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CN-119425542-B - Method and system for producing chemical industry material including ethylene based on constant-line-speed fluidized bed reactor

CN119425542BCN 119425542 BCN119425542 BCN 119425542BCN-119425542-B

Abstract

The invention relates to a method and a system for producing chemical industry materials comprising ethylene based on an equilinear speed fluidized bed reactor, wherein the method comprises the following steps of (1) enabling raw oil and a shape selective molecular sieve catalyst to react in a contact manner in the equilinear speed fluidized bed reactor to obtain an oiling agent mixture; and (2) separating the oil-gas mixture to obtain reaction oil-gas and a catalyst to be generated, and (3) separating the reaction oil-gas in an oil-gas separation system to obtain a chemical material comprising ethylene, C4 olefin and the like. In the invention, light petroleum hydrocarbon such as diesel oil is contacted with a shape selective molecular sieve catalyst in an equilinear fluidized bed reactor, and ethylene, propylene and the like are produced by maintaining self-heating balance through recycling regenerated flue gas. The method disclosed by the invention can process light hydrocarbon such as diesel oil and the like, and simultaneously process heavy oil such as naphtha, wax oil, residual oil and the like, has high yield of ethylene and propylene, can realize self-heating balance, solves the problem of excessive capacity of diesel oil in a refinery, and also makes up the defect of chemical industry materials.

Inventors

  • TANG JINLIAN
  • LIU WENMING
  • GONG JIANHONG
  • ZHANG JIUSHUN
  • LI RUI
  • WEI XIAOLI

Assignees

  • 中国石油化工股份有限公司
  • 中石化石油化工科学研究院有限公司

Dates

Publication Date
20260505
Application Date
20230731

Claims (20)

  1. 1. A process for producing a chemical industry feedstock comprising ethylene based on an equilinear fluidized bed reactor, the process comprising the steps of: (1) Enabling raw oil and a shape selective molecular sieve catalyst to contact and react in an equilinear velocity fluidized bed reactor to obtain an oil mixture, wherein the raw oil is diesel oil or the raw oil comprises diesel oil and heavy oil; The shape selective molecular sieve catalyst comprises a shape selective molecular sieve, wherein the shape selective molecular sieve is selected from ten-membered ring structure molecular sieves, the catalyst in the constant-speed fluidized bed reactor flows in an upward way, and the inner diameter of a reaction section is sequentially reduced from top to bottom; (2) Separating the oil mixture to obtain reaction oil gas and spent catalyst; The method comprises the steps of carrying out cyclone separation and sedimentation on an oil-gas mixture to obtain a spent catalyst of first reaction oil gas and residual oil gas, stripping the spent catalyst of the residual oil gas to obtain second reaction oil gas and the spent catalyst, wherein the reaction oil gas comprises the first reaction oil gas and the second reaction oil gas; (3) Separating the reaction oil gas in an oil-gas separation system to obtain chemical materials comprising ethylene, C4 olefin, light gasoline fraction, heavy aromatic fraction and slurry oil; (4) The spent catalyst is put into a regenerator to be regenerated in an oxygen-containing atmosphere to obtain regenerated catalyst and flue gas, at least part of the regenerated catalyst is returned to the constant-speed fluidized bed reactor for recycling, at least part of the flue gas is returned to the regenerator for recycling, Wherein the conditions for the contact reaction of the diesel fuel with the shape selective molecular sieve catalyst in step (1) comprise: The reaction temperature is 620-720 ℃, the reaction pressure is 0.2-0.5 MPa, the reaction time is 3.0-7.0 seconds, and the weight ratio of the shape selective molecular sieve catalyst to the diesel oil is (6-10): 1; the diesel oil is fed into the constant-speed fluidized bed reactor under fluidization of a fluidization medium; The fluidization medium is atomized water, and the mass ratio of the atomized water to the diesel oil is (0.20-0.30): 1; the linear speed of oil gas in the reaction section is 1.0-2.0 m/s, The raw oil is diesel oil, and the diesel oil is fed into the constant-velocity fluidized bed reactor from the lower part of the reaction section; And, step (1) further comprises: contacting the heavy oil with a shape selective molecular sieve catalyst in a riser reactor; In the step (2), one part of the oil mixture is derived from the contact reaction of the diesel oil and the shape selective molecular sieve catalyst, the other part of the oil mixture is derived from the contact reaction of the heavy oil and the shape selective molecular sieve catalyst, in the step (4), one part of the regenerated catalyst is returned to the constant-velocity fluidized bed reactor for recycling, the other part of the regenerated catalyst is returned to the riser reactor for recycling, Wherein the conditions for the contacting reaction of the heavy oil with the shape selective molecular sieve catalyst in the riser reactor include: The reaction temperature is 620-720 ℃, the reaction pressure is 0.2-0.5 MPa, the weight ratio of the shape selective molecular sieve catalyst to the heavy oil is (6-10): 1, and the reaction time is 3.0-7.0 seconds; the heavy oil is fed into the riser reactor under fluidization of a fluidizing medium; The fluidization medium is atomized water, and the mass ratio of the atomized water to the heavy oil is (0.20-0.30): 1; The linear velocity of oil gas in the riser reactor is 2.0-12.0 m/s, The diesel oil reacts in the constant-speed fluidized bed reactor, the heavy oil reacts in the riser reactor, The constant-speed fluidized bed reactor (1) is provided with a reactor pre-lifting section (I), a reactor reaction section (II), a reactor outlet section (III) and a catalyst stripping section (IV-2), wherein the catalyst in the constant-speed fluidized bed reactor (1) flows upwards, and a cyclone separator (IV-1) and a settler (IV) are positioned above the catalyst stripping section (IV-2); The oil outlet of the riser reactor (25) is communicated with the oil inlet of the cyclone separator (IV-1).
  2. 2. The method according to claim 1, wherein in step (1): The ten-membered ring structured molecular sieve is selected from one or a combination of a plurality of ZSM-5 molecular sieve, ZSM-11 molecular sieve, ZSM-12 molecular sieve, ZSM-23 molecular sieve, ZSM-35 molecular sieve, ZSM-38 molecular sieve, ZSM-48 molecular sieve and ZRP-5 molecular sieve, the average pore diameter of the ten-membered ring structured molecular sieve is 0.5-0.6nm, and/or, The shape selective molecular sieve catalyst further comprises an oxide and optionally clay, wherein the oxide is selected from one or a combination of more of aluminum oxide, silicon oxide and modified oxide, and the modified oxide is selected from one or more metal element oxides and/or nonmetal element oxides in group IA, group IIA, group VA, group IIIB and group VIII; The ten-membered ring structure molecular sieve is a molecular sieve obtained by modifying the mesoporous molecular sieve by the modified oxide; The weight ratio of the ten-membered ring structure molecular sieve in the shape selective molecular sieve catalyst is 40-70%, and the weight ratio of the modified oxide in the shape selective molecular sieve catalyst is 1.0-10.0%; And/or the number of the groups of groups, The average particle size of the shape selective molecular sieve catalyst is 40-150 microns.
  3. 3. The process of claim 1, wherein the feedstock oil is diesel oil, which is fed from a lower portion of the reaction zone into the equi-linear fluidized bed reactor.
  4. 4. A process according to claim 3, wherein at least a portion of one or more of the C4 olefins, the light gasoline fraction, the heavy aromatic fraction and the slurry oil is fed through the reaction section to the isoline fluidized bed reactor for reprocessing; The feeding positions of the C4 olefin, the light gasoline fraction and the heavy aromatic fraction are positioned below the feeding position of the diesel oil or fed through the feeding position of the diesel oil, and the feeding position of the slurry oil is positioned above the feeding position of the diesel oil.
  5. 5. The process of claim 1 wherein the feedstock oil comprises diesel oil fed into the isoline fluidized bed reactor from a lower portion of the reaction section and heavy oil fed into the isoline fluidized bed reactor from a middle portion of the reaction section.
  6. 6. The process of claim 5 wherein at least a portion of one or more of the C4 olefins, the light gasoline fraction, the heavy aromatic fraction, and the slurry oil is fed through the reaction section to the isoline fluidized bed reactor for reprocessing; wherein the feeding positions of the C4 olefin, the light gasoline fraction and the heavy aromatic fraction are positioned below the feeding position of the diesel oil or fed through the feeding position of the diesel oil, and the slurry oil is fed through the feeding position of the heavy oil.
  7. 7. The process of claim 1, wherein at least a portion of one or more of the C4 olefins, the light gasoline fraction, the heavy aromatic fraction, and the slurry oil is fed to the riser reactor for reprocessing; Wherein the feed locations of the C4 olefins, the light gasoline fraction, and the heavy aromatic fraction are located below the feed location of the heavy oil through which the slurry oil is fed.
  8. 8. The method according to any one of claims 3 to 7, wherein the diesel is selected from the group consisting of straight run diesel, catalytic cracking diesel and hydrogenated diesel, and/or, The boiling point of the diesel oil is 180-380 ℃, and the density is less than or equal to 850kg/m 3 .
  9. 9. The method according to any one of claims 5 to 7, wherein the heavy oil is a wax oil and/or a residuum.
  10. 10. The method of claim 1, wherein the step of determining the position of the substrate comprises, The method further comprises the following steps before the step (1): preheating the raw oil to a preheating temperature, wherein the preheating temperature is 200-400 ℃; The preheating is heated by a heating furnace or the raw oil is subjected to heat exchange with the chemical material obtained in the step (3).
  11. 11. The method of claim 10, wherein the preheating temperature is 260-360 ℃.
  12. 12. The method of any one of claims 1-7, wherein in step (3), the oil-gas separation system is selected from the group consisting of a combination of one or more of two or more fractionation columns having a theoretical plate number greater than 20, an absorption stabilization system, and a gas separation system; Propylene, H 2 and C1-C4 alkanes, BTX fractions and methyl naphthalene oil fractions are also obtained by the separation in step (3).
  13. 13. The method according to any one of claims 1-7, wherein in step (4): The regeneration temperature of the regenerator is 640-780 ℃ and the pressure is 0.3-0.6MPa; The circulation rate of the regenerated catalyst is 150-200 kg/(m 2 s); The regeneration atmosphere in the regenerator is selected from one of air, oxygen-enriched air and pure oxygen; And the flue gas returns to the regenerator for recycling after heat exchange, and the temperature of the flue gas returned to the regenerator for recycling is 340-580 ℃.
  14. 14. A system for carrying out the method according to any one of claims 1 to 13, characterized in that the system comprises an equilinear fluidized bed reactor (1), a cyclone separator (IV-1), a settler (IV), an oil and gas separation system (6) and a regenerator (20); the inner diameter of the outlet section (III) of the reactor is smaller than that of the reaction section (II) of the reactor; The outlet of the reactor pre-lifting section (I) is communicated with the inlet of the reactor reaction section (II), and the outlet of the reactor reaction section (II) is communicated with the inlet of the reactor outlet section (III); The reactor comprises a reactor reaction section (II), a light hydrocarbon raw oil inlet (2) and a first atomization steam inlet (3), wherein the reactor reaction section (II) is a reducing reaction section, and the inner diameter of the reactor reaction section (II) gradually reduces from top to bottom; The oil agent outlet of the reactor outlet section (III) is communicated with the oil agent inlet of the cyclone separator (IV-1), the catalyst outlet of the cyclone separator (IV-1) is communicated with the inlet of the settler (IV), and the oil gas outlet of the cyclone separator (IV-1) is communicated with the oil gas inlet of the oil gas separation system (6); The outlet of the settler (IV) is communicated with the inlet of the catalyst stripping section (IV-2), the catalyst outlet of the catalyst stripping section (IV-2) is communicated with the spent catalyst inlet of the regenerator (20), and the oil gas outlet of the catalyst stripping section (IV-2) is communicated with the oil gas separation system (6); The regenerator (20) is provided with an oxygen-containing regeneration gas inlet (21) and a flue gas outlet (23), the flue gas outlet (23) is communicated with the oxygen-containing regeneration gas inlet (21) through a flue gas circulation system (24), a regenerated catalyst outlet of the regenerator (20) is communicated with a catalyst inlet of the reactor pre-lifting section (I) through a first regeneration agent conveying pipeline (22), and a first fluidizing medium inlet (4) is arranged at the bottom of the reactor pre-lifting section (I); The oil-gas separation system (6) is provided with an ethylene outlet (7), a propylene outlet (8), an H 2 and C1-C4 alkane outlet (9), a C4 alkene outlet (10), a light gasoline fraction outlet (11), a BTX fraction outlet (12), a heavy aromatic fraction outlet (13), a methyl naphthalene oil fraction outlet (14) and a slurry oil outlet (15); the middle part of the reactor reaction section (II) is provided with a first heavy raw oil inlet (16) and a second atomization steam inlet (17), and the reactor reaction section (II) is provided with a first recycling inlet and a second recycling inlet; The C4 olefin outlet (10), the light gasoline fraction outlet (11) and the heavy aromatic fraction outlet (13) are respectively communicated with the first recycling inlet or the light hydrocarbon raw oil inlet (2), and the slurry oil outlet (15) is respectively communicated with the second recycling inlet or the first heavy raw oil inlet (16).
  15. 15. The system according to claim 14, characterized in that the oil and gas outlet of the cyclone separator (IV-1) is in communication with the oil and gas inlet of the oil and gas separation system (6) via a reaction oil and gas line (5), and the oil and gas outlet of the catalyst stripping section (IV-2) is in communication with the oil and gas inlet of the oil and gas separation system (6) via the reaction oil and gas line (5).
  16. 16. The system according to claim 14, characterized in that the lower part of the catalyst stripping section (IV-2) is provided with a stripping medium inlet (18).
  17. 17. The system according to claim 14, characterized in that the catalyst outlet of the catalyst stripping section (IV-2) communicates with the spent catalyst inlet of the regenerator (20) via a spent agent transfer line (19).
  18. 18. The system according to claim 14, characterized in that the first heavy raw oil inlet (16) communicates with the second atomizing steam inlet (17).
  19. 19. The system according to claim 16, characterized in that the first and second recycling inlets are located below and above the light hydrocarbon feedstock inlet (2), respectively.
  20. 20. The system according to any one of claims 14-19, characterized in that the system is further provided with a riser reactor (25), the riser reactor (25) being provided with a second heavy raw oil inlet (28) and a third atomizing steam inlet (29), the second heavy raw oil inlet (28) being in communication with the third atomizing steam inlet (29); the regenerated catalyst outlet of the regenerator (20) is communicated with a catalyst inlet at the bottom of the riser reactor (25) through a second regenerant conveying pipeline (27), and a second fluidizing medium inlet (26) is also arranged at the bottom of the riser reactor (25).

Description

Method and system for producing chemical industry material including ethylene based on constant-line-speed fluidized bed reactor Technical Field The invention relates to the technical field of hydrocarbon catalytic cracking, in particular to a method and a system for producing chemical industry materials including ethylene based on an isoline speed fluidized bed reactor. Background In recent years, the diesel ratio of the finished oil market is continuously reduced, and zero or negative increase occurs after the diesel consumption reaches the peak value 176Mt in 2014. It is counted that the unit mileage emission of a heavy diesel vehicle is about 150 times of that of a light diesel vehicle in the same stage, the annual emission is about 750 times of that of the light diesel vehicle in the same stage, and the pollution condition further limits the development of the diesel vehicle. By 2025, diesel consumption is expected to decrease to 168Mt consumption, and the consumption diesel to gasoline ratio will decrease from current 1.4 to less than 1. This would mean that there are millions of tons of diesel product surplus and that the high emissions of diesel engine particulates further limit diesel use, millions of tons of diesel for refinery vehicles. The problems of reducing the diesel-gasoline ratio of refinery products and seeking a way for diesel oil become urgent to be solved. The straight-run diesel oil accounts for about 50% of the total diesel oil, reduces the output of the straight-run diesel oil or converts the straight-run diesel oil into other high-added-value products so as to adapt to the change of the future diesel oil demand, and has great significance for guaranteeing the supply and demand balance of the finished oil market in China. For conversion of straight-run diesel, light diesel with a light diesel content of 10% or less can be blended in an ethylene cracking raw material, but compared with other light raw materials, the straight-run diesel has a lower yield of olefin by steam cracking, a short decoking period, and in addition, the hydrocracking can process the straight-run diesel, the hydrogen consumption is 2.5%, the naphtha yield is 50% -60%, and the liquefied gas yield is 4% -5%. In recent years, in order to reduce the diesel-gasoline ratio, domestic refineries also adopt a conventional catalytic cracking device to blend straight-run diesel, for example, the conventional catalytic cracking device of China petrochemical Hainan oil refining chemical industry Co., ltd. Is used for blending normal three-line straight-run diesel, the gasoline yield is 41 percent, but the volume fraction of propylene in liquefied gas is reduced by 0.52 percent and the volume fraction of isobutene is reduced by 0.12 percent, which is not beneficial to increasing the yield of low-carbon olefin. The single catalytic cracking or catalytic cracking technology of the straight-run diesel is slow in development, on one hand, the straight-run diesel is always used as the fuel for the high-cetane-number vehicle, the fuel is high in value, the consumption is large, the resources are few, on the other hand, the yield of the chemical materials such as gasoline, ethylene, propylene and the like produced by the catalytic cracking of the straight-run diesel is low, in addition, the coke formation of the catalytic cracking of the straight-run diesel is low, the conventional fluidized bed catalytic cracking which is insufficient for maintaining the self-heating balance is insufficient, and the catalytic cracking also needs a high temperature. Research has been focused at home and abroad mainly on improving conversion rate and compensating heat balance, for example, patent CN111607425A of China petroleum and natural gas corporation discloses a method for cracking straight-run diesel, namely, a method for catalytic cracking of straight-run diesel and inert gases such as nitrogen gas, etc. which are subjected to removal of basic nitrogen by dihydrogen phosphate, in a fixed bed or moving bed reactor equipped with an activated pretreated ZSM-5 type nano molecular sieve, and patent CN111718751a discloses a method for preparing a transition metal and/or nonmetal modified ZSM-5 type nano molecular sieve catalyst in the method. As described in the two patents, the straight-run diesel oil adopts a fixed bed reactor to realize the diesel oil conversion rate of 80.16% and the low-carbon olefin yield of 34.13% at the external heating reaction temperature of 600 ℃ and the single-pass period of the straight-run diesel oil of 47 hours, and the single-pass period of the straight-run diesel oil is short and needs to frequently switch the reactor, while the single-pass period of the moving bed reactor is prolonged to 78 hours, but the operation difficulty is high. The Chinese petrochemical Co-Ltd patents CN104418685B and CN104418686A both disclose a catalytic cracking method of straight-run diesel oil by taking methane as a diluent and exchang