Method and apparatus for distributing fuel and air to a catalyst regenerator

Abstract

An oxygen stream is distributed to the spent catalyst stream through oxygen nozzles of an oxygen distributor and a fuel gas stream is distributed to the spent catalyst stream through fuel nozzles of a fuel gas distributor. Oxygen jets generated from the oxygen nozzles and fuel gas jets generated from the fuel gas nozzles have the same height in the regenerator. In the regenerator, the oxygen distributor and the fuel gas distributor can be located in a mixing chamber. The fuel outlets of the fuel nozzles of the fuel gas distributor can be within one fifth of the mixing chamber height from the oxygen outlets of the oxygen nozzles of the oxygen distributor. Furthermore, a clear space is provided between the fuel gas nozzles on the fuel gas distributor and the nearest oxygen nozzles on the oxygen distributor.

Description

[0001] CLAIM OF PRIORITY

[0002] This application claims priority to U.S. Patent Application Serial No. 17 / 200,286, filed March 12, 2021, the entirety of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The field is the regeneration of catalysts, particularly the combustion of coke from fluidized catalysts. BACKGROUND

[0004] Light olefin production is critical to produce enough plastic to meet global demand. Paraffin dehydrogenation (PDH) is a process in which light paraffins such as ethane and propane can be dehydrogenated to make 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 to produce essential ethylene and propylene.

[0005] In both 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 combusting 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. However, the coke produced in the PDH reaction can provide insufficient heat from the combustion in the regenerator to facilitate the endothermic dehydrogenation process. Insufficient heat from the regenerated catalyst delivered to the reactor has been observed recently in FCC due to advances in stripping efficiency, resulting in less hydrocarbons on the spent catalyst delivered to the catalyst regenerator. Therefore, a supplemental fuel (such as fuel gas) can be fed to the catalyst regenerator to sufficiently heat the catalyst to transfer enough enthalpy to drive the endothermic reaction. Conversely, if insufficient heat is provided to drive the endothermic reaction, then olefin production can be impacted.

[0006] Dehydrogenation catalysts can utilize molecular sieves incorporated with dehydrogenation metals or amorphous materials. The catalyst must be robust enough and the right size to be able to withstand the abrasion expected in a fluidization system. FCC catalysts are typically Y zeolites with optional MFI zeolites to enhance propylene production.

[0007] The regeneration process and equipment must be designed to minimize damage to the catalyst and the regeneration equipment. This can be particularly challenging when fuel gas is added to the regenerator, which can promote hot spots in areas where the heat means is insufficient to disperse the heat. High levels of steam and catalyst mixing ensure complete combustion of the supplemental fuel gas and good heat transfer between the steam and the catalyst. The catalyst is a large heat sink, so the supplemental fuel gas should be combusted in close contact with sufficient catalyst to avoid excessive temperatures. Excessive catalyst temperatures can result in thermal damage to the surrounding catalyst and regeneration equipment as the heat cannot be adequately dispersed.

[0008] Poor mixing between the air and the supplemental fuel gas or insufficient contact time between the fuel gas, air, and catalyst can result in incomplete combustion of the coke on the catalyst or fuel gas. Unburned fuel gas that persists downstream of the primary catalyst separation equipment will tend to burn in the lean catalyst phase in a phenomenon known as afterburning, resulting in excessive temperatures as most of the catalyst heat sink has been separated from the gas. If for some reason the unburned fuel gas exits the regenerator without being completely combusted, the steam exiting the regenerator has the potential to burn in downstream equipment that is not rated for the high temperatures common in regenerators or results in the unburned fuel gas being released to the atmosphere. The conditions in the regenerator should be selected to minimize the occurrence of flames, which can damage the catalyst and equipment due to their intense heat.

[0009] Accordingly, there is a need for improved methods of contacting the catalyst with fuel gas and air and mixing the fuel and air during catalyst regeneration. SUMMARY

[0010] Oxygen and fuel gas are mixed in the catalyst regenerator by distributing them to the same location in the catalyst regenerator. The oxygen stream is distributed to the spent catalyst stream by oxygen nozzles of an oxygen distributor and the fuel gas stream is distributed to the spent catalyst stream by fuel nozzles of a fuel gas distributor. The oxygen jets generated from the oxygen nozzles and the fuel gas jets generated from the fuel gas nozzles have the same height in the regenerator. In the regenerator, the oxygen distributor and the fuel gas distributor can be located in a mixing chamber. The fuel outlets of the fuel nozzles of the fuel gas distributor can be within one fifth of the mixing chamber height from the oxygen outlets of the oxygen nozzles of the oxygen distributor. In additional embodiments, the fuel gas distributor can be below the oxygen distributor. In another embodiment, a clear space is provided between the fuel gas nozzles on the fuel gas distributor and the nearest oxygen nozzle on the oxygen distributor.

[0011] These arrangements ensure that the oxygen and fuel gas are mixed sufficiently in the regenerator to provide controlled combustion to heat and regenerate the spent catalyst in the regenerator. Attached Figure Description

[0012] Figure 1 This is a schematic front view of the method and apparatus of this disclosure;

[0013] Figure 2 For Figure 1 The front sectional view taken from line segment 2-2;

[0014] Figure 3 For Figure 1 A planar sectional view taken from line segment 3-3;

[0015] Figure 4 for Figure 1 A partial schematic front view of an alternative implementation scheme;

[0016] Figure 5 For Figure 4 A planar sectional view taken from line segment 5-5;

[0017] Figure 6 For Figure 4 A plan sectional view of an alternative embodiment, taken from line segment 5-5; and

[0018] Figure 7 for Figure 1 A partial schematic front view of an alternative implementation scheme.

[0019] definition

[0020] The term "connectivity" refers to the operative permission for fluid flow between enumerated components, which can be characterized as "fluid connectivity".

[0021] The term "downstream connectivity" means that in downstream connectivity at least a portion of the fluid flowing toward the body can be operatively flowed from the object with which it is fluidly connected.

[0022] The term "fuel gas" includes hydrocarbons, hydrogen, and mixtures thereof.

[0023] As used herein, the terms “major” or “most” mean greater than 50%, suitably greater than 75%, and preferably greater than 90%. Detailed Implementation

[0024] This disclosure provides a method and apparatus that facilitates thorough contact between the gas and the catalyst during supplemental fuel combustion to decarbonize the catalyst and heat it to a temperature sufficient to drive an endothermic reaction in the reactor. Combustion in the regenerator is necessary to balance heat generation between the regenerator and the reactor. The supplemental fuel gas is thoroughly mixed with oxygen, such as air, to provide consistent combustion without creating hot spots in the regenerator that could damage equipment and catalyst exposed to high-temperature intrusion.

[0025] The teachings herein can be applied to any process that requires a catalyst to be regenerated for an endothermic reaction. Paraffin 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 about atmospheric pressure and about 427°C (800°F) to 538°C (1000°F) and a catalyst to oil ratio of about 5 to about 30. PDH catalysts are used in a dehydrogenation reaction process to catalyze the dehydrogenation of ethane and / or propane to ethylene and propylene. A PDH process will be described exemplarily to illustrate the disclosed apparatus and method.

[0026] Conditions in the dehydrogenation reaction can include a temperature of about 500°C to about 800°C, a pressure of about 40 kPa to about 310 kPa, and a catalyst to oil ratio of about 5 to about 100. The dehydrogenation reaction can be conducted in a fluidized manner such that a gas of either the reactant paraffin or an inert gas for fluidization is distributed to the reactor in a manner that lifts the dehydrogenation catalyst in the reactor vessel while catalyzing the dehydrogenation of propane and / or ethane. During the catalytic dehydrogenation reaction, coke is deposited on the dehydrogenation catalyst, reducing the activity of the catalyst. The dehydrogenation catalyst must then be regenerated.

[0027] The spent catalyst standpipe 12 transports spent catalyst from a dehydrogenation reactor (not shown) to the catalyst regenerator 10 through a control valve. The heated regenerated catalyst from the regenerator 10 is transported back to the dehydrogenation reactor in a return regenerated catalyst standpipe 14 through a control valve, the regenerated catalyst having a lesser concentration of carbon or coke than the spent catalyst standpipe 12 to catalyze the dehydrogenation reaction and provide sufficient enthalpy to drive the endothermic dehydrogenation reaction.

[0028] The dehydrogenation catalyst can be any of a variety of catalysts suitable for use in a fluidized dehydrogenation unit. The selected dehydrogenation catalyst should minimize cracking reactions and favor dehydrogenation reactions. Catalysts suitable for use herein include amorphous materials or molecular sieves that can be dispersed in a porous inorganic support material such as silica, alumina, zirconia, or clays. Exemplary embodiments of the catalyst include crystalline silica-alumina or silica-alumina-phosphate as the primary active component, matrix, binder, and filler.

[0029] The primary active component is in the range of about 10 to about 50 weight percent of the catalyst and can have a crystal lattice structure that limits the size range of hydrocarbon molecules that can enter the lattice. Molecular sieves suitable for the primary active component should have a medium and small average pore size. Generally, molecular sieves having a medium and small average pore size have pores with openings of no more than 0.7 nm in the effective diameter defined by ten or fewer rings.

[0030] The matrix component can include amorphous alumina or silica, and the binder and filler provide physical strength and integrity. A silica sol or alumina sol can be used as the binder, and kaolin can be used as the filler. The nominal diameter of the catalyst particles can be from about 20 microns to about 150 microns, and the average diameter can be from about 70 microns to about 90 microns.

[0031] The dehydrogenation catalyst can support a dehydrogenation metal. The dehydrogenation metal can be one or a combination of transition metals. A noble metal can be the preferred dehydrogenation metal; however, a Group IIB or Group IIIB metal can be a suitable dehydrogenation metal, either alone or in combination with other dehydrogenation metals. Iron, tungsten, gallium, copper, zinc, or zirconium, alone or in combination with each other or with a noble metal, can be suitable dehydrogenation metals. In addition to the catalyst, a combustion promoter can also be utilized. The metal can be incorporated into the crystal lattice structure of the molecular sieve.

[0032] The acid functionality of the catalyst should be minimized to prevent cracking and to favor dehydrogenation. Alkali and alkaline earth metals can also be included in the catalyst to attenuate the acidity of the catalyst. Rare earth metals can be included in the catalyst to control the activity of the catalyst. Metals can be incorporated into the catalyst at a concentration of 0.05 wt% to 10 wt%. For noble metals, it is preferred to use about 0.05 wt% to about 2 wt% of the noble metal.

[0033] The spent catalyst is transported to a catalyst regenerator 10 to burn off coke and regenerate the spent catalyst into a regenerated catalyst. The catalyst regenerator 10 includes a combustion chamber 20 and a catalyst separator 22 in which the regenerated catalyst is separated from the flue gas generated in the combustion chamber 20. An oxygen distributor 52 provides oxygen from an oxygen line 49 to the combustion chamber 20, which lifts the spent catalyst in the combustion chamber 20 into the separation chamber 22. The oxygen nozzles 55 on the oxygen distributor 52 have oxygen outlets 56 from which the oxygen jets 57 are generated. The oxygen jets 57 are streams of oxygen such as air emitted from the oxygen outlets 56 of the oxygen nozzles 55 that are contiguous to the oxygen outlets. The oxygen nozzles 55 can be pointed downward, meaning that the oxygen outlets 56 are below the oxygen distributor 52 and / or at the lower end of the oxygen nozzles 55.

[0034] In one embodiment, the oxygen distributor 52 includes a plurality of oxygen nozzles 55, each having an oxygen outlet 56 from which an oxygen jet 57 is generated. The oxygen nozzles 55 can extend from an oxygen header 58 that conveys oxygen from the oxygen line 49 to the oxygen nozzles. The oxygen nozzles 55 distribute oxygen through the respective oxygen outlets 56 to produce the oxygen jets 57. The oxygen nozzles 55 can be pointed downward, meaning that the respective oxygen outlets 56 are below the oxygen distributor 52 and / or at the lower end of the oxygen nozzles 55. The oxygen distributor 52 can be lined with a refractory material.

[0035] The coke is burned off the spent catalyst by contact with oxygen under regenerative conditions. In an exemplary embodiment, air is used as the oxygen because air is readily available and provides sufficient oxygen for the combustion, but other gases with sufficient oxygen concentration can also be used, such as purified oxygen. If air is used as the oxygen, about 10 kg to about 15 kg of air per kg of coke burned off the spent catalyst is needed. Exemplary regenerative conditions include a temperature from about 500 °C (900 °F) to about 900 °C (1700 °F) and a pressure from about 150 kPa (gauge) (20 psig) to about 450 kPa (gauge) (70 psig) in the regenerator 10.

[0036] In some cases, the coke on the spent catalyst can not be sufficient to generate enough enthalpy from the combustion to drive the endothermic reactions in the reactor. This can be the case for a PDH unit or a FCC unit with a very efficient stripping section. Therefore, a supplemental fuel gas is added to the regenerator to provide additional combustion enthalpy to drive the endothermic reactions in the reactor. The regenerator 10 can include a fuel gas distributor 28 for distributing a fuel gas from a fuel gas supply line 27 to the combustion chamber 20 for combustion in the combustion chamber. In one embodiment, the fuel gas distributor 28 can be located below the oxygen distributor 52 and the oxygen distributor 52 can be located above the fuel gas distributor 28. Thus, on the left-hand side of the mixing chamber 50 in Figure 1 The fuel gas distributor 28 is shown in dashed lines to clearly show the fuel gas distributor 28 on the left-hand side of the mixing chamber 50. The fuel nozzles 29 on the fuel gas distributor 28 have outlets 30 from which fuel jets 33 are generated. The fuel jets 33 are streams of fuel gas such as natural gas emitted from the fuel outlets 30 of the fuel nozzles 29 abutting the fuel nozzles. The fuel nozzles 29 can be pointed downward, meaning the fuel outlets 30 are below the fuel distributor 28 and / or at the lower end of the fuel nozzles.

[0037] In one embodiment, the fuel gas distributor 28 includes a plurality of fuel nozzles 29 each having a fuel outlet 30 from which a fuel jet 33 is generated. The fuel nozzles 29 can extend from a fuel gas header 34 that carries the fuel gas from the fuel gas line 27 to the fuel nozzles. The fuel nozzles 29 distribute the fuel gas through the respective fuel outlets 30 to produce the fuel gas jets 33. The fuel nozzles 29 can be pointed downward, meaning the respective fuel outlets 30 are below the fuel distributor 28 and / or at the lower end of the fuel nozzles. The fuel gas distributor 28 can be lined with a refractory material.

[0038] In one embodiment, the fuel gas jet 33 and the oxygen jet 57 have the same height. In additional embodiments, the fuel gas jet 33 and the nearest oxygen jet 57 have or share the same height. In other words, a portion of the fuel gas jet 33 and a portion of the oxygen jet share the same vertical position. Both the fuel gas jet 33 and the oxygen jet 57 can be directed downward.

[0039] The fuel outlet 30 of the fuel nozzle 29 can be lower than the oxygen outlet 56 of the oxygen nozzle 55. No equipment can be provided between the fuel gas distributor 28 and the oxygen distributor 52, so no equipment is interposed between the fuel gas distributor 28 and the nearest oxygen distributor 52.

[0040] The catalyst, fuel gas, and oxygen supply gas in the combustion chamber 20 rise, and coke is combusted from the catalyst and the fuel gas is also combusted to regenerate and heat the catalyst and generate flue gas. In a fast fluidized flow regime, the fuel gas, flue gas, and catalyst rise, where the catalyst can slide relative to the gas, and the gas can take an indirect upward trajectory. The superficial velocity of the combustion gas in the combustion chamber is typically about 1.5 m / s (5 ft / s) to about 6 m / s (20 ft / s), and preferably about 2.1 m / s (7 ft / s) to about 5.4 m / s (18 ft / s), to provide a fast fluidized flow regime.

[0041] In an exemplary embodiment, the regenerator 10 includes a mixing chamber 50. The mixing chamber can be located at the lower end of the regenerator 10. The mixing chamber 50 can include a spent catalyst conduit inlet 12i from the spent catalyst standpipe 12 that serves as an outlet for the spent catalyst standpipe. The mixing chamber 50 can also contain a regenerated catalyst conduit inlet 16i from the regenerated catalyst standpipe 16 that serves as an outlet for the regenerated catalyst standpipe.

[0042] In one embodiment, the mixing chamber 50 has a mixing chamber height indicated by the double-headed arrow H. This height H is equal to the tangent length, which is essentially the height of the mixing chamber 50 from one end to the other end, beginning where the inner diameter of the chamber begins to decrease. In other words, the height H is the height of the vertical wall 62 of the mixing chamber 50. In some embodiments, the mixing chamber 50 can be cylindrical.

[0043] The mixing chamber 50 is downstream connected to the spent catalyst inlet 12i and the regenerated catalyst inlet 16i. The spent catalyst inlet 12i discharges a stream of spent catalyst from the spent catalyst riser 12 into the mixing chamber 50, and the regenerated catalyst inlet 16i discharges a recirculated portion of the regenerated catalyst from the regenerated catalyst riser 16 into the mixing chamber 50. The spent catalyst riser 12 may include a control valve thereon to control the flow rate of spent catalyst from the reactor to the mixing chamber 50. The recirculated regenerated catalyst riser 16 may also include a control valve thereon to control the flow rate of regenerated catalyst recirculated into the mixing chamber 50. In some embodiments, the catalyst is fluidized in the spent catalyst riser 12 and / or the recirculated regenerated catalyst riser 16 to promote catalyst flow. One or both of the spent catalyst inlet 12i and the regenerated catalyst inlet 16i may optionally be tangentially connected to the mixing chamber 50 to apply angular motion to the catalyst entering the mixing chamber 50 to promote mixing. Additionally, ramps 53 can be installed at the waste catalyst inlet 12i and / or the regenerated catalyst inlet 16i (not shown) to further promote mixing. In various embodiments, the ramps can guide the flowing catalyst upward, downward, to one side, or otherwise. The oxygen distributor 52 dispenses oxygen into the mixing chamber 50 to fluidize the catalyst feed within the mixing chamber 50 and to lift the catalyst upward from the mixing chamber into the combustion chamber 20. The oxygen discharged from the oxygen distributor 52 contains the oxygen necessary for combustion.

[0044] Mixing chamber 50 receives a waste catalyst stream and a regenerated catalyst stream, and mixes them together to provide a catalyst mixture. During mixing, the hotter regenerated catalyst heats the colder waste catalyst, which is used to provide the catalyst mixture at a temperature of at least 600°C, suitably at least 650°C, and preferably at least 660°C. The coke or fuel gas on the catalyst in contact with the catalyst mixture will immediately degrade to combustion with oxygen at these temperatures. The inner diameter of mixing chamber 50 may be larger than the inner diameter of combustion chamber 20. Mixing chamber 50 may be connected to combustion chamber 20 via a mixing transition section 54, which may be as follows: Figure 1 The truncated cone shape is shown, but it can be helical or elliptical. The apparent gas velocity in mixing chamber 50 can be approximately 0.9 m / s (3 ft / s) to approximately 5.4 m / s (18 ft / s), and the catalyst density can be approximately 112 kg / m³. 3 (7lb / ft 3 Approximately 400 kg / m 3 (25lb / ft 3), constituting a dense catalyst phase in the mixing chamber 50. A fuel gas distributor 28 can be located in the mixing chamber 50 and distributes fuel gas into the mixing chamber. An oxygen gas distributor 52 can also be located in the mixing chamber 50 and distributes oxygen gas into the mixing chamber. In one embodiment, the fuel outlet 30 is vertically located within one fifth, suitably one sixth, more suitably one seventh, preferably one eighth, more preferably one ninth, most preferably one tenth of the mixing chamber height H from the nearest oxygen outlet 56.

[0045] In the combustion chamber 20 a fast fluidized flow regime will be formed with a dilute catalyst phase. The catalyst density in the dilute catalyst phase in the combustion chamber 20 will be from about 16 kg / m 3 (1 lb / ft 3 ) to about 192 kg / m 3 (12 lb / ft 3 ). The catalyst density in the mixing chamber 50 will be from about 48 kg / m 3 (3 lb / ft 3 ) to about 288 kg / m 3 (18 lb / ft 3 ).

[0046] The blend of gas and catalyst rises from the combustion chamber 20 through the frustoconical transition section 41 to the standpipe 46, which has a smaller diameter than the combustion chamber 20. The blend of gas and catalyst accelerates in the narrower standpipe 46 and is discharged into the separation chamber 22 from the standpipe termination device 48. The standpipe termination device 48 can utilize centripetal acceleration to separate the regenerated catalyst from the flue gas. The superficial gas velocity in the standpipe 46 will be from about 6 m / s (20 ft / s) to about 15 m / s (50 ft / s) and constitutes a dilute catalyst phase.

[0047] The regenerated catalyst separated from the flue gas by the standpipe connection device 48 descends into the dense catalyst bed 32. The catalyst separation chamber 22 can include one or more regenerator cyclones 38 or other solid / gaseous separator devices to separate regenerated catalyst still entrained in the flue gas. In one aspect, a primary cyclone 38 can collect flue gas from the separation chamber 22 and transport the flue gas separated from the catalyst to a secondary cyclone 39 to further separate regenerated catalyst from the flue gas before directing the twice purified flue gas to the plenum 42. The flue gas is discharged from the regenerator 10 in a discharge line 44. The regenerated catalyst separated from the flue gas in the cyclones 38, 39 is distributed into the dense catalyst bed 32 through a dip leg. The portion of the regenerated catalyst collected in the dense bed 32 of the catalyst separation chamber 22 that is returned can be transported back to the dehydrogenation reactor in the return regenerated catalyst standpipe 14 to catalyze the dehydrogenation reaction. The portion of the regenerated catalyst collected in the dense bed 32 of the catalyst separation chamber 22 that is recycled can be recycled back to the combustion chamber 20 of the regenerator 10 via the mixing chamber 50 in the recycle regenerated catalyst standpipe 16.

[0048] The rate of recycle of the regenerated catalyst can be controlled by operating a control valve on the recycle regenerated catalyst standpipe 16, independent of the rate of spent catalyst to the regenerator 10 by operating a control valve on the spent catalyst conduit 12, to adjust the density of the catalyst. The density of the catalyst is directly proportional to the residence time of the catalyst in the regenerator 10, and in particular, the residence time of the catalyst in the mixing chamber 50. Thus, adjusting the density of the catalyst in the mixing chamber 50 by varying the rate of recycle of the regenerated catalyst by the control valve on the recycle regenerated catalyst standpipe 16 can adjust the residence time of the catalyst in the regenerator 10 to ensure sufficient combustion and enthalpy uptake by the catalyst and transfer to the dehydrogenation reactor.

[0049] The rate of recycle of the regenerated catalyst through the recycle regenerated catalyst standpipe 16 to the mixing chamber 50 can be from about 0.5 to about 10 times the rate of spent catalyst through the spent catalyst standpipe 12 to the mixing chamber. Suitably, the rate of recycle can be from about 1 to about 5 times the rate of spent catalyst through the spent catalyst standpipe 12 to the mixing chamber 50.

[0050] In one embodiment, a mixing baffle 60 may be positioned within a mixing chamber 50 to facilitate mixing between spent catalyst and regenerated catalyst. The mixing baffle 60 may be a tube, and a vertical wall 62 of the mixing chamber 50 may define an annular space 64 between the mixing baffle and the vertical wall. In one embodiment, spent catalyst inlet 12i and regenerated catalyst inlet 16i open into the annular space 64. The regenerated catalyst inlet 16i may have an inlet in the mixing chamber 60 that is lower than the spent catalyst inlet 12i. The mixing baffle 60 may be radially centered within the mixing chamber 50, and the mixing baffle 60 may be cylindrical. The mixing baffle 60 may have a central longitudinal axis (not shown) aligned with the central longitudinal axis (not shown) of the mixing chamber 50. In some embodiments, the transverse wall 66 of the mixing baffle 60 may be vertical. In one embodiment, an oxygen baffle distributor 65 including nozzles 67 may be positioned within the mixing baffle 60. The oxygen baffle distributor 65 may include a plurality of nozzles 67.

[0051] In an exemplary embodiment, one or more baffle openings 68 are defined in the transverse wall 66 of the mixing baffle 60. The baffle openings 68 serve as inlets for access into the interior 70 of the mixing baffle 60, and can also serve as outlets for the interior 70. In an exemplary embodiment, one or more of the baffle openings 68 have an elongated configuration such that the upper edge of the baffle opening 68 is spaced apart from the vicinity of the top of the mixing baffle 60, such as by 0.2 baffle diameters. Figure 1 In the alternative embodiment shown, one or more of the baffle openings 68 may include two or more openings, one above the other, such that the openings are radially aligned on the mixing baffle 60. Waste catalyst and regenerated catalyst from the waste catalyst inlet 12i and the regenerated catalyst inlet 16i, respectively, enter the interior 70 through the baffle openings 68 and exit the interior 70 through the baffle openings 68. This sequence facilitates the mixing of the waste catalyst stream and the regenerated catalyst stream within the interior 70 and the annular space 64 of the mixing baffle 60. The mixing of the waste catalyst and the regenerated catalyst in the mixing baffle 60 produces a thoroughly mixed catalyst with sufficient temperature to promote combustion when the coke on the catalyst comes into contact with the fuel gas. The mixing of the waste catalyst and the regenerated catalyst ensures that combustion occurs in the presence of sufficient catalyst, thus providing sufficient radiators to absorb heat and preventing excessive heat transfer to surrounding equipment and catalyst, potentially damaging it, and maximizing the enthalpy transferred back to the endothermic reaction via the regenerated catalyst medium.

[0052] The interior 70 of the mixing baffle 60 is in fluid communication with the annular space 64 through the baffle openings 68. In one exemplary embodiment, the upper edge of the uppermost baffle opening 68 is above the lower edge of the spent catalyst conduit inlet 12i and the lower edge of the regenerated catalyst conduit inlet 16i. The upper edge of the spent catalyst conduit inlet 12i is the highest elevation at which the spent catalyst standpipe 12 intersects the mixing chamber 50, and the lower edge is the lowest elevation at which the spent catalyst standpipe 12 intersects the mixing chamber 50, and the same relationship can apply to the other inlets. In embodiments in which the upper edge of the uppermost baffle opening 68 is above the upper edge of the spent catalyst conduit inlet 12i and the regenerated catalyst conduit inlet 16i, catalyst from the spent catalyst conduit inlet 12i and the regenerated catalyst conduit inlet 16i can flow upward with fluidizing gas from the oxygen distributor 52, through the baffle openings 68, and into the interior 70 of the mixing baffle 60.

[0053] A clear space is provided between the fuel outlet 30 of the fuel nozzle 29 and the nearest oxygen outlet 56 of an oxygen nozzle. Additionally, the fuel outlet 30 is lower than the nearest oxygen outlet 56. In one aspect, all of the fuel outlets 30 of the fuel gas distributor 28 can be lower than all of the oxygen outlets 56 of the oxygen distributor 52.

[0054] Figure 2 A cross-sectional elevation view is shown taken along a line segment 2-2 of Figure 1 The oxygen header 58 of the oxygen distributor 52 is directly above the fuel gas header 34 of the fuel gas distributor 28. The oxygen nozzles 55 are arranged in two opposing rows 72, 74 on the oxygen distributor 52. The oxygen nozzles 55 of the two opposing rows 72, 74 are connected to and depend from the oxygen header 58, and define an acute included angle a from their centerlines with each other. Additionally, the oxygen jets 57 from each oxygen nozzle 55 define an acute angle β with the horizontal. Furthermore, the oxygen jets 57 from the oxygen nozzles 55 of each row 72, 74 define an acute included angle a with the oxygen jets 57 of the opposing row 74, 72 taken from their centerlines.

[0055] Similarly, the fuel nozzles 29 are arranged in two opposing rows 76, 78 on the fuel gas distributor 28. The fuel nozzles 29 of the two opposing rows 76, 78 are connected to and depend from the fuel gas header 34, and define an acute included angle p with each other. Additionally, the fuel gas jets 33 from each fuel nozzle 29 define an acute angle Θ with the horizontal. Furthermore, the fuel gas jets 33 from the fuel nozzles 29 of each row 76, 78 define an acute included angle p with the fuel gas jets 33 of the opposing row 78, 76 taken from their centerlines.

[0056] The oxygen nozzles 55 have an inlet end that extends into the oxygen header 58. However, the sides of the oxygen nozzles 55 that extend from the oxygen header 58 are thicker than the inlet end that extends into the oxygen header. The inlet in the inlet end of the oxygen nozzles 55 has a smaller inner diameter than the inner diameter of the oxygen outlets 56. This allows a pressure drop to be applied by the inlet end, which ensures a more balanced flow and less stress on the oxygen outlets 56. The fuel nozzles 29 have an inlet end that extends into the fuel gas header 34. However, the sides of the fuel nozzles 29 that extend from the fuel gas header 34 are thicker than the inlet end that extends into the fuel gas header 34. The inlet in the inlet end of the fuel nozzles has a smaller inner diameter than the inner diameter of the fuel outlets 30. This allows a pressure drop to be applied by the inlet end, which ensures a more balanced flow and less stress on the fuel outlets 30.

[0057] It can be seen in Figure 2 that the lateral projections of the oxygen nozzles 55 of the rows 72, 74 encompass the lateral projections of the fuel nozzles 29 of the rows 76, 78.

[0058] A clear space without intermediate equipment is provided between the fuel outlets 30 of the fuel nozzles 29 and the nearest oxygen outlets 56 of the oxygen nozzles 55. For example, an imaginary line i between the center of the fuel outlet 30 of the fuel nozzle 29 and the center of the nearest oxygen outlet 56 of the oxygen nozzle 55 does not intersect with other equipment, as the imaginary line i does not intersect with other equipment except possibly the nozzles themselves between the outlets. There can be no equipment between the fuel nozzles 29 and the oxygen nozzles 55. This arrangement ensures thorough contact between the fuel gas jets 33 and the oxygen jets 57 in the catalyst environment. During operation, the catalyst will most likely be in the space between the fuel outlets 30 and the oxygen outlets 56, which is free of equipment.

[0059] Figure 3 A cross-sectional plan view taken along the line segment 3-3 of Figure 1 is shown. Figure 3 The oxygen distributor 52 is shown clearly, which obscures the view of the fuel gas distributor 28. Thus, for purposes of illustration, the oxygen distributor 52 is removed at the 10 o'clock position, and the oxygen distributor is shown at the 12 o'clock position in dashed lines. The inlets of the oxygen nozzles 55 of the oxygen distributor 52 at the 12 o'clock position are shown in dashed lines, while the fuel nozzles 29 of the fuel gas distributor 28 at the 12 o'clock position are shown in solid lines. The oxygen nozzles 55 in the first row 72 of the oxygen distributor 52 are longitudinally offset from the oxygen nozzles in the second row 74. Additionally, the fuel nozzles 29 in the first row 76 of the fuel gas distributor 28 are longitudinally offset from the fuel nozzles in the second row 78. Adjacent pairs of the oxygen distributor 52 and the fuel gas distributor 28 have their longitudinal centerlines arranged along the same radius in the mixing chamber 50, and are thus characterized as co-radial.

[0060] Figure 4 and Figure 5 shows Figures 1 to 3 alternative embodiments of the embodiments of the regenerator 10' in which the fuel gas jets and the oxygen jets have the same horizontal position. Figure 4 and Figure 5 many of the elements in Figures 1 to 3 have the same configuration as in Figure 4 and Figure 5 elements in Figures 1 to 3 corresponding to elements in Figures 1 to 3 have the same reference numerals but are marked with a prime (‘) sign.

[0061] Figure 4 shows a partial schematic elevational view of the mixing chamber 50' of the feed combustion chamber 20. The oxygen feed includes an oxygen distributor 52' of an oxygen header 58' with oxygen from the oxygen line 49'. The oxygen header 58' is defined between the bottom of the regenerator 10' and an upper wall 59, which can be concave to provide a dish-shaped upper surface. Oxygen nozzles 55' distribute oxygen from the oxygen header 58' to the mixing chamber 50' and the regenerator 10' through oxygen outlets 56'. One oxygen nozzle 67' or multiple nozzles 67' can be positioned within the mixing baffle 60' to distribute air from the oxygen header 58' to the mixing baffle. The oxygen nozzles 67' in the mixing baffle can be in communication with the oxygen distributor 52'.

[0062] The fuel gas distributor 28' fed by the fuel gas line 27' includes a fuel gas header 34' that distributes fuel gas to the mixing chamber 50' and the regenerator 10' through fuel outlets 30' of fuel nozzles 29'. In one embodiment, the fuel outlets 30' are vertically located within one fifth, suitably one sixth, more suitably one seventh, preferably one eighth, more preferably one ninth, most preferably one tenth of the mixing chamber height H from the nearest oxygen outlet 56'. The fuel distributor 28' can include multiple fuel nozzles 29' with corresponding fuel outlets 30', and the oxygen distributor 52' can include multiple oxygen nozzles 55' with corresponding oxygen outlets 56'. In one embodiment, the fuel outlets 30' are vertically located within one fifth, suitably one sixth, more suitably one seventh, preferably one eighth, more preferably one ninth, most preferably one tenth of the height H of the mixing chamber to the nearest oxygen outlet 56'.

[0063] Fuel nozzle 29' is disposed within oxygen nozzle 55'. Fuel outlet 30' of fuel nozzle 29' may be disposed within oxygen outlet 56' of oxygen nozzle 55'. Furthermore, fuel outlet 30' of fuel nozzle 29' may be located at the same height as oxygen outlet 56' of oxygen nozzle 55'. In one embodiment, some or all fuel nozzles 29' may be located within the respective oxygen nozzle 55', and / or have fuel outlet 30' at the same height as oxygen outlet 56'.

[0064] The oxygen jet 57' from the oxygen nozzle 55' is paired with the nearest fuel gas jet 33' from the fuel nozzle 29' located within the oxygen nozzle 55', as shown below. Figure 4 As shown. The fuel gas jet 33' and oxygen jet 57' have the same horizontal position and possibly the same radial position in the plan view. The paired fuel gas jet 33' and oxygen jet 57' can be concentric. In addition, the paired fuel nozzle 29' and oxygen nozzle 55' can be concentric.

[0065] Both the fuel gas jet 33' and the oxygen jet 55' point upwards. The oxygen outlet 56' may be located above the inlet leading to the corresponding oxygen nozzle 55' and above the corresponding oxygen manifold 58'. The fuel outlet 30' may be located above the inlet leading to the corresponding fuel nozzle 29' and above the corresponding fuel gas manifold 34'. A clear space without intermediate equipment is provided between the fuel outlet 30' of the fuel nozzle 29' and the oxygen outlet 56' of the nearest oxygen nozzle 55'.

[0066] Figure 5 It shows along Figure 4 The sectional plan view of the mixing chamber 50' cut off by line segment 5-5. Figure 5 A diagram showing fuel gas nozzles 29' disposed within oxygen nozzles 55' is illustrated. Not all oxygen nozzles 55' have fuel gas nozzles 29' disposed therein. Oxygen nozzles 67 are located within mixing baffles 60'. In one embodiment, no fuel gas nozzles 29' are located within mixing baffles 60'. As shown by dashed lines, fuel gas nozzles 29' extending from fuel gas manifold 34' define a row 76' of fuel gas nozzles 29' positioned using oxygen nozzles 55' in a first row 72'. A row 76' of fuel gas nozzles may be disposed between oxygen nozzles 55' in a second row 74'. In one aspect, a row 76' of fuel gas nozzles 29' may alternate with oxygen nozzles 55' in a second row 74', where the fuel gas nozzles are not located in the second row. Fuel nozzles 29' may be concentric with oxygen nozzles 55'.

[0067] Figure 6 It shows Figure 5An alternative embodiment of the implementation scheme, wherein the fuel nozzle 29* is surrounded by the oxygen nozzle 55* in the mixing chamber 50'. Figure 6 Many of the components in it have the same characteristics as Figure 5 They have the same configuration and the same reference numerals. Figure 6 The middle corresponds to Figure 5 The components in, but components with different configurations have the same Figure 5 Same as the reference numerals, but marked with an asterisk (*).

[0068] Figure 6 It also shows along Figure 4 The sectional plan view of the mixing chamber 50' cut off by line segment 5-5. Figure 6 A pattern is shown of a fuel nozzle 29* surrounded by an oxygen nozzle 55*. The fuel nozzle 29* does not necessarily reside within the oxygen nozzle 55*. The fuel nozzle 29* extends from a corresponding fuel gas manifold 58*, shown in dashed lines because it is concealed beneath the upper wall 59 of the oxygen distributor 28'. One or more fuel nozzles 29* may extend from the fuel gas manifold 58*. Each fuel nozzle 29* may replace the oxygen nozzle 55* in the form of an oxygen nozzle. In one aspect, each fuel nozzle 29* may be surrounded by an oxygen nozzle 55* in three, four, five, or six directions. Figure 6 In the middle, the fuel nozzle 29* is surrounded by oxygen nozzles in six directions.

[0069] Figure 7 It shows Figure 1 An alternative implementation scheme is provided in which oxygen manifold 58# is fed from a common oxygen distributor 52#, which also feeds oxygen to a mixing baffle 60#. Figure 7 Many of the components in it have the same characteristics as Figure 1 They have the same configuration and the same reference numerals. Figure 7 The middle corresponds to Figure 1 The components in, but components with different configurations have the same Figure 1 Same icon number, but marked with a hash symbol (#).

[0070] Oxygen distributor 52# distributes oxygen from oxygen supply line 49# to oxygen nozzle 55# on oxygen manifold 58#, oxygen nozzle 67# in mixing baffle 60#, and oxygen nozzle 69 between mixing baffle and oxygen manifold. Oxygen nozzle 55# points upward.

[0071] Figure 7Two types of fuel gas distributors 28A and 28B are shown in FIG. 1. Either or both of the fuel gas distributors 28A and 28B can be used in regenerator 10#. Fuel supply line 27# feeds annular header 36A of first fuel gas distributor 28A, which distributes fuel gas to fuel gas headers 34A. Fuel gas headers 34A can be disposed radially between adjacent oxygen gas headers 55#. Header fuel nozzles 29# can be located on fuel gas headers 34#, annular fuel nozzles 37 can be located on annular header 36A, and both sets of nozzles can point downward. A clear space, free of intervening equipment, is provided between each header fuel nozzle 29# or annular fuel nozzle 37 and the nearest oxygen gas nozzle 55#. For example, an imaginary line iA between the center of fuel outlet 30# of fuel nozzle 29# and the center of the nearest oxygen outlet 56# on oxygen gas nozzle 55# is free of equipment because the imaginary line does not intersect other equipment except for the nozzles between the outlets.

[0072] Second fuel gas distributor 28B includes annular header 36B, which distributes fuel gas to fuel gas headers 34B. Second fuel gas distributor 28B shades portions of adjacent oxygen gas headers 55#, so the shaded portions of oxygen gas headers 55# are shown in dashed lines. Fuel gas headers 34B can be disposed radially between adjacent oxygen gas headers 55#.

[0073] Header fuel nozzles 29# can be located on fuel gas headers 34B, annular fuel nozzles 37 can be located on annular header 36A, and both sets of nozzles can point upward. A clear space, free of intervening equipment, is provided between each header fuel nozzle 29# or annular fuel nozzle 37 and the nearest oxygen gas nozzle 55#. For example, an imaginary line iB between the center of fuel outlet 30# of fuel nozzle 29# and the center of the nearest oxygen outlet 56# on oxygen gas nozzle 55# is free of equipment because the imaginary line does not intersect other equipment except for the nozzles between the outlets. There is no equipment between fuel nozzles 29# and oxygen gas nozzles 55#. Oxygen gas jets 57 from oxygen gas nozzles 55# and fuel gas jets 33 from fuel nozzles 29# are at the same height.

[0074] Specific embodiments

[0075] While the following is described in conjunction with the specific embodiments, it will be understood that it is intended to cover not only the descriptions but also the forthcoming claims and their equivalents.

[0076] A first embodiment of the present disclosure is a method for regenerating a catalyst from a catalytic reaction, the method comprising providing a spent catalyst stream; dispensing an oxygen stream to the spent catalyst stream through an oxygen nozzle; generating an oxygen jet from the oxygen nozzle; dispensing a fuel gas stream to the spent catalyst stream through a fuel nozzle; generating a fuel gas jet from the fuel nozzle, the fuel gas jet and the oxygen jet having the same height; and combusting the fuel gas stream and carbon on the spent catalyst with the oxygen stream to provide a flue gas and a regenerated catalyst. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the first embodiment in this paragraph, wherein the fuel gas jet and the oxygen jet have the same horizontal position. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the first embodiment in this paragraph, wherein the fuel gas jet and the oxygen jet both point downward. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the first embodiment in this paragraph, further comprising a clear space between the fuel gas jet and the nearest oxygen jet. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the first embodiment in this paragraph, wherein the fuel gas jet and the oxygen jet abut each other. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the first embodiment in this paragraph, wherein the fuel gas jet and the oxygen jet are concentric. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the first embodiment in this paragraph, wherein the fuel gas jet points downward and the oxygen jet points upward. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the first embodiment in this paragraph, wherein the fuel gas jet and the oxygen jet both point upward. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the first embodiment in this paragraph, wherein a row of fuel gas jets is interleaved with a row of oxygen jets.

[0077] A second embodiment of the present disclosure is a regenerator for burning coke from spent catalyst, comprising a mixing chamber for mixing catalyst and gas, the mixing chamber comprising an inlet for allowing a spent catalyst stream to enter the regenerator, an oxygen distributor comprising oxygen nozzles for distributing oxygen to the regenerator; and a fuel gas distributor comprising fuel nozzles for distributing fuel gas to the regenerator, the fuel nozzles having fuel outlets and the oxygen nozzles having oxygen outlets, the fuel outlets being within one fifth of the mixing chamber height from the oxygen outlets; a catalyst outlet for discharging regenerated catalyst from the regenerator. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the second embodiment in this paragraph, wherein the oxygen distributor is located above the fuel gas distributor. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the second embodiment in this paragraph, wherein the oxygen nozzles and the fuel nozzles point downward. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the second embodiment in this paragraph, further comprising a clear space between the fuel nozzles and the nearest oxygen nozzles. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the second embodiment in this paragraph, further comprising a mixing baffle in the mixing chamber, the mixing baffle comprising openings in its outer wall and oxygen nozzles in the baffle. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the second embodiment in this paragraph, wherein there are no devices between the fuel nozzles and the oxygen nozzles. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the second embodiment in this paragraph, wherein the fuel nozzles are disposed within the oxygen nozzles. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the second embodiment in this paragraph, wherein the fuel nozzles are surrounded by the oxygen nozzles. The regenerator of claim 10, wherein the outlets of the fuel nozzles are lower than the outlets of the oxygen nozzles.

[0078] A third embodiment of the present disclosure is a regenerator for burning coke from spent catalyst, comprising an inlet for allowing a spent catalyst stream to enter the regenerator, an oxygen distributor comprising oxygen nozzles with oxygen outlets for distributing oxygen to the regenerator; a fuel gas distributor comprising fuel nozzles with fuel outlets for distributing fuel gas to the regenerator, wherein a clear space is provided between the fuel nozzles and the oxygen nozzles. One embodiment of the present disclosure is one, any or all of the previous embodiments in this paragraph through the third embodiment in this paragraph, wherein the fuel outlets are located below the oxygen outlets.

[0079] While the foregoing description has been made in the context of particular embodiments, it is to be understood that the disclosure can be carried out in ways other than those specifically set forth without departing from the spirit and essential characteristics of the disclosure. Thus, the foregoing description is to be considered as illustrative only and not as being limiting to the scope of the disclosure, with the true scope of the disclosure being indicated by the appended claims along with their full scope of equivalents. Although the foregoing description has been made in the context of particular embodiments, it is to be understood that the disclosure can be carried out in ways other than those specifically set forth without departing from the spirit and essential characteristics of the disclosure. Thus, the foregoing description is to be considered as illustrative only and not as being limiting to the scope of the disclosure, with the true scope of the disclosure being indicated by the appended claims along with their full scope of equivalents.

[0080] In the foregoing, all temperatures are shown in degrees Celsius, and all parts and percentages are by weight, unless otherwise indicated.

Claims

1. A method for regenerating a catalyst from a catalytic reaction, the method comprising: Provide waste catalyst feed stream; Oxygen streams are distributed to the waste catalyst streams via oxygen nozzles, wherein the oxygen nozzles are arranged at acute angles to each other. An oxygen jet is generated from the oxygen nozzle; The fuel gas stream is distributed to the waste catalyst stream via fuel nozzles; A fuel gas jet is generated from the fuel nozzle, the fuel gas jet and the oxygen jet having the same height; and The oxygen feed stream is used to burn the fuel gas feed stream and the carbon on the spent catalyst to provide flue gas and regenerated catalyst.

2. The method according to claim 1, wherein the fuel gas jet and the oxygen jet have the same horizontal position.

3. The method of claim 1, further comprising a net space between the fuel gas jet and the nearest oxygen jet.

4. A regenerator for burning coke from spent catalyst, comprising: A mixing chamber for mixing catalyst and gas, the mixing chamber including an inlet for allowing waste catalyst feed to enter the regenerator; an oxygen distributor including an oxygen nozzle for distributing oxygen to the regenerator; and a fuel gas distributor including a fuel nozzle for distributing fuel gas to the regenerator, the fuel nozzle having a fuel outlet and the oxygen nozzle having an oxygen outlet, the fuel outlet being within one-fifth of the height of the mixing chamber from the oxygen outlet; Catalyst outlet for discharging regenerated catalyst from the regenerator; The oxygen nozzles are arranged at an acute angle to each other.

5. The regenerator according to claim 4, wherein the oxygen distributor is located above the fuel gas distributor.

6. The regenerator according to claim 4, wherein the oxygen nozzle and the fuel nozzle are downwardly pointed.

7. The regenerator of claim 4 further includes a clear space between the fuel nozzle and the nearest oxygen nozzle.

8. The regenerator according to claim 4, wherein the fuel nozzle is disposed within the oxygen nozzle.

9. The regenerator of claim 4, wherein the fuel nozzle is surrounded by a plurality of oxygen nozzles.

10. The regenerator of claim 4, wherein the outlet of the fuel nozzle is lower than the outlet of the oxygen nozzle.

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