Suitable catalyst for producing light olefins by dehydrogenation containing chromium

Abstract

The catalyst contains 5 ppmw to 1000 ppmw of platinum, 0.1 wt% to 10 wt% of gallium, 1100 ppmw to 30000 ppmw of chromium, and at least 85 wt% of a carrier, and the carrier contains one or more of alumina, silica, or a combination thereof.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority to U.S. Provisional Application No. 63 / 352,024, filed on June 14, 2022, which is incorporated herein by reference in its entirety.

[0002] Embodiments described herein generally relate to chemical processing, and more particularly, to catalysts and systems for producing light olefins.

Background Art

[0003] Light olefins such as propylene can be used as base materials for producing many different materials such as polypropylene, isopropanol, and acrylic acid, and these materials can be used, for example, in packaging, construction, and fabrics. As a result of this utility, there is a global demand for light olefins. Suitable processes for producing light olefins generally depend on a given chemical feedstock 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, improvements are needed in the systems and related catalysts used to make light olefins.

Summary of the Invention

[0004] Some methods and related systems used to make light olefins utilize catalysts for the dehydrogenation of alkanes. Some such catalysts include platinum, gallium, and a support. It has been found that adding chromium in a specific amount to such catalysts improves the performance of the light olefin production system. More specifically, an amount of chromium from 1100 ppmw to 30000 ppmw can provide advantages such as improved combustion of auxiliary fuels such as methane that can be utilized to heat the catalyst to the reaction temperature for the dehydrogenation reaction.

[0005] According to one or more embodiments of the present disclosure, the catalyst may include platinum at 5 to 1000 ppmw, gallium at 0.1 wt% to 10 wt%, chromium at 1100 ppmw to 30000 ppmw, and at least 85 wt% of a carrier. The carrier may include one or more of alumina, silica, or a combination thereof.

[0006] It should be understood that both the foregoing general description and the following detailed description are intended to describe various embodiments and 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 described in the detailed description, and some of them will be readily apparent to those skilled in the art from that description, including the accompanying drawings and the claims, or will 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 shown in the drawings are exemplary and illustrative in nature and are not intended to limit the claimed subject matter.

Brief Description of the Drawings

[0007] The following detailed description is better understood when read in conjunction with the following drawings.

Figure 1

[0008] When explaining the simplified schematic diagram of FIG. 1, numerous valves, temperature sensors, electronic controllers, etc. that can be used and are well known to those skilled in the art are not included. Further, associated components that are often included within such a reactor system, such as air suppliers, heat exchangers, surge tanks, etc. are also not included. However, it should be understood that these components are within the scope of the present disclosure.

[0009] Here, various embodiments are referred to in more detail, some of which are illustrated in the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION

[0010] The present disclosure is directed to catalysts suitable for producing light olefins by dehydrogenation. For example, as described herein, a catalyst suitable for dehydrogenation comprises 0.1 wt% to 10 wt% gallium, 5 ppmw to 1000 ppmw platinum, 1100 ppmw to 30000 ppmw chromium, and at least 85 wt% carrier. In one or more embodiments, such catalysts provide a dual catalytic function for the dehydrogenation of alkanes and the combustion of auxiliary fuels. Such catalysts containing chromium may be particularly well-suited for the fluidized dehydrogenation of light alkanes such as propane to light olefins such as propylene, where methane is utilized as an auxiliary fuel to heat the catalyst.

[0011] In one or more embodiments, the catalyst may comprise, consist essentially of, or consist of gallium, platinum, chromium, and a carrier. As described herein, "consisting essentially of" refers to a material that contains less than 1 wt% of unlisted materials (i.e., consisting essentially of A and B means that A and B together are at least 99 wt% of the composition). As described herein, the catalyst can be solid particles suitable for fluidization.

[0012] In one or more embodiments, the catalyst may contain gallium in an amount of 0.1 wt% to 10 wt% based on the total mass of the catalyst. Gallium, particularly when used in combination with platinum, can catalyze the dehydrogenation of alkanes to alkenes. Such materials can further catalyze the combustion of coke and auxiliary fuels. For example, the catalyst may contain gallium 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 amounts within these ranges. In some embodiments, the catalyst may contain gallium in an amount of 0.1 wt% to 9 wt%, 0.1 wt% to 8 wt%, 0.1 wt% to 7 wt%, 0.1 wt% to 6 wt%, or 0.1 wt% to 5 wt%. Without being bound by theory, it is believed that compositions having gallium in an amount less than 0.1 wt% can negatively affect the ability of the catalyst to catalyze the alkane dehydrogenation process by decreasing both the percentage of total dehydrogenated alkanes and the percentage of dehydrogenated alkanes that are the intended product. However, it is believed that compositions having gallium in an amount greater than 10 wt% can negatively affect the ability of the catalyst to catalyze the alkane dehydrogenation process, the selectivity of the catalyst for the intended product, or both.

[0013] In one or more embodiments, the catalyst may contain platinum in an amount of 5 ppmw to 1000 ppmw, based on the total mass of the catalyst. Platinum, especially when used in combination with gallium, can catalyze the dehydrogenation of alkanes to alkenes. Such materials can further catalyze the combustion of coke and auxiliary fuels. For example, the catalyst may contain platinum in an amount of 5 ppmw to 50 ppmw, 50 ppmw to 100 ppmw, 100 ppmw to 200 ppmw, 200 ppmw to 300 ppmw, 300 ppmw to 400 ppmw, 400 ppmw to 500 ppmw, 500 ppmw to 600 ppmw, 600 ppmw to 700 ppmw, 700 ppmw to 800 ppmw, 800 ppmw to 900 ppmw, 900 ppmw to 1000 ppmw, or a combination of these ranges. In some embodiments, the catalyst may contain platinum 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. Without being bound by theory, it is believed that compositions having platinum in an amount less than 5 ppmw can adversely affect the ability of the catalyst to catalyze the alkane dehydrogenation process by reducing both the percentage of total dehydrogenated alkanes and the percentage of dehydrogenated alkanes that are the intended product. However, it is believed that compositions having platinum in an amount greater than 1000 ppmw can adversely affect either the ability of the catalyst to catalyze the alkane dehydrogenation process, the selectivity of the catalyst for the intended product, or both.

[0014] In one or more embodiments, the catalyst may contain chromium in an amount of 1100 ppmw to 30000 ppmw, based on the total weight of the catalyst. Incorporation of chromium can promote the combustion of methane while having less impact on the dehydrogenation of alkanes. For example, the catalyst may contain chromium in amounts of 1100 ppmw to 1500 ppmw, 1500 ppmw to 2000 ppmw, 2000 ppmw to 3000 ppmw, 3000 ppmw to 4000 ppmw, 4000 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 combinations of these ranges. In some embodiments, the catalyst may contain chromium in an amount of 1100 ppmw to 30000 ppmw, such as 1100 ppmw to 25000 ppmw, 1100 ppmw to 20000 ppmw, 1100 ppmw to 15000 ppmw, 1100 ppmw to 12500 ppmw, or 1100 ppmw to 10000 ppmw.

[0015] Although not bound by theory, it is believed that compositions having less than 1100 ppmw of chromium may not provide the desired improvement in the methane combustion performance of the catalyst. Catalyst compositions having from 1100 ppmw to 30000 ppmw of chromium can have significantly improved methane combustion performance even when compared to compositions that contain chromium but in an amount less than 1100 ppmw. However, compositions having more than 30000 ppmw of chromium can still improve methane combustion performance, but it is believed that amounts of chromium above 30000 ppmw can adversely affect the dehydrogenation performance of the catalyst by reducing both the percentage of dehydrogenated total alkanes and the percentage of dehydrogenated alkanes that are the intended product. The balance of performance between methane combustion and alkane dehydrogenation is ideal in compositions having from 1100 ppmw to 30000 ppmw of chromium. Although not bound by theory, it is further believed that compositions having a chromium loading of less than 1100 ppmw may experience an increase in catalyst deactivation over time during the dehydrogenation process when compared to catalyst compositions having a chromium loading of 1100 ppmw or more.

[0016] As described herein, in one or more embodiments, the catalyst may include a support. The support may include one or more of alumina, silica, or combinations thereof. For example, in some embodiments, the support may include one or more of alumina, silica-containing alumina, zirconia-containing alumina, titania-containing alumina, and lanthanum-containing alumina. The support may be present in an amount of at least 85 wt%, such as at least 85 wt%, at least 90 wt%, or at least 95 wt% based on the total weight of the catalyst. In some embodiments, the support comprises 99.5 wt% or less of the catalyst. Generally, the wt% of the support can account for the remainder of the total catalyst not specified by other materials.

[0017] In one or more embodiments, the catalyst may optionally contain 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 may contain one or more alkali metals, one or more alkaline earth metals, or both, in an amount of 0.01 wt% to 0.05 wt%, 0.05 wt% to 0.1 wt%, 0.1 wt% to 0.2 wt%, 0.2 wt% to 0.3 wt%, 0.3 wt% to 0.4 wt%, 0.4 wt% to 0.5 wt%, 0.5 wt% to 0.6 wt%, 0.6 wt% to 0.7 wt%, 0.7 wt% to 0.8 wt%, 0.8 wt% to 0.9 wt%, 0.9 wt% to 1 wt%, 1 wt% to 1.25 wt%, 1.25 wt% to 1.5 wt%, 1.5 wt% to 1.75 wt%, 1.75 wt% to 2 wt%, 2 wt% to 2.25 wt%, 2.25 wt% to 2.5 wt%, or any combination of these ranges. In some embodiments, the catalyst may contain one or more alkali metals, one or more alkaline earth metals, or both, in an amount of 0.01 wt% to 0.75 wt%, 0.02 wt% to 0.6 wt%, 0.03 wt% to 0.5 wt%, 0.04 wt% to 0.4 wt%, or 0.05 wt% to 0.3 wt%. 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 compositions having an amount of alkali metal or alkaline earth metal less than 0.01 wt% may cause the formation of undesirable products during the dehydrogenation process. However, it is believed that compositions having an amount of alkali metal or alkaline earth metal greater than 2.5 wt% may reduce the dehydrogenation activity of the catalyst.

[0018] 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, 1100 ppmw to 30000 ppmw chromium, and at least 85 wt% 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, 1100 ppmw to 10000 ppmw chromium, and at least 85 wt% support.

[0019] In one or more embodiments, the catalyst may include solid fine particles capable of fluidization. In some embodiments, the catalyst may exhibit properties known in the industry as "Geldart A" or "Geldart B" properties. The particle type may be classified as "Group A" or "Group B" according to D. Geldart, Gas Fluidization Technology, John Wiley & Sons (New York, 1986), 34-37, and D. Geldart, "Types of Gas Fluidization," Powder Technol. 7 (1973) 285-292, the disclosures of which are hereby incorporated by reference in their entirety.

[0020] Group A of Geldart is understood by those skilled in the art to represent a ventable powder having the following: fluidization in the bubble-free range, high bed expansion, slow and linear deaeration rate, divided / recombined bubbles may be dominant, bubble characteristics with a maximum bubble size and a large wake, high levels of solid mixing and gas backmixing assuming equal U-Umf (U is the velocity of the carrier gas and Umf is the minimum fluidization velocity, typically not necessarily measured in meters per second, m / s, i.e., there is an excess gas velocity), axisymmetric slug characteristics, and no ejection except for very shallow beds.

[0021]

Number

[0022] Geldart group B powders are understood by those skilled in the art to represent powders that begin to foam at Umf, exhibit moderate bed expansion, rapid deaeration, have no limitation on bubble size, and assuming U - Umf is equal, have a moderate level of solid mixing and gas backmixing; both axisymmetric slugs and asymmetric slugs; and "sand-like" powders that jet only in shallow beds. These properties tend to improve as the average particle size decreases, but the particle size distribution and, with some uncertainty, the gas pressure, temperature, viscosity, or density do not appear to contribute much to the improvement of the above properties. Generally, when the density (ρp) is 1.4 < ρp < 4 g / cm 3 ³, most of the particles

[0023]

Number

[0024]

Number

[0025] In one or more embodiments, the catalyst may be prepared by 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 hereby incorporated by reference in its entirety. For example, the support may be impregnated with a metal precursor and then dried at a temperature below 200 °C and then calcined at a temperature below 800 °C to produce the catalyst. For example, suitable metal precursors may include nitrates or amine nitrate metal precursors. Further, as known to those skilled in the art, other suitable metal precursors are contemplated herein. In some embodiments, the method of making the catalyst includes impregnating a support with gallium, platinum, and chromium, drying the support, and calcining the support, and the catalyst includes 0.1 wt% to 10 wt% gallium, 5 ppmw to 1000 ppmw platinum, 1100 ppmw to 30000 ppmw chromium, and at least 85 wt% support.

[0026] In one or more embodiments, the catalyst may be prepared by incipient wetness sequential impregnation, and the materials are impregnated in a specific order either 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 then undergoes at least one additional cycle of impregnation, drying, and calcination using additional metal precursors to yield the finished catalyst. In incipient wetness sequential impregnation, the metals added to the catalyst can be added sequentially in successive impregnation cycles. In one or more embodiments, the support is sequentially impregnated with gallium and platinum, and then chromium. In some embodiments, the method of making the catalyst may include impregnating the support with gallium and platinum, drying the support, calcining the support, impregnating the support with chromium after drying and calcination, and drying and calcining the support after chromium impregnation, and the catalyst comprises 0.1 wt% to 10 wt% gallium, 5 ppmw to 1000 ppmw platinum, 1100 ppmw to 30000 ppmw chromium, and at least 85 wt% support. In additional embodiments, the method of making the catalyst may include impregnating the support with chromium to create 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 calcination, and drying and calcining the chromium-impregnated support after gallium and platinum impregnation, and the catalyst comprises 0.1 wt% to 10 wt% gallium, 5 ppmw to 1000 ppmw platinum, 1100 ppmw to 30000 ppmw chromium, and at least 85 wt% support.

[0027] Incipient wetness sequential impregnation allows the support to be impregnated with metals in a sequential order in which some metals can be impregnated onto the support before others. Thus, the order of impregnation can be changed as desired. Further, as will be known to those skilled in the art, other suitable methods for making the catalysts described herein are contemplated.

[0028] In one or more embodiments, the catalyst described herein can be used in the reactor system of FIG. 1 that operates as a fluidized dehydrogenation reactor system for producing light olefins, such as propylene. However, it should be understood that the principles disclosed and taught herein may be applicable to other systems that utilize different system components oriented in different manners. For example, the concepts described herein can be equally applied to other systems with alternative reactor units and regeneration units that operate in a non-fluidized state or include a downer instead of a riser. Further, it should be understood that not all parts of FIG. 1 should be construed as essential to the claimed subject matter. Additionally, although the catalyst compositions in the appended claims are described herein in the context of FIG. 1, such listed compositions should be understood to be adaptable to other systems, as would be understood by those skilled in the art.

[0029] Referring now to FIG. 1, an exemplary reactor system 102 that may be suitable for use with the catalysts described herein is schematically shown. 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 when describing, "system component" refers to a part of the reactor system 102 such as a reactor, a separator, a transfer line, combinations thereof, etc. In the context of FIG. 1 as used herein, the reactor section 200 generally refers to the part of the reactor system 102 where a main process reaction (e.g., dehydrogenation) takes place to form an olefin-containing effluent. A hydrocarbon-containing feed enters the reactor section 200, contacts the catalyst, is converted to an olefin-containing effluent (containing product and unreacted feed), and exits the reactor section 200. The reactor section 200 includes a reactor 202 that may comprise an upstream reactor section 250 and a downstream reactor section 230. According to one or more embodiments, as shown in FIG. 1, the reactor section 200 may further comprise a catalyst separation section 210 that serves to separate the catalyst from the olefin-containing effluent formed within the reactor 202. Also, as used herein, the catalyst treatment section 300 generally refers to the part of the reactor system 102 that treats the catalyst in some way, such as by combustion, to improve the catalyst activity, for example, by decoking and / or heating the catalyst. The catalyst treatment section 300 may comprise a combustor 350 and a riser 330, and may further comprise a catalyst separation section 310. In one or more embodiments, the catalyst separation section 210 can be in fluid communication with the combustor 350 (e.g., via a water distribution tower 426), and the catalyst separation section 310 can be in fluid communication with the upstream reactor section 250 (e.g., via a water distribution tower 424 and a transfer riser 430).

[0030] Generally, as described herein, in the embodiment shown in FIG. 1, the catalyst is circulated between the reactor section 200 and the catalyst treatment section 300. When "catalysts" are referred to herein, it should be understood that they may 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 a catalyst can catalyze the reactions taking place within the reactor system 102. The catalyst exiting the reactor section 200 may be a deactivated catalyst. As used herein, "deactivated" may refer to a catalyst having a lower catalytic activity or a lower temperature compared to the catalyst entering the reactor section 200. However, a deactivated catalyst may maintain some catalytic activity. The decrease in catalytic activity may be due to contamination by substances such as coke. Coke may be formed on the catalyst within the reactor section 200. By reactivation (also sometimes referred to herein as "regeneration"), contaminants such as coke can be removed, the temperature of the catalyst can be increased, or both can be done. 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 is not limited to, removing coke by combustion, oxidizing the catalyst, other reactivation processes, or combinations thereof. In some embodiments, the catalyst may be heated during reactivation by the combustion of an auxiliary fuel such as methane, ethane, propane, natural gas, or combinations thereof. The reactivated catalyst from the catalyst treatment section 300 is then returned to the reactor section 200.

[0031] As disclosed herein, in one or more embodiments, the auxiliary fuel may include methane. For example, the auxiliary fuel may include methane in an amount of 1 mol% or more, such as 2 mol% or more, 3 mol% or more, 4 mol% or more, or even 5 mol% or more. In some embodiments, the auxiliary fuel includes methane in an amount of 10 mol% or less. In some embodiments, the auxiliary fuel may include methane in an amount of more than 10 mol%, such as more than 20 mol%, more than 30 mol%, more than 40 mol%, more than 50 mol%, more than 60 mol%, more than 70 mol%, more than 80 mol%, more than 90 mol%, or even 100 mol%. A catalyst having improved methane combustion activity, such as the catalysts described herein that include manganese, can better utilize methane as an auxiliary fuel and facilitate reheating of the catalyst. The catalyst is heated during regeneration to assist in regeneration, as the heated catalyst serves as a heat carrier that transports heat from the combustor 350 to the reactor section 200 to promote the dehydrogenation reaction.

[0032] In a non-limiting example, the reactor system 102 described herein can be utilized to produce light olefins from a hydrocarbon-containing feed. According to one or more embodiments, the reaction can be a dehydrogenation reaction. According to such embodiments, the hydrocarbon-containing feed may include one or more of ethylbenzene, ethane, propane, n-butane, and i-butane. In one or more embodiments, the hydrocarbon-containing feed may include at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of ethylbenzene. In one or more embodiments, the hydrocarbon-containing feed may include at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of ethane. In additional embodiments, the hydrocarbon-containing feed may include at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of propane. In additional embodiments, the hydrocarbon-containing feed may include at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of n-butane. In additional embodiments, the hydrocarbon-containing feed may include at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of i-butane. In additional embodiments, the hydrocarbon-containing feed may include at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of the total of ethane, propane, n-butane, and i-butane.

[0033] As described with respect to FIG. 1, a hydrocarbon-containing feed may enter reactor 202 from feed inlet 434, and an olefin-containing effluent may exit reactor system 102 via pipe 420. According to one or more embodiments, reactor system 102 may be operated by feeding a hydrocarbon-containing feed (e.g., in a feed stream) and a fluid catalyst to upstream reactor section 250. The hydrocarbon-containing feed contacts the catalyst within upstream reactor section 250, and each flows upward into downstream reactor section 230 and through downstream reactor section 230 to produce an olefin-containing effluent.

[0034] Referring now in detail to FIG. 1, reactor section 200 may include an upstream reactor section 250, a transfer section 258, and a downstream reactor section 230 such as a riser. Transfer section 258 can connect upstream reactor section 250 to downstream reactor section 230. As shown in FIG. 1, upstream reactor section 250 may be disposed below downstream reactor section 230. Such a configuration can be referred to as an upflow configuration in reactor 202. Upstream reactor section 250 may include a tank, drum, barrel, vat, or other container suitable for a given chemical reaction. As shown in FIG. 1, upstream reactor section 250 can be connected to downstream reactor section 230 via transfer section 258. Upstream reactor section 250 can generally have a larger cross-sectional area than downstream reactor section 230. Transfer section 258 may be tapered from the cross-sectional size of upstream reactor section 250 toward the cross-sectional size of downstream reactor section 230 such that transfer section 258 projects inwardly from upstream reactor section 250 toward downstream reactor section 230. For example, transfer section 258 may be a frustum.

[0035] The upstream reactor section 250 can be connected to a transfer riser 430 that can provide reactivated catalyst in the feed stream to the reactor section 200 during operation. The reactivated catalyst and / or reaction chemicals can be mixed in a distributor 260 housed within the upstream reactor section 250. The catalyst entering the upstream reactor section 250 via the transfer riser 430 can be sent to the transfer riser 430 through a water distribution tower 424 and thus arrives from the catalyst treatment section 300. In some embodiments, the catalyst may enter directly into the transfer riser 430 from the catalyst separation section 210 via a standpipe 422, in which case the catalyst enters the upstream reactor section 250 and in such embodiments, a portion of the catalyst does not pass through the catalyst treatment section 300. The catalyst can also be directly supplied to the upstream reactor section 250 via the standpipe 422 (not shown in FIG. 1). This catalyst may be somewhat deactivated but may still be suitable for reaction within the upstream reactor section 250 in some embodiments, particularly when used in combination with the reactivated catalyst.

[0036] In one or more embodiments, the catalyst can have a residence time within the reactor section 200 of 3 minutes or less. As used herein, the term "residence time" refers to the average amount of time that a catalyst or other specific material spends within the reactor section 200. Since it is an average, the amount of time that the catalyst can spend within the reactor section 200 during any given cycle may not be equal to the average but will approximately equal the residence time on average over time. In some embodiments, the catalyst may have a residence time within the reactor section 200 of 2.5 minutes or less, 2 minutes or less, 1.5 minutes or less, 1 minute or less, 0.5 minutes or less, or 0.1 minutes or less. Without being bound by theory, it is believed that a catalyst residence time greater than 3 minutes can increase the equipment cost without increasing the matching in catalyst dehydrogenation performance. However, a catalyst residence time of less than 0.1 minutes is believed to possibly prevent the catalyst from sufficiently catalyzing the dehydrogenation reaction.

[0037] Referring further to FIG. 1, in one or more embodiments, based on the shape, size, and other processing conditions (such as temperature and pressure) of the upstream reactor section 250 and the downstream reactor section 230, the upstream reactor section 250 can operate as a fluidized bed, such as a fast fluidized bed, a turbulent fluidized bed, or a bubble bed riser reactor, while the downstream reactor section 230 can operate in a plug flow mode, such as a riser reactor. For example, the reactor 202 of FIG. 1 may include an upstream reactor section 250 that operates as a fast fluidized bed, a turbulent fluidized bed, or a bubble bed reactor, and a downstream reactor section 230 that operates as a dilute phase riser reactor, such that the average catalyst and gas flow move upward simultaneously. As used herein, the term "average flow" generally refers to the net flow, i.e., the flow obtained by subtracting the reverse or countercurrent flow from the total upward flow, as is typical of the behavior of fluidized particles. As described herein, a "fast fluidized" reactor may refer to a reactor that utilizes a fluidization regime in which the superficial gas velocity is faster than the choking velocity and may be semi-dense during operation. As described herein, a "turbulent" reactor may refer to a fluidization regime in which the superficial velocity is slower than the choking velocity and has a higher density than the fast fluidization regime. As described herein, a "bubble bed" reactor may refer to a fluidization regime in which distinct bubbles in a high density bed exist in two separate phases. The "choking 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 that operates at a velocity above the flooding velocity.

[0038] According to an embodiment, the olefin-containing effluent and the catalyst may be discharged from the downstream reactor section 230 and sent to the separator 220 within the catalyst separation section 210, where the catalyst is at least partially separated from the olefin-containing effluent and the olefin-containing effluent is transported from the catalyst separation section 210. According to one or more embodiments, following separation from the vapor in the separator 220, the catalyst may generally move through the stripper 224 to the catalyst outlet port 222, where the catalyst exits the reactor section 200 via the water distribution tower 426 and is transferred to the catalyst treatment section 300.

[0039] According to one or more embodiments, the separator 220 may be a cyclone separation system that can include two or more stages of cyclone separation. In embodiments where the separator 220 includes more than one cyclone separation stage, the first separator into which the fluidized stream enters is referred to as the primary cyclone separator. The fluid effluent from the primary cyclone separator can enter a secondary cyclone separator for further separation. Examples of primary cyclone separators can include the primary cyclone, as well as 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 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 the primary cyclone as the primary cyclone separator, one or more additional cyclones, such as secondary and tertiary cyclones, are used to further separate the catalyst from the product gas. It should be understood that any primary cyclone separator may be used in the embodiments of the present disclosure.

[0040] Referring further to FIG. 1, the separated catalyst moves from the catalyst separation section 210 to the combustor 350. In the combustor 350, the catalyst can be treated, for example, by combustion of coke with oxygen. For example, but not limited to, the catalyst can remove coke and / or burn auxiliary fuel to heat the catalyst. Next, the catalyst exits the combustor 350 and is sent through the riser 330 to the riser end separator 378, where the gas and solid components from the riser 330 are at least partially separated. The vapor and remaining solids are transferred to the secondary separator 320 within the catalyst separation section 310, where the remaining catalyst is separated from the gas from the catalyst treatment (e.g., the gas released by combustion of the spent catalyst or auxiliary fuel, referred to herein as flue gas). The flue gas can exit the catalyst treatment unit 300 via the outlet pipe 432. Next, the separated catalyst moves through the oxygen treatment zone 370 within the catalyst separation section 310 via the water distribution tower 424 and the transfer riser 430 to the upstream reactor section 250, where it is further utilized for the catalytic reaction. Thus, the catalyst can circulate between the reactor section 200 and the catalyst treatment section 300 during operation. Generally, the treated chemical stream containing the hydrocarbon-containing feed and the olefin-containing effluent may be gaseous, and the catalyst may be a fluid particulate solid.

[0041] Referring now to the catalyst treatment unit 300, as shown in FIG. 1, the combustor 350 of the catalyst treatment unit 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 such as air can move through the pipe 428 to the combustor 350. The combustor 350 can be in fluid communication with the catalyst separation section 210 via the water distribution tower 426, and the water distribution tower 426 can supply the spent catalyst from the reactor section 200 to the catalyst treatment unit 300 for regeneration. The combustor 350 and the riser 330, collectively referred to as the catalytic combustion reactor 302, can operate in a fluidization regime similar to or the same as that disclosed for the upstream reactor section 250 and the downstream reactor section 230 of the reactor section 200. That is, the combustor 350 can operate as a fluidized bed in a high-velocity fluidized bed, turbulent bed, or bubble bed riser reactor, etc., while the riser 330 can operate in a plug flow mode such as a riser reactor. The geometric shapes described for the upstream reactor section 250 and the downstream reactor section 230 can be equally applied to the combustor 350 and the riser 330. Further, the combustor 350 may also include a fuel inlet 354 through which a fuel such as a hydrocarbon stream can be supplied to the combustor 350.

[0042] As described herein, the catalyst may be heated within the catalyst treatment unit 300 by the combustion of auxiliary fuel. The auxiliary fuel may burn with oxygen to heat the catalyst, and auxiliary fuels such as hydrogen, methane, ethane, propane, natural gas, or combinations thereof may be utilized. Without being bound by any theory, when methane is utilized as the auxiliary fuel, the catalysts described herein containing chromium may better catalyze the combustion of methane to heat the catalyst. Catalysts that do not contain chromium may be insufficient by not promoting the heating of the catalyst to the temperature required for dehydrogenation when methane is utilized as the auxiliary fuel.

[0043] As described in one or more embodiments, following the separation of flue gas from the catalyst in the riser termination separator 378 and the secondary separation device 320, the treated 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 can include a baffle or grid structure to facilitate contact of the treated catalyst with the oxygen-containing gas. Examples of fluid-solid contact devices are described in more detail in U.S. Patent Nos. 9,827,543 and 9,815,040. The fluidization regime within the oxygen treatment zone may be a bubbling bed type fluidization. The oxygen treatment zone 370 can include an oxygen-containing gas inlet 372 that can feed an oxygen-containing gas into the oxygen treatment zone 370 for the oxygen treatment of the catalyst.

[0044] As disclosed herein, in one or more embodiments, the catalyst may be exposed to an oxygen-containing gas in the oxygen treatment zone 370. For example, the catalyst can be exposed to the oxygen-containing gas for 2 to 20 minutes, such as 2 to 4 minutes, 4 to 6 minutes, 6 to 8 minutes, 8 to 10 minutes, 10 to 12 minutes, 12 to 14 minutes, 14 to 16 minutes, 16 to 18 minutes, 18 to 20 minutes, or any combination of these ranges. In some embodiments, the catalyst may be exposed to the oxygen-containing gas for 4 to 18 minutes, 6 to 17 minutes, 8 to 16 minutes, or 10 to 15 minutes. Without being bound by theory, it is believed that exposure of the catalyst to the oxygen-containing gas for more than 20 minutes can increase the equipment cost without increasing the matching in catalyst regeneration efficiency. However, exposure of the catalyst to the oxygen-containing gas for less than 2 minutes can result in a decrease in catalyst regeneration efficiency that can reduce the dehydrogenation activity of the catalyst.

[0045] In one or more embodiments, the light olefins may be present in a “product stream,” sometimes referred to as an “olefin-containing effluent,” and may include light olefins. Such a stream exits the reactor system of FIG. 1 and may subsequently be processed. As used in this disclosure, the term “light olefins” refers to one or more of ethylene, propylene, and butenes. The term butenes includes any isomers of butenes such as α-butylene, cis-β-butylene, trans-β-butylene, and isobutylene. In some embodiments, the olefin-containing effluent includes at least 25 wt % light olefins, based on the total weight of the olefin-containing effluent. For example, the olefin-containing effluent can include at least 35 wt % light olefins, at least 45 wt % light olefins, at least 55 wt % light olefins, at least 65 wt % light olefins, or at least 75 wt % light olefins, based on the total weight of the olefin-containing effluent. The olefin-containing effluent may further include unreacted components of the hydrocarbon-containing effluent and other reaction products not considered light olefins. The light olefins can be separated from the unreacted components in a subsequent separation step.

Examples

[0046] The various embodiments of the present disclosure are further clarified by the following examples. These examples are illustrative in nature and are not to be understood as limiting the subject matter of this application.

[0047] Example 1 - Effect of Chromium Loading In Example 1, eight different samples of catalytically active particles (i.e., catalysts) were prepared and the effect of chromium loading on the catalytically active particles was observed. For the purposes of Example 1, first, a microspherical alumina support was prepared by spray drying a mixture of hydrated alumina and Ludox® silica, and then the resulting spray-dried particles were sized in the range of 5 μm to 300 μm, had a pore volume of 0.20 ± 0.10 mL / g, and a surface area of 70 ± 20 m 2Samples were prepared by heating to a temperature of at least 1000 °C, sufficient to achieve particles having a surface area of / g and a silica content of 2.5 ± 2.5 wt%. The catalyst material was prepared by using the incipient wetness impregnation method to load the specified metal onto the support using a nitrate or metal amine nitrate precursor, followed by drying at a temperature below 200 °C and then calcining at a temperature below 800 °C. The exact composition of the samples is provided in Table 1.

[0048] Samples were tested at ambient pressure under the condition that 0.5 grams (g) of the sample was mixed with 1.0 g of inert carbonized silicon and loaded into a quartz reactor. The reaction combustion reactivation cycle was performed with 10 rest cycles, followed by dehydrogenation and regeneration test cycles. Interruptions in the cycle were carried out by performing two steps: 10 hours -1 of propane hourly weight hourly space velocity "WHSV" and a feed composition of 90% propane / 10% nitrogen to perform a dehydrogenation process at 625 °C for 60 seconds; and a reactivation step of heating the catalyst to 730 °C for 5 minutes under 100% air at a flow rate of 50 standard cubic centimeters per minute (sccm). After the catalyst was run through 10 interruption cycles, it was tested in dehydrogenation and regeneration test cycles. The dehydrogenation and regeneration test cycles were carried out by performing the following three steps: a dehydrogenation step using the same conditions as the dehydrogenation step of the interruption in the cycle where dehydrogenation performance data was collected over a 30 - second on - stream time, a combustion step where combustion was carried out at 730 °C for 3 minutes under 2.5 mol% methane / balance air having a WHSV of methane of 0.1 hour -1 and combustion performance data was collected over a 60 - second on - stream time, and a reactivation step where the sample was heated to 730 °C for 2 minutes under 100% air having a flow rate of 50 sccm. The dehydrogenation and combustion performance of the samples after 25 cycles are reported in Table 1.

[0049]

Table 1

[0050] Table 1 shows that for samples having an amount of chromium in the range of 1100 ppmw to 30000 ppmw (i.e., Samples 1 to 7), the methane conversion rate was improved when compared with Comparative Example A (chromium-free). Some samples containing an amount of chromium in the range of 1100 ppmw to 30000 ppmw have an improved methane conversion rate and propane conversion rate. For example, Comparative Example A (chromium-free) has a worse methane conversion rate, propane conversion rate, and propylene selectivity than Sample 2 which is identical to Comparative Example A except for the presence of chromium. Further, Table 1 shows that a catalyst composition containing an amount of chromium in the range of 1100 ppmw to 30000 ppmw but not containing platinum and gallium (i.e., Comparative Example B) has a lower propane conversion rate and propylene selectivity than samples containing platinum, gallium, and chromium (i.e., Samples 1 to 7). That is, Table 1 shows that the overall catalyst composition of platinum, gallium, and chromium is important for improving the methane conversion rate while maintaining an acceptable propane conversion rate and propylene selectivity. Finally, Table 1 shows that sufficient methane conversion rate, propane conversion rate, and propylene selectivity can be achieved over a range of platinum and gallium compositions. For example, Samples 5 to 7 have an improved methane conversion rate and propane conversion rate when compared with Comparative Example A, despite having different amounts of platinum and gallium.

[0051] In a first aspect of the present disclosure, the catalyst may include 0.1 wt% to 10 wt% of gallium, 5 ppmw to 1000 ppmw of platinum, 1100 ppmw to 30000 ppmw of chromium, and at least 85 wt% of a carrier. Here, the carrier may include one or more of alumina, silica, or a combination thereof.

[0052] A second aspect of the present disclosure may include the first aspect, where the catalyst includes 10 ppmw to 400 ppmw of platinum.

[0053] A third aspect of the present disclosure may include Aspect 1 or 2, where the catalyst includes 0.1 wt% to 5 wt% of gallium.

[0054] A fourth aspect of the present disclosure may include any one of aspects 1 to 3, wherein the catalyst contains 1100 ppmw to 10000 ppmw of chromium.

[0055] A fifth aspect of the present disclosure may include any one of aspects 1 to 4, wherein the catalyst further contains 0.01 wt% to 2.5 wt% of one or more alkali metals or alkaline earth metals.

[0056] A sixth aspect of the present disclosure may include the first aspect, wherein the catalyst further contains 0.01 wt% to 2.5 wt% of potassium.

[0057] A seventh aspect of the present disclosure may include any one of aspects 1 to 6, wherein the catalyst contains 10 ppmw to 400 ppmw of platinum, 0.1 wt% to 5 wt% of gallium, and 1100 ppmw to 10000 ppmw of chromium.

[0058] An eighth aspect of the present disclosure may include the first aspect, wherein the catalyst consists essentially of 5 ppmw to 1000 ppmw of platinum, 0.1 wt% to 10 wt% of gallium, 1100 ppmw to 30000 ppmw of chromium, and at least 85 wt% of a carrier. Here, the carrier includes one or more of alumina, silica, or a combination thereof.

[0059] A ninth aspect of the present disclosure may include the first aspect, wherein the catalyst consists essentially of 10 ppmw to 400 ppmw of platinum, 0.1 wt% to 5 wt% of gallium, 1100 ppmw to 10000 ppmw of chromium, and at least 85 wt% of a carrier. Here, the carrier includes one or more of alumina, silica, or a combination thereof.

[0060] A tenth aspect of the present disclosure may include the first aspect, wherein the catalyst consists of 5 ppmw to 1000 ppmw of platinum, 0.1 wt% to 10 wt% of gallium, 1100 ppmw to 30000 ppmw of chromium, and at least 85 wt% of a carrier. Here, the carrier includes one or more of alumina, silica, or a combination thereof.

[0061] The 11th aspect of the present disclosure may include the 1st aspect, where the catalyst consists of platinum of 10 ppmw to 400 ppmw, gallium of 0.1 wt% to 5 wt%, chromium of 1100 ppmw to 10000 ppmw, and at least 85 wt% of a carrier. Here, the carrier includes one or more of alumina, silica, or a combination thereof.

[0062] The 12th aspect of the present disclosure may include any of the above aspects, where the catalyst has the characteristics of Geldart group A or Geldart group B.

[0063] The 13th aspect of the present disclosure is a method for preparing a catalyst, which may include impregnating a carrier with gallium and platinum to create a gallium- and platinum-impregnated carrier, drying the gallium- and platinum-impregnated carrier, firing the gallium- and platinum-impregnated carrier, impregnating the gallium- and platinum-impregnated carrier with chromium after firing the carrier, and drying and firing the impregnated carrier after impregnating it with chromium. Here, the catalyst is the catalyst of the 1st aspect.

[0064] The 14th aspect of the present disclosure is a method for preparing a catalyst, which may include impregnating a carrier with chromium to create a chromium-impregnated carrier, drying the chromium-impregnated carrier, firing the chromium-impregnated carrier, impregnating the chromium-impregnated carrier with gallium and platinum after firing the carrier, and drying and firing the chromium-impregnated carrier after impregnating it with gallium and platinum. Here, the catalyst is the catalyst of the 1st aspect.

[0065] The 15th aspect of the present disclosure is a method for preparing a catalyst, which may include impregnating a carrier with gallium, platinum, and chromium, drying the carrier after impregnation, and firing the carrier. Here, the catalyst is the catalyst of the 1st aspect.

[0066] It will be apparent to those skilled in the art that various modifications and changes can be made to the technology of the present disclosure without departing from the spirit and scope of the technology. Combinations, sub-combinations, and variations of modifications of the disclosed embodiments that incorporate the spirit and substance of the technology of the present disclosure can be conceived by those skilled in the art, and thus the technology should be construed to include all within the scope of the appended claims and their equivalents. Further, 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.

[0067] It should be noted that the various details described in the present disclosure should not be construed as implying that these details are related to elements that are essential components of the various embodiments described in the present disclosure, even if a particular element is illustrated in each of the accompanying drawings herein. Unless specifically so specified, the features disclosed and described herein should not be construed as "essential." The contemplated embodiments of the technology include those that include some or all of the features of the appended claims.

[0068] For the purposes of describing and defining the present disclosure, it should be noted that the term "about" is used in the present disclosure to represent the degree of inherent uncertainty that may result from any quantitative comparison, value, measurement, or other representation. The term "about" is also used in the present disclosure to represent the degree to which a quantitative expression may vary from the reference of the description without causing a change in the basic function of the subject matter in question.

[0069] When 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.

[0070] It should be understood that in some embodiments, the flow or the composition range of chemical components in the reactor contains a mixture of isomers of that component. For example, the composition range specifying butene can include a mixture of various isomers of butene. It should be understood that the examples supply various flow composition ranges and that the total amount of isomers of a particular chemical composition can constitute the range.

[0071] It should be noted that one or more of the following claims utilize the terms "where" or "wherein" as transitional phrases. For the purpose of defining the present technology, this term is introduced into the claims as a non-limiting transitional phrase used to introduce a recitation of a series of features of a structure and should be construed in the same manner as the more generally used non-limiting preamble term "comprising".

[0072] It should be understood that any two quantitative values assigned to a property can constitute a range of that property and that all combinations of ranges formed from all the recited quantitative values of a given property are contemplated in the present disclosure. If multiple ranges are given for a quantitative value, these ranges may be combined to form a broader range, which is contemplated in the embodiments described herein.

Claims

1. A catalyst suitable for producing light olefins by dehydrogenation, Platinum with a power output of 5 ppmW to 1000 ppmW, 0.1% to 10% by weight of gallium, Chromium in the range of 1100 ppmw to 30000 ppmw, and A catalyst comprising at least 85% by weight of a support, wherein the support comprises one or more of alumina, silica, or a combination thereof.

2. The catalyst according to claim 1, comprising 10 ppm W to 400 ppm W of platinum.

3. The catalyst according to claim 1, comprising 0.1% to 5% by weight of gallium.

4. The catalyst according to claim 1, comprising 1,100 ppmw to 10,000 ppmw of chromium.

5. The catalyst according to claim 1, further comprising 0.01% to 2.5% by weight of one or more alkali metals or alkaline earth metals.

6. The catalyst according to claim 1, further comprising 0.01% to 2.5% by weight of potassium.

7. Platinum from 10 ppmW to 400 ppmW, 0.1% to 5% by weight of gallium, and 1100 ppm to 10000 ppm chrome The catalyst according to claim 1, comprising:

8. Platinum with a power output of 5 ppmW to 1000 ppmW, 0.1% to 10% by weight of gallium, Chromium in the range of 1100 ppmw to 30000 ppmw, and The catalyst according to claim 1, comprising essentially 85% by weight of a support, wherein the support includes one or more alumina, silica, or a combination thereof.

9. Platinum from 10 ppmW to 400 ppmW, 0.1% to 5% by weight of gallium, and Chromium in the range of 1100 ppm to 10000 ppm, and The catalyst according to claim 1, comprising essentially 85% by weight of a carrier, wherein the carrier includes alumina, silica-containing alumina, zirconia-containing alumina, titania-containing alumina, or a combination thereof.

10. Platinum with a power output of 5 ppmW to 1000 ppmW, 0.1% to 10% by weight of gallium, Chromium in the range of 1100 ppmw to 30000 ppmw, and The catalyst according to claim 1, comprising at least 85% by weight of a support, wherein the support includes one or more of alumina, silica, or a combination thereof.

11. Platinum from 10 ppmW to 400 ppmW, 0.1% to 5% by weight of gallium, and Chromium in the range of 1100 ppm to 10000 ppm, and The catalyst according to claim 1, comprising at least 85% by weight of a support, wherein the support includes one or more of alumina, silica, or a combination thereof.

12. A catalyst according to any one of claims 1 to 11, having the properties of Geldart group A or Geldart group B.

13. A method for producing a catalyst, The process involves impregnating a carrier with gallium and platinum to create a gallium and platinum-impregnated carrier, The gallium and platinum-impregnated carrier is dried, The gallium and platinum-impregnated carrier is calcined, After the calcination of the carrier, the gallium and platinum-impregnated carrier is impregnated with chromium, The process includes impregnating the impregnated carrier with chromium, followed by drying and calcining the impregnated carrier. A method wherein the catalyst is the catalyst described in claim 1.

14. A method for producing a catalyst, The process involves impregnating a carrier with chromium to create a chromium-impregnated carrier, The chromium-impregnated carrier is dried, The chromium-impregnated carrier is fired, After firing the aforementioned carrier, the chromium-impregnated carrier is impregnated with gallium and platinum. The process includes drying and calcining the chromium-impregnated carrier after impregnation with gallium and platinum. A method wherein the catalyst is the catalyst described in claim 1.

15. A method for producing a catalyst, Impregnating the carrier with gallium, platinum, and chromium, After impregnating the carrier, the carrier is dried. This includes firing the aforementioned carrier, A method wherein the catalyst is the catalyst described in claim 1.

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