Process for producing olefins

Abstract

According to one or more embodiments of the present disclosure, a method for producing olefins includes contacting a hydrocarbon-containing feed with a catalyst in a reactor section of a reactor system to form an olefin-containing effluent, separating at least a portion of the olefin-containing effluent from the catalyst, passing the catalyst to a catalyst processing section of the reactor system and processing the catalyst to produce a processed catalyst and a combustion gas, passing the processed catalyst from the catalyst processing section to the reactor section, and introducing a combustion additive to the reactor system when the combustion gas comprises one or more hydrocarbons in an amount greater than 5% of the LFL of the combustion gas at the temperature and pressure of the catalyst processing section. The catalyst can comprise 1 ppmw to 150 ppmw of platinum. The combustion additive can comprise 150 ppmw to 1,000 ppmw of platinum.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 127,465, filed December 18, 2020, the entire contents of which are incorporated herein by reference. Background Technology Technical Field

[0004] This disclosure generally relates to chemical processing, and more specifically, to catalyst systems and methods for producing olefins using them. Background Technology

[0006] Light olefins, such as ethylene, can be used as base materials to produce many different materials, such as polyethylene, vinyl chloride, and ethylene oxide, which can be used in product packaging, construction, and textiles. As a result of this utility, the global demand for light olefins is increasing. Suitable processes for producing light olefins generally depend on the given chemical feedstock and include, for example, fluidized catalytic dehydrogenation (FCDh) processes. Summary of the Invention

[0007] Generally, in the FCDh process, a hydrocarbon feedstock and a fluidized catalyst are introduced into the reactor section of the FCDh system. The hydrocarbon feedstock contacts the catalyst, and the resulting mixture flows through the reactor section to produce an olefin-containing effluent through dehydrogenation. The catalyst can be separated from the olefin-containing effluent and transferred to the catalyst processing section of the FCDh system. Typically, the heat required for dehydrogenation in the FCDh process is primarily provided by the combustion of fuel, such as coke deposited on the catalyst and / or supplemental fuel, in the catalyst processing section. Specifically, the catalyst, heated by the combustion of fuel in the catalyst processing section, transfers heat to the reactor section. For the fuel to burn at a reasonable temperature, the catalyst is crucial for providing combustion activity. However, as the catalyst circulates through the FCDh system, its combustion activity typically decreases at a rate greater than its dehydrogenation activity. Consequently, fresh catalyst must be added to the FCDh system at a rate greater than necessary to maintain sufficient dehydrogenation activity in the reactor section in order to maintain sufficient combustion activity in the catalyst processing section, which significantly increases the economic cost of the FCDh process. However, the catalyst system and method for producing olefins disclosed herein can effectively maintain sufficient combustion activity in the catalyst processing section of the FCDh system without significantly increasing economic costs. This is achieved, at least in part, by utilizing both the catalyst and the combustion additive.

[0008] According to one or more embodiments of this disclosure, a method for producing olefins includes: contacting a hydrocarbon-containing feedstock with a catalyst in a reactor section of a reactor system to form an olefin-containing effluent; separating at least a portion of the olefin-containing effluent from the catalyst; transferring the catalyst to a catalyst processing section of the reactor system and processing the catalyst to produce a processed catalyst and a combustion gas; transferring the processed catalyst from the catalyst processing section to the reactor section; and introducing a combustion additive into the reactor system when the combustion gas contains one or more hydrocarbons in an amount greater than 5 percent (%) of the lower flammability limit (LFL) of the combustion gas at the temperature and pressure of the catalyst processing section. The catalyst may contain platinum from 1 parts per million (ppmw) to 150 ppmw. The combustion additive may contain platinum from 150 ppmw to 1,000 ppmw.

[0009] It should be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and characteristics of the claimed subject matter. Additional features and advantages of the embodiments will be set forth in the detailed description and, in part, will be readily apparent to those skilled in the art from the description, including the drawings and claims, or may be recognized by practice of the described embodiments. The drawings are included to provide a further understanding of the embodiments and, together with the detailed description, 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. Attached Figure Description

[0010] The following specific implementation methods can be better understood when read in conjunction with the following diagrams, wherein:

[0011] Figure 1 A reactor system according to one or more embodiments of the present disclosure is schematically depicted.

[0012] When description Figure 1 The simplified schematic illustrations do not include numerous valves, temperature sensors, electronic controllers, etc., which are available and well known to those skilled in the art. Furthermore, they do not include accompanying components typically included in such reactor systems, such as air supplies, heat exchangers, buffer tanks, etc. However, it should be understood that these components are within the scope of this disclosure.

[0013] The various implementation schemes will now be discussed in more detail, some of which are illustrated in the accompanying drawings. Detailed Implementation

[0014] This disclosure relates to catalyst systems and methods for producing olefins using them. More specifically, this disclosure relates to catalyst systems that can be used for dehydrogenation and methods for producing olefins using them via an FCDh process. As previously discussed, the heat required for dehydrogenation in an FCDh process is primarily provided by the combustion of fuel, such as coke deposited on the catalyst and / or supplemental fuel, in the catalyst processing section of the FCDh system. For the fuel to burn at a reasonable temperature, combustion activity depends on the catalyst. However, as the catalyst circulates through the FCDh system, its combustion activity typically decreases at a rate greater than its dehydrogenation activity. Consequently, fresh catalyst must be added to the FCDh system at a rate greater than necessary to maintain sufficient dehydrogenation activity in the reactor section in order to maintain sufficient combustion activity in the catalyst processing section, which significantly increases the economic cost of the FCDh process. However, the catalyst systems and methods for producing olefins disclosed herein can effectively maintain sufficient combustion activity in the catalyst processing section of the FCDh system without significantly increasing economic costs. This is achieved, at least in part, by utilizing both the catalyst and the combustion additive.

[0015] As used in this disclosure, the term "fluidized reactor system" refers to a reactor system in which one or more reactants are contacted with a catalyst in a fluidized manner (e.g., bubbling, slug flow, turbulent flow, rapid fluidization, pneumatic conveying, or a combination thereof) in different parts of the system. For example, in a fluidized reactor system, a chemical feed containing one or more reactants may be contacted with a circulating catalyst at operating temperatures to carry out a continuous reaction and produce an effluent.

[0016] As used in this disclosure, the term "deactivated catalyst" refers to a catalyst whose catalytic activity is reduced due to the accumulation of coke and / or the loss of active sites on the catalyst. The terms "catalytic activity" and "catalyst activity" refer to the degree to which a catalyst is capable of catalyzing a reaction carried out in a reactor system.

[0017] As used in this disclosure, the terms "catalyst reactivation" and "reactivated catalyst" refer to processing a deactivated catalyst to restore at least a portion of its activity to produce a reactivated catalyst. A deactivated catalyst can be reactivated by, but not limited to, restoring catalyst acidity, oxidizing the catalyst, other reactivation processes, or combinations thereof.

[0018] The catalyst system and method for producing olefins disclosed herein will now be described in the context of an example FCDh system. It should be understood that... Figure 1The schematic diagrams are merely illustrative of systems and other FCDh systems are also considered, and the described concepts can be utilized in these alternative systems. For example, the described concepts can be equivalently applied to other systems with alternative reactor and regeneration units, such as those operating under non-fluidized conditions, or those using a downer instead of a riser. Furthermore, the catalyst systems and methods for olefin production described in this invention should not be limited to embodiments of reactor systems designed for the production of light olefins via an FCDh process, such as those relating to… Figure 1 The reactor system described is based on the consideration of other dehydrogenation systems (e.g., those using different chemical feeds).

[0019] For reference Figure 1 An example reactor system 102 is schematically depicted. Reactor system 102 generally includes a reactor section 200 and a catalyst processing section 300. (As shown in...) Figure 1 In the context of this document, reactor section 200 refers to the portion of reactor system 102 where the main process reaction takes place. For example, reactor system 102 may be an FCDh system in which hydrocarbon feedstock is dehydrogenated in the presence of a dehydrogenation catalyst in reactor section 200 of reactor system 102. Reactor section 200 generally includes reactor 202, which may include an upstream reactor section 250, a downstream reactor section 230, and a catalyst separation section 210 for separating the catalyst from the effluent produced in reactor 202.

[0020] Similarly, as in Figure 1As used in the context of this document, catalyst processing section 300 refers to the portion of reactor system 102 that processes the catalyst in a manner such as removing coke deposits, heating, reactivating, or a combination thereof. Catalyst processing section 300 generally includes a combustion chamber 350, a riser 330, a catalyst separation section 310, and an oxygen treatment section 370. Combustion chamber 350 may be in fluid communication with riser 330. Combustion chamber 350 may also be in fluid communication with catalyst separation section 210 via riser 426, which supplies deactivated catalyst from reactor section 200 to catalyst processing section 300 for catalyst processing (e.g., coke removal, heating, reactivation, etc.). Oxygen treatment section 370 may be in fluid communication with upstream reactor section 250 (e.g., via riser 424 and transport riser 430), which supplies processed catalyst from catalyst processing section 300 back to reactor section 200. Combustion chamber 350 may include one or more lower combustion chamber inlet ports 352, through which air inlet 428 is connected to combustion chamber 350. Air inlet 428 may supply air and / or other reactive gases, such as oxygen-containing gases, to combustion chamber 350. Combustion chamber 350 may also include fuel inlet 354, which may supply fuel, such as hydrocarbon streams, to combustion chamber 350. Oxygen treatment zone 370 may include oxygen-containing gas inlet 372, which may supply oxygen-containing gas to oxygen treatment zone 370 for oxygen treatment of the catalyst.

[0021] Still referencing Figure 1 The general operation of reactor system 102 under normal operating conditions will be described. During operation of reactor section 200 of reactor system 102, a hydrocarbon feedstock may enter reactor section 200 through feed inlet 434 and contact a fluidized catalyst introduced into reactor section 200 through transport riser 430, and an olefin-containing effluent may exit reactor section 200 through pipe 420. In one or more embodiments, the hydrocarbon feedstock and fluidized catalyst are introduced into upstream reactor section 250, the hydrocarbon feedstock contacts the catalyst in upstream reactor section 250, and the resulting mixture flows upward into and through downstream reactor section 230 to produce an olefin-containing effluent.

[0022] In one or more embodiments, the hydrocarbon feed comprises ethane, propane, n-butane, isobutane, ethylbenzene, or combinations thereof. In some embodiments, the hydrocarbon feed comprises 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 at least 99 wt% of ethane. In some embodiments, the hydrocarbon feed comprises 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 at least 99 wt% of propane. In some embodiments, the hydrocarbon feed comprises 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 at least 99 wt% of n-butane. In some embodiments, the hydrocarbon feed comprises 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 at least 99 wt% of isobutane. In some embodiments, the hydrocarbon feed comprises 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 at least 99 wt% of ethylbenzene. In some embodiments, the hydrocarbon feed comprises 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 at least 99 wt% of the sum of ethane, propane, n-butane, isobutane, and ethylbenzene.

[0023] In one or more embodiments, the olefin-containing effluent comprises light olefins. As used in this disclosure, the term "light olefin" refers to one or more of ethylene, propylene, and butene. The term "butene" includes any butene isomer, such as α-butene, cis-β-butene, trans-β-butene, and isobutene. In some embodiments, the olefin-containing effluent comprises at least 25% by weight of light olefins based on the total weight of the olefin-containing effluent. For example, the olefin-containing effluent may comprise at least 35% by weight, at least 45% by weight of light olefins, at least 55% by weight of light olefins, at least 65% by weight of light olefins, or at least 75% by weight of light olefins based on the total weight of the olefin-containing effluent.

[0024] In one or more embodiments, the catalyst comprises catalytically active particles. In some embodiments, the catalyst comprises one or more of gallium, platinum, alkali metals, alkaline earth metals, and a support material.

[0025] In one or more embodiments, the catalyst comprises 1 ppmw to 150 ppmw of platinum based on the total weight of the catalyst. For example, the catalyst may comprise 1 ppmw to 100 ppmw, 1 ppmw to 50 ppmw, 1 ppmw to 25 ppmw, 1 ppmw to 15 ppmw, 1 ppmw to 5 ppmw, 5 ppmw to 150 ppmw, 5 ppmw to 100 ppmw, 5 ppmw to 50 ppmw, 5 ppmw to 25 ppmw, 5 ppmw to 15 ppmw, 15 ppmw to 150 ppmw, 15 ppmw to 100 ppmw, 15 ppmw to 50 ppmw, 15 ppmw to 25 ppmw, 25 ppmw to 150 ppmw, 25 ppmw to 100 ppmw, 25 ppmw to 50 ppmw, 50 ppmw to 150 ppmw, 50 ppmw to 100 ppmw, or 100 ppmw to 150 ppmw of platinum based on the total weight of the catalyst.

[0026] In one or more embodiments, the catalyst comprises 0.1 wt% to 10.0 wt% gallium based on the total weight of the catalyst. For example, the catalyst may comprise 0.1 wt% to 7.5 wt%, 0.1 wt% to 5.0 wt%, 0.1 wt% to 2.5 wt%, 0.1 wt% to 0.5 wt%, 0.5 wt% to 10.0 wt%, 0.5 wt% to 7.5 wt%, 0.5 wt% to 5.0 wt%, 0.5 wt% to 2.5 wt%, 2.5 wt% to 10.0 wt%, 2.5 wt% to 7.5 wt%, 2.5 wt% to 5.0 wt%, 5.0 wt% to 10.0 wt%, 5.0 wt% to 7.5 wt%, or 7.5 wt% to 10 wt% gallium based on the total weight of the catalyst.

[0027] In one or more embodiments, the catalyst optionally contains less than 5% by weight of an alkali metal or alkaline earth metal based on the total weight of the catalyst. For example, the catalyst may contain 0% to 5% by weight, 0% to 4% by weight, 0% to 3% by weight, 0% to 2% by weight, 0% to 1% by weight, 1% to 5% by weight, 1% to 4% by weight, 1% to 3% by weight, 1% to 2% by weight, 2% to 5% by weight, 2% to 4% by weight, 2% to 3% by weight, 3% to 5% by weight, 3% to 4% by weight, or 4% to 5% by weight of an alkali metal or alkaline earth metal based on the total weight of the catalyst.

[0028] In one or more embodiments, the catalyst comprises a support material. Specifically, the catalyst may comprise gallium, platinum, alkali metals, and / or alkaline earth metals disposed and / or dispersed on the support material. In some embodiments, the support material comprises one or more of alumina, silica, titanium dioxide, and zirconium. For example, the support material may comprise one or more of alumina, silica-containing alumina, titanium dioxide-containing alumina, and zirconium-containing alumina.

[0029] Still referencing Figure 1 The olefin-containing effluent and catalyst can be passed from the downstream reactor section 230 to a separation unit 220 in the catalyst separation section 210. The catalyst can be separated from the olefin-containing effluent in the separation unit 220. The olefin-containing effluent can then be conveyed out of the catalyst separation section 210. For example, the separated olefin-containing effluent can be removed from the reactor system 102 through a pipe 420 at the gas outlet port 216 of the catalyst separation section 210. In one or more embodiments, the separation unit 220 can be a cyclone separation system, which may include two or more cyclone separation stages.

[0030] Still referencing Figure 1 After separation from the olefin-containing effluent in separation unit 220, the catalyst is generally movable through stripper 224 to reactor catalyst outlet port 222, where it can be transferred from reactor section 200 via riser 426 and into combustion chamber 350 of catalyst processing section 300. Optionally, the catalyst can also be transferred directly back to upstream reactor section 250 via riser 422. In one or more embodiments, the recycled catalyst from stripper 224 can be premixed with the processed catalyst from catalyst processing section 300 in transport riser 430.

[0031] Once delivered to the catalyst processing section 300, the catalyst can be processed in the catalyst processing section 300. As used in this disclosure, the term "catalyst processing" refers to the preparation of the catalyst for reintroduction into the reactor section of the reactor system. In one or more embodiments, processing the catalyst includes removing coke deposits from the catalyst, increasing the temperature of the catalyst by combustion of fuel, reactivating the catalyst, stripping one or more components from the catalyst, or a combination thereof.

[0032] In some embodiments, processing the catalyst includes combustion of fuel in the presence of the catalyst in combustion chamber 350 to remove coke deposits on the catalyst and / or heating the catalyst to produce processed catalyst and combustion gases. As used in this disclosure, the term "processed catalyst" refers to a catalyst that has already been processed in the catalyst processing section 300 of reactor system 102. The processed catalyst may be separated from the combustion gases in catalyst separation section 310 and, in some embodiments, may subsequently be reactivated by oxygen treatment of the heated catalyst. Oxygen treatment may include a period of time sufficient to contact the catalyst with an oxygen-containing gas to reactivate the catalyst.

[0033] In one or more embodiments, the combustion fuel comprises coke or other contaminants deposited on the catalyst in reactor section 200. The catalyst may be coked after the reaction in reactor section 200, and the coke may be removed from the catalyst by a combustion reaction in combustion chamber 350. For example, an oxidant (such as air) may be fed into combustion chamber 350 through air inlet 428. Alternatively or additionally, when coke is not formed on the catalyst, or the amount of coke formed on the catalyst is insufficient to burn off and heat the catalyst to the desired temperature, supplemental fuel may be injected into combustion chamber 350, which may burn to heat the catalyst. Suitable supplemental fuel may comprise methane, natural gas, ethane, propane, hydrogen, or any gas that provides energy value during combustion.

[0034] The processed catalyst exits from combustion chamber 350 and reaches riser terminal separator 378 via riser 330, where the gaseous and solid components from riser 330 are at least partially separated. Vapors and remaining solids are conveyed to secondary separation unit 320 in catalyst separation section 310, where the remaining processed catalyst is separated from gases from catalyst processing (e.g., gases emitted from the combustion of coke deposits and supplementary fuel). In some embodiments, secondary separation unit 320 may comprise one or more cyclone separation units, which may be arranged in series or in pairs of cyclones. Combustion gases from the combustion of coke and / or supplementary fuel during catalyst processing, or other gases introduced into the catalyst during catalyst processing, can be removed from catalyst processing section 300 via combustion gas outlet 432.

[0035] As previously discussed, processing the catalyst in the catalyst processing section 300 of reactor system 102 may include catalyst reactivation. Combustion of make-up fuel in the presence of the catalyst to heat the catalyst can further deactivate it. Accordingly, in some embodiments, the catalyst may be reactivated by conditioning it with oxygen treatment. Oxygen treatment for catalyst reactivation may be performed after combustion of make-up fuel to heat the catalyst. In some embodiments, oxygen treatment includes treating the processed catalyst with oxygen-containing gas. Based on the total molar flow rate of the oxygen-containing gas, the oxygen-containing gas may contain an oxygen content of 5 mol.% to 100 mol.%. In some embodiments, oxygen treatment includes maintaining the processed catalyst at a temperature of at least 660 degrees Celsius (°C) while exposing the catalyst to the oxygen-containing gas flow for a period sufficient to reactivate the processed catalyst (e.g., increase the catalytic activity of the processed catalyst).

[0036] In one or more embodiments, the treatment of the processed catalyst with oxygen-containing gas is carried out in an oxygen treatment zone 370. In some embodiments, the oxygen treatment zone 370 is downstream of the catalyst separation zone 310 of the catalyst processing section 300, such that the processed catalyst is separated from the combustion gases before being exposed to oxygen-containing gas during oxygen treatment. In some embodiments, the oxygen treatment zone 370 includes a fluid-solid contact device. The fluid-solid contact device may include baffles or grid structures to facilitate 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.

[0037] In one or more embodiments, processing the catalyst in the catalyst processing section 300 of reactor system 102 includes stripping molecular oxygen trapped within or between catalyst particles and physically adsorbed oxygen that can be desorbed at a temperature of at least 660°C. The stripping step may include maintaining the processed catalyst at a temperature of at least 660°C and exposing the processed catalyst to a stripping gas that is substantially free of molecular oxygen and combustible fuel for a period of time sufficient to remove molecular oxygen between particles and physically adsorbed oxygen that can be desorbed at a temperature of at least 660°C. Further description of these catalyst reactivation processes is disclosed in U.S. Patent No. 9,834,496.

[0038] Still referencing Figure 1After catalyst processing, the processed catalyst can be transferred from the catalyst processing section 300 back to the reactor section 200 via riser 424. For example, the processed catalyst can be transferred from the oxygen treatment zone 370 to the upstream reactor section 250 via riser 424 and transport riser 430, where the processed catalyst can be further used in the dehydrogenation reaction of the hydrocarbon feed. Therefore, in operation, the catalyst can be circulated between the reactor section 200 and the catalyst processing section 300. Generally, the processed chemical feed stream containing the hydrocarbon feed and the olefin effluent can be gaseous, and the catalyst can be a fluidized particulate solid. In one or more embodiments, the reactor system 102 may include a hydrogen inlet stream 480 that supplies supplemental hydrogen to the reactor system 102.

[0039] As previously discussed, the combustion reaction (i.e., the combustion of the fuel) in the combustion chamber 350 can be promoted by a catalyst. That is, the catalyst can provide combustion activity in the combustion chamber 350. However, as the catalyst circulates between the reactor section 200 and the catalyst processing section 300, the combustion activity of the catalyst can decrease over time. As a result, during the operation of the reactor system 102, the fuel may no longer be able to burn at the typical operating temperature and pressure of the combustion chamber 350 without adequately maintaining the combustion activity in the combustion chamber 350. The typical operating temperature of the combustion chamber 305 can be from 600°C to 850°C, and the typical operating pressure of the combustion chamber 350 can be from 15 pounds per square inch (psia) to 60 psia.

[0040] In one or more embodiments, combustion activity in combustion chamber 350 can be adequately maintained by introducing a combustion additive into reactor system 102. In some embodiments, the combustion additive is introduced into reactor system 102 via reactor section 200, catalyst processing section 300, or both. For example, the combustion additive can be introduced into reactor system 102 via transport riser 430.

[0041] In some embodiments, the combustion additive includes catalytically active particles. In some embodiments, the combustion additive comprises one or more of gallium, platinum, alkali metals, alkaline earth metals, and a support material. In some embodiments, the combustion additive may comprise materials similar to and / or the same as the catalyst. For example, in some embodiments, both the catalyst and the combustion additive may comprise gallium and platinum disposed and / or dispersed on an alumina support material.

[0042] In one or more embodiments, the combustion additive comprises 150 ppmw to 1,000 ppmw of platinum based on the total weight of the catalyst. For example, the combustion additive may comprise 150 ppmw to 750 ppmw, 150 ppmw to 500 ppmw, 150 ppmw to 250 ppmw, 150 ppmw to 200 ppmw, 200 ppmw to 1,000 ppmw, 200 ppmw to 750 ppmw, 200 ppmw to 500 ppmw, 200 ppmw to 250 ppmw, 250 ppmw to 1,000 ppmw, 250 ppmw to 750 ppmw, 250 ppmw to 500 ppmw, 500 ppmw to 1,000 ppmw, 500 ppmw to 750 ppmw, or 750 ppmw to 1,000 ppmw of platinum based on the total weight of the catalyst.

[0043] In one or more embodiments, the combustion additive contains at least 1.1 times the amount of platinum as the catalyst. For example, the combustion additive may contain at least 1.5 times, at least 2 times, at least 5 times, at least 10 times, at least 20 times, or at least 50 times the amount of platinum as the catalyst. Without being bound by any particular theory, it is believed that the combustion activity of the catalyst and the combustion additive is primarily provided by platinum. Although the catalyst generally contains sufficient amounts of available platinum to provide suitable combustion activity, the combustion activity of the catalyst gradually decreases as previously discussed. Furthermore, it is believed that increasing the amount of platinum is not associated with an increase in the retention of combustion activity. Therefore, increasing the amount of platinum on the catalyst (which could increase the economic cost of the FCDh process) may not provide a significant increase in dehydrogenation activity or the catalyst's ability to maintain suitable combustion activity over an increased time period.

[0044] In one or more embodiments, the combustion additive comprises 0.1 wt% to 10.0 wt% gallium based on the total weight of the combustion additive. For example, the combustion additive may comprise 0.1 wt% to 7.5 wt%, 0.1 wt% to 5.0 wt%, 0.1 wt% to 2.5 wt%, 0.1 wt% to 0.5 wt%, 0.5 wt% to 10.0 wt%, 0.5 wt% to 7.5 wt%, 0.5 wt% to 5.0 wt%, 0.5 wt% to 2.5 wt%, 2.5 wt% to 10.0 wt%, 2.5 wt% to 7.5 wt%, 2.5 wt% to 5.0 wt%, 5.0 wt% to 10.0 wt%, 5.0 wt% to 7.5 wt%, or 7.5 wt% to 10 wt% gallium based on the total weight of the combustion additive.

[0045] In one or more embodiments, the combustion additive optionally contains less than 5% by weight of an alkali metal or alkaline earth metal based on the total weight of the combustion additive. For example, the combustion additive may contain 0% to 5% by weight, 0% to 4% by weight, 0% to 3% by weight, 0% to 2% by weight, 0% to 1% by weight, 1% to 5% by weight, 1% to 4% by weight, 1% to 3% by weight, 1% to 2% by weight, 2% to 5% by weight, 2% to 4% by weight, 2% to 3% by weight, 3% to 5% by weight, 3% to 4% by weight, or 4% to 5% by weight of an alkali metal or alkaline earth metal based on the total weight of the combustion additive.

[0046] In one or more embodiments, the combustion additive comprises a carrier material. Specifically, the combustion additive may comprise gallium, platinum, alkali metals, and / or alkaline earth metals disposed and / or dispersed on the carrier material. In some embodiments, the carrier material comprises one or more of alumina, silica, titanium dioxide, and zirconium. For example, the carrier material may comprise one or more of alumina, silica-containing alumina, titanium dioxide-containing alumina, and zirconium-containing alumina.

[0047] As previously discussed, a combustion additive may be introduced into reactor system 102 to maintain sufficient combustion activity in combustion chamber 350. In one or more embodiments, the combustion additive may be introduced into reactor system 102 when the combustion gas (i.e., the gas produced by combustion of fuel in combustion chamber 350) contains one or more hydrocarbons (e.g., methane, ethane, and / or propane) in an amount greater than 5% of the lower flammability limit (LFL) of the combustion gas at the temperature and pressure of catalyst processing section 300. For example, the combustion additive may be introduced into 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 catalyst processing section 300. As used in this disclosure, the term "lower flammability limit" refers to the lower limit of the range of concentrations of a combustible mixture of gas or vapor in air that can be ignited at a given temperature and pressure. The LFL of the combustion gas 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), where the pressure is adjusted according to Coward et al., Limits of Flammability of Gases and Vapors, 503 BUREAU 1 (1952). It should be understood that although hydrogen can be used as a suitable supplemental fuel as previously discussed, a typical hydrogen source may contain some amount of one or more hydrocarbons. Therefore, even in embodiments where hydrogen is used as the combustion fuel, a combustion additive may be introduced into reactor system 102 when the combustion gas contains one or more hydrocarbons in an amount greater than 5% of the LFL of the combustion gas at the temperature and pressure of the catalyst processing section 300.

[0048] In one or more embodiments, the amount of combustion additive introduced into reactor system 102 is from 0.05 volume percentage (volume%) to 2 volume% of the total volume of catalyst and combustion additive. For example, the amount of combustion additive introduced into reactor system 102 may be from 0.05 volume% to 1.5 volume%, from 0.05 volume% to 1 volume%, from 0.05 volume% to 0.5 volume%, from 0.5 volume% to 2 volume%, from 0.5 volume% to 1.5 volume%, from 0.5 volume% to 1 volume%, from 1 volume% to 2 volume%, from 1 volume% to 1.5 volume%, or from 1.5 volume% to 2 volume%.

[0049] It should be understood that once introduced into reactor system 102, the combustion additive will mix with the catalyst and, therefore, circulate through reactor system 102 as previously discussed regarding the catalyst. In other words, introducing the combustion additive into reactor system 102 produces a catalyst system that is a mixture of catalyst and combustion additive. Furthermore, as the catalyst system “ages” during use in reactor system 102 and / or catalytically active particles are naturally lost due to wear, the combustion additive and catalyst may become indistinguishable from each other. At this point, the catalyst system may become functionally equivalent to the original catalyst during operation of reactor system 102, and fresh combustion additive can be introduced into reactor system 102 again. The characteristics and amount of the combustion additive and / or catalyst can be referred to as those at the time of introduction of the combustion additive into reactor system 102, attributable to the natural changes in the properties of the catalyst and combustion additive during operation of reactor system 102.

[0050] In some embodiments, the catalyst system may contain 0.05 vol% to 2 vol% of a combustion additive. For example, the catalyst system may contain 0.05 vol% to 1.5 vol%, 0.05 vol% to 1 vol%, 0.05 vol% to 0.5 vol%, 0.5 vol% to 2 vol%, 0.5 vol% to 1.5 vol%, 0.5 vol% to 1 vol%, 1 vol% to 2 vol%, 1 vol% to 1.5 vol%, or 1.5 vol% to 2 vol% of a combustion additive. In some embodiments, the catalyst system may contain 98 vol% to 99.95 vol% of a catalyst. For example, the catalyst system may contain 98 vol% to 99.5 vol%, 98 vol% to 99 vol%, 98 vol% to 98.5 vol%, 98.5 vol% to 99.95 vol%, 98.5 vol% to 99.5 vol%, 98.5 vol% to 99 vol%, 99 vol% to 99.95 vol%, 99 vol% to 99.5 vol%, or 99.5 vol% to 99.95 vol%.

[0051] Example

[0052] Various embodiments of this disclosure will be further illustrated by the following examples. These examples are illustrative in nature and should not be construed as limiting the subject matter of this disclosure.

[0053] Example 1

[0054] In Example 1, seven different samples of catalytically active particles (i.e., catalysts and / or combustion additives) were prepared. For the purposes of Example 1, the gallium and potassium loadings of each sample were kept constant at 1.6 wt% and 0.25 wt%, respectively, while the platinum loading varied from sample to sample. Each sample was produced by loading an alumina support material with platinum, potassium, and optionally gallium, using conventional initial wet impregnation methods, such as those described in Marceau et al., Impregnation and Drying, Synthesis of Solid Catalysts (SYNTHESIS OF SOLID CATALYSTS) 59 (2008). The platinum loading of each sample is reported in Table 1.

[0055] Table 1

[0056]

[0057]

[0058] 1 Sample H does not contain gallium.

[0059] Example 2

[0060] In Example 2, the effects of various properties of the catalytically active particles (e.g., platinum loading) on ​​dehydrogenation activity were examined. To simulate the aging of catalytically active particles in a large-scale fluidized catalytic dehydrogenation system, several samples were subjected to an aging protocol. Specifically, samples A through C were subjected to four high-temperature treatment-jet treatment cycles (also known as "Program I"). Each cycle consisted of 10 hours of treatment in air at 750°C, followed by 48 hours of treatment under nitrogen jetting at a jetting velocity of 300 ft / s. The jetting treatment was performed in a pilot jet cup attrition facility, as described in Cocco et al., Jet Cup Attrition Testing, Powder Technology 224 (2010).

[0061] Next, the dehydrogenation activity of some samples in both fresh and aged forms was tested. Specifically, the dehydrogenation tests were conducted in a fixed-bed apparatus under laboratory-simulated reaction-regeneration cycles. Each reaction cycle was carried out at 625°C for 60 seconds, with a WHSV of 8 hours. -1 The feed composition was 95% propane / 5% nitrogen. Each regeneration cycle was performed in air at 750°C for 15 minutes. Data for each run were collected on the stream at 15 seconds. The results from each run of cycle 15 are reported in Table 2. It should be noted that all reported indices are based on performance normalized using the performance of sample B.

[0062] Table 2

[0063]

[0064] As indicated in Table 2, the gallium-free sample (i.e., sample H) provides only limited dehydrogenation activity. In contrast, the sample containing gallium but not platinum (i.e., sample G) provides suitable dehydrogenation activity. Furthermore, adding a relatively small amount of platinum to the gallium-containing catalytically active particles significantly enhances the dehydrogenation activity of the catalytically active particles, as indicated by comparing samples A and G. However, Table 2 indicates that further increases in the amount of platinum do not further increase the dehydrogenation activity, as indicated by comparing samples A and D.

[0065] Example 3

[0066] In Example 3, the effects of various properties of the catalytically active particles (e.g., platinum loading) on ​​combustion activity were examined. To simulate the aging of catalytically active particles in a large-scale fluidized catalytic dehydrogenation system, some samples were subjected to an aging protocol. Specifically, samples B through F and H were subjected to six high-temperature treatment-spray treatment cycles (also known as "Program II"). Each cycle was performed in a manner similar to Protocol I as described in Example 2, but with a 48-hour heat treatment and a 6-hour spray treatment at a spray rate of 150 ft / s.

[0067] Next, the combustion activity of some samples in both fresh and aged forms was tested. Specifically, the combustion tests were conducted for 100 minutes in a fixed-bed test apparatus at 750°C with 2 mol.% methane in air. The results of each run are reported in Table 3. It should be noted that all reported indices are based on performance normalized using the performance of sample B.

[0068] Table 3

[0069]

[0070] As indicated in Table 3, samples with increased platinum loading provide increased combustion activity. However, samples with increased platinum loading also exhibit poorer activity retention. That is, Table 3 indicates that increasing the platinum loading of the catalytically active particles will not necessarily result in a corresponding increase in the duration for which the catalytically active particles maintain suitable combustion activity. More simply, Table 3 indicates that increasing the platinum loading by 50% will not necessarily increase the duration for which the catalytically active particles maintain suitable combustion activity by 50%.

[0071] Several aspects are disclosed herein. One aspect is a method for producing olefins, the method comprising: contacting a hydrocarbon-containing feedstock with a catalyst in a reactor section of a reactor system to form an olefin-containing effluent; separating at least a portion of the olefin-containing effluent from the catalyst; transferring the catalyst to a catalyst processing section of the reactor system and processing the catalyst to produce a processed catalyst and a combustion gas; transferring the processed catalyst from the catalyst processing section to the reactor section; and introducing a combustion additive into the reactor system when the combustion gas contains one or more hydrocarbons in an amount greater than 5% of the lower flammability limit level of the combustion gas at the temperature and pressure of the catalyst processing section, wherein: the catalyst comprises 1 to 150 parts by weight of platinum; and the combustion additive comprises 150 to 1,000 parts by weight of platinum.

[0072] The other aspect is any other aspect disclosed herein, wherein the catalyst further comprises gallium and a support material.

[0073] The other aspect is any other aspect disclosed herein, wherein the catalyst comprises 0.1 to 10.0 wt% gallium.

[0074] The other aspect is any other aspect disclosed herein, wherein the carrier material comprises alumina, silicon dioxide, titanium dioxide, or zirconium.

[0075] On the other hand, for any other aspect disclosed herein, the catalyst further comprises less than or equal to 5% by weight of an alkali metal or alkaline earth metal.

[0076] On the other hand, as disclosed herein in any other aspect, the combustion additive also comprises gallium and a carrier material.

[0077] On the other hand, for any other aspect disclosed herein, the combustion additive contains 0.1 to 10.0 percent gallium by weight.

[0078] The other aspect is any other aspect disclosed herein, wherein the carrier material comprises alumina, silicon dioxide, titanium dioxide, or zirconium.

[0079] As in any other aspect disclosed herein, the combustion additive also contains less than or equal to 5% by weight of an alkali metal or alkaline earth metal.

[0080] The other aspect is any other aspect disclosed herein, wherein processing the catalyst includes burning supplemental fuel in the catalyst processing section to heat the catalyst.

[0081] The other aspect is any other aspect disclosed herein, wherein the supplementary fuel comprises methane, natural gas, ethane, propane, or hydrogen.

[0082] The other aspect is any other aspect disclosed herein, wherein processing the catalyst includes contacting the catalyst with an oxygen-containing gas.

[0083] The other aspect is any other aspect disclosed herein, in which the combustion additive is introduced into the reactor section, the catalyst processing section, or both.

[0084] On the other hand, as disclosed herein, the amount of the combustion additive introduced into the reactor system is from 0.05 to 2 volume percentages of the sum of the volume of the catalyst and the volume of the combustion additive.

[0085] On the other hand, as disclosed herein in any other aspect, the combustion additive contains at least 1.1 times the amount of platinum as the catalyst.

[0086] The dimensions and values ​​disclosed herein should not be construed as strictly limited to the exact numerical values ​​stated. In fact, unless otherwise specified, each such dimension or value is intended to refer to the stated value and a range of functionally equivalent values ​​around said value. For example, a value disclosed as "150 ppmw" is intended to mean "about 150 ppmw".

[0087] Unless expressly excluded or otherwise limited, every document referenced in this disclosure (if any), including any cross-references or related patent or patent application and any patent or patent application claiming priority or rights in this application, is incorporated by reference in its entirety. No reference to any document acknowledges that it is prior art with respect to any disclosed or claimed embodiment, or that it teaches, illustrates, or discloses any such embodiment, alone or in combination with any other reference document or plural references. Furthermore, in the event of any conflict between the meaning or definition of any term in this document and any meaning or definition of the same term in a document incorporated by reference, the meaning or definition given to the term in this document shall prevail.21

[0088] It should be noted that one or more of the appended claims use the term "wherein" as a transitional expression. For the purpose of defining embodiments of this disclosure, it should be noted that this term is introduced in the claims as an open-ended transitional phrase used to introduce a description of a series of features of the embodiments, and should be interpreted in a similar manner to the more commonly used open-ended prepositional term "comprising".

[0089] It will be apparent to those skilled in the art that various modifications and variations can be made to embodiments of this disclosure without departing from the scope of this disclosure. Because modifications, combinations, sub-combinations, and variations of embodiments of this disclosure incorporated into the scope of this disclosure are likely to occur to those skilled in the art, this disclosure should be construed as including all contents within the scope of the appended claims and their equivalents.

Claims

1. A method for producing olefins, the method comprising: The hydrocarbon-containing feed is brought into contact with the catalyst in the reactor section of the reactor system to form an olefin-containing effluent; To separate at least a portion of the olefin-containing effluent from the catalyst; The catalyst is fed to the catalyst processing section of the reactor system and processed to produce processed catalyst and combustion gas; The processed catalyst is transferred from the catalyst processing section to the reactor section; as well as When the combustion gas contains one or more hydrocarbons in an amount greater than 5% of the lower flammability limit of the combustion gas at the temperature and pressure of the catalyst processing section, a combustion additive is introduced into the reactor system, wherein: The catalyst comprises platinum at a weight percentage of 1 to 150 parts per million; and The combustion additive contains 150 parts by weight to 1,000 parts by weight of platinum.

2. The method according to claim 1, wherein the catalyst further comprises gallium and a support material.

3. The method of claim 2, wherein the catalyst comprises 0.1 to 10.0% by weight gallium.

4. The method according to claim 2 or 3, wherein the carrier material comprises alumina, silicon dioxide, titanium dioxide or zirconium.

5. The method according to any one of claims 1-3, wherein the catalyst further comprises less than or equal to 5% by weight of an alkali metal or alkaline earth metal.

6. The method according to any one of claims 1-3, wherein the combustion additive further comprises gallium and a carrier material.

7. The method of claim 6, wherein the combustion additive comprises 0.1 to 10.0% by weight gallium.

8. The method according to claim 6, wherein the carrier material comprises alumina, silicon dioxide, titanium dioxide, or zirconium.

9. The method according to any one of claims 1-3, wherein the combustion additive further comprises less than or equal to 5% by weight of an alkali metal or alkaline earth metal.

10. The method according to any one of claims 1-3, wherein processing the catalyst comprises burning supplementary fuel in the catalyst processing section to heat the catalyst.

11. The method of claim 10, wherein the supplemental fuel comprises methane, natural gas, ethane, propane, or hydrogen.

12. The method according to any one of claims 1-3, wherein processing the catalyst comprises contacting the catalyst with an oxygen-containing gas.

13. The method according to any one of claims 1-3, wherein the combustion additive is introduced into the reactor section, the catalyst processing section, or both.

14. The method according to any one of claims 1-3, wherein the amount of the combustion additive introduced into the reactor system is 0.05 to 2 volume percentages of the sum of the volume of the catalyst and the volume of the combustion additive.

15. The method according to any one of claims 1-3, wherein the combustion additive comprises at least 1.1 times the amount of platinum in the catalyst.

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