Method and apparatus for reacting a feed with a fluidized catalyst over a temperature profile

Abstract

A fluidized catalytic reactor utilizes an ascending temperature profile. The apparatus and method deliver cooler spent catalyst to a first catalyst distributor and warmer regenerated catalyst to a second catalyst distributor, the first and second catalyst distributors being spaced apart from each other. The reactant stream first encounters the first catalyst stream and then the second catalyst stream. The method and apparatus add hot catalyst to the reactant stream in stages. The method and apparatus can be particularly advantageous in endothermic reactions because the warmer catalyst encounters reactants that have cooled due to the endothermic reaction.

Description

[0001] Priority Declaration

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 16 / 942,240, filed on July 29, 2020, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to the reaction of a feed with a fluid catalyst. The present invention may specifically relate to reacting an alkane feed with a fluid dehydrogenation catalyst. Background Art

[0004] Light olefin production is crucial for producing enough plastics to meet global demand. Paraffin dehydrogenation (PDH) is a process by which light alkanes such as ethane and propane can be dehydrogenated to produce ethylene and propylene, respectively. Dehydrogenation is an endothermic reaction that requires external heat to drive the reaction to completion. Fluid catalytic cracking (FCC) is another endothermic process for producing the essential ethylene and propylene.

[0005] Dehydrogenation catalysts can utilize molecular sieves incorporating dehydrogenation metals or amorphous materials. The catalyst must be sufficiently robust and appropriately sized to withstand the expected grinding in the fluidized system. FCC catalysts are typically Y zeolite with an optional MFI zeolite to enhance propylene production.

[0006] In PDH and FCC reactions with fluidized catalysts, coke can be deposited on the catalyst while catalyzing the reaction. The catalyst can be regenerated in a catalyst regenerator by burning the coke from the catalyst in the presence of oxygen. The hot regenerated catalyst can then be transferred back to the reactor to catalyze the reaction. If insufficient heat is provided to drive the endothermic reaction, olefin production may be affected.

[0007] Compared to thermal cracking reactions, catalytic reactions are more selective for desired products such as propylene. Care must be taken to maximize the catalytic reaction relative to the thermal cracking reaction.

[0008] There is therefore a need for improved methods of contacting a feed with a catalyst in a fluid catalytic reaction process. Summary of the Invention

[0009] A fluidized catalytic reactor utilizes an ascending temperature profile. The apparatus and method deliver cooler spent catalyst to a first catalyst inlet and warmer regenerated catalyst to a second catalyst inlet, the first and second catalyst inlets being spaced apart from each other. The reactant stream first encounters the first catalyst stream and then the second catalyst stream. The method and apparatus distribute the hot catalyst to the reactant stream in stages. The method and apparatus can be particularly advantageous in endothermic reactions because the warmer catalyst encounters reactants that have cooled due to the endothermic reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic diagram of the method and apparatus of the present disclosure; and

[0011] Figure 2 Schematic diagram of a method and apparatus according to an alternative embodiment of the present disclosure.

[0012] definition

[0013] The term "communication" means that fluid flow is operatively permitted between enumerated components, which may be characterized as being in "fluid communication."

[0014] The term "downstream communication" means that at least a portion of the fluid flowing to the body in downstream communication can operatively flow from an object in fluid communication therewith.

[0015] The term "upstream communication" means that at least a portion of the fluid flowing out of the body in the upstream communication can be operatively flowed to an object in fluid communication therewith.

[0016] The term "direct communication" means that the fluid flows from the upstream component into the downstream component without passing through any other intervening container.

[0017] The term "indirect communication" means that the fluid flow from the upstream component enters the downstream component after passing through an intervening container.

[0018] The term "bypass" means that the object loses downstream communication with the bypassed body at least within the scope of the bypass.

[0019] As used herein, the term "predominantly" or "majority" means greater than 50%, suitably greater than 75%, and preferably greater than 90%. DETAILED DESCRIPTION

[0020] We have discovered methods and apparatus for providing a reactor with a varying temperature profile. In fluid catalytic reaction dynamics, by carefully ensuring that the reactants are not exposed to extremely high temperatures, the reaction will be directed toward greater selectivity for the desired product. In fluid catalytic endothermic reactions, the hot catalyst supplies the heat of reaction and catalyzes the conversion to the desired product. The catalyst is typically heated in a regenerator during the process of burning coke from the catalyst. The catalyst must transfer enough enthalpy to the reactor to supply the heat of reaction for all reactants in the feed. Providing enough heat to drive the endothermic conversion of all the feed distributed to the reactor while avoiding thermal cracking of the catalyst can be a challenge.

[0021] We have discovered a way to balance these two conflicting objectives by establishing a reaction zone with an ascending temperature profile. Hot catalyst is delivered to the reactor and brought into contact with the feed to initiate catalytic conversion. The feed and catalyst move toward another section of the reactor, where hotter catalyst is delivered and distributed to the partially converted feed. The ascending temperature profile avoids exposing the feed stream to overheated catalyst, which could promote non-selective thermal cracking. However, the portion of the feed that has not yet undergone conversion and has begun to cool due to the endothermic nature of the reaction will then be exposed to the hotter catalyst to increase the temperature of the cooled feed and provide sufficient heat to drive the reaction to increase the production of the desired product. The disclosed method and apparatus minimize or balance the time the feed is exposed to the hot catalyst.

[0022] The teachings herein are applicable to any process that requires catalyst regeneration to provide heat to drive an endothermic catalytic reaction. Alkane dehydrogenation (PDH) and fluid catalytic cracking (FCC) are examples of such processes. FCC catalysts are used to crack larger hydrocarbon molecules into smaller hydrocarbon molecules at approximately atmospheric pressure and temperatures between 427°C (800°F) and 538°C (1000°F) and a catalyst-to-oil ratio of 5 to 30. PDH catalysts are used in dehydrogenation processes to catalyze the dehydrogenation of alkanes such as ethane, propane, isobutane, and n-butane into olefins such as ethylene, propylene, isobutylene, and n-butene, respectively. The PDH process will be described exemplarily to illustrate the disclosed apparatus and methods.

[0023] The conditions in the dehydrogenation reactor may include a temperature of 500° C. to 800° C., a pressure of 40 kPa to 310 kPa, and a catalyst-to-oil ratio of 5 to 100. The dehydrogenation reaction may be carried out in a fluidized manner, such that a gas, which may contain the reactant alkane, with or without a fluidizing inert gas, is distributed to the reactor in a manner that elevates the dehydrogenation catalyst within the reactor vessel while catalyzing the dehydrogenation of the alkane. During the catalytic dehydrogenation reaction, coke is deposited on the dehydrogenation catalyst, resulting in a decrease in catalyst activity. The dehydrogenation catalyst must then be regenerated.

[0024] Figure 1An exemplary PDH reactor 12 is shown in FIG. The PDH reactor 12 may include two chambers: a reaction chamber 14 and a separation chamber 26. A feed line 10 may deliver a feed reactant stream to the reactor 12. The reactant stream may primarily comprise propane or butane, but other alkanes such as ethane may be present in the reactant stream along with or in place of the other alkanes. Any feed distributor may distribute the reactant stream to the reactor 12. A dome-shaped reactant distributor 32 may be utilized in the reaction chamber 14 of the reactor 12. The dome-shaped reactant distributor 32 receives the gaseous reactant stream through nozzles in the top dome of the dome-shaped reactant distributor 32 and distributes the reactant stream so as to distribute the reactant stream across the entire cross-section of the reaction chamber 14. It is contemplated that other fluidizing gases may also be used to promote fluidization in the reaction chamber 14. In an embodiment, the distributed reactant stream rises in the reaction chamber 14 and the reactor 12.

[0025] The recycle catalyst conduit 34 has an inlet 35 located in the separation chamber 26 and an outlet constituting a first catalyst inlet 39, which in embodiments may be connected to a first catalyst distributor 36. The recycle catalyst conduit 34 conveys a first recycled spent catalyst stream, which has not yet undergone regeneration, from the separation chamber 26 to the first section 38 of the reaction chamber 14 via the outlet and the first catalyst inlet 39, in embodiments, via the first catalyst distributor 36. The first catalyst inlet 39 and / or the first catalyst distributor 36 provide spent catalyst to the first section 38 of the reaction chamber 14. The recycled spent catalyst is fed to the reactor 12 via the first catalyst inlet 39, which is the outlet of the recycle catalyst conduit 34. The first catalyst inlet 39 and / or the first catalyst distributor 36 may be housed in the first reaction chamber 14.

[0026] The first catalyst distributor 36 may include a central conduit having conduits extending from the central conduit at different angles to distribute the spent catalyst horizontally across the entire cross-section of the reaction chamber 26. A gas assist, which may include a reactant gas or an inert gas such as steam, may be used to force the catalyst out of the conduits of the first spent catalyst distributor 36. The gas assist may be delivered from a pipeline through a nozzle 37 in the inlet to the first catalyst distributor 36. The recycled spent catalyst has been in contact with the reactant stream and has not been regenerated. Therefore, due to the endothermic nature of the reaction, the recycled spent catalyst has a reduced average temperature. However, the recycled spent catalyst still has sufficient enthalpy to catalyze and drive the conversion of the reactant stream distributed by the reactant distributor 32. The average temperature of the first catalyst stream may be 500°C to 800°C. Therefore, the temperature of the first reaction section 38 may be 450°C to 750°C.

[0027] In the first reaction zone 38, the fresh reactant stream contacts the first catalyst stream and the reactant alkanes begin to undergo conversion to olefins, typically propane to propylene. As the catalyst and reactants rise through the reactor, propelled by the reactant stream continuously entering the reactor through the reactant distributor 32, the endothermic dehydrogenation reaction absorbs heat from the mixture of the first catalyst stream and the reactant stream.

[0028] In order to supply additional heat and catalyst to the reaction chamber 14, a second catalyst inlet 43 delivers a second catalyst stream to the reactor 12, in an embodiment delivered through a second catalyst distributor 40. A regenerated catalyst conduit 16 has an inlet 17 located in the regenerator 20 and an outlet connected to the second catalyst inlet 43 and / or the second catalyst distributor 40. The regenerated catalyst conduit 16 delivers a second regenerated catalyst stream from the regenerator 20 to the second catalyst inlet 43 and / or the second catalyst distributor 40 via the outlet. The second catalyst inlet 43 and / or the second regenerated catalyst distributor 40 are housed in the second section 42 of the reaction chamber 14 and provide hot regenerated catalyst thereto. After the reactant stream contacts the first catalyst stream, the reactant stream contacts the second catalyst stream. In addition, the second catalyst stream has a higher temperature than the first catalyst stream. The second regenerated catalyst distributor 40 may include a central conduit having conduits extending from the central conduit at different angles to distribute the regenerated catalyst horizontally across the entire cross-section of the reaction chamber 14. Gas assist, which may include reactant gas or an inert gas such as steam, may be used to force the catalyst out of the conduit of the second regenerated catalyst distributor 40. A gas assist can be delivered from a pipeline through a nozzle 41 in the inlet to the second catalyst distributor 40. The regenerated catalyst has just undergone combustion regeneration and has a very hot average temperature and is active because coke deposits have been burned from the catalyst surface. Therefore, in the second section 42 of the reaction chamber 14, the reactant stream is provided with additional enthalpy and catalyst to catalytically convert alkanes to olefins, typically propane to propylene. The average temperature of the second catalyst stream can be 500°C to 900°C. Therefore, the temperature of the second reaction section 42 can be 400°C to 800°C. The first catalyst inlet 39 and / or the first catalyst distributor 36 are closer to the reactant distributor 32 than the second catalyst inlet 43 and / or the second catalyst distributor 40. The second catalyst inlet 39 can be spaced apart from the first catalyst inlet 39 and can be above the first catalyst inlet. The second catalyst distributor 40 can be spaced apart from the first catalyst distributor 36 and can be above the first catalyst distributor.

[0029] In the second reaction zone 42, the reactant stream contacts the second catalyst stream and the first catalyst stream that are mixed together in the second reaction zone, and the reactant alkane undergoes conversion to olefins, typically propane to propylene. The reactant stream and the first and second catalyst streams rise in the reaction chamber 14 of the reactor 12, driven by the reactant stream that continuously enters the reactor through the reactant distributor 32. At the interface 44, the fluid dynamics change from a catalyst dense phase to a fast fluidized flow state below the transition zone. The catalyst density in the catalyst dense phase is at least 200 kg / m 3 (12.5 lb / ft 3 ); and the catalyst density in the fast fluidized flow state is at least 100 kg / m 3 (6.3 lb / ft 3 The superficial velocity of the reactant streams and the first and second catalyst streams in the reaction chamber 14 will typically be at least 0.9 m / s (3 ft / s), suitably at least 1.1 m / s (3.5 ft / s), and preferably at least 1.4 m / s (4.5 ft / s) to 2.1 m / s (7 ft / s) to provide a fast fluidized flow regime. In the fast fluidized flow regime, the reactant gases and catalyst rise, wherein the catalyst can slide relative to the gas, and the gas can take an indirect upward trajectory.

[0030] The dehydrogenation catalyst can be any of a variety of catalysts suitable for fluidized dehydrogenation units. The selected dehydrogenation catalyst should minimize cracking reactions and be beneficial to the dehydrogenation reaction. Suitable catalysts for use herein include amorphous materials or molecular sieves that can be dispersed in porous inorganic support materials such as silica, aluminum, zirconium or clay. Exemplary embodiments of the catalyst include crystalline silica-alumina or silica-alumina-phosphate as the main active component, matrix, binder and filler.

[0031] The matrix component may include amorphous alumina or silica, and the binder and filler provide physical strength and integrity. Silica sol or alumina sol may be used as a binder, and kaolin may be used as a filler. The catalyst particles may have a nominal diameter of 20 to 150 microns and an average diameter of 70 to 90 microns.

[0032] The dehydrogenation catalyst may support a dehydrogenation metal. The dehydrogenation metal may be one or a combination of transition metals. Precious metals may be preferred dehydrogenation metals; however, IIB or IIIB metals may be suitable dehydrogenation metals, alone or in combination with other dehydrogenation metals. Iron, tungsten, gallium, copper, zinc, or zirconium, alone or in combination with each other or with precious metals, may be suitable dehydrogenation metals. In addition to the catalyst, a combustion promoter may also be utilized. The metal may be incorporated into the lattice structure of the molecular sieve.

[0033] The acid functionality of the catalyst should be minimized to prevent cracking and facilitate dehydrogenation. Alkali metals and alkaline earth metals may also be included in the catalyst to reduce the acidity of the catalyst. Rare earth metals may be included in the catalyst to control the activity of the catalyst. The metal may be incorporated into the catalyst at a concentration of 0.05% to 10% by weight. In the case of noble metals such as platinum, it is preferred to use 0.05% to 2% by weight of the noble metal.

[0034] The reactant stream lifts the first catalyst stream, which mixes with the second catalyst stream, upward in the reaction chamber while alkanes are converted to olefins in the presence of the dehydrogenation catalyst, which gradually becomes spent catalyst due to the accumulation of coke deposits on the catalyst. A fluidizing inert gas may be distributed to the reaction chamber to assist in lifting the catalyst and reactant mixture upward in the reaction chamber 14. As it ascends in the reaction chamber 14, the reactant gas is converted to product gas. The gas and catalyst mixture ascends from the reaction chamber 14 through a frusto-conical transition section 45 into a transport riser 46, which has a diameter smaller than the diameter 40 of the combustion chamber 20. The gas and catalyst mixture is accelerated in the narrower transport riser 46 and discharged from a primary catalyst separator 48 into the separation chamber 26. The primary catalyst separator 48 may be a riser termination device that utilizes horizontal, centripetal acceleration to separate the spent catalyst from the product gas. The curved conduit of the primary catalyst separator 48 guides the mixture of product gas and catalyst to exit from the riser 46 in a generally horizontal angular direction, accelerating the centripetally, thereby causing the denser catalyst to move outward under the action of gravity. The catalyst loses angular momentum and falls into the lower catalyst bed 49 depicted by the upper boundary. The lighter gas rises in the separation chamber 26 and enters the cyclone separators 50, 52. The cyclone separators 50, 52 may include a first cyclone separation stage and a second cyclone separation stage to further remove catalyst from the product gas. The product gas is transported to the plenum 54 by a conduit, and the product gas is discharged from the plenum 54 through the product outlet 56 in the product line from the reactor 12. The first catalyst inlet 39 and the second catalyst inlet 43 are closer to the product outlet 56 than to the reactant distributor 32. The primary catalyst separator 48 is located closer to the first catalyst inlet 39 and the second catalyst inlet 43 than to the product outlet 56. In an embodiment, the first catalyst distributor 36 and the second catalyst distributor 40 are closer to the reactant distributor 32 than to the product outlet 56. In addition, the primary catalyst separator 48 is located closer to the first catalyst distributor 36 and the second catalyst distributor 40 than to the product outlet 56. The superficial gas velocity in the transport riser 46 will be 12 m / s (40 ft / s) to 20 m / s (70 ft / s) and have a flow rate of 64 kg / m 3 (4lb / ft 3 ) to 160kg / m 3 (10lb / ft 3) density, thus constituting a catalyst dilute phase.

[0035] The catalyst separated from the product gas by the primary catalyst separator 48 falls into the dense catalyst bed 49. In one aspect, the primary cyclone 50 can collect the product gas from the separation chamber 26 and transport the product gas separated from the catalyst to the secondary cyclone 52 to further separate the catalyst from the product gas, and then guide the secondary purified product gas to the plenum 54. The catalyst separated from the product gas in the cyclone separators 50, 52 is distributed into the dense catalyst bed 49 through the dipleg. At this point, the catalyst separated in the separation chamber 26 is considered to be spent catalyst because the deposits of coke are agglomerated on it. The regenerated portion of the spent catalyst collected in the dense bed 49 in the separation chamber 26 is transported to the catalyst regenerator 20 in the spent catalyst conduit 18 to burn the coke from the catalyst, thereby regenerating and heating the dehydrogenation catalyst. The vertical section of the spent catalyst conduit 18 may include a stripping section 60. A stripping gas, such as steam or another inert gas, may be fed into the lower end of the stripping section 60 to strip hydrocarbons from the spent catalyst entering the stripping section 60. Baffles may also be provided in the stripping section 60 to cause the spent catalyst to travel laterally in the stripping section, thereby exposing more catalyst particles to the upwardly flowing stripping gas.

[0036] The recycled portion of the spent catalyst collected in the dense bed 49 of the separation chamber 26 enters the recycle catalyst conduit 34 through the inlet 35. The recycled portion of the spent catalyst is recycled in the recycle catalyst conduit 34 back to the first catalyst inlet 39 and / or the first catalyst distributor 36 in the reaction chamber 14 of the reactor 12 as a first catalyst stream. The recycled portion of the spent catalyst is not regenerated before being returned to the reaction chamber 14.

[0037] The separation chamber 26 may include a disengagement drum 70 surrounding the upper end of the riser 46 and the primary separator 48. A vertical wall 71 of the disengagement drum 70 is spaced from the separation chamber housing 27 to define an annular portion 72. The diplegs of the cyclones 50 and 52 may be located in the annular portion 72. The disengagement drum 70 serves to limit the travel of the product gas from the primary separator 48 so as to reduce the time the product gas spends in the reactor 12, thereby mitigating non-selective cracking reactions of undesirable products. The top of the disengagement drum 70 may be hemispherical and feed a gas recovery conduit 74 that transports the product gas to a conduit 76 that is directly conduit-connected or connected to the primary cyclone 50. The direct conduit connection from the disengagement drum 70 to the primary cyclone 50 also prevents the product gas from escaping into the larger volume of the reactor vessel, where excessive residence time may occur to allow non-selective cracking. A window in the lower section of the wall 71 of the disengagement tank 70 allows the catalyst in the disengagement tank to enter the recycle catalyst conduit 34 or the regeneration conduit 18. A quenching fluid, such as condensed product liquid or even cold catalyst, can be injected into the product gas through the quench nozzle 80 to cool the product gas to below the cracking temperature to limit non-selective cracking. The quenching fluid is advantageously injected into the gas recovery conduit 74 that directs the separated product gas to a narrow location. The gas recovery conduit 74 is connected downstream to the primary catalyst separator 48 that separates the majority of the spent catalyst from the product gas. The spent catalyst bypasses the quenching to retain heat in the catalyst. The product gas separated from the majority of the catalyst in the catalyst subjects a reduced amount of material to quenching, thereby requiring less quenching fluid to achieve sufficient cooling to reduce the temperature of the product gas to below the cracking temperature.

[0038] The stripped spent dehydrogenation catalyst is transported via spent catalyst line 18 to regenerator 20 to burn the coke on the spent catalyst and regenerate the spent catalyst into regenerated catalyst. Catalyst regenerator 20 includes a combustion chamber 21 and a catalyst separator 23. When the flue gas generated in combustion chamber 21 is discharged from catalyst separator 23, the catalyst separator separates the regenerated catalyst from the flue gas. An oxygen supply gas is provided to combustion chamber 21, which lifts the spent catalyst in combustion chamber 21 through catalyst separator 23 and into separation chamber 25. The coke is burned off the spent catalyst by contact with the oxygen supply gas under regeneration conditions. In an exemplary embodiment, air is used as the oxygen supply gas because it is readily available and provides sufficient oxygen for combustion. 10 kg to 15 kg of air is required for each kilogram of coke burned off the spent catalyst. Exemplary regeneration conditions include a temperature in regenerator 20 of 500°C (900°F) to 900°C (1700°F) and a pressure of 103 kPa (abs) (15 psia) to 450 kPa (abs) (70 psia). A hydrocarbon fuel may be added to the regenerator 20 , such as through a nozzle 28 , to facilitate heat generated in the regenerator to drive the reaction in the reactor 12 .

[0039] The regenerated catalyst is returned to the reactor 12 in the regenerated catalyst conduit 16. The regenerated catalyst conduit 16 has an inlet 17 connected to the regenerator 20 in the separation chamber 25, through which the regenerated catalyst from the regenerator is transported to the second catalyst distributor 40 in the reactor 12 as a second, hotter catalyst stream. The regenerated catalyst is fed to the reactor 12 through a second catalyst inlet 43, which is the outlet of the regenerated catalyst conduit 16. The regenerated catalyst conduit 16 is connected to the second catalyst inlet 43, which can deliver the regenerated catalyst to the reactor 12 without the aid of a distributor.

[0040] Figure 2 An alternative embodiment of a reactor 12' is shown that utilizes three reaction zones and three reactant distributors in a reaction chamber 14', rather than three reactors. Figure 1 Two reaction sections and two reactant distributors in the embodiment of Figure 1 The same configuration Figure 2 The elements in will have Figure 1 With the same reference numerals as in Figure 1 The corresponding components in different configurations Figure 2 Elements in the same figure have the same reference numerals but are indicated by a prime ('). Figure 2 The configuration and operation of the embodiment of Figure 1 Same as in with the following exceptions.

[0041] Between the first catalyst inlet 39 and / or the first catalyst distributor 36 and the second catalyst inlet 43' and / or the second catalyst distributor 40' in the reaction chamber 14' are a third catalyst inlet 94 and a fourth catalyst inlet 95. In an embodiment, the third catalyst inlet 94 and the fourth catalyst inlet 95 feed the third catalyst distributor 90. The third catalyst inlet 94 and / or the third catalyst distributor 90 receive recycled spent catalyst from a branch of the recycle conduit 34'. The fourth catalyst inlet 95 and / or the third catalyst distributor 90 receive regenerated catalyst from the regenerator through a branch of the regenerated catalyst conduit 16'. The two catalyst streams may be mixed in the third catalyst distributor 90 or between the third catalyst inlet 94 and the fourth catalyst inlet 95 to provide a third catalyst stream from the third catalyst distributor 90 at an intermediate temperature between the temperature of the first catalyst stream from the first catalyst inlet 39 and / or the first catalyst distributor 36 and the second catalyst stream from the second catalyst inlet 43' or the second catalyst distributor 40', in an embodiment. The second catalyst inlet 43' and / or the second catalyst distributor 40' is located at a temperature that is lower than the temperature of the first catalyst stream from the first catalyst inlet 39 and / or the first catalyst distributor 36. Figure 1The catalyst inlet 94 is located at a higher height in the separation chamber 26 to make room for the third catalyst inlet 94, the fourth catalyst inlet 95, and / or the third catalyst distributor 90. The regenerated catalyst conduit 16' has an inlet 17 located in the regenerator 20 and an outlet on a branch connected to the second catalyst inlet 43' and / or the second catalyst distributor 40', and an outlet on a branch connected to the fourth catalyst inlet 95 and / or the third catalyst distributor 90. The regenerated catalyst conduit 16 delivers the second regenerated catalyst stream from the regenerator 20 through the outlet to the second catalyst inlet 43' and / or the second catalyst distributor 40', and through the outlet to the fourth catalyst inlet 95 and / or the third catalyst distributor 90. The spent catalyst conduit 34' has an inlet 35 located in the separation chamber 26 and an outlet connected to the first catalyst inlet 39 and / or the first catalyst distributor 36, and an outlet connected to the third catalyst inlet 94 and / or the third catalyst distributor 90, which is opposite the fourth catalyst inlet 95 at the outlet of the regenerated catalyst conduit 16'. The spent catalyst conduit 34' transports the recycled spent catalyst from the separation chamber 26 through the outlet on the branch to the first catalyst inlet 39 and / or the first catalyst distributor 36, and transports it through the outlet on the branch to the third catalyst inlet and / or the third catalyst distributor 90. The third catalyst inlet 94 and the fourth catalyst inlet 95 and / or the third catalyst distributor 90 provide a mixture of hot regenerated catalyst and relatively cool spent catalyst to the third section 92 of the reaction chamber 14', forming a third catalyst stream. The third catalyst inlet 94 and the fourth catalyst inlet 95 can be spaced apart from the first catalyst distributor 36 and can be above the first catalyst distributor. The third catalyst distributor 90 can be spaced apart from the first catalyst distributor 36 and can be above the first catalyst distributor. After the reactant stream contacts the first catalyst stream, the reactant stream contacts the third catalyst stream. In addition, the third catalyst stream has a higher temperature than the first catalyst stream.

[0042] The third catalyst distributor 90 may include a central conduit with conduits extending from the central conduit at various angles to horizontally distribute the mixed spent catalyst and regenerated catalyst across the entire cross-section of the reaction chamber 14'. Gas assist, which may include reactant gas or an inert gas such as steam, may be used to force the catalyst through the third catalyst inlet 94, the fourth catalyst inlet, and / or the conduits exiting the third catalyst distributor 90. Gas assist may be delivered from a pipeline through nozzle 91 in the fourth catalyst inlet 95 to the third catalyst distributor 90 and through nozzle 93 in the third catalyst inlet 94 on the opposite side. In the third section 92 of the reaction chamber 14', the reactant stream is provided with additional enthalpy and catalyst to catalytically convert alkanes to olefins, typically propane to propylene. The average temperature of the third catalyst stream may be between the average temperature of the first catalyst stream and the average temperature of the second catalyst stream. Thus, the temperature of the third reaction zone 92 may be between the temperatures of the first reaction zone 38 and the second reaction zone 42'. The third catalyst inlet 94 and the fourth catalyst inlet 95 are located closer to the reactant distributor 32 than the second catalyst distributor 40'. The third catalyst distributor 90 is located closer to the reactant distributor 32 than the second catalyst distributor 40'. Then, after the reactant stream contacts the first and third catalyst streams, the reactant stream contacts the hottest second catalyst stream. The use of the third catalyst distributor extends the temperature profile of the catalyst distributed to the reaction chamber 14' over a greater height of the reactor 12'.

[0043]

[0014] Embodiments herein provide methods and apparatus for contacting a reactant stream with a fluidized catalyst utilizing an ascending temperature profile.

[0044] Specific implementation plan

[0045] While the following is described in conjunction with specific embodiments, it should be understood that this description is intended to illustrate and not to limit the scope of the foregoing description and the appended claims.

[0046] A first embodiment of the present invention is a method for contacting a reactant stream with a catalyst, the method comprising: feeding a reactant stream to a reactor; contacting the reactant stream with a first catalyst stream to produce a product gas; after contacting the reactant stream with the first catalyst stream, contacting the reactant stream with a second catalyst stream to produce a product gas, the second catalyst stream having a higher temperature than the first catalyst stream; separating the first catalyst stream and the second catalyst stream from the product gas; and discharging the product gas from the reactor. An embodiment of the present invention is one, any, or all of the previous embodiments in this paragraph through the first embodiment in this paragraph, wherein the first catalyst stream and the second catalyst stream separated from the product gas contain spent catalyst, and the method further comprises regenerating a portion of the spent catalyst to provide the second catalyst stream. An embodiment of the present invention is one, any, or all of the previous embodiments in this paragraph through the first embodiment in this paragraph, further comprising mixing the regenerated catalyst stream with another portion of the spent catalyst to provide a third catalyst stream and the second catalyst stream. Embodiments of the present invention are one, any or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the first catalyst stream and the second catalyst stream separated from the product gas contain spent catalyst, and the method further includes recycling a portion of the spent catalyst without regeneration to provide the first catalyst stream. Embodiments of the present invention are one, any or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, further including mixing the first catalyst stream and the second catalyst stream in the reactor. Embodiments of the present invention are one, any or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, further including forcing the reactant stream and the first catalyst stream and the second catalyst stream to flow upward in the reactor. Embodiments of the present invention are one, any or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, further including contacting the reactant stream with the first catalyst stream and the second catalyst stream in a first chamber, and separating the first catalyst stream and the second catalyst stream from the product gas in a second chamber to provide spent catalyst. An embodiment of the invention is one, any or all of the prior embodiments in this paragraph through the first embodiment in this paragraph, further comprising regenerating a portion of the spent catalyst from the second chamber to provide the second catalyst stream, and recycling another portion of the spent catalyst from the second chamber to provide the first catalyst stream.

[0047] A second embodiment of the present invention is a method of contacting an alkane reactant stream with a dehydrogenation catalyst, comprising: feeding the alkane reactant stream to a reactor; contacting the alkane reactant stream with a first dehydrogenation catalyst stream to produce an olefin product gas; after contacting the alkane reactant stream with the first dehydrogenation catalyst stream, contacting the alkane reactant stream with a second dehydrogenation catalyst stream to produce an olefin product gas, the second dehydrogenation catalyst stream having a higher temperature than the first dehydrogenation catalyst stream; separating the first dehydrogenation catalyst stream and the second dehydrogenation catalyst stream from the olefin product gas; and withdrawing the olefin product gas from the reactor. Embodiments of the present invention are one, any, or all of the preceding embodiments in this paragraph through the first embodiment in this paragraph, wherein the first dehydrogenation catalyst stream and the second dehydrogenation catalyst separated from the olefin product gas comprise spent dehydrogenation catalyst, and the method further comprises regenerating a portion of the spent dehydrogenation catalyst to provide the second dehydrogenation catalyst stream and recycling another portion of the spent dehydrogenation catalyst to provide the first dehydrogenation catalyst stream. Embodiments of the invention are one, any or all of the prior embodiments in this paragraph through the first embodiment in this paragraph, further comprising contacting the alkane reactant stream with the first dehydrogenation catalyst stream and the second dehydrogenation catalyst stream in a first chamber, and separating the first dehydrogenation catalyst stream and the second dehydrogenation catalyst stream from the olefin product gas in a second chamber to provide spent dehydrogenation catalyst. Embodiments of the invention are one, any or all of the prior embodiments in this paragraph through the first embodiment in this paragraph, further comprising forcing the alkane reactant stream and the first dehydrogenation catalyst stream and the second dehydrogenation catalyst stream to flow upward in the reactor.

[0048] Although there is no further detailed description, it is believed that those skilled in the art can utilize the present disclosure to its fullest extent by using the foregoing description and can easily ascertain the essential characteristics of the present disclosure without departing from the spirit and scope of the present disclosure, and can make various changes and modifications to the present disclosure and adapt it to various usages and conditions. Therefore, the foregoing preferred specific embodiments should be construed as merely illustrative and not limiting the remainder of the present disclosure in any way, and are intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0049] In the foregoing, all temperatures are set forth in degrees Celsius and all parts and percentages are by weight unless otherwise indicated.

Claims

1. A reactor for contacting a reactant stream with a catalyst, comprising: a reactant distributor, the reactant distributor being used to distribute the reactant flow to the reactor; a first catalyst inlet for feeding a first catalyst stream to the reactor; a second catalyst inlet for feeding a second catalyst stream to the reactor, the first catalyst inlet being closer to the reactant distributor than the second catalyst inlet; a product outlet, the product outlet being used to discharge a product from the reactor, the second catalyst inlet being closer to the reactant distributor than the product outlet; a regenerated catalyst conduit connected to the second catalyst inlet, the regenerated catalyst conduit having an inlet connected to a catalyst regenerator; a reaction chamber containing the first catalyst inlet and the second catalyst inlet and a separation chamber including a primary catalyst separator for separating catalyst from product gas, the primary catalyst separator being located closer to the second catalyst inlet than to the product outlet; a recycle catalyst conduit connected to the first catalyst inlet, the recycle catalyst conduit having an inlet in the separation chamber; and The second catalyst inlet is spaced apart from the first catalyst inlet and is located above the first catalyst inlet.

2. The reactor of claim 1, further comprising a disengagement tank surrounding the primary catalyst separator located in the separation chamber, the disengagement tank having a wall spaced apart from the shell of the separation chamber.

3. The reactor of claim 2, further comprising a plurality of cyclone separators in the separation chamber and direct conduits from the disengaging tank to the cyclone separators.

4. The reactor of claim 3, further comprising a baffle extending from the wall of the disengaging tank to the wall of the separation chamber and a dipleg of the cyclone separator protruding through an aperture in the baffle.

5. The reactor of claim 1 , further comprising feeding the first catalyst stream to the reactor through a first catalyst distributor and feeding the second catalyst stream to the reactor through a second catalyst distributor, and wherein the first catalyst distributor and the second catalyst distributor At least one of the catalyst distributors includes a central conduit having conduits extending therefrom.

6. A method of contacting a reactant stream with a catalyst, comprising: Feeding a reactant stream to the reactor according to any one of claims 1 to 5; contacting the reactant stream with a first catalyst stream to produce a product gas; contacting the reactant stream with a second catalyst stream after contacting the reactant stream with the first catalyst stream to produce a product gas, the second catalyst stream having a higher temperature than the first catalyst stream; separating the first catalyst stream and the second catalyst stream from a product gas; as well as The product gas is discharged from the reactor.

7. The method of claim 6, wherein the first catalyst stream and the second catalyst stream separated from the product gas comprise spent catalyst, and further comprising regenerating a portion of the spent catalyst to provide the second catalyst stream.

Images