System and method for alkane dehydrogenation process

Abstract

The invention relates to a system and a method for an alkane dehydrogenation process, and relates to the technical field of petrochemical engineering. A propane raw material inlet is formed in the bottom of the reactor, propane enters the reactor through a propane raw material distribution pipe, a regenerated catalyst enters the reactor through a regenerated catalyst distributor and moves upwards along with the propane, and the regenerated catalyst reaches an alkene phase region at the upper part of the reactor through a material lifting pipe; and the lower part of the reactor is a reaction dense-phase section and the like. Compared with the prior art that the residual carbon amount of the fluidized bed spent catalyst for reverse contact reaction of the catalyst and the raw materials is 3-5%, the average residual carbon amount of the fluidized bed spent catalyst for forward contact reaction of the catalyst and the raw materials is 2-4% through multiple sampling analysis, the deep reaction of product gas is greatly inhibited, and the product quality is improved. Therefore, the coke yield of the product olefin is inhibited, the yield of propylene is improved, and the defects in the prior art are overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of petrochemical industry, and in particular to a system and method for an alkane dehydrogenation process. Background Art

[0002] Propylene is widely used in the petrochemical industry in various industries such as materials, medicine, and textiles. Propylene is used as a raw material to produce a variety of chemical products such as polypropylene, acrylonitrile, propylene oxide, and acrylic acid. Currently, propylene products are mainly derived from processes such as steam cracking and catalytic cracking / cracking. In recent years, the process of producing propylene through propane dehydrogenation technology has received increasing attention. Compared with other preparation methods, the product yield of propane dehydrogenation process is higher and the selectivity is better, and it has a good development prospect.

[0003] The main reaction of propane dehydrogenation is:

[0004]

[0005] As shown above, the main reaction of propane dehydrogenation is the dehydrogenation of propane to propylene. Although the desired product is monoolefins, the high temperature and low pressure process conditions will lead to the formation of some diolefins; alkanes or olefins in the feed may also undergo cracking reactions. Although some other side reactions such as isomerization reactions are also possible, the catalyst has minimized the possibility of these reactions.

[0006] Side reactions of the dehydrogenation reaction: Diolefins are generated as follows:

[0007]

[0008] Although the catalyst has a high selectivity for producing the corresponding monoolefins, as the concentration of propylene increases, a small amount of propylene will undergo dehydrogenation on the catalyst to produce propadiene or propyne.

[0009] Cleavage reaction:

[0010]

[0011] In the high temperature area without catalyst, propane may undergo cracking reaction to produce methane, ethane and ethylene.

[0012] Polymerization reaction:

[0013]

[0014] During the reaction, heavy components will also be generated. For example, in the above reaction, two propylenes polymerize to form benzene.

[0015] In addition, there is a coke formation reaction. As the reaction proceeds, coke is generated on the catalyst. Coke is a highly polymerized C, containing up to 95% C and 5% H.

[0016] The core of current propane dehydrogenation technology is catalyst and reactor. The most widely used fluidized bed catalyst in industrial application is chromium catalyst. The core process of the reactor is the reaction flow state between the catalyst and the propane raw material. In the existing process, the catalyst goes down and the raw gas goes up, and the two are in reverse contact reaction. After the reaction, the product gas containing propylene continues to go up and continues to react with the down-going high-temperature catalyst. Part of the propylene generates coke, and the propylene yield will be reduced. Summary of the invention

[0017] In order to solve the above problems, the present invention provides a system and method for an alkane dehydrogenation process.

[0018] In a first aspect, the present invention provides a system for an alkane dehydrogenation process, the system comprising a reactor;

[0019] The bottom of the reactor is provided with a propane raw material inlet, propane enters the reactor through a propane raw material distribution pipe, the regenerated catalyst enters the reactor through a regenerated catalyst distributor and reacts with the propane in a forward direction and moves upward, and reaches the upper olefin phase area of ​​the reactor through a material lifting pipe, and the lower part of the reactor is a reaction dense phase section;

[0020] The top of the reactor is provided with a reaction product outlet, through which the reaction gas comes out of the reaction gas collecting chamber, the reaction gas collecting chamber is connected with the first and second cyclones, the first and second cyclones are connected with the second reaction dense phase storage through the cyclone legs and the wing valve, and the second reaction dense phase storage is connected with the lower part of the reactor through the catalyst external circulation pipe;

[0021] A material distributor is arranged inside the reactor, and the material distributor is communicated with the material lifting pipe.

[0022] Furthermore, the catalyst external circulation pipe is provided with a reactor external circulation slide valve.

[0023] Furthermore, the system further comprises a regenerator, the bottom of which is connected to the regenerated catalyst distributor via a regeneration inclined pipe;

[0024] The top of the regenerator is provided with a flue gas outlet, through which the flue gas comes out of the flue gas collecting chamber, and the flue gas collecting chamber is connected with the first and second cyclones;

[0025] The upper and lower parts of the regenerator are respectively a regenerator dilute phase section and a regenerator dense phase section, and the catalyst distributor to be regenerated in the dense phase section of the regenerator is connected to the reaction second dense phase storage volume in the reactor through the inclined tube to be regenerated and the inclined tube for the catalyst to be regenerated;

[0026] The regenerated catalyst at the bottom of the regenerator is stripped of flue gas, carbon dioxide, etc. by the stripping nitrogen in the stripping section, and then enters the regenerated catalyst inclined tube through the regenerated catalyst slide valve controlled by the hydraulic transmission mechanism and then to the reactor;

[0027] A main air inlet is arranged at the lower part of the regenerator, and the main air enters the regenerator through the main air distribution pipe.

[0028] Furthermore, the alkane dehydrogenation process is a fluidized bed alkane dehydrogenation to olefin process.

[0029] In a second aspect, an embodiment of the present invention provides a method for an alkane dehydrogenation process, wherein the method is performed using the system for an alkane dehydrogenation process as described in any one of the first aspects.

[0030] Further, the method comprises a reaction section and a regeneration section;

[0031] The reaction section includes the following processes:

[0032] 1) Raw material processing and reaction process:

[0033] The gaseous propane output from the cold box is heated to no more than 450°C by heat exchange with the rich gas after the reaction in the raw material preheating section; the heated propane enters the reactor through the raw material distributor at the bottom of the dense phase section of the reactor; the propane contacts the high-temperature catalyst transported from the regenerator to cause a dehydrogenation reaction; the average reaction temperature of the dense phase section is controlled within the range of 560-620°C;

[0034] 2) Gas-solid separation process:

[0035] The rich gas and catalyst after the reaction enter the dilute phase tube and undergo preliminary gas-solid separation through the quick separator at the top of the dilute phase tube; most of the catalyst falls into the second dense phase, and a small amount of catalyst enters the cyclone with the rich gas for further gas-solid separation; the rich gas leaves the reactor with a very small amount of catalyst fine powder;

[0036] Catalyst regeneration and recycling:

[0037] The catalyst entering the second dense phase uses steam as the fluidizing medium and returns to the regenerator through the inclined tube to be regenerated;

[0038] 3) Rich gas treatment and subsequent processes:

[0039] The rich gas leaving the reactor has a temperature of 570-600°C. After generating low-pressure steam in the waste heat recovery section, it enters the raw material preheating section for heat exchange with the raw material, and the temperature is reduced to 116°C.

[0040] The rich gas after heat exchange enters the bottom of the water washing tower, where dust is removed by water washing and the temperature is further reduced to 40°C; the treated rich gas enters the subsequent compression and separation system.

[0041] Furthermore, the regeneration stage includes the following process:

[0042] 1) Regenerator operation and gas-solid separation:

[0043] Air is provided by the main fan, and after being preheated in the auxiliary combustion chamber, it enters the regenerator through the main air distributor at the bottom of the regenerator; the air mixes with the fuel injected into the regenerator and burns to release heat; the flue gas and a small amount of catalyst enter the dilute phase section, and are separated from the gas and solid by the quick separator at the top of the dilute phase section; a small amount of catalyst falls into the air stripping section together with most of the catalyst to be regenerated through the cyclone legs, and after the flue gas carried by the catalyst is removed by gas stripping reduction, it is circulated back to the reactor through the regeneration inclined tube; a small amount of catalyst entrained in the flue gas is further separated from the gas and solid by the cyclone, and the catalyst returns to the regenerator, and the flue gas leaves the regenerator with a very small amount of catalyst fine powder;

[0044] 2) Flue gas treatment and waste heat recovery:

[0045] The flue gas leaving the regenerator has a temperature of 650℃-700℃. After entering the waste heat boiler to generate steam, the temperature drops to 150℃. The cooled flue gas enters the flue gas scrubber to remove dust and is then discharged directly.

[0046] The washing wastewater of the flue gas washing tower settles at the bottom of the tower, and the clean water after settling is pumped out by pump P-1001A / B and directly circulated back to the flue gas washing tower for use;

[0047] The concentrated slurry after settling at the bottom of the tower is pumped out and sent to the sedimentation tank of the sewage treatment plant for treatment;

[0048] 3) Regenerator pressure control:

[0049] The operating pressure of the regenerator is the same as that of the reactor, which is 0.035MPa; the pressure of the regenerator is controlled by a double-acting slide valve on the flue at the top of the regenerator;

[0050] 4) Catalyst storage tank configuration:

[0051] There are three catalyst storage tanks: cold catalyst storage tank D-1001, hot catalyst storage tank D-1002 and spent catalyst storage tank D-1003;

[0052] The three catalyst storage tanks are connected to the bottom of the regenerator through pipelines;

[0053] Both storage tanks D-1001 and D-1002 can add catalyst to the reaction regeneration system through pipelines;

[0054] 5) Flue gas waste heat recovery process:

[0055] High-temperature flue gas at 630℃-670℃ enters the waste heat boiler from the bottom; the flue gas passes through the high-temperature evaporator, superheater, low-temperature evaporator, high-temperature economizer and low-temperature economizer in the waste heat boiler for heat exchange; the flue gas temperature after heat exchange drops to 160℃, and then enters the subsequent dust removal and denitrification units for further treatment.

[0056] The above technical solution provided by the embodiment of the present invention has at least the following advantages compared with the prior art:

[0057] The embodiment of the present invention provides a system and method for an alkane dehydrogenation process. Compared with the prior art, the residual carbon content of the fluidized bed catalyst to be regenerated in the reverse contact reaction between the catalyst and the raw material is between 3-5%, while the residual carbon content of the fluidized bed catalyst to be regenerated in the forward contact reaction between the catalyst and the raw material designed by the present invention is between 2-4% on average after multiple sampling and analysis, which greatly inhibits the deep reaction of the product gas, thereby inhibiting the coking of the product olefins, improving the yield of propylene, and making up for the shortcomings of the prior art. Specifically:

[0058] 1. Aiming at the problems in the prior art, the present invention proposes a novel method and system for propane dehydrogenation production. First, a reactor is designed, the lower part is a dense phase reaction section, the middle and upper part is provided with a gas-solid material lifting pipe, and the lower part of the upper olefin phase zone is provided with a second dense phase, the second dense phase is used to control the storage of the reactor, the raw material propane gas phase enters the reactor from the bottom distribution pipe of the reactor, the high-temperature regenerated catalyst enters the reactor from the bottom of the reactor through a cross distributor, and reacts with the propane raw material gas phase coming from the bottom of the reactor upward in the same direction, while undergoing dehydrogenation reaction, while strongly absorbing heat and cooling upward, and reaches the upper reactor dilute phase section through the material lifting pipe, and the catalyst falls into the lower second dense phase of the reactor dilute phase section; the product gas carries a small amount of catalyst dust into the first and second cyclone separators, a small amount of catalyst dust is sent to the second dense phase through the cyclone separator feed leg and wing valve, and the product gas is sent to the outside of the reactor through the gas collecting chamber. During the dense phase reaction, the propylene reacting with the raw material gas and the high-temperature catalyst in the upstream direction will not contact the high-temperature catalyst, will not generate coke, and the propylene yield will not decrease, thereby overcoming the shortcomings of the ordinary fluidized bed dehydrogenation process.

[0059] 2. Then design a catalyst regenerator. This regenerator can be divided into three parts: upper, middle and lower. The middle part is the catalyst burning dense phase section, which is the place where the catalyst to be regenerated and the main air high-temperature supplementary combustion coke, the upper part is the dilute phase section, which is the place where the catalyst and flue gas are separated. The dilute phase section is equipped with one and two stage cyclones. The cyclone is a device for separating a small amount of catalyst carried by the flue gas, and then the flue gas is discharged out of the device. The lower part is the gas stripping section for the regenerated catalyst. The function of the gas stripping section is to strip the flue gas carried by the regenerated catalyst, and then the regenerated catalyst is discharged out of the device, and then the regeneration slide valve is used to control the circulation volume to the reactor, and it is lifted to the reactor through the regeneration inclined tube with nitrogen and other media. The main air enters the regenerator through the main air distribution pipe at the bottom of the middle of the regenerator, and contacts and burns the descending high-temperature catalyst to be regenerated in reverse.

[0060] 3. The reaction process technology features of the present invention:

[0061] 1) Radial distribution technology of raw material alkanes, sampling of mature raw material distribution tubular distributor.

[0062] 2) Radial distribution technology of regenerated catalyst.

[0063] 3) Highly efficient alkane and bed catalyst secondary distribution technology.

[0064] 4) High efficiency cyclone separator.

[0065] 5) Meet the requirements of high raw material conversion rate and high product selectivity.

[0066] 6) The process technology is mature, reliable and advanced.

[0067] 7) Low energy consumption, long cycle operation, easy operation and flexible adjustment.

[0068] 8) Low investment, small footprint, environmental protection and high safety factor.

[0069] 9) The catalyst has stable fluidization and good heat transfer properties.

[0070] 10) The dehydrogenation reaction is a highly endothermic process, and the heat is provided by the raw materials and the regenerated catalyst.

[0071] 11) The requirements are met at both low and high airspeeds.

[0072] 12) The dehydrogenation process is sensitive to oxides, and the regeneration agent adopts removal measures.

[0073] 13) The process characteristics of the regenerator are that the catalyst to be regenerated enters the middle of the dense phase bed through the catalyst delivery pipe and the catalyst distributor, and is well distributed, and then flows downward to form a gas-solid countercurrent contact with the main wind, which is beneficial to improve the overall charring intensity.

[0074] 14) A catalyst delivery pipe is provided. The catalyst is delivered by an inclined pipe. The circulation volume of the catalyst can be conveniently adjusted by adjusting the opening of the slide valve. An inner lining is provided in the delivery pipe to prevent pipe wear and extend the operation cycle.

[0075] 15) A reaction oil and gas washing tower is set up to purify the catalyst dust carried by the reaction products.

[0076] 16) Set up reaction oil gas waste heat boiler and regeneration flue gas waste heat boiler to generate 1.0MPa steam, reducing the energy consumption of the device.

[0077] 17) A three-stage cyclone separator is installed for regenerated flue gas to recover most of the catalyst and reduce ash accumulation in the flue gas waste heat boiler.

[0078] 18) A flue gas dust collector is installed to recover catalyst dust, and the dust is sent to the regenerator or waste catalyst tank.

[0079] 19) The position design of the regenerator and the reactor is parallel with each other in high and low arrangement. The reactor should be higher than the regenerator, which is beneficial for the catalyst to flow to the regenerator by gravity and is also beneficial for controlling the storage volume of the second dense phase in the reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0081] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0082] Figure 1 A schematic structural diagram of a system for an alkane dehydrogenation process provided by an embodiment of the present invention;

[0083] Figure 1Middle: 1-regeneration inclined pipe, 2-propane feed inlet, 3-propane feed distribution pipe, 4-regeneration catalyst distributor, 5-reaction dense phase section, 6-reactor external circulation slide valve, 7-catalyst external circulation pipe, 8-reaction second dense phase storage, 9-wing valve, 10-cyclone material leg, 11-material lifting pipe, 12-material distributor, 13-first and second cyclone, 14-reaction gas collection chamber, 15-reaction product outlet, 16-flue gas outlet, 17-flue gas collection chamber, 18-first and second stage cyclone, 19-regenerator dilute phase section, 20-catalyst distributor to be regenerated, 21-regenerator dense phase section, 22-main air distribution pipe, 23-main air inlet, 24-regenerated catalyst stripping section, 25-regenerated catalyst slide valve, 26-regenerated catalyst lifting nitrogen, 27-to-be-regenerated inclined tube, 28-to-be-regenerated catalyst inclined tube, 29-helium, 30-main air, 31-flue gas, 32-reaction gas, 33-regenerator, 34-reactor. DETAILED DESCRIPTION

[0084] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0085] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0086] In a first aspect, the present invention provides a system for an alkane dehydrogenation process, the system comprising a reactor;

[0087] The bottom of the reactor is provided with a propane raw material inlet, propane enters the reactor through a propane raw material distribution pipe, the regenerated catalyst enters the reactor through a regenerated catalyst distributor and reacts with the propane in a forward direction and moves upward, and reaches the upper olefin phase area of ​​the reactor through a material lifting pipe, and the lower part of the reactor is a reaction dense phase section;

[0088] The top of the reactor is provided with a reaction product outlet, through which the reaction gas comes out of the reaction gas collecting chamber, the reaction gas collecting chamber is connected with the first and second cyclones, the first and second cyclones are connected with the second reaction dense phase storage through the cyclone legs and the wing valve, and the second reaction dense phase storage is connected with the lower part of the reactor through the catalyst external circulation pipe;

[0089] A material distributor is arranged inside the reactor, and the material distributor is communicated with the material lifting pipe.

[0090] The embodiment of the present invention provides a system for an alkane dehydrogenation process. Compared with the prior art in which the residual carbon content of a fluidized bed catalyst to be spent in a reverse contact reaction between a catalyst and a raw material is between 3% and 5%, the residual carbon content of a fluidized bed catalyst to be spent in a forward contact reaction between a catalyst and a raw material designed by the present invention is, after multiple sampling and analysis, an average of between 1.5% and 3.5%. This greatly inhibits the deep reaction of the product gas, thereby also inhibiting the coking amount of the product olefins, improving the yield of propylene, and making up for the shortcomings of the prior art.

[0091] In some specific implementations, the catalyst external circulation pipe is provided with a reactor external circulation slide valve.

[0092] In some specific implementations, the system further comprises a regenerator, the bottom of which is connected to the regenerated catalyst distributor via a regeneration inclined pipe;

[0093] The top of the regenerator is provided with a flue gas outlet, through which the flue gas comes out of the flue gas collecting chamber, and the flue gas collecting chamber is connected with the first and second cyclones;

[0094] The upper and lower parts of the regenerator are respectively a regenerator dilute phase section and a regenerator dense phase section, and the catalyst distributor to be regenerated in the dense phase section of the regenerator is connected to the reaction second dense phase storage volume in the reactor through the inclined tube to be regenerated and the inclined tube for the catalyst to be regenerated;

[0095] The regenerated catalyst at the bottom of the regenerator removes flue gas through gas stripping nitrogen in the gas stripping section, and then enters the regenerated catalyst inclined pipe into the reactor through a regenerated catalyst slide valve controlled by a hydraulic transmission mechanism. A main air inlet is provided at the lower part of the regenerator, and the main air enters the regenerator through a main air distribution pipe.

[0096] In some specific implementations, the alkane dehydrogenation process is a fluidized bed alkane dehydrogenation to olefin process.

[0097] In some specific implementations, the structural schematic diagram of the system of the alkane dehydrogenation process is as follows: Figure 1 As shown, Figure 1Middle: 1-regeneration inclined pipe, 2-propane feed inlet, 3-propane feed distribution pipe, 4-regeneration catalyst distributor, 5-reaction dense phase section, 6-reactor external circulation slide valve, 7-catalyst external circulation pipe, 8-reaction second dense phase storage, 9-wing valve, 10-cyclone material leg, 11-material lifting pipe, 12-material distributor, 13-first and second cyclone, 14-reaction gas collection chamber, 15-reaction product outlet, 16-flue gas outlet, 17-flue gas collection chamber, 18-first and second stage cyclone, 19-regenerator dilute phase section, 20-catalyst distributor to be regenerated, 21-regenerator dense phase section, 22-main air distribution pipe, 23-main air inlet, 24-regenerated catalyst stripping section, 25-regenerated catalyst slide valve, 26-regenerated catalyst lifting nitrogen, 27-to-be-regenerated inclined tube, 28-to-be-regenerated catalyst inclined tube, 29-helium, 30-main air, 31-flue gas, 32-reaction gas, 33-regenerator, 34-reactor.

[0098] The connection relationship of the various components of the system of the alkane dehydrogenation process is as follows:

[0099] The regenerated catalyst from the regenerator enters the dehydrogenation reaction section 5 of the reactor through the regeneration inclined pipe 1. The main air from the main air pipeline 2 enters the reactor reaction section 5 through the main air distribution pipe 3, and the regenerated catalyst moves upstream to undergo dehydrogenation reaction. Under the action of the airflow, the reaction oil gas and the catalyst move upward through the material lifting pipe 11, and then through the reaction material distributor 12, and enter the reactor dilute phase section 34 for gas-solid separation. The carbon-containing catalyst to be regenerated falls downward by gravity to the bottom 8 (second dense phase) of the reactor dilute phase section. The reaction gas moves upward and enters the primary and secondary cyclone separation separators 13. The small amount of catalyst carried by the reactor gas is separated by the centrifugal principle and falls into The cyclone leg 10, through the wing valve 9, falls into the second dense phase 8, the reaction gas is discharged to the gas collecting chamber 14 by the cyclone, and then discharged to the reactor top outlet pipeline 15, to 32, for subsequent treatment. The second dense phase catalyst storage control is set at the bottom of the reactor dilute phase section. The control principle is to use the opening size of the catalyst slide valve 28 of the hydraulic transmission mechanism to control the height of the second dense phase storage. The second dense phase storage height can also be set to automatically adjust the flow of the catalyst to be regenerated through the catalyst inclined pipe 27 to the regenerator to maintain the second dense phase catalyst storage. In order to assist in adjusting the dosage of the reaction section, a small part of the catalyst passes through the external circulation pipe 7 and then through the external circulation slide valve 6 to achieve.

[0100] Detailed description of the connection relationship between the components of the regenerator

[0101] The main air from the outlet of the main fan is heated in the auxiliary combustion chamber, and then goes up through pipelines 30 and 23 and then through the main air distributor 22 into the charring section 21 of the regenerator, and reacts with the catalyst to be regenerated from the downstream of the reactor in a countercurrent charring reaction. The charred flue gas goes up to the dilute phase sections 19 and 33 of the regenerator, and enters the first and second stage cyclone separators 18. A small amount of catalyst carried by the flue gas is separated by the centrifugal principle, and returns to the charring section by gravity through the material legs and wing valves; the flue gas separated by the cyclone is discharged through the gas collecting chamber 17 to the top outlet pipeline 16 of the reactor to 31 for subsequent heat exchange treatment. The regenerated catalyst flows from the second dense phase of the reaction through the inclined pipe 27, the slide valve 28 and the distributor 20 to the regenerated catalyst, and then enters the charring section of the regenerator and is charred at 660°C in countercurrent with the upward main wind. The charred regenerated catalyst flows downward to the gas section 24 by gravity, and after the flue gas carried by the catalyst is removed by nitrogen gas lift, it flows downward to the regeneration slide valve 25 controlled by the hydraulic transmission mechanism, and then is lifted to the regeneration inclined pipe 1 by the lifting gases 29 and 26 and then to the reaction section of the reactor for cyclic dehydrogenation reaction.

[0102] In a second aspect, an embodiment of the present invention provides a method for an alkane dehydrogenation process, wherein the method is performed using the system for an alkane dehydrogenation process as described in any one of the first aspects.

[0103] In some specific embodiments, the method includes a reaction section and a regeneration section;

[0104] The reaction section includes the following processes:

[0105] 1) Raw material processing and reaction process:

[0106] The gaseous propane output from the cold box is heated to no more than 450°C by heat exchange with the rich gas after the reaction in the raw material preheating section;

[0107] The heated propane enters the reactor through the raw material distributor at the bottom of the dense phase section of the reactor;

[0108] Propane contacts the high-temperature catalyst delivered from the regenerator and undergoes a dehydrogenation reaction;

[0109] The average reaction temperature of the dense phase section is controlled within the range of 560-620°C;

[0110] 2) Gas-solid separation process:

[0111] The rich gas and catalyst after the reaction enter the dilute phase tube and undergo preliminary gas-solid separation through the quick separator at the top of the dilute phase tube;

[0112] Most of the catalyst falls into the second dense phase, and a small amount of catalyst enters the cyclone with the rich gas for further gas-solid separation;

[0113] The rich gas leaves the reactor carrying very small amounts of catalyst fines;

[0114] Catalyst regeneration and recycling:

[0115] The catalyst entering the second dense phase uses steam as the fluidizing medium and returns to the regenerator through the inclined tube to be regenerated;

[0116] 3) Rich gas treatment and subsequent processes:

[0117] The rich gas leaving the reactor has a temperature of 570-600°C. After generating low-pressure steam in the waste heat recovery section, it enters the raw material preheating section for heat exchange with the raw material, and the temperature is reduced to 116°C.

[0118] The rich gas after heat exchange enters the bottom of the water washing tower, where it is washed to remove dust and further cooled to 40°C;

[0119] The treated rich gas enters the subsequent compression and separation system.

[0120] In some specific embodiments, the regeneration stage includes the following process:

[0121] 1) Regenerator operation and gas-solid separation:

[0122] The air is provided by the main fan, preheated in the auxiliary combustion chamber, and then enters the regenerator through the main air distributor at the bottom of the regenerator;

[0123] The air mixes with the fuel injected into the regenerator and burns to release heat;

[0124] Flue gas and a small amount of catalyst enter the dilute phase section and undergo gas-solid separation in the quick separator at the top of the dilute phase section;

[0125] A small amount of catalyst falls into the gas stripping section together with most of the spent catalyst through the cyclone legs, and after gas stripping reduction to remove the flue gas carried by the catalyst, it is circulated back to the reactor through the regeneration inclined tube;

[0126] After a small amount of catalyst carried by the flue gas is further separated from the solid by the cyclone, the catalyst returns to the regenerator, and the flue gas leaves the regenerator with a very small amount of catalyst fine powder;

[0127] 2) Flue gas treatment and waste heat recovery:

[0128] The flue gas leaving the regenerator has a temperature of 650℃-700℃. After entering the waste heat boiler to generate steam, the temperature drops to 150℃.

[0129] The cooled flue gas enters the flue gas scrubber to remove dust and is then discharged directly;

[0130] The washing wastewater of the flue gas washing tower settles at the bottom of the tower, and the clean water after settling is pumped out by pump P-1001A / B and directly circulated back to the flue gas washing tower for use;

[0131] The concentrated slurry after settling at the bottom of the tower is pumped out and sent to the sedimentation tank of the sewage treatment plant for treatment;

[0132] 3) Regenerator pressure control:

[0133] The operating pressure of the regenerator is the same as that of the reactor, which is 0.035 MPa;

[0134] The regenerator pressure is controlled by a double-acting slide valve on the top flue of the regenerator;

[0135] 4) Catalyst storage tank configuration:

[0136] There are three catalyst storage tanks: cold catalyst storage tank D-1001, hot catalyst storage tank D-1002 and spent catalyst storage tank D-1003;

[0137] The three catalyst storage tanks are connected to the bottom of the regenerator through pipelines;

[0138] Both storage tanks D-1001 and D-1002 can add catalyst to the reaction regeneration system through pipelines;

[0139] 5) Flue gas waste heat recovery process:

[0140] High-temperature flue gas of 630℃-670℃ enters the waste heat boiler from the bottom;

[0141] The flue gas passes through the high-temperature evaporator, superheater, low-temperature evaporator, high-temperature economizer and low-temperature economizer in the waste heat boiler for heat exchange;

[0142] After heat exchange, the flue gas temperature drops to 160°C, and then enters the subsequent dust removal and denitrification units for further treatment.

[0143] In some specific embodiments, the above-mentioned alkane dehydrogenation process comprises:

[0144] 1. Reaction process

[0145] The gaseous propane coming out of the cold box is heated to no more than 450°C after heat exchange with the rich gas after reaction in the E-1001 raw material preheating section, and then enters the reactor through the raw material distributor at the bottom of the dense phase section of the reactor R-1001. It contacts with the high-temperature catalyst from the regenerator R-1002 and undergoes dehydrogenation reaction. The average reaction temperature of the dense phase section is controlled at 560-620°C. The rich gas and catalyst after reaction enter the dilute phase pipe, and the rapid separator at the top of the dilute phase pipe performs preliminary gas-solid separation. Most of the catalyst falls into the second dense phase, and a small amount of catalyst enters the cyclone with the rich gas for further gas-solid separation. Finally, the rich gas leaves the reactor with a very small amount of catalyst fine powder. The catalyst entering the second dense phase uses water vapor as the fluidized medium and returns to the regenerator through the waiting inclined pipe.

[0146] The rich gas at about 570-600℃ leaving the reactor generates low-pressure steam after passing through the E-1001 waste heat recovery section, and then enters the E-1001 raw material preheating section to exchange heat with the raw material. The temperature is reduced to about 116℃, and then enters the bottom of the water washing tower C-2001, where dust is removed by water washing and the temperature is further reduced to about 40℃, and then enters the subsequent compression and separation system.

[0147] Alkane dehydrogenation is not only an endothermic reaction with a relatively large thermal effect, but also a reversible reaction with an increase in the number of moles. High pressure or the presence of hydrogen is not conducive to dehydrogenation. The higher the single-pass conversion rate, the lower the total feed rate and the lower the energy consumption when the fresh raw material processing volume is the same. PDH technology uses a fluidized bed to achieve continuous reaction and catalyst regeneration, so there is no need to operate in the presence of hydrogen to slow down the coking and deactivation of the catalyst. Although from the perspective of improving the single-pass conversion rate, it should be operated under negative pressure, but the safety of the device is more important. Taking all factors into consideration, the pressure of the PDH reactor (top of the reactor settling section) is 0.035MPa.

[0148] 2. Regeneration process

[0149] The amount of coke produced in the dehydrogenation reaction is very small, and the coke content of the catalyst to be produced is very low. It is difficult to maintain the regeneration temperature of about 650℃-700℃ by burning coke alone. Therefore, the main task of the regenerator R-1002 is not only to regenerate the catalyst by burning coke, but more importantly, to heat the catalyst by burning supplementary fuel. The high-temperature regenerator entering the reactor provides heat for the material heating and endothermic alkane dehydrogenation reaction.

[0150] The air from the main fan K-1001A (standby fan K-1001B) is preheated in the auxiliary combustion chamber F-1002, and then enters the regenerator through the main air distributor at the bottom of the regenerator, where it is mixed with the fuel injected into the regenerator and burns to release heat. The structure of the regenerator is different from that of the reactor. The regenerated catalyst flows downward evenly through the distributor and burns in countercurrent with the upward main wind. The flue gas and a small amount of catalyst enter the dilute phase section and undergo gas-solid separation through the quick separator at the top of the dilute phase section. A small amount of catalyst falls into the air stripping section through the cyclone legs and most of the regenerated catalyst. The flue gas carried by the catalyst is reduced and removed by gas stripping, and then circulated back to the reactor R-1001 through the regeneration inclined tube. The flue gas carries a small amount of catalyst, and after further gas-solid separation through the cyclone, the catalyst returns to the regenerator, and the flue gas leaves the regenerator with a very small amount of catalyst fine powder.

[0151] The flue gas leaving the regenerator at about 650℃-700℃ is cooled to about 150℃ after generating steam in the waste heat boiler, and then enters the flue gas washing tower C-1001 to remove dust, and the flue gas is directly discharged. The washing wastewater of C-1001 settles at the bottom of the tower, and the clean water after sedimentation is pumped out by pump P-1001A / B and directly circulated back to C-1001. The thick slurry after sedimentation at the bottom of the tower is pumped out by pump P-1002A / B and sent to the sedimentation tank of the sewage treatment plant.

[0152] The operating pressure of the regenerator (at the top of the regenerator settling section) is the same as that of the reactor, which is also 0.035 MPa. The pressure of the regenerator is controlled by a double-acting slide valve on the flue at the top of the regenerator.

[0153] There are three catalyst storage tanks, one is the cold catalyst storage tank D-1001, one is the hot catalyst storage tank D-1002, and the other is the waste catalyst storage tank D-1003. All three catalyst storage tanks are connected to the bottom of the regenerator R-1002 through pipelines. Both D-1001 and D-1002 tanks can add catalyst to the reaction regeneration system through the pipeline connected to the bottom of the regenerator. The difference between D-102 and D-101 is that D-102 can accept high-temperature catalyst discharged from the reaction regeneration system when necessary.

[0154] Flue gas waste heat recovery process

[0155] High-temperature flue gas (630℃-670℃) enters the waste heat boiler from the bottom, and passes through the waste heat boiler high-temperature evaporator, superheater, low-temperature evaporator, high-temperature economizer and low-temperature economizer in sequence. After stabilizing to 160℃, it enters the subsequent dust removal and denitrification units.

[0156] use Figure 1 When the system shown in the figure performs an alkane dehydrogenation process, the flow directions of various materials between various components in the system of the alkane dehydrogenation process described in the first aspect are as follows:

[0157] Flow direction between the components of the reactor and regenerator system during operation:

[0158] Propane raw material 2 → propane raw material distributor 3, → reactor dense phase section 5, → dilute phase pipe 11, → dilute phase pipe distributor 12, → dilute phase section 8, 34, → first and second stage cyclone 13, → gas collecting chamber 14, → oil and gas pipelines 15, 32.

[0159] The regenerated catalyst comes from the regenerator, → passes through the regeneration inclined pipe 1, → passes through the regenerated catalyst distributor 4, → reaction section 5, → dilute phase pipe 11, → dilute phase pipe distributor 12, → dilute phase sections 8, 34, → inclined pipe to be regenerated 27 → slide valve to be regenerated 28 → catalyst distributor to be regenerated 20, → reactor burnt section 21, → gas section → regeneration slide valve 25, → regeneration inclined pipe 1.

[0160] Second dense phase 8 → external circulation pipe 7, → through external circulation slide valve 6 → reaction section 5.

[0161] Main air 23, 30 → main air distribution pipe → coke section 21, → regenerator dilute phase section 19, 33, → cyclone 18, → air collecting chamber 17, → flue gas pipeline 16, 31.

[0162] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0163] Example 1

[0164] This example provides a system for an alkane dehydrogenation process (specifically a fluidized bed alkane dehydrogenation process to olefins), such as Figure 1 As shown, the system includes a reactor;

[0165] The bottom of the reactor is provided with a propane raw material inlet, propane enters the reactor through a propane raw material distribution pipe, the regenerated catalyst enters the reactor through a regenerated catalyst distributor and reacts with the propane in a forward direction and moves upward, and reaches the upper olefin phase area of ​​the reactor through a material lifting pipe, and the lower part of the reactor is a reaction dense phase section;

[0166] The top of the reactor is provided with a reaction product outlet, through which the reaction gas comes out of the reaction gas collecting chamber, the reaction gas collecting chamber is connected with the first and second cyclones, the first and second cyclones are connected with the second reaction dense phase storage through the cyclone legs and the wing valve, and the second reaction dense phase storage is connected with the lower part of the reactor through the catalyst external circulation pipe;

[0167] A material distributor is provided inside the reactor, and the material distributor is communicated with the material lifting pipe;

[0168] The catalyst external circulation pipe is provided with a reactor external circulation slide valve;

[0169] The system further comprises a regenerator, the bottom of which is connected to the regenerated catalyst distributor via a regeneration inclined pipe;

[0170] The top of the regenerator is provided with a flue gas outlet, through which the flue gas comes out of the flue gas collecting chamber, and the flue gas collecting chamber is connected with the first and second cyclones;

[0171] The upper and lower parts of the regenerator are respectively a regenerator dilute phase section and a regenerator dense phase section, and the catalyst distributor to be regenerated in the dense phase section of the regenerator is connected to the reaction second dense phase storage volume in the reactor through the inclined tube to be regenerated and the inclined tube for the catalyst to be regenerated;

[0172] The regenerated catalyst at the bottom of the regenerator removes the flue gas carried by the catalyst through the stripping nitrogen in the stripping section, and enters the regenerated catalyst inclined tube through a regenerated catalyst slide valve controlled by a hydraulic transmission mechanism. A main air inlet is provided at the lower part of the regenerator, and the main air enters the regenerator through the main air distribution pipe.

[0173] Example 2

[0174] This example provides a method for alkane dehydrogenation process, using the system provided in the above embodiment 1, specifically including the following processes: 1. Supplying main air to the regenerator system and nitrogen to the reactor system, controlling the regeneration pressure to 0.035MPa and the reaction pressure to 0.035MPa.

[0175] 2. Add dehydrogenation catalyst to the regenerator.

[0176] 3. Start auxiliary combustion chamber FU-102, control furnace temperature ≤ 950℃, furnace outlet temperature ≤ 750℃, heat up the regenerator and reactor. When the regenerator is heated to 600℃, the reactor should be ≥ 380℃.

[0177] 4. Open the regeneration slide valve to transfer the reagent from the regenerator to the reactor.

[0178] 5. Open the slide valve to transfer the catalyst from the reactor to the regenerator and conduct a catalyst fluidization test.

[0179] 6. After the catalyst fluidization test is normal, raise the reaction temperature to 620℃ and the regeneration temperature to 660℃.

[0180] 7. Feed propane feed into the reactor, adjust the product separation unit, and separate the products.

[0181] Among them, the properties of the raw materials are shown in Table 1, the operating conditions of the reaction system are shown in Table 2, the operating conditions of the regeneration system are shown in Table 3, the specifications of polymerization-grade propylene are shown in Table 4, the operating parameters of the water scrubber and separation are shown in Table 5, the distribution of pure propane through the conversion product is shown in Table 6, and the comparison of the residual carbon of the catalyst in the countercurrent and cocurrent dehydrogenation contact reaction is shown in Table 7.

[0182] Table 1

[0183]

[0184] Table 2

[0185] project unit Numeric Reactor pressure MPa(a) 0.135 Reaction temperature ℃ 600～620 Propane preheat temperature ℃ 450～500 Catalyst circulation amount t / h 834 Quality Space Time t 2.5 First stage cyclone inlet linear speed m / s 18 Secondary cyclone inlet linear speed m / s 21

[0186] Table 3

[0187] project unit Regenerator Top pressure MPaG 0.055 Dilute phase temperature ℃ 630-650 Main air volume <![CDATA[Nm 3 / h]]> 18000 Auxiliary combustion chamber furnace temperature ℃ - Auxiliary combustion chamber outlet temperature ℃ - Nitrogen volume in gas section <![CDATA[Nm 3 / h]]> 200 Gas volume delivered by regeneration delivery pipe <![CDATA[Nm 3 / h]]> - Dense phase line speed m / s 0.58 Dilute phase line speed m / s 0.44 First-stage cyclone inlet linear speed m / s 18.8 Secondary cyclone inlet linear speed m / s 22.7 Dense phase storage (indicative value) t 62.9 Gas storage capacity (including cone section) t 14.1 Excess oxygen v％ 5 Regenerator dense phase combustion oil volume kg / h - Regenerator dense phase supplementary fuel gas volume kg / h 889 Fuel gas volume of regenerator gas section kg / h 90

[0188] Table 4

[0189] Components unit Index value Propylene mol ≥99.6％ Propane mol ≤0.4％ hydrogen mol ≤5ppm Methane mol ≤100ppm Ethane mol ≤200ppm MAPD mol ≤5ppm Butene + Butadiene mol ≤2ppm <![CDATA[C 4 + ]]> mol ≤200ppm Acetylene mol ≤1ppm Ethylene mol ≤10ppm <![CDATA[O 2 ]]> mol ≤4ppm C0 mol ≤0.05ppm C02 mol ≤5ppm Total sulfur content (measured in S) wt ≤1ppm Total alcohol content mol ≤4ppm Methanol mol ≤1ppm

[0190] Table 5

[0191] Serial number name Design Data one Washing part - (one) Water washing tower - 1 Water washing tower top temperature, ℃ 42 2 Water washing tower bottom temperature, ℃ 56 3 Water washing tower top pressure, MPa(A) 0.102 two Air compressor - 1 <![CDATA[Compressor load, m 3 n / min]]> 800 2 Air compressor outlet pressure, MPa(A) 1.35 three Depropanizer - 1 Depropanizer top temperature, ℃ 43 2 Depropanizer bottom temperature, ℃ 52 / 93 3 Depropanizer top pressure, MPa(A) 1.48 4 Depropanizer bottom reboiler inlet / outlet temperature, ℃ 52 / 53，93 / 95 (one) Propylene distillation tower - 1 Tower top temperature, °C 10 2 Alkane tower top pressure, MPa, (A) 0.79 3 Bottom reboiler inlet / outlet temperature, ℃ 22 / 22

[0192] Table 6

[0193] Serial number Components Yield, wt% Selectivity wt% Remark 1 <![CDATA[H 2 ]]> 1.57 4.2 - 2 Methane 0.86 2.3 - 3 Ethane 0.84 2.25 - 4 Ethylene 0.49 1.31 - 5 Propane 62.65 - - 6 Propylene 32.11 85.97 - 7 Isobutylene 0.27 0.72 - 8 <![CDATA[C5 + ]]> 0.21 0.56 - 9 Coke 1.00 2.68 - 10 Together 100.00 100.00 -

[0194] Table 7

[0195]

[0196] Compared with the prior art in which the residual carbon content of the fluidized bed catalyst to be spent in the reverse contact reaction between the catalyst and the raw material is between 3-5%, the residual carbon content of the fluidized bed catalyst to be spent in the forward contact reaction between the catalyst and the raw material designed in the present invention is between 2-4% on average after multiple sampling and analysis, which greatly inhibits the deep reaction of the product gas, thereby inhibiting the coking amount of the product olefins, improving the yield of propylene, and making up for the shortcomings of the prior art.

[0197] Various embodiments of the present invention may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present invention; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0198] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A system for an alkane dehydrogenation process, characterized in that: The system includes a reactor; The bottom of the reactor is provided with a propane raw material inlet, propane enters the reactor through a propane raw material distribution pipe, the regenerated catalyst enters the reactor through a regenerated catalyst distributor and reacts with the propane in a forward direction and moves upward, and reaches the upper olefin phase area of ​​the reactor through a material lifting pipe, and the lower part of the reactor is a reaction dense phase section; The top of the reactor is provided with a reaction product outlet, through which the reaction gas comes out of the reaction gas collecting chamber, the reaction gas collecting chamber is connected with the first and second cyclones, the first and second cyclones are connected with the second reaction dense phase storage through the cyclone legs and the wing valve, and the second reaction dense phase storage is connected with the lower part of the reactor through the catalyst external circulation pipe; A material distributor is arranged inside the reactor, and the material distributor is communicated with the material lifting pipe.

2. The system for alkane dehydrogenation process according to claim 1, characterized in that: The catalyst external circulation pipe is provided with a reactor external circulation slide valve.

3. The system for alkane dehydrogenation process according to claim 1, characterized in that: The system further comprises a regenerator, the bottom of which is connected to the regenerated catalyst distributor via a regeneration inclined pipe; The top of the regenerator is provided with a flue gas outlet, through which the flue gas comes out of the flue gas collecting chamber, and the flue gas collecting chamber is connected with the first and second cyclones; The upper and lower parts of the regenerator are respectively a regenerator dilute phase section and a regenerator dense phase section, and the catalyst distributor to be regenerated in the dense phase section of the regenerator is connected to the reaction second dense phase storage volume in the reactor through the inclined tube to be regenerated and the inclined tube for the catalyst to be regenerated; The regenerated catalyst at the bottom of the regenerator lifts the nitrogen into the regenerated catalyst stripping section through the regenerated catalyst slide valve. A main air inlet is provided at the lower part of the regenerator, and the main air enters the regenerator through the main air distribution pipe.

4. The system for alkane dehydrogenation process according to claim 1, characterized in that: The alkane dehydrogenation process is a fluidized bed alkane dehydrogenation process to produce olefins.

5. A method for dehydrogenating an alkane, characterized in that: The method is carried out using the alkane dehydrogenation process system described in any one of claims 1 to 4.

6. The method of alkane dehydrogenation process according to claim 5, characterized in that: The method comprises a reaction section and a regeneration section; The reaction section includes the following process: 1) Raw material processing and reaction process: The gaseous propane output from the cold box is heated to no more than 450°C by heat exchange with the rich gas after the reaction in the raw material preheating section; the heated propane enters the reactor through the raw material distributor at the bottom of the dense phase section of the reactor; the propane contacts the high-temperature catalyst transported from the regenerator to cause a dehydrogenation reaction; the average reaction temperature of the dense phase section is controlled within the range of 560-620°C; 2) Gas-solid separation process: The rich gas and catalyst after the reaction enter the dilute phase tube and undergo preliminary gas-solid separation through the quick separator at the top of the dilute phase tube; Most of the catalyst falls into the second dense phase, and a small amount of catalyst enters the cyclone with the rich gas for further gas-solid separation; the rich gas leaves the reactor carrying a very small amount of catalyst fine powder; Catalyst regeneration and recycling: The catalyst entering the second dense phase uses steam as the fluidizing medium and returns to the regenerator through the inclined tube to be regenerated; 3) Rich gas treatment and subsequent processes: The rich gas leaving the reactor has a temperature of 570-600°C. After generating low-pressure steam in the waste heat recovery section, it enters the raw material preheating section for heat exchange with the raw material, and the temperature is reduced to 116°C. The rich gas after heat exchange enters the bottom of the water washing tower, where dust is removed by water washing and the temperature is further reduced to 40°C. The treated rich gas enters the subsequent compression and separation system.

7. The method of alkane dehydrogenation process according to claim 5, characterized in that: The regeneration stage includes the following processes: 1) Regenerator operation and gas-solid separation: The air is provided by the main fan, preheated in the auxiliary combustion chamber, and then enters the regenerator through the main air distributor at the bottom of the regenerator; The air is mixed with the fuel injected into the regenerator and burns to release heat; the flue gas and a small amount of catalyst enter the dilute phase section and undergo gas-solid separation through the quick separator at the top of the dilute phase section; a small amount of catalyst falls into the air stripping section together with most of the catalyst to be regenerated through the cyclone legs, and after the flue gas carried by the catalyst is removed through gas stripping reduction, it is circulated back to the reactor through the regeneration inclined tube; a small amount of catalyst entrained in the flue gas is further separated from the gas and solid by the cyclone, and the catalyst returns to the regenerator, and the flue gas leaves the regenerator carrying a very small amount of catalyst fine powder; 2) Flue gas treatment and waste heat recovery: The flue gas leaving the regenerator has a temperature of 650℃-700℃. After entering the waste heat boiler to generate steam, the temperature drops to 150℃. The cooled flue gas enters the flue gas scrubber to remove dust and is then discharged directly. The washing wastewater of the flue gas washing tower settles at the bottom of the tower. The clean water after settling is pumped out by pump P-1001A / B and directly circulated back to the flue gas washing tower for use; the concentrated slurry after settling at the bottom of the tower is pumped out by the pump and sent to the sedimentation tank of the sewage treatment plant for treatment; 3) Regenerator pressure control: The operating pressure of the regenerator is the same as that of the reactor, which is 0.035MPa; the pressure of the regenerator is controlled by a double-acting slide valve on the flue at the top of the regenerator; 4) Catalyst storage tank configuration: There are three catalyst storage tanks: cold catalyst storage tank D-1001, hot catalyst storage tank D-1002 and spent catalyst storage tank D-1003; The three catalyst storage tanks are connected to the bottom of the regenerator through pipelines; both the D-1001 and D-1002 storage tanks can add catalyst to the reaction regeneration system through pipelines; 5) Flue gas waste heat recovery process: High-temperature flue gas of 630℃-670℃ enters the waste heat boiler from the bottom; The flue gas passes through the high-temperature evaporator, superheater, low-temperature evaporator, high-temperature economizer and low-temperature economizer in the waste heat boiler for heat exchange; After heat exchange, the flue gas temperature drops to 160°C, and then enters the subsequent dust removal and denitrification units for further treatment.

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