Fluidized bed reactor system and continuous process for catalytic cracking of light hydrocarbons

Abstract

A fluidized bed reactor system includes a fluidized bed reactor configured to receive an upwardly flowing heated light hydrocarbon feed stream and a heated regenerated catalyst at a temperature sufficient to crack the heated light hydrocarbon feed stream to produce a product effluent stream comprising hydrogen and a spent catalyst comprising coke deposits; a catalyst regeneration unit in operative connection with the bottom of the fluidized bed reactor, the catalyst regeneration unit configured to receive the spent catalyst flowing downward and to combust the coke deposit, to produce the heated regenerated catalyst and a heated gaseous effluent for producing the heated light hydrocarbon feed stream; and a riser externally connected to the fluidized bed reactor and the catalyst regeneration unit, the riser configured to receive the heated regenerated catalyst and a gas-based flow to cause the heated regenerated catalyst to flow upward to the fluidized bed reactor.

Description

[0001] Priority requirements

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 601,829, filed November 22, 2023, entitled “Fluidized Bed Reactor System for Catalytic Cracking of Light Hydrocarbons,” the contents of which are incorporated herein by reference in their entirety. Background Technology

[0003] The ongoing search for alternatives to crude oil is increasingly driven by a number of factors, including dwindling oil reserves, anticipated increases in energy demand, and growing concerns about greenhouse gas emissions from non-renewable carbon sources. Given abundant natural gas reserves and a rich gaseous stream from biogas sources, natural gas has become a focus of attention for providing multiple potential pathways for liquid hydrocarbons. Natural gas exists underground and is gaseous when ejected from the ground. It is primarily composed of methane (CH4) and other flammable compounds such as ethane (C2H6) and propane (C3H8). Therefore, converting light hydrocarbons such as methane into higher-value products such as hydrogen, olefins, and aromatics has become an attractive option. Summary of the Invention

[0004] According to the illustrative implementation scheme, a continuous method includes:

[0005] The fluidized bed reactor receives an upward-flowing first heated light hydrocarbon feed stream and a first heated regenerated catalyst at the top, the temperature of which is sufficient to crack the first heated light hydrocarbon feed stream to produce a first product effluent stream containing hydrogen and a spent catalyst containing coke deposits.

[0006] In a catalyst regeneration unit that is operationally connected to the bottom of the fluidized bed reactor, spent catalyst containing the coke deposits is burned to produce a second heated regenerated catalyst and a heated gas effluent.

[0007] The heated gas effluent is used to heat the light hydrocarbon feed stream to produce a second heated light hydrocarbon feed stream; and

[0008] In a riser externally connected to the catalyst regeneration unit and the fluidized bed reactor, the second heated regenerated catalyst from the catalyst regeneration unit flows together with the gas-based stream toward the top of the fluidized bed reactor to contact the upward-flowing second heated light hydrocarbon feed stream, thereby producing a second product effluent stream containing hydrogen and additional spent catalyst containing coke deposits.

[0009] According to another illustrative embodiment, a fluidized bed reactor system includes:

[0010] A fluidized bed reactor configured to receive an upward-flowing heated light hydrocarbon feed stream and a heated regenerated catalyst at a temperature sufficient to crack the heated light hydrocarbon feed stream to produce a product effluent stream containing hydrogen and a spent catalyst containing coke deposits.

[0011] A catalyst regeneration unit, operably connected to the bottom of the fluidized bed reactor, is configured to receive the downward-flowing spent catalyst and combust the coke deposit to produce the heated regenerated catalyst and a heated gaseous effluent for producing the heated light hydrocarbon feed stream; and

[0012] A riser is externally connected to the fluidized bed reactor and the catalyst regeneration unit. The riser is configured to receive the heated regenerated catalyst and a gas-based flow so that the heated regenerated catalyst flows upward toward the fluidized bed reactor. Attached Figure Description

[0013] Features, advantages, and other aspects of embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description, and several embodiments of this disclosure are illustrated herein by way of example rather than limitation. The principles shown in the exemplary embodiments in the drawings can be applied to other methods and apparatuses. Furthermore, the elements and features shown in the drawings are not necessarily drawn to scale, but rather the emphasis is on clearly illustrating the principles of the exemplary embodiments. To facilitate a more intuitive understanding of these principles, certain dimensions or locations may be exaggerated. In the drawings, the same reference numerals used in different embodiments denote similar or corresponding elements, but not necessarily the same elements. In the drawings:

[0014] Figure 1 A schematic diagram is shown of a fluidized bed reactor system and method for catalytic cracking heating of a light hydrocarbon feed stream to produce a product effluent stream containing hydrogen and spent catalyst, according to an illustrative embodiment.

[0015] Figure 2 A schematic diagram is shown of a fluidized bed reactor system and method for catalytic cracking heating of a light hydrocarbon feed stream to produce a product effluent stream containing hydrogen and spent catalyst, according to an alternative illustrative embodiment. Detailed Implementation

[0016] The various illustrative embodiments described herein relate to fluidized bed reactor systems and methods for catalytic cracking of light hydrocarbons to produce a product effluent containing hydrogen and spent catalyst. This provides an alternative to crude oil by converting light hydrocarbons into high-value-added chemicals, materials, and fuels.

[0017] The direct conversion of light hydrocarbons such as methane can produce high-molecular-weight hydrocarbons such as alkenes, alkynes, and aromatics (e.g., benzene) as high-value-added chemicals, while also generating hydrogen that can be used to manufacture fuels. Hydrogen energy is one of the important clean energy options for the future. However, the selectivity of the desired products obtained from catalytic cracking methods will depend on the specific type of catalyst and reaction conditions. Furthermore, the reaction is highly endothermic, and the exact value of the heat of reaction will depend on the desired product distribution; for example, the enthalpy of CH4 is in the range of approximately 90 kJ / mol. This is also an equilibrium-limited reaction, typically requiring high temperatures to achieve the conversion of CH4, which is feasible for commercial applications. For example, for commercial viability, the reactor temperature needs to be maintained in the range of 600°C to 1200°C.

[0018] Beyond the costs associated with such high-temperature reactions, the required heat presents other practical challenges. For example, the formation of coke or solid carbon in the reactor becomes common at these temperatures, negatively impacting the yield of valuable products and potentially leading to reactor blockage and catalyst deactivation. Such high temperatures may also necessitate expensive reactor materials and make reactor design highly challenging.

[0019] Given these challenges, there is a need for a cost-effective solution for producing hydrogen and high-value-added chemicals from light hydrocarbons. Furthermore, for the reactor design of this method, it would be advantageous if it could (1) provide the heat of reaction required to maintain an optimized temperature profile for high conversion rates, and (2) regenerate and recover the catalyst used. It would be even more advantageous if such a solution were more energy-efficient than existing methods for producing hydrogen and high-value-added chemicals.

[0020] definition

[0021] To more clearly define the terms used herein, the following definitions are provided. Unless otherwise stated, the following definitions apply to this disclosure. If a term is used in this disclosure but is not specifically defined herein, the definition from the IUPAC Compendium of Chemical Terminology may apply, provided that the definition does not conflict with any other disclosure or definition applied herein, or render any claim to which the definition applies ambiguous or impractical. If any definition or usage provided by reference in any document incorporated herein conflicts with the definition or usage provided herein, the definition or usage provided herein shall prevail.

[0022] Although systems and methods are described as “comprising” various components or steps, unless otherwise stated, systems and methods may also be “substantially composed of various components or steps” or “composed of various components or steps”.

[0023] The terms “an,” “a,” and “the” are intended to include multiple alternatives, such as at least one. The terms “including” and / or “with, having” as used herein are defined as comprising (i.e., open-ended terms) unless otherwise specified.

[0024] This document discloses various numerical ranges. When an applicant discloses or claims protection for any type of range, unless otherwise stated, the applicant's intent is to individually disclose or claim protection for every possible numerical value that such range can reasonably cover, including the endpoints of the range and any subranges and combinations of subranges covered therein. For example, all numerical endpoints of the ranges disclosed herein are approximate values ​​unless excluded by an accompanying clause.

[0025] Values ​​or ranges herein may be expressed as “about,” from “about” a particular value, and / or to “about” another particular value. When expressing such values ​​or ranges, other disclosed embodiments include the specific values ​​listed, from one particular value, and / or to another. Similarly, when a value is expressed as an approximation using the antecedent “about,” it should be understood that the specific value forms another embodiment. It will be further understood that numerous values ​​are disclosed herein, and each value is also disclosed herein as “about” that particular value, in addition to being the value itself. On the other hand, the use of the term “about” means ±20% of the value, ±15% of the value, ±10% of the value, ±5% of the value, ±3% of the value, or ±1% of the value.

[0026] If, for any reason, the applicant chooses not to claim protection for all publicly disclosed content, such as references that the applicant may not have been aware of at the time of filing, the applicant reserves the right to limit or exclude any individual member of any such value or group of ranges (including any sub-ranges or combinations of sub-ranges within a group) that can be claimed based on scope or in any similar manner. Furthermore, the applicant reserves the right to limit or exclude any member of the group for which protection is claimed.

[0027] The term “continuous” as used herein should be understood as a system that operates without interruption or cessation over a period of time, such as a system in which reactants and catalysts are continuously fed into the reaction zone and products are continuously or periodically removed without stopping the reaction within the reaction zone.

[0028] The term "fresh catalyst" as used in this article refers to a catalyst that has not been previously used in catalytic methods.

[0029] As used herein, “used catalyst” refers to a catalyst that exhibits lower activity under the same reaction conditions (e.g., temperature, pressure, inlet flow rate) than the catalyst initially exposed to the method. This can be due to a number of reasons, and several non-limiting examples of catalyst deactivation causes include adsorption or accumulation of coking or carbonaceous materials, steam or hydrothermal deactivation, adsorption or accumulation of metals (and ash), wear, morphological changes (including pore size changes), cation or anion substitution, and / or chemical or compositional changes.

[0030] As used herein, “regenerated catalyst” refers to a spent catalyst as defined above, which is then subjected to a process to increase its activity to a level higher than when it was a spent catalyst. This may involve, for example, reversing the conversion or removing contaminants outlined above as possible causes of reduced activity. The activity of a regenerated catalyst is typically equal to or lower than that of a fresh catalyst.

[0031] The term “primary” should be understood as a quantity greater than 50%, such as 50.01% to 100%, or any range between, for example, 51% to 95%, 75% to 90%, at least 60%, at least 70%, at least 80%, etc.

[0032] The non-limiting illustrative embodiments described herein provide a fluidized bed reactor system and method that utilizes at least one fluidized bed reactor, a catalyst regeneration unit, and a riser to catalytically crack a light hydrocarbon feed stream into, for example, components containing C2 to C3. 10 The product streams of hydrocarbon products and hydrogen overcome the aforementioned drawbacks.

[0033] The following describes in detail, with reference to the accompanying drawings, a non-limiting illustrative embodiment of the present disclosure. For clarity, details resulting from C2 to C2 may be omitted. 10 Hydrocarbon products and hydrogen effluents, as well as... Figure 1 and Figure 2 The accompanying drawings illustrate some steps of the spent catalyst process. In other words, one or more well-known processing steps, not shown but familiar to those skilled in the art, are not included in the drawings. This should not be construed as limiting any particular embodiment, example, or the scope of the claims.

[0034] General methods

[0035] The non-limiting illustrative embodiments described herein relate to a continuous process for catalytically cracking a light hydrocarbon feed stream using a fluidized bed reactor system to produce a product containing C2 to C4 hydrocarbons. 10The method includes: hydrocarbon product and hydrogen effluent streams, and spent catalyst. In a non-limiting illustrative embodiment, the method comprises: receiving an upward-flowing heated light hydrocarbon feed stream and a first heated regenerated catalyst at the top of a fluidized bed reactor, the temperature of which is sufficient to pyrolyze the heated light hydrocarbon feed stream to produce a product effluent stream containing hydrogen and spent catalyst containing coke deposits; in a catalyst regeneration unit operatively connected to the bottom of the fluidized bed reactor, burning the spent catalyst containing the coke deposits to produce a second heated regenerated catalyst and a heated gas effluent; heating the light hydrocarbon feed stream with the heated gas effluent to produce a second heated light hydrocarbon feed stream; and in a riser externally connected to the catalyst regeneration unit and the fluidized bed reactor, allowing the second heated regenerated catalyst from the catalyst regeneration unit to flow along with a gas-based stream to the top of the fluidized bed reactor to contact the second heated light hydrocarbon feed stream, thereby producing a second product effluent stream containing hydrogen and additional spent catalyst containing coke deposits.

[0036] There are no particular limitations on the light hydrocarbon stream used, and it may include, for example, C1 to C6, C1 to C4, C1 to C3, or C1 to C2 alkanes, such as methane, ethane, or natural gas, either pure or in any suitable mixture. In some embodiments, the light hydrocarbon stream may also contain small amounts of other components, including, for example, sulfur compounds such as carbon dioxide, H2S, water, nitrogen, and mixtures thereof. In some embodiments, the light hydrocarbon stream may also include steam, superheated steam, inert gases such as nitrogen, or any mixture thereof. In some embodiments, the light hydrocarbon stream used may include any suitable composition such that the resulting product includes at least hydrogen.

[0037] In some embodiments, the light hydrocarbon stream comprises methane or natural gas, for example, a light hydrocarbon stream comprising more than about 80%, or more than about 90%, or more than about 95%, or more than about 99% methane. Natural gas as used herein comprises methane and possibly more carbon alkanes, carbon dioxide, nitrogen or other gases, and / or sulfur-containing compounds such as hydrogen sulfide, and mixtures thereof. In illustrative embodiments, the light hydrocarbon feed stream may further contain a portion of the generated products, which are recycled back to the light hydrocarbon feed stream along with unreacted methane.

[0038] The resulting products typically contain C2 to C3. 10 Hydrocarbon product hydrogen gas. C2 to C 10 The hydrocarbon product is not particularly limited and can be, for example, saturated hydrocarbons, unsaturated hydrocarbons, aromatic hydrocarbons, or mixtures of these compounds. Examples of aromatic hydrocarbons include benzene, toluene, xylene, naphthalene, and methylnaphthalene. In some embodiments, depending on the desired product and the reaction used, C2 to C3... 10Hydrocarbon products may include ethylene, propylene, acetylene, benzene, naphthalene, and various mixtures thereof. Furthermore, those skilled in the art will understand that, depending on the specific methane conversion method, the resulting C2 to C4 hydrocarbons will vary. 10 Hydrocarbon products can be liquid C2 to C2. 10 Hydrocarbon products or solid C2 to C 10 One of the hydrocarbon products.

[0039] As will be discussed below, the light hydrocarbon feed stream can be preheated before entering the gas mixer of the fluidized bed reactor system, and / or heated by the combustion products of spent catalyst to produce a heated light hydrocarbon feed stream. The heated light hydrocarbon feed stream flows upwards into the fluidized bed reactor, and in the presence of a heated regenerated catalyst, its temperature is sufficient to pyrolyze the heated light hydrocarbon feed stream to produce a product effluent containing hydrogen and spent catalyst containing coke deposits. Suitable reaction conditions may vary depending on the reactants, desired products, catalyst, and equipment used. In illustrative embodiments, a suitable temperature for the heated light hydrocarbon feed stream can be from about 500°C, about 700°C to at most about 1000°C, or about 1200°C. In some embodiments, the reaction can be carried out at pressures from about 1 atmosphere to at most about 3 atmospheres, or at most about 5 atmospheres, or at most about 10 atmospheres.

[0040] catalyst

[0041] In illustrative embodiments, as may be combined with one or more preceding paragraphs, the heated regenerated catalyst of the fluidized bed reactor is continuously circulated through the unit between the catalytic cracking reaction and regeneration, while the regenerated catalyst is continuously held in the fluidized bed reactor. In illustrative embodiments, as may be combined with one or more preceding paragraphs, the particulate catalyst used in the illustrative embodiments described herein can be a metal oxide catalyst supported on an oxide support. Suitable metal oxides include, for example, Na, K, Mg, Ca, Sr, Cr, Mo, Mn, Fe, Co, Ni, Cu, Zn, Al, rare earth metals, or mixtures thereof. In illustrative embodiments, the metal oxide can be present in an amount ranging from about 0.01 to about 10% by weight. In illustrative embodiments, a suitable oxide support can be any suitable inorganic oxide support. Representative examples of such suitable oxide supports include, but are not limited to, alumina, silica, silica-alumina, titanium dioxide, zirconium oxide, or mixtures thereof. In one embodiment, the oxide support is one of alumina and silica-alumina, wherein the silica content of the silica-alumina support can be from about 2% to about 30% by weight. The alumina can be any alumina conventionally used in hydrotreating catalysts. This alumina is typically porous amorphous alumina with an average pore size of about 50 to about 200 angstroms. In some embodiments, the oxide support may also be a non-porous oxide material melted in an electric arc furnace. Representative examples of such non-porous oxide materials include, but are not limited to, fused silica and fused alumina.

[0042] Metal oxide catalysts can be any commonly used catalyst shape known in the art, such as spheres, particles, pellets, fragments, rings, extrusions, or powders.

[0043] In illustrative embodiments, as may be referenced in one or more preceding paragraphs, the particulate catalyst used herein is a small particulate catalyst. The term "small particulate catalyst" as used herein should be understood as a catalyst with an average particle size of about 0.05 to about 4 millimeters (mm), or about 0.05 to about 2 mm, or about 0.06 to about 0.5 mm, or even about 100 micrometers. Any of the lower limits above may be combined with any of the upper limits.

[0044] reactor system

[0045] Now refer to the attached diagram for more details. Figure 1 and Figure 2 A fluidized bed reactor system 100 is shown, which includes at least a fluidized bed reactor, a gas mixer, a catalyst regeneration unit, and a riser. It should be understood that the fluidized bed reactor system 100, which includes at least a fluidized bed reactor, a gas mixer, a catalyst regeneration unit, and a riser, is not limited to... Figure 1 and Figure 2 The configuration of the illustrated implementation is given, and other configurations are also envisioned herein.

[0046] Fluidized bed reactor system 100 includes a fluidized bed reactor 102 having a reactor wall 104 defining a reaction chamber 106. In a non-limiting illustrative embodiment, the fluidized bed reactor 102 may have a cylindrical configuration with a constant diameter along all or part of its reactor wall 104 (the length of which may constitute a large portion of its length) (see [link to documentation]). Figure 1 In another non-limiting illustrative embodiment, the fluidized bed reactor 102 may have a cylindrical configuration with a constant diameter along all or part of its reactor wall 104 (which may constitute a large portion of its length) (see [link to relevant documentation]). Figure 1 In some embodiments, the fluidized bed reactor 102 may have a cylindrical configuration with a uniform diameter from the top to the bottom of the fluidized bed reactor 102. For example... Figure 2 As shown, in a non-limiting illustrative alternative embodiment, the fluidized bed reactor 102 may have a cylindrical configuration, wherein a first portion has a first diameter D1, and a second portion has a second diameter D2 that is larger than the first diameter D1. However, those skilled in the art will understand that the cylindrical configuration is merely illustrative, and any other suitable shape with the same or different diameters is also contemplated herein. For example, in an illustrative embodiment, the fluidized bed reactor 102 may have a cylindrical configuration with a first diameter at the top and a first diameter at the bottom that is different from the second diameter, i.e., the first diameter may be larger or smaller than the second diameter.

[0047] In an illustrative embodiment, the fluidized bed reactor 102 includes a reactor wall 104 surrounding its interior. In some embodiments, the reactor wall 104 may be formed of a reactor lining having one or more layers of refractory material lined inside the reactor wall 104 to reduce heat loss and withstand the high temperatures of the fluidized bed reactor 102. The reactor lining provides heat resistance and abrasion resistance and may extend to all or part of the fluidized bed reactor system 100, including at least the fluidized bed reactor 102. For example, the fluidized bed reactor 102 may operate at high or even extremely high temperatures and further includes a flowing, heated, regenerated catalyst. These factors, along with others, can result in, for example, highly corrosive environments. Furthermore, for operational reasons, minimizing heat loss, reducing sidewall temperatures, and maintaining the required temperatures within the reaction chamber 106 may be critical. The reactor lining helps address these and other related issues.

[0048] In some embodiments, the entire reactor liner, or at least a large portion thereof, is continuous. The term "continuous" as used herein is intended to broadly refer to a state in which there are essentially no seams or other breaks in the structure. In some embodiments, the reactor liner has an inner surface that is substantially parallel to the reactor wall 104. In some embodiments, the reactor liner may surround the fluidized bed reactor system (including, for example,...) Figure 1 and Figure 2 The entire surface of the catalyst regeneration unit 110 shown. In some embodiments, the reactor liner may have a thickness that will vary depending on the specific application and other factors, but in many applications, its thickness will be between about 1 inch and about 12 inches. In some embodiments, the reactor liner may have a thickness between about 3 inches and about 8 inches.

[0049] Materials suitable for use as refractory materials are those that provide good thermal insulation and abrasion resistance. In some embodiments, the reactor lining is castable. A variety of suitable refractory materials are known, including, for example, standard Portland cement. Those skilled in the art will understand that refractory materials can be inorganic, non-metallic, porous, and heterogeneous materials, including thermally stable mineral aggregates, binder phases, and one or more additives. In some embodiments, refractory materials may include one or more of silica, alumina, calcium oxide, titanium oxide, iron oxide, magnesium oxide, zirconium, etc. Different compositions can be selected for different applications, with design considerations including the required heat resistance and abrasion resistance. For sections of the lining that may be subject to severe wear, examples include refractory materials with higher abrasion resistance. Those skilled in the art will readily understand that different refractory materials and their thicknesses can be applied at different locations based on factors such as temperature, turbulence intensity, and erosion tendency.

[0050] The fluidized bed reactor 102 further includes a separator 108 located at the top of the fluidized bed reactor 102. The separator 108 receives a product effluent containing hydrogen, generated from the cracking of a heated light hydrocarbon feed stream in the presence of a heated regenerating catalyst, and a spent catalyst containing coke deposits. The separator 108 then separates the spent catalyst 112 from the product effluent to produce a product stream 113 containing hydrogen, which is then discharged from the fluidized bed reactor 102. The spent catalyst 112 then flows downwards from the separator 108 through a conduit 114 into a catalyst regeneration unit 110. In some embodiments, the conduit 114 may extend from the bottom of the fluidized bed reactor 102 to the middle or lower part of the catalyst regeneration unit 110 to prevent gas from rising within the conduit 114. The spent catalyst 112 flows downwards due to gravity, etc.

[0051] In some implementations, the separators to which this document applies include, for example, cyclone separators. While for... Figure 1Separator 108 in the diagram shows three separators, and is designed for... Figure 2 Two separators are shown in separator 108, but the number of separators is only illustrative and more or fewer may be used in fluidized bed reactor 102 depending on factors such as reactor design.

[0052] The fluidized bed reactor 102 further includes a catalyst regeneration unit 110 for receiving spent catalyst 112 from the separator 108 via a pipe 114 in fluid communication with the catalyst regeneration unit 110. As described above, coke containing particulate catalyst and coke deposits (i.e., coking catalyst particles) is formed on the surface of the spent catalyst 112. The spent catalyst 112 is continuously introduced into the catalyst regeneration unit 110 via the pipe 114, where the spent catalyst 112 is subjected to coke combustion conditions to burn most (if not all) of the coke in the spent catalyst 112 and to provide heated regenerated catalyst 118.

[0053] In an illustrative embodiment, the catalyst regeneration unit 110 includes a regeneration gas inlet adapted to receive an oxidation stream 116 into the catalyst regeneration unit 110. The regeneration gas inlet may be located at the bottom of the catalyst regeneration unit 110. However, this is only illustrative, and other locations for the regeneration gas inlet are also contemplated herein. The catalyst regeneration unit 110 further includes a flow distributor 120 configured to inject the oxidation stream 116 between spent catalysts 112 disposed within the catalyst regeneration unit 110. Coke can be burned from the spent catalysts 112 by exposing the spent catalysts 112 to the oxidation stream 116, such as an inert gas / air, like air, oxygen, nitrogen, methane, or combinations thereof, or a steam / air mixture, under suitable high temperature and duration conditions to burn off and remove substantially all coke deposits on the catalyst. In an illustrative embodiment, the temperature range can be from about 450°C to about 1400°C, and the time period can be from about 10 minutes to about 600 minutes. Therefore, the regeneration of spent catalyst 112 typically involves burning the spent catalyst 112 in an oxidizing atmosphere to burn off the coke deposits and redisperse the active metals on the catalyst particles. Coke combustion is an exothermic process that can provide the heat required for the reaction. In heat equilibrium operation, the amount of coke formed on the catalyst is large enough that no external heat source or fuel is needed to supplement the heat generated by coke combustion.

[0054] Coke combustion heats the spent catalyst 112 to an elevated temperature, for example, from about 450°C to about 1400°C, thereby providing a relatively coke-free or coke-free heated regenerated catalyst 118, wherein the catalyst particles are heated and produce a heated gaseous effluent 117. In some embodiments, the heated gaseous effluent 117 is, for example, regenerator flue gas composed of carbon dioxide and nitrogen. In some embodiments, the heated regenerated catalyst 118 may have a temperature between about 600°C and about 1500°C. Furthermore, the heated regenerated catalyst 118 is fluidized in the catalyst regeneration unit 110 using an oxidation stream 116 to form a thermally regenerated fluidized particulate catalyst. The heated regenerated catalyst 118 is continuously introduced as a thermally regenerated catalyst into the riser 126, i.e., the temperature of the regenerated catalyst is elevated relative to the temperature of the spent catalyst 112. The heat generated by coke combustion in the catalyst regeneration unit 110, together with the heated regenerated catalyst 118, is continuously transferred to the fluidized bed reactor 102 via the riser 126.

[0055] The heat generated by coke combustion in the catalyst regeneration unit 110 is also continuously transferred along with the upward-flowing heated gaseous effluent 117, and continuously flows out of the catalyst regeneration unit 110 and into the gas mixer 122. In some embodiments, the heated gaseous effluent 117 may have a temperature between about 600°C and about 1500°C. The gas mixer 122 is operatively connected to the catalyst regeneration unit 110. In the gas mixer 122, the heated gaseous effluent 117 is mixed with a light hydrocarbon feed stream 115. The light hydrocarbon feed stream 115 may be preheated before flowing into the gas mixer 122. When the light hydrocarbon feed stream 115 and the heated gaseous effluent 117 are mixed in the gas mixer 122, the light hydrocarbon feed stream 115 is heated, thereby producing a heated light hydrocarbon feed stream 132. In some embodiments, the light hydrocarbon feed stream 115 is heated to a temperature between about 500°C and about 1200°C, or between about 600°C and about 1200°C. Then, the heated light hydrocarbon feed stream 132 flows upward to the top of the fluidized bed reactor 102 via the flow distributor 124, where it is cracked with the heated regenerated catalyst 118.

[0056] In some embodiments, the fluidized bed reactor system 100 may further have one or more conduits between the top region of the catalyst regeneration unit 110 and different locations within the fluidized bed reactor 102, the conduits allowing hot gaseous effluent to be delivered to different locations within the fluidized bed reactor 102 to heat the fluidized bed reactor 102. In some embodiments, the one or more conduits may have valves to regulate the flow rate of the hot effluent gas.

[0057] Heated regenerated catalyst 118 is introduced into riser 126, where it is continuously fed into fluidized bed reactor 102 by gas flow 128. In some embodiments, it may be necessary to add fresh catalyst 130 to the heated regenerated catalyst 118. Therefore, fresh catalyst 130 can be introduced into riser 126 to mix with the heated regenerated catalyst 118 and gas flow 128. In an illustrative embodiment, the top of riser 126 is operatively connected to the top of fluidized bed reactor 102, and the bottom of riser 126 is operatively connected to catalyst regeneration unit 110. Riser 126 is essentially a conduit into which heated regenerated catalyst 118 can be introduced with gas flow 128 present at the bottom, wherein the gas flow is high enough to pneumatically deliver the heated regenerated catalyst 118 into fluidized bed reactor 102, where the heated regenerated catalyst 118 and heated light hydrocarbon feed stream 132 are cracked to produce product effluent stream. In some embodiments, gas flow 128 is a tail gas flow.

[0058] In the illustrative embodiment, the heated light hydrocarbon feed stream 132 and the heated regenerated catalyst 118 are under reaction conditions, for example, at a temperature of about 500°C to about 1200°C, and the residence time of the heated light hydrocarbon feed stream 132 in the fluidized bed reactor 102 is about 0.05 seconds to about 100 seconds, or about 0.1 seconds to about 2 seconds.

[0059] In some embodiments, the fluidized bed reactor system 100 may include a booster 134. In a non-limiting illustrative embodiment, the booster 134 includes a pressure balancing line. In some embodiments, the pressure balancing line is configured to allow process gas to flow into the fluidized bed reactor 102, thereby increasing or decreasing the pressure gradient across the fluidized bed reactor 102. In some embodiments, the pressure balancing line may further include valves for controlling the flow rate of the process gas. In some embodiments, the process gas may be a heated process gas to provide additional heat to the fluidized bed reactor 102.

[0060] According to one aspect of this disclosure, a continuous method comprises:

[0061] The fluidized bed reactor receives an upward-flowing first heated light hydrocarbon feed stream and a first heated regenerated catalyst at the top, the temperature of which is sufficient to crack the first heated light hydrocarbon feed stream to produce a first product effluent stream containing hydrogen and a spent catalyst containing coke deposits.

[0062] In a catalyst regeneration unit that is operatively connected to the bottom of the fluidized bed reactor, the spent catalyst containing the coke deposits is burned to produce a second heated regenerated catalyst and a heated gas effluent.

[0063] The heated gas effluent is used to heat the light hydrocarbon feed stream to produce a second heated light hydrocarbon feed stream; and

[0064] In a riser externally connected to the catalyst regeneration unit and the fluidized bed reactor, the second heated regenerated catalyst from the catalyst regeneration unit flows together with the gas-based stream toward the top of the fluidized bed reactor to contact the upward-flowing second heated light hydrocarbon feed stream, thereby producing a second product effluent stream containing hydrogen and additional spent catalyst containing coke deposits.

[0065] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the combustion of the spent catalyst containing the coke deposits is carried out in the catalyst regeneration unit by contacting the spent catalyst with an oxidation stream.

[0066] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the oxidation stream may be an inert gas, air, or a mixture thereof.

[0067] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the oxidation stream comprises a mixture of steam and air.

[0068] In one or more additional illustrative embodiments, heating the light hydrocarbon feed stream with the heated gas effluent may, in conjunction with the preceding paragraphs, involve introducing the light hydrocarbon feed stream and the heated gas effluent into a gas mixer to produce the second heated light hydrocarbon feed stream.

[0069] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the first heated light hydrocarbon feed stream and the second heated light hydrocarbon feed stream are respectively at a temperature of about 500°C to about 1200°C.

[0070] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the continuous method further comprises using a flow distributor to direct the second heated light hydrocarbon feed stream upward toward the top of the fluidized bed reactor.

[0071] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the continuous process further includes separating the spent catalyst from the first product effluent containing hydrogen and the spent catalyst containing the coke deposit in one or more cyclone separators, wherein the spent catalyst flows downward into the catalyst regeneration unit through one or more pipes.

[0072] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the light hydrocarbon feed stream comprises C1 to C6 alkanes. In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the light hydrocarbon feed stream is a natural gas stream.

[0073] According to another aspect of this disclosure, a fluidized bed reactor system includes:

[0074] A fluidized bed reactor configured to receive an upward-flowing heated light hydrocarbon feed stream and a heated regenerated catalyst at a temperature sufficient to crack the heated light hydrocarbon feed stream to produce a product effluent stream containing hydrogen and a spent catalyst containing coke deposits.

[0075] A catalyst regeneration unit, operably connected to the bottom of the fluidized bed reactor, is configured to receive the downward-flowing spent catalyst and combust the coke deposit to produce the heated regenerated catalyst and a heated gaseous effluent for producing the heated light hydrocarbon feed stream; and

[0076] A riser is externally connected to the fluidized bed reactor and the catalyst regeneration unit. The riser is configured to receive the heated regenerated catalyst and a gas-based flow so that the heated regenerated catalyst flows upward toward the fluidized bed reactor.

[0077] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the fluidized bed reactor system further comprises:

[0078] A gas mixer, operatively connected to the catalyst regeneration unit, is configured to receive a light hydrocarbon feed stream and the heated gas effluent to generate the heated light hydrocarbon feed stream.

[0079] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the top of the fluidized bed reactor has a first diameter, and the bottom of the fluidized bed reactor has a second diameter different from the first diameter.

[0080] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the fluidized bed reactor system further comprises:

[0081] A flow distributor located above the gas mixer and configured to direct the heated light hydrocarbon feed stream upward toward the top of the fluidized bed reactor.

[0082] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the fluidized bed reactor system further comprises:

[0083] One or more cyclone separators are located at the top of the fluidized bed reactor and configured to separate the spent catalyst from the product effluent containing hydrogen and the spent catalyst containing the coke deposits.

[0084] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the spent catalyst separated from the product effluent flows downward to the catalyst regeneration unit and enters the catalyst regeneration unit through one or more pipes.

[0085] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the catalyst regeneration unit includes an inlet for receiving an oxidation stream to burn the coke deposits.

[0086] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the fluidized bed reactor system further comprises:

[0087] A flow distributor is located below the catalyst regeneration unit to ensure that the oxidation flow flows uniformly within the catalyst regeneration unit.

[0088] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the fluidized bed reactor system may further include one or more layers of refractory material disposed on the sidewalls of the fluidized bed reactor.

[0089] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the light hydrocarbon feed stream is a natural gas stream.

[0090] For the sake of brevity, the various features disclosed herein are described in the context of a single embodiment, but may also be provided individually or in any suitable sub-combination. All combinations of embodiments are specifically included in the illustrative embodiments disclosed herein as if each combination were disclosed individually and explicitly. Furthermore, all sub-combinations listed in embodiments describing such variations are also specifically included in this disclosure and disclosed herein as if each such sub-combination were disclosed individually and explicitly herein.

[0091] While the above description contains many details, these details should not be construed as limiting the invention, but merely as examples of preferred embodiments. Those skilled in the art will contemplate many other embodiments within the scope and spirit of the invention as defined by the appended claims.

Claims

1. A continuous method, comprising: The fluidized bed reactor receives an upward-flowing first heated light hydrocarbon feed stream and a first heated regenerated catalyst at the top, the temperature of which is sufficient to crack the first heated light hydrocarbon feed stream to produce a first product effluent stream containing hydrogen and a spent catalyst containing coke deposits. In a catalyst regeneration unit that is operatively connected to the bottom of the fluidized bed reactor, the spent catalyst containing the coke deposits is burned to produce a second heated regenerated catalyst and a heated gas effluent. The heated gas effluent is used to heat the light hydrocarbon feed stream to generate a second heated light hydrocarbon feed stream; as well as In a riser externally connected to the catalyst regeneration unit and the fluidized bed reactor, the second heated regenerated catalyst from the catalyst regeneration unit flows together with the gas-based stream toward the top of the fluidized bed reactor to contact the upward-flowing second heated light hydrocarbon feed stream, thereby producing a second product effluent stream containing hydrogen and additional spent catalyst containing coke deposits.

2. The continuous method according to claim 1, wherein the combustion of the spent catalyst containing the coke deposit is carried out in the catalyst regeneration unit by contacting the spent catalyst with the oxidation stream.

3. The continuous method according to claim 2, wherein the oxidation stream is an inert gas, air, or a mixture thereof.

4. The continuous method according to claim 2, wherein the oxidation stream comprises a mixture of steam and air.

5. The continuous method according to any one of claims 1 to 4, wherein heating the light hydrocarbon feed stream with the heated gas effluent comprises flowing the light hydrocarbon feed stream and the heated gas effluent into a gas mixer to produce the second heated light hydrocarbon feed stream.

6. The continuous method according to any one of claims 1 to 5, wherein the first heated light hydrocarbon feed stream and the second heated light hydrocarbon feed stream are respectively at a temperature of about 500°C to about 1200°C.

7. The continuous method according to any one of claims 1 to 6, further comprising using a flow distributor to direct the second heated light hydrocarbon feed stream upward toward the top of the fluidized bed reactor.

8. The continuous method according to any one of claims 1 to 7, further comprising separating the spent catalyst from the first product effluent containing hydrogen and the spent catalyst containing the coke deposit in one or more cyclone separators, wherein the spent catalyst flows downward into the catalyst regeneration unit through one or more pipes.

9. The continuous method according to any one of claims 1 to 8, wherein the light hydrocarbon feed stream comprises C1 to C6 alkanes.

10. The continuous method according to any one of claims 1 to 8, wherein the light hydrocarbon feed stream is a natural gas stream.

11. A fluidized bed reactor system, comprising: A fluidized bed reactor configured to receive an upward-flowing heated light hydrocarbon feed stream and a heated regenerated catalyst at a temperature sufficient to crack the heated light hydrocarbon feed stream to produce a product effluent stream containing hydrogen and a spent catalyst containing coke deposits. A catalyst regeneration unit is operatively connected to the bottom of the fluidized bed reactor. The catalyst regeneration unit is configured to receive the downward-flowing spent catalyst and burn the coke deposit to produce the heated regenerated catalyst and a heated gas effluent for producing the heated light hydrocarbon feed stream. as well as A riser is externally connected to the fluidized bed reactor and the catalyst regeneration unit. The riser is configured to receive the heated regenerated catalyst and a gas-based flow so that the heated regenerated catalyst flows upward toward the fluidized bed reactor.

12. The fluidized bed reactor system according to claim 11, further comprising: A gas mixer, operatively connected to the catalyst regeneration unit, is configured to receive a light hydrocarbon feed stream and the heated gas effluent to generate the heated light hydrocarbon feed stream.

13. The fluidized bed reactor system according to claim 11 or 12, wherein the top of the fluidized bed reactor has a first diameter and the bottom of the fluidized bed reactor has a second diameter different from the first diameter.

14. The fluidized bed reactor system according to claim 12, further comprising: A flow distributor located above the gas mixer and configured to direct the heated light hydrocarbon feed stream upward toward the top of the fluidized bed reactor.

15. The fluidized bed reactor system according to any one of claims 11 to 14, further comprising: One or more cyclone separators are located at the top of the fluidized bed reactor and configured to separate the spent catalyst from the product effluent containing hydrogen and the spent catalyst containing the coke deposits.

16. The fluidized bed reactor system of claim 15, wherein the spent catalyst separated from the product effluent flows downward toward the catalyst regeneration unit and enters the catalyst regeneration unit through one or more pipes.

17. The fluidized bed reactor system according to any one of claims 11 to 16, wherein the catalyst regeneration unit comprises an inlet for receiving an oxidation stream to burn the coke deposit.

18. The fluidized bed reactor system according to claim 17, further comprising: A flow distributor is located below the catalyst regeneration unit to ensure that the oxidation flow flows uniformly within the catalyst regeneration unit.

19. The fluidized bed reactor system according to any one of claims 11 to 18, further comprising one or more layers of refractory material disposed on the sidewall of the fluidized bed reactor.

20. The fluidized bed reactor system of claim 12, wherein the light hydrocarbon feed stream is a natural gas stream.

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