Method for forming light olefins utilizing a heat exchanger system

Abstract

A method for forming light olefins may include reacting a feed stream in the presence of a catalyst in a reactor to form a product stream, separating at least a portion of the product stream from the catalyst, and transferring the catalyst to a catalytic treater of a reactor system and treating the catalyst to produce treated catalyst and flue gas. The catalyst may be heated, coke may be removed from the catalyst, or both, in a combustor in the catalytic treater. The method may further include separating the catalyst from the flue gas and passing the flue gas through a heat exchanger system to cool the flue gas. Heat may be exchanged from the flue gas to an oxygen-containing gas in an inlet stream. The oxygen-containing gas may exit the heat exchanger system in a first stream and a second stream. The oxygen-containing gas in the first stream may have a higher temperature than the temperature of the oxygen-containing gas in the second stream. The method may further include transferring the oxygen-containing gas in the first stream directly to the combustor and transferring the oxygen-containing gas in the second stream as a solid transport fluid to one or more of a catalyst transport pipe or an oxygen treatment zone.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63 / 325,276, filed March 30, 2022, the entire disclosure of which is incorporated herein by reference.

[0002] FIELD OF THE DISCLOSURE Embodiments described herein relate generally to chemical processing, and more specifically to methods and systems for producing light olefins. [Background technology]

[0003] Light olefins such as ethylene can be used as a base material 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, there is a global demand for light olefins. Suitable processes for producing light olefins generally depend on a given chemical feed and include those that utilize fluidized catalysts. However, improvements in the systems and associated methods used to make light olefins are needed. Summary of the Invention

[0004] Some systems for producing light olefins may include a combustor, and a catalyst transport pipe, an oxygen treatment zone, or both. An oxygen-containing gas may be transferred to these parts of the system. In some embodiments, the oxygen-containing gas, such as air, may be heated from a relatively low temperature, such as ambient temperature or room temperature, by heat exchange with a flue gas stream. However, it may be desirable to inject the oxygen-containing gas into the combustor at a higher temperature than it is injected into the catalyst transport pipe or the oxygen treatment zone. Described herein is a method for delivering oxygen-containing gas at two different temperatures to components of these systems using a heat exchanger system that can heat the oxygen-containing gas delivered to the combustor to a relatively high temperature and the oxygen-containing gas delivered to the catalyst transport pipe or the oxygen treatment zone at a relatively low temperature.

[0005] According to one or more embodiments of the present disclosure, a method for forming light olefins may include reacting a feed stream in the presence of a catalyst in a reactor to form a product stream, separating at least a portion of the product stream from the catalyst, and transferring the catalyst to a catalytic treater of a reactor system and treating the catalyst to produce treated catalyst and flue gas. The catalyst may be heated, coke may be removed from the catalyst, or both, in a combustor in the catalytic treater. The method may further include separating the catalyst from the flue gas and passing the flue gas through a heat exchanger system to cool the flue gas. Heat may be exchanged from the flue gas to an oxygen-containing gas in an inlet stream. The oxygen-containing gas may exit the heat exchanger system in a first stream and a second stream. The oxygen-containing gas in the first stream may have a higher temperature than the temperature of the oxygen-containing gas in the second stream. The method may further include transferring the oxygen-containing gas in the first stream directly to the combustor and transferring the oxygen-containing gas in the second stream as a solid transport fluid to one or more of a catalyst transport pipe or an oxygen treatment zone.

[0006] It should be understood that both the general description above and the detailed description below are intended to describe various embodiments and provide an overview or framework for understanding the nature and features of the claimed subject matter. Additional features and advantages of the embodiments are described in the detailed description and in part will become readily apparent to those skilled in the art from the description, including the accompanying drawings and claims, or can be learned by practicing the described embodiments. The drawings are included to provide a further understanding of the embodiments and, together with the detailed description, serve to explain the principles and operation of the claimed subject matter. However, the embodiments set forth in the drawings are illustrative and exemplary in nature and are not intended to be limiting of the claimed subject matter. [Brief description of the drawings]

[0007] The following detailed description can be better understood when read in conjunction with the following drawings. [Figure 1] 1 illustrates a schematic of a reactor system according to one or more embodiments of the present disclosure. [Diagram 2] 1 illustrates a schematic diagram of an embodiment of a heat exchanger system according to one or more embodiments of the present disclosure. [Diagram 3] 1 illustrates a schematic diagram of another embodiment of a heat exchanger system in accordance with one or more embodiments of the present disclosure.

[0008] In describing the simplified schematic diagram of Figure 1, numerous valves, temperature sensors, electronic controllers, etc. that may be used and that are well known to those skilled in the art are not included. Additionally, accompanying components that are often included within such reactor systems are also not included, such as air supplies, heat exchangers, surge tanks, etc. However, it should be understood that these components are within the scope of the present disclosure.

[0009] Reference will now be made in more detail to various embodiments, some of which are illustrated in the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The embodiments disclosed herein are described in detail herein in the context of the reactor system of FIG. 1 operating as a fluidized dehydrogenation reactor system to produce light olefins. However, it should be understood that the principles disclosed and taught herein may be applicable to other systems utilizing different system components oriented in different ways, or different reaction schemes utilizing various catalyst compositions. For example, the concepts described may be equally applicable to other systems with alternative reactor and regeneration units, such as those operating under non-fluidized conditions or those including a downer rather than a riser. Furthermore, light olefins may be produced from a wide variety of hydrocarbon feed streams by utilizing different reaction mechanisms. For example, light olefins may be catalytically produced by at least dehydrogenation reactions, cracking reactions, dehydration reactions, and methanol to olefins reactions. In some embodiments, oxygen carrier materials may also be utilized as described herein. These reaction types may utilize different feed streams and / or different catalysts to produce light olefins. Furthermore, it should be understood that not all portions of FIG. 1 should be construed as essential to the claimed subject matter.

[0011] Referring now to FIG. 1, an exemplary reactor system 102 that may be suitable for use with the methods and / or apparatus described herein is shown generally. The reactor system 102 generally includes multiple system components, such as a reactor section 200 and a catalytic treatment section 300. As described herein, "system components" refer to portions of the reactor system 102, such as reactors, separators, transfer lines, combinations thereof, and the like. As used herein in the context of FIG. 1, the reactor section 200 generally refers to the portion of the reactor system 102 where the primary process reaction (e.g., dehydrogenation) takes place to form a product stream. A feed stream enters the reactor section 200, is converted to a product stream (containing products and unreacted feed), and exits the reactor section 200. The reactor section 200 includes a reactor 202, which may include an upstream reactor section 250 and a downstream reactor section 230. According to one or more embodiments, as shown in FIG. 1, the reactor section 200 may further comprise a catalyst separation section 210 that serves to separate the catalyst from the chemical products formed in the reactor 202. Also, as used herein, a catalyst treatment section 300 generally refers to a portion of the reactor system 102 that treats the catalyst in some manner, such as by combustion, for example, to improve catalytic activity by decoking and / or heating the catalyst. The catalyst treatment section 300 may comprise a combustor 350 and a riser 330, and may further comprise a catalyst separation section 310. In one or more embodiments, the catalyst separation section 210 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).

[0012] Generally, as described herein, in the embodiment shown in FIG. 1, the catalyst is circulated between the reactor section 200 and the catalyst treatment section 300. It should be understood that when referring to a "catalyst" herein, it may refer to a solid material that is catalytically active for a desired reaction, or it may equally refer to other particulate solids mentioned with respect to the system of FIG. 1 that do not necessarily have catalytic activity but affect the reaction, such as oxygen carriers. The terms "catalytic activity" and "catalyst activity" refer to the degree to which a catalyst is capable of catalyzing a reaction taking place in a reactor system. The catalyst that exits the reactor section 200 may be a deactivated catalyst. As used herein, "deactivated" may refer to a catalyst that is less catalytically active or at a lower temperature compared to the catalyst that enters the reactor section 200. However, a deactivated catalyst may still retain some catalytic activity. The reduction in catalytic activity may be due to contamination with materials such as coke. Reactivation (sometimes referred to herein as "regeneration") can remove contaminants such as coke, increase the temperature of the catalyst, or both. In embodiments, the deactivated catalyst can be reactivated by catalyst reactivation in the catalyst treater 300. The deactivated catalyst can be reactivated by, but is not limited to, removing coke by combustion, restoring catalyst acidity, oxidizing the catalyst, other reactivation processes, or combinations thereof. In some embodiments, the catalyst may be heated during reactivation by combustion of a supplemental fuel, such as methane, ethane, propane, natural gas, or combinations thereof. The reactivated catalyst from the catalyst treater 300 is then returned to the reactor section 200.

[0013] 1, a feed stream can enter the reactor 202 at the feed inlet 434, and a product stream can exit the reactor system 102 via pipe 420. According to one or more embodiments, the reactor system 102 can operate by supplying a chemical feed (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 upward into and through the downstream reactor section 230 to produce the chemical product.

[0014] Referring now in detail to FIG. 1, the reactor section 200 may comprise an upstream reactor section 250, a transfer section 258, and a downstream reactor section 230, such as a riser. The transfer section 258 may connect the upstream reactor section 250 with the downstream reactor section 230. As shown in FIG. 1, the upstream reactor section 250 may be disposed below the downstream reactor section 230. Such a configuration may be referred to as an upflow configuration in the reactor 202. The upstream reactor section 250 may comprise a vessel, drum, barrel, vat, or other vessel suitable for a given chemical reaction. As shown in FIG. 1, the upstream reactor section 250 may be connected to the downstream reactor section 230 via the transfer section 258. The upstream reactor section 250 may generally comprise a larger cross-sectional area than the downstream reactor section 230. The transfer section 258 may taper from the cross-sectional size of the upstream reactor section 250 to the cross-sectional size of the downstream reactor section 230 such that the transfer section 258 projects inwardly from the upstream reactor section 250 toward the downstream reactor section 230. For example, the transfer section 258 may be a frustum.

[0015] The upstream reactor section 250 can be connected to a transfer riser 430 that can provide reactivated catalyst in the feed stream to the reactor section 200 during operation. The reactivated catalyst and / or reaction chemicals can be mixed in a distributor 260 housed within the upstream reactor section 250. Catalyst entering the upstream reactor section 250 via the transfer riser 430 can be sent to the transfer riser 430 through a distribution tower 424 and thus arrives from the catalyst treatment section 300. In some embodiments, the catalyst may enter the transfer riser 430 directly from the catalyst separation section 210 via a standpipe 422, in which case the catalyst enters the upstream reactor section 250, and in such embodiments, a portion of the catalyst does not pass through the catalyst treatment section 300. Catalyst can also be fed directly to the upstream reactor section 250 via the standpipe 422 (not shown in FIG. 1 ). This catalyst may be somewhat deactivated, but may still be suitable for reaction in the upstream reactor section 250 in some embodiments, especially when used in conjunction with a reactivated catalyst.

[0016] 1, in one or more embodiments, depending on the shape, size, and other process conditions (such as temperature and pressure) of the upstream reactor section 250 and the downstream reactor section 230, the upstream reactor section 250 can operate as a fluidized bed, such as a fast fluidized bed, turbulent bed, or bubbling bed upflow reactor, while the downstream reactor section 230 can operate more in a plug flow mode, such as a riser reactor. For example, the reactor 202 of FIG. 1 may have the upstream reactor section 250 operating as a fast fluidized bed, turbulent bed, or bubbling bed reactor, and the downstream reactor section 230 operating as a dilute phase riser reactor, such that the average catalyst and gas flows move upward simultaneously. "Average flow," as that term is used herein, refers to the net flow, i.e., total upward flow minus countercurrent or reflux flow, as is typically typical for the behavior of fluidized particles. As described herein, a "fast-fluid" reactor may refer to a reactor that utilizes a fluidization regime in which the superficial velocity of the gas phase is greater than the choking velocity and may be semi-dense during operation. As described herein, a "turbulent" reactor may refer to a fluidization regime in which the superficial velocity is less than the choking velocity and is denser than the fast fluidization regime. As described herein, a "bubble bed" reactor may refer to a fluidization regime in which well-defined bubbles in a dense bed exist in two separate phases. "Choking velocity" refers to the minimum velocity required to maintain solids in a dilute phase mode in a vertical conveying line. As described herein, a "dilute phase riser" may refer to a riser reactor that operates at a conveying velocity, where the gas and catalyst have approximately the same velocity in the dilute phase.

[0017] According to an embodiment, the chemical products and catalyst may be discharged from the downstream reactor section 230 and sent to a separation unit 220 in the catalyst separation section 210 where the catalyst is separated from the chemical products and the chemical products are transported from the catalyst separation section 210. According to one or more embodiments, following separation from the vapor in the separation unit 220, the catalyst may generally travel through a stripper 224 to a catalyst outlet port 222 where the catalyst is transported out of the reactor section 200 via a standpipe 426 to a catalyst treatment unit 300.

[0018] According to one or more embodiments, the separator 220 may be a cyclonic separation system that may include two or more stages of cyclonic separation. In embodiments where the separator 220 includes more than one cyclonic separation stage, the first separator into which the fluidized stream enters is referred to as the primary cyclonic separator. The fluidized effluent from the primary cyclonic separator may enter a secondary cyclonic separator for further separation. Primary cyclonic separators may include, for example, primary cyclones and systems commercially available under the names VSS (commercially available from UOP), LD2 (commercially available from Stone and Webster), and RS2 (commercially available from Stone and Webster). Primary cyclones are described, for example, in U.S. Pat. Nos. 4,579,716, 5,190,650, and 5,275,641, each of which is incorporated herein by reference in its entirety. Some separation systems utilizing a primary cyclone as a primary cyclonic separator use one or more sets of additional cyclones, e.g., secondary and tertiary cyclones, to further separate the catalyst from the product gas. It should be understood that any primary cyclonic separator may be used in embodiments of the present technology.

[0019] 1, the separated catalyst travels from the catalyst separation section 210 to a combustor 350. In the combustor 350, the catalyst can be treated, for example, by combustion with oxygen. For example, but not limited to, the catalyst can be decoked and / or an auxiliary fuel can be burned to heat the catalyst. The catalyst then exits the combustor 350 and passes through the riser 330 to an end-of-riser separator 378, where gas and solid components from the riser 330 are at least partially separated. The steam and remaining solids are transferred to a secondary separator 320 in the catalyst separation section 310, where the remaining catalyst is separated from gases from the catalyst treatment (e.g., gases released by combustion of spent catalyst or auxiliary fuel, referred to herein as flue gas). The flue gas can exit the catalyst treatment section 300 via an outlet pipe 432. The separated catalyst then travels through the oxygen treatment zone 370 in the catalyst separation section 310 via the standpipe 424 and the 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. In general, the processed chemical streams, including the feed stream and the product stream, may be gaseous and the catalyst may be a fluidized particulate solid.

[0020] Referring now to the catalytic treater 300, as shown in FIG. 1, the combustor 350 of the catalytic treater 300 may include one or more lower reactor section inlet ports 352 and may be in fluid communication with the riser 330. An oxygen-containing gas, such as air, may travel to the combustor 350 through a pipe 428. The combustor 350 may be in fluid communication with the catalyst separation section 210 through a water column 426, which may feed spent catalyst from the reactor section 200 to the catalytic treater 300 for regeneration. The combustor 350 and the riser 330, collectively referred to as the catalytic combustion reactor 302, may operate with a similar or identical fluidization regime as disclosed for the upstream reactor section 250 and downstream reactor section 230 of the reactor section 200. That is, the combustor 350 may operate as a fluidized bed, such as in a fast fluidized bed, turbulent bed, or bubbling bed upflow reactor, while the riser 330 may operate more in a plug flow manner, such as a riser reactor. The geometries described with respect to the upstream reactor section 250 and the downstream reactor section 230 are equally applicable to the combustor 350 and the riser 330. Additionally, the combustor 350 may also include a fuel inlet 354 through which a fuel, such as a hydrocarbon stream, may be provided to the combustor 350.

[0021] Following separation of the flue gas from the catalyst in the end-of-riser separator 378 and secondary separation unit 320, treatment of the treated catalyst with an oxygen-containing gas occurs in the oxygen treatment zone 370, as described in one or more embodiments. In some embodiments, the oxygen treatment zone 370 includes a fluid-solid contactor. The fluid-solid contactor may include a baffle or grid structure to facilitate contact of the treated catalyst with the oxygen-containing gas. Examples of fluid-solid contactors are described in more detail in U.S. Pat. Nos. 9,827,543 and 9,815,040. The fluidization regime within the oxygen treatment zone may be a bubbling bed type fluidization. The oxygen treatment zone 370 may include an oxygen-containing gas inlet 372 through which oxygen-containing gas may be delivered to the oxygen treatment zone 370 for oxygen treatment of the catalyst.

[0022] In an embodiment, a portion of the catalyst may be returned from the catalyst separation section 310 to the combustor 350 via the standpipe 385. Thus, the catalyst passing through the standpipe 385 bypasses the reactor section 200.

[0023] In one or more embodiments, light olefins may be present in the "product stream", sometimes referred to as the "olefin-containing effluent", and may include light olefins. Such streams may exit the reactor system of FIG. 1 and be subsequently processed. As used in this disclosure, the term "light olefins" refers to one or more of ethylene, propylene, and butene. The term butene includes any isomer of butene, such as α-butylene, cis-β-butylene, trans-β-butylene, and isobutylene. In some embodiments, the olefin-containing effluent includes 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 include at least 35% by weight of light olefins, 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. The olefin-containing effluent may further include unreacted components of the feed stream, as well as other reaction products that are not considered light olefins. The light olefins can be separated from the unreacted components in a subsequent separation step.

[0024] In one or more embodiments, the flue gas exits the catalytic treater 300 via the outlet pipe 432 and travels to a heat exchanger system 500 via line 502. The flue gas in line 502 is cooled in the heat exchanger system 500 and exits as cooled flue gas in line 504. The heat exchanger system 500 can cool the flue gas and simultaneously heat an oxygen-containing gas in line 506 (sometimes referred to as an inlet stream of oxygen-containing gas), such as air, that is used throughout the catalytic treater 300 as described herein. The oxygen-containing gas in line 506 can enter the heat exchanger system 500 and exit in two streams, line 508 and line 510. The oxygen-containing gas in line 510 is at a lower temperature than line 508. Various techniques are disclosed herein for creating two streams of oxygen-containing gas with different temperatures.

[0025] The heat exchanger system 500 may include any suitable gas-gas heat exchanger. Without limitation, contemplated heat exchangers include shell-and-tube heat exchangers, dual pipe heat exchangers, and plate heat exchangers. Multiple heat exchangers of any type may be used in series in the heat exchanger system 500. Additionally, parallel flow, counter flow, and cross flow heat exchangers are contemplated for use herein. Without limitation, two exemplary heat exchanger systems are shown in Figures 2 and 3, which are discussed in detail below.

[0026] The flue gas in line 502 may be at about the operating temperature of combustor 350. For example, the flue gas in line 502 may have a temperature between 650° C. and 900° C. For example, the flue gas in line 502 may have a temperature between 650° C. and 700° C. and 750° C. and 750° C. and 800° C. and 850° C. and 850° C. and 900° C., or a combination of these ranges. The cooled flue gas in line 504 may have a temperature between 150° C. and 400° C. For example, the flue gas in line 504 may have a temperature between 150° C. and 200° C. and 250° C. and 250° C. and 300° C. and 350° C. and 350° C. and 400° C., or a combination of these ranges. The temperature difference between the flue gas in line 502 and the flue gas in line 504 may be at least 300°C, at least 350°C, at least 400°C, at least 450°C, or even at least 500°C.

[0027] According to one or more embodiments, the oxygen-containing gas in line 506 may have a temperature between 0° C. and 200° C., which may be at about room temperature or ambient conditions at the plant site. For example, the oxygen-containing gas in line 506 may have a temperature between 0° C. and 50° C., between 50° C. and 100° C., between 100° C. and 150° C., between 150° C. and 200° C., or any combination of these ranges.

[0028] As described herein, the oxygen-containing gas exits heat exchanger system 500 in two streams (sometimes referred to herein as a first stream and a second stream) each having a different temperature via line 508 and line 510. As described herein, the "first stream of oxygen-containing gas" is synonymous with the oxygen-containing gas in line 508, and the "second stream of oxygen-containing gas" is synonymous with the oxygen-containing gas in line 5010.

[0029] The oxygen-containing gas in line 510 may have a temperature between 200°C and 500°C. For example, the oxygen-containing gas in line 510 may have a temperature between 200°C and 250°C, 250°C and 300°C, 300°C and 350°C, 350°C and 400°C, 400°C and 450°C, 450°C and 500°C, or any combination of these ranges. The oxygen-containing gas in line 508 may have a temperature between 500°C and 875°C. For example, the oxygen-containing gas in line 510 may have a temperature between 500°C and 550°C, 550°C and 600°C, 600°C and 650°C, 650°C and 700°C, 700°C and 750°C, 750°C and 800°C, 800°C and 850°C, 850°C and 875°C, or any combination of these ranges. According to embodiments, the temperature difference between the oxygen-containing gas in line 508 and the oxygen-containing gas in line 510 may be at least 100°C, at least 150°C, at least 200°C, at least 250°C, at least 300°C, at least 350°C, at least 400°C, at least 450°C, or even at least 500°C.

[0030] In one or more embodiments, the mass flow rate of the oxygen-containing gas in line 508 may be 70%-95% of the mass flow rate in line 506. For example, the mass flow rate of the oxygen-containing gas in line 508 may be 70%-75%, 75%-80%, 80%-85%, 85%-90%, 90%-95%, or any combination of ranges thereof, of the mass flow rate in line 506. The mass flow rate of the oxygen-containing gas in line 510 may be 5%-15% of the mass flow rate in line 506. For example, the mass flow rate of the oxygen-containing gas in line 510 may be 5%-7%, 7%-9%, 9%-11%, 11%-13%, 13%-15%, or any combination of ranges thereof, of the mass flow rate in line 506.

[0031] The oxygen-containing gas in line 508 can travel directly to the combustor 350 via pipe 428. The relatively high temperature of the oxygen-containing gas is beneficial for heating the combustor 350. A lower temperature oxygen-containing gas would increase the required supplemental fuel addition to the combustor 350 to maintain heat balance in the system. A relatively high temperature in the combustor 350 may be desirable for burning coke on the catalyst, or for burning less supplemental fuel that may be required if the temperature in the combustor is relatively low. That is, it is desirable to maintain a relatively high temperature in the combustor 350 so that the catalyst is relatively hot when it is returned to the reactor section 200.

[0032] In one or more embodiments, the oxygen-containing gas in line 510 may travel to one or more catalyst transport pipes as a solid transport fluid. A catalyst transport pipe as described herein refers to a pipe that transports catalyst into a system component, such as a combustor. The oxygen-containing gas may be used as a solid transport fluid, meaning that the oxygen-containing gas is injected into the pipe to move solids, such as catalyst, in a desired direction.

[0033] 1, the oxygen-containing gas in line 510 can travel to the standpipe 385, the standpipe 426, or both. The standpipe 385 and the standpipe 426 in the system of FIG. 1 are catalyst transport pipes since they transport catalyst. The oxygen-containing gas can be injected and traveled through the "J bends" 329, 393 of the catalyst transport pipes (the standpipe 385 and / or the standpipe 426). A J bend is a section of pipe that resembles the shape of the letter "J" and may require a solid transport fluid, such as the oxygen-containing gas in line 510, to propel the catalyst in its intended direction, e.g., upward into the combustor 350. Although the J bends 392, 393 are shown in FIG. 1, it is contemplated that the oxygen-containing gas in line 510 may be useful for propelling the catalyst through other shapes, as would be understood by one of ordinary skill in the art.

[0034] According to additional embodiments, the oxygen-containing gas in line 510 may travel to an oxygen treatment zone 370 downstream of separation of the catalyst from the flue gas, such as in end-of-riser separator 378 and secondary separation unit 320. The oxygen-containing gas may contact a catalyst present in oxygen treatment zone 370 as described herein.

[0035] According to an embodiment, a relatively low temperature oxygen-containing gas in line 510 (compared to line 508) may be desirable for injection into the oxygen treatment zone 370 or catalyst transport pipes (standpipe 385 and / or standpipe 426) for various reasons. For example, the equipment utilized in transporting oxygen-containing gas to these components is not equipped to handle the high temperature (e.g., at least 600° C.) oxygen-containing gas in line 508. Upgrading the instrumentation to accommodate the high temperature oxygen-containing gas would be costly and require a plant shutdown. However, utilizing the relatively low temperature oxygen-containing gas in line 510 in combustor 350 would further increase process costs by cooling combustor 350 and requiring additional energy input. Thus, the systems and methods described herein address the needs of the system of FIG. 1, for example.

[0036] 2, in one or more embodiments, the separate flows of oxygen-containing gas in lines 510 and 508 at different temperatures can be achieved by a single heat exchanger 530 that discharges the oxygen-containing gas in line 510 (the cooler stream) upstream of the discharge of the oxygen-containing gas in line 508 (the hotter stream) relative to the flow direction of the oxygen-containing gas through the heat exchanger 530. The heat exchanger 530 can be a tube-and-shell heat exchanger. The oxygen-containing gas line 510 is at a lower temperature than line 508 because it is withdrawn upstream in the tube-and-shell heat exchanger 530, which has more time to transfer heat between the flue gas in lines 502 and 504. It should be noted that while FIG. 2 shows a counter-flow heat exchanger, parallel flow heat exchangers are contemplated as suitable for use in the methods described herein.

[0037] 3, in one or more embodiments, the separate flows of oxygen-containing gas in lines 510 and 508 at different temperatures can be achieved by two heat exchangers 540, 550 in series, which are fed with separate oxygen-containing gas flows via lines 522 and 524, respectively. The first heat exchanger 540 and the second heat exchanger 550 can each be a tube-and-shell heat exchanger (such as a counter-flow heat exchanger as shown or a parallel flow heat exchanger). The first heat exchanger 540 can be upstream of the second heat exchanger 550 with respect to the flow direction of the flue gases passing through lines 502, 512, and 504 (from right to left in FIG. 3). The oxygen-containing gas in line 508 (the hotter stream) exits the first heat exchanger 540, and the oxygen-containing gas in line 510 (the cooler stream) exits the second heat exchanger 550. Specifically, the oxygen-containing gas in line 524 passes through a first heat exchanger 540 and is withdrawn from the first heat exchanger 540 in line 508. Similarly, the oxygen-containing gas in line 522 passes through a second heat exchanger 550 and is withdrawn from the second heat exchanger 550 in line 510. Because the flue gas in the first heat exchanger 540 is at a higher temperature than the flue gas in the second heat exchanger 550, the oxygen-containing gas in line 508 is at a higher temperature than the oxygen-containing gas in line 510.

[0038] In some embodiments, the oxygen-containing gas in line 524 followed by line 508 has a lower pressure than the oxygen-containing gas in line 522 followed by line 510. One advantage of the embodiment of FIG. 3 is that the pressures of lines 508 and 510 may be different, which is beneficial when different delivery pressures are required depending on the destination. For example, in some embodiments, the pressure of the oxygen-containing gas entering combustor 350 via line 508 may be lower than the pressure of line 510, which may desirably operate at a higher pressure. For example, line 508 may have a pressure of about 75 psia, e.g., 65-85 psia, while line 510 may have a pressure of about 50 psia, e.g., 40 psia-60 psia. The use of two heat exchangers allows the pressures of lines 508 and 510 to be different since the air sources can come from different stages of air compression.

[0039] In a non-limiting example, the reactor system 102 described herein may be utilized to produce light olefins from a hydrocarbon feed stream. Light olefins may be produced from a wide variety of hydrocarbon feed streams by utilizing different reaction mechanisms. For example, light olefins may be produced by at least dehydrogenation reactions, cracking reactions, dehydration reactions, and methanol to olefins reactions. These reaction types may utilize different feed streams and different particulate solids to produce light olefins. It should be understood that when "catalysts" are referred to herein, they may equally refer to the particulate solids referred to with respect to the system of FIG. 1.

[0040] According to one or more embodiments, the reaction may be a dehydrogenation reaction. According to such embodiments, the hydrocarbon feed stream may comprise one or more of ethylbenzene, ethane, propane, n-butane, and i-butane. In one or more embodiments, the hydrocarbon feed stream may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% ethylbenzene. In one or more embodiments, the hydrocarbon feed stream may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% ethane. In additional embodiments, the hydrocarbon feed stream may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% propane. In additional embodiments, the hydrocarbon feed stream may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% n-butane. In additional embodiments, the hydrocarbon feed stream may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% i-butane. In additional embodiments, the hydrocarbon feed stream may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of the sum of ethane, propane, n-butane, and i-butane.

[0041] In one or more embodiments, the dehydrogenation reaction may utilize gallium and / or platinum particulate solids as catalysts. In such embodiments, the particulate solids may include gallium and / or platinum catalysts. As described herein, the gallium and / or platinum catalysts include gallium, platinum, or both. The gallium and / or platinum catalysts 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.

[0042] In one or more embodiments, the reaction mechanism may be dehydrogenation followed by combustion (in the same chamber). In such embodiments, the dehydrogenation reaction may produce hydrogen as a by-product, and the oxygen carrier material may contact the hydrogen to promote combustion of the hydrogen to form water. Examples of such reaction mechanisms contemplated as possible reaction mechanisms for the systems and methods described herein are disclosed in WO2020 / 046978, the teachings of which are incorporated herein by reference in their entirety.

[0043] According to one or more embodiments, the reaction may be a cracking reaction. According to such embodiments, the hydrocarbon feed stream may comprise one or more of naphtha, n-butane, or i-butane. According to one or more embodiments, the hydrocarbon feed stream may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% naphtha. In additional embodiments, the hydrocarbon feed stream may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% n-butane. In additional embodiments, the hydrocarbon feed stream may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% i-butane. In additional embodiments, the hydrocarbon feed stream may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of naphtha, n-butane, and i-butane combined.

[0044] In one or more embodiments, the cracking reaction may utilize one or more zeolites as a catalyst. In such embodiments, the particulate solids may include one or more zeolites. In some embodiments, the one or more zeolites utilized in the cracking reaction may include ZSM-5 zeolites. However, it should be understood that other suitable catalysts may be utilized to carry out the cracking reaction. For example, suitable catalysts that are commercially available may include Intercat Super Z Excel or Intercat Super Z Exceed. In additional embodiments, the cracking catalyst may include platinum in addition to the catalytically active material. For example, the cracking catalyst may include 0.001% to 0.05% platinum by weight. The platinum may be sprayed as platinum nitrate and calcined at high temperatures, such as about 700° C. Without being bound by theory, it is believed that the addition of platinum to the catalyst may allow for easier combustion of auxiliary fuels, such as methane.

[0045] According to one or more embodiments, the reaction may be a dehydration reaction. According to such embodiments, the hydrocarbon feed stream may comprise one or more of ethanol, propanol, or butanol. According to one or more embodiments, the hydrocarbon feed stream may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% ethanol. In additional embodiments, the hydrocarbon feed stream may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% propanol. In additional embodiments, the hydrocarbon feed stream may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% butanol. In additional embodiments, the hydrocarbon feed stream may comprise 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 the total of ethanol, propanol, and butanol.

[0046] In one or more embodiments, the dehydration reaction may utilize one or more acid catalysts. In such embodiments, the particulate solid may include one or more acid catalysts. In some embodiments, the one or more acid catalysts utilized in the dehydration reaction may include a zeolite (such as ZSM-5 zeolite), an alumina, an amorphous aluminosilicate, an acid clay, or a combination thereof. For example, commercially available alumina catalysts that may be suitable include SynDol (available from Scientific Design Company), V200 (available from UOP), or P200 (available from Sasol), according to one or more embodiments. Commercially available zeolite catalysts that may be suitable include CBV 8014, CBV 28014 (each available from Zeolyst). Commercially available amorphous aluminosilicate catalysts that may be suitable include silica-alumina catalyst support, grade 135 (available from Sigma Aldrich). However, it should be understood that other suitable catalysts may be utilized to carry out the dehydration reaction.

[0047] According to one or more embodiments, the reaction can be a methanol to olefins reaction. According to such embodiments, the hydrocarbon feed stream can include methanol. According to one or more embodiments, the hydrocarbon feed stream can include at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% methanol.

[0048] In one or more embodiments, the methanol to olefins reaction may utilize one or more zeolites as a catalyst. In such embodiments, the particulate solid may include one or more zeolites. In some embodiments, the one or more zeolites utilized in the methanol to olefins reaction may include one or more of ZSM-5 zeolite or SAPO-34 zeolite. However, it should be understood that other suitable catalysts may be utilized to carry out the methanol to olefins reaction.

[0049] Several embodiments are described herein. In a first embodiment, a method for forming light olefins includes reacting a feed stream in a reactor in the presence of a catalyst to form a product stream; separating at least a portion of the product stream from the catalyst; transferring the catalyst to a catalytic section of a reactor system and processing the catalyst to produce a processed catalyst and flue gas, where the catalyst is heated in a combustor in the catalytic section, coke is removed from the catalyst, or both; separating the catalyst from the flue gas; passing the flue gas through a heat exchanger system to cool the flue gas, where heat is exchanged from the flue gas to an oxygen-containing gas in an inlet stream, the oxygen-containing gas exits the heat exchanger system in a first stream and a second stream, and the oxygen-containing gas in the first stream has a higher temperature than the oxygen-containing gas in the second stream; transferring the oxygen-containing gas in the first stream directly to the combustor, and transferring the oxygen-containing gas in the second stream as a solid transport fluid to one or more of a catalyst transport pipe or an oxygen processing zone.

[0050] Another embodiment includes any other embodiment in which the heat exchanger system comprises a heat exchanger that discharges a second flow of oxygen-containing gas upstream of the discharge of the first flow of oxygen-containing gas relative to the flow direction of the oxygen-containing gas through the heat exchanger.

[0051] Another aspect includes any other aspect in which the heat exchanger system includes a first heat exchanger and a second heat exchanger in series, the first heat exchanger being upstream of the second heat exchanger relative to the flow direction of the flue gas, a first flow of oxygen-containing gas being discharged from the first heat exchanger, and a second flow of oxygen-containing gas being discharged from the second heat exchanger.

[0052] Alternative embodiments include any other embodiment in which the oxygen-containing gas is air.

[0053] Alternative embodiments include any other embodiment that includes transferring the oxygen-containing gas in the second stream to the catalyst transport pipe as a solid transport fluid.

[0054] Alternative embodiments include any other embodiment in which the oxygen-containing gas in the second stream travels to a "J-bend" in the catalyst transport pipe.

[0055] Alternative embodiments include any other embodiment in which a catalyst transport pipe delivers catalyst to the combustor.

[0056] Alternative embodiments include any other embodiment that includes passing the oxygen-containing gas in the second stream to an oxygen treatment zone downstream of separation of the catalyst from the flue gas.

[0057] Alternative embodiments include any other embodiment in which the oxygen-containing gas in the second stream has a temperature between 200°C and 500°C.

[0058] Alternative embodiments include any other embodiment in which the oxygen-containing gas in the first stream has a temperature between 500°C and 875°C.

[0059] Alternative embodiments include any other embodiment in which the temperature of the oxygen-containing gas in the first stream is at least 100° C. higher than the temperature of the oxygen-containing gas in the second stream.

[0060] Alternative embodiments include any other embodiment in which the flue gas passing into the heat exchanger system has a temperature between 650°C and 900°C.

[0061] Alternative embodiments include any other embodiment in which the flue gas exiting the heat exchanger system has a temperature between 150°C and 400°C.

[0062] Alternative embodiments include any other embodiment in which the oxygen-containing gas in the inlet stream has a temperature between 0°C and 200°C.

[0063] Alternative embodiments include any other embodiment in which the mass flow rate of the oxygen-containing gas in the first stream is between 70% and 95% of the oxygen-containing gas in the inlet stream.

[0064] For purposes of describing and defining the present technology, it should be noted that the term "about" is utilized herein to express the degree of inherent uncertainty that may result from any quantitative comparison, value, measurement, or other representation. The term is also utilized herein to express the degree to which a quantitative representation may vary from the stated basis without resulting in a change in the basic functionality of the subject matter in question.

[0065] It should be noted that one or more of the claims below utilize the term "herein" 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."

[0066] 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 material into a particular system unit, and an outlet port allows for the outflow of material from a particular system unit. In general, an outlet port or inlet port defines an area of ​​a 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 a 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 features, and their respective functions in an operational system should not be construed as limiting their physical structure.

[0067] It will be apparent to those skilled in the art that various modifications and changes can be made to the present technology without departing from the spirit and scope of the present technology. Since combinations, subcombinations, and modifications of the disclosed embodiments incorporating the spirit and substance of the present technology can be conceived by those skilled in the art, the present technology should be construed as including all within the scope of the appended claims and their equivalents.

Claims

1. 1. A process for forming light olefins comprising the steps of: reacting a feed stream in a reactor in the presence of a catalyst to form a product stream; separating at least a portion of the product stream from the catalyst; moving the catalyst to a catalytic treater of a reactor system and treating the catalyst to produce treated catalyst and flue gas, wherein a combustor in the catalytic treater heats the catalyst, removes coke from the catalyst, or both; Separating the catalyst from the flue gas; moving the flue gas into a heat exchanger system to cool the flue gas, wherein heat is exchanged from the flue gas to an oxygen-containing gas in an inlet stream, the oxygen-containing gas exiting the heat exchanger system in a first stream and a second stream, the oxygen-containing gas in the first stream having a higher temperature than a temperature of the oxygen-containing gas in the second stream; transferring the oxygen-containing gas in the first stream directly to the combustor; transferring the oxygen-containing gas in the second stream as a solid transport fluid to one or more of a catalyst transport pipe or an oxygen treatment zone; A method comprising:

2. 2. The method of claim 1, wherein the heat exchanger system comprises a heat exchanger that discharges the oxygen-containing gas of the second stream upstream of the discharge of the oxygen-containing gas of the first stream relative to a flow direction of the oxygen-containing gas through the heat exchanger.

3. 2. The method of claim 1, wherein the heat exchanger system comprises a first heat exchanger and a second heat exchanger in series, the first heat exchanger being upstream of the second heat exchanger relative to a flow direction of the flue gas, the first flow of the oxygen-containing gas being discharged from the first heat exchanger, and the second flow of the oxygen-containing gas being discharged from the second heat exchanger.

4. The method according to any one of claims 1 to 3, wherein the oxygen-containing gas is air.

5. The method according to any one of claims 1 to 4, comprising transferring said oxygen-containing gas in said second stream as a solid transport fluid to a catalyst transport pipe.

6. 6. The method of claim 5, wherein the oxygen-containing gas in the second stream travels to a "J-bend" in the catalyst transport pipe.

7. The method of claim 6 , wherein the catalyst transport pipe delivers catalyst to the combustor.

8. A method according to any preceding claim, comprising passing the oxygen-containing gas in the second stream to an oxygen treatment zone downstream of separation of the catalyst from the flue gas.

9. The method of any of claims 1 to 8, wherein the oxygen-containing gas in the second stream has a temperature of from 200°C to 500°C.

10. The method of any of claims 1 to 9, wherein the oxygen-containing gas in the first stream has a temperature of from 500°C to 875°C.

11. The method according to any of the preceding claims, wherein the temperature of the oxygen-containing gas in the first stream is at least 100°C higher than the temperature of the oxygen-containing gas in the second stream.

12. A method according to any preceding claim, wherein the flue gas passed to the heat exchanger system has a temperature of between 650°C and 900°C.

13. A method according to any preceding claim, wherein the flue gas leaving the heat exchanger system has a temperature of from 150°C to 400°C.

14. A method according to any preceding claim, wherein the oxygen-containing gas in the inlet stream has a temperature of from 0°C to 200°C.

15. The method of any preceding claim, wherein the mass flow rate of the oxygen-containing gas in the first stream is between 70% and 95% of the oxygen-containing gas in the inlet stream.

Images