Method of operating a gas dispenser

Abstract

According to the embodiments disclosed in this specification, a method for operating a gas distributor includes a step of passing solid particles through a processing unit, where the processing unit includes at least a first distributor and a second distributor, and the first distributor and the second distributor are operable to pass combustible gas and decoking gas into the processing unit; a step of passing combustible gas through the processing unit via the first distributor, where the combustible gas contacts the solid particles and coke is formed on the first distributor; a step of stopping the passage of the combustible gas through the first distributor while the combustible gas passes through the second distributor; a step of passing decoking gas through the first distributor while the combustible gas passes through the second distributor, where the decoking gas removes the coke formed on the first distributor; and a step of resuming the passage of the combustible gas through the first distributor.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority to U.S. Provisional Patent Application No. 63 / 340,675, filed May 11, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure generally relates to chemical processing, and more specifically, to the processing of solid microparticles in chemical processes.

Background Art

[0003] Many chemical processes, such as catalytic reactions, utilize solid microparticles. Sometimes in such processes, those solid microparticles must be regenerated or reheated. Some regeneration / reheating processes involve the combustion of coke or the combustion of auxiliary fuel. Other solid microparticles may be regenerated by contact with a gas, for example, when oxidizing or reducing the solid microparticles.

Summary of the Invention

[0004] On a gas distributor, there is a possibility of coke formation when combustible gas passes through the distributor and enters the processing unit. For example, when heating a combustible gas containing ethane, ethylene, which can be a coke precursor, may be formed. The formed coke continues to grow and may clog the orifices in the distributor, thus inefficiently distributing the gas into the processing unit. To remove the formed coke from the distributor, many different decoking techniques can be used. However, these conventional decoking techniques require stopping the process at the scheduled cleaning time to remove the coke from the distributor. Therefore, a new decoking technique is needed to prevent process stoppage for removing coke from the distributor.

[0005] Embodiments of the present disclosure provide a method for injecting combustible gas and decoking gas through a plurality of distributors within a processing unit. In some embodiments, it may be possible to stop passing combustible gas through the distributor in which coke has formed and continue passing combustible gas through all other distributors. Next, in order to remove the coke, decoking gas may be passed through one or more distributors in which coke has formed. Next, combustible gas may be passed again through the distributor(s) from which coke has been partially or completely removed. This method can increase the production volume of the processing unit because it is not necessary to stop passing combustible gas through all the distributors within the processing unit in order to remove coke from other distributors. In such embodiments, the system may be operated without stopping while the use of decoking gas is repeated throughout the plurality of distributors, enabling the normal operation of the process while decoking is taking place.

[0006] According to one or more embodiments of the present disclosure, a method of operating a gas distributor includes passing solid particles through a processing unit, wherein the processing unit comprises at least a first distributor and a second distributor, and each of the first distributor and the second distributor is operable to pass combustible gas and decoking gas within the processing unit; passing combustible gas through the processing unit through the first distributor, wherein the combustible gas contacts the solid particles and coke is formed in the first distributor; stopping the passage of the combustible gas through the first distributor while the combustible gas passes through the second distributor; passing decoking gas through the first distributor while the combustible gas passes through the second distributor, wherein the decoking gas removes the coke formed in the first distributor; and resuming the passage of the combustible gas through the first distributor.

[0007] These and other embodiments are described in more detail in the "Detailed Description of the Invention". It should be understood that both the foregoing general description and the following detailed description are intended to represent embodiments of the technology and to provide an overview or framework for understanding the nature and characteristics of the technology as individually disclosed as claimed. The accompanying drawings are included to provide a further understanding of the technology disclosed herein, are incorporated herein, and constitute a part hereof. The drawings illustrate various embodiments and, together with the description, serve to explain the principles and operation of the technology disclosed herein. Additionally, the drawings and description are intended to be illustrative only and are not intended to limit the claims in any way.

Brief Description of the Drawings

[0008] The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, in which like structures are indicated by like reference numerals.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0009] Here, various embodiments are referred to in more detail, some of which are illustrated in the accompanying drawings. Whenever possible, the same reference numbers will be used throughout the drawings to refer to the same or similar parts.

Best Mode for Carrying Out the Invention

[0010] A method for operating a gas dispenser that injects gas into a processing unit is described herein. FIGS. 1 to 5 each show different operating states of the gas dispenser. Generally, the operating state of FIG. 2 follows the operating state of FIG. 1, then the operating state of FIG. 3 follows, then the operating state of FIG. 4 follows, and then the operating state of FIG. 5 follows. FIG. 1 shows the operation in the "normal state" in which all dispensers inject combustible gas into the processing unit. FIGS. 2 to 5 show other operating states as described herein. Overall, FIGS. 2 to 5 show an operating state in which decoking gas is introduced into a certain dispenser to remove coke, and other dispensers continue to inject combustible gas. Note that FIGS. 1 to 5 show dispensers in operating states 100, 200, 300, 400, and 500, respectively. As described herein with respect to FIGS. 1 to 5, decoking gas is introduced only into one or some dispensers to remove the accumulated coke formed in the dispenser, and other dispensers continue to pass combustible gas. It should be understood that these systems are merely application examples of the embodiments disclosed and claimed herein.

[0011] Referring generally to all of FIGS. 1-5, according to one or more embodiments, a plurality of dispensers 165, 166, 167, and 168 are operable to distribute gas to a processing unit 190. In an embodiment, combustible gas 110, purge gas 118, and decoking gas 115 may be injected into the processing unit 190 through any of the dispensers 165, 166, 167, and 168. A pipe network, described in detail below, connects each of the combustible gas 110, purge gas 118, and decoking gas 115 to the dispensers 165, 166, 167, and 168. Valves within the pipe network may be turned on or off to regulate the flow of fluid. As shown in FIGS. 1-5, a valve indicating a passage aligned with the pipe means an open valve, and a valve indicating a passage not aligned with the pipe means a closed valve. For example, in FIG. 1, valve 151 is closed and valve 157 is open.

[0012] As described herein, in one or more embodiments, combustible gas 110, purge gas 118, and decoking gas 115 may enter processing unit 190 by passing through one or more distributors 165, 166, 167, and 168. The term "distributor" may refer to a conduit that can pass gas into processing unit 190 so that the gas is substantially distributed inside processing unit 190. The gas may pass through the distributor body and out through orifice 172. In some embodiments, the distributor may comprise at least one orifice 172 that allows the gas in the distributor to exit the distributor and enter processing unit 190. For example, the distributor may be a cylindrical pipe having a plurality of orifices 172, processing unit 190 may be a fluidized bed combustor, the solid particulate may be a catalyst bed, and as a result, when one or more gases pass through the distributor, the gas then contacts the catalyst bed and suspends the catalyst bed, and as a result, the catalyst bed fluidizes. An exemplary distributor system is described in U.S. Patent No. 9,889,418, the teachings and disclosures of which are incorporated herein by reference. Further, it should be noted that the processes described herein may be used for various chemical processes such as dehydrogenation, cracking, conversion of methanol to olefins, or similar chemical processes, such as heating or decoking of catalysts, reduction or oxidation of catalysts, reduction or oxidation of oxygen carrier materials that are not catalysts. The dehydrogenation process may include dehydrogenation of light alkanes to form light olefins.

[0013] In the method described herein, the solid microparticles are passed through the processing unit 190. The combustible gas 110 is also passed through the processing unit 190 and interacts with the solid microparticles for the desired result. For example, the combustible gas 110 may burn with oxygen, which can heat the solid microparticles. Also, the combustible gas 110 may act to reduce the solid microparticles. The solid microparticles may be regenerated in such a process and the solid microparticles may then be sent to the reactor for subsequent reactions. The solid microparticles may be circulated through the reactor and the processing unit 190 such that the solid microparticles are deactivated during the reaction and then regenerated in the processing unit 190.

[0014] Referring to FIG. 1, in one or more embodiments, the combustible gas 110 entering the processing unit 190 through the distributors 165, 166, 167, and 168 may first enter the distributors 165, 166, 167, and 168 at a relatively low temperature such as room temperature. Next, when the combustible gas 110 passes through the distributors 165, 166, 167, and 168, the combustible gas 110 may be heated. For example, if the processing unit 190 is a fluidized combustor containing a catalyst bed as solid particles, when the combustible gas 110 flows through the distributors 165, 166, 167, and 168, the combustible gas 110 in the distributors 165, 166, 167, and 168 may be heated to the reaction temperature within the processing unit 190. The surface of the combustible gas 110 as well as the distributors 165, 166, 167, and 168 may reach a temperature of at least 600°C. In some embodiments, the combustible gas 110 may contain at least one coke precursor such as ethylene, and due to these high temperatures, coke is formed on the distributors 165, 166, 167, and 168. The formation of coke may clog one or more orifices 172 of the distributors 165, 166, 167, and 168 that allow the gas in the distributors 165, 166, 167, and 168 to enter the processing unit 190, thereby reducing or completely stopping the flow of gas from the distributors 165, 166, 167, and 168 into the processing unit 190. The coke formed on the distributors 165, 166, 167, and 168 may be removed by passing a decoking gas 115 through the distributors 165, 166, 167, and 168 on which the coke is formed. The decoking gas 115 may be heated when passing through the distributors 165, 166, 167, and 168 and may contact the formed coke, as a result of which the formed coke is oxidized and removed from the distributors 165, 166, 167, and 168.

[0015] Referring to FIGS. 1-5, in one or more embodiments, for the coke accumulated in one or more distributors 165, 166, 167, and 168, it may be possible to stop passing the combustible gas 110 through the one or more distributors 165, 166, 167, and 168. Before stopping passing the combustible gas 110 through the one or more distributors 165, 166, 167, and 168, it may be possible to pass the purge gas 118 through the one or more distributors 165, 166, 167, and 168, whereupon it becomes possible to stop passing the combustible gas 110 through the one or more distributors 165, 166, 167, and 168. It may be possible to stop passing the purge gas 118 through the one or more distributors 165, 166, 167, and 168. Before stopping passing the purge gas 118 through the one or more distributors 165, 166, 167, and 168, it may be possible to pass the decoking gas 115 through the one or more distributors 165, 166, 167, and 168, whereupon it becomes possible to stop passing the purge gas 118 through the one or more distributors 165, 166, 167, and 168. Next, it may be possible to again permit passing the purge gas 118 through the one or more distributors 165, 166, 167, and 168, whereupon it becomes possible to again stop passing the decoking gas 115 through the one or more distributors 165, 166, 167, and 168. It may be possible to stop passing the purge gas 118 through the one or more distributors 165, 166, 167, and 168. Before stopping passing the purge gas 118 through the one or more distributors 165, 166, 167, and 168, it may be possible to again permit passing the combustible gas 110 through the one or more distributors 165, 166, 167, and 168. In some embodiments, the one or more distributors 165, 166, 167, and 168 may include from one to all of the distributors within the processing unit 190 (it is possible to provide more distributors than the four distributors 165, 166, 167, and 168 shown in the figure).In any embodiment of the present disclosure, when passing any of the combustible gas 110, purge gas 118, and / or decoking gas 115 through one dispenser in the processing unit 190, or when stopping the passage, passing or stopping the passage of the combustible gas 110, purge gas 118, and / or decoking gas 115 may also occur at at least one or more other dispensers 165, 166, 167, and 168 in the processing unit 190. Note this point.

[0016] In one or more embodiments, the combustible gas 110 may include a hydrocarbon stream. The combustible gas 110 may include one or more of hydrogen, nitrogen, methane, ethane, propane, natural gas, combinations thereof, and the like. The combustible gas 110 may include one or more olefins. For example, the combustible gas 110 may include one or more of ethylene, propylene, butadiene, isoprene, piperylene, combinations thereof, and the like.

[0017] In one or more embodiments, the combustible gas 110 may include less than 5 mol% olefins. For example, in one or more embodiments, the combustible gas 110 may include less than 5 mol% olefins, less than 4.5 mol% olefins, less than 4 mol% olefins, less than 3.5 mol% olefins, less than 3 mol% olefins, less than 2.5 mol% olefins, less than 2 mol% olefins, less than 1.5 mol% olefins, less than 1 mol% olefins, less than 0.5 mol% olefins, or even less than 0.1 mol% olefins.

[0018] In one or more embodiments, the combustible gas 110 may include at least 30 mol% nitrogen. For example, in one or more embodiments, the combustible gas 110 may include at least 0.1 mol% nitrogen, at least 1 mol% nitrogen, at least 2 mol% nitrogen, at least 5 mol% nitrogen, at least 10 mol% nitrogen, at least 20 mol% nitrogen, at least 25 mol% nitrogen, at least 29 mol% nitrogen, or at least 30 mol% nitrogen.

[0019] In one or more embodiments, the purge gas 118 may include a gas capable of removing the combustible gas 110 and / or the decoking gas 115 present in any of the distributors 165, 166, 167, and 168. In some embodiments, the purge gas 118 may include nitrogen, steam, or a combination thereof. For example, in order to remove the formed coke, steam may be passed through one or more of the distributors 165, 166, 167, and 168 to partially or completely remove the combustible gas 110 from the distributors 165, 166, 167, and 168 before passing the decoking gas 115 through the one or more distributors 165, 166, 167, and 168. In another example, nitrogen may be passed through the distributors 165, 166, 167, and 168 for the purpose of partially or completely removing the decoking gas 115 from the distributors 165, 166, 167, and 168 so that the combustible gas 110 can be passed through the one or more distributors 165, 166, 167, and 168 again.

[0020] In one or more embodiments, the decoking gas 115 may include a gas capable of contacting and removing the coke formed in any of the distributors 165, 166, 167, and 168. In some embodiments, the decoking gas 115 may include a gas capable of oxidizing the coke formed in any of the distributors 165, 166, 167, and 168. For example, the decoking gas 115 may include air, oxygen, steam, or a combination thereof.

[0021] In one or more embodiments, the temperature on at least a portion of the surface of the first dispenser 165, on at least a portion of the surface of the second dispenser 166, on at least a portion of the surface of the third dispenser 167, or on at least a portion of the surface of the fourth dispenser 168 may reach at least 1000°C. For example, the surface temperature of at least a portion of the first dispenser 165, the surface temperature of at least a portion of the second dispenser 166, the surface temperature of at least a portion of the third dispenser 167, or the surface temperature of at least a portion of the fourth dispenser 168 may be at least 50°C, at least 100°C, at least 200°C, at least 300°C, at least 500°C, at least 750°C, at least 900°C, at least 990°C, or even at least 1000°C.

[0022] In one or more embodiments, the processing unit 190 may include a plurality of dispensers 165, 166, 167, and 168. For example, the processing unit 190 may include the first dispenser 165, the second dispenser 166, the third dispenser 167, and the fourth dispenser 168. In one or more embodiments, the processing unit 190 may include additional dispensers. For example, the processing unit 190 may include at least two dispensers, the processing unit 190 may include at least three dispensers, the processing unit 190 may include at least four dispensers, the processing unit 190 may include at least five dispensers, the processing unit 190 may include at least ten dispensers, the processing unit 190 may include at least fifteen dispensers, or the processing unit 190 may even include at least twenty dispensers.

[0023] Referring to FIG. 1, the operating state 100 of one or more embodiments is shown. In the operating state 100, injecting the combustible gas 110 through the plurality of dispensers 165, 166, 167, and 168 may include passing only the combustible gas 110 through the plurality of dispensers 165, 166, 167, and 168. The combustible gas 110 may pass through the first dispenser 165, the second dispenser 166, the third dispenser 167, and the fourth dispenser 168. The combustible gas 110 passes through the first dispenser combustible gas first section 140, through the valve 157, through the first dispenser combustible gas second section 141, and through the first dispenser mixed gas section 142, and thus may pass through the first combustible gas conduit 133 and be passed to the first dispenser 165. The combustible gas 110 passes through the first dispenser 165 within the processing unit 190, contacts the solid particles, and may form coke on the first dispenser 165. The combustible gas 110 passes through the second dispenser combustible gas first section 138, through the valve 158, through the second dispenser combustible gas second section 139, and through the second dispenser mixed gas section 143, and thus may pass through the first combustible gas conduit 133 and be passed to the second dispenser 166. The combustible gas 110 passes through the second dispenser 166 within the processing unit 190, contacts the solid particles, and may form coke on the second dispenser 166.

[0024] In one or more embodiments, the operating state 100 may include the combustible gas 110 passing through the third dispenser combustible gas first section 136, through the valve 159, through the third dispenser combustible gas second section 137, and through the third dispenser mixed gas section 144, and then being passed through the first combustible gas conduit 133 to the third dispenser 167. The combustible gas 110 may pass through the third dispenser 167 within the processing unit 190, contact solid particles, and form coke on the third dispenser 167. The combustible gas 110 may pass through the fourth dispenser combustible gas first section 134, through the valve 160, through the fourth dispenser combustible gas second section 135, and through the fourth dispenser mixed gas section 145, and then be passed through the first combustible gas conduit 133 to the fourth dispenser 168. The combustible gas 110 may pass through the fourth dispenser 168 within the processing unit 190, contact solid particles, and form coke on the fourth dispenser 168.

[0025] In one or more embodiments, the operating state 100 may include that the decoking gas 115 is not passed through any of the dispensers 165, 166, 167, and 168. In one or more embodiments, the valve 151 may be closed so that the decoking gas 115 in the first decoking gas conduit 121 does not pass through the valve 151. The decoking gas 115 in the first decoking gas conduit 121 may not be allowed to be passed to the first dispenser 165 by not being passed through the first decoking / purge gas conduit 123, the first dispenser decoking / purge gas first section 124, the valve 153, the first dispenser decoking / purge gas second section 126, and the first dispenser mixed gas section 142. The decoking gas 115 in the first decoking gas conduit 121 may not be allowed to be passed to the second dispenser 166 by not being passed through the first decoking / purge gas conduit 123, the second decoking / purge gas conduit 125, the second dispenser decoking / purge gas first section 127, the valve 154, the second dispenser decoking / purge gas second section 128, and the second dispenser mixed gas section 143. The decoking gas 115 in the first decoking gas conduit 121 may not be allowed to be passed to the third dispenser 167 by not being passed through the first decoking / purge gas conduit 123, the second decoking / purge gas conduit 125, the third dispenser decoking / purge gas first section 129, the valve 155, the third dispenser decoking / purge gas second section 130, and the third dispenser mixed gas section 144. The decoking gas 115 in the first decoking gas conduit 121 may not be allowed to be passed to the fourth dispenser 168 by not being passed through the first decoking / purge gas conduit 123, the second decoking / purge gas conduit 125, the fourth dispenser decoking / purge gas first section 131, the valve 156, the fourth dispenser decoking / purge gas second section 132, and the fourth dispenser mixed gas section 145.

[0026] In one or more embodiments, in the operating state 100, the purge gas 118 is not passed through any of the dispensers 165, 166, 167, and 168. In one or more embodiments, the valve 152 may be closed so that the purge gas 118 in the first purge gas conduit 122 does not pass through the valve 152. The purge gas 118 in the first purge gas conduit 122 is not allowed to be passed to the first dispenser 165 by not being passed through the first decoking / purge gas conduit 123, the first dispenser decoking / purge gas first section 124, the valve 153, the first dispenser decoking / purge gas second section 126, and the first dispenser mixed gas section 142. The purge gas 118 in the first purge gas conduit 122 is not allowed to be passed to the second dispenser 166 by not being passed through the first decoking / purge gas conduit 123, the second decoking / purge gas conduit 125, the second dispenser decoking / purge gas first section 127, the valve 154, the second dispenser decoking / purge gas second section 128, and the second dispenser mixed gas section 143. The purge gas 118 in the first purge gas conduit 122 is not allowed to be passed to the third dispenser 167 by not being passed through the first decoking / purge gas conduit 123, the second decoking / purge gas conduit 125, the third dispenser decoking / purge gas first section 129, the valve 155, the third dispenser decoking / purge gas second section 130, and the third dispenser mixed gas section 144. The purge gas 118 in the first purge gas conduit 122 is not allowed to be passed to the fourth dispenser 168 by not being passed through the first decoking / purge gas conduit 123, the second decoking / purge gas conduit 125, the fourth dispenser decoking / purge gas first section 131, the valve 156, the fourth dispenser decoking / purge gas second section 132, and the fourth dispenser mixed gas section 145.

[0027] Referring to FIG. 2, an operating state 200 according to one or more embodiments is shown. In the operating state 200, the valve 157 may be closed so that the combustible gas 110 is not passed to the first distributor 165. Although the combustible gas 110 may continue to be passed to the second distributor 166, the third distributor 167, and the fourth distributor 168, it is not permitted to be passed to the first distributor 165. Although the combustible gas 110 may continue to be passed to the second distributor 166, the third distributor 167, and the fourth distributor 168, the valves 152 and 153 may be opened so that the purge gas 118 can be passed to the first distributor 165. In some embodiments, the combustible gas 110 and the purge gas 118 may be passed through the first distributor 165, and then the valve 157 may be closed so that the combustible gas 110 is not passed through the first distributor 165 while the purge gas 118 continues to be passed through the first distributor 165.

[0028] Still referring to FIG. 2, in one embodiment, while the combustible gas 110 continues to be passed through the first distributor 165, the third distributor 167, and the fourth distributor 168, the valve 158 may be closed so that the combustible gas 110 is not passed to the second distributor 166. The valve 152 and / or the valve 154 may be opened so that the purge gas 118 can pass through the second distributor 166. In another embodiment, while the combustible gas 110 continues to be passed through the first distributor 165, the second distributor 166, and the fourth distributor 168, the valve 159 may be closed so that the combustible gas 110 is not passed to the third distributor 167. The valve 152 and / or the valve 155 may be opened so that the purge gas 118 can pass through the third distributor 167. In another embodiment, while the combustible gas 110 continues to be passed through the first distributor 165, the second distributor 166, and the third distributor 167, the valve 160 may be closed so that the combustible gas 110 is not passed to the fourth distributor 168. The valve 152 and / or the valve 156 may be opened so that the purge gas 118 can pass through the fourth distributor 168.

[0029] Referring to FIG. 3, the operating state 300 is shown. In the operating state 300, after passing the purge gas 118 through the first distributor 165, the valve 152 and / or the valve 153 are closed to prevent the purge gas 118 from passing through the first distributor 165, and then while the combustible gas 110 is continuously passed through the second distributor 166, the third distributor 167, and the fourth distributor 168, the valve 151 and the valve 153 may be opened so that the decoking gas 115 can be passed through the first distributor 165.

[0030] Referring further to FIG. 3, in one embodiment, after passing the purge gas 118 through the second distributor 166, the valve 152 and / or the valve 154 are closed to prevent the purge gas 118 from passing through the second distributor 166, and then while the combustible gas 110 is continuously passed through the first distributor 165, the third distributor 167, and the fourth distributor 168, the valve 151 and the valve 154 may be opened so that the decoking gas 115 can be passed through the second distributor 166. In another embodiment, after passing the purge gas 118 through the third distributor 167, the valve 152 and / or the valve 155 are closed to prevent the purge gas 118 from passing through the third distributor 167, and then while the combustible gas 110 is continuously passed through the first distributor 165, the second distributor 166, and the fourth distributor 168, the valve 151 and the valve 155 may be opened so that the decoking gas 115 can be passed through the third distributor 167. In another embodiment, after passing the purge gas 118 through the fourth distributor 168, the valve 152 and / or the valve 156 are closed to prevent the purge gas 118 from passing through the fourth distributor 168, and then while the combustible gas 110 is continuously passed through the first distributor 165, the second distributor 166, and the third distributor 167, the valve 151 and the valve 156 may be opened so that the decoking gas 115 can be passed through the fourth distributor 168.

[0031] Referring to FIG. 4, an operating state 400 is shown. In the operating state 400, after passing the purge gas 118 through the first distributor 165, the valve 152 and / or the valve 153 are closed to prevent the purge gas 118 from passing through the first distributor 165. After passing the decoking gas 115 through the first distributor 165, the valve 151 and / or the valve 153 are closed to prevent the decoking gas 115 from passing through the first distributor 165. While continuously passing the combustible gas 110 through the second distributor 166, the third distributor 167, and the fourth distributor 168, the valves 152 and 153 may be opened so that the purge gas 118 can pass through the first distributor 165.

[0032] In one embodiment, after passing the purge gas 118 through the second distributor 166, the valve 152 and / or the valve 154 are closed to prevent the purge gas 118 from passing through the second distributor 166. After that, after passing the decoking gas 115 through the second distributor 166, the valve 151 and / or the valve 154 are closed to prevent the decoking gas 115 from passing through the second distributor 166. While the combustible gas 110 is continuously passed through the first distributor 165, the third distributor 167, and the fourth distributor 168, the valves 152 and 154 may be opened so that the purge gas 118 can pass through the second distributor 166. In another embodiment, after passing the purge gas 118 through the third distributor 167, the valve 152 and / or the valve 155 are closed to prevent the purge gas 118 from passing through the third distributor 167. After that, after passing the decoking gas 115 through the third distributor 167, the valve 151 and / or the valve 155 are closed to prevent the decoking gas 115 from passing through the third distributor 167. While the combustible gas 110 is continuously passed through the first distributor 165, the second distributor 166, and the fourth distributor 168, the valves 152 and 155 may be opened so that the purge gas 118 can pass through the third distributor 167. In another embodiment, after passing the purge gas 118 through the fourth distributor 168, the valve 152 and / or the valve 156 are closed to prevent the purge gas 118 from passing through the fourth distributor 168. After that, after passing the decoking gas 115 through the fourth distributor 168, the valve 151 and / or the valve 156 are closed to prevent the decoking gas 115 from passing through the fourth distributor 168. While the combustible gas 110 is continuously passed through the first distributor 165, the second distributor 166, and the third distributor 167, the valves 152 and 156 may be opened so that the purge gas 118 can pass through the fourth distributor 168.

[0033] Referring to FIG. 5, the operating state 500 is shown. In the operating state 500, after passing the purge gas 118 through the first distributor 165, the valve 152 and / or the valve 153 are closed to prevent the purge gas 118 from passing through the first distributor 165. Then, after passing the decoking gas 115 through the first distributor 165, the valve 151 and / or the valve 153 are closed to prevent the decoking gas 115 from passing through the first distributor 165. After passing the purge gas 118 through the first distributor 165 again, the valve 152 and / or the valve 153 are closed to prevent the purge gas 118 from passing through the first distributor 165. Then, the valve 157 may be opened so that the combustible gas 110 can pass through the first distributor 165. In one or more embodiments, before closing the valve 152 and / or the valve 153 to prevent the purge gas 118 from passing through the first distributor 165, the combustible gas 110 and the purge gas 118 may be passed through the first distributor 165.

[0034] In one embodiment, after passing purge gas 118 through the second distributor 166, valves 152 and / or 154 are closed to prevent purge gas 118 from passing through the second distributor 166. Then, after passing decoking gas 115 through the second distributor 166, valves 151 and / or 154 are closed to prevent decoking gas 115 from passing through the second distributor 166. After passing purge gas 118 through the second distributor 166 again, valves 152 and / or 154 are closed to prevent purge gas 118 from passing through the second distributor 166. Then, valve 158 may be opened to allow combustible gas 110 to pass through the second distributor 166. In another embodiment, after passing purge gas 118 through the third distributor 167, valves 152 and / or 155 are closed to prevent purge gas 118 from passing through the third distributor 167. Then, after passing decoking gas 115 through the third distributor 167, valves 151 and / or 155 are closed to prevent decoking gas 115 from passing through the third distributor 167. After passing purge gas 118 through the third distributor 167 again, valves 152 and / or 155 are closed to prevent purge gas 118 from passing through the third distributor 167. Then, valve 159 may be opened to allow combustible gas 110 to pass through the third distributor 167. In another embodiment, after passing purge gas 118 through the fourth distributor 168, valves 152 and / or 156 are closed to prevent purge gas 118 from passing through the fourth distributor 168. Then, after passing decoking gas 115 through the fourth distributor 168, valves 151 and / or 156 are closed to prevent decoking gas 115 from passing through the fourth distributor 168. After passing purge gas 118 through the fourth distributor 168 again, valves 152 and / or 156 are closed to prevent purge gas 118 from passing through the fourth distributor 168. Then, valve 160 may be opened to allow combustible gas 110 to pass through the fourth distributor 168.

Example

[0035] Examples are provided herein that may disclose one or more embodiments of the present disclosure. However, the examples should not be considered as limiting the claimed embodiments provided below.

[0036] Example 1 Use of Computational Fluid Dynamics Tools to Model Coke Removal Rates and Maximum Tube Metal Temperatures at Various Distributor Inlet Temperatures In this example, a computational fluid dynamics (CFD) tool coupled with a decoking model is used to evaluate the performance of the decoking techniques presented herein. Specifically, the coke removal rate and tube metal temperature are predicted for one of the eight arms of the fuel gas distributor in the combustor. The shape and dimensions of the fuel gas distributor are summarized in Table 1. Under normal operating conditions, the inlet temperature of the fuel gas is 52 °C at a flow rate of 214 lb / hr. The combustor temperature is 730 °C. Based on these conditions, as shown in Table 2, the CFD model predicts that the tube metal temperature reaches 700 °C at the end of the distributor where coke is most likely to form. Therefore, in the CFD model, it is assumed that there is a coke layer 0.5 inches thick in the last 6.5 inches of the distributor, but at a coke formation rate of 3 mg / hr / in 2 (a conservative estimate suggested by available experimental data at 700 °C of 2 mg / hr / in 2 and estimated by a six-month duration. The corresponding coke mass is 1,296 grams. Based on this initial condition, CFD simulations using the decoking model were performed to predict the coke removal rate and tube metal temperature during the decoking process.)

[0037] Use air as the decoking gas at a rate of 880 lb / hr and compare the coke removal rates at four different intake temperatures, 52 °C, 250 °C, 275 °C, and 635 °C. As shown in Tables 3 - 6, the coke removal rate increases as the intake temperature rises due to faster decoking kinetics. In the case of 52 °C, the model predicts that approximately 30% of the coke will be removed in 2 days. It is expected that almost all coke lumps can be removed in one week per distribution arm. Based on this result, the total decoking time defined as the period during which at least one dispenser is in the decoking mode will be 8 weeks (2 months) if each of the 8 dispensers takes one week for decoking and only one dispenser is in the decoking mode at a time. If two dispensers are in the decoking mode simultaneously, the total decoking time will be shortened to 4 weeks. This indicates that the coke lumps formed in 6 months can be removed in at most 2 months. That is, the overall coke removal rate is at least 3 times faster than the coke formation rate, which will effectively prevent the accumulation of coke and the eventual blockage of the dispenser orifices. The coke removal rate further increases with the rise of the intake temperature. Compared with the case of 52 °C, the coke removal rate is 1.35 times higher at an intake temperature of 250 °C, 2.25 times higher at 275 °C, and 20 times higher at 635 °C.

[0038] Since the decoking reaction is exothermic, further investigation is required to ensure that the tube metal temperature is below the design temperature of the tube material. The design temperature of the tube material in this case is 800 °C. As shown in Tables 7 - 10, the higher the intake temperature, the higher the maximum tube metal temperature. In the cases of 52 °C and 250 °C, the maximum tube metal temperature during the decoking process is less than 750 °C. In the case of 275 °C, the maximum tube metal temperature slightly exceeds 800 °C. In the case of 635 °C, the maximum tube metal temperature is 1200 °C, which is considerably higher than the design temperature. These results suggest that the decoking air is preferably preheated to at least 52 °C to achieve the desired decoking rate, but not preheated above 275 °C to ensure that the maximum tube metal temperature is below the design temperature.

[0039]

Table 1

[0040]

Table 2

[0041]

Table 3

[0042]

Table 4

[0043]

Table 5

[0044]

Table 6

[0045]

Table 7

[0046]

Table 8

[0047]

Table 9

[0048]

Table 10

[0049] The present disclosure includes one or more non-limiting aspects. A first aspect is a process of passing solid particles through a processing unit, where the processing unit includes at least a first distributor and a second distributor, and each of the first distributor and the second distributor is operable to pass combustible gas and decoking gas into the processing unit; a process of passing combustible gas into the processing unit through the first distributor, where the combustible gas contacts the solid particles and coke is formed on the first distributor; a process of stopping the passage of the combustible gas through the first distributor while the combustible gas passes through the second distributor; a process of passing decoking gas through the first distributor while the combustible gas passes through the second distributor, where the decoking gas removes the coke formed on the first distributor; and a process of resuming the passage of the combustible gas through the first distributor.

[0050] A second aspect includes the above aspect, and further includes a process of stopping the passage of the combustible gas through the second distributor while the combustible gas continuously passes through the first distributor; a process of passing decoking gas through the second distributor, where the decoking gas removes the coke formed on the second distributor; and a process of resuming the passage of the combustible gas through the second distributor.

[0051] A third aspect includes any of the above aspects, where the combustible gas burns or reduces the solid particles in the processing unit when contacting the solid particles.

[0052] A fourth aspect includes any of the above aspects, where the temperature of at least a part of the surface of the first distributor or at least a part of the surface of the second distributor is at least 500 °C.

[0053] A fifth aspect includes any of the above aspects, where the combustible gas is continuously passed into the processing unit through the first distributor, the second distributor, or both.

[0054] The sixth aspect includes any of the above aspects, and the purge gas passes through the first distributor after the passage of the combustible gas through the first distributor is stopped and before passing the decoking gas through the first distributor.

[0055] The seventh aspect includes any of the above aspects, and the purge gas passes through the first distributor after the passage of the decoking gas through the first distributor is stopped and before the combustible gas continues to pass the combustible gas through the first distributor.

[0056] The eighth aspect includes any of the above aspects, and the purge gas contains nitrogen or steam.

[0057] The ninth aspect includes any of the above aspects, and the combustible gas contains one or more olefins.

[0058] The tenth aspect includes any of the above aspects, and the combustible gas contains less than 5 mol% of olefins.

[0059] The eleventh aspect includes any of the above aspects, and the combustible gas contains ethylene.

[0060] The twelfth aspect includes any of the above aspects, and the combustible gas contains one or more of hydrogen, nitrogen, methane, ethane, propane, natural gas, or combinations thereof.

[0061] The thirteenth aspect includes any of the above aspects, and the decoking gas contains air, oxygen, steam, or combinations thereof.

[0062] The fourteenth aspect includes any of the above aspects, and the processing unit includes additional distributors each operable to pass the combustible gas and the decoking gas through the processing unit.

[0063] The fifteenth aspect includes any of the above aspects, and the first distributor, the second distributor, and the additional distributors pass the decoking gas alternately.

[0064] The subject matter of the present disclosure is described in detail with reference to specific embodiments. It should be understood that any detailed description of a component or feature of an embodiment does not necessarily mean that the component or feature is essential to that embodiment or any other embodiment. Further, it should be apparent to those skilled in the art that various modifications and changes can be made to the described embodiments without departing from the spirit and scope of the claimed subject matter.

[0065] It should also be noted that the description herein of "at least one" component, element, etc. should not be used to create an inference that the alternative use of the articles "a" or "an" should be limited to a single component, element, etc.

[0066] It should be noted that one or more of the following claims utilize the term "wherein" as a transitional phrase. For the purpose of defining the present technology, this term is introduced into the claims as a non-limiting transitional phrase used to introduce a recitation of a series of features of a structure and should be interpreted in the same manner as the more commonly used non-limiting preamble term "comprising".

[0067] When a first component is described as "comprising" a second component, it should be understood that in some embodiments, the first component is contemplated to "consist" or "consist essentially of" that second component. When a first component is described as "comprising" a second component, it should be further understood that in some embodiments, the first component is contemplated to comprise at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or even at least 99% of that second component (where % can be weight % or mole %).

Claims

1. A step of passing solid fine particles through a processing unit, wherein the processing unit includes at least a first distributor and a second distributor, and each of the first distributor and the second distributor is operable to pass a combustible gas and a decoking gas into the processing unit; A step of passing the combustible gas through the first distributor into the processing unit, wherein the combustible gas contacts the solid fine particles and coke is formed on the first distributor; A step of stopping the combustible gas from passing through the first distributor while the combustible gas passes through the second distributor; A step of passing the decoking gas through the first distributor while the combustible gas passes through the second distributor, wherein the decoking gas removes the coke formed on the first distributor; A step of resuming the passage of the combustible gas through the first distributor; A method for operating a gas distributor, comprising the above steps.

2. A step of stopping the combustible gas from passing through the second distributor while the combustible gas continuously passes through the first distributor; A step of passing the decoking gas through the second distributor, wherein the decoking gas removes the coke formed on the second distributor; A step of resuming the passage of the combustible gas through the second distributor. The method according to claim 1, further comprising the above steps.

3. The method according to claim 1 or 2, wherein the combustible gas burns in the processing unit or reduces the solid fine particles when contacting the solid fine particles.

4. The method according to any one of claims 1 to 3, wherein at least a part of the surface temperature of the first distributor or at least a part of the surface temperature of the second distributor is at least 500 °C.

5. The method according to any one of claims 1 to 4, wherein the combustible gas is continuously passed into the processing unit through the first distributor, the second distributor, or both.

6. The method according to any one of claims 1 to 5, wherein a purge gas passes through the first distributor after the passage of the combustible gas through the first distributor is stopped and before the decoking gas is passed through the first distributor.

7. The purge gas passes through the first distributor after the decoking gas is stopped from passing through the first distributor and before the combustible gas continues to pass through the first distributor, according to the method of any one of claims 1 to 6.

8. The purge gas contains nitrogen or steam, according to the method of claim 6 or 7.

9. The combustible gas contains one or more olefins, according to the method of any one of claims 1 to 8.

10. The combustible gas contains less than 5 mol% olefins, according to the method of claim 9.

11. The combustible gas contains ethylene, according to the method of any one of claims 1 to 10.

12. The combustible gas contains one or more of hydrogen, nitrogen, methane, ethane, propane, natural gas, or combinations thereof, according to the method of any one of claims 1 to 11.

13. The decoking gas contains air, oxygen, steam, or combinations thereof, according to the method of any one of claims 1 to 12.

14. The processing unit comprises additional distributors each operable to pass the combustible gas and the decoking gas into the processing unit, according to the method of any one of claims 1 to 13.

15. The first distributor, the second distributor, and the additional distributor alternately pass the decoking gas, according to the method of claim 14.

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