Method and system for fractionating pyrolysis effluent

Abstract

Methods and systems for fractionating a pyrolysis effluent. The effluent may be separated into a first liquid and a first vapor within a flash zone of the primary fractionator. Pyrolysis tar may be recovered from the flash zone. The first vapor may flow into the quench zone and may be contacted with a first quench medium to produce a second liquid and a second vapor. Pyrolysis quench oil may be recovered from the quench zone. A second vapor may flow into the fractionation zone and may be contacted with a second quench medium. Pyrolysis gas oil and process gas may be recovered from the fractionation zone. Heat may be transferred indirectly from the pyrolysis quench oil to the heat transfer medium to produce a cooled pyrolysis quench oil. The first quench medium may include at least a portion of a cooled pyrolysis quench oil.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 354,252, filed on June 22, 2022, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Embodiments disclosed herein generally relate to methods and systems for separating a pyrolysis effluent into multiple products. Background Art

[0004] The pyrolysis effluent produced by pyrolysis processes such as steam cracking includes saturated hydrocarbons that have been converted into higher value products (e.g., light olefins such as ethylene and propylene). The products are usually separated via a fractionator, often referred to as a primary fractionator. In addition to the higher value products, other products such as naphtha, gas oil and quench oil are also recovered via the primary fractionator.

[0005] The processing conditions within the pyrolysis environment produce chemicals that lead to fouling of structures and / or surfaces within conventional primary fractionators and corrosion within associated equipment such as pumps and piping. Conventional primary fractionators also produce products with relatively poor product quality and require high quench oil make-up requirements. These problems limit operations and lead to premature shutdowns, corrosion within pumps, piping and / or quench fittings, reduced product value and reduced marketability, and / or increased costs associated with additional quench oil make-up.

[0006] Therefore, a need exists for improved methods and systems for fractionating pyrolysis effluents. Summary of the invention

[0007] Methods and systems for fractionating pyrolysis effluent are provided. In some embodiments, the method for fractionating pyrolysis effluent may include introducing the pyrolysis effluent into a flash zone located in a fractionator. The pyrolysis effluent may be separated into a first liquid fraction and a first gas fraction in the flash zone. A cracked tar that may contain the first liquid fraction may be recovered from the flash zone. The first gas fraction may flow into a quench zone arranged above the flash zone. The first gas fraction may be contacted with a first quench medium in the quench zone to produce a second liquid fraction and a second gas fraction. A pyrolysis quench oil that may contain at least a portion of the second liquid fraction and the first quench medium may be recovered from the quench zone. The second gas fraction may flow into a fractionation zone arranged above the quench zone. The second gas fraction may be contacted with a second quench medium in the fractionation zone to produce a third liquid fraction and a third gas fraction. A pyrolysis gas oil that may contain the third liquid fraction may be recovered from the fractionation zone. A third gas phase fraction, which may include at least a portion of the second quench medium, and a process gas, which may include ethylene, may be recovered from the fractionation zone. Heat may be indirectly transferred from at least a portion of the pyrolysis quench oil to a heat transfer medium in a heat exchange stage to produce cooled pyrolysis quench oil and heated heat transfer medium. The first quench medium may be or may include at least a portion of the cooled pyrolysis quench oil.

[0008] In some embodiments, the primary fractionator for the pyrolysis system may include a flash zone, which may include a pyrolysis effluent inlet and a pyrolysis tar outlet. The quench zone may be arranged above the flash zone and may include a pyrolysis quench oil inlet and a pyrolysis quench oil outlet. The vapor distribution device may be arranged between the flash zone and the quench zone. The vapor distribution device may be configured to allow vapor to flow out of the flash zone through it and flow into the quench zone. The vapor distribution device may also be configured to collect liquid thereon in the quench zone. The fractionation zone may be arranged above the quench zone and may include a pyrolysis gas oil outlet, a gas phase outlet, and a reflux inlet.

[0009] In some embodiments, a system for producing and processing pyrolysis effluent may include a pyrolysis reactor, which may include a pyrolysis effluent outlet. The system may also include a quenching device, which includes a first inlet, a second inlet and an outlet that are fluidly connected to the pyrolysis effluent outlet. The quenching device may be configured to mix the pyrolysis effluent introduced into the first inlet with the quenching medium introduced into the second inlet to produce a cooled pyrolysis effluent. The system may also include a primary fractionator. The primary fractionator may include a flash zone, a quenching zone, a vapor distribution device and a fractionation zone. The flash zone may include a pyrolysis effluent inlet and a pyrolysis tar outlet. The quenching zone may be arranged above the flash zone and may include a pyrolysis quench oil inlet and a pyrolysis quench oil outlet. The vapor distribution device may be arranged between the flash zone and the quenching zone. The vapor distribution device may be configured to allow vapor to flow out of the flash zone through it and flow into the quenching zone. The vapor distribution device may also be configured to collect liquid thereon in the quenching zone. The fractionation zone may be disposed above the quench zone and may include a pyrolysis gas oil outlet, a vapor phase outlet, and a reflux inlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to be able to understand the above-recorded features of the present invention in detail, the present invention briefly summarized above can be described in more detail with reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only typical embodiments of the present invention and are therefore not to be considered as limiting its scope, as the invention may admit to other equally effective embodiments.

[0011] Figure 1 A schematic diagram depicts an illustrative system for separating multiple products (eg, pyrolysis tar, pyrolysis quench oil, pyrolysis gas oil, and overheads) from a cooled pyrolysis effluent according to one or more embodiments described.

[0012] Figure 2 A schematic diagram depicts an illustrative system for steam cracking a hydrocarbon feed to produce a steam cracker effluent and separating various products therefrom, according to one or more embodiments described. DETAILED DESCRIPTION

[0013] It should be understood that the following disclosure describes several exemplary embodiments for implementing different features, structures and / or functions of the present invention. Exemplary embodiments of components, arrangements and configurations are described below to simplify the present disclosure; however, these exemplary embodiments are provided as examples only and are not intended to limit the scope of the present invention. In addition, the present disclosure may repeat the figure numbers and / or letters in various exemplary embodiments and in the figures provided herein. This repetition is for the purpose of brevity and clarity and does not itself specify the relationship between the configurations discussed in the various exemplary embodiments and / or figures. In addition, without departing from the scope of the present disclosure, the exemplary embodiments shown below may be combined in any combination, that is, any element from one exemplary embodiment may be used in any other exemplary embodiment.

[0014] definition

[0015] As used herein, the indefinite article "a" or "an" means "at least one", unless otherwise specified or the context clearly indicates otherwise. Thus, embodiments using "a separator" include embodiments in which one or two or more separators are used, unless otherwise specified or the context clearly indicates that only one separator is used, and similarly, embodiments using "a separation stage" include embodiments in which one or two or more separation stages are used, unless otherwise specified.

[0016] As used herein, the term "hydrocarbon" means a class of compounds containing hydrogen bonded to carbon. n "Hydrocarbon" means a hydrocarbon having n carbon atoms (one or more) per molecule, wherein n is a positive integer. The term "C n+ "Hydrocarbon" means a hydrocarbon having at least n carbon atoms (one or more) per molecule, where n is a positive integer. The term "C n- "Hydrocarbon" means a hydrocarbon having no more than n carbon atoms (one or more) per molecule, where n is a positive integer. "Hydrocarbon" includes (i) saturated hydrocarbons, (ii) unsaturated hydrocarbons and (iii) mixtures of hydrocarbons, including mixtures of hydrocarbon compounds (saturated and / or unsaturated), including mixtures of hydrocarbon compounds having different values ​​of n.

[0017] The term "unsaturated" or "unsaturated hydrocarbon" means a C-atom containing at least one carbon atom directly bonded to another carbon atom by a double bond or a triple bond. 2+ Hydrocarbon. The term "olefin" means an unsaturated hydrocarbon containing at least one carbon atom directly bonded to another carbon atom by a double bond. In other words, an olefin is a compound containing at least one pair of carbon atoms in which the first and second carbon atoms of the pair are directly connected by a double bond. "Light olefin" means a C 5- Olefins.

[0018] The term "predominantly liquid phase" means a composition of which ≥50 wt% is in liquid phase, such as ≥75 wt%, such as ≥90 wt%. A hydrocarbon feedstock is a predominantly liquid hydrocarbon feedstock when ≥50 wt%, such as ≥75 wt%, such as ≥90 wt%, of the hydrocarbon feedstock is in liquid phase at a temperature of 25°C and an absolute pressure of 1 bar.

[0019] The term "raw" feedstock, e.g., raw hydrocarbon feedstock, means a feedstock in a predominantly liquid phase comprising ≥ 25 wt% crude oil that has not been subjected to prior desalting and / or prior reflux fractionation, e.g., ≥ 50 wt%, such as ≥ 75 wt%, or ≥ 90 wt%.

[0020] The term "crude oil" means a mixture comprising naturally occurring hydrocarbons of geological origin, wherein the mixture (i) comprises ≥ 1 wt% residual oil, e.g., ≥ 5 wt%, such as ≥ 10 wt%, and (ii) has an API gravity index of ≤ 52°, e.g., ≤ 30°, such as ≤ 20°, or ≤ 10°, or < 8°. Crude oils can be classified by API gravity index, e.g., heavy crude oils have an API gravity index in the range of 5° up to (but not including) 22°.

[0021] Normal boiling points and normal boiling point ranges may be measured by gas chromatographic distillation according to the method described in ASTM D-6352-98 or D2887, extended by extrapolation for materials above 700°C. The term "T 50 ” means the temperature, determined according to the boiling point distribution, at which 50% by weight of a particular sample has reached its boiling point. Similarly, “T 90 ”,“T 95 ” and “T 98 " means the temperature at which 90, 95 or 98% by weight of a particular sample has reached its boiling point. The nominal final boiling point means the temperature at which 99.5% by weight of a particular sample has reached its boiling point.

[0022] Certain medium and / or heavy hydrocarbons, such as certain untreated hydrocarbon feedstocks, such as certain crude oils and crude oil mixtures contain one or more of asphaltenes, precursors of asphaltenes and particles. Asphaltenes are described in U.S. Patent No. 5,871,634. ASTM D6560-17 can be used to determine the asphaltene content. Asphaltenes in hydrocarbons can be in a liquid phase (e.g., a mutually soluble liquid phase), and can also be in a solid phase and / or a semi-solid phase (e.g., as a precipitate). Asphaltene and asphaltene precursors are typically present in the residual oil portion of crude oil. "Residual oil" means an oily mixture typically contained in or derived from crude oil, which mixture has a standard boiling point range of ≥566°C. Residual oil may contain "non-volatile components", meaning compositions (organic and / or inorganic) with a standard boiling point range of ≥590°C. Non-volatile components may be further limited to components with a boiling point of about 760°C or higher. The non-volatile components may include coke precursors, which are medium-heavy and / or reactive molecules, such as polycyclic aromatic compounds, which can condense from the gas phase and then form coke under specific steam cracking conditions. Medium and / or heavy hydrocarbons (particularly the residual oil portion thereof) may also contain particulates, meaning solids and / or semisolids in particulate form. The particulates may be organic and / or inorganic, and may include coke, ash, sand, precipitated salts, etc. Although precipitated asphaltenes may be solid or semisolid, it is considered that precipitated asphaltenes belong to the category of asphaltenes, not the category of particulates.

[0023] Hydrocarbon Fractionation

[0024] Figure 1 A schematic diagram of an illustrative system 100 for separating a plurality of products, such as pyrolysis tar via line 133, pyrolysis quench oil via line 135, pyrolysis gas oil via line 137, and overhead via line 139, from a cooled pyrolysis effluent introduced via line 107 according to one or more embodiments is depicted. The system 100 may include a primary fractionator 130. The primary fractionator 130 may include a flash zone 140, which may include a pyrolysis effluent inlet 141 and a pyrolysis tar outlet 143. In some embodiments, the pyrolysis effluent inlet 141 may be in fluid communication with a feed distribution device 142. The feed distribution device 142, if present, may be or may include, but is not limited to, a vapor horn, an annular ring, a V-shaped baffle, a perforated tube distributor, a dual flow tray, or any combination thereof.

[0025] The quench zone 145 may be disposed above the flash zone 140 and may include a pyrolysis quench oil inlet 146 and a pyrolysis quench oil outlet 148. A vapor distribution device 150 may be disposed between the flash zone 140 and the quench zone 145. The vapor distribution device 150 may be configured to allow vapor to flow out of the flash zone 140 through it and into the quench zone 145. In some embodiments, the vapor distribution device 150 may also be configured to collect liquid thereon within the quench zone 145. The liquid collected on the vapor distribution device 150 may be pyrolysis quench oil, which may be recovered therefrom via a line 135 in fluid communication with the pyrolysis quench oil outlet 148. In some embodiments, the vapor distribution device 150 may be a chimney tray, a dual flow tray, a baffle tray, or the like. In other embodiments, one or more internal structures 147 may be arranged within the quench zone 145 and at least one internal structure 147 (e.g., a bottom extraction tower plate) may be configured to collect pyrolysis quench oil thereon, which may be recovered therefrom via a pipeline 135 that is fluidly connected to the pyrolysis quench oil outlet 148.

[0026] The primary fractionator 130 may also include one or more fractionation zones disposed above the quench zone 145, for example, fractionation zones 155 and / or 165, which may include a pyrolysis gas oil outlet 161, a gas phase outlet 166, and a reflux inlet 163. As shown, in some embodiments, the fractionator 130 may include a lower fractionation zone 155, an upper fractionation zone 165, and a pump-circulation zone 160 disposed between the lower fractionation zone 155 and the upper fractionation zone 165. However, it should be understood that the primary fractionator 130 may include only one or two of the lower fractionation zone 155, the pump-circulation zone 160, and the upper fractionation zone 165.

[0027] In some embodiments, one or more of the quenching zone 145, the lower fractionation zone 155, the pump-around zone 160, and the upper fractionation zone 165 may independently include one or more internal structures 147. The internal structure(s) 147 may facilitate gas / liquid separation and / or liquid collection. Illustrative internal structures 147 may include, but are not limited to, trays, grids, packing, or any combination thereof. Illustrative trays may include, but are not limited to, fixed valve trays, jet tab trays, sieve trays, dual flow trays, baffle trays, angle iron trays, draw-off trays, lift trays, shed deck trays, tray trays, annular trays, side-by-side splash trays, or any combination thereof. Suitable fixed valve trays, sieve plate trays, dual flow trays and grid plates may include those disclosed in Henry Z. Kister's Distillation Design, McGraw-Hill Inc., 1992, pages 262-265 and 464-466. Suitable jet flap trays may include those disclosed in WO Publication No. WO2011 / 014345.

[0028] In some embodiments, the quench zone 145, the lower fractionation zone 155, the pump-circulation zone 160, and the upper fractionation zone 165 may independently include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more internal structures 147, for example, trays, such as sparger trays, dual-flow trays, multi-channel trays, and / or baffle trays. In some embodiments, the quench zone 145, the lower fractionation zone 155, the pump-circulation zone 160, and the upper fractionation zone 165 may independently include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more internal structures 147, for example, trays, such as sparger trays, dual-flow trays, multi-channel trays, and / or baffle trays having 2, 3, 4, 5, 6, or more liquid channels.

[0029] The pyrolysis quench oil via line 135 and the heat transfer medium or "first" heat transfer medium via line 162 may be introduced into one or more heat exchange stages 170 via inlet 172 to produce cooled pyrolysis quench oil in line 171 and heated heat transfer medium in line 173 via outlet 174. In some embodiments, all of the pyrolysis quench oil recovered from the primary fractionator 130 via line 135 may be introduced into the heat exchange stage 170. In other embodiments, a first portion of the quench oil recovered from the primary fractionator via line 135 may be introduced into the heat exchange stage 170 and a second portion may be removed from the system 100. In some embodiments, the pyrolysis quench oil recovered from the primary fractionator 130 via line 135 may be introduced into the heat exchange stage 170 without being subjected to any filtering or other particulate removal processes. In other embodiments, the pyrolysis quench oil recovered from the primary fractionator 130 via line 135 may be subjected to filtering or other particulate removal processes prior to being introduced into the heat exchange stage 170.

[0030] In some embodiments, the pyrolysis quench oil in line 135 may be at a temperature of about 185°C, about 200°C, or about 210°C to about 225°C, about 240°C, or about 250°C when leaving the primary fractionator 130. In some embodiments, the cooled pyrolysis quench oil in line 171 may be at a temperature of about 140°C, about 150°C, or about 160°C to about 180°C, about 190°C, or about 200°C. The heat transfer medium may be or may include, but is not limited to, water, steam, a mixture of water and steam, air, or any combination thereof. Thus, the heat exchange stage 170 may include one or more heat exchangers configured to transfer heat from the pyrolysis quench oil to water and / or steam and / or the heat exchange stage 170 may include one or more heat exchangers configured to transfer heat from the pyrolysis quench oil to air, for example, a heat exchanger equipped with air fins.

[0031] It should be understood that the heat exchange stage 170 may include two or more heat exchange stages in series and / or in parallel. In some embodiments, the first heat exchange stage may preheat boiler feed water, the second heat exchange stage may produce dilution steam, the third heat exchange stage may produce medium-pressure steam, the fourth heat exchange stage may produce low-pressure steam, and / or a fifth heat exchange stage, which may be used for temperature control cooling, for example, to cool or heat other steam such as feed to a steam cracking furnace. In some embodiments, the heated heat transfer medium in line 173 may be or may include, but is not limited to, low-pressure steam at a pressure of about 100 kPag to <827 kPag and / or medium-pressure steam at a pressure of about 827 kPag to about 1720 kPag, or a combination thereof. In some embodiments, the amount of medium-pressure steam generated by cooling the pyrolysis quench oil in the heat exchange stage 170 can be from about 0.3, about 0.35, or about 0.4 to about 0.45, about 0.5, or about 0.55 metric tons per metric ton of pyrolysis effluent ultimately introduced into the line 101 of the primary fractionator 130.

[0032] The first portion of the cooled pyrolysis quench oil via line 175 may be mixed, blended, or otherwise combined with the pyrolysis effluent in line 101, for example, within one or more quench units 105, to produce a cooled pyrolysis effluent in line 107. In some embodiments, the pyrolysis effluent in line 101 may be at a temperature of about 550° C., about 625° C., or about 700° C. to about 800° C., about 900° C., or about 1000° C. In some embodiments, the cooled pyrolysis effluent in line 107 may be at a temperature of ≤350° C., ≤325° C., ≤275° C., ≤250° C., or ≤235° C. In some embodiments, the amount of cooled pyrolysis quench oil in line 175 that contacts the pyrolysis effluent in line 101 can vary significantly from facility to facility, but the weight ratio of cooled pyrolysis quench oil to pyrolysis effluent is typically in the range of about 0.1:1 to about 10:1, e.g., about 0.5:1 to about 5:1, e.g., about 1:1 to about 4:1.

[0033] In some embodiments, a second portion of the cooled pyrolysis quench oil via line 176 can be recycled to quench zone 145 as a quench medium through pyrolysis quench oil inlet 146. In some embodiments, a third portion of the cooled pyrolysis quench oil can be removed from the system via line 177.

[0034] The cooled pyrolysis effluent in line 107 can be introduced into the flash zone 140 via the pyrolysis effluent inlet 141. In some embodiments, the cooled pyrolysis effluent in line 107 can be at a temperature of about 225° C., about 240° C., about 250° C., about 260° C., about 270° C., or about 280° C. to about 300° C., about 325° C., or about 350° C. when introduced into the flash zone 140. In some embodiments, the cooled pyrolysis effluent in line 107 can be at a temperature of ≥225° C., ≥235° C., ≥250° C., or ≥265° C. and ≤350° C., ≤325° C., or ≤315° C. when introduced into the flash zone 140. The cooled pyrolysis effluent can be separated into a first liquid fraction and a first vapor fraction within the flash zone 140. The first liquid fraction may be recovered therefrom as pyrolysis tar via a pipeline 133 in fluid communication with the pyrolysis tar outlet 143. The first liquid fraction or pyrolysis tar may be at a temperature of about 225°C, about 250°C, or about 265°C to about 285°C, about 300°C, about 315°C, about 325°C, or about 350°C when leaving the pyrolysis tar outlet 143.

[0035] In some embodiments, the pyrolysis tar via line 133 may be introduced into an optional upgrading unit 190 to produce an upgraded heavy fuel oil via line 191 and an overhead via line 192. In some embodiments, the upgrading unit 190 may include one or more hydroprocessing stages. The pyrolysis tar may be hydroprocessed in the upgrading unit 190 in the presence of molecular hydrogen and a catalyst under tar hydroprocessing conditions sufficient to produce an upgraded heavy fuel oil via line 191. The overhead in line 192, which may contain molecular hydrogen, may be introduced into the flash zone 140. Illustrative methods and systems that can be used for hydroprocessing pyrolysis tar may 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.

[0036] The first vapor fraction can flow through the vapor distribution device 150 and flow into the quench zone 145. As the first vapor fraction flows into the quench zone 145, the first vapor fraction can be at a temperature of about 235° C., about 250° C., or about 265° C. to about 285° C., about 300° C., or about 315° C. The first vapor fraction can be contacted with a first quench medium (e.g., a second portion of the cooled pyrolysis quench oil introduced via line 176) within the quench zone to produce a second liquid fraction and a second vapor fraction. In some embodiments, the first quench medium can include one or more additional quench media input to the process, such as quench oil produced in another process, in addition to the second portion of the cooled pyrolysis quench oil. In some embodiments, the cooled pyrolysis quench oil via line 176 can be introduced into the primary fractionator 130 at a weight ratio of about 7:1, about 9:1, or about 10:1 to about 12:1, about 13:1, or about 15:1 relative to the weight of hydrocarbons in the cooled pyrolysis effluent in line 107.

[0037] The second liquid fraction may be collected on the vapor distribution device 150 and / or on one or more internal structures 147 disposed within the quench zone 145 and may be recovered from the quench zone 145 as pyrolysis quench oil via a line 135 in fluid communication with a pyrolysis quench oil outlet 148. The one or more internal structures 147, if present, may facilitate separation of the second vapor fraction and the second liquid fraction. When the second vapor fraction flows into the lower fractionation zone 155, the second vapor fraction may be at a temperature of about 160° C., about 170° C., or about 175° C. to about 185° C., about 195° C., or about 200° C.

[0038] The weight ratio of the pyrolysis quench oil to the pyrolysis tar may depend at least in part on the hydrocarbon feed that is subjected to pyrolysis to produce the pyrolysis effluent. In some embodiments, the weight ratio of the pyrolysis quench oil in line 177 to the pyrolysis tar in line 133 recovered from the primary fractionator 130 may be from about 15:1, 20:1, 25:1, 30:1, 40:1, or 50:1 to 90:1, 100:1, 120:1, 140:1, 160:1, 180:1, or 200:1. In other embodiments, the weight ratio of the pyrolysis quench oil in line 177 to the pyrolysis tar in line 133 recovered from the primary fractionator 130 may be ≥15:1, ≥20:1, ≥30:1, ≥1:50, ≥70:1, ≥85:1, or ≥100:1.

[0039] It has been found that when the cooled pyrolysis effluent in line 107 contains coke particles, the coke particles can be removed with the pyrolysis tar in line 133 and / or can be retained in the flash zone 140, so that the first vapor fraction flows into the quench zone 145 substantially free of coke particles. In some embodiments, when the cooled pyrolysis effluent contains coke particles, the pyrolysis quench oil in line 135 can contain ≤10 wt%, ≤5 wt%, ≤3 wt%, ≤1 wt%, or ≤0.5 wt% of the coke particles present in the cooled pyrolysis effluent in line 107. In other embodiments, the pyrolysis quench oil in line 135 can be free of coke particles. In some embodiments, the pyrolysis tar in line 133 can contain about 50 wt%, about 70 wt%, or about 80 wt% to about 90 wt%, about 95 wt%, about 99 wt%, or about 99.5 wt% of the coke particles present in the cooled pyrolysis effluent in line 107. In some embodiments, about 0.5 wt%, about 1 wt%, or about 3 wt% to about 10 wt%, about 20 wt%, or about 25 wt% of the coke particles present in the cooled pyrolysis effluent in line 107 can remain in flash zone 140. In some embodiments, ≥50 wt%, ≥60 wt%, ≥70 wt%, ≥80 wt%, ≥85 wt%, ≥90 wt%, or ≥95 wt% of any coke particles not removed from fractionator 130 via the tar product in line 133 can remain in flash zone 140. The coke particles that remain in flash zone 140 can be removed during routine maintenance operations.

[0040] It has also been found that when the cooled pyrolysis effluent in line 107 contains asphaltenes, the asphaltenes can be removed to a great extent with the pyrolysis tar in line 133 and / or can be retained in the flash zone 140, so that the first vapor phase fraction flows into the quench zone which can be substantially free of asphaltenes. In some embodiments, when the cooled pyrolysis effluent in line 107 contains asphaltenes, the pyrolysis quench oil in line 135 can contain ≤20 wt%, ≤10 wt%, or ≤5 wt% of the asphaltenes present in the cooled pyrolysis effluent in line 107. In other embodiments, the pyrolysis quench oil in line 135 can be free of asphaltenes. In some embodiments, the pyrolysis tar in line 133 can contain about 80 wt%, about 85 wt%, or about 90 wt% to about 93 wt%, about 95 wt%, about 96 wt%, or more of the asphaltenes present in the cooled pyrolysis effluent in line 107. In some embodiments, about 1 wt %, about 3 wt %, or about 5 wt % to about 10 wt %, about 15 wt %, or about 20 wt % of the asphaltenes present in the cooled pyrolysis effluent in line 107 may remain in the flash zone. The asphaltenes retained in flash zone 140 may be removed during routine maintenance operations. In some embodiments, the pyrolysis quench oil in line 135 may include ≤30 wt %, ≤15 wt %, ≤10 wt %, ≤5 wt %, or ≤1 wt % of the combined amount of any coke and any asphaltenes present in the cooled pyrolysis effluent in line 107.

[0041] It has also been discovered that by separating the pyrolysis tar from the pyrolysis effluent in flash zone 140 rather than in a conventional primary fractionator, the viscosity of the pyrolysis quench oil in line 135 can be significantly reduced. In some embodiments, the pyrolysis quench oil in line 135 can have a viscosity of ≤10 cP, ≤7 cP, ≤5 cP, ≤4.5 cP, ≤4 cP, ≤3.5 cP, ≤3 cP, or ≤2.9 cP at a temperature of about 60° C., as measured in accordance with ASTM D2171 / D2171M-18. In contrast, when the cooled pyrolysis effluent is introduced into a conventional primary fractionator and a bottoms product containing pyrolysis tar and pyrolysis quench oil (commonly referred to as fuel oil bottoms) is recovered as a bottoms product, such a product typically has a viscosity significantly greater than 10 cP, as measured in accordance with ASTM D2171 / D2171M-18.

[0042] It has also been discovered that by separating the pyrolysis tar from the pyrolysis effluent in flash zone 140, the amount of insoluble polymers produced in the pyrolysis quench oil in line 135 under process conditions typically experienced by the pyrolysis quench oil can be reduced or even eliminated. In some embodiments, when the pyrolysis quench oil in line 135 is heat soaked at a temperature of about 160° C. for 6 hours, ≤15 wppm, ≤12 wppm, ≤10 wppm, ≤8 wppm, ≤6 wppm, ≤5 wppm, ≤3 wppm, or ≤1 wppm of insoluble polymers can be produced. In other embodiments, the pyrolysis quench oil in line 135 can be free of or substantially free of any detectable insoluble polymers when heat soaked at a temperature of about 160° C. for 6 hours. In contrast, when the cooled pyrolysis effluent is introduced into a conventional primary fractionator and a bottoms containing pyrolysis tar and pyrolysis quench oil is recovered as a bottoms product, such bottoms product typically has >15 wppm of insoluble polymer, e.g., from about 16 wppm to about 20 wppm or more, when heat soaked at a temperature of about 160°C for 6 hours.

[0043] It has also been discovered that by separating pyrolysis tar from the pyrolysis effluent in flash zone 140, the amount of pyrolysis quench oil recovered from quench zone 145 via line 135 can be increased. The amount of pyrolysis quench oil can be increased because pyrolysis tar can be separated from the higher temperature pyrolysis effluent in flash zone 140 compared to if the cooled pyrolysis effluent was introduced into a conventional primary fractionator that provides a bottoms product containing pyrolysis tar and pyrolysis quench oil (which is then separated into pyrolysis quench oil and pyrolysis tar). Thus, the amount of more valuable quench oil molecules that would otherwise be recovered as a component of pyrolysis tar can be reduced. By increasing the amount of quench oil recovered, the need to import quench oil can be reduced or even eliminated.

[0044] Returning to the second gas-phase fraction, the second gas-phase fraction may flow through the lower fractionation zone 155, through the pump-circulation zone 160, and flow into the upper fractionation zone 165 and may contact the second quench medium introduced into the upper fractionation zone 165 through the reflux inlet 163 via the pipeline 168 to produce a third liquid-phase fraction and a third gas-phase fraction. The third liquid-phase fraction via the pipeline 137 in fluid communication with the pyrolysis gas oil outlet 161 may be recovered from the upper fractionation zone 165 as pyrolysis gas oil. In some embodiments, the pyrolysis gas oil via the pipeline 137 may be recovered from the lower portion of the upper fractionation zone 165. In some embodiments, the pyrolysis gas oil may be at a temperature of about 120° C., about 125° C., or about 130° C. to about 145° C., about 150° C., or about 160° C. when leaving the pyrolysis gas oil outlet 161 via the pipeline 137.

[0045] A third vapor fraction may be recovered from the primary fractionator 130 via line 139 in fluid communication with the vapor phase outlet 166, which fraction may include ethylene and at least a portion of the second quench medium. The third vapor fraction in line 139 may be at a temperature of about 95°C, about 100°C, or about 105°C to about 110°C, about 115°C, about 120°C, about 135°C, or about 150°C upon leaving the primary fractionator 130. The third vapor fraction in line 139 may include steam, molecular hydrogen, C1-C4 hydrocarbons, pyrolysis naphtha, or any mixture thereof. In some embodiments, the second quench medium in line 168 may be or may include pyrolysis naphtha that may be separated from the third vapor fraction, as described below with reference to Figure 2 In some embodiments, the pyrolysis naphtha via line 168 can be introduced into the primary fractionator 130 at a weight ratio of about 0.45:1, about 0.47:1, or about 0.5:1 to about 0.55:1, about 0.6:1, about 0.66:1, or about 0.7:1 relative to the weight of hydrocarbons in the cooled pyrolysis effluent in line 107.

[0046] In some embodiments, the third liquid phase fraction via line 137 may be introduced into a stripping stage 180 and may be contacted with steam introduced via line 181. A pyrolysis gas oil product via line 182 and an overhead via line 183 may be recovered from the stripping stage 180. Contacting the third liquid phase fraction with steam may produce a pyrolysis gas oil product in line 182 that meets a desired flash point specification. The overhead may be recycled or refluxed to upper fractionation zone 165 via line 183 above where the third liquid phase fraction is withdrawn via line 137.

[0047] In some embodiments, when the primary fractionator 130 includes a pump-cycle zone 160, a pump-cycle fraction via line 185 may be withdrawn from the pump-cycle outlet 184 and introduced into a heat exchange stage 187 to produce a cooled pump-cycle fraction via line 188. The pump-cycle fraction in line 185 may be at a temperature of about 140° C., about 145° C., or about 150° C. to about 155° C., about 165° C., or about 170° C. A heat transfer medium or "second" heat transfer medium, e.g., water, steam, a mixture of water and steam, air, or any combination thereof, as described above with respect to the heat exchange stage 170, may be introduced into the heat exchange stage 187 via line 186 and a heated second heat transfer medium, e.g., low pressure steam at a pressure of about 100 kPag to <827 kPag, may be recovered therefrom via line 189. It should be understood that heat exchange stage 187, similar to heat exchange stage 170, may include two or more heat exchange stages connected in series and / or in parallel.

[0048] The cooled pump-recycle fraction via line 188 may be introduced into the upper portion of the pump-recycle zone 160 via the pump-recycle inlet 193. In some embodiments, the pump-recycle outlet 184 may be located below the pump-recycle inlet 193. The cooled pump-recycle fraction in line 188 may be at a temperature of about 85° C., about 90° C., about 100° C., or about 110° C. to about 120° C., about 135° C., about 150° C., or about 160° C. In some embodiments, the cooled pump-recycle fraction via line 188 may be introduced into the primary fractionator 130 at a weight ratio of about 2.5:1, about 3:1, or about 3.2:1 to about 3.5:1, about 3.7:1, or about 4:1 relative to the weight of hydrocarbons in the cooled pyrolysis effluent in line 107.

[0049] Generation of pyrolysis effluent

[0050] Figure 2 A schematic diagram of an illustrative system 200 for steam cracking a hydrocarbon feed 201 to produce a pyrolysis effluent (i.e., a steam cracker effluent) via line 219 and separating a variety of products therefrom is depicted according to one or more embodiments. For brevity and simplicity of description, the pyrolysis process is described in the context of a steam cracking process. However, it should be understood that any pyrolysis process can be used to produce the pyrolysis effluent in line 219.

[0051] The hydrocarbon feed in line 201 may be mixed, blended, combined, or otherwise contacted with water and / or steam in line 202 to produce a mixture via line 203. The mixture in line 203 may be heated in a convection section 216 of a steam cracker 215 to produce a heated mixture in line 217. The heated mixture in line 217 may be subjected to steam cracking conditions in a radiant section 218 of the steam cracker 215 to produce a steam cracker effluent via line 219. In some embodiments, when there is sufficiently heavy hydrocarbon feed in line 201, vapor and liquid products may be separated from the heated mixture in line 217 by introducing the heated mixture into one or more separation stages prior to subjecting the heated mixture to steam cracking. The vapor products may be heated to a temperature of ≥400°C, e.g., a temperature of about 425°C to about 825°C, and subjected to steam cracking conditions to produce a steam cracker effluent in line 219. If a liquid product is produced / recovered, it may be subjected to one or more additional upgrading processes well known in the art. In some embodiments, the optional hydrocarbon feed separation stages and upgrading of the liquid product may be or may include those disclosed in U.S. Pat. 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; 7,235,705; and 8,158,840.

[0052] The hydrocarbon feed that may be introduced into the steam cracker via line 201 / 203 may be or may include, but is not limited to, virgin crude oil, desalted crude oil, gas oil, heating oil, jet fuel, diesel, kerosene, gasoline, coker naphtha, steam cracked naphtha, catalytic cracked naphtha, hydrocracked products, reformate, raffinate reformate, Fischer-Tropsch liquids, Fischer-Tropsch gases, natural gasoline, distillate, straight run naphtha, atmospheric tube furnace bottoms, vacuum tube furnace charge Streams such as vacuum tube furnace bottoms and wide boiling range vacuum tube furnace naphtha to gas oil condensate, heavy non-straight run hydrocarbons from refineries, vacuum gas oil, heavy gas oil, naphtha contaminated with crude oil, atmospheric residue, heavy residue, C4 / residue blends, naphtha / residue blends, hydrocarbon gas / residue blends, hydrogen / residue blends, waxy residue, gas oil / residue blends, relatively light alkanes, for example, ethane, propane, butane, pentane, or mixtures thereof, fractions thereof, or any mixtures thereof. In at least some embodiments, the hydrocarbon feed can be or can include, but is not limited to, naphtha, gas oil, vacuum gas oil, waxy residue, atmospheric residue, crude oil, fractions thereof, or mixtures thereof. In some embodiments, if the salty crude oil or other hydrocarbon is to be steam cracked, the crude oil or other hydrocarbon may be optionally subjected to pretreatment (e.g., desalting) to remove at least a portion of any salt contained in the crude oil or other hydrocarbon before heating the hydrocarbon feed to produce a heated mixture. In some embodiments, the hydrocarbon feed may be composed primarily of relatively light hydrocarbons such as C2 to C8 alkanes. Suitable hydrocarbon feeds may also be or include hydrocarbons or hydrocarbon feeds disclosed in U.S. Patent Nos. 7,993,435; 8,277,639; 8,696,888; 9,327,260; 9,637,694; 9,657,239; and 9,777,227; and International Patent Application Publication No. WO 2018 / 111574.

[0053] Steam cracking conditions may include, but are not limited to, one or more of the following: exposing the hydrocarbon feed to a temperature of ≥400°C (as measured at the radiant outlet of the steam cracker), for example, a temperature of about 700°C, about 800°C, or about 900°C to about 950°C, about 1000°C, or about 1050°C, a pressure of about 0.1 bar to about 5 bars (absolute pressure) and / or a steam cracking residence time of about 0.01 seconds to about 5 seconds. In some embodiments, the hydrocarbon feed may be steam cracked 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; U.S. Patent Application Publication No. 2018 / 0170832; and International Patent Application Publication No. WO 2018 / 111574. The steam cracker effluent in line 219 can be at a temperature > 300 °C, > 400 °C, > 500 °C, > 600 °C, or > 700 °C, or > 800 °C, or higher.

[0054] The steam cracker effluent in line 219 can be used to produce a first cooled steam cracker effluent. In some embodiments, the steam cracker effluent in line 219 can be directly contacted with an optional quench fluid (e.g., a transfer line exchanger "TLE") and / or indirectly cooled via one or more heat exchangers in heat exchange stage 220 to produce a first cooled steam cracking effluent or pyrolysis effluent via line 101.

[0055] The first cooled steam cracking effluent or pyrolysis effluent via line 101 may be introduced into a quench unit to produce a second cooled steam cracking effluent or pyrolysis effluent in line 107. The second cooled steam cracking effluent or pyrolysis effluent in line 107 may be introduced into a primary fractionator 130 and steam cracking products or pyrolysis tar products via line 133, steam cracker quench oil or pyrolysis quench oil via line 135, steam cracking gas oil or pyrolysis gas oil via line 137, and overhead products via line 139 may be recovered from the primary fractionator 130 as described above with reference to Figure 1 discussed and described.

[0056] The overhead via line 139 may be introduced into a quench tower 228 along with quench water (e.g., recycled quench water) via line 244 to cool the overhead product. A process gas, which may include ethylene, propylene, or both, may be recovered via line 230 and a mixture including steam cracked naphtha and quench water may be directed away from the quench tower 228 via line 231. It should be understood that, although shown as separate vessels, the quench tower 228 may be integrated with the primary fractionator 130.

[0057] The mixture of steam cracked naphtha and quench water in line 231 may be introduced into one or more separators 240. Steam cracked or pyrolyzed naphtha via line 242, quench water via line 243, and recycle quench water via line 244 may be directed away from separator 240. The quench water via line 243 may be removed from the system, for example, introduced into a wastewater treatment process, sent to a sour water stripper, a dilution steam generation system, etc. The recycle quench water via line 244 may be recycled to quench tower 228. In some embodiments, the recycle quench water via line 244 may be cooled, for example, by air and / or water, and recycled to quench tower 228. In some embodiments, the recycle quench water via line 244 may be recycled to quench tower 228 as a single return stream and / or split into multiple return streams to quench tower 228 and / or other process equipment.

[0058] A portion of the steam cracked naphtha via lines 242 and 246 may be removed and further processed. A portion of the steam cracked naphtha via lines 242 and 168 may be recycled to the upper fractionation zone as reflux. The steam cracked naphtha in line 242 may have a final boiling point of ≤260°C, as measured according to ASTM D2887-18. In some embodiments, the steam cracked naphtha may have a final boiling point of about 220°C, about 221°C, about 225°C, or about 230°C to about 235°C, about 240°C, about 245°C, about 250°C, or about 255°C. In some embodiments, the amount of steam cracked gas oil via line 137 directed away from primary fractionator 130 may be controlled or adjusted to maintain the recovery of steam cracked naphtha in line 242, which has a final boiling point of ≤260°C, as measured according to ASTM D2887-18. The amount of steam cracked naphtha recycled via lines 242 and 168 relative to the cooled steam cracker effluent introduced into the primary fractionator 130 via line 107 can be adjusted or controlled to provide a desired temperature and / or liquid load within the upper fractionation zone 165 of the primary fractionator 130 .

[0059] Suitable steam crackers, process gas recovery configurations, other equipment, and process conditions may include those disclosed in U.S. Patent Nos. 6,419,885; 7,560,019; 7,993,435; 8,105,479; 8,197,668; 8,882,991; 8,894,844; 9,637,694; 9,777,227; U.S. Patent Application Publication Nos. 2014 / 0061096; 2014 / 0357923; 2016 / 0376511; 2018 / 0170832; 2019 / 0016975; and WO Publication No. WO 2018 / 111574. Example:

[0060] The foregoing discussion can be further described with reference to the following non-limiting prophetic examples.

[0061] Two simulations of separating steam cracker effluent in the primary fractionator 130 described herein were conducted. The first simulation (base case) used a primary fractionator 130 including a flash zone 140, a vapor distribution device 150, a quench zone 145, a lower fractionation zone 155 without any trays, a pump-around zone 160, and an upper fractionation zone 165. The second simulation used the same primary fractionator 130 as the first simulation, but with two trays arranged in the lower fractionation zone 155. The first simulation produced a substantial amount of high pressure steam (quantified in MW), medium pressure steam (quantified in MW), low pressure steam (quantified in MW), and recovered a substantial amount (in kg / hr) of steam cracked naphtha. As shown in Table 1 below, the second simulation produced approximately 1 MW more high pressure steam, approximately 10 MW more medium pressure steam, and approximately 500 kg / hr more steam cracked naphtha.

[0062] The increase in medium pressure steam in the second simulation corresponds to an approximately 1% increase in steam cracked naphtha and an approximately 5% increase in medium pressure steam compared to the first simulation.

[0063] In addition to the increase in steam cracked naphtha and energy recovery shown in Table 1 above, the lower fractionation zone 155 also facilitates the fractionation of the quench oil component from the steam cracked gas oil product. It is important to retain the heavier quench oil component in the quench oil to avoid or reduce the need for make-up quench oil. The steam cracked gas oil is typically recovered from the primary fractionator 130 at a temperature of about 120° C. to about 145° C. As shown in Table 2 below, when the lower fractionation zone 155 does not include two trays, the final boiling point of the steam cracked gas oil is higher.

[0064] List of implementation plans

[0065] The present disclosure may further include the following non-limiting embodiments.

[0066] A1. A method for fractionating a pyrolysis effluent, comprising: introducing the pyrolysis effluent into a flash zone located in a fractionator; separating the pyrolysis effluent into a first liquid fraction and a first gas fraction in the flash zone; recovering pyrolysis tar containing the first liquid fraction from the flash zone; allowing the first gas fraction to flow into a quench zone arranged above the flash zone; contacting the first gas fraction with a first quench medium in the quench zone to produce a second liquid fraction and a second gas fraction; recovering pyrolysis quench oil containing the second liquid fraction and at least a portion of the first quench medium from the quench zone; allowing the second gas fraction to flow into a quench zone arranged above the flash zone; a fractionation zone above the quench zone; contacting the second vapor fraction with a second quench medium in the fractionation zone to produce a third liquid fraction and a third vapor fraction; recovering pyrolysis gas oil containing the third liquid fraction from the fractionation zone; recovering a third vapor fraction containing at least a portion of the second quench medium and a process gas containing ethylene from the fractionation zone; and indirectly transferring heat from at least a portion of the pyrolysis quench oil to a heat transfer medium in a heat exchange stage to produce cooled pyrolysis quench oil and heated heat transfer medium, wherein the first quench medium contains at least a portion of the cooled pyrolysis quench oil.

[0067] A2. The method according to A1, further comprising recovering pyrolysis naphtha and process gas from the third gas-phase fraction, wherein the second quench medium comprises a portion of the pyrolysis naphtha separated from the third gas-phase fraction.

[0068] A3. A method according to A1 or A2, wherein: the heat transfer medium comprises water, steam, or a mixture thereof, and the heated heat transfer medium comprises low pressure steam having a pressure of about 100 kPag to <827 kPag, medium pressure steam having a pressure of about 827 kPag to about 1720 kPag, or a combination thereof.

[0069] A4. The method according to A1 or A2, wherein: the heat transfer medium comprises water, steam, or a mixture thereof, and the heated heat transfer medium comprises medium pressure steam at a pressure of about 827 kPag to about 1720 kPag.

[0070] A5. The process according to any one of A1 to A4, wherein the steam cracker quench oil recovered from the quench zone has a viscosity of ≤ 5 cP at a temperature of about 60°C, as measured according to ASTM D2171 / D2171M-18.

[0071] A6. The method according to any one of A1 to A5, wherein the weight ratio of the pyrolysis quench oil recovered from the fractionator to the pyrolysis tar is about 15:1 to about 200:1.

[0072] A7. The method according to any one of A1 to A6, wherein the pyrolysis effluent comprises coke particles, and wherein the pyrolysis quench oil comprises ≤ 10 wt % of the coke particles present in the pyrolysis effluent.

[0073] A8. A process according to any one of A1 to A7, wherein the pyrolysis effluent comprises coke particles, wherein the tar product comprises ≥50 weight % of the coke particles present in the pyrolysis effluent, and wherein ≥50 weight % of any coke particles not removed from the fractionator by the tar product remain in the flash zone.

[0074] A9. The method according to any one of A1 to A8, wherein the pyrolysis quench oil forms less than 15 wppm of insoluble polymer when heat soaked at a temperature of about 160°C for 6 hours.

[0075] A10. The method according to any one of A1 to A9, wherein the first gas phase fraction flows into the quenching zone through a lift tray, a dual-flow tray or a baffle tray.

[0076] A11. A method according to any one of A1 to A10, wherein the quenching zone includes one or more spray tower trays, one or more dual-flow tower trays, one or more fixed valve tower trays, one or more sieve plate tower trays, one or more baffle tower trays, one or more angle iron tower trays, one or more extraction tower trays, one or more gas lifting tower trays, one or more shelf tower trays, one or more tray tower trays, one or more annular tower trays, one or more side-by-side splash tower trays, or a combination thereof, arranged therein to promote the separation of the first gas phase fraction and the second liquid phase fraction.

[0077] A12. A method according to any one of A1 to A11, wherein the first gaseous fraction is at a temperature of about 225°C to about 300°C when the first gaseous fraction flows into the quench zone, and wherein the second gaseous fraction is at a temperature of about 160°C to about 200°C when the second gaseous fraction flows into the fractionation zone.

[0078] A13. The method according to any one of A1 to A12, wherein the fractionation zone comprises a lower fractionation zone and an upper fractionation zone, and wherein the pumping circulation zone is arranged between the lower fractionation zone and the upper fractionation zone.

[0079] A14. The method according to A13 further comprises: extracting the pumping circulation fraction from the lower part of the pumping circulation zone into the pumping circulation loop; cooling the pumping circulation fraction to produce a cooled pumping circulation fraction; and introducing the cooled pumping circulation fraction into the upper part of the pumping circulation zone.

[0080] A15. A method according to A14, wherein cooling the pump-around fraction produces low pressure steam at a pressure of about 100 kPag to <827 kPag.

[0081] A16. A method according to A14 or A15, wherein pyrolysis gas oil is recovered from the lower part of the upper distillation zone.

[0082] A17. The method according to any one of A14 to A16, wherein the pyrolysis gas oil is at a temperature of about 120°C to about 160°C when recovered from the pump-around zone.

[0083] A18. The method according to any one of A14 to A17, wherein the cooled pump-circulation fraction is introduced into the pump-circulation zone at a position below the position where the pyrolysis gas oil is recovered.

[0084] A19. A method according to any one of A1 to A18, wherein: the pyrolysis effluent is at a temperature of ≤350°C when introduced into the flash zone, and the pyrolysis tar is at a temperature of about 235°C to about 315°C when recovered from the flash zone; when the first gas phase fraction flows into the quench zone, the first gas phase fraction is at a temperature of about 235°C to about 315°C, and the pyrolysis quench oil is at a temperature of about 185°C to about 250°C when recovered from the quench zone; when the second gas phase fraction flows into the fractionation zone, the second gas phase fraction is at a temperature of about 160°C to 200°C; the pyrolysis gas oil is at a temperature of about 120°C to about 145°C when recovered from the fractionation zone; and the third gas phase fraction is at a temperature of about 95°C to about 120°C when recovered from the fractionation zone.

[0085] A20. The method according to any one of A1 to A19, wherein the composition of the pyrolysis quench oil recovered from the quench zone is the same as the composition of the cooled pyrolysis quench oil contacted with the first vapor fraction in the quench zone.

[0086] A21. A method according to any one of A1 to A20, wherein the pyrolysis quench oil recovered from the quench zone is not subjected to filtration.

[0087] A22. The process according to any one of A1 to A21, wherein the cooled pyrolysis effluent is at a temperature of ≥225°C, ≥240°C, ≥250°C, or ≥260°C and ≤350°C when introduced into the flash zone.

[0088] B1. A primary fractionator for a pyrolysis system, comprising: a flash zone including a pyrolysis effluent inlet and a pyrolysis tar outlet; a quench zone arranged above the flash zone and including a pyrolysis quench oil inlet and a pyrolysis quench oil outlet; a vapor distribution device arranged between the flash zone and the quench zone, the vapor distribution device being configured to allow vapor to flow out of the flash zone through it and into the quench zone and being configured to collect liquid thereon within the quench zone; and a fractionation zone arranged above the quench zone and including a pyrolysis gas oil outlet, a gas phase outlet and a reflux inlet.

[0089] B2. A system for producing and processing pyrolysis effluent, comprising: a pyrolysis reactor including a pyrolysis effluent outlet; a quench device including a first inlet, a second inlet, and an outlet fluidly connected to the pyrolysis effluent outlet, wherein the quench device is configured to mix the pyrolysis effluent introduced into the first inlet and the quench medium introduced into the second inlet to produce cooled pyrolysis effluent; and a primary fractionator including a flash zone, a quench zone, a steam distribution device, and a fractionation zone, wherein the flash zone includes a pyrolysis effluent inlet and a pyrolysis tar outlet; the quench zone is arranged above the flash zone, including a pyrolysis quench oil inlet and a pyrolysis quench oil outlet; the steam distribution device is arranged between the flash zone and the quench zone, the steam distribution device is arranged and configured to allow steam to flow out of the flash zone through it and flow into the quench zone and is configured to collect liquid on it within the quench zone; the fractionation zone is arranged above the quench zone, including a pyrolysis gas oil outlet, a gas phase outlet and a reflux inlet.

[0090] B3. A primary fractionator or system according to B1 or B2, wherein the pyrolysis quench oil outlet is connected to the inlet fluid of the pyrolysis quench oil heat exchange stage, the pyrolysis quench oil heat exchange stage is configured to indirectly transfer heat from the pyrolysis quench oil to the heat transfer medium, and wherein the pyrolysis quench oil inlet is connected to the outlet fluid of the pyrolysis heat exchange stage.

[0091] B4. The primary fractionator or system according to any one of B1 to B3, wherein the fractionation zone comprises a lower fractionation zone and an upper fractionation zone, and wherein the pumping circulation zone is arranged between the lower fractionation zone and the upper fractionation zone.

[0092] B5. A primary fractionator or system according to B4, wherein the pumping circulation zone includes one or more injection tower trays, one or more dual-flow tower trays, one or more baffle tower trays, one or more fixed valve tower trays, one or more sieve plate tower trays, one or more angle iron tower trays, one or more extraction tower trays, one or more lift tower trays, one or more shelf tower trays, one or more tray tower trays, one or more annular tower trays, one or more side-by-side splash tower trays, or a combination thereof.

[0093] B6. A primary fractionator or system according to B4 or B5, wherein the pumping circulation zone includes a pumping circulation outlet connected to the inlet fluid of the pumping circulation heat exchange stage and a pumping circulation inlet connected to the outlet fluid of the pumping circulation heat exchange stage, and wherein the pumping circulation outlet is below the pumping circulation inlet.

[0094] B7. A primary fractionator or system according to any one of B4 to B6, wherein the pyrolysis gas oil outlet is located above the pump-circulation outlet and the pump-circulation inlet.

[0095] B8. A primary fractionator or system according to any one of B1 to B7, wherein the vapor distribution device comprises an updraft tray, a dual flow tray or a baffle tray.

[0096] B9. A primary fractionator or system according to any one of B1 to B8, wherein the quench zone includes one or more spray tower trays, one or more dual-flow tower trays, one or more baffle tower trays, one or more fixed valve tower trays, one or more sieve plate tower trays, one or more angle iron tower trays, one or more extraction tower trays, one or more lift tower trays, one or more shelf tower trays, one or more tray tower trays, one or more annular tower trays, one or more side-by-side splash tower trays, or a combination thereof.

[0097] B10. The primary fractionator or system according to any one of B1 to B9, wherein the lower fractionation zone and the upper fractionation zone each comprise one or more fixed valve trays, one or more sieve plate trays, one or more dual flow trays, or a combination thereof disposed therein.

[0098] B11. A primary fractionator or system according to any one of B1 to B10, wherein the pyrolysis effluent inlet is in fluid communication with the feed distribution device.

[0099] B12. A primary fractionator or system according to any one of B1 to B11, wherein the feed distribution device comprises a steam horn, an annular ring, a V-shaped baffle, a perforated tube distributor, a dual flow tray, or any combination thereof.

[0100] B13. A system according to any one of B2 to B12, wherein the system further comprises a heat exchange stage, which includes a pyrolysis effluent inlet connected to the pyrolysis effluent outlet fluid, a heat transfer medium inlet, a cooled pyrolysis effluent outlet and a heated heat transfer medium outlet, and the heat exchange stage is configured to indirectly transfer heat from the pyrolysis effluent to the heat transfer medium.

[0101] B14. A system according to any one of B2 to B13, wherein the system further includes a transfer line exchanger having a first inlet connected to the pyrolysis effluent outlet fluid, a second inlet, and an outlet, the transfer line exchanger being configured to mix the pyrolysis effluent introduced into the first inlet and the quench medium introduced into the second inlet, and wherein the outlet is connected to the first inlet fluid of the quench device.

[0102] The use of numerical upper limit groups and numerical lower limit groups to describe certain embodiments and features. It should be understood that the combination of any two values ​​is encompassed, for example, the combination of any lower value with any higher value, the combination of any two lower values, and / or the range of any two higher values ​​is considered, unless otherwise indicated. Certain lower limits, upper limits and ranges appear in one or more claims below. All numerical values ​​are "about" or "approximately" the indicated value, and take into account the experimental errors and deviations expected by those of ordinary skill in the art.

[0103] Various terms have been defined above. When a term used in a claim is not defined above, it should be given the broadest definition given to that term by persons skilled in the art as reflected in at least one printed publication or issued patent. In addition, all patents, test procedures, and other documents cited in this application are fully incorporated by reference to the extent such disclosure is not inconsistent with this application and for all jurisdictions in which such incorporation is permitted.

[0104] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the following claims.

Claims

1. A method for fractionating a pyrolysis effluent, comprising: introducing the pyrolysis effluent into a flash zone located within the fractionator; separating the pyrolysis effluent into a first liquid fraction and a first vapor fraction in a flash zone; recovering pyrolysis tar comprising a first liquid phase fraction from the flash zone; allowing the first gas phase fraction to flow into a quenching zone disposed above the flash zone; contacting the first vapor fraction with a first quench medium in a quench zone to produce a second liquid fraction and a second vapor fraction; recovering a pyrolysis quench oil comprising a second liquid phase fraction and at least a portion of the first quench medium from the quench zone; allowing the second gas phase fraction to flow into a fractionation zone disposed above the quenching zone; contacting the second vapor fraction with a second quench medium in a fractionation zone to produce a third liquid fraction and a third vapor fraction; recovering a pyrolysis gas oil comprising a third liquid phase fraction from the fractionation zone; recovering from the fractionation zone a third vapor fraction comprising at least a portion of the second quench medium and a process gas comprising ethylene; as well as Heat is indirectly transferred from at least a portion of the pyrolysis quench oil to a heat transfer medium in a heat exchange stage to produce cooled pyrolysis quench oil and heated heat transfer medium, wherein the first quench medium comprises at least a portion of the cooled pyrolysis quench oil.

2. The method according to claim 1, further comprising recovering pyrolysis naphtha and process gas from the third gas-phase fraction, wherein the second quench medium comprises a portion of the pyrolysis naphtha separated from the third gas-phase fraction.

3. The method according to claim 1 or claim 2, wherein: The heat transfer medium comprises water, steam, or a mixture thereof, and The heated heat transfer medium comprises low pressure steam having a pressure of about 100 kPag to <827 kPag, medium pressure steam having a pressure of about 827 kPag to about 1720 kPag, or a combination thereof.

4. A method according to any one of the preceding claims, wherein: The heat transfer medium comprises water, steam, or a mixture thereof, and The heated heat transfer medium comprises medium pressure steam at a pressure of about 827 kPag to about 1720 kPag.

5. The process according to any one of the preceding claims, wherein the steam cracker quench oil recovered from the quench zone has a viscosity of ≤ 5 cP at a temperature of about 60°C as measured according to ASTM D2171 / D2171M-18.

6. The process of any one of the preceding claims, wherein the weight ratio of pyrolysis quench oil recovered from the fractionator to pyrolysis tar is from about 15:1 to about 200:

1.

7. The process according to any one of the preceding claims, wherein the pyrolysis effluent comprises coke particles, and wherein the pyrolysis quench oil comprises ≤ 10 wt% of the coke particles present in the pyrolysis effluent.

8. The process of any one of the preceding claims, wherein the pyrolysis effluent comprises coke particles, wherein the tar product comprises ≥50 wt % of the coke particles present in the pyrolysis effluent, and wherein ≥50 wt % of any coke particles not removed from the fractionator by the tar product remain in the flash zone.

9. The method of any one of the preceding claims, wherein the pyrolysis quench oil forms less than 15 wppm of insoluble polymer when heat soaked at a temperature of about 160°C for 6 hours.

10. A process according to any one of the preceding claims, wherein the first gaseous fraction flows into the quench zone via upflow trays, dual flow trays or baffle trays.

11. The method according to any one of the preceding claims, wherein the quench zone includes one or more spray trays, one or more dual-flow trays, one or more fixed valve trays, one or more sieve plate trays, one or more baffle trays, one or more angle iron trays, one or more extraction trays, one or more lift trays, one or more shelf trays, one or more tray trays, one or more annular trays, one or more side-by-side splash trays, or a combination thereof, arranged therein to facilitate separation of the first vapor fraction and the second liquid fraction.

12. The method of any one of the preceding claims, wherein the first vapor fraction is at a temperature of about 225°C to about 300°C when the first vapor fraction flows into the quench zone, and wherein the second vapor fraction is at a temperature of about 160°C to about 200°C when the second vapor fraction flows into the fractionation zone.

13. The method according to any one of the preceding claims, wherein the fractionation zone comprises a lower fractionation zone and an upper fractionation zone, and wherein a pump-around zone is arranged between the lower fractionation zone and the upper fractionation zone.

14. The method according to claim 13, further comprising: extracting the pump-circulation fraction from the lower part of the pump-circulation zone into the pump-circulation loop; cooling the pump-around fraction to produce a cooled pump-around fraction; and The cooled pump-circulation fraction is introduced into the upper part of the pump-circulation zone.

15. The process of claim 14, wherein cooling the pump-around fraction produces low pressure steam at a pressure of about 100 kPag to <827 kPag.

16. A process according to claim 14 or claim 15, wherein pyrolysis gas oil is recovered from the lower part of the upper fractionation zone.

17. The method of claim 16, wherein the pyrolysis gas oil is at a temperature of about 120°C to about 160°C when recovered from the pump-around zone.

18. The method of claim 16, wherein the cooled pump-around fraction is introduced into the pump-around zone at a location below the location where the pyrolysis gas oil is recovered.

19. A method according to any one of the preceding claims, wherein: The pyrolysis effluent is at a temperature of ≤350°C when introduced into the flash zone. The pyrolysis tar is at a temperature of about 235°C to about 315°C when recovered from the flash zone; The first vapor fraction is at a temperature of about 235° C. to about 315° C. when it flows into the quench zone, The pyrolysis quench oil is at a temperature of about 185°C to about 250°C when recovered from the quench zone; the second vapor fraction is at a temperature of about 160° C. to 200° C. when the second vapor fraction flows into the fractionation zone; The pyrolysis gas oil is at a temperature of about 120°C to about 145°C when recovered from the fractionation zone; and The third vapor fraction is at a temperature of about 95°C to about 120°C when recovered from the fractionation zone.

20. A primary fractionator for a pyrolysis system, comprising: a flash zone including a pyrolysis effluent inlet and a pyrolysis tar outlet; A quenching zone, which is arranged above the flashing zone and includes a pyrolysis quenching oil inlet and a pyrolysis quenching oil outlet; a vapor distribution device disposed between the flash zone and the quench zone, the vapor distribution device configured to allow vapor to flow therethrough from the flash zone and into the quench zone and configured to collect liquid thereon within the quench zone; and The fractionation zone is arranged above the quenching zone and comprises a pyrolysis gas oil outlet, a gas phase outlet and a reflux inlet.

21. The primary fractionator of claim 20, wherein the pyrolysis quench oil outlet is in fluid communication with an inlet of a pyrolysis quench oil heat exchange stage, the pyrolysis quench oil exchange stage being configured to indirectly transfer heat from the pyrolysis quench oil to a heat transfer medium, and wherein the pyrolysis quench oil inlet is in fluid communication with an outlet of the pyrolysis heat exchange stage.

22. A primary fractionator according to claim 20 or claim 21, wherein the fractionation zone comprises a lower fractionation zone and an upper fractionation zone, and wherein the pumping circulation zone is arranged between the lower fractionation zone and the upper fractionation zone.

23. The primary fractionator of claim 22, wherein the pump-around zone comprises one or more spray trays, one or more dual-flow trays, one or more baffle trays, one or more fixed valve trays, one or more sieve trays, one or more angle iron trays, one or more extraction trays, one or more lift trays, one or more shelf trays, one or more tray trays, one or more annular trays, one or more side-by-side splash trays, or a combination thereof disposed therein.

24. A primary fractionator according to claim 22 or claim 23, wherein the pumping circulation zone comprises a pumping circulation outlet in fluid communication with the pumping circulation heat exchange stage and a pumping circulation inlet in fluid communication with the pumping circulation heat exchange stage, and wherein the pumping circulation outlet is located below the pumping circulation inlet.

25. The primary fractionator of claim 24, wherein the pyrolysis gas oil outlet is located above the pump-circulation outlet and the pump-circulation inlet.

26. The primary fractionator of any one of claims 22 to 25, wherein the lower fractionation zone and the upper fractionation zone each comprise one or more fixed valve trays, one or more sieve trays, one or more dual flow trays, or a combination thereof disposed therein.

27. A primary fractionator according to any one of claims 20 to 26, wherein the vapour distribution means comprises updraft trays, dual flow trays, or baffle trays.

28. A primary fractionator according to any one of claims 20 to 27, wherein the quench zone includes one or more spray trays, one or more dual flow trays, one or more baffle trays, one or more fixed valve trays, one or more sieve plate trays, one or more angle iron trays, one or more extraction trays, one or more lift trays, one or more shelf trays, one or more tray trays, one or more annular trays, one or more side-by-side splash trays, or a combination thereof disposed therein.

29. A primary fractionator according to any one of claims 20 to 28, wherein the pyrolysis effluent inlet is in fluid communication with the feed distribution means.

30. The primary fractionator of claim 29, wherein the feed distribution device comprises a steam horn, an annular ring, a V-shaped baffle, a perforated pipe distributor, a dual flow tray, or any combination thereof.

31. A system for producing and processing pyrolysis effluent, comprising: a pyrolysis reactor comprising a pyrolysis effluent outlet; a quench device comprising a first inlet in fluid communication with the pyrolysis effluent outlet, a second inlet, and an outlet, wherein the quench device is configured to mix the pyrolysis effluent introduced into the first inlet and a quench medium introduced into the second inlet to produce a cooled pyrolysis effluent; as well as A primary fractionator comprising: a flash zone including a pyrolysis effluent inlet and a pyrolysis tar outlet; A quenching zone, which is arranged above the flashing zone and includes a pyrolysis quenching oil inlet and a pyrolysis quenching oil outlet; a vapor distribution device disposed between the flash zone and the quench zone, the vapor distribution device configured to allow vapor to flow therethrough from the flash zone and into the quench zone and configured to collect liquid thereon within the quench zone; and The fractionation zone is arranged above the quenching zone and comprises a pyrolysis gas oil outlet, a gas phase outlet and a reflux inlet.

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