Method and system for quenching pyrolysis effluent

Abstract

Methods and systems for quenching effluents. In certain embodiments, the method may include contacting the pyrolysis effluent with a first quenching medium to produce a first quenched effluent. A bottoms stream that may include tar and an overhead stream that may include ethylene and propylene may be obtained from the first quenched effluent. The first quenching medium may include a first portion of the bottoms stream, and the first portion of the bottoms stream may include a first portion of tar. In certain embodiments, the method may also include hydrotreating a second portion of the bottoms stream that may include a second portion of tar to produce a hydrotreated product. The hydrotreating bottoms stream may be obtained from the hydrotreating product. In certain embodiments, the method may also include contacting at least a portion of the hydrotreating bottoms stream with a first portion of the bottoms stream to produce the first quenching medium.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit and priority of U.S.S.N. 62 / 929,326, filed on November 1, 2020, and EP application No. 20151752.1, filed on January 14, 2020, which are hereby incorporated by reference herein. Technical field

[0003] The present disclosure relates to methods and systems for converting hydrocarbon - containing feeds via pyrolysis. More specifically, the present disclosure relates to methods and systems for quenching pyrolysis effluents. Background art

[0004] Pyrolysis processes, such as steam cracking, convert saturated hydrocarbons into higher - value products, such as light olefins, like ethylene and propylene. However, in addition to these higher - value products, pyrolysis processes also produce significant amounts of relatively low - value heavy products, such as pyrolysis tar. Pyrolysis tar is a high - boiling - point, viscous, reactive material that contains complex, cyclic, and branched molecules that can polymerize and foul equipment. Pyrolysis tar also contains high - molecular - weight non - volatile components, including alkane - insoluble compounds, such as pentane - insoluble compounds and heptane - insoluble compounds.

[0005] One difficulty encountered in pyrolysis processes is the reactive composition of the pyrolysis effluent. The pyrolysis effluent contains a large number of reactive free radicals formed during the high - temperature pyrolysis of the hydrocarbon - containing feed. When the pyrolysis effluent cools, some of the reactive free radicals react to form stable products. However, some free radicals remain and act as initiators for olefin polymerization, which can cause fouling.

[0006] Typically, the pyrolysis effluent recovered from a pyrolysis process (such as steam cracking) is quenched by indirectly transferring heat from the pyrolysis effluent to a quench fluid (such as water and / or steam) in an indirect heat exchanger (i.e., a transfer line exchanger). The main purpose of the transfer line exchanger is to rapidly quench the pyrolysis effluent as soon as the effluent leaves the radiant section of the pyrolysis furnace to stop non - selective cracking reactions and, at the same time, recover energy at the highest available level. The dew point of the pyrolysis effluent is greater than the inner wall or inner surface temperature of the transfer line exchanger. As a result, the heaviest fractions of the pyrolysis effluent (tar) condense on the inner wall of the transfer line exchanger and turn into coke over time. The deposition of this coke on the inner surface of the transfer line exchanger rapidly reduces the heat transfer efficiency of the transfer line exchanger. When the transfer line exchanger efficiency is reduced due to coke accumulation, the outlet temperature of the transfer line exchanger increases, which results in less heat recovery. Once the transfer line exchanger outlet temperature approaches the design temperature of the downstream pipeline, the pyrolysis furnace and the transfer line exchanger must be decoked.

[0007] Accordingly, there is still a need for improved methods and systems for reducing fouling during the quenching of pyrolysis effluents. The present disclosure meets such needs and others. SUMMARY OF THE INVENTION OVERVIEW OF THE INVENTION

[0009] The inventors have designed methods and systems for quenching pyrolysis effluents. In some embodiments, the method may include contacting the pyrolysis effluent with a first quench medium to produce a first quenched effluent. A bottoms stream that may include tar and a tops stream that may include ethylene and propylene may be obtained from the first quenched effluent. The first quench medium may include a first portion of the bottoms stream, and the first portion of the bottoms stream may include a first portion of the tar.

[0010] In some embodiments, the method may include contacting the pyrolysis effluent with a first quench medium to produce a first quenched effluent. A bottoms stream that may include tar and a tops stream that may include ethylene and propylene may be obtained from the first quenched effluent. The first quench medium may include a first portion of the bottoms stream, and the first portion of the bottoms stream may include a first portion of the tar. A second portion of the bottoms stream that may include a second portion of the tar may be hydrotreated to produce a hydrotreated product. A hydrotreated bottoms stream may be obtained from the hydrotreated product. At least a portion of the hydrotreated bottoms stream and the first portion of the bottoms stream may be contacted to produce the first quench medium.

[0011] In some embodiments, a method for quenching an effluent may include obtaining a vapor product and a liquid product from a heated mixture that includes steam and a hydrocarbon feed. The vapor product may be steam cracked to produce a pyrolysis effluent. The pyrolysis effluent having a first temperature may be contacted with a first quench medium to produce a first quenched effluent having a second temperature. Heat may be indirectly transferred from the first quenched effluent to a second quench medium to produce a second quenched effluent having a third temperature and a heated second quench medium. Heat may be indirectly transferred from the second quenched effluent to a third quench medium, or the second quenched effluent may be contacted with the third quench medium to produce a third quenched effluent having a fourth temperature. A bottoms stream that may include tar and a tops stream that may include ethylene, propylene, and quench oil may be obtained from the third quenched effluent. A first portion of the bottoms stream that may include tar may be recycled as the first quench medium. In some embodiments, the method may further include hydrotreating a second portion of the bottoms stream that may include a second portion of the tar to produce a hydrotreated product. In some embodiments, the method may further include recycling a first portion of the hydrotreated product as the first quench medium.

[0012] In some embodiments, a system for converting a hydrocarbon-containing feed by pyrolysis can include a first gas-liquid separator, a pyrolysis reactor, a quench section, a second gas-liquid separator, and a first conduit. The first gas-liquid separator can be adapted to receive the hydrocarbon-containing feed, separate the hydrocarbon-containing feed into a first gaseous hydrocarbon stream and a first liquid hydrocarbon stream, discharge the first gaseous hydrocarbon stream, and discharge the first liquid hydrocarbon stream. The pyrolysis reactor can be adapted to receive the first gaseous hydrocarbon stream, heat the first gaseous hydrocarbon stream to effect pyrolysis of at least a portion of the first gaseous hydrocarbon stream, and discharge a pyrolysis effluent stream. The quench section can be adapted to receive the pyrolysis effluent stream, quench the pyrolysis effluent stream, and discharge a quenched pyrolysis effluent stream. The second gas-liquid separator can be adapted to receive the quenched pyrolysis effluent stream, separate the quenched pyrolysis effluent stream to obtain a second gaseous hydrocarbon stream containing olefins and a second liquid hydrocarbon stream containing tar, discharge the second gaseous hydrocarbon stream, and discharge the second liquid hydrocarbon stream. The first conduit can be adapted to convey a first portion of the second liquid hydrocarbon stream containing tar to the quench section such that the first portion of the second liquid hydrocarbon stream contacts the pyrolysis effluent to produce a mixture containing the first portion of the second liquid hydrocarbon stream and the pyrolysis effluent. In some embodiments, the system can further include a hydrotreating unit, a third gas-liquid separator, and a second conduit. The hydrotreating unit can be adapted to receive a second portion of the second liquid hydrocarbon stream containing tar and optionally at least a portion of the first liquid hydrocarbon stream, hydrotreat the second portion of the second liquid hydrocarbon stream and optionally at least a portion of the first liquid hydrocarbon stream under hydrotreating conditions to produce a hydrotreated product, and discharge the hydrotreated product. The third gas-liquid separator can be adapted to separate a hydrotreating overhead stream containing at least 1 wt% of the hydrotreated product, a hydrotreating middle distillate stream containing at least 20 wt% of the hydrotreated product; and a hydrotreating bottoms stream containing at least 20 wt% of the hydrotreated product. The second conduit can be adapted to transfer at least a portion of the hydrotreating bottoms stream from the separator to the quench section such that the hydrotreating bottoms stream contacts the pyrolysis effluent to produce a mixture containing the first portion of the second liquid hydrocarbon stream, the pyrolysis effluent, and the hydrotreating bottoms stream. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 An illustrative system for converting a hydrocarbon-containing feed by pyrolysis to produce a pyrolysis effluent and quenching the pyrolysis effluent via a first quench configuration in accordance with one or more of the embodiments is depicted.

[0014] Figure 2Depicts another illustrative system for converting a hydrocarbonaceous feed by pyrolysis to produce a pyrolysis effluent and quenching the pyrolysis effluent via a second quench configuration, according to the one or more embodiments.

[0015] Figure 3 Depicts another illustrative system for converting a hydrocarbonaceous feed by pyrolysis to produce a pyrolysis effluent and quenching the pyrolysis effluent via a third quench configuration, according to the one or more embodiments.

[0016] Figure 4 Depicts another illustrative system for converting a hydrocarbonaceous feed by pyrolysis to produce a pyrolysis effluent and quenching the pyrolysis effluent via a fourth quench configuration, according to the one or more embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0018] Various specific embodiments, versions, and implementations of the present invention will now be described, including the preferred embodiments and definitions employed herein for understanding the present invention. While the following detailed description sets forth specific preferred embodiments, those skilled in the art will appreciate that these embodiments are merely exemplary, and the present invention may be practiced otherwise. For purposes of determining infringement, the scope of the present invention refers to any one or more of the appended claims, including their equivalents, and elements or limitations equivalent to those listed. Any reference to the "invention" may refer to one or more, but not necessarily all, of the invention as defined by the claims.

[0019] In the present disclosure, a method is described as including at least one "step", and it should be understood that each step is an action or operation that can be performed one or more times in a continuous or discontinuous manner in the method. Unless otherwise provided to the contrary or the context clearly indicates otherwise, the multiple steps in the method can be carried out in the order in which they are listed, with or without overlapping one or more other steps, or in any other order, as the case may be. Additionally, one or more, or even all, of the steps can be carried out simultaneously in terms of the same or different batches of material. For example, in a continuous method, while the first step in the method is being carried out on the raw material just fed into the starting point of the method, the second step can be carried out simultaneously on the intermediate product produced by processing the raw material fed into the method earlier in the first step. Preferably, these steps are carried out in the order described.

[0020] Unless otherwise indicated, all numbers expressing quantities in this disclosure should be understood as being modified in all instances by the term "about." It should also be understood that the exact numerical values used in the specification and claims constitute specific embodiments. Efforts have been made to ensure the accuracy of the data in the examples. However, it should be understood that any measured data inherently contains a certain level of error due to limitations in the techniques and / or equipment used to obtain the measurements.

[0021] Certain embodiments and features are described herein using a set of numerical upper limits and a set of numerical lower limits. It is understood that ranges including any combination of any two values, such as any combination of any lower value and any upper value, any combination of any two lower values, and / or any combination of any two upper values, are contemplated, unless otherwise indicated.

[0022] As used herein, the indefinite article "a" or "an" should mean "at least one," unless the contrary is specified or the context clearly indicates otherwise. Thus, embodiments using a "pyrolysis reactor" include embodiments in which one, two, or more pyrolysis reactors are used, unless otherwise indicated or the context clearly dictates that only one pyrolysis reactor is used.

[0023] "Crude" or "crude oil" in this disclosure may interchangeably mean whole crude oil as it flows from a wellhead, production site facility, transportation facility, or other initial site processing facility, and / or crude oil that has been processed by 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 as used herein is assumed to contain resid.

[0024] "Crude oil fraction" as used herein refers to a hydrocarbon fraction that can be obtained by the fractional distillation of crude oil.

[0025] As used herein, "residual oil" refers to (i) the bottom fraction of the crude oil distillation process containing non-volatile components, and / or (ii) a material containing organic compounds such as hydrocarbons having boiling points within the boiling point range of the residual oil in category (i). The residual oil of category (i) is a complex mixture of heavy petroleum compounds, which is also referred to as residue or bottoms in the art. Atmospheric residue is the bottom product produced by the atmospheric distillation of crude oil, where the typical end point of the heaviest distillation product is labeled as 650°F (343°C), and it is called 650°F (343°C) residual oil. The term "nominal" in this article means that reasonable experts may disagree on the exact fractionation points of these terms, but not by more than + / -100°F (+ / -55.6°C), preferably not more than + / -50°F (+ / -27.8°C). Vacuum residue is the bottom product from a distillation column operating under vacuum, where the heaviest distillation product can nominally be 1050°F (566°C), and it is called 1050°F (566°C) residual oil. This 1050°F (566°C) fraction contains a high concentration of asphaltenes, which are traditionally considered problematic for steam crackers, leading to severe fouling and potential corrosion or erosion of the equipment. Vacuum residue can be advantageously mixed with crude oil and / or light crude oil fractions such as atmospheric residue to form a suitable feed for the flash drum of the methods of the present disclosure. The residual oil of category (ii) in the present disclosure may include, for example, (a) natural or synthetic polymer materials such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, etc.; (b) biofuels (such as biodiesel) derived from biological materials (such as lignin, plant waste, algae waste, and food waste); (c) biological materials such as algae, corn, soybeans; and (d) any mixture of one or more of (a), (b), and / or (c).

[0026] The term "hydrocarbon" as used herein refers to (i) any compound composed of hydrogen and carbon atoms or (ii) any mixture of two or more such compounds in (i). The term "C n hydrocarbon", where n is a positive integer, refers to (i) any hydrocarbon compound containing a total of n carbon atoms (one or more) in its molecule, or (ii) any mixture of two or more such hydrocarbon compounds in (i). Thus, C 2 hydrocarbon can be ethane, ethylene, acetylene, or a mixture of at least two of these compounds in any proportion. "C m to C n hydrocarbon" or "C m -C n hydrocarbon", where m and n are positive integers and m < n, refers to C m 、C m+1 、C m+2 、…、C n-1 、C nAny one of the hydrocarbons, or any mixture of two or more thereof. Thus, "C 2 to C 3 hydrocarbons" or "C 2 -C 3 hydrocarbons" can be any one of ethane, ethylene, acetylene, propane, propylene, propyne, allene, cyclopropane, and any mixture of two or more thereof in any proportion between and among the components. "Saturated C 2 -C 3 hydrocarbons" can be ethane, propane, cyclopropane, or any mixture of two or more thereof in any proportion. "C n+ hydrocarbons" refers to (i) any hydrocarbon compound that contains a total of at least n carbon atoms in its molecule, or (ii) any mixture of two or more such hydrocarbon compounds in (i). "C n- hydrocarbons" refers to (i) any hydrocarbon compound that contains a total of at most n carbon atoms in its molecule, or (ii) any mixture of two or more such hydrocarbon compounds in (i). "C m hydrocarbon stream" refers to a hydrocarbon stream that consists essentially of C m hydrocarbon(s). "C m -C n hydrocarbon stream" refers to a hydrocarbon stream that consists essentially of C m -C n hydrocarbon(s).

[0027] As used herein, the term "non-volatile component" refers to the fraction of the petroleum feed having a nominal boiling point of at least 590 °C as measured by ASTM D6352-15 or D-2887-18. Non-volatiles include coke precursors, which are large, condensable molecules that condense in the vapor and then form coke during the pyrolysis of the petroleum feed.

[0028] As used herein, the term "olefin product" refers to a product that includes olefins, preferably a product that consists essentially of olefins. An olefin product within the meaning of the present disclosure can be, for example, an ethylene stream, a propylene stream, a butene stream, an ethylene / propylene mixed stream, etc.

[0029] As used herein, the term "consisting essentially of" means that a composition, feed, or effluent contains a given component at a concentration of at least 60 wt%, preferably at least 70 wt%, more preferably at least 80 wt%, more preferably at least 90 wt%, still more preferably at least 95 wt%, based on the total weight of the composition, feed, or effluent being discussed.

[0030] The terms "passage" and "line" are used interchangeably and refer to any conduit configured or adapted to feed, flow into, and / or discharge gas, liquid, and / or fluidized solid feed into, through, and / or from a conduit. For example, a composition can be fed into, flow through, and / or discharged from a conduit to move the composition from a first location to a second location. Suitable conduits can be or can include, but are not limited to, tubes, hoses, ducts, pipes, etc.

[0031] In the present disclosure, a "reactor" includes a reaction vessel in which an intended chemical reaction occurs to convert a feed into a product mixture, and any equipment peripheral to the reaction vessel, such as feed pretreatment equipment (heat exchangers, compressors, purification equipment, etc.), product mixture treatment equipment (heat exchangers, compressors, separation equipment, including but not limited to distillation columns, etc.), recycle management equipment (heat exchangers, compressors, etc.), reboilers, condensers, catalyst regeneration equipment, pumps (one or more), valves, gauges, etc. Thus, a reactor can be understood as a reactor unit or a reactor subsystem.

[0032] As used herein, "wt%" refers to weight percentage, "vol%" refers to volume percentage, "mol%" refers to mole percentage, "ppm" refers to parts per million, and "ppm wt" and "wppm" are used interchangeably to refer to parts per million by weight. All concentrations herein are expressed based on the total amount of the composition under discussion. Thus, the concentrations of the various components of an "oil feed" are expressed based on the total weight of the oil feed. All ranges expressed herein should include the two endpoints as two specific embodiments, unless otherwise specified or indicated.

[0033] The nomenclature of the elements and their groups used herein follows the periodic table used by the International Union of Pure and Applied Chemistry after 1988. An example of the periodic table is shown on the inner page of the cover of the sixth edition of Advanced Inorganic Chemistry, edited by F. Albert Cotton et al. (John Wiley & Sons, Inc., 1999).

[0034] A hydrocarbon-containing feedstock, or simply hydrocarbon feedstock, can be, can include, or can be derived from petroleum, plastic materials, natural gas condensate, landfill gas (LFG), biogas, coal, biomass, bio-based oil, rubber, or any mixture thereof. In certain embodiments, the hydrocarbon-containing feedstock can include non-volatile components. In certain embodiments, the petroleum can be or can include any crude oil or any mixture thereof, any crude oil fraction or any mixture thereof, or any mixture of any crude oil and any crude oil fraction. Typical crude oils include mixtures of hydrocarbons having different carbon numbers and boiling points. Thus, by using conventional atmospheric distillation and vacuum distillation, a series of fuel products having different boiling points can be produced, such as naphtha, gasoline, kerosene, distillates, and tars. However, there is a great need to convert the large hydrocarbon molecules contained in crude oil into more valuable lighter products, including but not limited to ethylene, propylene, butene, etc., which can be further made into more valuable products, such as polyethylene, polypropylene, ethylene-propylene copolymers, butyl rubber, etc.

[0035] In certain embodiments, the petroleum can be or can include: crude oil, atmospheric residue, vacuum residue, steam-cracked gas oil and residues, gas oil, heating oil, hydrocracked products, atmospheric pipe still bottoms, vacuum pipe still feed streams including bottoms, gas oil condensate, heavy non-distillate hydrocarbon feed streams from refineries, vacuum gas oil, heavy gas oil, naphtha, naphtha contaminated with crude oil, heavy residue, C4 / residue blends, naphtha / residue blends, hydrocarbon gas / residue blends, hydrogen / residue blends, gas oil / residue blends, or any mixture thereof. Non-limiting examples of crude oil can be or can include but are not limited to Tapis, Murban, Arab Light, Arab Medium, and / or Arab Heavy.

[0036] In certain embodiments, the plastic material can be or can include, but is not limited to, polyethylene terephthalate (PETE or PET), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polystyrene (PS), polycarbonate (PC), polylactic acid (PLA), acrylic (PMMA), acetal (polyoxymethylene, POM), acrylonitrile - butadiene - styrene (ABS), fiberglass, nylon (polyamide, PA), polyester (PES), rayon, phenol formaldehyde (bakelite), polyurethane (PU), polyepoxide (epoxy resin), or any mixture thereof. The rubber can be or can include natural rubber, synthetic rubber, or a mixture thereof. In certain embodiments, biogas can be produced via anaerobic digestion, such as biogas produced during the anaerobic digestion of sewage. In certain embodiments, the bio - based oil can be or can include an oil that can be biologically degraded over time. In certain embodiments, the bio - based oil can be degraded via a bacterial decomposition process and / or by enzymatic biodegradation by other living organisms such as yeast, protozoa, and / or fungi. The bio - based oil can be derived from vegetable oils, such as rapeseed oil, castor oil, palm oil, soybean oil, sunflower oil, corn oil, hemp oil, or chemically synthesized esters. In certain embodiments, the biomass can be or can include, but is not limited to, wood, agricultural residues such as straw, stalks, bagasse, and green agricultural waste, agro - industrial waste such as bagasse and rice husk, animal waste such as cow dung and poultry litter, industrial waste such as black liquor from paper making, sewage, municipal solid waste, food processing waste, or any mixture thereof.

[0037] If the hydrocarbon - containing feed includes materials that are solid at room temperature, such as plastic materials, biomass, coal, and / or rubber, the solid materials can be reduced to any desired particle size via well - known methods. For example, if the hydrocarbon - containing feed includes solid materials, the solid materials can be ground, crushed, pulverized, or otherwise reduced to particles having any desired average particle size. In certain embodiments, the solid material can be reduced to an average particle size that can be sub - micron or from about 1 μm, about 10 μm, or about 50 μm to about 100 μm, about 150 μm, or about 200 μm. For example, the average particle size of the solid material can be in the range of about 75 μm to about 475 μm, about 125 μm to about 425 μm, or about 175 μm to about 375 μm.

[0038] In certain embodiments, the hydrocarbon-containing feed may include one or more crude oils or fractions thereof and one or more plastic materials. In certain embodiments, the hydrocarbon-containing feed may include petroleum and one or more plastic materials, and the one or more plastic materials are present in an amount of 1 wt%, 3 wt%, 5 wt%, 7 wt%, 10 wt% or 15 wt% to 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt% or 45 wt% based on the total weight of the hydrocarbon-containing feed.

[0039] Petroleum, such as crude oil or fractions thereof, can act as a solvent for the plastic material and dissolve at least a portion of the plastic material in the crude oil or its fractions. In certain embodiments, at least 30 wt%, at least 40 wt%, at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, or even 100 wt% of the plastic material mixed with the crude oil or its fractions can be dissolved in the crude oil or its fractions. Thus, in certain embodiments, when the hydrocarbon-containing feed includes one or more plastic materials, the hydrocarbon-containing feed can be in the form of a solution in which the plastic material is uniformly dispersed in the crude oil or its fractions.

[0040] The terms "pyrolysis tar" and "tar" are used interchangeably and refer to (a) a mixture of hydrocarbons having one or more aromatic components and optionally, (b) non-aromatic and / or non-hydrocarbon molecules, the mixture being derived from hydrocarbon pyrolysis, wherein 70 wt% of the mixture has a boiling point of at least 290 °C at atmospheric pressure. Certain pyrolysis tars have an initial boiling point of at least 200 °C. For certain pyrolysis tars, at least 80 wt%, at least 85 wt% or at least 90 wt% of the pyrolysis tar has a boiling point of at least 290 °C at atmospheric pressure. The pyrolysis tar may include, for example, at least 50 wt%, at least 75 wt% or at least 90 wt% of hydrocarbon molecules (including mixtures and aggregates thereof) having (i) one or more aromatic components and (ii) at least 15 carbon atoms, based on the weight of the pyrolysis tar. Pyrolysis tar generally has a metal content of 1×10 3 ppmw or less, based on the weight of the pyrolysis tar, which is a much lower amount of metal than the amount of metal present in a crude oil (or crude oil component) of the same average viscosity. The terms "steam cracker tar" and "SCT" refer to pyrolysis tar obtained from steam cracking. The term "biomass pyrolysis tar" refers to pyrolysis tar obtained from the thermal cracking of biomass. The term "coal pyrolysis tar" refers to pyrolysis tar obtained from the thermal cracking of hydrocarbons derived from coal.

[0041] Quenching the pyrolysis effluent

[0042] The pyrolysis effluent and the quench medium or first quench medium can be mixed, blended, combined, or otherwise contacted with each other to produce a quenched effluent or first quenched effluent. In certain embodiments, the pyrolysis effluent can be at a temperature of at least 750 °C, such as from 775 °C to 1,100 °C, when initially contacted with the first quench medium. In certain embodiments, the first quenched effluent can undergo one or more additional quenching stages, such as indirect heat transfer, direct contact with one or more additional quench media, or combinations thereof, to produce a cooled or quenched effluent having a temperature of from 250 °C to 350 °C, such as 300 °C. The cooled or quenched effluent can be introduced into one or more separation stages, such as a tar separation drum, to separate a bottoms stream that can contain tar and a tops stream that can contain ethylene, propylene, quench oil, and other light hydrocarbons relative to the bottoms stream. In certain embodiments, suitable separation stages can include those disclosed in U.S. Patent No. 8,083,931.

[0043] It has been surprisingly and unexpectedly found that, upon leaving the pyrolysis reactor, the pyrolysis effluent can contact a first portion of a bottoms stream that contains a first portion of tar as the first quench medium. In other words, the first quench medium can be or can include, but is not limited to, a first portion of a bottoms stream obtained from the quenched effluent. The tar contained in the first portion of the bottoms stream that can constitute at least a portion of the first quench medium can be referred to as virgin tar or un-upgraded tar, i.e., tar that has not undergone any upgrading process (such as hydrotreating) once separated from the quenched pyrolysis effluent. Without wishing to be bound by theory, it is believed that the virgin tar in the first portion of the bottoms stream can be used as a quench medium because a portion or fraction thereof will remain liquid when contacted with the pyrolysis effluent.

[0044] In certain embodiments, a second portion of the bottoms stream that contains a second portion of tar can be subjected to hydrotreating conditions sufficient to produce a hydrotreating product. The hydrotreating bottoms stream can be separated from or otherwise obtained from the hydrotreating product. It should be understood that the first portion of the bottoms stream that includes the first portion of tar and the second portion of the bottoms stream that includes the second portion of tar can have the same or substantially the same composition.

[0045] In certain embodiments, upon leaving the pyrolysis reactor, the pyrolysis effluent can contact at least a portion of a hydrotreating bottoms stream and a first portion of a bottoms stream that contains a first portion of tar as the first quench medium. In other words, the first quench medium can be or can include, but is not limited to, a first portion of the bottoms stream that includes the first portion of tar or a mixture of a first portion of the bottoms stream and a first portion of the hydrotreating bottoms stream.

[0046] In certain embodiments, when the first quench medium comprises a first portion of the bottoms stream that comprises a first portion of the tar and a first portion of the hydrotreated bottoms stream, the first quench medium may comprise 1 wt%, 5 wt%, 10 wt%, 20 wt%, 30 wt%, 40 wt%, or 45 wt% to 55 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, 95 wt%, or 99 wt% of the first portion of the hydrotreated bottoms stream, based on the total weight of the first portion of the bottoms stream and the first portion of the hydrotreated bottoms stream. In certain other embodiments, the first quench medium may comprise 10 wt% to 90 wt%, 20 wt% to 80 wt%, 30 wt% to 70 wt%, 40 wt% to 60 wt%, 40 wt% to 50 wt%, 45 wt% to 55 wt%, or 50 wt% to 60 wt% of the first portion of the hydrotreated bottoms stream, based on the total weight of the first portion of the bottoms stream and the first portion of the hydrotreated bottoms stream. In certain embodiments, the weight ratio of the first quench medium to the pyrolysis effluent that can be used to produce the first quenched effluent may be 1:1, 1.3:1, 1.5:1, or 1.7:1 to 2:1, 2.5:1, 3:1, or 3.5:1.

[0047] The first portion of the bottoms stream that comprises the first portion of the tar may comprise 2 wt%, 2.5 wt%, 3 wt%, or 3.5 wt% to 4 wt%, 5 wt%, 6 wt%, or 7 wt% sulfur measured according to ASTM D4294-16e1. The first portion of the bottoms stream may have 1 g / cm 3 , 1.05 g / cm 3 , 1.07 g / cm 3 or 1.1 g / cm 3 to 1.13 g / cm 3 , 1.15 g / cm 3 , 1.17 g / cm 3 or 1.19 g / cm 3Density. The density can be measured according to ASTM D4052-18a. The first part of the bottoms stream can have an API gravity at 15.6 °C of 1 or less. For example, the first part of the bottoms stream can have an API gravity at 15.6 °C of -13, -10, -7, or -5 to -3, -1, 0, or 1. The API gravity can be measured according to ASTM D4052-18a. At least 75 wt% of the first part of the bottoms stream can have a boiling point at atmospheric pressure of at least 300 °C, 310 °C, 320 °C, 325 °C, 330 °C, 335 °C, or 340 °C. At least 25 wt% of the first part of the bottoms stream can have a boiling point at atmospheric pressure of at least 490 °C, 500 °C, 510 °C, 515 °C, 520 °C, 525 °C, or 530 °C. In certain embodiments, the bottoms stream can have a final atmospheric boiling point greater than 600 °C. The atmospheric boiling point can be measured according to ASTM D2887-18.

[0048] The first part of the bottoms stream can have a 25 / 75 solubility value (25 / 75SBN) of 0.6 wt%, 0.8 wt%, 1 wt%, 1.5 wt%, 2 wt%, or 3 wt% to 5 wt%, 6 wt%, 8 wt%, or 10 wt%. The 25 / 75 solubility value is measured by weight separation according to the following procedure. Mix 1 part of the sample and 10 parts of the solvent by weight overnight. Then filter the precipitated asphaltenes, wash with additional solvent, and dry in a vacuum oven at 120 °C. The wt% of insolubles is determined by the weight of the solid asphaltenes after drying. The solvent is a mixture containing 25 wt% heptane and 75 wt% toluene.

[0049] The first part of the bottoms stream can have an H-NMR analysis of 5%, 5.5%, or 6% to 6.5%, 7%, or 7.5%. The H-NMR value can be measured according to the following procedure. Weigh out a known amount of the sample in a sealed NMR vial and generate a proton signal by NMR. Compare this signal with a set of known standard samples to calculate the hydrogen percentage of the sample. By providing a solvent and back-calculating the hydrogen percentage of the sample, the viscosity of the sample can be reduced to less than 25 cSt.

[0050] The hydrotreated bottoms stream can contain less than 2 wt%, less than 1.5 wt%, less than 1 wt%, or less than 0.7 wt% sulfur. For example, the hydrotreated bottoms stream can contain 0.1 wt%, 0.3 wt%, or 0.5 wt% to 0.7 wt%, 1 wt%, 1.5 wt%, or 1.7 wt% sulfur. The hydrotreated bottoms stream can have a density of 0.95 g / cm 3 , 0.98 g / cm 3 , 1 g / cm 3 , 1.05 g / cm 3 , 1.07 g / cm3 or 1.1 g / cm 3 The density of the hydroprocessing bottoms stream can be less than 3 or lower API gravity at 15.6 °C. For example, the hydroprocessing bottoms stream can have an API gravity at 15.6 °C of from -10, -5, -3, or -2 to -1, 0, 1, or 2. The hydroprocessing bottoms stream can have a 25 / 75 solubility value of from 0 wt%, 0.3 wt%, 0.5 wt%, or 0.7 wt% to 1 wt%, 1.3 wt%, 1.5 wt%, 1.7 wt%, or 2 wt%. The hydroprocessing bottoms stream can have an H-NMR analysis of from 6.5%, 7%, or 7.5% to 8%, 9%, or 10%. At least 75 wt% of the hydroprocessing bottoms stream can have a boiling point at atmospheric pressure of at least 330 °C, 340 °C, 350 °C, 355 °C, 360 °C, 365 °C, or 370 °C. At least 25 wt% of the hydroprocessing bottoms stream can have a boiling point at atmospheric pressure of at least 510 °C, 520 °C, 530 °C, 535 °C, 540 °C, 545 °C, or 550 °C.

[0051] Compared to the hydroprocessing bottoms stream, the first portion of the bottoms stream containing tar can have a greater density and a greater 25 / 75 solubility value and contain a greater amount of sulfur. Compared to the API gravity at 15.6 °C of the hydroprocessing bottoms stream, the first portion of the bottoms stream can have a greater API gravity at 15.6 °C. The H-NMR analysis value of the first portion of the bottoms stream containing tar can be less than the H-NMR analysis value of the hydroprocessing bottoms stream. The boiling point at atmospheric pressure of the first portion of the bottoms stream for a given fraction can be greater than that of the hydroprocessing bottoms stream for the same given fraction. For example, the boiling point at atmospheric pressure of 75 wt% of the first portion of the bottoms stream can be greater than the boiling point of 75 wt% of the hydroprocessing bottoms stream.

[0052] It may be desirable to rapidly cool the pyrolysis effluent upon exiting the pyrolysis reactor (e.g., the radiant section of a feedstock cracking furnace) to reduce the conversion of desired products (e.g., olefins) to less desired products (e.g., paraffins). Thus, upon exiting the pyrolysis zone, the pyrolysis effluent can be contacted with a first quench medium, such as within a quench header or at the inlet of an indirect heat exchanger (e.g., a transfer line exchanger), for a contact time of from 100 milliseconds, 150 milliseconds, or 200 milliseconds to 300 milliseconds, 500 milliseconds, or 800 milliseconds, such as from 100 milliseconds to 200 milliseconds, to produce a quenched effluent or a first quenched effluent. In certain embodiments, the pyrolysis effluent can be cooled to a temperature of from 450°C to 550°C by contacting the pyrolysis effluent with the first quench medium within a quench header. In certain embodiments, the pyrolysis effluent can be cooled from a temperature of at least 750°C, such as from 775°C to 1,000°C, to a temperature of from 450°C to 550°C within a quench header in a time of from 20 milliseconds, 30 milliseconds, or 40 milliseconds to 50 milliseconds, 75 milliseconds, or 100 milliseconds, such as from 20 milliseconds to 40 milliseconds. In certain other embodiments, the pyrolysis effluent can be cooled to a temperature of from 350°C to 450°C within an indirect heat exchanger, such as a transfer line exchanger. In certain embodiments, the pyrolysis effluent can be cooled from a temperature of at least 750°C, such as from 775°C to 1,100°C, to a temperature of from 450°C to 550°C within an indirect heat exchanger in a time of from 100 milliseconds, 150 milliseconds, or 200 milliseconds to 300 milliseconds, 500 milliseconds, or 800 milliseconds, such as from 100 milliseconds to 400 milliseconds.

[0053] After contacting the pyrolysis effluent with the first quench medium to produce a first quenched effluent, the first quenched effluent can be further cooled through one or more additional heat exchange stages. In certain embodiments, the first quenched effluent can be cooled by transferring heat from the first quenched effluent to a second quench medium (e.g., water, steam, or a mixture thereof) within an indirect heat exchanger (e.g., a transfer line exchanger). In certain other embodiments, the first quenched effluent can be cooled by contacting the first quenched effluent with a third quench medium (e.g., quench oil separated from the pyrolysis effluent in a downstream separation stage). Any number of heat exchange stages (indirect heat exchange or by contact with a quench medium) can be used to produce a quenched effluent having a temperature of from 250°C to 350°C or from 275°C to 325°C.

[0054] It has surprisingly and unexpectedly been found that when used to cool a pyrolysis effluent via direct contact, a first quench medium comprising a first portion of a bottoms stream (which comprises tar or a mixture of the first portion of the bottoms stream and the first portion of a hydrotreated bottoms stream) can provide significant advantages. For example, at least a portion of the first quench medium can remain in the liquid phase when contacted with the pyrolysis effluent. In certain embodiments, when contacted with the pyrolysis effluent, at least 2 wt%, at least 3 wt%, at least 4 wt% or at least 5 wt% to 7 wt%, 8.5% or 10 wt% of the quench medium can remain in the liquid phase. Without wishing to be bound by theory, it is believed that the fraction or portion of the quench medium that remains in the liquid phase when contacted with the pyrolysis effluent can flow along the surface of the inner wall of a quench header, a transfer line exchanger, a conduit or other equipment through which the mixed stream flows. It is believed that the liquid fraction can "wash" or otherwise facilitate the removal of at least a portion of any coke deposits, which can reduce, mitigate, delay or even prevent fouling due to coke deposition.

[0055] In certain embodiments, the flow path of the mixture of the first quench medium and the pyrolysis effluent or the first quenched effluent through an indirect heat exchanger (such as a transfer line exchanger) can be in a downward direction. In certain other embodiments, the flow path of the mixture of the first quench medium and the pyrolysis effluent or the first quenched effluent through an indirect heat exchanger can be in an upward direction. In certain other embodiments, the flow path of the mixture of the first quench medium and the pyrolysis effluent or the first quenched effluent can flow horizontally or in any direction between horizontal and vertical through the indirect heat exchanger, and if the flow path is not horizontal, the flow travels in an upward or downward direction. In certain other embodiments, the flow path of the mixture of the first quench medium and the pyrolysis effluent or the first quenched effluent through an indirect heat exchanger can include at least two of an upward direction, a downward direction and a horizontal direction.

[0056] It has also been found that the hydrotreated bottoms stream can be used as a substantially non-reactive solvent and hydrogen donor (H-donor) which can quench reactive species in the pyrolysis effluent and / or the raw or non-hydrotreated tar and reduce or prevent the conversion of such reactive species into heavier fouling species. In certain embodiments, the hydrotreated bottoms stream can be at least 0.3 wt%, at least 0.5 wt%, at least 0.7 wt%, at least 1 wt% or at least 1.5 wt% hydrogen available for donation, based on the total weight of the hydrotreated bottoms stream. Fouling within an indirect heat exchanger (e.g., a transfer line exchanger) can also increase the pressure drop over time, which can affect the pyrolysis effluent yield. Since the bottoms stream containing tar or a mixture of the bottoms stream and the hydrotreated bottoms stream can reduce, mitigate, delay or even prevent fouling due to coke deposition within the indirect heat exchanger, it is also believed that a preferred pyrolysis effluent yield can be maintained for a longer period compared to conventional pyrolysis processes that use quench oil recovered from a primary fractionator as a direct contact quench medium.

[0057] The concentration of hydrogen available for donation in a sample of the hydrotreated bottoms stream can be determined by the following procedure. To a 20 mL scintillation vial in a glove box, add 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ, 2.7 mmol) and approximately 8 mL of toluene. With rapid stirring, add a sample of the hydrotreated bottoms stream (approximately 100 mg) to the solution of DDQ. Then seal the vial and heat at approximately 110 °C for approximately 1 hour, during which time a precipitate forms. Cut off the heating, open the vial, and add 9,10-dihydroanthracene (2.7 mmol) in approximately 3 mL of toluene to the vial. Then seal the vial and heat at approximately 110 °C for approximately 2 hours, during which time more precipitate forms. After 2 hours, take an aliquot of the mixture, filter through a glass frit to remove the solid residue, and recover the filtrate. Analyze the % composition of 9,10-dihydroanthracene and anthracene in the filtrate by gas chromatography mass spectrometry (GCMS) to determine the weight % of hydrogen that can be donated by the hydrotreated bottoms stream. GC analysis of two replicate samples gives the average weight % of hydrogen available for donation, based on the total weight of the hydrotreated bottoms stream sample.

[0058] It has also surprisingly and unexpectedly been found that by contacting the pyrolysis effluent with the first quenched effluent, the length of the flow path through the indirect heat exchanger is significantly extended relative to conventional systems. For example, the pyrolysis effluent produced from a heavy hydrocarbon-containing feed (such as Murban crude oil or a blend of Murban crude oil and one or more crude oil fractions) can be contacted within a quench manifold fluidly connected to the indirect heat exchanger or within the inlet to the indirect heat exchanger and can flow through a significantly longer flow path through the indirect heat exchanger compared to conventional methods. For example, the transfer line exchanger used in a conventional steam cracking process for producing 1,200 KTA of ethylene from a heavy hydrocarbon-containing feed (such as Murban) typically has a flow path through it of 10 m to 11.7 m. In contrast, when using the first quench medium as described herein, a transfer line exchanger with a flow path of at least 10 m to 18.5 m can be used. Thus, the length of the transfer line exchanger can be significantly increased compared to conventional methods, which can allow for a greater amount of heat to be recovered from the pyrolysis effluent via the transfer line exchanger and a greater degree of cooling of the pyrolysis effluent.

[0059] By indirectly quenching the first quenched effluent in a transfer line exchanger having this increased length compared to conventional methods, a significant increase in the heat transferred from the first quenched effluent to the second quench medium can be achieved. For example, in a conventional steam cracking process where the pyrolysis effluent is first cooled in a transfer line exchanger to produce a first cooled effluent and then the first cooled effluent is contacted with quench oil recovered from a primary fractionator, when producing approximately 1,200 KTA of ethylene from a given hydrocarbon-containing feed by steam cracking, the heat recovered from the pyrolysis effluent is typically capable of generating only up to approximately 135 MW to approximately 140 MW of power via one or more turbines while quenching the pyrolysis effluent to a temperature of only 625°C to 725°C. In contrast, when using the first quench medium as described herein, the heat recoverable during the quenching of the first quenched effluent can be sufficient to generate at least 150 MW, at least 175 MW, at least 200 MW, at least 225 MW, or at least 240 MW of power via one or more turbines while quenching the pyrolysis effluent to a temperature of 350°C to 450°C when producing approximately 1,200 KTA of ethylene from the same hydrocarbon-containing feed.

[0060] In certain embodiments, the pyrolysis effluent can be contacted with a first quench medium within a quench header to produce a first cooled effluent. The first cooled effluent can be at a temperature of about 475 °C to 550 °C. Heat can be indirectly transferred from the first cooled effluent to a second quench medium, such as steam, water, or a mixture thereof, to produce a second quenched effluent. The second quenched effluent can be at a temperature of about 350 °C to 450 °C. In certain embodiments, the second quenched effluent can be contacted with a third quench medium (such as quench oil separated from the pyrolysis effluent in a downstream processing stage) to produce a third quenched effluent. In certain other embodiments, heat can be indirectly transferred from the second quenched effluent to a third quench medium, such as steam and / or water, to produce a third quenched effluent. The third quenched effluent can be at a temperature of 250 °C to 350 °C. An overhead stream and a bottoms stream can be obtained from the third quenched effluent. The overhead stream can include ethylene, propylene, and quench oil. In certain embodiments, a first portion of the bottoms stream containing tar can be recycled as the first quench medium. In certain other embodiments, a second portion of the bottoms stream containing tar can be hydrotreated to produce a hydrotreated product from which a hydrotreated bottoms stream can be obtained, and a first portion of the hydrotreated bottoms stream can also be recycled and form part of the first quench medium.

[0061] In certain other embodiments, the pyrolysis effluent can be contacted with a first quench medium within the inlet of an indirect heat exchanger (such as a transfer line exchanger) to produce a first cooled effluent. Heat can be indirectly transferred from the first cooled effluent to a second quench medium, such as steam, water, or a mixture thereof, within the indirect heat exchanger to produce a second cooled effluent and a heated second quench medium. The second quenched effluent can be at a temperature of about 350 °C to 450 °C. In certain embodiments, the second quenched effluent can be contacted with a third quench medium (such as quench oil separated from the pyrolysis effluent in a downstream processing stage) to produce a third quenched effluent. In certain other embodiments, heat can be indirectly transferred from the second quenched effluent to a third quench medium, such as steam and / or water, to produce a third quenched effluent. The third quenched effluent can be at a temperature of 250 °C to 350 °C. From the third quenched effluent, an overhead stream and a bottoms stream can be obtained. The overhead stream can include ethylene, propylene, and quench oil. In certain embodiments, a first portion of the bottoms stream containing tar can be recycled as the first quench medium. In certain other embodiments, a second portion of the bottoms stream containing tar can be hydrotreated to produce a hydrotreated product from which a hydrotreated bottoms stream can be obtained, and a first portion of the hydrotreated bottoms stream can also be recycled and form part of the first quench medium.

[0062] Bottoms stream of the hydrotreating column

[0063] A second portion of the bottoms stream may be subjected to hydrotreating conditions sufficient to produce a hydrotreated product from which the bottoms stream of the hydrotreating column can be obtained. In certain embodiments, the hydrotreating conditions may be or may include a solvent-assisted tar conversion (“SATC”) process. The hydrotreating conditions may be sufficient to convert at least a portion of the tar in the first portion of the bottoms stream into a lighter product similar to fuel oil. In certain embodiments, further upgrading of the tar may be required to increase the content of compounds having a standard boiling point within the distillate range. The solvent-assisted tar conversion process can be effectively used to sharply reduce the viscosity from up to about 500,000 cSt to about 15 cSt at 50 °C, with a sulfur conversion rate exceeding 90%. The main types of reactions in the solvent-assisted tar conversion process may include, but are not limited to, hydrocracking, hydrodesulfurization, hydrodenitrogenation, thermal cracking, hydrogenation, oligomerization, or any combination thereof.

[0064] In certain embodiments, the solvent-assisted tar conversion process may include a multi-stage hydrocarbon conversion process, which may include, but is not limited to, optionally thermally soaking the second portion of the bottoms stream and hydrotreating the second portion of the bottoms stream in a first hydrotreating zone by contacting the second portion of the bottoms stream with at least one hydrotreating catalyst in the presence of molecular hydrogen and an optional application fluid under catalytic hydrotreating conditions to convert at least a portion of the bottoms stream into a hydrotreated product. In one or more separation stages, an overhead stream containing at least 1 wt% of the hydrotreated product, an intermediate distillate stream containing at least 20 wt% of the hydrotreated product and having a boiling point distribution of about 120 °C to about 480 °C measured according to ASTM D7500-15, and a bottoms stream containing at least 20 wt% of the hydrotreated product can be separated from the hydrotreated product. At least a portion of the intermediate distillate stream can be recycled and used as the application fluid in the first hydrotreating zone.

[0065] In certain embodiments, a second portion of the hydrotreated bottoms stream can be hydrotreated in a second hydrotreating zone by contacting the bottoms stream with at least one hydrotreating catalyst in the presence of molecular hydrogen under catalytic hydrotreating conditions to hydrotreat at least a portion of the second portion of the hydrotreated bottoms stream to a second hydrotreated product. In an alternative example, all of the first portion of the bottoms stream can be hydrotreated in both a first hydrotreating stage and a second hydrotreating stage, and a hydrotreated overhead distillate, a hydrotreated middle distillate, and a hydrotreated bottoms stream can be separated therefrom. The multistage configuration provides a second stage (or last stage if more than two hydrotreating stages are used) hydrotreated product having a sulfur content of 1.5 wt% or less, such as 1 wt% or less or 0.5 wt% or less, based on the total weight of the second hydrotreated product.

[0066] In certain embodiments, the first hydrotreating stage can include a first set of hydrotreating conditions. In certain embodiments, a second portion of the bottoms stream can be hydrotreated at a temperature of 400 °C or lower, a weight hourly space velocity (WHSV) of at least 0.3 h -1 -1 based on the weight of the second portion of the bottoms stream undergoing the first set of hydrotreating conditions, a total pressure of at least 6 MPa, and in the presence of molecular hydrogen supplied at a rate of less than 534 standard cubic meters per cubic meter of the second portion of the bottoms stream.

[0067] In certain embodiments, a portion of the hydrotreated bottoms stream separated from the first hydrotreated product or the first hydrotreated product can be subjected to a second set of hydrotreating conditions. In certain embodiments, the second set of hydrotreating conditions can include a temperature of at least 200 °C, a weight hourly space velocity (WHSV) of at least 0.3 h -1 -1 based on the weight of the first hydrotreated product or the hydrotreated bottoms stream separated from the first hydrotreated product undergoing the second hydrotreating, a total pressure of at least 6 MPa, and in the presence of molecular hydrogen supplied at a rate of at least 534 standard cubic meters per cubic meter of the first hydrotreated product or the hydrotreated bottoms stream separated from the first hydrotreated product undergoing tar hydrotreating to hydrotreat the first hydrotreated product or the hydrotreated bottoms stream separated from the first hydrotreated product. In certain embodiments, the WHSV experienced by the first hydrotreated product or the hydrotreated bottoms stream separated from the first hydrotreated product can be less than the WHSV experienced by the first portion of the bottoms stream.

[0068] In certain embodiments, a first portion of the first hydrotreating bottoms stream and / or a first portion of the second hydrotreating bottoms stream can be used to form part of a first quench medium. Illustrative methods and systems for hydrotreating a second portion of a bottoms stream containing tar can include those disclosed in U.S. Patent Nos. 9,090,836; 9,637,694; and 9,777,227; and International Patent Application Publication No. WO 2018 / 111574.

[0069] Pyrolysis of a hydrocarbon feed

[0070] A hydrocarbon feed, such as a gaseous hydrocarbon feed obtained from a separation zone, can undergo any one of a number of pyrolysis processes to produce a pyrolysis effluent. In certain embodiments, the pyrolysis effluent can be prepared by steam cracking the hydrocarbon feed; contacting the hydrocarbon feed with a plurality of heated particles having a temperature high enough to pyrolyze at least a portion of the hydrocarbon feed; subjecting the hydrocarbon feed to a coking process; or any combination thereof. Pyrolysis methods for pyrolyzing a hydrocarbon feed are well known and understood by those skilled in the art.

[0071] In certain embodiments, steam cracking can be carried out in at least one steam cracker furnace including one or more radiant sections and one or more convection sections. Combustion heaters (such as burners) are located in the radiant section, and flue gas from the combustion carried out with the combustion heaters travels from the radiant section, through the convection section, and then away from the flue gas outlet of the steam cracker furnace. The hydrocarbon feed can be preheated by indirect exposure to the flue gas in the convection section. The preheated hydrocarbon feed can be combined with steam to produce a steam cracker feed. The steam cracker feed can undergo additional preheating in the convection section. The preheated steam cracker feed can be transferred to the radiant section, where the steam cracker feed can be indirectly exposed to the combustion carried out by the burners.

[0072] Based on the total weight of the hydrocarbon feed and steam, the steam cracker feed can contain steam in an amount of 10 wt% to 90 wt%, with the remainder containing the hydrocarbon feed (or consisting essentially of the hydrocarbon feed, or consisting of the hydrocarbon feed). In certain embodiments, the weight ratio of steam to hydrocarbon feed can be in the ratio of 0.1:1 to 1:1, such as 0.2:1 to 0.6:1.

[0073] The steam cracking conditions can include, for example, exposing a mixture of a hydrocarbon feed and steam to a temperature of at least 400 °C (measured at the pyrolysis effluent outlet in the radiant section), for example, at a temperature of 400 °C to 900 °C and a pressure of at least 0.1 bar, with a steam cracking residence time of 0.01 seconds to about 5.0 seconds. In certain embodiments, the mixture of the hydrocarbon feed and steam can be exposed to a temperature sufficient to produce a pyrolysis effluent having a temperature of at least 750 °C, at least 775 °C, at least 800 °C, or at least 825 °C to 850 °C, 875 °C, or 900 °C. In certain other embodiments, the mixture of the hydrocarbon feed and steam can be exposed to a temperature sufficient to produce a pyrolysis effluent having a temperature of at least 760 °C, at least 800 °C, at least 850 °C, or at least 900 °C to 950 °C, 1,000 °C, or 1,100 °C.

[0074] In certain embodiments, the steam cracking process can further include a separation zone, such as a K drum, which can separate the heated hydrocarbon feed into a liquid-phase hydrocarbon stream and a gas-phase hydrocarbon stream, and subject the gas-phase hydrocarbon stream to pyrolysis conditions sufficient to produce a pyrolysis effluent. It has also been found that a first quenching medium comprising a first portion of the bottoms stream (which comprises a first portion of the tar and / or a mixture of the first portion of the bottoms stream and the first portion of the hydrotreated bottoms stream) can allow the separation zone to operate at an elevated fractionation point temperature, which can enable a reduced hydrocarbon feed rate while still producing the same amount of the desired final products, such as ethylene and / or propylene. Thus, the quenching medium can convert an increased amount of a given hydrocarbon feed into valuable products, such as ethylene and propylene. In certain embodiments, the amount of the hydrocarbon feed (e.g., Arabian Light) can be increased from 65 wt% in a conventional steam cracking process to at least 68 wt%, at least 70 wt%, at least 71 wt%, at least 73 wt%, at least 75 wt%, or at least 77 wt%. In certain embodiments, the separation zone in the steam cracking pyrolysis process can operate at a fractionation point temperature of at least 350 °C, at least 400 °C, at least 450 °C, at least 475 °C, at least 500 °C, at least 515 °C, at least 530 °C, or at least 550 °C. In certain embodiments, suitable steam cracking processes can include those described in U.S. Patent Nos. 6,419,885; 6,632,351; 7,090,765; 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; 7,488,459; 7,578,929; and 7,820,035; 7,993,435; 9,637,694; and 9,777,227; and U.S. Patent Application Publication Nos. 2015 / 0315494.

[0075] In certain other embodiments, the pyrolysis effluent can be produced by contacting a hydrocarbon-containing feed with a plurality of heated particles having a temperature high enough such that at least a portion of the hydrocarbon-containing feed is capable of pyrolyzing. In certain embodiments, the hydrocarbon-containing feed can be heated, e.g., via indirect heat exchange with a heating medium, to a temperature of 100 °C, 150 °C, or 200 °C to 300 °C, 350 °C or 400 °C, e.g., 250 °C to 300 °C, before being fed into the pyrolysis zone. A plurality of fluidized particles can also be introduced, supplied, or otherwise fed into the pyrolysis zone. When fed into the pyrolysis zone, the plurality of fluidized particles can have a first temperature. The first temperature can be high enough such that at least a portion of the hydrocarbon-containing feed is capable of pyrolyzing when contacting the particles within the pyrolysis zone. The pyrolysis effluent can be recovered from the pyrolysis zone, and the particles can be separated therefrom, e.g., via a cyclone separator, and the pyrolysis effluent can be contacted with a first quenching medium to produce a first quenched effluent.

[0076] In certain other embodiments, the plurality of fluidized particles can include oxides of transition metal elements capable of oxidizing molecular hydrogen (H 2 ) at the first temperature. In this embodiment, contacting at least a portion of the hydrocarbon-containing feed with the particles in the pyrolysis reaction zone to effect pyrolysis of at least a portion of the hydrocarbon-containing feed can produce a pyrolysis effluent that can include olefins, hydrogen, and particles, wherein at least a portion of the transition metal elements in the particles of the pyrolysis effluent are in a reduced state compared to the transition metal elements in the particles fed into the pyrolysis reaction zone. The particles can be separated from the pyrolysis effluent, heated and oxidized in a combustion zone such that at least a portion of the transition metal elements in the particles are oxidized to a higher oxidation state compared to the transition metal elements in the particles of the pyrolysis effluent, and recycled to the pyrolysis zone. Suitable pyrolysis methods for pyrolyzing a hydrocarbon-containing feed using heated particles can include those described in U.S. Patent Nos. 3,163,496; 4,323,446; 4,828,681; 5,952,539; 6,179,993; and 8,361,311; and U.S. Patent Application Publication No. 2012 / 012581.

[0077] The coking process can generally be classified as either delayed coking or fluid coking. Fluid coking is a petroleum refining process in which a hydrocarbon feedstock is converted into lighter, more useful products by thermal decomposition (coking) at elevated reaction temperatures (typically from about 480 °C to 590 °C, and in most cases 500 °C to 550 °C). Fluid coking can be carried out in a unit having a large reactor containing hot coke particles that are maintained in a fluidized condition at the desired reaction temperature, where steam is injected at the bottom of the vessel, and where the average direction of movement of the coke particles is downward through the bed. The hydrocarbon feedstock can be heated to a pumpable temperature, typically in the range of 350 °C to 400 °C, mixed with atomizing steam, and fed through a plurality of feed nozzles disposed at several successive levels in the reactor. Steam can be injected into the stripping section at the bottom of the reactor and can pass upward through the coke particles, which descend through the dense phase of the fluidized bed in the reactor body portion above the stripping section. A portion of the feed liquid coats the coke particles in the fluidized bed and subsequently cracks into a solid coke layer and lighter products that are evolved as gases or vaporized liquids. The reactor pressure can be relatively low to facilitate the evaporation of hydrocarbon vapors, which pass upward from the dense phase of the fluidized bed in the coking zone into the dilute phase and into a cyclone separator at the top of the coking zone, where most of the entrained solids are separated from the gas phase by centrifugal force in one or more cyclone separators and return to the dense fluidized bed by gravity through dip tubes in the cyclone separators. The mixture of steam and hydrocarbon vapors (pyrolysis effluent) from the reactor is then discharged from the cyclone separator gas outlet into a scrubber section in a plenum chamber located above the coking zone and separated therefrom by a baffle. It can be quenched in the scrubber section by contact with a first quenching medium descending on a runner. A pump circulation loop can circulate the condensed liquid to an external cooler and back to the top shed row of the scrubber section to provide cooling of the quenching medium and condensation of the heaviest fractions of the liquid product. This heavy fraction is typically recycled to extinction by feeding back into the coking zone in the reactor.

[0078] The coke particles formed in the coking zone pass downward through the reactor and leave the bottom of the reactor vessel through a stripper section, where they are exposed to steam to remove occluded hydrocarbons. The solid coke from the reactor (composed mainly of carbon with lesser amounts of hydrogen, sulfur, nitrogen, and trace amounts of vanadium, nickel, iron, and other elements derived from the feedstock) passes through the stripper and out of the reactor vessel to a burner or heater, where it is partially burned with air in a fluidized bed to raise its temperature from about 480 °C to 700 °C to supply the heat required for the endothermic coking reaction. After that, a portion of the hot coke particles is recycled to the fluidized bed reaction zone to transfer heat to the reactor and act as nuclei for coke formation. The balance is withdrawn as a coke product. The net coke yield is only about 65% of the coke yield produced by delayed coking.

[0079] Flexicoking, developed by Exxon Research and Engineering Company TM is a variation of the fluid coking process that operates in a unit including a reactor and a heater, but also includes a gasifier for gasifying the coke product by reaction with an air / steam mixture to form a low heat value fuel gas. The coke stream flows from the heater to the gasifier where, by adding steam and air in a fluidized bed in an oxygen-deficient environment, all of the coke stream except for a small fraction is gasified to a low BTU gas (~120 BTU / standard cubic foot) to form a fuel gas containing carbon monoxide and hydrogen. In a conventional Flexicoking TM configuration, the fuel gas product containing entrained coke particles from the gasifier is sent back to the heater to provide most of the heat required for thermal cracking in the reactor while balancing the reactor heat demand provided by combustion in the heater. A small amount of net coke (about 1% of the feed) is removed from the heater to purge metals and ash from the system. The liquid yields and properties are comparable to those from fluid coking. The fuel gas product is removed from the heater after separation in an internal cyclone separator that returns the coke particles through its dip tube.

[0080] Flexicoking TM is described in patents of Exxon Research and Engineering Company, including for example U.S. Patent Nos. 3,661,543; 3,759,676; 3,816,084; 3,702,516; and 4,269,696. A variation is described in U.S. Patent No. 4,213,848 where the heat demand in the coking zone of the reactor is met by introducing a light hydrocarbon stream from a product fractionator rather than a hot coke particle stream from the heater. Another variation is described in U.S. Patent No. 5,472,596 which uses a light paraffin stream injected into the hot coke return line to produce olefins. Early work proposed units with a stacked configuration, but later units have migrated to a side-by-side arrangement. In certain embodiments, additional coking processes may include but are not limited to the coking processes described in U.S. Patent Nos. 6,860,985; 7,914,668; 8,101,066; 8,147,676; 8,496,805; 9,139,781; 9,670,417; 10,400,177; and 10,421,915.

[0081] Figure 1Depicts an illustrative system 100 according to one or more embodiments, for converting a hydrocarbon feed in line 101 by pyrolysis and quenching the pyrolysis effluent in line 125 via a first quench configuration. System 100 may include, but is not limited to, one or more pyrolysis reactors, such as steam cracker 110, one or more separation sections (four shown) 120, 140, 150, and 180, one or more pre-quench sections 130, one or more heat exchange sections (two shown) 135 and 145, and one or more hydrotreating sections 170.

[0082] In certain embodiments, the hydrocarbon feed in line 101 and steam via line 102 may be mixed, blended, combined, or otherwise contacted to produce a mixture via line 103, which may be heated within the convective section 104 of the pyrolysis reactor 110 to produce a heated mixture via line 106. In certain embodiments, the hydrocarbon feed in line 101 may be heated within the convective section 104 to produce a heated hydrocarbon feed, and the steam in line 102 may be mixed, blended, combined, or otherwise contacted with the pre-heated hydrocarbon feed to produce a mixture thereof. In certain embodiments, based on the total weight of the hydrocarbon feed and water and / or steam, the mixture in line 103 may include from about 10 wt% to about 95 wt% water and / or steam. In certain embodiments, the heated mixture in line 106 may be at a temperature of 200 °C to 585 °C. The heated mixture via line 106 may be introduced into the first separation section 120. In certain embodiments, the heated mixture in line 106 may be prepared as disclosed in U.S. Patent Application Publication No. 2015 / 0315494.

[0083] A vapor stream or “first vapor stream” via line 121 and a liquid stream or “first liquid stream” via line 123 can be obtained from the first separation section 120. In certain embodiments, the first separation section 120 can operate at a fractionation point temperature of at least 350 °C, at least 400 °C, at least 450 °C, at least 475 °C, at least 500 °C, at least 515 °C, at least 530 °C, or at least 550 °C. In certain embodiments, based on the total weight of the hydrocarbon feed, the vapor stream can include at least 67 wt%, at least 70 wt%, at least 73 wt%, at least 75 wt%, at least 77 wt%, at least 80 wt%, at least 83 wt%, at least 85 wt%, at least 87 wt%, or at least 90 wt% of the total amount of hydrocarbons in the hydrocarbon feed in line 101. In certain embodiments, the first separation section 120 can be or can include the separators and / or other equipment disclosed in U.S. Patent Nos. 7,138,047; 7,090,765; 7,097,758; 7,820,035; 7,311,746; 7,220,887; 7,244,871; 7,247,765; 7,351,872; 7,297,833; 7,488,459; 7,312,371; 6,632,351; 7,578,929; and 7,235,705.

[0084] The first vapor stream in line 121 can be heated to a temperature of at least 400 °C, such as a temperature of about 425 °C to about 825 °C, in the convection section 104, and the heated mixture via line 124 can be introduced into the radiant section 108 of the steam cracker 110 to produce a pyrolysis effluent via line 125. In certain embodiments, additional water and / or steam can be mixed, blended, combined, or otherwise contacted with the first vapor stream in line 121 before introducing the vapor stream into the radiant section 108 of the steam cracker 110. The pyrolysis effluent in line 125 can be at a temperature of at least 750 °C, such as 775 °C to 1,100 °C. In certain embodiments, the first vapor stream in line 121 can undergo steam cracking according to the methods and systems disclosed in U.S. Patent Nos. 6,419,885; 7,993,435; 9,637,694; and 9,777,227; and WO Publication No. WO 2018 / 111574.

[0085] The pyrolysis effluent in line 125 can be mixed, blended, combined, or otherwise contacted with the quench medium or first quench medium in line 161 to produce a cooled or first quenched effluent in line 131. For example, the pyrolysis effluent in line 125 can be contacted with the quench medium in line 161 within the pre-quench section 130 and can obtain a pre-cooled or first quenched effluent via line 131 therefrom. In certain embodiments, when initially contacted with the quench medium in line 161, the pyrolysis effluent in line 125 can be at a temperature of at least 750 °C, at least 775 °C, or at least 800 °C to 815 °C, 825 °C, or 1,100 °C. In certain embodiments, the first quenched effluent in line 131 can be at a temperature of 450 °C, 475 °C, or 500 °C to 525 °C, 550 °C, or 575 °C. The pyrolysis effluent in line 125 can be contacted with the first quench medium in line 161 within 100 milliseconds, 150 milliseconds, or 200 milliseconds to 300 milliseconds, 500 milliseconds, or 800 milliseconds, such as within 100 milliseconds to 200 milliseconds, after leaving the pyrolysis reactor 110 to produce a pre-quenched effluent in line 131. In some embodiments, the pre-quench section 130 can be or can include a quench header, such as those disclosed in U.S. Patent Nos. 7,780,843; and 8,177,200. In certain embodiments, the weight ratio of the first quench medium to the pyrolysis effluent in the first quenched effluent in line 131 can be from about 1:1, 1.3:1, 1.5:1, or 1.7:1 to 2:1, 2.5:1, 3:1, or 3.5:1.

[0086] As described above, the first quench medium in line 161 can provide several surprising and unexpected benefits. For example, at least 3 wt%, such as 5 wt% to 7 wt%, or 10 wt% of the quench medium can remain in the liquid phase and can flow along the inner surfaces of conduits, heat exchangers, etc. to remove coke that can deposit thereon, thereby significantly reducing or preventing fouling in the equipment through which the pyrolysis effluent or its fractions flow and / or in the equipment in which the pyrolysis effluent or its fractions flow through. The quench medium in line 161 can also allow for longer heat exchangers, such as a transfer line exchanger having an extended length compared to a conventional transfer line exchanger, which can allow for further quenching of the pyrolysis effluent and recovery of additional heat compared to conventional systems using quench oil or other conventional quench media. The quench medium in line 161 can also allow the separation section 120 to operate at an elevated fractionation point temperature, which can significantly increase the amount of hydrocarbon feed that can be introduced into the steam cracker 110 via the gas-phase stream in line 121 in line 101.

[0087] The first quenched effluent via line 131 can be introduced into the heat exchange section 135. As shown, the first quenched effluent via line 131 can be introduced into an indirect heat exchanger, such as a transfer line exchanger 135. Within the indirect heat exchanger 135, heat can be indirectly transferred from the first quenched effluent to a second quenching medium, such as water, steam, or a mixture thereof, which is introduced into the indirect heat exchange section 135 via line 134 to produce a second quenched effluent via line 137 and a heated second quenching medium via line 138.

[0088] The size of the indirect heat exchange section 135 can be such that sufficient heat can be transferred from the first quenched effluent to produce a second quenched effluent having a temperature of 450 °C or lower in line 137. For example, the second quenched effluent in line 137 can be at a temperature of 350 °C, 360 °C, or 370 °C to 400 °C, 425 °C, or 450 °C. In certain embodiments, when producing about 1,200 KTA of ethylene from a hydrocarbon feed, the heat transferred from the first quenched effluent to the second quenching medium can be sufficient to generate at least 150 MW, at least 175 MW, at least 200 MW, at least 225 MW, or at least 240 MW of power via one or more turbines while quenching the first quenched effluent to a temperature of 350 °C to 450 °C. It should be understood that the amount of power that can be generated from the heated second quenching medium in line 138 can be reduced or increased based on the amount of hydrocarbon feed being processed. However, the amount of power that can be generated by the second quenching medium in line 138 can be significantly greater than the heated second quenching medium in a conventional steam cracking process.

[0089] In certain embodiments, when the heat exchange section 135 includes a transfer line exchanger, the transfer line exchanger can have a significantly longer length than a conventional transfer line exchanger. In certain embodiments, the length of the transfer line exchanger, i.e., the length of the flow path through which the first quenched effluent passes through the transfer line exchanger, can be at least 10 m, at least 12 m, at least 14 m, at least 16 m, or at least 18 m. In contrast, a conventional transfer line exchanger typically has a length of only 10 m to 11.7 m.

[0090] The second quenched effluent in line 137 and a third quenching medium (such as quenching oil) via line 158 can be mixed, blended, or otherwise combined to produce a third quenched effluent via line 139. The third quenched effluent in line 139 can have a temperature of 250 °C to 350 °C, such as 300 °C. In certain embodiments, the weight ratio of the third quenching medium to the second quenched effluent in the third quenched effluent in line 139 can be 0.5:1, 0.71, or 1:1 to 1.4:1, 1.7:1, or 2:1.

[0091] The third quenched effluent via line 139 can be introduced into a second separation section, such as a gas-liquid separator 140. A bottoms stream or tar product via line 141 and an overhead stream or vapor stream via line 142 can be withdrawn from or otherwise obtained from the second separation section 140. The overhead distillate via line 142 can be introduced into a third heat exchange section, such as one or more indirect heat exchangers 145, to produce a cooled overhead distillate, which can be withdrawn from or otherwise obtained from the third heat exchange section 145 via line 146. In certain embodiments, the cooled overhead distillate can be at a temperature of 150 °C, 165 °C, 195 °C or 220 °C to 230 °C, 250 °C, 270 °C, 285 °C, 300 °C, 315 °C, 325 °C, 335 °C or 350 °C.

[0092] The cooled overhead distillate via line 147 can be introduced into a fourth separation section, such as a gas-liquid separator, such as a primary fractionator 150. A variety of products can be separated from the cooled overhead distillate and withdrawn from or otherwise obtained from the fourth separation section 150. Illustrative products that can be separated from and withdrawn from or otherwise obtained from the cooled overhead distillate in line 147 in the fourth separation section 190 can include, but are not limited to, quenching oil via line 151, gas oil via line 152, naphtha via line 153, and overhead distillate via line 154. The overhead distillate can be introduced via line 154 into a fifth separation section, such as a cooling equipment set (not shown), and various light products, such as molecular hydrogen, ethylene, and propylene, can be separated therefrom. Other products can include, but are not limited to, methane, ethane, propane, butane, etc. As described above, in certain embodiments, at least a portion of the quenching oil in line 151 can be combined with the second quenched effluent in line 137 via line 158 to produce the third quenched effluent in line 139. In certain embodiments, at least a portion of the quenching oil in line 151 can be removed from the system 100 via line 156.

[0093] Returning to the bottoms stream in line 141, a first portion of the bottoms stream in line 141 can be introduced as a first quenching medium via line 161 into the quench manifold 130 and can contact the pyrolysis effluent therein to produce a first quenched effluent via line 131. In certain embodiments, a second portion of the bottoms stream in line 141 can be introduced via line 162, and molecular hydrogen can be introduced into the hydrotreating section 170 via line 163. The hydrotreated product via line 175 can be withdrawn from or otherwise obtained from the hydrotreating section 170. The second portion of the bottoms stream can undergo the hydrotreating conditions discussed above in the hydrotreating section 170 to produce a hydrotreated product via line 175.

[0094] The hydrotreated product via line 175 can be introduced into a fourth separation section, such as a gas-liquid separator 180. In certain embodiments, a hydrotreated column bottoms stream via line 181, an intermediate fraction solvent via line 182, and an overhead distillate (such as molecular hydrogen) via line 183 can be withdrawn from or otherwise obtained from the fourth separation section 180. In certain embodiments, at least a portion of the intermediate fraction solvent via line 182 can be recycled as the application fluid as described above to the hydrotreating unit 170. In certain embodiments, a first portion of the hydrotreated column bottoms stream in line 181 can be introduced via line 186 and mixed with the first portion of the column bottoms stream in line 161 to produce the first quench medium. In certain embodiments, a second portion of the hydrotreated column bottoms stream in line 181 can be removed from the system 100 and / or introduced via line 188 into one or more upgrading sections, such as a second hydrotreating section.

[0095] In certain embodiments, at least a portion of the column bottoms stream in line 123 can also be introduced into the hydrotreating section 170 together with the second portion of the column bottoms stream in line 162 to produce the hydrotreated product in line 175. In certain embodiments, at least a portion of the column bottoms stream in line 123 can be removed from the system 100, via one or more additional process upgrades, or a combination thereof.

[0096] Figure 2 Another illustrative system 200 according to the one or more embodiments is depicted for converting a hydrocarbon feed 101 by pyrolysis to produce a pyrolysis effluent 125 and quenching the pyrolysis effluent via a second quench configuration. System 200 can be similar to system 100, but can include the second quench configuration as shown. More particularly, the pyrolysis effluent via line 125 and the first quench medium via line 161 can be directly introduced into the inlet of a first indirect heat exchanger (such as a first transfer line exchanger), and the first quenched effluent via line 231 can be withdrawn from or otherwise obtained therefrom. Although not shown, it should be understood that the pyrolysis effluent via line 125 and the first quench medium via line 161 can be introduced into the quench header 131 as described above. The first quenched effluent via line 231 can be introduced into a second indirect heat exchange section, such as a second transfer line exchanger 235, and the second quenched effluent via line 237 can be withdrawn from or otherwise obtained therefrom. Heat can be indirectly transferred from the first quenched effluent to another quench medium introduced via line 234 to produce another heated quench medium via line 238. Figure 1 The pyrolysis effluent via line 125 and the first quench medium via line 161 can be introduced into the quench header 131 as described above. The first quenched effluent via line 231 can be introduced into a second indirect heat exchange section, such as a second transfer line exchanger 235, and the second quenched effluent via line 237 can be withdrawn from or otherwise obtained therefrom. Heat can be indirectly transferred from the first quenched effluent to another quench medium introduced via line 234 to produce another heated quench medium via line 238.

[0097] In certain embodiments, the first heat exchange section 135 and the second heat exchange section 235 can be conventional transfer line heat exchangers. The mixture of the pyrolysis effluent and the first quench medium can continuously flow through the first and second heat exchange sections 135, 235 via line 237 to produce a second quenched effluent. As shown, the mixture of the pyrolysis effluent and the first quench medium can flow through the first heat exchange section 135 in an upward direction and can flow through the second heat exchange section 235 in a downward direction. In certain other embodiments, the mixture of the pyrolysis effluent and the first quench medium can flow through the first heat exchange section 135 in a downward direction and can flow through the second heat exchange section 235 in an upward direction. In certain other embodiments, the mixture of the pyrolysis effluent and the first quench medium can flow through the first and second heat exchange sections in an upward or downward direction. The second quenched effluent in line 237 can be further processed as referenced Figure 1 as described.

[0098] Figure 3 Depicted is another illustrative system 300 according to one or more embodiments, which is configured to convert a hydrocarbon feed in line 101 by pyrolysis to produce a pyrolysis effluent in line 125 and quench the pyrolysis effluent via a third quench configuration. System 300 can be similar to system 100, but can include the third quench configuration as shown. More specifically, instead of contacting the second quenched effluent in line 137 with quench oil in line 158, the second quenched effluent via line 137 can be introduced into an indirect heat exchange section 310 to produce a third quenched effluent via line 339. The third quenched effluent in line 339 can be further processed as referenced Figure 1 as described.

[0099] Figure 4 Depicted is another illustrative system 400 according to one or more embodiments, which is configured to convert a hydrocarbon feed in line 101 by pyrolysis to produce a pyrolysis effluent via line 125 and quench the pyrolysis effluent via a fourth quench configuration. System 400 can be similar to system 100, but can include the fourth quench configuration as shown. More specifically, the first heat exchange section 135 can be oriented such that the first quenched effluent introduced therein via line 131 flows through the first heat exchange section 135 in a downward direction. System 300 can also include the indirect heat exchange section 310 referenced above Figure 3 as described, which can cool the second quenched effluent in line 137 to produce a third quenched effluent via line 439. However, in certain other embodiments, the via Figure 1The third quenching medium of the pipeline 158 described in [reference] contacts the second quenched effluent to generate a third quenched effluent via pipeline 139. The third quenched effluent in pipeline 439 or 139 can be further processed as described above with reference to Figure 1 as described.

[0100] List of embodiments

[0101] The present disclosure may further include the following non-limiting embodiments.

[0102] A1. A method for quenching an effluent, comprising: (I) contacting a pyrolysis effluent with a first quenching medium to produce a first quenched effluent; and (II) obtaining a bottoms stream containing tar and a tops stream containing ethylene and propylene from the first quenched effluent, wherein the first quenching medium comprises a first portion of the bottoms stream, and the first portion of the bottoms stream comprises a first portion of the tar.

[0103] A2. The method of A1, further comprising: (III) hydrotreating a second portion of the bottoms stream containing a second portion of the tar to produce a hydrotreated product; (IV) obtaining a hydrotreated bottoms stream from the hydrotreated product; and (IV) contacting at least a portion of the hydrotreated bottoms stream with the first portion of the bottoms stream to produce the first quenching medium.

[0104] A3. The method of A1 or A2, wherein at least 3 wt% of the first quenching medium remains in the liquid phase when mixed with the pyrolysis effluent.

[0105] A4. The method of any one of A1 - A3, wherein the pyrolysis effluent and the first quenching medium flow through an indirect heat exchanger, and wherein the first quenching medium in the liquid phase flows along the surface of the inner wall of the indirect heat exchanger.

[0106] A5. The method of A4, wherein the indirect heat exchanger comprises a transfer line exchanger.

[0107] A6. The method of A4 or A5, wherein the pyrolysis effluent and the first quenching medium flow through the indirect heat exchanger in a downward direction.

[0108] A7. The method of A4 or A5, wherein the pyrolysis effluent and the first quenching medium flow through the indirect heat exchanger in an upward direction.

[0109] A8. The method of any one of A2 - A7, wherein the first quenching medium comprises from about 10 wt% to about 90 wt% of the hydrotreated bottoms stream, based on the total weight of the hydrotreated bottoms stream and the first portion of the bottoms stream.

[0110] A method of any one of A9.A2 to A8, wherein the first quenching medium comprises from about 40 wt% to about 60 wt% of the hydrotreating bottoms stream, based on the total weight of the hydrotreating bottoms stream and the first portion of the bottoms stream.

[0111] A method of any one of A10.A1 to A9, wherein: the pyrolysis effluent and the first quenching medium are contacted within a quench header or within an inlet of an indirect heat exchanger, the pyrolysis effluent has a temperature of at least 750 °C, at least 3 wt% of the first quenching medium remains in the liquid phase when contacted with the pyrolysis effluent, and at least a portion of the first quenching medium in the liquid phase flows along the surface of the inner wall of the quench header or along the surface of the inner wall of the indirect heat exchanger.

[0112] A method of any one of A11.A1 to A10, wherein step (I) further comprises indirectly transferring heat from the first quenched effluent to a second quenching medium to produce a second quenched effluent and a heated second quenching medium, wherein the bottoms stream is obtained from the second quenched effluent.

[0113] A method of A12.A11, wherein: the pyrolysis effluent has a temperature of at least 750 °C, the first quenched effluent has a temperature of 475 °C to 550 °C, and the second quenched effluent has a temperature of less than 450 °C.

[0114] A method of A13.A11 or A12, wherein the heat transferred to the second quenching medium is sufficient to generate at least 150 MW of power via a turbine.

[0115] A method of any one of A14.A11 to A13, wherein step (I) further comprises contacting the second quenched effluent with a third quenching medium to produce a third quenched effluent, wherein the bottoms stream is obtained from the third quenched effluent.

[0116] A method of A15.A14, wherein: the pyrolysis effluent has a temperature of at least 750 °C, the first quenched effluent has a temperature of 475 °C to 550 °C, the second quenched effluent has a temperature of 350 °C to 450 °C, and the third quenched effluent has a temperature of 250 °C to 350 °C.

[0117] A method of A16.A15, wherein the top stream further comprises quench oil, wherein step (II) further comprises obtaining a process gas stream comprising the ethylene and the propylene and a quench oil stream comprising the quench oil, and wherein the third quenching medium comprises at least a portion of the quench oil stream.

[0118] A method for any one of A17.A2 to A16, wherein the hydrotreating in step (III) comprises: hydrotreating the second portion of the bottoms stream in a first hydrotreating zone as follows: contacting the second portion of the bottoms stream with at least one first hydrotreating catalyst and molecular hydrogen under first catalytic hydrotreating conditions to convert the second portion of the bottoms stream into a hydrotreated product; obtaining from the first hydrotreated product: (i) a hydrotreated overhead stream comprising at least 1 wt% of the first hydrotreated product; (ii) a hydrotreated middle distillate stream comprising at least 20 wt% of the first hydrotreated product; and (iii) a hydrotreated bottoms stream, wherein the hydrotreated bottoms stream comprises at least 20 wt% of the first hydrotreated product, and wherein a first portion of the hydrotreated bottoms stream is contacted with the first portion of the bottoms stream to produce the first quench medium.

[0119] The method of A18.A17, further comprising hydrotreating the second portion of the hydrotreated bottoms stream in a second hydrotreating zone as follows: contacting the second portion of the hydrotreated bottoms stream with at least one second hydrotreating catalyst in the presence of molecular hydrogen under second catalytic hydrotreating conditions to convert at least a portion of the second portion of the hydrotreated bottoms stream into a second hydrotreated product, wherein the second hydrotreated product comprises less than 5,000 wppm of sulfur.

[0120] The method of A19.A17 or A18, wherein the hydrotreated bottoms stream comprises at least 0.5 wt% of available hydrogen, based on the total weight of the hydrotreated bottoms stream.

[0121] The method of A20.A17 to A19, wherein at least 75 wt% of the hydrotreated bottoms stream has a boiling point at atmospheric pressure of at least 350 °C, and at least 25 wt% of the hydrotreated bottoms stream has a boiling point at atmospheric pressure of at least 530 °C.

[0122] The method of A21.A2 to A20, wherein the hydrotreated bottoms stream comprises less than 1.5 wt% of sulfur, and has a density of at least 1 g / cm 3 and an API gravity of less than 5 at 15.6 °C and a 25 / 75 solubility value of 0 wt% to 2 wt%.

[0123] The method of A22.A1 to A21, wherein the first portion of the bottoms stream comprising the first portion of the tar comprises at least 2.5 wt% of sulfur, has a density of at least 1.05 g / cm 3 and an API gravity of less than 0 at 15.6 °C, and a 25 / 75 solubility value of 0.8 wt% to 10 wt%.

[0124] A method of any one of A2 to A22, wherein a first portion of the bottoms stream comprising the tar has a greater density, a greater 25 / 75 solubility value and contains a greater amount of sulfur compared to the hydrotreating bottoms stream.

[0125] A method of any one of A2 to A23, wherein a first portion of the bottoms stream comprising the tar has a greater API gravity at 15.6 °C compared to the API gravity of the hydrotreating bottoms stream at 15.6 °C.

[0126] A method of any one of A1 to A24, wherein the pyrolysis effluent is prepared by: (a) steam cracking a hydrocarbon feedstock, (b) contacting the hydrocarbon feedstock with a plurality of heated particles having a temperature high enough such that at least a portion of the hydrocarbon feedstock can be pyrolyzed; (c) subjecting the hydrocarbon feedstock to a coking process; or (d) a combination thereof.

[0127] A method of any one of A1 to A25, wherein the hydrocarbon feedstock comprises a residual oil.

[0128] A method of any one of A1 to A26, wherein the hydrocarbon feedstock comprises one or more plastic materials.

[0129] A method of any one of A1 to A27, wherein the hydrocarbon feedstock comprises crude oil or a fraction thereof.

[0130] B1. A method for quenching an effluent, comprising: (I) obtaining a gas-phase product and a liquid-phase product from a heated mixture comprising steam and a hydrocarbon feedstock; (II) steam cracking the gas-phase product to produce a pyrolysis effluent; (III) contacting the pyrolysis effluent having a first temperature with a first quenching medium to produce a first quenched effluent having a second temperature; (IV) indirectly transferring heat from the first quenched effluent to a second quenching medium to produce a second quenched effluent having a third temperature and a heated second quenching medium; (V) indirectly transferring heat from the second quenched effluent to a third quenching medium or contacting the second quenched effluent with a third quenching medium to produce a third quenched effluent having a fourth temperature; (VI) obtaining a bottoms stream comprising tar and a tops stream comprising ethylene, propylene and quenching oil from the third quenched effluent; and (VI) recycling a first portion of the bottoms stream comprising tar as the first quenching medium.

[0131] B2. The method of B1, further comprising: (VII) hydrotreating a second portion of the bottoms stream comprising the second portion of the tar to produce a hydrotreating product; and (VIII) recycling a first portion of the hydrotreating product to provide a portion of the first quenching medium.

[0132] A method of B3.B2, wherein a first portion of the bottoms stream and a first portion of the hydrotreated product are contacted with each other to produce a mixture before contacting the pyrolysis effluent.

[0133] A method of B4.B2 or B3, wherein the first quenching medium comprises from about 10 wt% to about 90 wt% of the first portion of the hydrotreated product, based on the total weight of the first portion of the bottoms stream and the first portion of the hydrotreated product.

[0134] A method of any one of B5.B2 to B4, wherein the hydrotreating in step (VII) comprises: hydrotreating a second portion of the bottoms stream in a first hydrotreating zone as follows: contacting the second portion of the bottoms stream with at least one first hydrotreating catalyst and molecular hydrogen under first catalytic hydrotreating conditions to convert the second portion of the bottoms stream into a hydrotreated product; obtaining from the first hydrotreated product: (i) a hydrotreated overhead stream comprising at least 1 wt% of the first hydrotreated product; (ii) a hydrotreated middle distillate stream comprising at least 20 wt% of the first hydrotreated product; and (iii) a hydrotreated bottoms stream, wherein the hydrotreated bottoms stream comprises at least 20 wt% of the first hydrotreated product, and wherein the first portion of the hydrotreated product recycled as the first quenching medium comprises the first portion of the hydrotreated bottoms stream.

[0135] A method of any one of B6.B1 to B5, wherein the heat transferred to the second quenching medium is sufficient to generate at least 150 MW of power via one or more turbines.

[0136] A method of any one of B7.B1 to B6, further comprising: (IX) obtaining a processed gas stream comprising the ethylene and the propylene and a quenching oil stream comprising the quenching oil from the overhead stream, wherein the second quenched effluent is contacted with a third quenching medium to produce a third quenched effluent, and wherein the third quenching medium comprises at least a portion of the quenching oil stream.

[0137] A method of any one of B8.B1 to B7, wherein at least 3 wt% of the first quenching medium remains in the liquid phase when contacted with the pyrolysis effluent.

[0138] A method of B9.B8, wherein in step (IV), the first quenched effluent flows through an indirect heat exchanger to transfer heat therefrom indirectly, and wherein the first quenching medium in the liquid phase flows along the surface of the inner wall of the indirect heat exchanger.

[0139] A method of B10.B9, wherein the indirect heat exchanger comprises a transfer line exchanger.

[0140] A method of B11.B9 or B10, wherein the first quenched effluent flows through the indirect heat exchanger in a downward direction.

[0141] A method of B12.B9 or B10, wherein the first quenched effluent flows through the indirect heat exchanger in an upward direction.

[0142] A method of B13.B2 to any one of B12, wherein the first quenching medium comprises from about 40 wt% to about 60 wt% of the hydrotreated product, based on the total weight of the hydrotreated product and the bottoms stream.

[0143] A method of B14.B1 to any one of B13, wherein the hydrocarbon feed comprises a residual oil.

[0144] A method of B15.B1 to any one of B14, wherein the hydrocarbon feed comprises one or more plastic materials.

[0145] A method of B16.B1 to any one of B15, wherein the hydrocarbon feed comprises crude oil or a fraction thereof.

[0146] A method of B17.B2 to any one of B16, wherein the hydrotreated bottoms stream comprises less than 1.5 wt% sulfur and has a density of at least 1 g / cm 3 and an API gravity of less than 5 at 15.6 °C and a 25 / 75 solubility value of from 0 wt% to 2 wt%.

[0147] A method of B18.B1 to any one of B17, wherein the first portion of the bottoms stream comprising the first portion of the tar comprises at least 2.5 wt% sulfur, has a density of at least 1.05 g / cm 3 and an API gravity of less than 0 at 15.6 °C and a 25 / 75 solubility value of from 0.8 wt% to 10 wt%.

[0148] C1. A system for converting a hydrocarbon-containing feed by pyrolysis, comprising: (i) a first gas-liquid separator adapted to receive a hydrocarbon-containing feed, separate the hydrocarbon-containing feed into a first gaseous hydrocarbon stream and a first liquid hydrocarbon stream, discharge the first gaseous hydrocarbon stream, and discharge the first liquid hydrocarbon stream; (ii) a pyrolysis reactor adapted to receive the first gaseous hydrocarbon stream, heat the first gaseous hydrocarbon stream to effect pyrolysis of at least a portion of the first gaseous hydrocarbon stream, and discharge a pyrolysis effluent stream; (iii) a quench section adapted to receive the pyrolysis effluent stream, quench the pyrolysis effluent stream, and discharge a quenched pyrolysis effluent stream; (iv) a second gas-liquid separator adapted to receive the quenched pyrolysis effluent stream, separate the quenched pyrolysis effluent stream to obtain a second gaseous hydrocarbon stream containing olefins and a second liquid hydrocarbon stream containing tar, discharge the second gaseous hydrocarbon stream, and discharge the second liquid hydrocarbon stream; and (v) a first conduit adapted to convey a first portion of the second liquid hydrocarbon stream containing a first portion of the tar to the quench section such that the first portion of the second liquid hydrocarbon stream contacts the pyrolysis effluent to produce a mixture comprising the first portion of the second liquid hydrocarbon stream and the pyrolysis effluent.

[0149] C2. The system of C1, further comprising: (vi) a hydrotreating unit adapted to receive a second portion of the second liquid hydrocarbon stream containing a second portion of the tar and optionally at least a portion of the first liquid hydrocarbon stream, hydrotreat the second portion of the second liquid hydrocarbon stream and optionally at least a portion of the first liquid hydrocarbon stream under hydrotreating conditions to produce a hydrotreated product, and discharge the hydrotreated product; (vii) a separator adapted to separate a hydrotreating overhead stream containing at least 1 wt% of the hydrotreated product, a hydrotreating middle distillate stream containing at least 20 wt% of the hydrotreated product; and a hydrotreating bottoms stream containing at least 20 wt% of the hydrotreated product; (viii) a second conduit adapted to transfer at least a portion of the hydrotreating bottoms stream from the separator to the quench section such that the hydrotreating bottoms stream contacts the pyrolysis effluent to produce a mixture comprising the first portion of the second liquid hydrocarbon stream, the pyrolysis effluent, and the hydrotreating bottoms stream.

[0150] C3. The system of C2, wherein the first conduit and the second conduit are in fluid communication such that a mixture comprising the first portion of the bottoms stream containing the tar and at least a portion of the hydrotreating bottoms stream contacts before contacting the pyrolysis effluent to produce a mixture comprising the first portion of the second liquid hydrocarbon stream, the pyrolysis effluent, and the hydrotreating bottoms stream.

[0151] A system according to any one of C1 to C3, wherein the quench section includes a transfer line exchanger, and wherein the transfer line exchanger is adapted to transfer heat from the pyrolysis effluent stream to a quench medium, the heat being sufficient to generate at least 150 MW of power via one or more turbines.

[0152] A system according to any one of C1 to C4, wherein the hydrotreating unit is adapted to operate under hydrotreating conditions sufficient to produce a first hydrotreating product, and wherein the first hydrotreating product has a hydrogen available concentration of at least 0.5 wt%, based on the total weight of the hydrotreating product.

[0153] A system according to any one of C1 to C5, wherein the quench section includes an indirect heat exchanger having a flow path therethrough such that a mixture comprising a first portion of the second liquid phase hydrocarbon stream and the pyrolysis effluent or a mixture comprising a first portion of the second liquid phase hydrocarbon stream, the pyrolysis effluent and the hydrotreating bottoms stream flows downwardly through the indirect heat exchanger.

[0154] Various terms have been defined above. If a term used in a claim is not defined above, it should be given the broadest definition as the term is known to those skilled in the relevant art as reflected in at least one printed publication or issued patent. Additionally, all patents, test procedures, and other documents cited in this application are hereby incorporated by reference in their entirety to the extent that this disclosure is consistent therewith and for all jurisdictions that permit such incorporation.

[0155] While the foregoing relates to embodiments of the invention, other and additional embodiments of the invention may be devised without departing from the basic scope thereof, and the scope of the invention is determined by the claims that follow.

Claims

1. A method for quenching the effluent, comprising: (I) contacting a pyrolysis effluent and a first quenching medium to produce a first quenched effluent, wherein the pyrolysis effluent and the first quenching medium flow through an indirect heat exchanger, and wherein the first quenching medium in a liquid phase flows along a surface of an inner wall of the indirect heat exchanger; and (II) obtaining a bottoms stream comprising tar and an overhead stream comprising ethylene and propylene from the first quenched effluent, wherein the first quench medium comprises a first portion of the bottoms stream and the first portion of the bottoms stream comprises a first portion of the tar.

2. The method of claim 1, further comprising: (III) hydroprocessing a second portion of the bottoms stream comprising a second portion of the tar to produce a hydroprocessed product; (IV) obtaining a hydroprocessing tower bottoms stream from the hydroprocessed product; and (IV) contacting at least a portion of the hydroprocessing bottoms stream with a first portion of the bottoms stream to produce the first quench medium.

3. The method of claim 1 or 2, wherein at least 3 weight percent of the first quenching medium remains in the liquid phase when mixed with the pyrolysis effluent.

4. The process of claim 1, wherein the indirect heat exchanger comprises a transfer line exchanger, and wherein the pyrolysis effluent and the first quenching medium flow through the indirect heat exchanger in a downward direction, an upward direction, or both.

5. The process of claim 2, wherein the first quench medium comprises from 10 wt% to 90 wt% of the hydroprocessing bottoms stream, based on the combined weight of the hydroprocessing bottoms stream and the first portion of the bottoms stream.

6. The method of claim 1, wherein: contacting the pyrolysis effluent and the first quenching medium in a quench header or in the inlet of an indirect heat exchanger, The pyrolysis effluent has a temperature of at least 750° C., At least 3 weight percent of the first quenching medium remains in the liquid phase when contacted with the pyrolysis effluent, and At least a portion of the first quenching medium in the liquid phase flows along a surface of an inner wall of the quench header or along a surface of an inner wall of the indirect heat exchanger.

7. The process of claim 1, wherein step (I) further comprises indirectly transferring heat from the first quenched effluent to a second quenching medium to produce a second quenched effluent and a heated second quenching medium, wherein the bottoms stream is obtained from the second quenched effluent.

8. The method of claim 7, wherein: The pyrolysis effluent has a temperature of at least 750° C., The first quenched effluent has a temperature of 475°C to 550°C, and The second quenched effluent has a temperature of less than 450°C.

9. The method of claim 7, wherein the heat transferred to the second quenching medium is sufficient to generate at least 150 MW of power via a turbine.

10. The process of claim 8 or 9, wherein step (I) further comprises contacting the second quenched effluent with a third quenching medium to produce a third quenched effluent, wherein the bottoms stream is obtained from the third quenched effluent.

11. The method of claim 10, wherein: The pyrolysis effluent has a temperature of at least 750° C., The first quenched effluent has a temperature of 475°C to 550°C, The second quenched effluent has a temperature of 350°C to 450°C, and The third quenched effluent has a temperature of 250°C to 350°C.

12. The process of claim 11, wherein the overhead stream further comprises a quench oil, wherein step (II) further comprises obtaining a process gas stream comprising the ethylene and the propylene and a quench oil stream comprising the quench oil, and wherein the third quench medium comprises at least a portion of the quench oil stream.

13. The process of claim 2, wherein the hydrotreating in step (III) comprises: hydroprocessing a second portion of the bottoms stream in a first hydroprocessing zone: contacting the second portion of the bottoms stream with at least one first hydroprocessing catalyst and molecular hydrogen under first catalytic hydroprocessing conditions to convert the second portion of the bottoms stream into a first hydroprocessed product; From the first hydroprocessed product: (i) a hydroprocessing tower overhead stream comprising at least 1 weight percent of the first hydroprocessed product; (ii) a hydrotreated middle distillate stream comprising at least 20 weight percent of said first hydroprocessed product; and (iii) a hydroprocessing bottoms stream, wherein the hydroprocessing bottoms stream comprises at least 20 weight percent of the first hydroprocessed product, wherein a first portion of the hydroprocessing bottoms stream is contacted with a first portion of the bottoms stream to produce the first quench medium.

14. The process of claim 13, wherein the hydroprocessing bottoms stream comprises at least 0.5 wt% supplyable hydrogen, based on the total weight of the hydroprocessing bottoms stream.

15. The process of claim 2 wherein the first portion of the bottoms stream comprising the first portion of the tar comprises at least 2.5 wt% sulfur, having a sulfur content of at least 1.05 g / cm 3 %, an API gravity of less than 0 at 15.6°C, and a 25 / 75 solubility value of 0.8 wt % to 10 wt %, and wherein the hydrotreating tower bottoms stream contains less than 1.5 wt % sulfur, and has a viscosity of at least 1 g / cm 3 A density of 1.50°C, an API gravity of less than 5 at 15.6°C, and a 25 / 75 solubility value of 0 wt % to 2 wt %.

16. The method of claim 1, wherein the pyrolysis effluent is prepared as follows: (a) steam cracking a hydrocarbon-containing feed, (b) contacting a hydrocarbon-containing feed with a plurality of heated particles having a temperature sufficiently high to enable pyrolysis of at least a portion of the hydrocarbon-containing feed; (c) subjecting a hydrocarbon-containing feed to a coking process; (d) combinations thereof.

17. A method for quenching the effluent, comprising: (I) obtaining a vapor product and a liquid product from a heated mixture comprising steam and a hydrocarbon-containing feed; (II) steam cracking the gas phase product to produce a pyrolysis effluent; (III) contacting the pyrolysis effluent having a first temperature with a first quenching medium to produce a first quenched effluent having a second temperature; (IV) indirectly transferring heat from the first quenched effluent to a second quenching medium to produce a second quenched effluent having a third temperature and a heated second quenching medium; (V) indirectly transferring heat from the second quenched effluent to a third quenching medium or contacting the second quenched effluent with a third quenching medium to produce a third quenched effluent having a fourth temperature; (VI) obtaining from the third quenched effluent a bottoms stream comprising tar and an overhead stream comprising ethylene, propylene, and quench oil; and (VII) recycling a first portion of the bottoms stream comprising a first portion of the tar as a first quenching medium.

18. The method of claim 17, further comprising: (VIII) hydroprocessing a second portion of the bottoms stream comprising a second portion of the tar to produce a hydroprocessed product; and (IX) recycling a first portion of the hydroprocessed product to provide a portion of the first quench medium.

19. The process of claim 18, wherein a first portion of the bottoms stream and a first portion of the hydroprocessed product are contacted with one another to produce a mixture prior to contacting the pyrolysis effluent.

20. The process of claim 18 or 19, wherein the first quench medium comprises from 10 wt% to 90 wt% of the first portion of the hydroprocessed product, based on the combined weight of the first portion of the bottoms stream and the first portion of the hydroprocessed product.

21. The method of claim 18, wherein the hydrotreating in step (VIII) comprises: hydroprocessing a second portion of the bottoms stream in a first hydroprocessing zone: contacting the second portion of the bottoms stream with at least one first hydroprocessing catalyst and molecular hydrogen under first catalytic hydroprocessing conditions to convert the second portion of the bottoms stream into a first hydroprocessed product; From the first hydroprocessed product: (i) a hydroprocessing tower overhead stream comprising at least 1 weight percent of the first hydroprocessed product; (ii) a hydrotreated middle distillate stream comprising at least 20 weight percent of said first hydroprocessed product; and (iii) a hydroprocessing bottoms stream, wherein the hydroprocessing bottoms stream comprises at least 20 weight percent of the first hydroprocessed product, wherein a first portion of the hydroprocessed product recycled as the first quench medium comprises a first portion of the hydroprocessing bottoms stream.

22. The method of claim 17, wherein at least 3 weight percent of the first quenching medium remains in the liquid phase when contacted with the pyrolysis effluent.

23. The method of claim 22, wherein in step (IV), the first quenched effluent flows through an indirect heat exchanger to indirectly transfer heat therefrom, and wherein the second quenching medium in a liquid phase flows along the surface of an inner wall of the indirect heat exchanger, and wherein the first quenched effluent flows through the indirect heat exchanger in a downward direction, an upward direction, or both.

24. The process of claim 18, wherein said first quench medium comprises from 40 wt% to 60 wt% of said hydroprocessed product, based on the combined weight of said hydroprocessed product and said bottoms stream.

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