Inventors: Sreenivasa Rao Gajula

Suman Kumar Jana

Debdut Roy

Girish Koripelly

Alexander Stanislaus

Ravichander Narayanaswamy

Anilkumar Mettu

Mahesh Kumar Srinivas

Jason Loiland

Ashim Kumar Ghosh

Dustin Farmer

Cross-Reference to Related Applications

[0001] This application claims the benefit of and priority to U.S. Provisional Application No. 63/264,102, filed on November 16, 2021, which is incorporated herein by reference in its entirety.

Technical Field

[0002] The present disclosure generally relates to modular systems and methods for removal of a portion of metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil. The disclosure also relates to subjecting the partially decontaminated pyrolysis oil to further processing in a hydrogenation unit to produce a decontaminated hydrogenated pyrolysis oil.

Background

[0003] Pyrolysis oil (py oil) from the mixed plastic waste is emerging as an alternative feedstock via chemical recycling. Single adsorbent systems may not be efficient in decontaminating the pyoil having multiple contaminants and as a result, the resultant pyoil from such processes would tend to degrade during storage and transportation as well as have hetero atoms, which are not acceptable in downstream large volume processing units. While hydroprocessing is effective to remove contaminants, it is expensive and mostly implemented in a central processing facility, like a refinery or steam cracker. However, the pyoil facilities are distributed in a decentralized manner due to the nature of feed availability and the pyoil needs to be transported to a central facility for further processing. Therefore, it is desired to have modular operations at decentralized facilities for decontamination.

[0004] Pyrolysis of mixed plastics is carried out in thermal reactors, such as tanks, kilns, auger reactors, and extruders. The mixed plastic waste pyrolysis oil from these operations contains several impurities, including metals, chlorides and olefins, which make transport and storage of this mixed plastic waste pyrolysis oil difficult from decentralized manufacturing facilities. Some of the practices of removal of heteroatoms, metals, unsaturated hydrocarbons can be accomplished by hydroprocessing, oxidation, extraction, adsorption and precipitation.

Summary

[0005] To address these shortcomings in the art, Applicant has developed modular decontamination systems and methods for processing mixed plastic waste pyrolysis oil and hydrocarbon streams. Also, provided here are systems and methods for processing the partially decontaminated pyrolysis oil by a hydrogenation processes, which can also be subject to further hydrocracking and distillation.

[0006] Provided here are methods for removing metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil. One such method includes the steps of obtaining a mixed plastic waste pyrolysis oil containing a plurality of metal compounds and non-metal compounds, passing the mixed plastic waste pyrolysis oil through a first adsorption bed having a first porous bed material to adsorb a portion of the metal compounds from the mixed plastic waste pyrolysis oil, passing the mixed plastic waste pyrolysis oil from the first adsorption bed through a second adsorption bed with a second porous bed material to adsorb a portion of the silica compounds from the mixed plastic waste pyrolysis oil, passing the mixed plastic waste pyrolysis oil from the second adsorption bed through a third adsorption bed with a third porous bed material to adsorb a portion of the halogenated compounds from the mixed plastic waste pyrolysis oil, and introducing the mixed plastic waste pyrolysis oil from the third adsorption bed into a vessel containing a plurality of molecular sieves to adsorb a portion of the oxygenates, phosphorous compounds, and nitrogenates from the mixed plastic waste pyrolysis oil and produce a partially decontaminated pyrolysis oil. This method further includes the steps of supplying the partially decontaminated pyrolysis oil from the vessel to a hydrogenation unit and processing the partially decontaminated pyrolysis oil in the presence of a hydrogenation catalyst in the hydrogenation unit to convert a portion of the olefin compounds in the partially decontaminated pyrolysis oil into saturated hydrocarbon compounds and to produce a decontaminated hydrogenated pyrolysis oil with a reduced amount of plurality of metal compounds and non-metal compounds as compared to the amount of plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil. In certain embodiments, operating the hydrogenation unit at a temperature between about 80 °C and about 120 °C. The non-metal compounds are two or more of silica compounds, halogenated compounds, phosphorous compounds, oxygenates, and nitrogenates. In certain embodiments, the pores of the first porous bed material are greater in size than pores of the second porous bed material and the pores of the second porous bed material are greater in size than the pores of the third porous bed material.

[0007] In certain embodiments, the first porous bed material contains one or more of alumina, ligand-modified alumina, magnesium metal alloys, calcium oxide, clay, calcium carbonate, acid- modified carbon, and activated charcoal. In certain embodiments, the second porous bed material contains one or more of nickel-impregnated silicates, nickel-impregnated hydrotalcites, magnesium-impregnated silicates, magnesium-impregnated hydrotalcites, nickel-modified zeolites, magnesium-modified zeolites, sulfonated silica, polyacrylamide, a copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resins, and a modified-polydivinylbenzene. In certain embodiments, the third bed material contains one or more of modified alumina, modified zeolites, modified silicates, modified phosphates, red mud, calcium hydroxide, aluminum-zinc carbon composites, calcium carbonate, and aluminum-magnesium composite oxides.

[0008] Embodiments can also include the step of adding an oxidation stabilizer to the decontaminated hydrogenated pyrolysis oil. Embodiments can also include the step of adding a nitrogen blanket to the decontaminated hydrogenated pyrolysis oil.

[0009] In certain embodiments, the method includes the step of passing the mixed plastic waste pyrolysis oil through a filter prior to passing the mixed plastic waste pyrolysis oil through the first adsorption bed. The filter removes at least a portion of solid particles greater than about 10 microns from the mixed plastic water pyrolysis oil to produce a filtered pyrolysis oil.

[0010] In certain embodiments, the method includes supplying the filtered pyrolysis oil from the filter to a coalescing unit with a coalescing medium therein to coalesce and separate at least a portion of water from the mixed plastic waste pyrolysis oil. In certain embodiments, the filtered pyrolysis oil is cooled to at least 50 °C before supplying the filtered pyrolysis oil to the coalescing unit. The coalescing medium is a pad or a filter cartridge. Certain embodiments include the step of supplying an acid scavenger to the mixed plastic waste pyrolysis oil prior to passing the mixed plastic waste pyrolysis oil through the first adsorption bed. Embodiments can also include the step of cooling the mixed plastic pyrolysis oil to a pre-selected temperature prior to passing the mixed plastic waste pyrolysis oil through the first adsorption bed. [0011] Embodiments can also include the step of determining, prior to introducing the mixed plastic waste pyrolysis oil into the vessel containing the plurality of molecular sieves, if concentrations of metal compounds or halogenated compounds in the mixed plastic waste pyrolysis oil are greater than a pre-selected level. In response to the concentration of metal compounds or halogenated compounds being greater than the pre-selected level, the mixed plastic waste pyrolysis oil is passed to a set of absorption beds that operate in parallel to the first adsorption bed, the second adsorption bed, and the third adsorption bed.

[0012] Embodiments can also include the step of determining if concentration of oxygenates and nitrogenates in the partially decontaminated pyrolysis oil are greater than a pre-selected level, prior to supplying the partially decontaminated pyrolysis oil to the hydrogenation unit. In response to the concentration of the oxygenates and nitrogenates in the partially decontaminated pyrolysis oil being greater than the pre-selected level, the partially decontaminated pyrolysis oil is introduced from the third adsorption bed into a second vessel containing a second plurality of molecular sieves.

[0013] Another method of removing metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil includes the steps of: obtaining a mixed plastic waste pyrolysis oil, filtering the mixed plastic waste pyrolysis oil with a filter medium to remove a portion of solid particles greater than about 10 microns from the mixed plastic water pyrolysis oil to produce a filtered mixed plastic waste pyrolysis oil, cooling the filtered mixed plastic waste pyrolysis oil to a temperature at least below 50 °C, introducing the filtered mixed plastic waste pyrolysis oil into a coalescing unit with a coalescing medium to separate at least a portion of water from the filtered mixed plastic waste pyrolysis oil, passing the filtered mixed plastic waste pyrolysis oil through a first medium in a first trap to remove a portion of the metal compounds from the filtered mixed plastic waste pyrolysis oil, passing the filtered mixed plastic waste pyrolysis oil from the first trap through a second medium in a second trap to remove a portion of the silica compounds from the filtered mixed plastic waste pyrolysis oil, passing the filtered mixed plastic waste pyrolysis oil from the second trap through a third medium in a third trap to remove a portion of the halogenated compounds from the filtered mixed plastic waste pyrolysis oil, conveying the filtered mixed plastic waste pyrolysis oil from the third trap to a molecular sieve unit with a plurality of molecular sieves to adsorb at least a portion of the oxygenates or nitrogenates or phosphorous compounds from the filtered mixed plastic waste pyrolysis oil to produce a partially decontaminated pyrolysis oil. The method further includes supplying the partially decontaminated pyrolysis oil to a hydrogenation unit and processing the partially decontaminated pyrolysis oil in the presence of a hydrogenation catalyst in the hydrogenation unit to convert at least a portion of the olefin compounds in the partially decontaminated pyrolysis oil into one or more saturated hydrocarbon compounds and produce a decontaminated hydrogenated pyrolysis oil with a reduced amount of plurality of metal compounds and non-metal compounds as compared to the amount of plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil.

[0014] In certain embodiments, the first medium contains one or more of alumina, ligand- modified alumina, magnesium metal alloys, calcium oxide, clay, calcium carbonate, acid-modified carbon, and activated charcoal. In certain embodiments, the first medium is a nanofiltration membrane or a polymeric membrane. In certain embodiments, the second medium contains one or more of nickel-impregnated silicates, nickel -impregnated hydrotalcites, magnesium-impregnated silicates, magnesium-impregnated hydrotalcites, nickel-modified zeolites, magnesium-modified zeolites, sulfonated silica, polyacrylamide, a copolymer of tetrafluoroethylene and perfluoro-3,6- dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resins, and a modified- polydivinylbenzene. In certain embodiments, the third medium contains one or more of modified alumina, modified zeolites, modified silicates, modified phosphates, red mud, calcium hydroxide, aluminum-zinc carbon composites, calcium carbonate, and aluminum-magnesium composite oxides. Certain embodiments include the step of operating the hydrogenation unit at a temperature between about 80 °C and about 120 °C. Certain embodiments include the step of adding an oxidation stabilizer to the decontaminated hydrogenated pyrolysis oil. Certain embodiments include the step of adding a nitrogen blanket to the decontaminated hydrogenated pyrolysis oil.

[0015] Certain embodiments include supplying an acid scavenger to the mixed plastic waste pyrolysis oil prior to passing the mixed plastic waste pyrolysis oil through the first trap. Certain embodiments include the step of cooling the mixed plastic pyrolysis oil to a pre-selected temperature prior to passing the mixed plastic waste pyrolysis oil through the first trap.

[0016] Provided here are modular systems for removing metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil. One such system includes the following: (a) a filter having a first inlet and a first outlet, the first inlet connected to and in fluid communication with a source of mixed plastic waste pyrolysis oil, the filter configured to remove solid particles greater than about 10 microns from the mixed plastic water pyrolysis oil to produce a filtered mixed plastic waste pyrolysis oil, (b) a coalescing unit having a second inlet and a second outlet, the second inlet connected to and in fluid communication with the first outlet, the coalescing unit containing a coalescing medium therein to separate water from the filtered mixed plastic waste pyrolysis oil, (c) a metals adsorption bed having a third inlet and a third outlet, the third inlet connected to and in fluid communication with the second outlet, the metals adsorption bed having a first porous bed material to adsorb metal compounds from the filtered mixed plastic waste pyrolysis oil, (d) a silica adsorption bed having a fourth inlet and a fourth outlet, the fourth inlet connected to and in fluid communication with the third outlet, the silica adsorption bed having a second porous bed material to adsorb silica compounds from the filtered mixed plastic waste pyrolysis oil, the pores of the second porous bed material being smaller in size than the pores of the first porous bed material, (e) a halogenated compounds adsorption bed having a fifth inlet and a fifth outlet, the fifth inlet connected to and in fluid communication with the fourth outlet, the halogenated compounds adsorption bed having a third porous bed material to adsorb halogenated compounds from the filtered mixed plastic waste pyrolysis oil, the pores of the third porous bed material being smaller in size than the pores of the second porous bed material and the pores of the first porous bed material, (f) a molecular sieve unit containing a plurality of molecular sieves and having a sixth inlet and a sixth outlet, the sixth inlet connected to and in fluid communication with the fifth outlet, each of the plurality of molecular sieves adsorbing a portion of the oxygenates or nitrogenates or phosphorous compounds from the filtered mixed plastic waste pyrolysis oil passing through the molecular sieve unit, and (g) a hydrogenation unit having a seventh inlet, the seventh inlet connected to and in fluid communication with the sixth outlet and receiving the filtered mixed plastic waste pyrolysis oil therefrom, the hydrogenation unit having a hydrogenation catalyst therein and being operable to convert at least some olefin compounds in the filtered mixed plastic waste pyrolysis oil into one or more saturated hydrocarbon compounds and to produce a decontaminated hydrogenated pyrolysis oil with a reduced amount of plurality of metal compounds and non-metal compounds as compared to the amount of plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil. In certain embodiments, the hydrogenation unit is operated at a temperature from about 80 °C and about 120 °C.

[0017] Embodiments of certain systems include an analyzer positioned to measure a concentration of metal compounds or halogenated compounds in the filtered mixed plastic waste pyrolysis oil before entering the sixth inlet. Embodiments of certain systems include an analyzer positioned to measure a concentration of metal compounds or halogenated compounds in the filtered mixed plastic waste pyrolysis oil downstream of the hydrogenation unit. Embodiments of certain systems include a heat exchanger in thermal communication with the mixed plastic waste pyrolysis oil and positioned upstream of the metals adsorption bed and configured to maintain temperature of the filtered mixed plastic waste pyrolysis oil within a pre-selected range. In certain embodiments, a first injector is positioned upstream of the metals adsorption bed to supply an acid scavenger into the filtered mixed plastic waste pyrolysis oil and a second injector is positioned downstream of the hydrogenation unit to supply an oxidation stabilizer into the decontaminated hydrogenated pyrolysis oil.

[0018] In certain embodiments, the first porous bed material contains one or more of alumina, ligand-modified alumina, magnesium metal alloys, calcium oxide, clay, calcium carbonate, acid- modified carbon, and activated charcoal. In certain embodiments, the second porous bed material contains one or more of nickel-impregnated silicates, nickel-impregnated hydrotalcites, magnesium-impregnated silicates, magnesium-impregnated hydrotalcites, nickel-modified zeolites, magnesium-modified zeolites, sulfonated silica, polyacrylamide, a copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resins, and a modified-polydivinylbenzene. In certain embodiments, the third porous bed material contains one or more of modified alumina, modified zeolites, modified silicates, modified phosphates, red mud, calcium hydroxide, aluminum-zinc carbon composites, calcium carbonate, and aluminum-magnesium composite oxides.

[0019] Still other aspects and advantages of these exemplary embodiments and other embodiments, 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 embodiments, and are intended to provide an overview or framework for understanding the nature and character of the claimed aspects and embodiments. 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. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and may exist in various combinations and permutations.

Brief Description of the Drawings

[0020] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present disclosure, are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure, and together with the detailed description, serve to explain principles of the embodiments 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 embodiments 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 embodiments of the disclosure.

[0021] FIG. 1 is a schematic flowchart for a method for removing metal compounds and non- metal compounds from a mixed plastic waste pyrolysis oil, according to an embodiment.

[0022] FIG. 2 is a diagrammatic representation of a modular system for removing metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil, according to an embodiment. Detailed Description

[0023] The present disclosure describes various embodiments related to processes and modular systems for removing metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil and subjecting it to a hydrogenation. Further embodiments may be described and disclosed.

[0024] In the following description, numerous details are set forth in order to provide a thorough understanding of the various embodiments. In other instances, well-known processes, devices, and systems may not have been described in particular detail in order not to unnecessarily obscure the various embodiments. Additionally, illustrations of the various embodiments may omit certain features or details in order to not obscure the various embodiments.

[0025] The description may use the phrases “in some embodiments,” “in various embodiments,” “in an embodiment,” or “in embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments of the present disclosure, are synonymous.

[0026] The term “about” is defined as being close to as understood by one of ordinary skill in the art. In one non -limiting embodiment, the terms are defined to be within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%.

[0027] The terms “reducing,” “reduced,” or any variation thereof, when used in the claims and/or the specification includes any measurable decrease or complete inhibition to achieve a desired result.

[0028] 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, that includes the component. In a non-limiting example, 10 grams of component in 100 grams of the material is 10 wt.% of component.

[0029] The words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0030] Disclosed here are modular systems and methods for consecutive traps to remove particular contaminants from a mixed plastic waste pyrolysis oil, along with a hydrogenation unit positioned downstream of the modular traps.

[0031] Certain embodiments include a modular decontamination system capable of processing pyoil and hydrocarbon streams. The system is configured to scavenge acids and polar components, facilitate saturation of dienes, removes metals and chlorides making the pyoil suitable for feeding a steam cracker or other units to the refinery. The system contains two or more modular units/traps to remove metal compounds and non-metal compounds. In certain embodiments, the regeneration of the adsorbent beds for polar compounds, nitrogenates, oxygenates, and silica compounds is by coke burning. These units can be equipped with sensors and/or analyzers for detecting levels of chloride and metal compounds beyond preset acceptance levels. Certain embodiments of the system include parallel traps for removal of metal compounds and non-metal compounds to facilitate continuous operation of the unit with reduced downtime. [0032] Embodiments of a method of removing metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil include the following steps. A mixed plastic waste pyrolysis oil with a plurality of metal compounds and non-metal compounds is passed through a first medium in a first trap to remove a portion of the metal compounds from the mixed plastic waste pyrolysis oil. In certain embodiments, the first medium contains one or more of alumina, ligand-modified alumina, magnesium metal alloys, calcium oxide, clay, calcium carbonate, acid- modified carbon, and activated charcoal. In certain embodiments, the first medium is a nanofiltration membrane or a polymeric membrane. Examples of metals that are present in the mixed plastic waste pyrolysis oil include vanadium, antimony, mercury, and cadmium. Metal compounds present in the pyoil can be present as either in the form of organometallic or inorganic metal salts and oxides. In certain embodiments, the amount of metallic compounds is reduced to about less than 50% by weight. Different alternative materials that can function as the first medium include acid modified carbon, activated charcoal materials, nanofiltration membranes (such as those made of montmorillonite, kaolin, tobermorite, magnetite, silica gel, and alumina), and polymeric membranes (such as those made of low-density polyethylene-styrene/acrylic acid copolymer).

[0033] The mixed plastic waste pyrolysis oil from the first trap is passed through a second medium in a second trap to remove a portion of the silica compounds from the mixed plastic waste pyrolysis oil. General silica compounds present in mixed plastic waste pyrolysis oil are organic siloxanes such as any of the cyclic polydimethylsiloxane (D3, D4, D5 and D6) or a linear volatile methylsiloxanes (L3, L4, L5, or L6). Silicon content in the pyrolysis oil is about 300ppm and the content varies depending on the source of plastics as measured by inductively coupled plasma mass spectrometry (ICP-MS). The silica removal method disclosed herein reduces the silicon content by more than about 50%. In some embodiments, the silicon content is reduced to about 120ppm. In certain embodiments, the second medium contains one or more of nickel-impregnated silicates, nickel-impregnated hydrotalcites, magnesium-impregnated silicates, magnesium- impregnated hydrotalcites, nickel-modified zeolites, magnesium-modified zeolites, sulfonated silica, polyacrylamide, a copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7- octene-sulfonic acid, polyvinyl alcohol, ion exchange resins, and a modified-polydivinylbenzene. [0034] The mixed plastic waste pyrolysis oil from the second trap is passed through a third medium in a third trap to remove a portion of the halogenated compounds from the mixed plastic waste pyrolysis oil. Examples of halogenated compounds present in the pyoil include 3-Chloro-3 methyl pentane, 2-chl oro-2 methyl pentane, (2-chloroethyl) benzene, 1 -chi oro-2, without limitations, ethyl benzene, 2-chloroethylbenzene, chlorobenzene, 3 -chloro-2-methyl-l -butene, Benzyl chloride, 3 -chloro- 1 -propenyl benzene, 3 -chloro cyclohexene, 1 -chi oro-3 -methyl butane, 3 -chloro- 1 -ph enyl-2 -butene, 2-chl oro-2 -butenyl-benzene, 1 -chlorocyclopentene, 3 -chi oro-3 - methyl pentane, 2-chloro-2-methyl pentane, (l-chlormethyl)-2- ethylbenzene, 3-chloro allyl benzene, and 3 -chi oro-3 -methyl heptane, (2-chl oroethyl)-benzene. In certain embodiments, the third medium contains one or more of modified alumina, modified zeolites, modified silicates, modified phosphates, red mud, calcium hydroxide, aluminum-zinc carbon composites, calcium carbonate, and aluminum-magnesium composite oxides.

[0035] The mixed plastic waste pyrolysis oil from the third trap is supplied to a molecular sieve unit with a plurality of molecular sieves to adsorb at least a portion of the oxygenates or nitrogenates or phosphorous compounds from the filtered mixed plastic waste pyrolysis oil to produce a partially decontaminated pyrolysis oil. Molecular sieves include acidified aluminas, molecular sieve 13X, and clays and acid-treated clays, such as bentonite and attapulgite. These small and medium pore molecular sieves are selected based on the size of oxygenates or nitrogenates or phosphorous compounds, and remove about 70% - 100% of the weight percent of oxygenates or nitrogenates or phosphorous compounds.

[0036] The method further includes supplying the partially decontaminated pyrolysis oil to a hydrogenation unit and processing the partially decontaminated pyrolysis oil in the presence of a hydrogenation catalyst in the hydrogenation unit to convert at least a portion of the olefin compounds in the partially decontaminated pyrolysis oil into one or more saturated hydrocarbon compounds and produce a decontaminated hydrogenated pyrolysis oil with a reduced amount of plurality of metal compounds and non-metal compounds as compared to the amount of plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil. Certain embodiments include operating the hydrogenation unit at a temperature between about 80 °C and about 120 °C. The partially decontaminated pyrolysis oil is subject to the hydrogenation process as a last step in order to minimize hydrogen consumption in removal of impurities, like halogenated compounds, oxygenates, nitrogenates, silica compounds and polar compounds and increases the hydrogen available for saturation of olefinic species. In certain embodiments, the modular traps are operated at progressively increasing temperatures with the metal trap at the lowest temperature and the hydrogenation unit at a temperature of about 100 °C to about 120 °C.

[0037] Methods can also include addition of an oxidation stabilizer to the decontaminated hydrogenated pyrolysis oil. The oxidation stabilizer quenches radicals in the decontaminated hydrogenated pyrolysis oil and stabilizes the decontaminated hydrogenated pyrolysis oil for long term storage and transport. For example, oxygen stabilizers, such as substituted phenols and substituted amines are provided in amounts ranging from 500 ppm to 2500 ppm and can potentially stabilize pyoil with an efficiency ranging from 80% to 95%. Use of a nitrogen blanket can further help in improving the efficiency of the stabilization process efficiency to almost about or equal to

100%.

[0038] Methods can also include addition of a nitrogen blanket to the decontaminated hydrogenated pyrolysis oil to protect it from any further potential oxidation reactions. Nitrogen blanketing can be achieved by purging dry nitrogen gas into the storage vessel to exclude the air above the decontaminated hydrogenated pyrolysis oil. Nitrogen blanketing can be achieved by sparging or bubbling nitrogen gas into the decontaminated hydrogenated pyrolysis oil. This may be more effective to remove dissolved air/oxygen from the pyoil as well as reduce the overhead space of the storage vessel. This nitrogen blanketing can additionally purge out any light chlorides compounds.

[0039] In certain embodiments, the mixed plastic waste pyrolysis oil is subject to filtration with a filter medium to remove a portion of solid particles greater than about 10 microns from the mixed plastic water pyrolysis oil to produce a filtered mixed plastic waste pyrolysis oil. The filtered mixed plastic waste pyrolysis oil is cooled to a temperature at least below 50 °C. In some embodiments, the filtered mixed plastic waste pyrolysis oil is cooled to room temperature, ranging from about 18 °C to about 28 °C. The filtered mixed plastic waste pyrolysis oil can be optionally passed through into a coalescing unit with a coalescing medium to separate at least a portion of water from the filtered mixed plastic waste pyrolysis oil. The coalescing medium provides a hydrophilic surface for coalescing water drops, where water is the dispersed phase. In certain embodiments, the interfacial area ranges from about 50 m ² /m ³ to greater than about 1000 m ² /m ³ . In certain embodiments, the coalescing unit contains one or more flat plate coalescers, mesh coalescers, or cartridge coalescers. In certain embodiments, the coalescing unit contains corrugated metal plates in a housing can also be used. Certain embodiments include supplying an acid scavenger to the mixed plastic waste pyrolysis oil prior to passing the mixed plastic waste pyrolysis oil through the first trap. An acid scavenger is added to the mixed plastic waste pyrolysis oil to neutralize acids and stabilize the mixed plastic waste pyrolysis oil for long term storage and transport. For example, inorganic oxide-supported functionalized amines and phosphines can be supplied as an acid scavenger. Acid scavengers used in these methods function at a temperature ranging from about 20 °C to about 75 °C. And, the amount of acid scavenger that is be used can range from about 20 mol% to about 40 mol% in excess based on the amount of acid component to be processed during a certain period of pyoil processing. Acid scavengers can remove about 80% to about 100% of the acidic components. Any solid compound formation in the acid scavenging is expected to separate by trap. Certain embodiments include steps of inter stage cooling of the mixed plastic waste pyrolysis oil to ambient temperature through inlet feed heat exchangers.

[0040] The design and sequencing of the modular traps include providing the large pore adsorbent beds as metal traps and silica traps as upfront units and the smaller pore adsorbents for halogenated compounds, oxygenates, nitrogenates, and polar compounds as downstream units. This design facilitates the additional removal of particulate matter in the large pore adsorbent beds, which also reduces any pressure drop issues that would be otherwise faced by the downstream adsorption units.

[0041] In certain embodiments, when the pyoil contains more than preferred free moisture that impacts the efficiency and life cycle of the modular beds, the pyoil is passed through a coalescing unit. The coalescing unit can be provided with a pad having hydrophobic surface for coalescing the free water. The collected water is then discharged as boot water in a gas-liquid-liquid separator. The design of this particular separator provides for a good column of boot water given for good separation. [0042] In other embodiments, instead of the coalescing bed design, the system includes a housing which traps moisture using water selective coalescing cartridges. This water removal unit is placed upstream of the modular adsorbent beds. The pyoil flows through each liquid - liquid coalescer cartridge in the inside-out direction. While flowing through the surface treated hydrophobic cartridge, free moisture combines, or coalesces, to form larger droplets. The coalesced water droplets quickly drain downwards along the cartridge, under the action of gravity and enhanced by surface treatment of the cartridge. The moisture-free pyoil flows upwards between the cartridges in the annular area, and exits the coalescer housing through the outlet nozzle. Once the droplets reach the bottom of the cartridge, they fall underneath into a still area where the liquid level progressively builds up over time. The liquid level in the lower and upper sections is monitored by level control which automatically controls the opening of the drain valves once the level has reached the high level. At the upstream of the liquid-liquid coalescing unit, the pyoil flows through the prefilter for effective removal of traces solid contamination to 10 microns or below. The prefilter will protect and prolong the life of the coalescer. The quality of the separation is measured with moisture measurements on the product pyoil line. The run length of the prefilter cartridge is a measure of its efficiency in removing suspended solids that would otherwise foul the coalescer element.

[0043] In certain embodiments, the large pore and high surface area aluminas are used as metal traps in refining the pyrolysis oil. In certain aspects, the efficiency of these metal traps is enhanced by modification with ligands which have capability to complex with metals. For example, surface hydroxyl groups present on the alumina can be treated with aminopropyltriethoxysilane followed by ligands such as ethylene diamine tetra acetic acid (EDTA) or nitrilo triacetic acid (NTA) to give the EDTA/NTA modified alumina. This surface modification of alumina with ligands can have the capability to trap metals, such as sodium, calcium, magnesium, and zinc. In other aspects, graded adsorbent metal trap beds are provided. In certain embodiments, the efficiency of the trap to remove a portion of the halogenated compounds can be increased by changing the ratio of divalent and trivalent cations.

[0044] For example, in a hydroprocessing experimental method, pyrolysis oil with about 2333 ppm chlorine and 57 ppm nitrogen was processed at 20 barg and 350 °C with a hydrogen to hydrocarbon ratio of 400 normal liters per liter in a tubular reactor using commercial hydrotreating catalyst. The resulting product had less than about 1 ppm of chlorine, about negligible amounts of Conradson Carbon Residue, less than about 0.1 ppm of nitrogen, and less than about 1 gram of iodine per 100g sample (low di olefin). This demonstrates that even with higher contamination, pyoil can be decontaminated to extremely low levels of contaminants through a polishing hydrotreating step.

[0045] In certain embodiments, the first and second traps or the second and third traps, or the first and third traps may be combined by use of a multi-functional trap capability medium. For example, metals, silica compounds, polar compounds and halogenated compounds can be removed by nickel and magnesium impregnated-hydrotalcite/ silicates, functionalized silicates such as sulfonated silica, or modified nickel and magnesium zeolites of different pore geometry. In another example, metals and silica compounds can be removed by sulfonated silica, polyacrylamide, Nafion®, polyvinyl alcohol, ion exchange resins, polydivinylbenzene modified with glycerol, or sugars.

[0046] Certain embodiments include supplying the decontaminated hydrogenated pyrolysis oil to a polishing trap. For example, a polishing trap can include high surface area structured silicates, positioned downstream of the molecular sieve unit(s) to remove very low level polar impurities that remained in the pyoil even after the multistage decontamination. In certain embodiments, the guard bed for removal of polar impurities is positioned downstream of hydrogenation units and can be integrated into a single unit. The process also includes a parallel system for adsorbent beds to be online during regeneration mode. Certain embodiments can include supplying the decontaminated hydrogenated pyrolysis oil to an optional diolefin saturator. The adsorbents can be in the form of a fixed bed or they can be presented in the form of a slurry/suspension.

[0047] Provided here are other embodiments of methods for removing metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil. FIG. 1 is a schematic flowchart for a method 100 for removing metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil. In step 102, a mixed plastic waste pyrolysis oil containing a plurality of metal compounds and non-metal compounds is supplied to a first adsorption bed having a first porous bed material to adsorb a portion of the metal compounds from the mixed plastic waste pyrolysis oil. In step 104, the mixed plastic waste pyrolysis oil from the first adsorption bed is passed through a second adsorption bed with a second porous bed material to adsorb a portion of the silica compounds from the mixed plastic waste pyrolysis oil. In step 106, the mixed plastic waste pyrolysis oil from the second adsorption bed is passed through a third adsorption bed with a third porous bed material to adsorb a portion of the halogenated compounds from the mixed plastic waste pyrolysis oil. In step 108, the mixed plastic waste pyrolysis oil from the third adsorption bed is introduced into a vessel containing a plurality of molecular sieves to adsorb a portion of the oxygenates, phosphorous compounds, and nitrogenates from the mixed plastic waste pyrolysis oil and produce a partially decontaminated pyrolysis oil. In step 110, the partially decontaminated pyrolysis oil from the vessel is supplied to a hydrogenation unit, where the partially decontaminated pyrolysis oil is processed in the presence of a hydrogenation catalyst in the hydrogenation unit to convert olefin compounds in the partially decontaminated pyrolysis oil into saturated hydrocarbon compounds. A decontaminated hydrogenated pyrolysis oil is produced with a reduced amount of plurality of metal compounds and non-metal compounds as compared to the amount of plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil. In certain embodiments, operating the hydrogenation unit at a temperature between about 80 °C and about 120 °C. The non-metal compounds are two or more of silica compounds, halogenated compounds, phosphorous compounds, oxygenates, and nitrogenates. Methods can also include adding an oxidation stabilizer to the decontaminated hydrogenated pyrolysis oil. Methods can also include adding a nitrogen blanket to the decontaminated hydrogenated pyrolysis oil.

[0048] In certain embodiments, the pores of the first porous bed material are greater in size than pores of the second porous bed material and the pores of the second porous bed material are greater in size than the pores of the third porous bed material. In certain embodiments, the method includes the step of passing the mixed plastic waste pyrolysis oil through a filter prior to passing the mixed plastic waste pyrolysis oil through the first adsorption bed. The filter removes at least a portion of solid particles greater than about 10 microns from the mixed plastic water pyrolysis oil to produce a filtered pyrolysis oil.

[0049] In certain embodiments, the method includes supplying the filtered pyrolysis oil from the filter to a coalescing unit with a coalescing medium therein to coalesce and separate at least a portion of water from the mixed plastic waste pyrolysis oil. In certain embodiments, the filtered pyrolysis oil is cooled to at least 50 °C before supplying the filtered pyrolysis oil to the coalescing unit. The coalescing medium is a pad or a filter cartridge. Certain embodiments include supplying an acid scavenger to the mixed plastic waste pyrolysis oil prior to passing the mixed plastic waste pyrolysis oil through the first adsorption bed. Methods can also include cooling the mixed plastic pyrolysis oil to a pre-selected temperature prior to passing the mixed plastic waste pyrolysis oil through the first adsorption bed.

[0050] Methods can also include determining, prior to introducing the mixed plastic waste pyrolysis oil into the vessel containing the plurality of molecular sieves, if concentration of metal compounds or halogenated compounds in the mixed plastic waste pyrolysis oil are greater than a pre-selected level. These pre-selected levels can range from about 0 ppm to about 500ppm of metal compounds and about 0 ppm to about 2000 ppm of halogenated compounds prior to processing methods described herein. In response to the concentration of metal compounds or halogenated compounds being greater than the pre-selected level, the mixed plastic waste pyrolysis oil is passed to a set of absorption beds that operate in parallel to the first adsorption bed, the second adsorption bed, and the third adsorption bed.

[0051] Methods can also include determining, prior to supplying the partially decontaminated pyrolysis oil to the hydrogenation unit, if concentrations of oxygenates and nitrogenates in the partially decontaminated pyrolysis oil are greater than a pre-selected level. These concentrations of oxygenates and nitrogenates can range from about 0 ppm to about 2000 ppm of oxygenates and about 0 ppm to about 1000 ppm of nitrogenates. In response to the concentration of the oxygenates and nitrogenates in the partially decontaminated pyrolysis oil being greater than the pre-selected level, the partially decontaminated pyrolysis oil is introduced from the third adsorption bed into a second vessel containing a second plurality of molecular sieves.

[0052] Provided here are modular systems for removing metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil. One such system includes the following modular apparatuses/units. A metals adsorption bed with an inlet and an outlet is configured to receive via the inlet a mixed plastic waste pyrolysis oil. The metals adsorption bed contains a porous bed material to adsorb metal compounds from the mixed plastic waste pyrolysis oil. In certain embodiments, this porous bed material in the metals adsorption bed contains one or more of alumina, ligand-modified alumina, magnesium metal alloys, calcium oxide, clay, calcium carbonate, acid-modified carbon, and activated charcoal.

[0053] A silica adsorption bed with an inlet and an outlet is positioned downstream of the metals adsorption bed. The inlet of the silica adsorption bed is connected to and in fluid communication with the outlet of the metals adsorption bed. The silica adsorption bed contains a porous bed material to adsorb silica compounds from the mixed plastic waste pyrolysis oil and the pores of this porous bed material are smaller in size than the pores of the porous bed material in the metals adsorption bed. In certain embodiments, the porous bed material in the silica adsorption bed contains one or more of nickel-impregnated silicates, nickel-impregnated hydrotalcites, magnesium-impregnated silicates, magnesium-impregnated hydrotalcites, nickel-modified zeolites, magnesium-modified zeolites, sulfonated silica, polyacrylamide, a copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resins, and a modified-polydivinylbenzene.

[0054] A halogenated compounds adsorption bed with an inlet and an outlet is positioned downstream of the silica adsorption bed. The inlet of the halogenated compounds adsorption bed is connected to and in fluid communication with the outlet of the silica adsorption bed. The halogenated compounds adsorption bed contains a porous bed material to adsorb halogenated compounds from the mixed plastic waste pyrolysis oil. The pores of the porous bed material of the halogenated compounds adsorption bed is smaller in size than the pores of the porous bed materials in the silica adsorption bed and the metals adsorption bed. In certain embodiments, the porous bed material of the halogenated compounds adsorption bed contains one or more of modified alumina, modified zeolites, modified silicates, modified phosphates, red mud, calcium hydroxide, aluminum-zinc carbon composites, calcium carbonate, and aluminum-magnesium composite oxides.

[0055] A molecular sieve unit containing a plurality of molecular sieves is positioned downstream of the halogenated compounds adsorption bed. The molecular sieve unit has an inlet connected to and in fluid communication with the outlet of the molecular sieve unit connected to the halogenated compounds adsorption bed. Each of the plurality of molecular sieves adsorb a portion of the oxygenates or nitrogenates or phosphorous compounds from the mixed plastic waste pyrolysis oil passing through the molecular sieve unit. A hydrogenation unit with an inlet and an outlet is positioned downstream of the molecular sieve unit. The inlet of the hydrogenation unit is connected to and in fluid communication with the outlet of the molecular sieve unit and receives the mixed plastic waste pyrolysis oil therefrom. The hydrogenation unit is configured with a hydrogenation catalyst therein and is operated under temperature and pressure conditions to facilitate conversion of at least a portion of the olefin compounds in the mixed plastic waste pyrolysis oil into one or more saturated hydrocarbon compounds and produce a decontaminated hydrogenated pyrolysis oil with a reduced amount of plurality of metal compounds and non-metal compounds as compared to the amount of plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil. In certain embodiments, the hydrogenation unit is operated at a temperature from about 80 °C and about 120 °C.

[0056] Embodiments of certain systems include one or more of a filter having an inlet and an outlet. The inlet of the filter is connected to and in fluid communication with a source of mixed plastic waste pyrolysis oil. The filter is configured to remove solid particles greater than about 10 microns from the mixed plastic water pyrolysis oil to produce a filtered mixed plastic waste pyrolysis oil. Embodiments of certain systems include a coalescing unit having an inlet and an outlet. The inlet of the coalescing unit is connected to and in fluid communication with the outlet of the filter. The coalescing unit contains a coalescing medium therein to separate water from the filtered mixed plastic waste pyrolysis oil. The outlet of the coalescing unit is connected to and in fluid communication with the inlet of the metals adsorption bed.

[0057] Embodiments of certain systems include an analyzer positioned to measure a concentration of metal compounds or halogenated compounds in the filtered mixed plastic waste pyrolysis oil before entering the molecular sieve unit. Embodiments of certain systems include an analyzer positioned to measure a concentration of metal compounds or halogenated compounds in the filtered mixed plastic waste pyrolysis oil downstream of the molecular sieve unit. Examples of such analyzers include those based on, without limitations, metal ions absorbance spectroscopy (such as OMA300) and energy dispersive X-ray fluorescence spectroscopy. Embodiments of certain systems include a heat exchanger in thermal communication with the mixed plastic waste pyrolysis oil. The heat exchanger is positioned upstream of the metals adsorption bed and configured to maintain temperature of the filtered mixed plastic waste pyrolysis oil within a preselected range.

[0058] In certain embodiments, an injector is positioned upstream of the metals adsorption bed to supply an acid scavenger into the filtered mixed plastic waste pyrolysis oil. Another injector can be positioned downstream of the hydrogenation unit to supply an oxidation stabilizer into the decontaminated hydrogenated pyrolysis oil.

[0059] Due to the modular nature of these adsorbent beds, the sequence of impurity removal can be partially implemented to get similar results or to meet product specifications. A parallel set of adsorbent beds can be configured and brought online to increase the robustness for continuous operation.

[0060] FIG. 2 is a diagrammatic representation of a modular system 200 for removing metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil. A metals adsorption bed 204 is configured to receive a mixed plastic waste pyrolysis oil stream 202. The metals adsorption bed 204 contains a porous bed material to adsorb metal compounds from the mixed plastic waste pyrolysis oil. A silica adsorption bed 208 is positioned downstream of the metals adsorption bed 204 to receive the mixed plastic waste pyrolysis oil with reduced content of metal compounds 206 therefrom. The silica adsorption bed 208 contains a porous bed material to adsorb silica compounds from the mixed plastic waste pyrolysis oil with reduced content of metal compounds 206 and the pores of this porous bed material are smaller in size than the pores of the porous bed material in the metals adsorption bed. A halogenated compounds adsorption bed 212 is positioned downstream of the silica adsorption bed 208 to receive the mixed plastic waste pyrolysis oil with reduced content of metal and silica compounds 210 therefrom. The halogenated compounds adsorption bed 212 contains a porous bed material to adsorb halogenated compounds from the mixed plastic waste pyrolysis oil with reduced content of metal and silica compounds 210. The pores of the porous bed material of the halogenated compounds adsorption bed 212 is smaller in size than the pores of the porous bed materials in the silica adsorption bed 208 and the metals adsorption bed 204.

[0061] A molecular sieve unit 216 containing a plurality of molecular sieves is positioned downstream of the halogenated compounds adsorption bed 212 to receive the mixed plastic waste pyrolysis oil with reduced content of metal, silica, and halogenated compounds 214 therefrom. The molecular sieve unit 216 has a plurality of molecular sieves to adsorb a portion of the oxygenates or nitrogenates or phosphorous compounds from the mixed plastic waste pyrolysis oil with reduced content of metal, silica, and halogenated compounds 214 received from the halogenated compounds adsorption bed 212. A hydrogenation unit 220 is positioned downstream of the molecular sieve unit 216 to receive the partially decontaminated pyrolysis oil 218 therefrom. The hydrogenation unit 220 is configured with a hydrogenation catalyst therein and is operated under temperature and pressure conditions to convert at least a portion of the olefin compounds in the partially decontaminated pyrolysis oil 218 into one or more saturated hydrocarbon compounds and produce a decontaminated hydrogenated pyrolysis oil 222 with a reduced amount of plurality of metal compounds and non-metal compounds as compared to the amount of plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil 202.

[0062] This system 200 also includes a nitrogen blanketing unit 226 configured to receive the partially decontaminated pyrolysis oil 218 via bypass line 230 or the decontaminated hydrogenated pyrolysis oil 222. Nitrogen blanketing can be achieved by purging or sparging or bubbling nitrogen gas into the nitrogen blanketing unit 226 to produce the processed pyrolysis oil 228.

[0063] This system 200 also includes optionally a filter 234 that is connected to and in fluid communication with a source of raw mixed plastic waste pyrolysis oil feed 232. The filter 234 is configured to remove solid particles greater than about 10 microns from the raw mixed plastic waste pyrolysis oil feed 232 to produce a mixed plastic waste pyrolysis oil stream 202. This system 200 also includes optionally a coalescing unit 238 that is connected to and in fluid communication with the filter 234. The coalescing unit 238 contains a coalescing medium therein to separate water from the filtered mixed plastic waste pyrolysis oil 236 from the filter 234. The coalescing unit 238 is connected to and in fluid communication with the filter 234 and the metals adsorption bed 204. [0064] This system 200 also includes optionally additional metals adsorption bed 240, an additional silica adsorption bed 242, and an additional halogenated compounds adsorption bed 244 that operate in parallel to the metals adsorption bed 204, the silica adsorption bed 208, and the halogenated compounds adsorption bed 212. These parallel beds 240, 242, and 244 are brought online when any one or more of the corresponding adsorption beds 204, 208, and 212 are down or removed from operation, such as during regeneration of the porous bed materials.

[0065] This system 200 also includes optionally an additional molecular sieve unit 246 that operates in parallel to the molecular sieve unit 216. This parallel molecular sieve unit 246 is brought online when the molecular sieve unit 216 is down or removed from operation, such as during regeneration of the porous bed materials. This system 200 also includes optionally a polishing trap 248 positioned downstream of the molecular sieve unit 216 or polishing trap 250 positioned downstream of the molecular sieve unit 246. This system 200 also includes optionally a polishing trap 252 positioned downstream of the hydrogenation unit 220.

[0066] This system 200 also includes optionally one or more analyzers 254 and 256 positioned to measure a concentration of metal compounds or halogenated compounds in the mixed plastic waste pyrolysis oil 214 before entering the entering the molecular sieve unit 216 or 246. This system 200 also includes optionally an analyzer 258 positioned downstream of the molecular sieve unit 216 or 246 to measure a concentration of metal compounds or halogenated compounds in the partially decontaminated pyrolysis oil 218.

[0067] Other objects, features and advantages of the disclosure will become apparent from the following figures, detailed description, and examples. It should be understood, however, that the figures, detailed description, and examples, while indicating specific embodiments 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 this detailed description. In further embodiments, features from specific embodiments may be combined with features from other embodiments. For example, features from one embodiment may be combined with features from any of the other embodiments. In further embodiments, additional features may be added to the specific embodiments described herein.