Process for preparation of light olefins by dehydrogenation with combustion additive comprising transition metal

Abstract

A method for preparing a light olefin by dehydrogenation can include operating a catalytic dehydrogenation process; monitoring the composition of the combustion gases in the combustor to detect the concentration of one or more hydrocarbons; and selectively adding a combustion additive with the catalyst when the combustion gas contains one or more hydrocarbons in an amount greater than 5% of a lower combustible limit level of the combustion gas at the temperature and pressure of the combustor. The injection cup wear index of the combustion additive may be greater than the injection cup wear index of the catalyst. The combustion additive may include 1% to 10% by weight of one or more transition metals other than gallium and noble metals; from 0 parts by weight of millions (ppmw) to 100 ppmw of gallium and a noble metal; and at least 85% by weight of a carrier.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 352,013, filed on June 14, 2022, the entire disclosure of which is hereby incorporated by reference into this document. 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] Methods and related systems for preparing light olefins by dehydrogenation may include reacting a hydrocarbon-containing feed on a catalyst in a reactor. After the endothermic dehydrogenation reaction, the catalyst may be transferred to a burner, where the catalyst is heated by the combustion of a supplementary fuel. The catalyst provides dehydrogenation activity in the reactor and combustion activity in the burner for supplementary fuel combustion. Sometimes, the combustion rate may be lower than the desired rate, and the dehydrogenation rate is sufficient. For example, in some embodiments, it has been found that over time, the catalytic activity of the catalyst is more reduced for combustion than for dehydrogenation. In other embodiments, process fluctuations such as the composition of supplementary fuel may require additional catalytic activity for combustion. In some conventional systems, fresh catalyst is added to the system to compensate for performance losses caused by catalyst aging and / or catalyst wear, so as to maintain acceptable dehydrogenation activity and / or maintain acceptable supplementary fuel combustion activity. The loss of catalyst combustion activity may limit the available fuel composition, which may adversely affect process economics or flexibility.

[0006] The catalyst system and method for producing olefins disclosed in the present invention can effectively maintain the dehydrogenation catalytic activity in the reactor and maintain sufficient combustion activity in the burner of the system. In one or more embodiments, this is achieved at least in part by utilizing both catalyst and combustion additive, and when the combustion activity is lower than the expectation, the combustion additive is selectively added to the process. The combustion additive may contain less than 100ppmw of gallium and precious metals for dehydrogenation activity, thereby reducing the economic cost of the material. However, when necessary, the combustion additive can selectively promote combustion activity. Further, the combustion additive may have a greater wear rate than the catalyst, and therefore allows the removal of the combustion additive from the system and the removal of the catalyst separately. In some embodiments, the different wear characteristics of the catalyst and the combustion additive can reduce the dilution of the catalyst in the system, thereby improving the catalytic activity of the catalyst while reducing the economic cost of the process.

[0007] According to one or more embodiments of the present disclosure, a method for preparing light olefins by dehydrogenation may include: operating a catalytic dehydrogenation process; monitoring the composition of the combustion gas in a burner to detect the concentration of one or more hydrocarbons; and when the combustion gas contains one or more hydrocarbons in an amount greater than 5% of the lower flammable limit level of the combustion gas at the temperature and pressure of the burner, selectively adding a combustion additive to the catalyst. The operation may include: contacting a hydrocarbon-containing feed with a catalyst in a reactor to form an olefin-containing effluent; separating the olefin-containing effluent at least partially from the catalyst; transferring the catalyst to the burner and heating the catalyst by burning a supplemental fuel, wherein the supplemental fuel contains an amount greater than or equal to 1 mol% of methane; and transferring the catalyst 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 injection cup wear index of the combustion additive is greater than the injection cup wear index of the catalyst, wherein the injection cup wear is measured at a 45 μm threshold after 6 hours at ambient temperature, an injection velocity of 300 feet per second, a flow rate of 98 liters per minute, and a sample load of 100 grams. The combustion additive comprises 1 wt % to 10 wt % of one or more transition metals other than gallium and precious metals; 0 parts per million by weight (ppmw) to 100 ppmw of gallium and precious metals; and at least 85 wt % of a carrier.

[0008] It should be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and characteristics of the claimed subject matter. Additional features and advantages of the embodiments will be set forth in the 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

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

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

[0011] Figure 2 is a flow chart of a method according to one or more embodiments of the present disclosure.

[0012] 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.

[0013] Reference will now be made in greater detail to various embodiments, some of which are illustrated in the accompanying drawings. DETAILED DESCRIPTION

[0014] The present disclosure relates to methods for preparing light olefins by dehydrogenation, in which a combustion additive is utilized. These methods may generally include: operating a catalytic dehydrogenation process; monitoring the composition of the combustion gas in a burner to detect the concentration of one or more hydrocarbons; and selectively adding a combustion additive to the catalyst when the combustion gas contains one or more hydrocarbons in an amount greater than 5% of the lower flammable limit level of the combustion gas at the temperature and pressure of the burner. In embodiments described herein, the combustion additive comprises 1 wt % to 10 wt % of one or more transition metals other than gallium and precious metals; 0 ppmw to 100 ppmw of gallium and precious metals; and at least 85 wt % of a carrier. According to some embodiments, such combustion additives may be particularly suitable for fluidized dehydrogenation of light alkanes to light olefins, such as propane to propylene, where a supplemental fuel such as methane is used to heat the catalyst.

[0015] In the present invention, a method for producing light olefins such as propylene is described in detail below. Figure 1 Embodiments of the present disclosure 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, or to different reaction schemes utilizing various catalyst compositions. For example, the concepts described are equally applicable to other systems having alternative reactor units and regeneration units, such as those operating under non-fluidized conditions, or those systems including downers instead of risers. It should also be understood that not all systems are identical. Figure 1 All parts of the disclosure should be construed as essential to the claimed subject matter.

[0016] Reference now Figure 2 , according to one or more embodiments described herein, depicts a flow chart depicting a method 500 for producing light olefins by dehydrogenation. Step 502 generally includes operating a catalytic dehydrogenation process; step 504 includes monitoring the composition of the combustion gas in the combustor to detect the concentration of one or more hydrocarbons; and step 506 includes selectively adding a combustion additive with the catalyst when the combustion gas contains one or more hydrocarbons in an amount greater than 5% of the lower flammable limit level of the combustion gas at the temperature and pressure of the combustor.

[0017] In one or more embodiments, operation of the dehydrogenation process in step 502 generally includes contacting a hydrocarbon-containing feed with a catalyst in a reactor to form an olefin-containing effluent, wherein coke is formed on the catalyst in the reactor; and separating the olefin-containing effluent at least partially from the catalyst. Step 502 may also include: transferring the catalyst to a burner and heating the catalyst by burning 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%; and transferring the catalyst from the burner to the reactor such that at least a portion of the catalyst is continuously circulated between the reactor and the burner. Such embodiments are described hereinafter in Figure 1 is described in the context of a system.

[0018] 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 1As used in the context of , the reactor section 200 generally refers to the portion of the reactor system 102 where the primary process reaction (e.g., dehydrogenation) occurs to form a product stream. The feed stream enters the reactor section 200, is converted into a product stream (containing product and unreacted feed), and exits the reactor section 200. The reactor section 200 includes a reactor 202, which may include an upstream reactor section 250 and a downstream reactor section 230. According to one or more embodiments, as Figure 1 As depicted, the reactor section 200 can additionally include a catalyst separation section 210 for separating the catalyst from the chemical products formed in the reactor 202. Additionally, as used herein, the catalyst treatment section 300 generally refers to a portion of the reactor system 102 in which the catalyst is treated in some manner, such as by combustion, to improve catalytic activity, such as 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).

[0019] 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 "catalysts" are referred to herein, they may refer to a solid material that has catalytic activity for the desired reaction, or may also refer to a solid material that has catalytic activity for the desired reaction. Figure 1The system mentioned in the invention does not necessarily have catalytic activity but other particulate solids that affect the reaction, such as oxygen carriers. The terms "catalytic activity" and "catalyst activity" refer to the extent to which the catalyst can catalyze the reaction carried out in the reactor system. The catalyst leaving the reactor section 200 may be a deactivated catalyst. As used herein, "deactivated" may refer to a catalyst having a reduced catalytic activity or a colder catalyst than the catalyst entering the reactor section 200. However, the deactivated catalyst may retain some catalytic activity. The reduced catalytic activity may be caused by contamination of substances such as coke. Reactivation (sometimes referred to as "regeneration" in this article) may remove pollutants such as coke, increase the temperature of the catalyst, or both. In embodiments, the deactivated catalyst may be reactivated by catalyst reactivation in the catalyst treatment section 300. The deactivated catalyst may be reactivated by, but not limited to, removing coke by combustion, restoring catalyst acidity, oxidizing catalyst, other reactivation processes, or combinations thereof. In some embodiments, the catalyst may be heated by burning supplementary fuels such as methane, ethane, hydrogen, propane, natural gas, or combinations thereof during reactivation. The reactivated catalyst from the catalyst treatment section 300 is then transferred back to the reactor section 200 .

[0020] In embodiments, additional fresh catalyst may be added to the reactor system 102 to compensate for the decrease in catalytic activity of the catalyst. A catalyst may exhibit a decrease in catalytic activity due to loss of catalyst through attrition or degradation over time.

[0021] 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 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 % 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 % propane.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 % normal butane. In other embodiments, the hydrocarbon-containing feed can contain at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of isobutane. In other embodiments, the hydrocarbon-containing feed can contain at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of the sum of ethane, propane, n-butane, and isobutane.

[0022] 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; and a support. As described herein, "consisting essentially of" refers to a material having less than 1% by weight of an unlisted 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.

[0023] In one or more embodiments, based on the total mass of the catalyst, the catalyst may include one or more of gallium, indium or thallium in an amount of 0.05 wt % to 10 wt %. For example, the catalyst may include one or more of gallium, indium or thallium in an amount of 0.05 wt % to 0.1 wt %, 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 ranges. In some embodiments, the catalyst may include one or more of gallium, indium or thallium in an amount of 0.05 wt % to 5 wt %, 0.05 wt % to 4 wt % or 0.05 wt % to 3 wt %. In some embodiments, the catalyst only comprises gallium but does not include indium or thallium, only comprises indium but does not include gallium or thallium, or only comprises thallium but does not include gallium or indium.It should be understood that the composition range describing the amount of gallium, indium and thallium represents the scope of any one of these materials or the combination of these materials.Not bound by theory, it is believed that the composition with an amount less than one or more of the gallium, indium or thallium of 0.05 weight % negatively affects the ability of the catalyst catalysis alkane dehydrogenation process by reducing the percentage of total dehydrogenated alkanes and the percentage of dehydrogenated alkanes as the expected product.However, it is believed that the composition with an amount exceeding one or more of the gallium, indium or thallium of 10 weight % may increase the economic cost of operation, while not providing the substantial improvement of the catalytic function catalyst.

[0024] In one or more embodiments, the catalyst can include one or more of platinum, palladium, rhodium, iridium, ruthenium, or osmium in an amount of 5 ppmw to 1000 ppmw, based on the total mass of the catalyst. For example, the catalyst can include one or more of platinum, palladium, rhodium, iridium, ruthenium, or osmium 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 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 the alkane dehydrogenation process by reducing both the percentage of total dehydrogenated alkanes and the percentage of dehydrogenated alkanes that are desired products.

[0025] 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-containing aluminum oxide, zirconium oxide-containing aluminum oxide, or titanium dioxide-containing aluminum oxide. Relative to the gross weight of the catalyst, the carrier may be present in an amount of at least 50 weight %, such as at least 55 weight %, at least 60 weight %, at least 65 weight %, at least 70 weight %, at least 75 weight %, at least 80 weight % or even at least 85 weight %. In some embodiments, the carrier accounts for less than or equal to 95 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.

[0026] 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 1 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 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 %, or any combination of these ranges. In some embodiments, the catalyst may include 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 % of one or more alkali metals, one or more alkaline earth metals, or both.

[0027] 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".

[0028] 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 in proportion with <45 microns (μm); or increase with pressure, temperature, viscosity and density of the gas. In general, the particles may exhibit a small average particle size and / or a particle density (ρp) ρp < 1.4 g / cm3 (g / cm 3 ); easy fluidization, where smooth fluidization occurs at low gas velocities; and controlled bubbling with small bubbles may be exhibited at higher gas velocities. As used herein, the term "particle density ρp" refers to the envelope density, which includes the pore space within the material particles in a volumetric measurement (as determined using ASTM D4284-12), but does not include the inter-particle volume.

[0029] 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, the particles may exhibit a small average particle size And the particle density (ρp) is 1.4<ρp<4g / cm 3 .

[0030] 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 nitrate or nitrate amine 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, in some embodiments, a method of preparing a catalyst may include impregnating a support with gallium and platinum; drying the support; and calcining the support, wherein the catalyst comprises 0.05 wt% to 10 wt% gallium, 5 ppmw to 1000 ppmw platinum, 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] As about Figure 1 As depicted, a feed stream can enter feed inlet 434, enter reactor 202, and a product stream can exit reactor system 102 via tube 420. According to one or more embodiments, reactor system 102 can be operated by feeding a chemical feed (e.g., in a feed stream) and a fluidized catalyst into an upstream reactor section 250. The chemical feed contacts the catalyst in the upstream reactor section 250, and each chemical feed flows upwardly into and through the downstream reactor section 230 to produce a chemical product.

[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 1250). 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] Still refer to Figure 1 In one or more embodiments, based on the shapes, dimensions, and other process conditions (such as 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.

[0036] According to embodiments, the chemical product and catalyst can be transferred from the downstream reactor section 230 to the separation device 220 in the catalyst separation section 210, where the catalyst is separated from the chemical product that was conveyed from the catalyst separation section 210. According to one or more embodiments, after being separated from the vapor in the separation device 220, the catalyst can generally move through the stripper 224 to the 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.

[0037] 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 invention.

[0038] 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 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 treated chemical streams, including the feed stream and the product stream, may be gaseous, and the catalyst may be a fluidized particulate solid.

[0039] Referring now to the catalyst treatment section 300, as shown Figure 1As 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.

[0040] 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.

[0041] In one or more embodiments, light olefins may be present in a "product stream" sometimes referred to as an "olefin-containing effluent" and include light olefins. Figure 1The reactor system of olefins can be processed subsequently. As used in the present disclosure, the term "light olefins" refers to one or more of ethylene, propylene and butene. The term butene includes any butene isomers, 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 20 weight % of light olefins. For example, based on the gross weight of the olefin-containing effluent, the olefin-containing effluent can comprise at least 25 weight % of light olefins, at least 30 weight % of light olefins, at least 35 weight % of light olefins, at least 40 weight % of light olefins, at least 45 weight % of light olefins, at least 50 weight % of light olefins, at least 55 weight % of light olefins, at least 60 weight % of light olefins or at least 65 weight % of light olefins. The olefin-containing effluent can also include unreacted components of the feed stream and other reaction products that are not considered to be light olefins. The light olefins can be separated from the unreacted components in the subsequent separation step.

[0042] Now refer to it again Figure 2 , step 504 typically includes monitoring the composition of the combustion gas in the burner to detect the concentration of one or more hydrocarbons. Monitoring can be used to detect when the combustion activity in the burner is less than a desired threshold activity. As described herein, "combustion activity" refers to the rate of chemical combustion. Typically, the combustion activity can be monitored by the temperature of the catalyst leaving the burner. In other embodiments, the combustion activity can be monitored by analyzing the composition of the flue gas online.

[0043] Without being bound by theory, it is believed that several circumstances may lead to reduced combustion activity. In one or more embodiments, catalyst activity decreases over time and the combustion catalytic activity decreases more than the dehydrogenation activity. In such embodiments, the addition of a combustion additive may allow normal operation without the need to add fresh catalyst because the dehydrogenation activity is not reduced to an amount that requires fresh catalyst and combustion may be enhanced by the use of a combustion additive.

[0044] In embodiments, the composition of the supplemental fuel can be changed, which may result in a change in the combustion rate of the supplemental fuel. For example, methane can be burned at a lower rate than other fuels such as hydrogen, propane, etc. In such embodiments, an increase in the amount of the combustion additive in the reactor system can increase the combustion rate to an acceptable level. In addition, in some embodiments, the combustion additives described herein can provide enhanced combustion activity for the combustion of methane.

[0045] Still refer to Figure 2, step 506 generally includes selectively adding the combustion additive with the catalyst when the combustion gas contains one or more hydrocarbons in an amount greater than 5% of the lower flammable limit level of the combustion gas at the temperature and pressure of the combustor. In one or more embodiments, the combustion additive with the catalyst can be added to the reactor system 102 when the combustion gas (i.e., the gas produced by the combustion of the combustion fuel in the combustor 350) contains one or more hydrocarbons (e.g., methane, ethane, and / or propane) in an amount greater than 5% of the lower flammable limit (LFL) of the combustion gas at the temperature and pressure of the catalyst processing section 300 (such as the combustor 350). For example, the combustion additive with the catalyst can be added to the reactor system 102 when the combustion gas contains one or more hydrocarbons in an amount greater than 10% of the LFL of the combustion gas at the temperature and pressure of the catalyst processing section 300. As used in the present disclosure, the term "lower flammable limit" refers to the lower limit of the concentration range of a combustible mixture of gas or vapor in air that can ignite at a given temperature and pressure. The LFL of the combustion gases can be determined by reactive chemical testing, or as described in Michael G. Zabetakis, Flammability Characteristics of Combustible Gases and Vapors, 627 BUREAU OF MINES 1 (1965), with the pressure adjusted according to Coward et al., Limits of Flammability of Gases and Vapors, 503 BUREAU OF MINES 1 (1952).

[0046] In one or more embodiments, the combustion additive may include one or more transition metals. As used herein, the phrase "transition metal" refers to a metal selected from IUPAC Group 3-12 elements. In one or more embodiments, the combustion additive may include manganese, iron, cobalt, tin, or a combination of two or more thereof. In one or more embodiments, the combustion additive may be selected from manganese, iron, cobalt, tin, and a combination of two or more thereof.

[0047] In one or more embodiments, based on the total weight of the combustion additive, the combustion additive may include 1 wt % to 10 wt % of one or more transition metals other than gallium and noble metals. For example, based on the total weight of the combustion additive, the combustion additive may include an amount of 1 wt % to 2 wt %, 1 wt % to 3 wt %, 1 wt % to 4 wt %, 1 wt % to 5 wt %, 1 wt % to 6 wt %, 1 wt % to 7 wt %, 1 wt % to 8 wt %, 1 wt % to 9 wt %, 1 wt % to 10 wt %, 2 wt % to 3 wt %, 2 wt % to 4 wt %, 2 wt % to 5 wt %, 2 wt % to 6 wt %, 2 wt % to 7 wt %, 2 wt % to 8 wt %, 2 wt % to 9 wt % or 2 wt % to 10 wt % of one or more transition metals other than gallium and noble metals. Without wishing to be bound by any particular theory, it is believed that the combustion additive with one or more transition metals less than 1 wt % may need to use a higher amount of additives in the system to achieve the desired catalytic activity. However, it is believed that combustion additives having one or more transition metals in an amount exceeding 10 wt % may have reduced combustion performance efficiency.

[0048] In one or more embodiments, the combustion additive can comprise, consist essentially of, or consist of one or more of manganese, iron, cobalt, or tin in an amount of 1% to 10% by weight, based on the total weight of the combustion additive. For example, the combustion additive can comprise, consist essentially of, or consist of one or more of manganese, iron, cobalt, or tin in an amount of 1% to 2%, 1% to 3%, 1% to 4%, 1% to 5%, 1% to 6%, 1% to 7%, 1% to 8%, 1% to 9%, 1% to 10%, 2% to 3%, 2% to 4%, 2% to 5%, 2% to 6%, 2% to 7%, 2% to 8%, 2% to 9%, or 2% to 10% by weight, based on the total weight of the combustion additive. In some embodiments, the combustion additive includes only manganese but not iron, cobalt, or tin, only iron but not manganese, cobalt, or tin, only cobalt but not manganese, iron, or tin, or only tin but not manganese, iron, or cobalt. It should be understood that composition ranges describing amounts of manganese, iron, cobalt, and tin represent ranges for any one of these materials or a combination of these materials.

[0049] In one or more embodiments, based on the gross weight of the combustion additive, the combustion additive optionally can include gallium and precious metals less than 100ppmw. As used herein, "precious metal" refers to ruthenium, rhodium, palladium, osmium, iridium, platinum, silver and gold. In one or more embodiments, the combustion additive does not include gallium and precious metals. In one or more embodiments, based on the gross weight of the combustion additive, the combustion additive may include gallium and precious metals in an amount of 0ppmw to 100ppmw, 0ppmw to 50ppmw, 0ppmw to 25ppmw, 0ppmw to 10ppmw or 0ppmw to 5ppmw. Without being bound by any particular theory, it is believed that excluding or reducing gallium and precious metals in the combustion additive can reduce the economic cost of the dehydrogenation process.

[0050] In one or more embodiments, based on the gross weight of the combustion additive, the combustion additive may include one or more alkali metals, one or more alkaline earth metals or both less than 5 wt %. For example, based on the gross weight of the combustion additive, the combustion additive may include 0 wt % to 5 wt %, 0 wt % to 4 wt %, 0 wt % to 3 wt %, 0 wt % to 2 wt %, 0 wt % to 1 wt %, 1 wt % to 5 wt %, 1 wt % to 4 wt %, 1 wt % to 3 wt %, 1 wt % to 2 wt %, 2 wt % to 5 wt %, 2 wt % to 4 wt %, 2 wt % to 3 wt %, 3 wt % to 5 wt %, 3 wt % to 4 wt % or 4 wt % to 5 wt % of one or more alkali metals, one or more alkaline earth metals or both. It is not desirable to be bound by any particular theory, it is believed that the combustion additive with alkali metal, alkaline earth metal or both can reduce the side reaction of the desired dehydrogenation product. However, it is believed that the combustion additive with an amount exceeding 5 wt % of alkali metal, alkaline earth metal or both may no longer provide this function.

[0051] In one or more embodiments, the combustion additive may include a carrier material. Specifically, the combustion additive may include a transition metal, an alkali metal and / or an alkaline earth metal placed and / or dispersed on the carrier material. In some embodiments, the carrier material includes one or more of aluminum oxide, silicon dioxide, titanium oxide and zirconium. For example, the carrier material may include one or more of aluminum oxide, silicon dioxide-containing aluminum oxide, titanium oxide-containing aluminum oxide and zirconium-containing aluminum oxide. The carrier may be present in an amount of at least 85% by weight relative to the total weight of the combustion additive. In some embodiments, the carrier accounts for less than or equal to 99% by weight of the combustion additive. Typically, the weight % of the carrier can fill the remainder of the entire combustion additive that is not specified by other materials.

[0052] In one or more embodiments, the combustion additive 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 nitrate or nitrate amine metal precursor, then dried at a temperature below 200°C, and then calcined at a temperature below 800°C to produce the combustion additive. For example, in some embodiments, a method of preparing a combustion additive may include: impregnating a support with a transition metal; drying the support; and calcining the support, wherein the combustion additive comprises 1 wt% to 10 wt% of one or more transition metals other than gallium and precious metals; 0 ppmw to 100 ppwm of gallium and precious metals; and at least 85 wt% of the support.

[0053] 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 combustion additives described herein are contemplated.

[0054] In one or more embodiments, the dehydrogenation catalytic activity of the combustion additive may be less than 25% of the dehydrogenation catalytic activity of the catalyst, wherein the dehydrogenation catalytic activity refers to the feed conversion percentage in the propane dehydrogenation test described herein. For example, the dehydrogenation catalytic activity of the combustion additive may be less than 20%, less than 15%, less than 10%, or even less than 5% of the dehydrogenation catalytic activity of the catalyst. In embodiments, the dehydrogenation catalytic activity is propane dehydrogenation catalytic activity.

[0055] In one or more embodiments, the near equilibrium (ATE) conversion of the combustion additive can be less than 15% of the ATE conversion of the catalyst, wherein the ATE conversion refers to the near equilibrium conversion calculation in the test methods described herein. For example, the near equilibrium (ATE) conversion of the combustion additive can be less than 12%, less than 10%, less than 8%, less than 7%, less than 6%, or even less than 5% of the ATE conversion of the catalyst, as measured in the near equilibrium conversion calculation in the test methods described herein.

[0056] In an embodiment, adding a combustion additive together with a catalyst may result in dilution of the catalyst, thereby reducing the dehydrogenation catalytic activity of the system. However, the wear characteristics of the combustion additive and the catalyst may be controlled to reduce or eliminate this dilution effect. During the operation of the catalytic dehydrogenation process, both the catalyst and the combustion additive may experience wear. As used herein, the term "wear" may refer to the undesirable mechanical breakage and degradation of solid materials into catalyst fines and smaller particles via attrition and fracturing mechanisms (such as catalysts and combustion additives). The wear of the catalyst may result in the loss of the catalyst from the unit because the fine powder with a particle size below a certain threshold (such as less than 20 microns) may not be retained by the reactor system 102. The wear of the combustion additive may result in a reduction in combustion activity. The wear of the combustion additive may also reduce the dilution effect on the dehydrogenation activity. When the solid experiences wear, the worn material may be discharged from the reactor system. The wear characteristics of the catalyst and the combustion additive may affect the life of the catalyst and the combustion additive in a fluidized bed process (such as a fluidized dehydrogenation reactor described herein). For example, if the combustion additive has a higher wear rate than the catalyst in a commercial operation, the combustion additive may stay in the unit for a shorter period of time than the catalyst in the fluidized bed process. Wear evaluation can be performed by various laboratory scale or pilot scale wear tests, such as ASTM D5757, immersion jet test, and jet cup wear test.

[0057] The jet cup wear index is one of the standard laboratory test methods for characterizing the wear characteristics of catalysts for fluidized bed applications, as described in Cocco et al., Jet Cup Attrition Testing, 200 Powder Technology 224 (2010). Although laboratory tests cannot provide actual wear rates for commercial-scale units, laboratory tests provide wear trend ratings. In one or more embodiments, the jet cup wear index of the combustion additive is greater than the jet cup wear index of the catalyst, wherein the jet cup wear is measured at a 45 μm threshold after 6 hours at ambient temperature, a jet velocity of 300 feet per second, a flow rate of 98 liters per minute, and a sample load of 100 grams. In an embodiment, the jet cup wear index of the combustion additive is at least 4 times the jet cup wear index of the catalyst, wherein the jet cup wear is measured at a 45 μm threshold after 6 hours at ambient temperature, a jet velocity of 300 feet per second, a flow rate of 98 liters per minute, and a sample load of 100 grams. For example, the combustion additive may have a jet cup wear index that is at least 5 times, at least 6 times, or even at least 7 times greater than the catalyst's jet cup wear index, where the jet cup wear is measured at a 45 μm threshold after 6 hours at ambient temperature, a 300 ft / sec injection velocity, a 98 liter / min flow rate, and a 100 gram sample load. In an embodiment, the combustion additive has a jet cup wear index that is greater than the catalyst's jet cup wear index, where the jet cup wear is measured at a 20 μm threshold after 6 hours at ambient temperature, a 300 ft / sec injection velocity, a 98 liter / min flow rate, and a 100 gram sample load. In an embodiment, the combustion additive has a jet cup wear index that is at least 4 times greater than the catalyst's jet cup wear index, where the jet cup wear is measured at a 20 μm threshold after 6 hours at ambient temperature, a 300 ft / sec injection velocity, a 98 liter / min flow rate, and a 100 gram sample load. For example, the injection cup wear index of the combustion additive can be at least 5 times, at least 6 times, or even at least 7 times the injection cup wear index of the catalyst, wherein the injection cup wear is measured at a 20 μm threshold after 6 hours at ambient temperature, an injection velocity of 300 feet per second, a flow rate of 98 liters per minute, and a sample load of 100 grams. Without wishing to be bound by any particular theory, it is believed that the injection cup wear index of the combustion additive is less than 4 times the injection cup wear index of the catalyst can lead to dilution and / or deactivation of the catalyst. Conversely, it is believed that the injection cup wear index of the combustion additive is greater than at least 4 times the injection cup wear index of the catalyst can allow for improved selective removal of the combustion additive from the system. Therefore, it is believed that this difference in wear characteristics between the combustion additive and the catalyst can reduce the dilution effect of the catalyst because additional amounts of the combustion additive are added during operation of the reactor system.As used herein, the Wear Index is measured using the PSRI's standard jet cup method using a 3" conical jet cup with an orifice having an inner diameter of 0.1875 inches.

[0058] In one or more embodiments, the amount of combustion additive introduced into the reactor system 102 at each addition is between 0.01 volume percent (vol.%) and 2 vol.%, based on the total volume of the catalyst and the volume of the combustion additive. For example, the amount of combustion additive introduced into the reactor system 102 can be between 0.01 vol.% and 1.5 vol.%, between 0.01 vol.% and 1 vol.%, between 0.01 vol.% and 0.5 vol.%, between 0.05 vol.% and 1.5 vol.%, between 0.05 vol.% and 1 vol.%, between 0.05 vol.% and 0.5 vol.%, between 0.5 vol.% and 2 vol.%, between 0.5 vol.% and 1.5 vol.%, between 0.5 vol.% and 1 vol.%, between 1 vol.% and 2 vol.%, between 1 vol.% and 1.5 vol.%, or between 1.5 vol.% and 2 vol.%, based on the total volume of the catalyst and the volume of the combustion additive. In an embodiment, the amount of combustion additive to be introduced into the reactor system 102 can be varied based on monitoring the composition of the combustion gases in the combustor. Without wishing to be bound by any particular theory, it is believed that adding the combustion additive with the catalyst in an amount greater than 2 vol.% can dilute the catalyst in the reactor system, resulting in reduced catalytic dehydrogenation activity. Conversely, it is believed that not adding the combustion additive with the catalyst when the system lacks combustion activity can result in a reduction in fuel gas conversion.

[0059] It should be understood that once introduced into the reactor system 102, the combustion additive will mix with the catalyst and, therefore, circulate through the reactor system 102 as previously discussed with respect to the catalyst. In other words, the introduction of the combustion additive into the reactor system 102 may produce a catalyst system that is a mixture of the catalyst and the combustion additive. Due to natural variations in the properties of the catalyst and the combustion additive during operation of the reactor system 102, the properties and amounts of the combustion additive and / or catalyst may refer to the properties and amounts of the combustion additive and / or catalyst at the time the combustion additive is introduced into the reactor system 102.

[0060] Test Method

[0061] Various test methods disclosed herein will be further discussed and referenced in the subsequent examples.

[0062] Propane Dehydrogenation Test

[0063] Propane dehydrogenation tests were conducted on samples containing catalyst and combustion additives without additional modification in a fixed bed system at ambient pressure under laboratory simulated reaction and regeneration cycles. The cycle included reaction steps carried out under the following conditions: reactor temperature of 625°C, reaction time of 60 seconds, 10 hours -1 The reaction was carried out at a propane weight hourly space velocity (WHSV) of 1.5 % propane and a gas feed composition of 90 volume % (vol.%) propane and 10 vol.% N2, where WHSV is defined as the feed weight per unit weight of sample per hour. After completion of the reaction step, the sample was subjected to a regeneration step, in which the sample was heated in air at 730°C for 5 minutes. The reaction and regeneration cycles were repeated in turn for a total of 10 cycles. For each reaction step, the reaction effluent at a run time of 15 seconds was analyzed using gas chromatography (GC). Feed conversion and product selectivity were determined by equations (1) and (2):

[0064]

[0065] in:

[0066] k refers to product k, and the products analyzed include methane, ethane, ethylene, propylene, species including four carbon atoms (C4), species including five carbon atoms (C5), and species including six or more carbon atoms (C6+);

[0067] n k refers to the number of carbons in the chemical formula of product k; n C3＝ refers to the number of carbons in a particular product (propylene); while n C3 refers to the number of carbons in the chemical formula of the reactant (propane); n C3＝ and n C3 are all equal to 3; and

[0068] C k refers to the mole fraction of the general product k in the reaction effluent, and C C3＝ refers to the mole fraction of a specific product (propylene) in the reaction effluent; while C C3 Refers to the mole fraction of unreacted reactant (propane) in the reaction effluent. The generation of coke during conversion is not included in the feed conversion calculation due to its minimal contribution to the calculation (<0.5%).

[0069] Calculation of near equilibrium conversion

[0070] The near equilibrium conversion (ATE %) can be calculated using Equation 3. The near equilibrium conversion is the ratio of the feed conversion divided by the equilibrium conversion as measured in Equation 1:

[0071]

[0072] The equilibrium conversion is calculated as disclosed in D. Stull / The chemical thermodynamics of organic compounds (1969), John Wiley, ISBN-10:9780471834908.

[0073] Fuel gas combustion assessment

[0074] In a fixed bed laboratory reactor at ambient pressure, the -1 Fuel gas combustion tests were performed on samples containing catalysts and combustion additives without additional modifications at a WHSV CH4, where WHSV CH4 is defined as the weight of methane in the feed per unit weight of sample per hour. The sample (0.1 g catalyst or combustion additive mixed with 0.1 g SiC diluent) was heated to 730°C under a N2 flow. Subsequently, the N2 was replaced with an air and helium flow, with helium accounting for 1.2 vol.% of the feed. After 20 minutes, methane was introduced until the feed gas contained 2 vol.% methane and 1.2 vol.% helium, with the balance being synthetic air. These test conditions are more severe than commercial operations to allow for greater differences in combustion performance. GC samples were continuously taken from the outlet and feed gases and analyzed to determine the methane conversion. The methane conversion % was calculated at a run time of 3 hours using Equation 4:

[0075]

[0076] Where C refers to the concentration of the compound (CO, CO2 or CH4) in the effluent stream.

[0077] Jet Cup Wear Test

[0078] The wear evaluation of the catalyst support and the combustion additive support was performed using a 3-inch jet cup wear unit designed and manufactured by Particulate Solid Research, Inc, PSRI. The wear index obtained by the jet cup wear test is used to define the wear of the support material. Due to the low metal loading of the catalyst and the combustion additive, there is no difference (within the test error) in the wear index between the support material and the catalyst and the combustion additive prepared therefrom. Therefore, the wear of the catalyst support material represents the wear of the catalyst and the combustion additive comprising the support material described herein. The jet cup used in the test is a 3-inch conical jet cup with an orifice having an inner diameter of 0.1875 inches. The test was carried out at ambient temperature, a jet velocity of 300 feet per second, a flow rate of 98 liters per minute, a sample load of 100 grams, and a wear duration of 6 hours. The particle size distribution of the material before and after the wear test was characterized using laser diffraction technology (Beckman Coulter LS13 320). The absolute percentage increase in particles (“fines”) <20 μm and <45 μm is reported as the Abrasion Index (AI) (20 μm) and AI (45 μm) as shown in Equation 5 and Equation 6, respectively:

[0079] AI(20μm) = (% of fine powder < 20μm after test) - (% of fine powder < 20μm before test) (5);

[0080] AI(45μm) = (% of fine powder < 45μm after test) - (% of fine powder < 45μm before test) (6)

[0081] Example

[0082] 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.

[0083] The specified amount of metal was loaded into the nanostructured particles with an average particle size of 5 μm to 300 μm, a pore volume of 0.35 mL / g ± 0.20 mL / g, and a surface area of ​​100 m by conventional incipient wetness impregnation. 2 / g±50m 2The catalysts and combustion additives in the examples were prepared on microspherical supports containing aluminum oxide with a silica content of 2.5 wt% ± 2.5 wt% and different wear characteristics. The support material with low wear is called the base support, while the two materials support A and support B have higher wear (see Example 4). The metal precursors used are nitrates or nitrate amines. The obtained materials are dried at a temperature below 200°C and then calcined at a temperature below 800°C. The base support is used to prepare the catalyst, while support A and support B are used to prepare the combustion additive.

[0084] Example 1. Combustion additives containing manganese.

[0085] The combustion additive of Example 1 contained manganese and did not contain platinum or gallium. The specific support material and composition of each sample are listed in Table 1. Propane conversion %, near equilibrium (ATE) conversion %, propylene selectivity %, and methane conversion % were measured according to the test methods described herein and are reported in Table 1.

[0086] Table 1

[0087]

[0088] As shown in Table 1, the combustion additive of Example 1 exhibited improved combustion activity as indicated by a higher % methane conversion compared to the catalyst of Comparative Example A. Further, increasing the wt % of manganese in the combustion additive from 1 wt % (Ex. 1-1) to 2.5 wt % (Ex. 1-3) resulted in further improvement in the combustion activity of the combustion additive.

[0089] However, these combustion additives provide little dehydrogenation activity, and therefore if such combustion additives accumulate in the catalyst system, a dilution effect may occur. The support materials selected for these additives (support A and support B) have higher attrition than the catalysts of Example A (base support) and Example B (base support), and therefore the combustion additives can be selectively removed in fluid bed catalyst operation to reduce or eliminate the dilution effect.

[0090] Example 2. Combustion Additives Containing Iron

[0091] The combustion additive of Example 2 contained iron and did not contain platinum or gallium. The specific support material and composition of each sample are listed in Table 2. Propane conversion %, near equilibrium (ATE) conversion %, propylene selectivity %, and methane conversion % were measured according to the test methods described herein and are reported in Table 2.

[0092] Table 2

[0093]

[0094] As shown in Table 2, the combustion additive of Example 2 exhibited improved combustion activity as indicated by a higher % methane conversion compared to the catalyst of Comparative Example A. Further, increasing the wt % of iron in the combustion additive from 1 wt % (Ex. 2-1) to 2.5 wt % (Ex. 2-3) resulted in further improvement in the combustion activity of the combustion additive.

[0095] Similar to the combustion additive of Example 1, the combustion additive of Example 2 provided reduced dehydrogenation activity. Therefore, highly abrasive support materials (Support A and Support B) were selected for these additives so that they could be selectively removed in fluid bed catalyst operation to reduce the effect of dilution on dehydrogenation performance.

[0096] Example 3. Combustion Additives Containing Cobalt or Tin

[0097] The combustion additive of Example 3 contained cobalt or tin and did not contain platinum or gallium. The specific support material and composition of each sample are listed in Table 3. Propane conversion %, near equilibrium (ATE) conversion %, propylene selectivity %, and methane conversion % were measured according to the test methods described herein and are reported in Table 3.

[0098] Table 3

[0099]

[0100] As shown in Table 3, the combustion additive of Example 3 exhibits improved combustion activity, as indicated by a higher % methane conversion compared to the catalyst of Comparative Example A. Similar to the combustion additives of Examples 1 and 2, the combustion additive of Example 3 provides reduced dehydrogenation activity. Therefore, highly abrasive support materials (Support A and Support B) were selected for these additives so that they can be selectively removed in fluid bed catalyst operation to reduce the effect of dilution on dehydrogenation performance.

[0101] Comparative Example A. Catalyst containing platinum and gallium

[0102] The catalyst of Comparative Example A comprises platinum and gallium and does not comprise manganese. The specific support material and composition of each sample are listed in Table 4. Propane conversion %, near equilibrium (ATE) conversion %, propylene selectivity %, and methane conversion % are measured according to the test methods described herein and are reported in Table 4. In embodiments, these catalysts can be used to provide good dehydrogenation performance.

[0103] Table 4

[0104]

[0105] As shown in Table 4, the catalysts containing platinum and gallium (Ex. A-1 and Ex. A-2) exhibited lower combustion activity as shown by the lower % methane conversion compared to the combustion additives of Examples 1-3.

[0106] Comparative Example B. Combustion Additive Containing Manganese

[0107] The catalyst of Comparative Example B contained manganese and did not contain platinum or gallium. The specific support material and composition of each sample are listed in Table 5. Propane conversion %, near equilibrium (ATE) conversion %, propylene selectivity %, and methane conversion % were measured according to the test methods described herein and are reported in Table 5.

[0108] Table 5

[0109]

[0110]

[0111] As shown in Table 5, in the absence of platinum and gallium, the catalyst containing 0.15 wt.% manganese (Ex. B-1) exhibited lower combustion activity, as shown by the lower methane conversion % compared to the combustion additive of Example 1. When the manganese concentration was increased to 1 wt.%, a significant enhancement in combustion performance was observed (Ex. B-2). In the absence of platinum and gallium, the dehydrogenation performance of the catalyst of Comparative Example B was low. However, in contrast to the combustion additives of Examples 1-3, the support material (base support) selected for these catalysts will have a catalyst wear rate similar to that of Example A. Due to the low dehydrogenation performance of Comparative Example B, despite its enhanced combustion activity compared to Comparative Example A, a dilution effect may occur if such catalyst accumulates in the catalyst system.

[0112] Example 4. Wear test

[0113] The wear of the carrier materials was measured using a jet cup wear test, as described herein. The results for the AI ​​(20 μm) and AI (45 μm) for these carrier materials are shown in Table 6. The AI ​​represents the absolute difference in the percentage of fines having a particle size less than a certain threshold before and after the jet cup wear test, as described herein. For example, an AI (20 μm) of 3.7 indicates that the absolute percentage of fines having a particle size <20 μm increased by 3.7% after the wear test, while an AI (45 μm) of 5.1 indicates that after a 6-hour wear duration of the base carrier, the original percentage of fines having a particle size <45 μm increased by 5.1%. For Carrier A, the absolute percentage of fines having a particle size <20 μm increased by 23.9% after the wear test, while the absolute percentage of fines having a particle size <45 μm increased by 39.9% under the same conditions as the base carrier wear test.

[0114] Table 6

[0115] AI(20μm) AI(45μm) Basic carrier 3.7 5.1 Vector A 23.9 39.9 Vector B 18.1 28.3

[0116] As shown in Table 6, the AI ​​results indicate that the wear rate of Support A or the combustion additive is greater than 700% of the wear rate of the base support or catalyst under the standard PSRI test described herein. In other words, the unit time until mechanical wear of the combustion additive comprising Support A or Support B is expected to be less than the unit time of the catalyst comprising the base support in the reactor system.

[0117] A first aspect of the present disclosure relates to a method for preparing light olefins by dehydrogenation, the method comprising: operating a catalytic dehydrogenation process; monitoring the composition of the combustion gas in a burner to detect the concentration of one or more hydrocarbons; and selectively adding a combustion additive to the catalyst when the combustion gas contains one or more hydrocarbons in an amount greater than 5% of the lower flammable limit level of the combustion gas at the temperature and pressure of the burner. The operation comprises: contacting a hydrocarbon-containing feed with a catalyst in a reactor to form an olefin-containing effluent; separating the olefin-containing effluent at least partially from the catalyst; transferring the catalyst to the burner and heating the catalyst by burning a supplemental fuel, wherein the supplemental fuel contains an amount of methane greater than or equal to 1 mol%; and transferring the catalyst 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 injection cup wear index of the combustion additive is greater than the injection cup wear index of the catalyst, wherein the injection cup wear is measured at a threshold of 45 μm after 6 hours at ambient temperature, an injection velocity of 300 feet per second, a flow rate of 98 liters per minute, and a sample load of 100 grams. The combustion additive comprises 1 wt % to 10 wt % of one or more transition metals other than gallium and precious metals; 0 parts per million by weight (ppmw) to 100 ppmw of gallium and precious metals; and at least 85 wt % of a carrier.

[0118] A second aspect of the present disclosure may include the first aspect, wherein the one or more transition metals are selected from manganese, iron, cobalt, tin, or combinations thereof.

[0119] A third aspect of the present disclosure may include any of the second or third aspects, wherein the combustion additive comprises 1 wt % to 10 wt % manganese.

[0120] A fourth aspect of the present disclosure may include any one of the first to third aspects, wherein the combustion additive comprises 1 wt % to 10 wt % iron.

[0121] A fifth aspect of the present disclosure may include any one of the first to fourth aspects, wherein the combustion additive comprises 1 wt % to 10 wt % cobalt.

[0122] A sixth aspect of the present disclosure may include any one of the first to fifth aspects, wherein the combustion additive comprises 1 wt % to 10 wt % tin.

[0123] A seventh aspect of the present disclosure may include any one of the first to sixth aspects, wherein the combustion additive further comprises 0.01 wt % to 5 wt % of one or more alkali metals or alkaline earth metals.

[0124] An eighth aspect of the present disclosure may include any one of the first to seventh aspects, wherein the injection cup wear index of the combustion additive is at least 4 times the injection cup wear index of the catalyst.

[0125] A ninth aspect of the present disclosure may include any one of the first to eighth aspects, wherein the dehydrogenation catalytic activity of the combustion additive is less than 25% of the dehydrogenation catalytic activity of the catalyst.

[0126] A tenth aspect of the present disclosure may include any one of the first to ninth aspects, wherein the hydrocarbon-containing feed comprises one or more of ethane, propane, n-butane, or isobutane, and the olefin-containing effluent comprises one or more of ethylene, propylene, and butene.

[0127] An eleventh aspect of the present disclosure may include any one of the first to tenth aspects, wherein the olefin-containing effluent comprises at least 20 wt% light olefins.

[0128] A twelfth aspect of the present disclosure may include any one of the first to eleventh aspects, wherein the hydrocarbon-containing feed comprises propane and the olefin-containing effluent comprises propylene.

[0129] A thirteenth aspect of the present disclosure may include any one of the first to twelfth aspects, wherein the supplemental fuel further comprises natural gas, ethane, propane, hydrogen, or a combination of two or more thereof.

[0130] The fourteenth aspect of the present disclosure may include any one of the first to thirteenth aspects, wherein the catalyst comprises 0.05 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, and at least 85 wt% of a carrier.

[0131] A fifteenth aspect of the present disclosure may include any one of the first to fourteenth aspects, wherein the catalyst comprises 0.05 wt% to 10 wt% gallium, 5 ppmw to 1000 ppmw platinum, and at least 85 wt% of the support.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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."

[0138] 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: Operating a catalytic dehydrogenation process, the operation 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, 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; monitoring the composition of the combustion gases in the burner to detect the concentration of one or more hydrocarbons; and When the combustion gas contains one or more hydrocarbons in an amount greater than 5% of the lower flammable limit level of the combustion gas at the temperature and pressure of the combustor, a combustion additive is selectively added with the catalyst, wherein the combustion additive has a jet cup wear index greater than the jet cup wear index of the catalyst, wherein the jet cup wear is measured at a 45 μm threshold after 6 hours at ambient temperature, a jet velocity of 300 feet per second, a flow rate of 98 liters per minute, and a sample load of 100 grams, and wherein the combustion additive comprises: 1 to 10 wt. % of one or more transition metals other than gallium and noble metals; 0 parts per million by weight (ppmw) to 100 ppmw of gallium and precious metals; and At least 85% by weight of carrier.

2. The method of claim 1, wherein the one or more transition metals are selected from manganese, iron, cobalt, tin, or combinations thereof.

3. A method according to any one of the preceding claims, wherein the combustion additive comprises 1 to 10 wt% manganese.

4. A method according to any one of the preceding claims, wherein the combustion additive comprises from 1 to 10 wt% iron.

5. A method according to any one of the preceding claims, wherein the combustion additive comprises 1 to 10 wt% cobalt.

6. A method according to any one of the preceding claims, wherein the combustion additive comprises 1 to 10 wt% tin.

7. The method according to any one of the preceding claims, wherein the combustion additive further comprises 0.01 wt% to 5 wt% of one or more alkali metals or alkaline earth metals.

8. The method of any one of the preceding claims, wherein the injection cup wear index of the combustion additive is at least 4 times the injection cup wear index of the catalyst.

9. The method according to any one of the preceding claims, wherein the combustion additive has a dehydrogenation catalytic activity of less than 25% of the dehydrogenation catalytic activity of the catalyst.

10. A process according to any one of the preceding claims, wherein the hydrocarbon-containing feed comprises one or more of ethane, propane, n-butane or isobutane, and the olefin-containing effluent comprises one or more of ethylene, propylene and butenes.

11. The process according to any one of the preceding claims, wherein the olefin-containing effluent comprises at least 20 wt% light olefins.

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

13. The method of any one of the preceding claims, wherein the supplemental fuel further comprises natural gas, ethane, propane, hydrogen, or a combination of two or more thereof.

14. The process according to any one of the preceding claims, wherein the catalyst comprises: 0.05 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 combinations thereof; and At least 85% by weight of carrier.

15. The process according to any one of the preceding claims, wherein the catalyst comprises: 0.05 to 10 wt % gallium; 5 ppmw to 1000 ppmw platinum; and At least 85% by weight of carrier.

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