Fluidized bed catalytic conversion process for the production of low-carbon olefins from hydrocarbons.

Abstract

The invention proposes a fluidized bed catalytic conversion process for the production of low-carbon olefins (light olefins) from hydrocarbons, including: catalytic conversion of olefin-rich feedstock in the first reaction zone of a fluidized bed catalytic converter, contacting the heavy feedstock with the reaction stream from the first reaction zone in the second reaction zone of the reactor for reaction, separation of effluent from the reactor, and recycling the resulting olefin-rich stream back to the first reaction zone for further reaction. This process can improve the utilization rate of petrochemical resources and yield high production and selectivity of ethylene, propylene, and butylene.

Description

A fluidized catalytic conversion method for producing light olefins from hydrocarbons

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to patent application number 202110031551.4, filed on January 11, 2021, entitled “A catalytic conversion method for producing ethylene, propylene and butene”, patent application number 202110245789.7, filed on March 5, 2021, entitled “A catalytic conversion method for maximizing the production of ethylene and concurrently producing propylene”, and patent application number 202110296896.2, filed on March 19, 2021, entitled “A catalytic conversion method for producing low-carbon olefins”, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present application relates to the technical field of fluidized catalytic conversion, and in particular to a fluidized catalytic conversion method for producing light olefins from hydrocarbons. Background Art

[0004] Olefins with four carbon atoms or fewer are important chemical raw materials, with typical products including ethylene, propylene, and butene. On the one hand, with the accelerating economic development, demand for light oil products and clean fuel oil is rapidly increasing across various industries. On the other hand, with the continuous increase in oil field production, the available output of conventional crude oil is decreasing, and crude oil quality is deteriorating, tending towards inferior and heavier grades. Although my country's light olefin production capacity has grown rapidly, it currently cannot meet the domestic market demand for light olefins.

[0005] Among them, the main products produced from ethylene include polyethylene, ethylene oxide, ethylene glycol, polyvinyl chloride, styrene, and vinyl acetate. The main products produced from propylene include acrylonitrile, propylene oxide, and acetone. The main products produced from butene include butadiene, which is also used to make methyl ethyl ketone, sec-butyl alcohol, butylene oxide, and butene polymers and copolymers. The main products produced from isobutylene include butyl rubber, polyisobutylene rubber, and various plastics. Therefore, ethylene, propylene, and butene are used to produce a variety of important organic chemical raw materials, synthetic resins, synthetic rubber, and various fine chemicals, and demand is growing.

[0006] The petroleum route uses traditional steam cracking to produce ethylene and propylene, which requires a large amount of light hydrocarbons, such as naphtha, for chemical production. It is estimated that 700,000 tons of chemical light oil will be needed annually by 2025. However, domestic crude oil is generally heavy, and chemical light oil cannot meet the demand for the raw materials for producing ethylene, propylene, and butenes. Steam cracking feedstocks mainly include light hydrocarbons (such as ethane, propane, and butane), naphtha, diesel, condensate, and hydroprocessing tail oil. Of these, naphtha accounts for over 50% by mass. The ethylene yield of a typical naphtha steam cracking process is approximately 29%-34%, and the propylene yield is 13%-16%. The low ethylene / propylene output ratio makes it difficult to meet the current demand for low-carbon olefins.

[0007] CN101092323A discloses a method for producing ethylene and propylene using a C4-C8 olefin mixture as a raw material, conducting a reaction at a temperature of 400-600°C and an absolute pressure of 0.02-0.3 MPa, and recycling 30-90% by weight of the C4 fraction via a separation device into a reactor for further cracking. This method primarily improves olefin conversion by recycling the C4 fraction, resulting in ethylene and propylene of no less than 62% of the total raw olefin content. However, the ethylene / propylene ratio is relatively small, making it difficult to flexibly adjust to market demand, and the reaction selectivity is low.

[0008] CN101239878A discloses a method using a C4 or higher olefin-rich mixture as a raw material, and carrying out the reaction at a reaction temperature of 400-680°C, a reaction pressure of -0.09 MPa to 1.0 MPa, and a weight space velocity of 0.1 to 50 h-1. The product ethylene / propylene ratio is low, less than 0.41. As the temperature rises, the ethylene / propylene ratio increases, and at the same time, the hydrogen, methane and ethane increase.

[0009] The non-petroleum route primarily uses oxygenated organic compounds, such as methanol or dimethyl ether, as feedstocks to produce light olefins, primarily ethylene and propylene. Methanol and dimethyl ether are typical oxygenated organic compounds. Their reaction characteristics for producing light olefins are rapid reaction, strong exotherm, low alcohol content, and a long induction period. Rapid catalyst deactivation is a major challenge facing the MTO process. Scientifically and efficiently addressing these issues, such as the long induction period and susceptibility to catalyst deactivation, has long been a challenge for researchers and engineers.

[0010] Therefore, in the new stage of transformation of oil refining enterprises into power centers integrating refining and chemical industry, the field urgently needs a new catalytic conversion model to integrate multiple catalytic conversion reaction forms and increase the production of high-value low-carbon olefins ethylene and propylene, and improve the selectivity of ethylene and propylene.

[0011] Summary of the Invention

[0012] The purpose of the present application is to provide a fluidized catalytic conversion method for producing light olefins (such as ethylene, propylene and butene) from hydrocarbons, which can significantly improve the yield and selectivity of ethylene, propylene and butene.

[0013] To achieve the above objectives, the present application provides a fluidized catalytic conversion method for producing light olefins from hydrocarbons, comprising the following steps:

[0014] 1) introducing an olefin-rich feedstock into a first reaction zone of a fluidized catalytic conversion reactor, contacting the feedstock with a catalytic conversion catalyst at a temperature of 650° C. or higher, and reacting the feedstock under first catalytic conversion conditions, wherein the feedstock has an olefin content of 50% by weight or higher;

[0015] 2) introducing the heavy feedstock into a second reaction zone of the fluidized catalytic conversion reactor located downstream of the first reaction zone, contacting the heavy feedstock with the catalytic conversion catalyst from the first reaction zone after the reaction in step 1), and reacting the heavy feedstock under second catalytic conversion conditions;

[0016] 3) separating the effluent from the fluidized catalytic conversion reactor to obtain reaction oil and gas and spent catalyst, and performing a first separation treatment on the reaction oil and gas to obtain ethylene, propylene, butene, a first catalytic cracking distillate, and a second catalytic cracking distillate; the first catalytic cracking distillate has an initial boiling point in the range of greater than 20° C. to less than 140° C., the second catalytic cracking distillate has an end boiling point in the range of greater than 250° C. to less than 550° C., and the cut point between the first catalytic cracking distillate and the second catalytic cracking distillate is in the range of 140-250° C.;

[0017] 4) performing a second separation treatment on the first catalytic cracking distillate to obtain an olefin-rich stream, wherein the olefin-rich stream has a C5 and above olefin content of at least 50% by weight; and

[0018] 5) returning at least a portion of the olefin-rich stream to step 1) to continue the reaction,

[0019] The first catalytic conversion conditions include:

[0020] The reaction temperature is 600-800°C, preferably 630-780°C;

[0021] The reaction pressure is 0.05-1 MPa, preferably 0.1-0.8 MPa;

[0022] The reaction time is 0.01-100 seconds, preferably 0.1-80 seconds;

[0023] The weight ratio of the catalytic conversion catalyst to the olefin-rich feedstock is (1-200):1, preferably (3-180):1; and

[0024] The second catalytic conversion conditions include:

[0025] The reaction temperature is 400-650°C, preferably 450-600°C;

[0026] The reaction pressure is 0.05-1 MPa, preferably 0.1-0.8 MPa;

[0027] The reaction time is 0.01-100 seconds, preferably 0.1-80 seconds;

[0028] The weight ratio of the catalytic conversion catalyst to the heavy feedstock is (1-100):1, preferably (3-70):1.

[0029] Optionally, the method may further comprise one or more of the following steps 6), 7) and 2a):

[0030] 6) contacting the second catalytically cracked distillate with a hydrogenation catalyst and reacting under hydrogenation reaction conditions to obtain a hydrocatalytically cracked distillate, and returning the hydrocatalytically cracked distillate to the fluidized catalytic conversion reactor for further reaction;

[0031] 7) upstream of the introduction point of the olefin-rich feedstock, returning at least a portion of the butenes separated in step 3) to the catalytic conversion reactor to contact with the catalytic conversion catalyst and react under third catalytic conversion conditions, wherein the third catalytic conversion conditions include:

[0032] The reaction temperature is 650-800°C, preferably 680-780°C,

[0033] The reaction pressure is 0.05-1MPa, preferably 0.1-0.8MPa,

[0034] The reaction time is 0.01-10 seconds, preferably 0.05-8 seconds,

[0035] The weight ratio of the catalytic conversion catalyst to the butene is (20-200):1, preferably (30-180):1; and

[0036] 2a) introducing the oxygen-containing organic compound into the second reaction zone of the fluidized catalytic conversion reactor to contact the catalytic conversion catalyst therein, and reacting under fourth catalytic conversion conditions, wherein the fourth catalytic conversion conditions include:

[0037] The reaction temperature is 300-550°C, preferably 400-530°C,

[0038] The reaction pressure is 0.01-1 MPa, preferably 0.05-1 MPa,

[0039] The reaction time is 0.01-100 seconds, preferably 0.0-80 seconds,

[0040] The weight ratio of the catalytic conversion catalyst to the oxygen-containing organic compound raw material is (1-100):1, preferably (3-50):1.

[0041] In the fluidized catalytic conversion method of the present application, catalytic cracking is performed on an olefin-rich raw material in the first reaction zone of the fluidized catalytic conversion reactor, and then the heavy raw material is contacted with the mixed material flow from the first reaction zone in the second reaction zone and subjected to a catalytic cracking reaction, and then the reaction product is subjected to a first separation treatment and a second separation treatment. The obtained olefin-rich stream can be used again for catalytic cracking, and the olefin-containing material in the reaction product itself is used to further produce light olefins, which can improve the utilization rate of petrochemical resources; the present application introduces heavy raw materials into the production process, realizes the recycling of heavy oil, and reduces costs; the fluidized catalytic conversion method for producing light olefins provided by the present application has high ethylene, propylene and butene yields and selectivities; the yields of benzene, toluene and xylene are also improved.

[0042] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the following detailed description, they are used to explain the present application but do not constitute a limitation of the present application. In the accompanying drawings:

[0044] FIG1 is a schematic flow diagram of a preferred embodiment of the fluidized catalytic conversion method of the present application;

[0045] FIG2 is a schematic flow diagram of another preferred embodiment of the fluidized catalytic conversion method of the present application; and

[0046] FIG3 is a schematic flow diagram of another preferred embodiment of the fluidized catalytic conversion method of the present application.

[0047] BRIEF DESCRIPTION OF THE DRAWINGS

[0048] I first reaction zone II second reaction zone III third reaction zone

[0049] 101 pipeline 102 reactor 103 pipeline

[0050] Pipeline 104, Pipeline 105, Pipeline 106

[0051] 107 outlet section 108 cyclone separator 109 air collecting chamber

[0052] 110 stripping section 111 pipeline 112 inclined pipe

[0053] 113 regenerator 115 pipeline 116 pipeline

[0054] 117 pipeline, 118 pipeline, 119 large oil and gas pipeline

[0055] 120 Fractionation Unit 121 Pipeline 122 Pipeline

[0056] Pipeline 123, Pipeline 124, Pipeline 125

[0057] Pipeline 126, Pipeline 127, Pipeline 128, Olefin Separation Unit

[0058] Pipeline 129, Pipeline 130, Pipeline 131, Hydrotreating Unit

[0059] 132 pipeline

[0060] 201 pipeline 202 reactor 203 pipeline

[0061] Pipeline 204, Pipeline 205, Pipeline 206

[0062] 207 outlet section 208 cyclone separator 209 air collecting chamber

[0063] 210 stripping section 211 pipeline 212 inclined pipe

[0064] 213 regenerator 215 pipeline 216 pipeline

[0065] 217 Pipeline, 218 Pipeline, 219 Large Oil and Gas Pipeline

[0066] 220 fractionation unit 221 pipeline 222 pipeline

[0067] Pipeline 223, Pipeline 224, Pipeline 225

[0068] Pipeline 226, Pipeline 227, Pipeline 228, Olefin Separation Unit

[0069] Pipeline 229, Pipeline 230, Pipeline 231

[0070] 232 Hydroprocessing Unit 233 Pipeline

[0071] 301 pipeline 302 reactor 303 pipeline

[0072] 304 pipeline 305 pipeline 306 pipeline

[0073] 307 pipeline 308 outlet section 309 cyclone separator

[0074] 310 Gas collecting chamber 311 Stripping section 312 Pipeline

[0075] 313 inclined tube 314 regenerator 315 pipeline

[0076] Pipeline 316, Pipeline 317, Pipeline 318

[0077] 319 large oil and gas pipeline 320 fractionation unit 321 pipeline

[0078] Pipeline 322, Pipeline 323, Pipeline 324

[0079] Pipeline 325, Pipeline 326, Pipeline 327

[0080] Pipeline 328, Pipeline 329, Olefin Separation Unit, Pipeline 330

[0081] Pipeline 331, Pipeline 332, Hydrotreating Unit, Pipeline 333 DETAILED DESCRIPTION

[0082] The following describes the specific embodiments of the present application in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application and are not intended to limit the present application.

[0083] Any specific numerical value disclosed herein (including the endpoints of a numerical range) is not limited to the exact value of the numerical value, but should be understood to also include values ​​close to the exact value, such as all possible values ​​within ±5% of the exact value. Moreover, for a disclosed numerical range, any combination of the endpoints of the range, between the endpoints and the specific points in the range, and between the specific points can be used to generate one or more new numerical ranges, and these new numerical ranges should also be considered to be specifically disclosed herein.

[0084] Unless otherwise specified, the terms used herein have the same meaning as commonly understood by those skilled in the art. If a term is defined herein and its definition is different from the commonly understood meaning in the art, the definition herein shall prevail.

[0085] In this application, the term "C5 and above" refers to having at least 5 carbon atoms, for example, the term "C5 and above olefins" refers to olefins having at least 5 carbon atoms, and the term "C5 and above fraction" refers to compounds in the fraction having at least 5 carbon atoms.

[0086] In this application, except for the contents explicitly stated, any matters or issues not mentioned are directly applicable to those known in the art without any changes. Moreover, any embodiment described herein can be freely combined with one or more other embodiments described herein, and the technical solutions or technical ideas formed thereby are deemed to be part of the original disclosure or original record of this application, and should not be regarded as new content not disclosed or anticipated herein, unless a person skilled in the art considers that the combination is obviously unreasonable.

[0087] All patent and non-patent literature, including but not limited to textbooks and journal articles, mentioned herein are incorporated by reference in their entirety.

[0088] As described above, the present application provides a fluidized catalytic conversion method for producing light olefins from hydrocarbons, comprising the following steps:

[0089] 1) introducing an olefin-rich feedstock into a first reaction zone of a fluidized catalytic conversion reactor, and contacting and reacting the feedstock with a catalytic conversion catalyst at a temperature of 650° C. or higher, wherein the olefin-rich feedstock has an olefin content of 50% by weight or higher;

[0090] 2) introducing the heavy feedstock into a second reaction zone of the fluidized catalytic conversion reactor located downstream of the first reaction zone, and causing the feedstock to contact and react with the catalytic conversion catalyst from the first reaction zone after the reaction in step 1);

[0091] 3) separating the effluent from the fluidized catalytic conversion reactor to obtain reaction oil and gas and spent catalyst, and performing a first separation treatment on the reaction oil and gas to obtain ethylene, propylene, butene, a first catalytic cracking distillate, and a second catalytic cracking distillate; the first catalytic cracking distillate has an initial boiling point in the range of greater than 20° C. to less than 140° C., the second catalytic cracking distillate has an end boiling point in the range of greater than 250° C. to less than 550° C., and the cut point between the first catalytic cracking distillate and the second catalytic cracking distillate is in the range of 140-250° C.;

[0092] 4) performing a second separation treatment on the first catalytic cracking distillate to obtain an olefin-rich stream, wherein the olefin-rich stream has a C5 and above olefin content of at least 50% by weight; and

[0093] 5) returning at least a portion of the olefin-rich stream to step 1) for further reaction.

[0094] The inventors of the present application have surprisingly discovered, through conducting a large number of catalytic cracking tests on alkanes and alkenes, that when alkenes and alkanes are reacted separately under the same catalytic cracking reaction conditions, the yield and selectivity of light olefins produced by olefin cracking are significantly superior to those of alkanes; and the differences in product distribution between the catalytic cracking of alkenes and alkanes are also quite obvious, which led to the technical solution of the present application.

[0095] In a preferred embodiment, the reaction in step 1) is carried out under first catalytic conversion conditions, which include:

[0096] The reaction temperature is 600-800°C, preferably 630-780°C;

[0097] The reaction pressure is 0.05-1 MPa, preferably 0.1-0.8 MPa;

[0098] The reaction time is 0.01-100 seconds, preferably 0.1-80 seconds;

[0099] The weight ratio of the catalytic conversion catalyst to the olefin-rich feedstock is (1-200):1, preferably (3-180):1.

[0100] In a preferred embodiment, the reaction in step 2) is carried out under second catalytic conversion conditions, wherein the second catalytic conversion conditions include:

[0101] The reaction temperature is 400-650°C, preferably 450-600°C;

[0102] The reaction pressure is 0.05-1 MPa, preferably 0.1-0.8 MPa;

[0103] The reaction time is 0.01-100 seconds, preferably 0.1-80 seconds;

[0104] The weight ratio of the catalytic conversion catalyst to the heavy feedstock is (1-100):1, preferably (3-70):1.

[0105] In a preferred embodiment, the olefin-rich feedstock used in this application has an olefin content of 80% or more by weight, preferably 90% or more by weight; more preferably, the olefin-rich feedstock is a pure olefin feedstock. The inventors of this application have discovered that increasing the olefin content in the olefin-rich feedstock is beneficial for improving the yield and selectivity of light olefins in the product, and that using olefins above C5 achieves even better results.

[0106] In a preferred embodiment, the olefins in the olefin-rich feedstock are essentially composed of C5 or higher olefins, for example, more than 80%, more than 85%, more than 90% or more than 95% of the olefins in the olefin-rich feedstock, more preferably 100%, are C5 or higher olefins.

[0107] In this application, the olefin-rich feedstock may come from a variety of sources, and this application does not impose strict restrictions thereon. In certain embodiments, the olefin-rich feedstock may be derived solely from a stream containing C5 or higher olefins separated from the catalytic conversion products of a heavy oil feedstock, i.e., the olefin-rich feedstock is olefins recycled within the system. In other embodiments, the olefin-rich feedstock may include, in addition to the aforementioned stream containing C5 or higher olefins, additional olefin feedstock, with no particular requirement for the amount of the additional olefin feedstock.

[0108] In certain specific embodiments, the olefin-rich feedstock used in step 1) may be derived from any one or more of the following sources: a C5+ fraction produced by an alkane dehydrogenation unit, a C5+ fraction produced by a catalytic cracking unit in a refinery, a C5+ fraction produced by a steam cracker in an ethylene plant, or a C5+ olefin-rich fraction produced as a by-product of MTO (methanol to olefins) and MTP (methanol to propylene). In a preferred embodiment, the alkane feedstock used in the alkane dehydrogenation unit may be derived from at least one of naphtha, aromatic raffinate, and / or other light hydrocarbons. In actual production, alkane products produced by other petrochemical plants may also be used.

[0109] In certain embodiments, the olefin-rich feedstock used in the present application can be obtained by contacting alkanes with a dehydrogenation catalyst in a dehydrogenation reactor under catalytic dehydrogenation reaction conditions, wherein the dehydrogenation reaction conditions include: an inlet temperature of the dehydrogenation reactor of 400-700° C., a volume space velocity of the alkanes of 500-5000 h / min, and a reaction temperature of 100-2000 ℃. -1 , the pressure of the contact reaction is 0.04-1.1 bar.

[0110] Preferably, the dehydrogenation catalyst consists of a carrier and an active component and an auxiliary agent supported on the carrier; based on the total weight of the dehydrogenation catalyst, the content of the carrier is 60-90 weight%, the content of the active component is 8-35 weight%, and the content of the auxiliary agent is 0.1-5 weight%.

[0111] Further preferably, the support may be alumina containing a modifier; wherein the modifier content is 0.1-2% by weight based on the total weight of the dehydrogenation catalyst, and the modifier may be La and / or Ce; the active component may be platinum and / or chromium; and the promoter may be a combination of bismuth and an alkali metal component or a combination of bismuth and an alkaline earth metal component, wherein the molar ratio of bismuth to the active component is 1:(5-50), the molar ratio of bismuth to the alkali metal component is 1:(0.1-5), and the molar ratio of bismuth to the alkaline earth metal component is 1:(0.1-5). Particularly preferably, the alkali metal component may be selected from one or more of Li, Na, and K; and the alkaline earth metal component may be selected from one or more of Mg, Ca, and Ba.

[0112] In certain preferred embodiments, the fluidized catalytic conversion method of the present application further comprises the following steps:

[0113] 6) contacting the second catalytically cracked distillate with a hydrogenation catalyst and reacting under hydrogenation reaction conditions to produce a hydrocatalytically cracked distillate, which is then returned to the fluidized catalytic conversion reactor for continued reaction. In this embodiment, the reaction product, the catalytic wax oil, is hydrogenated and then reintroduced into the fluidized catalytic conversion reactor for continued reaction, thereby improving feedstock utilization and increasing the yields of ethylene, propylene, and butenes.

[0114] Preferably, the hydrocatalytically cracked distillate is returned to the second reaction zone of the fluidized catalytic converter reactor for further reaction. In this embodiment, the higher carbon number saturated hydrocarbons contained in the hydrocatalytically cracked distillate can be initially cracked into C5-C9 olefins in the second reaction zone under relatively mild reaction conditions. The resulting olefins are then returned to the first reaction zone of the reactor along with the olefin-rich stream in step 5) for further high temperature cracking, thereby further improving the ethylene yield.

[0115] According to the present application, the hydrogenation reaction conditions of step 6) can be those commonly used in the art, and the present application does not strictly limit them. In a further preferred embodiment, the reaction conditions for the contact reaction of the second catalytic cracking distillate oil with the hydrogenation catalyst may include: a hydrogen partial pressure of 3.0-20.0 MPa, a reaction temperature of 300-450°C, a hydrogen-to-oil volume ratio of 300-2000, and a volume space velocity of 0.1-3.0 hours. -1 .

[0116] According to the present application, the hydrogenation catalyst used in step 6) may be those commonly used in the art, and the present application does not impose strict restrictions thereon. For example, the hydrogenation catalyst may include a carrier and a metal component supported on the carrier and optional additives. Preferably, based on the total weight of the hydrogenation catalyst, the hydrogenation catalyst comprises 20-90 wt% of a carrier, 10-80 wt% of a supported metal and 0-10 wt% of an additive. Further preferably, the carrier is alumina and / or amorphous silica-alumina, the metal component is a VIB group metal and / or a VIII group metal, and the additive is selected from at least one of fluorine, phosphorus, titanium and platinum; further preferably, the VIB group metal is Mo or / and W, and the VIII group metal is Co or / and Ni. Particularly preferably, based on the total weight of the hydrogenation catalyst, the content of the additive is 0-10 wt%, the content of the VIB group metal is 12-39 wt%, and the content of the VIII group metal is 1-9 wt%.

[0117] In certain preferred embodiments, the fluidized catalytic conversion method of the present application further comprises the following steps:

[0118] 7) upstream of the introduction point of the olefin-rich feedstock, returning at least a portion of the butenes separated in step 3) to the catalytic conversion reactor for contact reaction with the catalytic conversion catalyst.

[0119] In this embodiment, the high-temperature catalytic conversion catalyst first contacts and reacts with the butenes returning to the reactor, then contacts and reacts with the olefin-rich feedstock, and finally contacts and reacts with the heavy feedstock. The difficulty of hydrocarbon cracking increases with decreasing carbon number, and butene cracking requires a high energy requirement. Therefore, in this embodiment, the high-temperature catalytic conversion catalyst first contacts butenes, then contacts the feedstock rich in C5 and higher olefins. This allows the butenes to be cracked first at a higher temperature, which not only improves butene conversion and product ethylene and propylene selectivity but also avoids the generation of a large number of byproducts when olefins are fed simultaneously, achieving efficient resource utilization.

[0120] Preferably, the reaction in step 7) is carried out under third catalytic conversion conditions, wherein the third catalytic conversion conditions include: a reaction temperature of 650-800°C, a reaction pressure of 0.05-1 MPa, a reaction time of 0.01-10 seconds, and a weight ratio of the catalytic conversion catalyst to the butene of (20-200):1. Further preferably, the third catalytic conversion conditions include: a reaction temperature of 680-780°C, a reaction pressure of 0.1-0.8 MPa, a reaction time of 0.05-8 seconds, and a weight ratio of the catalytic conversion catalyst to the butene of (30-180):1.

[0121] In a preferred embodiment, the fluidized catalytic conversion method of the present application further comprises the following steps:

[0122] 2a) introducing an oxygen-containing organic compound into the second reaction zone of the fluidized catalytic conversion reactor to contact and react with the catalytic conversion catalyst therein.

[0123] Preferably, the reaction in step 2a) is carried out under fourth catalytic conversion conditions, which include: a reaction temperature of 300-550° C., a reaction pressure of 0.01-1 MPa, a reaction time of 0.01-100 seconds, and a weight ratio of the catalytic conversion catalyst to the oxygen-containing organic compound feedstock of (1-100): 1. Further preferably, the fourth catalytic conversion conditions include: a reaction temperature of 400-530° C., a reaction pressure of 0.1-0.8 MPa, a reaction time of 0.1-80 seconds, and a weight ratio of the catalytic conversion catalyst to the oxygen-containing organic compound feedstock of (3-80): 1.

[0124] In this embodiment of the present application, the oxygen-containing organic compound can be fed alone or mixed with other raw materials. For example, the oxygen-containing organic compound can be mixed with the heavy feedstock and then fed into the second reaction zone of the fluidized catalytic converter reactor, or the oxygen-containing organic compound can be fed into the second reaction zone of the fluidized catalytic converter reactor downstream of the location where the heavy feedstock is introduced.

[0125] Particularly preferably, the organic oxygen-containing compound comprises at least one of methanol, ethanol, dimethyl ether, methyl ethyl ether and ethyl ether. For example, the oxygen-containing organic compound represented by methanol and dimethyl ether can be derived from coal-based or natural gas-based synthesis gas.

[0126] In a preferred embodiment, the fluidized catalytic conversion method of the present application further comprises the following steps:

[0127] 8) The spent catalyst separated in step 3) is charred and regenerated to obtain a regenerated catalyst having a temperature above 650° C., and then the regenerated catalyst is returned to the upstream of the first reaction zone of the fluidized catalytic conversion reactor as the catalytic conversion catalyst.

[0128] In a preferred embodiment, the catalytic conversion catalyst used in the present application may contain 1-50 wt% of molecular sieve, 5-99 wt% of inorganic oxide and 0-70 wt% of clay based on the total weight of the catalyst.

[0129] In a further preferred embodiment, the catalytic conversion catalyst uses the molecular sieve as an active component, and the molecular sieve can be selected from large-pore molecular sieves, medium-pore molecular sieves and small-pore molecular sieves, or a combination thereof.

[0130] In certain further preferred embodiments, the medium-pore molecular sieve may be a ZSM molecular sieve, for example, the ZSM molecular sieve may be selected from ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-48, or a combination thereof; the small-pore molecular sieve may be a SAPO molecular sieve and / or a SSZ molecular sieve, for example, the SAPO molecular sieve may be selected from SAPO-34, SAPO-11, SAPO-47, or a combination thereof, and the SSZ molecular sieve may be selected from SSZ-13, SSZ-39, SSZ-62, or a combination thereof; the large-pore molecular sieve may be selected from rare earth Y molecular sieve, rare earth hydrogen Y molecular sieve, ultrastable Y molecular sieve, high silicon Y molecular sieve, Beta molecular sieve and other molecular sieves of similar structure, or a mixture thereof.

[0131] In a particularly preferred embodiment, based on the total weight of the molecular sieve, the molecular sieve comprises 40 wt%-100 wt%, preferably 50 wt%-100 wt% of medium-pore molecular sieve, and 0 wt%-30 wt%, preferably 0 wt%-25 wt% of small-pore molecular sieve, and 0 wt%-30 wt%, preferably 0 wt%-25 wt% of large-pore molecular sieve.

[0132] In a further preferred embodiment, the catalytic conversion catalyst uses the inorganic oxide as a binder. Preferably, the inorganic oxide can be selected from silicon dioxide (SiO2) and / or aluminum oxide (Al2O3).

[0133] In a further preferred embodiment, the catalytic conversion catalyst uses the clay as a matrix. Preferably, the clay can be selected from kaolin and / or halloysite.

[0134] In a further preferred embodiment, the catalytic conversion catalyst used in this application may also be loaded with a modifying element to further enhance the catalytic performance of the catalytic conversion catalyst. For example, the catalytic conversion catalyst may contain 0.1-3% by weight of the modifying element, based on the weight of the catalyst. The modifying element may be selected from one or more of Group VIII metals, Group IVA metals, Group V elements, and rare earth metals. In an even more preferred embodiment, the modifying element may be selected from one or more of phosphorus, iron, cobalt, and nickel.

[0135] According to the present application, the heavy feedstock used in step 2) can be those commonly used in the art, and the present application does not strictly limit this. In a preferred embodiment, the heavy feedstock can be selected from petroleum hydrocarbons and / or mineral oils; the petroleum hydrocarbons can be selected from vacuum gas oil, atmospheric gas oil, coker gas oil, deasphalted oil, vacuum residue oil, atmospheric residue oil and heavy aromatic raffinate oil, or a combination thereof; the mineral oil can be selected from coal liquefaction oil, oil sand oil and shale oil, or a combination thereof.

[0136] According to the present application, the fluidized catalytic conversion reactor may include one reactor or multiple reactors connected in series and / or in parallel.

[0137] In a preferred embodiment, the fluidized catalytic conversion reactor can be selected from a riser reactor, a fluidized bed reactor, an upward conveyor line, a downward conveyor line or a combination of two or more thereof, wherein the riser reactor can be a constant diameter riser reactor or a variable diameter riser reactor, the fluidized bed reactor can be a constant linear velocity fluidized bed reactor or a constant diameter fluidized bed reactor, and the variable diameter riser reactor can be, for example, the riser reactor described in Chinese patent CN1078094C.

[0138] In a further preferred embodiment, the fluidized catalytic conversion reactor is a riser reactor, more preferably a variable diameter riser reactor.

[0139] In a preferred embodiment, the olefin-rich stream separated in step 4) has an olefin content of 80% by weight or greater, more preferably 80% by weight or greater of C5 or higher olefins. The higher the olefin content in the olefin-rich stream, the better the recycling effect and resource utilization.

[0140] According to the present application, the first separation treatment in step 3) can be performed using a separation device commonly used in the art, such as a product fractionation device.

[0141] In a preferred embodiment, the second separation treatment in step 4) can be performed using an olefin separation unit to obtain an olefin-depleted stream and the olefin-rich stream. The second separation treatment can increase the olefin content of the olefin-rich stream returned to the fluidized catalytic conversion reactor, thereby further improving the yield and selectivity of light olefins.

[0142] In certain further preferred embodiments, the olefin-rich stream is further separated in the olefin separation unit to obtain a large-molecule olefin-rich stream and a small-molecule olefin-rich stream, and the cut point between the two streams can be, for example, in the range of 140-200°C, wherein the small-molecule olefin-rich stream is returned to the first reaction zone of the fluidized catalytic conversion reactor in step 5) to continue the reaction; and the large-molecule olefin-rich stream is returned to the second reaction zone of the fluidized catalytic conversion reactor to continue the reaction.

[0143] As shown in FIG1 , in a preferred embodiment, the fluidized catalytic conversion method of the present application is carried out as follows:

[0144] The pre-lifting medium enters the fluidized catalytic converter reactor (riser reactor) 102 from the bottom through pipeline 101, and the regenerated catalytic converter catalyst from pipeline 117 moves upward along the fluidized catalytic converter reactor 102 under the lifting action of the pre-lifting medium. The olefin-rich feedstock (olefin content ≥ 50%) is injected into the bottom of the first reaction zone I of the reactor 102 through pipeline 103 together with the atomized steam from pipeline 104, where it contacts and reacts with the hot catalyst with a temperature above 650°C and continues to move upward.

[0145] The heavy feedstock oil is injected into the lower middle portion of the fluidized catalytic converter reactor 102 through pipeline 105 together with the atomizing steam from pipeline 106, and is mixed with the material flow from the first reaction zone I in the second reaction zone II. The heavy feedstock oil contacts and reacts with the hot catalyst and moves upward.

[0146] The generated reaction products and the deactivated catalyst to be regenerated enter the cyclone separator 108 in the settler through the outlet section 107 to separate the catalyst to be regenerated from the reaction products. The reaction products enter the gas collecting chamber 109, and the catalyst fines return to the settler through the feed leg. The regenerated catalyst in the settler flows to the stripping section 110 and comes into contact with the stripping steam from the pipeline 111. The oil and gas stripped from the regenerated catalyst enter the gas collecting chamber 109 after passing through the cyclone separator. The stripped regenerated catalyst enters the regenerator 113 through the inclined pipe 112, and the main air enters the regenerator through the pipeline 116 to burn off the coke on the regenerated catalyst and regenerate the deactivated regenerated catalyst. The flue gas enters the smoke exhaust fan through the pipeline 115. The regenerated catalyst enters the reactor 102 through the pipeline 117.

[0147] The reaction products (reaction oil and gas) enter the subsequent product fractionation device 120 through the large oil and gas pipeline 119, the separated hydrogen, methane and ethane are drawn out through pipeline 121, ethylene is drawn out through pipeline 122, propylene is drawn out through pipeline 123, and butene is drawn out through pipeline 124, and optionally returned to the bottom of the reactor 102 to continue the reaction. Propane and butane are drawn out through pipeline 125, and the first catalytic cracking distillate is introduced into the olefin separation device 128 through pipeline 126. The separated olefin-poor stream is drawn out through pipeline 129, and the olefin-rich stream is introduced into the bottom of the first reaction zone I through pipeline 130 to continue the reaction. The second catalytic cracking distillate is introduced into the hydrotreatment reactor 131 through pipeline 127. After hydrotreatment, light components and hydrocatalytic cracking distillate are obtained. The light components are drawn out through pipeline 118, and the hydrocatalytic cracking distillate is drawn out through pipeline 132, and optionally returned to the second reaction zone II to continue the reaction.

[0148] As shown in FIG2 , in another preferred embodiment, the fluidized catalytic conversion method of the present application is carried out as follows:

[0149] The pre-lifting medium enters the fluidized catalytic converter reactor (riser reactor) 202 from the bottom through pipeline 201, and the regenerated catalytic converter catalyst from pipeline 217 moves upward along the fluidized catalytic converter reactor 202 under the lifting action of the pre-lifting medium. The olefin-rich raw material (olefin content ≥ 50%) is injected into the bottom of the first reaction zone I of the reactor 202 through pipeline 203 together with the atomized steam from pipeline 204, where it contacts and reacts with the hot catalyst with a temperature above 650°C and continues to move upward.

[0150] The heavy feedstock oil is injected into the lower middle part of the fluidized catalytic converter reactor 202 through pipeline 205 together with the atomized steam from pipeline 206, and is mixed with the material flow from the first reaction zone I in the second reaction zone II. The heavy feedstock oil contacts and reacts with the hot catalyst and moves upward.

[0151] The generated reaction products and deactivated spent catalyst enter the cyclone separator 208 in the settler through the outlet section 207, separating the spent catalyst from the reaction products. The reaction products enter the gas collecting chamber 209, and the catalyst fines return to the settler through the feed leg. The spent catalyst in the settler flows to the stripping section 210, where it comes into contact with the stripping steam from pipeline 211. The oil and gas stripped from the spent catalyst enter the gas collecting chamber 209 after passing through the cyclone separator. The stripped spent catalyst enters the regenerator 213 through the inclined pipe 212, and the main air enters the regenerator through pipeline 216, burning off the coke on the spent catalyst and regenerating the deactivated spent catalyst. The flue gas enters the smoke exhaust fan through pipeline 215. The regenerated catalyst enters the reactor 202 through pipeline 217.

[0152] The reaction products (reaction oil and gas) enter the subsequent product fractionation device 220 through the large oil and gas pipeline 219, the separated hydrogen, methane and ethane are drawn out through pipeline 221, ethylene is drawn out through pipeline 222, propylene is drawn out through pipeline 223, butene is drawn out through pipeline 224, and optionally returned to the bottom of the reactor 202 to continue the reaction, propane and butane are drawn out through pipeline 225, the first catalytic cracking distillate oil is introduced into the olefin separation device 228 through pipeline 226, the separated olefin-poor stream is drawn out through pipeline 229, and the small molecule olefin-rich stream is drawn out through pipeline 229. The logistics is introduced into the first reaction zone I through pipeline 230 to continue the reaction, the logistics rich in large molecular olefins is introduced into the middle part of the reactor 202 through pipeline 231, and continues to react in the third reaction zone III downstream of the second reaction zone II, and the second catalytic cracking distillate oil is introduced into the hydrotreatment reactor 232 through pipeline 227. After hydrogenation, light components and hydrocatalytic cracking distillate oil are obtained. The light components are drawn out through pipeline 218, and the hydrocatalytic cracking distillate oil is drawn out through pipeline 233, and optionally returned to the second reaction zone II to continue the reaction.

[0153] As shown in FIG3 , in another preferred embodiment, the fluidized catalytic conversion method of the present application is carried out as follows:

[0154] The pre-lifting medium enters the fluidized catalytic converter reactor (riser reactor) 302 from the bottom through pipeline 301, and the regenerated catalytic converter catalyst from pipeline 317 moves upward along the fluidized catalytic converter reactor 302 under the lifting action of the pre-lifting medium. The olefin-rich feedstock (olefin content ≥ 50%) is injected into the bottom of the first reaction zone I of the reactor 302 together with the atomizing steam from pipeline 304 through pipeline 303, where it contacts and reacts with the hot catalyst with a temperature above 650°C and continues to move upward.

[0155] The heavy feedstock oil is injected into the lower middle portion of the fluidized catalytic converter reactor 302 through pipeline 305 together with the atomized steam from pipeline 306, and is mixed with the material flow from the first reaction zone I in the second reaction zone II. The heavy feedstock oil contacts and reacts with the hot catalyst and moves upward.

[0156] Oxygen-containing organic compounds (such as methanol) are injected into the second reaction zone II via pipeline 307 downstream of the heavy feedstock injection point and mixed with the material flow therein. The oxygen-containing organic compounds contact and react with the catalytic conversion catalyst and move upward.

[0157] The generated reaction products and deactivated spent catalyst enter the cyclone separator 309 in the settler through the outlet section 308, separating the spent catalyst from the reaction products. The reaction products enter the gas collection chamber 310, and the catalyst fines return to the settler through the feed leg. The spent catalyst in the settler flows to the stripping section 311, where it comes into contact with the stripping steam from pipeline 312. The oil and gas stripped from the spent catalyst pass through the cyclone separator and enter the gas collection chamber 310. The stripped spent catalyst enters the regenerator 314 through the inclined pipe 313, and the main air enters the regenerator through pipeline 316, burning off the coke on the spent catalyst and regenerating the deactivated spent catalyst. The flue gas enters the smoke exhaust fan through pipeline 315. The regenerated catalyst enters the reactor 302 through pipeline 317.

[0158] The reaction products (reaction oil and gas) enter the subsequent product fractionation device 320 through the large oil and gas pipeline 319, the separated hydrogen, methane and ethane are drawn out through pipeline 321, ethylene is drawn out through pipeline 322, propylene is drawn out through pipeline 323, butene is drawn out through pipeline 324, and optionally returned to the bottom of the reactor 302 to continue the reaction, propane and butane are drawn out through pipeline 325, and the separated unconverted oxygen-containing organic compounds are drawn out through pipeline 326, and optionally returned to the second reaction zone II to continue the reaction; the first catalytic cracking The catalytic cracking fraction oil is introduced into the olefin separation unit 329 via pipeline 327, the separated olefin-poor stream is drawn out via pipeline 331, and the olefin-rich stream is introduced into the bottom of the first reaction zone I via pipeline 330 for further reaction; the second catalytic cracking fraction oil is introduced into the hydrotreatment reactor 332 via pipeline 328, and after hydrogenation, light components and hydrocatalytic cracking fraction oil are obtained, the light components are drawn out via pipeline 318, and the hydrocatalytic cracking fraction oil is introduced into the bottom of the second reaction zone II via pipeline 333 for further reaction.

[0159] In a particularly preferred embodiment, the present application provides the following technical solutions:

[0160] A1. A catalytic conversion method for producing ethylene, propylene and butene, the method comprising the steps of:

[0161] (1) contacting an olefin-rich feedstock with a catalytic conversion catalyst at a temperature of 650° C. or higher in a first reaction zone of a catalytic conversion reactor under first catalytic conversion reaction conditions, wherein the olefin-rich feedstock contains 50% by weight or more of olefins;

[0162] (2) contacting and reacting the heavy feedstock with the stream from the first reaction zone in the second reaction zone of the catalytic conversion reactor under second catalytic conversion reaction conditions to obtain reaction oil and gas and spent catalyst;

[0163] (3) subjecting the reaction oil and gas to a first separation treatment to separate ethylene, propylene, butene, a first catalytic cracking distillate oil, and a second catalytic cracking distillate oil; the first catalytic cracking distillate oil has an initial boiling point of any temperature greater than 20° C. and less than 140° C., the second catalytic cracking distillate oil has an end boiling point of any temperature less than 550° C. and greater than 250° C., and the cut point between the first catalytic cracking distillate oil and the second catalytic cracking distillate oil is any temperature between 140° C. and 250° C.;

[0164] subjecting the first catalytic cracking distillate to a second separation treatment to separate an olefin-rich stream, wherein the olefin-rich stream contains more than 50% by weight of C5 and higher olefins;

[0165] (4) returning the olefin-rich stream to the catalytic conversion reactor to continue the reaction.

[0166] A2. The method according to item A1, wherein the method further comprises: contacting the second catalytically cracked distillate with a hydrogenation catalyst under hydrogenation reaction conditions to obtain a hydrogenated second catalytically cracked distillate, and returning the hydrogenated second catalytically cracked distillate to the catalytic conversion reactor for further reaction.

[0167] A3. The method according to item A2, wherein the hydrogenated second catalytic cracking distillate oil is returned to the second reaction zone of the catalytic conversion reactor to continue reaction, and the olefin-rich stream is returned to the first reaction zone of the catalytic conversion reactor to continue reaction; wherein, along the flow direction of the reaction feed, the first reaction zone is located upstream of the second reaction zone.

[0168] A4. The method according to item A3, wherein the separation system comprises a product fractionation unit and an olefin separation unit, the method comprising:

[0169] allowing the reaction oil and gas to enter the product fractionation device to separate ethylene, propylene, butene, the first catalytic cracking distillate oil and the second catalytic cracking distillate oil;

[0170] The first catalytic cracking distillate enters the olefin separation unit to separate a first olefin-containing stream and a second olefin-containing stream; the cut point between the first olefin-containing stream and the second olefin-containing stream is any temperature between 140-200° C.;

[0171] Returning the first olefin-containing stream to the first reaction zone of the catalytic conversion reactor for further reaction, and returning the second olefin-containing stream to the third reaction zone of the catalytic conversion reactor for further reaction;

[0172] Wherein, along the flow direction of the reaction feed, the third reaction zone is located downstream of the second reaction zone.

[0173] A5. The method according to any one of items A1 to A4, wherein the catalytic conversion reactor is a riser reactor, preferably a variable diameter riser reactor.

[0174] A6. The method according to item A1, wherein the first catalytic conversion reaction conditions include:

[0175] The reaction temperature is 650-750°C, preferably 630-750°C, more preferably 630-720°C;

[0176] The reaction pressure is 0.05-1 MPa, preferably 0.1-0.8 MPa, more preferably 0.2-0.5 MPa;

[0177] The reaction time is 0.01-100 seconds, preferably 0.1-80 seconds, more preferably 0.2-70 seconds;

[0178] The weight ratio of the catalytic conversion catalyst to the olefin-rich feedstock is (1-100):1, preferably (3-150):1, more preferably (4-120):1;

[0179] The second catalytic conversion reaction conditions include:

[0180] The reaction temperature is 400-650°C, preferably 450-600°C, more preferably 480-580°C;

[0181] The reaction pressure is 0.05-1 MPa, preferably 0.1-0.8 MPa, more preferably 0.2-0.5 MPa;

[0182] The reaction time is 0.01-100 seconds, preferably 0.1-80 seconds, more preferably 0.2-70 seconds;

[0183] The weight ratio of the catalytic conversion catalyst to the heavy feedstock is (1-100):1, preferably (3-70):1, and more preferably (4-30):1.

[0184] A7. The method according to item A2, wherein the hydrogenation reaction conditions include: a hydrogen partial pressure of 3.0-20.0 MPa, a reaction temperature of 300-450°C, a hydrogen-to-oil volume ratio of 300-2000, and a volume space velocity of 0.1-3.0 h / min. -1 .

[0185] A8. The method according to item A1, wherein the method further comprises: regenerating the spent catalyst by burning it to obtain a regenerated catalyst; and returning the regenerated catalyst to the first reaction zone of the catalytic conversion reactor as the catalytic conversion catalyst.

[0186] A9. The method according to item A1, wherein the olefin content in the olefin-rich feedstock is 80% by weight or more, preferably 90% by weight or more, and is more preferably a pure olefin feedstock; and the olefins in the olefin-rich feedstock are selected from olefins having 5 or more carbon atoms;

[0187] The heavy oil is selected from petroleum hydrocarbons and / or mineral oils; the petroleum hydrocarbons are selected from one or more of vacuum gas oil, atmospheric gas oil, coker gas oil, deasphalted oil, vacuum residue oil, atmospheric residue oil and heavy aromatic raffinate oil; the mineral oil is selected from one or more of coal liquefaction oil, oil sand oil and shale oil.

[0188] A10. The method according to item A1 or A9, wherein the olefin-rich feedstock is selected from at least one of a C5+ fraction produced by an alkane dehydrogenation unit, a C5+ fraction produced by a catalytic cracking unit of an oil refinery, a C5+ fraction produced by a steam cracking unit of an ethylene plant, a C5+ olefin-rich fraction produced as a by-product of MTO, and a C5+ olefin-rich fraction produced as a by-product of MTP.

[0189] Optionally, the alkane feedstock of the alkane dehydrogenation unit comes from at least one of naphtha, aromatic raffinate oil and other light hydrocarbons.

[0190] A11. The method according to item A1, wherein the catalytic conversion catalyst comprises 1-50 wt% of a molecular sieve, 5-99 wt% of an inorganic oxide, and 0-70 wt% of a clay, based on the total weight of the catalytic conversion catalyst;

[0191] The molecular sieve includes one or more of a large pore molecular sieve, a medium pore molecular sieve and a small pore molecular sieve;

[0192] Based on the total weight of the catalytic conversion catalyst, the catalytic conversion catalyst further comprises 0.1 wt% to 3 wt% of metal ions, wherein the metal ions are selected from one or more of Group VIII metals, Group IVA metals and rare earth metals.

[0193] A12. The method according to item A2, wherein the hydrogenation catalyst comprises 20-90 wt% of a support, 10-80 wt% of a supported metal, and 0-10 wt% of an additive, based on the total weight of the hydrogenation catalyst;

[0194] Wherein, the carrier is alumina and / or amorphous silicon-alumina, the additive is selected from at least one of fluorine, phosphorus, titanium and platinum, and the supported metal is a VIB group metal and / or a VIII group metal;

[0195] Preferably, the VIB group metal is Mo and / or W, and the VIII group metal is Co and / or Ni.

[0196] A13. The method according to item A1, wherein the olefin-rich stream contains more than 50% by weight of olefins, preferably more than 80% by weight of olefins.

[0197] B1. A catalytic conversion method for maximizing the production of ethylene and concurrently producing propylene, the method comprising the following steps:

[0198] S1. contacting a hydrocarbon oil feedstock having an olefin content of greater than 50% by weight with a catalytic conversion catalyst at a temperature of greater than 650° C. and performing a first catalytic conversion reaction in a first reaction zone of a catalytic conversion reactor to obtain a first mixed stream;

[0199] S2. contacting the heavy feedstock with the first mixed stream in a second reaction zone of the catalytic conversion reactor and performing a second catalytic conversion reaction to obtain a reactant stream and a spent catalyst; the second reaction zone is located downstream of the first reaction zone;

[0200] S3. performing a first separation on the reactant stream to obtain ethylene, propylene, butene, a first catalytic cracking distillate oil, and a second catalytic cracking distillate oil; the first catalytic cracking distillate oil has an initial boiling point of any temperature greater than 20° C. and less than 140° C., the second catalytic cracking distillate oil has an end boiling point of any temperature less than 550° C. and greater than 250° C., and the cut point between the first catalytic cracking distillate oil and the second catalytic cracking distillate oil is any temperature between 140° C. and 250° C.;

[0201] The first catalytic cracking fraction is subjected to a second separation to obtain an olefin-rich stream; and the butenes and the olefin-rich stream are respectively introduced into the catalytic conversion reactor to continue the reaction.

[0202] B2. The method according to item B1, wherein, in step S3, the butene introduced into the catalytic conversion reactor for further reaction contacts the catalytic conversion catalyst before the olefin-rich stream.

[0203] B3. The method according to item B1, wherein the olefins in the olefin-rich stream are C4 or higher olefins;

[0204] The olefin content in the olefin-rich stream is 50 wt% to 100 wt%.

[0205] B4. The method according to item B1, wherein the butene and the olefin-rich stream are separately introduced into the first reaction zone of the catalytic conversion reactor for further reaction.

[0206] B5. The method according to item B1, wherein the catalytic conversion reactor further comprises a reaction zone a and a reaction zone b; the reaction zone a is located between the first reaction zone and the second reaction zone; and the reaction zone b is located downstream of the second reaction zone;

[0207] The second separation comprises: separating a first stream rich in olefins and a second stream rich in olefins from the first catalytic cracking distillate; a cut point between the first stream and the second stream is any temperature between 140-200° C.;

[0208] introducing the butene into the first reaction zone to continue the reaction;

[0209] Introducing the first stream into the a reaction zone to continue the reaction;

[0210] The second stream is introduced into the reaction zone b to continue the reaction.

[0211] B6. The method according to item B1, wherein the method further comprises: regenerating the spent catalyst by burning it to obtain a regenerated catalyst; and

[0212] The regenerated catalyst is preheated and then returned to the catalytic conversion reactor.

[0213] B7. The method according to item B1, wherein the method further comprises:

[0214] subjecting the second catalytic cracking distillate to hydrogenation treatment to obtain a hydrogenated product, and separating a hydrocatalytic cracking distillate from the hydrogenated product;

[0215] The hydrocatalytically cracked distillate is introduced into the second reaction zone to continue the reaction.

[0216] B8. The method according to item B7, wherein:

[0217] The conditions of the hydrotreatment include: hydrogen partial pressure of 3.0-20.0 MPa, reaction temperature of 300-450°C, hydrogen-to-oil volume ratio of 300-2000, volume space velocity of 0.1-3.0 h -1 .

[0218] B9. The method according to item B1, wherein the catalytic conversion reactor is selected from one or a series combination of a riser, a fluidized bed with a constant linear velocity, a fluidized bed with a constant diameter, an upward conveying line, and a downward conveying line;

[0219] The riser is preferably a variable diameter riser reactor.

[0220] B10. The method according to item B1, wherein the conditions of the first catalytic conversion reaction include: a reaction temperature of 600-800°C, a reaction pressure of 0.05-1 MPa, a reaction time of 0.01-100 s, and a weight ratio of the catalytic conversion catalyst to the hydrocarbon oil feedstock of (1-200):1;

[0221] The conditions of the second catalytic conversion reaction include: a reaction temperature of 400-650° C., a reaction pressure of 0.05-1 MPa, a reaction time of 0.01-100 seconds, and a weight ratio of the catalytic conversion catalyst to the heavy feedstock oil of (1-100):1;

[0222] Preferably, the conditions of the first catalytic conversion reaction include: a reaction temperature of 630-780° C., a reaction pressure of 0.1-0.8 MPa, a reaction time of 0.1-80 seconds, and a weight ratio of the catalytic conversion catalyst to the hydrocarbon oil feedstock of (3-180):1;

[0223] The conditions of the second catalytic conversion reaction include: reaction temperature of 450-600°C, reaction pressure of 0.1-0.8 MPa, reaction time of 0.1-80 seconds, and a weight ratio of the catalytic conversion catalyst to the heavy crude oil of (3-70):1.

[0224] B11. The method according to item B1, wherein:

[0225] The reaction conditions for introducing the butene into the catalytic reactor for continued reaction include: a reaction temperature of 650-800° C., a reaction pressure of 0.05-1 MPa, a reaction time of 0.01-10 seconds, and a weight ratio of the catalytic conversion catalyst to the butene of (20-200):1;

[0226] Preferably, the reaction temperature is 680-780° C., the reaction pressure is 0.1-0.8 MPa, the reaction time is 0.05-8 seconds, and the weight ratio of the catalytic conversion catalyst to the butene is (30-180):1.

[0227] B12. The method according to item B1, wherein the olefin content in the hydrocarbon oil feedstock is 80% by weight or more; preferably, the olefin content in the hydrocarbon oil feedstock is 90% by weight or more; more preferably, the hydrocarbon oil feedstock is a pure olefin feedstock;

[0228] The heavy feedstock oil is petroleum hydrocarbons and / or mineral oil; the petroleum hydrocarbons are selected from at least one of vacuum gas oil, atmospheric gas oil, coker gas oil, deasphalted oil, vacuum residue oil, atmospheric residue oil and heavy aromatic raffinate oil; and the mineral oil is selected from at least one of coal liquefaction oil, oil sand oil and shale oil.

[0229] B13. The method according to item B1 or B12, wherein the olefins in the hydrocarbon oil feedstock are selected from the C4 and higher fractions produced by dehydrogenation of alkane feedstock, the C4 and higher fractions produced by a catalytic cracking unit in a refinery, the C4 and higher fractions produced by a steam cracking unit in an ethylene plant, the C4 and higher olefin-rich fraction produced as a by-product of MTO, and the C4 and higher olefin-rich fraction produced as a by-product of MTP;

[0230] The alkane feedstock is selected from at least one of naphtha, aromatic raffinate oil and light hydrocarbons.

[0231] B14. The method according to item B1, wherein the catalytic conversion catalyst comprises 1-50 wt% of a molecular sieve, 5-99 wt% of an inorganic oxide, and 0-70 wt% of a clay, based on the weight of the catalytic conversion catalyst;

[0232] The molecular sieve includes one or more of a large pore molecular sieve, a medium pore molecular sieve and a small pore molecular sieve;

[0233] Based on the weight of the catalytic conversion catalyst, the catalytic conversion catalyst further contains 0.1-3 weight percent of a modifying element; the modifying element is selected from one or more of Group VIII metals, Group IVA metals and rare earth metals.

[0234] C1. A catalytic conversion method for producing light olefins, comprising the following steps:

[0235] (1) contacting an olefin-rich feedstock with a catalytic conversion catalyst at a temperature of 650° C. or higher in a first reaction zone of a catalytic conversion reactor under first catalytic conversion reaction conditions and performing a first catalytic conversion reaction to obtain a first mixed stream; the olefin-rich feedstock containing olefins in an amount of 50% by weight or higher;

[0236] (2) contacting the heavy feedstock and the organic oxygen-containing compound feedstock with the first mixed stream from the first reaction zone in the second reaction zone of the catalytic conversion reactor under second catalytic conversion reaction conditions and performing a second catalytic conversion reaction to obtain reaction oil and gas and a spent catalyst;

[0237] (3) subjecting the reaction oil and gas to a first separation treatment to separate ethylene, propylene, butene, organic oxygen-containing compounds, a first catalytic cracking distillate oil, and a second catalytic cracking distillate oil; the first catalytic cracking distillate oil has an initial boiling point of any temperature greater than 20° C. and less than 140° C., the second catalytic cracking distillate oil has an end boiling point of any temperature less than 550° C. and greater than 250° C., and the cut point between the first catalytic cracking distillate oil and the second catalytic cracking distillate oil is any temperature between 140° C. and 250° C.;

[0238] subjecting the first catalytic cracking distillate to a second separation treatment to separate an olefin-rich stream;

[0239] (4) returning the olefin-rich stream to the catalytic conversion reactor to continue the reaction.

[0240] C2. The method according to item C1, wherein the method comprises: passing the reaction oil and gas into a product fractionation device for a first separation treatment to separate ethylene, propylene, butene, the organic oxygen-containing compound, the first catalytic cracking distillate, and the second catalytic cracking distillate;

[0241] allowing the first catalytic cracking distillate oil to enter an olefin separation unit for a second separation treatment to separate the olefin-rich stream;

[0242] The olefin-rich stream is returned to the first reaction zone of the catalytic conversion reactor to continue the reaction.

[0243] C3. The method according to item C1, wherein the method comprises: passing the reaction oil and gas into a product fractionation device for a first separation treatment to separate ethylene, propylene, butene, the organic oxygen-containing compound, the first catalytic cracking distillate, and the second catalytic cracking distillate;

[0244] The first catalytic cracking distillate oil enters an olefin separation unit for a third separation process to separate a large molecular olefin stream and a small molecular olefin stream;

[0245] The small molecule olefin stream is returned as the olefin-rich stream to the first reaction zone of the catalytic conversion reactor for further reaction; and the large molecule olefin stream is returned to the second reaction zone of the catalytic conversion reactor for further reaction.

[0246] C4. A method according to any one of items C1 to C3, wherein the method further comprises: returning the separated butenes to the first reaction zone of the catalytic conversion reactor for further reaction; preferably, the butenes returned to the catalytic conversion reactor for further reaction contact the catalytic conversion catalyst before the olefin-rich logistics.

[0247] C5. The method according to item C4, wherein the reaction conditions for returning the butene to the catalytic reactor for continued reaction include: a reaction temperature of 650-800° C., a reaction pressure of 0.05-1 MPa, a reaction time of 0.01-10 seconds, and a weight ratio of the catalytic conversion catalyst to the returned butene of (20-200):1;

[0248] Preferably, the reaction temperature is 680-780° C., the reaction pressure is 0.1-0.8 MPa, the reaction time is 0.05-8 seconds, and the weight ratio of the catalytic conversion catalyst to the returned butene is (30-180):1.

[0249] C6. The method according to item C1, wherein the first catalytic conversion reaction conditions include:

[0250] The reaction temperature is 600-800°C, preferably 630-780°C;

[0251] The reaction pressure is 0.05-1 MPa, preferably 0.1-0.8 MPa;

[0252] The reaction time is 0.01-100 seconds, preferably 0.1-80 seconds;

[0253] The weight ratio of the catalytic conversion catalyst to the olefin-rich feedstock is (1-200):1, preferably (3-180):1.

[0254] C7. The method according to item C1 or C6, wherein the second catalytic conversion reaction conditions include:

[0255] The reaction temperature is 300-650°C, preferably 400-600°C;

[0256] The reaction pressure is 0.01-1 MPa, preferably 0.05-1 MPa;

[0257] The reaction time is 0.01-100 seconds, preferably 0.1-80 seconds;

[0258] The weight ratio of the catalytic conversion catalyst to the heavy raw material is (1-100):1, preferably (3-70):1; the weight ratio of the catalytic conversion catalyst to the organic oxygen-containing compound raw material is (1-100):1, preferably (3-50):1;

[0259] The reaction temperature of the first catalytic conversion reaction is 30-380° C. higher than the reaction temperature of the second catalytic conversion reaction.

[0260] C8. The method according to item C1 or C6, wherein the second reaction zone is divided into a second reaction zone upstream and a second reaction zone downstream based on the flow direction of the reactants, with the feed position of the organic oxygen-containing compound raw material as the boundary, and the second reaction zone downstream is located after the feed position of the organic oxygen-containing compound raw material; the method further comprises:

[0261] The first mixed material flow from the first reaction zone is brought into contact with the heavy feedstock upstream of the second reaction zone and subjected to a catalytic conversion reaction to obtain a second mixed material flow; then the second mixed material flow is brought into contact with the organic oxygen-containing compound feedstock downstream of the second reaction zone and subjected to a catalytic conversion reaction to obtain the reaction oil and gas and the catalyst to be generated.

[0262] C9. The method according to item C8, wherein the catalytic conversion reaction conditions of the heavy feedstock and the first mixed stream in the upstream of the second reaction zone include:

[0263] The reaction temperature is 400-650°C, preferably 450-600°C;

[0264] The reaction pressure is 0.05-1 MPa, preferably 0.1-0.8 MPa;

[0265] The reaction time is 0.01-100 seconds, preferably 0.1-80 seconds;

[0266] The weight ratio of the catalytic conversion catalyst to the heavy raw material is (1-100):1, preferably (3-70):1;

[0267] The catalytic conversion reaction conditions of the organic oxygen-containing compound feedstock and the second mixed stream in the downstream of the second reaction zone include:

[0268] The reaction temperature is 300-550°C, preferably 400-530°C;

[0269] The reaction pressure is 0.01-1 MPa, preferably 0.05-1 MPa;

[0270] The reaction time is 0.01-100 seconds, preferably 0.1-80 seconds;

[0271] The reaction temperature in the upstream of the second reaction zone is 0-200° C. higher than the reaction temperature in the downstream of the second reaction zone, preferably 10-190° C. higher;

[0272] The weight ratio of the catalytic conversion catalyst to the organic oxygen-containing compound raw material is (1-100):1, preferably (3-50):1.

[0273] C10. The method according to item C1, wherein the method further comprises: returning the separated organic oxygen-containing compound to the second reaction zone of the catalytic conversion reactor for further reaction.

[0274] C11. The method according to any one of items C1 to C10, wherein the catalytic conversion reactor is a riser reactor, preferably a variable diameter riser reactor.

[0275] C12. The method according to item C1, wherein the method further comprises: regenerating the spent catalyst by burning it to obtain a regenerated catalyst; and returning the regenerated catalyst to the first reaction zone of the catalytic conversion reactor as the catalytic conversion catalyst.

[0276] C13. The method according to item C1, wherein the olefin content in the olefin-rich feedstock is 80 wt% or more, preferably 90 wt% or more, and more preferably is a pure olefin feedstock;

[0277] The heavy oil is selected from petroleum hydrocarbons and / or mineral oils; the petroleum hydrocarbons are selected from one or more of vacuum gas oil, atmospheric gas oil, coker gas oil, deasphalted oil, vacuum residue oil, atmospheric residue oil and heavy aromatic raffinate oil; the mineral oil is selected from one or more of coal liquefaction oil, oil sand oil and shale oil;

[0278] Optionally, the organic oxygen-containing compound raw material comprises at least one of methanol, ethanol, dimethyl ether, methyl ethyl ether and ethyl ether.

[0279] C14. The method according to item C1 or C13, wherein the olefin-rich feedstock is selected from at least one of a C5+ fraction produced by an alkane dehydrogenation unit, a C5+ fraction produced by a catalytic cracking unit of an oil refinery, a C5+ fraction produced by a steam cracking unit of an ethylene plant, a C5+ olefin-rich fraction produced as a by-product of MTO, and a C5+ olefin-rich fraction produced as a by-product of MTP.

[0280] Optionally, the alkane feedstock of the alkane dehydrogenation unit comes from at least one of naphtha, aromatic raffinate oil and other light hydrocarbons.

[0281] C15. The method according to item C1, wherein the catalytic conversion catalyst comprises 1-50 wt% of molecular sieve, 5-99 wt% of inorganic oxide and 0-70 wt% of clay, based on the total weight of the catalytic conversion catalyst;

[0282] The molecular sieve includes one or more of a large pore molecular sieve, a medium pore molecular sieve and a small pore molecular sieve;

[0283] Based on the total weight of the catalytic conversion catalyst, the catalytic conversion catalyst further comprises 0.1 wt% to 3 wt% of metal ions, wherein the metal ions are selected from one or more of Group VIII metals, Group IVA metals and rare earth metals.

[0284] C16. The method according to item C1, wherein the second catalytically cracked distillate is contacted with a hydrogenation catalyst under hydrogenation reaction conditions to produce a hydrogenated second catalytically cracked distillate, and the hydrogenated second catalytically cracked distillate is returned to the catalytic conversion reactor for further reaction;

[0285] The hydrogenation reaction conditions include: hydrogen partial pressure of 3.0-20.0 MPa, reaction temperature of 300-450°C, hydrogen-to-oil volume ratio of 300-2000, volume space velocity of 0.1-3.0 h -1 , based on the total weight of the hydrogenation catalyst, the hydrogenation catalyst comprises 20-90 weight % of a carrier, 10-80 weight % of a supported metal and 0-10 weight % of an additive;

[0286] Wherein, the carrier is alumina and / or amorphous silicon-alumina, the additive is selected from at least one of fluorine, phosphorus, titanium and platinum, and the supported metal is a VIB group metal and / or a VIII group metal;

[0287] Preferably, the VIB group metal is Mo and / or W, and the VIII group metal is Co and / or Ni.

[0288] C17. The method according to item C1, wherein the olefins in the olefin-rich stream are C5 or higher olefins;

[0289] The content of C5 and higher olefins in the olefin-rich stream is greater than 50 wt%, preferably greater than 80 wt%.

[0290] Example

[0291] The present application is further described in detail below through examples. The raw materials used in the examples can be obtained through commercial channels.

[0292] Raw materials and catalysts

[0293] The raw materials I and II used in the following examples are heavy raw oils, namely heavy oil I and heavy oil II, respectively. The properties are shown in Tables 1-1 and 1-2 below.

[0294] Table 1-1 Properties of heavy oil I

[0295]

[0296]

[0297] Table 1-2 Properties of heavy oil II

[0298]

[0299] The preparation or sources of the various catalysts used in the following examples and comparative examples are as follows:

[0300] 1) Catalyst i: prepared by the following preparation method:

[0301] 969 g of halloysite (produced by China Kaolin Corporation, with a solid content of 73%) was slurried with 4300 g of decationized water. 781 g of pseudo-boehmite (produced by Shandong Zibo Aluminum Ore Plant, with a solid content of 64%) and 144 ml of hydrochloric acid (30% concentration, specific gravity 1.56) were added and stirred uniformly. The mixture was allowed to stand for 1 hour at 60°C, maintaining a pH of 2-4. After cooling to room temperature, 5000 g of a pre-prepared slurry containing 1600 g of medium-pore ZSM-5 molecular sieve and large-pore Y-type molecular sieve (produced by Sinopec Catalyst Qilu Branch) in a weight ratio of 9:1 was added. The mixture was stirred uniformly, spray-dried, and free Na+ was washed off to obtain a catalyst. The resulting catalyst was aged at 800°C under 100% steam. The aged catalyst is designated Catalyst I. The properties of Catalyst I are shown in Table 2.

[0302] 2) Catalyst II: The trade name is CEP-1, and it is an industrial product produced by Sinopec Catalyst Qilu Branch. The properties of Catalyst II are shown in Table 2.

[0303] 3) Catalyst III: The trade name is CHP-1, which is an industrial product produced by Sinopec Catalyst Qilu Branch. The properties of Catalyst III are shown in Table 2.

[0304] 4) Catalyst iv: prepared by the following preparation method:

[0305] Weigh ammonium metatungstate ((NH4)2W4O 13 ·18H2O, chemically pure) and nickel nitrate (Ni(NO3)2·18H2O, chemically pure) were prepared into a 200 ml solution in water. This solution was added to a 50 g alumina support and impregnated at room temperature for 3 hours. During the impregnation process, the solution was ultrasonically treated for 30 minutes, cooled, filtered, and dried in a microwave oven for approximately 15 minutes. This catalyst composition was: 30.0 wt% WO3, 3.1 wt% NiO, and the balance alumina; this was Catalyst IV.

[0306] 5) Catalyst v: prepared by the following preparation method:

[0307] 1000 g of pseudo-boehmite produced by Sinopec Catalyst Changling Branch was weighed, and then 1000 ml of an aqueous solution containing 10 ml of nitric acid (chemically pure) was added. The mixture was extruded on a twin-screw extruder, dried at 120° C. for 4 hours, and calcined at 800° C. for 4 hours to obtain a catalyst carrier. The catalyst was immersed in 900 ml of an aqueous solution containing 120 g of ammonium fluoride for 2 hours, dried at 120° C. for 3 hours, and calcined at 600° C. for 3 hours; after cooling to room temperature, the catalyst was immersed in 950 ml of an aqueous solution containing 133 g of ammonium metamolybdate for 3 hours, dried at 120° C. for 3 hours, and calcined at 600° C. for 3 hours; after cooling to room temperature, the catalyst was immersed in 900 ml of an aqueous solution containing 180 g of nickel nitrate and 320 g of ammonium metatungstate for 4 hours; the fluorine-containing alumina support was immersed in a mixed aqueous solution of 0.1 wt % of ammonium metamolybdate (chemically pure) relative to the catalyst support and 0.1 wt % of nickel nitrate (chemically pure) relative to the catalyst support for 4 hours, dried at 120° C. for 3 hours, and calcined at 600° C. for 4 hours to obtain Catalyst V.

[0308] Table 2 Properties of catalysts i-iii

[0309]

[0310]

[0311] Example 1

[0312] The test was conducted on a medium-sized device of a riser reactor according to the process shown in Figure 1. The specific process is as follows:

[0313] The raw material 1-pentene is brought into contact with a 750°C high-temperature catalytic conversion catalyst i at the bottom of the first reaction zone of the riser reactor for reaction. The reaction temperature is 700°C, the reaction pressure is 0.1 MPa, the reaction time is 5 seconds, and the weight ratio of the catalyst to the raw material is 45:1.

[0314] The heavy oil I is mixed with the feed stream from the first reaction zone at the bottom of the second reaction zone of the riser reactor and is contacted with the catalytic conversion catalyst i for reaction. The reaction temperature is 530° C., the reaction pressure is 0.1 MPa, the reaction time is 6 seconds, and the weight ratio of the catalyst to the heavy oil I is 5:1.

[0315] The reaction products and the regenerated catalyst are separated, the regenerated catalyst is charred and regenerated in the regenerator, and the regenerated catalyst is returned to the bottom of the riser reactor; the reaction products are separated to obtain products such as ethylene, propylene, butene, a stream containing C5 or higher olefins with an olefin content of 80% by weight, and a second catalytic cracking distillate oil with a boiling point greater than 250°C.

[0316] The second catalytic cracking distillate and hydrogenation catalyst IV were heated at 350 ° C, hydrogen partial pressure 18 MPa, volume space velocity 1.5 hours -1, and the reaction was carried out at a hydrogen-to-oil volume ratio of 1500 to obtain hydrocatalytic cracking distillate oil.

[0317] The separated olefin-rich stream is returned to the bottom of the first reaction zone for further cracking; the hydrocatalytic cracking distillate is mixed with the heavy feedstock and returned to the second reaction zone for further reaction. The reaction conditions and product distribution are listed in Table 3.

[0318] Comparative Example 1

[0319] A pilot plant with a riser reactor was tested using the method described in Example 1. The differences included not introducing 1-pentene feed into the first reaction zone and not separating the olefin-rich stream. The specific process was as follows:

[0320] A 600°C catalytic conversion catalyst i is introduced into the bottom of the riser reactor, and the heavy oil I contacts and reacts with the catalytic conversion catalyst i at the bottom of the second reaction zone. The reaction temperature is 530°C, the reaction pressure is 0.1 MPa, the reaction time is 6 seconds, and the weight ratio of the catalyst to the heavy oil I is 5:1.

[0321] The reaction products and the regenerated catalyst are separated, the regenerated catalyst is charred and regenerated in the regenerator, and the regenerated catalyst is returned to the bottom of the riser reactor; the reaction products are separated to obtain products such as ethylene, propylene, butene and a second catalytic cracking distillate oil with a boiling point greater than 250°C.

[0322] The second catalytic cracking distillate and hydrogenation catalyst IV were heated at 350 ° C, hydrogen partial pressure 18 MPa, volume space velocity 1.5 hours -1 The reaction was carried out at a hydrogen-to-oil volume ratio of 1500 to produce a hydrocatalytically cracked distillate. The resulting hydrocatalytically cracked distillate was mixed with the heavy feedstock and returned to the second reaction zone for further reaction. The reaction conditions and product distribution are listed in Table 3.

[0323] Example 2

[0324] A test was conducted on a medium-sized riser reactor unit according to the method described in Example 1, except that no olefin-rich feedstock from an external source was introduced into the first reaction zone. The specific process was as follows:

[0325] A 750°C catalytic conversion catalyst i is introduced into the bottom of the riser reactor, and the heavy oil I contacts and reacts with the catalytic conversion catalyst i at the bottom of the second reaction zone. The reaction temperature is 530°C, the reaction pressure is 0.1 MPa, the reaction time is 6 seconds, and the weight ratio of the catalyst to the heavy oil I is 5:1.

[0326] The reaction products and the regenerated catalyst are separated, the regenerated catalyst is charred and regenerated in a regenerator, and the regenerated catalyst is returned to the bottom of the riser reactor; the reaction products are separated to obtain products such as ethylene, propylene, butene, a stream containing C5 or higher olefins with an olefin content of 80% by weight, and a second catalytic cracking distillate oil with a boiling point greater than 250°C.

[0327] The second catalytic cracking distillate and hydrogenation catalyst IV were heated at 350 ° C, hydrogen partial pressure 18 MPa, volume space velocity 1.5 hours -1 The reaction was carried out at a hydrogen-to-oil volume ratio of 1500 to produce a hydrocatalytically cracked distillate. The resulting olefin-rich stream was returned to the bottom of the first reaction zone for further cracking at a temperature of 700°C, a pressure of 0.1 MPa, and a reaction time of 5 seconds. The hydrocatalytically cracked distillate was mixed with a heavy feedstock and returned to the second reaction zone for further reaction. The reaction conditions and product distribution are listed in Table 3.

[0328] Comparative Example 2

[0329] In a test conducted on a medium-sized unit of a riser reactor, heavy oil I was contacted and reacted with a 680°C catalytic conversion catalyst II at the bottom of the riser reactor. The reaction temperature was 610°C, the reaction pressure was 0.1 MPa, the reaction time was 6 seconds, and the weight ratio of catalyst to feedstock was 16.9:1.

[0330] The resulting reaction products and spent catalyst were separated. The spent catalyst was coked and regenerated in a regenerator, and the regenerated catalyst was returned to the bottom of the riser reactor. The separated reaction products were not subjected to hydrogenation or further reaction. The reaction conditions and product distribution are listed in Table 3.

[0331] Example 3

[0332] The experiment was carried out in accordance with the method described in Example 2, except that heavy oil II was used instead of heavy oil I. The second catalytic cracking distillate oil with a boiling point greater than 250°C was contacted with the hydrodesulfurization catalyst v in the hydrodesulfurization reactor. The reaction pressure was 6.0 MPa, the reaction temperature was 350°C, the hydrogen-to-oil volume ratio was 350, and the volume space velocity was 2.0 h. -1 The resulting low-sulfur hydrocatalytic cracking fraction was withdrawn as a light oil component and not returned to the riser reactor for further reaction. The reaction conditions and product distribution are listed in Table 3.

[0333] Comparative Example 3

[0334] The test was carried out on a medium-sized device of a riser reactor. Heavy oil II was contacted with a 680°C catalytic conversion catalyst III at the bottom of the riser reactor for reaction. The reaction temperature was 530°C, the reaction pressure was 0.1 MPa, the reaction time was 6 seconds, and the weight ratio of catalyst to raw material was 5:1.

[0335] The resulting reaction product and spent catalyst were separated, the spent catalyst was coked and regenerated in a regenerator, and the regenerated catalyst was returned to the bottom of the riser reactor. The separated reaction product was not returned to the riser reactor for further reaction. The hydrotreatment of the second catalytic cracking distillate was the same as in Example 3. The reaction conditions and product distribution are listed in Table 3.

[0336] Example 4

[0337] The test was carried out according to the method described in Example 1, except that the reaction conditions shown in Table 3 were used.

[0338] Example 5

[0339] The test was carried out according to the method described in Example 1, except that the reaction conditions shown in Table 3 were used.

[0340] Example 6

[0341] The experiment was conducted according to the method described in Example 1, except that the separated butene was returned to the bottom of the riser reactor for further cracking. The reaction temperature was 710°C, the weight ratio of catalyst to butene was 100:1, and the reaction time was 0.2 s. The reaction conditions and product distribution are shown in Table 3.

[0342]

[0343]

[0344] The results shown in Table 3 show that compared to Comparative Examples 1-3, the fluidized catalytic conversion method of the present application has higher yields of ethylene, propylene, and butene, with the total yield of the three olefins reaching over 50%. When olefin cracking was performed at 700°C in Examples 1-3, the total yield of ethylene, propylene, and butene in the product reached over 60%. Furthermore, the higher the olefin content of the feedstock, the better the yield improvement. When 1-pentene with a 100% olefin content was used as the olefin-rich feedstock (Example 1), the product yield of ethylene was 11.43%, the yield of propylene was 26.92%, and the yield of butene was 24.01%, for a total yield of 62.36%. As the catalytic cracking temperature increased, as shown in Example 5, the ethylene yield was further increased. By recycling butene from the product, as shown in Example 6, the total yield of ethylene and propylene was significantly increased.

[0345] Example 7

[0346] The test was conducted on a medium-sized device of a riser reactor with reference to the process shown in FIG2 . The specific operation was as follows:

[0347] The raw material 1-octene is contacted with a 750°C high-temperature catalytic conversion catalyst i at the bottom of the first reaction zone of the riser reactor for reaction at a reaction temperature of 700°C, a reaction pressure of 0.1 MPa, a reaction time of 5 seconds, and a weight ratio of catalyst to raw material of 45:1.

[0348] The heavy oil I is mixed with the feed stream from the first reaction zone at the bottom of the second reaction zone of the riser reactor and is contacted with the catalytic conversion catalyst i for reaction. The reaction temperature is 530° C., the reaction pressure is 0.1 MPa, the reaction time is 6 seconds, and the weight ratio of the catalyst to the heavy oil I is 5:1.

[0349] The reaction products and the regenerated catalyst are separated, the regenerated catalyst is charred and regenerated in the regenerator, and the regenerated catalyst is returned to the bottom of the riser reactor; the reaction products (reaction oil and gas) are separated to obtain ethylene, propylene, butene, the first catalytic cracking distillate oil and the second catalytic cracking distillate oil.

[0350] The second catalytic cracking distillate and hydrogenation catalyst IV were heated at 350 ° C, hydrogen partial pressure 18 MPa, volume space velocity 1.5 hours -1 , and the hydrogen-to-oil volume ratio is 1500 to obtain a hydrocatalytic cracking distillate oil; the hydrocatalytic cracking distillate oil is mixed with the heavy feed oil and then returned to the second reaction zone to continue the reaction.

[0351] The first catalytically cracked distillate enters an olefin separation unit, where it is separated into a first olefin-containing stream (i.e., a stream containing small olefins) with a boiling point less than 140°C and a second olefin-containing stream (i.e., a stream containing large olefins) with a boiling point between 140°C and 250°C. The first olefin-containing stream is returned to the bottom of the first reaction zone I for further cracking. The second olefin-containing stream is introduced into the bottom of the third reaction zone III, downstream of the second reaction zone II, for further cracking. The reaction temperature is 530°C and the reaction time is 5 seconds. The reaction conditions and product distribution are listed in Table 4.

[0352] Example 8

[0353] The test was conducted on a medium-sized device of a riser reactor according to the process shown in FIG3 . The specific process is as follows:

[0354] The raw material 1-pentene is contacted with a 750°C high-temperature catalytic conversion catalyst i at the bottom of the first reaction zone of the riser reactor for reaction. The reaction temperature is 700°C, the reaction pressure is 0.1 MPa, the reaction time is 5 seconds, and the weight ratio of the catalyst to the raw material is 45:1.

[0355] The heavy oil I is mixed with the feed stream from the first reaction zone at the bottom of the second reaction zone of the riser reactor and is contacted with the catalytic conversion catalyst i for reaction. The reaction temperature is 530° C., the reaction pressure is 0.1 MPa, the reaction time is 6 seconds, and the weight ratio of the catalyst to the heavy oil I is 5:1.

[0356] Methanol is introduced into the second reaction zone downstream of the heavy oil I introduction position to participate in the reaction. The reaction temperature is 500° C., the reaction pressure is 0.1 MPa, the reaction time is 3 seconds, and the weight ratio of catalyst to methanol is 10:1.

[0357] The reaction products and the regenerated catalyst are separated, the regenerated catalyst is charred and regenerated in the regenerator, and the regenerated catalyst is returned to the bottom of the riser reactor; the reaction products are separated to obtain products such as ethylene, propylene, butene, a stream containing C5 or higher olefins with an olefin content of 80% by weight, and a second catalytic cracking distillate oil with a boiling point greater than 250°C.

[0358] The second catalytic cracking distillate and hydrogenation catalyst IV were heated at 350 ° C, hydrogen partial pressure 18 MPa, volume space velocity 1.5 hours -1 , and the reaction was carried out at a hydrogen-to-oil volume ratio of 1500 to obtain hydrocatalytic cracking distillate oil.

[0359] The separated olefin-rich stream is returned to the bottom of the first reaction zone for further cracking. The hydrocatalytically cracked distillate is mixed with heavy oil I and returned to the second reaction zone for further reaction. The reaction conditions and product distribution are listed in Table 4.

[0360] Table 4 Reaction conditions and product distribution of Examples 7 and 8

[0361]

[0362]

[0363] As shown in the data of Table 4, the methods of Examples 7 and 8 of the present application also achieved a total yield of ethylene, propylene and butene of more than 60%, and further improved the total yield of ethylene and propylene compared to Example 1, while significantly reducing the total yield of hydrogen, methane and ethane.

[0364] The preferred embodiments of the present application are described in detail above. However, the present application is not limited to the specific details of the above embodiments. Within the technical concept of the present application, various simple modifications can be made to the technical solution of the present application, and these simple modifications all fall within the scope of protection of the present application.

[0365] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this application will not further describe various possible combinations.

[0366] In addition, the various implementation methods of the present application may be arbitrarily combined, and as long as they do not violate the concept of the present application, they should also be regarded as the contents disclosed in the present application.

Claims

1. A fluid catalytic conversion method for producing light olefins from hydrocarbons, comprising the following steps: 1) Introduce an olefin-rich feedstock into the first reaction zone of a fluid catalytic conversion reactor, contact it with a catalytic conversion catalyst at a temperature above 650 °C, and react under the first catalytic conversion conditions, wherein the olefin-rich feedstock has an olefin content of more than 50% by weight; 2) Introduce a heavy feedstock into the second reaction zone of the fluid catalytic conversion reactor, which is downstream of the first reaction zone, contact it with the catalytic conversion catalyst that has undergone the reaction in step 1) from the first reaction zone, and react under the second catalytic conversion conditions; 3) Separate the effluent of the fluid catalytic conversion reactor to obtain reaction oil gas and spent catalyst, and perform a first separation treatment on the reaction oil gas to obtain ethylene, propylene, butene, a first catalytic cracking fraction oil, and a second catalytic cracking fraction oil; the initial boiling point of the first catalytic cracking fraction oil is in the range of greater than 20 °C to less than 140 °C, the final boiling point of the second catalytic cracking fraction oil is in the range of greater than 250 °C to less than 550 °C, and the cut-off point between the first catalytic cracking fraction oil and the second catalytic cracking fraction oil is in the range of 140 - 250 °C; 4) Perform a second separation treatment on the first catalytic cracking fraction oil to obtain an olefin-rich stream, and the olefin-rich stream has an olefin content of C5 and above of at least 50% by weight; and 5) Return at least a part of the olefin-rich stream to step 1) for continuous reaction, wherein the first catalytic conversion conditions include: The reaction temperature is 600 - 800 °C, preferably 630 - 780 °C; The reaction pressure is 0.05 - 1 MPa, preferably 0.1 - 0.8 MPa; The reaction time is 0.01 - 100 seconds, preferably 0.1 - 80 seconds; The weight ratio of the catalytic conversion catalyst to the olefin-rich feedstock is (1 - 200):1, preferably (3 - 180):1; and The second catalytic conversion conditions include: The reaction temperature is 400 - 650 °C, preferably 450 - 600 °C; The reaction pressure is 0.05 - 1 MPa, preferably 0.1 - 0.8 MPa; The reaction time is 0.01 - 100 seconds, preferably 0.1 - 80 seconds; The weight ratio of the catalytic conversion catalyst to the heavy feedstock is (1 - 100):1, preferably (3 - 70):

1.

2. The method according to claim 1, further comprising the following steps: 6) Contact the second catalytic cracking fraction oil with a hydrogenation catalyst and react under hydrogenation reaction conditions to obtain a hydrogenated catalytic cracking fraction oil, and return the hydrogenated catalytic cracking fraction oil to the second reaction zone of the fluid catalytic conversion reactor for continuous reaction.

3. The method according to claim 2, wherein the conditions of the hydrogenation reaction include: The hydrogen partial pressure is 3.0 - 20.0 MPa, the reaction temperature is 300 - 450 °C, the hydrogen-oil volume ratio is 300 - 2000, and the volume space velocity is 0.1 - 3.0 h-1 -1 .

4. The method according to any one of claims 1 - 3, further comprising the following steps: 7) Upstream of the introduction position of the olefin-rich feedstock, at least a part of the butene separated in step 3) is returned to the catalytic conversion reactor to contact the catalytic conversion catalyst and react under the third catalytic conversion conditions, and the third catalytic conversion conditions include: The reaction temperature is 650 - 800 °C, preferably 680 - 780 °C, The reaction pressure is 0.05 - 1 MPa, preferably 0.1 - 0.8 MPa, The reaction time is 0.01 - 10 seconds, preferably 0.05 - 8 seconds, The weight ratio of the catalytic conversion catalyst to the butene is (20 - 200):1, preferably (30 - 180):

1.

5. The method according to any one of claims 1 - 4, further comprising the following steps: 2a) Introduce an oxygen-containing organic compound into the second reaction zone of the fluidized catalytic conversion reactor to contact the catalytic conversion catalyst therein and react under the fourth catalytic conversion conditions, and the fourth catalytic conversion conditions include: The reaction temperature is 300 - 550 °C, preferably 400 - 530 °C, The reaction pressure is 0.05 - 1 MPa, preferably 0.1 - 0.8 MPa, The reaction time is 0.01 - 100 seconds, preferably 0.1 - 80 seconds, The weight ratio of the catalytic conversion catalyst to the oxygen-containing organic compound feedstock is (1 - 100):1, preferably (3 - 80):1, Preferably, the oxygen-containing organic compound comprises at least one of methanol, ethanol, dimethyl ether, methyl ethyl ether, and ethyl ether.

6. The method according to any one of claims 1 - 5, further comprising the following steps: 8) Coke-burn and regenerate the spent catalyst separated in step 3) to obtain a regenerated catalyst with a temperature above 650 °C, and then return the regenerated catalyst upstream of the first reaction zone of the fluidized catalytic conversion reactor as the catalytic conversion catalyst.

7. The method according to any one of claims 1 - 6, wherein: The olefin-rich feedstock has an olefin content of more than 80% by weight, preferably more than 90% by weight, and more preferably, the olefin-rich feedstock is a pure olefin feedstock; The olefins in the olefin-rich feedstock are basically composed of olefins with 5 or more carbon atoms; The olefin-rich feedstock comes from at least one of the C5+ fractions produced by an alkane dehydrogenation unit, the C5+ fractions produced by a refinery catalytic cracking unit, the C5+ fractions produced by an ethylene plant steam cracking unit, the C5+ olefin-rich fractions by-produced from MTO, and the C5+ olefin-rich fractions by-produced from MTP; and / or The heavy feedstock is selected from petroleum hydrocarbons and / or mineral oils; the petroleum hydrocarbons are selected from vacuum gas oil, atmospheric gas oil, coker gas oil, deasphalted oil, vacuum residue, atmospheric residue, heavy aromatic raffinate, or a combination thereof; the mineral oils are selected from coal liquefied oil, oil sand oil, shale oil, or a combination thereof.

8. The method according to any one of claims 1 - 7, wherein, Based on the weight of the catalytic conversion catalyst, the catalytic conversion catalyst comprises 1 - 50% by weight of molecular sieve, 5 - 99% by weight of inorganic oxide, and 0 - 70% by weight of clay; The molecular sieve includes one or more of a macroporous molecular sieve, a mesoporous molecular sieve, and a microporous molecular sieve; and Based on the weight of the catalytic conversion catalyst, the catalytic conversion catalyst further includes 0.1-3% by weight of a modified element, and the modified element is selected from one or more of Group VIII metals, Group IVA metals, Group V elements, and rare earth metals.

9. The method according to claim 2 or 3, wherein, Based on the weight of the hydrogenation catalyst, the hydrogenation catalyst includes 20-90% by weight of a carrier, 10-80% by weight of a supported metal, and 0-10% by weight of an additive; wherein the carrier is alumina and / or amorphous silica-alumina, the additive is selected from fluorine, phosphorus, titanium, platinum, or a combination thereof, and the supported metal is a Group VIB metal and / or a Group VIII metal; Preferably, the Group VIB metal is Mo or / and W, and the Group VIII metal is Co or / and Ni.

10. The method according to any one of claims 1-9, wherein the olefin-rich stream obtained in step 4) has an olefin content of C5 and above of at least 80%.

11. The method according to any one of claims 1-10, wherein the fluidized catalytic conversion reactor is selected from a fluidized bed reactor and a riser reactor, preferably a variable-diameter riser reactor.

12. The method according to claim 5, wherein the oxygen-containing organic compound is mixed with the heavy feedstock and then fed into the second reaction zone of the fluidized catalytic conversion reactor, or the oxygen-containing organic compound is fed into the second reaction zone of the fluidized catalytic conversion reactor downstream of the heavy feedstock introduction position.

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