High-density fast fluidized bed reactor, apparatus for preparing light olefins by means of catalytic cracking, and method thereof

Abstract

A high-density fast fluidized bed reactor (1), an apparatus for preparing light olefins by means of catalytic cracking, and a method thereof. The apparatus comprises the high-density fast fluidized bed reactor (1) and a fluidized bed regenerator (2). In the high-density fast fluidized bed reactor (1), the circulating strength of a catalyst flowing to a reaction area (A) through a catalyst retention area (B) reaches 500-1000 kg / (m2·s), so that the bed density of the reaction area (A) is improved, and the high bed density is obtained under the condition of a high superficial linear velocity. By means of a fluidized bed reaction-regeneration process, the method realizes continuous catalytic cracking of mixed hydrocarbons to prepare the light olefins, and heat is provided for the reaction by means of oil injection and afterburning. The reaction contact time of product gas in the high-density fast fluidized bed reactor (1) is shorter than 2 s, and the selectivity of the light olefins is effectively improved. According to the method, the single-pass conversion rate of a raw material is greater than or equal to 50%wt, the selectivity of "ethylene and propylene" is greater than or equal to 70%wt, and propylene / ethylene (mass ratio) is greater than or equal to 3.

Description

High-density fast fluidized bed reactor, device and method for producing light olefins by catalytic cracking Technical Field

[0001] The present application relates to a high-density fast fluidized bed reactor, a device for catalytic cracking to produce light olefins and a method thereof, and belongs to the field of chemical catalysis. Background Art

[0002] Olefins are important basic organic chemical raw materials and the cornerstone of the modern chemical industry. Olefin production technologies primarily include naphtha cracking, methanol to olefins, propane dehydrogenation to propylene, alkane cracking to olefins, and olefin cracking to olefins. Light olefins are highly reactive and prone to reactions such as polymerization, alkylation, and aromatization, generating byproducts that reduce light olefin yields.

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

[0004] Sinopec has developed olefin catalytic cracking (OCC) technology, which cracks olefins contained in mixed C4-C6 raw materials into propylene, ethylene, etc. under the action of molecular sieve catalysts. OCC unit

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

[0006] Catalytic cracking to produce light olefins is a highly endothermic process. Radial flow reactors and fixed-bed reactors typically use elevated feed temperatures to provide heat. However, excessively high preheat temperatures for feedstock components such as olefins, diolefins, and alkynes can lead to coking, hindering continuous operation. Furthermore, the catalyst gradually loses activity during the reaction, necessitating switching reactors to achieve continuous operation. These heating and deactivation challenges have limited the development and advancement of radial flow and fixed-bed reactor technologies.

[0007] Summary of the Invention

[0008] Light olefins are highly reactive and prone to polymerization, alkylation, aromatization, and other reactions, generating byproducts that reduce light olefin yield. Reaction contact time is a key factor influencing light olefin selectivity in the catalytic cracking of mixed hydrocarbons to produce light olefins. Increasing the superficial linear velocity in the reaction zone of a fluidized bed reactor can reduce reaction contact time and improve light olefin selectivity. However, this typically results in a significant decrease in bed density and catalyst inventory, leading to a decrease in cracking feedstock conversion. Consequently, there is a negative correlation between light olefin selectivity and feedstock conversion.

[0009] In order to improve the yield of light olefins and the conversion rate of cracking raw materials, according to the first aspect of the present application, a high-density fast fluidized bed reactor is provided.

[0010] A high-density fast fluidized bed reactor, comprising an outer reactor shell, an inner reactor shell and a delivery pipe;

[0011] The reactor inner shell is located at the lower part of the reactor outer shell;

[0012] The delivery pipe is located in the central area of ​​the upper middle part of the high-density fast fluidized bed reactor.

[0013] The area enclosed by the inner shell of the reactor is the reaction zone;

[0014] The bottom end of the delivery pipe is connected to the top end of the reaction zone;

[0015] The annular area enclosed by the reactor outer shell and the reactor inner shell is the catalyst retention area;

[0016] The bottom of the reaction zone is connected to the bottom of the catalyst retention zone;

[0017] The area enclosed by the reactor shell and the delivery pipe is the gas-solid separation area;

[0018] The catalyst retention zone is communicated with the gas-solid separation zone and is located below the gas-solid separation zone.

[0019] Optionally, the bottom end of the delivery pipe is connected to the top end of the reaction zone.

[0020] Optionally, the high-density fast fluidized bed reactor includes a catalyst distribution pipe, a fluidizing steam distributor, and a raw material distributor;

[0021] The catalyst distribution pipe passes through the inner shell of the reactor and connects the catalyst retention zone and the reaction zone;

[0022] The fluidizing steam distributor is located at the bottom of the catalyst retention zone;

[0023] The raw material distributor is located at the bottom of the reaction zone.

[0024] Optionally, the lower surface of the catalyst distribution tube is opened.

[0025] Optionally, the high-density fast fluidized bed reactor includes a first gas-solid separation device and a second gas-solid separation device;

[0026] The first gas-solid separation equipment and the second gas-solid separation equipment are located in the gas-solid separation zone;

[0027] The inlet of the first gas-solid separation device is connected to the outlet of the conveying pipe;

[0028] The catalyst outlet of the first gas-solid separation device is located at the lower part of the gas-solid separation zone, and the gas outlet of the first gas-solid separation device is located at the upper part of the gas-solid separation zone;

[0029] The catalyst outlet of the second gas-solid separation device is located at the lower part of the gas-solid separation zone.

[0030] Optionally, the first gas-solid separation device surrounds the conveying pipe.

[0031] Optionally, the first gas-solid separation device uses an inertial separator to achieve rapid separation of the product gas and the catalyst.

[0032] Optionally, the second gas-solid separation equipment adopts one or more groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0033] Optionally, the high-density fast fluidized bed reactor includes a reactor gas collecting chamber and a product gas conveying pipe;

[0034] The reactor gas collecting chamber is located at the top of the high-density fast fluidized bed reactor;

[0035] The product gas delivery pipe is connected to the top of the reactor gas collecting chamber;

[0036] The gas outlet of the second gas-solid separation device is connected to the gas collecting chamber of the reactor.

[0037] As a preferred embodiment, the high-density fast 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 fluidized steam distributor, a catalyst distribution pipe, a second gas-solid separation device, a reactor gas collecting chamber, a product gas conveying pipe, a catalyst extraction pipe, a reactor stripper, a slide valve to be regenerated and a conveying pipe for the catalyst to be regenerated.

[0038] The area enclosed by the inner shell of the reactor is the reaction zone, the annular area enclosed by the outer shell of the reactor and the inner shell of the reactor is the catalyst retention zone, the bottom of the reaction zone is connected to the bottom of the catalyst retention zone, the area enclosed by the outer shell of the reactor and the conveying pipe is the gas-solid separation zone, the catalyst retention zone is connected to the gas-solid separation zone and is located below the gas-solid separation zone.

[0039] The raw material distributor is located at the bottom of the reaction zone, the delivery pipe is located in the central area of ​​the upper part of the high-density fast fluidized bed reactor, the bottom end of the delivery pipe is connected to the top of the reaction zone, and the outlet of the delivery pipe is connected to the inlet of the first gas-solid separation device.

[0040] 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.

[0041] The fluidizing steam distributor is located at the bottom of the catalyst retention zone.

[0042] The catalyst distribution pipe passes through the inner shell of the reactor and is connected with the catalyst retention zone and the reaction zone, and a hole is opened on the lower surface of the catalyst distribution pipe.

[0043] The second gas-solid separation equipment is located in the gas-solid separation zone, the inlet of the second gas-solid separation equipment is located in the gas-solid separation zone, the gas outlet of the second gas-solid separation equipment is connected to the reactor gas collecting chamber, and the catalyst outlet of the second gas-solid separation equipment is located at the lower part of the gas-solid separation zone.

[0044] The reactor gas collecting chamber is located at the top of the high-density fast fluidized bed reactor, and the product gas conveying pipe is connected to the top of the reactor gas collecting chamber.

[0045] The catalyst extraction pipe passes through the outer shell of the reactor and is located at the lower part of the catalyst retention zone.

[0046] The reactor stripper is connected to the catalyst extraction pipe, the inlet of the spent catalyst slide valve is connected to the bottom of the reactor stripper, the outlet of the spent catalyst slide valve is connected to the inlet of the spent catalyst delivery pipe, and the outlet of the spent catalyst delivery pipe is connected to the fluidized bed regenerator.

[0047] According to a second aspect of the present application, a device for producing light olefins by catalytic cracking is provided.

[0048] A device for producing light olefins by catalytic cracking, comprising the high-density fast fluidized bed reactor and the fluidized bed regenerator described above;

[0049] The catalyst extraction pipe passes through the reactor shell and is located at the lower part of the catalyst retention zone; the reactor stripper is connected to the catalyst extraction pipe, the inlet of the spent catalyst slide valve is connected to the bottom of the reactor stripper, the outlet of the spent catalyst slide valve is connected to the inlet of the spent catalyst delivery pipe, and the outlet of the spent catalyst delivery pipe is connected to the middle part of the fluidized bed regenerator;

[0050] 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 regeneration agent delivery pipe, and the outlet of the regeneration agent delivery pipe is connected to the lower part of the gas-solid separation zone of the high-density fast fluidized bed reactor.

[0051] Optionally, the fluidized bed regenerator includes a regenerator housing, a regenerator distributor, a fuel distributor, a third gas-solid separation device, a regenerator gas collecting chamber, and a flue gas conveying pipe;

[0052] The regenerator distributor is located at the bottom of the fluidized bed regenerator;

[0053] The fuel distributor is located above the regenerator distributor;

[0054] The third gas-solid separation device is located at the upper part of the fluidized bed regenerator, the inlet of the third gas-solid separation device is located at the upper part of the fluidized bed regenerator, the gas outlet of the third gas-solid separation device is connected to the regenerator gas collecting chamber, and the catalyst outlet of the third gas-solid separation device is located at the lower part of the fluidized bed regenerator;

[0055] The regenerator air collecting chamber is located at the top of the fluidized bed regenerator, and the flue gas conveying pipe is connected to the top of the regenerator air collecting chamber.

[0056] Optionally, the inlet pipe of the regenerator stripper penetrates the regenerator shell and opens above the regenerator distributor.

[0057] Optionally, the third gas-solid separation equipment adopts one or more groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0058] The fluidized bed regenerator of the present application can achieve thermal balance in the process of catalytic cracking to produce light olefins and restore the activity of the catalyst through regeneration.

[0059] As a preferred embodiment, the fluidized bed regenerator comprises: a regenerator shell, a regenerator distributor, a fuel distributor, a third gas-solid separation device, a regenerator gas collecting chamber, a flue gas conveying pipe, a regenerator stripper, a regeneration slide valve and a regeneration agent conveying pipe.

[0060] 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 equipment is located at the upper part of the fluidized bed regenerator, the inlet of the third gas-solid separation equipment is located at the upper part of the fluidized bed regenerator, the gas outlet of the third gas-solid separation equipment is connected to the regenerator gas collecting chamber, the catalyst outlet of the third gas-solid separation equipment is located at the lower part of the fluidized bed regenerator, the regenerator gas collecting chamber is located at the top of the fluidized bed regenerator, and the flue gas conveying pipe is connected to the top of the regenerator gas collecting chamber.

[0061] 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, the outlet of the regeneration slide valve is connected to the inlet of the regeneration agent delivery pipe, and the outlet of the regeneration agent delivery pipe is connected to the lower part of the gas-solid separation zone of the high-density fast fluidized bed reactor.

[0062] According to a third aspect of the present application, a method for producing light olefins by catalytic cracking is provided, wherein the method adopts a continuous reaction-regeneration fluidized bed process.

[0063] A method for preparing light olefins by catalytic cracking is carried out using the above-mentioned device for preparing light olefins by catalytic cracking.

[0064] A method for preparing light olefins by catalytic cracking, comprising the following steps:

[0065] The gasified mixed hydrocarbon feedstock is passed into the reaction zone, where it contacts the catalyst and reacts to generate a stream I containing product gas and catalyst;

[0066] Logistics I passes through the delivery pipe and undergoes gas-solid separation, and then the catalyst enters the catalyst retention area;

[0067] Steam enters the catalyst retention zone, and the steam carries a small amount of catalyst from the catalyst retention zone into the gas-solid separation zone;

[0068] After the product gas and steam in the gas-solid separation zone carry the catalyst through gas-solid separation, the catalyst returns to the catalyst retention zone, and the product gas and steam enter the downstream process section;

[0069] A portion of the catalyst in the catalyst retention zone enters the reaction zone through the catalyst distribution pipe, and a portion of the catalyst in the catalyst retention zone enters the bottom of the reaction zone through the bottom of the catalyst retention zone;

[0070] A portion of the catalyst in the catalyst retention zone enters the fluidized bed regenerator for regeneration, and the regenerated catalyst enters the high-density fast fluidized bed reactor.

[0071] Optionally, the process operating conditions of the reaction zone of the high-density fast fluidized bed reactor are: gas superficial velocity of 1.5-7.0 m / s, temperature of 500-680°C, pressure of 50-250 kPa, bed density of 150-500 kg / m 3 , the reaction contact time is 0.5-2s.

[0072] Optionally, the process operating conditions of the catalyst retention zone of the high-density fast fluidized bed reactor are: gas superficial velocity of 0.02-0.2 m / s, temperature of 500-680°C, bed density of 600-800 kg / m 3 .

[0073] Optionally, the catalyst circulation intensity of the catalyst flowing from the catalyst retention zone to the reaction zone is 500-1000 kg / (m 2 ·s).

[0074] Optionally, the mixed hydrocarbon feedstock is C4+ hydrocarbons, including alkanes and alkenes with carbon atoms ≥4.

[0075] Optionally, the mixed hydrocarbon feedstock is C4-C 12 hydrocarbon.

[0076] Optionally, the catalyst is ZSM-5 molecular sieve.

[0077] Optionally, in the fluidized bed regenerator, the regeneration gas contacts the catalyst, and the fuel oil enters the bottom of the fluidized bed regenerator from the fuel oil distributor. The regeneration gas and the fuel oil contact and burn, and the flue gas formed by the combustion carries the catalyst and undergoes 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 through steam stripping.

[0078] Optionally, the regeneration gas is air and the fuel is diesel.

[0079] Optionally, the process operating conditions of the fluidized bed regenerator are: gas superficial velocity of 0.5-2.0 m / s, regeneration temperature of 600-750°C, regeneration pressure of 50-250 kPa, bed density of 200-800 kg / m 3 .

[0080] As a preferred embodiment, the method for producing light olefins by catalytic cracking comprises:

[0081] The catalyst from the regeneration agent delivery pipe enters the gas-solid separation zone of the high-density fast fluidized bed reactor and then enters the catalyst retention zone; the gasified raw material enters the reaction zone from the raw material distributor, contacts the catalyst, and generates product gas containing light olefins. The product gas carries the catalyst through the delivery pipe and enters the first gas-solid separation equipment. After gas-solid separation, the catalyst enters the catalyst retention zone; steam enters the catalyst retention zone from the fluidized steam distributor, and the steam carries a small amount of catalyst from the catalyst retention zone into the gas-solid separation zone; the product gas and steam in the gas-solid separation zone carry the catalyst and enter the second gas-solid separation equipment. After gas-solid separation, the gas enters the reactor gas collection chamber and the catalyst returns to the catalyst retention zone; the product gas and steam enter the downstream section through the product gas delivery pipe; the catalyst in the catalyst retention zone enters the reaction zone through the catalyst distribution pipe; the catalyst in the catalyst retention zone enters the bottom of the reaction zone through the bottom of the catalyst retention zone; the catalyst in the catalyst retention zone enters the reactor stripper through the catalyst extraction pipe. After stripping, the catalyst enters the middle part of the fluidized bed regenerator through the regeneration slide valve and the regeneration agent delivery pipe;

[0082] The regeneration gas enters the bottom of the fluidized bed regenerator from the regenerator distributor. In the fluidized bed regenerator, the regeneration gas contacts the catalyst and the carbon deposits in the catalyst are burned and eliminated. The fuel oil enters the bottom of the fluidized bed regenerator from the fuel oil distributor. The regeneration gas contacts the fuel oil and burns to increase the temperature of the catalyst. The flue gas formed by the combustion carries the catalyst into the third gas-solid separation equipment. 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 conveying 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 regeneration agent conveying pipe.

[0083] The beneficial effects of this application include:

[0084] (1) The high-density fast fluidized bed reactor provided in this application mainly comprises a reaction zone, a catalyst retention zone and a gas-solid separation zone. The catalyst circulation intensity flowing from the catalyst retention zone to the reaction zone is as high as 500-1000 kg / (m 2 ·s), thereby increasing the bed density in the reaction zone, achieving high bed density under high superficial velocity conditions, and overcoming the negative correlation between light olefin selectivity and feed conversion rate.

[0085] (2) The device for catalytic cracking to produce light olefins provided in the present application sprays oil and performs supplementary combustion in the 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 reaction to produce light olefins, thereby achieving thermal balance.

[0086] (3) The method for producing light olefins by catalytic cracking provided in this application achieves a continuous mixed hydrocarbon catalytic cracking process to produce light olefins through a fluidized bed reaction-regeneration process. The product gas has a reaction contact time of <2 seconds in a high-density fast fluidized bed reactor, effectively improving the selectivity for light olefins. The feedstock single-pass conversion rate is ≥50% wt, the "ethylene + propylene" selectivity is ≥70% wt, and the propylene / ethylene (mass ratio) is ≥3. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] FIG1 is a schematic diagram of an apparatus according to an embodiment of the present application.

[0088] The reference numerals in Figure 1 are explained as follows: 1-High-density fast fluidized bed reactor; 1-1 Reactor outer shell 1-2 Reactor inner shell 1-3 Delivery pipe 1-4 Raw material distributor 1-5 First gas-solid separation equipment 1-6 Fluidized steam distributor 1-7 Catalyst distribution pipe 1-8 Second gas-solid separation equipment 1-9 Reactor gas collecting chamber 1-10 Product gas delivery pipe 1-11 Catalyst extraction pipe 1-12 Reactor stripper 1-13 Waiting slide valve 1-14 Waiting agent delivery pipe 2-Fluidized bed regenerator; 2-1 Regenerator shell 2-2 Regenerator distributor 2-3 Fuel oil distributor 2-4 Third gas-solid separation equipment 2-5 Regenerator gas collecting chamber 2-6 Flue gas delivery pipe 2-7 Regenerator stripper 2-8 Regeneration slide valve 2-9 Regeneration agent delivery pipe. DETAILED DESCRIPTION

[0089] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0090] Unless otherwise specified, the raw materials and catalysts in the examples of this application were purchased from commercial sources.

[0091] In a specific embodiment, a schematic diagram of an apparatus according to an embodiment of the present application is shown in FIG1 , wherein the apparatus comprises a high-density fast fluidized bed reactor ( 1 ) and a fluidized bed regenerator ( 2 ).

[0092] 1. The high-density fast fluidized bed reactor (1) comprises: a reactor outer shell (1-1), a reactor inner 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 collecting chamber (1-9), a product gas conveying pipe (1-10), a catalyst extraction pipe (1-11), a reactor stripper (1-12), a slide valve for regeneration (1-13) and a regeneration catalyst conveying pipe (1-14); The area enclosed by the reactor inner shell (1-2) is the reaction zone (A), the annular area enclosed by the reactor outer shell (1-1) and the reactor inner shell (1-2) is the catalyst retention zone (B), the bottom of the reaction zone (A) is connected to the bottom of the catalyst retention zone (B), the area enclosed by the reactor outer shell (1-1) and the conveying pipe (1-3) is the gas-solid separation zone (C), the catalyst retention 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 in the reaction zone (A) The bottom of the high-density fast fluidized bed reactor, the delivery pipe (1-3) is located in the central area of ​​the upper part of the high-density fast fluidized bed reactor, the bottom end of the delivery pipe (1-3) is connected to the top of the reaction zone (A), and the outlet of the delivery 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 in 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 in the upper part of the gas-solid separation zone (C); the fluidized steam distributor (1- 6) is located at the bottom of the catalyst retention zone (B); the catalyst distribution pipe (1-7) passes through the reactor inner shell (1-2) to connect the catalyst retention zone (B) and the reaction zone (A), and the lower surface of the catalyst distribution pipe (1-7) is opened; 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 reactor gas collecting chamber (1-9), and the catalyst outlet of the second gas-solid separation device (1-8) is located at the bottom of the gas-solid separation zone (C); the reactor gas collecting chamber (1-9) is located at the top of the high-density fast fluidized bed reactor, and the product gas conveying pipe (1-10) is connected to the top of the reactor gas collecting chamber (1-9); the catalyst extraction pipe (1-11) passes through the reactor outer shell (1-1) and is located at the bottom of the catalyst retention zone (B);The reactor stripper (1-12) is connected to the catalyst extraction pipe (1-11), the inlet of the spent catalyst slide valve (1-13) is connected to the bottom of the reactor stripper (1-12), the outlet of the spent catalyst slide valve (1-13) is connected to the inlet of the spent catalyst delivery pipe (1-14), and the outlet of the spent catalyst delivery pipe (1-14) is connected to the fluidized bed regenerator (2).

[0093] 2. The fluidized bed regenerator (2) comprises: a regenerator shell (2-1), a regenerator distributor (2-2), a fuel distributor (2-3), a third gas-solid separation device (2-4), a regenerator gas collecting chamber (2-5), a flue gas conveying pipe (2-6), a regenerator stripper (2-7), a regeneration slide valve (2-8) and a regeneration agent conveying pipe (2-9); the regenerator distributor (2-2) is located at the bottom of the fluidized bed regenerator (2), and the fuel distributor (2-3) is located above the regenerator distributor (2-2); the third gas-solid separation device (2-4) is located at the upper part of the fluidized bed regenerator (2), the inlet of the third gas-solid separation device (2-4) is located at the upper part 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 collecting chamber (2- 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 collecting 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 collecting 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 regeneration agent conveying pipe (2-9), and the outlet of the regeneration agent 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).

[0094] Specifically, the first gas-solid separation equipment (1-5) uses an inertial separator to achieve rapid separation of product gas and catalyst.

[0095] Specifically, the second gas-solid separation equipment (1-8) adopts one or more groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0096] Specifically, the third gas-solid separation equipment (2-4) adopts one or more groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0097] In a specific embodiment, the method for producing light olefins by catalytic cracking described in the present application comprises the following steps:

[0098] 1. The catalyst from the regeneration agent 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 retention zone (B); the gasified raw material enters the reaction zone (A) from the raw material distributor (1-4), contacts with the catalyst, and generates product gas containing light olefins. The product gas carries the catalyst through the delivery pipe (1-3) and enters the first gas-solid separation device (1-5). After gas-solid separation, the catalyst enters the catalyst retention zone (B); steam enters the catalyst retention zone (B) from the fluidized steam distributor (1-6), and the steam carries a small amount of catalyst from the catalyst retention zone (B) into the gas-solid separation zone (C); the product gas and steam in the gas-solid separation zone (C) carry the catalyst and enter the first gas-solid separation device (1-5). Second gas-solid separation equipment (1-8), after gas-solid separation, the gas enters the reactor gas collecting chamber (1-9), and the catalyst returns to the catalyst retention zone (B); the product gas and steam enter the downstream section through the product gas conveying pipe (1-10); the catalyst in the catalyst retention zone (B) enters the reaction zone (A) through the catalyst distribution pipe (1-7); the catalyst in the catalyst retention zone (B) enters the bottom of the reaction zone (A) through the bottom of the catalyst retention zone (B); the catalyst in the catalyst retention zone (B) enters the reactor stripper (1-12) through the catalyst extraction pipe (1-11), and after stripping, the catalyst enters the middle part of the fluidized bed regenerator (2) through the regeneration slide valve (1-13) and the regeneration agent conveying pipe (1-14);

[0099] 2. The regeneration gas enters the bottom of the fluidized bed regenerator (2) from the regenerator distributor (2-2). In the fluidized bed regenerator (2), the regeneration gas contacts the catalyst and the carbon deposits in the catalyst are burned and eliminated. The fuel oil enters the bottom of the fluidized bed regenerator (2) from the fuel oil distributor (2-3). The regeneration gas contacts the fuel oil and burns to increase the temperature of the catalyst. The flue gas formed by the 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 regeneration agent conveying pipe (2-9).

[0100] The method described in this application, the calculation method of the raw material single-pass conversion rate and the "ethylene + propylene" selectivity is as follows:

[0101] Raw material single-pass conversion rate = (1-mass flow rate of C4+ hydrocarbons in product gas / mass flow rate of C4+ hydrocarbon feed) × 100%

[0102] "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%

[0103] Example 1

[0104] This embodiment adopts the device shown in Figure 1.

[0105] In this embodiment, the raw material is a C4-C6 hydrocarbon, 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: gas superficial linear velocity of 1.5m / s, temperature of 500°C, pressure of 250kPa, bed density of 500kg / m 3 The process operating conditions of the catalyst retention zone (B) are: gas superficial velocity of 0.10 m / s, temperature of 500°C, bed density of 670 kg / m 3 The catalyst circulation intensity flowing from the catalyst retention zone (B) to the reaction zone (A) is 500 kg / (m 2 ·s).

[0106] The regeneration gas is air. The fuel is diesel. The process operating conditions of the fluidized bed regenerator (2) are: gas superficial linear velocity of 0.5m / s, regeneration temperature of 600℃, regeneration pressure of 250kPa, bed density of 800kg / m 3 .

[0107] The raw material single-pass conversion rate was 81%wt, the "ethylene+propylene" selectivity was 83%wt, and the propylene / ethylene (mass ratio) was 3.

[0108] Example 2

[0109] This embodiment adopts the device shown in Figure 1.

[0110] In this embodiment, the raw material is a C4-C6 hydrocarbon, 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: gas superficial linear velocity of 2.6m / s, temperature of 600°C, pressure of 170kPa, bed density of 310kg / m 3 The process operating conditions of the catalyst retention zone (B) are: gas superficial velocity of 0.2 m / s, temperature of 600°C, bed density of 600 kg / m 3The catalyst circulation intensity flowing from the catalyst retention zone (B) to the reaction zone (A) is 720 kg / (m 2 ·s).

[0111] The regeneration gas is air. The fuel is diesel. The process operating conditions of the fluidized bed regenerator (2) are: gas superficial linear velocity of 2.0 m / s, regeneration temperature of 680°C, regeneration pressure of 170 kPa, bed density of 200 kg / m 3 .

[0112] The raw material single-pass conversion rate was 51% wt, the "ethylene + propylene" selectivity was 75% wt, and the propylene / ethylene (mass ratio) was 4.2.

[0113] Example 3

[0114] This embodiment adopts the device shown in Figure 1.

[0115] In this embodiment, the raw material is C5-C 12 Hydrocarbons, wherein the olefin content is 64%wt and the alkane content is 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: gas superficial linear velocity of 4.1m / s, temperature of 650°C, pressure of 110kPa, bed density of 190kg / m 3 The process operating conditions of the catalyst retention zone (B) are: gas superficial velocity of 0.08 m / s, temperature of 650°C, bed density of 720 kg / m 3 The catalyst circulation intensity flowing from the catalyst retention zone (B) to the reaction zone (A) is 810 kg / (m 2 ·s).

[0116] The regeneration gas is air. The fuel is diesel. The process operating conditions of the fluidized bed regenerator (2) are: gas superficial velocity of 1.5 m / s, regeneration temperature of 720°C, regeneration pressure of 110 kPa, bed density of 340 kg / m 3 .

[0117] The raw material single-pass conversion rate was 76% wt, the "ethylene + propylene" selectivity was 77% wt, and the propylene / ethylene (mass ratio) was 6.3.

[0118] Example 4

[0119] This embodiment adopts the device shown in Figure 1.

[0120] In this embodiment, the raw material is C5-C 12Hydrocarbons, wherein the olefin content is 8%wt and the alkane content is 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: gas superficial linear velocity of 7.0m / s, temperature of 680℃, pressure of 50kPa, bed density of 150kg / m 3 The reaction contact time is 0.5s. The process operating conditions of the catalyst retention zone (B) are: gas superficial velocity of 0.02m / s, temperature of 680℃, bed density of 800kg / m 3 The catalyst circulation intensity flowing from the catalyst retention zone (B) to the reaction zone (A) is 1000 kg / (m 2 ·s).

[0121] The regeneration gas is air. The fuel is diesel. The process operating conditions of the fluidized bed regenerator (2) are: gas superficial linear velocity of 0.8 m / s, regeneration temperature of 750°C, regeneration pressure of 50 kPa, bed density of 520 kg / m 3 .

[0122] The raw material single-pass conversion rate was 63% wt, the "ethylene + propylene" selectivity was 70% wt, and the propylene / ethylene (mass ratio) was 8.5.

[0123] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications 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 fast fluidized bed reactor includes a reactor outer shell, a reactor inner shell, and a conveying pipe; The reactor inner shell is located at the lower part of the reactor outer shell; The conveying pipe is located in the central area of the upper and middle parts of the high-density fast fluidized bed reactor, The area enclosed by the reactor inner shell is the reaction zone; The bottom end of the conveying pipe is connected to the top end of the reaction zone; The annular area enclosed by the reactor outer shell and the reactor inner shell is the catalyst residence zone; The bottom of the reaction zone is communicated with the bottom of the catalyst residence zone; The area enclosed by the reactor outer shell and the conveying pipe is the gas-solid separation zone; The catalyst residence zone is communicated with the gas-solid separation zone and is located below the gas-solid separation zone.

2. The high-density fast fluidized bed reactor according to claim 1, wherein The high-density fast fluidized bed reactor includes a catalyst distribution pipe, a fluidizing steam distributor, and a raw material distributor; The catalyst distribution pipe passes through the reactor inner shell to communicate the catalyst residence zone and the reaction zone; The fluidizing 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.

3. The high-density fast fluidized bed reactor according to any one of claims 1-2, characterized in that, The lower surface of the catalyst distribution pipe is provided with openings.

4. The high-density fast fluidized bed reactor according to any one of claims 1-3, characterized in that, The high-density fast 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 at the lower part of the gas-solid separation zone, and the gas outlet of the first gas-solid separation device is located at the upper part of the gas-solid separation zone; The catalyst outlet of the second gas-solid separation device is located at the lower part of the gas-solid separation zone.

5. The high-density fast fluidized bed reactor according to any one of claims 1-4, characterized in that, The first gas-solid separation device adopts an inertial separator.

6. The high-density fast fluidized bed reactor according to any one of claims 1-5, characterized in that, The second gas-solid separation device adopts one or more groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

7. The high-density fast fluidized bed reactor according to any one of claims 1-6, characterized in that, The high-density fast fluidized bed reactor includes a reactor gas collection chamber and a product gas conveying pipe; The reactor gas collection chamber is located at the top of the high-density fast fluidized bed reactor; The product gas conveying 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 reactor gas collection chamber.

8. An apparatus for catalytic cracking to produce light olefins, characterized in that, The device includes the high-density fast fluidized bed reactor according to any one of claims 1-7 and a fluidized bed regenerator; The catalyst extraction pipe passes through the reactor outer shell 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 spent catalyst slide valve is connected to the bottom of the reactor stripper, the outlet of the spent catalyst slide valve is connected to the inlet of the spent catalyst conveying pipe, and the outlet of the spent catalyst conveying pipe is connected to the middle part of the fluidized bed regenerator; The regenerator stripper is located at the bottom of the fluidized bed regenerator, the inlet of the regenerated catalyst slide valve is connected to the bottom of the regenerator stripper, the outlet of the regenerated catalyst slide valve is connected to the inlet of the regenerated catalyst conveying pipe, and the outlet of the regenerated catalyst conveying pipe is connected to the lower part of the gas-solid separation zone of the high-density fast fluidized bed reactor.

9. The device according to claim 8, 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 in the upper part of the fluidized bed regenerator. The inlet of the third gas-solid separation device is located in the upper part of the fluidized bed regenerator. The gas outlet of the third gas-solid separation device is connected to the regenerator gas collection chamber. The catalyst outlet of the third gas-solid separation device is located in the lower part of the fluidized bed regenerator; The regenerator gas collection chamber is located at the top of the fluidized bed regenerator. The flue gas delivery pipe is connected to the top of the regenerator gas collection chamber.

10. The device according to any one of claims 8-9, characterized in that, The inlet pipe of the regenerator stripper penetrates the regenerator shell and opens above the regenerator distributor.

11. The device according to any one of claims 8 to 10, characterized in that The third gas-solid separation device employs one or more groups of gas-solid cyclone separators. Each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

12. A method for catalytic cracking to produce light olefins, characterized in that, It is carried out using the device according to any one of claims 8-11.

13. The method according to claim 12, characterized in that, It includes the following steps: The gasified mixed hydrocarbon raw material is introduced into the reaction zone, contacts with the catalyst, and reacts to generate a stream I containing product gas and catalyst; Stream I passes through the delivery pipe, and after gas-solid separation, the catalyst enters the catalyst residence zone; Steam enters the catalyst residence zone, and the steam carries a small amount of catalyst and enters the gas-solid separation zone from the catalyst residence zone; After the product gas and the steam carrying the catalyst in the gas-solid separation zone are subjected to gas-solid separation, the catalyst returns to the catalyst residence zone, and the product gas and the steam enter the downstream section; A part of the catalyst in the catalyst residence zone enters the reaction zone through the catalyst distribution pipe, and a part of the catalyst in the catalyst residence zone enters the bottom of the reaction zone through the bottom of the catalyst residence zone; A part 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.

14. The method according to any one of claims 12 - 13, characterized in that, The process operating conditions in the reaction zone of the high-density fast fluidized bed reactor are as follows: the superficial gas linear velocity is 1.5 - 7.0 m / s, the temperature is 500 - 680 °C, the pressure is 50 - 250 kPa, and the bed density is 150 - 500 kg / m 3 , and the reaction contact time is 0.5 - 2 s.

15. The method according to any one of claims 12 - 14, characterized in that, The process operating conditions of the catalyst residence zone in the high-density fast fluidized bed reactor are as follows: the superficial gas linear velocity is 0.02 - 0.2 m / s, the temperature is 500 - 680 °C, and the bed density is 600 - 800 kg / m 3 .

16. The method according to any one of claims 12 - 15, characterized in that, The catalyst circulation intensity of the catalyst flowing from the catalyst residence zone to the reaction zone is 500 - 1000 kg / (m 2 ·s).

17. The method according to any one of claims 12-16, characterized in that, The mixed hydrocarbon raw material is C4+ hydrocarbon, including alkanes and alkenes with carbon atoms ≥4.

18. The method according to any one of claims 12 - 17, characterized in that, The mixed hydrocarbon raw material is C4-C 12 hydrocarbon.

19. The method according to any one of claims 12 - 18, characterized in that The catalyst is ZSM-5 molecular sieve.

20. The method according to any one of claims 12-19, characterized in that, In the fluidized bed regenerator, the regeneration gas contacts with the catalyst, fuel enters the bottom of the fluidized bed regenerator from the fuel distributor, the regeneration gas and the fuel burn after contact, and 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.

21. The method according to any one of claims 12 - 20, characterized in that, The regeneration gas is air, and the fuel is diesel.

22. The method according to any one of claims 12-21, characterized in that, The process operating conditions of the fluidized bed regenerator are as follows: the apparent gas linear velocity is 0.5 - 2.0 m / s, the regeneration temperature is 600 - 750 °C, the regeneration pressure is 50 - 250 kPa, and the bed density is 200 - 800 kg / m 3 .

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