Start-up method of hydrocracking unit

Abstract

The present invention relates to the technical field of catalyst start-up, and discloses a start-up method of a hydrocracking unit, the method comprising: (1) loading a hydrocracking catalyst in a reaction bed of a hydrocracking unit; (2) introducing hydrogen into a reaction bed loaded with the hydrocracking catalyst, heating the reaction bed temperature to 100-140°C, then introducing a diesel fraction and optionally a vegetable oil to wet the reaction bed, and establishing a closed loop; (3) continuing to heat the reaction bed temperature described in step (2) to 300-350°C, then switching the feedstock oil, continuing to heat up to the hydrocracking reaction temperature, and the hydrocracking catalyst is an ammonia passivated sulfurized state hydrocracking catalyst. The method has the advantages of simple start-up process, safe, stable and environmentally friendly start-up process, and effectively avoiding the potential risks of injecting a vulcanizing agent and a passivating agent.

Description

Technical Field

[0001] The invention relates to the technical field of device startup, and in particular to a startup method for a hydrocracking device. Background Art

[0002] With the development of the global aviation industry and the increasing demand for clean fuels, the demand for clean aviation kerosene is showing an increasing trend. At present, the sources of clean aviation kerosene are, on the one hand, straight-run aviation kerosene hydrotreated to obtain aviation kerosene with indicators and performance that meet the requirements of jet fuel standards, and on the other hand, heavy oil products are hydrocracking to break the chain of macromolecular raw materials to obtain a certain proportion of aviation kerosene that meets the requirements. Since straight-run aviation kerosene is affected by the processing volume of crude oil, it is difficult to achieve rapid growth in the processing volume of straight-run aviation kerosene raw materials. Heavy oil hydrocracking to produce aviation kerosene has become an important method to meet the growing demand of the aviation kerosene market.

[0003] The active metal components of the hydrocracking catalyst will have a high catalytic activity only when they are converted into a sulfided state. Therefore, it is very important to sulfidize the catalyst to give full play to the performance of the catalyst. At present, the sulfidation of hydrogenation catalysts is divided into three forms: in-situ sulfidation, in-situ activation with sulfur-carrying outside the vessel, and ex-situ sulfidation. Among them, in-situ sulfidation is the sulfidation process of the catalyst in the reactor, which requires the use of a large amount of sulfidizing agent and carrier oil. At the same time, the waste gas and wastewater generated in the sulfidation process will pollute the environment; in-situ activation with sulfur-carrying outside the vessel is to complete the loading of sulfur-containing substances on the catalyst outside the vessel, and the active metal fails to be converted into a sulfided state. After being loaded into the reactor, it is activated with hydrogen. During this period, a high concentration of hydrogen sulfide gas will be generated. At the same time, when the circulating gas is emptied, it is still necessary to add sulfidizing agent to maintain a certain hydrogen sulfide concentration. The operation process is relatively complicated and there is a risk of hydrogen sulfide leakage. Ex-situ sulfidation is a process in which the catalyst is sulfided outside the reactor to generate highly active metal sulfides, which can be directly added to the reactor and started after oil is added. This is the sulfidation method that is currently more advocated and promoted. The use of ex-situ sulfidation can effectively save start-up time, while ensuring the safety of the start-up process, reducing the use of hazardous chemicals and the leakage of high-concentration hydrogen sulfide.

[0004] After sulfurization, the hydrocracking catalyst containing molecular sieve has a high hydrocracking activity. During the heating process, the raw oil will undergo cracking reaction and hydrogenation reaction, releasing huge reaction heat, and there is a risk of "flying temperature" of the catalyst bed. Therefore, it is necessary to passivate the hydrocracking catalyst to suppress its excessive initial activity and ensure the safety of the catalyst, equipment and personnel. At present, injecting nitrogen-containing compounds such as anhydrous liquid ammonia at the start of operation is a passivation method that can effectively suppress the initial activity of the catalyst, but anhydrous liquid ammonia is an irritating toxic liquid with flammable and explosive properties. The industrial use of anhydrous liquid ammonia has certain dangers. If it leaks, it will cause great harm to the environment and the human body, which does not meet the concept of safety, health and environmental protection. Therefore, the molecular sieve passivation work of the hydrocracking catalyst is completed outside the device, and the molecular sieve with high cracking activity is protected by a certain alkaline substance, which can effectively reduce the steps in the start-up stage, avoid the risk of ammonia leakage, and reduce the risk of "flying temperature" in the start-up stage. Patent application CN101492613A discloses a method for starting a hydrocracking unit. During the start-up process, a sulfur-loaded hydrocracking catalyst that has been pre-sulfurized off-site is used, and anhydrous liquid ammonia is used for catalyst passivation. A large amount of hydrogen sulfide gas and acid-containing wastewater will be generated during the start-up process. During the activation process, there is a risk of overheating due to concentrated decomposition and exothermic release of sulfides. At the same time, the disadvantages of ammonia injection in the prior art mentioned above exist, which has certain hidden dangers and hazards.

[0005] Patent application CN109777472A discloses a method for hydrogenation start-up. In the catalyst passivation stage, the cracking agent is passivated by using a pre-loaded nitride as a passivating agent, thereby achieving the purpose of not using a passivating agent. However, during the start-up process, a sulfiding agent needs to be continuously injected to sulfide the catalyst, and a dedicated sulfiding equipment needs to be installed. In addition, there are problems such as incomplete sulfidation, hydrogen sulfide leakage, long start-up time and high cost during the sulfidation process.

[0006] Patent application CN103059969A discloses a method for passivating a cracking agent by using ammonia generated by the reaction of high-nitrogen raw materials and hydrogen as a passivating agent during the start-up process, thereby achieving the purpose of reducing the use of anhydrous liquid ammonia. Although it can temporarily inhibit the cracking activity, the operation is relatively complicated and the stability is poor. It is difficult to ensure the passivation effect of the molecular sieve. At the same time, the additional introduction of high-nitrogen raw oil is likely to introduce new impurities into the reaction system, affecting the activity of the catalyst.

[0007] Patent application CN103566963A discloses a method of introducing alkaline nitrides onto a catalyst at a low temperature stage, followed by in-situ sulfidation and activation. Although the cracking reaction can be controlled to a certain extent, the introduction of nitrides into the sulfided catalyst in the form of an aqueous solution will greatly affect the hydrogenation activity of the catalyst, resulting in the destruction of the active center of the catalyst.

[0008] Patent application CN105419865A discloses a method for producing jet fuel. By strictly controlling the composition of the raw materials, the saturation rate of dicyclic aromatics is 70-90%, and the saturation rate of monocyclic aromatics is 75-95%. The method proposes to use catalytic cracking diesel as the raw material, which has strict requirements on the raw materials, limiting the practicality of the method.

[0009] Patent application CN103013559A discloses a hydrocracking method for selectively increasing the production of jet fuel, which involves returning the heavy diesel fraction (320-370°C) to the crude oil, mixing it with the raw material and then continuing the subsequent hydrocracking reaction, which will lead to a decrease in the processing capacity of the device, while the average energy consumption and material consumption of the product will be further increased.

[0010] Patent application CN107460003A discloses a method for increasing the production of jet fuel by hydrocracking. The method mixes hydrocracking feedstock oil, cyclic hydrocarbon feedstock and optionally added nitrogen-containing compounds to obtain a mixed feedstock oil, and then performs hydrocracking. Although the yield of jet fuel can be increased to a certain extent, the configuration of the feedstock is relatively complex, the source of the feedstock needs to be accurately controlled, and the adaptability of the feedstock is relatively poor.

[0011] Different product distributions in the hydrocracking process have a huge impact on the results. Good catalyst selectivity helps to improve the yield of the target product and maximize the target product yield and benefits. It is of great significance to improve the catalyst selectivity through process adjustment and optimization during the start-up process. Summary of the invention

[0012] The purpose of the present invention is to overcome the problems of long sulfurization time, need for passivating agent and complicated start-up process in the start-up process of hydrocracking device in the prior art, and provide a start-up method of hydrocracking device, which has the advantages of short start-up time, no need to carry out sulfurization and passivation process on the catalyst in the reactor, can directly heat up and feed oil to start, and enter a stable production state in a short time. At the same time, the provided method can improve the activity of the catalyst, use wax oil as raw material, and has the characteristics of improving the yield of aviation kerosene.

[0013] In order to achieve the above object, the present invention provides a method for starting up a hydrocracking unit, wherein the method comprises:

[0014] (1) loading a hydrocracking catalyst into a reaction bed of a hydrocracking unit;

[0015] (2) introducing hydrogen into a reaction bed loaded with a hydrocracking catalyst, raising the temperature of the reaction bed to 100-140° C., and then introducing a diesel fraction and optionally a vegetable oil to wet the reaction bed to establish a closed loop;

[0016] (3) the temperature of the reaction bed in step (2) is further raised to 300-350° C., and then the feedstock oil is replaced step by step, and the temperature is further raised to the hydrocracking reaction temperature;

[0017] The hydrocracking catalyst is an ammonia-passivated sulfided hydrocracking catalyst.

[0018] Preferably, the nitrogen content in the diesel fraction is 0-900 ppm, preferably 0-500 ppm, and more preferably 10-300 ppm.

[0019] Preferably, the vegetable oil is selected from at least one of corn oil, soybean oil, peanut oil, rapeseed oil, coconut oil, sunflower oil, olive oil and cottonseed oil, and more preferably at least one of corn oil, soybean oil, peanut oil, rapeseed oil, coconut oil, sunflower oil and cottonseed oil.

[0020] Preferably, the distillation range of the vegetable oil is 180-540° C., and the bromine value is 10-25 gBr / 100 mL.

[0021] Preferably, compared to 100 parts by weight of the hydrocracking catalyst, the amount of the diesel fraction used is 100-2000 parts by weight, and the amount of the vegetable oil used is 0-300 parts by weight.

[0022] The method provided by the present invention has a short start-up time and a simple start-up process. The method can directly heat up and add oil to start the operation, and can enter a stable production state in a relatively short time. Compared with the conventional start-up process, the method saves 2-4 days of time, avoids the use of sulfiding agents and the leakage of hydrogen sulfide, reduces the risk of temperature runaway, saves a lot of manpower and material resources, and also avoids environmental pollution and the difficulty and danger of operation, reduces the investment in the start-up process, and has certain economic and practical value.

[0023] The inventors of the present invention have found in their research that by using the ammonia-passivated sulfided hydrocracking catalyst of the present invention in combination with a low-nitrogen diesel fraction and a suitable proportion of vegetable oil as the start-up oil, on the one hand, since the heating process will inevitably cause the alkaline nitrides to fall off and separate from the catalyst molecular sieve, resulting in the exposure of the acidic sites, the nitrides in the low-nitrogen diesel are used to supplement the passivation of the molecular sieve in the catalyst, thereby ensuring the smoothness of the start-up heating process and avoiding the occurrence of excessive cracking reactions. On the other hand, the unsaturated hydrocarbons in the vegetable oil have a higher polarity and will be preferentially adsorbed around the active sites of the catalyst. During the heating process, long-chain unsaturated hydrocarbons with a larger molecular weight condense to form carbon deposit precursors that exist around the active sites, effectively avoiding the disordered growth of the active phase and improving the activity and stability of the catalyst. At the same time, the carbon deposit precursor can modify the structure of the active phase of the catalyst, which is helpful to improve the selectivity of the cracking catalyst, effectively improve the yield of the target product when aviation kerosene is the target product, and maximize the overall benefit of the device. DETAILED DESCRIPTION

[0024] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0025] The present invention provides a method for starting up a hydrocracking unit, wherein the method comprises:

[0026] (1) loading a hydrocracking catalyst into a reaction bed of a hydrocracking unit;

[0027] (2) introducing hydrogen into a reaction bed loaded with a hydrocracking catalyst, raising the temperature of the reaction bed to 100-140° C., and then introducing a diesel fraction and optionally a vegetable oil to wet the reaction bed to establish a closed loop;

[0028] (3) the temperature of the reaction bed in step (2) is further raised to 300-350° C., and then the feedstock oil is replaced step by step, and the temperature is further raised to the hydrocracking reaction temperature;

[0029] The hydrocracking catalyst is an ammonia-passivated sulfided hydrocracking catalyst.

[0030] The inventors found in their research that the existing hydrocracking units often leak hydrogen sulfide or ammonia during start-up, and excessive cracking reactions occur during the heating process, causing the problem of reactor overheating. By starting up with an ammonia-passivated sulfided hydrocracking catalyst, the process of in-vessel sulfidation and in-vessel ammonia passivation can be effectively avoided, the use of sulfiding agents and ammonia can be reduced, and the safety and environmental protection of the start-up process of the unit can be ensured. At the same time, a low-nitrogen diesel fraction and a suitable proportion of vegetable oil are matched as the start-up oil, and the nitride in the low-nitrogen diesel is used to supplement the passivation of the molecular sieve in the catalyst, ensuring the smoothness of the start-up heating process. At the same time, the unsaturated hydrocarbons in the start-up oil have a higher polarity, and the formed carbon deposit precursors exist around the active sites, which improves the activity and stability of the catalyst. The carbon deposit precursors can also modify the active phase structure of the catalyst, which helps to improve the selectivity of the hydrocracking catalyst.

[0031] In the present invention, there is no particular limitation on the preparation method of the ammonia-passivated sulfided hydrogenation catalyst. For example, a method conventionally defined in the art may be used, such as sulfurizing the oxidized hydrocracking catalyst by introducing a sulfiding agent into a hydrocracking unit, and passivating the catalyst by introducing a passivating agent. The specific method will not be described in detail. Other methods may also be selected for preparation, as described below.

[0032] In a preferred embodiment, in step (1), the preparation method of the ammonia-passivated sulfurized hydrocracking catalyst comprises: first subjecting the oxidized hydrocracking catalyst to a sulfurization treatment outside the hydrocracking unit and then to a passivation treatment. The advantages of adopting this preferred embodiment are that the hydrogenation activity of the catalyst is ensured while the safety of the cracking is ensured, and the sulfurization and ammonia passivation process is avoided after the catalyst is loaded into the reactor, which can effectively save time and ensure the convenience and safety of the start-up.

[0033] In the present invention, there is no particular limitation on the method of the vulcanization treatment, and the methods conventionally defined in the art are applicable to the present invention. Preferably, in step (1), the vulcanization treatment is wet vulcanization or dry vulcanization.

[0034] In a preferred embodiment, the sulfidation treatment comprises: sulfiding the oxidized hydrocracking catalyst in the presence of a sulfiding agent and hydrogen to obtain a sulfided hydrocracking catalyst.

[0035] In the present invention, there is no particular limitation on the type of oxidative hydrocracking catalyst, and it may be, for example, an oxidative hydrocracking catalyst conventionally defined in the art, or an oxidative hydrocracking catalyst containing a molecular sieve (eg, a hydrogenation modification catalyst).

[0036] In a preferred embodiment, the oxidized hydrocracking catalyst comprises a cracking component, a hydrogenation component and a carrier.

[0037] In a preferred embodiment, the cracking component comprises an amorphous acidic component and / or a molecular sieve.

[0038] In a preferred embodiment, the amorphous acidic component includes amorphous silicon aluminum and / or amorphous silicon magnesium.

[0039] In a preferred embodiment, the molecular sieve is at least one selected from Y-type molecular sieve, ZSM-5 molecular sieve, SAPO molecular sieve and MCM-41 mesoporous molecular sieve.

[0040] In a preferred embodiment, the hydrogenation component includes at least one of a Group VIII metal and a Group VIB metal.

[0041] In a preferred embodiment, the Group VIII metal is Co and / or Ni, and the Group VIB metal is Mo and / or W.

[0042] In a preferred embodiment, the carrier comprises a refractory porous material, for example, the refractory porous material is selected from at least one of aluminum oxide, silicon oxide, titanium oxide, magnesium oxide, zirconium oxide and activated carbon.

[0043] In a preferred embodiment, based on the weight of the oxidized hydrocracking catalyst, the content of the cracking component is 10-60% by weight, the content of the carrier is 30-70% by weight, the content of the Group VIII metal calculated as oxide is 1-15% by weight, and the content of the Group VIB metal calculated as oxide is 5-30% by weight; further preferably, based on the weight of the oxidized hydrocracking catalyst, the content of the cracking component is 13-50% by weight, the content of the carrier is 35-65% by weight, the content of the Group VIII metal calculated as oxide is 3-12% by weight, and the content of the Group VIB metal calculated as oxide is 8-28% by weight.

[0044] In the present invention, there is no specific limitation on the vulcanization method, and all vulcanization methods conventionally defined in the art are applicable to the present invention, such as wet vulcanization and dry vulcanization.

[0045] In the present invention, the type of the vulcanizing agent in the wet vulcanization can be selected from a wide range. Preferably, the vulcanizing agent in the wet vulcanization is selected from at least one of carbon disulfide, dimethyl disulfide and polysulfide.

[0046] In the present invention, the range of selection of the type of vulcanizing agent in the dry vulcanization is relatively wide. Preferably, the vulcanizing agent in the dry vulcanization is selected from at least one of sulfuric acid-containing gases, preferably hydrogen sulfide.

[0047] In the present invention, there is no particular limitation on the treatment conditions of dry vulcanization. Preferably, the conditions of dry vulcanization treatment include: a heating rate of 5-100°C / h, a maximum vulcanization temperature of 240-400°C, a constant temperature time of 1-15h, a vulcanization pressure of 0.1-10MPa, and an aerosol volume ratio of 50-1000:1; further preferably, the conditions of dry vulcanization treatment include: a heating rate of 10-80°C / h, a maximum vulcanization temperature of 260-380°C, a constant temperature time of 2-12h, a vulcanization pressure of 0.3-8MPa, and an aerosol volume ratio of 100-800:1.

[0048] In the present invention, there is no particular limitation on the treatment conditions of wet vulcanization. Preferably, the conditions of wet vulcanization treatment include: a heating rate of 5-100°C / h, a maximum vulcanization temperature of 240-400°C, a constant temperature time of 1-15h, a vulcanization pressure of 0.1-10MPa, and a volume space velocity of 0.3-8h. -1 , the volume ratio of hydrogen to oil is 100-1000:1; further preferably, the conditions of the wet vulcanization treatment include: a heating rate of 10-80°C / h, a maximum vulcanization temperature of 260-380°C, a constant temperature time of 2-12h, a vulcanization pressure of 0.3-8MPa, and a volume space velocity of 0.5-6h -1 , the volume ratio of hydrogen to oil is 150-800:1.

[0049] In the present invention, preferably, a dry sulfurization treatment oxidized hydrocracking catalyst is selected, and the specific conditions are as described above.

[0050] In the present invention, there is no particular limitation on the passivation treatment method. Preferably, in step (1), the passivation treatment comprises: in the presence of an organic solvent, the organic nitrogen-containing compound and the organic sulfur-containing compound are loaded onto the sulfided hydrogenation catalyst by an impregnation method, and then the passivation treatment is performed to obtain an ammonia-passivated sulfided hydrocracking catalyst.

[0051] In the present invention, there is no particular limitation on the type of organic solvent. Preferably, the organic solvent is selected from at least one of hydrocarbon oil, hydrocarbon oil oxygen-containing derivatives and organic carboxylic acid esters.

[0052] In a preferred embodiment, the hydrocarbon oil and the oxygen-containing derivatives of hydrocarbon oil are each independently selected from at least one of alcohols, ethers and light fraction hydrocarbon oils, and more preferably at least one of ethanol, propanol, butanediol, ethyl ether, cyclohexane, n-heptane, n-decane, methylcyclopentane, naphtha, gasoline, kerosene, diesel, white oil, kerosene and lubricating oil base oil.

[0053] In a preferred embodiment, the organic carboxylic acid ester is a fatty acid glyceride, and more preferably at least one of corn oil, peanut oil, soybean oil, olive oil and cottonseed oil.

[0054] In the present invention, the range of carbon number of the organic solvent is relatively wide. Preferably, the carbon number of the organic solvent is 2-35, preferably 5-30, and more preferably 10-20.

[0055] The advantage of using the above-mentioned organic solvent is that it can dissolve most nitrogen-containing compounds and sulfur-containing compounds well. At the same time, it is composed of only carbon, hydrogen and oxygen elements, and does not contain other impurity elements. It can be well miscible with the start-up oil in the subsequent start-up.

[0056] In the present invention, there is no particular limitation on the type of organic nitrogen-containing compound, and those skilled in the art can select it according to actual needs. Preferably, the organic nitrogen-containing compound is selected from at least one of alkylamine compounds, arylamine compounds, aniline compounds, methylaniline compounds, amide compounds, alcoholamine compounds and polyamine compounds, more preferably alkylamine compounds and / or alcoholamine compounds, and more preferably alkylamine compounds and alcoholamine compounds, for example, it can be selected from at least one of ethylenediamine, propylamine, butylamine, pentylamine, hexylamine, triethylamine, tert-butylamine, N,N-dihydroxyethylaniline, acetanilide, ethanolamine, diethanolamine, triethanolamine, diisopropanolamine, N-(2-hydroxyethyl)ethylenediamine, N-methyldiethanolamine, N,N-diisopropylethanolamine, 1,2-cyclohexanediamine, 1,3-propylenediamine, triethylenediamine, N,N-dimethyldipropylenetriamine, triethylenetetramine and hexamethylenetetramine.

[0057] In the present invention, the carbon number of the organic nitrogen-containing compound can be selected in a wide range. Preferably, the carbon number of the organic nitrogen-containing compound is 1-20, preferably 2-15.

[0058] The advantage of using the above organic nitrogen-containing compounds is that the nitrogen-containing compounds exhibit weak alkalinity and can form good acid-base adsorption with the acidic sites on the molecular sieve to cover the acidic sites. At the same time, the appropriate carbon number ensures that they can be well dissolved in the solvent.

[0059] In the present invention, there is no particular limitation on the type of organic sulfur-containing compound. Preferably, the organic sulfur-containing compound is selected from at least one of thiol compounds, thiophenol compounds, sulfide compounds, thiourea compounds, sulfone compounds, sulfoxide compounds, sulfonic acid compounds, sulfinic acid compounds and disulfides, more preferably sulfide compounds and / or disulfides, and even more preferably sulfide compounds and disulfides, for example, it can be selected from at least one of carbon disulfide, dimethyl disulfide, dibutyl monosulfide, dibutyl disulfide, dibutyl trisulfide and dibutyl tetrasulfide and derivatives of the above compounds.

[0060] In the present invention, the carbon number of the organic sulfur-containing compound can be selected in a wide range. Preferably, the carbon number of the organic sulfur-containing compound is 1-15, preferably 1-10.

[0061] The advantage of using the above-mentioned organic sulfur-containing compounds is that the sulfur content is relatively high. During the start-up process, they can react with hydrogen at a certain temperature to decompose and form hydrogen sulfide to supplement the sulfurization of the catalyst. At the same time, they have good miscibility with the solvent to form a sulfur-containing organic solvent that is impregnated into the catalyst.

[0062] In a preferred embodiment, the organic nitrogen-containing compound, the organic sulfur-containing compound and the organic solvent are used in such an amount that the nitrogen content in the ammonia-passivated sulfided hydrocracking catalyst, calculated as an element, accounts for 0.1-5% of the weight of the sulfided hydrocracking catalyst before passivation, and the sulfur content, calculated as an element, accounts for 0.1-3% of the weight of the sulfided hydrocracking catalyst before passivation; further preferably, the nitrogen content, calculated as an element, accounts for 0.5-3% of the weight of the sulfided hydrocracking catalyst before passivation, and the sulfur content, calculated as an element, accounts for 0.3-2% of the weight of the sulfided hydrocracking catalyst before passivation.

[0063] In the present invention, a conventionally defined impregnation method may be selected, such as saturated impregnation, unsaturated impregnation or supersaturated impregnation. Preferably, the loading may be carried out in at least one of the following ways, such as impregnating the sulfided hydrogenation catalyst into a solution containing an organic nitrogen-containing compound and an organic sulfur-containing compound in the presence of an organic solvent; or spraying the solution containing an organic nitrogen-containing compound and an organic sulfur-containing compound onto the sulfided hydrogenation catalyst in the presence of an organic solvent.

[0064] In the present invention, there is no particular limitation on the conditions for loading the organic nitrogen-containing compound and the organic sulfur-containing compound by the impregnation method. Preferably, the loading temperature is 10-100°C, preferably 20-90°C.

[0065] In the present invention, the conditions for the passivation treatment are selected in a wide range. Preferably, the conditions for the passivation treatment include: temperature of 10-120°C, pressure of 0.01-0.5MPa, and time of 0.5-10h; further preferably, the conditions for the passivation treatment include: temperature of 10-100°C, pressure of 0.03-0.3MPa, and time of 1-8h; further preferably, the conditions for the passivation treatment include: temperature of 20-80°C, pressure of 0.05-0.15MPa, and time of 2-6h.

[0066] In the present invention, the pressure is absolute pressure.

[0067] In a preferred embodiment, the passivation treatment is performed under a passivation atmosphere.

[0068] In the present invention, the passivation atmosphere has a wide range of choices, and can be a passivation atmosphere conventionally defined in the art. Preferably, the passivation atmosphere is selected from at least one of an inert gas, an oxygen atmosphere, and air.

[0069] In a preferred embodiment, the inert atmosphere is selected from at least one of nitrogen, helium and argon.

[0070] In a preferred embodiment, the passivation treatment is performed in a stationary treatment device.

[0071] In a preferred embodiment, the passivation treatment is carried out in a non-flowing atmosphere, a naturally flowing atmosphere or a forced flowing atmosphere.

[0072] In the present invention, the temperature of the reaction bed is increased by introducing hydrogen into the reaction bed as a heating medium. Preferably, in step (2), the temperature of the hydrogen is 150-230°C, more preferably 150-200°C.

[0073] In the present invention, there is no particular limitation on the heating rate of the reaction bed, as long as the desired temperature is reached. Preferably, in step (2), the heating rate of the reaction bed by introducing hydrogen is 5-20°C / h, preferably 5-15°C / h.

[0074] In a preferred embodiment, in step (2), hydrogen is introduced to raise the temperature of the reaction bed to 110-140° C. The advantage of adopting this preferred embodiment is that part of the liquid water contained in the catalyst, reactor and pipeline is removed to avoid the formation of water vapor after the subsequent temperature rise to damage the catalyst structure.

[0075] In the present invention, a diesel fraction is introduced into step (2) as a start-up oil for start-up treatment to meet the start-up requirements. Preferably, in step (2), the diesel fraction is selected from at least one of straight-run diesel, catalytic cracking diesel, coker diesel and hydrocracked diesel, preferably straight-run diesel and / or hydrocracked diesel.

[0076] In a preferred embodiment, the distillation range of the diesel fraction is 180-380°C, preferably 180-360°C.

[0077] In a preferred embodiment, the nitrogen content in the diesel fraction is 0-900 ppm, preferably 0-500 ppm, and more preferably 10-300 ppm.

[0078] In the present invention, by selecting the diesel fraction of the above type and parameters as the start-up oil, it has the advantages of dissolving the solvent oil on the catalyst and providing a certain amount of nitride to supplement the passivation of the molecular sieve acid sites on the catalyst.

[0079] In the present invention, there is no particular limitation on the type of the vegetable oil, which can be any vegetable oil conventionally defined in the art. Preferably, the vegetable oil is selected from at least one of corn oil, soybean oil, peanut oil, rapeseed oil, coconut oil, sunflower oil, olive oil and cottonseed oil, preferably at least one of corn oil, soybean oil, peanut oil, rapeseed oil, coconut oil, sunflower oil and cottonseed oil.

[0080] In a preferred embodiment, the distillation range of the vegetable oil is 200-540°C, and the bromine value is 10-25 gBr / 100 mL; preferably, the distillation range of the vegetable oil is 210-530°C, and the bromine value is 12-20 gBr / 100 mL. The advantage of adopting this preferred embodiment is that it can effectively ensure the subsequent improvement of catalyst activity and stability under the action of vegetable oil, and utilize the modification effect of carbon deposit precursors to help improve the selectivity of hydrocracking catalysts.

[0081] In the present invention, there is no particular limitation on the amount of diesel fraction and vegetable oil. Preferably, compared with 100 parts by weight of the hydrocracking catalyst, the amount of the diesel fraction is 100-2000 parts by weight, and the amount of the vegetable oil is 0-300 parts by weight; further preferably, compared with 100 parts by weight of the hydrocracking catalyst, the amount of the diesel fraction is 200-1500 parts by weight, and the amount of the vegetable oil is 10-250 parts by weight.

[0082] In the present invention, by selecting low-nitrogen diesel fractions and / or vegetable oil as the start-up oil, the advantages of supplementing the passivation effect and improving the activity and stability of the catalyst are achieved. At the same time, the use of the start-up oil can effectively improve the selectivity of the catalyst and the yield of the target product. In the prior art, straight-run diesel is usually selected as the start-up oil, which has the defects of not being able to supplement the passivation, easily causing temperature runaway, and being unable to modify the active phase structure of the catalyst.

[0083] In the present invention, there is no particular limitation on the closed-loop circulation conditions. Preferably, in step (2), the closed-loop circulation conditions include: a pressure of 8-17 MPa, a hydrogen-to-oil volume ratio of 300:1-1000:1, and a volume space velocity of 0.5-3 h -1 Further preferably, the pressure is 8-15 MPa, the hydrogen-oil volume ratio is 500:1-1000:1, and the volume space velocity is 0.5-2h -1 The advantage of adopting this preferred embodiment is that the organic solvent loaded on the ammonia-passivated sulfided catalyst can be better dissolved or decomposed, and at the same time, it is beneficial for the nitride in the start-up oil to combine with the acidic sites on the molecular sieve, playing a role in supplementing passivation and ensuring that the unsaturated hydrocarbons form a certain degree of condensation around the active sites.

[0084] In a preferred embodiment, in step (3), the temperature of the reaction bed in step (2) is further increased to 310-350° C. The advantage of adopting this preferred embodiment is to reduce the over-cracking of the start-up oil at the high temperature stage and the over-condensation of unsaturated hydrocarbons that affect the activity.

[0085] In the present invention, there is no particular limitation on the heating rate in step (3). Preferably, in step (3), the heating rate of the reaction bed temperature is 10-35°C / h, preferably 10-30°C / h.

[0086] In the present invention, there is no particular limitation on the type of feedstock oil. Preferably, in step (3), the feedstock oil is selected from at least one of straight-run wax oil, straight-run diesel and catalytic diesel.

[0087] In a preferred embodiment, the density of the feedstock oil is 0.85-1.0 g.cm -3 , sulfur content 0.5-2wt%, nitrogen content 0.05-0.6wt%, distillation range 350-500℃.

[0088] In a preferred embodiment, in step (3), the conditions of the hydrocracking reaction include: reaction temperature of 300-380°C, pressure of 8-17 MPa, hydrogen-oil volume ratio of 300-1000, volume space velocity of 0.5-3h -1 .

[0089] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0090] The properties of the start-up oil and feed oil used in the following examples and comparative examples are shown in Table 1.

[0091] Table 1

[0092]

[0093] To illustrate the characteristics of the present invention, the embodiments and comparative examples are all based on commercially produced batches of commercially oxidized hydrocracking catalysts containing 3 wt% Ni oxide, 27 wt% W oxide, 35 wt% Y-type molecular sieve and the remainder being alumina. Dry sulfidation is selected, and sulfidation is performed using a combination of hydrogen sulfide and hydrogen. The sulfidation treatment is performed outside the hydrocracking unit. The sulfidation treatment conditions are: H 2 The volume fraction of S is 3%, and the volume fraction of H 2The volume fraction is 97%, the heating rate is 20℃ / h, the vulcanization temperature is 340℃, the constant temperature time is 8h, the vulcanization pressure is 4MPa, and the gas-agent volume ratio is 400:1, and a vulcanized hydrocracking catalyst is obtained. The embodiments and comparative examples both use wax oil as raw material to obtain the main product of aviation kerosene and other series of low-carbon products by hydrocracking.

[0094] Example 1

[0095] The hydrocracking unit was filled with hydrocracking catalyst. After the unit was gas-tight, the circulating hydrogen compressor was started. The bed of the hydrocracking unit was heated by hydrogen at a heating rate of 15°C / h, so that the bed temperature was controlled at 140°C. Start-up diesel A was introduced into the hydrocracking unit to wet and flush the bed. After the bed was fully wetted and flushed, the start-up diesel A and vegetable oil C were switched for closed-loop circulation. The weight ratio of diesel A to catalyst was 15, and the weight ratio of vegetable oil C to catalyst was 2.5. The bed was heated at a rate of 30°C / h. When the temperature reached 350°C, the feedstock oil was switched. At the same time, the reaction temperature was gradually increased by the heating furnace until the product was qualified. At this time, the temperature was 362°C, and the reaction was officially started. The operating conditions of the heating and reaction process were a pressure of 13MPa, a hydrogen-to-oil volume ratio of 800:1, and a volume space velocity of 1h. -1 , the product was subjected to simulated distillation. The specific test conditions were as follows: the sample was analyzed using the multidimensional gas chromatography SH / T 0558-2016 petroleum fraction boiling range distribution determination method, and the proportion of each fraction was determined according to the different distillation ranges. After the reaction was completed, the catalyst was characterized by unloading agent, and the active phase structure of the catalyst was characterized by HRTEM. The active phase refers to the microstructure with catalytic activity in the catalyst. The specific presentation form is Ni-WS, and the overall layered crystal structure is present. Through high-resolution transmission electron microscopy, it can be observed that the projection of the layered structure is a stripe phase of varying lengths. It is generally believed that the shorter the stripe phase, the higher the catalytic activity. The specific test conditions are as follows: the sample was characterized by a Tecnai G2 F20 S-TWIN high-resolution transmission electron microscope (HRTEM) produced by FEI Company, with an accelerating voltage of 200kV, and the WS in the sample was observed. 2 The size and stacking of the platelets. When preparing the sample, the ground sample was ultrasonically dispersed in a cyclohexane solution, and a small amount of the upper suspension was collected and dropped onto a carbon-coated copper mesh.

[0096] The hydrocracking catalyst is an ammonia-passivated sulfurized hydrocracking catalyst. The passivation treatment is carried out outside the hydrocracking reaction device. Tri-n-butylamine and dimethyl disulfide are added to diesel, stirred evenly at 90° C. to obtain a nitrogen- and sulfur-containing solution. The nitrogen- and sulfur-containing solution is introduced into the sulfurized hydrocracking catalyst in a saturated impregnation manner to load 3% by weight of nitrogen and 2% by weight of sulfur, wherein the nitrogen element comes from tri-n-butylamine and the sulfur element comes from dimethyl disulfide. Then, the catalyst is passivated at 100° C., 0.3 MPa, and in a flowing nitrogen atmosphere for 8 hours to prepare an ammonia-passivated sulfurized hydrocracking catalyst.

[0097] Example 2

[0098] The hydrocracking unit was filled with hydrocracking catalyst. After the unit was gas-tight, the circulating hydrogen compressor was started. The bed of the hydrocracking unit was heated by hydrogen at a heating rate of 10°C / h, so that the bed temperature was controlled at 125°C. Start-up diesel A was introduced into the hydrocracking unit to wet and flush the bed. After the bed was fully wetted and flushed, the start-up diesel A and vegetable oil C were switched for closed-loop circulation. The weight ratio of diesel A to catalyst was 10, and the weight ratio of vegetable oil C to catalyst was 1. The bed was heated at a rate of 15°C / h. When the temperature reached 335°C, the feedstock oil was switched. At the same time, the reaction temperature was gradually increased by the heating furnace until the product was qualified. At this time, the temperature was 361°C, and the reaction was officially started. The operating conditions of the heating and reaction process were a pressure of 13MPa, a hydrogen-to-oil volume ratio of 800:1, and a volume space velocity of 1h. -1 The product was subjected to simulated distillation according to the method of Example 1 to determine the proportion of each fraction. After the reaction was completed, the catalyst was subjected to catalyst unloading characterization and the active phase structure of the catalyst was subjected to HRTEM characterization analysis.

[0099] The hydrocracking catalyst is an ammonia-passivated sulfurized hydrocracking catalyst, and the passivation treatment is carried out outside the hydrocracking reaction device. Tri-n-butylamine and dimethyl disulfide are added to diesel, and stirred evenly at 50° C. to obtain a nitrogen- and sulfur-containing solution. The nitrogen- and sulfur-containing solution is introduced into the sulfurized hydrocracking catalyst in a saturated impregnation manner to load 2% by weight of nitrogen and 1% by weight of sulfur, wherein the nitrogen element comes from tri-n-butylamine and the sulfur element comes from dimethyl disulfide. Then, the catalyst is passivated for 4 hours at 40° C., 0.1 MPa, and a flowing nitrogen atmosphere to prepare an ammonia-passivated sulfurized hydrocracking catalyst.

[0100] Example 3

[0101] The hydrocracking unit was filled with hydrocracking catalyst. After the unit was qualified for airtightness, the circulating hydrogen compressor was started. The bed of the hydrocracking unit was heated by hydrogen at a heating rate of 5°C / h, so that the bed temperature was controlled at 110°C. Start-up diesel A was introduced into the hydrocracking unit to wet and flush the bed. After the bed was fully wetted and flushed, the start-up diesel A and vegetable oil C were switched for closed-loop circulation, wherein the weight ratio of diesel A to catalyst was 2, and the weight ratio of vegetable oil C to catalyst was 0.1. The bed was heated at a rate of 10°C / h. When the temperature reached 310°C, the feedstock oil was switched, and the reaction temperature was gradually increased by the heating furnace until the product was qualified. At this time, the temperature was 362°C, and the reaction was officially started. The operating conditions of the heating and reaction process were a pressure of 13MPa, a hydrogen-to-oil volume ratio of 800:1, and a volume space velocity of 1h. -1 The product was subjected to simulated distillation according to the method of Example 1 to determine the proportion of each fraction. After the reaction was completed, the catalyst was subjected to catalyst unloading characterization and the active phase structure of the catalyst was subjected to HRTEM characterization analysis.

[0102] The hydrocracking catalyst is an ammonia-passivated sulfurized hydrocracking catalyst, and the passivation treatment is carried out outside the hydrocracking reaction device. Tri-n-butylamine and dimethyl disulfide are added to diesel, and stirred evenly at 20° C. to obtain a nitrogen- and sulfur-containing solution. The nitrogen- and sulfur-containing solution is introduced into the sulfurized hydrocracking catalyst in a saturated impregnation manner to load 0.5% by weight of nitrogen and 0.3% by weight of sulfur, wherein the nitrogen element comes from the tri-n-butylamine and the sulfur element comes from the dimethyl disulfide. Then, the catalyst is passivated for 1 hour at 10° C. and 0.03 MPa in a flowing nitrogen atmosphere to prepare an ammonia-passivated sulfurized hydrocracking catalyst.

[0103] Example 4

[0104] The catalyst in Example 2 was filled into the hydrocracking unit. After the unit was airtight, the circulating hydrogen compressor was started. The bed of the hydrocracking unit was heated by hydrogen at a heating rate of 10°C / h, so that the bed temperature was controlled at 125°C. The start-up diesel B was introduced into the hydrocracking unit to wet and flush the bed. After the bed was fully wetted and flushed, the start-up diesel B and vegetable oil C were switched for closed-loop circulation, wherein the weight ratio of the diesel B used to the catalyst was 10, and the weight ratio of the vegetable oil C to the catalyst was 1. The bed was heated at a rate of 15°C / h. When the temperature reached 335°C, the feedstock oil was switched, and the reaction temperature was gradually increased by the heating furnace until the product was qualified. At this time, the temperature was 365°C, and the reaction was officially started. The operating conditions of the heating and reaction process were a pressure of 13MPa, a hydrogen-to-oil volume ratio of 800:1, and a volume space velocity of 1h -1The product was subjected to simulated distillation according to the method of Example 1 to determine the proportion of each fraction. After the reaction was completed, the catalyst was subjected to catalyst unloading characterization and the active phase structure of the catalyst was subjected to HRTEM characterization analysis.

[0105] Example 5

[0106] The catalyst in Example 2 was added to the hydrocracking unit. After the unit was airtight, the circulating hydrogen compressor was started. The bed of the hydrocracking unit was heated by hydrogen at a heating rate of 10°C / h, so that the bed temperature was controlled at 125°C. The start-up diesel A was introduced into the hydrocracking unit to wet and flush the bed. After the bed was fully wetted and flushed, the start-up diesel A and vegetable oil C were switched for closed-loop circulation, wherein the weight ratio of the diesel A to the catalyst was 1.5, and the weight ratio of the vegetable oil C to the catalyst was 0.08. The bed was heated at a rate of 15°C / h. When the temperature reached 335°C, the feedstock oil was switched, and the reaction temperature was gradually increased by the heating furnace until the product was qualified. At this time, the temperature was 366°C, and the reaction was officially started. The operating conditions of the heating and reaction process were a pressure of 13MPa, a hydrogen-to-oil volume ratio of 800:1, and a volume space velocity of 1h -1 The product was subjected to simulated distillation according to the method of Example 1 to determine the proportion of each fraction. After the reaction was completed, the catalyst was subjected to catalyst unloading characterization and the active phase structure of the catalyst was subjected to HRTEM characterization analysis.

[0107] Example 6

[0108] The catalyst in Example 2 was added to the hydrocracking unit. After the unit was airtight, the circulating hydrogen compressor was started. The bed of the hydrocracking unit was heated by hydrogen at a heating rate of 20°C / h, so that the bed temperature was controlled at 105°C. Start-up diesel A was introduced into the hydrocracking unit to wet and flush the bed. After the bed was fully wetted and flushed, the start-up diesel A and vegetable oil C were switched for closed-loop circulation, wherein the weight ratio of diesel A to the catalyst was 18, and the weight ratio of vegetable oil C to the catalyst was 0.05. The bed was heated at a rate of 35°C / h. When the temperature reached 300°C, the feedstock oil was switched, and the reaction temperature was gradually increased by the heating furnace until the product was qualified. At this time, the temperature was 365°C, and the reaction was officially started. The operating conditions of the heating and reaction process were a pressure of 13MPa, a hydrogen-to-oil volume ratio of 800:1, and a volume space velocity of 1h -1 The product was subjected to simulated distillation according to the method of Example 1 to determine the proportion of each fraction. After the reaction was completed, the catalyst was subjected to catalyst unloading characterization and the active phase structure of the catalyst was subjected to HRTEM characterization analysis.

[0109] Example 7

[0110] The catalyst in Example 2 was added to the hydrocracking unit. After the unit was airtight, the circulating hydrogen compressor was started. The bed of the hydrocracking unit was heated by hydrogen at a heating rate of 12°C / h, so that the bed temperature was controlled at 130°C. Start-up diesel A was introduced into the hydrocracking unit to wet and flush the bed. After the bed was fully wetted and flushed, the start-up diesel A and vegetable oil D were switched for closed-loop circulation, wherein the weight ratio of diesel A to the catalyst was 10, and the weight ratio of vegetable oil D to the catalyst was 1. The bed was heated at a rate of 20°C / h. When the temperature reached 340°C, the feedstock oil was switched, and the reaction temperature was gradually increased by the heating furnace until the product was qualified. At this time, the temperature was 366°C, and the reaction was officially started. The operating conditions of the heating and reaction process were a pressure of 13MPa, a hydrogen-to-oil volume ratio of 800:1, and a volume space velocity of 1h -1 The product was subjected to simulated distillation according to the method of Example 1 to determine the proportion of each fraction. After the reaction was completed, the catalyst was subjected to catalyst unloading characterization and the active phase structure of the catalyst was subjected to HRTEM characterization analysis.

[0111] Example 8

[0112] The catalyst in Example 2 was added to the hydrocracking unit. After the unit was airtight, the circulating hydrogen compressor was started. The bed of the hydrocracking unit was heated by hydrogen at a heating rate of 15°C / h, so that the bed temperature was controlled at 125°C. Diesel A was introduced into the hydrocracking unit to wet and flush the bed. After the bed was fully wetted and flushed, a closed-loop cycle was performed. The bed was heated at a rate of 20°C / h. When the temperature reached 330°C, the feedstock oil was switched. At the same time, the reaction temperature was gradually increased by the heating furnace until the product was qualified. At this time, the temperature was 369°C, and the reaction was officially started. The operating conditions of the heating and reaction process were a pressure of 13MPa, a hydrogen-to-oil volume ratio of 800:1, and a volume space velocity of 1h -1 The product was subjected to simulated distillation according to the method of Example 1 to determine the proportion of each fraction. After the reaction was completed, the catalyst was subjected to catalyst unloading characterization and the active phase structure of the catalyst was subjected to HRTEM characterization analysis.

[0113] Comparative Example 1

[0114] The catalyst in Example 2 was added to the hydrocracking unit. After the unit was gas-tight, the circulating hydrogen compressor was started. The bed of the hydrocracking unit was heated by hydrogen at a heating rate of 10°C / h, so that the bed temperature was controlled at 130°C. The raw oil was introduced into the hydrocracking unit to wet and flush the bed. After the bed was fully wetted and flushed, a closed-loop cycle was performed. The bed was heated at a rate of 20°C / h. When the temperature reached 320°C, the reaction temperature was gradually increased by a heating furnace until the product was qualified. At this time, the temperature was 375°C, and the reaction was officially started. The operating conditions of the heating and reaction process were a pressure of 13MPa, a hydrogen-to-oil volume ratio of 800:1, and a volume space velocity of 1h -1 The product was subjected to simulated distillation according to the method of Example 1 to determine the proportion of each fraction. After the reaction was completed, the catalyst was subjected to catalyst unloading characterization and the active phase structure of the catalyst was subjected to HRTEM characterization analysis.

[0115] Comparative Example 2

[0116] The catalyst in Example 2 was added to the hydrocracking unit. After the unit was airtight, the circulating hydrogen compressor was started. The bed of the hydrocracking unit was heated by hydrogen at a heating rate of 15°C / h, so that the bed temperature was controlled at 140°C. Vegetable oil C was introduced into the hydrocracking unit to wet and flush the bed. After the bed was fully wetted and flushed, a closed-loop cycle was performed. The bed was heated at a rate of 15°C / h. When the temperature reached 330°C, the feedstock oil was switched. At the same time, the reaction temperature was gradually increased by the heating furnace until the product was qualified. At this time, the temperature was 372°C, and the reaction was officially started. The operating conditions of the heating and reaction process were a pressure of 13MPa, a hydrogen-to-oil volume ratio of 800:1, and a volume space velocity of 1h -1 The product was subjected to simulated distillation according to the method of Example 1 to determine the proportion of each fraction. After the reaction was completed, the catalyst was subjected to catalyst unloading characterization and the active phase structure of the catalyst was subjected to HRTEM characterization analysis.

[0117] Comparative Example 3

[0118] The catalyst in Example 2 was added to the hydrocracking unit. After the unit was airtight, the circulating hydrogen compressor was started. The bed of the hydrocracking unit was heated by hydrogen at a heating rate of 35°C / h, so that the bed temperature was controlled at 150°C. Start-up diesel A was introduced into the hydrocracking unit to wet and flush the bed. After the bed was fully wetted and flushed, the start-up diesel A and vegetable oil C were switched for closed-loop circulation, wherein the weight ratio of diesel A to the catalyst was 0.8, and the weight ratio of vegetable oil C to the catalyst was 4. The bed was heated at a rate of 5°C / h. When the temperature reached 280°C, the feedstock oil was switched, and the reaction temperature was gradually increased by the heating furnace until the product was qualified. At this time, the temperature was 370°C, and the reaction was officially started. The operating conditions of the heating and reaction process were a pressure of 13MPa, a hydrogen-to-oil volume ratio of 800:1, and a volume space velocity of 1h -1 The product was subjected to simulated distillation according to the method of Example 1 to determine the proportion of each fraction. After the reaction was completed, the catalyst was subjected to catalyst unloading characterization and the active phase structure of the catalyst was subjected to HRTEM characterization analysis.

[0119] The effects of the above embodiments and comparative examples are listed in Tables 2-4 for comparison, wherein each fraction in the product is analyzed to achieve the corresponding product index (the 140-240°C fraction is aviation kerosene, which satisfies the mercaptan sulfur content of less than 0.002%, the smoke point of not less than 25.0 mm, and the freezing point of not higher than -47°C). Under the condition that the product index is qualified, the reaction temperature of the device is examined. The lower the reaction temperature, the higher the activity of the catalyst, as shown in Table 2; the higher the yield of aviation kerosene, the better the selectivity of the catalyst, as shown in Table 3; the shorter the length of the catalyst active phase, the higher the catalyst activity potential, as shown in Table 4.

[0120] The yield of aviation kerosene (%) = weight of aviation kerosene / total weight of product*100%.

[0121] The length of the stripe of the active phase of the catalyst is measured by high-resolution transmission electron microscopy. It is necessary to count the length of the stripe of the sample, take 20 photos, and count the length of the stripe phase on the photo. 2 The average length of the platelets Calculated according to the formula.

[0122] Average length of platelets (Unit: nm):

[0123]

[0124] Among them: i is the i-th WS 2 The length of the lamellar stripe phase; n is the total number of lamellar crystals in the statistical area.

[0125] Table 2

[0126]

[0127] Table 3

[0128]

[0129] Table 4

[0130]

[0131] It can be seen from the above embodiments and comparative examples that the greatest advantage of the start-up method is that it optimizes and improves some of the drawbacks existing in the current start-up method, avoids the safety and environmental risks brought by the sulfiding agent, avoids the risk of over-temperature caused by in-vessel activation, reduces the use and emission of toxic substances such as ammonia, reduces the waste of passivating agents, etc. At the same time, through the use of start-up oil and vegetable oil in appropriate proportions, due to the special properties of the start-up oil, certain carbon deposit precursors are formed on the catalyst surface, which slows down the growth of the catalyst active phase size, effectively improves the activity of the catalyst reaction and the selectivity of the target product, achieves qualified products at a lower temperature, and obtains a higher aviation kerosene yield, thereby increasing the added value of the product.

[0132] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for starting up a hydrocracking unit, characterized in that: The method includes: (1) Loading a hydrocracking catalyst into a reaction bed of a hydrocracking unit; (2) hydrogen is introduced into the reaction bed filled with hydrocracking catalyst, the temperature of the reaction bed is raised to 100-140°C, and then diesel fraction and vegetable oil are introduced to wet the reaction bed to establish a closed loop; (3) The temperature of the reaction bed in step (2) is further increased to 300-350°C, and then the feedstock oil is switched and the temperature is further increased to the hydrocracking reaction temperature; The hydrocracking catalyst is an ammonia-passivated sulfided hydrocracking catalyst; The nitrogen content in the diesel fraction is 10-300 ppm; Compared to 100 parts by weight of the hydrocracking catalyst, the amount of the diesel fraction is 200-1500 parts by weight, and the amount of the vegetable oil is 10-250 parts by weight; In step (3), the feedstock oil is selected from at least one of straight-run wax oil, straight-run diesel and catalytic diesel; The distillation range of the vegetable oil is 200-550° C., and the bromine value is 10-25 gBr / 100 mL.

2. The method according to claim 1, wherein: In step (1), the method for preparing the ammonia-passivated sulfided hydrocracking catalyst comprises: subjecting the oxidized hydrocracking catalyst to a sulfiding treatment and then a passivation treatment outside a hydrocracking unit.

3. The method according to claim 2, wherein: In step (1), the vulcanization treatment is wet vulcanization or dry vulcanization.

4. The method according to claim 3, wherein: The sulfidation treatment comprises: sulfiding the oxidized hydrocracking catalyst in the presence of a sulfiding agent and hydrogen to obtain a sulfided hydrocracking catalyst.

5. The method according to claim 4, wherein: The oxidized hydrocracking catalyst comprises a cracking component, a hydrogenation component and a carrier.

6. The method according to claim 5, wherein: The cracking component includes an amorphous acidic component and / or a molecular sieve, the amorphous acidic component includes amorphous silicon aluminum and / or amorphous silicon magnesium, and the molecular sieve is at least one selected from Y-type molecular sieve, ZSM-5 molecular sieve, SAPO molecular sieve and MCM-41 mesoporous molecular sieve.

7. The method according to claim 5, wherein: The hydrogenation component includes at least one of a Group VIII metal and a Group VIB metal.

8. The method according to claim 5, wherein: The carrier comprises a refractory porous substance, and the refractory porous substance is selected from at least one of aluminum oxide, silicon oxide, titanium oxide, magnesium oxide, zirconium oxide and activated carbon.

9. The method according to any one of claims 5 to 8, wherein: Based on the weight of the oxidized hydrocracking catalyst, the content of the cracking component is 10-60 wt%, the content of the carrier is 30-70 wt%, the content of the Group VIII metal calculated as oxide is 1-15 wt%, and the content of the Group VIB metal calculated as oxide is 5-30 wt%.

10. The method according to claim 9, wherein: Based on the weight of the oxidized hydrocracking catalyst, the content of the cracking component is 13-50 wt%, the content of the carrier is 35-65 wt%, the content of the Group VIII metal calculated as oxide is 3-12 wt%, and the content of the Group VIB metal calculated as oxide is 8-28 wt%.

11. The method according to claim 3, wherein: The vulcanizing agent in the wet vulcanization is selected from at least one of polysulfides.

12. The method according to claim 3, wherein: The vulcanizing agent in the wet vulcanization is selected from carbon disulfide and / or dimethyl disulfide.

13. The method according to claim 3, wherein: The vulcanizing agents in the dry vulcanization are hydrogen sulfide and hydrogen.

14. The method according to claim 3, wherein: The dry vulcanization treatment conditions include: a heating rate of 5-100°C / h, a maximum vulcanization temperature of 240-400°C, a constant temperature time of 1-15h, a vulcanization pressure of 0.1-10MPa, and an aerosol volume ratio of 50-1000:

1.

15. The method according to claim 14, wherein: The conditions of the dry vulcanization treatment include: a heating rate of 10-80°C / h, a maximum vulcanization temperature of 260-380°C, a constant temperature time of 2-12h, a vulcanization pressure of 0.3-8MPa, and an aerosol volume ratio of 100-800:

1.

16. The method according to claim 3, wherein: The conditions of the wet vulcanization treatment include: a heating rate of 5-100°C / h, a maximum vulcanization temperature of 240-400°C, a constant temperature time of 1-15h, a vulcanization pressure of 0.1-10MPa, and a volume space velocity of 0.3-8h -1 , the volume ratio of hydrogen to oil is 100-1000:

1.

17. The method according to claim 16, wherein: The conditions of the wet vulcanization treatment include: a heating rate of 10-80°C / h, a maximum vulcanization temperature of 260-380°C, a constant temperature time of 2-12h, a vulcanization pressure of 0.3-8MPa, and a volume space velocity of 0.5-6h -1 , the volume ratio of hydrogen to oil is 150-800:

1.

18. The method according to claim 2, wherein: In step (1), the passivation treatment comprises: in the presence of an organic solvent, loading the organic nitrogen-containing compound and the organic sulfur-containing compound onto the sulfided hydrogenation catalyst by an impregnation method, and then performing a passivation treatment to obtain an ammonia-passivated sulfided hydrocracking catalyst.

19. The method according to claim 18, wherein: The organic solvent is selected from hydrocarbon oils and / or hydrocarbon oil oxygenated derivatives.

20. The method according to claim 18, wherein: The organic solvent is an organic carboxylate.

21. The method according to claim 19, wherein: The hydrocarbon oil is at least one selected from light fraction hydrocarbon oils.

22. The method according to claim 20, wherein: The organic carboxylic acid ester is fatty acid glyceride.

23. The method according to any one of claims 18 to 22, wherein: The organic solvent has 2-35 carbon atoms.

24. The method according to claim 23, wherein: The organic solvent has 5-30 carbon atoms.

25. The method according to claim 24, wherein: The organic solvent has 10-20 carbon atoms.

26. The method of claim 18, wherein: The organic nitrogen-containing compound is selected from at least one of alkylamine compounds, arylamine compounds, amide compounds, alcoholamine compounds and polyamine compounds.

27. The method according to claim 18, wherein: The organic nitrogen-containing compound is an aniline compound and / or a methylaniline compound.

28. The method according to claim 26, wherein: The organic nitrogen-containing compound is an alkylamine compound and / or an alcoholamine compound.

29. The method of claim 18, wherein: The organic nitrogen-containing compound has 1-20 carbon atoms.

30. The method of claim 29, wherein: The organic nitrogen-containing compound has 2-15 carbon atoms.

31. The method of claim 18, wherein: The organic sulfur-containing compound is selected from at least one of thiol compounds, thiophenol compounds, thioether compounds, thiourea compounds, sulfone compounds, sulfoxide compounds, sulfonic acid compounds, sulfinic acid compounds and disulfide compounds.

32. The method according to claim 31, wherein: The organic sulfur-containing compound is a sulfide compound and / or a disulfide.

33. The method of claim 18, wherein: The organic sulfur-containing compound has 1-15 carbon atoms.

34. The method of claim 33, wherein: The organic sulfur-containing compound has 1-10 carbon atoms.

35. The method of claim 18, wherein: The amounts of the organic nitrogen-containing compound, the organic sulfur-containing compound and the organic solvent are such that the nitrogen content in the ammonia-passivated sulfided hydrocracking catalyst, calculated as an element, accounts for 0.1-5% of the weight of the sulfided hydrocracking catalyst before passivation, and the sulfur content, calculated as an element, accounts for 0.1-3% of the weight of the sulfided hydrocracking catalyst before passivation.

36. The method of claim 35, wherein: The amounts of the organic nitrogen-containing compound, the organic sulfur-containing compound and the organic solvent are such that the nitrogen content in the ammonia-passivated sulfided hydrocracking catalyst, calculated as an element, accounts for 0.5-3% of the weight of the sulfided hydrocracking catalyst before passivation, and the sulfur content, calculated as an element, accounts for 0.3-2% of the weight of the sulfided hydrocracking catalyst before passivation.

37. The method of claim 18, wherein: The load temperature is 10-100°C.

38. The method of claim 37, wherein: The load temperature is 20-90°C.

39. The method of claim 18, wherein: The conditions of the passivation treatment include: temperature of 10-120° C., pressure of 0.01-0.5 MPa, and time of 0.5-10 h.

40. The method of claim 39, wherein: The passivation treatment conditions include: temperature of 10-100° C., pressure of 0.03-0.3 MPa, and time of 1-8 h.

41. The method of claim 18, wherein: The passivation treatment is performed under a passivation atmosphere.

42. The method according to claim 41, wherein: The passivation atmosphere is selected from at least one of an inert gas and an oxygen atmosphere.

43. The method of claim 42, wherein: The inert gas is selected from at least one of nitrogen, helium and argon.

44. The method of claim 18, wherein: The passivation treatment is carried out in a stationary treatment device.

45. The method of claim 18, wherein: The passivation treatment is carried out in a stagnant atmosphere, a naturally flowing atmosphere or a forced flowing atmosphere.

46. ​​The method according to claim 1 or 2, wherein: In step (2), the temperature of the hydrogen is 150-230°C.

47. The method according to claim 1 or 2, wherein: In step (2), the temperature of the hydrogen is 150-200°C.

48. The method according to claim 1 or 2, wherein: In step (2), hydrogen is introduced to increase the temperature of the reaction bed at a rate of 5-20°C / h.

49. The method of claim 48, wherein: In step (2), hydrogen is introduced to increase the temperature of the reaction bed at a rate of 5-15°C / h.

50. The method according to claim 1 or 2, wherein: In step (2), hydrogen is introduced to raise the temperature of the reaction bed to 110-140°C.

51. The method according to claim 1 or 2, wherein: In step (2), the diesel fraction is selected from at least one of straight-run diesel, catalytic cracking diesel, coking diesel and hydrocracking diesel.

52. The method of claim 51, wherein: In step (2), the diesel fraction is straight-run diesel and / or hydrocracked diesel.

53. The method according to claim 1 or 2, wherein: The distillation range of the diesel fraction is 180-380°C.

54. The method of claim 53, wherein: The distillation range of the diesel fraction is 180-360°C.

55. The method according to claim 1 or 2, wherein: In step (2), the vegetable oil is selected from at least one of corn oil, soybean oil, peanut oil, rapeseed oil, coconut oil, sunflower oil, olive oil and cottonseed oil.

56. The method of claim 55, wherein: In step (2), the vegetable oil is selected from at least one of corn oil, soybean oil, peanut oil, rapeseed oil, coconut oil, sunflower seed oil and cottonseed oil.

57. The method according to claim 1 or 2, wherein: In step (2), the distillation range of the vegetable oil is 210-530° C., and the bromine value is 12-20 gBr / 100 mL.

58. The method according to claim 1 or 2, wherein: In step (2), the closed-loop circulation conditions include: pressure of 8-17 MPa, hydrogen-to-oil volume ratio of 300:1-1000:1, and volume space velocity of 0.5-3 h -1 .

59. The method of claim 58, wherein: In step (2), the closed-loop circulation conditions include: pressure of 8-15 MPa, hydrogen-to-oil volume ratio of 500:1-1000:1, and volume space velocity of 0.5-2 h -1 .

60. The method according to claim 1 or 2, wherein: In step (3), the temperature of the reaction bed in step (2) is further increased to 310-350°C.

61. The method of claim 60, wherein: In step (3), the heating rate of the reaction bed temperature is 10-35°C / h.

62. The method of claim 61, wherein: In step (3), the heating rate of the reaction bed temperature is 10-30°C / h.

63. The method according to claim 1 or 2, wherein: The density of the raw oil is 0.85-1g.cm -3 , sulfur content 0.5-2wt%, nitrogen content 0.05-0.6wt%, distillation range 350-500℃.

64. The method of claim 19, wherein: The oxygen-containing derivative of hydrocarbon oil is selected from at least one of alcohols and ethers.

65. The method of claim 41, wherein: The passivation atmosphere is air.

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