Method and system for purification of pyrolysis oil using modular units 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

Abstract

A modular system and method for removing contaminants from mixed plastic waste pyrolysis oil and optionally processing it in a hydrogenation unit to produce purified hydrogenated pyrolysis oil. These contaminants include metal and non-metal compounds, such as silica compounds, halogenated compounds, phosphorus compounds, oxygenates and nitrogenates.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 264,102, filed November 16, 2021, which is incorporated by reference herein in its entirety. The present disclosure generally relates to a modular system and method for removing a portion of metal and non-metal compounds from mixed plastic waste pyrolysis oil. The present disclosure also relates to subjecting the partially clarified pyrolysis oil to further processing in a hydrogenation unit to produce a purified hydrogenated pyrolysis oil. [Background technology]

[0002] Pyrolysis oil (pyoil) from mixed plastic waste has emerged as an alternative feedstock via chemical recycling. Single sorbent systems may not be efficient in purifying pyrolysis oil with a large number of contaminants, and as a result, pyrolysis oil obtained from such processes is prone to decomposition during storage and transportation as well as has heteroatoms that are not tolerated in downstream large volume processing units. Although hydroprocessing is effective in removing contaminants, it is costly and is mostly implemented in central processing facilities such as refineries or steam crackers. However, pyrolysis oil facilities are distributed in a decentralized manner due to the availability of feed, and pyrolysis oil needs to be transported to a central facility for further processing. Therefore, it is desirable to have modular operations in a decentralized facility for purification. Pyrolysis of mixed plastics is carried out in thermal reactors such as tanks, furnaces, auger reactors and extruders. The mixed plastic waste pyrolysis oil from these operations contains several impurities including metals, chlorides and olefins, which makes the transportation and storage of this mixed plastic waste pyrolysis oil difficult from decentralized manufacturing facilities. Part of the implementation of the removal of heteroatoms, metals and unsaturated hydrocarbons can be achieved by hydrotreating, oxidation, extraction, adsorption and precipitation. Summary of the Invention

[0003] To address these shortcomings in the art, applicants have developed a modular purification system and method for processing mixed plastic waste pyrolysis oil and hydrocarbon streams. Also provided herein is a system and method for processing the partially purified pyrolysis oil by a hydrogenation process, which can also be subjected to further hydrocracking and distillation.

[0004] Herein, a method for removing metal and non-metal compounds from mixed plastic waste pyrolysis oil is provided. One such method includes the steps of obtaining mixed plastic waste pyrolysis oil containing a plurality of metal 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 having 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 having a third porous 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, phosphorus compounds and nitrogenates from the mixed plastic waste pyrolysis oil to produce a partially purified pyrolysis oil. The method further includes feeding the partially purified pyrolysis oil from the vessel to a hydrogenation unit, and treating the partially purified pyrolysis oil in the hydrogenation unit in the presence of a hydrogenation catalyst to convert a portion of the olefinic compounds in the partially purified pyrolysis oil to saturated hydrocarbon compounds and produce a purified hydrogenated pyrolysis oil having a reduced amount of the plurality of metal compounds and non-metal compounds compared to the amount of the 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 between about 80° C. and about 120° C. The non-metal compounds are two or more of silica compounds, halogenated compounds, phosphorus compounds, oxygenates, and nitrogenates. In certain embodiments, the pores of the first porous bed material are larger in size than the pores of the second porous bed material, and the pores of the second porous bed material are larger in size than the pores of the third porous bed material.

[0005] In certain embodiments, the first porous bed material contains one or more of alumina, ligand-modified alumina, magnesium metal alloy, calcium oxide, clay, calcium carbonate, acid-modified carbon, and activated carbon. In certain embodiments, the second porous bed material contains one or more of nickel-impregnated silicate, nickel-impregnated hydrotalcite, magnesium-impregnated silicate, magnesium-impregnated hydrotalcite, nickel-modified zeolite, magnesium-modified zeolite, sulfonated silica, polyacrylamide, copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resin, and modified polydivinylbenzene. In certain embodiments, the third bed material contains one or more of modified alumina, modified zeolite, modified silicate, modified phosphate, red mud, calcium hydroxide, aluminum-zinc carbon complex, calcium carbonate, and aluminum-magnesium complex oxide. Embodiments may also include adding an oxidation stabilizer to the purified hydrotreated pyrolysis oil.Embodiments may also include adding a nitrogen blanket to the purified hydrotreated pyrolysis oil.

[0006] In certain embodiments, the method includes 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 removing at least a portion of solid particles larger than about 10 μm from the mixed plastic waste pyrolysis oil to produce a filtered pyrolysis oil.

[0007] In certain embodiments, the method includes feeding the filtered pyrolysis oil from the filter to a coalescing unit containing a coalescing medium to coalesce and separate at least a portion of the water from the mixed plastic waste pyrolysis oil. In certain embodiments, the filtered pyrolysis oil is cooled to at least 50° C. before feeding the filtered pyrolysis oil to the coalescing unit. The coalescing medium is a pad or a filter cartridge. Certain embodiments include feeding an acid scavenger to the mixed plastic waste pyrolysis oil before passing the mixed plastic waste pyrolysis oil through the first adsorption bed. Embodiments may also include cooling the mixed plastic waste pyrolysis oil to a preselected temperature before passing the mixed plastic waste pyrolysis oil through the first adsorption bed.

[0008] An embodiment may also include determining whether a concentration of metal or halogenated compounds in the mixed plastic waste pyrolysis oil is greater than a preselected level prior to introducing the mixed plastic waste pyrolysis oil into the vessel containing the plurality of molecular sieves. If the concentration of metal or halogenated compounds is greater than a preselected level, the mixed plastic waste pyrolysis oil is passed through a set of adsorption beds operating in parallel with the first adsorption bed, the second adsorption bed, and the third adsorption bed.

[0009] Embodiments may also include determining whether the concentration of oxygenates and nitrogenates in the partially clarified pyrolysis oil is greater than a preselected level prior to feeding the partially clarified pyrolysis oil to the hydrogenation unit. If the concentration of oxygenates and nitrogenates in the partially clarified pyrolysis oil is greater than a preselected level, the partially clarified pyrolysis oil is introduced from the third adsorbent bed into a second vessel containing a second plurality of molecular sieves.

[0010] Another method for removing metal and non-metal compounds from 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 filtering medium to remove a portion of solid particles larger than about 10 μm from the mixed plastic waste pyrolysis oil to produce a filtered mixed plastic waste pyrolysis oil, cooling the filtered mixed plastic waste pyrolysis oil to a temperature of at least less than 50° C., introducing the filtered mixed plastic waste pyrolysis oil into a coalescing unit including a coalescing medium to separate at least a portion of the water from the filtered mixed plastic waste pyrolysis oil, and passing the filtered mixed plastic waste pyrolysis oil through a first medium in a first trap to separate the filtered mixed plastic waste pyrolysis oil from the filtered mixed plastic waste pyrolysis oil. The method includes the steps of removing a portion of the metal compounds from the 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, and conveying the filtered mixed plastic waste pyrolysis oil from the third trap to a molecular sieve unit having a plurality of molecular sieves to adsorb at least a portion of the oxygenates, nitrogenates, or phosphorus compounds from the filtered mixed plastic waste pyrolysis oil to produce a partially purified pyrolysis oil. The method further includes the steps of feeding the partially purified pyrolysis oil to a hydrogenation unit and treating the partially purified pyrolysis oil in the hydrogenation unit in the presence of a hydrogenation catalyst to convert at least a portion of the olefinic compounds in the partially purified pyrolysis oil to one or more saturated hydrocarbon compounds and produce a purified hydrogenated pyrolysis oil having a reduced amount of a plurality of metal compounds and non-metal compounds compared to the amount of the plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil.

[0011] In certain embodiments, the first medium contains one or more of alumina, ligand-modified alumina, magnesium metal alloy, calcium oxide, clay, calcium carbonate, acid-modified carbon, and activated carbon. In certain embodiments, the first medium is a nanofiltration membrane or a polymer membrane. In certain embodiments, the second medium contains one or more of nickel-impregnated silicate, nickel-impregnated hydrotalcite, magnesium-impregnated silicate, magnesium-impregnated hydrotalcite, nickel-modified zeolite, magnesium-modified zeolite, sulfonated silica, polyacrylamide, copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resin, and modified polydivinylbenzene. In certain embodiments, the third medium contains one or more of modified alumina, modified zeolite, modified silicate, modified phosphate, red mud, calcium hydroxide, aluminum-zinc carbon complex, calcium carbonate, and aluminum-magnesium complex oxide. Certain embodiments include operating the hydrogenation unit at a temperature between about 80° C. and about 120° C. Certain embodiments include adding an oxidation stabilizer to the clarified hydrogenated pyrolysis oil. Certain embodiments include adding a nitrogen blanket to the clarified hydrogenated pyrolysis oil.

[0012] Certain embodiments include providing 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 cooling the mixed plastic waste pyrolysis oil to a preselected temperature prior to passing the mixed plastic waste pyrolysis oil through the first trap.

[0013] Provided herein is a modular system for removing metal and non-metal compounds from mixed plastic waste pyrolysis oil. One such system includes (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 larger than about 10 μm from the mixed plastic waste pyrolysis oil to produce a filtered mixed plastic waste pyrolysis oil; and (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 configured to remove solid particles larger than about 10 μm from the mixed plastic waste pyrolysis oil to produce a filtered mixed plastic waste pyrolysis oil. (c) a metal sorbent bed having a third inlet and a third outlet, the third inlet being connected and in fluid communication with the second outlet, the metal sorbent bed containing a first porous bed material that sorbs metal compounds from the filtered mixed plastic waste pyrolysis oil; and (d) a silica sorbent bed having a fourth inlet and a fourth outlet, the fourth inlet being connected and in fluid communication with the third outlet, the silica sorbent bed absorbing metal compounds from the filtered mixed plastic waste pyrolysis oil. (e) a halogenated compound adsorption bed having a fifth inlet and a fifth outlet, the fifth inlet being connected to and in fluid communication with the fourth outlet, the halogenated compound adsorption bed having a third porous bed material for adsorbing 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 being connected and in fluid communication with the fifth outlet, the plurality of molecular sieves adsorbing a portion of the oxygenates or nitrogenates or phosphorus 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 being connected and in fluid communication with the sixth outlet.and a hydrogenation unit operable to receive the filtered mixed plastic waste pyrolysis oil therefrom, the hydrogenation unit containing a hydrogenation catalyst and operable to convert at least a portion of the olefinic compounds in the filtered mixed plastic waste pyrolysis oil to one or more saturated hydrocarbon compounds and produce a purified hydrogenated pyrolysis oil having reduced amounts of a plurality of metal compounds and non-metal compounds compared to the amount of the plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil. In a particular embodiment, the hydrogenation unit is operated at a temperature of about 80° C. to about 120° C.

[0014] Certain system embodiments include an analyzer arranged to measure the concentration of metal compounds or halogenated compounds in the filtered mixed plastic waste pyrolysis oil before it enters the sixth inlet. Certain system embodiments include an analyzer arranged to measure the concentration of metal compounds or halogenated compounds in the filtered mixed plastic waste pyrolysis oil downstream of the hydrogenation unit. Certain system embodiments include a heat exchanger in thermal communication with the mixed plastic waste pyrolysis oil, arranged upstream of the metal sorption bed, and configured to maintain the temperature of the filtered mixed plastic waste pyrolysis oil within a preselected range. In certain embodiments, a first injector is arranged upstream of the metal sorption bed to supply an acid scavenger to the filtered mixed plastic waste pyrolysis oil, and a second injector is arranged downstream of the hydrogenation unit to supply an oxidation stabilizer to the purified hydrogenated pyrolysis oil.

[0015] In certain embodiments, the first porous bed material contains one or more of alumina, ligand-modified alumina, magnesium metal alloy, calcium oxide, clay, calcium carbonate, acid-modified carbon, and activated carbon. In certain embodiments, the second porous bed material contains one or more of nickel-impregnated silicate, nickel-impregnated hydrotalcite, magnesium-impregnated silicate, magnesium-impregnated hydrotalcite, nickel-modified zeolite, magnesium-modified zeolite, sulfonated silica, polyacrylamide, copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resin, and modified polydivinylbenzene. In certain embodiments, the third porous bed material contains one or more of modified alumina, modified zeolite, modified silicate, modified phosphate, red mud, calcium hydroxide, aluminum-zinc carbon complex, calcium carbonate, and aluminum-magnesium complex oxide.

[0016] Still other aspects and advantages of these exemplary embodiments and other embodiments are discussed in detail herein. Furthermore, it should be understood that both the preceding information and the following detailed description provide merely illustrative examples of the various aspects and embodiments and are intended to provide an overview or framework for understanding the nature and features of the claimed aspects and embodiments. Thus, these and other objects, together with advantages and features of the present disclosure, will become apparent with reference to the following description and the accompanying drawings. Furthermore, it will be understood that the features of the various embodiments described herein are not mutually exclusive and may exist in various combinations and permutations. The accompanying drawings 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 the embodiments of the present disclosure, and together with the detailed description, serve to explain the principles of the embodiments discussed herein. There is no intention to show the 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 implemented. 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 the embodiments of the present disclosure. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic flow chart of a method for removing metal and non-metal compounds from mixed plastic waste pyrolysis oil, according to an embodiment. [Diagram 2] FIG. 1 is a schematic diagram of a modular system for removing metal and non-metal compounds from mixed plastic waste pyrolysis oil, according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The present disclosure describes various embodiments relating to a method and modular system for removing metal and non-metal compounds from mixed plastic waste pyrolysis oil and subjecting it to hydrogenation. Further embodiments may be described and disclosed. 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 be described in particular detail so as not to unnecessarily obscure the various embodiments. Further, illustrations of the various embodiments may omit certain features or details so as not to obscure the various embodiments.

[0019] The description may use the phrases "in some embodiments," "in various embodiments," "in an embodiment," or "in an embodiment," each of which may refer to one or more of the same or different embodiments. Additionally, the terms "comprising," "including," "having," and the like are synonymous when used in reference to embodiments of the present disclosure. The term "about" is defined as close as understood by one of ordinary skill in the art. In one non-limiting embodiment, these terms are defined as within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%. The terms "reduce," "reduced," or any variation thereof, as used in the claims and / or this specification, include any measurable decrease or complete inhibition of achieving a desired result.

[0020] The use of "a" or "an" in the claims or this specification in combination with any of the terms "comprising," "including," "containing," or "having" can mean "one," but is also consistent with the meanings of "one or more," "at least one," and "one or more than one." The terms "wt. %, "vol. %, or "mole %" refer to the weight, volume, or mole percentage of a component relative to the total weight, total volume, or total moles of a material, respectively, including the component. In a non-limiting example, 10 grams of a component in 100 grams of a material is 10 wt. % of the component.

[0021] "Comprising" (and any form of comprising, e.g., "comprise" and "comprises"), "having" (and any form of comprising, e.g., "have" and "has"), "including" (and any form of comprising, e.g., "includes" and "include"), or "containing" (and any form of containing, e.g., "contains" and "contain") are inclusive or open-ended and do not exclude additional, unrecited elements or method steps. Disclosed herein is a modular system and method for continuous trapping to remove specific contaminants from mixed plastic waste pyrolysis oil along with a hydrogenation unit located downstream of the modular trap.

[0022] Certain embodiments include a modular purification system capable of processing pyrolysis oil and hydrocarbon streams. The system is configured to capture acids and polar components, promote diene saturation, and remove metals and chlorides to make the pyrolysis oil suitable for feeding to a steam cracker or other unit to the refinery. The system contains two or more modular units / traps for removing metal and non-metal compounds. In certain embodiments, regeneration of the adsorbent beds of polar compounds, nitrogenates, oxygenates, and silica compounds is by coke burning. These units may be equipped with sensors and / or analyzers to detect when the chloride and metal compound levels exceed preset acceptable levels. Certain embodiments of the system include parallel traps to remove metal and non-metal compounds to facilitate continuous operation of the unit with reduced downtime. An embodiment of the method for removing metal and non-metal compounds from mixed plastic waste pyrolysis oil includes the following steps: Passing the mixed plastic waste pyrolysis oil having a plurality of metal and non-metal compounds 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 alloy, calcium oxide, clay, calcium carbonate, acid-modified carbon, and activated carbon. In certain embodiments, the first medium is a nanofiltration membrane or a polymer membrane. Examples of metals present in the mixed plastic waste pyrolysis oil include vanadium, antimony, mercury, and cadmium. The metal compounds present in the pyrolysis oil may be in either the form of organic metal or inorganic metal salts and oxides. In certain embodiments, the amount of metal compounds is reduced to less than about 50% by weight. Different alternative materials that can function as the first medium include acid-modified carbon, activated carbon materials, nanofiltration membranes (e.g., montmorillonite, kaolin, tobermorite, magnetite, silica gel and alumina), and polymeric membranes (e.g., low density polyethylene-styrene / acrylic acid copolymers).

[0023] 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. Common silica compounds present in the mixed plastic waste pyrolysis oil are either organosiloxanes, such as cyclic polydimethylsiloxanes (D3, D4, D5 and D6) or linear volatile methylsiloxanes (L3, L4, L5 or L6). The silicon content in the pyrolysis oil is about 300 ppm, and this content varies depending on the source of the plastic, 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 120 ppm. In certain embodiments, the second medium contains one or more of nickel-impregnated silicate, nickel-impregnated hydrotalcite, magnesium-impregnated silicate, magnesium-impregnated hydrotalcite, nickel-modified zeolite, magnesium-modified zeolite, sulfonated silica, polyacrylamide, copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resin, and modified polydivinylbenzene.

[0024] 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 pyrolysis oil include, without limitation, 3-chloro-3-methylpentane, 2-chloro-2-methylpentane, (2-chloroethyl)benzene, 1-chloro-2, ethylbenzene, 2-chloroethylbenzene, chlorobenzene, 3-chloro-2-methyl-1-butene, benzyl chloride, 3-chloro-1-propenylbenzene, 3-chlorocyclohexene, 1-chloro-3-methylbutane, 3-chloro-1-phenyl-2-butene, 2-chloro-2-butenyl-benzene, 1-chlorocyclopentene, 3-chloro-3-methylpentane, 2-chloro-2-methylpentane, (1-chloromethyl)-2-ethylbenzene, 3-chloroallylbenzene, and 3-chloro-3-methylheptane, (2-chloroethyl)-benzene. In certain embodiments, the third medium contains one or more of modified alumina, modified zeolite, modified silicate, modified phosphate, red mud, calcium hydroxide, aluminum-zinc carbon complex, calcium carbonate, and aluminum-magnesium complex oxide.

[0025] The mixed plastic waste pyrolysis oil from the third trap is fed to a molecular sieve unit having a plurality of molecular sieves that adsorb at least a portion of the oxygenates or nitrogenates or phosphorus compounds from the filtered mixed plastic waste pyrolysis oil to produce a partially purified pyrolysis oil. The molecular sieves include acidic alumina, 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 the oxygenates or nitrogenates or phosphorus compounds to remove about 70% to 100% weight percent of the oxygenates or nitrogenates or phosphorus compounds.

[0026] The method further includes feeding the partially purified pyrolysis oil to a hydrogenation unit, and treating the partially purified pyrolysis oil in the hydrogenation unit in the presence of a hydrogenation catalyst to convert at least a portion of the olefinic compounds in the partially purified pyrolysis oil to one or more saturated hydrocarbon compounds and produce a purified hydrogenated pyrolysis oil having a reduced amount of a plurality of metal compounds and non-metal compounds compared to the amount of the plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil. A particular embodiment includes operating the hydrogenation unit at a temperature between about 80°C and about 120°C. The partially purified pyrolysis oil is subjected to a hydrogenation process as a final step to minimize hydrogen consumption in the removal of impurities such as halogenated compounds, oxygenates, nitrogenates, silica compounds and polar compounds and to increase hydrogen available for saturation of olefinic species. In a particular embodiment, the modular trap is operated at gradually increasing temperatures with the metal trap being the lowest temperature, and the hydrogenation unit is operated at a temperature between about 100°C and about 120°C.

[0027] The method may also include the addition of an oxidation stabilizer to the purified hydrogenated pyrolysis oil. The oxidation stabilizer quenches radicals in the purified hydrogenated pyrolysis oil and stabilizes the purified hydrogenated pyrolysis oil for long-term storage and transportation. For example, oxygen stabilizers such as substituted phenols and substituted amines may be provided in an amount ranging from 500 ppm to 2500 ppm to stabilize the pyrolysis oil with an efficiency ranging from 80% to 95%. The use of a nitrogen blanket may further help improve the efficiency of the stabilization process efficiency to approximately or equal to 100%.

[0028] The method may also include adding a nitrogen blanket to the purified hydrotreated pyrolysis oil to protect the purified hydrotreated pyrolysis oil from any further potential oxidation reactions. Nitrogen blanketing may be achieved by purging dry nitrogen gas into the storage vessel to eliminate air above the purified hydrotreated pyrolysis oil. Nitrogen blanketing may be achieved by sparging or bubbling nitrogen gas into the purified hydrotreated pyrolysis oil. This may be more effective in reducing the overhead space of the storage vessel as well as removing dissolved air / oxygen from the pyrolysis oil. This nitrogen blanketing may further purge light chloride compounds.

[0029] In certain embodiments, the mixed plastic waste pyrolysis oil is subjected to filtration through a filtration medium to remove a portion of the solid particles larger than about 10 μm from the mixed plastic waste pyrolysis oil to produce a filtered mixed plastic waste pyrolysis oil. The filtered mixed plastic waste pyrolysis oil is cooled to a temperature of at least less than 50° C. In some embodiments, the filtered mixed plastic waste pyrolysis oil is cooled to a room temperature in the range of about 18° C. to about 28° C. The filtered mixed plastic waste pyrolysis oil may be passed through a coalescing unit containing a coalescing medium to separate at least a portion of the water from the filtered mixed plastic waste pyrolysis oil. The coalescing medium provides a hydrophilic surface that coalesces the water droplets, where the water becomes the dispersed phase. In certain embodiments, the interfacial area is less than 50 m 2 / m 3 ~about 1000m 2 / m 3In certain embodiments, the coalescing unit contains one or more flat plate coalescers, mesh coalescers, or cartridge coalescers. In certain embodiments, a coalescing unit containing corrugated metal plates in a housing may also be used. Certain embodiments include a step of providing an acid scavenger to the mixed plastic waste pyrolysis oil before passing the mixed plastic waste pyrolysis oil through the first trap. The acid scavenger is added to the mixed plastic waste pyrolysis oil to neutralize the acid and stabilize the mixed plastic waste pyrolysis oil for long-term storage and transportation. For example, inorganic oxide-supported functionalized amines and phosphines may be provided as acid scavengers. The acid scavengers used in these methods function at temperatures ranging from about 20° C. to about 75° C. Also, the amount of acid scavenger used may range from about 20 mol % to about 40 mol % excess relative to the amount of acid components treated during a certain period of pyrolysis oil treatment. The acid scavenger may remove about 80% to about 100% of the acid components. The solid compound formation in the acid trap is expected to separate by the trap. Certain embodiments include an interstage step of cooling the mixed plastic waste pyrolysis oil to ambient temperature via an inlet feed heat exchanger.

[0030] The modular trap design and arrangement includes large pore adsorbent beds as metal and silica traps as the frontal units and smaller pore adsorbents for halide, oxygenate, nitrogenate and polar compounds as downstream units. This design facilitates further removal of particulate matter in the large pore adsorbent beds, which also reduces the pressure drop challenges that would otherwise be faced by the downstream adsorption units. In one particular embodiment, when the pyrolysis oil contains more than a preferred amount of free moisture that affects the efficiency and life cycle of the modular beds, the pyrolysis oil is passed through a coalescing unit. The coalescing unit may comprise a pad with a hydrophobic surface that coalesces the free water. The collected water is then discharged as boot water in a gas-liquid-liquid separator. This particular separator design provides a good column of well separated boot water.

[0031] In another embodiment, instead of a coalescing bed design, the system includes a housing that traps water using a water-selective coalescing cartridge. This water removal unit is located upstream of the modular adsorbent bed. The pyrolysis oil flows inward and outward through each liquid-liquid coalescing cartridge. While flowing through the surface-treated hydrophobic cartridge, the free water is combined or coalesced to form larger droplets. The aggregated water droplets flow quickly downward along the cartridge under the action of gravity and are enhanced by the surface treatment of the cartridge. The water-free pyrolysis oil flows upward between the cartridges in the annular zone and exits the coalescing housing through the outlet nozzle. Once the droplets reach the bottom of the cartridge, they fall into a quiescent region where the liquid level gradually builds up over time. The liquid level in the lower and upper sections is monitored by a level control that automatically controls the opening of a drain valve when the level reaches a high level. Upstream of the liquid-liquid coalescing unit, the pyrolysis oil flows through a prefilter for effective removal of trace solid contaminants to 10 μm or less. The prefilter protects the coalescer and extends its life. The quality of separation is measured by moisture measurements on the product pyrolysis oil line. The run length of the prefilter cartridge is a measure of its efficiency in removing suspended solids that would otherwise foul the coalescer elements.

[0032] In certain embodiments, large pore and large surface area aluminas are used as metal traps in the purification of pyrolysis oils. In certain aspects, the efficiency of these metal traps is enhanced by modification with ligands capable of complexing with metals. For example, hydroxyl groups present on the surface of alumina can be treated with aminopropyltriethoxysilane followed by ligands such as ethylenediaminetetraacetic acid (EDTA) or nitrilotriacetic acid (NTA) to obtain EDTA / NTA modified alumina. This surface modification of alumina with ligands can have the ability to trap metals such as sodium, calcium, magnesium, and zinc. In other aspects, a graded sorbent metal trap bed is provided. In certain embodiments, the efficiency of the trap to remove a portion of the halogenated compounds can be increased by modifying the ratio of divalent to trivalent cations.

[0033] For example, in a hydrotreating experiment, pyrolysis oil with about 2333 ppm chlorine and 57 ppm nitrogen was treated in a tubular reactor at 20 barg and 350° C. with a hydrogen to hydrocarbon ratio of 400 normal liters per liter using a commercial hydrotreating catalyst. The resulting product had less than about 1 ppm chlorine, almost negligible Conradson carbon residue, less than about 0.1 ppm nitrogen, and about 1 gram iodine per 100 g of sample (low diolefins). This shows that pyrolysis oil, even when it is more contaminated, can be purified to very low levels of contaminants by a polishing hydrotreating step.

[0034] In certain embodiments, the first and second traps, or the second and third traps, or the first and third traps, may be combined by using a medium with multifunctional trapping capabilities. For example, metals, silica compounds, polar compounds, and halide compounds may be removed by nickel and magnesium impregnated hydrotalcites / silicates, functionalized silicates such as sulfonated silica, or modified nickel and magnesium zeolites of different pore geometries. In another example, metals and silica compounds may be removed by sulfonated silica, polyacrylamides, Nafion®, polyvinyl alcohol, ion exchange resins, polydivinylbenzene modified with glycerol, or sugars.

[0035] Certain embodiments include feeding the purified hydrotreated pyrolysis oil to a polishing trap. For example, the polishing trap may be placed downstream of a molecular sieve unit and include a high surface area structured silicate to remove very low levels of polar impurities remaining in the pyrolysis oil even after multi-stage purification. In certain embodiments, a guard bed for the removal of polar impurities may be placed downstream of the hydrogenation unit and integrated into a single unit. The method also includes a parallel system of adsorbent beds that are online during the regeneration mode. Certain embodiments may include feeding the purified hydrotreated pyrolysis oil to an optional diolefin saturator. The adsorbent may be in the form of a fixed bed or the adsorbent may be in the form of a slurry / suspension.

[0036] Another embodiment of a method for removing metal and non-metal compounds from mixed plastic waste pyrolysis oil is provided herein. FIG. 1 is a schematic flow chart of a method 100 for removing metal and non-metal compounds from mixed plastic waste pyrolysis oil. In step 102, the mixed plastic waste pyrolysis oil containing a plurality of metal and non-metal compounds is fed 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 having 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 having 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, phosphorus compounds, and nitrogenates from the mixed plastic waste pyrolysis oil, and a partially purified pyrolysis oil is produced. In step 110, the partially purified pyrolysis oil from the vessel is fed to a hydrogenation unit, where the partially purified pyrolysis oil is treated in the presence of a hydrogenation catalyst to convert the olefin compounds in the partially purified pyrolysis oil into saturated hydrocarbon compounds. The purified hydrogenated pyrolysis oil is produced with a reduced amount of a plurality of metal compounds and non-metal compounds compared to the amount of a plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil. In a particular embodiment, the hydrogenation unit is operated at a temperature between about 80° C. and about 120° C. The non-metal compounds are two or more of silica compounds, halogenated compounds, phosphorus compounds, oxygenates, and nitrogenates. The method may also include adding an oxidation stabilizer to the purified hydrogenated pyrolysis oil. The method may also include the step of adding a nitrogen blanket to the clarified hydrotreated pyrolysis oil.

[0037] In certain embodiments, the pores of the first porous bed material are larger in size than the pores of the second porous bed material, and the pores of the second porous bed material are larger in size than the pores of the third porous bed material. In certain embodiments, the method includes passing the mixed plastic waste pyrolysis oil through a filter before passing the mixed plastic waste pyrolysis oil through the first adsorption bed. The filter removes at least a portion of the solid particles larger than about 10 μm from the mixed plastic waste pyrolysis oil to produce a filtered pyrolysis oil.

[0038] In certain embodiments, the method includes feeding the filtered pyrolysis oil from the filter to a coalescing unit containing a coalescing medium to coalesce and separate at least a portion of the water from the mixed plastic waste pyrolysis oil. In certain embodiments, the filtered pyrolysis oil is cooled to at least 50° C. before feeding the filtered pyrolysis oil to the coalescing unit. The coalescing medium is a pad or a filter cartridge. Certain embodiments include feeding an acid scavenger to the mixed plastic waste pyrolysis oil before passing the mixed plastic waste pyrolysis oil through the first adsorption bed. The method may also include cooling the mixed plastic waste pyrolysis oil to a preselected temperature before passing the mixed plastic waste pyrolysis oil through the first adsorption bed.

[0039] The method may also include determining whether the concentration of metal compounds or halogenated compounds in the mixed plastic waste pyrolysis oil is greater than a preselected level prior to introducing the mixed plastic waste pyrolysis oil into the vessel containing the plurality of molecular sieves. These preselected levels may range from about 0 ppm to about 500 ppm of metal compounds and about 0 ppm to about 2000 ppm of halogenated compounds prior to the treatment methods described herein. If the concentration of metal compounds or halogenated compounds is greater than the preselected levels, the mixed plastic waste pyrolysis oil is passed through a set of adsorption beds operating in parallel with the first adsorption bed, the second adsorption bed, and the third adsorption bed. The method also includes determining whether concentrations of oxygenates and nitrogenates in the partially clarified pyrolysis oil are greater than a preselected level prior to feeding the partially clarified pyrolysis oil to the hydrogenation unit. These concentrations of oxygenates and nitrogenates can range from about 0 ppm to about 2000 ppm oxygenates and about 0 ppm to about 1000 ppm nitrogenates. If the concentrations of oxygenates and nitrogenates in the partially clarified pyrolysis oil are greater than the preselected levels, the partially clarified pyrolysis oil is introduced from the third adsorbent bed into a second vessel containing a second plurality of molecular sieves.

[0040] Provided herein is a modular system for removing metal and non-metal compounds from mixed plastic waste pyrolysis oil. One such system comprises the following modular devices / units: A metal sorbent bed having an inlet and an outlet is configured to receive the mixed plastic waste pyrolysis oil via the inlet. The metal sorbent bed contains a porous bed material that adsorbs metal compounds from the mixed plastic waste pyrolysis oil. In certain embodiments, the porous bed material in the metal sorbent bed contains one or more of alumina, ligand-modified alumina, magnesium metal alloy, calcium oxide, clay, calcium carbonate, acid-modified carbon, and activated carbon.

[0041] A silica sorbent bed having an inlet and an outlet is disposed downstream of the metal sorbent bed. The inlet of the silica sorbent bed is connected to and in fluid communication with the outlet of the metal sorbent bed. The silica sorbent bed contains a porous bed material that adsorbs silica compounds from the mixed plastic waste pyrolysis oil, and the pores of the porous bed material are smaller in size than the pores of the porous bed material in the metal sorbent bed. In certain embodiments, the porous bed material in the silica sorbent bed contains one or more of nickel-impregnated silicate, nickel-impregnated hydrotalcite, magnesium-impregnated silicate, magnesium-impregnated hydrotalcite, nickel-modified zeolite, magnesium-modified zeolite, sulfonated silica, polyacrylamide, copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resin, and modified polydivinylbenzene.

[0042] A halogenated compound adsorbent bed having an inlet and an outlet is disposed downstream of the silica adsorbent bed. The inlet of the halogenated compound adsorbent bed is connected to and in fluid communication with the outlet of the silica adsorbent bed. The halogenated compound adsorbent bed contains a porous bed material that adsorbs halogenated compounds from the mixed plastic waste pyrolysis oil. The pores of the porous bed material of the halogenated compound adsorbent bed are smaller in size than the pores in the porous bed material in the silica adsorbent bed and the metal adsorbent bed. In certain embodiments, the porous bed material of the halogenated compound adsorbent bed contains one or more of modified alumina, modified zeolite, modified silicate, modified phosphate, red mud, calcium hydroxide, aluminum-zinc carbon complex, calcium carbonate, and aluminum-magnesium complex oxide.

[0043] A molecular sieve unit containing a plurality of molecular sieves is disposed downstream of the halogenated compound adsorption bed. The molecular sieve unit has an inlet connected to and in fluid communication with an outlet of the molecular sieve unit connected to the halogenated compound adsorption bed. Each of the plurality of molecular sieves adsorbs a portion of the oxygenates or nitrogenates or phosphorus compounds from the mixed plastic waste pyrolysis oil passing through the molecular sieve unit. A hydrogenation unit having an inlet and an outlet is disposed 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 and is operated under temperature and pressure conditions that promote the conversion of at least a portion of the olefinic compounds in the mixed plastic waste pyrolysis oil to one or more saturated hydrocarbon compounds and produce a purified hydrogenated pyrolysis oil having a reduced amount of the plurality of metal compounds and non-metal compounds compared to the amount of the plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil. In one particular embodiment, the hydrogenation unit is operated at a temperature of from about 80°C to about 120°C.

[0044] Certain system embodiments include one or more of a filter having an inlet and an outlet. The inlet of the filter is connected and in fluid communication with a source of mixed plastic waste pyrolysis oil. The filter is configured to remove solid particles larger than about 10 μm from the mixed plastic waste pyrolysis oil to produce a filtered mixed plastic waste pyrolysis oil. Certain system embodiments include a coalescing unit having an inlet and an outlet. The inlet of the coalescing unit is connected and in fluid communication with the outlet of the filter. The coalescing unit contains a coalescing medium that separates water from the filtered mixed plastic waste pyrolysis oil. The outlet of the coalescing unit is connected and in fluid communication with the inlet of the metal adsorption bed.

[0045] Certain system embodiments include an analyzer arranged to measure the concentration of metal or halogenated compounds in the filtered mixed plastic waste pyrolysis oil before entering the molecular sieving unit. Certain system embodiments include an analyzer arranged to measure the concentration of metal or halogenated compounds in the filtered mixed plastic waste pyrolysis oil downstream of the molecular sieving unit. Examples of such analyzers include, without limitation, those based on metal ion absorbance analysis (e.g., OMA300) and energy dispersive X-ray fluorescence spectroscopy. Certain system embodiments include a heat exchanger in thermal communication with the mixed plastic waste pyrolysis oil. The heat exchanger is arranged upstream of the metal adsorption bed and is configured to maintain the temperature of the filtered mixed plastic waste pyrolysis oil within a preselected range. In one particular embodiment, an injector is placed upstream of the metal adsorption bed to supply an acid scavenger to the filtered mixed plastic waste pyrolysis oil. Another injector can be placed downstream of the hydrogenation unit to supply an oxidation stabilizer to the purified hydrogenated pyrolysis oil. Due to the modular nature of these adsorbent beds, an array of impurity removals can be implemented in portions to achieve similar results or meet product specifications. Parallel sets of adsorbent beds can be configured and brought online to increase the robustness of continuous operation.

[0046] FIG. 2 is a schematic diagram of a modular system 200 for removing metal and non-metal compounds from mixed plastic waste pyrolysis oil. A metal sorbent bed 204 is configured to receive a mixed plastic waste pyrolysis oil stream 202. The metal sorbent bed 204 contains a porous bed material that adsorbs metal compounds from the mixed plastic waste pyrolysis oil. A silica sorbent bed 208 is disposed downstream of the metal sorbent bed 204 to receive therefrom the mixed plastic waste pyrolysis oil 206 having a reduced content of metal compounds. The silica sorbent bed 208 contains a porous bed material that adsorbs silica compounds from the mixed plastic waste pyrolysis oil 206 having a reduced content of metal compounds, the pores of the porous bed material being smaller in size than the pores of the porous bed material in the metal sorbent bed. A halogenated compound sorbent bed 212 is disposed downstream of the silica sorbent bed 208 to receive therefrom the mixed plastic waste pyrolysis oil 210 having a reduced content of metal and silica compounds. The halogenated compound sorbent bed 212 contains a porous bed material that sorbs halogenated compounds from the mixed plastic waste pyrolysis oil 210 having a reduced content of metal and silica compounds. The pores of the porous bed material of the halogenated compound sorbent bed 212 are smaller in size than the pores in the porous bed material in the silica sorbent bed 208 and the metal sorbent bed 204.

[0047] The molecular sieve unit 216 containing a plurality of molecular sieves is disposed downstream of the halogenated compound adsorption bed 212 to receive therefrom the mixed plastic waste pyrolysis oil 214 having a reduced content of metals, silica and halogenated compounds. The molecular sieve unit 216 has a plurality of molecular sieves for adsorbing a portion of the oxygenates, nitrogenates or phosphorus compounds from the mixed plastic waste pyrolysis oil 214 having a reduced content of metals, silica and halogenated compounds received from the halogenated compound adsorption bed 212. The hydrogenation unit 220 is disposed downstream of the molecular sieve unit 216 to receive therefrom the partially purified pyrolysis oil 218. The hydrogenation unit 220 is configured to have a hydrogenation catalyst and is operated under temperature and pressure conditions to convert at least a portion of the olefin compounds in the partially purified pyrolysis oil 218 to one or more saturated hydrocarbon compounds and to produce a purified hydrogenated pyrolysis oil 222 having a reduced amount of a plurality of metal compounds and non-metal compounds compared to the amount of the plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil 202. The system 200 also includes a nitrogen blanketing unit 226 configured to receive the partially purified pyrolysis oil 218 or the purified hydrotreated pyrolysis oil 222 via a bypass line 230. Nitrogen blanketing may be achieved by purging or sparging or bubbling nitrogen gas through the nitrogen blanketing unit 226 to produce a treated pyrolysis oil 228.

[0048] The system 200 may also include a filter 234 connected to and in fluid communication with the raw mixed plastic waste pyrolysis oil feed 232. The filter 234 is configured to remove solid particles larger than about 10 μm from the raw mixed plastic waste pyrolysis oil feed 232 to produce the mixed plastic waste pyrolysis oil stream 202. The system 200 may also include a coalescing unit 238 connected to and in fluid communication with the filter 234. The coalescing unit 238 contains a coalescing media that separates 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 metal sorbent bed 204.

[0049] The system 200 may also include an additional metal sorbent bed 240, an additional silica sorbent bed 242, and an additional halogenated compound sorbent bed 244 operating in parallel with the metal sorbent bed 204, the silica sorbent bed 208, and the halogenated compound sorbent bed 212. These parallel beds 240, 242, and 244 are brought on-line when any one or more of the corresponding sorbent beds 204, 208, and 212 is shut down or taken out of operation, for example, during regeneration of the porous bed material.

[0050] The system 200 may also include an additional molecular sieve unit 246 operating in parallel to the molecular sieve unit 216. The parallel molecular sieve unit 246 is brought on-line when the molecular sieve unit 216 is shut down or taken out of operation, such as during regeneration of the porous bed material. The system 200 may also include a polishing trap 248 disposed downstream of the molecular sieve unit 216, or a polishing trap 250 disposed downstream of the molecular sieve unit 246. The system 200 may also include a polishing trap 252 disposed downstream of the hydrogenation unit 220.

[0051] The system 200 may also include one or more analyzers 254 and 256 positioned to measure the concentration of metal or halogenated compounds in the mixed plastic waste pyrolysis oil 214 prior to entering the molecular sieve unit 216 or 246. The system 200 may also include an analyzer 258 positioned downstream of the molecular sieve unit 216 or 246 to measure the concentration of metal or halogenated compounds in the partially clarified pyrolysis oil 218.

[0052] Other objects, features and advantages of the present disclosure will become apparent from the following figures, detailed description and examples. However, it should be understood that the figures, detailed description and examples, while showing specific embodiments of the present disclosure, are shown by way of illustration only and are not meant to be limiting. Furthermore, it is contemplated that changes and modifications within the spirit and scope of the present disclosure will become apparent to those skilled in the art from this detailed description. In further embodiments, features from a specific embodiment 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.

Claims

1. A method for removing metal and non-metal compounds from mixed plastic waste pyrolysis oil, comprising: Obtaining a mixed plastic waste pyrolysis oil containing metal compounds and non-metal compounds, wherein the non-metal compounds are two or more of silica compounds, halogenated compounds, phosphorus compounds, oxygenates, and nitrogenates; 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, the second adsorption bed having a second porous bed material that adsorbs a portion of the silica compounds from the mixed plastic waste pyrolysis oil, the pores of the first porous bed material being larger in size than the pores of the second porous bed material; passing the mixed plastic waste pyrolysis oil from the second adsorption bed through a third adsorption bed, the third adsorption bed having a third porous material that adsorbs a portion of the halogenated compounds from the mixed plastic waste pyrolysis oil, the pores of the second porous bed material being larger in size than the pores of the third porous bed material; introducing the mixed plastic waste pyrolysis oil from the third adsorption bed into a vessel containing a plurality of molecular sieves, wherein the plurality of molecular sieves adsorb a portion of the oxygenates, phosphorus compounds, and nitrogenates from the mixed plastic waste pyrolysis oil to produce a partially purified pyrolysis oil; feeding the partially clarified pyrolysis oil from the vessel to a hydrogenation unit; treating the partially purified pyrolysis oil in a hydrogenation unit in the presence of a hydrogenation catalyst to convert a portion of the olefinic compounds in the partially purified pyrolysis oil to saturated hydrocarbon compounds to produce a purified hydrogenated pyrolysis oil having reduced amounts of metal and non-metal compounds compared to the amounts of metal and non-metal compounds in the mixed plastic waste pyrolysis oil; A method comprising:

2. prior to passing the mixed plastic waste pyrolysis oil through the first adsorption bed, passing the mixed plastic waste pyrolysis oil through a filter that removes at least a portion of solid particles larger than about 10 μm from the mixed plastic waste pyrolysis oil to produce a filtered pyrolysis oil. The method of claim 1 further comprising:

3. feeding the filtered pyrolysis oil from the filter to a coalescing unit containing a coalescing medium to coalesce and separate at least a portion of the water from the mixed plastic waste pyrolysis oil. The method of claim 2 , further comprising:

4. 4. The method of claim 3, further comprising cooling the filtered pyrolysis oil to at least 50° C. before feeding the filtered pyrolysis oil to the coalescing unit.

5. The method of claim 3 , wherein the coalescing media is a pad or a filter cartridge.

6. feeding the partially clarified pyrolysis oil to a coalescing unit including a coalescing medium to coalesce and separate at least a portion of the water from the partially clarified pyrolysis oil. The method of claim 1 further comprising:

7. providing an acid scavenger to the mixed plastic waste pyrolysis oil prior to passing the mixed plastic waste pyrolysis oil through the first adsorption bed; The method of claim 1 further comprising:

8. determining whether a concentration of metal or halogenated compounds in the mixed plastic waste pyrolysis oil is greater than a preselected level prior to introducing the mixed plastic waste pyrolysis oil into a vessel containing a plurality of molecular sieves; if the concentration of metal or halogenated compounds is greater than a preselected level, passing the mixed plastic waste pyrolysis oil through a set of absorption beds operating in parallel with the first absorption bed, the second absorption bed, and the third absorption bed; The method of claim 1 further comprising:

9. determining whether concentrations of oxygenates and nitrogenates in the partially clarified pyrolysis oil are greater than a preselected level prior to feeding the partially clarified pyrolysis oil to a hydrogenation unit; directing the partially clarified pyrolysis oil from the third adsorbent bed to a second vessel containing a second plurality of molecular sieves if the concentrations of oxygenates and nitrogenates in the partially clarified pyrolysis oil are greater than a preselected level; The method of claim 1 further comprising:

10. Adding an oxidation stabilizer to the purified hydrotreated pyrolysis oil The method of claim 1 further comprising:

11. adding a nitrogen blanket to the purified hydrotreated pyrolysis oil; The method of claim 1 further comprising:

12. cooling the mixed plastic waste pyrolysis oil to a preselected temperature prior to passing the mixed plastic waste pyrolysis oil through the first adsorption bed. The method of claim 1 further comprising:

13. 10. The method of claim 1, further comprising operating the hydrogenation unit at a temperature between about 80°C and about 120°C.

14. 10. The method of claim 1, wherein the first porous bed material comprises one or more of alumina, ligand modified alumina, magnesium metal alloy, calcium oxide, clay, calcium carbonate, acid modified carbon, and activated carbon.

15. 10. The method of claim 1, wherein the second porous bed material contains one or more of nickel impregnated silicate, nickel impregnated hydrotalcite, magnesium impregnated silicate, magnesium impregnated hydrotalcite, nickel modified zeolite, magnesium modified zeolite, sulfonated silica, polyacrylamide, copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resins, and modified polydivinylbenzene.

16. 2. The method of claim 1, wherein the third bed material comprises one or more of modified alumina, modified zeolite, modified silicate, modified phosphate, red mud, calcium hydroxide, aluminum-zinc carbon complex, calcium carbonate, and aluminum-magnesium complex oxide.

17. A method for removing metal and non-metal compounds from mixed plastic waste pyrolysis oil, comprising: Obtaining a mixed plastic waste pyrolysis oil containing metal compounds and non-metal compounds, wherein the non-metal compounds are two or more of silica compounds, halogenated compounds, phosphorus compounds, oxygenates, and nitrogenates; passing the mixed plastic waste pyrolysis oil through a filtration medium to remove a portion of the solid particles larger than about 10 μm from the mixed plastic waste pyrolysis oil to produce a filtered mixed plastic waste pyrolysis oil; Cooling the filtered mixed plastic waste pyrolysis oil to a temperature of at least less than 50°C; Introducing the filtered mixed plastic waste pyrolysis oil into a coalescing unit having a coalescing medium to separate at least a portion of the 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 having a plurality of molecular sieves, each of the plurality of molecular sieves containing pores that adsorb at least a portion of the oxygenates, nitrogenates, or phosphorus compounds from the filtered mixed plastic waste pyrolysis oil to produce a partially purified pyrolysis oil; feeding the partially clarified pyrolysis oil to a hydrogenation unit; treating the partially purified pyrolysis oil in a hydrogenation unit in the presence of a hydrogenation catalyst to convert at least a portion of the olefinic compounds in the partially purified pyrolysis oil to one or more saturated hydrocarbon compounds and produce a purified, hydrogenated pyrolysis oil having reduced amounts of metal and non-metal compounds compared to the amount of metal and non-metal compounds in the mixed plastic waste pyrolysis oil; A method comprising:

18. operating the hydrogenation unit at a temperature between about 80° C. and about 120° C.

20. The method of claim 17, further comprising:

19. 20. The method of claim 17, wherein the first media comprises one or more of alumina, ligand modified alumina, magnesium metal alloy, calcium oxide, clay, calcium carbonate, acid modified carbon, and activated carbon.

20. 20. The method of claim 17, wherein the first medium is a nanofiltration membrane or a polymeric membrane.

21. 18. The method of claim 17, wherein 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 silicas, polyacrylamides, copolymers of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohols, ion exchange resins, and modified polydivinylbenzenes.

22. 18. The method of claim 17, wherein the third medium contains one or more of modified alumina, modified zeolite, modified silicate, modified phosphate, red mud, calcium hydroxide, aluminum-zinc carbon complex, calcium carbonate, and aluminum-magnesium complex oxide.

23. Adding an acid scavenger to the filtered mixed plastic waste pyrolysis oil before passing the mixed plastic waste pyrolysis oil through the first trap.

20. The method of claim 17, further comprising:

24. Adding an oxidation stabilizer to the purified hydrotreated pyrolysis oil 20. The method of claim 17, further comprising:

25. A modular system for removing metal and non-metal compounds from mixed plastic waste pyrolysis oil, comprising: a filter having a first inlet and a first outlet, the first inlet connected to and in fluid communication with the mixed plastic waste pyrolysis oil feed, the filter configured to remove solid particles greater than about 10 μm from the mixed plastic waste pyrolysis oil feed to produce a filtered mixed plastic waste pyrolysis oil; a coalescing unit having a second inlet and a second outlet, the second inlet being connected and in fluid communication with the first outlet, the coalescing unit containing a coalescing medium for separating water from the filtered mixed plastic waste pyrolysis oil; a metal adsorbent bed having a third inlet and a third outlet, the third inlet being connected and in fluid communication with the second outlet, the metal adsorbent bed containing a first porous bed material that adsorbs a portion of the metal compounds from the filtered mixed plastic waste pyrolysis oil; a silica adsorption bed having a fourth inlet and a fourth outlet, the fourth inlet being connected and in fluid communication with the third outlet, the silica adsorption bed having a second porous bed material that adsorbs a portion of the 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; a halogenated compound adsorbent bed having a fifth inlet and a fifth outlet, the fifth inlet being connected and in fluid communication with the fourth outlet, the halogenated compound adsorbent bed having a third porous bed material that adsorbs a portion of the 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; a molecular sieve unit containing a plurality of molecular sieves, the molecular sieve unit having a sixth inlet and a sixth outlet, the sixth inlet being connected and in fluid communication with the fifth outlet, each of the plurality of molecular sieves adsorbing a portion of the oxygenates, nitrogenates, or phosphorus compounds from the filtered mixed plastic waste pyrolysis oil passing through the molecular sieve unit; a hydrogenation unit having a seventh inlet, the seventh inlet being connected to and in fluid communication with the sixth outlet of the molecular sieve unit for receiving the filtered mixed plastic waste pyrolysis oil therefrom, the hydrogenation unit having a hydrogenation catalyst and operable to convert at least a portion of the olefinic compounds in the filtered mixed plastic waste pyrolysis oil to one or more saturated hydrocarbon compounds and produce a purified hydrogenated pyrolysis oil having reduced amounts of a plurality of metal compounds and non-metal compounds compared to the amount of the plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil; A modular system that includes:

26. an analyzer configured to measure the concentration of metal compounds or halogenated compounds in the filtered mixed plastic waste pyrolysis oil prior to entering the third inlet of the metal adsorption bed.

26. The system of claim 25, further comprising:

27. an analyzer arranged downstream of the halogenated compound adsorption bed to measure the concentration of metal compounds or halogenated compounds in the filtered mixed plastic waste pyrolysis oil; 26. The system of claim 25, further comprising:

28. a heat exchanger in thermal communication with the mixed plastic waste pyrolysis oil, the heat exchanger being disposed upstream of the metal adsorption bed and configured to maintain a temperature of the filtered mixed plastic waste pyrolysis oil within a preselected range.

26. The system of claim 25, further comprising:

29. a first injector disposed upstream of the metal adsorption bed for supplying an acid scavenger to the filtered mixed plastic waste pyrolysis oil; a second injector disposed downstream of the hydrogenation unit for supplying an oxidation stabilizer to the purified hydrogenated pyrolysis oil; 26. The system of claim 25, further comprising:

30. 26. The system of claim 25, wherein the hydrogenation unit has an operating temperature of about 80°C to about 120°C.

31. 26. The system of claim 25, wherein the first porous bed material comprises one or more of alumina, ligand modified alumina, magnesium metal alloy, calcium oxide, clay, calcium carbonate, acid modified carbon, and activated carbon.

32. 26. The system of claim 25, wherein the second porous bed material contains one or more of nickel impregnated silicate, nickel impregnated hydrotalcite, magnesium impregnated silicate, magnesium impregnated hydrotalcite, nickel modified zeolite, magnesium modified zeolite, sulfonated silica, polyacrylamide, copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resins, and modified polydivinylbenzene.

33. 26. The system of claim 25, wherein the third porous bed material contains one or more of modified alumina, modified zeolite, modified silicate, modified phosphate, red mud, calcium hydroxide, aluminum zinc carbon complex, calcium carbonate, and aluminum magnesium complex oxide.

Images