Co-treatment of pyrolysis oil to produce recycle products via desalter and cracking furnace with integrated gas-liquid separator

Abstract

Various methods and systems are disclosed, in one embodiment, including a method comprising: treating at least a plastic-derived pyrolysis oil in a desalter to at least form a desalted pyrolysis oil; heating the desalted pyrolysis oil; separating the desalted pyrolysis oil to form a gas 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 cracked effluent; and separating the cracked effluent into at least an additional gas phase and an additional liquid phase.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Application No. 63 / 387,209, filed December 13, 2022, the disclosure of which is incorporated herein by reference. Technical Field

[0002] The present 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 gas-liquid separator to produce recycle products. Background Art

[0003] In history, steam cracker feedstock is from the refinery process stream produced by industry standard refining practice.These practices are usually carried out by downstream equipment, and are very suitable for accepting the purer injection stream that is significantly refined, because any pollutant is usually removed in the early stage during refining and obviously earlier than before cracking.Yet, along with the demand for olefins with the rate growth that exceeds the demand growth for refined fuel, more and more hope is sought the substitute of conventional raw materials commonly used during olefin production.For example, recently devised the method utilizing raw material (for example, various crude oils, condensates and fractions thereof) as the feed of steam cracker.

[0004] Given the enormous scale of global plastic production (e.g., 400 million tons in 2016), less than 10% of which is currently recycled, utilizing feedstocks derived from waste plastics during olefin production would be advantageous. However, existing systems may not be suitable for processing unconventional feedstocks containing significant amounts of materials with final boiling points (FBP) above 590° C. (e.g., resid, residual oil, crude oil, condensates, and fractions thereof), non-volatile components (e.g., contaminants, high-boiling hydrocarbons, etc.), insoluble materials, inorganic substances, polar organic molecules, non-hydrocarbon contaminants such as metals and metalloids (e.g., silicon, mercury), and other contaminants. Summary of the Invention SUMMARY OF THE INVENTION

[0005] Disclosed herein are example methods comprising: processing at least plastic-derived pyrolysis oil in a desalter to form at least 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 process comprising: mixing plastic-derived pyrolysis oil to be desalted with water at a temperature of about 100° C. to 200° C. to form a first oil / water emulsion; conveying 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; feed); mixing the interstage feed with additional water to form a second oil / water emulsion; passing the second oil / water emulsion to a second desalter vessel for separation of hydrocarbons and additional water; removing desalted pyrolysis oil from the second desalter vessel, wherein the chloride concentration of the desalted pyrolysis oil is 90% by weight lower than the chloride concentration of the plastic-derived pyrolysis oil; introducing the desalted pyrolysis oil into a steam cracking furnace for preheating; mixing the desalted pyrolysis oil with at least steam; separating the mixture of desalted pyrolysis oil and steam into a vapor phase and a liquid phase, wherein the vapor phase comprises volatile hydrocarbons in an amount of from about 55% by weight to about 70% by weight and steam in an amount of from about 30% by weight to about 45% by weight; heating the vapor phase to a temperature of from 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 properties of the disclosed methods and systems of the present disclosure, as well as their advantageous applications and / or uses, will become apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] To assist one skilled in the relevant art in making and using the subject matter of the present invention, reference is made to the accompanying drawings, in which:

[0009] Figure 1 is a simplified block diagram illustrating an example system including a desalter, a cracking furnace, and an integrated gas-liquid separator according to some embodiments of the present disclosure; and

[0010] Figure 2 is a flow chart of an embodiment of an apparatus for removing contaminants from a feedstock according to some embodiments of the present disclosure. Detailed Description of the Invention

[0011] The present 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 gas-liquid separator to produce recycle products.

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

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

[0014] Furthermore, when an amount, concentration, or other value or parameter is given as a list of upper and lower limits, this should be understood as specifically disclosing all ranges formed by any pair of upper and lower limits, regardless of whether a range is disclosed individually.

[0015] In addition, the non-volatile component used herein can be measured as follows: the boiling point distribution of the feed is measured by gas chromatograph distillation (GCD) according to ASTM D-352-98 or other suitable methods. The non-volatile component is the feed fraction having a nominal boiling point above 590° C. as measured by ASTM D-6352-98. In some embodiments, the non-volatiles have a nominal boiling point above 760° C.

[0016] As used herein, the terms "cycled products", "cycled materials", "cycled compounds" and the like refer to cycled chemical products. Cyclic chemical products are chemical products derived from polymer waste, wherein the molecules of the chemical products can be attributed to the polymers in the polymer waste, for example by crediting, allocating, offsetting and / or replacing other hydrocarbons in the mass or energy balance of the system. Cyclic chemical products include, in particular, cycled monomers, cycled aromatics and cycled polymers. Polymers that have their circularity certified by a third party certification can be referred to as certified cycle. An example of such certification is the material balance chain of custody approach proposed by International Sustainability and Carbon Certification.

[0017] The "C x Reference to a "fraction, stream, portion, feed, or other quantity" is defined as the fraction (or other quantity) in which 50% by weight or more of the fraction corresponds to hydrocarbons having "x" carbon numbers. When a range is specified, e.g., "C x -C y ", 50 wt% or more of the fraction corresponds to hydrocarbons having carbon numbers from "x" to "y." C x+ "(or "C x- ") corresponds to a fraction in which 50% by weight or more of the fraction corresponds to hydrocarbons having a specified carbon number or more (or a specified carbon number or less).

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

[0019] In some embodiments, pyrolysis oil feed 104 includes plastic-derived pyrolysis oil. As used herein, "plastic-derived pyrolysis oil" refers to pyrolysis oil ("pyrolysis oil") in which at least 50% by weight of the pyrolysis oil is derived from a plastic source. That is, the pyrolyzed feedstock (also referred to as plastic feedstock) contains at least 50% by weight plastic.

[0020] Examples of plastic sources include, but are not limited to, plastic waste (e.g., plastic straws, plastic utensils, plastic bags, food containers, etc.), composite materials (e.g., composite packaging, artificial turf, artificial turf components, etc.), and the like, and any combination thereof. The plastic source may comprise one or more polymers, including, but not limited to, polyolefins (e.g., homopolymers or copolymers of ethylene, propylene, butylene, hexene, butadiene, isoprene, isobutylene, and other olefins), polystyrene, polyvinyl chloride, polyamides (e.g., nylon), polyethylene terephthalate, polyurethane, ethylene vinyl acetate, and the like. Other materials may be used in combination with the plastic source to produce plastic-derived pyrolysis oil, such as paper, cardboard, textiles, tires, fabrics, and the like, and any combination thereof. The plastic portion of the plastic feedstock used for pyrolysis may comprise 50% to 100% by weight (or 65% to 80% by weight, or 75% to 90% by weight, or 80% to 100% by weight) of polyolefins, with the remainder being one or more other polymers.

[0021] Pyrolysis of the plastic feedstock can be carried out by known methods and in known systems (e.g., at a temperature of 400° C. to 850° C., or 400° C. to 600° C., or 500° C. to 850° C.). The pyrolysis products are then distilled (or separated) into one or more fractions, including a plastic-derived pyrolysis oil fraction.

[0022] Plastic derived pyrolysis oil can be C 5+ Stream (or C5-C 30 Stream, or C5-C 20 Stream, or C5-C 25 Stream, or C5-C 20 The 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 C 5+ 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] The 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] Plastic-derived pyrolysis oils may contain an olefin content of 0 to 60 wt%, a diolefin content of 0 to 25 wt%, and the balance other materials such as aromatics and paraffins.

[0025] The plastic-derived pyrolysis oil may have an initial boiling point of 30°C or higher, 100°C or higher, 200°C or higher, 300°C or higher, 400°C or higher, 450°C or higher, 500°C or higher, or 600°C or higher. 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. The plastic-derived pyrolysis oil may have a final boiling point of 850°C or lower, 700°C or lower, or 600°C or lower. For example, the plastic-derived pyrolysis oil may have a final boiling point 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] Plastic-derived pyrolysis oil can have properties similar to naphtha, distillate, wax, atmospheric residue, etc.

[0027] The quality of pyrolysis oil can vary widely and depends on many factors, including the quality of the plastic waste, the conversion technology (e.g., pyrolysis, catalytic pyrolysis, etc.), and the pre- or post-contaminant removal included in the pyrolysis unit. In order to process pyrolysis oil via a steam cracker, it must be compatible with the furnace technology and have a composition that the recovery unit can handle without causing process safety, environmental, reliability, or product quality issues. Many available pyrolysis oils contain a small portion of high-boiling hydrocarbon components that are incompatible with processing via typical liquid steam crackers (e.g., naphtha crackers, gas oil crackers, etc.). In addition, pyrolysis oil, particularly the high-boiling 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 the deposition of non-volatile materials (e.g., asphaltenes) in the convection section of the steam cracking furnace, which cannot be removed via decoking or other online cleaning methods. Additionally, some of these contaminants may react or otherwise interact with the metallurgy of the radiant or convection sections of the furnace and reduce the operating life of these components in various ways (eg, causing corrosion or otherwise degrading the metallurgy).

[0028] Plastic-derived pyrolysis oil may include high-boiling hydrocarbons. For example, plastic-derived pyrolysis oil may include one or more heavy petroleum compounds, such as those typically found in crude oil, residual oil, resid, asphalt, atmospheric residue, and vacuum residue. The term "crude oil" refers to whole crude oil as it exits a wellhead, production site facility, transportation facility, or other initial on-site processing facility, optionally including crude oil that has been processed through a desalting step, treatment step, and / or other steps that may be required to make it acceptable for conventional distillation in a refinery. Crude oil is assumed to contain residual oil. Non-limiting examples of crude oils may include or include Tapis, Murban, Arab Light, Arab Medium, and / or Arab Heavy. The term "residue" refers to the bottoms fraction of a crude oil distillation process containing non-volatile components. Residue is a complex mixture of heavy petroleum compounds, also known in the art as residual oil, residue, or asphalt. Atmospheric residue is the bottoms product produced by the atmospheric distillation of crude oil, with the heaviest distillate having a typical endpoint nominally 343°C and referred to as 343°C resid. As used herein, the term "nominal" means that reasonable experts may disagree about the exact cut point of these terms, but not by more than + / - 55.6°C, preferably not by more than + / - 27.8°C. Vacuum residue is the bottoms product from a distillation column operated under vacuum, where the heaviest distillate may be nominally 566°C and referred to as 566°C residue. Plastic-derived pyrolysis oil may also have common components with one or more fractions from a typical crude oil distillation process, including any of residuum, residual oil, residue, asphalt, atmospheric residue, vacuum residue, and the like.

[0029] Plastics derived pyrolysis oil can also contain high levels of certain pollutants, such as metals and salts. Metals can 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 pollutants can include, for example, bromine, fluorine, phosphorus and boron. Pyrolysis oil can have a total chloride content of 160wppm or higher. For example, pyrolysis oil can have a total chloride content of 170wppm to 1000wppm, 170wppm to 500wppm, 170wppm to 275wppm, 170wppm to 250wppm, 200wppm to 300wppm or 200wppm to 250wppm. Total chloride content used herein is the measured sum of total chlorides (organic and inorganic) in the recycled pyrolysis oil measured according to ASTM D7359.

[0030] In some embodiments, pyrolysis oil can have a total acid number of 0mgKOH / g to 1.7mgKOH / g, 1.7mgKOH / g to 4mgKOH / g, 1.7mgKOH / g to 3mgKOH / g, 1.7mgKOH / g to 2.5mgKOH / g, 2mgKOH / g to 4mgKOH / g, 2mgKOH / g to 3mgKOH / g or 2mgKOH / g to 2.5mgKOH / g.

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

[0032] According to this embodiment, the desalter 102 includes one or more desalter vessels, such as multiple vessels in semi-continuous operation (e.g., one drum in use and other drums in maintenance). The desalter and related equipment in the desalter 102 can be arranged in series, parallel, and / or series-parallel. Optionally, at least one of the desalter vessels can include mud washing capabilities and / or three-line sampling capabilities, and can also include auxiliary equipment, such as one or more brine tanks. Although the acceptable salt and / or particulate matter concentration varies with the furnace design, the addition of the desalter 102 can be advantageous when the sodium chloride and / or other salts are greater than a predetermined amount for the feed, and can further depend on the operating conditions of the specific feed.

[0033] In the desalter 102, 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 salts, brine, and particles from the oil. The wash water used to treat the feed can be derived from a variety of sources. For example, the water can be recycled and / or recirculated water from other units in the facility, such as acid water stripper bottoms, overhead condensate, boiler feed water, with and / or without purification, purification, etc. Alternatively, or in addition, the wash water can be obtained from other sources, such as from surface water sources (e.g., from rivers), from geological water sources (e.g., from one or more wells), and / or from separate facilities (e.g., softened and purified water), etc. The concentration of various salts in the wash water can be expressed in parts by weight per thousand parts by weight (ppt), and typically the salt concentration ranges from the salt concentration of fresh water (less than 0.5 ppt sodium chloride), brackish water (0.5-30 ppt sodium chloride), or salt water (30-50 ppt sodium chloride) to the salt concentration of salt water (greater than 50 ppt sodium chloride). Although deionized water can be used to facilitate the exchange of salts from the plastic-derived pyrolysis oil into the aqueous solution, deionized water is generally not required to desalt the feedstock. However, in certain aspects, deionized water can be mixed with recirculating water from the desalter 102 to achieve a specific ionic content in the wash water prior to emulsification or to achieve a specific ionic strength in the final emulsified product. The wash water rate is typically in the range of 5% to 7% by volume of the total crude oil or pyrolysis oil to be desalted, but can be higher or lower, depending on the pyrolysis oil source and quality. Various 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 desalination conditions (eg, size of the separator and degree of desalination desired).

[0034] In some embodiments, the pyrolysis oil feed 104 is preheated before mixing with the wash water. Increasing the temperature can improve desalination efficiency. In some embodiments, the pyrolysis oil feed 104 is preheated to a temperature of 30°C or higher, such as 100°C or higher, such as 120°C or higher, 140°C or higher, or 150°C or higher. For example, the pyrolysis oil feed 104 can have a temperature of 100°C to 200°C, 120°C to 180°C, 140°C to 180°C, 150°C to 200°C, 200°C to 400°C, 200°C to 300°C, or 300°C to 400°C.

[0035] During the separation stage of the desalting process, emulsion phases of different compositions and thicknesses can be formed at the interface of the hydrocarbon layer and the water layer. If not split, these emulsions may be carried with the desalted pyrolysis oil or carried into the water layer. If carried, the emulsions may cause the destruction of the coking or scaling of downstream equipment and the downstream fractionation process. If carried down, they can destroy the downstream water treatment process. Therefore, for the desalting of crude oil, refiners usually wish to control the formation / growth of these emulsions or remove the emulsion from the desalter unit, and use additional processing steps to split the emulsion into its components (that is, destroy the emulsion, resulting in separated oil, water and solid phases) to allow reuse and / or disposal of oil, water and solids.

[0036] Methods for separating the hydrocarbon phase and the aqueous phase can include gravity or centrifugal methods. In the gravity method, the emulsion is allowed to stand in a separator, and the density difference between the hydrocarbons and water causes the water to settle through the oil and out of the oil by gravity. In the centrifugal method, the stable emulsion is moved from the desalter unit to a centrifuge (not shown) that separates the emulsion into separate water, hydrocarbons, and solids. Gravity methods typically require the use of time-consuming and therefore inefficient settling tanks and expensive methods for handling the partially separated emulsion, while centrifugal methods may require the construction and operation of large, expensive centrifuges.

[0037] Typically, an electric field is established in an area within the desalter 102 (e.g., within the desalter vessel) to enhance the coalescence of small water droplets. This, in turn, causes the emulsion to break down, forming an oily continuous phase and an aqueous continuous phase. Even when a relatively strong electric field is established within the desalter 102, an emulsion layer (referred to as a "rag layer") can form, typically beneath the area where the electric field is established. This emulsion layer has been observed to be stable, even when adjacent to a strong electric field. The strength of this emulsion layer (sometimes referred to as a "persistent emulsion," indicating its resistance to emulsion breakdown) generally depends on factors such as the gravity of the feed hydrocarbons (e.g., the gravity of the pyrolysis oil in the feed, the presence and amount of solids and semi-solids (e.g., particulates), etc.). This rag layer typically contains high concentrations of hydrocarbons, residual water, suspended solids, and salts. In a typical example, it may be 70% v / v water, 30% v / v oil, with 14 to 23 g / l of solids, and 570 to 1100 mg / l of salts. The aqueous phase contains salts transferred from the desalting pyrolysis oil feed 104. Conventional methods for manipulating the debris layer can be used, but the disclosure is not limited thereto. For example, one or more demulsifier compositions can be introduced into the desalter 102 and / or at least a portion of the emulsion can be separated and carried away.

[0038] In some embodiments, a demulsifier may be added to the pyrolysis oil feed 104, the wash water, or a combination thereof, for example, to reduce the debris layer size (e.g., height, when the plane of the debris layer is substantially parallel to the Earth's surface) and persistence. Examples of suitable demulsifiers may be one or more of the following: polyethyleneimines, polyamines, succinate polyamines, polyols, ethoxylated alcohol sulfates, long-chain alcohol ethoxylates, long-chain alkyl sulfates, such as sodium lauryl sulfate, epoxy resins, and diepoxides (which may be ethoxylated and / or propoxylated).

[0039] Now refer to Figure 2 , shows a flow diagram for removing contaminants from plastic-derived pyrolysis oil using a two-stage desalter 200 while maintaining flow to one or more downstream steam crackers. Storage tank 202 contains plastic-derived pyrolysis oil. Pyrolysis oil feed 204, comprising at least plastic-derived pyrolysis oil, can be transferred from storage tank 202 to pump 206. The pressure and flow rate of pyrolysis oil feed 204 are 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 high enough to prevent water and hydrocarbons in the pyrolysis oil from evaporating at the temperatures used in the desalting process. Pressurized pyrolysis oil feed 208 is fed to heat exchanger 210 to provide heated pyrolysis oil feed 212. Heated pyrolysis oil feed 212 can undergo further heating. Additional heating can be performed in one or more additional heat exchangers (not shown), which can be located before and / or after heat exchanger 210. This additional heat transfer increases the temperature of the plastic-derived pyrolysis oil beyond that achievable through heat exchanger 210 alone. Doing so reduces the viscosity of the feed and promotes mixing with water, as described below. Suitable heat transfer fluids for additional heat exchangers include, for example, (i) steam, such as low-pressure, medium-pressure, high-pressure or ultrahigh-pressure steam (typically using the lowest pressure steam that effectively transfers heat, typically medium-pressure steam (1500kPa-3000kPa) or low-pressure steam (<1500kPa) steam is sufficient), (ii) oily heat transfer fluids from a recovery system, such as from the bottom circulating oil (a bot toms pump around oil) of a primary fractionator, and (iii) aqueous quenching fluids. For example, in some 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, which utilizes the bottom circulating oil of the primary fractionator 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 a first desalter vessel 216 for optional additional mixing and then separation. In the first desalter vessel 216, the hydrocarbons and brine are separated, producing, for example, (i) an aqueous byproduct (brine) that is sent via line 218, and (ii) an interstage feed that is removed from the first desalter vessel via line 220. The desalted oily phase forms a top layer that is continuously removed as interstage feed 220, and the split aqueous phase accumulates at the bottom of the desalter and is continuously removed as a brine stream via line 218. The brine stream can be sent for deionization and recycling, or used in other processes with or without further processing. In some embodiments, a single desalter vessel (e.g., a single-stage desalter) provides sufficient contaminant removal so that additional desalting is not required. Using a single-stage desalter (e.g., with a recycle line to the vessel inlet and / or surge tank) may be sufficient if flow rate fluctuations (such as those caused by a steam cracker being brought online or offline) are managed to allow a steady flow of feed through the desalter.

[0041] One way to manipulate the flow rate of the steam cracker without sacrificing contaminant removal 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 adequate contaminant removal even through rapid flow rate fluctuations. The (optional) addition of the second desalting vessel 222 Figure 2 2, wherein the interstage feed 220 is mixed with additional water from water line 224 and then passed to the second desalter vessel 222. The oil / water emulsion formed by the combination enters the second desalter vessel 222 via line 226. In the second desalter vessel 222, the hydrocarbons and water are separated, thereby producing (i) a clean water product stream that is sent away via line 228, and (ii) desalted pyrolysis oil that is removed from the second desalter vessel 222 at a hydrocarbon outlet (not shown) via line 230. Line 230 is coupled to heat exchanger 210 to allow heat exchange between plastic-derived pyrolysis oil (e.g., pressurized pyrolysis oil feed 208) and the desalted pyrolysis oil. The desalted feed transferred to steam cracking via line 232 (after heat exchange) has a lower temperature than the desalted feed in line 230, for example to meet furnace requirements depending on the specific furnace design. The clean water product stream from the second desalination vessel 222 can contain a sufficiently low sodium content (e.g., 10 wppm or less) and can be recycled to line 214 via line 228 for reuse in the first desalination vessel 216. Alternatively, the clean water product from the second desalination vessel 222 can be treated in other ways, for example, for use in other processes in the facility (lines not shown) with or without further processing.

[0042] Certain embodiments are compatible with the use of one or more surge tanks as a means to assist in providing a substantially uninterrupted flow rate of desalted feed to the steam cracker furnace. The surge tank can be filled with desalted feed during use. The desalted feed in the filled surge tank can be transferred to the feed line of the steam cracker furnace. Doing so can provide a short-term flow of desalted feed during a flow reduction, such as when a pump fails or must be taken offline for maintenance when starting a backup pump. A certain volume of desalted feed in the surge tank can be transferred to the feed line at a similar pressure in various ways (e.g., using N2 as power, together with an automatic valve). In certain aspects (e.g., in the absence of such a surge tank and / or when the inventory of desalted feed in the surge tank is exhausted), one or more desalters can be bypassed to maintain sufficient feed flow to the stream cracker furnace.

[0043] Refer again Figure 1 , after desalting in the desalter 100, the desalted cracker feed 108 can be introduced into the steam cracker furnace 105. The at least partially desalted cracker feed 108 has a reduced risk of adversely affecting the steam cracker furnace 105, including negatively impacting furnace metallurgy (e.g., corrosion) and depositing non-volatile materials into portions of the convection section 106 of the steam cracker furnace 105 where decoking or other in-line cleaning is typically unable to remove deposits. The desalted cracker feed 108 can be characterized by a reduction in contaminant concentration (relative to the plastic-derived pyrolysis oil of the pyrolysis oil feed 104) of more than 90% by weight of inorganic halides (e.g., Cl, F, Br), more than 10% by weight of organic halides (e.g., 10% to 30% by weight), more than 90% by weight of nitrates and nitrites (e.g., 90% to 99% by weight), more than 10% by weight of silica and silicon (e.g., 10% to 30% by weight), and / or more than 10% by weight of other salts and particulates (e.g., 10% to 50% by weight). In addition, acids (as represented by the total acid number) can be reduced by more than 10% (e.g., 10% to 50%). Typically, the desalting cracker feed 108 comprises < 1 wppm salts, such as < 0.5 wppm, eg, < 0.25 wppm, or < 0.125 wppm, or < 0.0625 wppm, or in the range of 0.01 wppm to 0.125 wppm.

[0044] The steam cracking furnace 105 includes a convection section 106 and a radiant section 107. Desalted cracker feed 108 can be heated in the convection section 106 via indirect exposure to flue gas in the convection section 106 and semi-purified in a gas-liquid separator 110. The heated desalted cracker feed 112 can be discharged from the convection section 106 of the steam cracking furnace 105 and passed to the gas-liquid separator 110 to be separated into a gas phase 122 and a liquid phase 124. The gas phase 122 can be returned to the steam cracking furnace 105. For example, the gas phase 122 can 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 to produce a steam cracker effluent 116, which is transferred for further purification in an effluent vapor-liquid separator 114 and a cracker recovery unit 118. The cracker recovery unit 118 may contain a plurality of fractionators, separation columns, purification and / or catalyst beds, cooling and / or quenching columns, and / or other devices for separating the vapor phase 120 from the steam cracker effluent 116 into various product streams.

[0045] Steam cracking is a technology 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, multiple steam cracker furnaces in parallel can be used at the facility to improve the production efficiency of light hydrocarbons. The steam cracker is usually offline for regular maintenance and / or decoking, and having multiple parallel furnaces allows continuous operation of the rest of the steam cracking and light hydrocarbon purification processes without excessive downtime. Typically, the steam cracker furnace 105 includes a convection section 106 in which the desalting cracker feed 108 is preheated, 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 shown, the steam cracker furnace 105 has a gas-liquid separator 110 integrated therein. For example, the gas-liquid separator 110 can be integrated by fluid connection between the convection section and the radiant section. The radiant section 107 may include a fired heater, and flue gas from combustion with the fired heater travels upward from the radiant section through the convection section before exiting as flue gas.

[0046] Heating the desalting cracker feed 108 in the convection section 106 of the steam cracking furnace 105 can include indirect contact with hot flue gas from the radiant section of the steam cracking furnace 105 (e.g., within a line or duct within the furnace). Heating the desalting cracker feed 108 can be achieved, for example, by passing the desalting cracker feed 108 through a set of heat exchange tubes located within the convection section 106 of the steam cracking furnace 105. The desalting cracker feed 108 can be heated to a temperature of 315° C. to 560° C., e.g., 370° C. to 510° C., 430° C. to 480° C., or 480° C. to 700° C. In some embodiments, the desalting cracker feed 108 is first heated to a temperature of 150° C. to 260° C., then combined with steam and optionally additional fluids, and then heated to a temperature of 315° C. to 700° C. The desalting cracker feed 108 and / or the combined feed with steam / optional fluid may be heated to a temperature of, for example, 315°C to 560°C before the gas-liquid separator 110 and then further heated, for example up to 700°C, in a countercurrent separation after separation of the liquid in the gas-liquid separator 110.

[0047] As previously mentioned, pyrolysis oil may contain insoluble materials. These insoluble materials may deposit in the convection section 106 during heating. This can be problematic when processing pyrolysis oil in certain areas (e.g., portions of the convection section 106 where decoking or other online cleaning processes typically fail to remove deposits), as the steam cracker 105 must be taken offline to remove deposits that cannot be removed via other online or offline methods (e.g., decoking). To prevent unwanted deposition of non-volatile components in these areas, a vapor-liquid separator 110 may be integrated with the process. This vessel, sometimes referred to as a flash tank or flash drum, can provide for upgrading the heated cracker feed 112. Such a flash separation vessel is suitable when the preheated feed includes 0.1% by weight or more, e.g., 5% by weight or more, of asphaltenes and / or other non-volatile components, based on the weight of the hydrocarbon components of the convection section effluent. Upgrading the preheated feed via vapor / liquid separation can be accomplished via a flash separation vessel or other suitable device. Suitable apparatus may include one or more conventional knockout drums, but the invention is not limited thereto. Examples of such conventional knockout drums may 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 of which is incorporated herein by reference.

[0048] One advantage of integrating the vapor-liquid separator 110 downstream into the convection section and upstream of the radiant section is the increased breadth of hydrocarbon types that can be used directly as feed without pretreatment. For example, the addition of the vapor-liquid separator 110 allows the utilization of feeds containing, for example, plastic-derived pyrolysis oil in amounts of 0.1 wt % to 90 wt %. In some embodiments, the feed may contain plastic-derived pyrolysis oil in amounts 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, typically 50 wt % to 95 wt % of the mixture entering the vapor-liquid separator 110 is evaporated to the upper portion of the flash drum, e.g., 60 wt % to 90 wt %, or 65 wt % to 85 wt %, or 70 wt % to 85 wt %. The gas-liquid separator 110 can be operated at a temperature of 315° C. to 560° C. and / or a pressure of 275 kPa to 1400 kPa, for example, a temperature of 430° C. to 480° C. and / or a pressure of 700 kPa to 760 kPa. The hydrocarbon partial pressure of the feed to the gas-liquid separator 110 (e.g., the heated desalting cracker feed 112) can be 25 kPa to 175 kPa. Typically, only the gas phase 122 within the gas-liquid separator 110 is directed to the radiant section of the steam cracking furnace 105, while the liquid phase 124 can be removed from the gas-liquid separator 110, for example, for storage and / or further processing. For example, the gas phase 122 can be returned to the convection section for further preheating before being transferred to the radiant section for cracking.

[0049] The liquid phase 124 from the gas-liquid separator 110 may contain, for example, 2% to 50% by weight of the heated cracker feed 112 fed to the gas-liquid separator 110. The liquid phase 124 from the gas-liquid separator 110 may be processed using any suitable technology. For example, the non-volatile components separated into the liquid phase 124 may be sent to the bottom of a vacuum column and disposed of as high sulfur fuel oil. As a 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 the remainder of the liquid phase being sold or disposed of as high sulfur fuel oil (HSFO). In some embodiments, the deasphalting unit includes a solvent extraction process for removing insoluble materials, which may be fed into a fuel oil blend or to a partial oxidation unit. The soluble materials may be sent to a hydrocracker and a dewaxer to produce naphtha, diesel and / or other valuable liquid byproducts. The naphtha and / or diesel can be recycled to the front end of the steam cracker 105 for upgrading to higher value molecules (e.g., ethylene, propylene, etc.). Because the pyrolysis oil can be derived from polyolefins, the heavy fraction separated into the liquid phase 124 should have high molecular weight linear molecules compared to the heavier crude oil molecules and thus can ultimately enter the soluble fraction of the hydrocracking and dewaxing units. An example deasphalting unit including 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 gas phase 122 from the gas-liquid separator 110 can be returned to the steam cracking furnace 105. In the steam cracking furnace 105, the gas phase 122 can be further heated in the convection section, for example, to 425° C. to 700° C., and then passed to the radiant section for cracking. The gas phase 122 can contain, for example, 50% to 95% by weight of the heated cracker feed 112 fed to the gas-liquid separator 110. The gas phase 122 can also have a 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 gas phase 122 is very rich in volatile hydrocarbons. In some embodiments, the gas phase 122 contains volatile hydrocarbons in an amount of 55% to 75% by weight. The gas phase 122 can also contain steam, for example, 25% to 45% by weight. The gas phase 122 may have a final boiling point of 760° C. or less, eg, 600° C. or less, 570° C. or less, or 540° C. or less.

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

[0052] Continue to refer to Figure 1 , an additional vapor-liquid separation stage (or multiple stages, e.g., in series, 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 using one or more flash tanks or flash drums as previously described in this disclosure, or by any suitable means. Figure 1 In FIG, an additional gas-liquid separation stage is shown as an effluent gas-liquid separator 114.

[0053] The steam cracker effluent 116 can be introduced into the effluent gas-liquid separator 114. Depending on the operating conditions of the steam cracking furnace 105, the cracking furnace effluent 116 can contain volatile, non-volatile components and / or steam. The additional liquid phase 126 separated from the steam cracker effluent 116 can be removed and processed using any suitable technology. The additional liquid phase 126 can include recycled products and / or be upgraded to recycled 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 can include recycled tar. Circulating tar can be used as a blending stock (ablending stock), for example, in low sulfur fuel oil. Circulating tar can be used as a raw material to produce recycled carbon black, for example, by burning at least a portion of the circulating tar. As another example, the additional liquid phase 126 can be sent to a secondary heavy fuel unit to upgrade to produce recycled products, such as naphtha and low sulfur fuel oil. The naphtha can be recycled to the front end of the steam cracking 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 includes one or more hydroprocessing stages. An exemplary method of a secondary heavy fuel unit is described in more detail in U.S. Patent No. 10,968,404, the disclosure of which is incorporated herein by reference.

[0054] The additional vapor phase 120 separated from the steam cracker effluent 116 can be fed to a recovery section 118 for separation into one or more desired product streams. Products that can be recovered 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. For example, the recovery section 118 can separate the additional vapor phase 120 into one or more of a C2 stream 132 comprising primarily ethylene, a C3 stream 134 comprising primarily propylene, a C4 stream 136 comprising primarily various C4 hydrocarbons (including 1-butene and / or 1,3-butene), and / or a naphtha range stream 138. Although not shown, additional streams (e.g., a hydrogen stream, a C5 stream comprising isoprene) can also be recovered from the additional vapor phase 120 in the recovery section 118. The recovery section 118 can include any number of equipment items and unit operations required to separate and purify the various components of the additional vapor phase 120 into various product streams. These include primary fractionators, quench pump-around towers, compressors, pumps, flash drums, heat exchangers, scrubbers and absorber towers, fractionating columns, and adsorbent beds for purposes such as drying. Additionally, the recovery section may include reactors and subprocesses for tasks such as removing heteroatoms (such as sulfur) or partially or completely saturating certain acetylenic, diolefinic, olefinic, or aromatic molecules (which need to be reacted with hydrogen). Recovering by-products is well known to those skilled in the art of olefin production.

[0055] Advantageously, the products recovered in the recovery section 118 are considered to be recycled, for example, by attributing the molecules of the recycled products to polymers in the plastic waste, wherein the plastic-derived pyrolysis oil is at least partially derived from the plastic waste. Circulating products may include, for example, ethylene, propylene, 1-butene, 1,3-butene, pentene, steam cracked naphtha, and steam cracked gas oil. Attribution can be accomplished by any suitable technique, including attributing, allocating, offsetting, and / or replacing other hydrocarbons in the mass or energy balance of the system. Circulating chemical products include recycled monomers, recycled aromatic compounds, and recycled polymers. Polymers that have their circularity certified by third-party certification can be called certified recycled. An example of such certification is the material balance chain of custody approach proposed by International Sustainability and Carbon Certification. In some embodiments, recycled olefins and recycled diolefins are separated and then polymerized according to one or more embodiments. After separation in the recovery section 118, one or more recovered monomers derived from the pyrolysis oil can be suitable for various syntheses, including polymer synthesis. For example, recovered monomers can be synthesized to form recycled polymers. For example, recycled olefins can be polymerized to form recycled polyolefins.

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

[0057] Suitable liquid hydrocarbon co-feeds may include any of the various 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, residual oils (e.g., atmospheric residue, vacuum residue), asphalt, crude oil, naphtha, gas oils (e.g., vacuum gas oil, heavy gas oil), kerosene, liquefied petroleum gas, condensates, one or more other hydrocarbons, or combinations thereof. In some embodiments, the liquid hydrocarbon co-feeds include liquid refinery products derived at least in part from the co-processing of plastic waste. In some embodiments, more than one liquid hydrocarbon co-feed may be present, e.g., 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 different steam cracking furnaces) while being separated from the desalted pyrolysis oil. The separated second liquid hydrocarbon co-feed may be the same or different from the liquid hydrocarbon co-feed combined with the purified pyrolysis oil. For example, the first liquid hydrocarbon co-feed combined with the desalted pyrolysis oil can be a heavier hydrocarbon liquid (eg, gas oil) than the separated second liquid hydrocarbon co-feed (eg, butane, naphtha).

[0058] The pyrolysis oil and liquid hydrocarbon co-feed can be combined in any suitable ratio. For example, the pyrolysis oil and liquid hydrocarbon co-feed can be combined in a pyrolysis oil to liquid hydrocarbon co-feed weight ratio of 1:10.00 to 1:1.5, including a weight ratio 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 about 1:5, 1:25 to 1:1.5, 1:20 to 1:1.5, or 1:20 to 1:5. In addition, when combined with the co-feed, the mixture of the pyrolysis oil and liquid hydrocarbon co-feed can be combined with steam for cracking in the steam cracking furnace 105 in any suitable ratio, for example, including a steam to mixture ratio of 0.1 to 0.5 based on weight. Additional Implementation Options

[0059] Thus, the present disclosure may provide methods and systems that include processing pyrolysis oil through a desalter and a cracking furnace with an integrated gas-liquid separator to produce recycled products. In particular, certain embodiments may be well suited for removing contaminants from pyrolysis oil feeds and may allow for faster throughput of pyrolysis oil through a steam cracking furnace compared to conventional refining processes. The methods and systems may include any of the various features disclosed herein, including one or more of the following.

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

[0061] Embodiment 2. The method of embodiment 1, wherein the treating comprises: mixing at least the 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 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 of the above embodiments, wherein the steam cracking occurs in the presence of a liquid hydrocarbon co-feed.

[0065] Embodiment 6. The method of Embodiment 5, further comprising blending 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 blending the liquid hydrocarbon co-feed with the plastic-derived pyrolysis oil upstream of the desalter.

[0067] Embodiment 8. The method of any one 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, gas oil, kerosene, and combinations thereof.

[0068] Embodiment 9. The method of any of Embodiments 5-7, wherein the liquid hydrocarbon co-feed comprises liquid refinery products defined at least in part by co-processed plastic waste.

[0069] Embodiment 10. The method of any of the above embodiments, further comprising recovering at least olefins from the additional gas phase.

[0070] Embodiment 11. The method of Embodiment 10, wherein at least a portion of the olefins comprises recycled olefins.

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

[0072] Embodiment 13. The method of any of the above embodiments, further comprising separating at least a portion of the additional gaseous phase into a C2 fraction comprising ethylene, a C3 fraction comprising propylene, a mixed C4 fraction comprising butanes and butenes, 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 of the above embodiments, further comprising mixing the desalted pyrolysis oil with at least a portion of the steam before separating the desalted pyrolysis oil.

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

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

[0077] Embodiment 18. The method of Embodiment 17, wherein at least a portion of the recycled tar is at least partially combusted to produce at least recycled 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 recycled naphtha and / or recycled low sulfur fuel oil.

[0079] Embodiment 20. The method of any of the above embodiments, wherein the desalted pyrolysis oil is characterized by a reduction in inorganic halide contaminant concentration of about 90% by weight or more, a reduction in organic halide contaminant concentration of about 10% by weight or more, a reduction in nitrate and nitrite contaminant concentration of about 90% by weight or more, a reduction in silica and silicon contaminant concentration of about 10% by weight or more, and a reduction in total acid number of about 10% by weight or more relative to the plastic-derived pyrolysis oil.

[0080] Embodiment 21. A method comprising: mixing plastic-derived pyrolysis oil to be desalted with water at a temperature of about 100° C. to 200° C. to form a first oil / water emulsion; transferring 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 interstage feed; mixing the interstage feed with additional water to form a second oil / water emulsion; transferring the second oil / water emulsion to a second desalting vessel for separation of hydrocarbons and additional water; removing the desalted pyrolysis oil from the second desalting vessel, wherein the desalted pyrolysis oil the chloride concentration being 90 weight percent lower than the chloride concentration of the plastic-derived pyrolysis oil; introducing the desalted pyrolysis oil into a steam cracking furnace for preheating; mixing the desalted pyrolysis oil with at least steam; separating the mixture of desalted pyrolysis oil and steam into a vapor phase and a liquid phase, wherein the vapor phase comprises volatile hydrocarbons in an amount of about 55 weight percent to about 70 weight percent and steam in an amount of about 30 weight percent to about 45 weight percent; 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 blending 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 blending a liquid hydrocarbon co-feed with the plastic-derived pyrolysis oil upstream of the first desalting vessel.

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

[0084] Although the present disclosure has been described in terms of a number of embodiments and examples, those skilled in the art will appreciate, after reading this disclosure, that other embodiments may be designed without departing from the scope and spirit of the present disclosure as described herein. Although various embodiments have been discussed, this disclosure encompasses all combinations of all those embodiments.

[0085] Although compositions, methods, and processes are described herein as "comprising," "containing," "having," or "including" various components or steps, the compositions and methods may also "consist essentially of" or "consist of" the various components and steps. Unless otherwise specified, the phrase "consisting essentially of does not exclude the presence of other steps, elements, or materials (whether or not specifically mentioned in the specification), so long as these steps, elements, or materials do not affect the basic and novel characteristics of the disclosure, and further, they do not exclude impurities and variations normally associated with the elements and materials used.

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

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

Claims

1. Methods, including: treating at least the plastic-derived pyrolysis oil in a desalter to form at least desalted pyrolysis oil; heating the desalted pyrolysis oil; separating the desalted pyrolysis oil to form a gas phase and a liquid phase; steam cracking at least a portion of the first gas phase in the presence of steam to form at least a cracked effluent; and The cracking effluent is separated 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 the plastic-derived pyrolysis oil with water in one or more stages; and separating at least the desalted pyrolysis oil from water.

3. The method of claim 2, wherein the separating the desalted pyrolysis oil comprises separating at least the interstage pyrolysis oil from the 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 current.

5. The process 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 blending the liquid hydrocarbon co-feed with the desalted pyrolysis oil upstream of a cracking furnace.

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

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

9. The method of claim 5, wherein the liquid hydrocarbon co-feed comprises liquid refinery products defined at least in part by co-processed plastic waste.

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

11. The process of claim 10, wherein at least a portion of the olefins comprises recycled olefins.

12. The process of claim 11 further comprising polymerizing at least a portion of the olefin to produce at least a recycle polymer product.

13. The process of claim 1, further comprising separating at least a portion of the additional gaseous phase into a C2 fraction comprising ethylene, a C3 fraction comprising propylene, a mixed C4 fraction comprising butanes and butenes, 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 before separating the desalted pyrolysis oil.

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

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

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

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

20. The method of claim 1, wherein the desalted pyrolysis oil is characterized by a reduction in inorganic halide contaminant concentration of about 90% by weight or more, a reduction in organic halide contaminant concentration of about 10% by weight or more, a reduction in nitrate and nitrite contaminant concentration of about 90% by weight or more, a reduction in silica and silicon contaminant concentration of about 10% by weight or more, and a reduction in total acid number of about 10% by weight or more relative to the plastic-derived pyrolysis oil.

21. A method comprising: mixing the plastic-derived pyrolysis oil to be desalted with water at a temperature of about 100° C. to 200° C. to form a first oil / water emulsion; conveying the oil / water emulsion to a first desalting vessel, wherein the oil / water emulsion is separated into an aqueous phase and an oily phase; removing at least a portion of the oily phase from the first desalting vessel as an interstage feed; mixing the interstage 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 additional water; removing desalted pyrolysis oil from the second desalting vessel, wherein the desalted pyrolysis oil has a chloride concentration that is 90 weight percent less than the chloride concentration of the plastic-derived pyrolysis oil; introducing the desalted pyrolysis oil into a steam cracking furnace for preheating; mixing the desalted pyrolysis oil with at least steam; separating the mixture of desalted pyrolysis oil and steam into a vapor phase and a 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 gas phase to a temperature of about 425°C to about 650°C; and steam cracking at least a portion of the gas phase to form at least a cracked effluent; and At least olefins are recovered from the cracking effluent.

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

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

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