High-density rapid fluidized bed reactor, and device and method for preparing low-carbon olefin through catalytic cracking

Abstract

The invention discloses a high-density rapid fluidized bed reactor, and a device and a method for preparing low-carbon olefin through catalytic cracking. The device comprises a high-density fast fluidized bed reactor and a fluidized bed regenerator. According to the high-density rapid fluidized bed reactor, the circulation strength of a catalyst flowing from the catalyst retention zone to the reaction zone reaches up to 500-1000 kg / (m < 2 >. S), so that the bed density of the reaction zone is improved, and high bed density is obtained under the condition of high apparent linear velocity. According to the method, the continuous process of preparing the low-carbon olefin through catalytic cracking of the mixed hydrocarbon is realized through a fluidized bed reaction-regeneration process, and heat is provided for the reaction through oil injection and afterburning. The reaction contact time of the product gas in the high-density rapid fluidized bed reactor is lt; the selectivity of the low-carbon olefin is effectively improved. According to the method, the raw material conversion per pass is greater than or equal to 50% wt, the ethylene and propylene selectivity is greater than or equal to 70% wt, and the propylene / ethylene (mass ratio) is greater than or equal to 3.

Description

Technical Field

[0001] This application relates to a high-density fast fluidized bed reactor, an apparatus and method for catalytic cracking to produce low-carbon olefins, and belongs to the field of chemical catalysis. Background Technology

[0002] Olefins are important basic organic chemical raw materials and the cornerstone of modern chemical industry. Olefin production technologies mainly include naphtha cracking to olefins, methanol to olefins, propane dehydrogenation to propylene, alkane cracking to olefins, and olefin cracking to olefins. Low-carbon olefins are very reactive and readily undergo polymerization, alkylation, and aromatization reactions, generating byproducts and reducing the yield of low-carbon olefins.

[0003] UOP has developed olefin catalytic cracking (OCP) technology, which converts C4-C8 olefin feedstocks into ethylene and propylene under high temperature and low pressure conditions, with a propylene to ethylene ratio of approximately 4:1. The OCP unit has two radial flow reactors, one operating online and the other regenerated and on standby. The reactor regeneration cycle is 48 hours. Switching between online and offline regeneration is achieved through valve assemblies located at the reactor inlet and outlet.

[0004] Sinopec has developed olefin catalytic cracking (OCC) technology, in which olefins in a mixed C4-C6 feedstock are cracked into propylene, ethylene, and other products under the action of a molecular sieve catalyst. OCC unit

[0005] There are two fixed-bed reactors, one in operation and one on standby. The reaction system operates in a continuous switching mode, and the catalyst regeneration process is controlled by an automatic switching regeneration program.

[0006] The catalytic cracking reaction to produce low-carbon olefins is a strongly endothermic process. Radial flow reactors and fixed-bed reactors typically achieve heating by increasing the feed temperature. However, excessively high preheating temperatures for feed components such as olefins, dienes, and alkynes can lead to coking, affecting continuous operation. Furthermore, the catalyst gradually loses activity during the reaction, necessitating reactor switching for continuous operation. These challenges of heating and deactivation have limited the development and advancement of radial flow reactor and fixed-bed reactor technologies. Summary of the Invention

[0007] Low-carbon olefins are highly reactive and readily undergo polymerization, alkylation, and aromatization reactions, generating byproducts and reducing their yield. Reaction contact time is a crucial factor affecting the selectivity of low-carbon olefins in the catalytic cracking of mixed hydrocarbons to produce low-carbon olefins. Increasing the apparent linear velocity in the reaction zone of a fluidized bed reactor can reduce the reaction contact time and improve low-carbon olefin selectivity; however, the bed density in the reaction zone usually decreases significantly at the same time, leading to a substantial reduction in catalyst content and consequently a decrease in the conversion rate of the cracking feedstock. In other words, there is a negative correlation between low-carbon olefin selectivity and feedstock conversion rate.

[0008] To improve the yield of low-carbon olefins and the conversion rate of pyrolysis feedstock, a high-density rapid fluidized bed reactor is provided according to the first aspect of this application.

[0009] A high-density rapid fluidized bed reactor, the high-density rapid fluidized bed reactor comprising a reactor outer shell, a reactor inner shell, and a delivery pipe;

[0010] The inner shell of the reactor is located at the lower part of the outer shell of the reactor;

[0011] The delivery pipe is located in the upper central region of the high-density rapid fluidized bed reactor.

[0012] The area enclosed by the inner shell of the reactor is the reaction zone;

[0013] The bottom end of the delivery pipe is connected to the top end of the reaction zone;

[0014] The annular region formed by the outer shell and the inner shell of the reactor is the catalyst residence zone;

[0015] The bottom of the reaction zone and the bottom of the catalyst residence zone are connected;

[0016] The area enclosed by the reactor shell and the delivery pipe is the gas-solid separation zone;

[0017] The catalyst residence zone and the gas-solid separation zone are connected, and the catalyst residence zone is located below the gas-solid separation zone.

[0018] Optionally, the bottom end of the delivery pipe is connected to the top end of the reaction zone.

[0019] Optionally, the high-density rapid fluidized bed reactor includes a catalyst distribution tube, a fluidized steam distributor, and a feed distributor;

[0020] The catalyst distribution pipe passes through the inner shell of the reactor and connects the catalyst residence area and the reaction area;

[0021] The fluidized steam distributor is located at the bottom of the catalyst residence zone;

[0022] The raw material distributor is located at the bottom of the reaction zone.

[0023] Optionally, the lower surface of the catalyst distribution tube has openings.

[0024] Optionally, the high-density rapid fluidized bed reactor includes a first gas-solid separation device and a second gas-solid separation device;

[0025] The first gas-solid separation device and the second gas-solid separation device are located in the gas-solid separation zone;

[0026] The inlet of the first gas-solid separation device is connected to the outlet of the conveying pipe;

[0027] The catalyst outlet of the first gas-solid separation device is located in the lower part of the gas-solid separation zone, and the gas outlet of the first gas-solid separation device is located in the upper part of the gas-solid separation zone;

[0028] The catalyst outlet of the second gas-solid separation device is located in the lower part of the gas-solid separation zone.

[0029] Optionally, the first gas-solid separation device surrounds the delivery pipe.

[0030] Optionally, the first gas-solid separation device employs an inertial separator to achieve rapid separation of product gas and catalyst.

[0031] Optionally, the second gas-solid separation device employs one or more sets of gas-solid cyclone separators, each set of gas-solid cyclone separators including a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0032] Optionally, the high-density rapid fluidized bed reactor includes a reactor gas collection chamber and a product gas delivery pipe;

[0033] The gas collection chamber of the reactor is located at the top of the high-density fast fluidized bed reactor;

[0034] The product gas delivery pipe is connected to the top of the reactor gas collection chamber;

[0035] The gas outlet of the second gas-solid separation device is connected to the gas collection chamber of the reactor.

[0036] In a preferred embodiment, the high-density rapid fluidized bed reactor comprises: a reactor outer shell, a reactor inner shell, a conveying pipe, a raw material distributor, a first gas-solid separation device, a fluidizing steam distributor, a catalyst distribution pipe, a second gas-solid separation device, a reactor gas collection chamber, a product gas conveying pipe, a catalyst extraction pipe, a reactor stripper, a pre-generation slide valve, and a pre-generation agent conveying pipe.

[0037] The area enclosed by the inner shell of the reactor is the reaction zone. The annular area enclosed by the outer shell and the inner shell of the reactor is the catalyst residence zone. The bottom of the reaction zone and the bottom of the catalyst residence zone are connected. The area enclosed by the outer shell and the delivery pipe is the gas-solid separation zone. The catalyst residence zone and the gas-solid separation zone are connected and located below the gas-solid separation zone.

[0038] The raw material distributor is located at the bottom of the reaction zone, and the conveying pipe is located in the central area of ​​the upper part of the high-density rapid fluidized bed reactor. The bottom end of the conveying pipe is connected to the top end of the reaction zone, and the outlet of the conveying pipe is connected to the inlet of the first gas-solid separation device.

[0039] The first gas-solid separation device is located in the gas-solid separation zone, the catalyst outlet of the first gas-solid separation device is located in the lower part of the gas-solid separation zone, and the gas outlet of the first gas-solid separation device is located in the upper part of the gas-solid separation zone.

[0040] The fluidized steam distributor is located at the bottom of the catalyst residence zone.

[0041] The catalyst distribution pipe passes through the inner shell of the reactor and connects the catalyst residence area and the reaction area. The lower surface of the catalyst distribution pipe has an opening.

[0042] The second gas-solid separation device is located in the gas-solid separation zone, the inlet of the second gas-solid separation device is located in the gas-solid separation zone, the gas outlet of the second gas-solid separation device is connected to the gas collection chamber of the reactor, and the catalyst outlet of the second gas-solid separation device is located in the lower part of the gas-solid separation zone.

[0043] The reactor gas collection chamber is located at the top of the high-density rapid fluidized bed reactor, and the product gas delivery pipe is connected to the top of the reactor gas collection chamber.

[0044] The catalyst extraction pipe passes through the outer shell of the reactor and is located in the lower part of the catalyst residence zone.

[0045] The reactor stripper is connected to the catalyst extraction pipe, the inlet of the pre-regenerating slide valve is connected to the bottom of the reactor stripper, the outlet of the pre-regenerating slide valve is connected to the inlet of the pre-regenerating agent delivery pipe, and the outlet of the pre-regenerating agent delivery pipe is connected to the fluidized bed regenerator.

[0046] According to a second aspect of this application, an apparatus for catalytic cracking to produce low-carbon olefins is provided.

[0047] An apparatus for catalytic cracking to produce low-carbon olefins, the apparatus comprising the high-density fast fluidized bed reactor and fluidized bed regenerator described above;

[0048] The catalyst extraction pipe passes through the outer shell of the reactor and is located at the lower part of the catalyst residence zone; the reactor stripper is connected to the catalyst extraction pipe, the inlet of the regenerator slide valve is connected to the bottom of the reactor stripper, the outlet of the regenerator slide valve is connected to the inlet of the regenerator delivery pipe, and the outlet of the regenerator delivery pipe is connected to the middle of the fluidized bed regenerator.

[0049] The regenerator stripper is located at the bottom of the fluidized bed regenerator. The inlet of the regeneration slide valve is connected to the bottom of the regenerator stripper, the outlet of the regeneration slide valve is connected to the inlet of the regenerant delivery pipe, and the outlet of the regenerant delivery pipe is connected to the lower part of the gas-solid separation zone of the high-density fast fluidized bed reactor.

[0050] Optionally, the fluidized bed regenerator includes a regenerator shell, a regenerator distributor, a fuel distributor, a third gas-solid separation device, a regenerator gas collection chamber, and a flue gas conveying pipe;

[0051] The regenerator distributor is located at the bottom of the fluidized bed regenerator;

[0052] The fuel distributor is located above the regenerator distributor;

[0053] The third gas-solid separation device is located at the top of the fluidized bed regenerator. The inlet of the third gas-solid separation device is located at the top of the fluidized bed regenerator. The gas outlet of the third gas-solid separation device is connected to the gas collection chamber of the regenerator. The catalyst outlet of the third gas-solid separation device is located at the bottom of the fluidized bed regenerator.

[0054] The regenerator gas collection chamber is located at the top of the fluidized bed regenerator, and the flue gas delivery pipe is connected to the top of the regenerator gas collection chamber.

[0055] Optionally, the inlet pipe of the regenerator stripper penetrates the regenerator housing and opens above the regenerator distributor.

[0056] Optionally, the third gas-solid separation device employs one or more sets of gas-solid cyclone separators, each set of gas-solid cyclone separators including a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0057] The fluidized bed regenerator of this application can achieve thermal equilibrium in the catalytic cracking process to produce low-carbon olefins and restore the activity of the catalyst through regeneration.

[0058] In a preferred embodiment, the fluidized bed regenerator includes: a regenerator housing, a regenerator distributor, a fuel distributor, a third gas-solid separation device, a regenerator gas collection chamber, a flue gas delivery pipe, a regenerator stripper, a regenerator slide valve, and a regenerator delivery pipe.

[0059] The regenerator distributor is located at the bottom of the fluidized bed regenerator, the fuel oil distributor is located above the regenerator distributor, the third gas-solid separator is located at the top of the fluidized bed regenerator, the inlet of the third gas-solid separator is located at the top of the fluidized bed regenerator, the gas outlet of the third gas-solid separator is connected to the regenerator gas collection chamber, the catalyst outlet of the third gas-solid separator is located at the bottom of the fluidized bed regenerator, the regenerator gas collection chamber is located at the top of the fluidized bed regenerator, and the flue gas delivery pipe is connected to the top of the regenerator gas collection chamber.

[0060] The regenerator stripper is located outside the regenerator shell. The inlet pipe of the regenerator stripper penetrates the regenerator shell and opens above the regenerator distributor. The inlet of the regeneration slide valve is connected to the bottom of the regenerator stripper, and the outlet of the regeneration slide valve is connected to the inlet of the regenerant delivery pipe. The outlet of the regenerant delivery pipe is connected to the lower part of the gas-solid separation zone of the high-density fast fluidized bed reactor.

[0061] According to a third aspect of this application, a method for catalytic cracking to produce low-carbon olefins is provided. This method employs a continuous reaction-regeneration fluidized bed process.

[0062] A method for producing low-carbon olefins by catalytic cracking, using the apparatus for producing low-carbon olefins as described above.

[0063] A method for catalytic cracking to produce low-carbon olefins includes the following steps:

[0064] The gasified mixed hydrocarbon feedstock is fed into the reaction zone, where it comes into contact with the catalyst and reacts to generate stream I containing product gas and catalyst.

[0065] After passing through the conveying pipe and undergoing gas-solid separation, the catalyst enters the catalyst residence area;

[0066] Steam enters the catalyst residence zone, and the steam carries a small amount of catalyst from the catalyst residence zone into the gas-solid separation zone;

[0067] In the gas-solid separation zone, the product gas and steam carrying the catalyst are separated and the catalyst is returned to the catalyst residence zone, while the product gas and steam enter the downstream process.

[0068] A portion of the catalyst in the catalyst residence zone enters the reaction zone through the catalyst distribution pipe, and another portion of the catalyst in the catalyst residence zone enters the bottom of the reaction zone through the bottom of the catalyst residence zone;

[0069] A portion of the catalyst in the catalyst residence zone enters the fluidized bed regenerator for regeneration, and the regenerated catalyst enters the high-density fast fluidized bed reactor.

[0070] Optionally, the process operating conditions of the reaction zone of the high-density rapid fluidized bed reactor are as follows: apparent gas linear velocity of 1.5-7.0 m / s, temperature of 500-680℃, pressure of 50-250 kPa, and bed density of 150-500 kg / m³. 3 The reaction contact time is 0.5-2 seconds.

[0071] Optionally, the process operating conditions of the catalyst residence zone in the high-density fast fluidized bed reactor are: apparent gas linear velocity of 0.02-0.2 m / s, temperature of 500-680℃, and bed density of 600-800 kg / m³. 3 .

[0072] Optionally, the catalyst circulation intensity flowing from the catalyst residence zone to the reaction zone is 500-1000 kg / (m²). 2 ·s).

[0073] Optionally, the mixed hydrocarbon feedstock is a C4+ hydrocarbon, including alkanes and alkenes with ≥4 carbon atoms.

[0074] Optionally, the mixed hydrocarbon feedstock is C4-C 12 hydrocarbon.

[0075] Optionally, the catalyst is a ZSM-5 molecular sieve.

[0076] Optionally, in the fluidized bed regenerator, the regenerated gas and the catalyst come into contact, and the fuel enters the bottom of the fluidized bed regenerator from the fuel distributor. After the regenerated gas and the fuel come into contact, they are combusted. The flue gas formed by combustion carries the catalyst and is separated into gas and solid. The catalyst is then returned to the bottom of the fluidized bed regenerator and stripped into the gas and solid separation zone of the high-density fast fluidized bed reactor.

[0077] Optionally, the regenerated gas is air, and the fuel is diesel.

[0078] Optionally, the process operating conditions of the fluidized bed regenerator are as follows: apparent gas linear velocity of 0.5-2.0 m / s, regeneration temperature of 600-750℃, regeneration pressure of 50-250 kPa, and bed density of 200-800 kg / m³. 3 .

[0079] As a preferred embodiment, the method for catalytic cracking to produce low-carbon olefins includes:

[0080] The catalyst from the regenerator delivery pipe enters the gas-solid separation zone of the high-density rapid fluidized bed reactor, and then enters the catalyst residence zone. The gasified feedstock enters the reaction zone from the feed distributor, contacts the catalyst, and generates product gas containing low-carbon olefins. The product gas, carrying the catalyst, enters the first gas-solid separation device via a delivery pipe. After gas-solid separation, the catalyst enters the catalyst residence zone. Steam enters the catalyst residence zone from the fluidized steam distributor, and the steam, carrying a small amount of catalyst, enters the gas-solid separation zone from the catalyst residence zone. The product gas and steam in the gas-solid separation zone, carrying the catalyst, enter the second gas-solid separation device. After gas-solid separation, the gas enters the reactor gas collection chamber, and the catalyst returns to the catalyst residence zone. The product gas and steam enter the downstream section via the product gas delivery pipe. The catalyst in the catalyst residence zone enters the reaction zone via the catalyst distribution pipe. The catalyst in the catalyst residence zone enters the bottom of the reaction zone via the bottom of the catalyst residence zone. The catalyst in the catalyst residence zone enters the reactor stripper via the catalyst extraction pipe. After stripping, the catalyst enters the middle of the fluidized bed regenerator via the regenerator slide valve and the regenerator delivery pipe.

[0081] Regenerated gas enters the bottom of the fluidized bed regenerator from the regenerator distributor. In the fluidized bed regenerator, the regenerated gas comes into contact with the catalyst, and the carbon deposits in the catalyst are burned off. Fuel enters the bottom of the fluidized bed regenerator from the fuel distributor. After the regenerated gas comes into contact with the fuel, combustion increases the temperature of the catalyst. The flue gas formed by combustion carries the catalyst into the third gas-solid separation device. After gas-solid separation, the flue gas enters the regenerator gas collection chamber and then enters the downstream flue gas treatment system through the flue gas delivery pipe. The catalyst returns to the bottom of the fluidized bed regenerator. The catalyst in the fluidized bed regenerator enters the regenerator stripper. After stripping, it enters the high-density fast fluidized bed reactor through the regeneration slide valve and the regenerator delivery pipe.

[0082] The beneficial effects that this application can produce include:

[0083] (1) The high-density rapid fluidized bed reactor provided in this application mainly comprises a reaction zone, a catalyst residence zone, and a gas-solid separation zone. The catalyst circulation intensity flowing from the catalyst residence zone to the reaction zone is as high as 500-1000 kg / (m³). 2 This increases the bed density in the reaction zone, achieving high bed density under high apparent linear velocity conditions and overcoming the negative correlation between low-carbon olefin selectivity and feed conversion rate.

[0084] (2) The apparatus for catalytic cracking to produce low-carbon olefins provided in this application injects oil and performs supplemental combustion in a fluidized bed regenerator to increase the temperature of the catalyst. The catalyst circulates between the fluidized bed regenerator and the high-density fast fluidized bed reactor to provide heat for the catalytic cracking to produce low-carbon olefins reaction, thus achieving thermal balance.

[0085] (3) The method for catalytic cracking to produce low-carbon olefins provided in this application realizes a continuous process of catalytic cracking of mixed hydrocarbons to produce low-carbon olefins through a fluidized bed reaction-regeneration process. The reaction contact time of the product gas in the high-density fast fluidized bed reactor is <2s, which effectively improves the selectivity of low-carbon olefins. The single-pass conversion rate of the feedstock is ≥50%wt, the "ethylene + propylene" selectivity is ≥70%wt, and the propylene / ethylene (mass ratio) is ≥3. Attached Figure Description

[0086] Figure 1 This is a schematic diagram of an apparatus according to one embodiment of this application.

[0087] Figure 1 The annotations in the accompanying drawings are explained as follows:

[0088] 1-High-density rapid fluidized bed reactor;

[0089] 1-1 Reactor outer shell; 1-2 Reactor inner shell; 1-3 Delivery pipe

[0090] 1-4 Raw material distributor; 1-5 First gas-solid separation equipment; 1-6 Fluidized steam distributor

[0091] 1-7 Catalyst distribution pipe; 1-8 Second gas-solid separation equipment; 1-9 Reactor gas collection chamber

[0092] 1-10 Product gas delivery pipe; 1-11 Catalyst extraction pipe; 1-12 Reactor stripper

[0093] 1-13 Preparatory slide valve; 1-14 Preparatory agent delivery pipe

[0094] 2- Fluidized bed regenerator;

[0095] 2-1 Regenerator housing; 2-2 Regenerator distributor; 2-3 Fuel distributor

[0096] 2-4 Third gas-solid separation equipment; 2-5 Regenerator gas collection chamber; 2-6 Flue gas conveying pipe

[0097] 2-7 Regenerator stripper; 2-8 Regeneration slide valve; 2-9 Regenerator delivery pipe. Detailed Implementation

[0098] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0099] Unless otherwise specified, the raw materials and catalysts used in the embodiments of this application were all purchased commercially.

[0100] In one specific implementation scheme, a schematic diagram of the apparatus of one embodiment of this application is shown below. Figure 1 As shown, the device comprises a high-density fast fluidized bed reactor (1) and a fluidized bed regenerator (2).

[0101] 1. The high-density rapid fluidized bed reactor (1) comprises: an outer reactor shell (1-1), an inner reactor shell (1-2), a conveying pipe (1-3), a raw material distributor (1-4), a first gas-solid separation device (1-5), a fluidizing steam distributor (1-6), a catalyst distribution pipe (1-7), a second gas-solid separation device (1-8), a reactor gas collection chamber (1-9), a product gas conveying pipe (1-10), a catalyst extraction pipe (1-11), a reactor stripper (1-12), a pre-treatment slide valve (1-13), and a pre-treatment agent conveying pipe (1-14); the area enclosed by the inner reactor shell (1-2) is the reaction zone (A). The annular region enclosed by the reactor outer shell (1-1) and the reactor inner shell (1-2) is the catalyst residence zone (B). The bottom of the reaction zone (A) is connected to the bottom of the catalyst residence zone (B). The region enclosed by the reactor outer shell (1-1) and the conveying pipe (1-3) is the gas-solid separation zone (C). The catalyst residence zone (B) is connected to the gas-solid separation zone (C) and is located below the gas-solid separation zone (C). The raw material distributor (1-4) is located at the bottom of the reaction zone (A). The conveying pipe (1-3) is located in the central area of ​​the upper part of the high-density rapid fluidized bed reactor. The bottom end of the conveying pipe (1-3) is connected to the reaction zone (A). At the top, the outlet of the conveying pipe (1-3) is connected to the inlet of the first gas-solid separation device (1-5); the first gas-solid separation device (1-5) is located in the gas-solid separation zone (C), the catalyst outlet of the first gas-solid separation device (1-5) is located at the lower part of the gas-solid separation zone (C), and the gas outlet of the first gas-solid separation device (1-5) is located at the upper part of the gas-solid separation zone (C); the fluidized steam distributor (1-6) is located at the bottom of the catalyst residence zone (B); the catalyst distribution pipe (1-7) passes through the inner shell of the reactor (1-2) and connects the catalyst residence zone (B) and the reaction zone (A), and the lower surface of the catalyst distribution pipe (1-7) has an opening; the first The second gas-solid separation device (1-8) is located in the gas-solid separation zone (C). The inlet of the second gas-solid separation device (1-8) is located in the gas-solid separation zone (C). The gas outlet of the second gas-solid separation device (1-8) is connected to the gas collection chamber (1-9) of the reactor. The catalyst outlet of the second gas-solid separation device (1-8) is located in the lower part of the gas-solid separation zone (C). The gas collection chamber (1-9) of the reactor is located at the top of the high-density rapid fluidized bed reactor. The product gas delivery pipe (1-10) is connected to the top of the gas collection chamber (1-9). The catalyst extraction pipe (1-11) passes through the outer shell of the reactor (1-1) and is located in the lower part of the catalyst residence zone (B).The reactor stripper (1-12) is connected to the catalyst extraction pipe (1-11). The inlet of the pre-regenerating slide valve (1-13) is connected to the bottom of the reactor stripper (1-12), the outlet of the pre-regenerating slide valve (1-13) is connected to the inlet of the pre-regenerating agent delivery pipe (1-14), and the outlet of the pre-regenerating agent delivery pipe (1-14) is connected to the fluidized bed regenerator (2).

[0102] 2. The fluidized bed regenerator (2) comprises: a regenerator housing (2-1), a regenerator distributor (2-2), a fuel oil distributor (2-3), a third gas-solid separation device (2-4), a regenerator gas collection chamber (2-5), a flue gas conveying pipe (2-6), a regenerator stripper (2-7), a regenerator slide valve (2-8), and a regenerator conveying pipe (2-9); the regenerator distributor (2-2) is located at the bottom of the fluidized bed regenerator (2), and the fuel oil distributor (2-3) is located above the regenerator distributor (2-2); the third gas-solid separation device (2-4) is located at the top of the fluidized bed regenerator (2), the inlet of the third gas-solid separation device (2-4) is located at the top of the fluidized bed regenerator (2), and the gas outlet of the third gas-solid separation device (2-4) is connected to the regenerator gas collection chamber (2-9). 5) The catalyst outlet of the third gas-solid separation device (2-4) is located at the lower part of the fluidized bed regenerator (2), the regenerator gas collection chamber (2-5) is located at the top of the fluidized bed regenerator (2), and the flue gas conveying pipe (2-6) is connected to the top of the regenerator gas collection chamber (2-5); the regenerator stripper (2-7) is located outside the regenerator shell (2-1), the inlet pipe of the regenerator stripper (2-7) penetrates the regenerator shell (2-1) and opens above the regenerator distributor (2-2), the inlet of the regeneration slide valve (2-8) is connected to the bottom of the regenerator stripper (2-7), the outlet of the regeneration slide valve (2-8) is connected to the inlet of the regenerator conveying pipe (2-9), and the outlet of the regenerator conveying pipe (2-9) is connected to the lower part of the gas-solid separation zone (C) of the high-density fast fluidized bed reactor (1).

[0103] Specifically, the first gas-solid separation device (1-5) uses an inertial separator to achieve rapid separation of product gas and catalyst.

[0104] Specifically, the second gas-solid separation device (1-8) employs one or more sets of gas-solid cyclone separators, each set of gas-solid cyclone separators including a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0105] Specifically, the third gas-solid separation device (2-4) employs one or more sets of gas-solid cyclone separators, each set of gas-solid cyclone separators including a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0106] In one specific embodiment, the method for catalytic cracking to produce low-carbon olefins according to this application includes the following steps:

[0107] 1. The catalyst from the regenerator delivery pipe (2-9) enters the gas-solid separation zone (C) of the high-density fast fluidized bed reactor (1), and then enters the catalyst residence zone (B); the gasified feedstock enters the reaction zone (A) from the feedstock distributor (1-4), contacts the catalyst, and generates product gas containing low-carbon olefins. The product gas carries the catalyst through the delivery pipe (1-3) into the first gas-solid separation device (1-5). After gas-solid separation, the catalyst enters the catalyst residence zone (B); steam enters the catalyst residence zone (B) from the fluidized steam distributor (1-6). The steam carries a small amount of catalyst from the catalyst residence zone (B) into the gas-solid separation zone (C); the product gas and steam in the gas-solid separation zone (C) carry the catalyst into the first gas-solid separation zone (A). In the gas-solid separation equipment (1-8), after gas-solid separation, the gas enters the gas collection chamber (1-9) of the reactor, and the catalyst returns to the catalyst residence area (B); the product gas and steam enter the downstream section through the product gas conveying pipe (1-10); the catalyst in the catalyst residence area (B) enters the reaction zone (A) through the catalyst distribution pipe (1-7); the catalyst in the catalyst residence area (B) enters the bottom of the reaction zone (A) through the bottom of the catalyst residence area (B); the catalyst in the catalyst residence area (B) enters the reactor stripper (1-12) through the catalyst extraction pipe (1-11); after stripping, the catalyst enters the middle part of the fluidized bed regenerator (2) through the waiting slide valve (1-13) and the waiting agent conveying pipe (1-14);

[0108] 2. The regenerated gas enters the bottom of the fluidized bed regenerator (2) from the regenerator distributor (2-2). In the fluidized bed regenerator (2), the regenerated gas comes into contact with the catalyst, and the carbon deposits in the catalyst are burned off. The fuel enters the bottom of the fluidized bed regenerator (2) from the fuel distributor (2-3). After the regenerated gas comes into contact with the fuel, it burns to increase the temperature of the catalyst. The flue gas formed by combustion carries the catalyst into the third gas-solid separation device (2-4). After gas-solid separation, the flue gas enters the regenerator gas collection chamber (2-5) and then enters the downstream flue gas treatment system through the flue gas conveying pipe (2-6). The catalyst returns to the bottom of the fluidized bed regenerator (2). The catalyst in the fluidized bed regenerator (2) enters the regenerator stripper (2-7). After stripping, it enters the high-density fast fluidized bed reactor (1) through the regeneration slide valve (2-8) and the regenerator conveying pipe (2-9).

[0109] The method described in this application, and the calculation methods for the single-pass conversion rate of raw materials and the selectivity of "ethylene + propylene" are as follows:

[0110] Feed single-pass conversion rate = (1 - mass flow rate of C4+ hydrocarbons in product gas / mass flow rate of C4+ hydrocarbons in feed) × 100%

[0111] "Ethylene + Propylene" selectivity = Mass flow rate of "ethylene + propylene" in product gas / (Mass flow rate of product gas - Mass flow rate of C4+ hydrocarbons in product gas) × 100%

[0112] Example 1

[0113] This implementation plan adopts Figure 1 The apparatus shown.

[0114] In this embodiment, the raw material is C4-C6 hydrocarbons, wherein the olefin content is 91% wt and the alkane content is 9% wt. The catalyst is a ZSM-5 molecular sieve catalyst. The process operating conditions of the reaction zone (A) of the high-density fast fluidized bed reactor (1) are: apparent gas linear velocity of 1.5 m / s, temperature of 500℃, pressure of 250 kPa, and bed density of 500 kg / m³. 3 The reaction contact time is 2 seconds. The process operating conditions of the catalyst residence zone (B) are: apparent gas linear velocity of 0.10 m / s, temperature of 500℃, and bed density of 670 kg / m³. 3 The catalyst circulation intensity flowing from the catalyst residence zone (B) to the reaction zone (A) is 500 kg / (m²). 2 ·s).

[0115] The regeneration gas is air. The fuel oil is diesel. The process operating conditions of the fluidized bed regenerator (2) are: apparent gas linear velocity of 0.5 m / s, regeneration temperature of 600℃, regeneration pressure of 250 kPa, and bed density of 800 kg / m³. 3 .

[0116] The single-pass conversion rate of the raw materials is 81% wt, the "ethylene + propylene" selectivity is 83% wt, and the propylene / ethylene (mass ratio) is 3.

[0117] Example 2

[0118] This implementation plan adopts Figure 1 The apparatus shown.

[0119] In this embodiment, the raw material is C4-C6 hydrocarbons, wherein the olefin content is 46% wt and the alkane content is 54% wt. The catalyst is a ZSM-5 molecular sieve catalyst. The process operating conditions of the reaction zone (A) of the high-density fast fluidized bed reactor (1) are: apparent gas linear velocity of 2.6 m / s, temperature of 600℃, pressure of 170 kPa, and bed density of 310 kg / m³. 3 The reaction contact time is 1.2 s. The process operating conditions of the catalyst residence zone (B) are: apparent gas linear velocity of 0.2 m / s, temperature of 600℃, and bed density of 600 kg / m³.3 The catalyst circulation intensity flowing from the catalyst residence zone (B) to the reaction zone (A) is 720 kg / (m²). 2 ·s).

[0120] The regeneration gas is air. The fuel oil is diesel. The process operating conditions of the fluidized bed regenerator (2) are: apparent gas linear velocity of 2.0 m / s, regeneration temperature of 680℃, regeneration pressure of 170 kPa, and bed density of 200 kg / m³. 3 .

[0121] The single-pass conversion rate of the raw materials is 51% wt, the "ethylene + propylene" selectivity is 75% wt, and the propylene / ethylene (mass ratio) is 4.2.

[0122] Example 3

[0123] This implementation plan adopts Figure 1 The apparatus shown.

[0124] In this embodiment, the raw material is C5-C. 12 Hydrocarbons, of which olefins account for 64% wt and alkanes account for 36% wt. The catalyst is a ZSM-5 molecular sieve catalyst. The process operating conditions of the reaction zone (A) of the high-density fast fluidized bed reactor (1) are: apparent gas linear velocity of 4.1 m / s, temperature of 650℃, pressure of 110 kPa, and bed density of 190 kg / m³. 3 The reaction contact time was 0.8 s. The process operating conditions of the catalyst residence zone (B) were: apparent gas linear velocity of 0.08 m / s, temperature of 650 °C, and bed density of 720 kg / m³. 3 The catalyst circulation intensity flowing from the catalyst residence zone (B) to the reaction zone (A) is 810 kg / (m²). 2 ·s).

[0125] The regeneration gas is air. The fuel oil is diesel. The process operating conditions of the fluidized bed regenerator (2) are: apparent gas linear velocity of 1.5 m / s, regeneration temperature of 720℃, regeneration pressure of 110 kPa, and bed density of 340 kg / m³. 3 .

[0126] The single-pass conversion rate of the raw materials is 76% wt, the "ethylene + propylene" selectivity is 77% wt, and the propylene / ethylene (mass ratio) is 6.3.

[0127] Example 4

[0128] This implementation plan adopts Figure 1 The apparatus shown.

[0129] In this embodiment, the raw material is C5-C. 12 Hydrocarbons, of which olefins account for 8% wt and alkanes account for 92% wt. The catalyst is a ZSM-5 molecular sieve catalyst. The process operating conditions of the reaction zone (A) of the high-density fast fluidized bed reactor (1) are: apparent gas linear velocity of 7.0 m / s, temperature of 680℃, pressure of 50 kPa, and bed density of 150 kg / m³. 3 The reaction contact time is 0.5 s. The process operating conditions of the catalyst residence zone (B) are: apparent gas linear velocity of 0.02 m / s, temperature of 680 ℃, and bed density of 800 kg / m³. 3 The catalyst circulation intensity flowing from the catalyst residence zone (B) to the reaction zone (A) is 1000 kg / (m²). 2 ·s).

[0130] The regeneration gas is air. The fuel oil is diesel. The process operating conditions of the fluidized bed regenerator (2) are: apparent gas linear velocity of 0.8 m / s, regeneration temperature of 750℃, regeneration pressure of 50 kPa, and bed density of 520 kg / m³. 3 .

[0131] The single-pass conversion rate of the raw materials is 63% wt, the "ethylene + propylene" selectivity is 70% wt, and the propylene / ethylene (mass ratio) is 8.5.

[0132] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A high-density, fast fluidized bed reactor, characterized in that, The high-density rapid fluidized bed reactor includes an outer reactor shell, an inner reactor shell, and a delivery pipe; The inner shell of the reactor is located at the lower part of the outer shell of the reactor; The delivery pipe is located in the upper central region of the high-density rapid fluidized bed reactor. The area enclosed by the inner shell of the reactor is the reaction zone; The bottom end of the delivery pipe is connected to the top end of the reaction zone; The annular region formed by the outer shell and the inner shell of the reactor is the catalyst residence zone; The bottom of the reaction zone and the bottom of the catalyst residence zone are connected; The area enclosed by the reactor shell and the delivery pipe is the gas-solid separation zone; The catalyst residence zone and the gas-solid separation zone are connected, and the catalyst residence zone is located below the gas-solid separation zone.

2. The high-density rapid fluidized bed reactor according to claim 1, characterized in that, The high-density rapid fluidized bed reactor includes a catalyst distribution tube, a fluidized steam distributor, and a feed distributor; The catalyst distribution pipe passes through the inner shell of the reactor and connects the catalyst residence area and the reaction area; The fluidized steam distributor is located at the bottom of the catalyst residence zone; The raw material distributor is located at the bottom of the reaction zone; Preferably, the lower surface of the catalyst distribution tube has an opening.

3. The high-density rapid fluidized bed reactor according to claim 1, characterized in that, The high-density rapid fluidized bed reactor includes a first gas-solid separation device and a second gas-solid separation device. The first gas-solid separation device and the second gas-solid separation device are located in the gas-solid separation zone; The inlet of the first gas-solid separation device is connected to the outlet of the conveying pipe; The catalyst outlet of the first gas-solid separation device is located in the lower part of the gas-solid separation zone, and the gas outlet of the first gas-solid separation device is located in the upper part of the gas-solid separation zone; The catalyst outlet of the second gas-solid separation device is located in the lower part of the gas-solid separation zone; Preferably, the first gas-solid separation device is an inertial separator; Preferably, the second gas-solid separation device employs one or more sets of gas-solid cyclone separators, each set of gas-solid cyclone separators including a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator. Preferably, the high-density rapid fluidized bed reactor includes a reactor gas collection chamber and a product gas delivery pipe; The gas collection chamber of the reactor is located at the top of the high-density fast fluidized bed reactor; The product gas delivery pipe is connected to the top of the reactor gas collection chamber; The gas outlet of the second gas-solid separation device is connected to the gas collection chamber of the reactor.

4. An apparatus for catalytic cracking to produce low-carbon olefins, characterized in that, The apparatus includes the high-density rapid fluidized bed reactor and fluidized bed regenerator as described in any one of claims 1-3; The catalyst extraction pipe passes through the outer shell of the reactor and is located at the lower part of the catalyst residence zone; the reactor stripper is connected to the catalyst extraction pipe, the inlet of the regenerator slide valve is connected to the bottom of the reactor stripper, the outlet of the regenerator slide valve is connected to the inlet of the regenerator delivery pipe, and the outlet of the regenerator delivery pipe is connected to the middle of the fluidized bed regenerator. The regenerator stripper is located at the bottom of the fluidized bed regenerator. The inlet of the regeneration slide valve is connected to the bottom of the regenerator stripper, the outlet of the regeneration slide valve is connected to the inlet of the regenerant delivery pipe, and the outlet of the regenerant delivery pipe is connected to the lower part of the gas-solid separation zone of the high-density fast fluidized bed reactor.

5. The apparatus according to claim 4, characterized in that, The fluidized bed regenerator includes a regenerator shell, a regenerator distributor, a fuel distributor, a third gas-solid separation device, a regenerator gas collection chamber, and a flue gas conveying pipe. The regenerator distributor is located at the bottom of the fluidized bed regenerator; The fuel distributor is located above the regenerator distributor; The third gas-solid separation device is located at the top of the fluidized bed regenerator. The inlet of the third gas-solid separation device is located at the top of the fluidized bed regenerator. The gas outlet of the third gas-solid separation device is connected to the gas collection chamber of the regenerator. The catalyst outlet of the third gas-solid separation device is located at the bottom of the fluidized bed regenerator. The regenerator gas collection chamber is located at the top of the fluidized bed regenerator, and the flue gas delivery pipe is connected to the top of the regenerator gas collection chamber; Preferably, the inlet pipe of the regenerator stripper penetrates the regenerator housing and opens above the regenerator distributor; Preferably, the third gas-solid separation device employs one or more sets of gas-solid cyclone separators, each set of gas-solid cyclone separators including a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

6. A method for catalytic cracking to produce low-carbon olefins, characterized in that, Performed using the apparatus described in claim 4 or 5.

7. The method according to claim 6, characterized in that, Includes the following steps: The gasified mixed hydrocarbon feedstock is fed into the reaction zone, where it comes into contact with the catalyst and reacts to generate stream I containing product gas and catalyst. After passing through the conveying pipe and undergoing gas-solid separation, the catalyst enters the catalyst residence area; Steam enters the catalyst residence zone, and the steam carries a small amount of catalyst from the catalyst residence zone into the gas-solid separation zone; In the gas-solid separation zone, the product gas and steam carrying the catalyst are separated and the catalyst is returned to the catalyst residence zone, while the product gas and steam enter the downstream process. A portion of the catalyst in the catalyst residence zone enters the reaction zone through the catalyst distribution pipe, and another portion of the catalyst in the catalyst residence zone enters the bottom of the reaction zone through the bottom of the catalyst residence zone; A portion of the catalyst in the catalyst residence zone enters the fluidized bed regenerator for regeneration, and the regenerated catalyst enters the high-density fast fluidized bed reactor.

8. The method according to claim 7, characterized in that, The process operating conditions of the reaction zone of the high-density fast fluidized bed reactor are as follows: apparent gas linear velocity of 1.5-7.0 m / s, temperature of 500-680℃, pressure of 50-250 kPa, and bed density of 150-500 kg / m³. 3 The reaction contact time is 0.5-2 seconds; Preferably, the process operating conditions of the catalyst residence zone in the high-density fast fluidized bed reactor are: apparent gas linear velocity of 0.02-0.2 m / s, temperature of 500-680℃, and bed density of 600-800 kg / m³. 3 ; Preferably, the catalyst circulation intensity flowing from the catalyst residence zone to the reaction zone is 500-1000 kg / (m²). 2 ·s).

9. The method according to claim 7, characterized in that, The mixed hydrocarbon feedstock is a C4+ hydrocarbon, including alkanes and alkenes with ≥4 carbon atoms; Preferably, the mixed hydrocarbon feedstock is C4-C 12 hydrocarbon; Preferably, the catalyst is ZSM-5 molecular sieve.

10. The method according to claim 7, characterized in that, In the fluidized bed regenerator, the regenerated gas and the catalyst come into contact. Fuel enters the bottom of the fluidized bed regenerator from the fuel distributor. After the regenerated gas and fuel come into contact, they burn. The flue gas formed by combustion carries the catalyst. After gas-solid separation, the catalyst returns to the bottom of the fluidized bed regenerator and enters the gas-solid separation zone of the high-density fast fluidized bed reactor after stripping. Preferably, the regenerated gas is air, and the fuel is diesel. Preferably, the process operating conditions of the fluidized bed regenerator are: apparent gas linear velocity of 0.5-2.0 m / s, regeneration temperature of 600-750℃, regeneration pressure of 50-250 kPa, and bed density of 200-800 kg / m³. 3 .

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