阅读说明：本技术 加氢裂化催化剂的开工方法及其应用 (Start-up method and application of hydrocracking catalyst ) 是由 郑均林 宋奇 姜向东 孔德金 于 2019-09-30 设计创作，主要内容包括：本发明涉及一种加氢裂化催化剂的开工方法及其应用。所述方法包括将所述加氢裂化催化剂进行氢气还原,以及还原之后与富含单环芳烃的烃类油接触进行钝化,具体包括步骤：a)在含氢气氛中的还原程序,还原终温介于350℃-550℃；b)采用单环芳烃含量大于90％的烃类油作为开工油,投料温度介于250-400℃。该方法用于加氢裂化催化剂的开工,解决开工过程催化剂活化、原料过度裂解、床层飞温风险高的问题,取得了较好的技术效果。(The invention relates to a startup method and application of a hydrocracking catalyst. The method comprises the steps of reducing the hydrocracking catalyst by hydrogen, and contacting the reduced hydrocracking catalyst with hydrocarbon oil rich in monocyclic aromatic hydrocarbon for passivation, and specifically comprises the following steps: a) reduction procedure in hydrogen-containing atmosphere, the final temperature of reduction is between 350 ℃ and 550 ℃; b) the hydrocarbon oil with the monocyclic aromatic hydrocarbon content of more than 90 percent is used as the start oil, and the feeding temperature is between 250 ℃ and 400 ℃. The method is used for startup of the hydrocracking catalyst, solves the problems of catalyst activation, excessive cracking of raw materials and high risk of bed temperature runaway in the startup process, and achieves better technical effects.)

1. A start-up method of a hydrocracking catalyst comprises the steps of carrying out hydrogen reduction on the hydrocracking catalyst, and then contacting the hydrocracking catalyst with hydrocarbon oil rich in monocyclic aromatic hydrocarbon.

2. The method of operating a building according to claim 1, comprising the steps of:

a) reducing the hydrocracking catalyst in hydrogen-containing atmosphere, wherein the final reduction temperature is 350-550 ℃, and preferably 380-480 ℃;

b) the hydrocarbon oil rich in monocyclic aromatic hydrocarbon is contacted with the reduced hydrocracking catalyst, and the feeding temperature is 250-400 ℃, preferably 300-400 ℃.

3. The start-up method according to claim 1, wherein in the reduction process of the step a:

the pressure is 0.5-10.0 MPa, preferably 1.0-8.0 MPa; and/or the presence of a gas in the gas,

keeping the temperature for 1 to 24 hours, preferably 2 to 18 hours at the final reduction temperature; and/or the presence of a gas in the gas,

heating to the final reduction temperature at a heating rate of 0.01-5 ℃/min, preferably 0.1-2 ℃/min.

4. The start-up process according to claim 1, wherein the reactor containing the hydrocracking catalyst and the circulating system thereof are replaced with an inert gas, preferably until the oxygen content is less than 0.1 wt%, more preferably less than 0.05 wt%; then replacing with hydrogen so that the reaction system is under hydrogen atmosphere, and the purity of the hydrogen is preferably more than 85%.

5. The start-up method according to claim 1, wherein in the step b:

the monocyclic aromatic hydrocarbon in the hydrocarbon oil comprises benzene, toluene, ethylbenzene, xylene, carbon nonaromatic hydrocarbon, carbon decaaromatic hydrocarbon or the mixture of the benzene, the toluene, the ethylbenzene, the xylene, the carbon nonaromatic hydrocarbon and the carbon decaaromatic hydrocarbon; and/or the presence of a gas in the gas,

the content of monocyclic aromatic hydrocarbon in the hydrocarbon oil is more than or equal to 90 wt%, preferably more than or equal to 95 wt%; and/or the presence of a gas in the gas,

the running time of the step b under the condition that the feeding temperature is stable is not less than 10 hours, and more preferably more than 24 hours; and/or the presence of a gas in the gas,

the pressure in the step b is controlled to be 1-10 MPa, and preferably 1-5 MPa; and/or the presence of a gas in the gas,

the volume ratio of the hydrogen to the oil in the step b is 1000-5000, and preferably 1500-; and/or the presence of a gas in the gas,

the airspeed of the step b is 0.5-4 h^-1Preferably 0.5 to 2 hours^-1。

6. The method of claim 1, wherein step b specifically comprises:

reducing the temperature of the catalyst bed layer after hydrogen reduction in the step a to 300-320 ℃, keeping the maximum hydrogen circulation amount allowed by a device, and enabling the hydrocarbon oil rich in the monocyclic aromatic hydrocarbon to be in 0.5-0.8 h^-1Feeding under an airspeed condition; after the outlet of the reactor is exposed to oil and the temperature of the outlet of the reactor is increased and reduced to be below 330 ℃, the feeding airspeed of the start-up oil is increased to 0.8-4.0 h^-1And then slowly raising the temperature of the inlet of the reactor to 330-400 ℃, and stably operating for more than 10 hours.

7. The start-up process according to any of claims 1 to 6, characterized in that the hydrocracking catalyst comprises at least one of solid acid zeolites having a pore space index between 6 and 18;

the solid acid zeolite is preferably at least one of twelve-membered ring zeolite, more preferably at least one of beta zeolite and mordenite.

8. The start-up process of claim 7, wherein the metal component of the hydrocracking catalyst comprises a group VIII metal oxide and/or a group VIB metal oxide.

9. The start-up method of claim 8, wherein the hydrocracking catalyst comprises the following components in parts by weight: a) 15-80 parts of the solid acid zeolite; b) 0.01-7 parts of VIII group metal oxide; c) 2-24 parts of a group VIB metal oxide; d)15-80 parts of a binder; the solid acid zeolite has a pore space index of between 6 and 18.

10. Use of the method of any one of claims 1 to 9 in a hydrocracking reaction.

Technical Field

The invention relates to a catalyst technology in the field of petroleum refining, and further relates to a startup method of a hydrocracking catalyst.

Background

Hydrocracking is one of the main processes for deep processing of heavy distillate oil, and refers to a hydrocracking process in which 10% or more of molecules in a feedstock oil are reduced by hydrogenation. The hydrocracking technology is one of the important means for secondary processing of crude oil and heavy oil lightening, and has become an important way for producing high-quality gasoline and diesel oil products due to the characteristics of strong adaptability to raw materials, very flexible operation and product schemes, good product quality and the like. A great deal of patents relate to traditional oil refining type hydrocracking catalysts, and take the hydrocracking catalyst provided by CN1040611A and its application in a hydrocracking process as an example, the hydrocracking catalyst contains a Y zeolite type acidic matrix and a group VIII-VIB metal sulfide hydrogenation active component.

The hydrocracking reaction is a reaction process which consumes hydrogen and releases heat violently, and the start-up method of the hydrocracking catalyst is an important content of the hydrocracking complete process technology. After decades of research and practice, the start-up process of hydrocracking catalysts has been normalized, mainly including the steps of sulfurizing and passivating the catalyst, such as the start-up activation method of hydrocracking process provided by CN 102443426A. The hydrocracking catalyst is shipped with the active metal components of groups VIII-VIB generally present in the oxidized form. Before industrial use, the active metal component in the catalyst needs to be converted into a sulfide state to have high catalytic activity. The catalyst presulfurization method can be divided into an in-situ presulfurization method and an out-situ presulfurization method according to different sulfur carrying modes. The initial activity of the catalyst in a sulfurized state is high, and the pre-sulfurized catalyst needs to be passivated by adopting alkane-rich raw oil such as low-nitrogen straight-run diesel oil and the like so as to reduce the initial activity of the catalyst and prevent accidents such as temperature runaway and the like.

CN101003749A provides a start-up method of an oxidation state hydrocracking catalyst, but only comprises a nitrogen replacement procedure and a hydrogen reduction procedure, and the problem of the initial activity of the catalyst is not solved.

The start-up of the chemical hydrocracking catalyst needs to specifically solve the problems of catalyst activation, prevention of excessive cracking of raw materials in the feeding process, high risk of bed temperature runaway and the like. The start-up method of the hydrocracking catalyst needs to be further optimized.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a startup method of a hydrocracking catalyst, in particular to a startup method of a hydrocracking catalyst for converting catalytic diesel into high-quality light aromatic hydrocarbon and cracking materials, which has the characteristics of simple catalyst activation procedure, stable reaction in the feeding process, controllable bed temperature rise and the like.

The invention aims to provide a start-up method of a hydrocracking catalyst.

The start-up method of the hydrocracking catalyst comprises the steps of reducing the hydrocracking catalyst by hydrogen and then contacting the hydrocracking catalyst with hydrocarbon oil rich in monocyclic aromatic hydrocarbon.

The method specifically comprises the following steps:

a) reducing the hydrocracking catalyst in hydrogen-containing atmosphere, wherein the final reduction temperature (the temperature of a catalyst bed layer in a reactor) is 350-550 ℃;

b) after the reduction, hydrocarbon oil rich in monocyclic aromatic hydrocarbon is used as start oil to contact with the reduced hydrocracking catalyst obtained in the step, and the feeding temperature (reactor inlet temperature) is 250-400 ℃, preferably 300-400 ℃, and more preferably 300-350 ℃.

The start-up method can be directly carried out in a hydrocracking reactor filled with a hydrocracking catalyst; after the steps of the start-up method, the reaction system can be replaced by hydrofined oil and the normal operation stage is carried out.

According to an aspect of the present invention, in the start-up method of the present invention, the reduction procedure of step a preferably includes: heating is carried out at a heating rate of 0.01-5 ℃/min, preferably 0.1-2 ℃/min, the temperature is raised to 350-550 ℃, preferably 380-480 ℃, and is preferably kept for 1-24 hours, more preferably 2-18 hours. The pressure of the reduction process in the step a is 0.5-10.0 MPa, and preferably 1.0-8.0 MPa.

The step a further comprises, before the step a, replacing the reactor containing the hydrocracking catalyst and the circulating system thereof with inert gas, preferably to an oxygen content of less than 0.1 wt%, more preferably less than 0.05 wt%; then, the reaction system was replaced with hydrogen gas so that the reaction system was in a hydrogen atmosphere. The hydrogen gas for replacement may be fresh hydrogen, recycled hydrogen, or reformed hydrogen; the purity of the above hydrogen source is preferably at least 85 wt%, more preferably at least 92 wt%.

The inert gas is a common inert gas, and includes, but is not limited to, nitrogen and the like.

The step a is to reduce the hydrocracking catalyst in order to convert the metal oxide in a high valence state into the metal oxide in a low valence state with hydrogenation activity.

According to one aspect of the invention, in the start-up method, in step b:

the process oil used is a hydrocarbon oil having a monocyclic aromatic content preferably greater than 90 wt.%, more preferably greater than 95 wt.%.

The monocyclic aromatic hydrocarbon in the start oil comprises benzene, toluene, xylene, carbon nonaromatic hydrocarbon, carbon decaaromatic hydrocarbon or a mixture of the benzene, the toluene, the xylene, the carbon nonaromatic hydrocarbon and the carbon decaaromatic hydrocarbon. May be from an aromatics complex.

The feeding temperature is 250-400 ℃, preferably 300-400 ℃, and more preferably 300-350 ℃.

The pressure is controlled to be 1-10 MPa, preferably 1-5 MPa.

Controlling the airspeed to be 0.5-4 h^-1Preferably 0.5 to 2 hours^-1。

The volume ratio of the hydrogen to the oil is controlled to be 1000-5000, and 1500-3000 is preferred.

After the feeding temperature of the step b reaches the stable temperature, the continuous operation time is preferably not less than 10 hours, more preferably more than 24 hours, and more preferably more than 48 hours;

specifically, considering the superposition factor of the heat of adsorption and the heat of reaction, in order to enable the heat to be released slowly at the initial stage of the startup oil, step b of the startup method of the present invention may be specifically preferred as follows:

c, slowly reducing the temperature of the catalyst bed layer after hydrogen reduction in the step a to 300-320 ℃, keeping the maximum hydrogen circulation amount allowed by a device, and enabling the working oil to be used for 0.5-0.8 h^-1The reactor is put under the condition of space velocity, and oil appears at the outlet of the reactor after 30-60 minutesThe temperature at the outlet of the reactor will continue to rise to the maximum and then slowly decrease; in the step b of the invention, the temperature of the outlet of the reactor begins to decrease when the temperature is up to 330-350 ℃. After the adsorption heat and the reaction heat are slowly released to the outlet temperature of the reactor and reduced to below 330 ℃, the feeding airspeed of the start-up oil is gradually increased to 0.8-4 h^-1Preferably 1.0 to 2.0 hours^-1Then slowly increasing the inlet temperature (feeding temperature) of the reactor to 300-400 ℃, and preferably 330-350 ℃; after the temperature is stabilized in the range, the continuous operation is stabilized for more than 10 hours.

And b, carrying out startup oil passivation on the reduced hydrocracking catalyst in order to release adsorption heat, and reducing the initial activity of the catalyst by adding startup oil with high aromatic hydrocarbon content to prevent the occurrence of bed temperature runaway after adding hydrofined oil.

According to the method for starting the hydrocracking catalyst, the hydrocracking catalyst is preferably the hydrocracking catalyst containing at least one of the solid acid zeolites with the pore space index of 6-18.

The solid acid zeolite with the channel space index between 6 and 18 is preferably at least one of twelve-membered ring zeolite, more preferably at least one of beta zeolite and mordenite.

Furthermore, the start-up method is more suitable for the start-up of the hydrocracking catalyst which takes the composite phase of the VIII-VIB group metal oxides as a metal component (a hydrogenation active phase) and takes the twelve-membered ring zeolite with the space index between 6 and 18 as an acid center. The composite phase of the VIII-VIB group metal oxides of the hydrogenation active component comprises VIII oxides and/or VIB oxides.

In particular, the method for starting up the hydrocracking catalyst is more suitable for the start-up preparation of a chemical hydrocracking catalyst provided by a patent application CN201810153543.5(CN 110180581A) filed by the applicant at 2018, 4, month and 22. The contents of chinese patent application CN201810153543.5 are hereby incorporated by reference in their entirety.

The hydrocracking catalyst described in the Chinese patent application CN201810153543.5 adopts solid acid boilingStone is used as the acid functional center of the catalyst, and the hydrogenation active phase mainly containing metal oxide is used as the hydrogenation functional center of the catalyst. The catalyst can be applied to C₁₁ ⁺Carrying out light-weight reaction on heavy aromatics; the inferior oil product rich in the polycyclic aromatic hydrocarbon can be converted into the light aromatic hydrocarbon meeting the quality index of the aromatic hydrocarbon combination device to the maximum extent, the high-quality light hydrocarbon which can be used as the olefin raw material is produced, the raw material is provided for chemical devices such as aromatic hydrocarbon, olefin and the like, the inferior heavy aromatic hydrocarbon resource utilization is realized through the refining and chemical integration, the cost reduction and the efficiency improvement of an aromatic hydrocarbon industrial chain are assisted, and the requirement of the steam cracking device for the raw material lightening is met.

The start-up method of the invention is more preferably applicable to the hydrocracking catalyst which uses low-space-index solid acid zeolite with a space index between 6 and 18, preferably beta zeolite and/or mordenite as a carrier in Chinese patent application CN 201810153543.5. The low-space-index solid acid zeolite with the space index between 6 and 18 is used as a carrier, the shape selective effect is better, but the cracking effect on non-aromatic hydrocarbon is strong, and if the non-aromatic hydrocarbon with low aromatic hydrocarbon content is used as the working oil, severe deep cracking reaction can occur, and temperature runaway is caused. The adoption of the start-up method of the invention avoids the situation.

More preferably, the catalyst precursor described in chinese patent application CN201810153543.5 is applied to hydrocracking reaction by directly adopting the start-up method of the present invention. The method can ensure that the catalyst has good hydrocracking effect, can ensure that the reaction is stably carried out, and avoids the temperature runaway phenomenon at the initial stage of the reaction.

The catalyst precursor described in CN201810153543.5 is a preferred mode of the catalyst suitable for the start-up method of the present invention: the paint comprises the following components in parts by weight: a) 15-80 parts of solid acid zeolite with pore space index of 6-18; b) 0.01-7 parts of VIII group metal oxide; c) 2-24 parts of a group VIB metal oxide; d)15-80 parts of a binder; the weight parts of the components are based on 100 parts of the total weight of the components.

The solid acid zeolite described above is preferably at least one of twelve-membered ring zeolites, more preferably beta zeolite and/or mordenite. The solid acid zeolite is 15-80 parts, preferably 25-75 parts, and more preferably 30-70 parts in the catalyst composition containing the components.

The above-mentioned group VIII metal oxide is preferably at least one selected from oxides of platinum, palladium, cobalt, nickel and iridium. The group VIII metal oxide is 0.01 to 7 parts, preferably 0.05 to 6 parts, specifically, for example, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 6.5, 6, 5.5, 6, 6.5, 6, 5.5, 6, 6.5, 6, 6.5, 6, 5, 6, 5, 6.5.

The above-mentioned group VIB metal oxide is preferably at least one selected from molybdenum oxide and tungsten oxide. The amount of the group VIII metal oxide in the catalyst composition containing the above-mentioned component is 2 to 24 parts, preferably 3 to 20 parts, specifically, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 parts.

The above binder is preferably at least one selected from the group consisting of alumina, a silica-alumina composite, a titania-alumina composite, and a magnesia-alumina composite. The binder is 15-80 parts, preferably 25-70 parts, and more preferably 30-60 parts in the catalyst composition comprising the components.

The hydrocracking catalysts described above may also include components conventional in the art such as diatomaceous earth and the like.

The hydrocracking catalyst described above can be prepared by any method known in the art for the preparation of catalysts, and is not particularly limited. For example, the preparation of the catalyst of the present invention may include forming a catalyst support containing the solid acid zeolite and supporting the metal, followed by calcination and activation to obtain the catalyst. Wherein the carrier molding can be carried out by molding the solid acid zeolite together with the binder or the like by a method such as extrusion, rolling ball or oil column molding which is usual in the art; the supported metal may be prepared by coprecipitation, cogelling, kneading, ion exchange or impregnation of the metal with the catalyst support as is conventional in the art.

The method specifically comprises the following steps: and mixing the solid acid zeolite with a binder, kneading, extruding, drying at 60-150 ℃, and roasting in an air atmosphere at 500-600 ℃ for 3-6 hours to obtain the required catalyst carrier. Preparing a metal aqueous solution from a VIII group metal compound and a VIB group metal compound, impregnating a catalyst carrier by an isovolumetric impregnation method, drying at 60-150 ℃, and roasting at 450-580 ℃ for 1-6 hours in an air atmosphere to obtain the catalyst.

After the catalyst is subjected to the reduction procedure of the step a of the start-up method, the catalyst comprises the following components in parts by weight: a) 15-80 parts of solid acid zeolite with pore space index of 6-18; b) 0.01-6 parts of VIII group metal; c) 2-18 parts of a group VIB metal oxide; d)15-80 parts of a binder; the weight parts of the components are based on 100 parts of the total weight of the components.

The invention also aims to provide the application of the start-up method of the hydrocracking catalyst in hydrocracking reaction.

The method for starting the hydrocracking catalyst can be well applied to the existing hydrocracking catalyst, and is particularly suitable for starting the hydrocracking catalyst which takes the VIII-VIB group metal oxide composite phase as a metal component (hydrogenation active phase) and takes the twelve-membered ring zeolite with the space index between 6 and 18 as an acid center. The hydrocracking catalyst can obtain a metal oxide hydrogenation active phase with a certain valence state through the reduction procedure in the hydrogen-containing atmosphere in the step a of the invention, and compared with a catalyst adopting VIII-VIB group metal sulfide as the hydrogenation phase, the hydrocracking catalyst has the characteristics of greatly simplified start-up process and moderate hydrogenation activity; on the other hand, the low space index zeolite has strong deep cracking capability on alkane and cycloalkane, and the hydrocarbon oil with the monocyclic aromatic hydrocarbon content of more than 90 percent is used as the working oil, so that the problems of deep cracking and excessive heat release in the initial activity period of the catalyst are solved. By adopting the start-up method, the catalyst activation procedure is simple, the reaction in the feeding process is stable, the bed temperature rise is controllable, and a better technical effect is achieved.

Detailed Description

The present invention is further illustrated and described in detail by the following detailed description. It is to be noted, however, that the scope of the present invention is not limited thereto, but is defined by the appended claims. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, and these simple modifications all belong to the protection scope of the invention.

It is to be further understood that the various features described in the following detailed description may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

Moreover, any combination of the various embodiments of the present invention may be made without departing from the spirit of the present invention, and the technical solutions formed thereby are part of the original disclosure of the present specification and also fall within the scope of the present invention, and should not be considered as new matters which are not disclosed or contemplated herein, unless such combination is considered obvious and unreasonable by those skilled in the art.

In the context of the present specification, anything or things which are not mentioned, except where explicitly stated, are directly applicable to those known in the art without any changes.

All publications, patent applications, patents, and other references mentioned in this specification are herein incorporated by reference in their entirety. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present specification, including definitions, will control.

When the specification concludes with claims with the heading "known to those skilled in the art", "prior art", or the like, to derive materials, substances, methods, procedures, devices, or components, etc., it is intended that the subject matter derived from the heading encompass those conventionally used in the art at the time of filing this application, but also include those that are not currently in use, but would become known in the art to be suitable for a similar purpose.

Unless otherwise expressly indicated, all percentages, parts, ratios, etc. mentioned in this specification are by weight unless otherwise not in accordance with the conventional knowledge of those skilled in the art; the temperature is given in units of degrees Celsius, the pressure is in gauge pressure, and the space velocity mentioned is the liquid hourly space velocity LHSV.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein. In the following, various technical solutions can in principle be combined with each other to obtain new technical solutions, which should also be regarded as specifically disclosed herein.

Test methods and standards related to the detailed description of the invention section:

1. in the present invention, the composition of the catalyst was analyzed by ICP (inductively coupled plasma) and XRF (X-ray fluorescence) methods. The composition ratio of the group VIB metal oxides is determined by the XPS (X-ray photoelectron spectroscopy) method. The ICP test conditions were: the Varian 700-ES series XPS instrument. XRF test conditions were: rigaku ZSX 100e model XRF instrument. XPS test conditions: perkin Elmer PHI 5000C ESCA type X-ray photoelectron spectrometer with Mg K exciting light source, operation voltage l0kV, current 40mA, vacuum degree 4.0X 10^-8Pa。

2. The Space Index (SI) is an Index representing the channel width of twelve-membered ring zeolites and is between 3 and 21. After the specific hydrogen type twelve-membered ring zeolite is loaded with 0.1-0.5 wt% of platinum or palladium noble metal, the hydrogen type twelve-membered ring zeolite is used for hydrocracking reaction of butylcyclohexane, and the molar ratio of isobutane to normal butane in the product is analyzed, namely the channel space index of the twelve-membered ring zeolite. The spaciousness of the solid acid zeolite pore channel can be characterized by the space index.

The specific embodiment of the invention relates to the following raw materials: the raw materials including but not limited to the catalysts involved in the examples and comparative examples of the present invention are commercially available.

Comparative example 1

Mixing appropriate amount of hydrogen type beta zeolite (SAR ═ proportion 58) with pore space index of 17.1 and pseudo-boehmite, kneading, extruding, drying at 120 deg.C, and calcining at 500 deg.C for 5 hr to obtain the required catalyst carrier. Preparing a bimetallic aqueous solution by using cobalt nitrate and ammonium tungstate, impregnating a catalyst carrier by an isometric impregnation method, drying at 120 ℃, and roasting for 3 hours at 480 ℃ in an air atmosphere; the composition of the obtained catalyst was 4.2 parts by weight of CoO-16.2 parts by weight of WO₃51.0 parts of beta zeolite-28.6 parts of Al₂O₃。

The catalyst is loaded into a fixed bed reactor, the reactor and a circulating system are replaced by nitrogen until the oxygen content is less than 0.1 percent, and then replaced by reformed hydrogen with the hydrogen purity of 92 percent, and the pressure is increased to 7.0 MPa. Slowly increasing the inlet temperature by 420 ℃ according to a temperature increasing program of 0.1 ℃/min, and then keeping the temperature for 15 hours to complete the reduction program, wherein the catalyst after reduction comprises the following components in parts by weight: 3.5 parts Co-6.3 parts WO₂8.9 parts of WO₃52 parts of beta zeolite-29.3 parts of Al₂O₃。

The temperature of a catalyst bed layer is slowly reduced to 305 ℃, the maximum hydrogen circulation amount allowed by a device is kept, the pressure is 5.0MPa, the straight-run diesel oil with the nitrogen content of 87ppm and the distillation range of 195-. For 0.5h^-1After the start-up oil is put into the reactor under the airspeed condition, the temperature of the outlet of the reactor is quickly raised to be higher than 420 ℃, and exceeds the maximum allowable temperature of the hydrocracking reactor, so that the start-up fails.

[ example 1 ]

The catalyst composition and hydrogen reduction procedure were the same as in comparative example 1.

Slowly reducing the temperature of a catalyst bed layer to 310 ℃, and keeping the maximum hydrogen circulation allowed by a device and the pressure of 5.0 MPa; toluene with purity of more than 99% is used as start-up oil for 0.5h^-1Space velocity input, hydrogen oil volumeA ratio of 1500; after 30 minutes, oil is seen at the outlet of the reactor, the temperature at the outlet of the reactor is slowly reduced after reaching 346 ℃, and the heat of adsorption is slowly released. After the outlet temperature of the reactor is reduced to be below 320 ℃, the feeding space velocity of the toluene is gradually increased to 2.0h^-1After which the reactor inlet temperature was again increased to 340 c and the operation was stabilized for 72 hours. During the period, the initial activity of the catalyst is gradually reduced, and the temperature difference between the inlet and the outlet of the reactor is gradually reduced from 29 ℃ to below 15 ℃ and is kept stable. Switching the hydrofined oil, and turning to a normal operation stage to finish the start-up procedure.

[ example 2 ]

Mixing appropriate amount of hydrogen mordenite (SAR 25) with pore space index of 7.2 with pseudo-boehmite, kneading, extruding, drying at 120 deg.C, and calcining at 550 deg.C for 4 hr to obtain the required catalyst carrier. Preparing a bimetallic solution by using tetrammine platinum chloride and ammonium molybdate, impregnating a catalyst carrier by using an isometric impregnation method, drying at 120 ℃, and roasting for 2 hours at 500 ℃ in an air atmosphere. The obtained catalyst composition was, in parts by weight, 0.12 part of PtO₂-11.70MoO₃/53.65 parts of mordenite-34.53 parts of Al₂O₃。

The catalyst is loaded into a fixed bed reactor, the reactor and a circulating system are replaced by nitrogen until the oxygen content is less than 0.1 percent, then replaced by PSA (pressure swing adsorption) hydrogen with the hydrogen purity of 99 percent, and the pressure is increased to 3.0 MPa. Slowly increasing the inlet temperature by 470 ℃ according to a temperature increasing program of 0.1 ℃/min, and then maintaining the temperature for 10 hours to complete the reduction program, wherein the catalyst after reduction comprises the following components in parts by weight: 0.10 part of Pt-4.25 parts of MoO₂6.87 parts of MoO₃54.10 parts of mordenite-34.68 parts of Al₂O₃。

Slowly reducing the temperature of a catalyst bed layer to 310 ℃, and keeping the maximum allowable hydrogen circulation amount of the device and the pressure of 3.0 MPa; reforming deheptanizer residue with aromatic hydrocarbon content of more than 90.5% is used as start-up oil, which contains xylene, nona-carbon aromatic hydrocarbon and deca-carbon aromatic hydrocarbon, for 0.5h^-1Inputting under the condition of airspeed and the volume ratio of hydrogen to oil is 1500; after 30 minutes, oil appears at the outlet of the reactor, the temperature at the outlet of the reactor is slowly reduced after reaching 347 ℃, and the heat of adsorption is slowly reducedAnd (4) slow release. After the outlet temperature of the reactor is reduced to below 325 ℃, the feeding airspeed of the reforming deheptanizer kettle material is gradually increased to 2.0h^-1After that, the reactor inlet temperature was increased to 345 ℃ again, and the operation was stabilized for 120 hours, during which the initial activity of the catalyst gradually declined. The temperature difference between the inlet and the outlet of the reactor is gradually reduced from 35 ℃ to below 18 ℃ and kept stable. Then switching the hydrofined oil, and turning to a normal operation stage to finish the start-up procedure.

[ example 3 ]

Proper amount of beta zeolite with space index of 17.1, pseudoboehmite with dry basis content of 70 percent and amorphous silicon-aluminum (SiO)₂6 wt% and 80% dry basis) through kneading and extruding. Preserving the mixture at room temperature for 24h, drying the mixture at 90 ℃ for 12h, and roasting the mixture in air atmosphere at 580 ℃ for 3 h to obtain the hydrocracking catalyst carrier. Proper amount of nickel nitrate and ammonium tungstate are prepared into clear solution, and after equal volume of impregnation, the clear solution is dried at 100 ℃ and roasted in air at 560 ℃ for 2.5 hours. The composition of the obtained catalyst precursor was 4.6 parts NiO-3.0 parts WO by weight₃34.2 parts of beta-57.3 parts of Al₂O₃-0.9 part of SiO₂。

The catalyst is loaded into a fixed bed reactor, the reactor and a circulating system are replaced by nitrogen until the oxygen content is less than 0.1 percent, then replaced by PSA (pressure swing adsorption) hydrogen with the hydrogen purity of 99 percent, and the pressure is increased to 8.0 MPa. Slowly increasing the inlet temperature by 520 ℃ according to a temperature increasing program of 2 ℃/min, and then maintaining the temperature for 4 hours to complete the reduction program, wherein the catalyst after reduction comprises the following components in parts by weight: 4.1 parts of Ni-1.5 parts of WO₂-1.4 parts of WO₃34.3 parts of beta-57.8 parts of Al₂O₃-0.9 part of SiO₂。

Slowly reducing the temperature of a catalyst bed layer to 305 ℃, and keeping the maximum allowable hydrogen circulation amount of the device and the pressure of 7.0 MPa; mixed xylene with aromatic hydrocarbon content of more than 98.7 percent is used as the starting oil for 0.8h^-1Inputting under the condition of airspeed, wherein the volume ratio of hydrogen to oil is 3000; after 30 minutes, oil is seen at the outlet of the reactor, the temperature at the outlet of the reactor is slowly reduced after reaching 339 ℃, and the heat of adsorption is slowly released. After the outlet temperature of the reactor is reduced to be below 320 ℃, the feeding space velocity of the reforming deheptanizer kettle material is gradually increasedIncreased to 1.0h^-1After which the reactor inlet temperature was again increased to 350 ℃. The operation was stable for 24 hours, during which the initial activity of the catalyst gradually decayed. The temperature difference between the inlet and the outlet of the reactor is gradually reduced from 45 ℃ to below 21 ℃ and kept stable. Then switching the hydrofined oil, and turning to a normal operation stage to finish the start-up procedure.