A system and method for catalytic conversion of light hydrocarbon oils to produce lower carbon olefins and aromatics

Abstract

The present disclosure relates to a system and method for producing low-carbon olefins and aromatics from catalytic conversion of light hydrocarbon oil, which independently sets the device for cracking reaction and the device for catalyst regeneration, and can improve the adaptability and safety of the system. A second regeneration catalyst cooler is arranged on the second regeneration inclined pipe to reduce the temperature of a part of the regenerated catalyst, which can flexibly adjust the catalyst activity and concentration in the riser reactor, significantly increase the catalyst / oil ratio, improve the contact area between the raw material and the catalyst, significantly enhance the catalytic reaction, improve the yield of low-carbon olefins and low-carbon aromatics, and reduce the yield of methane hydrogen and coke. In addition, an oil-gas quencher is arranged in the system of the present disclosure to quickly reduce the temperature of the reaction oil-gas at the outlet of the reactor, avoid the safety hazards caused by excessive thermal cracking and condensation coking of the reaction oil-gas in the large oil-gas pipeline at the outlet of the reactor, and effectively utilize the heat in the high-temperature reaction oil-gas.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of petroleum chemical industry, in particular, to a system and method for catalytic conversion of light hydrocarbon oil to produce low-carbon olefins and aromatic hydrocarbons. BACKGROUND

[0002] Low-carbon olefins (ethylene, propylene) and low-carbon aromatic hydrocarbons (BTX) are important basic organic raw materials for petroleum chemical industry, and play an important role in the petrochemical industry.

[0003] In recent years, new technologies for producing low-carbon olefins and low-carbon aromatic hydrocarbons have attracted more and more attention, and the technology for catalytic cracking to produce low-carbon olefins and low-carbon aromatic hydrocarbons is one of the most widely used technologies. For example, Chinese patents CN103509589A, CN103509593A, CN103509594A and CN103509595A disclose a method for catalytic conversion of light hydrocarbon oil. The light hydrocarbon oil raw material enters the catalytic cracking device for catalytic cracking reaction, and the generated reaction oil gas is separated to obtain low-carbon olefins. The spent catalyst is regenerated and recycled. The C4 light fraction in the reaction product is returned to the riser reactor for refining. In order to reduce the heat dissipation energy consumption of the reactor, the riser reactor and other all or part of the reactor components are arranged inside the regenerator. In order to further meet the heat demand of the reaction-regeneration system, fuel is directly introduced into the regenerator and / or the spent inclined pipe.

[0004] The above-mentioned prior art proposes a method for converting petroleum hydrocarbon raw materials into low-carbon olefins through a catalytic cracking (cracking) reaction process, but still fails to solve the problems of insufficient heat of the reaction-regeneration system, safety hazards caused by reactor wear, high-temperature crushing and deactivation of catalyst, etc. in the process of catalytic conversion of light hydrocarbon oil due to low coke, and does not involve a scheme for recovering high-value low-carbon aromatic hydrocarbons and improving the yield of low-carbon aromatic hydrocarbons. SUMMARY

[0005] The purpose of the present disclosure is to provide a system and method for catalytic conversion of light hydrocarbon oil to produce low-carbon olefins and aromatic hydrocarbons, in order to solve the problems of insufficient heat of the reaction-regeneration system, safety hazards caused by reactor wear, high-temperature crushing and deactivation of catalyst, etc. in the prior art.

[0006] In order to achieve the above-mentioned purpose, the first aspect of the present disclosure provides a system for producing low-carbon olefins and aromatic hydrocarbons by catalytic conversion of light hydrocarbon oil, which comprises a riser reactor, a reaction product purification and separation unit, and an oil gas quencher arranged coaxially; the oil gas quencher is arranged at the top of the reaction product purification and separation unit; the reaction product purification and separation unit comprises a stripping section and a reaction settler from bottom to top; the stripping section and the reaction settler are separated by a sealing cover plate; the stripping section comprises a spent catalyst outlet and an optional reaction circulating catalyst outlet; the riser reactor comprises a first regenerated catalyst inlet, a second regenerated catalyst inlet, and an optional reaction circulating catalyst inlet; the spent catalyst outlet of the stripping section is communicated with the inlet of a catalyst regeneration device through a spent catalyst inclined pipe; the first regenerated catalyst inlet of the riser reactor is communicated with the outlet of the catalyst regeneration device through a first regenerated catalyst inclined pipe; the second regenerated catalyst inlet of the riser reactor is communicated with the outlet of a second catalyst regeneration device through a second regenerated catalyst inclined pipe; wherein, a second regenerated catalyst cooler is arranged on the second regenerated catalyst inclined pipe; the reaction circulating catalyst outlet of the stripping section is communicated with the circulating catalyst inlet of the riser reactor through a reaction circulating inclined pipe.

[0007] Optionally, a fully-closed anti-coking cyclone assembly is arranged in the reaction settler; the fully-closed anti-coking cyclone assembly comprises a cyclone quick separation head, a closed cover, and a reaction cyclone separator; the closed cover is a sealing cylinder arranged at the upper part of the stripping section; the outlet at the upper part of the sealing cylinder is communicated with the inlet of the reaction cyclone separator through a flow guide cylinder; the lower part of the sealing cylinder extends downward into the stripping section through the sealing cover plate, and the lower part of the closed cover is provided with a notch to make the inside and outside of the closed cover communicated only through the notch; the upper part of the riser reactor is embedded inside the reaction product purification and separation unit, and the top of the riser reactor extends into the sealing cylinder, and the cyclone quick separation head is arranged at the top outlet of the riser reactor; or, a coarse cyclone top cyclone closed direct connection assembly is arranged in the reaction settler; the coarse cyclone top cyclone closed direct connection assembly comprises a coarse cyclone, an oil gas collecting pipe, an oil gas closed guide pipe, and a reaction cyclone separator; the top outlet of the riser reactor is communicated with the inside of the oil gas collecting pipe through the coarse cyclone; the gas outlet of the oil gas collecting pipe is communicated with the inlet of the reaction cyclone separator; the bottom inlet of the oil gas closed guide pipe extends downward into the gas phase space at the upper part of the stripping section through the sealing cover plate; the gas phase space at the lower part of the sealing cover plate is communicated with the oil gas collecting pipe through the oil gas closed guide pipe.

[0008] Optionally, the reaction cyclone is at least one stage, preferably two stages; the outlet of the draft tube at the upper part of the closed cover is communicated with the inlet of the first stage reaction cyclone; the gas outlet of the last stage reaction cyclone is communicated with the inlet of the reaction gas collecting chamber; the catalyst outlet of the reaction cyclone extends downward through the seal cover plate to the gas phase space formed by the outer wall of the closed cover and the seal cover plate; or, the gas outlet of the oil gas collecting pipe is communicated with the inlet of the first stage reaction cyclone; the gas outlet of the last stage reaction cyclone is communicated with the inlet of the reaction gas collecting chamber; the catalyst outlet of the coarse cyclone, the inlet of the oil gas closed guide pipe and the catalyst outlet of the reaction cyclone extend downward through the seal cover plate to the gas phase space at the lower part of the seal cover plate.

[0009] Optionally, the riser reactor comprises a pre-lifting section, a variable-diameter section and a reaction section communicated in sequence from bottom to top; the pre-lifting section and the reaction section are respectively equal-diameter cylindrical; the ratio of the inlet diameter of the reaction section to the diameter of the pre-lifting section is 1-5; the ratio of the lengths of the pre-lifting section, the variable-diameter section and the reaction section is 1:(0.05-0.5):(1-10); the pre-lifting section is provided with a pre-lifting medium nozzle, a first regenerated catalyst inlet and a back-fining medium nozzle; the pre-lifting medium nozzle is communicated with a pre-lifting medium source, the back-fining medium nozzle is communicated with a back-fining medium source, and the first regenerated catalyst inlet is communicated with one end of the first regenerated catalyst inclined pipe; the variable-diameter section is provided with a raw material nozzle, which is communicated with a light hydrocarbon oil raw material source; the reaction section is provided with the second regenerated catalyst inlet, the reaction circulating catalyst inlet and a dilution steam nozzle; the dilution steam nozzle is communicated with a dilution steam source; the second regenerated catalyst inlet is communicated with the outlet of the second regenerated catalyst cooler; and the reaction circulating catalyst inlet is communicated with one end of the reaction circulating inclined pipe.

[0010] Optionally, the reaction settler is further provided with a reaction gas collecting chamber and an anti-coking steam ring located below the reaction gas collecting chamber; the outlet of the reaction gas collecting chamber is communicated with the top outlet of the reaction settler; the inlet of the anti-coking steam ring is communicated with an anti-coking steam source; steam injection holes are formed on the upper surface and / or the lower surface of the anti-coking steam ring; the stripping section comprises stripping section internals, at least one set of stripping steam rings and loosening steam rings; the stripping section internals comprise one or more of herringbone baffles, annular baffles, disc umbrella baffles, packings and grates; the stripping steam rings are located in the middle and / or lower part of the stripping section; the loosening steam rings are located at the bottom of the stripping section; steam wear-resistant nozzles are arranged on the upper surface and / or the lower surface of the stripping steam rings and the loosening steam rings.

[0011] Optionally, the oil-gas quencher comprises an oil-gas distributor, a quencher baffle, a quenching medium distributor and a stirring steam ring; the oil-gas distributor is located at the bottom of the oil-gas quencher and the top outlet of the reaction settler is in communication with the inlet of the oil-gas distributor; the quencher baffle is located above the oil-gas distributor; the quencher baffle has 1-20 layers; the quenching medium distributor is located at the upper part of the quencher baffle; the lower surface of the quenching medium distributor is provided with injection holes, the airflow direction of the injection holes of the quenching medium distributor is vertically downward and / or obliquely downward; the stirring steam ring is located at the lower part of the oil-gas quencher; the upper surface of the stirring steam ring is provided with injection holes, the airflow direction of the injection holes of the stirring steam ring is vertically upward and / or obliquely upward.

[0012] The second aspect of the present disclosure adopts the system of the first aspect of the present disclosure to produce low-carbon olefins and aromatic hydrocarbons from catalytic conversion of light hydrocarbon oil, the method comprising: feeding the light hydrocarbon oil feedstock into the riser reactor to contact the regenerated catalyst for cracking reaction to obtain a reaction material containing cracking reaction products and spent catalyst; passing the reaction material through the outlet of the riser reactor into the reaction product purification separation unit for separation to obtain high-temperature reaction oil gas and spent catalyst; passing the high-temperature reaction oil gas into the oil-gas quencher to exchange heat with the quenching medium to obtain low-temperature reaction oil gas; further separating the low-temperature reaction oil to obtain low-carbon olefins and low-carbon aromatic hydrocarbons; passing the spent catalyst through the spent catalyst inclined pipe into the catalyst regeneration device to obtain regenerated catalyst; passing a part of the regenerated catalyst as first regenerated catalyst through the first regenerated catalyst inclined pipe into the riser reactor, and passing another part of the regenerated catalyst as second regenerated catalyst into the riser reactor after cooling through the second regenerated catalyst inclined pipe;

[0013] Optionally, a part of the spent catalyst is returned to the riser reactor as reaction cycle catalyst through the reaction cycle inclined pipe.

[0014] Optionally, the light hydrocarbon oil feedstock is selected from one or more of light distillate with a distillation range of 20-300℃, preferably catalytic cracking gasoline, catalytic cracking gasoline, straight-run naphtha, coking naphtha, thermal cracking naphtha, thermal cracking naphtha, hydrogenated naphtha, reforming raffinate, straight-run kerosene, and hydrogenated kerosene; the regenerated catalyst comprises zeolite, inorganic oxide, and clay; the content of zeolite is 0.5-90% by weight, the content of inorganic oxide is 1-99% by weight, and the content of clay is 0-80% by weight, based on the total weight of the regenerated catalyst; the zeolite comprises mesoporous zeolite, medium-pore zeolite, and optionally macroporous zeolite; the content of mesoporous zeolite is 10-90% by weight, the content of medium-pore zeolite is 10-90% by weight, and the content of macroporous zeolite is 0-50% by weight, based on the total weight of the zeolite; and the quenching medium is selected from heavy oil products with an initial boiling point of 300℃ or higher, preferably one or more of pyrolysis heavy oil, catalytic cracking slurry, catalytic cracking slurry, coking slurry, atmospheric residue, and vacuum residue.

[0015] Optionally, the reaction conditions of the cracking reaction include a preheating temperature of 40-600℃, a reaction temperature of 400-900℃, a reaction pressure of 0.01-1.0 MPa(g), a reaction time of 0.1-30 s, a mass flow rate ratio of the regenerated catalyst to the light hydrocarbon oil feedstock of 1-100, and a mass flow rate ratio of water vapor to the light hydrocarbon oil feedstock of 0.05-2; the operating conditions of the stripping section include an average gas superficial linear velocity of 0.05-1 m / s and an average catalyst residence time of 0.5-10 min; the operating conditions of the oil-gas quenching device include an outlet temperature of the cooled reaction oil gas of 200-550℃, a bottom liquid temperature of 200-500℃, and a bottom liquid residence time of 0-15 min; the mass flow rate ratio of the regenerated catalyst passing through the first regenerated inclined pipe to the regenerated catalyst passing through the second regenerated inclined pipe is (1-50):1; and the mass flow rate ratio of the spent catalyst to the reaction circulating catalyst is (0.5-10):1.

[0016] Optionally, the reaction settler is provided with a fully-closed anti-coking cyclone assembly; the fully-closed anti-coking cyclone assembly comprises a cyclone quick separation head, a closed cover and a reaction cyclone separator; or, the reaction settler is provided with a coarse-rotation top-rotation closed direct-connection assembly; the coarse-rotation top-rotation closed direct-connection assembly comprises a coarse-rotation, an oil-gas collecting pipe, an oil-gas closed guide pipe and a reaction cyclone separator; the method further comprises: making the reaction material pass through the cyclone quick separation head at the outlet of the riser reactor to obtain the first spent catalyst and the coarsely separated oil gas through first separation; making the first spent catalyst flow downward in the internal space of the closed cover and flow into the stripping section; making the coarsely separated oil gas flow upward along the internal space of the closed cover and enter the reaction cyclone separator through the draft tube to obtain the second spent catalyst and the high-temperature reaction oil gas through second separation; making the high-temperature reaction oil gas enter the oil-gas quenching device from the gas phase outlet of the reaction cyclone separator; and making the second spent catalyst enter the gas phase space formed by the outer wall of the closed cover and the sealing cover plate from the catalyst outlet of the reaction cyclone separator, and finally enter the stripping section through the slot; or, the method further comprises: making the reaction material pass through the coarse-rotation to obtain the first spent catalyst and the coarsely separated oil gas through first separation; making the coarsely separated oil gas enter the reaction cyclone separator to obtain the second spent catalyst and the high-temperature reaction oil gas through second separation; making the high-temperature reaction oil gas enter the oil-gas quenching device from the gas phase outlet of the reaction cyclone separator; and making the first spent catalyst flowing out of the catalyst outlet of the coarse-rotation and the second spent catalyst flowing out of the catalyst outlet of the reaction cyclone separator enter the stripping section.

[0017] By the above technical solution, the device for performing cracking reaction and the device for regenerating catalyst are independently arranged, which can improve the adaptability and safety of the system. The second regeneration catalyst cooler is arranged on the second regeneration inclined pipe, which is used to reduce the temperature of part of the regenerated catalyst. The catalyst activity and concentration in the riser reactor can be flexibly adjusted, the catalyst contact area with the raw material is increased, the catalytic reaction is significantly enhanced, the yield of low-carbon olefins and low-carbon aromatic hydrocarbons is improved, and the yield of methane and coke is reduced. In addition, the oil-gas quenching device is arranged in the system of the present application, which can quickly reduce the temperature of the reaction oil gas, avoid the safety hazards caused by excessive thermal cracking and condensation coking of the reaction oil gas in the pipeline, and effectively utilize the heat in the high-temperature reaction oil gas.

[0018] Other features and advantages of the present disclosure will be described in detail in the following detailed description section. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, which together with the detailed description, serve to explain the present disclosure. In the drawings:

[0020] Figure 1 is a schematic diagram of a system for catalytic conversion of light hydrocarbon oil to produce low-carbon olefins and aromatic hydrocarbons in the embodiment 1 of the present disclosure.

[0021] Figure 2 is a schematic diagram of a system for catalytic conversion of light hydrocarbon oil to produce low-carbon olefins and aromatic hydrocarbons in the embodiment 2 of the present disclosure.

[0022] Figure 3 is a schematic diagram of a system for catalytic conversion of light hydrocarbon oil to produce low-carbon olefins and aromatic hydrocarbons in the embodiment 3 of the present disclosure.

[0023] Figure 4 is a schematic diagram of a system for catalytic conversion of light hydrocarbon oil to produce low-carbon olefins and aromatic hydrocarbons in the embodiment 4 of the present disclosure.

[0024] BRIEF DESCRIPTION OF DRAWINGS

[0025] 1, riser reactor; 2, stripping section; 3, reaction settler; 4, oil gas quencher; 5, second regenerated catalyst cooler; 10, first regenerated catalyst inclined pipe; 11, spent catalyst inclined pipe; 12, reaction circulating inclined pipe; 14, second regenerated catalyst inclined pipe; 18, stripping section internal component; 19, stripping steam ring; 20, loosening steam ring; 21, cyclone quick separation head; 22, closed cover; 23, sealing cover plate; 24, slot; 25, reaction cyclone separator; 26, anti-coking steam ring; 27, reaction gas collecting chamber; 28, oil gas distributor; 29, quencher baffle; 30, quenching medium distributor; 31, stirring steam ring; 100, pre-lifting medium; 101, back-fining medium; 102, light hydrocarbon oil feedstock; 103, dilution steam; 104, loosening steam; 105, stripping steam; 106, anti-coking steam; 107, stirring steam; 108, quenching medium; 109, temperature-reduced reaction oil gas; 110, heat-exchanged quenching medium; 121, coarse cyclone; 122, oil gas collecting pipe; 124, oil gas closed guide pipe. DETAILED DESCRIPTION

[0026] The specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present disclosure, and are not intended to limit the present disclosure.

[0027] The first aspect of the present disclosure provides a system for producing low-carbon olefins and aromatic hydrocarbons by catalytic conversion of light hydrocarbon oil, which comprises a riser reactor 1, a reaction product purification and separation unit, and an oil gas quencher 4 arranged coaxially; the oil gas quencher 4 is arranged at the top of the reaction product purification and separation unit; the reaction product purification and separation unit comprises a stripping section 2 and a reaction settler 3 arranged in sequence from bottom to top, and the stripping section 2 and the reaction settler 3 are separated by a sealing cover plate 23; the stripping section 2 comprises a spent catalyst outlet and an optional reaction circulating catalyst outlet; the riser reactor 1 comprises a first regenerated catalyst inlet, a second regenerated catalyst inlet, and an optional reaction circulating catalyst inlet; the spent catalyst outlet of the stripping section 2 is connected to the inlet of a catalyst regeneration device through a spent catalyst inclined pipe 11, so that the spent catalyst can enter the regeneration device for regeneration treatment; the first regenerated catalyst inlet of the riser reactor 1 is connected to the outlet of the catalyst regeneration device through a first regenerated catalyst inclined pipe 10, so that a part of the regenerated catalyst can directly return to the riser reactor 1 to participate in the reaction; the second regenerated catalyst inlet of the riser reactor 1 is connected to the outlet of the catalyst regeneration device through a second regenerated catalyst inclined pipe 14; wherein a second regenerated catalyst cooler 5 is arranged on the second regenerated catalyst inclined pipe 14, so that another part of the regenerated catalyst can return to the riser reactor 1 to participate in the reaction after being cooled by the second regenerated catalyst cooler 5; the reaction circulating catalyst outlet of the stripping section 2 is connected to the reaction circulating catalyst inlet of the riser reactor 1 through a reaction circulating inclined pipe 12, so that part of the spent catalyst can return to the riser reactor 1 to participate in the reaction.

[0028] By the above technical solution, the device for performing cracking reaction and the device for catalyst regeneration are independently arranged, which can improve the adaptability and safety of the system. The second regenerated catalyst cooler 5 is arranged on the second regenerated catalyst inclined pipe 14, which is used to reduce the temperature of a part of the regenerated catalyst, so that the catalyst activity and concentration in the riser reactor 1 can be flexibly adjusted, the catalyst / oil ratio is significantly increased, the contact area between the raw material and the catalyst is improved, the catalytic reaction is significantly enhanced, the yield of low-carbon olefins and low-carbon aromatic hydrocarbons is improved, and the yield of methane and coke is reduced. In addition, the oil gas quencher 4 is arranged in the system of the present application, which can quickly reduce the temperature of the reaction oil gas at the outlet of the reactor, avoid the safety hazards caused by excessive thermal cracking and condensation coking of the reaction oil gas in the large oil gas pipeline at the outlet of the reactor, and effectively utilize the heat in the high-temperature reaction oil gas.

[0029] As Figure 1As shown, the riser reactor 1 includes a pre-lifting section, a variable-diameter section and a reaction section connected in sequence from bottom to top; the pre-lifting section and the reaction section are both equal-diameter cylindrical; the ratio of the inlet diameter of the reaction section to the diameter of the pre-lifting section is 1-5, preferably 1-3, more preferably 1-2; the length ratio of the pre-lifting section, the variable-diameter section and the reaction section is 1:(0.05-0.5):(1-10), preferably 1:(0.1-0.3):(3-8), more preferably 1:(0.1-0.2):(4-6).

[0030] The pre-lifting section is provided with a pre-lifting medium nozzle, a first regenerated catalyst inlet and a back-refining medium nozzle; the pre-lifting medium nozzle is used to communicate with a pre-lifting medium source to enable the pre-lifting medium 100 to enter the riser reactor 1 to lift the light hydrocarbon oil raw material 102 and the regenerated catalyst to the reaction area; the back-refining medium nozzle is used to communicate with a back-refining medium source to enable the back-refining medium 101 to return to the riser reactor 1 to participate in the reaction.

[0031] In this embodiment, the mixed C4 and / or mixed C5 and / or cracked naphtha in the reaction product are returned to the riser reactor 1 for back-refining; the mixed C4 and / or mixed C5 and / or cracked naphtha enter the riser reactor 1 before and / or after the light hydrocarbon oil raw material nozzle; back-refining of the mixed C4, mixed C5 and cracked naphtha can further improve the yield of low-carbon olefins and low-carbon aromatic hydrocarbons.

[0032] The variable-diameter section is provided with a raw material nozzle, which is used to communicate with a light hydrocarbon oil raw material source to enable the light hydrocarbon oil raw material 102 to enter the variable-diameter section of the riser reactor 1 and then enter the reaction area through the pre-lifting medium 100.

[0033] The reaction section is provided with the second regenerated catalyst inlet, the reaction circulating catalyst inlet and a dilution steam nozzle, which is used to communicate with a dilution steam source to enable the dilution steam 103 to enter the riser reactor 1 to participate in the reaction.

[0034] The first regenerated catalyst inlet communicates with one end of the first regenerated inclined pipe 10 to enable the first regenerated catalyst to enter the riser reactor 1 through the first regenerated inclined pipe 10 to participate in the reaction; the second regenerated catalyst inlet communicates with the outlet of the second regenerated catalyst cooler 5 to enable the cooled second regenerated catalyst to enter the reaction section to participate in the reaction; the reaction circulating catalyst inlet communicates with one end of the reaction circulating inclined pipe 12 to enable the reaction circulating catalyst to return to the reaction section to participate in the reaction.

[0035] Wherein, in order to further improve the flexibility of adjusting the catalyst flow and temperature in the riser reactor 1, a valve for controlling the flow is independently arranged on the reaction cycle inclined pipe 12 and the second regeneration inclined pipe 14. Further, the second regeneration catalyst cooler 5 is provided with a measure for controlling the temperature of the cooled second regeneration catalyst, that is, the outlet second regeneration catalyst temperature is controlled by controlling the heat removal load of the second regeneration catalyst cooler 5.

[0036] As shown in Figure 1 The reaction settler 3 is provided with a fully closed anti-coking cyclone assembly; the fully closed anti-coking cyclone assembly includes a cyclone quick separation head 21, a closed cover 22, and a reaction cyclone separator 25; the closed cover 22 is a sealed cylinder arranged at the upper part of the stripping section 2; the outlet at the upper part of the sealed cylinder is in communication with the inlet of the reaction cyclone separator 25 through a flow guide cylinder; the lower part of the sealed cylinder extends downward into the stripping section 2 through the sealing cover plate 23, and the lower part of the closed cover 22 is provided with a slot 24 to make the inside and outside of the closed cover 22 communicate only through the slot 24; the upper part of the riser reactor 1 is embedded inside the reaction product purification and separation unit, and the top of the riser reactor 1 extends into the sealed cylinder, and the cyclone quick separation head 21 is arranged at the top outlet of the riser reactor 1.

[0037] Wherein, the closed cover 22 in the fully closed anti-coking cyclone assembly used in the present disclosure is a cylinder with a closed top, wherein the cylinder of the closed cover 22 includes a lower end cylinder, a variable diameter section cylinder, and a top cylinder which are sequentially communicated from bottom to top.

[0038] As shown in Figure 3 The reaction settler 3 is provided with a coarse cyclone top cyclone closed direct connection assembly; the coarse cyclone top cyclone closed direct connection assembly includes a coarse cyclone 121, an oil and gas collecting pipe 122, an oil and gas closed guide pipe 124, and a reaction cyclone separator 25; the top outlet of the riser reactor 1 is in communication with the inside of the oil and gas collecting pipe 122 through the coarse cyclone 121; the gas outlet of the oil and gas collecting pipe 122 is in communication with the inlet of the reaction cyclone separator 25; the bottom inlet of the oil and gas closed guide pipe 124 extends downward to the gas phase space at the upper part of the stripping section 2 through the sealing cover plate 23; the gas phase space at the lower part of the sealing cover plate 23 is in communication with the oil and gas collecting pipe 122 through the oil and gas closed guide pipe 124.

[0039] Wherein, the coarse cyclone 121 and the oil and gas collecting pipe 122 in the coarse cyclone top cyclone closed direct connection assembly used in the present disclosure are in closed communication with the outlet of the riser reactor 1.

[0040] The reaction cyclone separator 25 is at least one stage, preferably two stages. The outlet of the guide tube at the top of the enclosure 22 is connected to the inlet of the first-stage reaction cyclone separator, so that the oil and gas materials from the reaction products of the riser reactor 1 can enter the reaction cyclone separator 25 for separation to obtain high-temperature reaction oil and gas and catalyst material to be generated. The gas outlet of the last-stage reaction cyclone separator is connected to the inlet of the reaction gas collection chamber 27, so that the reaction oil and gas can enter the reaction gas collection chamber 27 for later use. The catalyst outlet of the reaction cyclone separator 25 extends downward through the sealing cover plate 23 via a material leg. The gas phase space extends to the outer wall of the enclosure 22 and below the sealing cover 23, so that the catalyst to be generated can finally enter the stripping section 2 through the slot 24; or, the gas outlet of the oil and gas collection pipe 122 is connected to the inlet of the first-stage reaction cyclone separator; the gas outlet of the last-stage reaction cyclone separator is connected to the inlet of the reaction gas collection chamber 27; the catalyst outlet of the coarse cyclone 121, the inlet of the oil and gas sealed guide pipe 124, and the catalyst outlet of the reaction cyclone separator 25 extend downward through the sealing cover 23 to the gas phase space below the sealing cover 23 via the material leg.

[0041] In the above embodiments, equipping the outlet of the riser reactor 1 with a fully enclosed anti-coking cyclone assembly or a coarse cyclone top-cyclone closed direct-connection assembly allows the reaction products obtained from the riser reactor 1 to directly enter the reaction cyclone separator 25 for separation under the action of the sealing shroud 22 or the oil and gas manifold 122. On the one hand, this avoids the reaction products from staying in the large-volume reaction settling tank 3 for too long, thus preventing secondary cracking reactions and improving the yield of low-carbon olefins and / or low-carbon aromatics. On the other hand, it prevents the reaction products from coking in the reaction settling tank 3, which would lead to poor stability of the unit. To further prevent coking in the reaction settling tank 3, such as... Figure 1 As shown, this disclosure provides an anti-coking steam ring 26 below the reaction gas collection chamber 27 and above the enclosure 22 or the oil and gas collection pipe 122; the inlet of the anti-coking steam ring 26 is used to communicate with the anti-coking steam source; steam injection holes are provided on the upper surface and / or lower surface of the anti-coking steam ring 26 so that the anti-coking steam 106 can pass through the anti-coking steam ring 26 and be ejected through the steam injection holes.

[0042] The material and the setting position of the sealing cover plate 23 are conventional choices in the art, and only need to set holes at different positions according to the components used in the reaction settler 3, for example, when the full-closed anti-coking cyclone component is used in the reaction settler 3, the sealing cover plate 23 is tightly combined with the outer wall of the closed cover 22, the inner wall of the reaction settler 3, and the outer wall of the leg of the reaction cyclone separator 25, or a gap is left; when the coarse-rotation top-rotation closed direct-connection component is used in the reaction settler 3, the sealing cover plate 23 is tightly combined with the outer wall of the riser reactor 1, the inner wall of the reaction settler 3, the outer wall of the leg of the coarse-rotation 121, the outer wall of the leg of the reaction cyclone separator 25, and the outer wall of the oil-gas closed guide pipe 124, or a gap is left. In addition, a plurality of round holes can be uniformly arranged on the sealing cover plate 23 to make the fluid communicate between the stripping section 2 and the reaction settler 3, wherein the diameter of the round hole is 1-100 mm.

[0043] The stripping section 2 comprises at least one set of stripping steam rings 19 and loosening steam rings 20, and stripping section internals 18; the stripping section internals 18 comprise one or more of a herringbone baffle, an annular baffle, a disc umbrella baffle, a packing, and a grid; the stripping steam rings 19 are located in the middle and / or lower part of the stripping section 2; the loosening steam rings 20 are located at the bottom of the stripping section 2; the upper surface and / or the lower surface of the stripping steam rings 19 and the loosening steam rings 20 are provided with steam-wear-resistant nozzles.

[0044] The oil-gas quencher 4 comprises an oil-gas distributor 28, a quencher baffle 29, a quenching medium distributor 30, and a stirring steam ring 31; the oil-gas distributor 28 is located at the bottom of the oil-gas quencher 4, and the top outlet of the reaction settler 3 is communicated with the inlet of the oil-gas distributor 28, so that the high-temperature reaction oil-gas can enter the oil-gas distributor 28 for distribution; the quencher baffle 29 is located above the oil-gas distributor 28; the number of layers of the quencher baffle 29 is 1-20, preferably 3-10, and more preferably 4-8; the quenching medium distributor 30 is located at the upper part of the quencher baffle 29; the lower surface of the quenching medium distributor 30 is provided with injection holes, and the airflow direction of the injection holes of the quenching medium distributor 30 is vertically downward and / or obliquely downward; the stirring steam ring 31 is located at the lower part of the oil-gas quencher 4; the upper surface of the stirring steam ring 31 is provided with injection holes, and the airflow direction of the injection holes of the stirring steam ring 31 is vertically upward and / or obliquely upward.

[0045] In this embodiment, the quenching medium 108 is a heavy oil product with a first distillation point > 300°C, including but not limited to one or more combinations of self-produced pyrolysis heavy oil, catalytic cracking slurry oil, catalytic cracking slurry oil, coking slurry oil, atmospheric residue, vacuum residue, etc. The use of heavy oil products can control the liquid temperature at the bottom of the oil gas quenching device 4 above 300°C. The use of this part of the high-temperature liquid can heat the light and heavy hydrocarbon oil feedstock or generate steam, better utilize the high-temperature heat in the high-temperature reaction oil gas, and reduce the energy consumption of the device. The oil gas quenching device 4 is directly arranged above the reaction settler 3 and integrated with the reaction settler 3; or the oil gas quenching device 4 is separately arranged near the reaction settler 3, so that the high-temperature reaction oil gas can be cooled in the shortest possible time to avoid coking of the high-temperature oil gas. Due to the fact that the catalytic cracking gas yield of light hydrocarbon oil is much higher than that of conventional catalytic cracking, the total amount of catalyst fines entrained by the reaction oil gas is relatively large, and the slurry oil yield is much lower than that of conventional catalytic cracking, which will result in a high solid content in the slurry oil. In order to reduce the catalyst content in the quenching medium 108, reduce the wear of equipment and pipelines, and ensure the long-term safe and stable operation of the device, the heat-exchanged quenching medium 110 is cooled by heat exchange and all or part of it enters the catalyst removal system to reduce the solid content and then circulates back to the oil gas quenching device 4; the catalyst removal system includes but is not limited to one or more combinations of filters, cyclones, centrifugal separators, and electric filters.

[0046] The second aspect of the present disclosure adopts the system of the first aspect of the present disclosure to produce low-carbon olefins and aromatic hydrocarbons from light hydrocarbon oil catalytic conversion, which comprises:

[0047] The light hydrocarbon oil feedstock 102 enters the riser reactor 1 to contact with the regenerated catalyst for cracking reaction, to obtain a reaction material containing cracking reaction products and spent catalyst; the reaction material passes through the outlet of the riser reactor 1 to enter the reaction product purification separation unit for separation, to obtain high-temperature reaction oil gas and spent catalyst; the high-temperature reaction oil gas enters the oil gas quenching device 4 to exchange heat with the quenching medium 108, to obtain cooled reaction oil gas 109; the low-temperature reaction oil is further separated to obtain low-carbon olefins and low-carbon aromatic hydrocarbons, as well as other products and backsteaming medium 101; the spent catalyst passes through the spent catalyst inclined pipe 11 to enter the catalyst regeneration device, to obtain regenerated catalyst; part of the regenerated catalyst as first regenerated catalyst passes through the first regenerated catalyst inclined pipe 10 to enter the riser reactor 1, and another part of the regenerated catalyst as second regenerated catalyst enters the riser reactor 1 after being cooled by the second regenerated catalyst inclined pipe 14; optionally, part of the spent catalyst as reaction circulating catalyst returns to the riser reactor 1 through the reaction circulating catalyst inclined pipe 12.

[0048] By the above technical solution, the present application can maximize catalytic conversion of light oil feedstocks such as gasoline, naphtha and kerosene into basic chemicals such as low-carbon olefins and low-carbon aromatic hydrocarbons, so as to transform a traditional fuel-type refinery or fuel-lubricant oil-type refinery into a chemical-type refinery, and develop and extend the refinery from a single oil refining to chemical feedstock production, which not only solves the problem of excess finished oil, but also increases the problem of shortage of chemical feedstock, and significantly improves the economic benefit of the enterprise. In addition, by cooling a part of the regenerated catalyst to the reaction temperature, the second regenerated catalyst circulation amount becomes an independent variable. By the low-temperature second regenerated catalyst circulation amount, the catalyst activity and concentration of the riser reactor 1 can be flexibly adjusted, the catalyst / oil ratio is significantly increased, the contact area of the feedstock and the catalyst is improved, the catalytic reaction is significantly enhanced, the yield of low-carbon olefins and low-carbon aromatic hydrocarbons is improved, and the yield of methane hydrogen and coke is reduced. Among them, the mass flow ratio of the regenerated catalyst passing through the first regeneration inclined pipe 10 to the regenerated catalyst passing through the second regeneration inclined pipe 14 is (1-50):1, preferably (1-20):1, and more preferably (2-5):1; the mass flow ratio of the spent catalyst to the reaction circulating catalyst is (0.5-10):1, preferably (1-5):1, and more preferably (2-4):1.

[0049] The light hydrocarbon oil feedstock 102 used in the present disclosure is selected from a light fraction with a distillation range of 20-300°C, preferably one or more of catalytic cracking gasoline, catalytic cracking gasoline, straight-run naphtha, coking naphtha, thermal cracking naphtha, thermal cracking naphtha, hydrogenated naphtha, reforming raffinate, straight-run kerosene and hydrogenated kerosene.

[0050] The catalyst used in the present disclosure is conventionally selected in the art, and the present application does not make special requirements, for example, the regenerated catalyst includes zeolite, inorganic oxide and clay; the content of zeolite is 0.5-90% by weight, the content of inorganic oxide is 1-99% by weight, and the content of clay is 0-80% by weight, based on the total weight of the regenerated catalyst; the zeolite includes mesoporous zeolite, medium-pore zeolite and optional macroporous zeolite; the content of the mesoporous zeolite is 10-90% by weight, the content of the medium-pore zeolite is 10-90% by weight, and the content of the macroporous zeolite is 0-50% by weight, based on the total weight of the zeolite.

[0051] In one embodiment, the method further comprises introducing the recycle medium 101, the regenerated catalyst, the light hydrocarbon oil feedstock 102 and the dilution steam 103 into the riser reactor 1 and moving upward and reacting under the action of the pre-lift medium 100. The main operating conditions of the riser reactor 1 are as follows: the preheating temperature of the light hydrocarbon oil feedstock 102 is 40-600°C, preferably 100-400°C, and more preferably 200-300°C; the reaction temperature is 400-900°C, preferably 500-800°C, and more preferably 550-700°C; the reaction pressure is 0.01-1.0 MPa(g), preferably 0.05-0.4 MPa(g), and more preferably 0.1-0.2 MPa(g); the reaction time is 0.1-30 s, preferably 1-10 s, and more preferably 2-4 s; the mass flow rate ratio of the regenerated catalyst to the light hydrocarbon oil feedstock 102 is 1-100, preferably 10-50, and more preferably 20-40; and the mass flow rate ratio of the injected steam to the light hydrocarbon oil feedstock 102 is 0.05-2, preferably 0.1-0.5, and more preferably 0.2-0.4.

[0052] The pre-lift medium 100 is selected from one or more mixed gases of water vapor, nitrogen, catalytic dry gas, self-produced methane hydrogen gas and light hydrocarbon oil feedstock 102 gas.

[0053] In one embodiment, the operating conditions of the stripping section 2 include: the average gas apparent linear velocity of the gas is 0.05-1 m / s, preferably 0.1-0.5 m / s, and more preferably 0.2-0.4 m / s; and the average residence time of the catalyst is 0.5-10 min, preferably 1-5 min, and more preferably 2-4 min.

[0054] In one embodiment, the operating conditions of the reaction settler 3 include: the average gas apparent linear velocity is 0.01-1 m / s, preferably 0.03-0.5 m / s, and more preferably 0.05-0.2 m / s; and the pressure of the reaction settler 3 is 0-20 kPa higher than that of the stripping section 2, preferably 0.02-10 kPa, and more preferably 0.05-5 kPa.

[0055] In one embodiment, the operating conditions of the oil-gas quenching device 4 include: the temperature of the outlet reaction oil gas 109 is 200-550°C, the temperature of the bottom liquid is 200-500°C, and the residence time of the bottom liquid is 0-15 min.

[0056] In one embodiment, the method further comprises, when a full-closed anti-coking cyclone assembly is used in the reaction settler 3, allowing the reaction material to pass through the cyclone quick separation head 21 at the outlet of the riser reactor 1 to be first separated to obtain a first separated oil gas and a first spent catalyst; allowing the first spent catalyst to flow downward through the internal space of the closed cover 22 and flow into the stripping section 2; allowing the first separated oil gas to flow upward along the internal space of the closed cover 22 and pass through the draft tube to enter the reaction cyclone 25 to be second separated to obtain the high-temperature reaction oil gas and the second spent catalyst; allowing the high-temperature reaction oil gas to enter the oil gas quenching device 4 after entering the reaction gas collection chamber 27 from the gas phase outlet of the reaction cyclone 25; and allowing the second spent catalyst to enter the gas phase space below the outer wall of the closed cover 22 and the sealing cover plate 23 from the catalyst outlet of the reaction cyclone 25 and finally enter the stripping section 2 through the slot 24.

[0057] In another embodiment, the method further comprises, when a rough cyclone top cyclone dense closed direct connection assembly is used in the reaction settler 3, allowing the reaction material to pass through the rough cyclone 121 to be first separated to obtain a first separated oil gas and a first spent catalyst; allowing the first separated oil gas to enter the reaction cyclone 25 to be second separated to obtain the high-temperature reaction oil gas and the second spent catalyst; allowing the high-temperature reaction oil gas to enter the oil gas quenching device 4 after entering the reaction gas collection chamber 27 from the gas phase outlet of the reaction cyclone 25; and allowing the first spent catalyst flowing out from the catalyst outlet of the rough cyclone 121 and the second spent catalyst flowing out from the catalyst outlet of the reaction cyclone 25 to enter the internal space of the stripping section 2.

[0058] In the above embodiments, in the normal operation state of the stripping section 2, the loosening steam 104 and the stripping steam 105 can be allowed to enter to participate in the stripping treatment; in the normal operation state of the reaction settler 3, the anti-coking steam 106 can be allowed to enter to prevent coking; and in the normal operation state of the oil gas quenching device 4, the stirring steam 107 can be allowed to enter to be stirred. The loosening steam 104, the stripping steam 105, the anti-coking steam 106 and the stirring steam 107 are selected from 0.7-1.6 MPa(g) low-pressure steam and / or 1.6-4.6 MPa(g) medium-pressure steam, and are further superheated to 400-700°C, preferably superheated to 480-600°C.

[0059] The method provided by the present application is further described below through specific examples, but the present application is not limited by the examples. The catalyst used in the examples has the properties shown in Table 1, and the raw material used has the properties shown in Table 2.

[0060] Table 1 Catalyst properties

[0061] Item Unit Value Average particle size μm 50～100 Apparent density g / cm 3 ]] 0.75～0.90 Specific surface area m 2 / g]]> ≥100 Pore volume mL / g ≥0.2 Wear index wt% ≤4.0

[0062] Table 2 Light hydrocarbon oil feedstock properties

[0063]

[0064]

[0065] Example 1

[0066] The system for catalytic conversion of the light hydrocarbon oil used in this example to produce low carbon olefins and aromatic hydrocarbons is shown in Figure 1 ;

[0067] Taking the light hydrocarbon oil feedstock 102 (straight-run naphtha, straight-run kerosene and coking naphtha) with a feedstock amount of 0.9 million tons / year as an example, the method for catalytic conversion of light hydrocarbon oil to produce low carbon olefins and aromatic hydrocarbons includes:

[0068] The light hydrocarbon oil feedstock 102 is preheated to 300°C and then enters the riser reactor 1 to contact with the regenerated catalyst to carry out a cracking reaction, to obtain a reaction material containing cracking reaction products and spent catalyst.

[0069] The reaction material is subjected to a first separation by a cyclone quick separator 21 at the outlet of the riser reactor 1 to obtain a crude oil gas and a first spent catalyst; the first spent catalyst flows downward through the internal space of the closed cover 22 and flows into the stripping section 2; the crude oil gas flows upward along the internal space of the closed cover 22 and enters the reaction cyclone separator 25 through the flow guide cylinder to be separated, to obtain the high-temperature reaction oil gas and the second spent catalyst; the high-temperature reaction oil gas enters the reaction gas chamber 27 from the gas phase outlet of the reaction cyclone separator 25, and the second spent catalyst enters the gas phase space below the outer wall of the closed cover 22 and the sealing cover plate 23 from the catalyst outlet of the reaction cyclone separator 25, and finally enters the internal space of the stripping section 2 through the slot 24.

[0070] The high-temperature reaction oil gas is made to enter the oil gas quenching device 4 from the reaction gas collecting chamber 27, and the high-temperature reaction oil gas is cooled to 350 DEG C by the heat-removed oil slurry to enter the product separation unit, and low-carbon olefins (ethylene, propylene), low-carbon aromatic hydrocarbons (benzene, toluene, xylene), methane hydrogen, ethane, propane, mixed carbon four, mixed carbon five, cracked naphtha, cracked light oil and cracked heavy oil and other products are separated. Part of the mixed carbon four, mixed carbon five and cracked naphtha are returned to the reaction riser reactor 1 to increase the yield of low-carbon olefins and low-carbon aromatic hydrocarbons. The spent catalyst separated by the full-closed anti-coking cyclone assembly is made to enter the stripping section 2 downward, and the spent catalyst is stripped of the entrained oil gas, and then the spent catalyst is made to enter the regeneration device through the spent catalyst inclined pipe 11 after coke burning and regeneration, and part of the regenerated catalyst obtained is made to return to the riser reactor 1 through the first regenerated catalyst inclined pipe 10 for recycling; another part of the regenerated catalyst is made to enter the second regenerated catalyst cooler 5 after cooling through the second regenerated catalyst inclined pipe 14, and then enters the riser reactor 1 to participate in the reaction.

[0071] The operating conditions of the method are shown in Table 3; and the product distribution of the device is shown in Table 4.

[0072] Example 2

[0073] The system for catalytically converting the light hydrocarbon oil to produce low-carbon olefins and aromatic hydrocarbons used in this example is shown in Figure 2 ;

[0074] The method for catalytically converting the light hydrocarbon oil to produce low-carbon olefins and aromatic hydrocarbons is the same as that in Example 1, except that part of the spent catalyst is made to return to the riser reactor 1 as a reaction circulating catalyst through the reaction circulating inclined pipe 12 for recycling.

[0075] The operating conditions of the method are shown in Table 3; and the product distribution of the device is shown in Table 4.

[0076] Example 3

[0077] The system for catalytically converting the light hydrocarbon oil to produce low-carbon olefins and aromatic hydrocarbons used in this example is shown in Figure 3 ;

[0078] The method for catalytically converting the light hydrocarbon oil to produce low-carbon olefins and aromatic hydrocarbons is the same as that in Example 1, except that the reaction material is made to pass through the rough cyclone top spin-tight closed direct connection assembly for treatment, which specifically includes:

[0079] The reaction mass is subjected to a first separation by a coarse cyclone 121 to obtain a coarse separation oil gas and a first spent catalyst; the coarse separation oil gas is subjected to a separation by a reaction cyclone 25 to obtain the high temperature reaction oil gas and the second spent catalyst; the high temperature reaction oil gas is passed from the gas phase outlet of the reaction cyclone 25 into a reaction plenum 27; the first spent catalyst from the catalyst outlet stream of the coarse cyclone 121 and the second spent catalyst from the catalyst outlet stream of the reaction cyclone 25 are passed into the interior of the stripping section 2.

[0080] The operating conditions of the process are shown in Table 3; the product distribution of the plant is shown in Table 4.

[0081] Example 4

[0082] The system for the catalytic conversion of a light hydrocarbon oil to produce low carbon olefins and aromatics used in this example is shown in Figure 4

[0083] The process for the catalytic conversion of a light hydrocarbon oil to produce low carbon olefins and aromatics is the same as in Example 3, with the difference that a part of the spent catalyst is returned to the riser reactor 1 as reaction recycle catalyst through a reaction recycle elbow 12 for reuse.

[0084] The operating conditions of the process are shown in Table 3; the product distribution of the plant is shown in Table 4.

[0085] Comparative Example 1

[0086] The process for the catalytic conversion of a light hydrocarbon oil to produce low carbon olefins and aromatics using the method of patent CN103509589A, specifically includes: using straight-run naphtha as raw material, a test is carried out on a pilot plant of a riser reactor, the preheated raw material oil enters the bottom of the riser, under the conditions of a reaction temperature of 675°C, a reaction time of 2 seconds, a weight ratio of catalytic cracking catalyst to raw material oil of 25, and a weight ratio of water vapor to raw material oil of 0.55, the raw material oil is cracked, the reaction products, water vapor and spent catalyst are discharged from the outlet of the reactor into a closed cyclone separator, the reaction products and the catalyst are rapidly separated, the reaction products are cut according to the distillation range after heat exchange with the raw material in a separation system, thereby obtaining dry gas, propylene, carbon four and gasoline fractions. The spent catalyst is introduced into a regenerator under the action of gravity and is regenerated by contacting with air. The regenerated catalyst is introduced into a degassing tank to remove non-hydrocarbon gas impurities adsorbed and carried by the regenerated catalyst. The stripped regenerated catalyst is returned to the riser reactor for recycling.

[0087] The operating conditions of the process are shown in Table 3; the product distribution of the plant is shown in Table 4.

[0088] Table 3 Operating conditions

[0089] ​

[0090]

[0091] Table 4 Device product distribution

[0092] Component Unit Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Methane hydrogen wt% 9.22 9.14 9.21 9.16 15.10 Ethylene wt% 24.55 24.66 24.56 24.64 23.84 Propylene wt% 26.36 26.61 26.37 26.60 26.96 mixed c4 wt% 9.24 9.25 9.27 9.23 15.99 BTX wt% 11.01 11.16 11.03 11.17 - Cracked naphtha wt% 12.98 12.85 12.97 12.85 14.20 Light diesel oil wt% 2.62 2.45 2.61 2.46 1.98 Oil slurry wt% 0.25 0.22 0.24 0.22 - Coke wt% 3.77 3.66 3.74 3.67 1.93 Total wt% 100.00 100.00 100.00 100.00 100.00

[0093] As shown in Table 4, according to the comparison of the data of Examples 1-4 and Comparative Example 1, it can be seen that, by using the technical scheme of the present disclosure, low-carbon olefins and aromatic hydrocarbons can be produced by catalytic conversion of light hydrocarbon oil, and by arranging a full-closed anti-coking cyclone assembly or a coarse-rotation top-rotation closed direct-connection assembly in the reaction settler, the risk of coking of high-temperature oil gas in the reaction settler can be reduced, and the risk of secondary cracking can be reduced, thereby the yield of the target product can be improved; in addition, by arranging a second regeneration catalyst cooler on the second regeneration inclined pipe to reduce the temperature of a part of the regenerated catalyst, the catalyst activity and concentration in the riser reactor can be flexibly adjusted, the catalyst / oil ratio can be significantly increased, the contact area of the raw material and the catalyst can be improved, the catalytic reaction can be significantly enhanced, the yield of low-carbon olefins and low-carbon aromatic hydrocarbons can be improved, and the yield of methane and coke can be reduced.

[0094] The preferred embodiments of the present disclosure are described in detail above in combination with the drawings, but the present disclosure is not limited to the specific details in the above-described embodiments, and various simple modifications can be made to the technical scheme of the present disclosure within the scope of the technical concept of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0095] In addition, it should be noted that each specific technical feature described in the above-described specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, various possible combination manners are not described again in the present disclosure.

[0096] In addition, various different embodiments of the present disclosure can also be combined in any appropriate manner, as long as they do not deviate from the idea of the present disclosure, and they should also be considered as disclosed by the present disclosure.

Claims

1. A system for the catalytic conversion of light hydrocarbon oil to produce low-carbon olefins and aromatics, characterized in that, The system includes a riser reactor (1) arranged coaxially, a reaction product purification and separation unit, and an oil-gas quencher (4); the oil-gas quencher (4) is located at the top of the reaction product purification and separation unit; the reaction product purification and separation unit includes a stripping section (2) and a reaction settling tank (3) from bottom to top, and the stripping section (2) and the reaction settling tank (3) are separated by a sealing cover plate (23); the stripping section (2) includes a catalyst outlet; the riser reactor (1) includes a first regenerated catalyst inlet and a second regenerated catalyst inlet; The outlet of the stripping section (2) is connected to the inlet of the catalyst regeneration unit via a pre-regeneration inclined tube (11); The first regenerated catalyst inlet of the riser reactor (1) is connected to the outlet of the catalyst regeneration device through the first regeneration inclined tube (10); the second regenerated catalyst inlet of the riser reactor (1) is connected to the outlet of the catalyst regeneration device through the second regeneration inclined tube (14); wherein, the second regeneration inclined tube (14) is provided with a second regenerated catalyst cooler (5).

2. The system according to claim 1, characterized in that, The stripping section (2) also includes a reaction circulation catalyst outlet; the riser reactor (1) also includes a reaction circulation catalyst inlet; The reaction cycle catalyst outlet of the stripping section (2) is connected to the reaction cycle catalyst inlet of the riser reactor (1) through the reaction cycle inclined tube (12).

3. The system according to claim 1, characterized in that, The reaction settling tank (3) is equipped with a fully enclosed anti-coking cyclone assembly; the fully enclosed anti-coking cyclone assembly includes a cyclone quick separator head (21), a sealing cover (22), and a reaction cyclone separator (25); the sealing cover (22) is a sealed cylinder located on the upper part of the stripping section (2); the outlet of the upper part of the sealing cylinder is connected to the inlet of the reaction cyclone separator (25) through a guide tube; the lower part of the sealing cylinder extends downward through the sealing cover plate (23) into the stripping section (2), and the lower part of the sealing cover (22) is provided with a slot (24) so ​​that the inner and outer sides of the sealing cover (22) are connected only through the slot (24); the upper part of the riser reactor (1) is embedded inside the reaction product purification and separation unit, and the top of the riser reactor (1) extends into the sealing cylinder, and the cyclone quick separator head (21) is located at the top outlet of the riser reactor (1); or, The reaction settling device (3) is equipped with a coarse vortex top-vortex sealed direct connection assembly; the coarse vortex top-vortex sealed direct connection assembly includes a coarse vortex (121), an oil-gas manifold (122), an oil-gas sealed guide pipe (124), and a reaction cyclone separator (25); the top outlet of the riser reactor (1) is connected to the interior of the oil-gas manifold (122) through the coarse vortex (121); the gas outlet of the oil-gas manifold (122) is connected to the inlet of the reaction cyclone separator (25); the bottom inlet of the oil-gas sealed guide pipe (124) extends downward through the sealing cover plate (23) to the gas phase space above the stripping section (2); the gas phase space below the sealing cover plate (23) is connected to the oil-gas manifold (122) through the oil-gas sealed guide pipe (124).

4. The system according to claim 3, characterized in that, The reaction cyclone separator (25) is at least a single stage; The outlet of the guide tube at the top of the enclosed hood (22) is connected to the inlet of the first-stage reaction cyclone separator; the gas outlet of the last-stage reaction cyclone separator is connected to the inlet of the reaction gas collection chamber (27); the catalyst outlet of the reaction cyclone separator (25) extends downward through the material leg through the sealing cover plate (23) to the gas phase space formed by the outer wall of the enclosed hood (22) and the sealing cover plate (23); or, The gas outlet of the oil and gas manifold (122) is connected to the inlet of the first-stage reaction cyclone separator; the gas outlet of the last-stage reaction cyclone separator is connected to the inlet of the reaction gas collection chamber (27); the catalyst outlet of the coarse cyclone (121), the inlet of the oil and gas sealed guide pipe (124) and the catalyst outlet of the reaction cyclone separator (25) extend downward through the material leg through the sealing cover plate (23) to the gas phase space below the sealing cover plate (23).

5. The system according to claim 4, characterized in that, The reaction cyclone separator (25) has two stages.

6. The system according to claim 2, characterized in that, The riser reactor (1) includes a pre-lifting section, a variable diameter section, and a reaction section connected sequentially from bottom to top; the pre-lifting section and the reaction section are both cylindrical with equal diameters. The ratio of the inlet diameter of the reaction section to the diameter of the pre-lifting section is 1 to 5; the ratio of the lengths of the pre-lifting section, the variable diameter section, and the reaction section is 1:(0.05~0.5):(1~10). The pre-lifting section is provided with a pre-lifting medium nozzle, a first regenerated catalyst inlet, and a remelting medium nozzle; the pre-lifting medium nozzle is used to communicate with the pre-lifting medium source, the remelting medium nozzle is used to communicate with the remelting medium source, and the first regenerated catalyst inlet is connected to one end of the first regenerated inclined tube (10); The variable diameter section is equipped with a raw material nozzle, which is used to connect with a light hydrocarbon oil feedstock source; The reaction section is provided with a second regenerated catalyst inlet, a reaction cycle catalyst inlet and a dilution steam nozzle; the dilution steam nozzle is used to communicate with a dilution steam source; the second regenerated catalyst inlet is communicated with the outlet of the second regenerated catalyst cooler (5); the reaction cycle catalyst inlet is communicated with one end of the reaction cycle inclined tube (12).

7. The system according to claim 1, characterized in that, The reaction settling device (3) is also provided with a reaction gas collecting chamber (27) and an anti-scorching steam ring (26) located below the reaction gas collecting chamber (27); the outlet of the reaction gas collecting chamber (27) is connected to the top outlet of the reaction settling device (3); the inlet of the anti-scorching steam ring (26) is used to connect with the anti-scorching steam source; steam injection holes are opened on the upper and / or lower surfaces of the anti-scorching steam ring (26); The stripping section (2) includes stripping section internal components (18), at least one set of stripping steam rings (19) and loosening steam rings (20); the stripping section internal components (18) include one or more of the following: herringbone baffle, annular baffle, disc-shaped baffle, packing and grid; the stripping steam rings (19) are located in the middle and / or lower part of the stripping section (2); the loosening steam rings (20) are located at the bottom of the stripping section (2); the upper and / or lower surfaces of the stripping steam rings (19) and the loosening steam rings (20) are provided with steam wear-resistant nozzles.

8. The system according to claim 1, characterized in that, The oil-gas quencher (4) includes an oil-gas distributor (28), a quencher baffle (29), a quenching medium distributor (30), and a stirring steam ring (31). The oil-gas distributor (28) is located at the bottom of the oil-gas quencher (4), and the top outlet of the reaction settling device (3) is connected to the inlet of the oil-gas distributor (28). The quench cooler baffle (29) is located above the oil-gas distributor (28); the number of layers of the quench cooler baffle (29) is 1 to 20. The quench medium distributor (30) is located on the upper part of the quench baffle (29); the lower surface of the quench medium distributor (30) is provided with injection holes, and the airflow direction of the injection holes of the quench medium distributor (30) is vertically downward and / or obliquely downward. The stirring steam ring (31) is located at the lower part of the oil-gas quencher (4); the upper surface of the stirring steam ring (31) is provided with injection holes, and the airflow direction of the injection holes of the stirring steam ring (31) is vertically upward and / or obliquely upward.

9. A method for catalytic conversion of light hydrocarbon oils to produce low-carbon olefins and aromatics using the system described in any one of claims 1 to 8, characterized in that, The method includes: Light hydrocarbon oil feedstock is fed into riser reactor (1) and comes into contact with regenerated catalyst to carry out cracking reaction, to obtain reaction material containing cracking reaction products and regenerated catalyst; the reaction material is then sent through the outlet of riser reactor (1) to reaction product purification and separation unit for separation, to obtain high temperature reaction oil and gas and regenerated catalyst; The high-temperature reaction oil and gas are introduced into the oil and gas quencher (4) to exchange heat with the quenching medium to obtain the cooled reaction oil and gas; the cooled reaction oil and gas are further separated to obtain low-carbon olefins and low-carbon aromatics. The catalyst to be generated is introduced into the catalyst regeneration device through the catalyst regeneration tube (11) to obtain the regenerated catalyst; a portion of the regenerated catalyst is introduced into the riser reactor (1) through the first regeneration tube (10) as the first regeneration catalyst, and another portion of the regenerated catalyst is introduced into the riser reactor (1) after being cooled through the second regeneration tube (14) as the second regeneration catalyst.

10. The method according to claim 9, characterized in that, A portion of the spent catalyst is returned to the riser reactor (1) via the reaction circulation inclined tube (12) as a reaction recycling catalyst.

11. The method according to claim 9, characterized in that, The light hydrocarbon oil feedstock is selected from light fractions with a distillation range of 20–300°C; The regenerated catalyst comprises zeolite, inorganic oxides, and clay; based on the total weight of the regenerated catalyst, the zeolite content is 0.5–90 wt%, the inorganic oxide content is 1–99 wt%, and the clay content is 0–80 wt%; the zeolite comprises mesoporous zeolite and mesoporous zeolite; based on the total weight of the zeolite, the mesoporous zeolite content is 10–90 wt%, and the mesoporous zeolite content is 10–90 wt%. The quenching medium is selected from heavy oil products with an initial boiling point of 300°C or higher.

12. The method according to claim 11, characterized in that, The light hydrocarbon oil feedstock is selected from one or more of the following: catalytic cracking gasoline, catalytic pyrolysis gasoline, straight-run naphtha, coking naphtha, thermally cracked naphtha, thermally cracked naphtha, hydrotreated naphtha, reforming residue oil, straight-run kerosene, and hydrotreated kerosene. The zeolite also includes macroporous zeolite; based on the total weight of the zeolite, the content of macroporous zeolite is 0-50% by weight%. The quenching medium is selected from one or more of the following: cracked heavy oil, catalytic cracking slurry oil, catalytic cracking slurry oil, coking slurry oil, atmospheric residue oil, and vacuum residue oil.

13. The method according to claim 9, characterized in that, The reaction conditions for the pyrolysis reaction include: a preheating temperature of 40–600°C, a reaction temperature of 400–900°C, a reaction pressure of 0.01–1.0 MPaG, a reaction time of 0.1–30 s, a mass flow rate ratio of the regenerated catalyst to the light hydrocarbon feedstock of 1–100, and a mass flow rate ratio of steam to the light hydrocarbon feedstock of 0.05–2. The operating conditions of the stripping section (2) include: the average apparent linear velocity of the gas is 0.05 to 1 m / s, and the average residence time of the catalyst is 0.5 to 10 min; The operating conditions of the oil-gas quencher (4) include: the temperature of the cooling reaction oil-gas at the outlet is 200-550°C, the temperature of the bottom liquid is 200-500°C, and the residence time of the bottom liquid is 0-15 min. The mass flow rate ratio of the regenerated catalyst passing through the first regeneration inclined tube (10) to the regenerated catalyst passing through the second regeneration inclined tube (14) is (1~50):1; The mass flow rate ratio of the generated catalyst to the reaction cycle catalyst is (0.5~10):

1.

14. The method according to claim 9, characterized in that, The reaction settling device (3) is equipped with a fully enclosed anti-coking cyclone assembly; the fully enclosed anti-coking cyclone assembly includes a cyclone separator head (21), a sealing cover (22), and a reaction cyclone separator (25); or, The reaction settling device (3) is equipped with a coarse cyclone top cyclone sealed direct connection assembly; the coarse cyclone top cyclone sealed direct connection assembly includes a coarse cyclone (121), an oil and gas manifold (122), an oil and gas sealed guide pipe (124), and a reaction cyclone separator (25). The method further includes: allowing the reactants to undergo a first separation through a cyclone separator (21) at the outlet of the riser reactor (1) to obtain coarse oil gas and a first catalyst to be generated; allowing the first catalyst to flow downward through the internal space of the sealed cover (22) and into the stripping section (2); allowing the coarse oil gas to flow upward along the internal space of the sealed cover (22) and enter the reaction cyclone separator (25) through the guide tube for a second separation to obtain the high-temperature reaction oil gas and the second catalyst to be generated; allowing the high-temperature reaction oil gas to enter the oil gas quencher (4) from the gas phase outlet of the reaction cyclone separator (25), and allowing the second catalyst to enter the gas phase space formed by the outer wall of the sealed cover (22) and the sealing cover plate (23) from the catalyst outlet of the reaction cyclone separator (25), and finally entering the stripping section (2) through the slot (24); or, The method further includes: subjecting the reactants to a first separation via a coarse cyclone (121) to obtain coarse oil and gas and a first catalyst to be generated; subjecting the coarse oil and gas to a second separation via a reaction cyclone separator (25) to obtain the high-temperature reaction oil and gas and the second catalyst to be generated; subjecting the high-temperature reaction oil and gas to an oil and gas quencher (4) via the gas phase outlet of the reaction cyclone separator (25); and subjecting the first catalyst to be generated via the catalyst outlet of the coarse cyclone (121) and the second catalyst to be generated via the catalyst outlet of the reaction cyclone separator (25) to the stripping section (2).

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