CN117186936A

CN117186936A - Catalytic cracking reaction method and system for heavy raw oil

Info

Publication number: CN117186936A
Application number: CN202210613510.0A
Authority: CN
Inventors: 龚剑洪; 魏晓丽; 张执刚; 王迪
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2022-05-31
Filing date: 2022-05-31
Publication date: 2023-12-08

Abstract

The application relates to a catalytic cracking reaction method and a catalytic cracking reaction system for heavy raw oil, wherein the catalytic cracking reaction system comprises a catalytic cracking reactor, a coke generator, an oil agent separation device, a sedimentation stripper and a regenerator. The method comprises the following steps: 1) carrying out catalytic cracking reaction on heavy raw oil to obtain a first reaction product and a first spent catalyst, 2) introducing a raw coke raw material into a coke generator to carry out a coking reaction to obtain a second reaction product and a second catalyst, 3) introducing the first reaction product and the second reaction product into a separation system to separate, 4) conveying the first spent catalyst and the second spent catalyst to a regenerator to carry out coking regeneration, and respectively returning the obtained regenerated catalyst to the bottoms of the catalytic cracking reactor and the coke generator for recycling. When the catalytic cracking method and the system of the application are adopted, the coke source can be provided for the regeneration process when the yield of ethylene and propylene is improved, the problem of reaction heat balance is solved, the regeneration process is not influenced, and the physical and chemical properties of the catalyst are not damaged.

Description

Catalytic cracking reaction method and system for heavy raw oil

Technical Field

The application relates to the technical field of fluidized catalytic cracking, in particular to a reaction method and a reaction system suitable for catalytic cracking of heavy raw oil.

Background

The fluidized catalytic cracking reaction process is an autothermal equilibrium process, and the catalyst scorching regeneration process releases a large amount of heat energy at high temperature so as to just meet the requirements of the cracking reaction process at lower temperature. The catalyst circulating between the reactor and the regenerator has a sufficient amount and heat capacity so that the catalyst can act as both an active site for the reaction and a heat carrier for transferring heat energy. The catalyst flows between the reactor and the regenerator, constantly taking heat from one end and supplying heat to the other. The establishment of the thermal equilibrium requires certain conditions on the basis of which the cracking and regeneration are maintained up to the prescribed temperature. For a catalytic cracking industry, the thermal balance between the reactor and the regenerator is based on the fact that the reaction produces sufficient coke that burns during regeneration to release heat for the reaction.

Catalytic cracking processes typically employ feedstocks having relatively high hydrogen content, such as vacuum wax oils or atmospheric residuum of paraffinic crude oils. Although high-quality catalytic cracking raw materials can obtain higher low-carbon olefin yield, the coke generation amount is insufficient, the heat required by the catalytic cracking reaction cannot be met, and the raw materials need to be externally supplemented. Along with the development of oil refining technology, particularly the heavy/inferior trend of crude oil is aggravated, and the quality of oil is improved, so that the hydrogenation technology is widely applied. When the raw material subjected to hydrogenation upgrading is used as a catalytic cracking raw material, although the structure and quality of the product are greatly improved, the catalytic cracking device is also insufficient in coking, so that the problem of insufficient heat supply is caused. In addition, in the catalytic cracking technology using low-carbon olefin as a main target product, the cracking reaction conversion rate is high, the reaction temperature is high, the reaction heat is large, more heat is required in the reaction aspect than that of a conventional fluidized catalytic regenerator or other catalytic conversion methods, and the coke generated by self-cracking cannot always meet the self-heat balance requirement of a reaction-regeneration system. When coke formation is insufficient in the reaction process, the required heat is usually provided for the reaction by adopting a mode of slurry oil recycling or fuel oil supplementing outside the regenerator. Because the slurry oil contains more polycyclic aromatic hydrocarbon, the slurry oil is easy to adsorb in the active center of the catalyst, the accessibility of the active center of raw material molecules is influenced, and the catalytic reaction selectivity is influenced. To solve this problem, the prior art solutions start from a regenerator system, such as an oxygen-deficient area arranged in the regenerator, and introduce fuel oil into the oxygen-deficient area to mix with the catalyst, and enter the regenerator to burn and regenerate; or disposing a heater within the regenerator and employing a fuel nozzle configured to inject a mixture of fuel and an oxygen-containing gas for combustion of supplemental heat; or injecting methane, and supplementing heat for the reaction by means of the combustion heat release of methane. The heat supplementing mode in the technology can relieve adverse effects on the catalyst, but does not fundamentally solve the influence of high-temperature hot spots generated by local combustion of the external fuel oil on the skeleton structure and the reaction performance of the catalyst.

Disclosure of Invention

The application aims to provide a catalytic cracking reaction method and a catalytic cracking reaction system for heavy raw oil, which have higher ethylene and propylene selectivity, provide a required coke source for a regeneration process, solve the problem of heat balance in the catalytic cracking reaction process from the aspect of reaction, and do not influence the physical and chemical properties of a catalyst.

In one aspect, the present application provides a catalytic cracking reaction-regeneration system comprising:

a catalytic cracking reactor, wherein the catalyst is a catalyst,

a coke-producing device,

an oil agent separating device is provided with a plurality of oil agent separating devices,

a sedimentation stripper, and

the regeneration device comprises a regenerator, a first heat exchanger, a second heat exchanger, a third heat exchanger and a,

the catalytic cracking reactor is provided with a lifting medium inlet, a regenerated catalyst inlet, a cracking raw oil inlet and an oil agent outlet;

the oil agent outlet of the catalytic cracking reactor is communicated with the oil agent separation equipment, so that the oil agent of the catalytic cracking reactor enters the oil agent separation equipment to be separated into a first reaction product and a first spent catalyst;

the coke generator is coaxially arranged with the sedimentation stripper, and the coke generator sequentially comprises:

a pre-lifting area is provided for the pre-lifting area,

a coking reaction zone which is a bubbling fluidized bed or a turbulent fluidized bed, and

an outlet region for the fluid to flow from the fluid outlet,

the top end of the pre-lifting area is communicated with the coking reaction area, and the top end of the coking reaction area is communicated with the outlet area;

At least one fuel oil feed inlet is arranged at the upstream of the coking reaction zone;

the outlet area of the coke generator is communicated with the oil agent separation equipment, so that the materials of the coke generator enter the oil agent separation equipment to be separated into a second reaction product and a second spent catalyst;

the oil agent separation device is accommodated in the settling stripper, so that the first spent catalyst and the second spent catalyst separated by the oil agent separation device settle in the settling stripper; and, the sedimentation stripper is in communication with the regenerator such that the first spent catalyst and the second spent catalyst within the sedimentation stripper are transported to the regenerator;

the regenerator is provided with a first regenerated catalyst outlet and a second regenerated catalyst outlet, the first regenerated catalyst outlet being in communication with the regenerated catalyst inlet of the catalytic cracking reactor such that at least a portion of the regenerated catalyst is recycled back to the catalytic cracking reactor;

the bottom end of the pre-lift zone of the coke breeder and/or the bottom end of the coke breeder reaction zone is configured to communicate with a second regenerated catalyst outlet of a regenerator for delivering at least a portion of the regenerated catalyst of the regenerator to the coke breeder.

In one embodiment, the coke generator is provided with the pre-lifting gas inlet, the catalyst inlet and the raw coke inlet in sequence from bottom to top.

In one embodiment, the raw coke inlets are each independently disposed upstream of the coke breeder; preferably, the distance of the raw coke inlet from the bottom of the coke generator is 5% to 15% of Jiao Qigao degrees each independently.

In one embodiment, the green coke reaction zone is hollow cylindrical with an aspect ratio of 20:1 to 2:1, a step of;

in one embodiment, the pre-lift region is hollow cylindrical with an aspect ratio of 10:1-2:1, a step of;

the outlet zone is hollow cylindrical with an aspect ratio of 30:1-5:1.

in one embodiment, the ratio of the inner diameters of the pre-lift zone, the raw coke reaction zone, and the exit zone is 1:2:1 to 1:10:2.

in another aspect, the present application also provides a catalytic cracking method for heavy feedstock, the method comprising:

1) Introducing heavy raw oil into a catalytic cracking reactor, contacting with a regenerated catalyst from a regenerator and performing catalytic cracking reaction to obtain a first reaction product and a first spent catalyst,

2) Introducing raw coke raw material from the lower part of a coke generator to contact with regenerated catalyst from the regenerator and carrying out coke generation reaction from bottom to top to obtain a second reaction product and a second catalyst,

3) Introducing the first reaction product and the second reaction product into a separation system for separation,

4) And conveying the first spent catalyst and the second spent catalyst to a regenerator for burning regeneration, and returning the obtained regenerated catalyst to the catalytic cracking reactor and the bottom of the coke generator for recycling.

In one embodiment, the conditions of the catalytic cracking reaction include: the reaction temperature is 510-650 ℃, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the oil is (3-30): 1, the weight ratio of the pre-lifting gas to the raw oil is (0.03-1.0): 1, the reaction pressure is 130-450 kilopascals.

In one embodiment, the conditions of the coking reaction include: the reaction temperature is 460-460 ℃, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the oil is (3-30): 1, the weight ratio of the pre-lifting gas to the raw coke is (0.01-0.5): 1, the linear velocity is 0.2 m/s to 1.2 m/s, and the catalyst particle density is 300 kg/cubic meter to 700 kg/cubic meter.

In one embodiment, the properties of the heavy feedstock oil meet one, two, three or four of the following criteria: the density at 20 ℃ is 850-920 kg/m ³ 0-2 wt% of carbon residue, a characteristic factor K value of more than 12.1, and a saturated hydrocarbon content of 60-100 wt%; preferably, the heavy raw oil is one or a mixture of more than one selected from petroleum hydrocarbon, non-petroleum hydrocarbon mineral oil, synthetic oil, animal fat and vegetable fat.

In one embodiment, the raw coke is a plant self-produced slurry and a secondary process distillate, or a mixture thereof; preferably, the secondary processing distillate oil can be selected from one or more of catalytic cracking diesel oil, catalytic cracking slurry oil, coker gasoline, coker diesel oil and coker wax oil; more preferably, the char-forming feedstock is a plant self-produced slurry.

In one embodiment, the process is carried out in the above-described catalytic cracking reaction-regeneration system of the present application.

The coke generator is added in the catalytic cracking reaction system, the coke generation reaction occurs in the coke generator, and the reaction oil generated by the cracking reactor and the reaction oil generated by the coke generator enter the settler together, so that the temperature of the mixed oil gas is reduced, and the overcracking reaction is reduced; the coke generator in the catalytic cracking reaction system also generates a catalyst with coke, and the catalyst with coke generated by the cracking reactor can enter a regeneration system for regeneration, so that the operation of the regeneration system is not influenced, the catalyst with coke has no local hot spot in the coke burning process of the regenerator, and the physical and chemical properties of the catalyst are not damaged. The reaction system has simple structure, easy implementation and strong applicability, can be suitable for catalytic cracking devices with insufficient raw coke, in particular to catalytic cracking devices with low-carbon olefin and other chemical raw materials as main target products, fundamentally solves the problem of heat balance of catalytic cracking reaction from the reaction system end, reduces the damage to the catalyst and the regeneration system caused by the traditional fuel oil spraying mode, saves the catalyst cost and improves the economic benefit of refineries.

Drawings

The accompanying drawings are included to provide a further understanding of the application, and are incorporated in and constitute a part of this specification, illustrate the application and together with the description serve to explain, without limitation, the application. In the drawings:

FIG. 1 is a schematic diagram of a coke oven;

FIG. 2 is a schematic diagram of one embodiment of a catalytic cracking system for heavy feedstock.

Detailed Description

The application is further described in detail below by means of the figures and examples. The features and advantages of the present application will become more apparent from the description.

The word "exemplary" is used herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are illustrated in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

In addition, the technical features described below in the different embodiments of the present application may be combined with each other as long as they do not collide with each other.

Any particular value disclosed herein (including the endpoints of the numerical ranges) is not limited to the precise value of the value, and is to be understood to also encompass values near the precise value, such as all possible values within the range of + -5% of the precise value. Also, for a range of values disclosed, any combination of one or more new ranges of values between the endpoints of the range, between the endpoints and the specific points within the range, and between the specific points is contemplated as being specifically disclosed herein.

In the present application, both the terms "upstream" and "downstream" are based on the flow direction of the reaction mass. For example, when the reactant stream flows from bottom to top, "upstream" means a location below, and "downstream" means a location above.

Unless otherwise indicated, terms used herein have the same meaning as commonly understood by one of ordinary skill in the art, and if a term is defined herein and its definition is different from the ordinary understanding in the art, then the definition herein controls.

The present application provides a catalytic cracking reaction-regeneration system, comprising:

a catalytic cracking reactor, wherein the catalyst is a catalyst,

a coke-producing device,

a sedimentation stripper, and

a regenerator.

The application also provides a catalytic cracking method of the heavy raw oil, which comprises the following steps:

3) Introducing the first reaction product and the second reaction yield into a separation system for separation to obtain dry gas, liquefied gas, pyrolysis gasoline, pyrolysis diesel oil and slurry oil,

FIG. 2 shows a catalytic cracking reaction-regeneration system of the present application. The catalytic cracking process of the present application is further described below in conjunction with the catalytic cracking reaction-regeneration system. The following description of the catalytic cracking process according to the application applies equally to the catalytic cracking reaction-regeneration system according to the application and vice versa.

The catalytic cracking reaction-regeneration system of the present application comprises:

the catalytic cracking reactor 100 is configured to operate,

the coke oven 300 is configured to receive a plurality of coke oven parameters,

the oil agent separating apparatus 201,

a sedimentation stripper 200, and

regenerator 500.

As shown in fig. 2, the catalytic cracking reactor 100 is provided with a pre-lift gas inlet 101, a lower cracking raw material inlet 102, a bottom catalyst inlet 103, and a top oil outlet 104. In the present application, the catalyst inlet 103 of the cracking reactor 100 is in fluid communication with the first regenerated catalyst outlet 508 of the regenerator 500 such that at least a portion of the regenerated catalyst is recycled back to the catalytic cracking reactor 100. The oil outlet 104 of the cracking reactor is in fluid communication with the oil inlet of the oil separation device 201, such that the oil of the catalytic cracking reactor enters the oil separation device to be separated into a first reaction product and a first spent catalyst. After the first reaction product is collected by the gas collection chamber 202, the first reaction product is introduced into a reaction product separation system (not shown) through an oil gas pipeline 203 to be separated, so as to obtain various products, such as dry gas, liquefied gas, pyrolysis gasoline, pyrolysis diesel oil, slurry oil and the like.

In the catalytic cracking system of the present application, the catalytic cracking reactor may be one or more, may be a combination of one catalytic cracking reactor of the present application and other existing catalytic cracking reactors, or may be a combination of a plurality of catalytic cracking reactors of the present application. The reactors may be connected in parallel and with an oil separation device.

The reaction product separation system can be provided with a reaction product inlet, a dry gas outlet, a liquefied gas outlet, a pyrolysis gasoline outlet, a pyrolysis diesel oil outlet and a pyrolysis heavy oil outlet, and is used for separating dry gas, liquefied gas, pyrolysis gasoline, pyrolysis diesel oil, pyrolysis heavy oil and the like according to the distillation range of the reaction product. And then the dry gas and the liquefied gas are further separated by a gas separation device to obtain methane, ethylene, propylene, mixed C4 components and the like, the pyrolysis gasoline is further separated to obtain pyrolysis light gasoline and heavy gasoline, and the method for separating ethylene, propylene and the like from the reaction product is similar to the conventional technical method in the field, and the application is not limited thereto and is not described in detail herein.

In one embodiment, the cracking reactor is selected from one or a combination of several of a fast bed, a dilute phase transport bed (riser), a dense phase fluidization reactor and a downer, or a combination of two or more of the same reactor, wherein the combination comprises series connection or/and parallel connection. The lifting pipe is one or more selected from the group consisting of an equal diameter lifting pipe, an equal linear speed lifting pipe and various variable diameter lifting pipes.

In one embodiment, the heavy feedstock oil is one or more mixtures selected from petroleum hydrocarbons, non-petroleum hydrocarbon mineral oils, synthetic oils, animal fats and oils, and vegetable fats and oils, which are well known to those skilled in the art, and may be, for example, vacuum wax oil, atmospheric residuum, vacuum residuum blended with vacuum wax oil, or other hydrocarbon oils obtained from secondary processing. And hydrocarbon oil obtained by other secondary processing, such as one or more of coker gas oil, deasphalted oil and furfural refined raffinate oil. The non-petroleum hydrocarbon mineral oil is selected from one or more of coal liquefied oil, oil sand oil and shale oil. The synthetic oil is distillate oil obtained by F-T synthesis of coal, natural gas or asphalt.

In one embodiment, the properties of the heavy feedstock oil meet one, two, three or four of the following criteria: the density at 20 ℃ is 850-920 kg/m ³ Carbon residue 0-2 wt%, characteristic factor K greater than 12.1, and saturated hydrocarbon content 60-100 wt%.

In one embodiment, the catalytic cracking catalyst comprises zeolite, inorganic oxide, and optionally clay. The catalyst comprises 1-60 wt% of zeolite, 5-99 wt% of inorganic oxide and 0-70 wt% of clay based on dry basis and dry basis weight of the catalyst. The zeolite comprises large pore zeolite and medium pore zeolite, wherein the large pore zeolite accounts for 50-80 wt% of the total weight of the zeolite, and the medium pore zeolite accounts for 20-50 wt% of the total weight of the zeolite. The medium pore zeolite is selected from ZSM series zeolite and/or ZRP zeolite, and the medium pore zeolite can be modified by non-metal elements such as phosphorus and/or transition metal elements such as iron, cobalt and nickel. For a more detailed description of ZRP zeolites see U.S. patent US5,232,675A. The ZSM series of zeolites is preferably selected from one or more of ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38, ZSM-48 and other zeolites of similar structure. For a more detailed description of ZSM-5, see U.S. patent US3,702,886A.

The macroporous zeolite is one or more selected from the group consisting of Rare Earth Y (REY), rare Earth Hydrogen Y (REHY), ultrastable Y obtained by different methods and high silicon Y.

According to the application, the inorganic oxide is selected from silica (SiO ₂ ) And/or aluminum oxide (Al) ₂ O ₃ ). The clay is selected from kaolin and/or halloysite as a matrix (i.e., carrier).

In one embodiment, the conditions for the catalytic cracking reaction of the heavy feedstock oil include: the reaction temperature is 510-650 ℃, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the oil is (3-30): 1, the weight ratio of the pre-lifting gas to the raw oil is (0.03-1.0): 1, the reaction pressure is 130-450 kilopascals.

In one embodiment, the heavy feedstock is introduced into the cracking reactor at one location or the feedstock is introduced into the cracking reactor at more than one same or different location.

In one embodiment, the C4 components separated from the reaction product are introduced into the cracking reactor as C4 component feedstock from one or more of the same or different locations for contact reaction with the catalytic cracking catalyst.

In the application, the C4 component refers to low-molecular hydrocarbon which takes C4 fraction as a main component and exists in a gas form at normal temperature and normal pressure, and the low-molecular hydrocarbon comprises alkane, alkene and alkyne with the carbon number of 4 in the molecule. It includes the gaseous hydrocarbon product enriched in the C4 fraction produced by the apparatus of the present application and may also include the gaseous hydrocarbon enriched in the C4 fraction produced by other apparatus processes, wherein the C4 fraction produced by the apparatus of the present application is preferred. The C4 hydrocarbons are preferably olefin-rich C4 fractions, wherein the content of C4 olefins is more than 50 wt.%, preferably more than 60 wt.%, most preferably more than 70 wt.%.

In one embodiment, the light gasoline component separated from the reaction product is introduced into the cracking reactor as a light gasoline feedstock from one or more of the same or different locations for contact reaction with a catalytic cracking catalyst.

In the application, the light gasoline refers to hydrocarbon with C5-C6 as a main component, and comprises alkane, alkene and small amount of aromatic hydrocarbon with the carbon number of 5 or 6 in the molecule. It includes the products of the application which are rich in C5-C6 fractions and can also include the products of other device processes which are rich in C5-C6 fractions, wherein the application is preferably used for producing light gasoline. The light gasoline is preferably an olefin-rich fraction, wherein the olefin content is greater than 50 wt%, preferably greater than 60 wt%.

As shown in FIG. 1, the catalytic pyrolysis coke generator 300 of the present application is suitable for regulating thermal equilibrium. The coke oven 300 comprises, in order from bottom to top: a pre-lifting zone I, a coking reaction zone II, and an outlet zone III.

The coke generator 300 is provided with a pre-lifting gas inlet 301, a catalyst inlet 303 and a coke raw material inlet 302 from bottom to top. The pre-lift gas inlet 301 is typically disposed at the pre-lift zone I and typically at the bottom of the pre-lift zone I. The catalyst inlet 303 may be disposed in the pre-lift zone I and/or the raw coke reaction zone II, but is typically disposed in the pre-lift zone I, below the pre-lift zone I, but above the pre-lift gas inlet 301, to enable the pre-lift gas to lift the incoming catalyst. Therefore, the regenerated catalyst can be pre-accelerated and pre-fluidized, the distribution condition of the catalyst is improved, and the catalyst is beneficial to uniform contact and rapid mixing with fuel oil.

The bottom of the regenerator 500 (shown in fig. 2) communicates with the coker 300 through a catalyst inlet 303 so that catalyst can enter the coker to be coked, resulting in a coked catalyst. The top of the coke generator 300 is communicated with the oil separating device 201, so that the catalyst with coke is separated from the reaction oil and gas.

In one embodiment, the pre-lift zone I, the green coke reaction zone II, and the exit zone III are connected in sequence, i.e., the top end of the pre-lift zone I is in communication with the green coke reaction zone II and the top end of the green coke reaction zone II is in communication with the exit zone III.

In the present application, the pre-lift gas inlet 301, the regenerated catalyst inlet 303, and the raw coke inlet 302, which are each independently provided on the coke breeder 300, are located at different heights of the coke breeder 300. Preferably, the coke generator 1 is provided with a pre-lifting gas inlet 301, a regenerated catalyst inlet 303 and a coke raw material inlet 302 in sequence from bottom to top, and all are positioned at the lower part of the coke generator 300.

In the present application, the reaction zone ii of the coke oven 300 is a bubbling bed or a turbulent fluidized bed. In one embodiment, the reaction zone ii is hollow cylindrical with an aspect ratio of 20:1 to 2:1.

in the present application, the coker can be provided with one or more, such as one, two, or more, coker feedstock inlets 302, which can each be independently provided at the outlet end of the coker pre-lift region I, or at the bottom or side walls of the coker reaction region II. Further preferably, the raw coke inlets 302 are each independently disposed upstream of the coke breeder 300. Further preferably, the distance h of the raw coke inlet 302 from the bottom of the coke maker is 5% to 15% of Jiao Qigao degrees each independently.

In the present application, the fuel oil injected through the raw coke feed inlet 302 may include straight distillate or secondary process distillate. Preferably, the secondary processing distillate oil can be selected from a mixed oil of one or more of catalytic pyrolysis diesel oil, catalytic pyrolysis slurry oil, coker gasoline, coker diesel oil and coker wax oil.

In one embodiment, the pre-lift region I is hollow cylindrical with an aspect ratio of 10:1-2:1. in one embodiment, the outlet zone III is hollow cylindrical with an aspect ratio of 30:1-5:1. in one embodiment, the ratio of the inner diameters of the pre-lift zone I, the raw coke reaction zone II, and the exit zone III is 1:2:1-:1:10:1.

in one embodiment, the coke breeder 300 is disposed coaxially with the sedimentation stripper 200 and below the oil separation device 201. The outlet area of the coke generator 300 is communicated with the oil separating device 201, so that the materials of the coke generator enter the oil separating device to be separated into oil gas and catalyst with coke. In one embodiment, the outlet end 304 of the coke oven 300 communicates with the inlet of the oil separation apparatus 201. In one embodiment, the oil separation apparatus 201 is housed inside the settling stripper 200 such that spent catalyst and coked catalyst separated by the oil separation apparatus 201 settle within the settling stripper 200.

In one embodiment, the settling stripper 200 includes a stripping section 205 located in a lower portion of the settling stripper, the stripping section 205 configured for stripping the collected coked catalyst and spent catalyst (i.e., first spent catalyst and second spent catalyst); and, the regenerator 500 is in communication with the stripping section 205 such that stripped first spent catalyst and second spent catalyst are conveyed to the regenerator 500. The lower part of the stripping section 205 is provided with a stripping gas inlet 207 for feeding a stripping gas, such as water vapour or the like.

It should be noted that, the oil separating device 201 is also connected to the outlet of the catalytic cracking reactor 100, so that the materials in the catalytic cracking reactor 100 are also separated by the oil separating device 201, and the separated spent catalyst enters the catalytic cracking regeneration system for regeneration cycle.

In one embodiment, the coke generator 300 is in fluid communication with the oil separating device 201, such that after the reaction oil and the catalyst with coke generated by the coke generator 300 are separated by the oil separating device 201, the reaction oil is collected by the gas collection chamber 202, and then introduced into the reaction product separating system for recycling through the oil gas pipeline 203, the catalyst with coke cloth enters the stripping section 205 at the lower part of the settling stripper 200, and is burnt by introducing into the regenerator 500 through the stand pipe 206 after stripping, and heat is released. In the present application, the oil separating apparatus 201 may employ an apparatus well known to those skilled in the art, such as a cyclone.

In one embodiment, the conditions of the coking reaction include: the reaction temperature is 460-460 ℃, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the oil is (3-30): 1, the weight ratio of the pre-lifting gas to the raw coke is (0.01-0.5): 1, the linear velocity is 0.2 m/s to 1.2 m/s, and the catalyst particle density is 300 kg/cubic meter to 700 kg/cubic meter. In one embodiment, the raw coke feedstock may be injected in an amount of 10 to 50% by weight of the total weight of the feedstock introduced into the catalytic cracking reactor.

In one embodiment, the raw coke is a plant self-produced slurry and a secondary process distillate, or a mixture thereof. Preferably, the secondary processed distillate oil can be selected from one or more of catalytic cracking diesel oil, catalytic cracking slurry oil, coker gasoline, coker diesel oil and coker wax oil. More preferably, the char-forming feedstock is a plant self-produced slurry.

In one embodiment, the raw coke is introduced into the coker at one location or at more than one same or different locations.

In one embodiment, the linear velocity of the reaction zone of the coke breeder is from 0.2 meters/second to 1.2 meters/second and the catalyst particle density is from 300 kilograms per cubic meter to 700 kilograms per cubic meter.

In one embodiment, the pre-lift gas is selected from steam, nitrogen, dry gas, rich gas or carbon four fraction or mixtures thereof, the mass ratio of the pre-lift gas to the fuel oil is 0.01:1 to 0.05:1.

in one embodiment, the raw coke feedstock comprises a straight run distillate or a secondary process distillate. Preferably, the secondary processing distillate oil can be selected from a mixed oil of one or more of catalytic pyrolysis diesel, coker gasoline, coker diesel and coker wax oil.

In one embodiment, the atomizing medium of the raw coke feedstock may be selected from steam, nitrogen, or mixtures thereof, the mass ratio of the atomizing medium to the combustion oil being 0.01:1 to 0.5:1.

in one embodiment, the exit temperature of the coke oven is 460-560 ℃.

As shown in fig. 2, the regenerator 500 is used for regenerating a spent catalyst, an oxygen-containing gas inlet 501, a spent catalyst inlet 505, two regenerated catalyst outlets 506 and outlets 508 are arranged at the lower part, a cyclone 503 is arranged inside, and a flue gas outlet 504 is arranged at the top.

As shown in fig. 2, the first regenerated catalyst outlet 508 communicates with the regenerated catalyst inlet 103 of the catalytic cracking reactor such that at least a portion of the regenerated catalyst is recycled back to the catalytic cracking reactor 100. In one embodiment, the bottom end of the pre-lift zone of the coke breeder and/or the bottom end of the coke breeder reaction zone is configured to communicate with a second regenerated catalyst outlet 506 of a regenerator for delivering at least a portion of the regenerated catalyst of the regenerator to the coke breeder. In one embodiment, a second regenerated catalyst outlet 506 (shown in FIG. 2) of the regenerator 500 communicates with the coker 300 through a catalyst inlet 303 such that catalyst can enter the coker to be coked, resulting in a coked catalyst. In one embodiment, a part of regenerated catalyst after regeneration is returned to the catalytic cracking reactor, and a part of regenerated catalyst after regeneration is returned to the coke generator for recycling, wherein the weight ratio of the regenerated catalyst recycled to the catalytic cracking reactor to the regenerated catalyst recycled to the coke generator can be 1:1 to 10:1, e.g., 2:1 to 10:1.

The conditions of the regenerator are: the regeneration temperature is 550-750deg.C, preferably 600-730 deg.C, more preferably 650-700 deg.C; the gas superficial linear velocity is 0.5 to 3 m/s, preferably 0.8 to 2.5 m/s, more preferably 1 to 2 m/s, and the average residence time of the spent catalyst is 0.6 to 3 minutes, preferably 0.8 to 2.5 minutes, more preferably 1 to 2 minutes.

In the catalytic cracking system provided by the application, the sedimentation stripper, the oil agent separation device, the regenerator, other devices, the reaction product separation system and the like can be devices which are well known to those skilled in the art, and the connection mode between the devices can also be performed according to the known mode in the art. For example, the oil separation device may comprise a cyclone separator, an outlet flash separator.

The catalytic cracking system comprises a coke generator, so that the coke-carrying catalyst from the coke generator and the spent catalyst from the catalytic cracking reactor can be regenerated in the regenerator together, heat is released, and the regenerated catalyst carrying the heat is circulated back to the catalytic cracking reactor to supply heat for the reaction. The catalytic cracking system is suitable for catalytic cracking of various raw materials with insufficient coke formation, such as the reaction of producing propylene or fuel oil by catalytic cracking of petroleum hydrocarbon and oxygenated hydrocarbon, or the reaction of producing low-carbon olefin by catalytic cracking. It should be noted that, although the coke generator in the catalytic cracking system of the present application also sprays the raw coke material, the main purpose of the raw coke material is not to be used as the raw oil for catalytic cracking, but to be used for supplementing coke on the catalyst, which is beneficial to the heat balance of the catalytic cracking reaction.

In the application, the coke forming device is arranged to enable the coke forming raw material to be mixed with the catalyst under the low-temperature and oxygen-free fluidization condition, and the coke forming reaction occurs in the coke forming reaction zone with the characteristics of a bubbling bed or a turbulent fluidized bed, so that the coke selectivity is high, the coke is uniformly distributed on the catalyst, and the uniform combustion in a regeneration system is facilitated.

In the application, the coke-carrying catalyst generated by the coke generator can be mixed with the coke-carrying catalyst generated by the catalytic cracking reactor to enter a regeneration system, and the catalyst is fully burnt and released under the action of high-temperature oxygen-enriched gas, so that the heat required by the reaction is supplied, the catalyst property is not damaged, the coke source is supplemented from the end of the reaction system, and the heat balance problem of the catalytic cracking device is solved.

The application has simple structure, only carries out the adaptability improvement through the reactor system, the regeneration system still adopts the prior art, is easy to implement, has strong applicability, and especially adopts the catalytic cracking device which takes the chemical raw materials such as low-carbon olefin and the like as main target products, thereby not only fundamentally solving the problem of heat balance, but also reducing the damage to the catalyst and the regeneration system caused by the traditional fuel oil spraying mode, saving the catalyst cost and improving the economic benefit of refineries.

The application will be further described with reference to the preferred embodiments shown in the drawings to which, however, the application is not limited.

FIG. 2 shows a preferred embodiment of the catalytic cracking reaction system of the present application.

The pre-lifting gas enters the cracking reactor from the bottom of the cracking reactor 100 through a pre-lifting gas inlet 101, and the high-temperature regenerated catalyst from the regenerator enters the lower part of the cracking reactor 100 through a catalyst inlet 103, is mixed with the pre-lifting gas and moves upwards, and contacts with the raw oil from a raw oil inlet 102 to perform catalytic cracking reaction; the catalyst with carbon and the generated oil gas flow upwards and enter the oil-gas separation equipment 201 through the outlet 104;

the pre-lifting gas enters the coke generator from the bottom of the coke generator 300 through a pre-lifting gas inlet 301, the high-temperature regenerated catalyst from the regenerator enters the lower part of the coke generator 300 through a catalyst inlet 303, and is mixed with the pre-lifting gas to move upwards, and the mixture contacts with the coke raw material from a coke raw material inlet 302 to enter the coke generator together for coke generation reaction; the catalyst with carbon and the generated oil gas flow upwards and enter the oil-gas separation equipment 201 through the outlet area 304;

the reaction oil gas separated by the oil agent separating device 201 enters the gas collection chamber 202 and is introduced into a product separating system through an oil gas pipeline 203; the separated catalyst with coke enters the stripping section 205 of the sedimentation stripper 200, and after stripping, part of the spent catalyst enters the regenerator 500 through the spent riser 206 and the spent catalyst inlet 505; the oxygen-containing gas from the oxygen-containing gas inlet 501 enters the regenerator after passing through the gas distributor 502, contacts with the coke-containing catalyst to generate complete combustion reaction, thoroughly emits heat, and part of regenerated catalyst enters the cracking reactor 100 for recycling through the regenerated catalyst outlet 508, part of regenerated catalyst is sent to the coke generator for recycling through the regenerated catalyst outlet 506 and the catalyst inlet 303, and the regenerated flue gas is sent to a subsequent energy recovery system through the flue outlet 504 after the entrained catalyst is recovered through the cyclone 503.

Examples

The following examples further illustrate the application, but are not intended to limit it. The catalyst used in the test is an industrial catalyst, and the trade mark is SHMP-4; raw coke is catalytic cracking slurry oil, and is taken from an Anqing petrochemical catalytic cracking device, and the properties are shown in table 1.

Example 1

Experiments were performed in the system of fig. 2, wherein the catalytic cracking reactor was a riser reactor;

the coke oven 300 used comprises:

a pre-lifting zone I, the length of which is 1 meter and the inner diameter of which is 0.2 meter;

the raw coke reaction zone II is a turbulent bed reactor, the length of the reactor is 3 meters, and the inner diameter of the reactor is 0.4 meter;

the outlet zone III has a length of 2 meters and an inner diameter of 0.2 meters.

The coke generator is provided with a pre-lifting gas inlet 301, a regenerated catalyst inlet 303 and a coke raw material inlet 302 from bottom to top in sequence, and is positioned at the lower part of the coke generator 300.

The distance of the raw coke inlet 302 from the bottom of the coke generator is 10% of Jiao Qigao degrees each independently.

And (3) carrying out a cracking reaction test of Daqing wax oil on a riser reactor, introducing preheated raw oil from the lower part of the cracking reactor, contacting with regenerated catalyst from a regenerator and carrying out catalytic cracking reaction from bottom to top to obtain an oil mixture of a reaction product and a spent catalyst, enabling the oil mixture to enter a cyclone separator from an outlet of the reactor, quickly separating the reaction product and the spent catalyst, and cooling and collecting the reaction product. The properties of the Daqing wax oil used are shown in Table 3.

The nitrogen gas of the pre-lifting medium enters the lower part of the coke generator to be mixed with the regenerated catalyst and then flows upwards, the mixture of the Anqing slurry oil (raw coke material) and the atomizing medium (steam) enters the coke generator through the raw coke material inlet to be contacted with the hot regenerated catalyst and carry out coke generation reaction, the reaction product and the spent catalyst enter the cyclone 201 from the outlet (outlet area) of the coke generator, the reaction product and the spent catalyst are rapidly separated, and the reaction product is cooled and collected.

The spent catalyst and the catalyst with carbon enter a stripping section of a settler under the action of gravity, hydrocarbon products adsorbed on the spent catalyst are stripped by steam, and the stripped spent catalyst enters a regenerator to be in contact with air for regeneration; the regenerated catalyst is returned to the reactor and the coke generator for recycling, wherein the weight ratio of the regenerated catalyst recycled to the catalytic cracking reactor to the regenerated catalyst recycled to the coke generator is 5:1. the operating conditions and product distribution are listed in Table 2.

As can be seen from the results in Table 2, the methane yield was 1.92%, the ethylene yield was 5.39% by weight, the propylene yield was 21.96% by weight, and the coke yield was 8.47%.

Comparative example 1

The procedure of fig. 2 was followed and tested with reference to example 1, except that comparative example 1 did not turn on the coke breeder, i.e., regeneration of the catalyst was performed as follows:

The spent catalyst enters a stripping section of a settler under the action of gravity, hydrocarbon products adsorbed on the spent catalyst are stripped by steam, and the stripped spent catalyst directly enters a regenerator to be in contact with air for regeneration; meanwhile, the Anqing slurry oil is introduced into the bed layer of the regenerator to be used as fuel oil for combustion, the heat of the regenerator is supplemented, and the regenerated catalyst is returned to the reactor for recycling. The operating conditions and product distribution are listed in Table 2.

As can be seen from the results in Table 2, the methane yield was 2.37%, the ethylene yield was 5.09% by weight, the propylene yield was 20.01% by weight, and the coke yield was 4.37%.

From the results of example 1 and comparative example 1 above, it can be seen that not only can methane yield be reduced, ethylene and propylene be increased, but also a desired coke source can be provided for the regeneration process by using the catalytic cracking reaction system of the present application.

In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", "front", "rear", "left", "right", etc. are directions or positional relationships based on the operation state of the present application are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

In the description of the present application, it should be noted that the terms "mounted," "connected," and "connected" are to be construed broadly, unless otherwise specifically defined and limited. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

The application has been described above in connection with preferred embodiments, which are, however, exemplary only and for illustrative purposes. On this basis, the application can be subjected to various substitutions and improvements, and all fall within the protection scope of the application.

TABLE 1 cracking reaction feedstock and raw coke feedstock Properties

	Daqing wax oil	Anqing oil slurry
			Density at 20 ℃ kilogram/meter ³	864.0	1068.6
Refractive index at 70 DEG C	1.4624	1.6361
			Viscosity at 100 ℃ of millimeter ² Per second	4.648	11.5
Carbon residue,% (by weight)	0.04	4.79
			Carbon content,% (by weight)	86.40	91.22
Hydrogen content,% (by weight)	13.44	8.06
			Sulfur content,% (by weight)	0.12	0.331
Nitrogen content,% (by weight)	0.0657	0.21
			Basic nitrogen, mg/kg	/	86
Distillation range, DEG C
			5% (volume)	331	364.5
10% (volume)	354	373.2
			30% (volume)	402	400.6
50% (volume)	435	425.6
			70% (volume)	467	464.8

Table 2 example 1 and comparative example 1 operating conditions and results

	Example 1	Comparative example 1
			Cracking reactor conditions
The outlet temperature of the cracking reactor, DEG C	560	560
			Weight ratio of catalyst to raw material feed	10：1	10：1
Reaction time, seconds	2.5	2.5
			Weight ratio of steam to raw material feed	0.25	0.25
Coke generator conditions
			Outlet temperature of coke generator, DEG C	540
Catalyst and raw coke raw material feed weight ratio	7
			Reaction time, seconds	5
Steam to raw coke raw material feed weight ratio	0.16
			Nitrogen and raw coke feed weight ratio	0.05
Raw coke raw material feed amount accounts for the proportion of the cracking reactor feed amount, percent	30
			Regenerator conditions
Temperature in regenerator, DEG C	720	720
			The feed amount of the slurry oil in the regenerator accounts for the feed amount proportion of the cracking reactor, percent		30
Product yield, wt%
			Dry gas	8.88	9.00
Wherein methane is	1.92	2.37
			Wherein ethylene is	5.39	5.09
Liquefied gas	47.67	48.57
			Wherein propylene is	21.96	20.01
C ₅ ⁺ Gasoline	21.75	24.20
			Diesel oil	10.26	10.39
Heavy oil	2.97	3.47
			Coke	8.47	4.37
Totalizing	100.00	100.00

Claims

1. A catalytic cracking reaction-regeneration system, comprising:

a catalytic cracking reactor, wherein the catalyst is a catalyst,

a coke-producing device,

a sedimentation stripper, and

A pre-lifting area is provided for the pre-lifting area,

an outlet region for the fluid to flow from the fluid outlet,

2. The system of claim 1, wherein the coke breeder is provided with the pre-lift gas inlet, catalyst inlet and raw coke feed inlet in order from bottom to top.

3. The system of claim 2, wherein the raw coke inlets are each independently disposed upstream of the coke breeder; preferably, the distance of the raw coke inlet from the bottom of the coke generator is 5% to 15% of Jiao Qigao degrees each independently.

4. The system of claim 1, wherein the green coke reaction zone is hollow cylindrical with an aspect ratio of 20:1 to 2:1.

5. the system of claim 4, wherein the system further comprises a controller configured to control the controller,

the pre-lifting area is hollow cylindrical, and the length-diameter ratio of the pre-lifting area is 10:1-2:1, a step of;

the outlet zone is hollow cylindrical with an aspect ratio of 30:1-5:1.

6. the system of claim 5, wherein the ratio of the inner diameters of the pre-lift zone, the raw coke reaction zone, and the exit zone is 1:2:1 to 1:10:2.

7. A method for catalytic cracking of heavy feedstock, the method comprising:

4) And conveying the first spent catalyst and the second spent catalyst to a regenerator for burning regeneration, and respectively returning the obtained regenerated catalysts to the catalytic cracking reactor and the bottom of the coke generator for recycling.

8. The method of claim 7, wherein the conditions of the catalytic cracking reaction comprise: the reaction temperature is 510-650 ℃, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the oil is (3-30): 1, the weight ratio of the pre-lifting gas to the raw oil is (0.03-1.0): 1, the reaction pressure is 130-450 kilopascals.

9. The method of claim 7, wherein the conditions of the coking reaction comprise: the reaction temperature is 460-460 ℃, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the oil is (3-30): 1, the weight ratio of the pre-lifting gas to the raw coke is (0.01-0.5): 1, the linear velocity is 0.2 m/s to 1.2 m/s, and the catalyst particle density is 300 kg/cubic meter to 700 kg/cubic meter.

10. The method of claim 7, wherein the properties of the heavy feedstock oil meet one, two, three, or four of the following criteria: the density at 20 ℃ is 850-920 kg/m ³ 0-2 wt% of carbon residue, a characteristic factor K value of more than 12.1, and a saturated hydrocarbon content of 60-100 wt%; preferably, the heavy feedstock oil is selected from petroleum hydrocarbon, non-petroleum hydrocarbon mineral oil, synthetic oil, animal fat and vegetable oilOne or more of the fats.

11. The method of claim 7, wherein the raw coke feed is plant self-produced slurry and secondary process distillate, or a mixture thereof; preferably, the secondary processing distillate oil can be selected from one or more of catalytic cracking diesel oil, catalytic cracking slurry oil, coker gasoline, coker diesel oil and coker wax oil; more preferably, the char-forming feedstock is a plant self-produced slurry.

12. The method according to claim 7, wherein the method is performed in a catalytic cracking reaction-regeneration system according to any one of claims 1-6.