WO2024129372A1 - Co-processing pyoil through desalter and cracking furnace with integral vapor-liquid separator to generate circular products - Google Patents

Abstract

A variety of methods and systems are disclosed, including, in one embodiment, a method including; processing at least a plastic-derived pyrolysis oil in a desalter to form at least a desalted pyrolysis oil; heating the desalted pyrolysis oil; separating the desalted pyrolysis oil to form a vapor phase and a liquid phase; steam cracking at least a portion of the first vapor phase in the presence of steam to form at least a cracking effluent; and separating the cracking effluent into at least an additional vapor phase and an additional liquid phase.

Description

CO PROCESSING PYOIL THROUGH DESALTER AND CRACKING FURNACE WITH INTEGRAL VAPOR-LIQUID SEPARATOR TO GENERATE CIRCULAR PRODUCTS

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority' to US Provisional Application No. 63/387.209 filed December 13, 2022, the disclosure of which is incorporated herein by reference.

FIELD

[0002] This application relates to cracking hydrocarbons and, more particularly, in one or more embodiments, to methods and systems that include processing pyrolysis oil through a desalter and cracking furnace with an integrated vapor-liquid separator to generate circular products.

BACKGROUND

[0003] Historically, steam cracker feedstocks have come from refinery' process streams produced by industrially standard refinement practices. Such practices are generally carried out by downstream equipment and are well suited for accepting relatively pure influent streams which are substantially⁷ refined, as any contaminants would ty pically be removed early on during refinement and markedly prior to cracking. However, as demand for olefins have grown at a rate exceeding that of the growth in demand for refined fuels, it has become increasingly desirable to look for alternatives to the conventional feedstocks typically utilized during olefin production. For example, processes have recently been engineered to utilize raw feedstocks (e.g, various crudes, condensates, and their fractions) as feed to steam crackers.

[0004] Given the immensity' of the global production of plastic (e.g, 400 million tons in 2016) less than 10% of which is currently recycled, it would be advantageous to utilize feedstocks derived from waste plastics during the production of olefins. However, existing systems may not be well adapted to processing unconventional feedstocks containing high amounts of materials having final boiling point (FBP) above 590°C (e.g, resids, residuum, crude oil, condensates, and their fractions), nonvolatile components (e.g, contaminants, high boiling point hydrocarbons, etc., insoluble materials, inorganic species, polar organic molecules, non-hydrocarbon contaminants such as metals and metalloids (e.g, silicon, mercury ), and other contaminants. SUMMARY

[0005] Disclosed herein is an example method comprising: processing at least a plastic- derived pyrolysis oil in a desalter to form at least a desalted pyrolysis oil; heating the desalted pyrolysis oil; separating the desalted pyrolysis oil to form a vapor phase and a liquid phase; steam cracking at least a portion of the first vapor phase in the presence of steam to form at least a cracking effluent; and separating the cracking effluent into at least an additional vapor phase and an additional liquid phase.

[0006] Further disclosed herein is an example method comprising: mixing a plastic-derived pyrolysis oil at a temperature of about 100°C to 200°C to be desalted with water to form a first oil/water emulsion; passing the oil/water emulsion to a first desalting vessel, wherein the oil/water emulsion is separated into an aqueous phase and an oleaginous phase; removing at least a portion of the oleaginous phase from the first desalting vessel as an inter-stage feed; mixing the inter-stage feed with additional water to form a second oil/water emulsion; passing the second oil/water emulsion to a second desalting vessel for separation of hydrocarbons and the additional water; removing a desalted pyrolysis oil from the second desalting vessel, wherein the desalted pyrolysis oil has a chloride concentration 90 wt.% less than a chloride concentration of the plastic-derived pyrolysis oil; introducing desalted pyrolysis oil to a steam cracking furnace for preheating; mixing the desalted pyrolysis oil with at least steam; separating a mixture of the desalted pyrolysis oil and the steam into a vapor phase and liquid phase, wherein the vapor phase comprises volatile hydrocarbons in an amount of about 55 wt.% to about 70 wt.% and steam in an amount of about 30% to about 45 wt.%; heating the vapor phase to a temperature of about 425°C to about 650°C; and steam cracking at least a portion of the vapor phase to form at least a cracking effluent; and recovering at least olefins from the cracking effluent.

[0007] These and other features and attributes of the disclosed methods and systems of the present disclosure and their advantageous applications and/or uses will be apparent from the detailed description which follow-s.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] To assist those of ordinary' skill in the relevant art in making and using the subject matter hereof, reference is made to the appended drawings, wherein:

[0009] FIG. 1 is a simplified block diagram illustrating an example system that includes a desalter, a cracking furnace, and an integrated vapor-liquid separator in accordance with some embodiments of the present disclosure; and [0010] FIG. 2 is a flow diagram of an embodiment of an apparatus for removal of contaminants in a feedstock in accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION

[0011] This application relates to cracking hydrocarbons and, more particularly, in or more embodiments, to methods and systems that include processing pyrolysis oil through a desalter and cracking furnace with an integrated vapor-liquid separator to generate circular products.

[0012] As discussed previously, existing processes are not well adapted to processing feedstocks comprising resids and other contaminants. For example, some gas oil furnaces can accommodate between 230°C and 540°C final boiling point (FBP) material. Certain embodiments of the present disclosure are configured to process materials with boiling points up to and in excess of 590°C) and may result in a total circular product yield between 30% and 50%. In addition, certain embodiments may be well suited for removing inorganic species (e.g, halides, silica, nitrates, nitrites) and/or polar organic molecules from a pyrolysis oil feed prior to introduction to a furnace cracker. Lastly, certain embodiments may allow for at least 5% to at least 100% faster throughput of pyrolysis oil through a process as compared to conventional refining methods.

[0013] Unless otherwise stated, all percentages, parts, ratios, etc., are by weight. Unless otherwise stated, a reference to a compound or component includes the compound or component by itself, as well as in combination with other compounds or components, such as mixtures of compounds.

[0014] Further, when an amount, concentration, or other value or parameters is given as a list of upper values and lower values, this is to be understood as specifically disclosing all ranges formed from any pair of an upper value and a lower value, regardless of whether ranges are separately disclosed.

[0015] Also as used herein, non-volatile components can be measured as follows: The boiling point distribution of a feed is measured by Gas Chromatograph Distillation (GCD) by ASTM D-352-98 or another suitable method. The non-volatile components are the fraction of the feed with a nominal boiling point above 590°C as measured by ASTM D-6352-98. In some embodiments, non-volatiles have a nominal boiling point above 760°C.

[0016] As used herein, the terms “circular products/’ “circular materials,” “circular compounds,” etc., refer to circular chemical products. Circular chemical products are chemical products derived from polymeric waste wherein the molecules of the chemical product can be attributed to the polymers in the polymeric waste, such as by crediting, allocating offsetting for other hydrocarbons, and/or substituting for other hydrocarbons in a mass or energy balance for a system. Circular chemical products include circular monomers, circular aromatics, and circular polymers, among others. Polymers that are certified for their circularity by third party certification may be referred to as certified circular. One example of such a certification is the mass balance chain of custody method set forth by the International Sustainability and Carbon Certification.

[0017] As used herein, a reference to a “C_x” fraction, stream, portion, feed, or other quantity is defined as a fraction (or other quantity) where 50 wt.% or more of the fraction corresponds to hydrocarbons having “x” number of carbons. When a range is specified, such as “Cx-Cy”, 50 wt.% or more of the fraction corresponds to hydrocarbons having a number of carbons from “x” to “y”. A specification of “C_x+” (or “C_x-”) corresponds to a fraction where 50 wt.% or more of the fraction corresponds to hydrocarbons having the specified number of carbons or more (or the specified number of carbons or less).

[0018] FIG. 1 is a simplified block diagram illustrating a system 100 for processing pyrolysis oil in accordance with some embodiments. As illustrated the system may include the following units: (i) a desalter 102 that to removes inorganic species from a pyrolysis oil feed 104; (ii) a steam cracking furnace 105 for cracking at least desalted pyrolysis oil in a desalted cracker feed 108 from the desalter 102; (iii) an integrated vapor-liquid separator 110 for separating at least a vapor fraction from a liquid fraction in a heated desalted cracker feed 112 from the steam cracking furnace 105, (iv) an effluent vapor-liquid separator 114 for separating a liquid fraction from a steam cracker effluent 116; and (iv) a cracker recovery unit 118 for separating an additional vapor phase stream 120 from the effluent vapor-liquid separator 114 into two or more streams. It should be understood that FIG. 1 is not intended to imply that a direct fluid connection between the desalter 102 and the steam cracking furnace 105 is required. Rather, the pyrolysis oil feed 104 can be washed at one site and transported to another site for cracking. In addition, while the pyrolysis oil is referred to as ’ desalted." it is not intended to imply that 100% of salts are removed from the pyrolysis oil feed 104, but rather that the desalter 102 purifies the pyrolysis oil feed 104 by removing at least a portion of inorganic species.

[0019] In some embodiments, the pyrolysis oil feed 104 includes a plastic-derived pyrolysis oil. As used herein, ‘‘plastic-derived pyrolysis oil” refers to pyrolysis oil (“pyoil”) where at least 50 wt.% of the pyrolysis oil is derived from a plastic source. That is, the feedstock (also referred to as plastic feedstock) that is pyrolyzed comprises at least 50 wt.% plastic.

[0020] Examples of plastic sources include, but are not limited to, plastic waste (e.g., plastic straws, plastic utensils, plastic bags, food containers, and the like), composite materials (e.g., composite packaging, artificial turf, artificial turf components, etc.), and the like, and any combination thereof. Said plastic sources may comprise one or more polymers that include, but are not limited to, polyolefins (e.g., homopolymer or copolymers of ethylene, propylene, butene, hexene, butadiene, isoprene, isobutylene, and other olefins), polystyrene, polyvinylchloride, polyamide (e.g., nylon), polyethylene terephthalate, polyurethane, ethylene vinyl acetate, and the like. Other materials may be used in combination wi th the plastic source to produce the plastic-derived pyrolysis oil, for example, paper, cardboard, textiles, tires, tissues, and the like, and any combination thereof. The plastic portion of the plastic feedstock for pyrolysis may comprise polyolefin at 50 wt.% to 100 wt.% (or 65 wt.% to 80 wt.%, or 75 wt.% to 90 wt.%, or 80 wt.% to 100 wt.%) with a balance of one or more other polymers.

[0021] Pyrolysis of a plastic feedstock may be performed by known methods and in known systems (e.g., at temperatures of 400°C to 850°C, or 400°C to 600°C, or 500°C to 850°C). A pyrolysis product is then distilled (or separated) into one or more cuts including a plastic- derived pyrolysis oil cut.

[0022] A plastic-derived pyrolysis oil may be a C5+ stream (or a C5-C30 stream, or a C5-C20 stream, or a C5-C25 stream, or a C5-C20 stream). A plastic-derived pyrolysis oil may comprise 50 wt.% or more (or 50 wt.% to 100 wt.%, or 50 wt.% to 75 wt.%, or 70 wt.% to 90 wt.%, or 80 wt.% to 100 wt .%) of C5+ hydrocarbons and less than 50 wt.% (or 0 wt.% to less than 50 wt.%, or 25 wt.% to 50 wt.%, or 10 wt.% to 30 wt.%, or 0 wt.% to 20 wt.%, or 0 wt.% to 5 wt.%, or 0 wt.% to 2 wt.%) of C4 hydrocarbons.

[0023] A plastic-derived pyrolysis oil may have a specific gravity of 0.5 to 1.0 (or 0.5 to 0.7, or 0.6 to 0.9, or 0.7 to 1.0).

[0024] A plastic-derived pyrolysis oil may comprise 0 wt.% to 60 wt.% olefin content, 0 wt.% to 25 wt.% diolefin content, and balance other species like aromatics and paraffins for example.

[0025] A plastic-derived pyrolysis oil may have an initial boiling point of 30°C or greater, 100°C or greater, 200°C or greater, 300°C or greater, 400°C or greater, 450°C or greater, 500°C or greater, or 600°C or greater. For example, the plastic-derived pyrolysis oil may have an initial boiling point of 30°C to 200°C, 30°C to 70°C, 50°C to 150°C, or 100°C to 200°C. A plastic-derived pyrolysis oil may have a final boiling point of 850°C or less, 700°C or less, 600°C or less. For example, the plastic-derived pyrolysis oil may have a final boiling of 150°C to 850°C, 150°C to 600°C, 250°C to 400°C, 300°C to 500°C, 400°C to 600°C, 600°C to 700°C, or 700°C to 800°C. [0026] A plastic-derived pyrolysis oil may have properties similar to a naphtha, a distillate, a wax, an atmospheric resid, and the like.

[0027] Pyrolysis oil quality can vary widely and depends on a number of factors, including quality of the plastic waste, conversion technology (e.g. , thermal pyrolysis, catalytic pyrolysis, etc.) and pre- or post-contaminant clean up included with the pyrolysis unit. In order to process pyrolysis oil through a steam cracker, it must be compatible with the furnace technology' and have a composition that a recovery unit can handle without causing process safety, environmental, reliability, or product quality issues. Many’ pyrolysis oils available contain small fractions of high boiling point hydrocarbon components that are not compatible for processing through a typical liquids steam cracker (e.g., naphtha cracker, gas oil cracker, etc.). Additionally, the pyrolysis oils and especially the high boiling point hydrocarbon components contain high levels of certain contaminants (e.g , metals, salts, total acid number, etc.) that typical liquid steam crackers are not designed to handle. For example, processing pyrolysis oil can result in deposition of non-volatile materials (e.g., asphaltenes) in the convection section of the steam cracking furnace that cannot be removed through decoking or other on-line cleaning methods. Additionally, some of these contaminants may react with or otherwise interact with the metallurgy of the furnace radiant or convection sections and decrease the operational life of these components in a variety of ways (e.g., causing corrosion or otherwise degrading the metallurgy).

[0028] The plastic-derived pyrolysis oil can include high boiling point hydrocarbons. For example, the plastic-derived pyrolysis oil may include one or more heavy petroleum compounds, such as those commonly present in crude oil, resids, residuum, pitch, atmospheric resid, and vacuum resid. The term “crude oil” means whole crude oil as it flows from a wellhead, a production field facility, a transportation facility', or other initial field processing facility, optionally including crude that has been processed by a step of desalting, treating, and/or other steps as may be necessary to render it acceptable for conventional distillation in a refinery. Crude oil is presumed to contain resid. Non-limiting examples of crude oils can be or can include Tapis, Murban, Arab Light, Arab Medium, and/or Arab Heavy. The term “resid” refers to a bottoms cut of a crude distillation process that contains non-volatile components. Resids are complex mixtures of heavy petroleum compounds otherwise known in the art as residuum or residual or pitch. Atmospheric resid is the bottoms product produced from atmospheric distillation of crude where a typical endpoint of the heaviest distilled product is nominally 343°C and is referred to as 343°C resid. The term “nominally”, as used herein, means that reasonable experts may disagree on the exact cut point for these terms, but by no more than +/- 55.6°C preferably no more than +/- 27.8°C. Vacuum resid is the bottoms product from a distillation column operated under vacuum where the heaviest distilled product can be nominally 566°C. and is referred to as 566°C resid. The plastic-derived pyrolysis oil may also have in common components of one or more cuts in a typical crude distillation process including any of resids, residuum, residual, pitch, atmospheric resid, vacuum resid, etc.

[0029] The plastic-derived pyrolysis oil can also include high levels of certain contaminants, such as metals and salts. Metals may include, for example, mercury, aluminum, vanadium, nickel, lead, chromium, iron, arsenic, sodium, potassium, magnesium, beryllium, antimony, barium, cadmium, calcium, cobalt, copper, manganese, molybdenum, selenium, silver, tin, titanium, zinc, lithium, and/or combinations thereof. Other non-metallic contaminants may include, for example, bromine, fluorine, phosphorus, and boron. The pyrolysis oil may have a total chlorides content of 160 wppm or greater. For example, the pyrolysis oil may have a total chlorides content of 170 wppm to 1000 wppm, 170 wppm to 500 wppm, 170 wppm to 275 wppm, 170 wppm to 250 wppm, 200 wppm to 300 wppm, or 200 wppm to 250 wppm. As used herein, the total chlorides content is the sum of measure of the total chlorides (organic and inorganic) in the recycle pyrolysis oil, as determined in accordance with ASTM D7359.

[0030] In addition to specific concentrations of contaminants, certain contaminants can cause the pyrolysis oil to have a high acidity⁷ that can be problematic for further processing. The total acid number, as determined in accordance with ASTM D664, is a measurement that can be used to quantify the acidity of the pyrolysis oil. The pyrolysis oil may have a total acid number of 1.7 mg KOH/g or greater. In some embodiments, the pyrolysis oil may have a total acid number of 0 mg KOH/g to 1.7 mg KOH/g, 1.7 mg KOH/g to 4 mg KOH/g, 1.7 mg KOH/g to 3 mg KOH/g, 1.7 mg KOH/g to 2.5 mg KOH/g, 2 mg KOH/g to 4 mg KOH/g, 2 mg KOH/g to 3 mg KOH/g, or 2 mg KOH/g to 2.5 mg KOH/g.

[0031] With continued reference to FIG. 1, the pyrolysis oil feed 104 comprising a plastic- derived pyrolysis oil may be fed to a desalter 102. In the desalter 102, the plastic-derived pyrolysis oil may be processed in the desalter 102 to remove inorganic species to produce a desalted pyrolysis oil. For example, the desalter 102 can remove various contaminants from the plastic-derived pyrolysis oil. such as salts and/or particulate matter. For example, the desalter 102 may reduce contaminants in the plastic-derived pyrolysis oil by more than 90 wt.% for inorganic halides (e.g., Cl, F, Br) (e.g., 90 wt.% to 99 wt.%), by more than 10 wt.% for organic halides (e.g., 10 wt.% to 30 wt.%), by more than 90 wt.% for nitrates and/or nitrites (e.g., 90 wt.% to 99 wt.%), by more than 10 wt. % for phosphates (e.g., between 10 wt.% and 50 wt.%), by more than 10 wt.% for silica and silicon (e.g., 10 wt.% to 30 wt.%), and/or more than 10 wt.% for other salts and particulates (e.g., 10 wt.% to 50 wt.%).

[0032] In accordance with present embodiments, the desalter 102 includes one or more desalter vessels such as a plurality of vessels in semi-continuous operation (e.g, one drum in use and the other under maintenance). The desalting and related equipment in the desalter 102 can be configured in series, parallel, and/or series parallel. Optionally, at least one of the desalting vessels can include a mud-wash functionality and/or a tri-line sampling functionality and can further include auxiliary equipment such as one or more brine tanks. While acceptable salt and/or particulate matter concentration vary with furnace design, the addition of the desalter 102 may be advantageous when sodium chloride and/or other salts are greater than a predetermined amount of a feed and can further depend on the operating conditions of a particular feed.

[0033] In the desalter 102, a wash water (e.g, fresh water or deionized water) is typically mixed with the pyrolysis oil feed 104 to produce a water-in-oil emulsion, which in turn extracts salt, brine and particulates from the oil. The wash water used to treat a feed may be derived from various sources. For example, the water may be recycled and/or recirculated water from other units in the facility, e.g. , sour water stripper bottoms, overhead condensate, boiler feed water, with and/or without clarification, purification, etc. Alternately, or in addition, the wash water may be obtained from other sources, e.g, from surface water sources such as from a river, from geological water sources, such as from one or more wells, and/or from a separate facility, such as demineralized water and clarified water, among others. The concentration of various salts in the wash water can be expressed in parts per thousand by weight (ppt), and typically salt concentration is in the range of from that of fresh w ater (less than 0.5 ppt of sodium chloride), brackish water (0.5-30 ppt of sodium chloride), or saline w ater (30-50 ppt of sodium chloride) to that of brine (more than 50 ppt of sodium chloride). Although deionized water may be used to favor exchange of salt from the plastic-derived pyrolysis oil into the aqueous solution, de-ionized water is not normally required to desalt feedstocks. In certain aspects, how ever, deionized w ater may be mixed with recirculated water from the desalter 102 to achieve a specific ionic content in either the wash water before emulsification or to achieve a specific ionic strength in the final emulsified product. Wash water rates are typically in a range of from 5% to 7% by volume of the total crude oil or pyrolysis oil to be desalted but may be higher or lower dependent upon the pyrolysis oil source and quality. A variety of water sources may be combined as determined by cost requirements, supply, salt content of the water, salt content of the pyrolysis oil feed 104, and other factors specific to the desalting conditions such as the size of the separator and the degree of desalting required.

[0034] In some embodiments, the pyrolysis oil feed 104 is preheated prior to mixing with the wash water. Elevating temperatures can increase desalting efficiency. In some embodiments, pyrolysis oil feed 104 is preheated to a temperature of 30°C or greater, e.g., 100°C or greater, such as 120°C or greater, 140°C or greater, or 150°C or greater. For example, the pyrolysis oil feed 104 may have a temperature of from 100°C to 200°C, from 120°C to 180°C, from 140°C to 180°C, from 150°C to 200°C. from 200°C to 400°C. from 200°C to 300°C, or from 300°C to 400°C.

[0035] During the separation phase of a desalting process, an emulsion phase of varying composition and thickness may form at the interface of the hydrocarbon and aqueous layers. If unresolved, these emulsions may carry-over with the desalted pyrolysis oil or carry-under into the aqueous layer. If carried over, the emulsions may lead to coking or fouling of downstream equipment and disruption of the downstream fractionation process. If carried- under, they can disrupt the downstream water treatment process. Consequently, for desalting of crude oil, refiners typically desire to either control the formation/growth of these emulsions or remove the emulsions from desalter units and, using an additional processing step, to resolve the emulsion into its constituent parts (i.e., to break the emulsion, resulting in separate oil, water, and solid phases) to allow for reuse and/or disposal of the oil, w ater, and solids.

[0036] Methods for separating the hydrocarbon and w ater phases may include gravitational or centrifugal methods. In a gravity method, the emulsion is allowed to stand in the separator and the density difference between the hydrocarbon and the water causes the water to settle through and out of the oil by gravity. In the centrifugation method, the stable emulsion is moved from the desalter unit to a centrifuge (not shown) which separates the emulsion into separate water, hydrocarbon, and solids. The gravity method generally requires the use of timeintensive, and thus inefficient, settling tanks as w ell as costly methods for disposing of the partially resolved emulsion, while the centrifugation method may require large centrifuges that are costly to build and operate.

[0037] Typically, an electric field is established in a region within the desalter 102 (e.g. , in a desalting vessel) to enhance water droplet coalescence. This in turn breaks the emulsion to form an oleaginous continuous phase and an aqueous continuous phase. Even when a relatively strong electric field is established in the desalter 102, an emulsion layer (called a “rag layer”) may form, ty pically below' the region in which the electric field is established. This emulsion layer is observed to be stable, even when adjacent to the strong electric field. The strength of this emulsion layer (sometimes called a “persistent emulsion”, indicating its resistance to emulsion-breaking) typically depends on factors such as feed hydrocarbon gravity (e.g., the gravity of pyrolysis oil in a feed, the presence and amount of solids and semi-solids, such as particles, etc.). Such a rag layer typically contains a high concentration of hydrocarbon, residual water, suspended solids and salts which, in atypical example, might be 70% v/v water, 30% v/v oil, with 14 to 23 g/1 solids, and 570 to 1100 mg/1 salts. The aqueous phase contains salts transferred from the pyrolysis oil feed 104 being desalted. Conventional methods for managing the rag layer can be used, but the disclosure is not limited thereto. For example, introducing into the desalter 102 one or more de-emulsifier compositions and/or separating and conducting away at least a portion of the emulsion.

[0038] In some embodiments, a de-emulsifier may be added to the pyrolysis oil feed 104, wash water, or a combination thereof, for example, to decrease rag layer size (e.g. , height, when the plane of the rag layer is substantially parallel to the surface of the earth) and persistence. Examples of suitable demulsifiers may be one or more of: polyethyleneimines, polyamines, succinated polyamines, polyols, ethoxylated alcohol sulfates, long chain alcohol ethoxylates, long-chain alkyl sulfate salts, e.g., sodium salts of lauryl sulfates, epoxies, and di-epoxides (which may be ethoxylated and/or propoxylated).

[0039] Referring now' to FIG. 2, a flow diagram is illustrated for using a two-stage desalter 200 to remove contaminants from a plastic-derived pyrolysis oil while maintaining flow⁷ to one or more downstream steam crackers. A storage tank 202 contains a plastic-derived pyrolysis oil. A pyrolysis oil feed 204 comprising at least plastic-derived pyrolysis oil may be transferred from storage tank 202 to pump 206. The pressure and flow rate of the pyrolysis oil feed 204 is determined by the salt content of the plastic-derived pyrolysis oil and the size and number of desalting vessels and furnaces, but the pressure should be sufficiently high as to avoid vaporization of the water and hydrocarbons in the pyrolysis oil at the temperatures used in the desalting process. Pressurized pyrolysis oil feed 208 is fed to heat exchanger 210 to provide a heated pyrolysis oil feed 212. The heated pyrolysis oil feed 212 may undergo further heating. The additional heating can be carried out in one or more additional heat exchangers (not shown), which can be located before and/or after heat exchanger 210. The additional transfer of heat results in an increased temperature of the plastic-derived pyrolysis oil beyond what can be achieved by heat exchanger 210 alone. Doing so decreases the viscosity of the feed, and promotes mixing with w'ater, as described below⁷. Suitable heat transfer fluids for the additional heat exchangers include, e.g., (i) steam such as low⁷ pressure, medium pressure, high pressure, or super high pressure steam (generally the lowest pressure steam that is effective for carrying out the heat transfer is used, typically medium pressure steam (1500 kPa-3000 kPa) or low pressure steam (<1500 kPa) steam is sufficient), (ii) an oleaginous heat transfer fluid from a recovery’ system, e.g, a bottoms pump around oil from a primary fractionator, and (iii) an aqueous quench fluid. For example, in certain aspects heat exchanger 210 is located upstream of a first additional heat exchanger utilizing low pressure steam as a heat transfer fluid. The first additional heat exchanger is located upstream of a second additional heat exchanger utilizing a primary fractionator bottoms pump around oil as a heat transfer fluid.

[0040] The heated pyrolysis oil feed 212 is mixed with water from water line 214 to form an oil/water emulsion, which is then fed to first desalting vessel 216 for optional additional mixing followed by separation. In first desalting vessel 216, hydrocarbons and salt water are separated producing, for example, (i) an aqueous by-product (brine) sent away via line 218, and (ii) inter-stage feed removed from first desalting vessel via line 220. The desalted oleaginous phase forms a top layer which is continuously removed as inter-stage feed 220 and the resolved aqueous phase accumulates in the bottom of the desalter and is continuously removed as a brine stream via line 218. The brine stream may be sent for deionization and recycling or used with or without further processing in other processes. In some embodiments, a single desalting vessel (e.g., single stage desalter) provides sufficient contaminant removal that no additional desalting is necessary'. The use of a single stage desalter (e.g. , with a recycle line to the vessel inlet and/or a surge drum) may be sufficient if fluctuations in flow rate, such as those caused by steam crackers being brought online or offline, are managed to allow steady flow of the feed through the desalter.

[0041] One method of managing flow rate to steam crackers without sacrificing removal of contaminants is to add a second desalting vessel 222 in series with the first desalting vessel 216. In some embodiments, the addition of the second desalting vessel 222 allows for sufficient removal of contaminants even through rapid flow rate fluctuations. The (optional) addition of the second desalting vessel 222 is shown on FIG. 2. where the inter-stage feed 220 is mixed with additional water from water line 224 and then passed to the second desalting vessel 222. The oil/water emulsion formed from the combination is passed via line 226 into the second desalting vessel 222. In second desalting vessel 222, the hydrocarbons and w ater are separated producing (i) a clean water product stream sent away via line 228, and (ii) desalted pyrolysis oil removed at the hydrocarbon outlet (not shown) from the second desalting vessel 222 via line 230. Line 230 is coupled with heat exchanger 210 to allows heat exchange between the feed of plastic-derived pyrolysis oil (e.g., pressurized pyrolysis oil feed 208) and the desalted pyrolysis oil. The desalted feed (after heat exchange) transferred to steam cracking via line 232 is lower in temperature than the desalted feed in line 230, e.g. , to meet furnace requirements that depend on specific furnace design. The clean water product stream from the second desalting vessel 222 may contain a sufficiently low sodium content (e.g.. 10 wppm or less) and may be recycled via line 228 to line 214 for reuse in the first desalting vessel 216. Alternatively, the clean water product from the second desalting vessel 222 may otherwise disposed, for example, used with or without further processing in other processes at the facility (line not shown).

[0042] Certain embodiments are compatible with the use of one or more surge drums as an aid in providing a substantially uninterrupted flow rate of desalted feed to steam cracker furnaces. A surge drum can be filled with desalted feed during use. The desalted feed in the filled surge drum could be transferred into a steam cracker furnace's feed line. Doing so can provide a short-term flow of desalted feed during a decrease in flow, as might occur when a pump fails or must be taken offline for servicing while spare pumps are being started. The volume of desalted feed in the surge drum could be transferred into the feed line at a similar pressure in a variety of ways (e.g., using N2 as a motive force, along with automatic valving). In certain aspects (e.g., where such a surge drum is not used and/or where the surge drum's inventory of desalted feed is depleted), one or more of the desalters can be bypassed to maintain a sufficient flow of feed to the stream cracker furnaces.

[0043] Referring agent to Figure 1, after desalting in the desalter 100, a desalted cracker feed 108 may be introduced into a steam cracker furnace 105. The at least partially desalted cracker feed 108 has a reduced risk of causing adverse effects on the steam cracker furnace 105, including negatively impacting the furnace metallurgy (e.g, corrosion) and depositing non-volatile material into portions of the convection section 106 of the steam cracker furnace 105 where decoking or other on-line cleaning is typically unable to remove deposits. The desalted cracker feed 108 may be characterized as having a contaminant concentration reduced (with respect to the plastic-derived pyrolysis oil of the pyrolysis oil feed 104) by more than 90 wt.% for inorganic halides (e.g., Cl, F, Br), by more than 10wt.% for organic halides (e.g., 10 wt.% to 30 wt.%), by more than 90 wt.% for nitrates and nitrites (e.g. , 90 wt.% to 99 wt.%), by more than 10 wt.% for silica and silicon (e.g., 10 wt.% to 30 wt.%), and/or more than 10 wt.% for other salts and particulates (e.g., 10 wt.% and 50 wt.%). In addition, acids (represented by the Total Acid Number) may be reduced by more than 10% (e.g. , 10% to 50%). Typically, the desalted cracker feed 108 comprises <1 wppm of salt, e.g., <0.5 wppm. such as <0.25 wppm, or <0.125 wppm, or <0.0625 wppm, or in a range of from 0.01 wppm to 0.125 wppm. [0044] The steam cracking furnace 105 comprises a convection section 106 and a radiant section 107. The desalted cracker feed 108 may be heated in the convection section 106 via indirect exposure to flue gases in the convection section 106 and semi-purified in a vapor-liquid separator 110. A heated desalted cracker feed 112 may be withdrawn from the convection section 106 of the steam cracking furnace 105 and passed to the vapor-liquid separator 110 for separation into a vapor phase 122 and a liquid phase 124. The vapor phase 122 may be returned to the steam cracker furnace 105. For example, the vapor phase 122 may be returned to the convection section 106 via line 122 for further preheating before being provided to the radiant section 107 via line 123. In the radiant section 107, the vapor phase 122 may be pyrolyzed producing a steam cracker effluent 116, which is transferred for further purification in effluent vapor-liquid separator 114 and a cracker recovery unit 118. Cracker recovery unit 118 may contain a number of fractionators, separation columns, purification and/or catalyst beds, cooling and/or quench towers, and/or other devices for separation of the vapor phase 120 from the steam cracker effluent 116 into various product streams.

[0045] Steam cracking is a technique that can be used to thermally crack various hydrocarbons into lighter hydrocarbons, such as olefins and aromatics. Steam cracking can be carried out in at least one steam cracker (e.g , steam cracking furnace 105). In some embodiments, a plurality of steam cracker furnaces in parallel may be used at a facility to improve efficiency in production of light hydrocarbons. Steam crackers are typically taken offline for periodic maintenance and/or decoking and having a plurality of furnaces in parallel, allow for continuous operation of the remainder of the steam cracking and light hydrocarbon purification process without undue downtime. Generally, the steam cracker furnace 105 includes a convection section 106 where the desalted cracker feed 108 is pre-heated, and steam is added before entering the radiant section 107 of the steam cracker furnace 105 where the heat is sufficient for cracking to occur. As illustrated, the steam cracker furnace 105 has a vapor-liquid separator 110 integrated therein. For example, the vapor-liquid separator 110 may be integrated by fluid connection between the convection section and the radiant section. The radiant section 107 may comprise a fired heater, and flue gas from combustion carried out with the fired heaters travels upward from the radiant section through the convection section and then away as flue gas.

[0046] The heating of the desalted cracker feed 108 in the convection section 106 of the steam cracking furnace 105 may include indirect contact (e.g., within a line or tube within the furnace) with hot flue gases from a radiant section of the steam cracking furnace 105. The heating of the desalted cracker feed 108 can be accomplished, for example, by passing the desalted cracker feed 108 through a bank of heat exchange tubes located within the convection section 106 of the steam cracking furnace 105. The desalted cracker feed 108 may be heated to a temperature of 315°C to 560°C. such as 370°C to 510°C, 430°C to 480°C, or 480°C to 700°C. In some embodiments, the desalted cracker feed 108 is first heated to a temperature of 150°C to 260°C then combined with steam and an optional additional fluid then heated to a temperature of 315°C to 700°C. Prior to the vapor-liquid separator 110, the desalted cracker feed 108 and/or combined feed with steam/optional fluid may be heated to a temperature, for example, of 315°C to 560°C then further heated in the convection separation after separation of liquid in the vapor-liquid separator 110, for example, up to 700°C.

[0047] As mentioned previously, pyrolysis oil may contain insoluble materials. These insoluble materials that have the potential to deposit in the convection section 106 during heating. This may pose problems when the pyrolysis oil is processed in certain regions (e.g, portions of the convection section 106 where decoking or other on-line cleaning is typically unable to remove deposits, as the steam cracking furnace 105 must be brought offline to remove deposits that could not be removed through other online or offline means (e.g., decoking). To avoid unwanted deposition of nonvolatile components in these regions, the vapor-liquid separator 110 may be integrated with the process. Such vessels, sometimes referred to as flash pot or flash drum, can provide upgrading of the heated cracker feed 112. Such flash separation vessels are suitable when the preheated feed includes 0.1 wt.% or more of asphaltenes and/or other nonvolatile components based on the weight of the hydrocarbon components of the convection section effluent, e.g, 5 wt.% or more. Upgrading the preheated feed through vapor/liquid separation may be accomplished through flash separation vessels or other suitable means. Suitable means may comprise one or more conventional separation drums, though the invention is not limited thereto. Examples of such conventional separation drums can include those disclosed in U.S. Patent Nos. 7,097.758; 7,138.047; 7,220.887; 7,235.705; 7,244.871; 7.247.765; 7.297,833; 7.311,746; 7,312,371; 7,351,872; 7,427,381; 7,488.459; 7.578.929; 7,674,366; 7,767,008; 7,820,035; 7,993,435; 8,105,479; and 9,777,227, each herein incorporated by reference.

[0048] One advantage of having the vapor-liquid separator 110 downstream integrated into the convection section and upstream of the radiant section, is an increased breadth of hydrocarbon types available to be used directly, without pretreatment, as feed. For example, the addition of the vapor-liquid separator 110 allows for utilization of a feed that contains plastic-derived pyrolysis oil, for example, in an amount of 0.1 wt.% to 90 wt.%. In some embodiments, the feed may include the plastic-derived pyrolysis oil in an amount of 50 wt.% or greater or 75 wt.% or greater, or 90 wt.% or greater. Depending on the temperature of the heated cracker feed 112, usually 50 wt.% to 95 wt.% of the mixture entering the vapor-liquid separator 110 is vaporized to the upper portion of the flash drum, for example, 60 wt.% to 90 wt.%, or 65 wt.% to 85 wt.%, or 70 wt.% to 85 wt.%. The vapor-liquid separator 110 may operate at a temperature from 315°C to 560°C and/or a pressure from 275 kPa to 1400 kPa, such as, a temperature from 430°C to 480°C, and/or a pressure from 700 kPa to 760 kPa. The hydrocarbon partial pressure of the feed to the vapor-liquid separator 110 (e.g., the heated desalted cracker feed 112) may be from 25 kPa to 175 kPa. Typically, only the vapor phase 122 within the vapor-liquid separator 110 is conducted on to the radiant section of the steam cracking furnace 105, while the liquid phase 124 can be conducted away from the vapor-liquid separator 110, e.g, for storage and/or further processing. For example, the vapor phase 122 may be returned to the convection section for further pre-heating then conveyed to the radiant section for cracking.

[0049] The liquid phase 124 from the vapor-liquid separator 110 may contain, for example, from 2 wt.% to 50 wt.% of the heated cracker feed 112 fed to the vapor-liquid separator 110. The liquid phase 124 from the vapor-liquid separator 110 may be processed using any suitable technique. For example, the non-volatile components separated into the liquid phase 124 may be passed to a vacuum tower bottoms and disposed as high sulfur fuel oil. By way of further example, the non-volatile components separated into the liquid phase may be upgraded in a deasphalting unit, for example, to produce naphtha, diesel, and/or other high-value liquid products (e.g., Group II lubricants) with a remainder of the liquid phase sold or disposed as high sulfur fuel oil (HSFO). In some embodiments, the de-asphalting unit includes a solvent extraction process for removal of insoluble materials, which can either go into fuel oil blending or to a partial oxidation unit. The soluble material may be sent to a hydrocracker and dewaxer to produce naphtha, diesel, and/or other valuable liquid byproducts. The naphtha and/or diesel may be recycled to the front end of the steam cracker furnace 105 for upgrading to higher value molecules (e.g., ethylene, propylene, etc.). Since the pyrolysis oil may be derived from polyolefins, the heavy cut separated into the liquid phase 124 should have high molecular weight linear molecules compared to heavier crude molecules and therefore can end up in the soluble portion to the hydrocracking and dewaxing unit. An example de-asphalting unit that includes solvent extraction is described in more detail in U.S. Patent No. 7,578,929, the disclosure of which is incorporated herein by reference.

[0050] The vapor phase 122 from the vapor-liquid separator 110 may be returned to the steam cracker furnace 105. In the steam cracking furnace 105. the vapor phase 122 may be further heated in the convection section, for example, to 425°C to 700°C, then passed to the radiant section for cracking. The vapor phase 122 may contain, for example, 50 wt.% to 95 wt.% of the heated cracker feed 112 fed to the vapor-liquid separator 110. The vapor phase 122 also may have small concentration of non-volatile hydrocarbons, for example, 400 ppmw or less, 100 ppmw or less, 80 ppmw or less, or 50 ppmw or less. The vapor phase 122 is very' rich in volatile hydrocarbons. In some embodiments, the vapor phase 122 contains volatile hydrocarbons in an amount of 55 wt.% to 75 wt.%. The vapor phase 122 may also contain steam, for example. 25 wt.% to 45 wt.%. The vapor phase 122 may have a final boiling point of 760°C or less, for example, 600°C or less, 570°C or less, or 540°C or less.

[0051] In the radiant section, the vapor phase 122 may be cracked at temperature up to 900°C (e.g., 400°C to 900°C, 700°C to 900°C, or 750°C to 850°C), a pressure of 10 kPa to 500 kPa (e.g., 100 kPa to 500 kPa, or 200 kPa to 400 kPa).

[0052] With continued reference to Figure 1, an additional vapor-liquid separation stage (or a plurality of stages, e.g., in series, in parallel, or series-parallel) may occur at a location downstream of the steam cracking furnace 105. The additional vapor-liquid separation stage may be accomplished by means of one or more flash pots or flash drums as previously described in this disclosure, or by any suitable means. On Figure 1, the additional vapor-liquid separation stage is shown as effluent vapor-liquid separator 114.

[0053] The steam cracker effluent 116 may be introduced into the effluent vapor-liquid separator 114. Depending on the operating conditions of the steam cracking furnace 105, the cracking furnace effluent 116 may comprise volatile, non-volatile components, and/or steam. An additional liquid phase 126 separated from the steam cracker effluent 116 may be removed and processed using any suitable technique. The additional liquid phase 126 may include circular products and/or be upgraded to circular products, such as carbon black, naphtha, and low sulfur fuel oil (i.e., <0.1 wt.% S). For example, at least a portion of the additional liquid phase 126 may include a circular tar. The circular tar may be used as a blending stock, for example, in low sulfur fuel oil. The circular tar may be used as a feedstock to product circular carbon black, for example, by combusting at least a portion of the circular tar. By way of further example, the additional liquid phase 126 may be sent to a secondary heavy fuels unit for upgrading to produce circular products, such as naphtha and low sulfur fuel oil. The naphtha may be recycled to the front end of the steam cracker furnace 105 for upgrading to higher value molecules (e.g., ethylene, propylene, etc.). In some embodiments, upgrading at least a portion of the additional liquid phase incudes one or more hydroprocessing stages. An example process for a secondary heavy fuels unit is described in more detail in U. S. Patent No. 10,968,404, the disclosure if which is incorporated herein by reference.

[0054] The additional vapor phase 120 separated from the steam cracker effluent 116 may be fed to a recovery section 118 for separation into one or more desirable product streams. Products recoverable from the vapor overhead stream include, for example, hydrogen, ethylene, propylene, 1-butene, 1,3-butene, pentenes, steam cracked naphtha, and steam cracked gas oil, among others. For example, the recovery section 118 may separate the additional vapor phase 120 into one or more of a C2 stream 132 comprising predominantly ethylene, a C3 stream 134 comprising predominantly propylene, a C4 stream 136 comprising predominantly a variety of C4 hydrocarbons, including 1-butene and/or 1,3-butene, and/or a naphtha range stream 138. While not shown, additional streams (e.g. , a hydrogen stream, a C5 stream comprising isoprene) may also be recovered from the additional vapor phase 120 in the recovery’ section 118. Recovery section 118 may include any number of equipment items and unit operations required to separate and purity various constituents of the additional vapor phase 120 into various product streams. These include primary' fractionators, quench pump-around towers, compressors, pumps, flash drums, heat exchangers, yvash and absorber columns, fractional distillation columns, adsorbent beds for such purposes as drying. In addition, recovery' section may' include reactors and sub-processes for such tasks as removing heteroatoms such as sulfur, or partially or fully saturating certain acetylenic, di olefinic, olefinic or aromatic molecules, that require reaction with hydrogen. Recovery byproducts are well known to those skilled in the art of olefin generation.

[0055] Advantageously, the products recovered in the recovery' section 118 are considered circular, for example, by attributing molecules of the recovered products to polymers in the plastic waste, wherein the plastic-derived pyrolysis oil is at least partially derived from the plastic yvaste. Circular products may include, for example, example, ethylene, propylene, 1-butene, 1,3-butene, pentenes, steam cracked naphtha, and steam cracked gas oil, among others. The attribution can be done by' any suitable technique, including crediting, allocating offsetting for other hydrocarbons, and/or substituting for other hydrocarbons in a mass or energy balance for a system. Circular chemical products include circular monomers, circular aromatics, and circular polymers, among others. Polymers that are certified for their circularity’ by third party certification may be referred to as certified circular. One example of such a certification is the mass balance chain of custody method set forth by the International Sustainability and Carbon Certification. In some embodiments, circular olefins and circular diolefins are separated and then polymerized in accordance with one or more embodiments. After being separated in recovery section 118, one or more recovered monomers derived from pyrolysis oil may be suitable for use in various syntheses including polymer synthesis. For example, recovered monomers may be synthesized to form circular polymers. For example, the circular olefins may be polymerized to form circular polyolefins.

[0056] In some embodiments, the plastic-derived pyrolysis oil in the desalted cracker feed 108 can be cracked in the presence of a liquid hydrocarbon co-feed. By blending with a liquid hydrocarbon co-feed, any remaining contaminants in the pyrolysis oil may be diluted. For example, the plastic-derived pyrolysis oil can be steam cracked in the steam cracking furnace 105 in the presence of a liquid hydrocarbon co-feed. As illustrated in Figure 1, the liquid hydrocarbon co-feed can be mixed with the plastic-derived pyrolysis oil at various point. For example, a liquid hydrocarbon co-feed 128 can be combined with the pyrolysis oil feed 104 comprising the plastic-derived pyrolysis oil at first admix point before the desalter 102. In addition to or as an alternative to the first admix point, for example, a liquid hydrocarbon cofeed can be combined with the desalted cracker feed 108 at second admix point 130 to yield a mixed feed to the steam cracking furnace 105. While not show n, additional admix points may also be used, for example, addition to the vapor phase 122 downstream of the vapor-liquid separator 110.

[0057] Suitable liquid hydrocarbon co-feeds may include any of a variety of hydrocarbon steam cracker feeds that can be cracked in a steam cracker. Examples of suitable liquid hydrocarbon co-feeds may include, but are not limited to, naphtha, asphaltenes, resid (e.g., atmospheric resid, vacuum resid). pitch, crude oil, naphtha, gas oil (e.g., vacuum gas oil. heavy gas oil), kerosene, liquefied petroleum gas, condensate, one or more other hydrocarbons, or combinations thereof. In some embodiments, the liquid hydrocarbon co-feed comprises a liquid refinery product at least partially derived from co-processing of plastic waste. In some embodiments, there may be more than one liquid hydrocarbon co-feed, for example, a first liquid hydrocarbon co-feed may be combined with the pyrolysis oil in the desalted cracker feed 108 for cracking while a second liquid hydrocarbon co-feed may be simultaneously cracked in the same (or a different steam cracking furnace) while segregated from the desalted pyrolysis oil. The second liquid hydrocarbon co-feed that is segregated may be the same or different than the first liquid hydrocarbon co-feed that is combined with the purified pyrolysis oil. For example, the first liquid hydrocarbon co-feed combined with the desalted pyrolysis oil may be a heavier hydrocarbon liquid (e.g., gasoil) than the second liquid hydrocarbon co-feed (e.g., butane, naphtha) that is segregated. [0058] The pyrolysis oil and liquid hydrocarbon co-feed can be combined at any suitable ratio. For example, pyrolysis oil and liquid hydrocarbon co-feed may be combined at a pyrolysis oil and liquid hydrocarbon co-feed weight ratio of 1 : 1000 to 1: 1.5, including weight ratios of 1: 100 to 1 : 1.5, 1 : 100 to 1 :4, 1 : 100 to 1:5, 1: 100 to 1 : 10, 1:50 to 1 : 1.5, 1 :50 to bout 1 :5, 1:25 to 1:1.5, 1:20 to 1 : 1.5, or 1:20 to 1:5. In addition, where combined with a co-feed, a mixture of pyrolysis oil and liquid hydrocarbon co-feed may combined with steam for cracking in the steam cracker furnace 105 at any suitable ratio, for example, including a steam to mixture ratio of 0. 1 to 0.5 on a weight basis.

Additional Embodiments

[0059] Accordingly, the present disclosure may provide methods and systems that include processing pyrolysis oil through a desalter and cracking furnace with an integrated vapor-liquid separator to generate circular products. Particularly, certain embodiments may be well suited for removing contaminants from a pyrolysis oil feed and may allow for faster throughput of pyrolysis oil through a steam cracking furnace as compared to conventional refining methods. The methods and sy stems may include any of the various features disclosed herein, including one or more of the following statements.

[0060] Embodiment 1. A method comprising: processing at least a plastic-derived pyrolysis oil in a desalter to form at least a desalted pyrolysis oil; heating the desalted pyrolysis oil; separating the desalted pyrolysis oil to form a vapor phase and a liquid phase; steam cracking at least a portion of the first vapor phase in the presence of steam to form at least a cracking effluent; and separating the cracking effluent into at least an additional vapor phase and an additional liquid phase.

[0061] Embodiment 2. The method of embodiment 1, wherein the processing comprises: mixing at least a plastic-derived pyrolysis oil with water in one or more stages; and separating at least the desalted pyrolysis oil from the water.

[0062] Embodiment 3. The method of embodiment 1 or embodiment 2, wherein the separating the desalted pyrolysis oil comprises separating at least an interstage pyrolysis oil from an oil-water emulsion, mixing the interstage pyrolysis oil with at least interstage water to form an interstage emulsion, and separating at least the desalted pyrolysis oil from the interstage emulsion.

[0063] Embodiment 4. The method of embodiment 3, further comprising subjecting the oil-water emulsion to an electric field and subjecting the interstage emulsion to an additional electric current. [0064] Embodiment 5. The method of any preceding embodiment, wherein the steam cracking occurs in the presence of a liquid hydrocarbon co-feed.

[0065] Embodiment 6. The method of embodiment 5, further comprising admixing the liquid hydrocarbon co-feed with the desalted pyrolysis oil upstream of the cracking furnace.

[0066] Embodiment 7. The method of embodiment 5, further comprising admixing the liquid hydrocarbon co-feed with the plastic-derived pyrolysis oil upstream of the desalter.

[0067] Embodiment 8. The method of any of embodiments 5-7, wherein the liquid hydrocarbon co-feed comprises at least one hydrocarbon liquid selected from the group consisting of naphtha, crude oil, a gas oil, kerosene, and combinations thereof.

[0068] Embodiment 9. The method of any of embodiments 5-7, wherein the liquid hydrocarbon co-feed comprises a liquid refinery' product at least partially defined from coprocessing plastic waster.

[0069] Embodiment 10. The method of any preceding embodiment, further comprising recovering at least olefins from the additional vapor phase.

[0070] Embodiment 11. The method of embodiment 10, yvherein at least a portion of the olefins comprise circular olefins.

[0071] Embodiment 12. The method of embodiment 11 further comprising polymerizing at least a portion of the olefins to produce at least a circular polymer product.

[0072] Embodiment 13. The method of any preceding embodiment, further comprising separating at least a portion of the additional vapor phase into an C2 fraction comprising ethylene, a C3 fraction comprising propylene, a mixed C4 fraction comprising butane and butylene, and a naphtha fraction.

[0073] Embodiment 14. The method of embodiment 13, further comprising separating into a C5 fraction comprising isoprene.

[0074] Embodiment 15. The method of any preceding embodiment, further comprising mixing the desalted pyrolysis oil with at least a portion of steam prior to the separating the desalted pyrolysis oil.

[0075] Embodiment 16. The method of any preceding embodiment, further comprising removing at least a portion of the insoluble materials from the liquid phase and then hydrocracking at least a portion of the liquid phase to produce one or more circular products.

[0076] Embodiment 17. The method of any preceding embodiment, wherein the additional liquid comprises circular tar.

[0077] Embodiment 18. The method of embodiment 17, yvherein at least a portion of the circular tar is at least partially combusted to product at least circular carbon black. [0078] Embodiment 19. The method of embodiment 17 or embodiment 18, further comprising hydroprocessing at least a portion of the tar to produce at least circular naphtha and/or circular low sulfur fuel oil.

[0079] Embodiment 20. The method of any preceding embodiment, wherein the desalted pyrolysis oil is characterized as having a contaminant concentration reduced wi th respect to the plastic-derived pyrolysis oil by about 90 wt.% or more for inorganic halides, about 10 wt.% or more for organic halides, about 90 wt.% or more for nitrates and nitrites, about 10 wt.% or more for silica and silicon, and a total acid number by about 10 wt.% or more.

[0080] Embodiment 21. A method comprising: mixing a plastic-derived pyrolysis oil at a temperature of about 100°C to 200°C to be desalted with water to form a first oil/water emulsion; passing the oil/water emulsion to a first desalting vessel, wherein the oil/water emulsion is separated into an aqueous phase and an oleaginous phase; removing at least a portion of the oleaginous phase from the first desalting vessel as an inter-stage feed; mixing the inter-stage feed with additional water to form a second oil/water emulsion; passing the second oil/water emulsion to a second desalting vessel for separation of hydrocarbons and the additional water; removing a desalted pyrolysis oil from the second desalting vessel, wherein the desalted pyrolysis oil has a chloride concentration 90 wt.% less than a chloride concentration of the plastic-derived pyrolysis oil; introducing desalted pyrolysis oil to a steam cracking furnace for preheating; mixing the desalted pyrolysis oil with at least steam; separating a mixture of the desalted pyrolysis oil and the steam into a vapor phase and liquid phase, wherein the vapor phase comprises volatile hydrocarbons in an amount of about 55 wt.% to about 70 wt.% and steam in an amount of about 30wt.% to about 45 wt.%; heating the vapor phase to a temperature of about 425°C to about 650°C; and steam cracking at least a portion of the vapor phase to form at least a cracking effluent; and recovering at least olefins from the cracking effluent.

[0081] Embodiment 22. The method of embodiment 21, further comprising admixing a liquid hydrocarbon co-feed with the desalted pyrolysis oil upstream of the cracking furnace.

[0082] Embodiment 23. The method of embodiment 21, further comprising admixing a liquid hydrocarbon co-feed with the plastic-derived pyrolysis oil upstream of the first desalting vessel.

[0083] Various flow diagrams representing various systems have been provided throughout the body of this disclosure. It should be understood that, while certain flow paths have been illustrated (i.e., with arrows) for the purposes of the disclosure, that any system component shown or described may be fluidically and/or energetically coupled to any other system component, and that such fluidic and/or energetic communication between coupled components may be either direct or indirect (e.g., via one or more intermediate components).

[0084] While the disclosure has been described with respect to a number of embodiments and examples, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope and spirit of the disclosure as disclosed herein. Although individual embodiments are discussed, the present disclosure covers all combinations of all those embodiments.

[0085] While compositions, methods, and processes are described herein in terms of ‘'comprising,” ‘'containing,” “having,” or '‘including” various components or steps, the compositions and methods can also “consist essentially of’ or “consist of’ the various components and steps. The phrases, unless otherwise specified, “consists essentially of and “consisting essentially of do not exclude the presence of other steps, elements, or materials, whether or not, specifically mentioned in this specification, so long as such steps, elements, or materials, do not affect the basic and novel characteristics of the disclosure, additionally, they do not exclude impurities and variances normally associated with the elements and materials used.

[0086] All numerical values within the detailed description are modified by “about” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary' skill in the art.

[0087] Many alterations, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description without departing from the spirit or scope of the present disclosure and that when numerical lower limits and numerical upper limits are listed herein, ranges from any lower limit to any upper limit are contemplated.

Claims

CLAIMS:

1. A method comprising: processing at least a plastic-derived pyrolysis oil in a desalter to form at least a desalted pyrolysis oil; heating the desalted pyrolysis oil; separating the desalted pyrolysis oil to form a vapor phase and a liquid phase; steam cracking at least a portion of the first vapor phase in the presence of steam to form at least a cracking effluent; and separating the cracking effluent into at least an additional vapor phase and an additional liquid phase.

2. The method of claim 1, wherein the processing comprises: mixing at least a plastic- derived pyrolysis oil with water in one or more stages; and separating at least the desalted pyrolysis oil from the water.

3. The method of claim 2, wherein the separating the desalted pyrolysis oil comprises separating at least an interstage pyrolysis oil from an oil-water emulsion, mixing the interstage pyrolysis oil with at least interstage water to form an interstage emulsion, and separating at least the desalted pyrolysis oil from the interstage emulsion.

4. The method of claim 3, further comprising subjecting the oil-water emulsion to an electric field and subjecting the interstage emulsion to an additional electric cunent.

5. The method of claim 1, wherein the steam cracking occurs in the presence of a liquid hydrocarbon co-feed.

6. The method of claim 5, further comprising admixing the liquid hydrocarbon co-feed with the desalted pyrolysis oil upstream of the cracking furnace.

7. The method of claim 5, further comprising admixing the liquid hydrocarbon co-feed with the plastic-derived pyrolysis oil upstream of the desalter.

8. The method of claim 5, wherein the liquid hydrocarbon co-feed comprises at least one hydrocarbon liquid selected from the group consisting of naphtha, crude oil, a gas oil, kerosene, and combinations thereof.

9. The method of claim 5, wherein the liquid hydrocarbon co-feed comprises a liquid refinery product at least partially defined from co-processing plastic waster.

10. The method of claim 1 , further comprising recovering at least olefins from the additional vapor phase.

11. The method of claim 10, wherein at least a portion of the olefins comprise circular olefins.

12. The method of claim 11 further comprising polymerizing at least a portion of the olefins to produce at least a circular polymer product.

13. The method of claim 1, further comprising separating at least a portion of the additional vapor phase into an C2 fraction comprising ethylene, a C3 fraction comprising propylene, a mixed C4 fraction comprising butane and buty lene, and a naphtha fraction.

14. The method of claim 13, further comprising separating into a C5 fraction comprising isoprene.

15. The method of claim 1, further comprising mixing the desalted pyrolysis oil with at least a portion of steam prior to the separating the desalted pyrolysis oil.

16. The method of claim 1, further comprising removing at least a portion of the insoluble materials from the liquid phase and then hydrocracking at least a portion of the liquid phase to produce one or more circular products.

17. The method of claim 1, wherein the additional liquid comprises circular tar.

18. The method of claim 17, wherein at least a portion of the circular tar is at least partially combusted to product at least circular carbon black.

19. The method of claim 17, further comprising hydro-processing at least a portion of the tar to produce at least circular naphtha and/or circular low sulfur fuel oil.

20. The method of claim 1. wherein the desalted pyrolysis oil is characterized as having a contaminant concentration reduced with respect to the plastic-derived pyrolysis oil by about 90 wt.% or more for inorganic halides, about 10 wt.% or more for organic halides, about 90 wt.% or more for nitrates and nitrites, about 10 wt.% or more for silica and silicon, and a total acid number bv about 10 wt.% or more.

21. A method comprising: mixing a plastic-derived pyrolysis oil at a temperature of about 100°C to 200°C to be desalted with water to form a first oil/water emulsion; passing the oil/water emulsion to a first desalting vessel, wherein the oil/water emulsion is separated into an aqueous phase and an oleaginous phase; removing at least a portion of the oleaginous phase from the first desalting vessel as an inter-stage feed; mixing the inter-stage feed with additional water to form a second oil/water emulsion; passing the second oil/water emulsion to a second desalting vessel for separation of hydrocarbons and the additional water; removing a desalted pyrolysis oil from the second desalting vessel, wherein the desalted pyrolysis oil has a chloride concentration 90 wt.% less than a chloride concentration of the plastic-derived pyrolysis oil; introducing desalted pyrolysis oil to a steam cracking furnace for preheating; mixing the desalted pyrolysis oil with at least steam; separating a mixture of the desalted pyrolysis oil and the steam into a vapor phase and liquid phase, wherein the vapor phase comprises volatile hydrocarbons in an amount of about 55 wt.% to about 70 wt.% and steam in an amount of about 30% wt.% to about 45 wt.%; heating the vapor phase to a temperature of about 425 °C to about 650°C; and steam cracking at least a portion of the vapor phase to form at least a cracking effluent; and recovering at least olefins from the cracking effluent.

22. The method of claim 21. further comprising admixing a liquid hydrocarbon co-feed with the desalted pyrolysis oil upstream of the cracking furnace.

23. The method of claim 21. further comprising admixing a liquid hydrocarbon co-feed w ith the plastic-derived pyrolysis oil upstream of the first desalting vessel.