Method and device for continuously producing aromatic hydrocarbon by hydrocatalytically cracking FCC circulating oil
阅读说明：本技术 临氢催化裂解fcc循环油连续生产芳烃的方法和装置 (Method and device for continuously producing aromatic hydrocarbon by hydrocatalytically cracking FCC circulating oil ) 是由 唐津莲 龚剑洪 毛安国 刘宪龙 李泽坤 袁起民 于 2019-10-31 设计创作，主要内容包括：公开了一种临氢催化裂解FCC循环油连续生产芳烃的方法和装置。该方法包括在包括移动床反应器或者流化床反应器等的动态反应器装置中,富含芳烃催化裂化循环油在临氢氛围下接触芳烃脱烷基催化剂临氢流化催化裂解脱烷基,脱烷基油脱硫、氮后进行芳烃抽提生产苯、甲苯、二甲苯和萘等芳烃,结焦失活催化剂经催化剂料斗系统脱氢降压后再生循环使用。本发明提供的FCC循环油临氢流化催化裂解反应再生连续生产BTX与萘等芳烃的方法,芳烃产率高,焦炭产率低,FCC循环油的利用率高。(A process and apparatus for continuously preparing arylhydrocarbon by hydrocatalytically cracking FCC circulating oil are disclosed. The method comprises the steps that in a dynamic reactor device comprising a moving bed reactor or a fluidized bed reactor and the like, aromatic hydrocarbon-rich catalytic cracking cycle oil is contacted with an aromatic hydrocarbon dealkylation catalyst in a hydrogen atmosphere for hydrodealkylation catalytic cracking dealkylation, aromatic hydrocarbon extraction is carried out after the dealkylation of base oil is desulfurized and nitrogen to produce aromatic hydrocarbons such as benzene, toluene, xylene and naphthalene, and a coking deactivation catalyst is subjected to dehydrogenation and depressurization by a catalyst hopper system and then is regenerated and recycled. The method for continuously producing the aromatic hydrocarbons such as BTX, naphthalene and the like by regenerating and catalyzing the cracking reaction of the FCC circulating oil by the hydro-fluidization has the advantages of high aromatic hydrocarbon yield, low coke yield and high utilization rate of the FCC circulating oil.)
1. A method for continuously producing aromatic hydrocarbon by hydrocracking FCC circulating oil comprises the following steps:
(1) atomizing the FCC circulating oil by using an atomizing medium and feeding the atomized FCC circulating oil into a reactor device, wherein the reactor device comprises a moving bed reactor, a fluidized bed reactor or a riser reactor;
(2) in the reactor device, in the hydrogen atmosphere, the atomized FCC circulating oil contacts the aromatic hydrocarbon dealkylation catalyst to carry out dealkylation reaction, so as to obtain reaction oil gas;
(3) obtaining the aromatic hydrocarbons from the reaction oil gas;
(4) and (3) the spent catalyst obtained in the step (2) enters a regeneration device, the spent catalyst is in contact with oxygen-containing regeneration gas in the regeneration device for regeneration, and the regenerated catalyst is returned to the reactor device for recycling.
2. The method of claim 1, wherein step (4) is performed by: the catalyst to be regenerated is dehydrogenated and depressurized by a catalyst hopper system to enter the regeneration device, the catalyst is contacted with the oxygen-containing regeneration gas in the regeneration device for regeneration, and the regenerated catalyst is deoxidized and pressurized by the catalyst hopper and then returns to the reactor device for recycling; the regeneration operating conditions were: the temperature is 500 ℃ and 680 ℃, and the pressure is 0.2-2.0 MPa.
3. The process of claim 1, wherein the dealkylation conditions are: the reaction temperature is 500-800 ℃, the reaction pressure is 0.2-6.0MPa, the reaction time is 1-40 seconds, and the weight ratio of the catalyst to the FCC circulating oil is 1-10: 1.
4. The process as claimed in claim 3, wherein the reactor apparatus comprises a moving bed reactor, the reaction temperature is 500-650 ℃, the reaction pressure is 0.2-6.0MPa, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the FCC cycle oil is 1-10: 1.
5. The process as claimed in claim 4, wherein the reaction temperature is 520 ℃ and 630 ℃, the reaction pressure is 1.0-5.0MPa, the reaction time is 2-15 seconds, and the weight ratio of the catalyst to the FCC cycle oil is 3-8: 1.
6. The method as claimed in claim 3, wherein the reactor device is a fluidized bed reactor or a riser reactor, the reaction temperature is 500-800 ℃, the reaction pressure is 0.2-6.0MPa, the reaction time is 0.1-10 seconds, and the weight ratio of the catalyst to the FCC cycle oil is 1-10: 1.
7. The method as claimed in claim 6, wherein the reaction temperature is 550-700 ℃, the reaction pressure is 1.0-5.0MPa, the reaction time is 0.5-5.0 seconds, and the weight ratio of the catalyst to the FCC cycle oil is 3-7: 1.
8. The method of claim 1, wherein the atomizing medium comprises a hydrogen-containing gas and/or a hydrogen-free gas, the atomizing medium containing no or trace amounts of oxygen, wherein the volume fraction of oxygen in the atomizing medium is no greater than 1%.
9. The method of claim 8, wherein the hydrogen-containing gas is selected from one or more of hydrogen, dry gas; the gas containing no hydrogen is selected from one or more of nitrogen and water vapor.
10. The process of claim 1, wherein the FCC cycle oil is a distillate from a catalytic cracker having a boiling range of 80-360 ℃ and a total aromatics content of 40-98 wt.%, based on the total weight of the FCC cycle oil.
11. The method of claim 1, wherein obtaining the aromatics from the reaction oil gas comprises:
introducing the reaction oil gas into a separation device, and separating to obtain cracked gas, dealkylated aromatic oil and oil slurry;
and introducing the dealkylated aromatic oil into an aromatic extraction device to obtain the aromatic hydrocarbon and aromatic hydrocarbon raffinate oil.
12. The process of claim 11, further comprising feeding the oil slurry and/or the aromatic raffinate oil to the reactor unit.
13. The process of claim 1 wherein the aromatics dealkylation catalyst comprises an active metal component selected from the group consisting of group IA, group IIA, group VIA, VIIA, IB, group IIB and one or more of group 4 and 5 periodic elements of the transition metals in amounts of from 5 to 50 wt.% on an oxide basis based on the total weight of the catalyst, a zeolite, a binder and optionally a clay; said zeolite comprising a large pore zeolite and optionally a medium pore zeolite, in an amount of 1 to 50 wt% based on the total weight of said catalyst; the adhesive is selected from silicon dioxide and/or aluminum oxide and accounts for 5-95 wt% of the total weight of the catalyst; the clay comprises 0-70 wt% of the total weight of the catalyst.
14. The method of claim 13, wherein the active metal component comprises one or more of Cr, Ni, Mo, Cu, and one or more of an alkali metal K and an alkaline earth metal Mg.
15. The process of claim 13, wherein the reactor apparatus comprises a fluidized bed reactor or a riser reactor, and the catalyst has an average particle size of 40 to 100 microns.
16. The process of claim 13, wherein the reactor apparatus is a moving bed reactor and the catalyst has an average particle size of 1 to 6 millimeters.
17. Device of full production arene of FCC circulating oil of hydrocatalytic pyrolysis, include:
the reactor device is provided with a material inlet, a reaction oil gas outlet, a catalyst inlet and a catalyst outlet, and comprises a moving bed reactor or a fluidized bed;
the separation device comprises a material inlet, a cracked gas outlet, a dealkylated aromatic oil outlet and an oil slurry outlet; the material inlet of the separation device is connected with the reaction oil gas outlet of the reactor device;
the aromatic hydrocarbon extraction device comprises a material inlet, an aromatic hydrocarbon outlet and an aromatic hydrocarbon raffinate oil outlet, and the material inlet of the aromatic hydrocarbon extraction device is communicated with the dealkylated aromatic hydrocarbon oil outlet of the separation device;
the regeneration device is provided with a catalyst inlet, a catalyst outlet, a regeneration gas inlet and a regeneration gas outlet;
and the catalyst hopper system is connected with the catalyst inlet and the catalyst outlet of the reactor device and is connected with the catalyst inlet and the catalyst outlet of the regeneration device, so that the catalyst to be regenerated from the reactor device enters the regeneration device for regeneration after passing through the catalyst hopper system, and the regenerated catalyst from the regeneration device is circulated back to the reactor device after passing through the catalyst hopper system.
18. The apparatus of claim 17, wherein the aromatics raffinate outlet of the aromatics extraction unit is further in communication with the feed inlet of the reactor unit.
19. The apparatus of claim 17 wherein the slurry outlet of the separation device is further in communication with the feed inlet of the reactor apparatus.
Technical Field
The invention belongs to a method and a device for continuously producing aromatic hydrocarbon by FCC circulating oil reaction regeneration, and particularly relates to a high-efficiency continuous production method and a device for producing aromatic hydrocarbon such as benzene, toluene, xylene, naphthalene and the like by hydrocatalytically cracking FCC circulating oil by adopting a dynamic reactor device.
Background
As environmental regulations become more stringent, the use of catalytic cracking cycle oil (FCC cycle oil, abbreviated LCO) is limited. On one hand, the quality of the fuel oil is rapidly upgraded, the catalytic cracking cycle oil has high content of sulfur-containing compounds and nitrogen-containing compounds, high content of aromatic hydrocarbons, particularly polycyclic aromatic hydrocarbons, and low cetane number, and even if the catalytic cracking cycle oil is subjected to hydro-upgrading, the catalytic cracking cycle oil is difficult to be used as a blending component of the diesel oil for vehicles; on the other hand, the economic slow-down causes the diesel oil to have excessive structure, the diesel oil sales is greatly reduced, and the reduction of the diesel-gasoline ratio becomes a necessary trend, so that a new path must be found for the catalytic cracking cycle oil.
For the efficient conversion and utilization of the aromatic-rich catalytic diesel oil (LCO), two technologies exist at present: one technology for producing high-octane gasoline or aromatic hydrocarbon material by selective hydrogenation and catalytic cracking of LCO (liquid crystal oxygen) is LTAG technology, and the other technology for producing gasoline by hydrocracking of LCO and BTX (BTX) is RLG or FD2G technology. The LTAG technology taking patents such as CN201310516479.X, CN201310517666.X, CN201310517080.3 and the like as cores and the LTAG technology taking patents such as CN201080071134.2 and the like utilize a combination of a hydrogenation unit and a catalytic cracking unit to hydrogenate and then carry out catalytic cracking on LCO fraction. The LTAG technology realizes the maximized production of high-octane gasoline or light aromatic hydrocarbon by designing a hydrogenation LCO conversion area and simultaneously optimizing and matching the technological parameters of hydrogenation and catalytic cracking and the like. RLG or FD2G technology effectively converts poor quality catalytic diesel into high octane gasoline fraction through hydrocracking catalyst and process optimization. The above technology can effectively reduce the catalytic diesel oil and improve the benefit of the catalytic diesel oil. However, due to the aggravation of crude oil deterioration and the increasing strictness of environmental regulations, both raw materials and products of the catalytic cracking unit need to be hydrogenated, so that the hydrogen source of a refinery is seriously insufficient, and the efficient utilization of catalytic cracking cycle oil through hydrogenation re-catalytic cracking or hydrocracking is hindered. In addition, with the increase and continuous energy expansion of oil refineries and the popularization of electric automobiles, the energy production of the oil refining industry mainly based on gasoline and diesel oil production is excessive, and statistics shows that the energy production of the oil refining industry is excessive by 1 hundred million tons in 2016 in China, so that the oil conversion is a necessary trend.
The shortage of domestic petroleum resources and the increasing demand for high-quality gasoline, diesel oil, low-carbon olefin and aromatic hydrocarbon are caused, the content of C9-C11 monocyclic aromatic hydrocarbon in the catalytic cracking cycle oil LCO is higher than 20%, the content of bicyclic aromatic hydrocarbon such as naphthalene, alkyl naphthalene and the like is higher than 30%, and the potential content of BTXN is high, so that the catalyst is one of important chemical raw materials. LCO is directly extracted from aromatic hydrocarbon, and the monocyclic aromatic hydrocarbon has large molecules and is difficult to utilize; the content of the bicyclic aromatic hydrocarbon is high, but the content of the naphthalene is low and is only 1% -3%, and the separation effect is poor. If the aromatics in LCO are to be utilized, catalytic diesel aromatics dealkylation processing is necessary.
The method for producing BTXN by catalytic dealkylation of diesel oil arene includes hydrodealkylation, such as 700-800 deg.C, 2.0-3.0MPa and H for catalytic diesel oil by Daqing petrochemical research institute2The dealkylated base oil which is reacted for 5 to 10 seconds and has the oil volume ratio of 3000:1 is extracted by dimethyl sulfoxide, the liquid yield of LCO aromatic hydrocarbon feeding reaches 70 percent, the BTX yield is 13 percent, the naphthalene yield is 33 percent, and the methylnaphthalene yield is 14.5 percent.BTXN produced by LCO thermal cracking is difficult to be widely popularized and applied, and has the following problems: LCO hydrogen thermal cracking dealkylation reaction temperature is high, coke production is high, liquid yield is low, and utilization rate is low.
In addition, patents CN201510664856.3, CN106588537, CN201410202025.X, CN105085154, CN105085134 and CN105085135 disclose a method for producing benzene and xylene from catalytic cracking light diesel oil or poor quality heavy aromatics by a hydrofining-hydrocracking combined process, wherein 0.05 wt% of Pt-0.15 wtPd-70% of ZSM-5/Al is adopted2O3The catalyst has the hydrofining operation pressure of 3.5-10.0MPa, the inlet temperature of 330-; the hydrocracking operating pressure is 2.5-3.0MPa, the inlet temperature is 360-460 ℃, and the hydrogen-oil volume ratio is 400-1000.
The problems with these techniques are: the LCO direct catalytic cracking or hydrocracking method for producing BTX or naphthalene has low concentration, low recovery rate, small scale and large energy consumption, especially the catalyst is easy to coke, which causes the fixed bed reactor to have short production period, and the catalyst needs to be shut down for regeneration or replacement in half a year; the LCO hydrofining-hydrocracking or hydrocracking also has the problem of high hydrogen partial pressure, the hydrogen partial pressure generally reaches more than 2.5MPa, and the high hydrogen partial pressure also leads to high device investment.
Therefore, in order to efficiently utilize the poor LCO resources and meet the increasing demand for chemical raw materials such as low-carbon olefins and aromatics, it is necessary to develop a catalytic conversion method for efficiently dealkylating the poor catalytic cracking cycle oil to produce aromatics BTXN.
Disclosure of Invention
The invention relates to a method and a device for continuously producing aromatic hydrocarbon by FCC circulating oil reaction regeneration, wherein the method adopts a dynamic reactor device comprising a moving bed reactor or a fluidized bed reactor and the like to carry out catalytic cracking on FCC circulating oil in a hydro-fluidized manner to produce aromatic hydrocarbon such as benzene, toluene, xylene, naphthalene and the like, and a coking deactivated catalyst is regenerated and recycled after being dehydrogenated and depressurized by a catalyst hopper system, so that the method can be efficiently and continuously used, the yield of the aromatic hydrocarbon is high, the yield of coke is low, and the utilization rate of the FCC circulating oil is high.
In one aspect, the present application provides a method for continuously producing aromatic hydrocarbons by hydrocatalytically cracking FCC cycle oil, comprising the steps of:
(1) atomizing the FCC circulating oil by using an atomizing medium and feeding the atomized FCC circulating oil into a reactor device, wherein the reactor device comprises a moving bed reactor, a fluidized bed reactor or a riser reactor;
(2) in the reactor device, in the hydrogen atmosphere, the atomized FCC circulating oil contacts the aromatic hydrocarbon dealkylation catalyst to carry out dealkylation reaction, so as to obtain reaction oil gas;
(3) obtaining the aromatic hydrocarbons from the reaction oil gas;
(4) and (3) the spent catalyst obtained in the step (2) enters a regeneration device, the spent catalyst is in contact with oxygen-containing regeneration gas in the regeneration device for regeneration, and the regenerated catalyst is returned to the reactor device for recycling.
In one embodiment, step (4) is performed as follows: and (3) dehydrogenating and depressurizing the catalyst to be regenerated through a catalyst hopper system, feeding the catalyst to be regenerated into the regeneration device, contacting the catalyst with the oxygen-containing regeneration gas in the regeneration device for regeneration, deoxidizing and boosting the regenerated catalyst through the catalyst hopper, and returning the regenerated catalyst to the reactor device for recycling. In one embodiment, the regeneration operating conditions are: the temperature is 500 ℃ and 680 ℃, and the pressure is 0.2-2.0 MPa.
In one embodiment, the dealkylation conditions are: the reaction temperature is 500-800 ℃, the reaction pressure is 0.2-6.0MPa, the reaction time is 1-40 seconds, and the weight ratio of the catalyst to the FCC circulating oil is 1-10: 1.
In one embodiment, the reactor apparatus comprises a moving bed reactor, the reaction temperature is 500-650 ℃, the reaction pressure is 0.2-6.0MPa, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the FCC cycle oil is 1-10: 1.
In one embodiment, the reaction temperature is 520-630 ℃, the reaction pressure is 1.0-5.0MPa, the reaction time is 2-15 seconds, and the weight ratio of the catalyst to the FCC cycle oil is 3-8: 1.
In one embodiment, the reactor device is a fluidized bed reactor and/or a riser reactor, the reaction temperature is 500-800 ℃, the reaction pressure is 0.2-6.0MPa, the reaction time is 0.1-10 seconds, and the weight ratio of the catalyst to the FCC cycle oil is 1-10: 1.
In one embodiment, the reaction temperature is 550-700 ℃, the reaction pressure is 1.0-5.0MPa, the reaction time is 0.5-5.0 seconds, and the weight ratio of the catalyst to the FCC cycle oil is 3-7: 1.
In one embodiment, the atomizing medium comprises a hydrogen-containing gas and/or a non-hydrogen-containing gas, and the atomizing medium contains no or trace amounts of oxygen, wherein the volume fraction of oxygen in the atomizing medium is no greater than 1%.
In one embodiment, the hydrogen-containing gas is selected from one or more of hydrogen, dry gas; the gas containing no hydrogen is selected from one or more of nitrogen and water vapor.
In one embodiment, the FCC cycle oil is a distillate from a catalytic cracking unit having a boiling range of 80 to 360 ℃ and a total aromatics content of 40 to 98 wt.%, based on the total weight of the FCC cycle oil.
In one embodiment, obtaining the aromatics from the reaction oil gas comprises:
introducing the reaction oil gas into a separation device, and separating to obtain cracked gas, dealkylated aromatic oil and oil slurry;
and introducing the dealkylated aromatic oil into an aromatic extraction device to obtain the aromatic hydrocarbon and aromatic hydrocarbon raffinate oil.
In one embodiment, the process further comprises feeding the oil slurry and/or the aromatic raffinate oil to the reactor unit.
In one embodiment, the aromatics dealkylation catalyst comprises an active metal component selected from the group consisting of group IA, group IIA, group VIA, VIIA, IB, IIB and one or more of the 4 th and 5 th periodic elements of the transition metals in amounts of from 5 to 50 wt.% on an oxide basis, based on the total weight of the catalyst, a zeolite, a binder and optionally a clay; said zeolite comprising a large pore zeolite and optionally a medium pore zeolite, in an amount of 1 to 50 wt% based on the total weight of said catalyst; the adhesive is selected from silicon dioxide and/or aluminum oxide and accounts for 5-95 wt% of the total weight of the catalyst; the clay comprises 0-70 wt% of the total weight of the catalyst.
In one embodiment, the active metal component includes one or more of Cr, Ni, Mo, Cu, and one or more of an alkali metal K and an alkaline earth metal Mg.
In one embodiment, the reactor apparatus comprises a fluidized bed reactor or riser reactor, and the catalyst has an average particle size of 40 to 100 microns.
In one embodiment, the reactor apparatus is a moving bed reactor and the catalyst has an average particle size of 1 to 6 millimeters.
In another aspect, the present application provides an apparatus for continuously producing aromatic hydrocarbons by hydrocatalytically cracking FCC cycle oil, comprising:
the reactor device is provided with a material inlet, a reaction oil gas outlet, a catalyst inlet and a catalyst outlet, and comprises a moving bed reactor or a fluidized bed;
the separation device comprises a material inlet, a cracked gas outlet, a dealkylated aromatic oil outlet and an oil slurry outlet; the material inlet of the separation device is connected with the reaction oil gas outlet of the reactor device;
the aromatic hydrocarbon extraction device comprises a material inlet, an aromatic hydrocarbon outlet and an aromatic hydrocarbon raffinate oil outlet, and the material inlet of the aromatic hydrocarbon extraction device is communicated with the dealkylated aromatic hydrocarbon oil outlet of the separation device;
the regeneration device is provided with a catalyst inlet, a catalyst outlet, a regeneration gas inlet and a regeneration gas outlet;
and the catalyst hopper system is connected with the catalyst inlet and the catalyst outlet of the reactor device and is connected with the catalyst inlet and the catalyst outlet of the regeneration device, so that the catalyst to be regenerated from the reactor device enters the regeneration device for regeneration after passing through the catalyst hopper system, and the regenerated catalyst from the regeneration device is circulated back to the reactor device after passing through the catalyst hopper system.
In one embodiment, the aromatics raffinate outlet of the aromatics extraction unit is further in communication with the feed inlet of the reactor unit.
In one embodiment, the slurry outlet of the separation device is also in communication with the feed inlet of the reactor device.
Through years of research, the inventor of the invention finds that: (1) the content of C9-C11 monocyclic aromatics in the catalytic cracking cycle oil LCO is higher than 20%, the content of bicyclic aromatics such as naphthalene and alkyl naphthalene is higher than 30%, and BTXN in the LCO can be utilized through a hydrocatalytic cracking dealkylation reaction to supplement aromatic chemical raw materials; (2) the reaction conditions with high reaction temperature and hydrogen and the molecular sieve catalyst with cracking function are favorable for the dealkylation of the aromatic hydrocarbon, the higher the reaction temperature and the higher the activity of the cracking catalyst are, the more favorable the dealkylation of the aromatic hydrocarbon is, however, the higher the reaction temperature and the cracking catalyst with high activity are easy to cause the coking and inactivation of the catalyst; (3) the catalyst containing the metal component and the hydrogen atmosphere can inhibit the coking of the catalyst, the reaction pressure is 0.2-6.0MPa, and the higher the hydrogen partial pressure is, the lower the coke formation is; (4) the regeneration of the coking catalyst needs to be carried out in a high-temperature oxygen-rich system under the pressure of 0.1-0.25 MPa, and the conventional fixed bed hydrogenation device or the fluidized catalytic cracking device is difficult to coordinate the requirements of the hydrocracking and oxygen-rich regeneration of the aromatic hydrocarbon on different reaction atmospheres and reaction pressures.
Based on the discovery, the invention provides a method for producing aromatic hydrocarbon by hydrocracking FCC circulating oil in a dynamic reactor device comprising a moving bed reactor or a fluidized bed reactor and the like, wherein in the reactor device, the aromatic hydrocarbon-rich catalytic cracking circulating oil contacts an aromatic hydrocarbon dealkylation catalyst in a hydrogenation atmosphere for hydrocracking and dealkylation, and aromatic hydrocarbon extraction is carried out after the dealkylation of base oil is desulfurized and nitrogen to produce aromatic hydrocarbon such as benzene, toluene, xylene, naphthalene and the like; the coking deactivation catalyst is regenerated and recycled after dehydrogenation and depressurization by a catalyst hopper system; therefore, the efficient continuous production of the aromatic hydrocarbons such as BTX, naphthalene and the like produced by the FCC circulating oil hydro-fluidized catalytic cracking is realized, the aromatic hydrocarbon yield is high, the coke yield is low, and the utilization rate of the FCC circulating oil is high.
The invention adopts a dynamic reactor device such as a fluidized bed reaction system or a riser reactor system or a moving bed reactor system and a catalyst hopper system to isolate reaction and regeneration atmosphere, and changes reaction pressure, thereby realizing continuous operation of aromatic hydrocarbon hydrocracking dealkylation reaction and coking catalyst oxygen-containing regeneration reaction under the condition of hydrogen pressure (0.2-7.0 MPa), and further realizing higher aromatic hydrocarbon product yield of catalytic cracking cycle oil.
Compared with the prior art, the invention has the following technical effects:
(1) the FCC circulating oil can be directly subjected to hydrocatalytic cracking dealkylation to produce BTX and naphthalene oil without refining (such as hydrogenation), can be carried out under lower pressure (and further lower hydrogen partial pressure), has short flow and low hydrogen consumption, and realizes long-period continuous production;
(2) the method comprises the following steps of (1) realizing switching of different reaction atmospheres and reaction pressures through a catalyst hopper system, namely completing a hydrodealkylation catalytic cracking dealkylation reaction of FCC circulating oil under the condition of hydrogen pressure (0.2-7.0 MPa) in a dynamic reactor device, and recovering the activity of a catalyst in a regenerated oxygen-containing atmosphere;
(3) the FCC circulating oil hydrocatalytic cracking has low reaction temperature compared with the aromatics dealkylation hydrocracked method; compared with the catalytic cracking method for dealkylation of aromatic hydrocarbon, the method has low reaction pressure; compared with the FCC circulating oil non-hydrocatalysis method, the yield of the cracked gas alkane and coke is low, the yield of the dealkylated aromatic oil is high, and the yield of the aromatic hydrocarbon is high;
(4) the reaction and the regeneration are continuously carried out, the self-heating of the reaction can be realized, the heat generated by the regeneration and the burning is supplied to the heat required by the reaction, the external heating is not needed, and the energy consumption is greatly saved;
(5) the reaction and regeneration of the moving bed reactor are continuously and stably operated, the requirement on the strength of the catalyst is low, long-period operation can be realized, and the existing moving bed or semi-moving bed reforming device can be used for modification;
(6) the fluidized bed reactor is more suitable for the characteristic of fast catalytic cracking dealkylation reaction, has high requirement on the strength of the catalyst compared with a fixed bed and a moving bed, but has high volume utilization rate of the reactor, short reaction time and large handling capacity, is more suitable for long-period continuous operation of large-scale production, and can be reconstructed by utilizing the existing catalytic cracking device of a riser reactor or an S Zorb device.
Drawings
FIG. 1 is a schematic view of an apparatus and material flow direction according to an embodiment of the present invention.
FIG. 2 is a schematic view of an apparatus and material flow direction according to another embodiment of the present invention.
Description of the reference numerals
1 fraction oil rich in aromatic hydrocarbon
2 atomizing medium
3 Hydrogen containing Pre-lifting Medium
4 fluidized bed reactor
5 stripping Medium
6 settling vessel
7 reaction oil gas pipeline
8. Oil-gas separation system
9 cracking gas
10 dealkylated aromatic oils
11 heavy cycle oil or slurry
12 aromatic extraction system
13 mixed aromatic hydrocarbons
14 aromatic raffinate oil
15 regenerant feed line
16 pipeline to be regenerated I
17 catalyst hopper system
18 regeneration line
19 spent pipeline II
20 regenerator
21 oxygen-containing regeneration gas
22 flue gas
23 hydrogenated FCC cycle oil
40 moving bed reactor
Detailed Description
The technical solution of the present invention is further explained below according to specific embodiments. The scope of protection of the invention is not limited to the following examples, which are set forth for illustrative purposes only and are not intended to limit the invention in any way.
The application provides a method for continuously producing aromatic hydrocarbon by hydrocatalytically cracking FCC circulating oil, which comprises the following steps:
(1) atomizing the FCC circulating oil by using an atomizing medium and feeding the atomized FCC circulating oil into a reactor device, wherein the reactor device comprises a moving bed reactor, a fluidized bed reactor or a riser reactor;
(2) in the reactor device, in the hydrogen atmosphere, the atomized FCC circulating oil contacts the aromatic hydrocarbon dealkylation catalyst to carry out dealkylation reaction, so as to obtain reaction oil gas;
(3) obtaining the aromatic hydrocarbons from the reaction oil gas;
(4) and (3) the spent catalyst obtained in the step (2) enters a regeneration device, the spent catalyst is in contact with oxygen-containing regeneration gas in the regeneration device for regeneration, and the regenerated catalyst returns to the reactor for recycling.
In the present application, "hydrocatalytic cracking" refers to the catalytic cracking of FCC cycle oil in the presence of hydrogen, i.e., in a hydrogen atmosphere. The 'hydrogen atmosphere' refers to the existence of hydrogen in the system, wherein the hydrogen accounts for 30-90% of the volume of the system.
In one embodiment, the dealkylation conditions are: the reaction temperature is 500-800 ℃, the reaction pressure is 0.2-6.0MPa, the reaction time is 1-40 seconds, and the weight ratio of the catalyst to the FCC circulating oil is 1-10: 1. In this application, the reaction time refers to the inlet to outlet residence time of the FCC cycle oil in the reactor.
In the present application, the process of the present application can be carried out using a dynamic reactor apparatus. In one embodiment, the reactor apparatus comprises a fluidized bed reactor and/or a riser reactor. In the reactor device (fluidized bed reactor and/or riser reactor), a certain catalyst inventory is maintained under a relatively high reaction pressure in a hydrogen atmosphere, the catalyst is in a fluidized state, preferably in a turbulent fluidized state, and the apparent average linear velocity of oil gas is 15.0-30.0 m/s; the catalyst and reactant flow in the reactor can be ascending bed or descending bed, and can be regular equal diameter or variable diameter; the reactor and the regenerator can be arranged in parallel or overlapped, and N is adopted2The catalyst is lifted up to circulate between the reactor and the regenerator. Typically, the reactor unit is also provided with a settler for rapid separation of catalyst from the oil and gas. In one embodiment, after the reaction, the catalyst to be regenerated is dehydrogenated and depressurized through a catalyst hopper system to enter the regeneration device, and is in contact with the oxygen-containing regeneration gas in the regeneration device for regeneration, and the regenerated catalyst is deoxidized and pressurized through the catalyst hopper and then is returned to the reactor device for recycling; the regeneration operating conditions were: the temperature is 500 ℃ and 680 ℃, and the pressure is 0.2-2.0 MPa. Both the dehydrogenation depressurization and the deoxygenation pressurization in the catalyst hopper system can be treated with an inert gas such as nitrogen.
In one embodiment, the reactor apparatus comprises a fluidized bed reactor and/or a riser reactor, the reaction temperature is 500-800 ℃, the reaction pressure is 0.2-6.0MPa, the reaction time is 0.1-10 seconds, and the weight ratio of the catalyst to the FCC cycle oil is 1-10: 1. Preferably, the reaction temperature is 550-700 ℃, the reaction pressure is 1.0-5.0MPa, the reaction time is 0.5-5.0 seconds, and the weight ratio of the catalyst to the FCC circulating oil is 3-7: 1. In one embodiment, the reaction temperature is 550-650 ℃, or 550-600 ℃. In another embodiment, the reaction pressure is 1.0 to 3.0MPa, or 1.0 to 2.0 MPa.
In one embodiment, the reactor apparatus comprises a moving bed reactor. In one embodiment, the moving bed reactor is a conventional constant-diameter or variable-diameter moving bed reactor, the catalyst can be an ascending bed or a descending bed, the catalyst and the reactant flow can be in concurrent contact reaction or countercurrent contact reaction in the hydrogen atmosphere, the catalyst is in a moving state under relatively high reaction pressure, and the catalyst and the reactant flow are preferably in countercurrent contact reaction; the reactor and the regenerator can be arranged in parallel or overlapped, and N is adopted2The catalyst is lifted up to circulate between the reactor and the regenerator. In one embodiment, after the reaction, the spent catalyst is dehydrogenated and depressurized through a catalyst hopper system to enter the regeneration device, the spent catalyst is contacted with the oxygen-containing regeneration gas in the regeneration device for regeneration, and the regenerated catalyst is deoxidized and pressurized through the catalyst hopper and then returned to the reactor device for recycling. In one embodiment, the regeneration operating conditions are: the temperature is 500 ℃ and 680 ℃, and the pressure is 0.2-2.0 MPa. In one embodiment, the catalyst enters a catalyst hopper system, adsorbed oil gas is removed through nitrogen or steam stripping so as to be dehydrogenated and depressurized, the spent catalyst after the dehydrogenation and depressurization enters a regeneration device, and the catalyst is regenerated through countercurrent contact or concurrent contact with oxygen-containing regeneration gas; and conveying the regenerated catalyst into a catalyst hopper system again, removing air carried by the catalyst through nitrogen stripping so as to perform deoxidation and pressure boosting, and returning the regenerated agent subjected to deoxidation and pressure boosting to the reactor.
In one embodiment, the reactor apparatus comprises a moving bed reactor, the reaction temperature is 500-650 ℃, the reaction pressure is 0.2-6.0MPa, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the FCC cycle oil is 1-10: 1. Preferably, the reaction temperature is 520-630 ℃, the reaction pressure is 1.0-5.0MPa, the reaction time is 2-15 seconds, and the weight ratio of the catalyst to the FCC circulating oil is 3-8: 1. In one embodiment, the reaction temperature is 550-650 ℃, or 550-600 ℃. In another embodiment, the reaction pressure is 1.0 to 3.0MPa, or 1.0 to 2.0 MPa.
In one embodiment, the FCC cycle oil in the present invention is an aromatic-rich catalytic cracking cycle oil, which refers to distillate oil with a distillation range of 80-360 ℃ from a catalytic cracking unit, and a total aromatic content of 40-98 wt%, and comprises distillate oil directly from the catalytic cracking unit and/or hydrogenated catalytic cracking distillate oil, and aromatic-rich distillate oil from other units, such as reformed heavy aromatics rich in C9-C11 aromatics. The distillation range of the catalytic cracking cycle oil can be selected according to the requirement of producing a target aromatic hydrocarbon product, the distillate with the distillation range of 150-. The hydrogenated catalytic cracking distillate oil can be mixed with distillate oil directly coming from a catalytic cracking unit and/or distillate oil rich in aromatic hydrocarbon coming from other units, or can be fed upstream or downstream of the distillate oil directly coming from the catalytic cracking unit, preferably the distillate oil directly coming from the catalytic cracking unit is fed upstream, and the reaction time is 0.1-10 seconds before the distillate oil directly coming from the catalytic cracking unit is fed.
In one embodiment, the atomizing medium comprises a hydrogen-containing gas and/or a non-hydrogen-containing gas, and the atomizing medium contains no or trace amounts of oxygen, wherein the volume fraction of oxygen in the atomizing medium is no greater than 1%. In one embodiment, the hydrogen-containing gas is selected from one or more of hydrogen, dry gas; the gas containing no hydrogen is selected from one or more of nitrogen and water vapor. When a hydrogen-free gas is used as the atomizing medium, it is necessary to introduce H into the reaction apparatus2To provide a hydrogen atmosphere. In one embodiment, H2The volume ratio of/FCC circulating oil is 100-1000.
The aromatic dealkylation catalyst is a bifunctional catalyst consisting of metal and a molecular sieve, and is characterized in that: the metal component of the aromatic hydrocarbon dealkylation catalyst is a metal element of IA group, IIA group, VIA group, VIIA group, IB group and IIB group or transition metal, mainly a metal element of fourth period and fifth period, preferably any one or any two, three or more of secondary group metals of Cr, Ni, Mo, Cu and the like, alkali metal K, alkaline earth metal Mg and the like, and the metal component exists in the form of oxide; the catalyst molecular sieve comprises a large pore zeolite and optionally a medium pore zeolite. Preferably, the catalyst is a composite of a large pore zeolite and optionally an inorganic oxide such as a medium pore zeolite, alumina, silica, and optionally a metal oxide supported on a refractory inorganic oxide support such as a clay, natural porous support material, and the like. The active metal component represents 5 to 50 wt.%, preferably 15 to 30 wt.%, calculated as oxide, of the total amount of the catalyst. If the composite metal oxide is used as the active component of the adsorbent, the molar ratio of the transition metal elements in the fourth and fifth periods to the metal elements in the IA group, the IIA group, the VIA group, the VIIA group, the IB group and the IIB group can be selected from 0:1-0:100, preferably 1:1-1: 10. In one embodiment, the catalyst molecular sieve comprises from 1 to 50 wt%, preferably from 20 to 40 wt% of the total catalyst.
In one embodiment, the aromatics dealkylation catalyst comprises an active metal component selected from one or more of group IA, group IIA, group VIA, VIIA, IB, IIB and transition metals group 4 and 5 period elements (preferably, the active metal component comprises one or more of Cr, Ni, Mo, Cu, and one or more of alkali metal K and alkaline earth metal Mg) in an amount of from 5 to 50 wt%, preferably from 15 to 30 wt%, calculated as oxides, based on the total weight of the catalyst, a zeolite, a binder and optionally a clay.
In one embodiment, the zeolite comprises a large pore zeolite and optionally a medium pore zeolite, and comprises from 1 to 50 weight percent of the total weight of the catalyst. The large pore zeolite accounts for 80-100 wt%, preferably 90-100 wt% of the total weight of the zeolite; the medium pore zeolite constitutes 0 to 20 wt%, preferably 0 to 10 wt%, of the total weight of the zeolite. The large-pore zeolite can be selected from Y series zeolite, including Rare Earth Y (REY), Rare Earth Hydrogen Y (REHY), ultrastable Y obtained by different methods and high-silicon Y. The medium pore zeolite is selected from ZSM series zeolite and/or ZRP zeolite, and can also be modified by nonmetal elements such as phosphorus; the ZSM series zeolite may be selected from one or a mixture of two or more of ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38, ZSM-48 and other zeolites of similar structure, and more detailed description of ZSM-5 may be found in U.S. Pat. No. 3,702,886.
In one embodiment, the binder is selected from silica and/or alumina and is present in an amount of from 5 to 95 wt% based on the total weight of the catalyst. The inorganic oxide may be used as a binder and may be selected from silicon dioxide (SiO)2) And/or aluminum oxide (Al)2O3). In one embodiment, the binder may comprise silica in an amount of 50 to 90 wt.% and alumina in an amount of 10 to 50 wt.%, on a dry weight basis.
In one embodiment, the clay comprises from 0 to 70 weight percent of the total weight of the catalyst. The clay as matrix (i.e. carrier) can be selected from one or more of silica, kaolin and/or halloysite, montmorillonite, diatomite, halloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite and bentonite.
Preferably, the large pore and medium pore zeolites, the inorganic oxide binder, the clay, and the like are modified with a transition metal element such as iron, cobalt, and nickel.
The average particle size of the catalyst varies slightly depending on the type of reactor. In one embodiment, the reactor apparatus comprises a fluidized bed reactor and/or a riser reactor, and the catalyst has an average particle size of 40 to 100 microns. The catalyst is mainly microspherical, has a diameter of 0-200 microns, preferably 40-150 microns, and has a particle apparent density of 0.4-0.9g/cm3More preferably 0.8 to 1.5g/cm3。
In another embodiment, the reactor apparatus is a moving bed reactor, and in order to facilitate movement and reduce attrition, the catalyst is preferably in the form of pellets having an average particle size of from 1 to 6mm, preferably from 2 to 4 mm.
In one embodiment, the FCC cycle oil is preheated prior to being fed to the reactor unit, the temperature of the preheating being 180 ℃ and 450 ℃, preferably 200 ℃ and 400 ℃, such as 200 ℃ and 360 ℃.
In one embodiment, obtaining the aromatics from the reaction oil gas comprises: introducing the reaction oil gas into a separation device, and separating to obtain cracked gas, dealkylated aromatic oil and oil slurry; and introducing the dealkylated aromatic oil into an aromatic extraction device to obtain aromatic hydrocarbon and aromatic hydrocarbon raffinate oil. In the present application, "separation system", "oil and gas separation system" and "separation device" have the same meaning; the term "aromatics extraction unit" is also synonymous with the term "aromatics extraction system".
In the present invention, the reaction oil gas is fed into a separation device to perform product separation, for example, the product is separated into the dealkanized aromatic oil, slurry oil and cracked gas such as propylene, etc., which are well known to those skilled in the art, and fractionation, rectification, etc. may be used. The distillation range of the dealkanized aromatic oil and the like can be adjusted as required.
In the present invention, a method of extracting aromatics from the dealkanized aromatic oil in an aromatics extraction apparatus is also well known to those of ordinary skill in the art. In one embodiment, the dealkylated aromatic oil is subjected to aromatic extraction by one aromatic extraction unit and/or a plurality of identical/different aromatic extraction units, the aromatic extraction solvent comprises a conventional solvent and a plasma solvent, and the aromatic mixture obtained by aromatic extraction is further subjected to aromatic separation to obtain BTX (benzene-toluene-xylene) monocyclic aromatic hydrocarbon and bicyclic aromatic hydrocarbons such as naphthalene and dimethylnaphthalene. In one embodiment, the dealkylated aromatic oil is further treated to remove impurities such as nitrides and sulfides before the dealkylated aromatic oil is subjected to aromatic extraction, and this may be by adsorption and/or selective hydrogenation, preferably adsorption. In one embodiment, the impurity-removed dealkylated aromatic oil has an impurity level of nitrides, sulfides, etc. of no greater than 30 micrograms/gram, preferably no greater than 10 micrograms/gram.
In one embodiment, the slurry oil and/or the aromatic raffinate oil may also be fed to the alternating fixed bed reactor unit to further process these streams to increase the yield of high value aromatics.
According to the invention, reaction oil gas obtained by reaction enters a separation system for product separation, and a spent catalyst enters a regenerator for regeneration; in the regeneration process, the regeneration gas can be one or more of air, oxygen and oxygen-containing gas, and the regeneration temperature can be 500-800 ℃, preferably 550-750 ℃; the pressure is 0.2-2.0 MPa. The heat exchange of the regenerated catalyst can be carried out by methods known to those skilled in the art to control the coke formation and the oil contact temperature.
In another aspect, the present application provides an apparatus for continuously producing aromatic hydrocarbons by hydrocatalytically cracking FCC cycle oil, comprising:
the reactor device is provided with a material inlet, a reaction oil gas outlet, a catalyst inlet and a catalyst outlet, and comprises a moving bed reactor or a fluidized bed;
the separation device comprises a material inlet, a cracked gas outlet, a dealkylated aromatic oil outlet and an oil slurry outlet; the material inlet of the separation device is connected with the reaction oil gas outlet of the reactor device;
the aromatic hydrocarbon extraction device comprises a material inlet, an aromatic hydrocarbon outlet and an aromatic hydrocarbon raffinate oil outlet, and the material inlet of the aromatic hydrocarbon extraction device is communicated with the dealkylated aromatic hydrocarbon oil outlet of the separation device;
the regeneration device is provided with a catalyst inlet, a catalyst outlet, a regeneration gas inlet and a regeneration gas outlet;
and the catalyst hopper system is connected with the catalyst inlet and the catalyst outlet of the reactor device and is connected with the catalyst inlet and the catalyst outlet of the regeneration device, so that the catalyst to be regenerated from the reactor device enters the regeneration device for regeneration after passing through the catalyst hopper system, and the regenerated catalyst from the regeneration device is circulated back to the reactor device after passing through the catalyst hopper system.
In one embodiment, the aromatics raffinate outlet of the aromatics extraction unit is further in communication with the feed inlet of the reactor unit. In a further embodiment, the slurry outlet of the separation device is also in communication with the feed inlet of the reactor device.
In the application, a dynamic reactor device and a catalyst hopper system are adopted, the reaction can be isolated to be divided into and regenerated atmosphere, the reaction pressure is changed simultaneously, the continuous operation of the aromatic hydrocarbon hydrocracking dealkylation reaction and the coking catalyst oxygen-containing regeneration reaction under the hydrogen pressure (0.2-7.0 MPa) can be realized, and the higher aromatic hydrocarbon product yield of the catalytic cracking cycle oil is realized. The catalyst hopper system may be a lock hopper, as is well known to those skilled in the relevant art, a device that allows the same stream to be switched between different atmospheres (e.g., oxidizing and reducing atmospheres) and/or between different pressure environments (e.g., from high pressure to low pressure, or vice versa), as described in CN 101558138A.
FIG. 1 is a schematic diagram of the apparatus and material flow direction for an embodiment using a fluidized bed reactor, in which aromatics-rich distillate is hydrodealkylated by downfeed hydrocatalytic cracking in a fluidized bed reactor using an upflow fluidized bed reactor, and reacted oil and gas are separated from the catalyst.
The catalytic cracking cycle oil (rich in aromatic hydrocarbon distillate oil) 1 adopts an up-going fluidized bed reactor for hydro-fluidized catalytic cracking dealkylation, and a fluidized bed reactor 4 introduces a thermal regenerant which is stripped, deoxidized and boosted by nitrogen through a catalyst hopper system 17 through a regenerant feeding pipeline 15; in the fluidized bed reactor 4, catalytic cracking cycle oil (aromatic-rich distillate oil) 1 and optional hydrogenated FCC cycle oil 23 are injected from the bottom of the fluidized bed reactor 4, and are subjected to hydrodealkylation reaction on a thermal regenerant along with the ascending of a hydrogen-containing pre-lifting medium 3 and a hydrogen-containing or non-hydrogen-containing atomizing medium 2; after reaction, oil gas and a catalyst are settled and separated in a settler 6, the catalyst after reaction is stripped by a stripping medium 5 and then enters a catalyst hopper system 17 from a spent pipeline 16, and after nitrogen stripping, dehydrogenation and pressure reduction, the catalyst enters a regenerator 20 through a spent agent conveying pipeline 19 and is regenerated in an oxygen-containing atmosphere; the separated reaction oil gas enters an oil-gas separation system 8 through a pipeline 7 to obtain a cracking gas 9, dealkylated aromatic oil 10 and heavy cycle oil or oil slurry 11; the dealkylated aromatic oil is further extracted in an aromatic extraction system 12 to obtain mixed aromatic hydrocarbon 13 containing benzene, toluene, xylene, naphthalene, methyl naphthalene and the like and aromatic raffinate oil 14. The aromatic raffinate oil 14 is preferably recycled, part of the gas alkane in the cracking gas 9 is selected to be recycled to the reactor as a hydrogen-containing fluidizing medium or a pre-lifting medium according to needs, and the oil slurry 11 is selected to be recycled or not recycled according to needs. After the adsorbed oil gas of the separated catalyst is stripped and removed by nitrogen or steam, the separated catalyst is sent to a catalyst hopper system 17 by a spent pipeline I16 for dehydrogenation and depressurization, a spent pipeline II 19 of the spent catalyst after dehydrogenation and depressurization enters a regeneration device 20, oxygen-containing regeneration gas 21 is introduced for regeneration, the regeneration temperature is 500-800 ℃, and the flue gas 22 is discharged; the regenerated catalyst returns to the catalyst hopper system through a regeneration pipeline 18 for deoxidation and pressure boosting, and the regenerant after deoxidation and pressure boosting returns to the fluidized bed reactor 4 through a regenerant feeding pipeline 15.
FIG. 2 shows a schematic diagram of the apparatus and material flow for an embodiment using a moving bed reactor with downfeed hydrodealkylation of aromatics-rich distillate in a moving bed reactor with countercurrent contacting of the distillate with a catalyst.
The catalytic cracking cycle oil (rich in aromatic hydrocarbon distillate oil) 1 is dealkylated by the hydrogenation fluidized catalytic cracking of a descending moving bed reactor, and a hot regenerant which is stripped, deoxidized and boosted by nitrogen through a catalyst hopper system 17 is introduced into the moving bed reactor 40 through a regenerant feeding pipeline 16; in a moving bed reactor 40, catalytic cracking cycle oil (rich in aromatic hydrocarbon distillate oil) 1, atomizing medium 2 containing hydrogen or not and optional hydrogenated FCC cycle oil 23 are injected from the upper part of the moving bed reactor 40, and the hydrodealkylation reaction is carried out on a thermal regenerant; the reacted oil gas enters an oil-gas separation system 8 through a pipeline 7 to obtain a cracking gas 9, dealkylated aromatic oil 10 and heavy cycle oil or oil slurry 11; the dealkylated aromatic oil is further extracted in an aromatic extraction system 12 to obtain mixed aromatic hydrocarbon 13 containing benzene, toluene, xylene, naphthalene, methyl naphthalene and the like and aromatic raffinate oil 14; the aromatic raffinate oil 14 is preferably recycled, part of the gas alkane in the cracking gas 9 is selected to be recycled to the reactor as a hydrogen-containing fluidizing medium or a pre-lifting medium according to needs, and the oil slurry 11 is selected to be recycled or not recycled according to needs. The reacted catalyst is sent into a catalyst hopper system 17 through a spent pipeline I15, adsorbed oil gas is removed through stripping by nitrogen or steam so as to be dehydrogenated and depressurized, the spent agent after dehydrogenation and depressurization enters the upper part of a regeneration device 20 through a spent pipeline II 18, the catalyst is in countercurrent contact with oxygen-containing regeneration gas 21 for regeneration, the regeneration temperature is 500-750 ℃, and smoke 22 is discharged; the regenerated catalyst returns to the catalyst hopper system through a regeneration pipeline 19, the air carried by the catalyst is removed through nitrogen stripping so as to carry out deoxidation and pressure boosting, and the regenerant after deoxidation and pressure boosting returns to the upper part of the moving bed reactor 40 through a regenerant feeding pipeline 16.
The following examples further illustrate the process using a fluidized bed and a moving bed, but are not intended to limit the process. The properties of the feed catalytically cracked cycle oil used in the following examples are shown in table 1.
Examples 1-3 the catalysts used in the examples were the same and were prepared in the following manner:
1) 20kgNH4Cl is dissolved in 1000kg water, 100kg (dry basis) of crystallized DASY zeolite (manufactured by catalyst works of Qilu petrochemical company, 2.445-2.448nm, RE content2O32.0 wt%), exchanged at 90 deg.C for 0.5h, filtered to obtain filter cake; 94.0kgCr (NO) was added3)3·9H2Dissolving O in 540kg of water, mixing with the filter cake, soaking and drying; then roasting at 550 deg.C for 2 hr to obtain chromium-containing macroporous zeolite with elemental analysis chemical composition of 0.1Na2O·5.1Al2O3·19.0Cr2O3·3.8RE2O3·88.1SiO2。
2) Pulping 75.4kg of halloysite (industrial product of Suzhou china clay company, with a solid content of 71.6 m%) with 250kg of decationized water, adding 54.8kg of pseudo-boehmite (industrial product of Shandong aluminum plant, with a solid content of 63 m%), adjusting the pH to 2-4 with hydrochloric acid, and stirring uniformlyHomogenizing, standing at 60-70 deg.C for aging for 1 hr, maintaining pH at 2-4, cooling to below 60 deg.C, adding 41.5Kg of aluminum sol (product of catalyst plant of Qilu petrochemical company, Al)2O3Content 21.7 m%), and stirred for 40 minutes to obtain a mixed slurry.
3) The chromium-containing large-pore zeolite prepared in the step 1) (33.8 kg on a dry basis) and MFI structure medium-pore ZRP-1 zeolite (industrial product of catalyst plant of Qilu petrochemical company, SiO)2/Al2O330 dry basis of 3.0kg) was added to the mixed slurry obtained in step 2), stirred uniformly, and 4.0g of a commercial alumina binder was added, mixed and placed in a bonder, an appropriate amount of water was added, stirred sufficiently and uniformly, left to stand in the air for 4 hours, spray-dried and formed, dried in a drying oven at 120 ℃ for 3 hours, washed with a monoammonium phosphate solution (phosphorus content of 1 m%), and free Na was washed off+Washing to remove free Na+And drying again to obtain the catalyst which is marked as CAT-1. The catalyst consists of chromium oxide 7.4 wt%, MFI structure mesoporous zeolite 2.2 wt%, DASY zeolite 20.6 wt%, pseudoboehmite 24.8 wt%, alumina sol 6.5 wt% and kaolin for the rest. The properties are shown in Table 2.
Example 1
This example was tested according to the apparatus and flow scheme of fig. 1, using FCC cycle oil a in table 1 as feedstock, on a fluidized bed reactor using CAT-1 catalyst with catalyst MAT of 68. The fluidized bed reactor is a small-sized riser fluidized bed reactor, and the inventory of the catalyst is 10 kilograms; unlike conventional small riser fluidized bed reactors, a catalyst hopper system is provided between the reactor and the regenerator.
Preheating FCC circulating oil A at 260 ℃, then feeding the preheated FCC circulating oil A into the bottom of a fluidized bed reactor, and reacting under the pressure of 0.2MPa and H2The volume ratio of the circulating oil is 500, the hydrogen-containing fluidized medium flows from bottom to top, and the hydrocracking dealkylation reaction is carried out under the conditions that the reaction temperature is 540 ℃, the weight ratio of the catalyst to the raw oil is 3.2 and the reaction time is 3.5 seconds; the reaction oil gas is subjected to product separation by a separation system to obtain a gas product and dealkylated aromatic oil, the dealkylated aromatic oil is desulfurized,Aromatic extraction is carried out after nitrogen to obtain high-value aromatic hydrocarbons such as benzene, toluene, xylene and naphthalene, and the aromatic raffinate oil is recycled by 100 percent; after the reacted catalyst to be regenerated is stripped by nitrogen gas to remove oil gas adsorbed in the catalyst to be regenerated, the catalyst to be regenerated is sent to a regenerator through a catalyst hopper system for dehydrogenation and depressurization, and air is used as regeneration gas to be contacted with a catalyst to be regenerated for regeneration at the regeneration temperature of 550-750 ℃; the regenerated regenerant is recycled. The operating conditions and the product distribution are listed in Table 3.
As can be seen from table 3, in example 1, the monocyclic aromatic-rich FCC cycle oil was hydrodealkylated in the fluidized bed reactor, the dealkylated base oil yield was 83.82 wt%, the BTX yield was 29.50 wt%, the naphthalene yield was 15.09 wt%, the methylnaphthalene yield was 3.52 wt%, and the triene (ethylene + propylene + butylene) yield was 7.4 wt%; the slurry yield was 0.10 wt% and the coke yield was 3.24 wt%; the total yield of high value aromatics (BTXN) such as benzene, toluene, xylene and naphthalene was 48.11 wt%.
Comparative example 1
Catalytic cracking was carried out by the same apparatus and method as in example 1, except that in comparative example 1: non-hydrocatalytic cracking, wherein fluidizing medium is water vapor and nitrogen without hydrogen; the catalyst and the process conditions are the same as those in the example 1, under the reaction pressure of 0.2MPa, the FCC circulating oil A flows from bottom to top along with the non-hydrogen-containing fluidized medium, the non-hydrocatalytic cracking dealkylation reaction is carried out under the conditions of the reaction temperature of 540 ℃, the weight ratio of the catalyst to the raw oil of 3.2 and the reaction time of 3.5 seconds, and the weight ratio of the steam to the total raw material is 5 percent; separating the reaction oil gas by a separation system to obtain a gas product and dealkylated aromatic oil, desulfurizing and extracting aromatic hydrocarbon after nitrogen removal to obtain high-value aromatic hydrocarbon such as benzene, toluene, xylene and naphthalene, and refining 100% of the aromatic hydrocarbon raffinate oil; stripping the reacted spent catalyst with nitrogen to remove oil gas adsorbed in the spent catalyst, directly sending the spent catalyst into a regenerator, and using air as a regeneration gas to contact the spent catalyst at the regeneration temperature of 550-750 ℃ for regeneration; the regenerated regenerant is recycled. The operating conditions and the product distribution are listed in Table 3.
As can be seen from table 3, in example 1 (hydrocatalytic cracking), the yield of the dealkylated base oil and the yields of BTX and naphthalene were high, the recycle ratio of the aromatic raffinate was low, and the coke yield was low, and the yields of the dealkylated base oil and the yields of BTX and naphthalene were respectively increased by 0.61, 10.20 and 4.27 percentage points, and the yields of slurry and coke were respectively decreased by 0.12 and 1.01 percentage points, as compared with comparative example 1 (non-hydrocatalytic cracking).
Example 2
This example was tested according to the apparatus and procedure of fig. 1 (apparatus as in example 1) using FCC cycle oil B in table 1 as feedstock in a fluidized bed reactor using CAT-1 catalyst with catalyst MAT of 68. Preheating FCC circulating oil B at 260 ℃, then feeding the preheated FCC circulating oil B into the bottom of a fluidized bed reactor, and reacting under the reaction pressure of 6.0MPa and H2The volume ratio of the circulating oil is 1000, and the hydro-cracking dealkylation reaction is carried out along with the flowing of the hydrogen-containing fluidized medium from bottom to top under the conditions of the reaction temperature of 660 ℃, the weight ratio of the catalyst to the raw oil of 6.5 and the reaction time of 4.8 seconds; separating the reaction oil gas by a separation system to obtain a gas product, dealkylated aromatic oil and oil slurry, desulfurizing the dealkylated aromatic oil, extracting aromatic hydrocarbon after nitrogen to obtain high-value aromatic hydrocarbon such as benzene, toluene, xylene and naphthalene, and refining 100% of the aromatic hydrocarbon raffinate oil; after the reacted catalyst to be regenerated is stripped by nitrogen gas to remove oil gas adsorbed in the catalyst to be regenerated, the catalyst to be regenerated is sent to a regenerator through a catalyst hopper system for dehydrogenation and depressurization, and air is used as regeneration gas to be contacted with a catalyst to be regenerated for regeneration at the regeneration temperature of 600-750 ℃; the regenerated regenerant is recycled. The operating conditions and the product distribution are listed in Table 4.
As can be seen from table 4, in example 2, the recycle FCC oil rich in monocyclic aromatic hydrocarbon is hydrodealkylated in the fluidized bed reactor, the yield of the dealkylated base oil is 75.14 wt%, the yield of BTX is 9.92 wt%, the yield of naphthalene is 44.78 wt%, the yield of methylnaphthalene is 12.92 wt%, and the yield of trienes (ethylene + propylene + butylene) is 10.66 wt%; the slurry yield was 1.35 wt% and the coke yield was 5.86 wt%; the overall yield of high value aromatics (BTXN) such as benzene, toluene, xylene and naphthalene was 67.63 wt%.
Comparative example 2
Catalytic cracking was carried out by the same apparatus and method as in example 2, except that in comparative example 1: the hydrocracking reaction system has no catalyst and needs no hydrogenationThe catalyst is regenerated, but external heating, namely electric heating is adopted to maintain the reaction temperature; the fluidized media are hydrogen containing gas and catalytic cracking dry gas, the process conditions are the same as example 2, and the reaction pressure is 6.0MPa, H2The volume ratio of the circulating oil to the FCC circulating oil B is 1000, the FCC circulating oil B enters the bottom of the fluidized bed reactor after being preheated at 260 ℃ and flows from bottom to top along with a hydrogen-containing fluidized medium, and the hydrocracking dealkylation reaction is carried out under the conditions that the reaction temperature is 660 ℃, the weight ratio of the catalyst to the raw oil is 6.5 and the reaction time is 4.8 seconds; and (3) separating the reaction oil gas by a separation system to obtain a gas product, dealkylated aromatic oil and slurry oil, desulfurizing the dealkylated aromatic oil, extracting aromatic hydrocarbon after nitrogen to obtain high-value aromatic hydrocarbon such as benzene, toluene, xylene and naphthalene, and refining the raffinate oil of the aromatic hydrocarbon by 100%. The operating conditions and the product distribution are listed in Table 4.
As can be seen from Table 4, in example 2 (hydrocatalytic cracking), the yield of the dealkylated base oil and BTX and naphthalene were high, the recycle ratio of the aromatic raffinate was low, and the coke yield was low, and the yield of the dealkylated base oil and BTX and naphthalene were respectively improved by 2.73, 5.63 and 9.81 percentage points, and the yield of slurry oil and coke were respectively reduced by 1.13 and 3.88 percentage points, as compared with comparative example 2 (hydrocracked).
Example 3
This example was tested according to the apparatus and flow scheme of fig. 1 (apparatus as in example 1) using 30 wt% FCC cycle oil a and 70 wt% hydrogenated FCC cycle oil C of table 1 as feed on a fluidized bed reactor using CAT-1 catalyst with catalyst MAT of 68. Preheating FCC circulating oil A at 160 ℃, then feeding the FCC circulating oil A into the bottom of a fluidized bed reactor, feeding hydrogenated FCC circulating oil C at the upstream of the FCC circulating oil A, firstly contacting a high-temperature regenerant, reacting for a certain time, ascending to contact a catalyst together with the FCC circulating oil A for reaction, and reacting H under the reaction pressure of 1.8MPa2The volume ratio of the circulating oil is 800, the hydrogen-containing fluidized medium flows from bottom to top, and the hydrocracking dealkylation reaction is carried out under the conditions that the reaction temperature is 600 ℃, the weight ratio of the catalyst to the mixed raw oil is 5.2, and the reaction time is 5 seconds; the reaction oil gas is subjected to product separation by a separation system to obtain a gas product and dealkylated aromatic oil, and the dealkylated aromatic oil is subjected to desulfurization and denitrification and then to aromatic hydrocarbonExtracting to obtain high-value aromatic hydrocarbons such as benzene, toluene, xylene and naphthalene, and refining aromatic hydrocarbon raffinate oil by 100%; after the reacted catalyst to be regenerated is stripped by nitrogen gas to remove oil gas adsorbed in the catalyst to be regenerated, the catalyst to be regenerated is sent to a regenerator through a catalyst hopper system for dehydrogenation and depressurization, and air is used as regeneration gas to be contacted with a catalyst to be regenerated for regeneration at the regeneration temperature of 600-750 ℃; the regenerated regenerant is recycled. The operating conditions and the product distribution are listed in Table 5.
As can be seen from table 5, in example 3, the recycle FCC oil rich in monocyclic aromatic hydrocarbon is hydrodealkylated in the fluidized bed reactor, the yield of the dealkylated base oil is 77.85 wt%, the yield of BTX is 30.83 wt%, the yield of naphthalene is 7.44 wt%, the yield of methylnaphthalene is 3.39 wt%, and the yield of trienes (ethylene + propylene + butylene) is 8.96 wt%; the slurry yield was 0.56 wt% and the coke yield was 4.23 wt%; the overall yield of high value aromatics (BTXN) such as benzene, toluene, xylene and naphthalene was 41.66 wt%.
Comparative example 3
Catalytic cracking was performed by the same method as in example 1, except that in comparative example 1: non-hydrocatalytic cracking, wherein fluidizing medium is water vapor and nitrogen without hydrogen; the catalyst and the process conditions are the same as those in the example 1, the hydrogenated FCC cycle oil C is fed at the upstream of the FCC cycle oil A under the reaction pressure of 1.8MPa, firstly contacts with a high-temperature regenerant, goes upward after reacting for a certain time to contact with the catalyst together with the FCC cycle oil A for reaction, the non-hydrocatalytic cracking dealkylation reaction is carried out under the conditions of the reaction temperature of 600 ℃, the weight ratio of the catalyst to the mixed raw oil of 5.2 and the reaction time of 1.8 seconds, and the weight ratio of the steam to the total raw material is 0.5; separating the reaction oil gas by a separation system to obtain a gas product and dealkylated aromatic oil, desulfurizing and extracting aromatic hydrocarbon after nitrogen removal to obtain high-value aromatic hydrocarbon such as benzene, toluene, xylene and naphthalene, and refining 100% of the aromatic hydrocarbon raffinate oil; stripping the reacted spent catalyst with nitrogen to remove oil gas adsorbed in the spent catalyst, directly sending the spent catalyst into a regenerator, and using air as a regeneration gas to contact the spent catalyst at the regeneration temperature of 600-750 ℃ for regeneration; the regenerated regenerant is recycled. The operating conditions and the product distribution are listed in Table 5.
As can be seen from table 5, in example 1 (hydrocatalytic cracking), the yield of the dealkylated base oil and the yields of BTX and naphthalene were high, the recycle ratio of the aromatic raffinate was low, and the coke yield was low, and the yields of the dealkylated base oil and the yields of BTX and naphthalene were respectively increased by 0.90, 7.36 and 4.64 percentage points, and the yields of slurry and coke were respectively decreased by 0.38 and 1.15 percentage points, as compared with comparative example 1 (non-hydrocatalytic cracking).
TABLE 1
Raw oil name
FCC cycle oil
FCC cycle oil
Hydrogenated FCC cycle oil
Raw oil numbering
A
B
C
Density (20 deg.C), kg/m3
876
939
912
Sulfur content, wt.%
0.19
0.56
0.01
Nitrogen content, weight%
0.052
0.16
0.01
Composition of hydrocarbons
Saturated hydrocarbon, weight%
19.8
17.2
23.4
Monocyclic aromatic hydrocarbon, by weight%
60.3
16.6
64.3
Bicyclic aromatic hydrocarbon, weight%
19.6
64.8
11.2
Tricyclic aromatic hydrocarbons, by weight%
0.3
1.4
1.1
Distillation range, deg.C
Initial boiling point
168
210
176
10％
206
242
208
50％
219
284
243
90％
224
339
300
End point of distillation
245
357
342
TABLE 2
Catalyst numbering
CAT-1
Chemical composition, weight%
Chromium oxide
7.4
Alumina oxide
43.6
Sodium oxide
0.14
Rare earth element
1.2
Apparent density, kg/m3
850
Pore volume, ml/g
0.32
Specific surface area, rice2Per gram
174
Abrasion index in% by weight-1
1.3
Sieving to obtain fine powder
0-40 micron
18.5
40-80 microns
57.4
>80 micron
24.1
TABLE 3
Example 1
Comparative example 1
Raw oil
A
A
Reaction mode
Hydrocatalytic cracking
Non-hydrocatalytic cracking
Name of catalyst
CAT-1
CAT-1
Catalyst Activity (MAT)
68
68
Recycle ratio of aromatic raffinate oil
0.03
0.07
Reaction operating conditions
Reaction pressure, MPa
0.2
0.2
Partial pressure of hydrogen, MPa
0.1
-
Reactor inlet temperature,. deg.C
680
680
Middle temperature of the reactor, deg.C
580
580
Reactor outlet temperature,. deg.C
540
540
Catalyst/feed oil weight ratio
3.2
3.2
Oil gas residence time, s
3.5
3.5
H2Volume ratio of circulating oil
500
-
The weight ratio of water vapor/total feedstock,％
-
5
product yield, weight%
Cracked gas
12.84
12.32
Wherein the triene
7.40
6.45
Gaseous alkane
5.44
5.87
Dealkylated base oil
83.82
83.21
Wherein BTX
29.50
19.30
Naphthalene
15.09
10.82
Methylnaphthalene
3.52
2.88
Oil slurry
0.10
0.22
Coke
3.24
4.25
Total up to
100.00
100.00
BTXN yield
76.11
73.87
TABLE 4
TABLE 5
The following examples further illustrate the process using a moving bed, but are not intended to limit the process. The properties of the feed catalytically cracked cycle oil used in the following examples are shown in table 1.
The catalysts used in examples 4-6 below were the same and were prepared in the following manner:
1) 20kgNH4Cl is dissolved in 1000kg water, 100kg (dry basis) of crystallized DASY zeolite (manufactured by catalyst works of Qilu petrochemical company, 2.445-2.448nm, RE content2O32.0 wt%), exchanged at 90 deg.C for 0.5h, filtered to obtain filter cake; 94.0kgCr (NO) was added3)3·9H2Dissolving O in 540kg of water, mixing with the filter cake, soaking and drying; then roasting at 550 deg.C for 2 hr to obtain chromium-containing macroporous zeolite with elemental analysis chemical composition of 0.1Na2O·5.1Al2O3·19.0Cr2O3·3.8RE2O3·88.1SiO2。
2) Pulping 75.4Kg of halloysite (industrial product of Suzhou china clay company, with a solid content of 71.6 m%) with 250Kg of decationized water, adding 54.8Kg of pseudo-boehmite (industrial product of Shandong aluminum plant, with a solid content of 63 m%), adjusting the pH to 2-4 with hydrochloric acid, stirring uniformly, standing and aging at 60-70 deg.C for 1 hour, maintaining the pH at 2-4, cooling to below 60 deg.C, adding 41.5Kg of alumina sol (product of catalyst plant of Qilu petrochemical company, Al)2O3Content 21.7 m%), and stirred for 40 minutes to obtain a mixed slurry.
3) The chromium-containing large-pore zeolite prepared in the step 1) (33.8 kg on a dry basis) and MFI structure medium-pore ZRP-1 zeolite (industrial product of catalyst plant of Qilu petrochemical company, SiO)2/Al2O330 dry basis of 3.0kg) was added to the mixed slurry obtained in step 2), stirred uniformly, and 4.0g of a commercial alumina binder was added, mixed and placed in a bonder, an appropriate amount of water was added, stirred sufficiently and uniformly, placed in the air for 4 hours, ball-rolled by a ball roller, dried in a drying oven at 120 ℃ for 3 hours, washed with a solution of ammonium dihydrogen phosphate (phosphorus content: 1 m%), and free Na was washed off+Washing to remove free Na+And drying again to obtain the catalyst CAT-2 (the average particle size is 2-4 mm). The catalyst consists of chromium oxide 7.4 wt%, MFI structure mesoporous zeolite 2.2 wt%, DASY zeolite 20.6 wt%, pseudoboehmite 24.8 wt%, alumina sol 6.5 wt% and kaolin for the rest. The properties are shown in Table 6.
Example 4
This example was tested according to the apparatus and flow scheme of fig. 2 using FCC cycle oil a in table 1 as feedstock on a moving bed reactor using CAT-2 catalyst with catalyst MAT 66. The moving bed reactor is a small tubular moving bed reactor, and the inventory of the catalyst is 10 kg; unlike conventional small tubular moving bed reactors, a catalyst hopper system is provided between the reactor and the regenerator.
Preheating FCC circulating oil A at 160 ℃, then feeding the FCC circulating oil A into the top of a moving bed reactor, and reacting under the pressure of 0.2MPa and H2The volume ratio of the circulating oil is 500, the circulating oil flows from top to bottom along with the hydrogen-containing fluidized medium and contacts with the descending catalyst in a concurrent flow manner, and the hydrocracking dealkylation reaction is carried out under the conditions that the reaction temperature (based on the bottom of the reactor) is 540 ℃, the weight ratio of the catalyst to the raw oil is 4.2 and the reaction time is 10 seconds; separating the reaction oil gas by a separation system to obtain a gas product and dealkylated aromatic oil, desulfurizing and extracting aromatic hydrocarbon after nitrogen removal to obtain high-value aromatic hydrocarbon such as benzene, toluene, xylene and naphthalene, and refining 100% of the aromatic hydrocarbon raffinate oil; after the reacted catalyst to be regenerated is stripped by nitrogen gas to remove oil gas adsorbed in the catalyst to be regenerated, the catalyst to be regenerated is sent to a regenerator through a catalyst hopper system for dehydrogenation and depressurization, and air is used as regeneration gas to be in countercurrent contact with a catalyst to be regenerated at the regeneration temperature of 550-650 ℃ for regeneration; the regenerated regenerant is recycled. The operating conditions and the product distribution are listed in Table 3.
As can be seen from table 3, in example 4, the recycle FCC oil rich in monocyclic aromatic hydrocarbon is hydrodecatalytically cracked and dealkylated in the moving bed reactor, the yield of the dealkylated base oil is 81.82 wt%, the yield of BTX is 28.23 wt%, the yield of naphthalene is 13.09 wt%, the yield of methylnaphthalene is 3.27 wt%, and the yield of trienes (low-carbon olefins ethylene + propylene + butylene) is 8.23 wt%; the yield of the slurry oil is 0.11 weight percent, and the yield of the coke is 3.42 weight percent; the total yield of high value aromatics (BTXN) such as benzene, toluene, xylene and naphthalene was 44.59 wt%.
Comparative example 4
Catalytic cracking was performed by the same method as in example 4, except that in comparative example 4: non-hydrocatalytic cracking, wherein fluidizing medium is water vapor and nitrogen without hydrogen; the catalyst and the process conditions are the same as those in the example 4, under the reaction pressure of 0.2MPa, the FCC circulating oil A flows from top to bottom along with the non-hydrogen-containing fluidized medium and contacts with the downstream catalyst in concurrent flow, the non-hydrocatalytic cracking dealkylation reaction is carried out under the conditions that the reaction temperature is 520 ℃, the weight ratio of the catalyst to the raw oil is 4.2 and the reaction time is 10 seconds, and the weight ratio of the steam to the total raw material is 5 percent; separating the reaction oil gas by a separation system to obtain a gas product and dealkylated aromatic oil, desulfurizing and extracting aromatic hydrocarbon after nitrogen removal to obtain high-value aromatic hydrocarbon such as benzene, toluene, xylene and naphthalene, and refining 100% of the aromatic hydrocarbon raffinate oil; stripping the reacted spent catalyst with nitrogen to remove oil gas adsorbed in the spent catalyst, directly sending the spent catalyst into a regenerator, and using air as a regeneration gas to contact the spent catalyst at the regeneration temperature of 550-680 ℃ for regeneration; the regenerated regenerant is recycled. The operating conditions and the product distribution are listed in Table 7.
As can be seen from table 7, compared with comparative example 4 (non-hydrocatalytic cracking), example 4 (hydrocatalytic cracking) has high yields of BTX, naphthalene and low carbon olefins, low recycle ratio of aromatic raffinate oil, and low yields of slurry oil and coke, and the yields of BTX, naphthalene and low carbon olefins are respectively increased by 11.69, 10.61 and 0.41 percentage points, and the yields of slurry oil and coke are respectively decreased by 0.17 and 1.13 percentage points.
Example 5
This example was tested according to the apparatus and procedure of fig. 2 (apparatus as in example 4) using FCC cycle oil B in table 1 as feed on a moving bed reactor using CAT-2 catalyst with catalyst MAT 66. Preheating FCC circulating oil B at 260 ℃, then feeding the FCC circulating oil B into the top of the moving bed reactor, and enabling the FCC circulating oil B to be in concurrent contact with a descending catalyst, wherein H is the reaction pressure of 6.0MPa2The volume ratio of the circulating oil is 1000, the hydrogen-containing fluidized medium flows from top to bottom, and the hydrocracking dealkylation reaction is carried out under the conditions of the reaction temperature (based on the bottom of the reactor) of 640 ℃, the weight ratio of the catalyst to the raw oil of 6.4 and the reaction time of 5 seconds; separating the reaction oil gas by a separation system to obtain a gas product, dealkylated aromatic oil and oil slurry, desulfurizing the dealkylated aromatic oil, extracting aromatic hydrocarbon after nitrogen to obtain high-value aromatic hydrocarbon such as benzene, toluene, xylene and naphthalene, and refining 100% of the aromatic hydrocarbon raffinate oil; after the reacted spent catalyst is subjected to nitrogen stripping to remove oil gas adsorbed in the catalyst, the catalyst is dehydrogenated and depressurized by a catalyst hopper system and is sent to a regenerator, and air is used as regeneration gas to contact with a spent agent at the regeneration temperature of 600-680 ℃ for regeneration; the regenerated regenerant is recycled. Operation stripThe piece and product distributions are listed in table 8.
As can be seen from table 8, in example 5, the FCC cycle oil rich in bicyclic aromatic hydrocarbons is hydrodecatalytically cracked and dealkylated in the moving bed reactor, the yield of dealkylated base oil is 71.94 wt%, the yield of BTX is 8.06 wt%, the yield of naphthalene is 42.44 wt%, the yield of methylnaphthalene is 11.87 wt%, and the yield of trienes (low-carbon olefins ethylene + propylene + butylene) is 11.52 wt%; the yield of the slurry oil is 1.86 percent by weight, and the yield of the coke is 6.44 percent by weight; the total yield of high value aromatics (BTXN) such as benzene, toluene, xylene and naphthalene was 62.37 wt%.
Comparative example 5
Catalytic cracking was performed by the same method as in example 5, except that in comparative example 5: the hydrocracking is carried out, the reaction system does not contain a catalyst, the catalyst regeneration operation is not needed, and the reaction temperature is maintained by adopting external heating, namely electric heating; the fluidized media are hydrogen containing gas and catalytic cracking dry gas, the process conditions are the same as example 5, and the reaction pressure is 6.0MPa, H2The volume ratio of the circulating oil is 1000, FCC circulating oil B enters the top of the moving bed reactor after being preheated at 260 ℃ and then flows from top to bottom along with a hydrogen-containing fluidized medium, and the hydrocracking dealkylation reaction is carried out under the conditions that the reaction temperature is 640 ℃, the weight ratio of the catalyst to the raw oil is 6.4 and the reaction time is 5 seconds; and (3) separating the reaction oil gas by a separation system to obtain a gas product, dealkylated aromatic oil and slurry oil, desulfurizing the dealkylated aromatic oil, extracting aromatic hydrocarbon after nitrogen to obtain high-value aromatic hydrocarbon such as benzene, toluene, xylene and naphthalene, and refining the raffinate oil of the aromatic hydrocarbon by 100%. The operating conditions and the product distribution are listed in Table 8.
As can be seen from table 8, compared with the comparative example 5 (hydrocracked), the BTX, naphthalene and low carbon olefins yield of example 5 (hydrocracked) is high, the aromatics raffinate oil recycle ratio is low, the slurry oil and coke yield is low, the BTX, naphthalene and low carbon olefins yield is respectively increased by 3.84, 8.23 and 3.99 percentage points, and the slurry oil and coke yield is respectively decreased by 0.71 and 3.81 percentage points.
Example 6
This example was tested according to the apparatus and procedure of FIG. 2 (apparatus as in example 4) using 30 wt% FCC cycle oil A and 70 wt% in Table 1Hydrogenated FCC cycle oil C was used as feedstock and tested in a moving bed reactor using CAT-2 catalyst with MAT 66. Preheating FCC circulating oil A at 160 ℃, then feeding the FCC circulating oil A into the top of a moving bed reactor, feeding hydrogenated FCC circulating oil C at the upstream of the FCC circulating oil A, firstly contacting with a high-temperature regenerant, and carrying out a reaction by the FCC circulating oil A and the hydrogenated FCC circulating oil C in concurrent contact with a catalyst under the reaction pressure of 1.8MPa and H2The volume ratio of the circulating oil is 800, the hydrogen-containing fluidized medium flows from top to bottom, and the hydrocracking dealkylation reaction is carried out under the conditions of the reaction temperature (based on the bottom of the reactor) of 560 ℃, the weight ratio of the catalyst to the mixed raw oil of 5.3 and the reaction time of 3.5 seconds; separating the reaction oil gas by a separation system to obtain a gas product and dealkylated aromatic oil, desulfurizing and extracting aromatic hydrocarbon after nitrogen removal to obtain high-value aromatic hydrocarbon such as benzene, toluene, xylene and naphthalene, and refining 100% of the aromatic hydrocarbon raffinate oil; after the reacted catalyst to be regenerated is stripped by nitrogen gas to remove oil gas adsorbed in the catalyst to be regenerated, the catalyst to be regenerated is sent to a regenerator through a catalyst hopper system for dehydrogenation and depressurization, and air is used as regeneration gas to be contacted with a catalyst to be regenerated for regeneration at the regeneration temperature of 550-650 ℃; the regenerated regenerant is recycled. The operating conditions and product distribution are listed in Table 9.
As can be seen from table 9, in example 6, the yield of the dealkylated base oil is 77.85 wt%, the yield of BTX is 30.83 wt%, the yield of naphthalene is 7.44 wt%, the yield of methylnaphthalene is 3.39 wt%, and the yield of trienes (low-carbon olefin ethylene + propylene + butylene) is 8.96 wt% when the monocyclic aromatic hydrocarbon-rich FCC cycle oil and the hydrogenated FCC cycle oil are subjected to hydrocatalytic cracking dealkylation in the moving bed reactor; the yield of the oil slurry is 0.56 weight percent, and the yield of the coke is 4.23 weight percent; the overall yield of high value aromatics (BTXN) such as benzene, toluene, xylene and naphthalene was 41.66 wt%.
Comparative example 6
Catalytic cracking was carried out by the same method as in example 6, except that in comparative example 6: non-hydrocatalytic cracking, wherein fluidizing medium is water vapor and nitrogen without hydrogen; the catalyst and the process conditions are the same as those in the example 6, the hydrogenated FCC cycle oil C is fed at the upstream of the FCC cycle oil A under the reaction pressure of 1.8MPa, the hydrogenated FCC cycle oil C and the catalyst firstly contact with a high-temperature regenerant, the FCC cycle oil A and the hydrogenated FCC cycle oil C perform downstream reaction with the catalyst, the non-hydrogenation catalytic cracking dealkylation reaction is performed under the conditions of the reaction temperature of 560 ℃, the weight ratio of the catalyst to the mixed raw oil of 5.3 and the reaction time of 3.5 seconds, and the weight ratio of the steam to the total raw material is 0.5; separating the reaction oil gas by a separation system to obtain a gas product and dealkylated aromatic oil, desulfurizing and extracting aromatic hydrocarbon after nitrogen removal to obtain high-value aromatic hydrocarbon such as benzene, toluene, xylene and naphthalene, and refining 100% of the aromatic hydrocarbon raffinate oil; stripping the reacted spent catalyst with nitrogen to remove oil gas adsorbed in the spent catalyst, directly sending the spent catalyst into a regenerator, and using air as a regeneration gas to contact the spent catalyst at the regeneration temperature of 550-650 ℃ for regeneration; the regenerated regenerant is recycled. The operating conditions and product distribution are listed in Table 9.
As can be seen from table 9, compared with comparative example 6 (non-hydrocracked), example 6 (hydrocracked) has high yields of BTX, naphthalene and lower olefins, low recycle ratio of the aromatic raffinate oil, and low yields of slurry oil and coke, the yields of BTX, naphthalene and lower olefins are respectively increased by 8.92, 4.64 and 1.86%, and the yields of slurry oil and coke are respectively decreased by 0.28 and 1.55%.
TABLE 6
Catalyst numbering
CAT-2
Catalyst type
Metal modified large and medium pore zeolites
Chemical composition, weight%
Chromium oxide
7.4
Alumina oxide
43.6
Sodium oxide
0.14
Rare earth element
1.2
Shape of
Spherical shape
Particle size range, mm
2-4
Apparent density in kg/m3
718
Pore volume, ml/g
0.35
Specific surface area, rice2Per gram
-174
Lateral pressure strength, N/cm2
>120
TABLE 7
Example 4
Comparative example 4
Raw oil
A
A
Reaction mode
Hydrocatalytic cracking
Non-hydrocatalytic cracking
Name of catalyst
CAT-2
CAT-2
Catalyst Activity (MAT)
66
66
Recycle ratio of aromatic raffinate oil
0.04
0.08
Reaction operating conditions
Reaction pressure, MPa
0.2
0.2
Partial pressure of hydrogen, MPa
0.1
-
Reactor inlet temperature,. deg.C
620
620
Middle temperature of the reactor, deg.C
575
575
Reactor outlet temperature,. deg.C
540
540
Catalyst/feed oil weight ratio
4.2
4.2
Oil gas residence time, s
10.0
10.0
H2Volume ratio of circulating oil
500
-
Water vapor/total raw material weight ratio%
-
2.0
Product yield, weight%
Cracked gas
14.65
12.46
Wherein the triene
8.23
6.45
Gaseous alkane
6.42
6.01
Dealkylated base oil
81.82
82.71
Wherein BTX
28.23
16.54
Naphthalene
13.09
2.48
Methylnaphthalene
3.27
9.93
Oil slurry
0.11
0.28
Coke
3.42
4.55
Total up to
100.00
100.00
BTXN yield
44.59
28.95
TABLE 8
TABLE 9
It should be noted by those skilled in the art that the described embodiments of the present invention are merely exemplary and that various other substitutions, alterations, and modifications may be made within the scope of the present invention. Accordingly, the present invention is not limited to the above-described embodiments, but is only limited by the claims.