size zeolite with 12-membered rings. Catalysts containing other large pore size zeolites such as ZSM-12, β, SSZ-24, SSZ-26, SSZ-33, SSZ-60, SSZ-65, SSZ-70, SSZ-81, SSZ-82 and SSZ-111 can be used for the conversion of plastics and bio-feedstock blends to simultaneously produce sustainable fuel and chemical intermediate products.

[0072] Stable blends of plastics and bio-feedstocks will allow for more efficient recycling of waste plastics and enable truly circular and sustainable production of plastics and chemicals. It is much more energy efficient than current pyrolysis methods and allows for recycling with a lower carbon footprint. This improved process will allow 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.

[0073] A dedicated conversion unit for converting blends of plastics and bio-feedstocks will produce sustainable, low-carbon chemical intermediates and fuels without the use of any petroleum feedstocks.

[0074] Alternatively, the plastic and biofeedstock blend can be fed to a refinery conversion unit for co-processing with petroleum-based oils. Refinery conversion units such as fluid catalytic cracking (FCC) units, hydrocracking units, and hydrotreating units are preferred for simultaneously converting plastic / biofeedstock and petroleum-based oils.

[0075] In such a case, the refinery usually has its own hydrocarbon feed flowing through the refinery unit. For example, the hydrocarbon feed may be VGO. The flow volume of the blend sent to a refinery unit such as an FCC unit may account for any actual or adapted volume % of the total flow sent to the refinery unit. Typically, for practical reasons, the flow of the blend may be up to about 50% by volume of the total flow (i.e., refinery flow and blend flow). In one embodiment, the flow of the blend is up to about 100% by volume of the total flow. The volume % of the blend will also depend on the desired final product. If aromatics and xylene are focus chemicals, the blend flow % may be much higher (if not 100%). In another embodiment, the volume flow of the blend is up to about 25% by volume of the total flow. It has been found that about 50% by volume is a very practical amount in terms of the impact on the refinery, while also providing excellent results, and is an adaptable amount. It is important to avoid any negative impact on the refinery and its products. If the amount of plastic in the final blend (comprising the plastic / oil blend and the co-feed petroleum) exceeds 20 wt% of the final blend, it may result in FCC unit operating difficulties. The final blend means the plastic / oil blend of the present invention and any co-feed petroleum. The plastic / oil blend may account for up to 100 volume % of the feed to the refinery unit.

[0076] Figure 5 One embodiment of the integrated process of the present invention is shown wherein the blend is sent to a fluid catalytic cracking (FCC) unit. Figure 5 Corresponding to Figure 2 and Figure 3 The same numbers in the figure refer to the same items / units. As shown, a blend 25 is prepared and then sent to the FCC conversion unit 27 via 26. The blend may or may not be mixed with co-feed vacuum gas oil (VGO). The blend is usually heated to a temperature above the melting point of the plastic before being sent to the FCC conversion unit 27.

[0077] exist Figure 5 In the FCC unit 27, cracking of the hot blend of plastic / bio-oil alone or in combination with a co-feed petroleum feed produces liquefied petroleum gas (LPG) of C3 and C4 olefin / paraffin streams 31 and 32, as well as naphtha 33 and heavy fraction 30. The C3 olefin / paraffin mixed stream of propane and propylene can be sent to a propane / propylene splitter (PP splitter) and separated to produce pure propane and propylene streams.

[0078] The C4 32 and other hydrocarbon product streams such as heavy ends 30 from the FCC unit 28 are sent to a suitable refinery unit 34 for upgrading to clean gasoline, diesel or jet fuel. The naphtha / gasoline 33 from the FCC unit can be sent directly to the gasoline pool 35, or further upgraded before being sent to the gasoline pool (not shown).

[0079] A portion of the naphtha 33 may be sent to produce chemicals. For example, the naphtha may be sent to an aromatic separation unit 60. Benzene, toluene, xylene, and ethylbenzene may be recovered from 60 and sent for intermediate processing 62 and / or other chemical manufacturing 63. From the intermediate processing 62 of chemicals, the resulting chemicals may be sent to a polymerization process unit 64. Based on the recovered processed chemicals and sent for polymerization, polymers such as polyethylene terephthalate and polystyrene may be manufactured. For example, para-xylene will readily be used to make polyethylene terephthalate (PET).

[0080] LPG and naphtha can be recovered and fed to a steam cracker to make ethylene and then ethylene-derived chemicals such as polyethylene, ethylene oxide, polyalphaolefins. C3 olefins in LPG can be recovered to make propylene and / or propylene oxide. C4 olefins in LPG can be recovered to make low density copolymers (process scheme not shown in the figure).

[0081] In one embodiment, the conversion unit 27 is not in a refinery and only the biofeedstock / plastic blend is sent to the unit. The emphasis would then be on recovering the naphtha to produce aromatics.

[0082] Figure 6 One embodiment of the integrated process of the present invention is shown wherein the blend is sent to a hydrocracking unit 77. Figure 6 Corresponding to Figure 2 , Figure 3 and Figure 5 Like numbers in the drawings refer to like items / units. As shown, the selected waste material 21 is cleaned 22 and then sent to a blend preparation unit 23 where the plastic and refinery feedstock 24 are blended to produce a hot blend of plastic and oil 25. When needed, refinery feedstock such as vacuum gas oil (VGO) 20 is added to the blend. If the plastic / oil blend is still hot ( Figure 2 25), it can be immediately mixed with the co-feed oil 20. However, if the plastic / oil stable blend needs to be heated for storage or transportation ( Figure 3 In the embodiment of the present invention, the blend is heated to a temperature above the melting point of the plastic, for example, using a preheater, and then mixed with the co-feed VGO oil. The uniform plastic / bio-oil blend (with or without a refinery hydrocarbon stream such as VGO oil) 26 is then sent to a hydrocracking unit 77 in a refinery. In another embodiment, the heated blend and the refinery feedstock co-feed are each sent directly but separately to the hydrocracking unit.

[0083] Any suitable hydrocracking operation can be performed. The catalyst in the hydrocracking unit can be selected from any known hydrocracking catalyst. Hydrocracking conditions generally include a temperature of 300° C. to 485° C., a molar ratio of hydrogen to hydrocarbon charge of 1 to 100, a pressure of 30 to 350 bar, and a liquid hourly space velocity (LHSV) of 0.1 to 10. Larger molecules are cracked into smaller molecules in the hydrocracking reactor. Hydrocracking catalysts generally contain large pore zeolites such as USY, and various combinations of group VI and group VIII base metals such as nickel, cobalt, molybdenum, and tungsten, which are finely dispersed on alumina or oxide carriers.

[0084] An LPG C3-C4 stream 30, a clean naphtha stream 31, and a heavy fraction 28 are recovered from the hydrocracking unit. The heavy fraction 28 may be sent to an isomerization / dewaxing unit 29. Within the isomerization / dewaxing reactor, the feed may first be contacted with a hydrotreating catalyst under hydrotreating conditions in a hydrotreating zone or guard layer to provide a hydrotreated feedstock. The hydrogenation catalyst typically contains various combinations of Group VI and Group VIII base metals such as nickel, cobalt, molybdenum, and tungsten, which are finely dispersed on an alumina or oxide support. Contact of the feed with the hydrotreating catalyst in the guard layer may be used to effectively hydrogenate the aromatics in the feedstock and remove N and S containing compounds from the feed, thereby protecting the hydroisomerization catalyst of the catalyst system. "Effectively hydrogenate aromatics" means that the hydrotreating catalyst is capable of reducing the aromatic content of the feedstock by at least about 20%. The hydrotreated feedstock may typically contain C 10+ Normal paraffins and lightly branched isoparaffins, wherein the wax content is generally at least about 20%.

[0085] The hydroisomerization catalyst that can be used for the method of the present invention generally contains a catalytically active hydrogenation metal. The presence of a catalytically active hydrogenation metal leads to product improvements, particularly improvements in VI and stability. Typical catalytically active hydrogenation metals include chromium, molybdenum, nickel, vanadium, cobalt, tungsten, zinc, platinum and palladium. Metallic platinum and palladium are particularly preferred, and platinum is most particularly preferred. If platinum and / or palladium are used, the total amount of active hydrogenation metal is generally 0.1% to 5% by weight of the total catalyst, generally 0.1% to 2% by weight. In addition, the hydroisomerization catalyst generally contains a medium pore size zeolite such as ZSM-23, ZSM-48, ZSM-35, SSZ-32, SSZ-91 dispersed on an oxide support.

[0086] The refractory oxide support may be selected from those oxide supports commonly used for catalysts, including silica, alumina, silica-alumina, magnesia, titania, and combinations thereof.

[0087] The conditions in the isomerization / dewaxing reactor unit 29 typically include temperatures in the range of about 390°F to about 800°F (199°C to 427°C). In embodiments, the hydroisomerization dewaxing conditions include temperatures of about 550°F to about 700°F (288°C to 371°C). In other embodiments, the temperature may be about 590°F to about 675°F (310°C to 357°C). The total pressure may be about 500 to about 3000 psig (0.10 to 20.68 MPa), and is typically about 750 to about 2500 psig (0.69 to 17.24 MPa).

[0088] Dewaxed oil 33 can be recovered from the isomerization / dewaxing unit 29, which can be used as a base oil. The oil can also be sent to a hydrofinishing unit 34 to prepare a high-quality base oil 35. In the hydrofinishing unit 34, hydrofinishing can be carried out in the presence of a hydrogenation catalyst known in the art. The hydrogenation catalyst used for hydrofinishing can include, for example, platinum, palladium, or a combination thereof on an alumina support. Hydrofinishing can be carried out at a temperature of about 350°F to about 650°F (176°C to 343°C) and a pressure of about 400psig to about 4000psig (2.76 to 27.581MPa). Hydrofinishing for lubricating oil production is described, for example, in U.S. Pat. No. 3,852,207, the disclosure of which is incorporated herein by reference.

[0089] like Figure 5 As shown, the cleaned naphtha stream 31 and / or the cleaned LPG stream 30 from the hydrocracker, the cleaned LPG stream 32 and / or the cleaned naphtha stream 36 from the isomerization unit 29 can be sent to produce chemicals. For example, naphtha can be sent to an aromatic separation unit 60. Benzene, toluene, xylene and ethylbenzene can be recovered from 60 and sent to intermediate processing 62 and / or other chemical manufacturing 63. From the intermediate processing 62 of chemicals, the resulting chemicals can be sent to a polymerization process unit 64. Based on the recovered processed chemicals and sent to polymerization, polymers such as polyethylene terephthalate and polystyrene can be manufactured. For example, paraxylene will be easily used to prepare polyethylene terephthalate (PET).

[0090] LPG and naphtha can be recovered and fed into a steam cracker to make ethylene, and then to make ethylene-derived chemicals such as polyethylene, ethylene oxide, polyalphaolefins. C3 olefins in LPG can be recovered to make propylene and / or propylene oxide. C4 olefins in LPG can be recovered to make low-density copolymers (process scheme not shown in the figure). The benefits of a circular economy and effective and efficient recycling activities are achieved through the integrated process of the present invention.

[0091] The following examples are provided as illustrations of the blends and methods of the present invention and are not meant to be limiting.

[0092] Example 1: Properties of plastic samples and biomaterials used for blend preparation Five plastic samples were purchased: low-density polyethylene (LDPE, plastic A), high-density polyethylene (HDPE, plastic B), two polypropylene samples with average molecular weights of ~12,000 (PP, plastic C) and ~250,000 (PP, plastic D), and polystyrene (PS, plastic E), and their properties are summarized in Table 1.

[0093] Table 1 Properties of plastics used

[0094]

[0095] The bio-feedstocks used to prepare blends with the plastic melt included palm oil, beef tallow and soybean oil, and their properties are shown in Table 2.

[0096] Table 2 Properties of biomaterials used for blend preparation

[0097]

[0098]

[0099] Thermogravimetric analysis (TGA) was performed on Plastic A (LDPE) and Plastic C (Polypropylene) to verify that the plastic materials were thermally stable at temperatures well above the melt preparation temperature. Figure 7 The TGA results shown indicate that the LPDE sample is stable up to 800°F, and the polypropylene sample is stable up to 700°F.

[0100] Example 2 - Preparation of stable blends of palm oil and plastic

[0101] Several blends of palm oil and plastic were prepared by adding plastic pellets (Plastics A to D) to palm oil (BioFeed #1).

[0102] The following procedure was used.At ambient temperature, palm oil (waxy solid) was added to a beaker.Palm oil was heated with a heating jacket while stirring with a magnetic stirrer.Palm oil temperature was gradually raised to 270-400°F, and then pre-weighed plastic pellets (solid) were slowly added to the hot palm oil while stirring and heating.Then, after the plastic pellets dissolved, for the blend of LDPE and plastic C polypropylene, the stirred solution was kept for another 30 minutes at the final temperature, or for the blend of HDPE and plastic D polypropylene for 60 minutes.Then the blend was cooled to ambient temperature while stirring.Visual observation showed that the blend was completely uniform.After cooling to ambient temperature, the blend of plastic and palm oil showed the visual appearance of the waxy solid of palm oil, but the hardening temperature (or solidification temperature) was different from the starting palm oil.

[0103] To assess 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 material was measured according to the ASTM D3279 procedure. The hot heptane insoluble method determines the weight percentage of material in 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 insoluble content provides information about the insoluble plastic in the blend.

[0104] Material stability was observed by visual observation. The blends of plastic and palm oil were stable and no changes were observed over the 3 month observation period.

[0105] Table 3 below summarizes the list of samples prepared and their properties.

[0106] Table 3 Preparation of stable blends of plastics and palm oil

[0107]

[0108] Pour point and viscosity values ​​are used to guide equipment selection and operating procedures. Compared with the pure bio-based example, the blends made by adding plastics show a moderate increase in pour point and viscosity. These changes can be handled with typical refinery operating equipment, with little or no modification. The blend tank is heated to above the pour point to change the physical state of the blend to a liquid that is easy to transfer. The liquid blend can then be transferred to a transport container or refinery unit via pumping or via gravity discharge or via transfer using a pressure difference.

[0109] Stable blends remain as physical mixtures at temperatures up to 80°C. Plastics are separated from blends using a hot heptane insolubility test. At 80°C, all waxes in palm oil are dissolved in heptane solvent (Example 2-1), and heptane insoluble solids are only 0.02 wt%. The weight percentage of heptane insoluble materials comes from undissolved plastics filtered out with a 0.8 micron membrane filter. The amount recovered as solid material in Examples 2-2 and 2-4 shows 7.6 wt% and 7.8 wt% heptane insoluble solids, which is similar to the amount of plastic added for blend preparation. The recovered amount is 2.2-2.4 wt% less, indicating that very fine particles of submicron size may exist in the blend. The heptane insolubility results in Table 3 clearly show that at 80°C, plastics are a physical mixture of solid particles in palm oil dispersed in the blend, and most of the plastic particles can be separated back with a 0.8 micron filter.

[0110] Example 3 - Preparation of Stable Blends of Tallow and Plastic

[0111] Several blends of tallow and plastic samples were prepared by adding plastic particles to the tallow feed (BioFeed #2).

[0112] The procedure described in Example 2 was used to prepare these blends.

[0113] Table 4 Preparation of stable blends of plastic and tallow

[0114]

[0115] The blends made by adding plastic to tallow showed a modest increase in pour point and viscosity compared to the pure bio-based example, similar to the palm oil results shown in Example 2.

[0116] The weight percentage of heptane insoluble material recovered as solid material matches well with the amount of plastic added to the blend formulation. The base tallow (Example 3-1) had only 0.04 wt% heptane insolubles, while the stabilized blends (Examples 3-2 and 3-4) showed heptane insoluble solids contents of 7.7 wt% and 8.6 wt%, which are similar to the amount of plastic added for blend preparation. The amount recovered was 1.4-2.3 wt% less, indicating that very fine particles of submicron size may be present in the blend. The heptane insolubility results in Table 4 clearly show that at 80°C, the plastic is a physical mixture of solid particles dispersed in the palm oil in the blend, and most of the plastic particles can be separated back with a 0.8 micron filter.

[0117] Example 4 - Preparation of blends of soybean oil and plastic (Comparative Example)

[0118] An attempt was made to prepare blends of soybean oil (biofeed #3) and plastic with plastic pellets (plastics A to D) using the procedure described in Example 2. Surprisingly, soybean oil and plastic do not form a hot, homogeneous liquid melt when heated together in the same manner as palm oil or tallow. When the mixture is heated to above the melting point of the plastic, the pellets soften and lose their shape. But instead of forming a homogeneous liquid as in other cases, the plastic melt forms a liquid phase that separates from the soybean oil (SBO). After cooling, the plastic phase aggregates and forms large solid blocks of plastic. A possible explanation for this is that SBO has a much higher degree of unsaturation, as evidenced by its lower H / C ratio than tallow or palm oil, and also from the measured iodine value. This also explains why most petroleum feeds, as well as highly saturated oils and fats determined by iodine value, easily dissolve plastics.

[0119] Table 5 Preparation of stable blends of plastics and soybean oil

[0120]

[0121] Example 5 - Preparation of blends of soybean oil, palm oil and plastic

[0122] A mixture of 1:1 weight ratio of soybean oil and palm oil (mixed bio-raw material) was prepared. Utilizing this mixed bio-raw material, a successful blend of palm oil, soybean oil and plastic was prepared by adding plastic pellets (Plastics A and C) to a 1:1 mixture of palm oil and soybean oil (Bio-feed #1 and Bio-feed #3). Therefore, soybean oil can be used as a component in mixed bio-raw materials. Stable blends showed good shelf life and did not show any changes within a few months. These results show that soybean oil can also be used as a bio-raw material to prepare stable blends with plastics by reducing its unsaturation with other bio-raw materials.

[0123] The test also shows acceptable iodine values ​​for making successful stable blends of plastics and bio-feedstocks. The iodine value of a 1:1 mixture of soybean oil and palm oil was estimated to be 91. These results indicate that soybean oil or other highly unsaturated oils can also be used as bio-feedstocks to make stable blends with plastics, as long as the total unsaturation of the mixed bio-feedstock has an iodine value of 95 or less, and preferably 91 or less.

[0124] Table 6 Preparation of stable blends of plastic, soybean oil and palm oil

[0125]

[0126] Example 6 - Preparation of a blend of soybean oil, tallow and plastic

[0127] A 1:1 mixture of soybean oil and beef tallow was prepared. Using this mixed biofeedstock, blends of beef tallow, soybean oil, and plastic were successfully prepared by adding plastic pellets (Plastics A and C) to a 1:1 mixture of beef tallow and soybean oil (BioFeed #1 and BioFeed #3). The stable blends showed good shelf life and no changes were observed over several months. These results again show that soybean oil can also be used as a biofeedstock to prepare stable blends with plastics by reducing its unsaturation with additional biofeedstock.

[0128] The test also showed acceptable iodine values ​​for making successful stable blends of plastics and biofeedstocks. The iodine value of a 1:1 mixture of soybean oil and beef tallow was estimated to be 88.

[0129] Table 7 Preparation of stable blends of plastic, soybean oil and beef tallow

[0130]

[0131] To study the impact of processing waste plastics and bio-feedstocks in an FCC unit, laboratory tests of a fluid catalytic cracking (FCC) process were conducted on a stable blend of plastics and bio-feedstocks. Two FCC catalysts were used for the study: a ZSM-5 FCC catalyst made from ZSM-5 zeolite (a 10-membered ring mesoporous zeolite) and a USY FCC catalyst made from USY (a 12-membered ring mesoporous zeolite). Three bio-feedstocks were used: palm oil, soybean oil, and beef tallow.

[0132] Catalytic cracking experiments were carried out in an ACE (Advanced Cracking Evaluation) Model C unit manufactured by Kayser Technology Inc. (Texas, USA). The reactor used in the ACE unit was a fixed fluidized reactor with an inner diameter of 1.6 cm. Nitrogen was used as the fluidizing gas and introduced from both the bottom and the top. The top fluidizing gas was used to carry the feed injected from a calibrated syringe feed pump via a three-way valve. The experiment was carried out at atmospheric pressure and a temperature of 975 ° F. For each experiment, a constant amount of 1.5 grams of feed was injected at a rate of 1.2 grams per minute for 75 seconds. The catalyst / oil ratio was maintained at 6. After the feed was injected for 75 seconds, the catalyst was stripped with nitrogen for a period of 525 seconds. During the catalytic cracking and stripping process, the liquid product was collected in a sample vial connected to a glass receiver, which was located at the end of the reactor outlet and was maintained at -15 ° C. The gaseous product was collected in a closed stainless steel container (12.6 L) pre-filled with 1 atm of N2. Once the feed injection is complete, the gaseous products are mixed by an electric stirrer rotating at 60 rpm. After stripping, the gaseous products are further mixed for 10 min to ensure homogeneity. The final gas products are analyzed using a refinery gas analyzer (RGA). After the stripping process is completed, in-situ catalyst regeneration is carried out at 1300 ° F in the presence of air. The regenerated flue gas is sent through a catalytic converter (LECO Inc.) filled with CuO pellets to oxidize CO to CO2. The flue gas is then analyzed by an online IR analyzer located downstream of the catalytic converter. The coke deposited during the cracking process is calculated by the CO2 concentration measured by the IR analyzer.

[0133] Gaseous products (mainly C1 to C7 hydrocarbons) are resolved in RGA. RGA is a customized Agilent 7890B GC equipped with three detectors: a flame ionization detector (FID) for hydrocarbons and two thermal conductivity detectors for nitrogen and hydrogen. A methanizer is also installed on the RGA to quantify trace CO and CO2 in the gas products when biological raw materials such as soybean oil, tallow or palm oil are cracked. The gas products are divided into dry gas (C2- hydrocarbons and hydrogen), LPG (C3 and C4 hydrocarbons). CO and CO2 are excluded from the dry gas. Their yields are reported separately. The liquid products are weighed and analyzed in a simulated distillation GC (Agilent 6890) using the ASTM D2887 method. The liquid products are fractionated into gasoline (C5-430℉), LCO (430-650℉) and HCO (650℉+). The gasoline (C5+ hydrocarbons) in the gaseous products are combined with the gasoline in the liquid products as total gasoline. The light fraction (C5-) in the liquid product was also subtracted from the liquid product and added back to the C3 and C4 species using some empirical distribution. For most experiments, the material balance was between 98% and 102%.

[0134] A detailed hydrocarbon analysis (DHA) of PONA and octane (RON and MON) was also performed on the gasoline portion of the liquid product using an Agilent 6890A and HydrocarbonExpert software from Separation Systems Inc., FL. DHA analysis was not performed on the gasoline portion of the gaseous product. However, the DHA results still provide valuable information for evaluating the properties of the catalytic cracking products.

[0135] Example 7 - Direct conversion of plastics and palm oil via FCC using ZSM-5 catalyst

[0136] Laboratory testing of the fluid catalytic cracking (FCC) process was performed on stable blends of plastic and biofeedstock (Examples 2-2 and 5-1) using an FCC catalyst made from ZSM-5 zeolite, and the results are summarized in Table 8.

[0137] Table 8 Evaluation of co-feeding plastics and palm oil to FCC using ZSM-5 catalyst

[0138]

[0139]

[0140] The results in Table 8 show that the blend of waste plastics and biomass (palm oil and soybean oil) is well converted with the FCC catalyst containing ZSM-5. Surprisingly, under typical FCC process conditions, the mesoporous 10 yuan ZSM-5 catalyst can convert more than 95% by weight of the plastic / biomass blend (Examples 7-1 to 7-3). This high conversion rate has resulted in very low yields of LCO and HCO. All of these situations have produced very high LPG and aromatics yields, indicating that the method can be used to produce raw materials for polymer and chemical manufacturing without the need for petroleum resources.

[0141] Adding 10 wt % of plastic to palm oil only causes a minor change in the performance of the FCC unit in terms of conversion and the yield of dry gas and coke, indicating that the co-processing of waste plastic and bio-based materials is readily feasible (Example 7-1 vs. Example 7-2). Although blending 10 wt % of low-density polyethylene (Plastic A) into palm oil only results in a minor increase in coke and dry gas yields, a significant positive increase in LPG yield (35 wt % vs. 37 wt %) and total aromatic yield (76 wt % vs. 81 wt % in the gasoline fraction) has been observed. The significant increase in LPG and aromatic yields from blends containing plastics is quite unexpected. This clearly shows the synergistic effect of blends of bio-based materials and plastics in providing increased LPG and aromatic yields.

[0142] Blending 10 wt% of plastic into palm and soybean oil (Example 7-3) also showed consistent results of high LPG and aromatics yields.

[0143] These results indicate that ZSM-5 catalysts made from medium pore size zeolites are preferred catalysts for LPG olefins and aromatics production when converting biofeed / plastic blends.

[0144] The high yield of LPG using this process is remarkable.LPG and LPG olefins are desirable feedstocks for polyethylene and polypropylene production.

[0145] The high yield of aromatics using this process is also quite significant, as these aromatics can be used in polystyrene or polyethylene terephthalate production. Another surprising discovery is the selectivity of para-xylene relative to total xylenes. Using the ZSM-5 catalyst, the xylenes produced by this process are essentially para-xylene, with a para-xylene selectivity of about 61-70% (relative to the total xylene production). Para-xylene is the most desired xylene isomer for polyethylene terephthalate polymer manufacturing.

[0146] Although this process is more suitable for chemical manufacturing, a portion of the product can be used to make high-quality gasoline fuel. The gasoline produced by this process has an excellent octane number of over 100, which is due to the high aromatic content in the gasoline fraction. Due to the high conversion rate, the LCO and HCO yields are small.

[0147] Example 8 - Direct conversion of plastics and palm oil via FCC using USY catalyst

[0148] The stable blends of plastic and palm oil (Examples 2-2 and 5-1) were subjected to laboratory testing of the fluid catalytic cracking (FCC) process using FCC catalysts made of USY zeolite, and the results are summarized in Table 9.

[0149] Table 9 Evaluation of co-feeding plastics and palm oil to FCC using USY catalyst

[0150]

[0151]

[0152] The results in Table 9 show that the blend of waste plastics and bio-feedstock (palm oil and soybean oil) was well converted using an FCC catalyst containing USY. Under typical FCC process conditions, the overall conversion of the blend was 86-87% (Examples 8-1 to 8-3). All of these cases produced low dry gas yields (undesirable products) and high LPG, gasoline and LCO yields (desirable products), indicating that this method can be used to simultaneously produce feedstock chemical manufacturing and high-quality renewable fuels without the need for petroleum resources.

[0153] Adding 10 wt% of plastic to palm oil caused only minor changes in the FCC unit performance in terms of conversion and yields of dry gas and coke, indicating that co-processing of waste plastic and bio-feedstock is readily feasible (Example 8-1 vs. Example 8-2). Blending 10 wt% of low-density polyethylene (Plastic A) to palm oil had only a minor effect on the product yields: LPG yield (19.5 wt% vs. 21.3 wt%), gasoline yield (45.4 wt% vs. 44.9 wt%), LCO (10.9 wt% vs. 10.0 wt%) and HCO yield (3.2 wt% vs. 3.3 wt%). However, due to the paraffinic nature of the plastic, a reduction of 3 values ​​in gasoline octane number (91 to 88) has been observed.

[0154] Blending 10 wt% of plastic into palm and soybean oil (Example 8-3) also showed consistent results of high LPG and gasoline yields.

[0155] Using the USY catalyst, no synergistic effect of biomass and plastics was observed, nor was the para-xylene selectivity using the ZSM-5 catalyst shown in Example 7-2 observed. Compared with the ZSM-5 catalyst (Example 8.2 vs. Example 7.2), the USY catalyst produced a much higher LCO yield (10.0 wt% vs. 1.4 wt%) and HCO yield (3.3 wt% vs. 0.7 wt%). In addition, USY showed a much higher coke selectivity (6.7 wt% vs. 1.7 wt%) and a lower waste gas yield (2.2 wt% vs. 6.5 wt%). These results show that the USY catalyst made of large pore size zeolite is a preferred FCC catalyst for the simultaneous production of chemical feedstocks and high-quality fuels.

[0156] A portion of the product can be used to make premium fuel. Gasoline produced by this process has an octane rating of 91 to 88. The addition of polyethylene plastic results in some reduction in octane due to the paraffinic nature of the plastic. With the flexibility of refinery blending, this octane reduction can be compensated with fewer blending adjustments.

[0157] The high yield of LPG using this process is remarkable.LPG and LPG olefins are desirable feedstocks for polyethylene and polypropylene production.

[0158] The high yields of aromatics using this process are also significant since these aromatics can be used in polystyrene or polyethylene terephthalate production.

[0159] Example 9 - Direct Conversion of Plastics and Tallow via FCC Using ZSM-5 Catalyst

[0160] Laboratory testing of the fluid catalytic cracking (FCC) process was performed on stable blends of plastic and biofeedstock (Examples 3-2, 3-4, and 6-1) using an FCC catalyst made from ZSM-5 zeolite, and the results are summarized in Table 10.

[0161] Table 10 Evaluation of plastic and tallow co-feed to FCC using ZSM-5 catalyst

[0162]

[0163]

[0164] The results in Table 10 show that blends of waste plastics and biomass (tallow and soybean oil) were well converted using FCC catalysts containing ZSM-5. Similar to co-processing with palm oil, the ZSM-5 catalyst showed very high conversions of over 95% by weight of the plastic / biomass blends under typical FCC process conditions (Examples 9-1 to 9-4). This high conversion resulted in very low yields of LCO and HCO. All of these cases produced very high LPG and aromatics yields, indicating that the process can be used to produce feedstocks for polymer and chemical manufacturing without the need for petroleum resources.

[0165] Adding 10 wt% of polyethylene or polypropylene plastic to beef tallow caused only minor changes in FCC unit performance in terms of conversion and yields of dry gas and coke, indicating that co-processing of waste plastics and bio-feedstocks is readily feasible (Example 9-1 compared with Examples 9-2 and 9-3). Unlike the case of palm oil shown in Example 7-2, blending 10 wt% of low density polyethylene (Plastic A) and polypropylene (Plastic C) to beef tallow did not show any synergistic effect in terms of LPG and aromatics yields. The LPG yield (36.5 wt% vs. 35.5-36.4 wt%) and total aromatics yield (80.6 wt% vs. 80.3-80.6 wt% in gasoline fraction) were similar for the plastic co-feed case.

[0166] Blending 10 wt% of plastic into beef tallow and soybean oil (Example 9-4) also showed consistent results of high LPG and aromatics yields and high para-xylene selectivity.

[0167] The high yields of LPG and aromatics shown in Table 10 again indicate that the ZSM-5 catalyst made from medium pore size zeolite is a preferred catalyst for producing LPG olefins and aromatics from a blend of plastics and bio-feedstocks such as tallow. Using the ZSM-5 catalyst, the xylenes produced by this process are essentially para-xylene, with a para-xylene selectivity of about 65-67% (relative to the total xylene production).

[0168] Example 10 - Direct Conversion of Plastics and Tallow via FCC Using USY Catalyst

[0169] Laboratory testing of the fluid catalytic cracking (FCC) process was performed on a stable blend of plastic and tallow biofeedstock (Examples 3-2, 3-4, 6-1) using an FCC catalyst made from USY zeolite, and the results are summarized in Table 11.

[0170] Table 11 Evaluation of plastic and tallow co-feed to FCC using USY catalyst

[0171]

[0172]

[0173] The results in Table 11 show that the blend of waste plastic and bio-feedstock (tallow and soybean oil) was well converted using the FCC catalyst containing USY. Under typical FCC process conditions, the overall conversion of the blend was 85-87% (Examples 10-1 to 10-4). All of these cases produced low dry gas yields (undesirable products) and high LPG, gasoline and LCO yields (desirable products), indicating that this method can be used to simultaneously produce feedstocks for chemical manufacturing and high-quality fuels without the need for petroleum resources.

[0174] Adding 10 wt% of plastic to tallow caused only minor changes in FCC unit performance in terms of conversion and yields of dry gas and coke, indicating that co-processing of waste plastic and bio-feedstock is readily feasible (Example 10-1 compared to Examples 10-2 and 10-3). Blending 10 wt% of low density polyethylene (Plastic A) or polypropylene (Plastic C) to tallow slightly increased LPG yield (20.1 wt% vs. 21.6-22.6 wt%), while having only minor effects on other product yields: gasoline yield (44.6 wt% vs. 43.6-44.3 wt%), LCO (10.5 wt% vs. 10.2-11.0 wt%), and HCO yield (3.5 wt% vs. 3.2-3.3 wt%). No reduction in gasoline octane was observed in the case of co-feeding polyethylene, and an increase of 2 values ​​in gasoline octane was observed in the case of co-feeding polypropylene (88.0 vs. 87.9 vs. 92.3).

[0175] These results indicate that USY catalysts made from large pore size zeolites are preferred catalysts for the simultaneous production of chemical feedstocks and high-quality renewable fuels.

[0176] 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 having any essential importance to the composition. The phrase "consisting of is intended to be transitional, meaning the exclusion of all elements other than the recited elements, except for only trace amounts of impurities.

[0177] To the extent not inconsistent with this article, 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 integrity 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 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 as defined by the appended claims.

Claims

1. A method for converting waste plastics into chemicals, comprising: (a) selecting waste plastics containing polyethylene and / or polypropylene; (b) preparing a blend of a bio-based feedstock and a selected plastic, wherein the blend comprises about 20% by weight or less of the selected plastic; and (c) sending the blend to a catalytic conversion unit.

2. A continuous process for converting waste plastics into aromatic hydrocarbons and chemical monomers, comprising: (a) selecting waste plastics comprising polyethylene and / or polypropylene; (b) preparing a blend of a bio-based feedstock and a selected plastic, wherein the blend comprises about 20% by weight or less of the selected plastic; (c) sending the blend to an FCC unit at a temperature above the melting point of the waste plastic in the blend; (d) recovering a naphtha mixture from the FCC unit; and (e) sending the naphtha mixture to an aromatic separation unit.

3. The process according to claim 2, wherein benzene, toluene, xylene, ethylbenzene or a mixture thereof is recovered from the aromatic separation unit.

4. The process according to claim 3, wherein the recovered chemicals are further separated and forwarded for polymerization.

5. The process according to claim 3, wherein the para-xylene is separated and forwarded for polymerization into PET.

6. The process of claim 2, wherein the catalyst in the FCC unit comprises a large pore zeolite.

7. The process of claim 2, wherein the catalyst in the FCC unit comprises a medium pore zeolite.

8. The method of claim 2, wherein the blend in (b) is a hot intimate blend of waste plastic and bio-oil.

9. The method of claim 2, wherein the blend in (b) is a stable blend of waste plastic and bio-oil.

10. The method of claim 2, wherein the waste plastic selected in (a) comprises plastic from classification groups 2, 4 and / or 5.

11. The process of claim 2, wherein the C4 stream and heavy fractions are recovered from the FCC unit distillation column and further processed into clean gasoline, diesel or jet fuel in a refinery.

12. The process of claim 2, wherein the volumetric flow rate of the blend sent to a refinery FCC unit in (c) accounts for at most 100 volume % of the total hydrocarbon flow rate sent to the FCC unit.

13. The process of claim 2, wherein the volume flow rate of the blend sent to a refinery FCC unit in (c) is at most 50 volume % of the total hydrocarbon flow rate sent to the FCC unit.

14. The process of claim 2, wherein the blend flow rate is at most 25 volume % of the total flow sent to the FCC unit.

15. The method of claim 2, wherein the blend of bio-raw material and selected waste plastic in (b) is prepared by heating the waste plastic and bio-raw material mixture to a temperature above the melting point of the plastic and then cooling the blend to a temperature below the melting point of the waste plastic.

16. The method of claim 2, wherein the biological feedstock comprises triglycerides and / or fatty acids.

17. The method of claim 2, wherein the biological feedstock comprises oils of plant origin and / or fats and oils of animal origin.

18. The method of claim 17, wherein the vegetable-derived oil comprises palm oil, rapeseed oil, corn oil, soybean oil, or a mixture thereof.

19. The method of claim 17, wherein the biological feedstock comprises beef tallow, lard, chicken fat, fish oil, or a mixture thereof.

20. The method of claim 2, wherein the biological feedstock comprises palm oil, beef tallow, soybean oil, or a mixture thereof.

21. The method of claim 2, wherein the biological feedstock comprises biomass pyrolysis oil.

22. The method of claim 2, wherein the biological raw material comprises one or more biological raw materials having an iodine value of 95 or less.

23. The method of claim 19, wherein the iodine value is 91 or less.

24. The method of claim 22, wherein the biological feedstock comprises a mixture of a biological oil or fat exhibiting an iodine value of 70 or less and a biological oil or fat exhibiting an iodine value of more than 70.

25. The method of claim 1, wherein a stream of a petroleum feedstock comprising LCO or gasoline is added to reduce the blend viscosity.

26. The process of claim 2, wherein the blend sent to the FCC unit is mixed with a petroleum feedstock.

27. The method of claim 26, wherein the petroleum feedstock comprises 1-50 volume % of the mixed blend.

28. The method of claim 27, wherein the petroleum-based feedstock comprises atmospheric gas oil, vacuum gas oil (VGO), atmospheric residue, petroleum-derived oils, petroleum-based materials, and / or heavy feedstocks recovered from refinery operations.

29. The method of claim 27, wherein the petroleum-based feedstock comprises light cycle oil (LCO), heavy cycle oil (HCO), FCC naphtha, gasoline, diesel, toluene, and / or aromatic solvents from petroleum.

30. The process of claim 2, wherein the blend sent to the FCC unit is mixed with a recycle stream, thereby reducing the viscosity of the blend.

31. The process of claim 1, wherein the catalytic conversion unit comprises a hydrocracking unit.

32. The process of claim 31 , wherein a heavy fraction is recovered from the hydrocracking unit and forwarded to an isomerization / dewaxing unit.

33. The process of claim 32, wherein dewaxed oil is recovered from the isomerization / dewaxing unit and further processed into high quality base oil in a hydrofinishing unit.

34. Chemicals, fuels and base oils produced from a blend of bio-based feedstocks and waste plastics according to the process of claim 1.

35. Chemicals, fuels and base oils produced according to the method of claim 1.

Images