How to handle chemicals

Abstract

According to one or more embodiments of the present disclosure, a method for processing a chemical may include reacting a feed stream in the presence of a catalyst to form a product stream, passing the catalyst through a regenerator, removing olefins from the auxiliary fuel stream to form an olefin-depleted auxiliary fuel stream, passing the olefin-depleted auxiliary fuel stream through the regenerator, combusting the olefin-depleted auxiliary fuel stream in the regenerator to heat the catalyst, and passing the heated catalyst through a reactor. The auxiliary fuel stream may include at least 90 mole % of a combination of hydrogen, methane, and nitrogen. The auxiliary fuel stream may include 0.1 mole % to 10 mole % olefins. The olefin-depleted auxiliary fuel stream may include up to 50% of the olefins present in the auxiliary fuel stream prior to olefin removal.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of and priority to U.S. Patent Application No. 63 / 251,873, entitled "Methods for Processing Chemicals," filed October 4, 2021, the entire contents of which are incorporated by reference into this disclosure.

[0002] FIELD OF THEINVENTION FIELD OF THE DISCLOSURE

[0002] Embodiments described herein relate generally to chemical processing, and more specifically to methods and systems for catalytic chemical conversion. [Background technology]

[0003] Chemical products can be produced by processes that use catalysts. During these processes, the catalyst can become "spent" and become less active in subsequent reactions. Additionally, endothermic processes require heat, which can necessitate reheating of the "spent" catalyst. As such, the spent catalyst can be transferred from the reactor to a regenerator for reheating and regeneration, increasing the activity of the catalyst for use in further reactions. Following regeneration, the catalyst can be returned to the reactor for use in subsequent reactions. Summary of the Invention

[0004] Regeneration of the catalyst may include burning an auxiliary fuel in the regenerator to heat the catalyst. The auxiliary fuel may be obtained from a variety of sources, including off-gas from propane dehydrogenation or steam cracking processes. The auxiliary fuel, which is obtained from some sources, such as the off-gas from some steam cracking processes, may contain olefins. It has been discovered that olefins found in the supplemental fuel may result in coke formation on the fuel gas distributor in the regenerator when the regenerator is at its operating temperature. The formation of coke on the fuel gas distributor is undesirable and may lead to process interruptions. The addition of sulfur to the auxiliary fuel may reduce the rate of coke formation, but the introduction of sulfur into the auxiliary fuel requires the management of SOx formation in the fuel gas and may adversely affect the performance of the catalyst in the reactor if the regenerated catalyst is returned to the reactor for use in further reactions.

[0005] Therefore, there is a need for an improved method for treating fuel gas to reduce the formation of coke on the fuel gas distributor of the regenerator. The methods described herein address one or more of these problems. As described herein, at least a portion of the olefins contained in the auxiliary fuel can be removed before the auxiliary fuel is sent to the regenerator. By removing the olefins from the auxiliary fuel, the rate of coke formation on the fuel gas distributor in the regenerator can be reduced. Reducing the rate of coke formation on the fuel gas distributor may be desirable to maintain a uniform distribution of fuel gas throughout the regenerator.

[0006] According to one or more embodiments of the present disclosure, a method for processing a chemical may include reacting a feed stream in the presence of a catalyst in a reactor to form a product stream, and passing the catalyst through a regenerator. The method may further include removing olefins from the auxiliary fuel stream to form an olefin-depleted auxiliary fuel stream. The auxiliary fuel stream comprises at least 90 mole % of a combination of hydrogen, methane, and nitrogen. The auxiliary fuel stream comprises 0.1 mole % to 10 mole % of olefins prior to removing olefins from the auxiliary fuel stream. The olefin-depleted auxiliary fuel stream comprises 50% or less of the olefins present in the auxiliary fuel stream prior to olefin removal. The method may further include passing the olefin-depleted auxiliary fuel stream through a regenerator, combusting the olefin-depleted auxiliary fuel stream in the regenerator to heat a catalyst to form a heated catalyst, and passing the heated catalyst through the reactor.

[0007] Additional features and advantages of the techniques disclosed herein will be set forth in the detailed description which follows, and will be readily apparent in part to those skilled in the art from that description, or will be learned by practicing the techniques as described herein, including the detailed description, claims, and accompanying drawings. [Brief description of the drawings]

[0008] The following detailed description of certain embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, in which like structure is indicated with like reference numerals and in which: [Figure 1] 1 illustrates a schematic diagram of a system for processing a chemical substance according to one or more embodiments disclosed herein. [Diagram 2] 1 illustrates a schematic of a reactor and regenerator for producing olefins according to one or more embodiments disclosed herein.

[0009] It should be understood that the drawings are schematic in nature and do not include some components of fluid catalytic reactor systems commonly used in the art, such as, without limitation, temperature transmitters, pressure transmitters, flow meters, pumps, valves, etc. It will be appreciated that these components are within the spirit and scope of the disclosed embodiments. However, operational components such as those described in this disclosure may be added to the embodiments described in this disclosure.

[0010] Reference will now be made in more detail to various embodiments, some of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] As described herein, a method for processing a chemical may include reacting a feed stream in the presence of a catalyst in a reactor to form a product stream and passing the catalyst through a regenerator. Olefins may be removed from the auxiliary fuel stream to form an olefin-depleted auxiliary fuel stream that may be sent to the regenerator. The olefin-depleted auxiliary fuel stream may be combusted in the regenerator to heat the catalyst, and the catalyst may be returned to the reactor after catalyst regeneration, which may include one or more of removing coke on the catalyst, heating the catalyst by burning the olefin-depleted auxiliary fuel, and catalyst reactivation by an oxygen treatment step. The methods described herein may be suitable for use in systems such as the system shown in FIG. 1. However, it should be understood that the principles disclosed and taught herein may be applicable to other systems utilizing different system components oriented in a different manner.

[0012] As described herein, the term "olefin" refers to a compound composed of hydrogen and carbon containing one or more pairs of carbon atoms connected by a double bond. For example, olefins include ethylene, propylene, or butene. As described herein, butene can include any isomer of butene, such as 1-butene, cis-2-butene, trans-2-butene, and isobutene.

[0013] Referring now to FIG. 1, as can be understood with reference to the preceding figures and description, in a system 100 for processing a chemical, a feed stream 202 may react in a reactor 200 in the presence of a catalyst to form a product stream 204. The catalyst may be sent via a catalyst stream 206 to a regenerator 300. In the regenerator 300, the catalyst may be heated and reactivated. In some embodiments, heating the catalyst may include burning an auxiliary fuel in the regenerator 300 in addition to burning coke present on the catalyst. The auxiliary fuel stream 402 from the auxiliary fuel source 400 may include olefins. The olefins may be removed from the auxiliary fuel stream 402 in an auxiliary fuel processing system 500 to form an olefin-depleted auxiliary fuel stream 502, which may be sent to the regenerator section 300. The heated and reactivated catalyst may be passed back to the reactor section 200 in stream 302 for a subsequent reaction cycle.

[0014] The method of processing a chemical may include reacting a feed stream 202 in the presence of a catalyst in a reactor 200 to form a product stream 204. The chemical stream to be processed may be referred to as a feed stream 202, which is processed by reaction to form a product stream 204. The feed stream 202 may include a composition, and depending on the feed stream composition, an appropriate catalyst may be utilized to convert the contents of the feed stream 202 to the product stream 204. In some embodiments, the feed stream 202 may include alkanes or alkyl aromatic compounds, and the product stream 204 may include light olefins.

[0015] As described herein, a "reactor" refers to a drum, barrel, vat, or other container suitable for a given chemical reaction. A reactor may generally be cylindrical (i.e., having a substantially circular diameter) or, alternatively, may be non-cylindrical, such as a prismatic shape having a triangular, square, pentagonal, hexagonal, octagonal, elliptical, or other polygonal or closed curved cross-sectional shape or a combination thereof. A reactor, as used throughout this disclosure, may generally include a metal frame and may further include a refractory lining or other material utilized to protect the metal frame and / or control process conditions.

[0016] Methods for processing chemicals described herein may include removing olefins from the auxiliary fuel stream 402 to form an olefin-depleted auxiliary fuel stream 502. In one or more embodiments, the auxiliary fuel stream 402 may include one or more combustible or non-combustible gases. For example, the auxiliary fuel stream 402 may include hydrogen, methane, ethane, nitrogen, or a combination of these gases. In an embodiment, the auxiliary fuel stream 402 may include at least 90 mol% of a combination of hydrogen, methane, nitrogen, and ethane. For example, the auxiliary fuel stream 402 may include at least 90 mol%, at least 92 mol%, at least 95 mol%, at least 97 mol%, at least 99 mol%, or at least 99.9 mol% of a combination of hydrogen, methane, nitrogen, and ethane. In an embodiment, the auxiliary fuel stream 402 includes between 0.1 mol% and 10 mol% of olefins. For example, the auxiliary fuel stream may include 0.1 mol%-10 mol%, 2 mol%-10 mol%, 4 mol%-10 mol%, 6 mol%-10 mol%, 8 mol%-10 mol%, 0.1 mol%-8 mol%, 0.1 mol%-6 mol%, 0.1 mol%-4 mol%, 0.1 mol%-2 mol%, or any combination or subset of these ranges. In some embodiments, the auxiliary fuel stream 402 may further include carbon monoxide, such as less than 1 mol%, less than 0.1 mol%, or even less.

[0017] In one or more embodiments, olefins may be removed from the auxiliary fuel stream 402 to form an olefin-depleted auxiliary fuel stream 502. The removal of olefins from the auxiliary fuel stream 402 may occur in an olefin removal system 500. The olefin-depleted auxiliary fuel stream 502 may comprise 50 mol % or less of the olefins present in the auxiliary fuel stream 402 prior to olefin removal. For example, the auxiliary fuel stream 402 may comprise 50 mol % or less, 40 mol % or less, 30 mol % or less, 20 mol % or less, 10 mol % or less, 5 mol % or less, or 1 mol % or less of the olefins present in the auxiliary fuel stream 402 prior to olefin removal. In an embodiment, the olefin-depleted auxiliary fuel stream 502 may be substantially free of olefins. As described herein, a stream that is "substantially free" of olefins comprises less than 0.1 mol % olefins, less than 0.05 mol % olefins, or even less than 0.01 mol % olefins.

[0018] In one or more embodiments, the removal of olefins from the auxiliary fuel stream or off-gas stream may include a hydrogenation reaction. As described herein, a "hydrogenation reaction" refers to a reaction in which a hydrogen atom is added to a molecule. For example, a hydrogenation reaction may be used to saturate a double bond in an alkene to form an alkane. Additionally, a hydrogenation reaction may be used to saturate a triple bond in an alkyne, such as acetylene, to form an alkane. Additionally, hydrogenation of carbon monoxide, which may be present in the auxiliary fuel stream, may result in the formation of methane. In an embodiment, olefins in the auxiliary fuel stream or off-gas stream may be hydrogenated to form an alkane, effectively removing the olefins from the auxiliary fuel stream or off-gas stream. In such an embodiment, the olefin removal system 500 may be operable to perform a hydrogenation reaction.

[0019] In one or more embodiments, the hydrogenation reaction may be carried out in a fixed bed reactor. As described herein, a "fixed bed reactor" is a vessel in which at least a portion of the vessel is filled with a catalyst bed so that reactants pass through the catalyst bed and are converted to products. The fixed bed reactor may be any fixed bed reactor operable to hydrogenate olefins. In an embodiment, the fixed bed reactor may be an adiabatic fixed bed reactor. In an embodiment, the fixed bed reactor may be an isothermal fixed bed reactor.

[0020] The catalyst of the catalyst bed in the fixed bed reactor may be any catalyst suitable for hydrogenating olefins. In embodiments where carbon monoxide is present in the stream, the catalyst may further be suitable for hydrogenating carbon monoxide. In embodiments, the catalyst may include Cu, Zn, Ni, Co, Mo, W, Pd, Rh, Pt, and combinations thereof. In embodiments, the catalyst may include an oxide or sulfide of a metal contemplated herein. The catalyst may further include a support. The support may include one or more of alumina, silica, zirconia, and titania. In embodiments, the catalyst may include a CoMoSx / NiMoSx catalyst. In embodiments, the catalyst may include a supported Ni catalyst. In embodiments, the catalyst may include a supported Pd catalyst or a supported Pd-Ag catalyst.

[0021] According to one or more embodiments, the fixed bed reactor may be operated at process conditions sufficient to convert olefins in the auxiliary fuel or off-gas to alkanes. In embodiments, the fixed bed reactor may be operated at a temperature between 30°C and 300°C. For example, the fixed bed reactor may be operated at a temperature between 30°C and 300°C, between 50°C and 300°C, between 100°C and 300°C, between 150°C and 300°C, between 200°C and 300°C, between 250°C and 300°C, between 30°C and 250°C, between 30°C and 200°C, between 30°C and 150°C, between 30°C and 100°C, between 30°C and 50°C, or any combination or subset of these ranges. In one or more embodiments, the fixed bed reactor may be operated at a temperature appropriate for the catalyst being used in the fixed bed. For example, if the catalyst includes Ni, the temperature of the fixed bed reactor may be between 210°C and 300°C.

[0022] In one or more embodiments, the fixed bed reactor may operate at a pressure from 25 psia to 500 psia. For example, the fixed bed reactor may operate at pressures of from 25 psia to 500 psia, 50 psia to 500 psia, 100 psia to 500 psia, 150 psia to 500 psia, 200 psia to 500 psia, 250 psia to 500 psia, 300 psia to 500 psia, 350 psia to 500 psia, 400 psia to 500 psia, 450 psia to 500 psia, 25 psia to 450 psia, 25 psia to 400 psia, 25 psia to 350 psia, 25 psia to 300 psia, 25 psia to 250 psia, 25 psia to 200 psia, 25 psia to 150 psia, 25 psia to 100 psia, 25 psia to 50 psia, or any combination or subset of ranges thereof.

[0023] In one or more embodiments, the fixed bed reactor is -1 ~10,000h -1 For example, a fixed bed reactor may have a gas hourly space velocity (GHSV) of 500 h -1 ~10,000h -1 , 1,000h -1 ~10,000h -1 , 3000h -1 ~10,000h -1 , 5000h -1 ~10,000h -1 , 7000h -1 ~10,000h -1 , 9000h -1 ~10,000h -1 , 500h -1 ~9000h -1 , 500h -1 ~7000h -1 , 500h -1 ~5000h -1 , 500h -1 ~3000h -1 , 500h -1 ~1,000h -1, or any combination or subset of these ranges.

[0024] In one or more embodiments, removal of olefins from the auxiliary fuel stream may include separating the olefins from the remainder of the auxiliary fuel stream. In such embodiments, the olefin removal means 500 may be operable to separate the olefins from the auxiliary fuel stream 402. In embodiments, separation of the olefins from the auxiliary fuel or off-gas stream may be accomplished by membrane separation. The membrane separation process may use a membrane to separate a permeate from a retentate, where the permeate passes through the membrane and the retentate does not pass through the membrane. In one or more embodiments, the membrane may be operable to separate the olefins from the alkanes and other components of the auxiliary fuel stream. In one or more embodiments, the membrane may comprise a polyimide membrane material or a polysulfone membrane material.

[0025] In one or more embodiments, separation of olefins from the auxiliary fuel stream or off-gas stream can be accomplished by an adsorption process. The adsorption process can be any adsorption process suitable for separating olefins from paraffins or alkanes in the auxiliary fuel stream or off-gas stream. In embodiments, the adsorption process can include pressure swing adsorption, vacuum swing adsorption, or temperature swing adsorption.

[0026] The method of treating a chemical may include sending an olefin-reduced auxiliary fuel stream 502 to the regenerator 300. In one or more embodiments, the olefin-reduced auxiliary fuel stream 502 may be introduced into the regenerator 300 through one or more fuel gas distributors. Each of the one or more fuel gas distributors may comprise a plurality of fuel gas injection diffusers. The fuel gas injection diffusers allow the olefin-reduced auxiliary fuel stream to exit the one or more fuel gas distributors and enter the regenerator. The one or more fuel gas distributors and the fuel gas injection diffusers may be positioned to provide a uniform distribution of the olefin-reduced auxiliary fuel to the regenerator. Fuel gas distributors and fuel gas injection diffusers that may be used in the regenerator 300 in one or more embodiments are described in detail in U.S. Pat. No. 9,889,418.

[0027] Without being bound by theory, the presence of olefins in the auxiliary fuel stream fed to the regenerator may result in coke formation on the fuel gas distributor and fuel gas injection diffuser. By reducing the concentration of olefins in the auxiliary fuel stream to form an olefin-reduced auxiliary fuel stream and passing the olefin-reduced auxiliary fuel stream to the regenerator, coke formation on the fuel gas distributor and fuel gas injection diffuser may be reduced. Coke formation on the fuel gas distributor and fuel gas injection diffuser may result in uneven distribution of fuel gas throughout the regenerator. Furthermore, removal of coke from the fuel gas distributor and fuel gas injection may result in system downtime. Minimizing the buildup of coke on the fuel gas distributor and injectors may facilitate even distribution of fuel gas in the regenerator 300 and reduce the need for maintenance of the fuel gas distributor and injectors.

[0028] In one or more embodiments, the temperature of one or more fuel gas distributors in regenerator 300 may be between 600° C. and 925° C. For example, the temperature of one or more fuel gas distributors in regenerator 300 may be between 600° C. and 925° C., 600° C. and 900° C., 600° C. and 880° C., 600° C. and 860° C., 600° C. and 840° C., 600° C. and 820° C., 600° C. and 800° C., 600° C. and 780° C., 600° C. and 760° C., 600° C. and 740° C., 600° C. and 720° C., 600° C. and 700° C., 600° C. and 680° C., 600° C. and 660° C., 600° C. and 640° C., 600° C. and 620° C. 0°C, 620°C-925°C, 640°C-925°C, 660°C-925°C, 680°C-925°C, 700°C-925°C, 720°C-925°C, 740°C-925°C, 760°C-925°C, 780°C-925°C, 800°C-925°C, 820°C-925°C, 840°C-925°C, 860°C-925°C, 880°C-925°C, 900°C-925°C, or any combination or subset of ranges thereof. Without being bound by theory, when the temperature of the one or more fuel gas distributors is between 600°C-780°C, coke may form on the one or more fuel gas distributors if the auxiliary fuel contains olefins. Reducing the concentration of olefins in the auxiliary fuel may reduce the rate of coke formation on one or more fuel gas distributors when the fuel gas distributors are at temperatures between 600° C. and 780° C.

[0029] The method of processing a chemical may include burning an olefin-depleted auxiliary fuel stream 502 in a regenerator 300 to heat a catalyst to form a heated catalyst. In one or more embodiments, the temperature of the heated catalyst is higher than the temperature of the catalyst sent to the regenerator in stream 206. The heated catalyst may be sent from the regenerator 300 to the reactor 200 in stream 302. In one or more embodiments, the catalyst may be heated in the regenerator 300 to a temperature sufficient to maintain the heat balance of the reactor 300. In other words, the catalyst heated in the regenerator 300 may be the primary heat source used to maintain the temperature of the reactor 200.

[0030] In one or more embodiments, the heated catalyst may be further treated by contacting the heated catalyst with oxygen to form an oxygen-treated catalyst, which may be sent to the reactor. For example, the heated catalyst may be contacted with an oxygen-containing gas, such as air, enriched air, or even pure oxygen. The oxygen-treated catalyst may have increased activity for one or more reactions, including but not limited to dehydrogenation reactions, occurring in the reactor.

[0031] In one or more embodiments, the auxiliary fuel stream 402 may be off-gas from a dehydrogenation process or a steam cracking process. For example, the auxiliary fuel stream 402 may be off-gas from a propane dehydrogenation process, an ethylbenzene dehydrogenation process, a butane dehydrogenation process, an ethane dehydrogenation process, or a steam cracking process.

[0032] In one or more embodiments, the supplemental fuel stream 402 is off-gas from a steam cracking process. In such embodiments, the fuel gas source 400 of Figure 1 is a steam cracking system. The steam cracking system may be operable to produce an off-gas stream that may be used as a supplemental fuel stream and a steam cracking product stream from a hydrocarbon feedstock.

[0033] In one or more embodiments, steam cracking of the hydrocarbon feedstock may occur in a steam cracking unit. The steam cracking unit may be operable to receive a hydrocarbon feedstock and crack one or more components of the hydrocarbon feedstock to form at least an off-gas stream and a steam cracked product stream. Ethane, propane, naphtha, and other hydrocarbons present in the hydrocarbon feedstock may be steam cracked in the steam cracking unit to produce at least one or more olefins, such as, but not limited to, ethylene, propylene, butenes, or combinations thereof. The steam cracking unit may be operated under conditions (i.e., temperature, pressure, residence time, etc.) sufficient to produce one or more light olefins, such as ethylene and propylene, from the hydrocarbons in the hydrocarbon feedstock. In some embodiments, the steam cracking unit may be operated at temperatures between 500°C and 950°C, between 500°C and 900°C, between 600°C and 950°C, between 600°C and 900°C, between 700°C and 900°C. The temperature of the steam cracking unit may depend on the composition of the hydrocarbon feedstock introduced into the steam cracking unit.

[0034] The hydrocarbon feedstock may be any hydrocarbon stream, such as a product stream from a petrochemical process, or naphtha from a crude oil refining process, natural gas liquids (NGLs), or other hydrocarbon sources. In some embodiments, the hydrocarbon feedstock may include multiple different hydrocarbon streams combined prior to or within the steam cracking unit. In some embodiments, the hydrocarbon feedstock may be a light hydrocarbon feedstock, such as a feedstock including ethane, propane, butane, naphtha, other light hydrocarbons, or combinations thereof.

[0035] In one or more embodiments, the steam cracking product stream may include one or more cracking reaction products, such as, but not limited to, ethylene, propylene, butenes (e.g., 1-butene, trans-2-butene, cis-2-butene, isobutene), or combinations thereof.

[0036] The off-gas stream can include at least 90 mol% of a combination of hydrogen, methane, and nitrogen. For example, the off-gas stream can include at least 90 mol%, at least 92 mol%, at least 95 mol%, at least 97 mol%, at least 99 mol%, or at least 99.9 mol% of a combination of hydrogen, methane, and nitrogen. The off-gas stream can include 0.1 mol% to 10 mol% olefins. For example, the off-gas stream can include 0.1 mol% to 10 mol%, 2 mol% to 10 mol%, 4 mol% to 10 mol%, 6 mol% to 10 mol%, 8 mol% to 10 mol%, 0.1 mol% to 8 mol%, 0.1 mol% to 6 mol%, 0.1 mol% to 4 mol%, 0.1 mol% to 2 mol%, or any combination or subset of ranges thereof. In one or more embodiments, at least a portion of the off-gas stream can be the auxiliary fuel stream 402.

[0037] In one or more embodiments, the reaction occurring in reactor 200 may be a dehydrogenation reaction. The dehydrogenation reaction may be a thermal dehydrogenation reaction or a catalytic dehydrogenation reaction. According to such embodiments, feed stream 202 may include one or more of ethylbenzene, ethane, propane, n-butane, and i-butane. In one or more embodiments, feed stream 202 may include at least 50% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, at least 95% by weight, or even at least 99% by weight of ethane. In additional embodiments, feed stream 202 may include at least 50% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, at least 95% by weight, or even at least 99% by weight of propane. In additional embodiments, feed stream 202 can include at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or even at least 99% by weight n-butane. In additional embodiments, feed stream 202 can include at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or even at least 99% by weight i-butane. In additional embodiments, feed stream 202 can include at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or even at least 99% by weight of the sum of ethane, propane, n-butane, and i-butane.

[0038] In one or more embodiments, product stream 204 may include at least 30% by weight olefins. For example, product stream 204 may include at least 30% by weight olefins, at least 40% by weight olefins, at least 50% by weight olefins, or even at least 60% by weight olefins. In one or more embodiments, the olefins comprising the product stream may include one or more of ethylene, propylene, styrene, and butenes, such as 1-butene, trans-2-butene, cis-2-butene, and isobutene.

[0039] In one or more embodiments, the dehydrogenation reaction may utilize gallium and / or platinum particulate solids as a catalyst. In such embodiments, the catalyst may include a gallium and / or platinum catalyst. As described herein, the gallium and / or platinum catalyst includes gallium, platinum, or both. The gallium and / or platinum catalyst may be supported by an alumina or alumina-silica support and may optionally include potassium. Such gallium and / or platinum catalysts are disclosed in U.S. Pat. No. 8,669,406, which is incorporated herein by reference in its entirety. However, it should be understood that other suitable catalysts may be utilized to carry out the dehydrogenation reaction. For example, in embodiments, a mixed metal oxide may be a suitable catalyst for carrying out the dehydrogenation reaction. In one or more embodiments, the catalyst may include a combination of catalysts, such as, but not limited to, a mixed metal oxide catalyst and a gallium and / or platinum catalyst.

[0040] In one or more embodiments, the catalyst may include Geldart A particles. Geldart A particles generally have a small average particle size and / or a small particle density (< about 1.4 grams per cubic centimeter, g / cm 3), easily fluidizes to exhibit smooth fluidization at low gas velocities, and may exhibit controlled small bubble bubbling at higher gas velocities. In one or more embodiments, Geldart A particles can form breathable powders with: bubble-free flow range, high bed expansion, slow and linear degassing rate, bubble characteristics with predominantly split / re-coalesced bubbles, maximum bubble size and large wake, UU mf A high level of solid mixing and gas backmixing, assumed to be equal to U mf is the minimum fluidization velocity, typically measured in meters per second, m / s, but not necessarily, i.e., excess gas velocity exists), axisymmetric slug characteristics, and no blowing except in very shallow beds. The listed characteristics tend to improve, assuming equal dp, as the average particle size decreases, or as the fraction < 45 micrometers (μm) increases, or as the gas pressure, temperature, viscosity, and density increase.

[0041] In one or more embodiments, the reactor 200 and regenerator 300 of FIG. 1 may be configured as shown in FIG. 2. However, it should be understood that other reactor system configurations may be suitable for the methods described herein. Referring now to FIG. 2, an exemplary reactor system 102 that may be suitable for use with the methods described herein is shown in schematic form. The reactor system 102 generally comprises multiple system components, such as a reactor 200 and / or a regenerator 300. As used herein in the context of FIG. 1, the reactor 200 generally refers to the portion of the reactor system 102 in which the primary process reactions take place. The reactor 200 includes a reaction vessel 202 that may include a downstream reactor section 230 and an upstream reactor section 250. According to one or more embodiments, as shown in FIG. 2, the reactor 200 may further include a catalyst separation section 210 that serves to separate the catalyst from the chemical products formed in the reaction vessel 202. Also, as used herein, the regenerator 300 generally refers to the portion of the reactor system 102 in which the catalyst is processed in some manner, such as by combustion. The regenerator section 300 may include a combustor 350 and a riser 330, and may optionally include a catalyst separation section 310. In some embodiments, the catalyst may be regenerated in the regenerator 300 by burning contaminants, such as coke. In embodiments, the catalyst may be heated in the regenerator 300. An olefin-reduced auxiliary fuel may be utilized to heat the catalyst in the regenerator 300. In one or more embodiments, the catalyst separation section 210 may be in fluid communication with the combustor 350 (e.g., via a water tower 426), and the catalyst separation section 310 may be in fluid communication with the upstream reactor section 250 (e.g., via a water tower 424 and a transfer riser 430).

[0042] As described with respect to FIG. 2, the feed stream 202 can enter the transfer riser 430 and the product stream 204 can exit the reactor system 102 via the pipe 420. According to one or more embodiments, the reactor system 102 can be operated by feeding a chemical feedstock (e.g., in a feed stream) and a fluidized catalyst to the upstream reactor section 250. The chemical feedstock contacts the catalyst in the upstream reactor section 250 and each flows upwardly to and through the downstream reactor section 230 to produce a chemical product. The chemical product and catalyst can exit the downstream reactor section 230 and be sent to a separation device 220 in the catalyst separation section 210, where the catalyst is separated from the chemical product and the chemical product is transported from the catalyst separation section 210. The separated catalyst is sent from the catalyst separation section 210 to the combustor 350. In the combustor 350, the catalyst can be processed, for example, by combustion. For example, but not by way of limitation, the catalyst may be decoked and an olefin-depleted auxiliary fuel may be burned to heat the catalyst. The olefin-depleted auxiliary fuel 502 may be sent to the combustor 350 through a pipe 428. The catalyst then exits the combustor 350 and passes through a riser 330 to a riser end separator 378 where the gas and solid components from the riser 330 are at least partially separated. The vapor and remaining solids are transferred to a secondary separation device 320 in the catalyst separation section 310 where the remaining catalyst is separated from the gases from the catalytic process (e.g., the spent catalyst or gases released by the combustion of the auxiliary fuel). The separated catalyst is then sent from the catalyst separation section 310 via a water column 424 and a transfer riser 430 to the upstream reactor section 250 where it is further utilized in the catalytic reaction. Thus, the catalyst may be circulated between the reactor section 200 and the catalyst treatment section 300 during operation. Generally, the processed chemical streams, including the feed stream and the product stream, may be gaseous and the catalyst may be a fluidized particulate solid.

[0043] It is understood that any two quantitative values ​​assigned to a property may constitute a range for that property, and all combinations of ranges formed from all the stated quantitative values ​​for a given property are contemplated in this disclosure. It is understood that a compositional range of a chemical component in a composition should be understood to contain, in some embodiments, a mixture of isomers of that component. In additional embodiments, a compound may exist in alternative forms, such as derivatives, salts, hydroxides, and the like. In general, the "inlet port" and "outlet port" of any system device of the reactor system 102 described herein refer to an opening, hole, channel, aperture, gap, or other similar mechanical feature of the system device. For example, an inlet port allows for the inflow of a material into a particular system unit, and an outlet port allows for the outflow of a material from a particular system unit. In general, an outlet port or inlet port defines an area of ​​the system device of the reactor system 102 to which a pipe, conduit, tube, hose, transfer line, or similar mechanical feature is attached, or a portion of the system device to which another system device is directly attached. Although inlet and outlet ports may be described herein functionally in operation, they may have similar or identical physical characteristics, and their respective functions in an operational system should not be construed as limitations on their physical structure. EXAMPLES

[0044] The following examples illustrate features of the present disclosure, but are not intended to limit the scope of the disclosure. The following examples discuss the rate of coke formation on stainless steel according to one or more embodiments disclosed herein.

[0045] The rate of coke formation on stainless steel was analyzed. A sample of off-gas from a steam cracking process containing 2 mole % ethylene, 80 mole % H2, and 18 mole % methane was passed through a 40 inch long 304H stainless steel tube. The stainless steel tube was coiled in a furnace, and the furnace was heated to 700°C. The off-gas was continuously fed through the stainless steel tube during the coking process, which ranged from 1 hour to 150 hours. The coke was then burned off in a decoking step using a gas containing 5 mole % oxygen and 95 mole % nitrogen. The gas produced during the decoking step was analyzed by mass spectrometry to determine the concentrations of CO and CO2 in the gas produced during the decoking step. The concentrations of CO and CO2 were used to determine the amount of coke formed in the stainless steel tube. The amount of coke, the internal surface area of ​​the stainless steel tube, and the duration of the coking process were then used to calculate the rate of coke formation.

[0046] For an off-gas containing 2 mol% ethylene, 80 mol% H2, and 18 mol% methane, the coke formation rate at 700 °C is approximately 3 mg / in 2 / h. The coke growth rate was constant and the estimated coke density was 0.2 g / cm 3 Assuming this, the thickness of coke accumulating on the system components is approximately 20.4 cm / year. Coke accumulation at this rate on various system components would likely lead to operational interruptions.

[0047] If the off-gas contains only hydrogen and methane and the concentration of ethylene is 0 mole %, then no coke is expected to form. Specifically, hydrogen does not contain carbon and therefore cannot form coke. Furthermore, the thermal decomposition of methane at 700°C is negligible. Since thermal decomposition generally results in the formation of coke, coke formation from methane at 700°C is expected to be negligible. Therefore, reducing the concentration of ethylene in the off-gas should reduce the rate of coke formation.

[0048] It should be noted that one or more of the claims below utilize the term "wherein" as a transitional phrase. It should be noted that for purposes of defining the present technology, this term is introduced into the claims as an open-ended transitional phrase used to introduce a recitation of a series of features of a structure, and should be interpreted in a similar manner to the more commonly used open-ended preamble term "comprising."

[0049] It should be understood that when a first component is described as "comprising" a second component, in some embodiments it is contemplated that the first component "consists of" or "consists essentially of" that second component. It should be further understood that when a first component is described as "comprising" a second component, in some embodiments it is contemplated that the first component comprises at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or even at least 99% of that second component (where % can be weight % or mole %).

[0050] Additionally, the term "consisting essentially of" is used in this disclosure to refer to quantitative values ​​that do not materially affect the basic and novel characteristics of the disclosure. For example, a chemical composition that "consists essentially of" a particular chemical component or group of chemical components should be understood to mean that the composition contains at least about 99.5% of that particular chemical component or group of chemical components.

[0051] The subject matter of the present disclosure has been described in detail with reference to specific embodiments. It should be understood that a detailed description of any element or feature of an embodiment does not necessarily imply that element or feature is essential to the particular embodiment or any other embodiment. Moreover, it should be apparent to those skilled in the art that various modifications and changes can be made to the described embodiments without departing from the spirit and scope of the claimed subject matter.

Claims

1. 1. A method for treating a chemical, comprising: reacting a feed stream in a reactor in the presence of a catalyst to form a product stream; passing the catalyst through a regenerator; removing olefins from the auxiliary fuel stream to form an olefin-depleted auxiliary fuel stream; the auxiliary fuel stream comprises at least 90 mole percent of a combination of hydrogen, methane, and nitrogen; the auxiliary fuel stream comprises 0.1 mol % to 10 mol % olefins prior to removing olefins from the auxiliary fuel stream; and the olefin-depleted auxiliary fuel stream contains no more than 50% of the olefins present in the auxiliary fuel stream prior to olefin removal; and passing the olefin-depleted auxiliary fuel stream through the regenerator; burning the olefin-depleted auxiliary fuel stream in the regenerator to heat the catalyst to form a heated catalyst; and passing the heated catalyst through the reactor.

2. 10. The method of claim 1, wherein the auxiliary fuel stream is an off-gas stream from a propane dehydrogenation process, an ethylbenzene dehydrogenation process, a butane dehydrogenation process, an ethane dehydrogenation process, or a stream cracking process.

3. 10. The method of claim 1, wherein removing olefins from the auxiliary fuel stream comprises a hydrogenation reaction or a membrane or adsorption separation.

4. 10. The method of claim 1, wherein removing olefins from the auxiliary fuel stream comprises a hydrogenation reaction occurring in a fixed bed reactor.

5. 5. The process of claim 4, wherein the fixed bed reactor operates at a temperature of from 30°C to 300°C.

6. 5. The process of claim 4, wherein the fixed bed reactor operates at a pressure of from 25 psia to 500 psia.

7. The fixed bed reactor is operated for 500 h －１ ~10,000 hours －１ 5. The method of claim 4, wherein the process operates at a gas hourly space velocity of

8. 10. The method of claim 1, wherein reacting the feed stream comprises performing a dehydrogenation reaction.

9. 10. The process of claim 1, wherein the feed stream comprises one or more alkanes or alkylaromatic compounds.

10. The method of claim 1 , wherein the catalyst comprises Geldart A particles.

11. 10. The method of claim 1, wherein the product stream comprises one or more of ethylene, propylene, butene, or styrene.

12. contacting the heated catalyst with oxygen to form an oxygenated catalyst; 10. The method of claim 1, further comprising passing the oxygenation catalyst through the reactor.

13. The method comprises: processing a hydrocarbon feedstock to form at least said auxiliary fuel stream and a product stream, said processing comprising one or more of a propane dehydrogenation reaction, an ethylbenzene dehydrogenation reaction, a butane dehydrogenation reaction, an ethane dehydrogenation reaction, or stream cracking; 10. The method of claim 1, further comprising: hydrogenating the auxiliary fuel stream to form an olefin-depleted auxiliary fuel stream.

14. The method of any one of claims 1 to 12, wherein the olefin-depleted auxiliary fuel stream is passed to the regenerator through one or more fuel gas distributors.

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