Process for forming light olefins using oxidation vessel

Abstract

Light olefins may be formed by a process that may include reacting a feed stream in a reactor in the presence of a catalyst to form a product stream and a deactivated catalyst comprising coke; separating at least a portion of the product stream from the deactivated catalyst; and passing the deactivated catalyst to an oxidation vessel and contacting the deactivated catalyst with a first oxygen-containing gas to remove at least a portion of the coke on the deactivated catalyst, thereby producing a decoked catalyst. The method may also include passing the decoking catalyst to a combustor and combusting a supplemental fuel in the combustor to heat the decoking catalyst and produce a heated catalyst; passing the heated catalyst to an oxygen soak zone and contacting the heated catalyst with a second oxygen-containing gas to produce a reactivated catalyst; and passing the reactivated catalyst to the reactor.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 428,500, filed on November 29, 2022, the entire disclosure of which is hereby incorporated by reference herein. Technical Field

[0003] The various embodiments described herein generally relate to chemical processing, and more specifically, to methods and systems for producing light olefins. Background Art

[0004] Light olefins such as propylene can be used as base materials to produce many different materials such as polypropylene, isopropyl alcohol, and acrylic acid, which can be used, for example, in packaging, construction, and textiles. As a result of this utility, there is a worldwide demand for light olefins. Suitable processes for producing light olefins generally depend on the given chemical feed and include those that utilize fluidized catalysts. For example, light olefins can be formed by catalytic dehydrogenation of alkanes in a fluidized - bed reactor. However, there is a need to improve the systems and related catalysts for preparing light olefins. Summary of the Invention

[0005] Some methods for producing light olefins utilize catalysts that may become coked after dehydrogenation. In conventional embodiments, the coked catalyst can then be directly introduced into a combustor, where coke is removed from the catalyst by combustion of the coke with oxygen (e.g., air), and where additional fuel in the combustor is also used to heat the catalyst. The heated catalyst can then be sent to an air - soak zone, where the catalyst is reactivated by an oxygen - containing gas (such as air) before being passed back to the dehydrogenation reaction reactor. It has now been found that in some embodiments, the conventional reactivation method of coke burning using a single combustor is not effective for catalyst reactivation. For example, it has been found that in such comparative embodiments, there may be a situation where an insufficient amount of coke is removed, or an insufficient structural change of the catalyst active sites (due to limited contact with oxygen before the catalyst interacts with the fuel gas), or both. Methods for forming light olefins using an oxidation vessel are described herein. The oxidation vessel can generally be upstream of the combustor. In some embodiments, in the oxidation vessel, in the presence of oxygen and before it reaches the combustor, some amount of coke can be burned and / or some structural change of the catalyst active sites can occur.

[0006] According to one or more embodiments of the present disclosure, light olefins can be formed by a method provided in the present application. The method may include: reacting a feed stream in a reactor in the presence of a catalyst to form a product stream and a deactivated catalyst containing coke, separating at least a portion of the product stream from the deactivated catalyst, and transferring the deactivated catalyst to an oxidation vessel and contacting the deactivated catalyst with a first oxygen-containing gas to remove at least a portion of the coke on the deactivated catalyst, thereby producing a decoked catalyst. The method may further include: transferring the decoked catalyst to a burner and burning a supplementary fuel in the burner to heat the decoked catalyst and produce a heated catalyst, transferring the heated catalyst to an oxygen soaking zone and contacting the heated catalyst with a second oxygen-containing gas to produce a reactivated catalyst, and transferring the reactivated catalyst to the reactor.

[0007] It should be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and characteristics of the claimed subject matter. Additional features and advantages of the embodiments will be set forth in the detailed description, and in part, will be readily apparent to those of ordinary skill in the art from the description including the drawings and the claims, or may be recognized by practicing the described embodiments. Drawings are included to provide a further understanding of the embodiments and, together with the detailed description, are used to explain the principles and operations of the claimed subject matter. However, the embodiments depicted in the drawings are illustrative and exemplary in nature and are not intended to limit the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The following detailed description can be better understood when read in conjunction with the following drawings, in which:

[0009] Figure 1 Schematically depicts a reactor system according to one or more embodiments of the present disclosure;

[0010] Figure 2 Schematically depicts another reactor system according to one or more embodiments of the present disclosure;

[0011] Figure 3 Schematically depicts another reactor system according to one or more embodiments of the present disclosure;

[0012] Figure 4 Schematically depicts another reactor system according to one or more embodiments of the present disclosure;

[0013] Figure 5 Schematically depicts another reactor system according to one or more embodiments of the present disclosure; and

[0014] Figure 6 Another reactor system according to one or more embodiments of the present disclosure is schematically depicted.

[0015] When describing Figures 1 to 6 the schematic diagrams, many valves, temperature sensors, electronic controllers, etc. that are available and well known to those of ordinary skill in the art are not included. In addition, the accompanying components that are typically included in such reactor systems, such as air supplies, heat exchangers, buffer tanks, etc., are not included. However, it should be understood that these components are within the scope of the present disclosure.

[0016] Reference will now be made in more detail to various embodiments, some of which are illustrated in the accompanying drawings. Detailed Description

[0017] The embodiments of the present disclosure are described in detail herein in the context of a reactor system Figures 1 to 6 operated as a fluidized dehydrogenation reactor system to produce light olefins. However, it should be understood that the principles disclosed and taught herein can be applied to other systems that utilize different system components oriented in different ways, or different reaction schemes that utilize various catalyst compositions. For example, the concepts described can be equivalently applied to other systems having alternative reactor units and regeneration units, such as those operated under non-fluidized conditions, or those that include downcomers instead of risers. Additionally, it is contemplated that light olefins can be produced from various hydrocarbon feedstreams by utilizing different reaction mechanisms. For example, light olefins can be catalytically produced by at least dehydrogenation reactions, cracking reactions, dehydration reactions, and methanol-to-olefins reactions. In some embodiments, an oxygen carrier material can also be used, as described herein. These reaction types can utilize different feedstreams and / or different catalysts to produce light olefins. It should also be understood that not Figures 1 to 6 all parts of

[0018] Now referring to Figure 1 , an example reactor system 101 that may be suitable for use with the methods and / or apparatuses described herein is schematically depicted. The reactor system 101 generally includes a plurality of system components, such as a reactor section 200 and a catalyst handling section 300. As used herein, a "system component" refers to a part of the reactor system 101, such as a reactor, a separator, a transfer line, a combination thereof, etc. As used herein in Figure 1As used in the context of, the reactor section 200 generally refers to the part of the reactor system 101 where the main process reaction (e.g., dehydrogenation) occurs to form the product stream. The feed stream enters the reactor section 200, is converted into a product stream (containing the product and unreacted feed), and exits the reactor section 200. The reactor section 200 includes a reactor 202, which may include an upstream reactor section 250 and a downstream reactor section 230. According to one or more embodiments, as Figure 1 depicted, the reactor section 200 may additionally include a catalyst separation section 210 for separating the catalyst from the chemical products formed in the reactor 202. Additionally, as used herein, the catalyst treatment section 300 generally refers to the part of the reactor system 101 where the catalyst is treated in some manner, such as by combustion, to improve the catalytic activity, for example, by decoking and / or heating the catalyst. The catalyst treatment section 300 may include an oxidation vessel 500, a burner 350, a riser 330, and may also include a catalyst separation section 310. In one or more embodiments, the catalyst separation section 210 of the reactor section 200 may be in fluid communication with the oxidation vessel 500 (e.g., via a standpipe 426), and the catalyst separation section 310 may be in fluid communication with the upstream reactor section 250 (e.g., via a standpipe 424 and a transfer riser 430).

[0019] Typically, as described herein, the catalyst cycles between the reactor section 200 and the catalyst treatment section 300. It should be understood that when "catalyst" is referred to herein, they can refer to solid materials that are catalytically active for the desired reaction, or can equally refer to other particulate solids that are not necessarily catalytically active but affect the reaction as referred to in the reference system, such as oxygen carriers. The terms "catalytic activity" and "catalyst activity" refer to the extent to which the catalyst is able to catalyze the reaction taking place in the reactor system 101. The catalyst leaving the reactor section 200 can be a deactivated catalyst. As used herein, "deactivated" can refer to a catalyst having reduced catalytic activity or a cooler catalyst compared to the catalyst entering the reactor section 200. However, the deactivated catalyst can retain some catalytic activity. The reduced catalytic activity can be caused by contamination with substances such as coke. Reactivation (sometimes referred to as "regeneration" herein) can remove contaminants such as coke, raise the temperature of the catalyst, or both. In an embodiment, the deactivated catalyst can be reactivated by catalyst reactivation in the catalyst treatment section 300. The deactivated catalyst can be reactivated by, but not limited to, the following: removing coke by contacting the deactivated catalyst with an oxygen-containing gas to produce a decoked catalyst, removing coke by combustion, restoring catalyst acidity, oxidizing the catalyst, other reactivation methods, or combinations thereof. In some embodiments, the catalyst can be heated during reactivation by combusting a supplemental fuel such as hydrogen, methane, ethane, propane, natural gas, or combinations thereof to produce a heated catalyst. The heated catalyst can be contacted with an oxygen-containing gas in the oxygen soak zone 370 of the catalyst treatment section 300 to produce a reactivated catalyst. The reactivated catalyst from the catalyst treatment section 300 can then be transferred back to the reactor section 200.

[0020] As regarding Figure 1 described, the feed stream can enter the feed inlet 434, enter the reactor 202, and the product stream can leave the reactor system 101 via the conduit 420. According to one or more embodiments, the reactor system 101 can be operated by feeding a chemical feed (e.g., in the feed stream) and a fluidized catalyst into the upstream reactor section 250. The chemical feed contacts the catalyst in the upstream reactor section 250, and each chemical feed flows upward and through the downstream reactor section 230 to produce a chemical product.

[0021] The reactor section 200 can include an upstream reactor section 250, a transition section 258, and a downstream reactor section 230, such as a riser. The transition section 258 can connect the upstream reactor section 250 to the downstream reactor section 230. As Figure 1As depicted, the upstream reactor section 250 can be positioned below the downstream reactor section 230. Such a configuration can be referred to as an upflow configuration in the reactor 202. The upstream reactor section 250 can include a vessel, a drum, a barrel, a tank, or other container suitable for a given chemical reaction. As Figure 1 depicted, the upstream reactor section 250 can be connected to the downstream reactor section 230 via a transition section 258. The upstream reactor section 250 generally can have a larger cross-sectional area than the downstream reactor section 230. The transition section 258 can taper from the size of the cross-section of the upstream reactor section 250 to the size of the cross-section of the downstream reactor section 230 such that the transition section 258 projects inward from the upstream reactor section 250 into the downstream reactor section 230. For example, the transition section 258 can be a frustum.

[0022] The upstream reactor section 250 can be connected to a transport riser 430 that, in operation, can provide reactivated catalyst in a feed stream to the reactor portion 200. The reactivated catalyst and / or reactant chemicals can be mixed with a distributor 260 housed in the upstream reactor section 250. The catalyst entering the upstream reactor section 250 via the transport riser 430 can pass through a standpipe 424 to the transport riser 430 and thus arrive from the catalyst processing section 300. In some embodiments, the catalyst can enter the transport riser 430 directly from the catalyst separation section 210 via a standpipe 422, where the catalyst enters the upstream reactor section 250, where in such embodiments, some of the catalyst does not pass through the catalyst processing section 300. The catalyst also can be fed directly to the upstream reactor section 250 via the standpipe 422 (not Figure 1 depicted). This catalyst can be slightly deactivated but still can be suitable for reaction in the upstream reactor section 250 in some embodiments, particularly when used in combination with the reactivated catalyst.

[0023] Still referring to Figure 1 , in one or more embodiments, based on the shape, size, and other processing conditions (such as temperature and pressure) in the upstream reactor section 250 and the downstream reactor section 230, the upstream reactor section 250 can operate as a fluidized bed, such as in a fast fluidized, turbulent, or bubbling bed upflow reactor, while the downstream reactor section 230 can operate in a more plug flow manner, such as in a riser reactor. By way of example, Figure 1The reactor 202 can include an upstream reactor section 250 operating as a fast fluidized, turbulent, or bubbling bed reactor and a downstream reactor section 230 operating as a dilute-phase riser reactor, with the result that the average catalyst and gas flows move upward simultaneously. As used herein, the term "average flow" refers to the net flow, i.e., the total upward flow minus the reverse or counter flow, which is typically characteristic of fluidized particles. As described herein, a "fast fluidized" reactor can refer to a reactor utilizing a fluidization scheme where the superficial velocity of the gas phase is greater than the choking velocity and can be semi-dense in operation. As described herein, a "turbulent" reactor can refer to a fluidization scheme where the superficial velocity is less than the choking velocity and is denser than the fast fluidization scheme. As described herein, a "bubbling bed" reactor can refer to a fluidization morphology where distinct bubbles exist in a highly dense bed in two distinct phases. The "choking velocity" is the minimum velocity required to maintain solids in a dilute-phase mode in a vertical transport line. As described herein, a "dilute-phase riser" can refer to a riser reactor operating at a transport velocity where the gas and catalyst have approximately the same velocity in the dilute phase.

[0024] According to an embodiment, the chemical product and catalyst can be transferred from the downstream reactor section 230 to a separation device 220 in the catalyst separation section 210, where the catalyst is separated from the chemical product, and the chemical product is transported out of the catalyst separation section 210. According to one or more embodiments, after separating the catalyst from the vapor in the separation device 220, the catalyst can typically move through a stripper 224 to a catalyst outlet port 222, where the catalyst is transferred out of the reactor section 200 via a standpipe 426 and into a catalyst processing section 300.

[0025] According to one or more embodiments, the separation device 220 may be a cyclone separation system, which may include two or more stages of cyclone separation. In embodiments where the separation device 220 includes more than one cyclone separation stage, the first separation device into which the fluidized stream enters is referred to as the primary cyclone separation device. The fluidized effluent from the primary cyclone separation device may enter a secondary cyclone separation device for further separation. The primary cyclone separation device may include, for example, a primary cyclone separator and systems commercially available under the names VSS (commercially available from UOP), LD2 (commercially available from Stone and Webster), and RS2 (commercially available from Stone and Webster). The primary cyclone separator is described, for example, in U.S. Patent Nos. 4,579,716, 5,190,650, and 5,275,641, each of which is incorporated herein by reference in its entirety. In some separation systems that utilize a primary cyclone separator as the primary cyclone separation device, one or more additional sets of cyclone separators, such as secondary and tertiary cyclone separators, are used to further separate the catalyst from the product gas. It should be understood that any primary cyclone separation device may be used in the embodiments of the present invention.

[0026] According to one or more embodiments and with reference to Figure 1 , the deactivated catalyst may be transferred from the reactor section 200 to the oxidation vessel 500 via the standpipe 426. A first oxygen-containing gas, such as air, may enter the oxidation vessel 500, for example, via the conduit 428 and contact the deactivated catalyst. The first oxygen-containing gas may contact the deactivated catalyst in the oxidation vessel 500 for 0.1 minutes to 10 minutes. The fluidization regime of the deactivated catalyst in the oxidation vessel 500 may be a dense-phase transport, bubbling bed, turbulent fluidized bed, or fast fluidized bed regime. The oxidation vessel 500 may include an inlet port 504 that may be in fluid communication with the burner 350 such that the oxidation vessel 500 is directly connected to the burner 350 and the decoked catalyst is transferred directly from the oxidation vessel 500 to the burner 350. Contacting the deactivated catalyst with the first oxygen-containing gas for a duration of 0.1 minutes to 10 minutes may remove at least a portion of the coke deposited on the deactivated catalyst to produce a decoked catalyst. It is contemplated that the "decoked" catalyst may still contain a certain amount of coke, but less coke than the catalyst entering the oxidation vessel 500. The decoked catalyst may pass through the inlet port 504 of the oxidation vessel 500 and into the burner 350. Without being bound by theory, it is believed that contacting the deactivated catalyst with the first oxygen-containing gas in the oxidation vessel 500 will remove at least a portion of the coke from the deactivated catalyst, which will prevent excessive oxygen depletion in the burner 350 in the case of uneven catalyst distribution in the burner 350.

[0027] In one or more embodiments, when entering the oxidation vessel 500 and after leaving the reactor section 200 via the riser 426, based on the total weight of the catalyst, the deactivated catalyst may contain from 0.01 wt% to 0.4 wt% coke. In additional embodiments, when entering the oxidation vessel 500 and after leaving the reactor section 200 via the riser 426, based on the total weight of the catalyst, the deactivated catalyst may contain from 0.01 wt% to 0.1 wt%, 0.1 wt% to 0.2 wt%, 0.2 wt% to 0.3 wt%, 0.3 wt% to 0.4 wt% or any combination of these ranges of coke.

[0028] Without being bound by any particular theory, it is believed that the coke present on the deactivated catalyst may include different types of coke, herein referred to as "hard" coke and "soft" coke, where hard coke may be more difficult to burn than soft coke. In one or more embodiments, the process in the oxidation vessel 500 may burn the hard coke, which if not removed may reduce the catalytic regeneration that the catalyst experiences in the burner 350 and in the oxygen soak zone 370.

[0029] In one or more embodiments, at least 70 wt% of the coke is removed from the deactivated catalyst in the oxidation vessel 500 to produce a decoked catalyst. For example, in some embodiments, at least 75 wt%, at least 80 wt%, at least 85 wt%, at least 90 wt%, at least 95 wt%, at least 99 wt% or even 100 wt% of the coke is removed from the deactivated catalyst in the oxidation vessel 500 to produce a decoked catalyst.

[0030] In one or more embodiments, from 0 wt% to 30 wt% of coke may be present in the decoked catalyst (such as the catalyst transferred from the oxidation vessel 500 to the burner 350). For example, from 0 wt% to 5 wt%, 5 wt% to 10 wt%, 10 wt% to 15 wt%, 15 wt% to 20 wt%, 20 wt% to 25 wt%, 25 wt% to 30 wt% or any combination of these ranges of coke is present in the decoked catalyst (such as the catalyst transferred from the oxidation vessel 500 to the burner 350).

[0031] In one or more embodiments, at least 95 wt% of the coke on the deactivated catalyst is burned in the oxidation vessel. In additional embodiments, at least 96 wt%, at least 97 wt%, at least 98 wt%, at least 99 wt% or even 100 wt% of the coke on the deactivated catalyst is burned in the oxidation vessel.

[0032] As Figure 1As depicted, the oxidation vessel 500 may have a shape similar to or the same as the shape described in the context of the reactor 202. For example, the oxidation vessel 500 may include an upstream section 550, a transition section 558, and a downstream section 530. As Figure 1 depicted, the upstream section 550 may be positioned below the downstream section 530. Such a configuration may be referred to as an upflow configuration in the oxidation vessel 500. The upstream section 550 may include a vessel, a drum, a barrel, a tank, or other vessel suitable for a given chemical reaction. As Figure 1 depicted, the upstream section 550 may be connected to the downstream section 530 via the transition section 558. The upstream section 550 generally may include a larger cross-sectional area than the downstream section 530. The transition section 558 may taper from the size of the cross-section of the upstream section 550 to the size of the cross-section of the downstream section 530 such that the transition section 558 projects inward from the upstream section 550 into the downstream section 530. For example, the transition section 558 may be a frustum.

[0033] Still referring to Figure 1 , in one or more embodiments, based on the shape, size, and other processing conditions (such as temperature and pressure) in the upstream section 530 and the downstream section 550, the upstream section 530 may operate as a fluidized bed, such as in a fast fluidized, turbulent, or bubbling bed upflow reactor, while the downstream section 550 may operate in a more plug flow manner, such as in a riser reactor. For example, Figure 1 the oxidation vessel 500 of

[0034] may include an upstream section 530 operating as a fast fluidized, turbulent, or bubbling bed reactor and a downstream section 550 operating as a dilute phase riser reactor, such that on average the catalyst and gas flow move upward simultaneously. 3 to 60 lb / ft 3 , such as 20 lb / ft 3 to 30 lb / ft 3 , 30 lb / ft 3 to 40 lb / ft 3 , 40 lb / ft3 from 0 to 50 lb / ft 3 、50 lb / ft 3 to 60 lb / ft 3 or a catalyst bed density of any combination of these ranges. The superficial gas velocity can be significantly accelerated through the downstream section 550 of the oxidation vessel 500. In one or more embodiments, the oxidation vessel 500 can operate at a catalyst flux of 100 to 300 lb / ft 2 sec, such as 100 to 150 lb / ft 2 sec, 150 to 200 lb / ft 2 sec, 200 to 250 lb / ft 2 sec, 250 to 300 lb / ft 2 sec or any combination of these ranges. In embodiments (such as Figure 2 or Figure 5 embodiments that utilize the conduit 438 as the oxidation vessel), these catalyst characteristics can also be present. The catalyst residence time in this conduit configuration can be in the range of 10 seconds to 240 seconds, 20 seconds to 120 seconds, or 25 seconds to 60 seconds.

[0035] As Figure 1 depicted, the oxidation vessel 500 can be directly connected to the burner 350 such that the catalyst is fluidized when in the oxidation vessel 500 and is directly fed to the burner 350.

[0036] Still referring to Figure 1, in the burner 350, the catalyst can be treated by, for example, burning oxygen with a supplementary fuel. By way of example and not limitation, the catalyst can be further decoked and / or the supplementary fuel can be burned to heat the catalyst. Burning the supplementary fuel in the burner 350 can increase the temperature of the decoked catalyst to greater than or equal to 660 °C. Then, the catalyst can be transferred out of the burner 350 and through the riser 330 to the riser termination separator 378, where the gas and solid components from the riser 330 are at least partially separated. The vapors and remaining solids are transported to the secondary separation device 320 in the catalyst separation section 310, where the remaining catalyst is separated from the gases from the catalyst treatment (e.g., the gases emitted by burning the spent catalyst or the supplementary fuel, referred to herein as flue gas). The flue gas can be transferred out of the catalyst treatment section 300 via the outlet pipe 432. The separated catalyst is then transferred through the oxygen soaking zone 370 within the catalyst separation section 310 via the standpipe 424 and the transport riser 430 to the upstream reactor section 250, where the catalyst is further used for catalytic reactions. Thus, the catalyst can be circulated between the reactor section 200 and the catalyst treatment section 300 during operation. Generally, the treated chemical stream, including the feed stream and the product stream, can be gaseous, and the catalyst can be a fluidized particulate solid.

[0037] As described herein, since most of the coke in the coke is eliminated in the oxidation vessel 500, according to one or more embodiments, the potential uneven distribution of such catalysts in the burner 350 may not result in extreme local concentration differences of oxygen in the burner 350.

[0038] Without being bound by any particular theory, it is believed that in conventional embodiments, when entering the burner and subsequently contacting the fuel gas, the coked deactivated catalyst may not be well distributed stoichiometrically with air. It is believed that this lack of local oxygen may be the result of uneven distribution of the catalyst in the burner. Such uneven distribution can lead to poor coke removal from the catalyst and, therefore, insufficient activity for burning the supplementary fuel. Thus, in some embodiments described herein, the above effects of uneven catalyst distribution in the burner can be minimized because less coke is available to locally reduce the oxygen concentration in the burner.

[0039] Additionally and without being bound by any theory, it is believed that in some embodiments, the non-uniform distribution of catalyst and coke can result in regions of the burner having an insufficient oxygen concentration due to the localized combustion of coke (thereby reducing the local oxygen concentration in those regions). Thus, these regions may not have sufficient oxygen to burn the make-up fuel at a desired rate, and as a result, there may be system inefficiencies. Without being bound by any particular theory, it is believed that such catalysts (by conventional methods) require longer reactivation to achieve the same dehydrogenation activity. Accordingly, the embodiments described herein can improve catalytic performance and overall system efficiency as well as product yield generation.

[0040] In additional embodiments and without being bound by theory, it is believed that in conventional methods there may be other mechanisms (e.g., not those having an oxidation vessel as described herein), such as a lack of the required structural changes for the catalyst active sites when the contact with oxygen is restricted prior to the contact of the catalyst with the fuel gas. Thus, in some embodiments, the use of an oxidation vessel can improve the structural changes in the catalyst that are sometimes required when in contact with the fuel gas.

[0041] Now referring to the catalyst treatment section 300, as Figure 1 depicted, the burner 350 of the catalyst treatment section 300 can be in fluid communication with the riser 330. An oxygen-containing gas (such as air) can be passed via line 428 and through the oxidation vessel 500, or a separate oxygen-containing gas line can be passed directly into the burner 350 (not depicted). The burner 350 and the riser 330 (collectively the catalyst combustion reactor 302) can be operated in a fluidization scheme similar or identical to that disclosed with respect to the upstream reactor section 250 and the downstream reactor section 230 of the reactor section 200. That is, the burner 350 can operate as a fluidized bed, for example, in a fast fluidization, turbulent, or bubbling bed upflow reactor, while the riser 330 can operate in a more plug flow manner, for example, in a riser reactor. The geometries described with respect to the upstream reactor section 250 and the downstream reactor section 230 can equally apply to the burner 350 and the riser 330. Additionally, the burner 350 can further include a fuel inlet 354 that can supply a fuel such as a hydrocarbon feed stream to the burner 350.

[0042] In one or more embodiments, the burner 350 may operate at an apparent gas velocity of less than 4 ft / s. In one or more embodiments, the burner 350 may operate at an apparent gas velocity of 0.1 ft / s to 4 ft / s, such as 0.1 ft / s to 3.5 ft / s, 0.1 ft / s to 3 ft / s, 0.1 ft / s to 2.5 ft / s, 0.1 ft / s to 2 ft / s, 0.1 ft / s to 1.5 ft / s, 0.1 ft / s to 1 ft / s, 0.5 ft / s to 4 ft / s, 1 ft / s to 4 ft / s, 1.5 ft / s to 4 ft / s, 2 ft / s to 4 ft / s, 2.5 ft / s to 4 ft / s, 3 ft / s to 4 ft / s, 0.5 ft / s to 3.5 ft / s, 1 ft / s to 3 ft / s, or 1.5 ft / s to 2.5 ft / s. In one or more embodiments, the coke removal catalyst in the burner 350 may have a catalyst bed density of 20 lb / ft 3 to 40 lb / ft 3 , such as 25 lb / ft 3 to 35 lb / ft 3 , 30 lb / ft 3 to 35 lb / ft 3 , 20 lb / ft 3 to 30 lb / ft 3 or 20 lb / ft 3 to 25 lb / ft 3 of the catalyst bed density.

[0043] As described in one or more embodiments, after separating the flue gas from the catalyst in the riser termination separator 378 and the secondary separation device 320, the treated catalyst is treated with a second oxygen-containing gas in the oxygen soaking zone 370. In some embodiments, the oxygen soaking zone 370 includes a fluid-solid contacting device. The fluid-solid contacting device may include a baffle or grid structure to promote contact between the treated catalyst and the second oxygen-containing gas. Examples of the fluid-solid contacting device are described in further detail in U.S. Patent Nos. 9,827,543 and 9,815,040. The fluidization regime within the oxygen soaking zone 370 may be of the bubbling bed type. The oxygen soaking zone 370 may include an oxygen-containing gas inlet 372 that may supply the second oxygen-containing gas to the oxygen soaking zone 370 for oxygen treatment of the catalyst. When the heated catalyst is in the oxygen soaking zone 370, the temperature of the heated catalyst may be greater than or equal to 660 °C. Without being bound by theory, it is believed that contacting the heated catalyst with the oxygen-containing gas in the oxygen soaking zone 370 increases the catalyst activity for dehydrogenating alkanes and results in increased alkane conversion in the reactor section 200.

[0044] In one or more embodiments, before the reactivated catalyst is delivered to the reactor section 200, the reactivated catalyst produced by treating the heated catalyst with a second oxygen-containing gas in the oxygen soak zone 370 can be further contacted with a stripping gas. In some embodiments, the stripping gas can be nitrogen, methane, steam, or one or more inert gases. Without being bound by theory, it is believed that contacting the reactivated catalyst with the stripping gas removes at least a portion of the molecular oxygen trapped within or between the catalyst particles, which will reduce the amount of oxygen carried into the reactor 200.

[0045] As Figure 1 depicted, in one or more embodiments, a portion of the heated catalyst can leave the catalyst treatment section 300 before being delivered to the oxygen soak zone 370. In some embodiments, a recycle portion of the heated catalyst from the catalyst treatment section 300 can be delivered directly to the oxidation vessel 500 via line 385. Such recycled catalyst can be exposed to some oxygen, but not to the normal amount of oxygen associated with the oxygen soak zone 370.

[0046] Now referring Figure 3 to, another embodiment of the reactor system 103 is depicted, which is similar or identical to the Figure 1 reactor system except for the differences described below. In the Figure 3 embodiment, the recycled catalyst in line 385 is delivered to the burner 350 instead of to the oxidation vessel 500 (as described in the Figure 1 embodiment). Such a scenario can be effective because the recycled catalyst is substantially coke-free, and thus uneven distribution of the catalyst in the burner 350 is not likely to cause problems.

[0047] Figure 2 Another embodiment of the exemplary reactor system 102 is depicted in, which is similar or identical to the Figure 1 reactor system except for the differences described below, and is similar or identical to the Figure 1 reactor system. In the Figure 2 embodiment, the oxidation vessel 500 and the burner 350 can be physically isolated from each other. In such embodiments, the oxidation vessel 500 and the burner 350 are connected via one or more lines, and the catalyst can be not exposed to oxygen and / or not fluidized throughout such lines. As Figure 2 depicted, the oxidation vessel 500 can be a separate reaction vessel operating as a fluidized bed. The oxygen-containing gas ( Figure 2(The inlet is not shown) The deactivated catalyst entering the oxidation vessel 500 via pipeline 426 can be accessed. Pipeline 506 can transfer the now decoked catalyst to pipeline 438, where oxygen-containing gas fluidizes the catalyst via 428 and transfers the catalyst through pipeline 438 to the burner 350. Some additional coke combustion can occur in pipeline 438, but most of the coke combustion in the coke combustion can occur in the oxidation vessel 500. Pipeline 510 can transfer the gas (after treatment) from the oxidation vessel 500 to the catalyst separation section 310, where the existing cyclone separator in the catalyst treatment system 300 can be used to separate the gas and a small amount of catalyst residue, as Figure 2 shown.

[0048] Figure 4 Another embodiment of the exemplary reactor system 104 is depicted, which is similar or identical in many aspects to Figure 2 the embodiment of. In Figure 4 the embodiment of, the isolated oxidation vessel 500 (as previously described in the context of Figure 4 ) decokes the catalyst. However, instead of transferring the catalyst via pipeline 506 to pipeline 438 where oxygen-containing gas fluidizes the catalyst, the catalyst is directly transferred via pipeline 506 to the burner 350. In such embodiments, it is believed that compared to Figure 2 the embodiment of (where combustion can occur in pipeline 438 in addition to in the oxidation vessel 500), very little or no coke is incandesced in the passage between the oxidation vessel 500 and the burner 350.

[0049] Now referring to Figure 5 the reactor system 105 of, another embodiment is depicted, which can be similar or identical in many aspects to Figure 1 the. In Figure 5 , the oxidation vessel 500 is pipeline 438, where oxygen-containing gas is transferred from port 428 via pipeline 429 into pipeline 438 and fluidizes the catalyst to transfer it upward to the burner 350. In such embodiments, an independent reaction drum is not included. Instead, the oxidation vessel 500 is a pipeline, which can have dilute-phase fluidization. Figure 5 An embodiment is depicted where the catalyst is recycled via pipeline 385 to the oxidation vessel 50, similar to Figure 1 the embodiment of. Figure 6 Another embodiment, the reactor system 106, is depicted, which is similar or identical to Figure 5 the reactor system of, but the catalyst is directly recycled via pipeline 385 to the burner 350 instead of to the oxidation vessel 500.

[0050] In one or more embodiments, light olefins may be present in a "product stream" sometimes referred to as an "olefin-containing effluent" and include light olefins. Such streams leave the reactor system 102 and may subsequently be processed. As used in this disclosure, the term "light olefins" refers to one or more of styrene, ethylene, propylene, and butene. The term butene includes any butene isomer, such as alpha-butene, cis-beta-butene, trans-beta-butene, and isobutene. In some embodiments, based on the total weight of the olefin-containing effluent, the olefin-containing effluent comprises at least 25 wt% light olefins. By way of example, based on the total weight of the olefin-containing effluent, the olefin-containing effluent may comprise at least 35 wt% light olefins, at least 45 wt% light olefins, at least 55 wt% light olefins, at least 65 wt% light olefins, or at least 75 wt% light olefins. The olefin-containing effluent may also comprise unreacted components of the feed stream and other reaction products that are not considered light olefins. The light olefins may be separated from the unreacted components in subsequent separation steps.

[0051] In a non-limiting example, the reactor systems described herein can be used to produce light olefins from a hydrocarbon feed stream. Light olefins can be produced from various hydrocarbon feed streams by utilizing different reaction mechanisms. For example, light olefins can be produced by at least dehydrogenation reactions, cracking reactions, dehydration reactions, and methanol-to-olefin reactions. These reaction types can utilize different feed streams and different particulate solids to produce light olefins. It should be understood that when "catalyst" is referred to herein, these catalysts may equally refer to the particulate solids referred to with respect to Figure 1 the systems.

[0052] According to one or more embodiments, the reaction can be a dehydrogenation reaction. According to such embodiments, the hydrocarbon feed stream can comprise one or more of ethylbenzene, ethane, propane, n-butane, and isobutane. In one or more embodiments, the hydrocarbon feed stream can comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of ethylbenzene. In one or more embodiments, the hydrocarbon feed stream can comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of ethane. In additional embodiments, the hydrocarbon feed stream can comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of propane. In additional embodiments, the hydrocarbon feed stream can comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of n-butane. In additional embodiments, the hydrocarbon feed stream can comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of isobutane. In additional embodiments, the hydrocarbon feed stream can comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of the sum of ethane, propane, n-butane, and isobutane.

[0053] In one or more embodiments, the dehydrogenation reaction can utilize gallium and / or platinum particulate solids as catalysts. In such embodiments, the particulate solids can comprise a gallium and / or platinum catalyst. As described herein, the gallium and / or platinum catalyst comprises gallium, platinum, or both. The gallium and / or platinum catalyst can be supported on an alumina or alumina-silica support and can optionally comprise potassium. Such gallium and / or platinum catalysts are disclosed in U.S. Patent No. 8,669,406, which is incorporated herein by reference in its entirety. However, it should be understood that other suitable catalysts can be utilized for the dehydrogenation reaction.

[0054] In one or more embodiments, the reaction mechanism can be dehydrogenation followed by combustion (in the same chamber). In such embodiments, the dehydrogenation reaction can produce hydrogen as a byproduct, and the oxygen carrier material can contact the hydrogen and promote the combustion of the hydrogen to form water. Examples of such reaction mechanisms are disclosed in WO 2020 / 046978, which are considered to be possible reaction mechanisms for the systems and methods described herein, the teachings of which are incorporated herein by reference.

[0055] According to one or more embodiments, the reaction can be a cracking reaction. According to such embodiments, the hydrocarbon feed stream can include one or more of naphtha, normal butane, or isobutane. According to one or more embodiments, the hydrocarbon feed stream can include at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of naphtha. In additional embodiments, the hydrocarbon feed stream can include at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of normal butane. In additional embodiments, the hydrocarbon feed stream can include at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of isobutane. In additional embodiments, the hydrocarbon feed stream can include at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of the total of naphtha, normal butane, and isobutane.

[0056] In one or more embodiments, the cracking reaction can utilize one or more zeolites as a catalyst. In such embodiments, the particulate solid can include one or more zeolites. In some embodiments, the one or more zeolites utilized in the cracking reaction can include ZSM-5 zeolite. However, it should be understood that other suitable catalysts can be utilized for the cracking reaction. For example, suitable commercially available catalysts can include Intercat Super Z Excel or Intercat Super Z Exceed. In additional embodiments, in addition to the catalytically active material, the cracking catalyst can further include platinum. For example, the cracking catalyst can contain from 0.001 wt% to 0.05 wt% of platinum. The platinum can be sprayed in the form of platinum nitrate and calcined at an elevated temperature (such as about 700 °C). Without being bound by theory, it is believed that adding platinum to the catalyst can allow for easier combustion of a supplemental fuel such as methane.

[0057] According to one or more embodiments, the reaction can be a dehydration reaction. According to such embodiments, the hydrocarbon feed stream can contain one or more of ethanol, propanol, or butanol. According to one or more embodiments, the hydrocarbon feed stream can contain at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% ethanol. In additional embodiments, the hydrocarbon feed stream can contain at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% propanol. In additional embodiments, the hydrocarbon feed stream can contain at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% butanol. In additional embodiments, the hydrocarbon feed stream can contain at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of the total of ethanol, propanol, and butanol.

[0058] In one or more embodiments, the dehydration reaction can utilize one or more acid catalysts. In such embodiments, the particulate solid can include one or more acid catalysts. In some embodiments, the one or more acid catalysts utilized in the dehydration reaction can include zeolites (such as ZSM-5 zeolite), alumina, amorphous aluminosilicate, acidic clay, or combinations thereof. For example, according to one or more embodiments, commercially available alumina catalysts that may be suitable include SynDol (available from Scientific Design Company), V200 (available from UOP), or P200 (available from Sasol). Commercially available zeolite catalysts that may be suitable include CBV 8014, CBV 28014 (each available from Zeolyst). Commercially available amorphous aluminosilicate catalysts that may be suitable include silica-alumina catalyst support, grade 135 (available from Sigma Aldrich). However, it should be understood that other suitable catalysts can be utilized for the dehydration reaction.

[0059] According to one or more embodiments, the reaction can be a methanol-to-olefins reaction. According to such embodiments, the hydrocarbon feed stream can contain methanol. According to one or more embodiments, the hydrocarbon feed stream can contain at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% methanol.

[0060] In one or more embodiments, the methanol-to-olefins reaction can utilize one or more zeolites as catalysts. In such embodiments, the particulate solid can include one or more zeolites. In some embodiments, the one or more zeolites utilized in the methanol-to-olefins reaction can include one or more of ZSM-5 zeolite or SAPO-34 zeolite. However, it should be understood that other suitable catalysts can be utilized to carry out the methanol-to-olefins reaction.

[0061] Example

[0062] This document provides examples that disclose one or more embodiments of the present disclosure. However, the examples should not be regarded as a limitation on the claimed embodiments provided below.

[0063] Example 1

[0064] The catalysts used in these experiments were prepared by a conventional incipient wetness impregnation method and contained platinum and gallium on alumina. The fresh catalyst had 300 ppm platinum, while the aged catalyst was the catalyst extracted from an experimental-scale operation after nine months and had 75 ppm platinum. Both catalysts had 1.6 wt% gallium.

[0065] The experiments were conducted in a fixed-bed laboratory-scale unit with simulated dehydrogenation, pre-combustion contact with air, combustion, and air soak steps. The catalyst was diluted with silicon carbide (99.8 wt% purity 220 mesh Go Products), with a dilution by weight of 1:2. The catalyst bed was held in place in the reactor, and its upstream and downstream sections were 20 - 40 mesh silicon carbide, 98.5 wt% purity 20 - 40 mesh Go Products. The cycle was established as follows: pre-combustion treatment, where the first gas stream was air with a weight hourly space velocity of 7.1 hr -1 where the temperature and time length of the catalyst's contact with the first gas stream are provided in Tables 1 to 3; combustion, where the fuel gas stream was a feed of 2.5 vol% methane / 97.5 vol% synthetic air with a weight hourly space velocity of 7.0 hr -1 where the fuel gas stream was contacted with the catalyst at 730 °C for 3 minutes; air soak, where the second gas stream was air with a weight hourly space velocity of 7.1 hr -1 where the second gas stream was contacted with the catalyst at 730 °C for the time length provided in Tables 1 to 3; and dehydrogenation, where the hydrocarbon feed stream was a feed called propane of 90 mol% propane / 10 mol% N2 with a weight hourly space velocity of 10 hr -1 where the hydrocarbon feed stream was contacted with the catalyst at 625 °C for 1 minute. Dehydrogenation performance data was collected at a run time of 25 seconds, and combustion data was collected at a run time of 75 seconds.

[0066] Perform an intermediate purge step with an inert gas to establish well-defined start and stop of the air soak, combustion, and dehydrogenation steps. Generally, include a 3- or 4-minute N2 purge step (at about 7 hr -1 ) between steps where the temperature does not change. For steps with a temperature change, heat / cool the catalyst under N2 (at about 7 hr -1 ) until the temperature stabilizes, then introduce the gas flow for the next step. Tables 1 to 3 below illustrate the propane conversion, propylene selectivity, and methane conversion achieved by following these experimental procedures and varying the temperature and reaction time of certain steps of the procedure. As can be seen, higher propane conversion and propylene selectivity are achieved when a pre-combustion step is utilized, and the lower temperature of the pre-combustion step indicates that higher propane conversion and propylene selectivity are achieved.

[0067] Table 1 - Fresh catalyst, where the same 3-minute combustion was carried out, followed by a 7-minute or 10-minute air soak, both at 730 °C. The data reported are for the results of cycle 80 Table 2 - Fresh catalyst, where the same 3-minute combustion was carried out, followed by a 2-minute air soak, both at 730 °C. The data reported are for the results of cycle 80 。

[0068]

[0069] Table 3 - Aged catalyst, where the same 3-minute combustion was carried out, followed by a 10-minute air soak, both at 730 °C. The data reported are for the results of cycle 150 Table 4 - Comparison of dehydrogenation performance after each step in cycle 80 with and without pre-combustion treatment 。

[0070]

[0071] Example 2 Table 4 - Comparison of dehydrogenation performance after each step in cycle 80 with and without pre-combustion treatment 。

[0072]

[0073] ​

[0074] The dehydrogenation performance after each step in this method was studied. Five cases were run for a total of 79 cycles, where the dehydrogenation step was carried out at 625 °C for 1 minute, the pre-combustion air treatment step was carried out at 625 °C for 3 minutes, the combustion step was carried out with 2.5 vol% methane / 97.5 vol% synthetic air at 730 °C for 3 minutes, and the air soak step was carried out at 730 °C for 7 minutes. In each case, cycle 80 was varied to determine the dehydrogenation performance after each step. In the first group with pre-combustion air treatment, the pre-combustion air treatment was carried out at 625 °C for 3 minutes, the combustion step was carried out with 2.5 vol% methane / 97.5 vol% synthetic air at 730 °C for 3 minutes, and the air soak step was carried out at 730 °C for 7 minutes. In the second group, the pre-combustion air treatment was not included, the combustion step was carried out with 2.5 vol% methane / 97.5 vol% synthetic air at 730 °C for 3 minutes, and the air soak step was carried out at 730 °C for 7 minutes. Dehydrogenation performance data were collected at a 25-second run time. Table 4 illustrates the results of these experiments. As can be seen, for the cycles utilizing the initial pre-combustion step, the percentage of propane conversion was higher after each step.

[0075] ​ ​

[0076]

[0077] This disclosure includes several aspects. A first aspect is a method for forming light olefins, the method comprising: reacting a feed stream in a reactor in the presence of a catalyst to form a product stream and a deactivated catalyst containing coke; separating at least a portion of the product stream from the deactivated catalyst; transferring the deactivated catalyst to an oxidation vessel and contacting the deactivated catalyst with a first oxygen-containing gas to remove at least a portion of the coke on the deactivated catalyst, thereby producing a decoked catalyst; transferring the decoked catalyst to a burner and burning a supplemental fuel in the burner to heat the decoked catalyst and produce a heated catalyst; transferring the heated catalyst to an oxygen soak zone and contacting the heated catalyst with a second oxygen-containing gas to produce a reactivated catalyst; and transferring the reactivated catalyst to the reactor.

[0078] Another aspect is any of the foregoing aspects or a combination of the foregoing aspects, wherein the deactivated catalyst contains 0.01 wt% to 0.4 wt% coke when entering the oxidation vessel.

[0079] Another aspect is any of the foregoing aspects or a combination of the foregoing aspects, wherein 0 wt% to 30 wt% of coke is present in the decoked catalyst.

[0080] Another aspect is any of the foregoing aspects or a combination of the foregoing aspects, wherein at least 70 wt% of the coke on the deactivated catalyst is combusted in the oxidation vessel.

[0081] Another aspect is any of the foregoing aspects or a combination of the foregoing aspects, wherein the first oxygen-containing gas is air.

[0082] Another aspect is any of the foregoing aspects or a combination of the foregoing aspects, wherein the oxidation vessel is operated at an apparent gas velocity of less than 8 ft / s, and the deactivated catalyst in the oxidation vessel has a catalyst bed density of 20 lb / ft 3 to 60 lb / ft 3 of catalyst bed density.

[0083] Another aspect is any of the foregoing aspects or a combination of the foregoing aspects, wherein when the supplementary fuel is combusted, the burner is operated at an apparent gas velocity of less than 4 ft / s, and the decoking catalyst in the burner has a catalyst bed density of 20 lb / ft 3 to 40 lb / ft 3 of catalyst bed density.

[0084] Another aspect is any of the foregoing aspects or a combination of the foregoing aspects, wherein combusting the supplementary fuel in the burner increases the temperature of the decoking catalyst to greater than or equal to 660 °C.

[0085] Another aspect is any of the foregoing aspects or a combination of the foregoing aspects, wherein when the heated catalyst is in the oxygen soaking zone, the temperature of the heated catalyst is greater than or equal to 660 °C.

[0086] Another aspect is any of the foregoing aspects or a combination of the foregoing aspects, further comprising: contacting the reactivated catalyst with a stripping gas before transferring the reactivated catalyst to the reactor.

[0087] Another aspect is any of the foregoing aspects or a combination of the foregoing aspects, wherein the oxidation vessel is a fluidized bed reactor.

[0088] Another aspect is any of the foregoing aspects or a combination of the foregoing aspects, wherein the oxidation vessel is a fluidized pipe.

[0089] Another aspect is any of the foregoing aspects or a combination of the foregoing aspects, wherein the oxidation vessel is physically isolated from the burner.

[0090] Another aspect is any of the foregoing aspects or a combination of the foregoing aspects, further comprising: directly transferring a recycled portion of the heated catalyst to the oxidation vessel.

[0091] On the other hand, any of the foregoing aspects or combinations of the foregoing aspects further includes: directly delivering a recycled portion of the heated catalyst to the combustor.

[0092] The subject matter of the present disclosure has been described in detail and with reference to specific embodiments. It should be understood that any detailed description of a component or feature of an embodiment does not necessarily imply that the component or feature is essential for a particular embodiment or any other embodiment. Further, it will be apparent to those skilled in the art that various modifications and changes can be made to the described embodiments without departing from the essence and scope of the claimed subject matter.

[0093] It should be noted that one or more of the appended claims utilize the term "wherein" as a transitional phrase. For the purpose of defining the present technology, it should be noted that this term is introduced in the claims as an open transitional phrase that is used to introduce a recitation of a series of characteristics of a structure and should be interpreted in a manner similar to the more common open preamble term "comprising".

[0094] It should be understood that where a first component is described as "comprising" a second component, it is contemplated that in some embodiments, the first component "consists of" or "consists essentially of" the second component. It should also be understood that where a first component is described as "comprising" a second component, it is contemplated that in some embodiments, the first component may comprise at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% or even at least 99% of the second component (wherein % may be weight % or mole %).

[0095] For the purpose of describing and defining the technology of the present invention, it should be noted that a reference herein to a variable as a "function" of a parameter or another variable is not intended to mean that the variable is uniquely a function of the listed parameter or variables. Instead, a reference herein to a variable as a "function" of the listed parameters is intended to be open-ended such that the variable can be a function of a single parameter or multiple parameters.

[0096] It should also be noted that a reference herein to "at least one" component, element, etc. should not be used to create an inference that the alternative use of the article "a / an" is limited to a single component, element, etc.

[0097] It should be noted that, unlike a recitation of intended use, a recitation herein that a component of the present disclosure is "configured" in a particular manner to embody a particular property or to function in a particular manner is a structural recitation. More specifically, a reference herein to the manner in which a component is "configured" represents the existing physical condition of the component and will thus be regarded as an express recitation of a structural feature of the component.

[0098] As understood in the context of the terms used herein, the term "transfer" can include directly transferring a substance between two parts of the disclosed system and, in some cases, means indirectly transferring a substance between two parts of the disclosed system. For example, indirect transfer can include steps in which the substance transfer passes through an intermediate separation device, valve, sensor, etc.

[0099] For purposes of describing and defining the technology of the present invention, it should be noted that the terms "substantially" and "about" are used herein to represent the inherent uncertainty that can be attributed to any quantitative comparison, value, measurement, or other representation. The terms "substantially" and "about" are also used herein to represent the degree to which a quantitative representation can vary from the stated reference without causing a fundamental change in the basic function of the subject matter being discussed.

Claims

1. A method for forming light olefins, the method comprising: reacting a feed stream in a reactor in the presence of a catalyst to form a product stream and a deactivated catalyst containing coke; separating at least a portion of the product stream from the deactivated catalyst; transferring the deactivated catalyst to an oxidation vessel and contacting the deactivated catalyst with a first oxygen-containing gas to remove at least a portion of the coke on the deactivated catalyst, thereby producing a decoked catalyst; transferring the decoked catalyst to a burner and burning a supplementary fuel in the burner to heat the decoked catalyst and produce a heated catalyst; transferring the heated catalyst to an oxygen soaking zone and contacting the heated catalyst with a second oxygen-containing gas to produce a reactivated catalyst; and transferring the reactivated catalyst to the reactor.

2. The method according to any one of the preceding claims, wherein the deactivated catalyst contains 0.01 wt% to 0.4 wt% coke when entering the oxidation vessel.

3. The method according to any one of the preceding claims, wherein 0 wt% to 30 wt% of coke is present in the decoked catalyst.

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