Systems and methods for hydrolytic dechlorination of pyrolysis oil

Abstract

Systems and methods are presented for performing a hydrolytic dechlorination of pyrolysis oil using a basic adsorbent to produce an upgraded pyrolysis oil having at least a lower organic chloride content. An example method includes the steps of performing a hydrolytic dechlorination of pyrolysis oil containing one or more organic chloride species by: introducing the pyrolysis oil into a reactor, the pyrolysis oil having a temperature ranging from about 100 °C to about 300 °C; and contacting the pyrolysis oil with a basic adsorbent within the reactor under autogenic pressure and in the absence of hydrogen to hydrolyze the one or more organic chloride species of the pyrolysis oil and yield an upgraded pyrolysis oil having a lower organic chloride content.

Description

SYSTEMS AND METHODS FOR HYDROLYTIC DECHLORINATION OF PYROLYSIS OILInventor: Fabrice Cuoq, Kae Wong, Hans Smeets, Ziyu LiuTECHNICAL FIELD

[0001] The present disclosure generally relates to systems and methods for treatment of pyrolysis oil derived from mixed plastic waste to remove at least organic chloride contaminants, among others. More specifically, the present disclosure relates to systems and methods for performing a hydrolytic dechlorination of pyrolysis oil under relatively mild conditions using a basic adsorbent that enables the hydrolytic dechlorination of organic chlorides present in the pyrolysis oil and that sequesters the resulting hydrogen chloride (HC1), yielding an upgraded pyrolysis oil having at least a decreased organic chloride content.BACKGROUND

[0002] Pyrolysis oil originates from the chemical recycling of mixed plastic waste (MPW). For example, pyrolysis oil can be formed by pyrolyzing MPW at sufficiently elevated temperatures (e.g., between 400 °C and 500 °C) under anaerobic conditions. MPW often contains polyvinyl chloride (PVC), among other polymers. Under the pyrolysis conditions, PVC can be converted into various organic chloride species (e.g., alkyl chlorides). These organic chloride species may release corrosive hydrogen chloride gas (HC1) during subsequent hydrotreatment and / or cracking, which can lead to undesirable corrosion issues in hydrotreatment and / or cracking reactors. Accordingly, there remains a need for improved techniques for dechlorinating pyrolysis oil.SUMMARY

[0003] Embodiments include systems and methods for performing a hydrolytic dechlorination of pyrolysis oil using a basic adsorbent to produce an upgraded pyrolysis oil having at least a lower organic chloride content. One such method includes the steps of performing a hydrolytic dechlorination of pyrolysis oil containing one or more organic chloride species by: introducing the pyrolysis oil into a reactor, the pyrolysis oil having a temperature ranging from about 100 degrees Celsius (°C) to about 300 °C; and contacting the pyrolysis oil with a basic adsorbent within the reactor under autogenic pressure and in the absence of hydrogen to hydrolyze the one or moreorganic chloride species of the pyrolysis oil and yield an upgraded pyrolysis oil having a lower organic chloride content. Depending on the reaction conditions, in some embodiments, the lower organic chloride content of the upgraded pyrolysis oil is at least 20% lower, at least 30% lower, at least 50% lower, at least 70% lower, at least 90% lower, or at least 95% lower than the organic chloride content of the pyrolysis oil prior to hydrolytic dechlorination treatment.

[0004] In some embodiments, the basic adsorbent includes a zeolite having a pore size greater than about 6 angstroms (A), a zeolite in the sodium form, or both. In some embodiments, the basic adsorbent is a basic zeolite 13X adsorbent capable of adsorbing at least 2 moles of CO2 per kilogram of basic zeolite 13X. In some embodiments, the reactor is a fixed bed reactor. In some embodiments, the basic zeolite 13X adsorbent comprises silica, alumina, one or more alkali metal oxides or hydroxides, one or more alkali earth metal oxides or hydroxides, or a combination thereof. In some embodiments, the basic zeolite 13X adsorbent consists essentially of silica, alumina, and one or more of sodium oxide or sodium hydroxide. In some embodiments, the basic zeolite 13X adsorbent consists essentially of silica, alumina, and one or more of calcium oxide or calcium hydroxide, or barium oxide. In some embodiments, the basic adsorbent comprises calcium oxide, calcium hydroxide, barium oxide, or a combination thereof. In some embodiments, the reactor is a fluidized bed reactor.

[0005] In some embodiments, after performing the hydrolytic dechlorination, the basic adsorbent has a chloride content greater than 8 milligrams (mg) of chloride per gram (g). In some embodiments, after performing the hydrolytic dechlorination, the basic adsorbent has a chloride content of 30 mg / g or more. In some embodiments, after performing the hydrolytic dechlorination, the method includes the step of regenerating the basic adsorbent by heating the basic adsorbent to a temperature from about 300 °C to about 600 °C in the presence of oxygen for a duration from about 4 hours to about 8 hours to remove a substantial portion of the chloride content of the basic adsorbent. In some embodiments, the method includes the step of, while regenerating the basic adsorbent, passing an exhaust gas stream through a caustic scrubber to treat hydrogen chloride (HC1) gas evolved as the substantial portion of the chloride content of the basic adsorbent is removed. In some embodiments, a mixture of the pyrolysis oil and the basic adsorbent within the reactor comprises between about 0.01 weight percent (wt.%) to about 4 wt.% basic adsorbent based on the weight of the mixture. In some embodiments, the temperature of the pyrolysis oil rangesfrom about 150 °C to about 250 °C during hydrolytic dechlorination. In some embodiments, the autogenic pressure ranges from about 2 bar gauge (barg) to about 15 barg.

[0006] In some embodiments, the organic chloride content of the upgraded pyrolysis oil is at least 50 wt.% lower than an organic chloride content of the pyrolysis oil. In some embodiments, the upgraded pyrolysis oil has a silicon content that is at least 20 wt.% lower than a silicon content of the pyrolysis oil. In some embodiments, the upgraded pyrolysis oil has an alcohol content that is at least 0.01 wt.% greater than an alcohol content of the pyrolysis oil. In some embodiments, the method includes the step of performing pyrolysis of mixed plastic waste at a temperature ranging from about 400 °C to about 500 °C under anaerobic conditions to yield the pyrolysis oil, wherein the temperature of the pyrolysis oil ranges from about 100 °C to about 300 °C (e.g., from about 150 °C to about 250 °C) during hydrolytic dechlorination due to residual heat from pyrolysis. In some embodiments, the pyrolysis oil is heated from ambient temperature to the temperature ranging from about 100 °C to about 300 °C (e.g., from about 150 °C to about 250 °C) prior to or upon entering the reactor. In some embodiments, the upgraded pyrolysis oil remains substantially free of gum impurities after 2 months. In some embodiments, the one or more organic chloride species comprise chloroalcohols, alkyl chlorides, and aromatic chlorides. In some embodiments, the pyrolysis oil comprises at least 0.01 wt.% water. In some embodiments, the method includes the step of adding water to the pyrolysis oil prior to contacting the basic adsorbent. In some embodiments, the method includes the step of steam cracking the upgraded pyrolysis oil without prior hydrotreatment. In some embodiments, the method includes the step of hydrotreating the upgraded pyrolysis oil prior to steam cracking. In some embodiments, during hydrolytic dechlorination, the pyrolysis oil contacts the basic adsorbent for between about 0.5 hour and about 10 hours.

[0007] One such system is a hydrolytic dechlorination system that includes a hydrolytic dechlorination reactor containing a basic adsorbent, the hydrolytic dechlorination reactor being configured to operate in hydrolytic dechlorination mode by to receiving pyrolysis oil having a first organic chloride content and contacting the pyrolysis oil with the basic adsorbent at a temperature ranging from about 100 °C to about 300 °C (e.g., from about 150 °C to about 250 °C) in the presence of at least 100 part-per-million- by- weight (ppmw) water, based on the weight of the pyrolysis oil, to hydrolytically dechlorinate one or more organic chloride species of the pyrolysis oil, thereby to generate an upgraded pyrolysis oil having a second organic chloride content that islower than the first organic chloride content. Depending on the reaction conditions, in some embodiments, the lower organic chloride content of the upgraded pyrolysis oil is at least 20% lower, at least 30% lower, at least 50% lower, at least 70% lower, at least 90% lower, or at least 95% lower than the organic chloride content of the pyrolysis oil prior to hydrolytic dechlorination treatment.

[0008] In some embodiments, the hydrolytic dechlorination reactor is configured to receive a flow of water in a liquid or a gaseous phase resulting in a water content within the hydrolytic dechlorination reactor ranging from about 100 ppmw to about 500 ppmw relative to the weight of the pyrolysis oil. In some embodiments, the second organic chloride content of the upgraded pyrolysis oil is at least 50 wt.% lower than the first organic chloride content of the pyrolysis oil. In some embodiments, the hydrolytic dechlorination reactor includes a heater configured to heat the pyrolysis oil to the temperature ranging from about 100 °C to about 300 °C (e.g., from about 150 °C to about 250 °C). In some embodiments, the basic adsorbent is a zeolite, and the hydrolytic dechlorination reactor is a fixed bed reactor. In some embodiments, the basic adsorbent is a nonzeolite, and the hydrolytic dechlorination reactor is a fluidized bed reactor. In some embodiments, the hydrolytic dechlorination reactor is fluidly connected to a pyrolysis reactor to receive the pyrolysis oil from the pyrolysis reactor, the pyrolysis oil being produced within the pyrolysis reactor via the pyrolysis of mixed plastic waste. In some embodiments, the hydrolytic dechlorination reactor is fluidly connected to a hydrotreatment reactor to provide the upgraded pyrolysis oil to the hydrotreatment reactor. In some embodiments, the hydrolytic dechlorination reactor is fluidly connected to a cracking reactor to provide the upgraded pyrolysis oil to the cracking reactor, wherein the cracking reactor is a steam cracking reactor or a fluid catalytic cracking (FCC) reactor.

[0009] In some embodiments, the hydrolytic dechlorination system includes a second hydrolytic dechlorination reactor disposed in parallel with the hydrolytic dechlorination reactor and containing a second basic adsorbent, the second hydrolytic dechlorination reactor being configured to operate in regeneration mode by contacting the second basic adsorbent with an oxygencontaining gas stream at a second temperature ranging from about 300 °C to about 600 °C to remove a substantial portion of a chloride content of the second basic adsorbent and regenerate the second basic adsorbent. In some embodiments, the hydrolytic dechlorination system includes an analyzer configured to measure the second organic chloride content of the upgraded pyrolysis oil,and a controller that is communicatively connected to the analyzer to receive the measurement of the second organic chloride content of the upgraded pyrolysis oil, wherein, in response to determining that the second organic chloride content is greater than a predetermined threshold value, the controller is configured to switch the hydrolytic dechlorination reactor into the regeneration mode and to switch the second hydrolytic dechlorination reactor into the hydrolytic dechlorination mode.

[0010] 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

[0011] 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. According to common practice, 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.

[0012] FIG. 1 is a diagrammatic representation of a pyrolysis oil production system that converts batches of mixed plastic waste to pyrolysis oil, and then hydrolytically dechlorinates the pyrolysis oil into upgraded pyrolysis oil having at least a decreased organic chloride content, according to an embodiment.

[0013] FIG. 2 is a diagrammatic representation of a method in which the pyrolysis oil production system of FIG. 1 produces pyrolysis oil, performs hydrolytic dechlorination of the pyrolysis oil toyield upgraded pyrolysis oil, and further processes the upgraded pyrolysis oil to yield one or more hydrocarbon products, according to an embodiment.

[0014] FIG. 3 is a diagrammatic representation of a method in which the basic adsorbent of the hydrolytic dechlorination reactor is regenerated, according to an embodiment.DETAILED DESCRIPTION

[0015] The present disclosure describes various embodiments related to systems and methods for performing a hydrolytic dechlorination of pyrolysis oil to decrease the at least the chloride content of the pyrolysis oil. The description may use the phrases “in certain 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. The term “plurality” as used herein refers to two or more items or components. The terms “about” or “approximately” are defined as being close to as understood by one of ordinary skill in the art. In one non-limiting embodiment, these terms are defined to be within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%.

[0016] The terms “removing,” “removed,” “reducing,” “reduced,” or any variation thereof, when used in the claims and / or the specification includes any measurable decrease of one or more components in a mixture to achieve a desired result. The use of the words “a” or “an” when used in conjunction with any of the terms “comprising,” “including,” “containing,” or “having,” in the claims or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” The terms “wt.%”, “vol.%”, or “mol.%” refers to a weight, volume, or molar percentage of a component, respectively, based on the total weight, the total volume of material, or total moles, which includes the component. In a non-limiting example, 10 grams of component in 100 grams of the material is 10 wt.% of component.

[0017] FIG. 1 is a diagrammatic representation of an embodiment of a pyrolysis oil production system 100 that converts batches of mixed plastic waste (MPW) 102 into upgraded pyrolysis oil 104 having a reduced organic chloride content. In some implementations, the MPW 102 consists of one or more chloride-containing polymers, while in other implementations, the MPW 102 includes a mixture of chloride-containing polymers and other polymers. Examples of chloride- containing polymers include polyvinyl chloride (PVC), poly vinylidene chloride (PVDC), chlorinated polyvinyl chloride (CPVC), other poly chloroolefins, and mixtures thereof. The MPW102 advances to the pyrolysis reactor 106 and is exposed to pyrolysis conditions to yield pyrolysis oil 108. For example, the pyrolysis conditions may include heating the MPW 102 to temperatures ranging from about 400 °C to about 500 °C under anaerobic conditions. Under these pyrolysis conditions, at least a portion of the chloride- containing polymers decompose to form various organic chloride species, such as chloroalcohols, alkyl chlorides and / or aromatic chlorides. These organic chloride species can subsequently release hydrogen chloride gas (HC1) during later processing (e.g., hydrotreating, cracking). Because HC1 is highly corrosive, it can corrode equipment when the pyrolysis oil 108 is subsequently refined or cracked. In some embodiments, the pyrolysis oil 108 may be produced at a pyrolysis reactor disposed first location before being transported to another location for further processing (e.g., hydrolytic dechlorination, hydrotreatment, and / or steam cracking). In such situations, the organic chloride content of the pyrolysis oil 108 additionally promotes the formation of undesirable gum deposits during storage and / or transport of the pyrolysis oil.

[0018] With the foregoing in mind, the embodiment of the pyrolysis oil production system 100 illustrated in FIG. 1 includes a hydrolytic dechlorination system 110 that is operably and fluidly connected to the pyrolysis reactor 106. The hydrolytic dechlorination system 110 enables hydrolytic dechlorination of the pyrolysis oil 108 to yield the upgraded pyrolysis oil 104 having at least a decreased organic chloride content. While referred to as a hydrolytic dechlorination system, it should be appreciated that, in certain implementations, the hydrolytic dechlorination system 110 may additionally or alternatively decrease the content of one or more other potentially problematic components of the pyrolysis oil 108, such as silicon-containing species and metal-containing species, in the upgraded pyrolysis oil 104.

[0019] It is also presently recognized that the decrease in chloride content provided by the hydrolytic dechlorination process enables the upgraded pyrolysis oil 104 to remain substantially free of gum impurities even after about 2 months or more (e.g., 3 months, 4 months, 5 months, or 6 months), which is especially beneficial when the upgraded pyrolysis oil 104 is stored or transported prior to hydrotreatment and / or cracking.

[0020] The embodiment of the hydrolytic dechlorination system 110 illustrated in FIG. 1 includes two hydrolytic dechlorination reactors 112, including hydrolytic dechlorination reactor 112 A and hydrolytic dechlorination reactor 112B. In other embodiments, the hydrolytic dechlorination system 110 may include only a single hydrolytic dechlorination reactor or mayinclude additional (e.g., 3, 4, 5, or more) hydrolytic dechlorination reactors arranged in series or in parallel. For the illustrated embodiment, the hydrolytic dechlorination reactors 112 are arranged in parallel, such that the hydrolytic dechlorination reactor 112A is online to treat the pyrolysis oil 108, while the hydrolytic dechlorination reactor 112B is operated in regeneration mode, as discussed in greater detail below. For embodiments having a third hydrolytic dechlorination reactor, the hydrolytic dechlorination reactor 112A may be online to treat the pyrolysis oil 108, the hydrolytic dechlorination reactor 112B may be operated in regeneration mode, and the third hydrolytic dechlorination reactor may be operated in standby mode. Accordingly, the hydrolytic dechlorination system 110 enables continuous treatment of pyrolysis oil 108 to yield the upgraded pyrolysis oil 104, even as one or more of the hydrolytic dechlorination reactors 112 are taken offline for regeneration.

[0021] For the embodiment illustrated in FIG. 1, the hydrolytic dechlorination reactor 112A includes a basic adsorbent 114A and a heater 116 A, and the hydrolytic dechlorination reactor 112B includes a basic adsorbent 114B and a heater 116B. The heater 116A can be operated to ensure that the pyrolysis oil 108 maintains a temperature from about 100 °C to about 300 °C (e.g., from about 100 °C to about 250 °C, from about 150 °C to about 250 °C, from about 200 °C to about 300 °C, from about 250 °C to about 300 °C) during the hydrolytic dechlorination treatment. Applicant recognized that, in some cases, temperatures above 300 °C may lead to substantial fouling, and as such, it may be desirable for the temperature range to remain below this temperature in some implementations. However, it may be appreciated that, for implementations in which the pyrolysis oil 108 is hydrolytically dechlorinated shortly after being generated by the pyrolysis reactor 106, then the pyrolysis oil 108 may already be in the desired temperature range as a result of the residual heat from pyrolysis and additional heat input may not be required, which can desirably reduce operational costs and power consumption of the system 100. In certain embodiments, the pyrolysis oil 108 is in liquid phase during hydrolytic dechlorination treatment, while in other embodiments, the pyrolysis oil 108 is in a gaseous phase or a mixed gaseous and liquid phase during hydrolytic dechlorination treatment.

[0022] During hydrolytic dechlorination treatment, no hydrogen gas (H2) is added to the hydrolytic dechlorination reactor 112A. Additionally, during the hydrolytic dechlorination process, the pressure within the hydrolytic dechlorination reactor 112A is autogenic pressure that results from the heated pyrolysis oil 108, and this autogenic pressure may range from about 2 bargauge (barg) to about 15 barg (e.g., from about 5 barg to about 7 barg), in certain embodiments, depending on the nature and composition of the pyrolysis oil 108. During hydrolytic dechlorination treatment, the pyrolysis oil 108 contacts the basic adsorbent 114A at the desired temperature range for a predetermined duration (e. g. , from about 0.5 hours to about 10 hours) to produce the upgraded pyrolysis oil 104. In some embodiments, the mixture of the pyrolysis oil 108 and the basic adsorbent 114A within the hydrolytic dechlorination reactor 112A ranges from about 0.01 wt.% to about 4 wt.% of the basic adsorbent 114A. At the conclusion of the hydrolytic dechlorination treatment, the basic adsorbent 114 A has a chloride content greater than 5 milligrams (mg) of chloride per gram (g), such as from about 6 mg / g to about 20 mg / g, or from about 8 mg / g to about 15 mg / g.

[0023] In some embodiments, the basic adsorbent 114 is a particulate adsorbent, while in other embodiments, the basic adsorbent 114 is a shaped adsorbent (e.g., an extruded adsorbent). The basic adsorbent 114 serves at least two roles during hydrolytic dechlorination of the pyrolysis oil 108: (1) it provides a basic catalytic surface that promotes the hydrolytic dechlorination of organic chloride species (R-Cl) to yield organic alcohol species (R-OH) and HC1, and (2) it reacts with the resulting HC1 to form a chloride salt that sequesters the chloride from the pyrolysis oil. As such, the chloride content of the basic adsorbent 114 A increases throughout a period of time that the hydrolytic dechlorination reactor 112A is online and treating the pyrolysis oil 108. Additionally, while not wishing to be bound by theory, it is believed that the hydrolytic dechlorination proceeds more effectively when the water content of the pyrolysis oil in the hydrolytic dechlorination reactor 112 A is sufficiently high. As such, in some implementations, the online hydrolytic dechlorination reactor 112A may receive water 118 (e.g., liquid water, steam) that can be added to the pyrolysis oil 108 to increase the water content within the hydrolytic dechlorination reactor 112A during the hydrolytic dechlorination treatment. In some embodiments, one or more polar protic solvents (e.g., isopropanol, ethanol, methanol) may be provided along with the water 118 to promote the hydrolytic dechlorination reaction.

[0024] It is further presently recognized that, unlike other reactions dechlorination reactions, the disclosed hydrolytic dechlorination process specifically results in organic chlorides (e.g., alkyl chlorides) being converted into corresponding organic alcohols (e.g., alkyl alcohols). This is in contrast with a hydrodechlorination reaction (also known as dehydrochlorination reaction), in which, for example, an alkyl chloride loses both a proton and a chloride group to form an alkene(also known as an olefin). More specifically, unlike other dechlorination reactions, the disclosed hydrolytic dechlorination process involves the presence of water (e.g., steam) to form a nucleophilic hydroxide species ('OH), which displaces chloride from the organic chloride structure, resulting in the organic alcohol, as illustrated in Scheme 1 for an example alkyl chloride species. While not wishing to be bound by theory, it is believed that the presence of the organic alcohols (e.g., alkyl alcohols) in the upgraded pyrolysis oil 104 can desirably decrease the rate of coke formation within later processing steps (e.g., hydrotreatment, steam or fluid catalytic cracking) compared to the olefin products of other dechlorination processes. Additionally, it is believed that, relative to the alkenes formed from other dechlorination reactions, the organic alcohols produced by the hydrolytic dechlorination are inactive when the upgraded pyrolysis oil is heated, while alkenes are reactive and promote or contribute to undesirable fouling. Therefore, the organic alcohols produced by the hydrolytic dechlorination increase the stability of the pyrolysis oil, which results in substantially less fouling than the alkenes formed using other dechlorination techniques. As noted, the hydrolytic dechlorination reaction further produces HC1, which reacts with the basic adsorbent to form a chloride salt and water. As such, it is believed that only a catalytic amount of water (e.g., from about 100 part-per-million-by-weight (ppmw) to about 500 ppmw) is required to drive the hydrolytic dechlorination reaction. While chloroethane is illustrated as an example in Scheme 1, it should be appreciated that the organic chloride may be any primary or secondary organic chloride that is present within pyoil.

[0025] Scheme 1: Hydrolytic dechlorination reaction. basic particulate adsorbentwater200 °C - 300 °C

[0026] It may be appreciated that, in the absence of water, the basic adsorbent instead enables a hydrodechlorination reaction of organic chlorides that results in the formation of alkene species. However, in addition to the alkene species being less desirable than the organic alcohols that result from the hydrolytic dechlorination process, it is presently recognized that the hydrodechlorination reaction that takes place in the absence of water is also less effective at removing organic chloride species from the pyrolysis oil than the hydrolytic dechlorination process. In an experimental example, hydrodechlorination of the pyrolysis oil was performed by contacting the basic adsorbent at 200 °C for 1 hour in the absence of water, and the results were compared to hydrolyticdechlorination of the pyrolysis oil under the same conditions but in the presence of water. Subsequent analysis of the upgraded pyrolysis oil after these treatments indicated that the pyrolysis oil that received the hydrodechlorination treatment in the absence of water retained 6 wt.% more organic chloride species compared to the upgraded pyrolysis oil that received the hydrolytic dechlorination in the presence of water.

[0027] While other particulate adsorbents that have previously been used for dechlorination treatments (e.g., hydrodechlorination or dehydrochlorination treatments) are typically acidic adsorbents (e.g., protonic zeolites), the particulate adsorbents of the present technique are basic. In certain embodiments, the basic adsorbent 114 may be a molecular sieve or zeolite having alkali metal and / or alkali earth metal cations (e.g., sodium, lithium, magnesium, calcium, barium). In some cases, carbon dioxide (CO2) adsorption can be used to identify materials having a suitably high basicity for use as the basic adsorbent 114. In certain embodiments, the basic adsorbent 114 is capable of adsorbing at least 2 moles of CO2 per kilogram (mol / kg) of basic adsorbent (e.g., zeolite 13X). For example, in some embodiments, the CO2 adsorption of the basic adsorbent 114 is at least 2 mol / kg, at least 3 mol / kg, at least 4 mol / kg, or at least 5 mol / kg. In some embodiments, the basic adsorbent 114 may be described as an alkali and / or alkali earth cationic zeolite or simply a cationic zeolite.

[0028] In some embodiments, the basic adsorbent 114 has a pore size greater than about 10 angstroms (A). In some embodiments, the basic adsorbent 114 is or includes a zeolite having a pore size greater than about 6 A, a zeolite in the sodium form (e.g., a Na-zeolite), or both. For example, in certain embodiments, the basic adsorbent 114 is a zeolite 13X that contains silica, alumina, one or more alkali metal oxides or hydroxides, one or more alkali earth metal oxides or hydroxides, or a combination thereof. In some embodiments, the basic adsorbent 114 is a zeolite 13X that consists essentially of silica, alumina, and one or more of sodium oxide or sodium hydroxide. In some embodiments, the basic adsorbent 114 is a zeolite 13X consists essentially of silica, alumina, and one or more of calcium oxide, calcium hydroxide, or barium oxide. In some embodiments, the basic adsorbent 114 contains or consists essentially of calcium oxide (e.g., calcined calcium oxide), barium oxide, calcium hydroxide, or a combination thereof. For certain embodiments in which the basic adsorbent 114 is a zeolite, the hydrolytic dechlorination reactors 112 may be implemented as fixed bed reactors. For certain embodiments in which the basicadsorbent 114 is a non- zeolite (e.g., calcined calcium oxide), the hydrolytic dechlorination reactors 112 may be implemented as fluidized bed reactors.

[0029] In an example embodiment, the basic adsorbent 114 is a zeolite 13X having a Chemical Abstracts Service (CAS) registry number of 63231-69-6 and a formula of Na86[(AlO2)s6(SiO2)i06] • xH O. While not wishing to be bound by theory, at least for the aforementioned zeolite 13X, it is believed that the reaction mechanism involves the organic chloride species being absorbed on a Na+ / Al- bond of the zeolite 13X structure via Van der Waals interactions with the carbon-chloride bond. The basic zeolite 13X also promotes the formation of hydroxide from water to displace the chloride, yielding the organic alcohol product and HC1. The basic zeolite 13X further binds and sequesters the HC1 from the reaction mixture as a chloride salt.

[0030] For the embodiment illustrated in FIG. 1, the resulting upgraded pyrolysis oil 104 advances to other treatment or processing steps, such as advancing to the hydrotreatment reactor 120 for hydrotreatment and / or advancing to the steam cracking reactor or fluid catalytic cracking (FCC) reactor 122 for cracking. For example, in certain embodiments, the hydrolytic dechlorination system 110 may be operably and fluidly connected to the hydrotreatment reactor 120 or the cracking reactor 122 to provide the upgraded pyrolysis oil 104 thereto. In some embodiments, the hydrolytic dechlorination removes a sufficient quantity of the organic chlorides, and potentially other undesirable components of the pyrolysis oil 108, that the upgraded pyrolysis oil 104 can proceed directly to steam or fluid catalytic cracking without hydrotreatment, which desirably reduces the operational costs and energy requirements of the system 100, thereby reducing the cost of producing the upgraded pyrolysis oil 104. For example, in certain embodiments, the chloride content of the upgraded pyrolysis oil 104 is at least 20 wt.%, at least 30 wt.%, at least 40 wt.%, at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, or at least 95 wt.% lower than the chloride content of pyrolysis oil 108 prior to the hydrolytic dechlorination process. In certain implementations, the chloride content of the upgraded pyrolysis oil 104 is less than 300 parts-per-million by weight (ppmw), less than 200 ppmw, less than 175 ppmw, or between 140 ppmw and 175 ppmw. The lower organic chloride content of the upgraded pyrolysis oil 104 substantially decreases or eliminates the production of HC1 during hydrotreatment and / or cracking, which desirably reduces corrosion and extends the lifetime of the hydrotreatment reactor 120 and the cracking reactor 122. Additionally, as noted, and it is believed that the additional organic alcohols within the upgraded pyrolysis oil 104 desirably reduces therate of coke formation within downstream components (e.g., the hydrotreatment reactor 120, the cracking reactor 122), enabling these components to operate for long periods of time without being taken offline (e.g., for decoking).

[0031] In certain embodiments, it is believed that the silicon content of the upgraded pyrolysis oil 104 is at least 10 wt.%, at least 20 wt.%, at least 30 wt.%, at least 40 wt.%, or at least 50 wt.% lower than the silicon content of pyrolysis oil 108 prior to the hydrolytic dechlorination process. In certain embodiments, it is believed that the content of certain metals in the upgraded pyrolysis oil 104 is at least 10 wt.%, at least 20 wt.%, at least 30 wt.%, at least 40 wt.%, or at least 50 wt.% lower than the content of these metals in the pyrolysis oil 108 prior to the hydrolytic dechlorination process.

[0032] For the embodiment illustrated in FIG. 1, the hydrolytic dechlorination reactor 112B was previously operated in an online mode to treat the pyrolysis oil 108 for a sufficient duration to substantially saturate the basic adsorbent 114B with chloride, and the hydrolytic dechlorination reactor 112B was then switched to regeneration mode operation. As discussed in greater detail below, during regeneration mode operation, the basic adsorbent 114B is heated by the heater 116B to a temperature ranging from about 300 °C to about 600 °C for a predetermined length of time (e.g., from about 4 hours to about 8 hours) while an oxygen-containing gas 124 is directed through the basic adsorbent 114B, which causes the adsorbent to release a substantial portion of the sequestered chloride content as HC1 gas. The exhaust gas, including the released HC1, is then directed to a scrubber 126 (e.g., an acid gas scrubber, a wet scrubber, a dry scrubber) for treatment, which removes the HC1 from the exhaust gas. In some embodiments, the scrubber 126 is loaded with a caustic material (e.g., NaOH, KOH) that reacts with the HC1 to form water and a salt. While illustrated as a separate component in FIG. 1, in other embodiments, the scrubber 126 is integrated as a component of the hydrolytic dechlorination reactor 112B or the hydrolytic dechlorination system 110.

[0033] For the embodiment illustrated in FIG. 1, the pyrolysis oil production system 100 includes a controller 128 that is communicatively connected to various components of the pyrolysis oil production system 100 to receive monitoring data and to provide control signals to control operation of the system. The controller 128 includes at least one processor 130 (e.g., a central processing unit (CPU), graphics processing unit (GPU), application-specific integrated circuit (ASIC)) and at least one memory 132 (e.g., random access memory (RAM), read-onlymemory (ROM), flash memory, solid state disk (SSD)). For the embodiment illustrated in FIG. 1, the memory 132 of the controller 128 stores instructions that are executed by the processor 130 to process measurement data collected by sensors and analyzers disposed throughout the pyrolysis oil production system 100 to determine operational parameters of the system, and to provide suitable control signals to modify the operational parameters of the system to ensure that they remain within pre-defined ranges.

[0034] For the embodiment illustrated in FIG. 1, the controller 128 is communicatively connected to a flow control valve 134 that controls the flow of water into the hydrolytic dechlorination reactor 112 A, a flow analysis and flow control element 136 that analyzes the pyrolysis oil 108 and controls its flow into the hydrolytic dechlorination reactor 112A, a flow analysis and flow control element 138 that analyzes the upgraded pyrolysis oil 104 and controls its flow from the hydrolytic dechlorination reactor 112A, a flow control valve 140 that controls the flow of the oxygen-containing gas 124 into the hydrolytic dechlorination reactor 112B during regeneration mode operation, and a flow control valve 142 that controls the flow of exhaust gas stream from the hydrolytic dechlorination reactor 112B during regeneration mode operation. In some embodiments, the elements 134, 136, 138, 140, and 142 are implemented as elements of the hydrolytic dechlorination system 110. The controller 128 is also communicatively connected to the heaters 116A and 116B, as well as any other components (e.g., various pumps, valves, pressure sensors, temperature sensors, flow sensors) of the hydrolytic dechlorination system 110 to control operation of the system. In some embodiments, the controller 128 may additionally be communicatively connected to other components of the system 100, such as the pyrolysis reactor 106, the hydrotreatment reactor 120, and the cracking reactor 122 to control the operation of these components. In other embodiments, operational parameters of the hydrolytic dechlorination system 110 and / or the pyrolysis oil production system 100 are monitored by a human operator, and certain processing steps can be manually performed or triggered by the human operator.

[0035] In some embodiments, the flow analysis and flow control element 136 analyzes the pyrolysis oil 108 to determine a temperature, a water content, a chloride content, or another impurity content, or a combination thereof, of the pyrolysis oil 108. In some embodiments, the flow analysis and flow control element 138 analyzes the upgraded pyrolysis oil 104 to determine a temperature, a water content, a chloride content, or another impurity content, or a combination thereof, of the upgraded pyrolysis oil 104. In some embodiments, the controller 128 determines,based on the chloride content of the upgraded pyrolysis oil not reaching a predetermined threshold value, that the hydrolytic dechlorination reactor 112A should be switched to regeneration mode operation to regenerate the basic adsorbent 114A. In other embodiments, the controller 128 may monitor a usage of the basic adsorbent 114A (e.g., volume of pyrolysis oil 108 treated, operational time since the previous regeneration) to determine when the hydrolytic dechlorination reactor 112 A should be switched to regeneration mode operation. For the embodiment illustrated in FIG. 1, the controller 128 may provide suitable control signals to the hydrolytic dechlorination system 110 that cause various flow control mechanisms of the system (not shown) to be switched to instead direct the pyrolysis oil 108 and water 118 to the hydrolytic dechlorination reactor 112B to produce the upgraded pyrolysis oil 104, and to instead direct the oxygen-containing gas 124 to the hydrolytic dechlorination reactor 112A to regenerate the basic adsorbent 114A. In some embodiments, the hydrolytic dechlorination system 110 is manually controlled to switch operation of the hydrolytic dechlorination reactors between online, regeneration, and / or standby modes.

[0036] FIG. 2 is a diagrammatic representation of an embodiment of a method 200 in which the pyrolysis oil production system 100 produces pyrolysis oil, performs hydrolytic dechlorination of the pyrolysis oil to yield upgraded pyrolysis oil, and further processes the upgraded pyrolysis oil to yield one or more hydrocarbon products. The method 200 is discussed with reference to elements illustrated in FIG. 1. In other embodiments, the method 200 may include additional steps, omitted steps, repeated steps, and so forth, relative to the embodiment illustrated in FIG. 2. In some embodiments, one or more of the steps of the method 200 may be stored as instructions in the memory 132 and executed by the processor 130 of the controller 128.

[0037] For the embodiment illustrated in FIG. 2, the method 200 begins with the step 202 of pyrolyzing MPW 102 in the pyrolysis reactor 106 to produce pyrolysis oil 108. For example, the MPW 102 may be heated to temperatures ranging from about 400 °C to about 500 °C under anaerobic conditions to yield the pyrolysis oil 108. After exiting the pyrolysis reactor 106, and prior to or upon entering the hydrolytic dechlorination reactor 112A, at step 204, the pyrolysis oil 108 is optionally heated to a temperature from about 100 °C to about 300 °C (e.g., from about 150 °C to about 250 °C). As noted, in some implementations, the pyrolysis oil 108 already has a temperature from about 100 °C to about 300 °C from the residual heat of the pyrolysis step 202, and the heater 116A may be operated only to maintain the temperature of the pyrolysis oil 108 from about 100 °C to about 300 °C (e.g., from about 150 °C to about 250 °C) throughout thehydrolytic dechlorination step, which desirably reduces the energy expenditure of the system 100 and the method 200.

[0038] For the embodiment illustrated in FIG. 2, the method 200 includes the step 206 of optionally adjusting the water content of the pyrolysis oil 108. For example, in some embodiments, the controller 128 may determine the water content of the pyrolysis oil 108 from measurements collected by the flow analysis and flow control element 136. In some embodiments, the controller 128 may compare the measured water content of the pyrolysis oil 108 to a predefined target water content value (e.g., from about 100 ppmw to about 500 ppmw, or about 0.01 wt.%), and may actuate the flow control valve 134 to introduce additional water content (e.g., steam) into the pyrolysis oil 108. In some embodiments, the flow control valve 134 instead may be controlled (e.g., manually or by the controller 128) to provide a predetermined amount of water or steam into the hydrolytic dechlorination reactor 112A before or during the hydrolytic dechlorination operation.

[0039] For the embodiment illustrated in FIG. 2, the method 200 includes the step 208 of contacting the pyrolysis oil 108 with a basic adsorbent 114A at a temperature from about 100 °C to about 300 °C (e.g., from about 150 °C to about 250 °C) for a predetermined period of time (e.g., from about 0.5 to about 10 hours) to hydrolyze one or more organic chloride species of the pyrolysis oil and yield the upgraded pyrolysis oil 104 having a lower organic chloride content. The method 200 includes the step 210 of optionally hydrotreating the upgraded pyrolysis oil 104 prior to steam or fluid catalytic cracking. As noted, in some embodiments, the hydrolytic dechlorination of step 208 removes a sufficient quantity of the organic chlorides, and potentially other undesirable components of the pyrolysis oil 108, to enable the upgraded pyrolysis oil 104 to proceed directly to steam or fluid catalytic cracking without hydrotreatment, which desirably reduces the operational costs and energy requirements of the system 100 and the method 200. The method 200 concludes with the step 212 of steam or FCC cracking the upgraded pyrolysis oil 104 to yield one or more hydrocarbon products, such as fuels and chemical feedstocks (e.g., olefins, such as ethylene and propylene).

[0040] FIG. 3 is a diagrammatic representation of an embodiment of a method 300 in which the basic adsorbent 114B of the hydrolytic dechlorination reactor 112B is regenerated. The method 200 is discussed with reference to elements illustrated in FIG. 1. In other embodiments, the method 200 may include additional steps, omitted steps, repeated steps, and so forth, relative to theembodiment illustrated in FIG. 3. In some embodiments, one or more of the steps of the method 300 may be stored as instructions in the memory 132 and executed by the processor 130 of the controller 128.

[0041] For the embodiment illustrated in FIG. 3, the method 300 includes the step 302 of heating the basic adsorbent 114B to a temperature from about 300 °C to about 600 °C. For example, the controller 128 may provide suitable control signals to cause the heater 116B to heat the basic adsorbent 114B to the desired temperature range. Additionally, the method 300 includes the step 304 of contacting the basic adsorbent 114B with a stream of the oxygen-containing gas 124 while the adsorbent is within the desired temperature range for a predetermined duration (e.g., from about 4 to about 8 hours) to regenerate the adsorbent. The method 300 further includes the step 306 of passing the resulting exhaust gas stream from the hydrolytic dechlorination reactor 112B through the scrubber 126 to treat the HC1 gas evolved as a substantial portion of the chloride content of the basic adsorbent 114B is removed and the adsorbent is regenerated.EXAMPLES

[0042] A first set of model hydrolytic dechlorination experiments were performed using an embodiment of the hydrolytic dechlorination reactor 112A illustrated in FIG. 1. For these model experiments, 0.320 grams (g) of calcium oxide or calcium hydroxide basic adsorbent was placed in reactor tubes with 20 milliliters (mL) (14 g) of pyrolysis oil containing 340 part-per-million-by- weight (ppmw) of organic chloride. The mixtures pyrolysis oil and basic adsorbent were stirred at high speed and maintained at different temperatures for a duration from between 5 hours and 10 hours, and subsequently the basic adsorbent and / or the upgraded pyrolysis oil were evaluated for chloride content. When the reaction was conducted at room temperature, the basic adsorbent demonstrated a chloride content from about 3 milligrams of chloride per gram of the basic adsorbent (mgCl / g) to about 5 mgCl / g. When the reaction was maintained at 120 °C and the basic adsorbent was calcium oxide, the upgraded pyrolysis oil demonstrated a chloride content of about 279 ppmw and the basic adsorbent demonstrated a chloride content of about 3 mgCl / g. When the reaction was maintained at 200 °C and the basic adsorbent was calcium oxide, the upgraded pyrolysis oil demonstrated a chloride content of about 121 ppmw and the basic adsorbent demonstrated a chloride content of about 11 mgCl / g. When the reaction was maintained at 200 °C and the basic adsorbent was calcium oxide that was previously calcined at 500 °C, the upgraded pyrolysis oil demonstrated a chloride content of about 124 ppmw and the basic adsorbentdemonstrated a chloride content of about 11 mgCl / g. When the reaction was maintained at 200 °C and the basic adsorbent was calcium hydroxide, the upgraded pyrolysis oil demonstrated a chloride content of about 170 ppmw and the basic adsorbent demonstrated a chloride content of about 8.5 mgCl / g.

[0043] A second set of model hydrolytic dechlorination experiments were performed using an embodiment of the hydrolytic dechlorination reactor 112A illustrated in FIG. 1. For these model experiments, basic zeolite 13X was placed in reactor tubes with pyrolysis oil containing 329 part- per-million-by-weight (ppmw) of organic chloride. The mixtures pyrolysis oil and basic adsorbent were stirred at high speed and maintained at different temperatures for a duration from between 5 hours and 10 hours, and subsequently the basic adsorbent and / or the upgraded pyrolysis oil were evaluated for chloride content. The results are summarized in Table 1.

[0044] Table 1: Summary of results for the second set of model hydrolytic dechlorination experiments.

[0045] A third set of model hydrolytic dechlorination experiments were performed using an embodiment of the hydrolytic dechlorination reactor 112A illustrated in FIG. 1. For these model experiments, mixtures of pyrolysis oil having an initial chloride content of 324 ppmw and a zeolite X13-sodium basic adsorbent were maintained 200 °C for a duration of 1 hour, and subsequently the upgraded pyrolysis oil was evaluated for chloride content. After each hydrolytic dechlorination treatment, the basic adsorbent was regenerated for a duration of 4 hours at a temperature from about 300 °C to about 600 °C before being used in the subsequent hydrolytic dechlorination treatment. The results are summarized in Table 2. As indicated in Table 2, while the virgin basic adsorbent performed the best, decreasing the chloride content of the upgraded pyrolysis oil by about 55% relative to the initial pyrolysis oil, the regenerated basic adsorbent desirably maintainsthe ability to remove between about 45% and about 51% of the chloride content of the initial pyrolysis oil after one or more regeneration operations.

[0046] Table 2: Summary of results for the third set of model hydrolytic dechlorination experiments.

[0047] A fourth set of model hydrolytic dechlorination experiments were performed using an embodiment of the hydrolytic dechlorination reactor 112A illustrated in FIG. 1 to study the effectiveness of silicon removal. For these model experiments, a first set of mixtures of pyrolysis oil having an initial silicon content of 33 ppmw and about 400 mg of zeolite X13-sodium basic adsorbent were maintained either at 150 °C or 250 °C for a duration of 1 hour, and subsequently the upgraded pyrolysis oil was evaluated for silicon content. A second set of mixtures of pyrolysis oil having an initial silicon content of 26.5 ppmw and about 400 mg of zeolite X13-sodium basic adsorbent were maintained either at 100°C, 150 °C, or 200 °C for a duration of 1 hour, and subsequently the upgraded pyrolysis oil was evaluated for silicon content. The results are summarized in Table 3. As indicated in Table 3, for the first set of pyoil samples, the silicon content decreased by about 20 wt.% when treated at 150 °C, and decreased by about 25 wt.% when treated at 250 °C. For the second set of pyoil samples, the silicon content decreased by about 15 wt.% when treated at 100 °C, decreased by about 25 wt.% when treated at 150 °C or 200 °C.

[0048] Table 3: Summary of results for the fourth set of model hydrolytic dechlorination experiments.

[0049] Other objects, features, and advantages of the disclosure will become apparent from the foregoing figures, detailed description, and examples. It should be understood, however, that the figures, detailed description, and examples, while indicating specific 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 the 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.

Claims

CLAIMSWhat is claimed is:

1. A method, comprising: performing a hydrolytic dechlorination of pyrolysis oil containing one or more organic chloride species by: introducing the pyrolysis oil into a reactor, the pyrolysis oil having a temperature ranging from about 100 degrees Celsius (°C) to about 300 °C; and contacting the pyrolysis oil with a basic adsorbent within the reactor under autogenic pressure and in the absence of hydrogen to hydrolyze the one or more organic chloride species of the pyrolysis oil and yield an upgraded pyrolysis oil having a lower organic chloride content.

2. The method of claim 1, wherein the basic adsorbent comprises a zeolite having a pore size greater than about 6 angstroms (A), a zeolite in the sodium form, or both.

3. The method of claim 1, wherein the basic adsorbent is a basic zeolite 13X adsorbent capable of adsorbing at least 2 moles of CO2 per kilogram of basic zeolite 13X, and wherein the reactor is a fixed bed reactor.

4. The method of claim 3, wherein the basic zeolite 13X adsorbent comprises silica, alumina, one or more alkali metal oxides or hydroxides, one or more alkali earth metal oxides or hydroxides, or a combination thereof.

5. The method of claim 4, wherein the basic zeolite 13X adsorbent consists essentially of silica, alumina, and one or more of sodium oxide or sodium hydroxide.

6. The method of claim 4, wherein the basic zeolite 13X adsorbent consists essentially of silica, alumina, and one or more of calcium oxide or calcium hydroxide, or barium oxide.

7. The method of claim 1, wherein the basic adsorbent comprises calcium oxide, calcium hydroxide, barium oxide, or a combination thereof.

8. The method of claim 7, wherein the reactor is a fluidized bed reactor.

9. The method of claim 1, wherein, after performing the hydrolytic dechlorination, the basic adsorbent has a chloride content greater than 8 milligrams (mg) of chloride per gram (g).

10. The method of claim 9, comprising: after performing the hydrolytic dechlorination, regenerating the basic adsorbent by heating the basic adsorbent to a temperature from about 300 °C to about 600 °C in the presence of oxygen for a duration from about 4 hours to about 8 hours to remove a substantial portion of the chloride content of the basic adsorbent.

11. The method of claim 10, comprising, while regenerating the basic adsorbent, passing an exhaust gas stream through a caustic scrubber to treat hydrogen chloride (HC1) gas evolved as the substantial portion of the chloride content of the basic adsorbent is removed.

12. The method of claim 1, wherein a mixture of the pyrolysis oil and the basic adsorbent within the reactor comprises between about 0.01 weight percent (wt.%) to about 4 wt.% basic adsorbent based on the weight of the mixture.

13. The method of claim 1, wherein the temperature of the pyrolysis oil ranges from about 150 °C to about 250 °C during hydrolytic dechlorination.

14. The method of claim 1, wherein the autogenic pressure ranges from about 2 bar gauge (barg) to about 15 barg.

15. The method of claim 1, wherein the organic chloride content of the upgraded pyrolysis oil is at least 50 wt.% lower than an organic chloride content of the pyrolysis oil.

16. The method of claim 1, wherein the upgraded pyrolysis oil has a silicon content that is at least 20 wt.% lower than a silicon content of the pyrolysis oil.

17. The method of claim 1, wherein the upgraded pyrolysis oil has an alcohol content that is at least 0.01 wt.% greater than an alcohol content of the pyrolysis oil.

18. The method of claim 1, comprising: performing pyrolysis of mixed plastic waste at a temperature ranging from about 400 °C to about 500 °C under anaerobic conditions to yield the pyrolysis oil, wherein the temperature of the pyrolysis oil ranges from about 100 °C to about 300 °C during hydrolytic dechlorination due to residual heat from pyrolysis.

19. The method of claim 1, wherein the pyrolysis oil is heated from ambient temperature to the temperature ranging from about 100 °C to about 300 °C prior to or upon entering the reactor.

20. The method of claim 1 , wherein the upgraded pyrolysis oil remains substantially free of gum impurities after 2 months.

21. The method of claim 1, wherein the one or more organic chloride species comprise chloroalcohols, alkyl chlorides, and aromatic chlorides.

22. The method of claim 1, wherein the pyrolysis oil comprises at least 0.01 wt.% water.

23. The method of claim 22, comprising: adding water to the pyrolysis oil prior to contacting the basic adsorbent.

24. The method of claim 1, comprising: steam cracking the upgraded pyrolysis oil without prior hydrotreatment.

25. The method of claim 1, comprising: hydrotreating the upgraded pyrolysis oil prior to steam cracking.

26. The method of claim 1, wherein, during hydrolytic dechlorination, the pyrolysis oil contactsthe basic adsorbent for between about 0.5 hour and about 10 hours.

27. A hydrolytic dechlorination system, comprising: a hydrolytic dechlorination reactor containing a basic adsorbent, the hydrolytic dechlorination reactor being configured to operate in hydrolytic dechlorination mode by to receiving pyrolysis oil having a first organic chloride content and contacting the pyrolysis oil with the basic adsorbent at a temperature ranging from about 100 degrees Celsius (°C) to about 300 °C in the presence of at least 100 part-per-million-by- weight (ppmw) water, based on the weight of the pyrolysis oil, to hydrolytically dechlorinate one or more organic chloride species of the pyrolysis oil, thereby to generate an upgraded pyrolysis oil having a second organic chloride content that is lower than the first organic chloride content.

28. The hydrolytic dechlorination system of claim 27, wherein the hydrolytic dechlorination reactor is configured to receive a flow of water in a liquid or a gaseous phase resulting in a water content within the hydrolytic dechlorination reactor ranging from about 100 ppmw to about 500 ppmw relative to the weight of the pyrolysis oil.

29. The hydrolytic dechlorination system of claim 27, wherein the second organic chloride content of the upgraded pyrolysis oil is at least 50 weight percent (wt.%) lower than the first organic chloride content of the pyrolysis oil.

30. The hydrolytic dechlorination system of claim 27, wherein the hydrolytic dechlorination reactor includes a heater configured to heat the pyrolysis oil to the temperature ranging from about 100 °C to about 300 °C.

31. The hydrolytic dechlorination system of claim 27, wherein the basic adsorbent is a zeolite, and the hydrolytic dechlorination reactor is a fixed bed reactor.

32. The hydrolytic dechlorination system of claim 27, wherein the basic adsorbent is a non- zeolite, and the hydrolytic dechlorination reactor is a fluidized bed reactor.

33. The hydrolytic dechlorination system of claim 27, wherein the hydrolytic dechlorination reactor is fluidly connected to a pyrolysis reactor to receive the pyrolysis oil from the pyrolysis reactor, the pyrolysis oil being produced within the pyrolysis reactor via the pyrolysis of mixed plastic waste.

34. The hydrolytic dechlorination system of claim 27, wherein the hydrolytic dechlorination reactor is fluidly connected to a hydrotreatment reactor to provide the upgraded pyrolysis oil to the hydrotreatment reactor.

35. The hydrolytic dechlorination system of claim 27, wherein the hydrolytic dechlorination reactor is fluidly connected to a cracking reactor to provide the upgraded pyrolysis oil to the cracking reactor, wherein the cracking reactor is a steam cracking reactor or a fluid catalytic cracking (FCC) reactor.

36. The hydrolytic dechlorination system of claim 27, comprising a second hydrolytic dechlorination reactor disposed in parallel with the hydrolytic dechlorination reactor and containing a second basic adsorbent, the second hydrolytic dechlorination reactor being configured to operate in regeneration mode by contacting the second basic adsorbent with an oxygencontaining gas stream at a second temperature ranging from about 300 °C to about 600 °C to remove a substantial portion of a chloride content of the second basic adsorbent and regenerate the second basic adsorbent.

37. The hydrolytic dechlorination system of claim 36, comprising an analyzer configured to measure the second organic chloride content of the upgraded pyrolysis oil, and a controller that is communicatively connected to the analyzer to receive the measurement of the second organic chloride content of the upgraded pyrolysis oil, wherein, in response to determining that the second organic chloride content is greater than a predetermined threshold value, the controller is configured to switch the hydrolytic dechlorination reactor into the regeneration mode and to switch the second hydrolytic dechlorination reactor into the hydrolytic dechlorination mode.

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