阅读说明：本技术 催化裂化方法及催化裂化装置 (Catalytic cracking method and catalytic cracking apparatus ) 是由 闫鸿飞 孙世源 孟凡东 张亚西 武立宪 张瑞风 杨鑫 于 2020-07-15 设计创作，主要内容包括：本发明公开了催化裂化方法及催化裂化装置,涉及石油炼制技术领域。催化裂化方法包括：将重油原料和重油催化剂在重油反应器内反应,将产物与重油待生催化剂进行气固分离后,将重油待生催化剂在第一再生区再生；将轻烃原料和轻烃催化剂在轻烃反应器内反应,将产物与轻烃待生催化剂进行气固分离后,将轻烃待生催化剂在第二再生区再生。催化裂化装置通过重油反应器进行重油原料的反应,经气固分离后输送至第一再生区进行再生,通过轻烃反应器进行轻烃原料的反应,经气固分离后输送至第二再生区进行再生。通过分区反应、分区再生的方式,避免了重油催化剂和轻烃催化剂的接触,彻底解决了重油催化剂和轻烃催化剂分离不彻底的问题。(The invention discloses a catalytic cracking method and a catalytic cracking device, and relates to the technical field of petroleum refining. The catalytic cracking method comprises the following steps: reacting a heavy oil raw material with a heavy oil catalyst in a heavy oil reactor, carrying out gas-solid separation on a product and the heavy oil spent catalyst, and regenerating the heavy oil spent catalyst in a first regeneration zone; the light hydrocarbon raw material and the light hydrocarbon catalyst are reacted in a light hydrocarbon reactor, the product and the light hydrocarbon spent catalyst are subjected to gas-solid separation, and the light hydrocarbon spent catalyst is regenerated in a second regeneration zone. The catalytic cracking device is used for carrying out reaction on heavy oil raw materials through a heavy oil reactor, conveying the heavy oil raw materials to a first regeneration area for regeneration after gas-solid separation, carrying out reaction on light hydrocarbon raw materials through a light hydrocarbon reactor, and conveying the light hydrocarbon raw materials to a second regeneration area for regeneration after gas-solid separation. The contact between the heavy oil catalyst and the light hydrocarbon catalyst is avoided by the way of zone reaction and zone regeneration, and the problem of incomplete separation of the heavy oil catalyst and the light hydrocarbon catalyst is thoroughly solved.)

1. A catalytic cracking process, characterized in that it is carried out in a catalytic cracking unit comprising a heavy oil reactor, a light oil reactor and a regenerator having a first regeneration zone and a second regeneration zone capable of independently regenerating the catalyst, comprising the steps of:

reacting a heavy oil raw material with a heavy oil catalyst in a heavy oil reactor, carrying out gas-solid separation on a product and the heavy oil spent catalyst, and regenerating the heavy oil spent catalyst in a first regeneration zone of the regenerator;

reacting light hydrocarbon raw materials with a light hydrocarbon catalyst in a light hydrocarbon reactor, carrying out gas-solid separation on a product and the light hydrocarbon spent catalyst, and regenerating the light hydrocarbon spent catalyst in a second regeneration zone of the regenerator.

2. The catalytic cracking method of claim 1, wherein oxygen-deficient regeneration is performed in the first regeneration zone, gas-solid separation is performed after the oxygen-deficient regeneration to obtain high-temperature flue gas, and the high-temperature flue gas is conveyed to the second regeneration zone to perform oxygen-enriched regeneration with the light hydrocarbon spent catalyst;

preferably, in the oxygen-deficient regeneration, the volume fraction of oxygen is 0.5-1%, and the volume fraction of carbon monoxide is 4-6%;

preferably, in the oxygen-rich regeneration, the volume fraction of oxygen is 2-5% and the carbon monoxide content is less than 100 ppm.

3. The catalytic cracking process of claim 1 or 2, wherein the regeneration temperature of the first regeneration zone and the second regeneration zone is 650-750 ℃;

preferably, the heavy oil spent catalyst and the light hydrocarbon spent catalyst are stripped respectively after gas-solid separation and before regeneration.

4. The catalytic cracking process of claim 1, wherein the heavy oil catalyst is a Y-type molecular sieve catalyst;

preferably, the heavy oil catalyst is selected from at least one of DASY molecular sieve, USY molecular sieve, REY molecular sieve, REHY molecular sieve and HY molecular sieve;

more preferably, the heavy oil catalyst is selected from at least one of rare earth-containing USY molecular sieves and rare earth-containing USY molecular sieves;

more preferably, the heavy oil feedstock has a hydrogen content of 9.5 to 13.0% and a carbon residue content of 1 to 7% by mass fraction.

5. The catalytic cracking method of claim 1 or 4, wherein the reaction temperature of the heavy oil reactor is 450-560 ℃, preferably 460-540 ℃, more preferably 480-530 ℃;

preferably, the reaction time of the heavy oil reactor is 0.6 to 5 seconds, more preferably 1.2 to 4.5 seconds, and even more preferably 1.5 to 4.0 seconds;

preferably, the reaction pressure of the heavy oil reactor is 0.05-0.35MPa, more preferably 0.08-0.32MPa, and further preferably 0.1-0.3 MPa;

preferably, the heavy oil reactor has a corresponding agent-to-oil ratio of 3-18:1, more preferably 5-15:1, and even more preferably 6-10: 1;

preferably, the heavy oil reactor is a riser reactor.

6. The catalytic cracking process of claim 1, wherein the light hydrocarbon feedstock is selected from at least one of straight run naphtha, catalytic gasoline, coker gasoline, reformate, hydrocracked naphtha, and tetracarbon hydrocarbons;

preferably, the light hydrocarbon catalyst is a ZSM series molecular sieve catalyst.

7. The catalytic cracking method of claim 1 or 6, wherein the reaction temperature of the light hydrocarbon reactor is 500-660 ℃, preferably 510-650 ℃, more preferably 530-640 ℃;

preferably, the reaction time of the light hydrocarbon reactor is 0.6 to 6.5 seconds, more preferably 1.2 to 6.0 seconds, and further preferably 1.5 to 5.5 seconds;

preferably, the reaction pressure of the light hydrocarbon reactor is 0.05-0.35MPa, more preferably 0.08-0.32MPa, and further preferably 0.1-0.3 MPa;

preferably, the ratio of the corresponding solvent to the oil of the light hydrocarbon reactor is 5-40:1, more preferably 7-35:1, and further preferably 9-30: 1;

preferably, the light hydrocarbon reactor is a riser reactor.

8. A catalytic cracking unit for carrying out the catalytic cracking process of any one of claims 1 to 7, comprising a heavy oil reaction unit, a light hydrocarbon reaction unit and a regenerator, the regenerator comprising a first regeneration zone and a second regeneration zone;

the heavy oil reaction device comprises a heavy oil reactor and a first settler which is communicated with the discharge end of the heavy oil reactor and is used for gas-solid separation, and a solid material outlet of the first settler is communicated with the first regeneration zone of the regenerator;

the light hydrocarbon reaction device comprises a light hydrocarbon reactor and a second settler communicated with the discharge end of the light hydrocarbon reactor and used for gas-solid separation, and the solid material outlet of the second settler is communicated with the second regeneration zone of the regenerator.

9. The catalytic cracking apparatus of claim 8, wherein the second regeneration zone of the regenerator is located above the first regeneration zone, the catalytic cracking apparatus further comprising a first to-be-regenerated chute, a first regeneration chute, a second to-be-regenerated chute, and a second regeneration chute;

the bottom of the first regeneration area is provided with a main air inlet, two ends of the first inclined tube to be regenerated are respectively communicated with the solid outlet of the first settler and the feed inlet of the first regeneration area, and two ends of the first inclined tube to be regenerated are respectively communicated with the discharge outlet of the first regeneration area and the feed inlet of the heavy oil reactor;

and a regeneration zone gas-solid separator is arranged in each of the first regeneration zone and the second regeneration zone, a gas outlet of the regeneration zone gas-solid separator in the first regeneration zone is communicated with a bottom gas inlet of the second regeneration zone, two ends of the second inclined tube to be regenerated are respectively communicated with a solid outlet of the second settler and a feed inlet of the second regeneration zone, and two ends of the second inclined tube to be regenerated are respectively communicated with a discharge hole of the second regeneration zone and a feed end of the heavy oil reactor.

10. The catalytic cracking device of claim 9, wherein the inner cavities of the first settler and the second settler are respectively provided with a gas collection chamber and a gas-solid separator from top to bottom, a first stripper for stripping the catalyst obtained after the gas-solid separation is arranged below the first settler, and a second stripper for stripping the catalyst obtained after the gas-solid separation is arranged below the second settler;

the feeding end of the first inclined tube to be regenerated is communicated with the discharge hole of the first stripper, and the feeding end of the second inclined tube to be regenerated is communicated with the discharge hole of the second stripper.

Technical Field

The invention relates to the technical field of petroleum refining, in particular to a catalytic cracking method and a catalytic cracking device.

Background

At present, a catalytic cracking unit can produce about 70% of motor gasoline and about 30% of motor diesel, and is one of the most important sources of profits of oil refining enterprises. The new market situation requires the continuous technical upgrading of the catalytic cracking process, which mainly has two directions: one is to produce more propylene-based low-carbon olefins, and the other is to produce more BTX-based aromatics.

The domestic developed catalytic cracking propylene production process mainly comprises the following steps: deep Catalytic Cracking (DCC), liquefied gas and gasoline rich catalytic cracking (MGG), liquefied gas and diesel maximum catalytic cracking (MGD), isoparaffin rich catalytic cracking (MIP), flexible multi-effect catalytic cracking (fdfdd), two-riser fcc, and fcc (two-riser catalytic cracking for propylene rich) processes. The foreign developed catalytic cracking propylene production process mainly comprises the following steps: SCC (selective catalytic cracking) process, petroFCC process, MAXOFIN process, INDAX process, HS-FCC (high-sensitivity fluidic cracking) process. Of these processes, many continue to use the riser reactor configuration while employing more severe reaction conditions, such as the DCC process, MGG, and ARGG processes; there are also gasoline fractions recycled to the riser reactor, such as MGD process, SCC process.

The raw material for catalytic cracking and high propylene yield comprises heavy oil and light oil, wherein the pore diameter of the catalyst required for cracking large molecules of the heavy oil is larger, and the pore diameter of the catalyst required for cracking small molecules of the light oil is smaller. For the same catalyst, it is difficult to achieve the above properties simultaneously, and this is often considered. In order to make up for the defect that the same catalyst cannot give consideration to multiple performances, the current method is to use two catalysts, but in a dual-catalyst system, the problem that different catalysts are difficult to completely separate in the catalyst regeneration process exists.

Disclosure of Invention

The invention aims to provide a catalytic cracking method, aiming at solving the problem of incomplete catalyst separation.

The invention also aims to provide a catalytic cracking device, which aims to thoroughly solve the problem of incomplete catalyst separation by a zone reaction and zone regeneration mode.

The technical problem to be solved by the invention is realized by adopting the following technical scheme.

The invention provides a catalytic cracking method.A catalytic cracking device comprises a heavy oil reactor, a light oil reactor and a regenerator, wherein the regenerator is provided with a first regeneration zone and a second regeneration zone which can independently regenerate a catalyst, and the catalytic cracking method comprises the following steps:

reacting a heavy oil raw material with a heavy oil catalyst in a heavy oil reactor, carrying out gas-solid separation on a product and the heavy oil spent catalyst, and regenerating the heavy oil spent catalyst in a first regeneration zone;

the light hydrocarbon raw material and the light hydrocarbon catalyst are reacted in a light hydrocarbon reactor, the product and the light hydrocarbon spent catalyst are subjected to gas-solid separation, and the light hydrocarbon spent catalyst is regenerated in a second regeneration zone.

The invention also provides a catalytic cracking device, which comprises a heavy oil reaction device, a light hydrocarbon reaction device and a regenerator, wherein the regenerator comprises a first regeneration area and a second regeneration area;

the heavy oil reaction device comprises a heavy oil reactor and a first settler which is communicated with the discharge end of the heavy oil reactor and used for gas-solid separation, and a solid material outlet of the first settler is communicated with a first regeneration zone of the regenerator;

the light hydrocarbon reaction device comprises a light hydrocarbon reactor and a second settler which is communicated with the discharge end of the light hydrocarbon reactor and is used for gas-solid separation, and a solid material outlet of the second settler is communicated with a second regeneration area of the regenerator.

The embodiment of the invention provides a catalytic cracking method, which has the beneficial effects that: the heavy oil raw material and the heavy oil catalyst are reacted in a heavy oil reactor, the light hydrocarbon raw material and the light hydrocarbon catalyst are reacted in the light hydrocarbon reactor, products corresponding to the heavy oil raw material and the light hydrocarbon catalyst are subjected to gas-solid separation after the reaction, and then the heavy oil spent catalyst and the light hydrocarbon spent catalyst are regenerated in a first regeneration area and a second regeneration area respectively. The inventor creatively adopts a zone reaction and zone regeneration mode, avoids the mixing of the heavy oil catalyst and the light hydrocarbon catalyst, and prevents the two catalysts from contacting in the whole reaction and regeneration processes, thereby avoiding the problem that the heavy oil catalyst and the light hydrocarbon catalyst are difficult to completely separate after being mixed.

It is emphasized that the separation of the heavy oil catalyst and the light hydrocarbon catalyst requires a significant difference in particle size and density between the two catalysts, but the two catalysts with too large a difference cannot be circulated and fluidized in the device after being mixed, so that the separation problem of the catalysts has long eluded those skilled in the art. The inventor creatively adopts the technical scheme of zone reaction and zone regeneration, and thoroughly solves the technical problem.

Meanwhile, in the technical scheme of the zone reaction and zone regeneration provided by the invention, the technical scheme of oxygen-poor regeneration and flue gas series connection is creatively adopted, the flue gas rich in carbon monoxide enters another regeneration zone for complete regeneration, the ZSM catalyst is kept at a higher temperature by the released heat, sufficient heat energy is provided for light hydrocarbon cracking, the defect of the self heat capacity of the flue gas is made up, and energy coupling is realized.

The embodiment of the invention also provides a catalytic cracking device, which is characterized in that a heavy oil reactor in a heavy oil reaction device is used for carrying out the reaction of heavy oil raw materials, a first settler is used for carrying out gas-solid separation, then the spent heavy oil catalyst is conveyed to a first regeneration zone of a regenerator for regeneration, a light hydrocarbon reactor in a light hydrocarbon reaction device is used for carrying out the reaction of light hydrocarbon raw materials, and then the spent light hydrocarbon catalyst is conveyed to a second regeneration zone of the regenerator for regeneration after the gas-solid separation is carried out in a second settler. The invention avoids the contact between the heavy oil catalyst and the light hydrocarbon catalyst by means of zone reaction and zone regeneration, and thoroughly solves the problem of incomplete separation of the heavy oil catalyst and the light hydrocarbon catalyst.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic diagram of a catalytic cracking unit according to an embodiment of the present invention;

FIG. 2 is a schematic view showing the structure of a catalytic cracking apparatus according to a comparative example of the present invention.

Icon: 100-a catalytic cracking unit; 20-lifting dry gas; 30-heavy oil feedstock feed line; 40-a reaction product line; 50-main wind; 60-a regenerated flue gas line; 70-lifting dry gas; 80-light hydrocarbon feedstock feed line; 90-a reaction product line; 101-gas collecting chamber; 102-top spin; 103-coarse spinning; 110-heavy oil reaction unit; 111-heavy oil reactor; 112-a first settler; 113-a first stripper; a 120-light hydrocarbon reaction unit; a 121-light hydrocarbon reactor; 122-a second settler; 123-a second stripper; 130-a regenerator; 131-a first regeneration zone; 132-a second regeneration zone; 133-primary cyclone separator; 134-secondary cyclone separator; 135-three stage cyclone separator; 136-four stage cyclone separator; 140-a first inclined tube to be grown; 150-a first regeneration chute; 160-a second inclined tube to be grown; 170-a second regenerative chute; 1-lifting dry gas; 2-a heavy oil feedstock feed line; 3-heavy oil riser reactor; 4-a settler; 5-a settler cyclone; 6-regenerator heat exchanger; 7-a regenerator cyclone; 8-a regenerator; 9-a stripping section; 10-a gas collection chamber; 11-regeneration inclined tube; 12-regeneration inclined tube; 13-lifting dry gas; 14-gasoline riser reactor; 15-a reaction product stream; a 16-light hydrocarbon feed line.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The following provides a detailed description of the catalytic cracking method and catalytic cracking apparatus provided in the embodiments of the present invention.

The embodiment of the invention provides a catalytic cracking method, wherein a catalytic cracking device comprises a heavy oil reactor, a light oil reactor and a regenerator, the regenerator is provided with a first regeneration zone and a second regeneration zone which can independently regenerate a catalyst, and the catalytic cracking method comprises the following steps: reacting a heavy oil raw material with a heavy oil catalyst in a heavy oil reactor, carrying out gas-solid separation on a product and the heavy oil spent catalyst, and regenerating the heavy oil spent catalyst in a first regeneration zone of a regenerator; the light hydrocarbon raw material and the light hydrocarbon catalyst are reacted in a light hydrocarbon reactor, the product and the light hydrocarbon spent catalyst are subjected to gas-solid separation, and the light hydrocarbon spent catalyst is regenerated in a second regeneration zone of the regenerator.

It should be noted that, the inventor creatively adopts a way of zone reaction and zone regeneration, avoids the mixing of the heavy oil catalyst and the light hydrocarbon catalyst, and prevents the two catalysts from contacting in the whole reaction and regeneration process, thereby thoroughly solving the problem of incomplete separation of the heavy oil catalyst and the light hydrocarbon catalyst.

The method of the invention has the following two advantages: (1) in one set of catalytic cracking device, two different reactors are respectively arranged, two different raw materials and two different catalysts are respectively in contact reaction in the two reactors, so that the high matching of the raw materials, the catalysts, the reactors and the process conditions is realized, and the purpose of maximizing the target product is achieved. (2) The method of the invention is provided with two regenerant regeneration zones, two different catalysts are burnt and regenerated in different regeneration zones, the problem of difficult subsequent catalyst separation caused by catalyst mixing can be avoided, and the catalyst circulation fluidization is easy to carry out, and the stable operation of the device can not be influenced.

In some embodiments, the heavy oil reactor and the light hydrocarbon reactor may be riser reactors, which can further increase the yield of the desired product.

The heavy oil raw material and the light hydrocarbon raw material can be common catalytic cracking raw materials, and the heavy oil raw material has 9.5-13.0% of hydrogen content and 1-7% of carbon residue in percentage by mass. The light hydrocarbon raw material is at least one of straight-run naphtha, catalytic gasoline, coking gasoline, reformed topping oil, hydrocracked naphtha and hydrocarbon.

Specifically, the heavy oil catalyst is a Y-type molecular sieve catalyst; preferably, the heavy oil catalyst is selected from at least one of DASY molecular sieve, USY molecular sieve, REY molecular sieve, REHY molecular sieve and HY molecular sieve; more preferably, the heavy oil catalyst is selected from at least one of rare earth-containing USY molecular sieves and rare earth-containing USY molecular sieves. Preferably, the light hydrocarbon catalyst is a ZSM series molecular sieve catalyst. The inventors have improved the yield of the target product by further optimizing the selection of the heavy oil catalyst and the light hydrocarbon catalyst.

In order to further improve the yield of the target product, the inventor controls the operation parameters of the heavy oil reactor, and the reaction temperature of the heavy oil reactor is 450-560 ℃, preferably 460-540 ℃, and more preferably 480-530 ℃; the reaction time of the heavy oil reactor is 0.6 to 5 seconds, preferably 1.2 to 4.5 seconds, more preferably 1.5 to 4.0 seconds; the reaction pressure of the heavy oil reactor is 0.05-0.35MPa, preferably 0.08-0.32MPa, and more preferably 0.1-0.3 MPa; the heavy oil reactor corresponds to a ratio of agent to oil of 3 to 18:1, more preferably 5 to 15:1, and even more preferably 6 to 10: 1. The reaction temperature, the reaction time, the reaction pressure and the catalyst-oil ratio are controlled in an optimal range, so that the conversion rate of the heavy oil raw material can be remarkably improved, and the utilization rate of the raw material is improved.

It should be noted that the "catalyst-to-oil ratio" mentioned in the examples of the present invention refers to the weight ratio of the catalyst circulation amount to the feeding amount; all references to "reaction pressure" in the examples of the present invention refer to gauge pressure.

Further, in order to improve the yield of the target product, the inventors also control the operation parameters of the light hydrocarbon reactor, and the reaction temperature of the light hydrocarbon reactor is 500-660 ℃, preferably 510-650 ℃, and more preferably 530-640 ℃; the reaction time of the light hydrocarbon reactor is 0.6-6.5 seconds, preferably 1.2-6.0 seconds, and more preferably 1.5-5.5 seconds; the reaction pressure of the light hydrocarbon reactor is 0.05-0.35MPa, preferably 0.08-0.32MPa, and more preferably 0.1-0.3 MPa; the light hydrocarbon reactor has a corresponding agent-to-oil ratio of 5-40:1, preferably 7-35:1, and more preferably 9-30: 1.

The inventor realizes the coupling of energy through the main wind series connection in the regeneration link. And carrying out oxygen-deficient regeneration in the first regeneration zone, carrying out gas-solid separation after the oxygen-deficient regeneration to obtain high-temperature flue gas, and conveying the high-temperature flue gas to the second regeneration zone to carry out oxygen-enriched regeneration with the light hydrocarbon spent catalyst. The high-temperature flue gas generated in the first regeneration area is combusted again in the second regeneration area to provide heat for the light hydrocarbon spent catalyst, so that the shortage of heat caused by low coke content of the spent catalyst is overcome.

Preferably, the regeneration temperature of the first regeneration zone and the second regeneration zone is 650-750 ℃; in the oxygen-deficient regeneration, the volume fraction of oxygen is 0.5-1%, and the volume fraction of carbon monoxide is 4-6%; in oxygen-enriched regeneration, the volume fraction of oxygen is 2-5%, and the content of carbon monoxide is less than 100 ppm. The inventor further improves the regeneration effect by optimizing the atmosphere condition and the regeneration temperature in the regeneration link, so that the carbon content of the regenerated catalyst is generally 0.02-0.2 wt%.

In some embodiments, the heavy oil spent catalyst and the light hydrocarbon spent catalyst are stripped separately after the gas-solid separation and before regeneration. The stripping process is a conventional operation of the carbon deposition catalyst, and the working conditions and the principle thereof are not described in detail herein.

The catalytic cracking method provided by the invention also has the following advantages: (1) the two regeneration zones are connected in series through flue gas, the lower regeneration zone is subjected to oxygen-deficient incomplete regeneration, the flue gas rich in carbon monoxide enters the upper regeneration zone for complete regeneration, and the released heat keeps the ZSM-5 catalyst at a higher temperature, so that sufficient heat energy is provided for light hydrocarbon cracking, the cracking depth of the light hydrocarbon is improved, and the yield of low-carbon olefin is increased. (2) The invention makes full use of the heat released by burning coke generated by heavy oil cracking through the technical means of flue gas series connection and zone regeneration, does not need a heat exchanger arranged outside a conventional catalytic cracking device for supplying heat, and saves the operation cost of the device.

Referring to fig. 1, an embodiment of the present invention further provides a catalytic cracking apparatus 100 for implementing the catalytic cracking method, including a heavy oil reaction device 110, a light hydrocarbon reaction device 120, and a regenerator 130, wherein the heavy oil reaction device 110 and the light hydrocarbon reaction device 120 respectively perform catalytic cracking on a heavy oil raw material and a light hydrocarbon raw material, and separate a product from a catalyst, and the regenerator 130 regenerates the separated catalyst.

Further, the regenerator 130 comprises a first regeneration zone 131 and a second regeneration zone 132, the heavy oil reaction device 110 comprises a heavy oil reactor 111 and a first settler 112 communicated with the discharge end of the heavy oil reactor 111 for gas-solid separation, and the solid material outlet of the first settler 112 is communicated with the first regeneration zone 131 of the regenerator 130; the light hydrocarbon reaction device 120 comprises a light hydrocarbon reactor 121 and a second settler 122 communicated with the discharge end of the light hydrocarbon reactor 121 and used for gas-solid separation, and the solid material outlet of the second settler 122 is communicated with a second regeneration zone 132 of the regenerator 130. The mode of zone reaction and zone regeneration is adopted, the mixing of the heavy oil catalyst and the light hydrocarbon catalyst is avoided, the two catalysts are not contacted in the whole reaction and regeneration processes, and the two catalysts after regeneration can respectively return to the reactor for the next cycle reaction.

Specifically, a gas collection chamber 101 and gas-solid separators (namely a coarse cyclone 103 and a top cyclone 102) are arranged in the first settler 112 and the second settler 122 from top to bottom, a first stripper 113 for stripping the catalyst obtained after the gas-solid separation is arranged below the first settler 112, and a second stripper 123 for stripping the catalyst obtained after the gas-solid separation is arranged below the second settler 122; the feeding end of the first to-be-grown inclined pipe 140 is communicated with the discharge hole of the first stripper 113, and the feeding end of the second to-be-grown inclined pipe 160 is communicated with the discharge hole of the second stripper 123. The coarse cyclone 103 and the top cyclone 102 are two cyclones for separating the reaction product and the heavy oil spent catalyst, and the two cyclones can be connected through a hose.

Further, the second regeneration zone 132 of the regenerator is located above the first regeneration zone 131, and the catalytic cracking unit 100 further includes a first to-be-regenerated inclined tube 140, a first regeneration inclined tube 150, a second to-be-regenerated inclined tube 160, and a second regeneration inclined tube 170; the bottom of the first regeneration zone 131 is provided with a main air inlet (i.e. the position of the main air 50 in fig. 1), two ends of the first inclined tube to be regenerated 140 are respectively communicated with the solid outlet of the first settler 112 and the feed inlet of the first regeneration zone 131, and two ends of the first inclined tube to be regenerated 150 are respectively communicated with the discharge outlet of the first regeneration zone 131 and the feed inlet of the heavy oil reactor 111. The heavy oil spent catalyst is conveyed to the first regeneration zone 131 through the first spent inclined tube 140, and the regenerated catalyst is returned to the heavy oil reactor 111 through the first regeneration inclined tube 150, so that the cyclic utilization of the catalyst is realized.

Further, regeneration zone gas-solid separators are arranged in the first regeneration zone 131 and the second regeneration zone 132, a gas outlet of the regeneration zone gas-solid separator in the first regeneration zone 131 is communicated with a bottom gas inlet of the second regeneration zone 132, two ends of the second inclined tube to be regenerated 160 are respectively communicated with a solid outlet of the second settler 122 and a feed inlet of the second regeneration zone 132, and two ends of the second inclined tube to be regenerated 170 are respectively communicated with a discharge hole of the second regeneration zone 132 and a feed end of the heavy oil reactor 111. Specifically, the regeneration zone gas-solid separators in the first regeneration zone 131 and the second regeneration zone 132 are the primary cyclone 133, the secondary cyclone 134, the tertiary cyclone 135, and the quaternary cyclone 136 in fig. 1.

It should be noted that, heavy oil enters the heavy oil reactor 111 through the heavy oil raw material feeding pipeline 30, contacts with a catalyst carried by the lifted dry gas 20, and undergoes a catalytic cracking reaction, a reaction product and the catalyst enter the first settler 112 together, the separation of the reaction product and the spent catalyst is realized through the rough cyclone 103 and the top cyclone 102, and the reaction product enters the plenum 101 and then enters the next operation unit through the reaction product pipeline 40; the spent catalyst enters a first regeneration zone 131 through a first spent inclined tube 140 after being stripped, contacts with main air 50 (air) to be subjected to oxygen-deficient coke burning regeneration, the regenerated catalyst returns to the bottom of the heavy oil reactor 111 through a first regeneration inclined tube 150, and the regenerated flue gas enters a second regeneration zone 132 after passing through a primary cyclone separator 133 and a secondary cyclone separator 134.

It should be noted that light hydrocarbons enter the light hydrocarbon reactor 121 through the light hydrocarbon raw material feeding pipeline 80, contact with the catalyst carried by the lifted dry gas 70, and undergo a catalytic cracking reaction, and the reaction product and the catalyst enter the second settler 122 together, and are separated from the spent catalyst through the coarse cyclone 103 and the top cyclone 102, and enter the gas collection chamber 101 and then enter the next operation unit through the reaction product pipeline 90; the spent catalyst enters the second regeneration zone 132 through the second spent inclined tube 160 after being stripped, contacts with the regenerated flue gas from the first regeneration zone 131 to carry out oxygen-enriched scorching regeneration, the regenerated catalyst returns to the bottom of the light hydrocarbon reactor 121 through the second regeneration inclined tube 170, and the regenerated flue gas enters the next operation unit through the regenerated flue gas pipeline 60 after passing through the third-stage cyclone separator 135 and the fourth-stage cyclone separator 136.

The features and properties of the present invention are described in further detail below with reference to examples.