Process and reactor for hydrocarbon conversion

Abstract

A reactor and method for conversion of hydrocarbon gases utilizes a reactor (12, 312, 412, 512, 612, 712) having a specific feed assembly with a primary vortex combustion chamber (40, 340, 436, 536, 636, 736), a diffusion conduit (48, 348, 448, 548, 648, 748), and a cylindrical reactor chamber (40, 340, 436, 536, 636, 736). The design creates a compact combustion zone and fluid flow pattern of the inwardly swirling feed gas to form a swirling gas mixture through the diffusion conduit (48, 348, 448, 548, 648, 748). The feed stream can be introduced into the reactor at any angle (perpendicular, axial, or an angle therebetween, or a combination of the above forms) to the swirling flow component. This provides suitable conditions for efficient cracking of hydrocarbons (such as ethane) to form olefins.

Description

Technical Field

[0001] This invention relates to a conversion method for converting various hydrocarbons to produce more valuable products, and to reactor design for such conversion. Background Technology

[0002] BASF has developed a single-stage combustion cracking method for acetylene production, disclosed in US Patent No. 5,789,644. This method has been commercialized in Germany and the US at a scale of 50 kTA using multiple reactors. In this process, natural gas is used as the feedstock for hydrocarbons, and pure oxygen is used as the oxidant to generate heat, which is crucial for acetylene production. The two fluid streams are premixed in a diffuser, and the premixed fuel-rich gas is combusted using a burner block via partial oxidation. The main disadvantages of this design are the risk of backfire in the premixed flame under various feedstock and operating conditions, and the use of multiple burners, which increases the overall operating cost, the difficulty of heat control, and the low carbon yield of olefin products. Furthermore, while acetylene was once a cornerstone of chemicals, olefins have become the cornerstone of the chemical industry over the past six or seven decades, and there is a growing expectation for the direct production of olefins rather than the indirect hydrogenation of acetylene.

[0003] Traditional steam crackers are industrially essential go-to reactors used to break down long-chain hydrocarbons and convert smaller alkanes (i.e., naphtha, butane, or ethane) into smaller molecules and olefins (e.g., ethylene and propylene). In these crackers, heavy gases such as naphtha, liquefied petroleum gas (LPG), propane, butane, and ethane are fed into the furnace along with steam and converted into smaller olefins. Steam is added during the process to improve selectivity for olefins and achieve a reasonable conversion rate. Typically, the process operates at high temperatures (i.e., 750°C to 900°C) with residence times of approximately 100 to 500 milliseconds. While this process has been optimized over the past fifty years, significant drawbacks remain. These include heat losses and complexity associated with separate exothermic (combustion in the furnace) and endothermic (cracking in the process tube) steps. The presence of combustion and process-side inert compounds also affects overall efficiency. Metallurgical limitations of the reactor also restrict the usable temperature. Ideally, higher temperatures with shorter contact times yield better selectivity and conversion to smaller olefins. Coking blockages also occur in these conventional processes, which can increase capital costs and operating expenses. Furthermore, there is a lack of flexibility regarding feedstock, as commercial crackers are typically optimized only for specific types of feedstock.

[0004] One solution to these challenges is the ANJEVOC reactor system. The basic ANJEVOC (ANnular JETVOrtex Chamber) system is disclosed in U.S. Patent No. 1,102,0719, which is incorporated herein by reference for all purposes. U.S. Patent No. 1,102,0719 describes a reactor system for the pyrolysis conversion of hydrocarbon gases. The ANJEVOC reactor can also be used for cracking, with a slightly different configuration, referred to as "ANJEVOC-C," the "C" type additionally used for cracking. This cracking system is described in International Publication No. WO2020 / 086681A2, which is incorporated herein by reference for all purposes.

[0005] This invention is dedicated to significant changes and improvements to the ANJEVOC-C system. Summary of the Invention

[0006] This invention includes an axial feed design. This design offers numerous advantages, including well-organized swirling flow fields between the fuel / oxidant streams, free from unwanted mixing, and without radial outflow of O2 into the lighter fuel stream. This results in lower premixing risk, lower reactor wall temperatures due to internal cooling by the cold cracking gas, easier placement of liquid fuel nozzles along the bottom centerline, lower pressure drop across the reactor, and a simplified axial feed mechanism design.

[0007] In a preferred embodiment of a reactor system for hydrocarbon conversion, the reactor system includes a reactor vessel having reactor walls to define a reaction chamber. The reactor system also includes a reactor inlet assembly having a diffusion conduit, as seen from upstream to downstream, having circumferential walls surrounding a central longitudinal axis and extending from opposite upstream and downstream ends of the diffusion conduit. The downstream end of the diffusion conduit is in fluid communication with the reaction chamber of the reactor, and the upstream end of the diffusion conduit forms the inlet of the reactor inlet assembly.

[0008] The reactor system also includes a feed assembly in fluid communication with the inlet of the reactor inlet assembly, wherein a central axis passes through the feed assembly. The feed assembly includes a downstream feed assembly wall that extends circumferentially around and connects to the upstream end of the reactor inlet assembly. The feed assembly also includes an upstream feed assembly wall that is axially spaced along the central axis from the upstream and downstream feed assembly walls. The downstream and upstream feed assembly walls together partially define a mixing chamber for mixing two or more feed streams.

[0009] The feed assembly also includes an upstream gas partition wall and a downstream gas partition wall, each axially spaced between the downstream feed assembly wall and the upstream feed assembly wall, and axially spaced apart from each other. Each upstream and downstream gas partition wall has a central opening around the central axis of the diffuser. An upstream annular hydrocarbon feed inlet flow space is defined between the upstream feed assembly wall and the upstream partition wall. An annular vapor inlet flow space is defined between the downstream feed assembly wall and the downstream gas partition wall. An annular fuel gas inlet flow space is defined between the downstream gas partition wall and the upstream gas partition wall.

[0010] The annular fuel gas inlet flow space is further divided by a fuel gas partition wall. This fuel gas partition wall is axially spaced between a downstream gas partition wall and an upstream gas partition wall to define the first and second annular fuel gas inlet flow spaces. The fuel gas partition wall has a central opening around the central axis of the diffuser duct. The periphery of the central opening of the fuel gas partition wall is radially outwardly spaced from the central openings of the upstream and downstream gas partition walls. A region radially inwardly spaced between the upstream and downstream gas partition walls from the central opening of the fuel gas partition wall defines an annular combustion zone in which heated combustion gases are formed.

[0011] The annular inlet flow space causes the introduced feed to flow in an inwardly swirling fluid flow pattern around the central axis of the diffuser within the flow space. The region extending from the central opening of the upstream and downstream partition walls to the inlet of the reactor inlet assembly defines the mixing chamber of the feed assembly. Heated combustion gases from the fuel gas inlet flow space and hydrocarbon feed from the upstream hydrocarbon feed inlet flow space are discharged into this mixing chamber, causing the hydrocarbon feed and heated combustion gases to mix together and form a swirling gas mixture within the mixing chamber. The swirling gas mixture reaches the reaction chamber through the diffuser. Finally, at least one inlet flow space causes its respective feed stream to enter the reactor in a direction not perpendicular to the central axis.

[0012] In another embodiment of the invention, the reactor system has all inlet flow spaces that allow their respective feed flows to enter the reactor in a direction not perpendicular to the central axis.

[0013] In another embodiment of the invention, the reactor inlet assembly further includes guide vanes, wherein the guide vanes provide a selected azimuth angle to radial velocity ratio of the feed flow into the mixing chamber, and wherein the guide vanes are movable to a selected position.

[0014] In another embodiment of the invention, one of the feed streams may include steam.

[0015] In another embodiment of the invention, at least four feed streams may exist, the feed streams including oxygen, methane, hydrogen, and one or more C2, C3, C4, naphtha or higher hydrocarbon feeds.

[0016] In another embodiment of the invention, oxygen, methane, and hydrogen flow axially to the central longitudinal axis, while C2, C3, C4, naphtha, or higher hydrocarbons are fed vertically.

[0017] In another embodiment of the invention, oxygen, methane, and hydrogen flow perpendicular to the central longitudinal axis, while C2, C3, C4, naphtha, or higher hydrocarbons are fed axially.

[0018] In another embodiment of the invention, all feed streams flow axially into the reactor along the central longitudinal axis.

[0019] In another embodiment of the invention, the feed stream entering via the swirl atomizer is naphtha, crude oil, or liquid natural gas (NGL).

[0020] In another embodiment of the invention, the remaining feed stream that does not enter through the cyclone atomizer is methane, hydrogen, oxygen, and water or steam.

[0021] In another embodiment of the invention, all remaining feed streams that do not pass through the cyclone atomizer enter the reactor perpendicular to the central longitudinal axis.

[0022] In another embodiment of the invention, one or more feed streams that do not enter the reactor through the swirl atomizer enter the reactor axially to the central longitudinal axis, and one or more remaining inlet streams enter the reactor vertically.

[0023] In another embodiment of the invention, the selection and arrangement of one or more flow inlet spaces allows control over the relative position of the flame front.

[0024] In another embodiment of the invention, the selection and arrangement of one or more flow inlet spaces enable control over the arrangement of a portion of the feed stream comprising cold raw materials relative to the arrangement of hot combustion gases present in the reactor, relative to the outer wall.

[0025] In another embodiment of the invention, the cold feedstock first enters the reactor as close as possible to the outer wall, and then moves radially inward to interact with the hot combustion gases.

[0026] In another embodiment of the invention, the cold feedstock enters the reactor at or near the center of the reactor and moves radially outward to interact with the hot combustion gases. Attached Figure Description

[0027] To gain a more complete understanding of the embodiments described herein and their advantages, reference is now made to the following description taken in conjunction with the accompanying drawings.

[0028] Figure 1 This is a process flow diagram of a cracking system for cracking hydrocarbons into cracked hydrocarbon products according to a specific embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of a conventional reactor system for cracking, shown in cross-section.

[0030] Figure 3 This is a partial schematic diagram of an improved lower or upstream portion of a reactor system constructed according to a specific embodiment of the present invention, showing the reactor feed assembly and a portion of the reactor;

[0031] Figure 4 This is a partial schematic diagram of the lower or upstream portion of a reactor system constructed according to a specific embodiment of the present invention, showing the reactor feed assembly and a portion of the reactor;

[0032] Figure 5 This is a partial schematic diagram of the lower or upstream portion of a reactor system constructed according to a specific embodiment of the present invention, showing the reactor feed assembly and a portion of the reactor;

[0033] Figure 6 This is a partial schematic diagram of the lower or upstream portion of a reactor system constructed according to a specific embodiment of the present invention, showing the reactor feed assembly and a portion of the reactor; and

[0034] Figure 7 This is a partial schematic diagram of the lower or upstream portion of a reactor system, showing a reactor feed assembly and a portion of the reactor constructed according to a specific embodiment of the present invention. Detailed Implementation

[0035] This disclosure utilizes a novel system that maximizes the yield of desired olefins at a very high productivity (cracking), converting hydrocarbons into higher-value products (e.g., olefins) by creating and controlling the reaction flow environment using high centrifugal force in a unique reactor configuration. This is achieved by utilizing an annular, highly swirling jet of the feed gas, where hydrogen (or other fuels, such as natural gas) and oxygen are primarily used to generate the heat required for hydrocarbon cracking. The cracking reactor used is similar to the pyrolysis reactor described in International Publication No. WO2020 / 086681A2, which is incorporated herein by reference for all purposes. International Publication No. WO2020 / 086681A2 describes a reactor that can be used for the pyrolysis cracking of hydrocarbon gases. This type of reactor may be referred to as an ANJEVOC-C (ANnular JEt VOrtex Chamber-Cracking) reactor.

[0036] refer to Figure 1 The diagram illustrates a flow chart of a hydrocarbon conversion system 10 for converting hydrocarbons into higher-value products, such as olefins. System 10 includes an ANJEVOC-C cracking reactor 12, described in more detail above. Cracking feed 14 is fed into reactor 12 as a separate stream. Cracking feed 14 may include hydrocarbons such as ethane, liquefied petroleum gas (LPG), butane, naphtha, natural gas, light gas oil, natural gas liquids (NGL), and / or heavy gas oil. Cracking feed stream 14 may be preheated or mixed with aromatics or other hydrocarbons to reduce viscosity before being introduced into reactor 12. In certain applications, feed stream 14 may be heated to temperatures ranging from 25°C to 500°C to improve conversion efficiency or to evaporate heavier liquid hydrocarbons outside or inside the reactor.

[0037] It is important to note in the specification that if numerical values, concentrations, or ranges are given, each value should be read once modified by the term "about" (unless explicitly modified), and then read again without such modification, unless the context otherwise indicates. Furthermore, it should be understood that in the specification, listing or describing a useful, suitable, or similar range of quantities is intended to treat any value within that range and each value (including endpoints) as already disclosed. For example, "a range from 1 to 10" refers to every possible number in the continuum between approximately 1 and approximately 10. Therefore, even if a specific point within the range is explicitly indicated or referred to, or even if no point within the range is specified, it should be understood that the inventor recognizes and understands that any and all points within that range will be considered specified, and the inventor claims the entire range and all points within it.

[0038] The oxygen-containing gas feed 16 for combustion of hydrogen-rich fuel gas feed 18 is also fed as a separate stream to reactor 12. Oxygen feed 16 can be a concentrated oxygen feed, wherein the majority (i.e., >50 mol%) of the feed consists of oxygen (O2). In many cases, the oxygen-containing gas will be a high-purity oxygen-containing gas feed consisting of 20 mol% to 100 mol% O2 in the oxygen feed stream. This can be provided from an air separation unit (not shown) used to separate oxygen from air or other oxygen sources. Air can also be used as the oxygen-containing gas. In cases where air is used as the oxygen-containing gas, or where there are significant impurities (e.g., N2) in the oxygen-containing gas feed, it may be necessary to separate these impurities from the product downstream.

[0039] Steam or water (H2O) feed is also fed to reactor 12 as a separate steam feed stream 20. In some embodiments, cracking feed 14 and / or oxygen feed 16 may also be premixed with steam. In some cases, the separate steam feed stream 20 may be removed if sufficient steam is provided and mixed with feeds 14 and / or 16.

[0040] The cracking reaction products 22 are removed from reactor 12, where they can be cooled by quenching in quenching unit 24 (e.g., a water-droplet-spray quenching container or other suitable gas quenching device). The cracking products 22 are typically a mixture of hydrogen, vapor, oxygen-containing compounds, some heavy compounds (>C4), some aromatics, and olefin products.

[0041] The quenched cracking product 26 can be fed to the separation unit 28, where the product gas is separated to form a product stream 30 containing olefin products such as ethylene (C2H4), propylene (C3H6), etc., and a separated gas stream 32. The feed recirculation stream 35 also returns the unconverted hydrocarbon feedstock to be mixed with the fresh cracking feed 14 to pass through the reactor 12 again.

[0042] The separated gas stream 32, removed from separator 28, typically contains hydrogen (H2) and small amounts of methane (CH4) and carbon oxides of CO and CO2. Because dehydrogenation occurs during the cracking reaction, sufficient hydrogen is typically produced to be used as a fuel gas to generate heat for the cracking reaction in reactor 12. Therefore, gas stream 32 can be recycled and fed as hydrogen-rich fuel feed 18. In some cases, sufficient hydrogen is produced during the cracking reaction so that no additional fuel is needed besides the fuel supplied by the recirculated stream 32. However, in other cases, additional fuel feed 34 from the hydrogen-rich feed can be used for fuel feed 18, for example, as the initial fuel feed during reactor start-up, or when there is not a sufficient amount of hydrogen in the recirculated stream 32 to provide heat for combustion, and is combined with the recirculated stream 32 to form fuel feed 18.

[0043] The operating conditions of reactor 12 may vary depending on the type of cracking feed. In a typical cracking reaction using an ANJEVO CC reactor, oxygen feed 16 is typically used in conjunction with excess hydrogen or fuel gas, such that all oxygen is consumed. Typically, the amount of hydrogen will be 2 to 4 times the stoichiometric amount required for oxygen combustion. Oxygen feed 16 provides oxygen at a molar ratio of 0.25 to 0.50 equivalent oxygen to fuel. Furthermore, the ratio between cracking feed and hydrogen fuel is typically in the range of 1.0 to 10, depending on the mass of the hydrocarbon feed. The residence time within reactor 12 can be 20 milliseconds or less. As will be discussed in more detail later, the temperature in the recirculation zone within the reactor is typically in the range of 1000°C to 1300°C.

[0044] It should be noted that, although Figure 1 System 10 illustrates a single unit for various process steps, but each unit may consist of one or more units that can be combined with each other (e.g., operated in parallel or sequentially) to perform the various process steps described.

[0045] refer to Figure 2 A schematic cross-sectional view of a cracking reactor system 12 for cracking hydrocarbons (e.g., ethane, propane, liquefied petroleum gas (LPG), butane, naphtha, natural gas, light gas oil, natural gas liquids (NGL), heavy gas oil, or combinations thereof) is shown. Reactor 12 constitutes an ANJEV OC-C reactor and includes a reactor vessel 36 having a reactor wall 38 defining an internal reaction chamber 40. The reactor wall 38 may have a cylindrical construction with a constant diameter along its entire length, or a portion thereof, which may constitute the majority of its length. In most cases, reactor 12 is vertically oriented such that the cylindrical reactor wall 38 is oriented vertically. However, the reactor may have other orientations (e.g., horizontal, inclined) because the process is controlled by centrifugal force, which exceeds gravity by several orders of magnitude. Reactor vessel 36 may be configured to provide a length-to-diameter ratio (L / D) of at least 2. In specific applications, the L / D ratio may be in the range of 2-10.

[0046] The reactor vessel 36 can be made of steel. In some embodiments, a cooling jacket can be provided around the reactor vessel, wherein a second steel wall 42 is positioned around and spaced from the inner reactor wall 38, and a cooling fluid, such as water, can circulate through the jacket formed between the walls 38 and 42. In other embodiments, the reactor wall 38 can be made of one or more layers of refractory material, which is lined inside the steel outer wall to reduce heat loss and maintain the high temperature of the reactor 12. As will be described later, due to the unique design and operation of the reactor 12, the reactor wall 38 is cooled internally by a high-speed near-wall airflow driven by centrifugal force on the reactor wall 38, making an external cooling jacket unnecessary in some applications. This also allows for the use of refractory material inside the reactor wall 38. Due to the high temperatures encountered (~2800°C), refractory material (without cooling) is generally not suitable for use with conventional oxygen-only cracking reactors.

[0047] Outlet 44 is located at the upper or lower end of reactor vessel 36 for removing or discharging cracking products from reaction chamber 40. Although outlet 44 is shown at the upper end of reactor vessel 36, in other embodiments it may be located at the lower end of reactor vessel 36, such that the flow through the reactor is in the opposite direction (i.e., from top to bottom). The outlet diameter may be the same as the diameter of reactor wall 38, or the outlet diameter may be reduced to accelerate the flow before downstream quenching and collection.

[0048] Reactor 12 includes a reactor inlet assembly 46, which is connected or linked to the lower or upstream end of the reactor wall 38 of reactor vessel 36. The inlet assembly 46 has a diffusion conduit 48 having a circumferential wall 50 surrounding the central longitudinal axis 52 of the reactor. When reactor 12 is vertically oriented, the central axis 52 will also be vertically oriented and will be concentric or parallel to the central vertical axis of reactor vessel 36. In the illustrated embodiment, axis 52 is concentric and aligned with the central longitudinal axis of reactor vessel 36. The circumferential wall 50 extends from opposite upstream and downstream ends of the diffusion conduit 48. As used herein, the terms “upstream” and “downstream” or similar expressions describing various components of reactor system 12 should refer to the position of the component relative to the overall direction of fluid flow through reactor 12 along the central axis 52. A converging conduit 54 (through which the central longitudinal axis 52 passes) having upstream and downstream ends is connected to the upstream end of the diffusion conduit 48 and the upstream end of the feed or reactor inlet assembly 46 to form a venturi tube. Figure 2 As can be seen, the circumferential wall 50 extends smoothly in width or diameter from the upstream end to the downstream end of the diffuser 48. The interior of the circumferential wall 50 may have a circular radial cross-section (relative to axis 52) along its length. The circumferential wall 50 defines the internal flow path of the inlet assembly 46.

[0049] Diffusion duct 48, and other diffusion ducts described herein, are configured for non-supersonic fluid flows. Ducts or nozzles configured for supersonic flows (e.g., de Laval nozzles) are configured differently from duct 48 to provide a supersonic flow downstream to form a shock wave. Diffusion duct 48 does not form such a supersonic flow or shock wave. Instead, duct 48 has a geometry that facilitates gas recirculation and backflow within the internal reaction chamber 40 near the central longitudinal axis 52, and an annular swirling jet of gas adjacent to the inner reactor wall 38. Therefore, diffusion duct 48 will have a larger divergence angle (e.g., 15° or less) than that typically used in de Laval nozzles. In some embodiments, the total divergence angle "A" relative to axis 52 is... Figure 2 The divergence angle A can be 25° or greater. In certain cases, the divergence angle A of the diffusion conduit discussed herein is 25° to 55°. In some embodiments, the divergence angle A is at least, equal to, and / or between any two of 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, and 55°. A large divergence angle does not cause fluid recirculation at the wall because, in this unique design, the upstream swirl is connected to a converging-split nozzle.

[0050] The downstream end of the diffusion conduit 48 is connected to the reactor wall 38 around its periphery, thereby enabling fluid communication between the diffusion conduit 48 and the reactor chamber 40 of the cracking reactor vessel 36. The upstream end of the diffusion conduit 48 or the converging conduit 54 forms the reactor inlet 56 of the reactor vessel 36.

[0051] The reactor feed assembly 58 is provided with the reactor 12. The reactor feed assembly 58 is in fluid communication with the reactor inlet 56 of the inlet assembly 46, wherein the central axis 52 passes through the reactor feed assembly 58. The feed assembly 58 includes a downstream feed assembly wall 60 that extends circumferentially around and connects to the upstream end of the reactor inlet 56. The feed assembly wall 60 is oriented perpendicular to or substantially perpendicular to the central axis 52 (i.e., ≤5 degrees from the vertical direction around its circumference).

[0052] The upstream feed assembly wall 62 is axially spaced upstream of the downstream wall 60 along the central axis 52. The upstream wall 62 is perpendicular to or substantially perpendicular to the central axis 52 (i.e., ≤5 degrees from the vertical direction around its circumference as it extends from the central axis) and extends through the central axis 52.

[0053] The upstream gas partition wall 64 and the downstream gas partition wall 66 are axially spaced apart between the downstream and upstream feed assembly walls 60, 62, and axially spaced apart from each other, with the upstream wall 64 positioned upstream of the downstream partition wall 66. The partition walls 64, 66 are also each oriented perpendicular to or substantially perpendicular to the central axis 52 (i.e., ≤5 degrees from the vertical direction around its circumference when extending from the central axis), with each partition wall having a central opening 68, 70 around the central axis 52 and concentric with the diffuser 48. The central openings 68, 70 are each circular in shape. Other shapes of the central openings 68, 70 (e.g., elliptical) may also be used, provided that such a configuration facilitates gas swirling to provide the desired flow pattern described herein. This shape may also correspond to the cross-sectional shape of the circumferential wall 50 of the diffuser 48. However, in most applications, the central openings 68, 70 may be circular. The diameter or width of the central openings 68, 70 may be the same as or slightly different (i.e., larger or smaller) than the diameter or width of the diffuser 48 at its narrowest point.

[0054] An upstream partition wall 64 defines an annular gas flow space 72 located between the upstream feed assembly wall 62 and the upstream side of the upstream partition wall 64. The flow space 72 constitutes the upstream annular hydrocarbon cracking feed inlet flow space. Similarly, an annular gas flow space 74 is defined by the downstream side of the downstream partition wall 66 and the downstream feed assembly wall 60. The flow space 74 constitutes the annular steam or water inlet flow space.

[0055] Another annular flow space 76 is defined between the upstream side of the downstream gas partition wall 66 and the downstream side of the upstream gas partition wall 64. Flow space 76 constitutes an annular fuel gas inlet flow space. The annular fuel gas inlet flow space 76 is further divided by a fuel gas partition wall 78, which is axially spaced between the downstream gas partition wall 66 and the upstream gas partition wall 64 to define the first and second annular fuel gas inlet flow spaces 80, 82. The fuel gas partition wall 78 has a central opening 84 surrounding the central axis 52 of the diffuser duct 48, and the periphery of the central opening 84 of the fuel gas partition wall 78 is radially outwardly spaced from the central openings 68, 70 and at a distance from the upstream gas partition wall 64 and the downstream gas partition wall 66, as shown. An annular combustion zone 86 is defined in the region between the upstream and downstream gas partition walls 64, 66, radially inwardly spaced from the central opening 84 of the fuel gas partition wall 78. The size of the central opening 84 can be varied to suit the vertical range of the combustion zone 86.

[0056] This configuration provides flow channels through which the hydrocarbon gas feed to be cracked, steam, oxygen, and hydrogen-rich fuel providing heat of combustion can be introduced individually and reach the central axis 52 of the diffuser duct 48 via flow spaces 72, 74, 80, and 82, respectively. In most cases, the lowest or upstream flow space 72 will constitute the hydrocarbon cracking feed inlet flow space. Steam feed is introduced into the uppermost or upstream annular steam inlet flow space 74. Fuel gas feed, including oxygen-containing gas feed and hydrogen-rich gas feed, is introduced into the first and second annular fuel gas inlet flow spaces 80 and 82. Typically, the downstream flow space 80 will be used to transport oxygen-containing gas, while the upstream flow space 82 will be used to transport hydrogen-rich fuel gas. In other cases, these may be reversed.

[0057] Flow channels 72, 74, 80, and 82 are configured such that different feeds flow through the flow space in an inwardly rotating fluid flow pattern to reach the central axis 52 of the diffuser 48, causing the feeds to flow around the central axis 52 of the diffuser 48. The fuel gas feed is primarily combusted in the small combustion zone 86 between the upstream and downstream partition walls 64 and 66 within the central opening 84 of the fuel gas partition wall 78.

[0058] The walls 60, 62, 64, 66, and 78, forming different flow spaces 72, 74, 80, and 82, are axially spaced to provide the desired volume and flow characteristics for the gases flowing through them. This can be based on the desired flow rate or linear velocity of each component in the feed gas and its relative quantity. For example, the relative volume of oxygen required for combustion is typically smaller than the relative volume of hydrogen-rich fuel gas required for combustion. Therefore, the partition wall 78 can be spaced closer to the downstream partition wall 66, resulting in a larger flow space 82 for hydrogen fuel to accommodate a larger fuel gas flow. The specific spacing can depend on the fuel gas mixture, the volume required for combustion, and the cracking feed.

[0059] Annular gas manifolds 88, 90, 92, and 94 can be arranged around the outer periphery of flow spaces 72, 74, 80, and 82, respectively. Gas manifold 88 is fluidly connected to a cracking feed source, for example... Figure 1 The cracking feed 14. Manifold 90 is fluidly connected to a steam source, for example... Figure 1 Steam feed 20. Manifold 92 is fluidly connected to an oxygen-containing gas source, such as... Figure 1 Oxygen feed 16. And manifold 92 is fluidly connected to a hydrogen-rich or fuel feed source, such as... Figure 1 The fuel feed 18. The manifolds 88, 90, 92, and 94 are equipped with reactor feed assemblies 58 to facilitate the introduction of feed gas into the flow spaces 72, 74, 80, and 82.

[0060] Gas inlets 96, 98, 100, and 102 from manifolds 88, 90, 92, and 94, respectively, can be tangentially guided into flow spaces 72, 74, 80, and 82, such that the gas is guided not only radially from inlets 96, 98, 100, and 102 towards the central axis 52, but primarily tangentially around the central axis 52 to provide an inward swirling flow pattern. Furthermore, the walls 60, 62, 64, 66, and 78 forming the different flow spaces of the feed assembly 58 prevent the gas introduced from manifolds 88, 90, 92, and 94 from flowing axially along the central axis 52 while contained within flow spaces 72, 74, 80, and 82. Manifolds 88, 90, 92, and 94 can be constructed as standard manifolds (e.g., volutes) typically used in vortex devices.

[0061] Refer again Figure 2 The mixing chamber 116 is defined by regions extending from the central openings 68 and 70 of the partition walls 62 and 70 to the reactor inlet 56. Here, heated combustion gas from the fuel gas inlet flow space 76, hydrocarbon cracking feed from the upstream hydrocarbon feed inlet flow space 72, and steam from the flow space 74 are discharged into the mixing chamber 116, causing the hydrocarbon cracking feed, steam, and heated combustion gas to mix together and form a swirling gas mixture within the mixing chamber 116. This swirling gas mixture then passes through the diffusion duct 48 and enters the reaction chamber 40 of the reactor vessel 36.

[0062] Because the oxygen-containing gas and the hydrogen-rich fuel gas are introduced separately into the flow spaces 80 and 82, rather than as a mixture, this eliminates the safety issues that would arise if these gases were premixed before being introduced into the feed assembly 58. Furthermore, the combustion reaction occurs very rapidly, with most of the combustion taking place within a very small space within the combustion zone 86, where the two oxygen-containing gas and hydrogen-rich fuel gas streams from flow spaces 80 and 82 mix immediately adjacent to the central opening 84 and before entering the mixing chamber 116.

[0063] The reaction temperature within reaction chamber 40 and recirculation zone 124 can range from 900°C to 1300°C. In specific embodiments, the temperature within the reactor and recirculation zone 124 can be from 600°C to 1300°C, more specifically from 900°C to 1250°C. In some embodiments, the reactor temperature is higher than that achieved in conventional cracking reactors, such as tubular furnace reactors, which typically operate at 800°C to 900°C. As previously mentioned, this is due to the temperature limitations of the metallic materials used in such conventional reactors. In this case, the swirling gas mixture helps keep the reactor walls much cooler than those of such conventional reactors. Using this higher temperature also allows for shorter residence or contact times, resulting in better selectivity and conversion without the formation of unwanted products. The reactor operating temperature can be selected to avoid the excessive formation of such unwanted compounds, such as acetylene.

[0064] Gas is introduced and flows through flow spaces 72, 74, 80, 82, thereby controlling the axial velocity (i.e., relative to axis 52) discharged into mixing chamber 116. The reactor inlet assembly may also include guide vanes 104, 106, 108, 110, which help provide a selected azimuthal-to-radial velocity ratio for the feed flow into the mixing chamber. Furthermore, the guide vanes are movable to selected positions. The orientation of inlets 96, 98, 100, 102 and / or guide vanes 104, 106, 108, 110 can be set for each flow space 72, 74, 80, 82 to achieve a selected azimuthal-to-radial velocity ratio for each of the feed flows through flow spaces 72, 74, 80, 82. Regarding the azimuth-to-radial velocity ratio, in specific embodiments, it can range from 0 to 30 or greater, more specifically from 0, 1, or 2 to 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30. In some applications, the azimuth-to-radial velocity ratio can range from 0 to 20, more specifically from 3 to 10. However, the specific azimuth-to-radial ratio can vary depending on the specific reactor configuration and the composition of the various feedstocks. This is more closely related to the mixing time and reaction time, depending on the flow rates and composition of the fuel and feedstock used for cracking.

[0065] The cracked hydrocarbon products generated in the reactor are removed from the reactor vessel 36 through outlet 44, where they can be quenched and further processed and recycled, as previously discussed. Figure 1 The process steps described herein are discussed.

[0066] Now for reference Figure 3The diagram shows a lower cross-sectional schematic of one embodiment of a cracking reactor system 312 of the present invention for cracking hydrocarbons (e.g., ethane, propane, LPG, butane, naphtha, natural gas, light gas oil, NGL, heavy gas oil, or combinations thereof). Reactor 312 constitutes an ANJ EVOC-C reactor and includes a reactor vessel 336 having reactor walls 338 defining an internal reaction chamber 340. Reactor walls 338 may have a cylindrical construction with a constant diameter along all or a portion of their length, which may constitute the majority of their length. In most cases, reactor 312 is vertically oriented such that the cylindrical reactor walls 338 are oriented vertically. However, the reactor may have other orientations (e.g., horizontal, inclined) because the process is controlled by centrifugal force, which exceeds gravity by several orders of magnitude. Reactor vessel 336 may be configured to provide a length-to-diameter ratio (L / D) of at least 2. In specific applications, the L / D ratio may be in the range of 2-10.

[0067] Reactor vessel 336 may be formed of steel. In some embodiments, a cooling jacket (not shown) may be provided around the reactor vessel, as taught in the prior art. In other embodiments, reactor wall 338 may be formed of one or more layers of refractory material, which is lined inside the outer steel wall to reduce heat loss and maintain the high temperature of reactor 312. Alternatively, as described elsewhere in this application, due to the unique design and operation of reactor 312, reactor wall 338 may be internally cooled by a high-speed near-wall airflow driven by centrifugal force on reactor wall 338, thus eliminating the need for an external cooling jacket in some applications. This also allows for the use of refractory material inside reactor wall 338. Refractory material (without cooling) is generally not suitable for use with conventional cracking reactors containing pure oxygen due to the high temperatures encountered (~2800°C).

[0068] An outlet (not shown) is located at the upper or lower end of reactor vessel 336 for removing or discharging cracking products from reaction chamber 340, as known in the prior art. The outlet may be located at the upper end of reactor vessel 336, or in other embodiments, it may be located at the lower end of reactor vessel 336, such that the flow through the reactor is in the opposite direction (i.e., from top to bottom). The outlet diameter may be the same as the diameter of reactor wall 338, or the outlet diameter may be reduced to accelerate flow before downstream quenching and collection.

[0069] Reactor 312 includes a diffusion conduit 348 connected to or linked to the lower or upper end of the reactor wall 338 of reactor vessel 336. The diffusion conduit 348 has a circumferential wall 350 surrounding the central longitudinal axis 352 of the reactor. In some embodiments, the wall 350 may be a straight wall; in other embodiments, the wall 350 may be similar to... Figure 2The divergent curved walls 54 and 55 are present. With reactor 312 vertically oriented, the central axis 352 will also be vertically oriented and will be concentric or parallel to the central vertical axis of reactor vessel 336. In the illustrated embodiment, the central axis 352 is concentric and aligned with the central longitudinal axis of reactor vessel 336. Circumferential walls 350 extend from opposite upstream and downstream ends of diffuser duct 348. As used herein, the terms “upstream” and “downstream” or similar expressions describing various components of reactor system 312 should refer to the position of the component relative to the overall fluid flow direction through reactor 312 along central axis 352.

[0070] like Figure 3 As can be seen, the circumferential wall 350 extends smoothly in width or diameter from the upstream end to the downstream end. The interior of the circumferential wall 350 may have a circular radial cross-section (relative to axis 352) along its length. The circumferential wall 350 defines the internal flow path of the diffuser duct 348. Although the diffuser duct 348 is... Figure 3 The diagram shows a linear expansion form, but it can take other shapes and rates of diameter change. The total divergence angle of the conduit 348 or wall 350 can be related to... Figure 2 The same as that described in reactor 12. The downstream end of diffusion conduit 348 is connected to reactor wall 338 around its periphery, such that diffusion conduit 348 is in fluid communication with reactor chamber 340 of cracking reactor vessel 336.

[0071] The upstream end of the diffusion conduit 348 is connected to the reactor feed assembly 358 of the reactor vessel 336. The feed assembly 358 includes an outer feed assembly wall 360 that extends circumferentially around and connects to the upstream end of the reactor inlet 356. The feed assembly wall 360 is oriented parallel to or substantially parallel to (i.e., ≤5 degrees axially around its circumference) the central axis 352. Although only a portion of the reactor 312 is shown, the feed assembly 358 extends concentrically around the entire circumference of the upstream end of the diffusion conduit 348.

[0072] A plurality of gas partition walls 364 are provided along the length of the feed assembly 358. The partition walls 364 are oriented each parallel to or substantially parallel to (i.e., ≤5 degrees axially from the central axis) the central axis 352, wherein each partition wall has an annular opening 368 surrounding the central axis 352 and aligned with the diffuser duct 348. Each opening 368 preferably has a circular or annular configuration. Other shapes of the annular opening 368 (e.g., elliptical) may also be used, as long as such configuration facilitates gas swirling to provide the desired flow pattern described herein. This shape may also correspond to the cross-sectional shape of the circumferential wall 350 of the diffuser duct 348. However, in most applications, the opening 368 will be circular or annular.

[0073] Partition wall 364 defines a series of annular flow spaces 372A, 372B, 372C, and 372D. Flow spaces 372A, 372B, 372C, and 372D constitute a set of feed inlet flow spaces. These feed inlet flow spaces are used to introduce various feeds into the reactor. Although shown here as having four inlets, any number of flow inlets may actually exist, depending on the number of partition walls 364.

[0074] Finally, each flow space 372 also includes guide vanes 304. Each guide vane 304 can control the direction in which the feed enters the reactor, preferably producing a swirling effect, as discussed further below.

[0075] The innermost flow space 372D is enclosed by a bluff body wall 380. The bluff body wall 380 is perpendicular to the central axis 352 and centered on the central axis 352. The radius of the bluff body wall can vary based on the application and flow analysis.

[0076] The arrangement of the feed inlet flow spaces 372 controls the relative positions of the flame front 320 and the hottest gas within the reaction chamber 340 relative to the central axis 352 and the reactor wall 338. The feed can be, for example, hydrocarbons for cracking, steam, an oxygen-enriched feed stream (e.g., oxygen or more steam), and a hydrocarbon- or hydrogen-enriched feed stream (e.g., methane or hydrogen). In a preferred embodiment, the outermost (i.e., furthest from the central axis) flow space 372A will deliver steam, the next flow space 372B will deliver an oxygen-enriched feed stream, the next flow space 372C will deliver a hydrocarbon or hydrogen-enriched feed stream, and finally, the innermost 372D will deliver the hydrocarbon feedstock to be cracked. This configuration with appropriate flow rates will create the flame front 320 within the reactor 336, where the hot combustion gases are closer to the reactor wall 338, while the relatively cooler feedstock is closer to the central axis 352. In another preferred embodiment, the four feeds can be reversed, with the hydrocarbon cracking feed on the outermost side, followed by a hydrogen-rich feed stream, then an oxygen-rich feed stream, and finally steam, with the steam closest to the central axis 352. This results in hot combustion gases surrounding the central axis 352 in the core of reactor 336, while the cooler feed gases will be closer to the reactor wall 338. Therefore, reactor wall 338 will require less heat-resistant material, thus reducing the cost of constructing reactor 336.

[0077] The flow channel 372 is configured such that different feeds pass through the flow space in an inward swirling fluid flow pattern to reach the central axis 352 of the diffuser 348, such that the feeds flow around the central axis 352 of the diffuser 348.

[0078] The walls 364 forming different flow spaces 372 are arranged to provide the desired volume and flow characteristics for the gases flowing through them. This can be based on the desired flow rate or linear velocity of each component in the feed gas and their relative amounts. For example, the relative volume of oxygen required for combustion is typically smaller than the relative volume of hydrogen-rich fuel gas required for combustion. Specific spacing can depend on the fuel gas mixture, the required volume for combustion, and the cracking feed.

[0079] refer to Figure 3 In operation, the cracking feed is introduced into one of the flow spaces 372, for example, the outermost flow space 372A. The cracking feed can be ethane, LPG, butane, naphtha, natural gas, light gas oil, NGL, heavy gas oil, or a combination thereof. While these cracking feeds are typically introduced in gaseous form, in some cases they can be introduced in liquid form. Once introduced as liquid, they evaporate rapidly within the reactor. This can be advantageous, for example, in conventional cracking systems where light and heavy gas oils typically evaporate outside the reactor. However, this external evaporation creates coking problems. These problems are avoided by injecting them directly into the reactor in liquid form. The cracking feed is typically denser than the combustion products. This is a result of the high molecular weight of the cracking feed and its density at a selected temperature. Due to very high centrifugal acceleration (100,000-1 mg force), the denser gas / liquid moves outward, while the lighter combustion products move inward. Due to high swirling, the denser hydrocarbons rapidly mix with the surrounding combustion products at very high temperatures.

[0080] Hydrogen-containing fuel gas is introduced into the next inward annular gas flow space 372B. The hydrogen- or hydrocarbon-containing fuel gas can be hydrogen (H2) and / or methane (CH4). In some embodiments using a combination of hydrogen and methane, methane may be present in the fuel gas in amounts of 20 mol%, 15 mol%, 10 mol%, 5 mol%, or less. Larger amounts of methane can affect the desired selectivity. However, in other embodiments, even larger amounts of methane can be used, including 100% methane in the fuel gas. Natural gas may also be used as the fuel gas.

[0081] Hydrogen-containing fuel gas can be a hydrogen-rich gas stream mainly composed of hydrogen, which can be a recirculation stream, such as recirculation stream 32. Figure 1 Alternatively, additional hydrogen gas, such as stream 34, may be present. The hydrogen-rich gas stream may contain other components, such as methane, CO, steam, or CO2. In some embodiments and applications, other hydrocarbons may also be used as fuel gases. Additionally, small amounts of N2 may be present. Sulfur may also be present in the fuel gas or other feed streams. If sulfur is present, additional downstream separation may be required. The reactor and process are robust enough to accommodate the presence of sulfur, especially since no catalyst is used. The mass ratio between cracking feed and hydrogen-containing fuel is typically 1 to 10.

[0082] The oxygen-containing gas can be concentrated or pure oxygen gas, for example from an air separation unit (not shown), introduced as oxygen feed through the next inward annular flow space 372C. In some applications, the H2 / O2 molar ratio can be 2 to 5, more particularly 2 to 4. The oxygen feed can provide an oxygen equivalent-to-fuel mole ratio of 0.2 to 1.0. Excess hydrogen also helps to scavenge free radicals (e.g., H, CH3, O, OOH, OH) that would otherwise react with the cracking feed.

[0083] Finally, steam or water is introduced through the innermost part of the flow space 372D. The introduced steam helps to lower the reaction temperature within reactor 312. The steam can also be premixed with various feeds, such as cracked gas feeds and / or oxygenated feeds. In some applications, steam with a steam-to-fuel ratio greater than 0 to 2.0 can be used.

[0084] Now for reference Figure 4 Another embodiment of the present invention is disclosed. (Compared to...) Figure 3 Similar to the implementation described above, reactor 412 includes a reactor vessel 436 having a reactor wall 438 connected to a diffusion conduit 448, which in turn connects to a reactor feed assembly 458. The total divergence angle of the diffusion conduit 448 can be the same as described above. In this case, a single flow space 474 enters the feed assembly 458 perpendicular to the central axis 452. The remaining two flow spaces 476 and 478 still flow into the feed assembly 458 parallel to the central axis. In this configuration, hydrocarbon feedstock enters the feed assembly 458 from flow space 474, while a hydrogen-rich feed stream enters via flow space 476, and an oxygen-rich feed stream and steam enter via flow space 478.

[0085] The feed assembly 458 will also include guide vanes 404 to further control the flow direction entering the feed assembly 458. Finally, the innermost flow space 478 is bordered by a blunt body wall 480. The blunt body wall 480 is perpendicular to and centered on the central axis 452. The radius of the blunt body wall can vary based on application and flow analysis. It should also be noted that the flame leading edge 420 will be affected by the selection of feed entering the feed assembly 458 from various flow spaces.

[0086] This arrangement alters the mixing and swirling characteristics within the reactor, thereby changing the reaction kinetics and consequently the conversion, selectivity, and yield exiting reactor 412. The improved and potentially optimal flow characteristics can be determined through experimental testing or using modern, sophisticated modeling tools known in the art.

[0087] Now for reference Figure 5 Another embodiment of the present invention is disclosed. Similar to... Figure 3 and 4 In this embodiment, reactor 512 includes reactor vessel 536, which is connected to diffusion conduit 548, which in turn is connected to reactor feed assembly 558. The total divergence angle of diffusion conduit 548 can be the same as described above. In this case, a single flow space 574 enters feed assembly 558 parallel to the central axis 552. The remaining two flow spaces 576 and 578 still flow into feed assembly 558 and are oriented perpendicular to the central axis. In this configuration, hydrocarbon feedstock will enter feed assembly 558 from flow space 574, while hydrogen-rich feed stream will enter via flow space 576, and oxygen-rich feed stream and steam will enter via flow space 578.

[0088] The feed assembly 558 will also include guide vanes 504 to further control the flow direction entering the feed assembly 558. Finally, the interior of the flow space 574 is a blunt body wall 580. The blunt body wall 580 is perpendicular to the central axis 552 and centered on the central axis 552. The radius of the blunt body wall can vary based on the application and flow analysis.

[0089] This arrangement again alters the mixing and swirling characteristics within the reactor, thereby changing the reaction kinetics and thus the conversion, selectivity, and yield of the feed from reactor 512. The improved and potentially optimal flow characteristics can be determined through experimental testing or using modern, sophisticated modeling tools known in the art. Importantly, this illustrates the concept that reactor performance can be improved by varying the angle of the inlet flow of different combustion components. In practice, while various flows are shown in these examples as axial, vertical, or some of each orientation, any other angle would be acceptable. It should be noted that this configuration will likely have a flame leading edge originating from the edge of the flow space 578.

[0090] Now for reference Figure 6 Another embodiment of the present invention is disclosed. Similar to... Figure 3-5In one embodiment, reactor 612 includes a reactor vessel 636 connected to a diffusion conduit 648, which in turn connects to a reactor feed assembly 658. The total divergence angle of the diffusion conduit 648 can be the same as described above. In this case, the three flow spaces 674, 676, and 678 of the feed assembly 658 are oriented parallel to the central axis 652. Additionally, compared to flow spaces 674, 676, and 678, the atomizer 690 is positioned closer to the central axis 652 and oriented parallel to it. The feed assembly 658 also includes guide vanes 604, each for each flow space. The atomizer 690 is used to inject liquid hydrocarbon feedstock, while flow spaces 674, 676, and 678 are used to inject other feed streams, including oxygen-enriched feed streams, hydrogen-enriched feed streams, and steam.

[0091] Furthermore, placing the hydrocarbon feed stream at the innermost edge means that the outer wall of reactor vessel 636 will be where the hot combustion gases reside during operation, while the core of reactor vessel 636 will be cooler due to the hydrocarbon feed stream, which enters via an atomizer. Other configurations can be utilized based on the desired reaction characteristics.

[0092] Similarly, this arrangement again alters the mixing and vortex characteristics within the reactor, thereby changing the reaction kinetics and thus the conversion, selectivity, and yield of the feed from reactor 612, as well as the position of the flame front 620. Improved and potentially optimal flow characteristics can be achieved through experimental testing or using modern, sophisticated modeling tools known in the art. Importantly, this demonstrates the concept that reactor performance can be improved by varying the angle of the inlet flow for various combustion components. In practice, while various flows are shown in these examples as axial, vertical, or some of each orientation, any other angle is acceptable.

[0093] Now for reference Figure 7 Another embodiment of the present invention is disclosed. Similar to... Figure 3-6 In one embodiment, reactor 712 includes a reactor vessel 736 connected to a diffusion conduit 748, which in turn is connected to a reactor feed assembly 758. The total divergence angle of the diffusion conduit 748 can be the same as described above. In this case, the two flow spaces 774 and 778 of the feed assembly 758 are oriented perpendicular to the central axis 752. Furthermore, compared to flow spaces 774 and 778, atomizer 790 is positioned closer to the central axis 752 and oriented parallel to it. Atomizer 790 is used to inject liquid hydrocarbon feedstock, while flow spaces 774 and 778 are used to inject other feed streams, such as oxygen-enriched vapor and hydrogen-enriched gas streams.

[0094] Secondly, placing the hydrocarbon feed stream at the innermost edge means that the outer wall of reactor vessel 636 will be where the hot combustion gases reside during operation, while the core of reactor vessel 636 will be cooler due to the hydrocarbon feed stream, which enters via an atomizer. Furthermore, this arrangement alters the mixing and swirling characteristics within the reactor, thereby changing the reaction kinetics and thus the conversion, selectivity, and yield of the output from reactor 712. The improved and potentially optimal flow characteristics can be determined through experimental testing or using modern, sophisticated modeling tools known in the art. Importantly, this illustrates the concept that reactor performance can be improved by varying the angle of the inlet flow of various combustion components. In practice, while various flows are shown in these examples as axial, vertical, or some of each orientation, any other angle is acceptable. It should be noted that this configuration will likely have a flame leading edge originating from the edge of the flow space 774.

[0095] In each case, from Figures 3 to 7 The volumetric flow rate is controlled to create a swirling pattern within the reactor, resulting in an excellent reaction with high yield and conversion. Optimal flow rates for all various flow streams, as well as the actual compositional details and shape of the reactor, are optimized through software modeling to achieve the best reaction outcomes. It is worth noting that if it is desired to keep the walls relatively cool, methods such as... Figure 4 The design shown is acceptable. If the coldest part of the reactor chamber is preferably oriented towards the center, one of the other designs can be used.

[0096] Compared to other conventional cracking methods, the reactor design described in this paper is characterized by high feed conversion and higher olefin selectivity. The reactor construction is relatively simple, which significantly reduces capital and operating costs. A highly swirling gas mixture is combusted with unmixed fuel gas (i.e., H₂ + O₂) in a small combustion zone within the feed assembly to achieve a stable and compact combustion process. The reactor walls are cooled by a swirling vapor stream against the walls, allowing for higher temperatures within the reactor and requiring shorter residence times, resulting in the production of more desirable products (e.g., ethylene). Maintaining lower reactor wall temperatures also allows for the use of refractory materials instead of metallic materials, thereby minimizing heat loss.

[0097] Because the heated combustion gases are directly mixed with the cracking feed in the swirling gas mixture, direct gas-to-gas heat transfer occurs for the cracking reaction. This differs from conventional cracking reactors, such as tubular furnaces, which rely on indirect heat transfer, where heat is transferred through the reactor tube walls from a separate heat source (e.g., external combustion gases). Here, the process is intensified by the immediate combination of the exothermic step of heat provided from the combustion of the fuel feed and the endothermic step of the cracking feed. Therefore, as with conventional systems, energy losses due to heat transfer through the reactor walls and equipment are eliminated or minimized. The reactor can be scaled up by increasing the feed rate or by increasing its size.

[0098] While the above discussion uses general terms to refer to various fluids, this does not mean that the method and apparatus require absolutely pure components. In fact, a certain amount of impurities can be tolerated without compromising the overall process. For example, air or any other oxygen-containing gas mixture can be used instead of oxygen.

[0099] The following examples are used to further illustrate various implementation methods and applications.

[0100] Example 1

[0101] These configurations have been used for CFD simulations to support the design concept. The following are... Figure 3 The results of the embodiments shown depict fluids arranged in two different patterns: Design A (feed near the central axis), where the fluid from the outermost center to the outermost edge comprises hydrocarbons, hydrogen-rich fuel, oxygen-rich fuel, and steam; and Design B (feed near the outer wall), where the flow from the outermost edge to the outermost center comprises hydrocarbons, hydrogen-rich fuel, oxygen-rich fuel, and steam. These results are compared with previous radial feed designs ( Figure 2 The results are compared (as shown in the diagram). Other designs exhibit similar performance to those shown here, but may offer different operational advantages. The operating conditions for the three designs are shown in Table 1. The new axial feed design features zero vapor dilution, resulting in higher hydrocarbon conversion, but slightly lower selectivity for C2H4 / C2H2.

[0102] Table 1 Operating conditions for feeding the ANJEVOC-C reactor.

[0103]

[0104] Table 1 shows the C2H4 mass fraction distribution in the previous radial feed design and the current axial feed design B (near-wall feed) reactor. The axial feed design can increase the feed hydrocarbon conversion from ~68% to 91%, but has slightly lower C2H4 and C2H2 selectivity, and an overall higher C2H4 and C2H2 yield of ~61.5%.

[0105] Similarly, axial feed designs with cracked gas feed near the shaft show slightly better performance, as shown in Table 2 below.

[0106] Table 2 Operating conditions for axial feed ANJEVOC-C reactor

[0107]

[0108] Table 2 shows a comparison of the C2H4 / C2H2 / CO distribution of the main product gas composition between the previous radial feed design and the current axial feed design (Design B). In all cases, the axial feed design yields a higher product gas concentration due to its higher hydrocarbon conversion (above 90%) compared to the previous radial feed design.

[0109] While the invention has been shown in some forms, it will be apparent to those skilled in the art that the invention is not limited thereto, but that various changes and modifications can be readily made based on experimental data or consideration of the overall economic efficiency of the process without departing from the scope of the invention. Therefore, it is reasonable that the appended claims be interpreted broadly and in a manner consistent with the scope of the invention.

Claims

1. A reactor system for hydrocarbon conversion comprising: a reactor vessel having a reactor wall to bound a reaction chamber; a reactor inlet assembly having a diffusion conduit having a circumferential wall that surrounds a central longitudinal axis and extends from opposite upstream and downstream ends of the diffusion conduit, the width of the circumferential wall expanding from the downstream end to the upstream end of the diffusion conduit, the downstream end of the diffusion conduit being in fluid communication with the reaction chamber of the reactor, the upstream end of the diffusion conduit forming an inlet of the reactor inlet assembly; a feed assembly in fluid communication with the inlet of the reactor inlet assembly, wherein a central axis passes through the feed assembly, the feed assembly extending concentrically around the entire circumference of the upstream end of the diffusion conduit, including: an outer feed assembly wall extending circumferentially around and connecting the upstream end of the reactor inlet, the outer feed assembly wall oriented parallel to the central axis; a plurality of gas partition walls disposed along the length of the feed assembly, the gas partition walls each oriented parallel to the central axis, wherein each of the partition walls has an annular opening that surrounds the central axis and is aligned with the diffusion conduit; the gas partition walls bounding a series of annular gas flow spaces that make up a set of feed inlet flow spaces; inside the innermost of the annular gas flow spaces is a bluff body wall that is perpendicular to and centered on the central axis; wherein the relative positions of the flame front and hottest gas within the reaction chamber relative to the central axis and the reactor wall are controlled by varying the feed inlet flow spaces through which the feed passes; the feed inlet flow spaces are configured so that different feeds pass through the flow spaces in an inwardly swirling fluid flow pattern within the feed flow space to the central axis of the diffusion conduit so that the feed flows around the central axis of the diffusion conduit.

2. The reactor system of claim 1, wherein, All of the inlet flow spaces have their respective feed streams enter the reactor in a direction that is generally parallel to the central longitudinal axis.

3. The reactor system of claim 2, wherein, The reactor inlet assembly further comprises guide vanes, wherein the guide vanes provide a selected azimuthal to radial velocity ratio of the feed stream flowing into the mixing chamber, and wherein the guide vanes are movable to selected positions.

4. The reactor system of claim 1, wherein, One of the feed streams comprises steam.

5. The reactor system of claim 1, wherein, There are at least four feed streams, the streams comprising oxygen, methane, hydrogen, and one or more of C2, C4, or naphtha; The feed assembly further comprises feed inlet flow spaces that enter the feed assembly perpendicular to the central axis.

6. The reactor system of claim 5, wherein, Further comprising a steam feed stream.

7. The reactor system of claim 5, wherein, The oxygen, methane, and hydrogen flow parallel to the central longitudinal axis, while the C2, C4, or naphtha flow perpendicularly.

8. The reactor system of claim 5, wherein, The oxygen, methane, and hydrogen flow perpendicular to the central longitudinal axis, while the C2, C3, C4, naphtha, or other higher hydrocarbon feed flows axially.

9. The reactor system of claim 6, wherein, All of the feed streams flow axially into the reactor relative to the central longitudinal axis.

10. The reactor system of claim 3, wherein, The feed stream that enters through a swirl atomizer is naphtha, crude oil, or liquid phase NGL.

11. The reactor system of claim 10, wherein, The remaining feed stream that does not pass through the cyclone atomizer is methane, hydrogen, oxygen, and water, including steam.

12. The reactor system of claim 10, wherein, All remaining feed streams enter the reactor parallel to the central longitudinal axis.

13. The reactor system of claim 10, wherein, All remaining feed streams enter the reactor perpendicular to the central longitudinal axis.

14. The reactor system of claim 10, wherein, One or more remaining feed streams enter the reactor axially to the central longitudinal axis and one or more remaining inlet streams enter the reactor perpendicular.

15. The reactor system of claim 1, wherein, The selection and arrangement of the one or more flow inlet spaces is such that the portion of the feed stream comprising the cold feedstock can be controlled relative to the arrangement of hot combustion gases present in the reactor, relative to the outer wall.

16. The reactor system of claim 15, wherein, The cold feedstock first enters the reactor in closest proximity to the outer wall and then moves radially inward to interact with the hot combustion gases.

17. The reactor system of claim 16, wherein, The cold feedstock enters the reactor at or near the center of the reactor and moves radially outward to interact with the hot combustion gases.

18. The reactor system of claim 1, wherein, The one or more feed streams comprise methane, hydrogen, and oxygen.

19. The reactor system of claim 18, wherein, Another of the one or more feed streams comprises water, including steam.

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