Methods and systems for production of LUBE oil base stocks from plastics

Abstract

Provided here are methods and systems for production of base oils from plastic feedstocks. One such method includes supplying a plastic feedstock to an extrusion unit configured to thermally degrade the plastic feedstock to produce a molten oligomer product stream, passing the molten oligomer product stream through an adsorption guard bed to produce a decontaminated oligomer product substantially void of inorganic substances, reacting the decontaminated oligomer product in a hydrogenolysis reactor containing a nickel-silica catalyst to produce a first reaction product slurry containing the nickel-silica catalyst and reaction base oil products, supplying n-hexane into the first reaction product slurry to produce a second reaction product slurry containing the catalyst and the reaction base oil products dissolved in n- hexane, and separating the base oil reaction products from the nickel-silica catalyst to produce base oil.

Description

24CHEM0023 - WO-ORD1METHODS AND SYSTEMS FOR PRODUCTION OF LUBE OIL BASE STOCKS FROM PLASTICSTECHNICAL FIELD

[0001] The present disclosure generally relates to methods and systems for production of lube oil base stocks from plastics. More specifically, the present disclosure relates to methods and systems for production of lube oil base stocks from oligomerized post-consumer recycled plastic to reduce dependency on petroleum feedstocks to produce base oils.BACKGROUND

[0002] Base oils are frequently used to manufacture various products, such as oils, including motor oils, or the like, metal processing fluids, and grease. These base oils may be manufactured to particular specifications dependent on the intended product, including, for example, each of the aforementioned uses. In one example, lubrication (lube) oil may be produced by incorporation of additives to the base oils. Conventionally, lube oil base stocks are manufactured from petroleum feedstocks. It is estimated about one barrel of lube oil requires about ten barrels of a petroleum feedstock. With evolving environmental concerns and increasing plastic wastes, alternative plastic uses may be a method to combat these concerns. Thus, Applicant has recognized a method to reduce dependency on petroleum feedstocks in the manufacturing of lube oil base stocks for subsequent lube oil manufacturing. Further, Applicant has recognized a system to produce the aforementioned lube oil base stocks from post-consumer plastics (PCR).SUMMARY

[0003] Applicant has recognized the need to reduce dependency on petroleum feedstocks by repurposing consumed plastics, such as post-consumer recycled plastics, for manufacturing lube oil base stocks for subsequent lube oil manufacturing. Further, Applicant has recognized a system to produce the aforementioned lube oil base stocks. Embodiments of the present disclosure include, for example, include a method to produce a base oil from a plastic feedstock includes supplying a plastic feedstock to an extrusion unit, the extrusion unit configured to thermally degrade the plastic feedstock to produce a molten oligomer product stream, filtering out the inorganic substances within the molten oligomer product stream using a micron filter and an adsorption guard bed to produce a decontaminated oligomer product substantially void of inorganic substances, reacting the purified oligomer product with hydrogen in a24CHEM0023 - WO-ORD2 hydrogenolysis reactor containing a nickel-silica catalyst to produce a first reaction product slurry containing the nickel-silica catalyst and reaction base oil products, supplying n-hexane into the first reaction product slurry to produce a second reaction product slurry containing the nickel-silica catalyst and the reaction base oil products dissolved in n-hexane, filtering the reaction base oil products from the nickel-silica catalyst through diatomaceous earth using suction to produce a filtered base oil product that contains n-hexane, removing n-hexane from the filtered base oil product using a rotary vacuum evaporator to produce a raw base oil, and separating a narrow-cut of the raw base oil with a vacuum distillation to produce the base oil. In certain embodiments, the base oil has a boiling point range of about 360 degrees Celsius to about 660 degrees Celsius, a viscosity index (VI) greater than about 110, and / or a molecular weight (MW) ranging from about 500 Daltons to about 3,000 Daltons.

[0004] In another embodiment of the present disclosure, a system includes an extrusion unit configured to receive a plastic feedstock and thermally degrade the plastic feedstock to produce a molten oligomer product stream, a decontamination unit in fluid communication with the extrusion unit and configured to receive the molten oligomer product stream and to produce a decontaminated oligomer product, a hydrogenolysis reaction unit in fluid communication with the decontamination unit and configured to receive the decontaminated oligomer product, react the decontaminated oligomer product with a nickel- silica catalyst in a presence of hydrogen, and to produce a first reaction product slurry containing the nickel-silica catalyst and reaction base oil products, and a purification unit in fluid communication with the hydrogenolysis reaction unit and configured to receive the first reaction product slurry, supply n- hexane into the first reaction product slurry to produce a second reaction product slurry containing the nickel-silica catalyst and the reaction base oil products dissolved in n-hexane, and separate the reaction base oil products from the nickel-silica catalyst to produce a base oil. In certain embodiments, the base oil has MW ranging from about 500 Daltons to about 3,000 Daltons and a viscosity index greater than about 110.

[0005] Aspects and advantages of these exemplary examples and other examples, are discussed in detail herein. Moreover, it is to be understood that both the foregoing information and the following detailed description provide merely illustrative examples of various aspects and are intended to provide an overview or framework for understanding the nature and character of the claimed aspects and examples. Accordingly, these and other objects, along with advantages and features of the present disclosure, will become apparent through reference to the following description and the accompanying drawings.24CHEM0023 - WO-ORD3Furthermore, it is to be understood that the features of the various examples described herein are not mutually exclusive and may exist in various combinations and permutations.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The accompanying drawings, which are included to provide a further understanding of the examples of the present disclosure, are incorporated in and constitute a part of this specification, illustrate examples of the present disclosure, and together with the detailed description, serve to explain principles of the examples discussed herein. No attempt is made to show structural details of this disclosure in more detail than may be necessary for a fundamental understanding of the examples discussed herein and the various ways in which they may be practiced. The various features of the drawings discussed below are not necessarily drawn to scale. Dimensions of various features and elements in the drawings may be expanded or reduced to more clearly illustrate examples of the disclosure.

[0007] FIG. 1 is a schematic diagram of an embodiment of a system using an extrusion unit, a decontamination unit, a hydrogenolysis unit, a purification unit, and a distillation unit to produce a narrowcut base oil, according to an example.

[0008] FIG. 2 is a schematic diagram of an embodiment of a system using an extrusion unit, a decontamination unit, a hydrogenolysis unit, a purification unit, and a distillation unit to produce narrowcut base oil with additional details as compared to FIG. 1, according to an example.

[0009] FIG. 3 is a schematic diagram of an embodiment of a system including a purification unit and distillation unit that purifies and refines produced base oil from the hydrogenolysis reactor of FIG. 2, according to an example.

[0010] FIG 4 is a schematic diagram of an embodiment of a system including a pre-distillation unit, a dehydroisomerization unit, a hydrofinishing unit, and a final distillation unit that purifies and refines produced base oil from the system of FIG. 2, according to an example.

[0011] FIG. 5 is a flow chart of a method in which a base oil may be produced from a plastic feedstock, according to one example.

[0012] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated into other embodiments without further recitation.DETAILED DESCRIPTION24CHEM0023 - WO-ORD4

[0013] Plastic waste is a growing environmental concern. Approximately 50 percent (%) of plastic waste is disposed in a landfill while about 20 % is incinerated. Of the balance, about 9 % is recycled while a significant fraction of about 21 % is pollution to the environment by reckless disposal in oceans, lands, or the like. Considerable efforts to recycle more plastic waste includes mechanical recycling. However, mechanical recycling is limited based on compositions of the plastic waste. Alternatively, advanced chemical recycling provides a breakdown of the plastic waste to original building blocks, thereby to create new products which suggests advanced chemical recycling as a possible solution to the plastic waste environmental concern. For example, advanced chemical recycling, by, for example, pyrolysis, gasification, hydrothermal liquefaction, or hydrocracking, enables recycling of plastics previously considered non-recyclable through mechanical recycling technologies. However, a great amount of energy is required for carbon-carbon bond breakage due to unfavorable thermodynamics, thus making chemical recycling energy intensive and challenging. Instead, the present disclosure relates to upcycling of plastic waste derivatives, such as plastic oligomers to produce high value products, e.g., lube oil base stocks through a hydrogenolysis reaction by selective cleavage of the carbon-carbon bond.

[0014] The description may use the phrases “in some examples,” “in various examples,” “in an example,” or “in examples,” which may each refer to one or more of the same or different examples. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to examples of the present disclosure, are synonymous. The term “plurality” as used herein refers to two or more items or components. The terms “about” or “approximately” are defined as being close to as understood by one of ordinary skill in the art. In one non-limiting example, these terms are defined to be within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5% of the specified value. In some examples, “about” refers to the specified value.

[0015] The terms “removing,” “removed,” “reducing,” “reduced,” or any variation thereof, when used in the claims and / or the specification includes any measurable decrease of one or more components in a mixture to achieve a desired result. The use of the words “a” or “an” when used in conjunction with any of the terms “comprising,” “including,” “containing,” or “having,” in the claims or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” The terms “wt. %,” “vol. %,” or “mol. %” refers to a weight, volume, or molar percentage of a component, respectively, based on the total weight, the total volume of material, or total moles, which includes the component. In a non-limiting example, 10 grams of a component in 100 grams of the material is 10 wt. % of the component. The term “rich”, such as X-rich stream, means that the stream includes at24CHEM0023 - WO-ORD5 least 50 mol. % of the named compound or class of compounds, such as at least 60 mol. %, at least 70 mol. %, at least 80 mol. %, at least 90 mol. %, at least 95 mol. %, at least 98 mol. %, at least 99 mol. %, or 100 mol. %, or any sub-ranges therebetween. The term “operable” is equivalent to “configured to” language presented in the below disclosure.

[0016] As used herein, when a first component is described as receiving (or being configured to receive) a stream from a second component, or when a first component is described as providing (or being configured to provide) a stream to a second component, the first and second components may be alternatively described as being in fluid communication, or in fluid connection, with one another. It may be appreciated that, for the various streams discussed herein, a given stream substantially contains the compound or class of compounds in the name of the stream (e.g., an ethene product stream substantially contains ethene, a hydrogen-rich stream substantially contains hydrogen, and the like), and the stream may also include other components.

[0017] FIG. 1 is a schematic diagram of an embodiment of a system 100 using an extrusion unit 110, a decontamination unit 120, a hydrogenolysis unit 130, a purification unit 140, and a distillation unit 150 to produce a narrow-cut base oil 114, according to an example. The system 100 further includes various streams, such as streams 102, 104, 106, 108, 112, 113, and 114, along with byproduct streams that may contain gas, naphtha, or diesel, to interconnect the system. The example of FIG. 1 omits various principle and auxiliary streams necessary for operation. However, the example of FIG. 1 may be used to understand the complexity of the system 100 and various units that may be utilized therein to produce narrow-cut lube oil base stocks. Additionally, the below disclosure may refer to “lube oil base stocks” interchangeably with “base oil” or “base stocks” as base stocks (or base oils) are equivalent and are produced by the following disclosure.

[0018] Generally, the system 100 produces the narrow-cut base oil 114 from a plastic feedstock 102. The plastic feedstock 102 may be thermally degraded and depolymerized by the extrusion unit 110 to produce a molten oligomers product stream 104. The molten oligomers product stream 104 may be filtered through a decontamination unit 120 to remove impurities via stream 106. The decontamination unit 120 may produce a decontaminated oligomer product 108 that may be processed by a hydrogenolysis unit 130 to produce a reaction base oil product, along with byproducts including gas, naphtha, and diesel. Finally, the base oil product may be purified by a purification unit 140, and further distilled with a distillation unit 150 to produce the narrow-cut base oil 114.24CHEM0023 - WO-ORD6

[0019] In more depth, the plastic feedstock 102 may be a post-consumer recycled plastic. For example, post-consumer recycled plastic may contain polypropylene, polyethylene, or polystyrene. In some examples, the plastic feedstock 102 may contain greater than about 95 % polypropylene by mass, such as greater than about 97 %, such as greater than about 99 % polypropylene. In another example, the plastic feedstock 102 may contain up to about 5 % polyethylene by mass, such as up to about 3%, such as up to about 1% polyethylene. In all examples, the plastic feedstock 102 may contain up to about 1 % polystyrene by mass. The plastic feedstock 102 may be sorted, or isolated, and washed, from generic plastic waste or may be commercially purchased, in some examples. Furthermore, plastic feedstock 102 may have a molecular weight ranging from about 3,000 Daltons to about 400,000 Daltons, such as about 3,000 Daltons to about 170,000 Daltons, such as about 5,000 Daltons to about 50,000 Daltons, such as about 30,000 Daltons, such as about 10,000 Daltons to about 14,000 Daltons, such as about 12,000 Daltons. Additionally, the plastic feedstock 102 may contain colored post-consumer recycled plastic or white postconsumer recycled plastic. However, the plastic feedstock 102 may not contain mixed plastic waste, such as medical waste, as experimentally, mixed plastic waste is undesirably highly contaminated and reduces the production of lube oil base stock. Furthermore, the plastic within the plastic feedstock 102 is isomeric. For purposes to facilitate understanding, the plastic feedstock 102 composition is critical to the success of the production of the lube oil base stock of the present disclosure.

[0020] The extrusion unit 110 may be configured to receive the plastic feedstock 102 and to produce a molten oligomer product stream 104. The extrusion unit 110 contains one or more extruders (not shown) that each may be configured to thermally degrade and depolymerize the plastic feedstock 102 at a temperature of greater than about 300 degrees Celsius, such as about 320 degrees Celsius to about 350 degrees Celsius, or such as about 300 degrees Celsius to about 450 degrees Celsius, such as about 300 degrees Celsius to about 420 degrees Celsius, or such as about 420 degrees Celsius to about 450 degrees Celsius. The temperature necessary for the thermal degradation of the plastic feedstock 102 may be dependent on the composition of the plastic feedstock 102, as discussed above. The extrusion unit 110 may thermally degrade stabilization plastic impurities. However, filler impurities may still remain after extrusion. In one example, an extruder within the extrusion unit 110 may be a mini twin-screw type, such as a process 11 parallel twin-screw extruder as commercially available by Thermo Fisher Scientific Inc. The extruder may have an operating temperature range of about room temperature (about 22 degrees Celsius) to about 450 degrees Celsius, a barrel diameter of about 11 millimeters (mm), a barrel length of about 440 mm (L / D=40), about 8-barrel segments, a maximum pressure of about 100 barg, with a typical24CHEM0023 - WO-ORD7 throughput of about 20 to about 2500 grams per hour. The extruder may be operable to produce molten oligomers derived from the plastic feedstock 102. In one example, the extruder may produce pelletized oligomers for storage prior to suppling the oligomers, in a molten, or liquid, state, to the decontamination unit 120. In another example, the extruder may produce molten oligomers at a temperature of about 350 degrees Celsius. However, a preferential temperature of the molten oligomer product stream 104 fed to the decontamination unit 120 is about or above 150 degrees Celsius to produce a liquid state. The extrusion process may a continuous operation with constant plastic feedstock 102 feed or may be an intermittent operation, such that predetermined quantities of plastic feedstock 102 are processed at a time.

[0021] The decontamination unit 120 may be configured to receive the molten oligomer product stream 104 and produce a decontaminated oligomer product, via stream 108. The decontamination unit 120 may be in fluid communication with the extrusion unit 110 and the hydrogenolysis unit 130. In some examples, the decontamination unit 120 serves to remove impurities, via stream 106, from the molten oligomer product stream 104. Impurities include plastic fillers found within the plastic feedstock 102, such as talc, magnesium silicate, calcium carbonate, silica, or the like. The decontamination unit 120 may contain suitable methods to remove such impurities, including filtration, high temperature filtration, or hydrothermal treatments. Details of an exemplary embodiment for equipment within the decontamination unit 120 will be discussed in FIG. 2. The removal of the impurities is critical for the upcoming reaction so as to not deactivate or reduce performance of the catalyst utilized in a hydrogenolysis reactor. In some examples, the impurities present in the decontaminated oligomer product 108 is desirably less than 5 parts per million (ppm). Similar to the extrusion unit 110 above, the decontamination unit 120 may be a continuous operation with constant molten oligomer product stream 104 supplied to the decontamination unit 120 or may be an intermittent operation, such that predetermined quantities of the molten oligomer product stream 104 are processed at a time.

[0022] The hydrogenolysis unit 130 may be configured to receive the decontaminated oligomer product, via stream 108, to produce a reaction product slurry 112 that contains the catalyst and reaction base oil products. The hydrogenolysis unit 130 may be in fluid communication with the decontamination unit 120 and a purification unit 140. In one example, the hydrogenolysis unit 130 may be further configured to receive off specification (off spec) base oil via recycle stream 115, and thus, hydrogenolysis unit 130 may also be in fluid communication with the distillation unit 150. The hydrogenolysis unit 130 contains one or more hydrogenolysis reactors operable to catalytically react the decontaminated oligomer product 108 in a presence of hydrogen to produce reaction base oil products. In some examples, the hydrogenolysis unit24CHEM0023 - WO-ORD8130 produces byproducts such as gas, naphtha, or diesel. In one example, the gas byproduct is separated after the reaction in the hydrogenolysis unit 130, as illustrated. Additional details of the hydrogenolysis unit 130 and the hydrogenolysis reactors will be discussed in FIG. 2.

[0023] The purification unit 140 may be configured to receive, and purify, the reaction product slurry 112 to produce a raw base oil 113. In more detail, the purification unit 140 may process the reaction product slurry 112 by removing the catalyst from the reaction base oil products and further separating the reaction base oil products to produce raw base oil 113 for subsequent distillation. Additional details of the purification unit 140 will be provided in FIG. 3 below.

[0024] The distillation unit 150 may be configured to receive, and distil, the raw base oil 113 to produce at least the narrow-cut base oil 114. Additional products of the distillation unit 150 may include naphtha, diesel, or off specification (off spec) base oil product. The distillation unit 150 may be further configured to recycle off spec base oil to the hydrogenolysis unit 130 via recycle stream 115. The distillation unit 150 may be in fluid communication with the purification unit 140 and the hydrogenolysis unit 130. The distillation unit 150 may be operated to obtain selected cuts of the raw base oil 113 by predetermined temperature ranges. For example, a desired product base oil may have a boiling point within 360 degrees Celsius to about 660 degrees Celsius. Thus, the raw base oil 113 may be distilled to produce the narrowcut base oil 114.

[0025] Both the purification unit 140 and the distillation unit 150 are utilized to produce the narrow-cut base oil 114. Thus, through the purification unit 140 and through the distillation unit 150, the reaction product slurry 112 may be conditioned to meet desired specifications, or “groups”, of lube oil base stocks. For example, industry base oils are categorized into groups, such as group I through group V. Groups I through III are base oils used to produce non-synthetic engine oil, for example. Typically, the viscosity index of groups I through III is less than about 120 and contain a small percentage of sulfur. Groups IV and V base oils have a viscosity index greater than about 120 and are used to produce superior synthetic lube oils as compared to groups 1 through 3. The base oils produced by the present disclosure produce group II or higher quality base oils by upcycling of recycled plastic, thereby to advantageously reduce dependency on petroleum feedstocks and simultaneously reduce environmental plastic pollution through repurposed plastics. For example, the base oil produced from the present disclosure may be compared to the polyalphaolefin (PAO) base oil quality of commercially available Durasyn® 166 or Cio PAO derived from Cio hydrocarbons.24CHEM0023 - WO-ORD9

[0026] FIG. 2 is a schematic diagram of an embodiment of a system 200 using an extrusion unit 210, a decontamination unit 220, a hydrogenolysis unit 230, a purification unit 240, and a distillation unit 250 to produce narrow-cut base oil 214 with additional details as compared to FIG. 1, according to an example. These aforementioned units are similarly labeled as compared to FIG. 1, and their descriptions are not repeated in detail for improved clarity, unless otherwise noted. FIG. 2 illustrates exemplary details of the decontamination unit 220, the hydrogenolysis unit 230, and further includes additional streams, such as streams 204A, 204B, 216, 218, and 222, to interconnect the system 200. The unlisted streams are similarly labeled as compared to FIG. 1, and their descriptions are not repeated in detail for improved clarity, unless otherwise noted. The example of FIG. 2 omits various principle and auxiliary streams necessary for operation. However, the example of FIG. 2 may be used to understand the complexity of the system 200 and exemplary units that may be utilized therein to produce desired lube oil base stocks.

[0027] The plastic feedstock 202 may be processed through the extrusion unit 210 to produce a molten oligomer product stream 204. The molten oligomer product stream 204 may be supplied to the decontaminated unit 220. As illustrated, the decontaminated unit 220 may contain a hot filter 259 and an adsorption guard bed 260. The hot filter 259 may be configured to receive the molten oligomer product stream 204, via stream 204A within the decontaminated unit 220 to remove impurities, via stream 206, from the liquid and produce an intermediate stream 204B substantially void of inorganic substances. The impurities, via stream 206, may be similar to the impurities, via stream 106, as discussed above in FIG. 1. The hot filter 259 may be in fluid communication with the extrusion unit 210 and the adsorption guard bed 260. While not illustrated, the hot filter 259 may be one or more filters. The hot filter 259 may be a micron filter rated to remove inorganic substances with particle sizes exceeding, for example, about 3 microns to about 60 microns in the molten oligomer product stream 204, such as about 10 microns to about 50 microns, such as about 10 microns to about 20 microns, or alternatively, such as about 3 microns to about 40 microns, or such as about 20 micron or less. The selection of the micron filter rating may necessitate knowledge of the impurities present in the plastic feedstock 202 such that impurity concentrations do not reduce catalyst effectiveness in the hydrogenolysis unit 230. For example, an impurity concentration exceeding 10 ppm of silica, may inactive a reaction catalyst supported on silica, such as nickel-silica catalyst discussed below.

[0028] The adsorption guard bed 260 may be operable to receive the intermediate stream 204B and to produce the purified oligomer product 208 that may be substantially void of inorganic substances. The adsorption guard bed 260 may be in fluid communication with the hot filter 259 and the hydrogenolysis24CHEM0023 - WO-ORD10 reactor 270. While illustrated to represent one guard bed, the adsorption guard bed 260 may be one or more guard beds to extract, or separate, desired impurities out of the intermediate stream 204B. In another embodiment, the hot filter 259 may be bypassed to directly feed the molten oligomer product stream 204, via stream 204A to the adsorption guard bed 260. The adsorption guard bed 260 may be operated in a continuous operation with a constant feed of the intermediate stream 204B, or stream 204A, or may be an intermittent operation, such that predetermined quantities of the intermediate stream 204B, or stream 204A, are processed at a time to remove inorganic substances. In one example, the adsorption guard bed 260 may be an arsenic removal adsorption guard bed, such as commercially available Catguard® As40. In another example, the adsorption guard bed 260 may be a silicon and phosphorus removal adsorption guard bed, such as commercially available Catguard® 20. In still another example, the adsorption guard bed capture neutral alumina or clay materials. In some examples, the impurity concentration tolerance may be less than about 20 ppm, such as less than or up to about 10 ppm leaving the decontamination unit 220. Additionally, the produced purified oligomer product 208 may be allowed to cool to solidify in preparation for the following hydrogenolysis reaction within the hydrogenolysis unit 230.

[0029] The hydrogenolysis unit 230 may contain one or more hydrogenolysis reactors 270 that are each in fluid communication with the adsorption guard bed 260 and the purification unit 240. Furthermore, the hydrogenolysis reactor 270 may be configured to receive the purified oligomer product 208, hydrogen gas (H2) via stream 216, nitrogen gas (N2) via stream 218, catalyst via stream 222, and to produce a reaction product slurry 212 containing the catalyst and any produced reaction base oil products. Additionally, the hydrogenolysis reaction may produce a byproduct stream that contains gas, naphtha, or diesel considered to be circular or sustainable. The hydrogenolysis reactor 270 is operable to react the purified oligomer product 208 in a hydrogenolysis reaction to produce at least base oil stocks. However, the produced base oil stocks, referred to as reaction base oil products includes residual byproducts and the catalyst within. Thus, purification may be needed to obtain the raw base oil 213. Additionally, the narrow-cut base oil 214 may be produced from the distillation of the raw base oil 213, as discussed in FIG. 1.

[0030] The catalytic reaction within the hydrogenolysis reactor 270 may be performed with a nickelsilica catalyst. For example, the nickel-silica catalyst may contain about, or greater than, 21 weight % of nickel on a silica support. The nickel-silica catalyst may be a preactivated commercial grade catalyst such as commercially available catalyst MONCAT™ 2021 manufactured by EVONIK Operations. In one example, the hydrogenolysis reactor 270 may be a batch reactor. In this example, the decontaminated oligomer product 208 is provided to the hydrogenolysis reactor 270 at a ratio of about 55 to 65 grams of24CHEM0023 - WO-ORD11 oligomer to about 2 to 7 grams of nickel-silica catalyst, such about 58 to 63 grams of oligomer to about 2 to 7 grams of nickel-silica catalyst, such as about 60 grams of oligomer to about 3 grams of nickel-silica catalyst, such as about 60 grams of oligomer to about 6 grams of nickel-silica catalyst. Stated differently, the ratio of oligomer to nickel-silica catalyst may be about 20: 1 to about 10: 1. In some examples, the MW of the decontaminated oligomer product 208 placed within hydrogenolysis reactor 270 may be about 3,000 Daltons to about 170,000 Daltons. Additional data is provided in the example section below. The reactor may be purged to remove air with N2 via stream 218. Additionally, the N2 inert gas stream 218 may be used to remove any oxidants from the reactor. The N2 within the batch reactor may then be purged with a hydrogen gas via stream 216 in preparation for the reaction. The hydrogen gas may be supplied to the hydrogenolysis reactor 270 at room temperature, such as about 22 degrees Celsius, and pressurized to about 10 barg to about 40 barg, such as about 15 barg to about 35 barg, such as about 20 barg to about 30 barg, such as about 20 barg to about 25 barg, such as about 20 barg to about 22 barg. The hydrogenolysis reactor 270 may be operated at a temperature ranging from about 200 degrees Celsius to about 380 degrees Celsius, such as about 280 degrees Celsius to about 380 degrees Celsius, such as about 310 degrees Celsius to about 330 degrees Celsius, such as about 310 degrees Celsius, or such as about 320 degrees Celsius to about 330 degrees Celsius, such as about 330 degrees Celsius. By trial and error, higher temperatures than listed above result in the production of excess gas and reduced production of reaction base oil products liquids. Thus, the temperature range provided is critical to production of base oil within the hydrogenolysis reactor 270. In some examples, the hydrogenolysis reaction may be performed for 1 hour to about 7 hours, such as about 2 hours to about 6 hours, such as about 2 hours, or such as about 6 hours. After the hydrogenolysis reaction, the gas sample, or byproducts, may be collected for gas analysis using, for example, a residual gas analyzer. The gas analysis enables to complete a mass balance about the hydrogenolysis reactor 270. In some examples, the reaction base oil products, including the catalyst, produce about 64.2 grams of base oil from about 66 grams of oligomer (about 60 grams) and catalyst (about 6 grams) with a balance loss to byproduct production and residual reactor chamber liquid stick, or coating. In another example, about 90 % base oil is produced from the hydrogenolysis reaction with about 10 % gas byproduct (substantially methane gas). Details of the experimental results will be discussed in the example section below. The reaction product slurry 212, containing the catalyst and any produced reaction base oil products, may be analyzed with various methods such as gel permeation chromatography, detailed hydrocarbon analysis, Simdi st method using ASTM D7169, two-dimensional gas chromatography, nuclear magnetic resonance, or the like.24CHEM0023 - WO-ORD12

[0031] In another example, an alternative catalyst may be platinum on alumina (Pt / AhCh). While Pt / AhCh has experimentally produced base oil from the hydrogenolysis reaction discussed above, the catalyst is expensive and deters continued exploration. For additional disclosure, the Pt / AhCh catalyst (having about 1% platinum, as commercially available by Sigma-Aldrich) produced about 56 % liquid base oils having a MW of about 1746 Daltons. The experimental conditions had a catalyst mass of about 6 grams, a 12,000 Daltons solidified oligomer product reactor feed at about 60 grams, a hydrogen gas initial pressure of about 20.7 barg, a reaction pressure of about 37 barg, and a reaction temperature of about 331 degrees Celsius. Additional catalysts to upcycle plastic oligomers include ruthenium on activated carbon (Ru / C) having a 5 weight% loading, as commercially available by Sigma-Aldrich).

[0032] FIG. 3 is a schematic diagram of an embodiment of a system 300 including a purification unit 340 and distillation unit 350 that purifies and refines produced base oil from the hydrogenolysis reactor 270 of FIG. 2, according to an example. As illustrated, the purification unit 340 includes a catalyst filter 380, and a hexane separator 390. Additionally, the system 300 further includes streams 312, 324, 326, 328, 332, 334, and 313. The example of FIG. 3 omits various principle and auxiliary streams necessary for operation. However, the example of FIG. 3 may be used to understand the complexity of the system 300 and exemplary units that may be utilized therein to purify lube oil base stocks from the hydrogenolysis reactor 270.

[0033] Stream 312 may be the reaction product slurry 212 from FIG. 2. In FIG. 3, stream 312 will be referenced as the first reaction product slurry 312. The first reaction product slurry 312 may be supplied to a mixing unit 394 to be mixed with an n-hexane stream 324 which provides high-performance liquid chromatography grade n-hexane. In some examples, the mixing unit 394 may a standalone vessel to perform the mix. In another example, the mixing unit 394 may be integrated into the hydrogenolysis reactor 270 by supplying the n-hexane stream 324 directly to the hydrogenolysis reactor 270 post reaction. In all examples, the n-hexane stream 324 dissolves the first reaction product slurry 312 at about room temperature to produce a second reaction product slurry 326 containing the nickel-silica catalyst, naphtha, diesel, and the base oil products both dissolved in the n-hexane. The second reaction product slurry 326 may be supplied to the catalyst filter 380 for catalyst removal.

[0034] The catalyst filter 380 may be configured to receive the second reaction product slurry 326 and separate the nickel-silica catalyst, via stream 328, to produce a filtered base oil products mixture 332 containing the reaction base oil products, including naphtha and diesel, dissolved in n-hexane. Furthermore, the catalyst filter 380 may be in fluid communication with the hexane separator 390. In one24CHEM0023 - WO-ORD13 example the catalyst filter 380 may possess a diatomaceous earth filter. In another example, the second reaction product slurry 326 may be filtered through a commercially available diatomaceous earth such as Celite® 545 provided by Sigma- Aldrich. In still another example, the catalyst filter 380 may be a bunker filter with filter paper and filter aid, such as the Celite® 545. Additionally, the catalyst filtration of the second reaction product slurry 326 may be assisted with air or through suction aiding the fluid to pass through the catalyst filter 380. The filtered base oil products mixture 332 may be substantially void of catalyst.

[0035] The filtered base oil products mixture 332, containing the reaction base oil products and naphtha and diesel dissolved in n-hexane, may be supplied to the hexane separator 390. The hexane separator 390 may be operable to receive the filtered base oil products mixture 332 and remove the n-hexane, via stream 334, to produce a raw base oil 313. Raw base oil 313 may equivalent to the raw base oil 212 from FIG. 2. Additionally, the hexane separator 390 may be in fluid communication with the catalyst filter 380 and the base oil separator 350. In an example, the technology utilized to remove the n-hexane from the filtered base oil products mixture 332 may be a rotary vacuum evaporator, or the like.

[0036] The raw base oil 313 may be supplied to the distillation unit 350. The distillation unit 350 may be in fluid communication with the hexane separator 390 and may be configured to receive the raw base oil 313 to separate a narrow cut of the raw base oil 313 to produce the narrow-cut base oil 314 of intended narrow cut base oil ranges. The distillation unit 350 also separates a naphtha diesel cut, from the narrowcut base oil 214 and the off spec base oil, via stream 392. The separated naphtha and diesel, or naphtha diesel cut, may be circular or sustainable cuts with a boiling point range less than about 360 degrees Celsius. The distillation unit 350 may contain a vacuum distillation column, or the like, to separate a narrow cut of the raw base oil 313 having a boiling point range of about 360 degrees Celsius to about 660 degrees Celsius, such as about 360 degrees Celsius to about 600 degrees Celsius, with a viscosity index greater than about 110, such as about or greater than 114, such as about or greater than 117. The narrowcut base oil 314 may have a MW ranging from about 500 Daltons to about 3,000 Daltons and be substantially void, or absent, of aromatics. As mentioned in FIG. 1, the distillation unit 350 may produce off spec base oil to recycle to the hydrogenolysis reactor 270, via the recycle stream 315.

[0037] FIG 4 is a schematic diagram of an embodiment of a system 400 including a pre-distillation unit 450A, a dehydroisomerization unit 460, a hydrofinishing unit 470, and a final distillation unit 450B that purifies and refines produced base oil from the system 200 of FIG. 2, according to an example. The units of FIG. 4 are similarly labeled as compared to FIG. 2, and their descriptions are not repeated in detail for24CHEM0023 - WO-ORD14 improved clarity, unless otherwise noted. FIG. 4 illustrates yet another contemplated process system to produce a narrow-cut base oil 414, using distillation, dehydroisomerization, and hydrofinishing, prior to a final distillation.

[0038] The details of system 400 closely follow the details of system 200 up to the produced raw base oil 213 from the purification unit 240. Instead of a distillation unit 250, a pre-distillation unit 450A may be operable to receive the raw base oil 213 from the purification unit 240, and separate naphtha and diesel via stream 451. In one example, the naphtha and diesel may be separated by distillation cuts of a boiling point of about less than 360 degrees Celsius. Further, the separated naphtha and diesel may be circular, or sustainable.

[0039] The pre-distillation unit 450A may be in fluid communication with the purification unit 240 and a dehydroisomerization unit 460. As illustrated, the stream produced from the pre-distillation unit 450A may have substantially reduced naphtha and diesel components and further, may be passed through the dehydroisomerization unit 460 and then a hydrofinishing unit 470 to increase isoparaffinic content of the base oil and to reduce the pour point of base oil. The dehydroisomerization and hydrofinishing processes are known to generate additional naphtha and diesel which is subsequently separated in a final distillation unit 450B. The dehydroisomerization unit 460 may be in fluid communication with the pre-distillation unit 450A and the hydrofinishing unit 470. The hydrofinishing unit 470 may be in fluid communication with the dehydroisomerization unit 460 and a final distillation unit 450B.

[0040] In some examples, the final distillation unit 450B may be operable to produce naphtha and diesel via stream 453, a narrow-cut base oil 414, and an off specification base oil, via stream 415, that may be recycled to the hydrogenolysis unit 230 for increased oil production.

[0041] FIG. 5 is a flow chart of a method 500 in which a base oil may be produced from a plastic feedstock, according to one example. The method 500 includes steps 502, 504, 506, 508, 510, 512, and 514. The following method 500 incorporates FIG. 2 and FIG. 3 reference numeral embodiments for ease of explanation. However, the method 500 is not limited to the examples of FIG. 2 and FIG. 3. Furthermore, the aforementioned steps of method 500 need not be performed in intermittent, or batch, operations but rather may be performed as continuous operations. In some examples, some of the steps of method 500 are bypassed or skipped as the, for example, filtration technology may be unavailable or undesired.

[0042] At step 502, a plastic feedstock is supplied to the extrusion unit 210. The extrusion unit 210 may be configured to thermally degrade the plastic feedstock 202 to produce a molten oligomer product stream 204.24CHEM0023 - WO-ORD15

[0043] At step 504, the inorganic substances within the molten oligomer product stream are filtering out using a micron filter, within hot filter 259, followed by impurity adsorption within adsorption guard bed 260 to produce a purified oligomer product 208 substantially void of inorganic substances. As mentioned above, the desired impurity concentration is target to less than about 20 ppm, such as less than 10 ppm.

[0044] The purified oligomer product 208 is then treated at step 506 in the presence of hydrogen 216 in a hydrogenolysis reactor 270 containing a nickel-silica catalyst 222 to produce a first reaction product slurry 212 containing the nickel-silica catalyst and reaction base oil products. The hydrogenolysis reaction is a catalytic chemical reaction that selectively cleaves carbon-carbon bonds such that plastic oligomers may be upcycled to produce base oil.

[0045] At step 508, n-hexane 324 is mixed with the first reaction product slurry 312 to produce a second reaction product slurry 326 containing the nickel-silica catalyst and the reaction base oil products dissolved in n-hexane. At step 510, the reaction base oil products are separated from the nickel-silica catalyst through diatomaceous earth in the catalyst filter 380 using suction to produce a filtered base oil products mixture 332 that contains n-hexane.

[0046] Next, at step 512, n-hexane is separated from the filtered base oil products mixture 332 using a rotary vacuum evaporator within the hexane separator 390 to produce raw base oil 313. A sample of the raw base oil product 313 may then be analyzed for measurement of properties, such as kinematic viscosity by ATSM D445, viscosity index by ATSM D2270, and pour point by ATSM D97. Here, additional analysis may be performed such as nuclear magnetic resonance, detailed hydrocarbon analysis, Simdist method using ASTM D7169, two-dimensional gas chromatography. As illustrated in FIG. 4, it is contemplated that optional purification steps may be performed, such as dehydroisomerization and hydrofinishing to further condition the raw base oil product.

[0047] At step 514, a narrow cut of the raw base oil is separated by vacuum distillation within the distillation unit 350 to produce the base oil 314 having a boiling point range of about 360 degrees Celsius to about 660 degrees Celsius with a viscosity index greater than about 120 and with a MW ranging from about 500 Daltons to about 3,000 Daltons. The quality of the base oil 314 is compared with PAO Durasyn® 166 such that production of the lube oil base stocks may advantageously reduce dependency on petroleum feedstocks to create such base oils and simultaneously reduce environmental plastic pollution.24CHEM0023 - WO-ORD16EXPERIMENTS A D EXAMPLES

[0048] The below experiments are presented to provide supporting data for various examples of operations discussed above.

[0049] Experiment: The hydrogenolysis reaction was performed using an aspect of the above system and method disclosed. A variety of experiments were performed to obtain proper temperature, reactor feed to catalyst ratios, reaction times, and the like, to produce increased base oils yields. The reactor volume is about 550 milliliters. The below table showcases a series of experimental batches that were run within the hydrogenolysis reactor, and the results obtained using analysis techniques discussed above. In addition, various values and calculations may be obtained and / or performed from the combination of information presented in the table below.

[0050] Table 1. Hydrogenolysis Reaction Results from Base Oil Production using Plastic Feedstocks.

[0051] In one example, Batch 1 was prepared with 60 grams of solid oligomers containing 12,000 Daltons of polypropylene and 3 grams of nickel-silica catalyst. The reaction temperature was performed24CHEM0023 - WO-ORD17 at about 310 degrees Celsius for a reaction time of about 6 hours. The reaction base oils produced by the hydrogenolysis reaction were analyzed by gel permeation chromatography and Simdist techniques to evaluate the produced base oil contents. As briefly discussed above, base oil stocks may be categorized by viscosity index. Table 2 below provides information on the recognized Groups I-V for easy reference.

[0052] Table 2. Base Oil Groups I-V Properties.Referring to the experiment, the batch results may be compared to, for example, commercial Cio PAO group IV base stocks having a viscosity index of about 135 and pour point -40 degrees Celsius. Referring back to Table 1, Batch 1 produced 52.9 % (63 % minus 10.1 %) base oil with boiling range of about 360- 660 degrees Celsius (see “Simdist Results” column). However, Batch 1 has a MW (6089) higher than the desired 5000 Daltons. Therefore, another experiment, Batch 5, was performed using 60 grams of solid oligomers containing 12,000 Daltons of polypropylene and 6 grams of nickel-silica catalyst. The results yield a desirable lower MW (927) while still producing about 48.5 % base oil stock with boiling range of about 360-660 degrees Celsius.

[0053] Table 3. Properties of Experimental Batches.24CHEM0023 - WO-ORD18

[0054] The results of the above Table 3 indicate the raw base oil, produced by the systems and methods of the present disclosure, tested on streams 113, 213, or 313 in FIGS 1-3, possess properties found within Group II or higher, commonly referred to as Group 11+ . Additionally, the viscosity index of the tested batches indicate the produced base oil is near Group III properties.

[0055] Other objects, features, and advantages of the disclosure will become apparent from the foregoing figures, detailed description, and examples. It should be understood, however, that the figures, detailed description, and examples, while indicating specific examples of the disclosure, are given by way of illustration only and are not meant to be limiting. Additionally, it is contemplated that changes and modifications within the spirit and scope of the disclosure will become apparent to those skilled in the art from the detailed description. In further examples, features from specific examples may be combined with features from other examples. For example, features from one example may be combined with features from any of the other examples. In further examples, additional features may be added to the specific examples described herein.

Claims

24CHEM0023 - WO-ORD19CLAIMSWhat is claimed is:

1. A method to produce a base oil from a plastic feedstock, the method comprising: supplying a plastic feedstock to an extrusion unit, the extrusion unit configured to thermally degrade the plastic feedstock to produce a molten oligomer product stream; passing the molten oligomer product stream through an adsorption guard bed to produce a decontaminated oligomer product substantially void of inorganic substances; reacting the decontaminated oligomer product with hydrogen in a hydrogenolysis reactor containing a nickel-silica catalyst to produce a first reaction product slurry containing the nickel-silica catalyst and reaction base oil products; supplying n-hexane into the first reaction product slurry to produce a second reaction product slurry containing the nickel-silica catalyst and the reaction base oil products dissolved in n- hexane; and separating the base oil reaction products from the nickel-silica catalyst to produce a base oil with molecular weight ranging from about 500 Daltons to about 3,000 Daltons and a viscosity index greater than about 110.

2. The method of claim 1, wherein separating the reaction base oil products from the nickel-silica catalyst further comprises: filtering the reaction base oil products from the nickel-silica catalyst through diatomaceous earth using suction to produce a filtered base oil product that contains n-hexane; removing n-hexane from the filtered base oil product using a rotary vacuum evaporator to produce a raw base oil; and separating a narrow cut of the raw base oil with a vacuum distillation column to produce the base oil having a boiling point range of about 360 degrees Celsius to about 660 degrees Celsius.

3. The method of claim 1, further comprising: filtering out the inorganic substances within the molten oligomer product stream using a hot micron filter prior to passing the molten oligomer product stream through an adsorption guard bed; and24CHEM0023 - WO-ORD20 separating a naphtha-diesel cut from the base oil reaction products, the naphtha-diesel cut having a boiling point of about less than 360 degrees Celsius.

4. The method of claim 3, wherein the hot micron filter is rated for about 20 micron or less, wherein the plastic feedstock includes a MW ranging from about 3,000 Daltons to about 50,000 Daltons, wherein the adsorption guard bed removes silicon, and wherein off specification base oil is recycled to the hydrogenolysis reactor.

5. The method of claim 1, wherein the plastic feedstock is a post-consumer recycled material containing polypropylene and includes a MW ranging from about 3,000 Daltons to about 170,000 Daltons.

6. The method of claim 5, wherein the plastic feedstock includes a MW ranging from about 3,000 Daltons to about 50,000 Daltons.

7. The method of claim 1, wherein a ratio of purified oligomer product to nickel-silica catalyst ranges from about 55 to 65 grams of purified oligomer product to about 2 to 7 grams of nickel-silica catalyst; and wherein a nickel content of the nickel-silica catalyst is greater than about 21 %.

8. The method of claim 1, wherein the hydrogenolysis reactor is a batch reactor operated at a temperature ranging from about 280 degrees Celsius to about 380 degrees Celsius with an initial hydrogen pressure ranging from about 10 barg to about 40 barg at about 22 degrees Celsius.

9. A system comprising: an extrusion unit configured to receive a plastic feedstock and thermally degrade the plastic feedstock to produce a molten oligomer product stream; a decontamination unit in fluid communication with the extrusion unit and configured to receive the molten oligomer product stream and to produce a purified oligomer product; a hydrogenolysis reaction unit in fluid communication with the decontamination unit and configured to receive the purified oligomer product, react the purified oligomer product with a nickel-silica catalyst in a presence of hydrogen, and to produce a first reaction product slurry containing the nickel-silica catalyst and reaction base oil products; and4CHEM0023 - WO-ORD21 a purification unit in fluid communication with the hydrogenolysis reaction unit and configured to receive the first reaction product slurry, supply n-hexane into the first reaction product slurry to produce a second reaction product slurry containing the nickel-silica catalyst and the reaction base oil products dissolved in n-hexane, and separate the reaction base oil products from the nickel-silica catalyst to produce a base oil with molecular weight ranging from about 500 Daltons to about 3,000 Daltons and a viscosity index greater than about 110.

10. The system of claim 9, wherein the decontamination unit further comprises: a hot micron filter in fluid communication with the extrusion unit and configured to receive the molten oligomer product stream and to produce an intermediate stream substantially void of inorganic substances; and an adsorption guard bed in fluid communication with the hot micron filter and configured to purify the intermediate stream to produce the purified oligomer product.

11. The system of claim 9, wherein the hydrogenolysis reaction unit further comprises: a batch reactor containing the nickel-silica catalyst and configured to receive hydrogen and the purified oligomer product and operated to conduct a hydrogenolysis reaction at a temperature ranging from about 280 degrees Celsius to about 380 degrees Celsius with an initial hydrogen pressure ranging from about 10 barg to about 40 barg at about 22 degrees Celsius.

12. The system of claim 9, wherein the purification unit further comprises: a diatomaceous earth filter configured to receive the second reaction product slurry and separate the nickel-silica catalyst from second reaction product slurry to produce a filtered base oil product containing the reaction base oil products dissolved in n-hexane; a rotary vacuum evaporator configured to separate the n-hexane from the filtered base oil product to produce a raw base oil; and a vacuum distillation column to separate a narrow cut of the raw base oil to produce the base oil having a boiling point range of about 360 degrees Celsius to about 660 degrees and a naphthadiesel cut having a boiling point range of less than about 360 degrees Celsius.4CHEM0023 - WO-ORD2213. The system of claim 9, wherein the plastic feedstock is a post-consumer recycled material and includes a MW ranging from about 3,000 Daltons to about 170,000 Daltons; and wherein a nickel content of the nickel-silica catalyst is greater than about 21 %.

14. The system of claim 9, wherein the plastic feedstock substantially contains polypropylene with aMW ranging from about 3,000 Daltons to about 50,000 Daltons.

15. The system of claim 9, wherein a ratio of reactor feed stream to nickel-silica catalyst is about 58 to 63 grams of reactor feed stream to about 2 to 7 grams of nickel-silica catalyst.

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