Process for preparation of light olefins by dehydrogenation using catalyst comprising chromium

Abstract

A method can include contacting a hydrocarbon-containing feed with a catalyst in a reactor to form an olefin-containing effluent, and then separating the olefin-containing effluent at least partially from the catalyst. The catalyst is passed to a combustor and heated by combusting a supplemental fuel. The supplemental fuel comprises methane in an amount greater than or equal to 1 mol%. The catalyst is passed from the combustor to the reactor such that at least a portion of the catalyst is continuously circulated between the reactor and the combustor. The catalyst comprises from 0.1% to 10% by weight of one or more metals selected from gallium, indium, thallium, or a combination thereof, from 5 ppmw to 1000 ppmw of one or more metals selected from platinum, palladium, rhodium, iridium, ruthenium, osmium, or a combination thereof, from 100 ppmw to 30000 ppmw of chromium, and at least 85% by weight of a support.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application Serial No. 63 / 352,023, filed on June 14, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0003]

[0013] Various embodiments described herein relate generally to chemical processing and, more particularly, to methods and systems for producing light olefins. Background Art

[0004] Light olefins such as propylene can be used as substrate materials to produce many different materials, such as polypropylene, isopropanol and acrylic acid, which can be used for example for packaging, construction and textiles. As a result of this utility, there is a demand for light olefins worldwide. Suitable processes for producing light olefins generally depend on given chemical feeds and include those processes utilizing fluidized catalysts. For example, light olefins can be formed by the catalytic dehydrogenation of alkanes in a fluidized bed reactor. However, it is necessary to improve the system and related catalysts for the preparation of light olefins. Summary of the invention

[0005] Some methods and related systems for preparing light olefins can utilize supplementary fuels that are burned during the production process to heat the catalyst. For example, the catalyst can circulate between a reactor and a burner, in which the light olefins are produced in an endothermic reaction, and in the burner, the catalyst is heated by the exothermic combustion of at least one supplementary fuel (sometimes accompanied by the combustion of coke). Such catalysts are not only catalytically active for the dehydrogenation of alkanes, but also catalytically active for the combustion of the supplementary fuel. Some embodiments of such suitable catalysts include, for example, gallium and platinum on a carrier. In some embodiments, methane can be used in the supplementary fuel. In such embodiments, conventional catalysts for dehydrogenation may have a problem of low methane combustion activity, which means that using methane as a supplementary fuel may not provide heat sufficient to raise the temperature of the catalyst to the desired temperature utilized in the dehydrogenation reaction. Further, the use of conventional catalysts that may have a problem of low methane combustion activity may adversely affect the safety of the dehydrogenation process, because unburned methane may exceed the low flammability level required in the regenerator. As described herein, it has been found that, compared with conventional catalysts that do not include chromium, additional catalysts that include chromium can enhance the combustion of methane.

[0006] According to one or more embodiments of the present disclosure, the method may include contacting a hydrocarbon-containing feed with a catalyst in a reactor to form an olefin-containing effluent, and then separating the olefin-containing effluent at least partially from the catalyst. The catalyst may be transferred to a burner, in which the catalyst may be heated by burning a supplementary fuel. The supplementary fuel may include an amount of methane greater than 1mol%. The catalyst may be transferred from the burner to the reactor so that at least a portion of the catalyst may be continuously circulated between the reactor and the burner. The catalyst may include 0.1 wt % to 10 wt % of one or more metals selected from gallium, indium, thallium or a combination thereof, 5 ppmw to 1000 ppmw of one or more metals selected from platinum, palladium, rhodium, iridium, ruthenium, osmium or a combination thereof, 100 ppmw to 30000 ppmw of chromium and at least 85 wt % of a carrier.

[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 specific embodiments, and in part, will be readily apparent to those of ordinary skill in the art from the description, including the drawings and 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 specific embodiments, to explain the principles and operation 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 may be better understood when read in conjunction with the following drawings, wherein:

[0009] Figure 1 A reactor system according to one or more embodiments of the present disclosure is schematically depicted.

[0010] When describing Figure 1 While the simplified schematic depiction of FIG. 1 does not include the many valves, temperature sensors, electronic controllers, etc. that may be used and are well known to those of ordinary skill in the art, are not included. Also, the accompanying components that are typically included in such reactor systems, such as air supply, heat exchangers, buffer tanks, etc., are not included. However, it should be understood that these components are within the scope of the present disclosure.

[0011] Reference will now be made in greater detail to various embodiments, some of which are illustrated in the accompanying drawings. DETAILED DESCRIPTION

[0012] As described herein, the present disclosure relates to a method for preparing light olefins by dehydrogenation, wherein a specific catalyst composition is utilized. For example, a catalyst that can be used for dehydrogenation may include a catalyst comprising: 0.1 wt % to 10 wt % of one or more metals selected from gallium, indium, thallium, or a combination thereof; 5 ppmw to 1000 ppmw of one or more metals selected from platinum, palladium, rhodium, iridium, ruthenium, osmium, or a combination thereof; 100 ppmw to 30,000 ppmw of chromium; and at least 85 wt % of a carrier. In one or more embodiments, such catalysts provide dual catalytic functions for the dehydrogenation of alkanes and the combustion of supplementary fuels. Such chromium-containing catalysts may be particularly suitable for fluidized dehydrogenation of light alkanes to light olefins, such as propane to propylene, where methane is used as a supplementary fuel to heat the catalyst.

[0013] In the present invention, a method for producing light olefins such as propylene is described in detail below. Figure 1 Embodiments of the disclosed methods are described in detail in the context of a reactor system for a reactor system. However, it should be understood that the principles disclosed and taught herein can be applied to other systems utilizing different system components oriented in different ways. For example, the concepts described herein can be equally applied to other systems having alternative reactor units and regeneration units, such as those operating under non-fluidized conditions, or those systems containing downcomers instead of risers. It should also be understood that not all systems are designed to be fluidized. Figure 1 All parts of the claims should be interpreted as being essential to the claimed subject matter. Furthermore, although the method steps listed in the appended claims are Figure 1 However, such enumerated method steps should be understood to be applicable to other systems, as understood by those skilled in the art.

[0014] Reference now Figure 1 , schematically depicts an exemplary reactor system 102 that may be suitable for use with the methods and / or apparatus described herein. The reactor system 102 generally includes a plurality of system components, such as a reactor section 200 and a catalyst treatment section 300. As used herein, a "system component" refers to a portion of the reactor system 102, such as a reactor, a separator, a transfer line, a combination thereof, and the like. As used herein, Figure 1 As used in the context of the present invention, the reactor section 200 generally refers to the portion of the reactor system 102 where the main process reaction (e.g., dehydrogenation) occurs to form an olefin-containing effluent. The hydrocarbon-containing feed enters the reactor section 200, contacts the catalyst, is converted into an olefin-containing effluent (containing products and unreacted feed), and leaves 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 1As depicted, the reactor section 200 can additionally include a catalyst separation section 210 for separating the catalyst from the olefin-containing effluent formed in the reactor 202. Additionally, as used herein, the catalyst treatment section 300 generally refers to a portion of the reactor system 102 in which the catalyst is treated in some manner, such as by combustion, to improve catalytic activity, for example, by decoking and / or heating the catalyst. The catalyst treatment section 300 can include a burner 350 and a riser 330, and can additionally include a catalyst separation section 310. In one or more embodiments, the catalyst separation section 210 can be in fluid communication with the burner 350 (e.g., via a standpipe 426), and the catalyst separation section 310 can be in fluid communication with the upstream reactor section 250 (e.g., via a standpipe 424 and a transport riser 430).

[0015] Generally, as described in this article, Figure 1 In the embodiment shown, the catalyst circulates between the reactor section 200 and the catalyst treatment section 300. It should be understood that when "catalyst" is mentioned in this article, they can refer to solid materials that are catalytically active for the desired reaction. 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 102. The catalyst leaving the reactor section 200 can be a deactivated catalyst. As used herein, "deactivated" can refer to a catalyst with reduced catalytic activity or cooler than 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 of substances such as coke. Coke can be formed on the catalyst in the reactor section 200. Reactivation (sometimes referred to as "regeneration" in this article) can remove contaminants such as coke, increase 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, removing coke by combustion, restoring catalyst acidity, oxidizing the catalyst, other reactivation processes, or combinations thereof. In some embodiments, the catalyst may be heated during reactivation by burning a supplemental fuel such as methane, ethane, propane, natural gas, or a combination thereof. The reactivated catalyst from the catalyst treatment section 300 is then transferred back to the reactor section 200.

[0016] As disclosed herein, in one or more embodiments, the supplementary fuel may include methane. For example, the supplementary fuel may include an amount of methane greater than or equal to 1mol%, such as greater than or equal to 2mol%, greater than or equal to 3mol%, greater than or equal to 4mol% or even greater than or equal to 5mol%. In some embodiments, the supplementary fuel includes an amount of methane no more than 10mol%. In some embodiments, the supplementary fuel may include an amount of methane greater than 10mol%, such as greater than 20mol%, greater than 30mol%, greater than 40mol%, greater than 50mol%, greater than 60mol%, greater than 70mol%, greater than 80mol%, greater than 90mol% or even 100mol%. Catalysts with improved methane combustion activity, such as those comprising manganese as described herein, can better utilize methane as supplementary fuel to promote the reheating of the catalyst. Catalysts are heated during regeneration to assist regeneration, and also because the heated catalyst acts as a heat carrier to carry heat from the burner 350 to the reactor portion 200 to promote the dehydrogenation reaction.

[0017] In non-limiting examples, reactor system 102 as described herein can be used for producing light olefins by hydrocarbon feed.According to one or more embodiments, reaction can be a dehydrogenation reaction.According to such embodiments, hydrocarbon feed can include one or more of ethylbenzene, ethane, propane, normal butane and isobutane.In one or more embodiments, hydrocarbon feed can include at least 50 weight %, at least 60 weight %, at least 70 weight %, at least 80 weight %, at least 90 weight %, at least 95 weight % or even at least 99 weight % of ethylbenzene.In one or more embodiments, hydrocarbon feed can include at least 50 weight %, at least 60 weight %, at least 70 weight %, at least 80 weight %, at least 90 weight %, at least 95 weight % or even at least 99 weight % of ethane.In other embodiments, hydrocarbon feed can include at least 50 weight %, at least 60 weight %, at least 70 weight %, at least 80 weight %, at least 90 weight %, at least 95 weight % or even at least 99 weight % of propane. In other embodiments, hydrocarbon-containing feed can comprise at least 50 weight %, at least 60 weight %, at least 70 weight %, at least 80 weight %, at least 90 weight %, at least 95 weight % or even at least 99 weight % normal butane.In other embodiments, hydrocarbon-containing feed can comprise at least 50 weight %, at least 60 weight %, at least 70 weight %, at least 80 weight %, at least 90 weight %, at least 95 weight % or even at least 99 weight % isobutane.In other embodiments, hydrocarbon-containing feed can comprise at least 50 weight %, at least 60 weight %, at least 70 weight %, at least 80 weight %, at least 90 weight %, at least 95 weight % or even at least 99 weight % ethane, propane, normal butane and isobutane.

[0018] In one or more embodiments, the catalyst may comprise, consist essentially of, or consist of: one or more of gallium, indium, or thallium; one or more of platinum, palladium, rhodium, iridium, ruthenium, or osmium; chromium; and a support. As described herein, "consisting essentially of" refers to a material having less than 1% by weight of an unrecited material (i.e., consisting essentially of A and B means that the combination of A and B accounts for at least 99% by weight of the composition). As described herein, the catalyst may be a solid particle suitable for fluidization.

[0019] In one or more embodiments, based on the total mass of the catalyst, the catalyst may include one or more of the gallium, indium or thallium in an amount of 0.1 wt % to 10 wt %. Such materials can catalyze the dehydrogenation of alkanes to olefins, particularly when used in combination with one or more of platinum, palladium, rhodium, iridium, ruthenium or osmium. Such materials can additionally catalyze the combustion of coke and supplementary fuel. For example, the catalyst may include one or more of the gallium, indium or thallium in an amount of 0.1 wt % to 0.25 wt %, 0.25 wt % to 0.5 wt %, 0.5 wt % to 0.75 wt %, 0.75 wt % to 1 wt %, 1 wt % to 2 wt %, 2 wt % to 3 wt %, 3 wt % to 4 wt %, 4 wt % to 5 wt %, 5 wt % to 6 wt %, 6 wt % to 7 wt %, 7 wt % to 8 wt %, 8 wt % to 9 wt %, 9 wt % to 10 wt % or any combination of these scopes. In some embodiments, the catalyst may include an amount of 0.1% to 9% by weight, 0.1% to 8% by weight, 0.1% to 7% by weight, 0.1% to 6% by weight, or 0.1% to 5% by weight of gallium, indium, or one or more of thallium. In some embodiments, the catalyst includes only gallium but not indium or thallium, only indium but not gallium or thallium, or only thallium but not gallium or indium. It should be understood that the composition range describing the amount of gallium, indium, and thallium represents the range of any one of these materials or the combination of these materials. Without being bound by theory, it is believed that the composition having an amount less than one or more of gallium, indium, or thallium of 0.1% by weight negatively affects the ability of the catalyst to catalyze the dehydrogenation of alkane by reducing the percentage of total dehydrogenated alkanes and the percentage of dehydrogenated alkanes as the expected product. However, it is believed that compositions having one or more of gallium, indium, or thallium in an amount exceeding 10 weight percent may negatively affect the ability of the catalyst to catalyze an alkane dehydrogenation process, negatively affect the selectivity of the catalyst to the desired product, or both.

[0020] In one or more embodiments, based on the total mass of the catalyst, the catalyst may include one or more of platinum, palladium, rhodium, iridium, ruthenium or osmium in an amount of 5ppmw to 1000ppmw. Such materials can catalyze the dehydrogenation of alkanes to olefins, particularly when used in combination with one or more of gallium, indium or thallium. Such materials can additionally catalyze the combustion of coke and supplementary fuel. For example, the catalyst may include one or more of platinum, palladium, rhodium, iridium, ruthenium or osmium in an amount of 5ppmw to 50ppmw, 50ppmw to 100ppmw, 100ppmw to 200ppmw, 200ppmw to 300ppmw, 300ppmw to 400ppmw, 400ppmw to 500ppmw, 500ppmw to 600ppmw, 600ppmw to 700ppmw, 700ppmw to 800ppmw, 800ppmw to 900ppmw, 900ppmw to 1000ppmw or any combination of these ranges. In some embodiments, the catalyst may include one or more of platinum, palladium, rhodium, iridium, ruthenium, or osmium in an amount of 5 ppmw to 900 ppmw, 5 ppmw to 800 ppmw, 5 ppmw to 600 ppmw, 5 ppmw to 500 ppmw, or 10 ppmw to 400 ppmw. In some embodiments, the catalyst includes only platinum but not palladium, rhodium, iridium, ruthenium, or osmium, only palladium but not platinum, rhodium, iridium, ruthenium, or osmium, only rhodium but not platinum, palladium, iridium, ruthenium, or osmium, only iridium but not platinum, palladium, rhodium, ruthenium, or osmium, or only osmium-containing but not platinum, palladium, rhodium, iridium, or ruthenium. It should be understood that the composition range describing the amount of platinum, palladium, rhodium, iridium, ruthenium, and osmium represents the range of any one of these materials or a combination of these materials. Without being bound by theory, it is believed that compositions having one or more of platinum, palladium, rhodium, iridium, ruthenium, or osmium in an amount less than 5 ppmw negatively impact the ability of the catalyst to catalyze an alkane dehydrogenation process by reducing both the percentage of total dehydrogenated alkanes and the percentage of dehydrogenated alkanes that are desired products. However, it is believed that compositions having one or more of platinum, palladium, rhodium, iridium, ruthenium, or osmium in an amount greater than 1000 ppmw may negatively impact the ability of the catalyst to catalyze an alkane dehydrogenation process, negatively impact the selectivity of the catalyst to the desired product, or both.

[0021] In one or more embodiments, based on the total weight of the catalyst, the catalyst may include chromium in an amount of 100 ppmw to 30000 ppmw. The incorporation of chromium can promote the combustion of methane without significantly affecting the dehydrogenation of alkanes. For example, the catalyst may include chromium in an amount of 100 ppmw to 500 ppmw, 500 ppmw to 1000 ppmw, 1000 ppmw to 2500 ppmw, 2500 ppmw to 5000 ppmw, 5000 ppmw to 7500 ppmw, 7500 ppmw to 10000 ppmw, 10000 ppmw to 15000 ppmw, 15000 ppmw to 20000 ppmw, 20000 ppmw to 25000 ppmw, 25000 ppmw to 30000 ppmw, or any combination of these ranges. In some embodiments, the catalyst may include an amount of 100ppmw to 25000ppmw, 150ppmw to 20000ppmw, 200ppmw to 15000ppmw, 250ppmw to 12500ppmw or 500ppmw to 10000ppmw of chromium. Without being bound by theory, it is believed that the composition with an amount of chromium less than 100ppmw may not increase the methane combustion performance of the catalyst. However, it is believed that the composition with an amount of chromium exceeding 30000ppmw may negatively affect the dehydrogenation performance of the catalyst by reducing the percentage of total alkanes dehydrogenated and the percentage of dehydrogenated alkanes as the expected product. Without being bound by theory, it is believed that chromium can also help reduce the rate at which the methane combustion activity of the catalyst decreases over time during the operation of the dehydrogenation process.

[0022] In one or more embodiments, the catalyst can include a combination of chromium and one or more of iron, manganese, or vanadium in an amount from 100 ppmw to 30,000 ppmw, based on the total weight of the catalyst. For example, the catalyst can include a combination of chromium and one or more of chromium, iron, manganese, or vanadium in an amount from 100 ppmw to 500 ppmw, from 500 ppmw to 1000 ppmw, from 1000 ppmw to 2500 ppmw, from 2500 ppmw to 5000 ppmw, from 5000 ppmw to 7500 ppmw, from 7500 ppmw to 10000 ppmw, from 10000 ppmw to 15000 ppmw, from 15000 ppmw to 20000 ppmw, from 20000 ppmw to 25000 ppmw, from 25000 ppmw to 30000 ppmw, or any combination of these ranges. In some embodiments, the catalyst comprises chromium and iron but not manganese or vanadium, comprises chromium and manganese but not iron or vanadium, comprises chromium and vanadium but not iron or manganese, comprises iron, chromium and manganese but not vanadium, comprises iron, chromium and vanadium but not manganese, or comprises chromium, manganese and vanadium but not iron.

[0023] As described herein, in one or more embodiments, the catalyst may include a carrier. The carrier may include one or more of aluminum oxide, silicon dioxide, or a combination thereof. For example, in some embodiments, the carrier may include one or more of aluminum oxide, silicon dioxide-containing aluminum oxide, zirconium oxide-containing aluminum oxide, titanium dioxide-containing aluminum oxide, and lanthanum-containing aluminum oxide. Relative to the gross weight of the catalyst, the carrier may be present in an amount of at least 85% by weight, such as at least 50% by weight, at least 55% by weight, at least 60% by weight, at least 65% by weight, at least 70% by weight, at least 75% by weight, at least 80% by weight. In some embodiments, the carrier accounts for less than or equal to 95% by weight of the catalyst. Typically, the weight % of the carrier can fill the remainder of the whole catalyst that is not specified by other materials.

[0024] In one or more embodiments, the catalyst can optionally include one or more alkali metals, one or more alkaline earth metals, or both in an amount of 0.01 wt % to 2.5 wt % based on the total weight of the catalyst. For example, the catalyst can include one or more alkali metals, one or more alkaline earth metals, or both in an amount from 0.01 wt % to 0.05 wt %, from 0.05 wt % to 0.1 wt %, from 0.1 wt % to 0.2 wt %, from 0.2 wt % to 0.3 wt %, from 0.3 wt % to 0.4 wt %, from 0.4 wt % to 0.5 wt %, from 0.5 wt % to 0.6 wt %, from 0.6 wt % to 0.7 wt %, from 0.7 wt % to 0.8 wt %, from 0.8 wt % to 0.9 wt %, from 0.9 wt % to 1 wt %, from 1 wt % to 1.25 wt %, from 1.25 wt % to 1.5 wt %, from 1.5 wt % to 1.75 wt %, from 1.75 wt % to 2 wt %, from 2 wt % to 2.25 wt %, from 2.25 wt % to 2.5 wt %, or any combination of these ranges. In some embodiments, the catalyst may include 0.01% to 0.75% by weight, 0.02% to 0.6% by weight, 0.03% to 0.5% by weight, 0.04% to 0.4% by weight, or 0.05% to 0.3% by weight of one or more alkali metals, one or more alkaline earth metals, or both. In some embodiments, one or more alkali metals or one or more alkaline earth metals may be potassium. Without being bound by theory, it is believed that the composition of the alkali metal or alkaline earth metal with an amount less than 0.01% by weight may cause the dehydrogenation reaction to produce undesirable products. However, it is believed that the composition of the alkali metal or alkaline earth metal with an amount exceeding 2.5% by weight may reduce the dehydrogenation activity of the catalyst.

[0025] In one or more embodiments, the catalyst may comprise, consist essentially of, or consist of gallium, platinum, chromium, and a support. For example, the catalyst may comprise, consist essentially of, or consist of 0.1 wt% to 10 wt% gallium; 5 ppmw to 1000 ppmw platinum; 100 ppmw to 30,000 ppmw chromium; and at least 85 wt% of the support. In an exemplary embodiment, the catalyst may comprise, consist essentially of, or consist of 0.1 wt% to 5 wt% gallium; 10 ppmw to 400 ppmw platinum; 500 ppmw to 10,000 ppmw chromium; and at least 85 wt% of the support.

[0026] In one or more embodiments, the catalyst may include solid particles capable of fluidization. In some embodiments, the catalyst may exhibit characteristics known in the industry as "Geldart A" or "Geldart B" characteristics. According to D. Geldart, "Gas Fluidization Technology", John Wiley & Sons (New York, 1986), pp. 34-37; and D. Geldart, "Types of Gas Fluidization", "Powder Technol. 7 (1973) 285-292, the disclosure of which is incorporated herein by reference in its entirety, catalyst types may be classified as "Group A" or "Group B".

[0027] The Geldart A group is understood by those skilled in the art to represent aerated powders with fluidization in the bubble-free range; high bed expansion; slow and linear degassing rates; bubble characteristics, which may include a predominance of splitting / recoalescing bubbles, with maximum bubble size and large wakes; high levels of solid mixing and gas backmixing, assuming that U-umf are equal (U is the velocity of the carrier gas, and Umf is the minimum fluidizing velocity, usually but not necessarily measured in meters per second (m / s), i.e., excessive gas velocities exist); axisymmetric lump characteristics; and no spurting except in very shallow beds. The listed characteristics tend to improve with decreasing average particle size, assuming that The particles may be equal; or increase with a ratio of <45 microns (μm); or increase with the pressure, temperature, viscosity and density of the gas. In general, the particles may exhibit a small average particle size and / or a low particle density (<1.4 g / cm3, g / cm 3 ); easy fluidization, with smooth fluidization at low gas velocities; and controlled bubbling with small bubbles can be exhibited at higher gas velocities.

[0028] The Geldart B group is understood by those skilled in the art to represent "sand-like" powders that begin bubbling at Umf; that exhibit moderate bed expansion; rapid degassing; no restrictions on bubble size; moderate levels of solid mixing and gas backmixing, assuming equal U-umf; both axisymmetric and asymmetric lumps; and spurting only in shallow beds. These properties tend to improve as the average particle size decreases, but the particle size distribution and some uncertainty in the gas, pressure, temperature, viscosity or density appear to play little role in improving these properties. In general, when the density (ρp) is 1.4<ρp<4 g / cm 3 When the particle size of most particles is for

[0029] In one or more embodiments, the catalyst may be prepared via incipient wetness impregnation (also known as dry impregnation or capillary impregnation). For example, such a process is described in Marceau et al., Impregnation and Drying, Synthesis of Solid Catalysts 59 (2008), which is incorporated herein by reference in its entirety. For example, a support may be impregnated with a metal precursor, then dried at a temperature below 200° C., and then calcined at a temperature below 800° C. to produce a catalyst. For example, a suitable metal precursor may include a nitrate or nitrate amine metal precursor. In addition, as will be appreciated by those skilled in the art, other suitable metal precursors are contemplated herein. In some embodiments, a method of preparing a catalyst may include impregnating a support with gallium, platinum, and chromium; drying the support; and calcining the support, wherein the catalyst comprises 0.1 wt % to 10 wt % gallium, 5 ppmw to 1000 ppmw platinum, 100 ppmw to 30000 ppmw chromium, and at least 85 wt % support.

[0030] In one or more embodiments, the catalyst can be prepared by incipient wetness sequential impregnation, wherein the materials are impregnated in a specific order before or after drying and calcination. In incipient wetness sequential impregnation, the catalyst is first impregnated with one or more metal precursors, dried at a temperature below 200°C, and then calcined at a temperature below 800°C. The catalyst is then subjected to at least one additional cycle of impregnation, drying, and calcination with additional metal precursors to produce a finished catalyst. In incipient wetness sequential impregnation, the metals added to the catalyst can be added in a sequential order in a continuous impregnation cycle. In one or more embodiments, the carrier is impregnated with gallium and platinum in sequence, and then impregnated with chromium. For some embodiments, the method for preparing the catalyst may include impregnating the carrier with gallium and platinum, drying the carrier, calcining the carrier, impregnating the carrier with chromium after drying and calcining, and drying and calcining the carrier after impregnation with chromium, wherein the catalyst comprises 0.1 wt% to 10 wt% of gallium, 5 ppmw to 1000 ppmw of platinum, 100 ppmw to 30000 ppmw of chromium, and at least 85 wt% of the carrier. In another embodiment, a method of preparing a catalyst may include impregnating a support with chromium to produce a chromium-impregnated support, drying the chromium-impregnated support, calcining the chromium-impregnated support, impregnating the chromium-impregnated support with gallium and platinum after drying and calcining, and drying and calcining the chromium-impregnated support after impregnating with gallium and platinum, wherein the catalyst comprises 0.1 wt% to 10 wt% gallium, 5 ppmw to 1000 ppmw platinum, 100 ppmw to 30,000 ppmw chromium, and at least 85 wt% support.

[0031] Incipient wetness sequential impregnation allows the support to be impregnated with metals in a sequential order, where some metals can be impregnated onto the support before other metals. Thus, the order of impregnation can be changed as desired. In addition, as will be appreciated by those skilled in the art, other suitable methods for preparing the catalysts described herein are contemplated.

[0032] Now refer to it again Figure 1 , a hydrocarbon-containing feed can enter feed inlet 434, enter reactor 202, and an olefin-containing effluent can exit reactor system 102 via pipe 420. According to one or more embodiments, reactor system 102 can be operated by feeding a hydrocarbon-containing feed (e.g., in a feed stream) and a fluidized catalyst into an upstream reactor section 250. The hydrocarbon-containing feed contacts the catalyst in the upstream reactor section 250, and each hydrocarbon-containing feed flows upwardly into and through the downstream reactor section 230 to produce an olefin-containing effluent.

[0033] 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 1 As depicted, the upstream reactor section 250 may be connected to the downstream reactor section 230 via a transition section 258. The upstream reactor section 250 may generally include a larger cross-sectional area than the downstream reactor section 230. The transition section 258 may 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 protrudes inwardly from the upstream reactor section 250 to the downstream reactor section 230. For example, the transition section 258 may be a frustum.

[0034] The upstream reactor section 250 can be connected to a transfer riser 430, which in operation can provide the reactivated catalyst in the feed stream to the reactor portion 200. The reactivated catalyst and / or reactant chemicals can be mixed with a distributor 260 contained in the upstream reactor section 250. Catalyst entering the upstream reactor section 250 via the transfer riser 430 can be transferred to the transfer riser 430 via a standpipe 424, thereby arriving from the catalyst treatment section 300. In some embodiments, catalyst can enter the transfer riser 430 directly from the catalyst separation section 210 via a standpipe 422, wherein the catalyst enters the upstream reactor section 250, wherein in such embodiments, some of the catalyst is not transferred through the catalyst treatment section 300. Catalyst can also be fed directly to the upstream reactor section 250 via the standpipe 422 (at Figure 1 250). This catalyst may be somewhat deactivated, but in some embodiments may still be suitable for reaction in the upstream reactor section 250, particularly when used in combination with a reactivated catalyst.

[0035] In one or more embodiments, the residence time of the catalyst in the reactor portion 200 may be less than or equal to 3 minutes. As used herein, the term "residence time" refers to the average amount of time that the catalyst or other specified material spends in the reactor portion 200. Because the residence time is an average value, the amount of time that the catalyst can spend in the reactor portion 200 during any given cycle may not be equal to the average value, but will average about the residence time over time. In some embodiments, the residence time of the catalyst in the reactor portion 200 may be less than or equal to 2.5 minutes, less than or equal to 2 minutes, less than or equal to 1.5 minutes, less than or equal to 1 minute, less than or equal to 0.5 minutes, or less than or equal to 0.1 minutes. Without being bound by theory, it is believed that a catalyst residence time greater than 3 minutes can increase equipment costs without a matching increase in catalyst dehydrogenation performance. However, it is believed that a catalyst residence time less than 0.5 minutes may not allow the catalyst to fully catalyze the dehydrogenation reaction.

[0036] Still refer to Figure 1 In one or more embodiments, based on the shapes, dimensions, and other process conditions (e.g., temperature and pressure) in the upstream reactor section 250 and the downstream reactor section 230, the upstream reactor section 250 can be operated as a fluidized bed, such as in a fast fluidized, turbulent, or bubbling bed flow reactor, while the downstream reactor section 230 can be operated in a more plug flow manner, such as in a riser reactor. For example, Figure 1 The reactor 202 may include an upstream reactor section 250 operated as a fast fluidization, turbulent or bubbling bed reactor and a downstream reactor section 230 operated as a dilute phase riser reactor, resulting in an average catalyst and gas flow moving upward simultaneously. As used herein, the term "average flow" refers to the net flow, i.e., the total upward flow minus the reverse or reverse flow, which is generally the typical behavior of fluidized particles. As described herein, a "fast fluidization" reactor may refer to a reactor utilizing a fluidization scheme in which the superficial velocity of the gas phase is greater than the choke velocity and can be semi-dense in operation. As described herein, a "turbulent" reactor may refer to a fluidization scheme in which the superficial velocity is less than the choke velocity and is denser than a fast fluidization scheme. As described herein, a "bubbling bed" reactor may refer to a fluidization morphology in which well-defined bubbles in a high density bed are present in two well-divided phases. "Choke velocity" refers to 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 operated at the above-mentioned choke velocity.

[0037] According to embodiments, the olefin-containing effluent and catalyst may be passed from the downstream reactor section 230 to a separation device 220 in the catalyst separation section 210 where the catalyst is at least partially separated from the olefin-containing effluent that is conveyed from the catalyst separation section 210. After the catalyst is separated from the vapor in the separation device 220, the catalyst may generally move through a stripper 224 to a catalyst outlet port 222 where the catalyst is transferred out of the reactor portion 200 via a standpipe 426 and into the catalyst treatment section 300, according to one or more embodiments.

[0038] According to one or more embodiments, the separation device 220 may be a cyclonic separation system, which may include two or more stages of cyclonic separation. In the embodiment where the separation device 220 includes more than one cyclonic separation stage, the first separation device in which the fluidized stream enters is referred to as a primary cyclonic separation device. The fluidized effluent from the primary cyclonic separation device can enter a secondary cyclonic separation device for further separation. The primary cyclonic separation device may include, for example, a primary cyclonic separator and a system commercially available under the name VSS (commercially available from UOP), LD2 (commercially available from Stone and Webster) and RS2 (commercially available from Stone and Webster). Primary cyclonic separators are described in, for example, U.S. Patents 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 utilizing a primary cyclone separator as a primary cyclone separation device, one or more additional cyclone separators, e.g., a secondary cyclone separator and a tertiary cyclone separator, 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 embodiments of the present disclosure.

[0039] Still refer to Figure 1, the separated catalyst is transferred from the catalyst separation section 210 to the burner 350. In the burner 350, the catalyst can be treated by, for example, burning coke with oxygen. For example, but not limited to, the catalyst can be decoked and / or supplementary fuel can be burned to heat the catalyst. Then, the catalyst is transferred from the burner 350 and passed through the riser 330 to the riser terminal separator 378, where the gas and solid components from the riser 330 are at least partially separated. The steam and the remaining solids are transported to the secondary separation device 320 in the catalyst separation section 310, where the remaining catalyst is separated from the gas from the catalyst treatment (for example, the gas emitted by burning the spent catalyst or supplementary fuel, referred to as flue gas in this article). The flue gas can be transferred from the catalyst treatment section 300 via the outlet pipe 432. The separated catalyst is then transferred to the upstream reactor section 250 via the vertical pipe 424 and the transport riser 430 through the oxygen treatment zone 370 in the catalyst separation section 310, where the catalyst is further used for catalytic reaction. Thus, the catalyst may be circulated during operation between the reactor section 200 and the catalyst treatment section 300. Generally speaking, the processed chemical stream comprising the hydrocarbon-containing feed and the olefin-containing effluent may be gaseous, and the catalyst may be a fluidized particulate solid.

[0040] Referring now to the catalyst treatment section 300, as shown Figure 1 As depicted, the burner 350 of the catalyst treatment section 300 may include one or more lower reactor section inlet ports 352 and may be in fluid communication with the riser 330. An oxygen-containing gas (e.g., air) may be delivered to the burner 350 via a pipe 428. The burner 350 may be in fluid communication with the catalyst separation section 210 via a riser 426, which may supply spent catalyst from the reactor section 200 to the catalyst treatment section 300 for regeneration. The burner 350 and the riser 330 (collectively referred to as the catalyst combustion reactor 302) may be operated in a fluidized manner similar to or the same as 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 be operated as a fluidized bed, such as in a fast fluidized, turbulent, or bubbling bed flow reactor, while the riser 330 may be operated in a more plug flow manner, such as in a riser reactor. The geometries as described with respect to the upstream reactor section 250 and the downstream reactor section 230 may be equally applicable to the burner 350 and the riser 330. In addition, the burner 350 may also include a fuel inlet 354 that may supply a fuel, such as a hydrocarbon stream, to the burner 350.

[0041] As described herein, the catalyst can be heated by combustion of a supplemental fuel in the catalyst treatment section 300. The supplemental fuel can be combusted with oxygen and a supplemental fuel to heat the catalyst, such as a supplemental fuel such as hydrogen, methane, ethane, propane, natural gas, or a combination thereof. Without being bound by any theory, when methane is used in the supplemental fuel, a catalyst comprising chromium as described herein can better catalyze the combustion of methane to heat the catalyst. When methane is used in the supplemental fuel, a catalyst that does not contain chromium may be disadvantageous in that it does not promote heating of the catalyst to the temperature required for dehydrogenation.

[0042] As described in one or more embodiments, after the catalyst is separated from the flue gas in the riser terminal separator 378 and the secondary separation device 320, the processed catalyst is treated with an oxygen-containing gas in the oxygen treatment zone 370. In some embodiments, the oxygen treatment zone 370 includes a fluid-solid contact device. The fluid-solid contact device may include a baffle or a grid structure to promote contact between the processed catalyst and the oxygen-containing gas. Examples of fluid-solid contact devices are further described in detail in U.S. Patents Nos. 9,827,543 and 9,815,040. The fluidization mode in the oxygen treatment zone can be a bubbling bed type fluidization. The oxygen treatment zone 370 may include an oxygen-containing gas inlet 372, which can supply oxygen-containing gas to the oxygen treatment zone 370 for oxygen treatment of the catalyst.

[0043] As disclosed herein, in one or more embodiments, the catalyst can be exposed to oxygen-containing gas in oxygen treatment zone 370. For example, the catalyst can be exposed to oxygen-containing gas for 2 minutes to 20 minutes, such as 2 minutes to 4 minutes, 4 minutes to 6 minutes, 6 minutes to 8 minutes, 8 minutes to 10 minutes, 10 minutes to 12 minutes, 12 minutes to 14 minutes, 14 minutes to 16 minutes, 16 minutes to 18 minutes, 18 minutes to 20 minutes or any combination of these ranges. In some embodiments, the catalyst can be exposed to oxygen-containing gas for 4 minutes to 18 minutes, 6 minutes to 17 minutes, 8 minutes to 16 minutes or 10 minutes to 15 minutes. Without being bound by theory, it is believed that exposing the catalyst to oxygen-containing gas for more than 20 minutes can increase equipment costs without the matching increase of catalyst regeneration efficiency. However, it is believed that exposure to oxygen-containing gas less than 2 minutes can lead to less efficient regeneration of the catalyst, which can reduce the dehydrogenation activity of the catalyst.

[0044] 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. Figure 1The reactor system of the present invention can be processed subsequently. As used in the present 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 isobutylene. In some embodiments, based on the gross weight of the olefin-containing effluent, the olefin-containing effluent comprises at least 25 weight % of light olefins. For example, based on the gross weight of the olefin-containing effluent, the olefin-containing effluent can comprise at least 35 weight % of light olefins, at least 45 weight % of light olefins, at least 55 weight % of light olefins, at least 65 weight % of light olefins or at least 75 weight % of light olefins. The olefin-containing effluent can also include unreacted components of the hydrocarbon-containing effluent and other reaction products that are not considered to be light olefins. The light olefin can be separated from the unreacted components in the subsequent separation step.

[0045] Example

[0046] Various embodiments of the present disclosure will be further illustrated by the following examples. The examples are illustrative in nature and should not be construed as limiting the subject matter of the present disclosure.

[0047] Example 1 - Effect of Chromium Loading

[0048] In Example 1, nine different catalytically active particle (i.e., catalyst) samples were prepared and the effect of chromium loading on the catalytically active particles was observed. For the purpose of Example 1, the samples were prepared by first spray drying hydrated alumina and The microspheroidal alumina support is prepared by mixing a mixture of silica and then heating the resulting spray-dried particles at a temperature of at least 1000° C., which is sufficient to obtain a particle size range of 5 μm to 300 μm, a pore volume of 0.20 ml / g ± 0.10 ml / g, and a surface area of ​​70 m 2 / g±20m 2 / g and particles with a silica content of 2.5 wt% ± 2.5 wt%. The catalyst materials were prepared using a conventional incipient wetness impregnation method to load the specified metal onto the support using a nitrate or nitrate amine metal precursor, followed by drying at a temperature below 200°C and then calcining at a temperature below 800°C. Table 1 provides the exact composition of the samples.

[0049] The samples were tested under ambient pressure with 0.5 grams (g) of sample mixed with 1.0 g of inert silicon carbide and loaded into a quartz reactor. The reaction combustion reactivation cycle was performed with 10 interruption cycles followed by a dehydrogenation and regeneration test cycle. The interruption cycle was run by performing two steps: a dehydrogenation step in which the dehydrogenation process was carried out at 625°C for 10 hours. -1The catalyst was run for 10 interruption cycles using a propane weight hourly space velocity "WHSV" of 100% propane and a feed composition of 90% propane / 10% nitrogen for 60 seconds; and a reactivation step in which the catalyst was heated to 730°C at a flow rate of 50 standard cubic centimeters per minute (sccm) at 100% air for 5 minutes. After the catalyst had been run for 10 interruption cycles, it was tested in a dehydrogenation and regeneration test cycle. The dehydrogenation and regeneration test cycle was run in three steps: a dehydrogenation step using the same conditions as the dehydrogenation step of the interruption cycle, in which dehydrogenation performance data was collected at a run time of 30 seconds; a combustion step in which the catalyst was heated to 730°C at 2.5 mol% methane / balance air at a total flow of 50 sccm and 0.1 hr -1 The samples were then subjected to combustion at a WHSV of 1.30 WHSV for 3 minutes, with combustion performance data collected at a run time of 60 seconds, and a reactivation step, where the sample was heated to 730°C at a flow rate of 50 sccm under 100% air for 2 minutes. The dehydrogenation and combustion performance of the samples after 25 cycles are reported in Table 1.

[0050] Table 1

[0051]

[0052] Table 1 shows that all samples containing chromium (i.e., samples 1-7) have improved methane conversion when compared to Comparative Example A (containing no chromium). Some samples containing chromium have improved methane conversion, propane conversion, and propylene selectivity. For example, Comparative Example A has a methane conversion, propane selectivity, and propylene selectivity that are worse than Sample 2, which is the same as Comparative Example A except for the presence of chromium. Further, Table 1 shows that the catalyst composition containing chromium but not containing platinum and gallium (i.e., Comparative Example B) has a lower propane conversion and propylene selectivity than the samples containing platinum, gallium, and chromium (i.e., samples 1-7). That is, Table 1 shows that the total catalyst composition of platinum, gallium, and chromium is important for increasing methane conversion while maintaining acceptable propane conversion and propylene selectivity. Finally, Table 1 shows that sufficient methane conversion, propane conversion, and propylene selectivity can be achieved within the range of platinum and gallium compositions. For example, when compared to Comparative Example A, Samples 5 and 6 both have improved methane conversion and propane conversion despite having less platinum and more gallium than Comparative Example A.

[0053] Example 2 - Effect of Metal Promoter Combinations

[0054] In Example 2, samples were prepared with both chromium and iron. The samples were prepared and tested using the procedure of Example 1. The composition of the samples as well as their dehydrogenation and combustion performance are reported in Table 2.

[0055] Table 2

[0056]

[0057] Tables 1 and 2 show that Sample 8, which has both iron and chromium as promoters, has improved methane conversion, propane conversion, and propylene conversion when compared to the base catalyst of Comparative Example A.

[0058] In a first aspect of the present disclosure, light olefins can be prepared by dehydrogenation, which is carried out by a method comprising: contacting a hydrocarbon-containing feed with a catalyst in a reactor to form an olefin-containing effluent, and then separating the olefin-containing effluent at least partially from the catalyst. The catalyst is transferred to a burner and heated by burning a supplementary fuel. The supplementary fuel contains an amount of methane greater than or equal to 1 mol%. The catalyst is transferred from the burner to the reactor so that at least a portion of the catalyst is continuously circulated between the reactor and the burner. The catalyst may include 0.1 wt % to 10 wt % of one or more metals selected from gallium, indium, thallium or a combination thereof, 5 ppmw to 1000 ppmw of one or more metals selected from platinum, palladium, rhodium, iridium, ruthenium, osmium or a combination thereof, 100 ppmw to 30000 ppmw of chromium and at least 85 wt % of a carrier.

[0059] A second aspect of the disclosure may include the first aspect, wherein the method further comprises transferring the catalyst from the burner to an oxygen treatment zone and exposing the catalyst to an oxygen-containing gas for 2 minutes to 20 minutes, and transferring the catalyst from the oxygen treatment zone to the reactor.

[0060] A third aspect of the present disclosure may include the second aspect, wherein the catalyst is exposed to the oxygen-containing gas in the oxygen treatment zone for 8 minutes to 20 minutes.

[0061] A fourth aspect of the present disclosure may include any of the preceding aspects, wherein the supplemental fuel comprises at least 3 mol% methane.

[0062] A fifth aspect of the present disclosure may include any of the preceding aspects, wherein the residence time of the catalyst in the reactor is less than or equal to 3 minutes.

[0063] A sixth aspect of the present disclosure may include any of the preceding aspects, wherein the residence time of the catalyst in the reactor is less than or equal to 1 minute.

[0064] A seventh aspect of the present disclosure may include any of the preceding aspects, wherein the catalyst comprises 0.1 wt% to 10 wt% gallium and 5 ppmw to 1000 ppmw platinum.

[0065] An eighth aspect of the present disclosure may include any of the preceding aspects, wherein the catalyst comprises 0.1 wt% to 5 wt% gallium and 10 ppmw to 400 ppmw platinum.

[0066] A ninth aspect of the present disclosure may include any of the preceding aspects, wherein the catalyst comprises 500 ppmw to 30,000 ppmw chromium.

[0067] A tenth aspect of the present disclosure may include any of the preceding aspects, wherein the catalyst further comprises 0.01 wt % to 2.5 wt % of one or more alkali metals or alkaline earth metals.

[0068] An eleventh aspect of the present disclosure may include the first aspect, wherein the catalyst further comprises 0.01 wt % to 2.5 wt % potassium.

[0069] A twelfth aspect of the present disclosure may include any of the preceding aspects, wherein the catalyst comprises 0.1 wt% to 5 wt% gallium, 10 ppmw to 400 ppmw platinum, and 500 ppmw to 10000 ppmw chromium.

[0070] A thirteenth aspect of the present disclosure may include any of the preceding aspects, wherein the support comprises one or more of alumina, silica, or a combination thereof.

[0071] A fourteenth aspect of the present disclosure may include any of the preceding aspects, wherein the catalyst has Geldart Group A or Geldart Group B characteristics.

[0072] A fifteenth aspect of the present disclosure may include any of the preceding aspects, wherein the hydrocarbon-containing feed comprises propane and the olefin-containing effluent comprises propylene.

[0073] It will be apparent to those skilled in the art that various modifications and variations may be made to the technology disclosed in the present invention without departing from the spirit and scope of the technology. Because those skilled in the art may make modifications, combinations, sub-combinations and variations of the disclosed embodiments that incorporate the spirit and essence of the technology disclosed in the present invention, the technology should be interpreted as including everything within the scope of the attached claims and their equivalents. In addition, although some aspects of the present disclosure may be identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not limited to these aspects.

[0074] It should be noted that the various details described in the present disclosure should not be considered to imply that these details relate to elements that are essential components of the various embodiments described in the present disclosure, even in the case where specific elements are shown in each of the drawings attached to this specification. Unless so explicitly stated, the features disclosed and described herein should not be interpreted as "essential". Contemplated embodiments of the present technology include those that include some or all of the features of the appended claims.

[0075] For purposes of describing and defining the present disclosure, it is noted that the term "about" is used herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term "about" is also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.

[0076] Where relevant, 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.

[0077] It should be understood that in some embodiments, the composition range of the chemical composition in a stream or reactor should be understood as a mixture of isomers containing the composition. For example, a composition range specifying butenes can include a mixture of various isomers of butenes. It should be understood that the embodiments provide composition ranges for various streams, and the total amount of isomers of a specific chemical composition can constitute a range.

[0078] It should be noted that one or more of the following claims and detailed description utilize the term "wherein" or "wherein" as a transition phrase. For purposes of defining the present technology, it should be noted that this term is introduced in the claims as an open transition phrase that is used to introduce a recitation of a series of features of a structure and should be interpreted in a manner similar to the more commonly used open-ended preamble term "comprising."

[0079] It should be understood that any two quantitative values ​​assigned to a characteristic may constitute a range for that characteristic, and all combinations of ranges formed by all said quantitative values ​​for a given characteristic are considered in the present disclosure. Where multiple ranges of quantitative values ​​are provided, these ranges may be combined to form a wider range, which is contemplated in the embodiments described herein.

Claims

1. A method for preparing light olefins by dehydrogenation, the method comprising: contacting a hydrocarbon-containing feed with a catalyst in a reactor to form an olefin-containing effluent; at least partially separating the olefin-containing effluent from the catalyst; passing the catalyst to a combustor and heating the catalyst by combusting a supplemental fuel and at least a portion of the coke on the catalyst, wherein the supplemental fuel comprises methane in an amount greater than or equal to 1 mol %; transferring the catalyst from the burner to the reactor such that at least a portion of the catalyst continuously circulates between the reactor and the burner; The catalyst comprises: 0.1 wt % to 10 wt % of one or more metals selected from gallium, indium, thallium, or a combination thereof; 5 ppmw to 1000 ppmw of one or more metals selected from platinum, palladium, rhodium, iridium, ruthenium, osmium or a combination thereof; 100 ppmw to 30,000 ppmw of chromium; and at least 85% by weight of a carrier.

2. The method according to claim 1, further comprising: transferring the catalyst from the burner to an oxygen treatment zone and exposing the catalyst to an oxygen-containing gas for 2 minutes to 20 minutes; as well as The catalyst is transferred from the oxygen treatment zone to the reactor.

3. The method of claim 2, wherein the catalyst is exposed to the oxygen-containing gas in the oxygen treatment zone for 8 minutes to 20 minutes.

4. A method according to any one of the preceding claims, wherein the supplementary fuel comprises methane in an amount of at least 3 mol%.

5. The process according to any one of the preceding claims, wherein the residence time of the catalyst in the reactor is less than or equal to 3 minutes.

6. The process according to any one of the preceding claims, wherein the residence time of the catalyst in the reactor is less than or equal to 1 minute.

7. The process according to any one of the preceding claims, wherein the catalyst comprises: 0.1 to 10 wt % gallium; and 5ppmw to 1000ppmw platinum.

8. The process according to any one of the preceding claims, wherein the catalyst comprises: 0.1 wt % to 5 wt % gallium; and 10 ppmw to 400 ppmw platinum.

9. A process according to any one of the preceding claims, wherein the catalyst comprises from 500 ppmw to 30000 ppmw chromium.

10. The process according to any one of the preceding claims, wherein the catalyst further comprises 0.01 wt% to 2.5 wt% of one or more alkali metals or alkaline earth metals.

11. The method of claim 1, wherein the catalyst further comprises 0.01 wt% to 2.5 wt% potassium.

12. The process according to any one of the preceding claims, wherein the catalyst comprises: 0.1 to 5 wt % gallium; 10 ppmw to 400 ppmw platinum; and 500ppmw to 10000ppmw chromium.

13. The method of any one of the preceding claims, wherein the support comprises one or more of alumina, silica, or a combination thereof.

14. A process according to any one of the preceding claims, wherein the catalyst has Geldart Group A or Geldart Group B characteristics.

15. The process according to any one of the preceding claims, wherein the hydrocarbon-containing feed comprises propane and the olefin-containing effluent comprises propylene.

Images