Process for forming light olefins with catalyst recycle

Abstract

In accordance with embodiments disclosed herein, a method for forming light olefins in a reactor system may include reacting a feed stream in the presence of a catalyst to form a deactivated catalyst, passing the deactivated catalyst to a combustor and processing the deactivated catalyst to produce a reactivated catalyst, combining a portion of the reactivated catalyst with the deactivated catalyst upstream of the combustor to form a mixed catalyst stream and contacting the mixed catalyst stream with a first oxygen-containing gas stream upstream of the combustor, and passing the mixed catalyst stream to the combustor and contacting the mixed catalyst stream with a second oxygen-containing gas stream while in the combustor, wherein the molar flow rate of the first oxygen-containing gas stream is from 1% to 15% of the combined molar flow rate of the first oxygen-containing gas stream and the second oxygen-containing gas stream.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 428,498, filed on November 29, 2022, the entire disclosure of which is hereby incorporated by reference. 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] Conventional methods for forming light olefins can transfer deactivated catalysts to a catalyst treatment system that includes a combustion step and a recovery step in order to heat and reactivate the catalyst, but these methods have several drawbacks. For example, the deactivated catalyst can directly enter the burner, where a relatively large amount of coke deposits on the deactivated catalyst, such that after treating the deactivated catalyst, the catalyst still contains a relatively large amount of coke. In another example, the deactivated catalyst can enter the burner at a relatively low temperature and can be unevenly heated to the regeneration temperature, resulting in some catalysts not achieving proper regeneration. In another example, the catalyst with coke can enter the burner and be unevenly distributed, which will preferentially consume the available oxygen, resulting in poor fuel - air mixing and incomplete combustion. Additionally, some conventional methods can treat at least a portion of the deactivated catalyst with an air stream in one or more separate units prior to entering the burner, where there will be a higher cost associated with having one or more separate units.

[0006] This disclosure describes methods for forming light olefins, which in some embodiments can overcome these deficiencies. According to the embodiments described herein, a portion of the reactivated catalyst can be recycled and combined with the deactivated catalyst upstream of the combustor to form a mixed catalyst stream, which then enters the combustor. This combination of the recycled portion of the reactivated catalyst and the deactivated catalyst can cause a reduction in the amount of coke deposited on the deactivated catalyst prior to entering the combustor, thereby exposing more catalyst active sites of the deactivated catalyst and improving the combustion of the supplementary fuel in the regenerator. Additionally, this combination of the recycled portion of the reactivated catalyst and the deactivated catalyst can heat the deactivated catalyst prior to entering the combustor, thereby achieving the target regeneration temperature more quickly and enabling more uniform catalyst regeneration. Further, if the coke burns prior to entering the combustor and the supplementary fuel is mixed with air in the combustor, the distribution of the catalyst may be less important because uneven distribution may not affect the mixing of fuel and air within the combustor to the same extent as in other cases. In one or more embodiments, the combination of the deactivated catalyst and the recycled portion of the reactivated catalyst does not require mixing in one or more separate units, thereby reducing the cost associated with this combination step. Additionally, the deactivated catalyst and the recycled portion of the reactivated catalyst can be contacted with a first oxygen-containing gas stream prior to entering the combustor, and a separate oxygen-containing gas stream can be introduced into the combustor, wherein the oxygen-containing gas stream used to convey the deactivated catalyst and the recycled portion of the reactivated catalyst to the combustor contributes to the total oxygen-containing gas in the combustor and reduces the cost associated with directly providing a separate oxygen-containing gas stream to the combustor.

[0007] According to one or more embodiments of the present disclosure, a method for forming light olefins in a reactor system can 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; conveying the deactivated catalyst to a combustor in a catalyst treatment section of the reactor system and treating the deactivated catalyst to produce a reactivated catalyst and flue gas, wherein coke is removed from the deactivated catalyst in the combustor, separating the reactivated catalyst from the flue gas and separating the reactivated catalyst into a first portion and a second portion, conveying the first portion of the reactivated catalyst to the reactor, combining the second portion of the reactivated catalyst with the deactivated catalyst upstream of the combustor to form a mixed catalyst stream, wherein the mixed catalyst stream is contacted with a first oxygen-containing gas stream upstream of the combustor and wherein the coke on the deactivated catalyst is oxidized when contacted with the first oxygen-containing gas stream upstream of the combustor, and conveying the mixed catalyst stream to the combustor and contacting the mixed catalyst stream with a second oxygen-containing gas stream in the combustor, wherein the sum of the molar flow rate of the first oxygen-containing gas stream and the molar flow rate of the second oxygen-containing gas defines the total oxygen-containing gas molar flow rate, and the molar flow rate of the first oxygen-containing gas stream is 1% to 15% of the total oxygen-containing gas molar flow rate.

[0008] 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. The drawings are included to provide a further understanding of the embodiments and, together with the detailed description, serve 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. Description of the Drawings

[0009] The following detailed description can be better understood when read in conjunction with the following drawings, in which:

[0010] Figure 1 schematically depicts a reactor system according to one or more embodiments of the present disclosure; and

[0011] Figure 2 schematically depicts a cross-sectional view of a burner of a catalyst treatment section of a reactor system according to one or more embodiments of the present disclosure.

[0012] When describing Figure 1 simplified schematic illustrations, many valves, temperature sensors, electronic controllers, etc. that can be used and are well known to those of ordinary skill in the art are not included. In addition, the accompanying components 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.

[0013] Reference will now be made in more detail to various embodiments, some of which are illustrated in the drawings. Detailed Description

[0014] As operated herein as a fluidized dehydrogenation reactor system for producing light olefins Figure 1The embodiments disclosed herein are described in detail in the context of a reactor system. 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 to 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 operating under non-fluidized conditions, or those including downcomers instead of risers. Additionally, it is contemplated that light olefins can be produced from various hydrocarbon feed streams 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 to selectively combust hydrogen, as described herein. These reaction types can utilize different feed streams and / or different catalysts to produce light olefins. It should also be understood that not all parts of Figure 1 should be construed as being necessary to the claimed subject matter.

[0015] Now referring to Figure 1 , an exemplary reactor system 102 that can be applicable to the methods and / or apparatuses described herein is schematically depicted. The reactor system 102 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 102, such as a reactor, a separator, a transfer line, combinations thereof, and the like. As used herein in the context of Figure 1 , the reactor section 200 generally refers to the part of the reactor system 102 where the main process reactions (e.g., dehydrogenation) occur to form a product stream. A feed stream enters the reactor section 200, is converted into a product stream (containing products and unreacted feed), and exits the reactor section 200. The reactor section 200 includes a reactor 202, which can include an upstream reactor zone 250 and a downstream reactor zone 230. According to one or more embodiments, as Figure 1As 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 102 where the catalyst is treated in some way, such as by combustion, to improve catalytic activity, for example, by decoking and / or heating the catalyst. The catalyst treatment section 300 may include a burner 350 and a riser 330 and may additionally include a catalyst separation section 310. In one or more embodiments, the catalyst separation section 210 may be in fluid communication with the burner 350 (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). In one or more embodiments, the catalyst from the catalyst separation section 210 (sometimes referred to as deactivated catalyst) is transferred towards the burner 350 via the standpipe 426. In one or more embodiments, a portion of the catalyst from the catalyst treatment section 300 (sometimes referred to as the first portion of the reactivated catalyst) may be transferred to the upstream reactor section 250 via the standpipe 424 and the transfer riser 430, and a portion of the catalyst from the catalyst treatment section 300 (sometimes referred to as the second portion of the reactivated catalyst) may be recycled and transferred towards the burner 350 via the standpipe 385.

[0016] As described herein, the deactivated catalyst from the standpipe 426 may be combined with the second portion of the reactivated catalyst from the standpipe 385 to form a mixed catalyst stream, which then enters the burner 350. Such a second portion of the reactivated catalyst may be considered a recycle stream within the catalyst treatment section 300. The advantages of such an arrangement are described in detail below.

[0017] Generally as described herein, in Figure 1 the embodiment shown, 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 may refer to solid materials that are catalytically active for the desired reaction, or may equally refer to reference Figure 1The system mentioned in the invention does not necessarily have catalytic activity but other particulate solids that affect the reaction, such as oxygen carriers. The terms "catalytic activity" and "catalyst activity" refer to the extent to which the catalyst can catalyze the reaction carried out in the reactor system. The catalyst leaving the reactor section 200 may be a deactivated catalyst. As used herein, "deactivated" may refer to a catalyst having a reduced catalytic activity or a colder catalyst than the catalyst entering the reactor section 200. However, the deactivated catalyst may retain some catalytic activity. The reduced catalytic activity may be caused by contamination of substances such as coke. Reactivation (sometimes referred to herein as "regeneration") may remove pollutants (such as coke), increase the temperature of the catalyst and / or reconstruct the catalytic site to restore or improve the dehydrogenation and / or combustion activity of the catalyst. In an embodiment, the deactivated catalyst may be reactivated by catalyst reactivation in the catalyst treatment section 300. The deactivated catalyst may be reactivated by, but not limited to, removing coke by combustion, restoring catalyst acidity, oxidizing the catalyst, heating the catalyst, other reactivation processes, or combinations thereof. In some embodiments, the catalyst may be heated during reactivation by combusting a supplemental fuel such as hydrogen, methane, ethane, propane, natural gas, or combinations thereof.

[0018] As about Figure 1 As depicted, a feed stream can enter feed inlet 434, enter reactor 202, and a product stream can exit reactor system 102 via tube 420. According to one or more embodiments, reactor system 102 can be operated by feeding a chemical feed (e.g., in a feed stream) and a fluidized catalyst into an upstream reactor section 250. The chemical feed contacts the catalyst in the upstream reactor section 250, and each chemical feed flows upwardly into and through the downstream reactor section 230 to produce a chemical product.

[0019] Now refer to the detailed Figure 1 , the reactor section 200 may include an upstream reactor section 250, a transition section 258, and a downstream reactor section 230, such as a riser. The transition section 258 may connect the upstream reactor section 250 with the downstream reactor section 230. Figure 1 As 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 container, a drum, a barrel, a barrel, or other container suitable for a given chemical reaction. Figure 1As 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 can generally 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.

[0020] The upstream reactor section 250 can be connected to a transport riser 430 which can, in operation, provide reactivated catalyst in a feed stream to the reactor section 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 can also be fed directly into the upstream reactor section 250 via the standpipe 422 (not depicted in Figure 1 ). This catalyst can be slightly deactivated but can still be suitable for reaction in the upstream reactor section 250 in some embodiments, particularly when used in combination with reactivated catalyst.

[0021] 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 may 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, such that the average catalyst and gas flow 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 may refer to a reactor utilizing a fluidization regime where the superficial velocity of the gas phase is greater than the choking velocity and may be semi-dense in operation. As described herein, a "turbulent" reactor may refer to a fluidization regime where the superficial velocity is less than the choking velocity and is denser than the fast fluidization regime. As described herein, a "bubbling bed" reactor may refer to a fluidization regime where distinct bubbles are present 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" may refer to a riser reactor operating at a transport velocity where the gas and catalyst have approximately the same velocity in the dilute phase.

[0022] According to an embodiment, the chemical product and the catalyst may 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 conveyed 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 may 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 toward a catalyst processing section 300.

[0023] According to one or more embodiments, the separation device 220 can be a cyclone separation system, which can 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 can enter a secondary cyclone separation device for further separation. The primary cyclone separation device can 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, e.g., 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 can be used in the currently disclosed embodiments.

[0024] Still referring to Figure 1 , the separated deactivated catalyst is transferred from the catalyst separation section 210 towards the burner 350 via the standpipe 426 and the J-bend 393. The deactivated catalyst is then combined with a second portion of the reactivated catalyst that is transferred via the standpipe 385 and the J-bend 392. The second portion of the reactivated catalyst can be transferred from the catalyst separation section 310 and recycled towards the burner 350 of the catalyst processing section 300 via the standpipe 385 and the J-bend 392. The deactivated catalyst is combined with the second portion of the reactivated catalyst to form a mixed catalyst stream. The combination of the deactivated catalyst and the second portion of the reactivated catalyst can be accomplished in the pipe 395, which can be in fluid communication with the burner 350 such that the components of the mixed catalyst stream can contact the first oxygen-containing gas stream and be thoroughly mixed for at least 1 second, at least 2 seconds, at least 3 seconds, at least 4 seconds, at least 5 seconds, or even longer, such as about 8 seconds, before the mixed catalyst stream is transferred to the burner 350. The mixed catalyst stream can then enter the burner 350. The mixing of these streams typically occurs upstream of their insertion into the burner 350.

[0025] In one or more embodiments, prior to the mixed catalyst stream being delivered to the combustor 350, the first oxygen-containing gas may contact the mixed catalyst stream via one or more tubes 510. The first oxygen-containing gas stream may enter at the J-bend 393 via the tube 510, the first oxygen-containing gas stream may enter at the J-bend 392 via the tube 510, and / or the first oxygen-containing gas stream may enter at the tube 395 via the tube 510. The first oxygen-containing gas may enter at one or more tubes 510. When the first oxygen-containing gas enters at the J-bend 393 via the tube 510, the first oxygen-containing gas will contact at least a portion of the deactivated catalyst being delivered in the riser 426 and then contact a second portion of the reactivated catalyst that is combined with the deactivated catalyst in the tube 395. Prior to contact with the tube 510, an inert gas, such as nitrogen or steam, may be present in the catalyst in the tube 426. When the first oxygen-containing gas enters at the J-bend 392 via the tube 510, the first oxygen-containing gas will contact at least a portion of the second portion of the reactivated catalyst being delivered in the riser 385 prior to the deactivated catalyst being combined with the second portion of the reactivated catalyst. When the first oxygen-containing gas enters at the tube 395 via the tube 510, the first oxygen-containing gas will contact the mixed catalyst stream in the tube 395, which mixed catalyst stream comprises the deactivated catalyst and the second portion of the reactivated catalyst. The use of oxygen from the tube 510 may additionally contribute to less oxygen being needed to be directly added to the combustor 350, which may be advantageous in achieving the desired fluidization regime in the combustor 350.

[0026] Without being bound by any particular theory, it is believed that combining the deactivated catalyst with the second portion of the reactivated catalyst to form a mixed catalyst stream and contacting the mixed catalyst stream with the first oxygen-containing gas stream will reduce the amount of coke deposited on the deactivated catalyst prior to the mixed catalyst stream entering the combustor 350. Additionally, it is believed that combining the deactivated catalyst with the second portion of the reactivated catalyst to form a mixed catalyst stream and contacting the mixed catalyst stream with the first oxygen-containing gas stream pre-oxidizes the coke on the deactivated catalyst prior to the deactivated catalyst entering the combustor 350 and also aids in achieving thorough mixing of the deactivated catalyst and the second portion of the reactivated catalyst in the tube 395. In summary, it is believed that this will result in improved performance of the catalyst in combusting the supplemental fuel in the combustor 350. In additional embodiments, the combining of the catalyst streams may introduce fluidization efficiency by having all of the catalyst enter the center of the combustor 350.

[0027] Furthermore, without being bound by any particular theory, it is believed that combining the deactivated catalyst with a second portion of the reactivation catalyst to form a mixed catalyst stream and contacting the mixed catalyst stream with a first oxygen-containing gas stream heats the deactivated catalyst before it enters the combustor 350. In many conventional methods, various distributors, mixing devices (such as tubes, baffles) attempt to rapidly disperse and mix the deactivated catalyst in order to heat the catalyst to the target regeneration temperature. However, in these conventional methods, the mixing devices may not be able to uniformly and sufficiently mix the catalyst throughout the catalyst processing section, or may not at least achieve the degree that the currently disclosed premixing scheme can achieve, resulting in regions within the catalyst processing section where the catalyst is not sufficiently heated, thereby causing some non-uniform regeneration of the deactivated catalyst. In the methods described herein, according to one or more embodiments, since the deactivated catalyst can be heated before entering the combustor 350, the deactivated catalyst can reach the target regeneration temperature more quickly and achieve a more uniform regeneration of the deactivated catalyst. For example, it is believed that compared to a method of simply transferring the deactivated catalyst directly from the reactor section 200 to the combustor 350, a higher conversion of supplemental fuel (such as methane) can be achieved since the deactivated catalyst is heated before entering the combustor 350.

[0028] In one or more embodiments, combining the second portion of the reactivation catalyst with the deactivated catalyst upstream of the combustor to form a mixed catalyst stream is accomplished in a tube 395 in a dense-phase lift fluidization scheme. The term "dense-phase lift fluidization scheme" can refer to a fluidization scheme that causes the mixed catalyst stream to contact the first oxygen-containing gas stream, where the first oxygen-containing gas stream has a velocity that causes thorough contact between the first oxygen-containing gas stream and the mixed catalyst stream, but the velocity is not high enough to transport the mixed catalyst stream into the combustor 350 before thorough mixing of the mixed catalyst stream is achieved. It is contemplated that the tube 395 can be a tube or vessel having various cross-sectional shapes and sizes and having a length that allows thorough mixing of the mixed catalyst stream and the first oxygen-containing gas stream before the mixed catalyst stream enters the combustor 350.

[0029] In one or more embodiments, the tube 395 can be operated at an apparent gas velocity of 0.3 m / s to 5 m / s, such as 0.4 m / s to 2.5 m / s, 0.6 m / s to 2.3 m / s, 0.7 m / s to 2.2 m / s, 0.9 m / s to 2.2 m / s, 1.0 m / s to 2.1 m / s, or 1.5 m / s to 2.1 m / s. In one or more embodiments, the tube 395 can be at 245 kg / m 2 -s to 1710 kg / m 2 -s, such as 300 kg / m 2 -s to 1500 kg / m 2 -s, 400 kg / m 2 -s to 1450 kg / m2 -s, 400 kg / m 2 -s to 1400 kg / m 2 -s, 500 kg / m 2 -s to 1,350 kg / m 2 -s, 500 kg / m 2 -s to 1,300 kg / m 2 -s, 550 kg / m 2 -s to 1,220 kg / m 2 -s or 600 kg / m 2 -s to 1,000 kg / m 2 Solid flux operation of -s.

[0030] In one or more embodiments, combining a second portion of the reactivated catalyst with the deactivated catalyst upstream of the burner 350 to form a mixed catalyst stream results in a temperature difference between the second portion of the reactivated catalyst and the deactivated catalyst before entering the burner 350 that is less than or equal to 10°C. For example, the temperature difference can be less than or equal to 10°C, less than or equal to 9°C, less than or equal to 8°C, less than or equal to 7°C, less than or equal to 6°C, less than or equal to 5°C, less than or equal to 4°C, less than or equal to 3°C, less than or equal to 2°C, or even less than or equal to 1°C.

[0031] In one or more embodiments, the mixed catalyst stream enters the catalyst treatment section 300 through the bottom central portion of the burner 350. The central portion of the burner 350 refers to a point that is approximately half of the diameter with respect to any two points along the circumference of the burner body. It should be noted that the mixed catalyst stream does not have to enter the burner 350 at the exact center point of the bottom of the burner 350, and the mixed catalyst stream can enter the burner 350 at any point along the bottom of the burner 350 that allows the flow to rise properly upward toward the riser 330.

[0032] In one or more embodiments, the mixed catalyst stream can enter the burner 350 at a flow rate of 0.5 m / s to 4.0 m / s. For example, the mixed catalyst stream can enter the burner 350 at a flow rate of 0.5 m / s to 3.5 m / s, 0.5 m / s to 3.0 m / s, 0.5 m / s to 2.5 m / s, 0.5 m / s to 2.0 m / s, 0.5 m / s to 1.5 m / s, 0.5 m / s to 1.0 m / s, 1.0 m / s to 4.0 m / s, 1.5 m / s to 4.0 m / s, 2.0 m / s to 4.0 m / s, 2.5 m / s to 4.0 m / s, 3.0 m / s to 4.0 m / s, 3.5 m / s to 4.0 m / s, 1.0 m / s to 3.5 m / s, 1.5 m / s to 3.0 m / s, or 2.0 m / s to 3.0 m / s.

[0033] The term "oxygen-containing gas" can refer to any gas containing at least 0.5 mass% oxygen. For example, the oxygen-containing gas can contain at least 1 mass%, at least 5 mass%, at least 10 mass%, at least 20 mass%, at least 30 mass%, at least 40 mass%, at least 50 mass%, at least 60 mass%, at least 70 mass%, at least 80 mass% or at least 90 mass% oxygen. In some embodiments, the oxygen-containing gas can contain from 0.5 mass% oxygen to 99.9 mass% oxygen, such as from 1 mass% oxygen to 99.9 mass% oxygen, from 10 mass% oxygen to 99.9 mass% oxygen, from 20 mass% oxygen to 99.9 mass% oxygen, from 50 mass% oxygen to 99.9 mass% oxygen, from 0.5 mass% oxygen to 80 mass% oxygen, from 0.5 mass% oxygen to 60 mass% oxygen, from 0.5 mass% oxygen to 40 mass% oxygen, or from 0.5 mass% oxygen to 30 mass% oxygen. In one or more embodiments, the oxygen-containing gas can be air.

[0034] In one or more embodiments, the temperature of the deactivated catalyst can be from 550 °C to 800 °C. For example, the temperature of the deactivated catalyst can be from 600 °C to 800 °C, from 650 °C to 800 °C, from 700 °C to 800 °C, from 750 °C to 800 °C, from 550 °C to 750 °C, from 550 °C to 700 °C, from 550 °C to 650 °C, from 500 °C to 600 °C, or from 600 °C to 650 °C. In one or more embodiments, the temperature of the second portion of the reactivated catalyst can be from 700 °C to 900 °C. For example, the temperature of the second portion of the reactivated catalyst can be from 750 °C to 900 °C, from 800 °C to 900 °C, from 850 °C to 900 °C, from 700 °C to 850 °C, from 700 °C to 800 °C, from 700 °C to 750 °C, or from 750 °C to 950 °C. In one or more embodiments, when combined with the second portion of the reactivated catalyst, the temperature of the deactivated catalyst increases. In some embodiments, after being combined with the second portion of the reactivated catalyst, the temperature of the deactivated catalyst can be from 600 °C to 850 °C. For example, after being combined with the second portion of the reactivated catalyst, the temperature of the deactivated catalyst can be from 650 °C to 850 °C, from 700 °C to 850 °C, from 750 °C to 850 °C, from 800 °C to 850 °C, from 600 °C to 800 °C, from 600 °C to 750 °C, from 600 °C to 700 °C, from 600 °C to 750 °C, from 650 °C to 750 °C, or from 700 °C to 800 °C.

[0035] Still referring to Figure 1, The mixed catalyst stream can enter the combustor 350, where the mixed catalyst stream then contacts a second oxygen-containing gas stream. One or more of the first oxygen-containing gas stream and / or the second oxygen-containing gas stream can be air. The second oxygen-containing gas stream can enter the combustor 350 via pipe 428. The second oxygen-containing gas stream can promote the combustion of one or more fuel gases or make-up gases present in the combustor 350 and burn at least a portion of the coke remaining on the catalyst present in the combustor 350. The catalyst is then transferred out of the combustor 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., gases emitted by burning spent catalyst or make-up 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. A first portion of the separated catalyst (also referred to as the first portion of the reactivated catalyst) is then transferred through the oxygen treatment 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. A second portion of the separated catalyst (also referred to as the second portion of the reactivated catalyst) is transferred towards the combustor 350 via the standpipe 385 and combined with the deactivated catalyst from the reactor section 200 to form a mixed catalyst stream, which then enters the combustor 350. The second portion of the catalyst can be exposed to the oxygen-containing gas for at least 5 seconds or even greater than 30 seconds (such as up to several minutes), which can be less than the time of the first portion of the catalyst on oxygen. The catalyst can cycle 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.

[0036] Referring to Figure 2 , a schematic cross-sectional view of one embodiment of the combustor 350 is shown. Figure 2 The combustor 350 is shown as a fluidized fuel gas combustor system for use in a catalytic dehydrogenation process. However, as described in detail herein, the chemical feed distributor 100 can be used in a variety of vessels. Also referring to Figure 2, the burner 350 may include a lower portion 201 that is generally cylindrical in shape and an upper portion that includes a frustum 202. The angle between the frustum 202 and an internal horizontal imaginary line drawn at the intersection of the frustum 202 and the lower portion 201 may be in the range of 10 degrees to 80 degrees. All individual values and subranges from 10 wt% to 80 wt% are included and disclosed herein; for example, the range of the angle between the tubular member and the frustum 202 may range from a lower limit of 10 degrees, 40 degrees, or 60 degrees to an upper limit of 30 degrees, 50 degrees, 70 degrees, or 80 degrees. For example, the angle may be from 10 degrees to 80 degrees; or in an alternative, from 30 degrees to 60 degrees; or in an alternative, from 10 degrees to 50 degrees; or in an alternative, from 40 degrees to 80 degrees. Additionally, in an alternative embodiment, the angle may change continuously or discontinuously along the height of the frustum 202. In some embodiments, the burner 350 may or may not be lined with a refractory material.

[0037] The deactivated catalyst may be transferred toward the burner 350 via the riser tube 426, and a second portion of the reactivated catalyst may be transferred toward the burner 350 via the riser tube 385, wherein the deactivated catalyst and the second portion of the reactivated catalyst may be combined and form a mixed catalyst stream in the tube 395. The mixed catalyst stream may be transferred upward toward the air distributor 205. Above the air distributor 205 may be a grid 207. Above the grid 207 may be a plurality of chemical feed distributors 100. One or more additional grids 208 may be positioned above the chemical feed distributors 100 within the burner 350. In an embodiment, the chemical feed distributors 100 may enter the burner 350 and substantially traverse the burner 350, as described in U.S. Publication No. US2017 / 0087528.

[0038] Now generally referring to the catalyst processing section 300, as Figure 1 depicted, the burner 350 of the catalyst processing section 300 may be in fluid communication with the riser tube 330. A second oxygen-containing gas stream may be transferred through the tube 428 into the burner 350. The burner 350 and the riser tube 330 (collectively referred to as the catalyst combustion reactor 302) may 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 may operate as a fluidized bed, such as in a fast fluidization, turbulent, or bubbling bed upflow reactor, while the riser tube 330 may operate in a more plug flow manner, such as in a riser reactor. The geometries described with respect to the upstream reactor section 250 and the downstream reactor section 230 may equally apply to the burner 350 and the riser tube 330. Additionally, the burner 350 may further include a fuel inlet 354 that may supply a fuel, such as a hydrocarbon stream, to the burner 350.

[0039] In one or more embodiments, a first oxygen-containing gas stream and a second oxygen-containing gas stream may be combined in a combustor 350 and have a combined oxygen-containing gas flow rate, wherein the flow rate of the first oxygen-containing gas stream is 1% to 15% of the combined oxygen-containing gas flow rate. It should be understood that since the first oxygen-containing gas stream can deliver the mixed catalyst stream to the combustor 350, the first oxygen-containing gas stream will also be present in the combustor 350 after contacting and reacting with the mixed catalyst stream, thereby contributing to the amount of oxygen-containing gas required in the combustor 350. Accordingly, the amount of the second oxygen-containing gas required during the combustion step in the combustor 350 will be less because the presence of the first oxygen-containing gas stream will supplement the total amount of oxygen-containing gas present in the combustor 350. Importantly, this will reduce the cost associated with providing a larger amount of the second oxygen-containing gas stream to the combustor 350, which would be necessary if the mixed catalyst stream did not contact and was not delivered to the combustor 350 by the first oxygen-containing gas stream.

[0040] As described in one or more embodiments, after separating the catalyst from the flue gas in the riser termination separator 378 and the secondary separation device 320, the processed catalyst is treated with an oxygen-containing gas in an oxygen treatment zone 370. In some embodiments, the oxygen treatment zone 370 includes a fluid-solid contacting device. The fluid-solid contacting device may include baffle or grid structures to facilitate contact between the processed catalyst and the oxygen-containing gas. Examples of fluid-solid contacting devices are described in further detail in U.S. Pat. Nos. 9,827,543 and 9,815,040. The fluidization regime within the oxygen treatment zone may be of the bubbling bed type. The oxygen treatment zone 370 may include an oxygen-containing gas inlet 372 that may supply the oxygen-containing gas to the oxygen treatment zone 370 for oxygen treatment of the catalyst.

[0041] 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 a stream exits Figure 1The reactor system can then be processed. As used in this disclosure, the term "light olefin" refers to one or more of ethylene, propylene, and butene. The term butene includes any butene isomer, such as α-butene, cis-β-butene, trans-β-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 can comprise at least 30 wt% light olefins, at least 35 wt% light olefins, at least 40 wt% light olefins, at least 45 wt% light olefins, at least 55 wt% light olefins, or at least 60 wt% light olefins. The olefin-containing effluent can also comprise unreacted components of the feed stream and other reaction products that are not considered light olefins. The light olefins can be separated from the unreacted components in a subsequent separation step.

[0042] In a non-limiting example, the reactor system 102 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 reaction, selective hydrogen combustion dehydrogenation reaction, cracking reaction, dehydration reaction, and methanol-to-olefins reaction. These reaction types can utilize different feed streams and different particulate solids to produce light olefins. It should be understood that when "catalyst" is mentioned herein, these catalysts can equally refer to the particulate solids mentioned with respect to Figure 1 the system.

[0043] 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.

[0044] 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.

[0045] 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 an oxygen-carrying material can contact the hydrogen and promote its combustion 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, and the teachings of which are incorporated herein by reference.

[0046] According to one or more embodiments, the reaction can be a cracking reaction. According to such embodiments, the hydrocarbon feed stream can comprise one or more of naphtha, normal butane, or isobutane. According to 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% naphtha. 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% normal 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% 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 total of naphtha, normal butane, and isobutane.

[0047] In one or more embodiments, the cracking reaction can utilize one or more zeolites as a catalyst. In such embodiments, the particulate solid can comprise one or more zeolites. In some embodiments, the one or more zeolites utilized in the cracking reaction can comprise 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 comprise platinum. For example, the cracking catalyst can comprise from 0.001 wt% to 0.05 wt% 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.

[0048] 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 sum of ethanol, propanol, and butanol.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] Example

[0053] Examples are provided herein. The examples should not be regarded as limiting the claimed embodiments provided below.

[0054] Example 1

[0055] A reactor system including a reactor section and a catalyst treatment section is operated for 60 cycles, wherein the deactivated catalyst is combined with a recycle portion of the reactivated catalyst from the catalyst treatment section. Thus, the process of using the catalyst for dehydrogenation reaction in the reactor section and burning methane in the catalyst treatment section occurs 60 times. This test is called the inventive test. In contrast, a reactor system including a reactor section and a catalyst treatment section is operated for 60 cycles, wherein the deactivated catalyst is directly sent to the burner in the catalyst treatment section and not combined with the recycle stream of the reactivated catalyst from the catalyst treatment section. Thus, the process of using the catalyst for dehydrogenation reaction in the reactor section and burning methane in the catalyst treatment section occurs 60 times. This test is called the comparative test.

[0056] Table 1 below illustrates the percentage conversion of methane achieved in the inventive test and the comparative test. It can be seen that, compared with the comparative test where the deactivated catalyst is only directly sent to the burner, the inventive test where the deactivated catalyst is combined with a portion of the reactivated catalyst from the catalyst treatment section achieves a higher percentage conversion of methane in the burner in each cycle.

[0057] Table 1 - Methane conversion rate and number of cycles

[0058] Number of cycles Methane conversion rate (%) of the present invention Methane conversion rate (%) of the comparison 1 83 79 5 79 76 10 76 71 15 75 69 20 74 68 25 73 68 30 72 67 35 72 67 40 71 66 45 70 66 50 68 65 55 68 65 60 68 64

[0059] Example 2

[0060] This example illustrates the effectiveness of combining the deactivated catalyst with the recycled reactivated catalyst before delivering the mixed catalyst stream to the burner. The process conditions and pipe dimensions of the pipe section where the two catalyst streams are mixed are summarized in Table 2 below.

[0061] Table 2. Process conditions and dimensions of the catalyst premixing tube

[0062] <![CDATA[Catalyst density (Kg / m 3 )]]> 2000 Flow rate of deactivated catalyst (Kg / hour) 2,400,000 Temperature of deactivated catalyst (°C) 610 Flow rate of recycled reactivated catalyst (Kg / hour) 2,400,000 Recycled reactivation temperature (°C) 730 Flow rate of the first oxygen-containing gas (Kg / hour) 16,000 Tube outlet pressure (bar-a) 3 Tube inner diameter (m) 1.473 Tube length (m) 7.620 Superficial gas velocity (m / second) 2.3 <![CDATA[Catalyst flux (Kg / m 2 -sec)]]> 782 Coking rate (m / second) 5.7 Flow scheme Dense-phase lift

[0063] Using the computational fluid dynamics (CFD) model developed in Ansys Fluent V19.2 and a drag model that has been extensively validated against experimental data, the mixing of deactivated catalyst and recycled reactivated catalyst was simulated. The predicted coefficient of variation (CoV) as shown in Table 3 was calculated using Equation 1 below ， where X 失活,i represents the mass fraction of deactivated catalyst relative to the mixed catalyst at position i of the tube where the mixed catalyst stream enters the combustor.

[0064]

[0065] Table 3 - Predicted mixing of deactivated catalyst and recycled reactivated catalyst entering the burner along the tube

[0066] Distance from the inlet of the premixing tube (m) Coefficient of variation (%) 6 0.3 4.7 2.9 3.4 4.9 2.2 6.8 1.1 21.0 0 25.7

[0067] Table 3 shows the mixing of deactivated catalyst and recycled reactivated catalyst along the tube length. Each percentage of CoV corresponds to a 1.2 °C temperature difference between the catalyst streams. It can be seen that the model predicts that at 2.5 m above the inlet of the premixing tube (corresponding to ), the CoV drops to approximately 6.6% (temperature change of approximately 8 °C). This demonstrates the effectiveness of the present invention in combining deactivated catalyst and recycled reactivated catalyst before the combustor and ensures that the mixed catalyst uniformly reaches the target regeneration temperature.

[0068] The present disclosure includes one or more non-limiting aspects. The first aspect includes a method for forming light olefins in a reactor system, 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 a burner in a catalyst treatment section of the reactor system and treating the deactivated catalyst to produce a reactivated catalyst and flue gas, wherein coke is removed from the deactivated catalyst in the burner; separating the reactivated catalyst from the flue gas, and separating the reactivated catalyst into a first portion and a second portion; transferring the first portion of the reactivated catalyst to the reactor; combining the second portion of the reactivated catalyst with the deactivated catalyst upstream of the burner to form a mixed catalyst stream, wherein the mixed catalyst stream contacts a first oxygen-containing gas stream upstream of the burner, and wherein the coke on the deactivated catalyst is oxidized when contacting the first oxygen-containing gas stream upstream of the burner; and transferring the mixed catalyst stream to the burner, and contacting the mixed catalyst stream with a second oxygen-containing gas stream in the burner, wherein the sum of the molar flow rate of the first oxygen-containing gas stream and the molar flow rate of the second oxygen-containing gas stream defines a total oxygen-containing gas molar flow rate, and the molar flow rate of the first oxygen-containing gas stream is 1% to 15% of the total oxygen-containing gas molar flow rate.

[0069] The second aspect includes any of the above aspects, wherein the flow rate of the mixed catalyst stream entering the burner is 0.5 m / s to 4 m / s.

[0070] The third aspect includes any of the above aspects, wherein the second portion of the reactivated catalyst is passed in an oxygen-containing gas for more than 5 seconds before being combined with the deactivated catalyst.

[0071] The fourth aspect includes any of the above aspects, wherein the temperature of the deactivated catalyst increases when combined with the second portion of the reactivated catalyst.

[0072] The fifth aspect includes any of the above aspects, wherein the temperature of the deactivated catalyst is 550 °C to 800 °C, and the temperature of the second portion of the reactivated catalyst is 700 °C to 900 °C.

[0073] The sixth aspect includes any of the above aspects, further comprising burning a supplementary fuel in the burner.

[0074] The seventh aspect includes any of the above aspects, wherein the supplementary fuel comprises hydrogen, methane, ethane, propane, or natural gas.

[0075] The eighth aspect includes any of the above aspects, wherein the mixed catalyst stream promotes the combustion of the supplemental fuel.

[0076] The ninth aspect includes any of the above aspects, wherein the feed stream reacts via a dehydrogenation reaction, a selective hydrogen combustion dehydrogenation reaction, a cracking reaction, a dehydration reaction, or a methanol-to-olefins reaction.

[0077] The tenth aspect includes any of the above aspects, wherein the product stream contains one or more of ethylene, propylene, styrene, or butene.

[0078] The eleventh aspect includes any of the above aspects, wherein the product stream contains at least 25 wt% light olefins.

[0079] The twelfth aspect includes any of the above aspects, wherein combining the second portion of the reactivated catalyst with the deactivated catalyst upstream of the combustor to form the mixed catalyst stream is done in a vessel or tube operating in a dense-phase lift fluidization regime.

[0080] The thirteenth aspect includes any of the above aspects, wherein the vessel or tube operates at an apparent gas velocity of 0.3 m / s to 5 m / s and a solids flux of 245 kg / m 2 -s to 1,710 kg / m 2 -s.

[0081] The fourteenth aspect includes any of the above aspects, wherein the vessel or tube has a choking velocity and the vessel or tube operates at an apparent gas velocity below the choking velocity.

[0082] The fifteenth aspect includes any of the above aspects, wherein combining the second portion of the reactivated catalyst with the deactivated catalyst upstream of the combustor to form the mixed catalyst stream results in a temperature difference between the second portion of the reactivated catalyst and the deactivated catalyst before entering the combustor that is less than or equal to 10 °C.

[0083] It will be apparent to those skilled in the art that various modifications and variations can be made to the technology disclosed herein without departing from the spirit and scope of the technology. Since those skilled in the art can make modifications, combinations, sub-combinations, and variations of the disclosed embodiments that incorporate the spirit and substance of the technology disclosed herein, the technology should be construed to include all things within the scope of the appended claims and their equivalents. Additionally, although some aspects of the present disclosure may be identified herein as preferred or particularly advantageous, the present disclosure is not limited to these aspects.

[0084] It should be noted that the various details described in this disclosure should not be taken to imply that these details pertain to elements that are fundamental components of each of the embodiments described in this disclosure, even in cases where a particular element is shown in each of the drawings appended to this specification. Unless explicitly stated otherwise, the features disclosed and described herein should not be construed as "essential." Embodiments contemplated by this technology include those that include some or all of the features of the appended claims.

[0085] For purposes of describing and defining this disclosure, it should be noted that the term "about" is used in this disclosure to denote the inherent uncertainty that can be attributed to any quantitative comparison, value, measurement, or other representation. The term "about" is also utilized in this disclosure to denote the degree to which a quantitative representation can vary from a stated reference without resulting in a change in the fundamental function of the subject matter of concern.

[0086] In relevant cases, where a composition is described as "comprising" one or more elements, embodiments of the composition "consisting of" or "consisting essentially of" those one or more elements are contemplated herein.

[0087] It should be understood that in some embodiments, the composition ranges of chemical components in a stream or reactor should be understood to contain mixtures of isomers of that component. For example, a specified composition range of butene can include mixtures of the various isomers of butene. It should be understood that the examples provide composition ranges for various streams, and the total amount of isomers of a particular chemical composition can constitute a range.

[0088] It should be noted that one or more of the following claims and detailed description utilize the terms "where" or "wherein" as transitional phrases. For purposes of defining this 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 commonly used open introductory term "comprising."

[0089] 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.

[0090] It should be understood that any two quantitative values assigned to a characteristic can form a range of that characteristic, and all combinations of ranges formed by all the said quantitative values of a given characteristic are contemplated in the present disclosure. In cases where multiple ranges of quantitative values are provided, these ranges can be combined to form a wider range, which is contemplated in the embodiments described herein.

Claims

1. A method for forming light olefins in a reaction system, 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 a burner in a catalyst treatment section of the reactor system and treating the deactivated catalyst to produce a reactivated catalyst and flue gas, wherein coke is removed from the deactivated catalyst in the burner; separating the reactivated catalyst from the flue gas, and separating the reactivated catalyst into a first portion and a second portion; transferring the first portion of the reactivated catalyst to the reactor; combining the second portion of the reactivated catalyst with the deactivated catalyst upstream of the burner to form a mixed catalyst stream, wherein the mixed catalyst stream contacts a first oxygen-containing gas stream upstream of the burner, and wherein coke on the deactivated catalyst is oxidized when contacting the first oxygen-containing gas stream upstream of the burner; and transferring the mixed catalyst stream to the burner, and contacting the mixed catalyst stream with a second oxygen-containing gas stream in the burner; wherein the sum of the molar flow rate of the first oxygen-containing gas stream and the molar flow rate of the second oxygen-containing gas stream defines a total oxygen-containing gas molar flow rate, and the molar flow rate of the first oxygen-containing gas stream is 1% to 15% of the total oxygen-containing gas molar flow rate.

2. The method according to claim 1, wherein the flow rate of the mixed catalyst stream entering the burner is 0.5 m / s to 4 m / s.

3. The method according to any one of the preceding claims, wherein the second portion of the reactivated catalyst is passed in an oxygen-containing gas for more than 5 seconds before being combined with the deactivated catalyst.

4. The method according to any one of the preceding claims, wherein the temperature of the deactivated catalyst increases when combined with the second portion of the reactivated catalyst.

5. The method according to any one of the preceding claims, wherein the temperature of the deactivated catalyst is 550 °C to 800 °C, and the temperature of the second portion of the reactivated catalyst is 700 °C to 900 °C.

6. The method according to any one of the preceding claims, the method further comprising burning a supplementary fuel in the burner.

7. The method according to claim 6, wherein the supplementary fuel comprises hydrogen, methane, ethane, propane or natural gas.

8. The method according to claim 6, wherein the mixed catalyst stream promotes the combustion of the supplementary fuel.

9. The method according to any one of the preceding claims, wherein the feed stream reacts by dehydrogenation reaction, selective hydrogen combustion dehydrogenation reaction, cracking reaction, dehydration reaction or methanol-to-olefins reaction.

10. The method according to any one of the preceding claims, wherein the product stream comprises one or more of ethylene, propylene, styrene or butene.

11. The method according to any one of the preceding claims, wherein the product stream comprises at least 25 wt% of light olefins.

12. The method according to any one of the preceding claims, wherein combining the second portion of the reactivated catalyst with the deactivated catalyst upstream of the combustor to form the mixed catalyst stream is accomplished in a vessel or tube operating in a dense phase lift fluidization regime.

13. The method according to claim 12, wherein the vessel or tube is operated at an apparent gas velocity of 0.3 m / s to 5 m / s and a solids flux of 245 kg / m 2 -s to 1,710 kg / m 2 -s.

14. The method according to claim 12, wherein the vessel or tube has a choking velocity and the vessel or tube is operated at an apparent gas velocity below the choking velocity.

15. The method according to any one of the preceding claims, wherein combining the second portion of the reactivated catalyst with the deactivated catalyst upstream of the combustor to form the mixed catalyst stream results in a temperature difference between the second portion of the reactivated catalyst and the deactivated catalyst before entering the combustor that is less than or equal to 10 °C.

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