阅读说明：本技术 一种用于劣质重油生产烯烃、芳烃的加工工艺 (Processing technology for producing olefin and aromatic hydrocarbon from inferior heavy oil ) 是由 韩保平 张小康 刘江 张琪 于 2019-07-03 设计创作，主要内容包括：本发明提供了一种用于劣质重油生产烯烃、芳烃的方法,劣质重油进行沸腾床加氢,在催化裂解提升管反应器内进行催化裂解,反应产物进入分馏吸收稳定单元；分馏所得的气体馏分进入气体精分离单元,分离出的C2+烷烃气体送入蒸汽裂解装置进一步产生烯烃；而分馏所得的石脑油进入芳烃抽提单元,得到苯、甲苯、二甲苯产品；分馏所得的重质循环油以及油浆则返回进入前处理工序；本发明所述的一种用于劣质重油生产烯烃、芳烃的方法,在最大程度上降低对原料的要求,提高了劣质重油转化为高附加值的烯烃及芳烃的转化率,有效缓解了催化剂失活及结焦问题,延长了生产设备的运行周期,实现经济效益最大化。(The invention provides a method for producing olefin and aromatic hydrocarbon from inferior heavy oil, wherein the inferior heavy oil is hydrogenated in a fluidized bed, catalytic cracking is carried out in a catalytic cracking riser reactor, and a reaction product enters a fractionation absorption stabilizing unit; feeding the gas fraction obtained by fractionation into a gas fine separation unit, and feeding the separated C2+ alkane gas into a steam cracking device to further generate olefin; and the naphtha obtained by fractionation enters an aromatic extraction unit to obtain benzene, toluene and xylene products; returning the heavy cycle oil and the oil slurry obtained by fractionation to a pretreatment process; the method for producing olefin and aromatic hydrocarbon from inferior heavy oil disclosed by the invention has the advantages that the requirement on raw materials is reduced to the greatest extent, the conversion rate of the inferior heavy oil into olefin and aromatic hydrocarbon with high added values is improved, the problems of catalyst deactivation and coking are effectively relieved, the operation period of production equipment is prolonged, and the maximization of economic benefit is realized.)

1. A processing technology for producing olefin and aromatic hydrocarbon from inferior heavy oil is characterized in that the inferior heavy oil is hydrogenated in a fluidized bed, catalytic cracking is carried out in a catalytic cracking riser reactor, and a reaction product enters a fractionation absorption stabilizing unit; feeding the gas fraction obtained by fractionation into a gas fine separation unit, and feeding the separated C2+ alkane gas into a steam cracking device to further generate olefin; and the naphtha obtained by fractionation enters an aromatic extraction unit to obtain benzene, toluene and xylene products; and returning the heavy cycle oil and the oil slurry obtained by fractionation to the pretreatment process.

2. The process for producing olefins and aromatic hydrocarbons from heavy oil of low quality as claimed in claim 1, wherein the catalyst for fluidized bed hydrogenation is a spherical catalyst with particle size of 0.6-2 mm and alumina as carrier and at least one of Mo, W, Ni or Co as active ingredient.

3. The process of claim 1, wherein the low-grade heavy oil comprises at least one of heavy crude oil, atmospheric residue, vacuum residue, catalytic cracking slurry oil, deasphalted oil, visbroken heavy oil, coker heavy oil, shale oil, oil sand bitumen oil, heavy cycle oil; wherein the property of the inferior heavy oil is one of the following indexes: the solid content is more than or equal to 10g/L, the Conradson carbon residue value is 10-25 wt%, the asphaltene content is 8-35 wt%, the toluene insoluble content is 1-5 wt%, and the metal impurity content is 15-600 ppm.

4. The process for producing olefins and aromatics from heavy oil of low quality as claimed in claim 1, wherein the hydrogenated heavy oil of low quality is fractionated before the heavy oil of low quality enters the catalytic cracking riser reactor.

5. The process for producing olefins and aromatics from inferior heavy oil according to claim 1, comprising the steps of:

s1, feeding the inferior heavy oil into a fluidized bed hydrogenation reaction unit for hydrogenation to obtain hydrogenated reaction distillate;

s2, feeding the reaction distillate into a catalytic cracking heavy oil riser reactor to perform fluidized catalytic cracking reaction;

s3, enabling reaction products generated by catalysis to enter a fractionation absorption stabilizing system to obtain gas fractions, naphtha and heavy oil;

s4, feeding naphtha into an aromatic extraction unit to obtain benzene, toluene and xylene products, and feeding C6-C8 non-aromatic components and C5 components into a steam cracking device to perform steam cracking reaction; returning the C8+ fraction to the catalytic cracking riser reactor for catalytic cracking reaction;

s5, feeding the gas fraction obtained by fractionation into a gas fine separation unit to obtain hydrogen, methane, ethylene and butylene products, and feeding the separated C2+ alkane gas into a steam cracking device for steam cracking reaction;

s6, returning the reaction product of steam cracking to a fractionation, absorption and stabilization system for separation;

and S7, returning the heavy oil and the slurry oil obtained by fractionation to the ebullated bed hydrogenation reaction unit or the catalytic cracking heavy oil riser for further reaction and conversion.

6. The process of claim 5, wherein the catalytic cracking reaction in step S2 is a single-riser, zone-feed, zone-separation reaction or a dual-riser zone-feed reaction or a dual-riser non-zone-feed reaction.

7. The process of claim 5, wherein the butenes separated in the step S5 are sold or enter a reactor for aromatization, and the reaction conditions are as follows: the reaction pressure is 0.3-0.5 MPa, the inlet temperature is 280-450 ℃, the volume space velocity is 0.5-0.8 h < -1 >, and the reaction product and naphtha obtained by the treatment of the fractionation absorption stabilizing unit enter the aromatic extraction unit for treatment.

8. The process of claim 5, wherein in step S1, the hydrogenation conditions of the ebullated bed in the hydrogenation unit are: the reaction pressure is 15-20 MPa, the inlet temperature is 220-260 ℃, and the volume space velocity is 0.6-1.2 h^-1The reaction temperature is 380-410 ℃, and the hydrogen-oil ratio is 600: 1-800: 1Nm³/m³。

Technical Field

The invention belongs to the technical field of petrochemical industry, and particularly relates to a processing technology for producing olefin and aromatic hydrocarbon from inferior heavy oil.

Background

Ethylene, propylene and butadiene are basic raw materials in the petrochemical industry, and the use amount of the ethylene, the propylene and the butadiene is rapidly increased year by year along with the development of economy. In order to meet the demand of these light olefins, conventional steam cracking technology is still under constant construction and development, and is still the largest source of light olefins. Meanwhile, the technology of catalytic cracking for producing more olefins is rapidly developed and becomes one of the sources of low-cost olefins, but the yield is limited, and the market supply of the low-carbon olefins is not influenced. Aromatic hydrocarbons represented by benzene, toluene and xylene are also important organic chemical raw materials, and are widely applied to industries of synthetic fibers, synthetic resins, synthetic rubbers and the like. At present, more than 70% of the triphenyl in the petrochemical industry is produced from a catalytic reforming device. The reforming unit has high investment, high requirement on raw materials and high operation cost, so the cost of aromatic hydrocarbon is always high. The olefins and aromatics are now produced from high-quality naphtha, and the demand of the petrochemical industry for low-cost olefins and aromatics is still very urgent.

Meanwhile, in the petrochemical production, a large amount of heavy fuel oil which is difficult to process by adopting a conventional process route is generated, and the heavy fuel oil becomes a low-cost raw material which is sufficiently supplied in the market. Such as domestic tower and river oil, superheavy oil from venezuela, oil sand bitumen from canada, and heavy fuel oil from russia (M100, M180, M380, etc.). Heavy fuel oil represented by M100 has high metal content, high colloid asphaltene content, high sulfur and nitrogen content, high density, high carbon residue value and difficult processing. If the inferior heavy oil is used as the raw material and the short process flow is adopted, the low-carbon olefin and the light aromatic hydrocarbon with high added value can be produced, and the method has wide prospect in the market undoubtedly.

At present, heavy oil treatment processes are divided into three types: (1) carrying out coking reaction; (2) dissolving and removing asphalt; (3) and (3) performing fixed bed hydrogenation reaction. Among them, the coking reaction is the most thorough decarburization process, but the coking process can produce about 30% of low-value coke, i.e. a part of oil is converted into coke, and the economy is poor. The asphalt dissolving and removing process is a physical process, light fuel is not directly produced, the process operation is complex, the energy consumption is high, and the main application is limited to producing lubricating oil raw materials. The fixed bed heavy oil hydrogenation is an important means for heavy oil modification and lightening, and has the advantages of good product quality, high light oil yield and the like, but when the fixed bed technology is used for treating inferior heavy oil, a catalyst bed is easy to coke, and the normal operation of a device is seriously influenced.

Under the influence, the conventional fixed bed hydrotreating process cannot increase the treatment depth and efficiently convert colloid, asphaltene and heavy components with the temperature of more than 525 ℃, so that the fixed bed technology can only be used for light raw materials with low metal content and cannot process inferior heavy oil with high metal and carbon residue content. Taking the fixed bed heavy oil hydrogenation technology as an example, only heavy oil with metal content lower than 150 mug/g and Conradson carbon residue lower than 15% can be processed. In fact, when the metal content is higher than 100. mu.g/g, the service life of the catalyst is seriously affected. Therefore, how to effectively pretreat the inferior heavy oil to reduce the problems of easy inactivation of the catalyst and easy coking of reaction equipment in the conversion of the inferior heavy oil into light oil is one of the key points in the development of the processing and treating technology of the inferior heavy oil.

CN1119397C discloses a residual oil hydrotreating-catalytic cracking combined process method, in which residual oil and clarified oil enter a residual oil hydrogenation device together, and react in the presence of hydrogen and a hydrogenation catalyst, and heavy cycle oil circulates in the catalytic cracking device; and separating the oil slurry obtained by the reaction by a separator to obtain clarified oil, and returning the clarified oil to the hydrogenation device. However, when the slurry oil enters the residual oil hydrotreatment device, coke deposits can be increased by coke-prone substances in the slurry oil, the hydrogenation activity and the operation period of the hydrogenation catalyst are reduced, and the heavy cycle oil is in the catalytic cracking device. Therefore, the method has limited effect on processing inferior heavy oil and improving the product quality.

At present, butylene is mainly derived from steam thermal cracking and hydrocarbon oil catalytic cracking of MTO, butane, LPG, condensate oil, naphtha, hydrocracking tail oil, gas oil and the like, and light aromatic hydrocarbon (benzene, toluene and xylene, BTX for short) is mainly derived from a light hydrocarbon reforming process and a steam thermal cracking process. With the use of new light feedstocks for steam cracking, the product distribution will change, for example, with ethane as the steam cracking feedstock, the ethylene fraction in the product will increase significantly and the yields of butenes and light aromatics will decrease compared to naphtha as the feedstock. Under the background, the method for producing the low-carbon olefin and the light aromatic hydrocarbon by using the catalytic conversion of the inferior heavy oil is an effective supplementary measure for preparing the ethylene by steam thermal cracking.

At present, more than 40 kinds of metal elements are detected in heavy oil, the content generally ranges from a few ppm to thousands of ppm, and certain metal elements (particularly nickel and vanadium) can damage catalysts in catalytic cracking and catalytic hydrogenation processes in a petroleum refining process. The metal impurities contained in the heavy oil not only cause the poisoning deactivation of the catalyst, the corrosion and scaling of the associated equipment, but also cause the pollution of the petroleum products. These problems not only bring serious safety hazards to the processing of heavy oil, but also cause the reduction of economic benefits of oil processing enterprises.

How to fully utilize various inferior heavy oil resources to combine hydrogenation, catalytic cracking and steam cracking to produce olefin and aromatic hydrocarbon, reduce the influence of metal impurities in heavy oil, effectively reduce the inactivation of a catalyst and the coking rate of equipment, and ensure the long running period of the equipment is a problem to be solved urgently at present.

Disclosure of Invention

In view of the above, the present invention aims to provide a method for producing olefins and aromatics from inferior heavy oil, so as to solve the problems in the prior art that inferior heavy oil is difficult to utilize, a catalyst is easy to deactivate during a treatment process, and the coking rate of equipment is high, and simultaneously produce more olefins and aromatics.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a processing technology for producing olefin and aromatic hydrocarbon from inferior heavy oil comprises subjecting inferior heavy oil to fluidized bed hydrogenation, performing catalytic cracking in a catalytic cracking riser reactor, and allowing reaction products to enter a fractionation absorption stabilization unit; feeding the gas fraction obtained by fractionation into a gas fine separation unit, and feeding the separated C2+ alkane gas into a steam cracking device to further generate olefin; and the naphtha obtained by fractionation enters an aromatic extraction unit to obtain benzene, toluene and xylene products; and returning the heavy cycle oil and the oil slurry obtained by fractionation to the pretreatment process.

Furthermore, the catalyst for fluidized bed hydrogenation is a spherical catalyst which takes alumina as a carrier, takes at least one of Mo, W, Ni or Co as an active ingredient and has a particle size of 0.6-2 mm.

Further, the inferior heavy oil comprises at least one of thick crude oil, atmospheric residue oil, vacuum residue oil, catalytic cracking slurry oil, deasphalted oil, visbroken heavy oil, coking heavy oil, shale oil, oil sand bitumen oil and heavy cycle oil; wherein the properties of the inferior heavy oil meet one or more of the following indexes: the solid content is more than or equal to 10g/L, the Conradson carbon residue value is 10-25 wt%, the asphaltene content is 8-35 wt%, the toluene insoluble content is 1-5 wt%, and the metal impurity content is 15-600 ppm.

Furthermore, before the inferior heavy oil enters the catalytic cracking riser reactor, the reaction product after hydrogenation is fractionated.

Further, the processing technology of the inferior heavy oil comprises the following steps:

s1, feeding the inferior heavy oil into a fluidized bed hydrogenation reaction unit for hydrogenation to obtain a hydrogenated reaction distillate;

s2, enabling the hydrogenation reaction product to enter a catalytic cracking heavy oil riser reactor to carry out fluidized catalytic cracking reaction;

s3, enabling the catalytic reaction product to enter a fractionation absorption stabilizing system to obtain gas fraction, naphtha and heavy oil;

s4, feeding naphtha into an aromatic extraction unit to obtain products such as benzene, toluene, xylene and the like, and feeding C6-C8 nonaromatic components and C5 components into a steam cracking device for steam cracking reaction; returning the C8+ fraction to the catalytic cracking riser reactor for catalytic cracking reaction;

s5, feeding the gas fraction obtained by fractionation into a gas fine separation unit to obtain products such as hydrogen, methane, ethylene, butylene and the like, and feeding the separated C2+ alkane gas into a steam cracking device for steam cracking reaction;

s6, returning the reaction product of steam cracking to a fractionation, absorption and stabilization system for separation;

and S7, returning the heavy oil and the slurry oil obtained by fractionation to a hydrogenation reaction unit or a catalytic cracking heavy oil riser for further reaction and conversion.

Further, the catalytic cracking reaction in step S2 is a single-riser, zoned feed, zoned reaction or a dual-riser zoned feed reaction or a dual-riser non-zoned feed reaction.

Further, the butene separated in the step S5 is sold or enters a reactor for aromatization reaction, and the reaction conditions are as follows: the reaction pressure is 0.3-0.5 MPa, the inlet temperature is 280-450 ℃, the volume space velocity is 0.5-0.8 h < -1 >, and the reaction product and naphtha obtained by the treatment of the fractionation absorption stabilizing unit enter the aromatic extraction unit for treatment.

Further, depending on the raw materials, step S1 may employ a single-stage ebullated bed, a multi-stage ebullated bed, a fixed bed, or a combination thereof; preferably, the ebullated bed hydrogenation reaction unit in step S1 adopts three-stage hydrogenation reactions, namely a third ebullated bed (11), a first ebullated bed (12) and a second ebullated bed (13). Accordingly, step S1 includes: s11: pumping the inferior heavy oil to a hydrogenation reaction unit, wherein the hydrogenation reaction unit comprises; s12: judging whether the Conradson carbon residue value in the inferior heavy oil is more than or equal to 20 percent; if yes, go to step S14; otherwise, go to step S13; s13: judging whether the Conradson carbon residue value in the inferior heavy oil is more than or equal to 15 percent; if yes, go to step S15; otherwise, go to step S16; s14: inferior heavy oil is pumped into a third boiling bed (11), a first boiling bed (12) and a second boiling bed (13) in sequence, and the inferior heavy oil is mixed with hydrogen respectively and then reacts for hydrogenation; s15: pumping the inferior heavy oil into a first boiling bed (12) and a second boiling bed (13) in sequence, mixing the inferior heavy oil with hydrogen respectively, and then reacting and hydrogenating the mixture; s16: pumping the inferior heavy oil into a second boiling bed (13), mixing with hydrogen, and reacting and hydrogenating.

Further, in step S1, the hydrogenation conditions of the ebullated bed in the hydrogenation reaction unit are: the reaction pressure is 15-20 MPa, the inlet temperature is 220-260 ℃, and the volume space velocity is 0.6-1.2 h^-1The reaction temperature is 380-410 ℃, and the hydrogen-oil ratio is 600: 1-800: 1Nm³/m³。

Compared with the prior art, the method for producing olefin and aromatic hydrocarbon from inferior heavy oil has the following advantages:

(1) according to the invention, the hydrogenation reaction unit is used for carrying out fluidized bed hydrogenation to remove heavy metals, and meanwhile, the classification treatment is carried out according to the content of the Conradson carbon residue, so that the hydrogenation efficiency is ensured, the problem of equipment coking caused by sediment deposition in the reactor can be effectively relieved, the running period of the reaction equipment is prolonged, and the equipment treatment capacity is improved.

(2) The invention organically combines fluidized bed hydrogenation, catalytic cracking, steam cracking and aromatization, and shares a set of aromatic extraction device to form a complete reaction system for converting inferior heavy oil into olefin and aromatic hydrocarbon, thereby fully playing the advantages of each device and section, avoiding repeated heating of raw materials, reducing energy consumption, simultaneously improving the conversion rate of inferior heavy oil and the yield of olefin, aromatic hydrocarbon, especially aromatic hydrocarbon, and improving production benefit.

(3) According to the invention, two-stage fractionation is adopted, the hydrogenated inferior heavy oil is subjected to primary fractionation, and each fraction is respectively treated, so that the reaction efficiency of a catalytic cracking unit is improved, the treatment capacity of equipment is increased, and the energy consumption ratio is effectively reduced; meanwhile, the inferior heavy oil after catalytic cracking is subjected to fractionation and absorption stabilization, namely secondary fractionation, so that the reaction efficiency of a steam cracking unit is improved, the yield of olefin and aromatic hydrocarbon is increased, and the energy efficiency ratio is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic process flow diagram of a method for producing olefins and aromatics from low-quality heavy oil according to the present invention;

FIG. 2 is an example of the present invention employing a 3-stage ebullated bed reactor;

FIG. 3 is a schematic of a process flow scheme for use in conjunction with fixed bed pyrolysis of naphtha in accordance with the present invention;

fig. 4 is a schematic of a process flow for use in conjunction with butene aromatization in accordance with the present invention.

Description of reference numerals:

a third bubbling bed 11, a first bubbling bed 12, a second bubbling bed 13, a main pipe 14, a first series pipe 111, a first feed pipe 112, a second series pipe 121, a second feed pipe 122, and a third feed pipe 132.

Detailed Description

The technical solutions in the embodiments of the present invention are further described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

The invention provides a method for producing olefin and aromatic hydrocarbon from inferior heavy oil aiming at the current situation of the current inferior heavy oil processing technology, which utilizes the ebullated bed hydrogenation technology to pretreat the inferior heavy oil, carries out catalytic cracking in a catalytic cracking riser reactor, and the reaction product enters a fractionation absorption stabilizing unit; the gas fraction obtained by fractionation enters a gas fine separation unit, and the separated gases such as C2+ alkane and the like are sent to a steam cracking device to further generate olefin; and the naphtha obtained by fractionation enters an aromatic extraction unit to obtain products such as benzene, toluene, xylene and the like; and returning the heavy cycle oil and the oil slurry obtained by fractionation to the pretreatment process.

The poor heavy oil has the characteristics of extremely complex composition, high viscosity, low API degree, high heavy metal content and the like, and particularly has the characteristic of high metal content, so that the petroleum processing is difficult, when the content of the Conradson carbon residue of the poor heavy oil is high, deposition and coking are easy to occur in the processing process, and the poor heavy oil is not suitable for being used as a raw material of the conventional fixed bed residual oil hydrocracking technology. The invention removes heavy metals by a fluidized bed hydrogenation technology and simultaneously reduces the content of Conradson carbon residue in inferior heavy oil. Through the fluidized bed hydrogenation, the hydrogenation requirement of different grades of inferior heavy oil can be met, the problems of system coking and deposition caused by high content of Conradson carbon residue can be effectively relieved, the operation period and the stability of the equipment are increased, and the deep hydrogenation of the inferior heavy oil is realized. In addition, the invention organically combines the hydrogenation, catalytic cracking, steam cracking and aromatization of the fluidized bed, the products and the raw materials of the fluidized bed are supported by each other, and the downstream separation unit is shared, so that the inferior heavy oil is dried and squeezed to the maximum extent, simultaneously, olefin and aromatic hydrocarbon are produced as much as possible, the operation period of each device in the system can be effectively prolonged, and the production cost is reduced.

Specifically, as shown in fig. 1, the method for producing olefins and aromatic hydrocarbons from inferior heavy oil comprises the following steps:

s1, mixing and preheating the treated inferior heavy oil and hydrogen, and introducing the mixture into a hydrogenation reaction unit for fluidized bed hydrogenation to obtain hydrogenated inferior heavy oil, wherein the hydrogenation treatment unit can convert fractions with the temperature higher than 500 ℃ in the inferior heavy oil into light components;

s2, feeding the hydrogenation distillate into a catalytic cracking heavy oil riser reactor to perform fluidized catalytic cracking reaction;

s3, enabling the catalytic reaction product to enter a fractionation absorption stabilizing system to obtain gas fraction, naphtha and heavy oil;

s4, the naphtha enters an aromatic extraction unit to obtain products such as benzene, toluene, xylene and the like, and in addition, C6-C8 non-aromatic components and C5 components are subjected to steam cracking reaction in a steam cracking device; returning the C8+ fraction to the catalytic cracking riser reactor for catalytic cracking reaction;

s5, feeding the gas fraction obtained by fractionation into a gas fine separation unit to obtain products such as hydrogen, methane, ethylene, butylene and the like, and feeding the separated gases such as C2+ alkane and the like into a steam cracking device for steam cracking reaction;

s6, returning the reaction product of steam cracking to the fractionation, absorption and stabilization unit for separation;

and S7, returning the heavy cycle oil and the slurry oil obtained by fractionation to the hydrogenation reaction unit or the catalytic cracking heavy oil riser for further reaction and conversion, and preferably returning to the ebullated bed hydrogenation reaction unit.

The catalytic cracking reaction in step S2 may be a single-riser, zoned-feed, zoned-reaction, or a dual-riser zoned-feed or non-zoned-feed reaction, and is preferably a dual-riser non-zoned-feed reaction. In addition, before the poor-quality heavy oil enters the catalytic cracking riser reactor, the hydrogenated poor-quality heavy oil is subjected to primary fractionation, and each fraction is respectively treated, so that the reaction efficiency of subsequent catalytic cracking units is improved, the treatment capacity of equipment is increased, and the energy consumption ratio is effectively reduced. Specifically, heavy oil components obtained by fractionation are conveyed to a catalytic cracking riser reactor for treatment; and (3) introducing the gas component obtained by fractionation into a gas fine separation unit for treatment, and introducing naphtha obtained by fractionation into an aromatic extraction unit for treatment.

The butenes separated in the step S5 can enter a reactor, a catalyst is added for aromatization reaction, and the reaction products and naphtha obtained by the treatment of the fractionation absorption stabilizing unit enter an aromatic extraction unit for treatment; the reaction temperature is 700-860 ℃, the residence time in the furnace is 0.1-1.0 s, and the total reaction pressure is 0-0.1 MPa. The reaction raw materials are light alkane from a gas fine separation unit, and C6-C8 non-aromatic part and C5 fraction of an aromatic hydrocarbon extraction unit. The reaction raw materials can also be supplemented from the outside.

Among them, the C2+ component, the C5 component, the C6-C8 nonaromatic component and the C8+ fraction are all clearly known to those skilled in the art from the prior art and are not listed.

H obtained by reaction₂Can be used for hydrogenation reaction in the S1 step, and can also be sold.

The fractionation absorption stabilization unit in step S3 is shared by catalytic cracking and steam cracking, and mainly comprises a fractionation tower, an absorption tower, a reabsorption tower, a desorption tower, and a stabilization tower.

In addition, the operating conditions in the method are specifically as follows:

TABLE 1 operating conditions of the ebullated-bed reactor

TABLE 2 operating conditions of the catalytic cracking reactor

TABLE 3 operating conditions of aromatization reactor

TABLE 4 steam cracking Process conditions

In addition, the catalysts used for the reactions in the process are respectively: the catalyst of the fluidized bed is a spherical catalyst, the particle diameter is 0.6-2 mm, alumina is used as a carrier, and at least one of Mo, W, Ni or Co is used as an active component; the catalytic cracking catalyst is alumina or alumina-silica containing molecular sieve; the aromatization catalyst is at least one of ZSM-5, Y, Beta or MCM-41 molecular sieve; the catalysts used in the steam cracking reaction are those commonly used in the art.

In step S6, heavy oil is collected from the bottom of the fractionating tower, and the rich gas separated from the top of the fractionating tower contains naphtha components, while the crude naphtha separated from the bottom of the fractionating tower contains C3 and C4 components dissolved therein. Preferably, the rich gas is absorbed by using raw naphtha as a solvent, and the rich gas and the raw naphtha are finally separated into a gas fraction and naphtha.

Aiming at various components generated in the process of treating the inferior heavy oil, the invention adopts targeted treatment equipment and methods to carry out combination and cyclic treatment to obtain olefin and aromatic hydrocarbon products, thereby realizing the advanced treatment and utilization of the inferior heavy oil. In addition, the invention organically combines equipment such as fluidized bed hydrogenation, catalytic cracking, steam cracking, aromatic hydrocarbon extraction, fractionation and the like, and shares a set of aromatic hydrocarbon extraction device and fractionation absorption stabilizing device to form a complete inferior heavy oil treatment system, thereby fully playing the advantages of each device and section, realizing 'drying and squeezing out' of inferior heavy oil as far as possible, simultaneously avoiding repeated heating of raw materials, reducing energy consumption and improving production benefits. Meanwhile, the invention utilizes the fluidized bed to carry out hydrogenation reaction, and effectively removes metal impurities in the inferior heavy oil, thereby ensuring the service life of the catalyst in the subsequent reaction, improving the operation efficiency of the equipment, prolonging the operation period of each device in the system and reducing the production cost.

In the invention, the inferior heavy oil comprises at least one of heavy crude oil, atmospheric residue oil, vacuum residue oil, catalytic cracking slurry oil, deasphalted oil, visbreaking heavy oil, coking heavy oil, shale oil, oil sand bitumen oil and heavy cycle oil, wherein the property of the inferior heavy oil meets one or more of the following indexes: the solid content is more than or equal to 10g/L, the Conradson carbon residue value is 10-25 wt%, and the content of metal impurities is 15-600 ppm. The method of the present invention can effectively treat the inferior heavy oil of the parameter index, but is not limited to the inferior heavy oil of the parameter index.

Wherein, the Conradson carbon residue value of the heavy oil is detected according to GB268-1987 & methods for determining carbon residue of petroleum products (Conradson method); detecting the content index of toluene insoluble substances according to GB/T2292-1997 determination of toluene insoluble substances in coking products; and detecting the solid content index in the heavy oil by using a commercially available oil solid content detector.

The content of metal impurities in the heavy oil is determined according to the following method: 10g of oil sample is weighed in a dry quartz crucible, 10mL of petroleum ether and 10mL of absolute ethyl alcohol are added respectively, the mixture is uniformly mixed, and then a temperature-regulating electric heater is used for slowly heating until the mixture is ignited. After the flame is extinguished and cooled, the quartz crucible is placed in a muffle furnace, the temperature is set to 550 ℃, and the quartz crucible is burned for 6 hours to remove carbon in the quartz crucible. After cooling, the inner wall of the crucible was rinsed with 3-4mL of ultrapure water to wet the sample, and then 3mL of an aqueous hydrochloric acid solution (1: 1) and 10mL of an aqueous nitric acid solution (1: 1) were measured in this order and added to the crucible. The solution was heated slowly again in a temperature-controlled electric heater to dissolve the ash and to volatilize most of the acid (2-3 ml remaining), after cooling, transferred to a 25ml volumetric flask and made to capacity with ultra pure water. The amount of metal in the prepared solution was determined using inductively coupled plasma emission spectroscopy (ICP-AES).

In the hydrogenation reaction unit, according to the different contents of the Conradson carbon residue in the inferior heavy oil, a single-stage fluidized bed, a multi-stage fluidized bed or a combined hydrogenation technology of the single-stage fluidized bed, the multi-stage fluidized bed and the fixed bed can be adopted, so that the inferior heavy oil can be hydrogenated more thoroughly, the problems of system coking and deposition caused by high content of the Conradson carbon residue can be effectively solved, the operation period and the stability of equipment can be effectively increased, and the hydrogenation requirements of different inferior heavy oils can be met.

The following examples are presented to further illustrate the embodiments of the present invention and are not intended to limit the scope of the invention.