CN102690679B - Catalytic cracking method for producing propylene - Google Patents

Abstract

A catalytic cracking method for producing propylene, comprising: making a first catalytic cracking catalyst composed of heavy feedstock, catalyst particles whose active components are mainly Y-type molecular sieves and catalyst particles whose active components are mainly β molecular sieves in the first riser Contact reaction in the reactor, the reacted catalyst is recycled after being stripped and regenerated; light hydrocarbons and the second catalytic cracking catalyst whose active component is a shape-selective molecular sieve with a pore size less than 0.7nm are contacted and reacted in the second reactor; the reaction The final catalyst is recycled after being stripped and regenerated. The production method provided by the invention has high propylene yield and relatively high butene yield.

Description

A catalytic cracking method for producing propylene

technical field

The present invention relates to a catalytic cracking method for producing propylene.

Background technique

Catalytic cracking of heavy oil is an important method for preparing small molecule olefins such as ethylene, propylene and butene, and the method of catalytic cracking of heavy oil commonly used in industry to produce low-carbon olefins is such as the catalytic cracking technology of maximum production of propylene (DCC, USP4980053 and USP5670037) and Catalytic pyrolysis technology (CPP, USP6210562) for the largest production of ethylene. These two technologies use a single riser reactor or a single riser reactor combined with a dense-phase fluidized bed reactor structure with a special catalyst at a higher temperature. For the reaction, the catalyst used is a single catalyst system composed of active components such as medium-pore zeolite (such as ZSM-5) and/or large-pore zeolite (such as Y molecular sieve) with MFI structure. On the basis of ensuring a certain amount of heavy oil conversion Pursue a higher yield of small molecule olefins. However, due to the large difference in the catalytic active centers required for the enhancement of heavy oil conversion and the improvement of small molecule olefins, it is sometimes difficult to react in a single riser reactor or a single riser reactor combined with a dense-phase fluidized bed in terms of catalyst formulations. The reactor takes into account the requirements of the heavy oil conversion reaction and the reaction of prolific small molecule olefins at the same time. In addition, some catalytic cracking units currently increase the yield of prolific small molecule olefins by adding additives containing ZSM-5 zeolite. Although this method has better flexibility, this method also has other defects that are difficult to overcome except that the rate of increase in the yield of small molecular olefins is relatively small: the first is that it is difficult to achieve when adding too little additive containing ZSM-5 zeolite. Prolific production of small molecular olefins is required; second, when the additive containing ZSM-5 zeolite is high, there is an obvious unfavorable physical dilution effect on the main catalytic cracking catalyst, thereby reducing the overall effect of the entire catalyst system, and there are additives Due to the problem of matching the performance of the main catalyst, it is difficult to further increase the propylene yield.

CN100448954C discloses a catalytic conversion method for increasing the production of propylene. The method adopts two catalyst mixtures to participate in the reaction, one is a catalyst containing Y-type molecular sieves, and the other is a catalyst containing ZSM-5 molecular sieves, transition metal additives and phosphorus additives. The reaction device adopts double riser design, mainly including main riser, auxiliary riser, common regenerator and gas-solid separation equipment. In the main riser, the heavy, macromolecular hydrocarbon oil feedstock is cracked to produce gasoline, diesel and liquefied gas; the liquefied gas intermediate product after propylene is separated is injected into the auxiliary riser reactor to contact with the hot two catalyst mixtures , successively carry out olefin superposition, superposition product cracking and alkane dehydrogenation reaction to increase the production of propylene product. This method cannot solve side effects such as interference and dilution between the above two catalysts, and the yield of propylene is not high; nor does it involve reaction and regeneration device structure.

CN101314724A discloses a combined catalytic conversion method of biological oil and mineral oil. The method uses modified β zeolite and zeolite with MFI structure as catalysts as essential active components to catalyze biogrease and mineral oil in a riser and fluidized bed composite reactor to produce small molecular olefins such as propylene. This method uses a single catalyst system containing multiple active components, and it is difficult to meet the requirements of the heavy oil conversion reaction and the reaction of prolific small molecule olefins, which are very different, and cannot well solve the interference and dilution between the above two zeolites. Side effects, the yield of propylene is not high, in addition, this patent does not have special requirements and regulations on the structure of the reaction device.

CN101134913A discloses a method for catalytic conversion of hydrocarbons to produce low-carbon olefins, in which hydrocarbon raw materials are catalytically cracked to obtain C2-C4 olefins, gasoline, diesel oil, heavy oil and other low-molecular-weight saturated hydrocarbons; the catalyst used in the method , containing beta zeolite modified by phosphorus and transition metal M and the balance of other types of zeolite. This method adopts a single catalyst system composed of multiple active components, and it is difficult to take into account the two very different reactions of heavy oil conversion and production of small molecule olefins at the same time, and the yield of propylene is not high.

Contents of the invention

The technical problem to be solved by the present invention is to provide a catalytic cracking method for producing propylene, which is used for the conversion of heavy raw materials and has a relatively high propylene yield.

The invention provides a catalytic cracking method for producing propylene, comprising:

(1) Make the heavy raw material and the first catalytic cracking catalyst contact and react in the first riser reactor, the oil gas after the reaction is separated from the first catalytic cracking catalyst, the oil gas is introduced into the product separation system, and the first catalytic cracking catalyst is placed in the first catalytic cracking catalyst A stripper is stripped and introduced into the first regenerator for regeneration, and the regenerated first catalytic cracking catalyst is introduced into the first reactor for recycling; wherein, the first catalytic cracking catalyst is composed of a catalyst whose active component is mainly Y-type molecular sieve The particles and active components are mainly composed of catalyst particles of β molecular sieve; the reaction temperature of the first riser reactor is 450-650°C, the agent-oil ratio is 1-25, and the reaction time is 0.50-10 seconds;

(2) make light hydrocarbons and the second catalytic cracking catalyst containing pore diameter less than 0.7nm shape-selective molecular sieve contact reaction in second reactor; Described second reactor comprises the second riser reactor and fluidized bed connected in series Reactor, the oil gas reacted in the second riser reactor and the reacted second catalytic cracking catalyst are introduced into the fluidized bed reactor connected in series with the second riser reactor for reaction; the oil gas reacted in the fluidized bed is introduced into the product separation system The catalyst is introduced into the second stripper for stripping and then introduced into the second regenerator for regeneration, and the regenerated second catalytic cracking catalyst is introduced into the second riser reactor for recycling; the light hydrocarbons include gasoline fractions and/or C4 hydrocarbons; When the light hydrocarbons include gasoline fractions, the gasoline fraction operates at an agent-to-oil ratio of 10 to 30 in the second riser reactor, and the reaction time is 0.10 to 1.5 seconds; when the light hydrocarbons include C4 hydrocarbons, The operating agent-oil ratio of C4 hydrocarbons in the second riser is 12-40, and the reaction time is 0.50-2.0 seconds; the reaction temperature of the fluidized bed reactor is 500-650°C, and the weight hourly space velocity is 1-35 hours ^-1 .

In the catalytic cracking method for producing propylene provided by the present invention, in the heavy raw material catalytic conversion reaction and regeneration cycle system, the cracking catalyst used is catalyst particles with Y-type molecular sieve as the main active component and β molecular sieve as the main active component. In the light hydrocarbon oil catalytic conversion reaction and regeneration cycle system, the cracking catalyst used has a shape-selective molecular sieve with an average pore size of less than 0.7nm as the main active component, which can fully and easily strengthen the conversion of heavy oil, high Selectively convert heavy raw materials into small molecule olefin products such as propylene, and the spent reagents after the reaction of the two reaction systems enter their respective regeneration zones for charring regeneration, which is easy to control, thus forming two independent closed catalyst reaction and regeneration cycles , can improve the conversion rate of heavy oil and at the same time increase the yield of small molecule olefins, especially propylene, with high selectivity, have higher conversion rate of heavy oil and yield of propylene, and surprisingly also have higher yield of butene.

Description of drawings

Figure 1 is a schematic diagram of a catalytic cracking unit provided by the present invention. Among them, 1 and 2 are the riser reactor, 3 is the dense-phase fluidized bed reactor, 4 is the regenerator, 5 is the stripping partition partition in the settler, 6 is the regeneration partition partition in the regenerator, and 7 is the regenerator. Gas-solid rapid separation equipment at the outlet of the hydrocarbon oil riser reactor, 8 is the gas-solid rapid separation equipment at the outlet of the combined reactor of the riser and the fluidized bed, and 9 is the combination of the riser reactor 1 and the riser 2 and the fluidized bed 3 The common settler for the reactor. 40 and 41 are respectively two strands of regenerated catalyst inclined tubes (the catalyst flow rate is controlled by the opening of the slide valve, not shown in the figure), 42 and 43 are respectively two strands of inclined tubes of the catalyst to be regenerated (the flow rate of the catalyst is controlled by the opening of the slide valve). Catalyst flow rate, not shown in the figure). 51 and 52 are the stripping zones corresponding to the two catalysts, 61 and 62 are the regeneration zones corresponding to the two catalysts, 50 is the steam stripping, and 60 is the regeneration air. As shown in FIG. 1 , the riser 2 and the fluidized bed 3 are arranged in parallel through the settler 9 and the riser 1 in series, and the settler 9 is arranged coaxially with the stripper including the stripping zone 51 and the stripping zone 52 .

Detailed ways

In the catalytic cracking method for producing propylene provided by the present invention, in the first riser reactor, the heavy raw material is contacted and reacted with the first catalytic cracking catalyst, and the generated oil mixture is separated from the oil gas and the carbon deposit after the reaction by the separation device at the end of the riser. Catalyst separation, the separation device is preferably a rapid separation device, which is used to quickly separate the reaction oil gas from the carbon-deposited catalyst. Existing rapid separation devices can be used, and the preferred rapid separation device is a rough cyclone separator. The rapid separation of oil and gas from the carbon-deposited catalyst after the reaction is carried out through the rapid separation device at the end of the riser reactor for the catalytic conversion of heavy raw materials, which can reduce the dry gas yield and inhibit the reconversion of low-carbon olefins, especially propylene, after formation. The oil and gas are separated by the subsequent product separation system to obtain products such as cracked gas, cracked gasoline, cracked light oil and cracked heavy oil; the spent agent enters the subsequent first stripper, and the stripped spent agent is introduced into the first regeneration unit through the delivery pipeline After the reactor is regenerated, it returns to the first riser reactor for recycling. The operating conditions in the first riser reactor include: the reaction temperature is 450 to 650°C, preferably 480 to 600°C; the ratio of catalyst to oil (the weight ratio of the first catalytic cracking catalyst to heavy feedstock) is 1 to 25, preferably 5-20; the reaction time is 0.50-10 seconds, preferably 1-10 seconds; the pressure (absolute pressure) in the reactor is 0.1-0.4 MPa, preferably 0.15-0.35 MPa.

The heavy raw materials are heavy hydrocarbons and/or various animal and vegetable oil raw materials rich in hydrocarbons, and the heavy hydrocarbons are selected from one or one of petroleum hydrocarbons, mineral oils and synthetic oils a mixture of the above. Petroleum hydrocarbons are well known to those skilled in the art, for example, they may be vacuum gas oil, atmospheric residue, vacuum gas oil mixed with vacuum residue or other hydrocarbon oils obtained through secondary processing. Said other hydrocarbon oil obtained through secondary processing, such as one or more of coker wax oil, deasphalted oil, furfural refined raffinate oil. Mineral oil is selected from one or a mixture of coal liquefied oil, oil sands oil and shale oil. Synthetic oil is the distillate obtained by F-T synthesis of coal, natural gas or asphalt. Various animal and vegetable oils rich in hydrocarbons such as animal fats and vegetable fats.

In the catalytic cracking method for producing propylene provided by the present invention, the light hydrocarbons are contacted and reacted with the second catalytic cracking catalyst in a combined reactor composed of a second riser reactor and a fluidized bed reactor in series to convert the light hydrocarbons, After the reaction, the oil and gas leaving the second reactor are separated from the catalyst, the catalyst enters the stripper to be stripped and then regenerated, and the regenerated catalyst is introduced into the second riser reactor for recycling. In the combined reactor composed of the second riser reactor and the fluidized bed reactor, after light hydrocarbons and the second catalytic cracking catalyst are contacted and reacted in the second riser reactor, the obtained oil mixture is introduced into the second The reaction continues in the fluidized bed reactor connected to the end of the riser reactor. The reacted hydrocarbon products enter the settler and then enter the subsequent product separation system through the gas-solid separation equipment connected to the settler to obtain cracked gas, cracked gasoline, cracked Light oil and pyrolysis heavy oil, the raw agent separated by gas-solid separation equipment enters the fluidized bed reaction zone, and the reacted catalyst that leaves the fluidized bed reaction zone enters the second stripper, and after stripping, it is introduced into the second regenerator for regeneration Then return to the second riser reactor for recycling. The gas-solid separation equipment connected to the settler is, for example, a cyclone separator.

In the catalytic cracking method for producing propylene provided by the present invention, the light hydrocarbons are gasoline fractions and/or C4 hydrocarbons, preferably including gasoline fractions and/or C4 hydrocarbons obtained from the product separation system of the method of the present invention. The operating condition of the second riser reactor is: when described light hydrocarbon comprises gasoline fraction, gasoline fraction is in the second riser operating agent oil ratio (introduces the second catalytic cracking catalyst of the second riser reactor and gasoline fraction weight ratio) is 10 to 30, and the reaction time is 0.10 to 1.5 seconds; when the light feedstock includes C4 hydrocarbons, the C4 hydrocarbons operate in the second riser at the ratio of operating agent to oil (introduced into the second riser reactor second The weight ratio of catalytic cracking catalyst to C4 hydrocarbon) is 12 to 40, and the reaction time is 0.50 to 2.0 seconds; the reaction temperature of the fluidized bed reactor is 500 to 650 ° C, and the weight hourly space velocity is 1 to 35 hours ^-1 , the reactor Internal pressure 0.1 ~ 0.4MPa (absolute pressure). Preferably, the reaction operating conditions of the gasoline fraction in the second riser reactor: the operating agent oil ratio of the gasoline fraction in the second riser is preferably 15 to 25; the reaction time is preferably 0.30 to 0.8 seconds; The distillate feed amount is preferably 10 to 20% by weight. The reaction operation condition of C4 cut: C4 hydrocarbon in the second riser reactor operating agent oil ratio (the second catalytic cracking catalyst that introduces the second riser reactor and the C4 hydrocarbon weight ratio that introduces the second riser reactor) Preferably 17-30; the reaction time of olefin-rich C4 in the second riser is preferably 0.8-1.5 seconds; the proportion of atomized water vapor in the C4 feed is preferably 15-25% by weight.

In the catalytic cracking method provided by the present invention, the reaction operating conditions of the fluidized bed reactor include: the reaction pressure (settler outlet pressure, absolute pressure) is 0.1～0.4MPa, preferably 0.15～0.35MPa; the fluidized bed reaction temperature is about 500-650°C, preferably 510-580°C; the weight hourly space velocity of the fluidized bed (total hydrocarbon feed to the fluidized bed reactor) is 1-35 hours ^-1 , preferably 3-30 hours ^-1 .

In the catalytic cracking method for producing propylene provided by the present invention, the light hydrocarbons introduced into the second riser reactor are gasoline fractions and/or C4 hydrocarbons, preferably gasoline fractions and/or C4 hydrocarbons rich in olefins. The gasoline fraction raw material rich in olefins comprises the gasoline fraction produced by the device of the present invention (i.e. from the product separation system described in the present invention) and/or other devices produce the gasoline fraction; the gasoline fraction produced by other devices can be selected from catalytic cracking naphtha, One or more mixtures of catalytic cracking stable gasoline, coker gasoline, visbreaking gasoline and gasoline fractions produced by other refining or chemical processes, the gasoline fraction produced by this unit is preferred. The gasoline raw material can be a full-range gasoline fraction with an end boiling point not exceeding 204°C, such as a distillation range of 40-204°C, or a narrow fraction thereof, such as a gasoline fraction with a distillation range of 40-85°C . The weight ratio of the gasoline fraction injected into the light hydrocarbon oil riser reactor to the heavy feedstock injected into the first riser reactor is 0.05-0.20:1, preferably 0.08-0.15:1. The gasoline raw material is preferably an olefin-rich gasoline fraction, and its olefin content is 20-95% by weight, preferably 35-90% by weight, and most preferably above 50% by weight.

The C4 hydrocarbons refer to low-molecular hydrocarbons that exist in the form of gases at normal temperature and pressure with C4 fraction as the main component, including alkanes, alkenes and alkynes with 4 carbon atoms in the molecule. It includes gaseous hydrocarbon products rich in C4 cuts produced by the device of the present invention, and may also include gaseous hydrocarbons rich in C4 cuts produced by other device processes, among which the C4 cuts produced by the device of the present invention are preferred. The C4 hydrocarbons are preferably C4 fractions rich in olefins, wherein the content of C4 olefins is greater than 50% by weight, preferably greater than 60% by weight, most preferably above 70% by weight. Preferably, the light hydrocarbons include gasoline fractions, with or without C4 hydrocarbons, and the weight ratio of C4 hydrocarbons to gasoline fractions is 0-2:1, preferably 0-1.2:1, most preferably 0-0.8:1.

Preferably, the cracked heavy oil obtained by the product separation system of the present invention is also introduced into the second riser reactor for reaction and/or introduced into the fluidized bed reactor for reaction, which is conducive to reducing the dry gas yield and coke yield, and Improve the yield of light olefins, especially propylene. When the cracked heavy oil is introduced into the second riser reactor, the introduction position of the cracked heavy oil is preferably at the part from the second riser reactor length to the outlet of the riser, that is, the introduction position is preferably at the second riser reactor. The middle and lower reaches of the riser reactor. Preferably, the cracked heavy oil is introduced into a fluidized bed reactor for reaction, more preferably introduced into the bottom of the fluidized bed reactor. The cracked heavy oil is the cracked heavy oil obtained by the product separation system of the present invention, that is, most of the remaining liquid products after the cracked products entering the product separation system are separated from gas, gasoline and diesel oil, and its atmospheric distillation range is between 330 and 550°C Between, preferably its normal pressure distillation range is 350～530 ℃. The weight ratio of the cracked heavy oil injected into the second riser and the fluidized bed reactor to the heavy raw material injected into the first riser reactor is 0.05-0.30:1, preferably 0.10-0.25:1.

In the catalytic cracking method for producing propylene provided by the present invention, the separation device at the end of the first riser reactor separates the reaction oil gas from the coke catalyst, and the oil gas product is introduced into the product separation system for separation; from the second reactor and the fluidized bed reactor. The oil and gas after the reaction in the combined reactor enters the settler and the gas-solid separation equipment successively to separate the catalyst carried in it, and then enters the subsequent product separation system. The oil and gas products of the first riser reactor and the oil and gas products of the fluidized bed reactor are introduced into the product separation system for separation, and the two streams of oil and gas are preferably mixed and then introduced into the product separation system for separation. In the product separation system, oil and gas products are separated to obtain cracked gas, cracked gasoline, cracked light oil and cracked heavy oil. The product separation system described is prior art, and the present invention has no special requirements.

In the catalytic cracking method for producing propylene provided by the present invention, the riser reactor is selected from one or a combination of two of equal-diameter risers, constant-linear-velocity risers, and variable-diameter risers, wherein heavy The hydrocarbon oil riser reactor and the light hydrocarbon oil riser reactor can be of the same type or of different types. The fluidized bed reactor is selected from one or a combination of fixed fluidized bed, dispersed fluidized bed, bubbling bed, turbulent bed, fast bed, conveying bed and dense bed reactor.

In the combined reactor of the second riser reactor and fluidized bed reactor, the outlet of the riser is preferably a low-pressure outlet distributor whose pressure drop is less than 10KPa. The low-pressure outlet distributor is, for example, an arched distributor.

In the catalytic cracking method for producing propylene provided by the invention, different catalysts and reaction-regeneration systems are used for heavy raw materials and light hydrocarbons. The first catalytic cracking catalyst is composed of catalytic cracking catalyst particles whose active components are mainly Y-type molecular sieves and catalytic cracking catalyst particles whose active components are mainly β molecular sieves. The active component is mainly catalytic cracking catalyst particles of Y-type molecular sieves, based on the dry weight of the catalyst particles, including at least 10 weight of Y-type molecular sieves, with or without other molecular sieves except Y-type molecular sieves, The content of molecular sieve is no more than 5% by weight; preferably, it includes 10-70% by weight of Y-type molecular sieve, 0-60% by weight of clay, and 15-60% by weight of inorganic oxide binder; more preferably 25-50% by weight % Y-type molecular sieve, 25-50% by weight of clay, and 25-50% by weight of inorganic oxide binder. The active component is mainly a catalytic cracking catalyst of β molecular sieve, including at least 10 wt. % of β-type molecular sieve, 0-60% by weight of clay, 15-60% by weight of inorganic oxide binder; more preferably including 25-50% by weight of β-type molecular sieve, 25-50% by weight of clay, 25-50% by weight 50% by weight inorganic oxide binder.

In the first catalytic cracking catalyst, the mass ratio of catalytic cracking catalyst particles whose active components are mainly Y-type molecular sieves to catalytic cracking catalyst particles whose active components are mainly β molecular sieves is 4～1:1～4, preferably 1.5～3.5: 3.5～1.5. The Y-type molecular sieves are various Y-type molecular sieves commonly used in the prior art, such as rare earth Y-type molecular sieves (REY), rare earth hydrogen Y-type molecular sieves (REHY), ultra-stable Y-type molecular sieves (USY), rare-earth ultra-stable Y-type molecular sieves One type or a mixture of two or more types of molecular sieves (REUSY). The β-type molecular sieves are various modified β-type molecular sieves commonly used in the prior art, such as hydrogen-type β-type molecular sieves, β-type molecular sieves modified with phosphorus and transition metal elements. The specific preparation of β-type molecular sieves can be found in CN1035668C and CN1041616C.

In the catalytic cracking method for producing propylene provided by the present invention, in the light hydrocarbon oil catalytic conversion reaction and the regeneration cycle system, the active component is mainly the second catalyst whose average pore diameter is less than 0.7nm shape-selective molecular sieve (such as ZSM-5 molecular sieve). The cracking catalyst is reacted in the second riser and the fluidized bed reactor. The content of shape-selective molecular sieves with an average pore diameter of less than 0.7nm in the second catalytic cracking catalyst is at least 10% by weight, containing or not containing other molecular sieves except shape-selective molecular sieves with an average pore diameter of less than 0.7nm, and the content of other molecular sieves is not more than 5% by weight, preferably based on the weight of the second catalytic cracking catalyst on a dry basis, the second catalytic cracking catalyst includes 10-65% by weight of a shape-selective molecular sieve with an average pore size of less than 0.7 nanometers, 0-60% by weight of clay and 15 to 60% by weight of an inorganic oxide binder, more preferably comprising 20 to 50% by weight of a shape-selective molecular sieve with an average average pore diameter of less than 0.7 nm, 10 to 45% by weight of clay and 25 to 50% by weight of an inorganic oxide material binder. The shape-selective molecular sieve catalyst with an average pore size of less than 0.7 nanometers can be one or a combination of several types provided by the prior art, and can be purchased commercially or prepared according to existing methods.

The shape-selective molecules with an average pore size of less than 0.7 nanometers are selected from ZSM series zeolites, ferrierites, chabazites, cyclospars, erionites, A zeolites, columnar zeolites, zeolites, and the above zeolites through physical and/or chemical methods. One or more mixtures of zeolites obtained after treatment. The ZSM series zeolite is selected from one or one of ZSM-5, ZSM-8, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-38, ZSM-48 and ZRP molecular sieves mixture of the above. The preferred shape-selective molecular sieve with an average pore size less than 0.7 nanometers is one or more of ZSM-5 molecular sieves, ZRP molecular sieves, element-modified ZSM-5 or element-modified ZRP molecular sieves, element-modified ZSM-5 molecular sieves For example ZSP molecular sieves. For a more detailed description of ZSM-5 molecular sieve, see USP3702886, and for a more detailed description of ZRP, see USP5232675, CN1211470A, CN1611299A.

The inorganic oxide as a binder may be selected from silicon dioxide (SiO ₂ ) and/or aluminum oxide (Al ₂ O ₃ ). The clay as a matrix, that is, a carrier, may be selected from kaolin and/or halloysite.

The operation mode and operating conditions of the regenerator described in the method of the present invention can refer to conventional catalytic cracking regenerators.

A catalytic cracking unit used in the present invention at least includes a reactor part, a stripper part, a regenerator part and a product separation system. Preferably, the reactor adopts double risers and a fluidized bed to form a combined reactor configuration, wherein one riser is connected in series with the fluidized bed reactor and is arranged side by side with the other riser, and the riser and the fluidized bed The reactor series structure is further arranged in series with the stripper. A partition is set in the above-mentioned stripper to divide it into two independent stripping zones, the reaction and stripping route formed by a combined reactor consisting of a stripping zone, a riser and a fluidized bed, which is used for light Catalytic conversion of hydrocarbons; another stripping zone and another riser form a corresponding reaction and stripping route, which is used for catalytic conversion of heavy raw materials. A separator is placed in the regenerator to divide it into two regeneration zones which are respectively connected with corresponding stripping zones, thus forming two independent catalyst reaction and regeneration circulation routes.

A kind of catalytic cracking unit that the present invention uses, as shown in Figure 1, described catalytic cracking unit comprises riser reactor 1, the gas-solid separation equipment 7 that is communicated with the outlet of riser reactor 1, riser reactor 2 and The fluidized bed reactor 3 connected in series, the gas-solid separation device 8 of the fluidized bed reactor, the settler 9, the stripper partition 5 and the first stripping zone 51 separated by the partition 5 and the second Stripping zone 52; The catalyst outlet of gas-solid separation equipment 7 is communicated with the first stripping zone 51, and the top of the first stripping zone is communicated with the settler 9; The top of the fluidized bed reactor 3 is communicated with the settler 9, and the flow The bottom of the bed reactor 3 is communicated with the stripping zone 52, and the inlet of the gas-solid separation device 8 is communicated with the settler 9; the catalyst outlet position of the gas-solid separation device 8 enables the catalyst therein to enter the stripping zone 52 or fluidized bed Reactor 3, for this reason, can be above the fluidized bed reactor, in the fluidized bed reactor or in the second stripping zone 52; After the oil-gas outlet of gas-solid separation device 7 and gas-solid separation device 8 is connected with the oil-gas separation system connected. The regenerators can be two separate regenerators, or a regenerator can be divided into two regeneration zones as shown in Figure 1, wherein the partition plate 6 arranged in the regenerator 4 separates the regenerator 4 It is two independent regeneration zones 61 and 62, which communicate with the stripping zones 51 and 52 respectively. In order to refine cracked heavy oil, the riser reactor 2 and/or fluidized bed reactor 3 also includes an inlet for cracked heavy oil. The stripper partition 5 preferably also extends into the settler, and the lower part of the settler is divided into two areas that are not connected, and are used as the settling of the combined reactor composed of the riser reactor 2 and the fluidized bed reactor 3 respectively. and the settler of the riser reactor 1, preferably the two settling zones communicate at the top of the settler 5, and share the headspace of the settler 9.

The above-mentioned catalytic cracking conversion device used in the method of the present invention can realize selective conversion of different fractions using different catalysts and stripping and regeneration of the catalysts used, and can simply and effectively complete the formation of two relatively independent catalysts for reaction and regeneration. The circulation route has a compact structure and is easy to implement, and the operation of the device is relatively simple and flexible, which solves the problem of eliminating the unfavorable mutual interference of the two catalyst systems from an engineering point of view. The combination reactor of riser and fluidized bed is arranged in series with the second stripping zone, which can realize the introduction of stripping water vapor into the fluidized bed reactor, make it pass through the fluidized bed reactor and then be discharged from the reactor, which can effectively reduce oil and gas Partial pressure shortens the residence time of oil and gas in the settling section, which is beneficial to increase the production of propylene and reduce the yield of dry gas and coke.

Below in conjunction with accompanying drawing, the present invention will be further described:

In the method shown in Figure 1, the first catalytic cracking catalyst derived from the first regeneration zone 61 of the regenerator 4 enters the bottom of the riser reactor 1 through the regenerant inclined pipe 40, and the second catalytic cracking catalyst derived from the regeneration zone 62 The cracking catalyst flows to the bottom of the riser reactor 2 through the inclined pipe 41 of the regenerant, and correspondingly, the two streams of catalyst are accelerated to flow upward under the action of the pre-lift medium injected from the pipelines 22 and 23 respectively. After the preheated heavy raw material (heavy hydrocarbons or various animal and vegetable oils rich in hydrocarbons) is mixed with the atomized steam from the pipeline 21 in a certain proportion through the pipeline 20, it is injected into the riser reactor 1, and the reaction The oil gas and catalyst mixture are separated by the rapid separation device 7 at the end of the riser 1 to separate the oil gas from the coke catalyst after the reaction; at the same time, the preheated or non-preheated light hydrocarbons (such as olefin-rich gasoline fractions and/or C4 hydrocarbons) are passed through After the pipeline 24 is mixed with the atomized steam from the pipeline 25 in a certain proportion, it is injected into the riser reactor 2, and then the reaction oil gas and catalyst mixture flow upward along the riser 2, and the reaction oil gas and catalyst mixture pass through the riser 2. The outlet distributor (not shown in the figure) enters the fluidized bed reactor 3 to continue the reaction, and finally enters the settler 9 to separate the oil gas from the catalyst through the gas-solid separation device 8 . All hydrocarbon oil products, including the oil and gas at the outlet of the riser 1 and the oil and gas flowing out from the fluidized bed reactor 3, are collected by the cyclone separation system (not shown in the figure) at the top of the settler and are drawn out of the reactor through the pipeline 26 to enter the subsequent product separation system. (not shown in the figure). In the product separation system, catalytic cracking products are separated into gaseous hydrocarbons, cracked gasoline, cracked light oil, cracked heavy oil and cracked oil slurry. Cracking gaseous hydrocarbons can obtain polymer grade propylene products and olefin-rich C4 fractions after the subsequent product separation and refining. Among them, the olefin-rich C4 fractions can be returned to the reactor for conversion to produce propylene. It is preferable to return the olefin-rich C4 fractions to upgrade Tube 2 was reinverted. Pyrolysis gasoline can be partially or completely returned to the reaction system for reconversion; gasoline can also be cut into light and heavy gasoline fractions first, and part or all of the light gasoline can be returned to the reaction system for reconversion. Preferably, the light gasoline is returned to the riser 2 for reconversion.

The coke-deposited catalyst separated by the rapid separation device 7 at the end of the riser 1 enters the stripping zone 51, and the spent agent separated by the separation device 8 enters the fluidized bed reactor 3 after being in contact with the oil agent mixture drawn from the riser 2 , and then enter the independent stripping zone 52; the stripping steam is injected into the stripper through the pipeline 50, and contacts with the coke catalyst in countercurrent, and the reaction oil gas carried by the coke catalyst is stripped as clean as possible, and the steam in the stripping zone 51 The stripping steam directly enters the settler 9, while the stripping steam in the stripping zone 52 first enters the fluidized bed reactor 3 and then enters the stripper 9, and is separated from the gas-solid separation device 8 together with other oil and gas, and then is drawn out of the reactor through the pipeline 26 . After stripping, the catalysts in the stripping zone 51 and the stripping zone 52 are sent to two independent regeneration zones 61 and 62 through the inclined tubes 42 and 43 of the spent agent, respectively, for coke regeneration. Oxygen-containing gas such as air is injected into the regenerator 4 through the pipeline 60, and the regenerated flue gas from the two regeneration zones is mixed in the common space at the top of the regenerator 4 and drawn out through the pipeline 63. The regenerated catalyst is returned to the riser reactors 1 and 2 for recycling through the regenerator inclined pipes 40 and 41 respectively.

During the above specific implementation process, the pre-lift medium is introduced into the riser 1 and the riser 2 through the pipelines 22 and 23, respectively. The pre-lifting medium is well known to those skilled in the art, and can be selected from one or more of steam, C1-C4 hydrocarbons or conventional catalytic cracking dry gas, preferably steam.

The following examples will further illustrate the present invention.

The raw material used in the embodiment and the comparative example comprises raw material A, raw material B, raw material C and raw material D, wherein raw material A and B are two kinds of different heavy oil cuts, raw material C and raw material D are respectively the pyrolysis light gasoline rich in olefins and Conventional full fraction catalytic cracking product gasoline, see Table 1 for specific properties. The catalysts used were CHP produced by Sinopec Catalyst Qilu Branch and four catalysts named Y, B and BY prepared in a laboratory. The specific properties of the four catalysts are shown in Table 2. Before use, they were subjected to steam aging pretreatment at 790°C × 100% H ₂ O × 14 hours (i.e. aged at 790°C and 100% steam atmosphere for 14 hours), among which catalyst Y The active component of catalyst B is USY molecular sieve, the active component of catalyst B is β-type molecular sieve, the active component of BY catalyst is USY molecular sieve and β molecular sieve, the active component of CHP catalyst is ZRP molecular sieve, and the active components of the three catalysts account for The proportion of the total amount is basically the same.

Y catalyst, B catalyst and BY catalyst are prepared according to the existing method, and the preparation steps are as follows: (1) water, kaolin, pseudo-boehmite and hydrochloric acid are added into the glue tank successively, wherein the consumption of water makes the solid content of the obtained slurry 30% by weight, the molar ratio of hydrochloric acid (calculated as HCl) to pseudo-boehmite (calculated as alumina) is 0.18:1, stir evenly; (2) heat the obtained slurry to 65°C, stop stirring, and age statically 1h; (3) Cool down to 50°C, add aluminum sol and molecular sieve slurry in turn (the content of molecular sieve in the molecular sieve slurry is 30% by weight), and continue stirring; (4) The slurry is formed by spray drying, washed and dried to obtain a catalyst sample . The composition of Y catalyst, B catalyst and BY catalyst is: containing 35% by weight of molecular sieve, 35% by weight of kaolin, 26% by weight of pseudoboehmite (calculated as alumina), 4% by weight of aluminum sol (calculated as alumina) . Wherein, the mass ratio of the two kinds of molecular sieves in the BY catalyst is Y-type molecular sieve:β-type molecular sieve=2:3, that is, the content of Y-type molecular sieve is 14% by weight, and the content of β-type molecular sieve is 21% by weight. Catalyst B contains 35% by weight of β molecular sieve, 35% by weight of kaolin, 26% by weight of pseudoboehmite (calculated by alumina), and 4% by weight of aluminum sol (calculated by alumina). Among them, the silicon-aluminum ratio (SiO ₂ /Al ₂ O ₃ molar ratio) _of β molecular sieve is 30, which is _hydrogen type _; 5.2; USY and β molecular sieves are produced by Sinopec Catalyst Qilu Company.

Comparative example 1

The experiment was carried out in a small fixed fluidized bed (FFB) catalytic cracking unit. The unit is designed for intermittent, one-way operation. The raw material is heavy oil A, and the catalyst is BY.

As shown in Table 2, the heavy oil A enters the fluidized bed reactor and contacts with the BY catalyst for catalytic reaction. The reaction conditions are: reaction temperature 520°C, agent-oil ratio 6, weight hourly space velocity 15h ^-1 , water vapor injection volume 5 weight%. The reaction product, steam and spent agent are separated in the settler, and the reaction product is separated to obtain gas product and liquid product, while the spent agent catalyst is stripped of the hydrocarbon product adsorbed on the spent agent by water vapor. The stripped spent catalyst is regenerated by contacting with heated hot air, and the regenerated catalyst undergoes a new catalytic conversion reaction. The test conditions and main test results are shown in Table 3.

Comparative example 2

Experiments were carried out on the FFB device described in Comparative Example 1. The raw materials and reaction conditions are exactly the same as in Comparative Example 1, except that the catalyst is a mechanical mixture of two catalysts B and Y, wherein the mixing weight ratio of Y catalyst and B catalyst is respectively 40% by weight and 60% by weight, forming a catalyst mixture. The contents of Y molecular sieve and β molecular sieve are respectively 14% by weight and 21% by weight, which are the same as those in the BY catalyst. The main operating conditions and results of the experiments are listed in Table 3.

Comparative example 3

Experiments were carried out on the FFB device described in Comparative Example 1. Raw material and reaction condition are identical with comparative example 1, difference is that catalyst is Y, and the main operation condition of experiment and result are listed in table 3.

Comparative example 4

The experiment was carried out in a small fixed fluidized bed (FFB) catalytic cracking unit. The raw material is heavy oil B, and the catalyst is CHP.

As shown in Table 2, the heavy oil B enters the fluidized bed reactor and contacts with the CHP catalyst for catalytic reaction. The reaction conditions are as follows: reaction temperature is 580°C, agent-oil ratio is 5, weight hourly space velocity is 1h ^-1 , and water vapor injection volume is 30 weight%. The reaction product, steam and spent agent are separated in the settler, and the reaction product is separated to obtain gas product and liquid product, while the spent agent catalyst is stripped of the hydrocarbon product adsorbed on the spent agent by water vapor. The stripped spent catalyst is regenerated by contacting with heated hot air, and the regenerated catalyst undergoes a new catalytic conversion reaction. The test conditions and main test results are shown in Table 3.

Comparative example 5

Experiments were carried out on the FFB device described in Comparative Example 4. Catalyst and reaction conditions are exactly the same as Comparative Example 4, the difference is that the raw material oil is changed to raw material D.

Comparative example 6

Experiments were carried out on the FFB device described in Comparative Example 5. The reaction conditions are the same as the catalyst and Comparative Example 5 and Comparative Example 4. The difference is that the raw materials change. The main operating conditions and results of the experiment are listed in Table 3.

Example 1

The experiment was carried out in a medium-sized catalytic cracking unit. This device comprises two sets of reaction regeneration systems: the first riser reactor, internal diameter is 16 millimeters, and length is 3800 millimeters, and the catalyst used is made up of the B catalyst of 40 weight % Y catalyst and 60 weight %, to table 1 shown Raw material A is cracked; the converted oil and gas are separated from the catalyst, the catalyst enters the first stripper and then enters the first regenerator for regeneration, and the regenerated catalyst returns to the first riser reactor for recycling; the oil and gas are introduced into the product separation system for separation. The inner diameter of the second riser reactor is 16mm, and the length is 3200mm. After the second riser reactor, the fluidized bed reactor is connected in series. The diameter of the fluidized bed reactor is 64 millimeters (internal diameter), and the length is 600 millimeters. The gasoline fraction (distillation range 30-85°C) in the separation system is converted, the catalyst used is CHP, the converted oil gas is separated from the catalyst, the catalyst enters the second stripper and then enters the second regenerator for regeneration, and the regenerated catalyst Return to the second riser reactor for recycling; oil and gas are introduced into the product separation system for separation. The oil and gas obtained after the reaction in the first riser reactor and the oil and gas obtained after the reaction in the fluidized bed reactor are mixed and then separated in the same product separation system. The oil gas stripped by the second stripper passes through the fluidized bed reactor and enters the corresponding settler. Its reaction and operating conditions and reaction results are shown in Table 4.

Comparative example 7

The experiment was carried out in a medium-sized catalytic cracking unit, with a riser plus a fluidized bed reaction.

The inner diameter of the riser reactor is 16mm, and the length is 3200mm. After the riser reactor, the fluidized bed reactor is connected in series. The diameter of the fluidized bed reactor is 64 millimeters (internal diameter), and the height is 600 millimeters. For the raw materials shown in table 1 A is converted, and the catalyst used is MMC-2 (product of Sinopec Catalyst Qilu Branch, containing USY type molecular sieve and ZRP molecular sieve). The converted oil and gas are separated from the catalyst, the catalyst enters the stripper and then enters the regenerator for regeneration, and the regenerated catalyst returns to the riser reactor for recycling; the oil and gas products are introduced into the product separation system for separation. The oil gas stripped by the stripper passes through the fluidized bed reactor and enters the corresponding settler. Its reaction and operating conditions and reaction results are shown in Table 4.

Example 2

With reference to Example 1, the difference is that cracking heavy oil is introduced into the second riser reactor at a distance of 1.5 meters from the outlet of the second riser reactor (the distillation range of the cracking heavy oil is 350～500 ° C), the introduction of the cracking heavy oil The weight ratio of the amount to the raw material A is 0.05:1.

Example 3

According to the method of Example 2, the difference is that the cracked heavy oil is introduced into the bottom of the fluidized bed reactor, and the riser reactor 2 is not introduced.

Example 4

Use the reaction device provided by the invention. As shown in Figure 1, the riser reactor 1 of the medium-sized device has an inner diameter of 16 mm and a length of 3800 mm, and the riser reactor 2 has an inner diameter of 16 mm and a length of 3200 mm, and is arranged in the form of an external riser. The outlet of the riser reactor 2 is connected to the fluidized bed reactor 3. The cross section of the fluidized bed reactor is semicircular, and its cross sectional area is equal to the area of a circle with a diameter of 64 mm and a length of 600 mm. Settler 9 length is 1520mm, and diameter is 250mm, and wherein stripper dividing plate 5 is a straight plate, and stripper is divided into two parts, and the cross-sectional area of the stripping zone 51 that forms circulation with riser reactor 1 accounts for the whole stripper. 85% of the cross-sectional area of the section, and the stripper partition 5 extends to the settler, and the upper edge of the partition is 500mm from the top of the settler. The test is operated in the way of back refining. The raw material B and the catalyst mixture composed of 40% by weight of Y catalyst and 60% by weight of B catalyst are introduced into the first riser reactor for reaction, and the reacted oil and gas enter the fast separation device for separation, and the separated catalyst enters the stripping zone 51. After stripping, it is introduced into the regeneration zone 61 for regeneration. The oil gas is mixed with the oil gas in the fluidized bed reactor and then enters the product separation system for separation. The weight ratio of the amount to the raw material B is 0.15:1, and reacts with the CHP catalyst introduced therein, and then enters the fluidized bed reactor 3 for the reaction, and the oil gas after the fluidized bed reaction enters the settler and is separated by the gas-solid separator 8 The catalyst carried in it is mixed with the oil and gas of the first reactor and then enters the product separation system. The catalyst in the fluidized bed reactor leaves from the bottom and enters the stripping zone 52. After stripping, it enters the regeneration zone 62 for regeneration. The stripper 52 The stripped oil and gas pass through the fluidized bed reactor 3 and enter the settler. The operating conditions and reaction results are shown in Table 4.

As can be seen from Table 4, the method of the present invention can improve the conversion capacity of heavy oil, reduce dry gas and coke yield while the productive rate of propylene and butene increases, and recycle cracked heavy oil to the riser and fluidized bed combined reactor, which can be further improved Reduce the yield of heavy oil and increase the yield of propylene and isobutene. Using the new structural device proposed by the invention can reduce the yield of heavy oil, increase the yield of propylene and isobutene, and increase the yield of high-value products, which has obvious effects.

Table 1

Table 2

catalyst name Y BY B CHP MMC-2 Main active components USY USY+β β ZRP USY+ZRP Chemical properties, weight % Al ₂ O ₃ 53.1 50.6 48.9 51 52.3 Na ₂ O / / / 0.066 0.072 RE ₂ O ₃ 0.67 / / / / physical properties Total pore volume, ml/g 0.196 0.165 0.144 0.22 0.164 Specific surface, m ² /g 144 129 120 105 113 Microreaction activity, weight % 69 66 64 52 64

table 3

Table 4

Claims (13)

1. A catalytic cracking method for producing propylene, comprising: (1) Make the heavy raw material and the first catalytic cracking catalyst contact and react in the first riser reactor, the oil gas after the reaction is separated from the first catalytic cracking catalyst, the oil gas is introduced into the product separation system, and the first catalytic cracking catalyst is placed in the first catalytic cracking catalyst A stripper is stripped and introduced into the first regenerator for regeneration, and the regenerated first catalytic cracking catalyst is introduced into the first riser reactor for recycling; wherein, the active component of the first catalytic cracking catalyst is mainly Y-type molecular sieve The catalyst particles and active components are mainly composed of β molecular sieve catalyst particles; the reaction temperature of the first riser reactor is 450-650°C, the agent-oil ratio is 1-25, and the reaction time is 0.5-10 seconds; (2) make light hydrocarbons and the second catalytic cracking catalyst containing pore diameter less than 0.7nm shape-selective molecular sieve contact reaction in second reactor; Described second reactor comprises the second riser reactor and fluidized bed connected in series Reactor, the oil gas reacted in the second riser reactor and the reacted second catalytic cracking catalyst are introduced into the fluidized bed reactor connected in series with the second riser reactor for reaction; the oil gas reacted in the fluidized bed is introduced into the product separation system The second catalytic cracking catalyst after the fluidized bed reaction is introduced into the second stripper for stripping and then introduced into the second regenerator for regeneration, and the regenerated second catalytic cracking catalyst is introduced into the second riser reactor for recycling; the light Hydrocarbons include gasoline fractions and/or C4 hydrocarbons; when the light hydrocarbons include gasoline fractions, the ratio of gasoline fraction to oil in the second riser reactor is 10 to 30, and the reaction time is 0.10 to 1.5 seconds; When the light hydrocarbons include C4 hydrocarbons, the operating agent-oil ratio of C4 hydrocarbons in the second riser is 12-40, and the reaction time is 0.50-2.0 seconds; the reaction temperature of the fluidized bed reactor is 500-650°C, and the The speed is 1 to 35 hours ^-1 . 2. according to the described method of claim 1, it is characterized in that, with active component mainly being the dry basis weight of the catalyst particle of Y-type molecular sieve, described active component is mainly that the catalyst particle of Y-type molecular sieve comprises 10～ 70% by weight of Y-type molecular sieve, 0-60% by weight of clay, 15-60% by weight of inorganic oxide binder; based on the dry weight of catalyst particles whose active component is mainly β molecular sieve, the activity The catalyst particles whose components are mainly β molecular sieves include 10-70% by weight of β-type molecular sieves, 0-60% by weight of clay, and 15-60% by weight of inorganic oxide binders; the active components are mainly Y-type The weight ratio of the catalyst particles of molecular sieve to the catalyst particles whose active component is mainly β molecular sieve is 4-1:1-4. 3. according to the described method of claim 2, it is characterized in that, the catalyst particle that described active component is mainly Y-type molecular sieve comprises the Y-type molecular sieve of 25～50% by weight, the clay of 25～50% by weight and 25～50% by weight % by weight of inorganic oxide binder; the active component is mainly β-type molecular sieve particles including 25-50% by weight of β-type molecular sieve, 25-50% by weight of clay and 25-50% by weight of inorganic oxide material binder. 4. according to the described method of claim 1, it is characterized in that, take the second catalytic cracking catalyst dry basis weight as a benchmark, described second catalytic cracking catalyst comprises 10～65% by weight of aperture less than 0.7nm shape-selective molecular sieve, 0-60% by weight of clay and 15-60% by weight of inorganic oxide binder. 5. according to the described method of claim 4, it is characterized in that, described second catalytic cracking catalyst comprises the aperture of 20～50% by weight less than the shape-selective molecular sieve of 0.7nm, the clay of 10～45% by weight, 25～50% by weight % of inorganic oxide binder. 6. according to the described method of claim 1, it is characterized in that, the operating conditions of the first riser reactor: reaction temperature is 480～600 ℃; Agent-oil ratio is 5～20; Reaction time is 1～10 seconds; Reaction The pressure is 0.15-0.35 MPa. 7. according to the described method of claim 1, it is characterized in that, when described light hydrocarbon comprises gasoline fraction, described gasoline fraction is 15～25 in the operating agent oil ratio in the second riser, and reaction time is 0.30～ 0.8 seconds. 8. according to the described method of claim 1 or 7, it is characterized in that, when described light hydrocarbon comprises C4 hydrocarbon, C4 hydrocarbon in the second riser reactor operating agent oil ratio is 17～30, reaction time 0.8 to 1.5 seconds. 9. according to the described catalytic cracking method of claim 1, it is characterized in that, described heavy feedstock is heavy hydrocarbons and/or various animal and vegetable oil feedstocks rich in hydrocarbons, and described heavy hydrocarbons One or more mixtures selected from petroleum hydrocarbons, mineral oils and synthetic oils. 10. The catalytic cracking method according to claim 1, wherein said light hydrocarbons include gasoline fraction and/or C4 hydrocarbons from said product separation system. 11. The method according to claim 1, characterized in that the cracked heavy oil obtained by the product separation system is introduced into the middle and downstream of the second riser reactor and/or introduced into the bottom of the fluidized bed reactor. 12. according to the described method of claim 1, it is characterized in that, the catalytic cracking unit that this method is used comprises riser reactor (1), the gas-solid separation equipment ( 7), the riser reactor (2), the fluidized bed reactor (3) connected in series with the riser reactor (2), the gas-solid separation equipment (8) of the fluidized bed reactor, the settler (9), The stripper partition (5) and the first stripping zone (51) and the second stripping zone (52) separated by the partition (5); the catalyst outlet position of the gas-solid separation device (7) makes it separate The catalyst obtained enters the first stripping zone (51), and the top of the first stripping zone is communicated with the settler (9); the inlet of the gas-solid separation device (8) is communicated with the settler (9), and the gas-solid separation device ( 8) The catalyst outlet position makes its separated catalyst can enter the second stripping zone (52) or fluidized bed reactor (3); the gas-solid separation device (7) is connected with the oil-gas outlet of the gas-solid separation device (8) Afterwards, it is communicated with the oil-gas separation system; the top of the fluidized bed reactor (3) is communicated with the settler (9), and the bottom of the fluidized bed reactor (3) is communicated with the stripping zone (52). 13. The method according to claim 12, characterized in that the riser reactor (2) and/or the fluidized bed reactor (3) further comprises an inlet for cracking heavy oil.