Fluidized bed reactor system for catalytic cracking of light hydrocarbons
Patent Information
- Application Number
- CN202580013387.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-02-05
- Filing Date
- 2025-01-10
- Publication Date
- 2026-09-01
Smart Images
Figure CN122680331A_ABST
Abstract
Description
Background Technology
[0001] 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
[0002] According to the illustrative embodiment, a continuous process includes: The first regenerated catalyst and the first light hydrocarbon feed stream are fed into the bottom portion of a riser that is in fluid communication with the fluidized bed reactor, so as to contact one or more heat sources, thereby generating a first heated light hydrocarbon feed stream and a first heated regenerated catalyst. The first heated light hydrocarbon feed stream and the first heated regenerated catalyst are allowed to flow upward from the bottom portion of the riser to the reaction chamber in the top portion of the riser, so as to crack the first heated light hydrocarbon feed stream in the presence of the first heated regenerated catalyst, thereby producing a first product effluent stream containing hydrogen and spent catalyst containing coke deposits. In a catalyst regeneration unit operatively connected to the fluidized bed reactor, the spent catalyst containing the coke deposits is combusted to produce a second regenerated catalyst, and The second regenerated catalyst and the second light hydrocarbon feed stream are fed into the bottom portion of the riser to contact the one or more heat sources, thereby generating a second heated light hydrocarbon feed stream and a second heated regenerated catalyst.
[0003] According to another illustrative embodiment, a fluidized bed reactor system includes: A riser is configured to receive a light hydrocarbon feed stream and a first regenerated catalyst in its bottom portion, the bottom portion of the riser including one or more heat sources to heat the light hydrocarbon feed stream and the first regenerated catalyst, thereby generating a heated light hydrocarbon feed stream and a heated regenerated catalyst. A reaction chamber in the top portion of the riser, in fluid communication with a fluidized bed reactor, is used to crack the heated light hydrocarbon feed stream in the presence of the heated regenerated catalyst flowing upwards from the bottom portion, thereby producing a product effluent stream containing hydrogen and spent catalyst containing coke deposits. A catalyst regeneration unit, operatively connected to the fluidized bed reactor and the riser, is configured to receive the downward-flowing spent catalyst and burn the coke deposit to produce a second regenerated catalyst for delivery to the bottom portion of the riser. Attached Figure Description
[0004] 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: Figure 1A A schematic diagram of a fluidized bed reactor system and process for heating a light hydrocarbon feed stream for catalytic cracking to produce a product effluent stream containing hydrogen and spent catalyst, according to an illustrative embodiment, is shown.
[0005] Figure 1B An enlarged schematic diagram of the bottom portion of the riser of a fluidized bed reactor system according to an illustrative embodiment is shown. Detailed Implementation
[0006] The various illustrative embodiments described herein relate to fluidized bed reactor systems and processes for the 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.
[0007] 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 options for future clean energy. However, the selectivity of the desired products obtained from catalytic cracking 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-limiting 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.
[0008] 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.
[0009] Fluidized catalytic cracking (FCC) reactors and regenerator systems are commonly used in petroleum refining to convert high-boiling, high-molecular-weight hydrocarbons into products such as gasoline, olefin gases, and other petroleum products. It typically consists of a reactor for heavy hydrocarbon conversion reactions, a regenerator for regenerating deactivated catalyst, and conduits for transferring spent catalyst / regenerated catalyst between the two. However, conventional FCC reactor and regenerator systems are designed to receive liquid feed (heavy hydrocarbons) in the reactor at relatively low temperature conditions (e.g., about 500°C to 600°C) and spent catalyst in the regenerator at relatively low temperature conditions (e.g., about 700°C to 750°C). Therefore, due to the drastically different reaction conditions, FCC reactor and regenerator systems are not designed for direct light hydrocarbon conversion.
[0010] Given these challenges, there is a need for solutions that can utilize light hydrocarbons to produce hydrogen and value-added chemicals in FCC reactor and regenerator systems. Therefore, for reactor design in this method, it would be advantageous to (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.
[0011] definition 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.
[0012] 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”.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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.
[0017] 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.
[0018] The term "fresh catalyst" as used in this article refers to a catalyst that has not been previously used in catalytic methods.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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. According to a non-limiting illustrative embodiment, the fluidized bed reactor system described herein can be a modification of an existing FCC reactor system commonly used in petroleum refining to convert high-boiling-point, high-molecular-weight hydrocarbons into products such as gasoline, olefin gases, and other petroleum products. In other words, according to some embodiments, the fluidized bed reactor system described herein can be a modified version of an existing FCC reactor system commonly used in petroleum refining to convert high-boiling-point, high-molecular-weight hydrocarbons into products such as gasoline, olefin gases, and other petroleum products. Alternatively, in some embodiments, the fluidized bed reactor system described herein can be constructed as a primary fluidized bed reactor system.
[0023] 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 1A and Figure 1B 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.
[0024] General process The non-limiting illustrative embodiments described herein relate to a continuous process for catalytic cracking light hydrocarbon feed streams using a fluidized bed reactor system to produce a product effluent stream containing hydrogen and spent catalyst. In some embodiments, the continuous process for catalytic cracking light hydrocarbon feed streams uses a fluidized bed reactor system to produce a product effluent stream also containing C2 to C4. 10 The process involves: flowing a first regenerated catalyst and a first light hydrocarbon feed stream into the bottom portion of a riser in fluid communication with a fluidized bed reactor to contact one or more heat sources, thereby generating a first heated light hydrocarbon feed stream and a first heated regenerated catalyst; flowing the first heated light hydrocarbon feed stream and the first heated regenerated catalyst upward from the bottom portion of the riser to a reaction chamber in the top portion of the riser to crack the first heated light hydrocarbon feed stream in the presence of the first heated regenerated catalyst, thereby generating a first product effluent stream containing hydrogen and a spent catalyst containing coke deposits; burning the spent catalyst containing the coke deposits in a catalyst regeneration unit operatively connected to the fluidized bed reactor to generate a second regenerated catalyst; and flowing the second regenerated catalyst and the second light hydrocarbon feed stream into the bottom portion of the riser to contact the one or more heat sources, thereby generating a second heated light hydrocarbon feed stream and a second heated regenerated catalyst.
[0025] There are no particular limitations on the light hydrocarbon feed 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 feed 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 feed stream may also include steam, superheated steam, inert gases such as nitrogen, or any mixture thereof. In some embodiments, the light hydrocarbon feed stream used may include any suitable composition such that the resulting product includes at least hydrogen.
[0026] In some embodiments, the light hydrocarbon feed 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.
[0027] The products generated from light hydrocarbon feed streams typically contain C2 to C3. 10 Hydrocarbon products and 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... 10 The hydrocarbon products may include ethylene, propylene, acetylene, benzene, naphthalene, and various mixtures thereof. Furthermore, as will be readily understood by those skilled in the art, the resulting C2 to C2 hydrocarbons... 10 Hydrocarbon products can be liquid hydrocarbon products, gaseous hydrocarbon products, solid hydrocarbon products, or combinations thereof, depending on the specific methane conversion process.
[0028] As will be discussed below, the light hydrocarbon feed stream and the regenerated catalyst are heated in the bottom portion of the riser using one or more heat sources to generate a heated light hydrocarbon feed stream and a heated regenerated catalyst. The heated light hydrocarbon feed stream and the heated regenerated catalyst flow upwards to a reaction chamber in the top portion of the riser, which is in fluid communication with the fluidized bed reactor, at a temperature sufficient to cause cracking of the heated light hydrocarbon feed stream in the presence of the heated regenerated catalyst, 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 may be from about 600°C, about 700°C to at most about 1000°C, or about 1200°C. In some embodiments, the reaction may 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.
[0029] catalyst In illustrative embodiments, as may be combined with one or more of the preceding paragraphs, the heated regenerated catalyst is continuously circulated through the fluidized bed reactor system between the catalytic cracking reaction and regeneration, while the heated regenerated catalyst is continuously maintained in the reaction chamber of the riser. In illustrative embodiments, in conjunction with one or more of the preceding paragraphs, the regenerated catalyst used in the illustrative embodiments described herein may 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 may be present in an amount ranging from about 0.1 to about 10% by weight. In illustrative embodiments, a suitable oxide support may 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 may be from about 2 to about 30% by weight. The alumina can be any type of alumina commonly used in hydrotreating catalysts. This alumina is typically porous amorphous alumina with an average pore size of about 50 to about 200 angstroms.
[0030] Metal oxide catalysts can be any commonly used catalyst shape known in the art, such as spheres, particles, pellets, fragments, rings, extrusions, or powders.
[0031] In the illustrative embodiments, as may be referenced in one or more preceding paragraphs, the 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 0.01 to about 4 millimeters (mm), or about 0.02 to about 1 mm, or about 0.05 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.
[0032] In illustrative embodiments, as may be referenced in one or more preceding paragraphs, the catalyst used herein is a large-particle catalyst. As used herein, the term "large-particle catalyst" should be understood to mean a catalyst with an average particle size of about 0.05 mm to about 10 mm, or about 0.1 mm to about 5 mm, or about 0.2 mm to about 2 mm. Any of the lower limits above may be combined with any of the upper limits.
[0033] reactor system Now refer to the attached diagram for more details. Figure 1A and Figure 1BThe illustration shows a fluidized bed reactor system 100, which includes at least a fluidized bed reactor 102, a riser 126, and a catalyst regeneration unit 145. It should be understood that the fluidized bed reactor system 100, including at least the fluidized bed reactor 102, the riser 126, and the catalyst regeneration unit 145, is not limited to... Figure 1A and Figure 1B The configuration of the implementation shown herein is provided, and other configurations are also envisioned herein.
[0034] The fluidized bed reactor system 100 includes a fluidized bed reactor 102 having a reactor wall 104. 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 (which may constitute a large portion of its length). 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. However, as those skilled in the art will understand, the cylindrical configuration is merely illustrative, and any other suitable shape with the same or varying diameter is contemplated herein.
[0035] 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, which lines the interior of the reactor wall 104 to reduce heat loss and maintain the high temperature of the fluidized bed reactor 102. The reactor lining provides heat resistance and abrasion resistance and may extend to cover all or part of each component of the fluidized bed reactor system 100, including at least the fluidized bed reactor 102, the riser 126, and the catalyst regeneration unit 145. For example, the fluidized bed reactor 102 may operate at high or even extremely high temperatures and includes a flowing, heated regeneration catalyst and a heated light hydrocarbon feed stream 138. These and other factors can result in, for example, a highly corrosive and aggressive environment. Furthermore, minimizing heat loss, minimizing sidewall temperatures, and maintaining the desired temperature in the reaction chamber 106 of the riser 126 may be important for operational reasons. Furthermore, the use of refractory lining significantly reduces the temperature of reactor wall 104, thus allowing the use of relatively inexpensive alloys to construct fluidized bed reactor 102 and other refractory-lined components of the fluidized bed reactor system 100, resulting in significant economic benefits. Reactor lining helps address these and other related issues.
[0036] 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 entire surface of the fluidized bed reactor system 100, including the fluidized bed reactor 102, riser 126, and catalyst regeneration unit 145. In some embodiments, the thickness of the reactor liner will vary depending on the specific application and other factors, but in many applications 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.
[0037] 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.
[0038] 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 hydrogen-containing product effluent and a spent catalyst containing coke deposits, resulting from the cracking of a heated light hydrocarbon feed stream in the presence of a heated regenerated catalyst. The separator 108 then separates the spent catalyst 113 from the product effluent to produce a hydrogen-containing product stream, which is then discharged from the fluidized bed reactor 102 via line 128. The spent catalyst 113 then flows downward from the separator 108 and through conduit 114 to the reaction stripper 110. In some embodiments, the spent catalyst 113 flows downward, for example, by gravity.
[0039] In some implementations, the separators to which this document applies include, for example, cyclone separators. Although in Figure 1A The intermediate separator 108 is shown as two separators, but the number of separators is merely illustrative and any higher or lower number can be used in the fluidized bed reactor 102 based on factors such as, for example, reactor design.
[0040] The fluidized bed reactor system 100 also includes a catalyst regeneration unit 145 for receiving spent catalyst 113 from a reaction stripper 110 in fluid communication with the fluidized bed reactor 102 and the riser 126. As described above, coke is formed on the surface of the spent catalyst 113, which contains catalyst and coke deposits. The spent catalyst 113 is continuously introduced into the catalyst regeneration unit 145 through the reaction stripper 110, in which the spent catalyst 113 is subjected to coke combustion conditions to burn off most (if not all) of the coke from the spent catalyst 113 and to provide a regenerated catalyst, which may be divided into regenerated catalyst 118-1 and optional regenerated catalyst 118-2.
[0041] In an illustrative embodiment, the catalyst regeneration unit 145 includes a reactor wall surrounding the interior. As described above, in some embodiments, the reactor wall may be formed of a reactor lining having one or more layers of refractory material, which is lined inside the reactor wall to reduce heat loss and maintain the high temperature of the catalyst regeneration unit 145. The reactor lining may be the same as or similar to the material discussed above with respect to reactor wall 104.
[0042] In an illustrative embodiment, the catalyst regeneration unit 145 includes a regeneration gas inlet adapted to receive the oxidant stream 140 into the catalyst regeneration unit 145. The regeneration gas inlet may be located at the bottom of the catalyst regeneration unit 145. However, this is only illustrative, and other locations for the regeneration gas inlet are also contemplated herein. The oxidant stream 140 enters the catalyst regeneration unit 145 via a heating unit 142 to generate a heated oxidant stream 144. The oxidant stream 140 may contain, for example, air, oxygen, nitrogen, methane, or combinations thereof, or a steam / air mixture.
[0043] Heating unit 142 can be any conventional heating unit known in the art, which is configured to heat oxidant stream 140 to generate heated oxidant stream 144 having a temperature sufficient to burn waste catalyst 113 and produce regenerated catalyst.
[0044] In some embodiments, heating unit 142 is an air heater, which may include a resistance or induction heating element configured to heat oxidant stream 140 to generate heated oxidant stream 144. In some embodiments, heating unit 142 is a steam heater and may include heating elements, such as resistance or induction heating elements configured to heat oxidant stream 140 to generate heated oxidant stream 144. In some embodiments, heating unit 142 may include a heat exchanger configured to heat steam using heat extracted from a high-temperature fluid, such as a fluid heated to about 1200°C or higher. This fluid may originate from a solar concentrator or power plant.
[0045] The catalyst regeneration unit 145 also includes a flow distributor 146 configured to inject a heated oxidizing feed stream 144 into the spent catalyst 113 disposed within the catalyst regeneration unit 145. Coke can be burned off from the spent catalyst 113 by exposing it to the heated oxidizing feed stream 144 under suitable high temperature and duration conditions, thereby burning off and removing substantially all coke deposits from the catalyst. In illustrative embodiments, 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 the spent catalyst 113 typically involves burning the spent catalyst 113 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 provides the heat required for the reaction process. In thermal equilibrium operation, the amount of coke formed on the catalyst is large enough that no external heat source or fuel is required to supplement the heat generated by coke combustion.
[0046] In some embodiments, the catalyst regeneration unit 145 operates as a moving bed, with the spent catalyst 113 continuously moving downwards. In some embodiments, the catalyst regeneration unit 145 operates as a fluidized bed.
[0047] Coke combustion heats the spent catalyst to elevated temperatures, such as from about 450°C to about 1400°C, to provide a heated regenerated catalyst that is substantially free of coke or free of char, wherein the catalyst particles are heated and fed to riser 126. Coke combustion also produces flue gas that passes through a series of separators 148, where entrained solid particles are separated and discharged back to the lower part of catalyst regeneration unit 145, producing a particulate-free flue gas stream 150, which is discharged through the top portion of catalyst regeneration unit 145. In some embodiments, flue gas stream 150 consists of, for example, carbon dioxide and nitrogen. In some embodiments, separator 148 is a series of cyclone separators. In some embodiments, the series of cyclone separators is configured in two or more stages, such that the gas effluent from the first stage enters the second stage to improve particle removal efficiency.
[0048] Furthermore, the heated oxidant stream 144 is used to fluidize the regenerated catalyst in the catalyst regeneration unit 145. The regenerated catalyst is continuously introduced into the riser 126 at a temperature higher than that of the spent catalyst. The heat generated by coke combustion in the catalyst regeneration unit 145 is continuously transferred to the riser 126 along with the regenerated catalyst.
[0049] In some embodiments, the catalyst regeneration unit 145 may also have one or more conduits between the catalyst regeneration unit 145 and different locations in the riser 126, said one or more conduits allowing the heated regenerated catalyst to be transferred to different locations in the riser 126. For example, the regenerated catalyst may be split into two or more streams, such as regenerated catalyst 118-1 and regenerated catalyst 118-2. In some embodiments, regenerated catalyst 118-1 or regenerated catalyst 118-2 may have a temperature of about 600°C to about 1500°C. In some embodiments, said one or more conduits may have valves to regulate the flow rate of the regenerated catalyst. For example, the flow rate of regenerated catalyst 118-1 may be controlled by regulating valve 120. In some embodiments, regenerated catalyst 118-1 is introduced through a first conduit in the bottom portion of the riser 126, where it contacts the light hydrocarbon feed stream 101 discussed below, and regenerated catalyst 118-2 enters through a second conduit located above the first conduit and flows upward together with the heated regenerated catalyst and the heated light hydrocarbon feed stream 138 discussed below.
[0050] The fluidized bed reactor system 100 includes a riser 126 for receiving regenerated catalyst 118-1 and optionally regenerated catalyst 118-2 from the catalyst regeneration unit 145.
[0051] In some embodiments, the riser 126 has a first diameter, and the fluidized bed reactor 102 has a second diameter larger than the first diameter. By making the riser 126 have a smaller diameter than the fluidized bed reactor 102, the regenerated catalyst 118-1 and regenerated catalyst 118-2 can be substantially or completely fluidized when in contact with the light hydrocarbon feed stream 101 to carry out a direct light hydrocarbon conversion reaction.
[0052] The riser 126 also receives the light hydrocarbon feed stream 101 through an inlet in the bottom portion of the riser 126. In some embodiments, the light hydrocarbon feed stream 101 is at or near room temperature. Figure 1BAs shown, the light hydrocarbon feed stream 101 enters through an inlet in the bottom portion of a riser 126 having reactor wall 132. The light hydrocarbon feed stream 101 then flows upward via a flow distributor 129, where it combines with regenerated catalyst 118-1 to form regenerated catalyst and light hydrocarbon feed stream 130. The flow rate of regenerated catalyst 118-1 is controlled by valve 120 as described above. In a non-limiting illustrative embodiment, the riser 126 may have a cylindrical configuration with a constant diameter along all or part of its length (which may constitute a large portion of its length) of reactor wall 132. In some embodiments, the riser 126 may have a cylindrical configuration with a uniform diameter from the top to the bottom of the riser 126. However, as those skilled in the art will understand, the cylindrical configuration is merely illustrative, and any other suitable shape with the same or varying diameter is contemplated herein.
[0053] In an illustrative embodiment, the riser 126 includes a reactor wall 132 surrounding its interior. As described above, in some embodiments, the reactor wall 132 may be formed of a reactor lining having one or more layers of refractory material, which is lined inside the reactor wall 132 to reduce heat loss and maintain the high temperature of the riser 126. The reactor lining may be the same as or similar to the material discussed above with respect to the reactor wall 104.
[0054] The regenerated catalyst and light hydrocarbon feed stream 130 flow upwards, where they may first contact a heat source 134 to generate a first heated regenerated catalyst and a first heated light hydrocarbon feed stream 133. The heat source 134 can be any suitable heat source capable of heating the regenerated catalyst and light hydrocarbon feed stream 130 to a sufficient temperature to crack the light hydrocarbon feed stream in the reaction chamber 106 of the riser 126. In some embodiments, the heat source 134 can be any conventional heating unit known in the art. For example, in some embodiments, the heat source 134 may include heating elements, such as resistance or induction heating elements. In some embodiments, the heat source 134 may include a heat exchanger configured to use heat extracted from a high-temperature fluid (e.g., a fluid heated to about 600°C or higher) to heat the regenerated catalyst and light hydrocarbon feed stream 130. This fluid may be from a solar concentrator or power plant. In some embodiments, the heat source 134 may be tail gas or other low-value fuel gas received through the inlet in riser 126, which may originate from the plant where the fluidized bed reactor system 100 is located, or any other suitable source may be used as fuel. In some embodiments, the heat source 134 may be preheated air or concentrated oxygen received through the inlet in riser 126 and may be used as an oxidant. In some embodiments, the heat source 134 is configured to heat the regenerated catalyst and light hydrocarbon feed stream 130 to a temperature of about 600°C to about 1200°C to generate a first heated regenerated catalyst and a first heated light hydrocarbon feed stream 133. In some embodiments, the heat source 134 is configured to heat the regenerated catalyst and light hydrocarbon feed stream 130 to a temperature below that sufficient to crack the light hydrocarbon feed stream to generate a first heated regenerated catalyst and a first heated light hydrocarbon feed stream 133.
[0055] In some embodiments, when the temperature of the first heated regenerated catalyst and the first heated light hydrocarbon feed stream 133 is insufficient to crack the light hydrocarbon feed stream, the first heated regenerated catalyst and the first heated light hydrocarbon feed stream 133 flow upward, where they can further contact the heat source 136 to generate a second heated regenerated catalyst and a heated light hydrocarbon feed stream 138 (i.e., a second heated regenerated catalyst and a second heated light hydrocarbon feed stream) having a temperature greater than that of the first heated regenerated catalyst and the first heated light hydrocarbon feed stream 133. The heat source 136 can be any suitable heat source as described above with respect to heat source 134. The heat source 136 is configured to heat the first heated regenerated catalyst and the first heated light hydrocarbon feed stream 133 to a temperature of about 600°C to about 1200°C to generate the second heated regenerated catalyst and the heated light hydrocarbon feed stream 138.
[0056] As will be readily understood by those skilled in the art, although Figure 1B Two heat sources are shown, but any number of heat sources are envisioned to provide additional heat sources for highly endothermic reactions.
[0057] Back Figure 1A The second heated regenerated catalyst and the heated light hydrocarbon feed stream 138 flow upward in the riser 126, where they are continuously fed to the reaction chamber 106. In some embodiments, it may be necessary to add additional catalyst to the second heated regenerated catalyst and the heated light hydrocarbon feed stream 138. Therefore, in some embodiments, the regenerated catalyst 118-2 flows into the riser 126 and combines with the second heated regenerated catalyst and the heated light hydrocarbon feed stream 138. The second heated regenerated catalyst and the heated light hydrocarbon feed stream 138, along with the regenerated catalyst 118-2, flow upward to the reaction chamber 106, where the second heated regenerated catalyst and the heated light hydrocarbon feed stream 138 undergo cracking.
[0058] In the illustrative embodiment, the second heated regenerated catalyst and the heated light hydrocarbon feed stream 138 are subjected to reaction conditions, such as temperatures from about 600°C to about 1200°C, and the residence time of the second heated regenerated catalyst and the heated light hydrocarbon feed stream 138 in the fluidized bed reactor 102 is from about 0.05 seconds to about 100 seconds, or from about 0.1 seconds to about 2 seconds.
[0059] In some embodiments, riser 126 is operatively connected to separator 108 of fluidized bed reactor 102. Thus, once the second heated regenerated catalyst and heated light hydrocarbon feed stream 138 are cracked, a stream containing C2 to C2 hydrocarbons can be produced. 10 The hydrocarbon products and hydrogen products (i.e., cracking products) are fed to separator 108 (cyclone separator), where spent catalyst containing coke deposits and unstripped hydrocarbons can be reacted with C2 to C3 hydrocarbons. 10 The hydrocarbon products and hydrogen gas are separated. The separated product contains C2 to C3. 10 The hydrocarbon products and hydrogen products can then exit the fluidized bed reactor 102 via line 128. The spent catalyst and unstripped hydrocarbons will fall into the reaction stripper 110. In some embodiments, a steam stream 112 can be introduced into the reaction stripper 110 to help separate the spent catalyst 113 from the unstripped hydrocarbons, thereby generating separated unstripped hydrocarbons and spent catalyst 113. The separated unstripped hydrocarbons can then exit the reaction stripper 110 as stream 115. The spent catalyst 113 is continuously introduced into the catalyst regeneration unit 145 as described above.
[0060] According to an aspect of the present invention, a continuous process comprises: The first regenerated catalyst and the first light hydrocarbon feed stream are fed into the bottom portion of a riser that is in fluid communication with the fluidized bed reactor, so as to contact one or more heat sources, thereby generating a first heated light hydrocarbon feed stream and a first heated regenerated catalyst. The first heated light hydrocarbon feed stream and the first heated regenerated catalyst are allowed to flow upward from the bottom portion of the riser to the reaction chamber in the top portion of the riser, so as to crack the first heated light hydrocarbon feed stream in the presence of the first heated regenerated catalyst, thereby producing a first product effluent stream containing hydrogen and spent catalyst containing coke deposits. In a catalyst regeneration unit operatively connected to the fluidized bed reactor, the spent catalyst containing the coke deposits is combusted to produce a second regenerated catalyst, and The second regenerated catalyst and the second light hydrocarbon feed stream are fed into the bottom portion of the riser to contact the one or more heat sources, thereby generating a second heated light hydrocarbon feed stream and a second heated regenerated catalyst.
[0061] In one or more additional non-limiting illustrative embodiments, such as those that may be combined with one or more of the preceding paragraphs, the first heated light hydrocarbon feed stream and the first heated regenerated catalyst are allowed to flow upward from the bottom portion of the riser, which is in fluid communication with the fluidized bed reactor, to the reaction chamber in the top portion of the riser using a flow distributor.
[0062] In one or more additional non-limiting illustrative embodiments, such as in combination with one or more of the preceding paragraphs, the riser is operatively connected to one or more separators in the fluidized bed reactor and feeds the first product effluent stream containing hydrogen and the spent catalyst containing coke deposits from the reaction chamber of the riser to the one or more separators.
[0063] In one or more additional non-limiting illustrative embodiments, such as in combination with one or more of the foregoing paragraphs, the first heated light hydrocarbon feed stream is cracked in the presence of the first heated regenerated catalyst to also produce unstripped hydrocarbons; and the process further includes: The separator separates the first product effluent containing hydrogen, the spent catalyst containing coke deposits, and the unstripped hydrocarbons. The spent catalyst containing coke deposits and the unstripped hydrocarbons flow downwards into the reaction stripper of the fluidized bed reactor. The spent catalyst containing coke deposits is stripped with the unstripped hydrocarbons, and The spent catalyst containing coke deposits is delivered to the catalyst regeneration unit via one or more conduits.
[0064] In one or more additional non-limiting illustrative embodiments, such as in combination with one or more of the preceding paragraphs, the spent catalyst containing the coke deposits is contained in the catalyst regeneration unit to contact the spent catalyst with an oxidation stream.
[0065] In one or more additional non-limiting illustrative embodiments, such as in combination with one or more of the preceding paragraphs, the oxidizing feed stream is one of air, oxygen, methane, or a combination thereof.
[0066] In one or more additional non-limiting illustrative embodiments, such as those that may be combined with one or more of the foregoing paragraphs, the first product outflow stream further comprises C2 to C 10 Hydrocarbon products.
[0067] In one or more additional non-limiting illustrative embodiments, such as in combination with one or more of the preceding paragraphs, the first heated light hydrocarbon feed stream and the second heated light hydrocarbon feed stream are each independently at a temperature of about 600°C to about 1200°C.
[0068] In one or more additional non-limiting illustrative embodiments, such as in combination with one or more of the preceding paragraphs, the process further includes: flowing the second heated light hydrocarbon feed stream and the second heated regenerated catalyst upward from the bottom portion of the riser to the reaction chamber in the top portion of the riser to crack the second heated light hydrocarbon feed stream in the presence of the second heated regenerated catalyst, thereby producing a second product effluent stream containing hydrogen and a spent catalyst containing coke deposits.
[0069] In one or more additional non-limiting illustrative embodiments, such as in combination with one or more of the preceding paragraphs, the process further includes separating the spent catalyst from the first product effluent containing hydrogen and the spent catalyst containing coke deposits in one or more cyclone separators, wherein the spent catalyst flows downward into the catalyst regeneration unit through one or more pipes.
[0070] In one or more additional non-limiting illustrative embodiments, such as those that may be combined with one or more of the preceding paragraphs, the riser, the fluidized bed reactor, and the catalyst regeneration unit each have an inner wall comprising a refractory material.
[0071] In one or more additional non-limiting illustrative embodiments, such as in combination with one or more of the preceding paragraphs, the first light hydrocarbon feed stream and the second light hydrocarbon feed stream each comprise C1 to C6 alkanes.
[0072] In one or more additional non-limiting illustrative embodiments, such as those that may be combined with one or more of the preceding paragraphs, the first light hydrocarbon feed stream and the second light hydrocarbon feed stream are each natural gas feed streams.
[0073] In one or more additional non-limiting illustrative embodiments, such as in combination with one or more of the preceding paragraphs, allowing the first heated light hydrocarbon feed stream and the first heated regenerated catalyst to flow upward from the bottom portion of the riser to the reaction chamber in the top portion of the riser also includes allowing a third regenerated catalyst to flow together with the first heated light hydrocarbon feed stream and the first heated regenerated catalyst.
[0074] According to another aspect of the present invention, a fluidized bed reactor system includes: A riser is configured to receive a light hydrocarbon feed stream and a first regenerated catalyst in its bottom portion, the bottom portion of the riser including one or more heat sources to heat the light hydrocarbon feed stream and the first regenerated catalyst, thereby generating a heated light hydrocarbon feed stream and a heated regenerated catalyst. A reaction chamber in the top portion of the riser, in fluid communication with a fluidized bed reactor, is used to crack the heated light hydrocarbon feed stream in the presence of the heated regenerated catalyst flowing upwards from the bottom portion, thereby producing a product effluent stream containing hydrogen and spent catalyst containing coke deposits. A catalyst regeneration unit, operatively connected to the fluidized bed reactor and the riser, is configured to receive the downward-flowing spent catalyst and burn the coke deposit to produce a second regenerated catalyst for delivery to the bottom portion of the riser.
[0075] In one or more additional non-limiting illustrative embodiments, such as those that may be combined with one or more of the preceding paragraphs, the riser also includes a flow distributor located in the bottom portion, the flow distributor being configured to allow the light hydrocarbon feed stream and the first regenerated catalyst to flow through the one or more heat sources and toward the top portion of the riser.
[0076] In one or more additional non-limiting illustrative embodiments, such as those that may be combined with one or more of the preceding paragraphs, the riser is operatively connected to one or more separators located in the fluidized bed reactor, and the one or more separators are configured to separate the spent catalyst from the product effluent stream containing hydrogen and the spent catalyst containing coke deposits.
[0077] In one or more additional non-limiting illustrative embodiments, such as those that may be combined with one or more of the preceding paragraphs, the fluidized bed reactor includes a reaction stripper for receiving the spent catalyst separated from and flowing downward from the product effluent stream. The reaction stripper is configured to separate the spent catalyst from any unstripped hydrocarbons, such that the separated spent catalyst flows downward to the catalyst regeneration unit and enters the catalyst regeneration unit through one or more conduits.
[0078] In one or more additional non-limiting illustrative embodiments, such as in combination with one or more of the preceding paragraphs, the riser, the fluidized bed reactor, and the catalyst regeneration unit each comprise one or more layers of refractory material.
[0079] In one or more additional illustrative embodiments, in conjunction with the preceding paragraphs, the light hydrocarbon feed stream is a natural gas stream.
[0080] In one or more additional non-limiting illustrative embodiments, such as those that may be combined with one or more of the preceding paragraphs, the fluidized bed reactor system is a modification of an existing fluidized bed reactor system.
[0081] In one or more additional non-limiting illustrative embodiments, such as those that may be combined with one or more of the preceding paragraphs, the riser tube includes a first heat source and a second heat source in the bottom portion of the riser tube.
[0082] In one or more additional non-limiting illustrative embodiments, such as in combination with one or more of the preceding paragraphs, the riser is also configured to receive a third regenerated catalyst through an injection point located above the one or more heat sources.
[0083] 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.
[0084] 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 process, comprising: The first regenerated catalyst and the first light hydrocarbon feed stream are fed into the bottom portion of a riser that is in fluid communication with the fluidized bed reactor to contact one or more heat sources, thereby generating a first heated light hydrocarbon feed stream and a first heated regenerated catalyst. The first heated light hydrocarbon feed stream and the first heated regenerated catalyst are allowed to flow upward from the bottom portion of the riser to the reaction chamber in the top portion of the riser, so as to crack the first heated light hydrocarbon feed stream in the presence of the first heated regenerated catalyst, thereby producing a first product effluent stream containing hydrogen and a spent catalyst containing coke deposits. In a catalyst regeneration unit operatively connected to the fluidized bed reactor, the spent catalyst containing the coke deposits is combusted to produce a second regenerated catalyst; as well as The second regenerated catalyst and the second light hydrocarbon feed stream are fed into the bottom portion of the riser to contact the one or more heat sources, thereby generating a second heated light hydrocarbon feed stream and a second heated regenerated catalyst.
2. The continuous process of claim 1, wherein the first heated light hydrocarbon feed stream and the first heated regenerated catalyst are flowed upward from the bottom portion of the riser, which is in fluid communication with the fluidized bed reactor, to the reaction chamber in the top portion of the riser using a flow distributor.
3. The continuous process of claim 1 or 2, wherein the riser is operatively connected to one or more separators in the fluidized bed reactor, and the first product effluent containing hydrogen and the spent catalyst containing coke deposits are fed from the reaction chamber of the riser to the one or more separators.
4. The continuous process of claim 3, wherein cracking of the first heated light hydrocarbon feed stream in the presence of the first heated regenerated catalyst further produces unstripped hydrocarbons; and the process further comprises: The separator separates the first product effluent containing hydrogen, the spent catalyst containing coke deposits, and the unstripped hydrocarbons. The spent catalyst containing coke deposits and the unstripped hydrocarbons flow downwards into the reaction stripper of the fluidized bed reactor; The spent catalyst containing coke deposits is stripped with the unstripped hydrocarbons; as well as The spent catalyst containing coke deposits is delivered to the catalyst regeneration unit via one or more conduits.
5. The continuous process of claim 4, wherein burning the spent catalyst containing coke deposits comprises contacting the spent catalyst with an oxidant stream in the catalyst regeneration unit.
6. The continuous process of claim 5, wherein the oxidant stream is one of air, oxygen, methane, or a combination thereof.
7. The continuous process according to any one of claims 1 to 6, wherein the first product outflow stream further comprises C2 to C 10 Hydrocarbon products.
8. The continuous process according to any one of claims 1 to 7, wherein the first heated light hydrocarbon feed stream and the second heated light hydrocarbon feed stream are respectively at a temperature of about 600°C to about 1200°C.
9. The continuous process according to any one of claims 1 to 8, further comprising causing the second heated light hydrocarbon feed stream and the second heated regenerated catalyst to flow upward from the bottom portion of the riser to the reaction chamber in the top portion of the riser, so as to crack the second heated light hydrocarbon feed stream in the presence of the second heated regenerated catalyst, thereby producing a second product effluent stream containing hydrogen and a spent catalyst containing coke deposits.
10. The continuous process of claim 1, further comprising separating the spent catalyst from the first product effluent containing hydrogen and the spent catalyst containing coke deposits in one or more cyclone separators, wherein the spent catalyst flows downward into the catalyst regeneration unit through one or more conduits.
11. The continuous process of claim 1, wherein the riser, the fluidized bed reactor and the catalyst regeneration unit each have an inner wall comprising a refractory material.
12. The continuous process according to any one of claims 1 to 11, wherein the first light hydrocarbon feed stream and the second light hydrocarbon feed stream each comprise C1 to C6 alkanes.
13. The continuous process according to any one of claims 1 to 12, wherein the first light hydrocarbon feed stream and the second light hydrocarbon feed stream are each natural gas feed streams.
14. The continuous process of claim 1, wherein flowing the first heated light hydrocarbon feed stream and the first heated regenerated catalyst upward from the bottom portion of the riser to the reaction chamber in the top portion of the riser further comprises flowing a third regenerated catalyst together with the first heated light hydrocarbon feed stream and the first heated regenerated catalyst.
15. A fluidized bed reactor system, comprising: A riser is configured to receive a light hydrocarbon feed stream and a first regenerated catalyst in its bottom portion, the bottom portion of the riser including one or more heat sources to heat the light hydrocarbon feed stream and the first regenerated catalyst, thereby generating a heated light hydrocarbon feed stream and a heated regenerated catalyst, and a reaction chamber in its top portion, the reaction chamber being in fluid communication with a fluidized bed reactor for cracking the heated light hydrocarbon feed stream in the presence of the heated regenerated catalyst flowing upward from the bottom portion, thereby generating a product effluent stream containing hydrogen and a spent catalyst containing coke deposits; as well as A catalyst regeneration unit, operatively connected to the fluidized bed reactor and the riser, is configured to receive the downward-flowing spent catalyst and burn the coke deposit to produce a second regenerated catalyst for delivery to the bottom portion of the riser.
16. The fluidized bed reactor system of claim 15, wherein the riser further includes a flow distributor located in the bottom portion, and the flow distributor is configured to allow the light hydrocarbon feed stream and the first regenerated catalyst to flow through the one or more heat sources and toward the top portion of the riser.
17. The fluidized bed reactor system of claim 15 or 16, wherein the riser is operatively connected to one or more separators located in the fluidized bed reactor, and the one or more separators are configured to separate the spent catalyst from the product effluent stream containing hydrogen and the spent catalyst containing coke deposits.
18. The fluidized bed reactor system of claim 17, wherein the fluidized bed reactor includes a reaction stripper for receiving the spent catalyst separated from and flowing downward from the product effluent stream, the reaction stripper being configured to separate the spent catalyst from any unstripped hydrocarbons such that the separated spent catalyst flows downward to the catalyst regeneration unit and enters the catalyst regeneration unit through one or more conduits.
19. The fluidized bed reactor system of any one of claims 15 to 18, wherein the riser, the fluidized bed reactor and the catalyst regeneration unit each comprise one or more layers of refractory material, and the light hydrocarbon feed stream is a natural gas feed stream.
20. The fluidized bed reactor system according to any one of claims 15 to 19, wherein the fluidized bed reactor system is an improvement on an existing fluidized bed reactor system.
21. The fluidized bed reactor system of any one of claims 15 to 20, wherein the riser further comprises a first heat source in the bottom portion of the riser and a second heat source located above the first heat source.