A hydrocracking method for producing diesel and tail oil from heavy distillate oil with low hydrogen consumption

Abstract

The present invention relates to a hydrocracking method for producing diesel and tail oil with low hydrogen consumption from heavy distillate oil, the method comprising contacting heavy distillate oil and hydrogen with a hydrogenation catalyst in a fixed bed hydrogenation reactor under hydrogenation conditions; the heavy distillate oil is a fraction with a dry point of not less than 650°C and a metal content of less than 20ppm; the hydrogenation catalyst comprises a carrier and an active metal component loaded on the carrier; based on the total mass of the hydrogenation catalyst, the content of the carrier is 50-88% by weight; the carrier contains a non-amorphous mesoporous acidic material and a Y-type molecular sieve; the content of the Y-type molecular sieve in the carrier is 5-45% by weight; the active metal component is a metal element of Group VIII and a metal element of Group VIB. The catalyst is suitable for producing diesel and tail oil with low hydrogen consumption from heavy distillate oil, and the content of aromatics in the diesel and tail oil produced by the catalyst of the present invention is higher.

Description

Technical Field

[0001] The present invention relates to the field of chemical technology, and in particular to a hydrocracking method for producing diesel and tail oil from heavy distillate oil with low hydrogen consumption. Background Art

[0002] As crude oil becomes heavier and inferior, the conversion of heavy distillate oil has become a difficult problem in refining catalysts and technologies. Hydrocracking is one of the key technologies for lightening oil products. In the processing of heavy oil products, polycyclic hydrocarbons, especially cycloalkanes and aromatic hydrocarbons with three or more rings, accumulate in the circulating oil, resulting in reduced catalyst activity and shortened operating cycles.

[0003] Hydrocracking technology is one of the classic means of hydrogenation conversion of heavy distillate oil, with the characteristics of high product quality, long service life, and flexible operation. It is used to process conventional oil products, such as VGO and LCO, and has advantages that other technologies do not have. However, when used to process heavy distillates, especially heavy distillates with a dry point greater than 650°C, problems such as insufficient catalyst activity stability and product quality that do not meet requirements often occur.

[0004] Improving the processing capacity of heavy distillate oil in hydrocracking technology mainly depends on hydrocracking catalysts. Hydrocracking catalyst is a bifunctional catalyst that has both cracking activity and hydrogenation activity, that is, it contains both acidic components and hydrogenation active components. Its acidity is mainly provided by heat-resistant inorganic oxides and / or various zeolites constituting the carrier; the hydrogenation active components are generally selected from metals, metal oxides and / or metal sulfides of Groups VIB and VIII in the periodic table. In order to meet different requirements for hydrocracking products, it is necessary to adaptively adjust the acidic components and hydrogenation active components in the catalyst.

[0005] Acidic components can be divided into two categories according to the degree of crystallization: molecular sieves and amorphous silica-alumina. Molecular sieves are used for catalysts that require more acid centers and high reactivity. Compared with molecular sieves, amorphous silica-alumina has a simple preparation method, low cost, larger pore size, larger silica-alumina ratio adjustment range and lower acid density. It is particularly suitable for processing macromolecular raw materials such as heavy oil and residual oil; it is often used in catalysts that require lower acid density, such as hydrocracking catalysts and hydroisomerization catalysts with high middle distillate selectivity. Amorphous silica-alumina is an acid carrier for many industrial amorphous catalysts and an important component of many molecular sieve catalysts, but the common disadvantage of amorphous silica-alumina materials is low cracking activity.

[0006] For hydrocracking catalysts, the improvement of catalyst performance requires, on the one hand, further improvement of hydrogenation performance; on the other hand, it requires suitable acidic components so that the cracking or isomerization performance can match the target product. Selecting molecular sieves or mesoporous materials, or even solid superacids, can adjust the properties of the acidic components within a larger range, thereby optimizing the acidic function of the catalyst. However, the space for adjusting the performance of the hydrogenation component is limited. Although precious metals can be used as hydrogenation components, they generally cannot process sulfur-containing raw materials. Therefore, the hydrogenation component of industrial hydrocracking catalysts generally selects non-precious metals as hydrogenation components. The hydrogenation activity of non-precious metals is lower than that of precious metals, and often cannot meet the requirements. How to improve the hydrogenation performance of the catalyst has become a problem that some hydrocracking catalysts need to solve.

[0007] Directly converting heavy fractions into diesel and wax oil fractions is one of the goals of lightening heavy oil. Generally speaking, heavy distillate oil has a higher density and a lower hydrogen content. An ideal processing technology is to convert as much heavy distillate oil as possible into light distillate oil while keeping the processing cost as low as possible during the processing.

[0008] For the processing of heavy distillate oil, the conventional processing methods are catalytic cracking and coking. The quality of diesel produced by these two processing methods is generally poor. The typical catalytic cracking process is to produce gas, gasoline, diesel, heavy oil (which can be recycled) and coke through cracking reaction at about 500°C, 2-4 atmospheres and contact with catalytic cracking catalyst. The yield of the reaction product is closely related to the properties of the raw materials, reaction conditions and the performance of the catalyst. Under general industrial conditions, the gas yield is about 10%~20%, mainly C3 and C4, and the olefin content is as high as about 50%; the gasoline yield is about 30%~60%, and its research octane number is about 80~90, and the stability is also good; the diesel yield is about 0~40%, and its cetane number is low due to the presence of more aromatics; the cetane number of diesel obtained by catalytic cracking of heavy oil is even lower, and the oxidation stability is also poor.

[0009] Similarly, vacuum residue can be coked to produce 70% to 80% distillate oil. Coking gasoline and coking diesel have high content of unsaturated hydrocarbons, as well as high content of non-hydrocarbon compounds such as sulfur and nitrogen. Their stability is very poor and they must be refined by hydrotreating before they can be used as engine fuel.

[0010] These two processing methods do produce a certain amount of light fractions, but there is also carbon with different yields. For FCC, if DAO is blended, the coke yield (mass fraction) can reach 20%, or even higher, and the light oil yield will be reduced to about 60% [Petroleum Refining Engineering (3rd Edition), edited by Lin Shixiong, Petrochemical Press, Beijing 2000, 329]. In the coking process, such as delayed coking, Shengli vacuum residue is used as raw material. Under the condition of 13.9% residual carbon, the coke yield is 23.9%, and 6.8% coking gas is produced. A total of about 30% of the components cannot be converted into high-value engine fuel or light oil products. The diesel and wax oil yields in the product are 35.6% and 19.0%, respectively, totaling 54.6%.

[0011] Unlike catalytic cracking and coking, hydrogenation, especially hydrocracking, can convert heavy fractions into fuel oil. However, conventional hydrocracking technology generally processes distillate oil components with a dry point not exceeding 550°C. For fractions with a dry point exceeding 650°C and oil products with a high metal content, residual oil hydrogenation is more often used for processing.

[0012] For some of these oil products, such as deasphalted oil (DAO) or residue hydrothermal conversion oil products, these oil products are characterized by high dry point, up to 680℃, or higher; high aromatic content, up to 70% or more, low metal content, Ni+V content is generally less than 1ppm, and can be used as a refining product for conventional hydrocracking units, mainly used to produce lubricating oil raw materials and catalytic cracking raw materials. How to process these oil products into high-value products, especially chemical raw materials, such as ethylene, propylene, butadiene, BTEX, etc., is a difficult point for hydrocracking. If reasonable grading is used to produce suitable catalytic cracking raw materials by hydrocracking, it is also an optional route.

[0013] According to the corresponding raw materials and investment in 2018, the cost of producing hydrogen from methanol is estimated to be 1.92 yuan / m 3 ; The total unit cost of hydrogen production by water electrolysis is 3.3 yuan / m 3 ; The unit cost of coal gasification hydrogen production is 0.9 yuan / m 3. The corresponding unit mass costs are: 21,357 yuan / ton for hydrogen production from methanol; 10,011 yuan / ton for hydrogen production from coal; and 36,707 yuan / ton for hydrogen production from water electrolysis. The hydrogen that a refinery can obtain is, on the one hand, self-produced hydrogen through processes such as reforming, or various process hydrogen purchased from the market. The cost of hydrogen is expected to be around the middle price of the above hydrogen costs, about 20,000 yuan / ton. Compared with the prices of crude oil and products, it is significantly higher. A more economical processing technology is to obtain the highest possible light oil yield at the lowest possible hydrogen consumption.

[0014] Patent CN101094720 proposes a hydrocracking catalyst for a mixture of vacuum gas oil (VGO) and demetallized oil (DMO), using MCM-41 as the main active component, and it is believed that VGO / DMO can be converted into hydrocarbon products with shorter carbon chains.

[0015] Chinese patent CN 110776953 and Chinese patent CN 110776954 propose a method including fixed bed hydroprocessing, which includes a series of specific steps, including a fixed bed hydroprocessing step, a deasphalting step of the heavy fraction produced by the fixed bed hydroprocessing step, a fixed bed hydrocracking step of the DAO component, an ebullated bed hydrocracking step of the asphalt component and a deasphalting step of the heavy component produced by the ebullated bed hydrocracking step.

[0016] Chinese patent CN 110835550 proposes a hydrocracking method for producing chemical raw materials, which comprises: introducing hydrocracking raw materials into a hydropretreatment reaction zone and a hydrocracking reaction zone in sequence for hydrogenation reaction to obtain a hydrocracking effluent; then fractionating the hydrocracking effluent; wherein the hydrocracking raw materials contain a VGO fraction and a DAO fraction, and the DAO fraction accounts for 10-30% by weight of the total amount of the hydrocracking raw materials, and the hydrogen partial pressure in the hydrocracking reaction zone is 20-80% of the hydrogen partial pressure in the hydropretreatment reaction zone. The method provided by the present invention can greatly increase the heavy naphtha yield of the hydrocracking unit, while also taking into account the production of high-quality DCC feed.

[0017] Although these methods can obtain diesel fractions, they do not provide diesel properties. In addition, the prior art uses a blending method, and the blending ratio is no more than 30%. Therefore, the art is in urgent need of a method for producing diesel and tail oil fractions by fully processing heavy fractions and under conditions of lower hydrogen consumption. Summary of the invention

[0018] The object of the present invention is to provide a hydrocracking process which converts as much heavy distillate as possible into light distillate.

[0019] In order to achieve the above-mentioned object, the present invention provides a hydrocracking method for producing diesel and tail oil with low hydrogen consumption from heavy distillate oil. Under hydrogenation conditions, heavy distillate oil and hydrogen are contacted with a hydrogenation catalyst in a fixed bed hydrogenation reactor; the heavy distillate oil is a fraction with a dry point of not less than 650° C. and a metal content of less than 20 ppm; the hydrogenation catalyst comprises a carrier and an active metal component loaded on the carrier; based on the total mass of the hydrogenation catalyst, the content of the carrier is 50-88% by weight; the carrier contains a non-amorphous mesoporous acidic material and a Y-type molecular sieve; the content of the Y-type molecular sieve in the carrier is 5-45% by weight; and the active metal component is a metal element of Group VIII and a metal element of Group VIB.

[0020] Optionally, based on the total mass of the hydrogenation catalyst, the content of the carrier is 62-77.5% by weight; the content of the Y-type molecular sieve in the carrier is 8-32% by weight, preferably 15-25% by weight.

[0021] Optionally, the content of Group VIB metals based on the total amount of the catalyst and calculated as oxide is 15-35% by weight, preferably 18-32% by weight, and more preferably 20-30% by weight; the content of Group VIII metals based on the total amount of the catalyst and calculated as oxide is 0.5-10% by weight, preferably 1-8% by weight, and more preferably 2-8% by weight.

[0022] Optionally, the Group VIII metal element is cobalt and / or nickel, and the Group VIB metal element is molybdenum and / or tungsten; preferably, the Group VIII metal element is nickel, and the Group VIB metal element is tungsten.

[0023] Optionally, the carrier has a porous structure; in the porous structure, the pore diameter of the pores is in the range of 5-20 nm, preferably in the range of 6-15 nm; the specific surface area of ​​the carrier is 140-350 m 2 / g, preferably 160-320m 2 / g; the pore volume of the carrier is 0.35-0.85mL / g, preferably 0.4-0.8mL / g; the pore concentration value of the pores is not less than 0.5, preferably not less than 0.75.

[0024] Optionally, pores with pore diameters in the range of 3-50 nm account for more than 30% of the total pore volume.

[0025] Optionally, the carrier is a non-amorphous mesoporous acidic material; preferably, the non-amorphous mesoporous acidic material is a silicon-aluminum composite oxide.

[0026] Optionally, the hydrogenation catalyst is prepared according to the following steps:

[0027] S1, impregnating the support with an aqueous solution containing a compound of a Group VIII metal and a compound of a Group VIB metal to obtain an impregnated support;

[0028] S2, subjecting the impregnated support to a first drying and a first calcination.

[0029] Optionally, the compound containing a Group VIII metal is selected from at least one of nitrates, chlorides, sulfates, formates, acetates, phosphates, citrates, oxalates, carbonates, basic carbonates, hydroxides, phosphates, phosphides, sulfides, aluminates, molybdates, tungstates and water-soluble oxides of nickel and cobalt; preferably selected from at least one of nickel nitrate, nickel sulfate, nickel acetate, basic nickel carbonate, cobalt nitrate, cobalt sulfate, cobalt acetate, basic cobalt carbonate, cobalt chloride and nickel chloride; the compound containing a Group VIB metal is selected from at least one of molybdic acid, paramolybdic acid, molybdates, paramolybdates, tungstic acid, metatungstic acid, ethylmetungstic acid, tungstates, metatungstates and ethylmetungstic acid.

[0030] Optionally, the aqueous solution containing the compound of the Group VIII metal and the compound of the Group VIB metal further contains an organic additive, and the organic additive is selected from organic acids and organic amines; the molar ratio of the organic additive to the Group VIII metal element is 0.1-10, preferably 0.4-8.

[0031] Optionally, in step S1, the impregnation conditions include: the impregnation temperature is 5-150°C, and the impregnation time is 0.5-12 hours; in step S2, the first drying treatment conditions include: the drying temperature is 50-300°C, preferably 100-250°C, and further preferably 110-180°C; the drying time is 1-12 hours, preferably 2-8 hours; the first calcination conditions include: the calcination temperature is 360-700°C, preferably 400-650°C; the calcination time is 0.2-12 hours, preferably 1-10 hours.

[0032] Optionally, the method for preparing the carrier comprises:

[0033] SS1, mixing pseudo-thin diatomite, amorphous silicon aluminum oxide, Y-type molecular sieve and sesbania powder to obtain a first mixed powder; or mixing pseudo-thin diatomite, amorphous silicon aluminum oxide, Y-type molecular sieve, methyl cellulose and sesbania powder to obtain a second mixed powder;

[0034] SS2, mixing the first mixed powder or the second mixed powder with a nitric acid solution, kneading and extruding to obtain an extruded strip;

[0035] SS3. subjecting the extruded strip to a second drying and a second calcination.

[0036] Optionally, in step SS1, the weight ratio of the pseudo-thin diatomite, the amorphous silica-aluminum oxide, the Y-type molecular sieve and the sesbania powder is 20-85:10-60:0.1-60:1-5; preferably 25-75:15-55:0.5-40:2-4; or the weight ratio of the pseudo-thin diatomite, the amorphous silica-aluminum oxide, the Y-type molecular sieve, the methyl cellulose and the sesbania powder is 20-85:10-60:0.1-60:0.01-5:1-5; preferably 25-75:15-55:0.5-40:0.1-3:2-4; in step SS2, the amount of the nitric acid solution used is 0.5-4mL per 100g of the mixed powder.

[0037] Optionally, the content of SiO2 in the pseudo-thin diatomite is less than 0.1wt%, the content of Fe2O3 is less than 0.01wt%, the content of Na2O is less than 0.15wt%, the content of water is less than 3wt%, and the loss on ignition is 32-38%; the pore volume of the pseudo-thin diatomite is 0.60-1.1mL / g, and the specific surface area is 220-310m 2 / g; the characteristics of the amorphous silicon aluminum oxide include: a SiO2 content of 15-55%, an Al2O3 content of 45-85%, and a bulk density of 250-450g / L; the mass concentration of the nitric acid solution is: 0.3-3%.

[0038] Optionally, in step SS2, the mixing conditions include: temperature of 10-40°C, time of 1-10 minutes; in step SS3, the second drying conditions include: temperature of 800-250°C, preferably 110-200°C; time of 1-12 hours; the second roasting conditions include: temperature of 300-650°C; time of 1-8 hours, preferably 2-6 hours; air flow rate of 20-50L / h.

[0039] Optionally, the hydrogenation conditions include: temperature of 200-650°C, preferably 300-510°C; hydrogen partial pressure of 3-24MPa, preferably 4-10MPa; liquid hourly volume space velocity of the raw material of 0.1-50h -1 , preferably 2-40h -1 .

[0040] Through the above technical scheme, the present invention provides a hydrocracking method for producing diesel and tail oil from heavy distillate oil with low hydrogen consumption. The method can realize the production of diesel and tail oil from heavy distillate oil with low hydrogen consumption. The diesel and tail oil produced by the method of the present invention have a higher aromatic content.

[0041] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0042] 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.

[0043] The invention provides a hydrocracking method for producing diesel and tail oil with low hydrogen consumption from heavy distillate oil. Under hydrogenation conditions, heavy distillate oil and hydrogen are contacted with a hydrogenation catalyst in a fixed bed hydrogenation reactor; the heavy distillate oil is a fraction with a dry point of not less than 650° C. and a metal content of less than 20 ppm; the hydrogenation catalyst comprises a carrier and an active metal component loaded on the carrier; based on the total mass of the hydrogenation catalyst, the content of the carrier is 50-88% by weight; the carrier contains a non-amorphous mesoporous acidic material and a Y-type molecular sieve; the content of the Y-type molecular sieve in the carrier is 5-45% by weight; and the active metal component is a metal element of Group VIII and a metal element of Group VIB.

[0044] The heavy distillate oil mentioned in the present invention refers to the distillate oil obtained by distilling or other processing methods of petroleum fractions, and common ones include DAO (deasphalted oil), some VGO (vacuum gas oil), etc. The oxygen content in general raw oil is less than 0.5%.

[0045] The present invention does not impose too many restrictions on other properties of heavy distillate oil, but needs to consider the requirements of equipment and process during processing, such as the content of components such as Cl and F. The total metal content in the feedstock oil, mainly Ni and V, is generally required to be no higher than 20ppm.

[0046] The heavy distillate oil mentioned in the present invention has a high dry point. The temperature of the 95% point of the distillation process of the distillate oil is not less than 620° C. by using simulated distillation. There is no restriction on the initial distillation point of the distillate oil and the temperature of other distillation sections.

[0047] The heavy distillate oil mentioned in the present invention has no limitation on the nitrogen content and sulfur content, but the residual carbon is required to be within 10%, preferably less than 5%, and most preferably less than 3%.

[0048] The heavy distillate oil mentioned in the present invention does not impose too many restrictions on the density and hydrogen content of the oil product, but the density is lower than 0.98 g / cm³, preferably lower than 0.96 g / cm³, and most preferably lower than 0.95 g / cm³. The hydrogen content is not lower than 10.5%, preferably higher than 10.8%, and most preferably higher than 11.0%.

[0049] The aromatic content of the heavy distillate oil mentioned in the present invention is not limited in any way, but generally, the oil products that meet the distillation range and metal content restrictions have a relatively high aromatic content, generally higher than 60%, and more often higher than 70% or even higher. For the production of low aromatic diesel, the lower the aromatic content, the more advantageous it is.

[0050] The hydroprocessing method improved by the present invention is fixed bed hydrogenation, and a moving bed or other processing method can also be used. The present invention is mainly used for a fixed bed reactor. The present invention does not limit the implementation method of the fixed bed, whether it is an axial adiabatic fixed bed reactor, a radial adiabatic fixed bed reactor, or a tubular fixed bed reactor.

[0051] The diesel mentioned in the present invention refers to a light petroleum product, which is a complex hydrocarbon mixture with a carbon number of about 10-22. It is generally used as a fuel for compression ignition engines (i.e., diesel engines). The main indicators are cetane number, viscosity, freezing point, etc. The quality requirements for diesel are good combustion performance and fluidity. The combustion performance is expressed by the cetane number. The higher the better. The cetane number of diesel made from Daqing crude oil can reach 68. The cetane number of light diesel used in high-speed diesel engines is 42-55, and that of low-speed engines is below 35.

[0052] The cetane number mentioned in the present invention refers to the volume percentage of normal hexadecane contained in the standard fuel equivalent to the self-ignition property of the measured diesel. It is measured according to the GB / T 386 method. The standard fuel is a mixture of normal hexadecane and α-methylnaphthalene in different volume percentages, wherein normal hexadecane has good self-ignition property and its cetane number is specified as 100, and α-methylnaphthalene has poor self-ignition property and its cetane number is specified as 0. There is also 2, 2, 4, 4, 6, 8, 8-heptamethylnonane instead of α-methylnaphthalene (1-methylnaphthalene), and its cetane number is set to 15. The cetane number measurement is carried out on a laboratory standard single-cylinder diesel engine under specified conditions. For the cetane number, the cetane number of aromatic hydrocarbons is the lowest, and the cetane number of chain alkanes is the highest. The fundamental way to improve the cetane number is to reduce the content of aromatic hydrocarbons and increase the content of chain alkanes and cycloalkanes.

[0053] According to the present invention, based on the total mass of the hydrogenation catalyst, the content of the carrier may be 62-77.5% by weight; the content of the Y-type molecular sieve in the carrier may be 8-32% by weight, preferably 15-25% by weight.

[0054] According to the present invention, the content of Group VIB metals based on the total amount of the catalyst and calculated as oxide can be 15-35% by weight, preferably 18-32% by weight, and more preferably 20-30% by weight; the content of Group VIII metals based on the total amount of the catalyst and calculated as oxide can be 0.5-10% by weight, preferably 1-8% by weight, and more preferably 2-8% by weight.

[0055] According to the present invention, the Group VIII metal element may be cobalt and / or nickel, and the Group VIB metal element may be molybdenum and / or tungsten; preferably, the Group VIII metal element is nickel, and the Group VIB metal element is tungsten.

[0056] As a preferred embodiment of the present invention, the carrier has a porous structure; in the porous structure, the pore diameter of the pores is in the range of 5-20nm, preferably in the range of 6-15nm; the specific surface area of ​​the carrier is 140-350m 2 / g, preferably 160-320m 2 / g; the pore volume of the carrier is 0.35-0.85mL / g, preferably 0.4-0.8mL / g;; the pore concentration value of the pores is not less than 0.5, preferably not less than 0.75.

[0057] Further preferably, the pores with pore diameters in the range of 3-50 nm account for more than 30% of the total pore volume.

[0058] According to the present invention, the carrier may be a non-amorphous mesoporous acidic material; preferably, the non-amorphous mesoporous acidic material may be a silicon-aluminum composite oxide.

[0059] Preferably, the hydrogenation catalyst in the present invention can be prepared according to the following steps:

[0060] S1, impregnating the support with an aqueous solution containing a compound of a Group VIII metal and a compound of a Group VIB metal to obtain an impregnated support;

[0061] S2, subjecting the impregnated support to a first drying and a first calcination.

[0062] In the present invention, the metal element of the group VIII and the metal element of the group VIB can be loaded on the carrier at the same time, or the metal element of the group VIII and the metal element of the group VIB can be loaded on the carrier separately. When the metal element of the group VIII and the metal element of the group VIB are loaded on the carrier separately, the loading order of the metal element of the group VIII and the metal element of the group VIB is not particularly limited, and the metal element of the group VIII can be loaded first and then the metal element of the group VIB, or the metal element of the group VIB can be loaded first and then the metal element of the group VIII, or the metal element of the group VIII and the metal element of the group VIB can be loaded at intervals. Interval loading of the metal element of the group VIII and the metal element of the group VIB is suitable for the situation that the metal element of the group VIII and the metal element of the group VIB are loaded on the carrier in multiple times. Preferably, the metal element of the group VIII and the metal element of the group VIB are loaded on the carrier at the same time, so that the simplicity of the process can be improved and the efficiency can be improved.

[0063] In the present invention, the impregnation solution can be prepared by using a compound containing a metal element of Group VIII and a compound containing a metal element of Group VIB. The specific types of the compound containing a metal element of Group VIII and the compound containing a metal element of Group VIB can be selected according to the solvent of the impregnation solution, so as to be dispersed in the solvent to form a stable impregnation solution. Preferably, the solvent of the impregnation solution is water, in which case the compound containing a metal element of Group VIII is preferably a water-soluble compound containing a metal element of Group VIII, and the compound containing a metal element of Group VIB is preferably a water-soluble compound containing a metal element of Group VIB.

[0064] According to the present invention, the compound containing the metal of Group VIII can be selected from at least one of nitrates, chlorides, sulfates, formates, acetates, phosphates, citrates, oxalates, carbonates, basic carbonates, hydroxides, phosphates, phosphides, sulfides, aluminates, molybdates, tungstates and water-soluble oxides of nickel and cobalt; preferably, it can be selected from at least one of nickel nitrate, nickel sulfate, nickel acetate, basic nickel carbonate, cobalt nitrate, cobalt sulfate, cobalt acetate, basic cobalt carbonate, cobalt chloride and nickel chloride; the compound containing the metal of Group VIB can be selected from at least one of molybdic acid, paramolybdic acid, molybdates, paramolybdates, tungstic acid, metatungstic acid, ethylmetungstic acid, tungstates, metatungstates and ethylmetungstic acid.

[0065] According to the present invention, the aqueous solution containing the compound of the metal of group VIII and the compound of the metal of group VIB may also contain an organic additive, and the organic additive may be selected from organic acids and organic amines; the organic acid refers to an organic compound containing at least one carboxyl group (-COOH) in the molecular structure, and the organic amine refers to an organic compound containing at least one amine group (-NH2) in the molecular structure. Preferably, the organic acid contains at least two carboxyl groups in the molecular structure, and the organic amine contains at least two amine groups in the molecular structure. The organic additive is preferably selected from citric acid, aminotriacetic acid, ethylenediamine and ethylenediaminetetraacetic acid. More preferably, the organic additive is selected from organic carboxylic acids, such as citric acid. The content of the organic additive can be selected according to the content of the compound containing the metal element of group VIII. The molar ratio of the organic additive to the metal element of group VIII in terms of element may be 0.1-10, preferably 0.4-8, more preferably 0.5-4, further preferably 0.8-2, and further preferably 0.9-1.5, such as 0.95-1.2.

[0066] According to the present invention, in step S1, the conditions for the impregnation include: an impregnation temperature of 5-150°C, and an impregnation time of 0.5-12 hours; in step S2, the conditions for the first drying treatment include: a drying temperature of 50-300°C, preferably 100-250°C, and more preferably 110-180°C; a drying time of 1-12 hours, and preferably 2-8 hours; the conditions for the first roasting include: a roasting temperature of 360-700°C, preferably 300-650°C; and a roasting time of 0.2-12 hours, and preferably 1-10 hours.

[0067] According to the present invention, the method for preparing the carrier may include:

[0068] SS1, mixing pseudo-thin diatomite, amorphous silicon aluminum oxide, Y-type molecular sieve and sesbania powder to obtain a first mixed powder; or mixing pseudo-thin diatomite, amorphous silicon aluminum oxide, Y-type molecular sieve, methyl cellulose and sesbania powder to obtain a second mixed powder;

[0069] SS2, mixing the first mixed powder or the second mixed powder with a nitric acid solution, kneading and extruding to obtain an extruded strip;

[0070] SS3. subjecting the extruded strip to a second drying and a second calcination.

[0071] According to the present invention, the weight ratio of the pseudo-thin alumina, the amorphous silica-aluminum oxide, the Y-type molecular sieve and the sesbania powder can be 20-85:10-60:0.1-60:1-5; preferably 25-75:15-55:0.5-40:2-4; or the weight ratio of the pseudo-thin alumina, the amorphous silica-aluminum oxide, the Y-type molecular sieve, the methyl cellulose and the sesbania powder can be 20-85:10-60:0.1-60:0.01-5:1-5; preferably 25-75:15-55:0.5-40:0.1-3:2-4; in step SS2, the amount of the nitric acid solution used can be 0.5-4mL per 100g of the mixed powder.

[0072] According to the present invention, the content of SiO2 in the pseudo-thin diatomite can be less than 0.1wt%, the content of Fe2O3 can be less than 0.01wt%, the content of Na2O can be less than 0.15wt%, the content of water can be less than 3wt%, and the loss on ignition can be 32-38%; the pore volume of the pseudo-thin diatomite can be 0.60-1.1mL / g, and the specific surface area can be 220-310m 2 / g; the characteristics of the amorphous silicon aluminum oxide may include: a SiO2 content of 15-55%, an Al2O3 content of 45-85%, and a bulk density of 250-450g / L; the mass concentration of the nitric acid solution is: 0.3-3%.

[0073] According to the present invention, in step SS2, the mixing conditions may include: a temperature of 10-40°C and a time of 1-10 minutes; in step SS3, the second drying conditions may include: a temperature of 80-250°C, preferably 110-200°C; a time of 1-12 hours; the second roasting conditions may include: a temperature of 300-650°C; a time of 1-8 hours, preferably 2-6 hours; and an air flow rate of 20-50L / h.

[0074] According to the present invention, the hydrogenation conditions may include: a temperature of 200-650°C, preferably 300-510°C; a hydrogen partial pressure of 3-24MPa, preferably 4-10MPa; a liquid hourly volume space velocity of the raw material of 0.1-50h -1 , preferably 2-40h -1 .

[0075] The present invention is further illustrated by the following examples, but the present invention is not limited thereto.

[0076] Example 1

[0077] Take 47.3g of SB powder (from the catalyst Changling branch, produced by SASOL, dry basis 74.0%), 43.9g of Siral40 powder (from the catalyst Changling branch, produced by SASOL, silicon oxide content 40.3%, dry basis 79.7%), and 37.69g of molecular sieve USY-1 (from the catalyst Changling branch, unit cell constant 24.47Å, crystallinity 83.7%, Na2O 0.01%, dry basis 79.6%); add 1.5g of methyl cellulose and 3.0g of sesbania powder, mix well and set aside. Add 1.0mL of concentrated nitric acid to 83mL with water and stir at room temperature for 5 minutes. The nitric acid solution was mixed with the mixed powder, and the mixture was repeatedly kneaded for 3 times using a small extruder. Then, the extruded strips were extruded using a Ø1.6mm trilobal orifice plate. The extruded strips were dried at 120°C for 6 hours, and the dried strips were put into a roasting furnace and roasted at 570°C for 3.0 hours, maintaining an air flow rate of 30L / h, cooled to room temperature, and taken out, which was recorded as carrier AC.

[0078] A mixed aqueous solution of nickel nitrate (analytical grade) and ammonium metatungstate (obtained from Changling Catalyst Factory) was prepared according to the content of tungsten oxide in the catalyst being 23.0% by weight and the content of nickel oxide being 5.5% by weight, and the amount of water was adjusted, and the prepared porous carrier was impregnated by the pore saturation method. The impregnated porous carrier was dried at 115°C for 5 hours, and then calcined at 440°C for 3 hours. During the calcination process, the air flow rate was maintained at not less than 27.5 cubic meters / (kg carrier•hour), thereby obtaining catalyst AS.

[0079] Example 2

[0080] Take SB powder (from catalyst Changling branch, produced by SASOL, dry basis 74.0%) 60.8g, Siral40 powder (from catalyst Changling branch, produced by SASOL, silicon oxide content 40.3%, dry basis 79.7%) 50.2g, molecular sieve USY-2 (from catalyst Changling branch, unit cell constant 24.42Å, crystallinity 81.7%, Na2O 0.01%, dry basis 82.7%) 18.14g; 3.0g sesbania powder, mix well and set aside. Add water to 3.1mL concentrated nitric acid to 87mL, and stir at room temperature for 5 minutes. The nitric acid solution was mixed with the mixed powder, and the mixture was repeatedly kneaded for 3 times using a small extruder. Then, the extruded strips were extruded using a Ø1.6mm trilobal orifice plate. The extruded strips were dried at 120°C for 6 hours, and the dried strips were put into a roasting furnace and roasted at 590°C for 2.5 hours, maintaining an air flow rate of 25L / h, and then cooled to room temperature and taken out, which was recorded as carrier BC.

[0081] A mixed aqueous solution of nickel nitrate (analytical grade) and ammonium metatungstate (obtained from Changling Catalyst Factory) was prepared according to the content of tungsten oxide in the catalyst being 25.0% by weight and nickel oxide being 7.0% by weight, and the amount of water was adjusted, and the prepared porous carrier was impregnated by the pore saturation method. The impregnated porous carrier was dried at 115°C for 5 hours, and then calcined at 450°C for 3 hours. During the calcination process, the air flow rate was maintained at not less than 35 cubic meters / (kg carrier•hour), thereby obtaining the catalyst BS.

[0082] Example 3

[0083] Take 84.5g of SB powder (from the catalyst Changling branch, produced by SASOL, dry basis 74.0%), 22.0g of Siral40 powder (from the catalyst Changling branch, produced by SASOL, silicon oxide content 40.3%, dry basis 79.7%), 24.18g of molecular sieve USY-2 (from the catalyst Changling branch, unit cell constant 24.42Å, crystallinity 81.7%, Na2O 0.01%, dry basis 82.7%), and 3.0g of sesbania powder, mix well and set aside. Add water to 2.5mL of concentrated nitric acid to 72mL, and stir at room temperature for 5 minutes. The nitric acid solution was mixed with the mixed powder, and the mixture was repeatedly kneaded for 3 times using a small extruder. Then, the extruded strips were extruded using a Ø1.6mm trilobal orifice plate. The extruded strips were dried at 120°C for 6 hours, and the dried strips were put into a roasting furnace and roasted at 590°C for 2.5 hours, maintaining an air flow rate of 25L / h. The strips were cooled to room temperature and taken out, which was recorded as carrier DC.

[0084] A mixed aqueous solution of nickel nitrate (analytical grade) and ammonium metatungstate (obtained from Changling Catalyst Factory) was prepared according to the content of tungsten oxide in the catalyst being 27.0% by weight and nickel oxide being 2.7% by weight, and the amount of water was adjusted, and the prepared porous carrier was impregnated by the pore saturation method. The impregnated porous carrier was dried at 115°C for 5 hours, and then calcined at 450°C for 3 hours. During the calcination process, the air flow rate was maintained at not less than 13.5 cubic meters / (kg carrier•hour), thereby obtaining the catalyst DS.

[0085] Comparative Example 1

[0086] Take 87.2g of CE powder (from the catalyst Changling branch, produced by SASOL, dry basis 74.5%), 37.6g of Siral40 powder (from the catalyst Changling branch, produced by SASOL, silicon oxide content 40.3%, dry basis 79.7%), 6.05g of molecular sieve USY-2 (from the catalyst Changling branch, unit cell constant 24.42Å, crystallinity 81.7%, Na2O 0.01%, dry basis 82.8%); add 1.0g of methyl cellulose and 3.0g of sesbania powder, mix well and set aside. Add 2.6mL of concentrated nitric acid to 80mL with water and stir at room temperature for 5 minutes. The nitric acid solution was mixed with the mixed powder, and the mixture was repeatedly kneaded for 3 times using a small extruder. Then, the extruded strips were extruded using a Ø1.6mm trilobal orifice plate. The extruded strips were dried at 120°C for 6 hours, and the dried strips were put into a roasting furnace and roasted at 580°C for 3.0 hours, maintaining an air flow rate of 30L / h, and then cooled to room temperature and taken out. This was recorded as carrier XC.

[0087] A mixed aqueous solution of nickel nitrate (analytical grade) and ammonium metatungstate (obtained from Changling Catalyst Factory) was prepared according to the content of tungsten oxide in the catalyst being 26.0% by weight and nickel oxide being 4.0% by weight, and the amount of water was adjusted, and the prepared porous carrier was impregnated by the pore saturation method. The impregnated porous carrier was dried at 115°C for 5 hours, and then calcined at 430°C for 3 hours. During the calcination process, the air flow rate was maintained at not less than 20 cubic meters / (kg carrier•hour), thereby obtaining the catalyst XS.

[0088] Comparative Example 2

[0089] Take 67.1g of CE powder (from the catalyst Changling branch, produced by SASOL, dry basis 74.5%), 61.5g of Siral40 powder (from the catalyst Changling branch, produced by SASOL, silicon oxide content 40.3%, dry basis 79.7%), and 1.18g of molecular sieve USY-3 (from the catalyst Changling branch, unit cell constant 24.37Å, crystallinity 71.3%, Na2O 0.01%, dry basis 84.8%); add 1.0g of methyl cellulose and 3.0g of sesbania powder, mix well and set aside. Add 1.5mL of concentrated nitric acid to 93mL with water and stir at room temperature for 5 minutes. The nitric acid solution was mixed with the mixed powder, and the mixture was repeatedly kneaded for 3 times using a small extruder. Then, the extruded strips were extruded using a Ø1.6mm trilobal orifice plate. The extruded strips were dried at 120°C for 6 hours, and the dried strips were put into a roasting furnace and roasted at 610°C for 2.0 hours, maintaining an air flow rate of 20L / h, and then cooled to room temperature and taken out, which was recorded as carrier CC.

[0090] A mixed aqueous solution of nickel nitrate (analytical grade) and ammonium metatungstate (obtained from Changling Catalyst Factory) was prepared according to the content of tungsten oxide in the catalyst being 26.0% by weight and nickel oxide being 4.0% by weight, and the amount of water was adjusted, and the prepared porous carrier was impregnated by the pore saturation method. The impregnated porous carrier was dried at 115°C for 5 hours, and then calcined at 430°C for 3 hours. During the calcination process, the air flow rate was maintained at not less than 20 cubic meters / (kg carrier•hour), thereby obtaining the catalyst CS.

[0091] Test Example 1

[0092] Catalysts were prepared by testing Examples 1-4 and Comparative Example 1, and the nickel content and tungsten content in each catalyst were tested based on the total amount of the catalyst and calculated as oxide; the carrier content based on the total mass of the hydrogenation catalyst; and the Y-type molecular sieve content based on the total mass of the carrier. The specific testing method was XRF, and the test results are shown in Table 1.

[0093] Table 1

[0094]

[0095] Test Example 2

[0096] This test example uses the catalysts prepared in Examples 1-4 and Comparative Example 1 to hydrocracking heavy reformed oil of residual oil, with a density of 0.9731 g / mL at 20°C; sulfur content of 25530 μg / g; nitrogen content of 2800 μg / g; Ni+V content of <2 μg / g. Hydrogen content of 10.8%; carbon residue of 3.2%; asphaltene of <0.1%, total aromatics of 70.3%. Distillation range ASTM-D1160, 10%, 371°C; 30%, 428°C; 50%, 494°C; 70%, 570°C; 90%, 630°C. Evaluation conditions: hydrogen partial pressure of 13.0 MPa, volume space velocity of 0.23 h-1, hydrogen-to-oil ratio of 800. The amount of refining agent and modifier is 1:1, the temperature of the refining agent is 380°C, and the temperature of the modifier controls the appropriate conversion rate. The reaction results of each catalyst are shown in Table 2.

[0097] Table 2

[0098]

[0099] It can be seen from Table 1 that, compared with the comparative agent, the catalyst provided by the present invention has a higher content of aromatic hydrocarbons in diesel and tail oil, so the chemical hydrogen consumption of the catalyst provided by the present invention is lower.

[0100] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0101] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0102] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A hydrocracking method for producing diesel and tail oil from heavy distillate oil with low hydrogen consumption, characterized in that: Under hydrogenation conditions, a heavy distillate oil and hydrogen are contacted with a hydrogenation catalyst in a fixed bed hydrogenation reactor; the heavy distillate oil is a fraction having a dry point of not less than 650° C. and a metal content of less than 20 ppm, and the aromatic content of the heavy distillate oil is greater than 60% by weight; The hydrogenation catalyst comprises a carrier and an active metal component supported on the carrier; Based on the total mass of the hydrogenation catalyst, the content of the carrier is 50-88% by weight; The carrier contains a non-amorphous mesoporous acidic material and a Y-type molecular sieve; the content of the Y-type molecular sieve in the carrier is 5-45% by weight; The active metal components are metal elements of Group VIII and Group VIB; The specific surface area of ​​the carrier is 140-350m 2 / g; the carrier has a porous structure; in the porous structure, the pore diameter of the pores is in the range of 5-20nm; the pore volume of the carrier is 0.35-0.85mL / g; the pore concentration value of the pores is not less than 0.5; The preparation method of the carrier comprises: SS1, mixing pseudo-thin diatomite, amorphous silicon aluminum oxide, Y-type molecular sieve and sesbania powder to obtain a first mixed powder; or mixing pseudo-thin diatomite, amorphous silicon aluminum oxide, Y-type molecular sieve, methyl cellulose and sesbania powder to obtain a second mixed powder; SS2, mixing the first mixed powder or the second mixed powder with a nitric acid solution, kneading and extruding to obtain an extruded strip; SS3, subjecting the extruded strip to a second drying and a second calcination; Wherein, in step SS1, the weight ratio of the pseudo-alumina, the amorphous silica-alumina, the Y-type molecular sieve and the sesbania powder is 20-85:10-60:0.1-60:1-5; or The weight ratio of the pseudo-alumina, the amorphous silica-alumina, the Y-type molecular sieve, the methyl cellulose and the sesbania powder is 20-85:10-60:0.1-60:0.01-5:1-5.

2. The hydrocracking method according to claim 1, wherein: Based on the total mass of the hydrogenation catalyst, the content of the carrier is 62-77.5% by weight; The content of the Y-type molecular sieve in the carrier is 8-32% by weight.

3. The hydrocracking method according to claim 2, wherein: The content of the Y-type molecular sieve in the carrier is 15-25% by weight.

4. The hydrocracking method according to claim 1, wherein: The content of Group VIB metal is 15-35% by weight based on the total amount of catalyst and calculated as oxide; The content of Group VIII metal calculated as oxide, based on the total amount of the catalyst, is 0.5 to 10% by weight.

5. The hydrocracking method according to claim 4, wherein: The content of Group VIB metal is 18-32% by weight based on the total amount of catalyst and calculated as oxide; The content of Group VIII metal calculated as oxide, based on the total amount of the catalyst, is 1 to 8% by weight.

6. The hydrocracking method according to claim 5, wherein: The content of Group VIB metal is 20-30% by weight based on the total amount of catalyst and calculated as oxide; The content of Group VIII metal calculated as oxide, based on the total amount of the catalyst, is 2 to 8% by weight.

7. The hydrocracking method according to claim 1, wherein: The Group VIII metal element is cobalt and / or nickel, and the Group VIB metal element is molybdenum and / or tungsten.

8. The hydrocracking method according to claim 7, wherein: The Group VIII metal element is nickel, and the Group VIB metal element is tungsten.

9. The hydrocracking method according to claim 1, wherein: In the porous structure, the pores have a pore size in the range of 6-15 nm; The specific surface area of ​​the carrier is 160-320m 2 / g; The pore volume of the carrier is 0.4-0.8 mL / g; The pore concentration value of the pores is not less than 0.

75.

10. The hydrocracking method according to claim 1, wherein: The non-amorphous mesoporous acidic material is a silicon-aluminum composite oxide.

11. The hydrocracking method according to any one of claims 1 to 10, wherein: The hydrogenation catalyst is prepared according to the following steps: S1, impregnating the support with an aqueous solution containing a compound of a Group VIII metal and a compound of a Group VIB metal to obtain an impregnated support; S2, subjecting the impregnated support to a first drying and a first calcination.

12. The hydrocracking method according to claim 11, wherein: The compound of the Group VIII metal is selected from at least one of nitrates, chlorides, sulfates, formates, acetates, citrates, oxalates, carbonates, basic carbonates, hydroxides, phosphates, phosphides, sulfides, aluminates, molybdates, tungstates and water-soluble oxides of nickel and cobalt; The compound of the VIB group metal is selected from at least one of molybdic acid, molybdates, tungstic acid and tungstates.

13. The hydrocracking method according to claim 11, wherein: The compound of the VIB Group metal is selected from at least one of paramolybdic acid and paramolybdate.

14. The hydrocracking method according to claim 11, wherein the compound of the VIB Group metal is at least one selected from metatungstic acid, metatungstate and ethyl metatungstic acid.

15. The hydrocracking method according to claim 12, wherein: The compound of the Group VIII metal is selected from at least one of nickel nitrate, nickel sulfate, nickel acetate, basic nickel carbonate, cobalt nitrate, cobalt sulfate, cobalt acetate, basic cobalt carbonate, cobalt chloride and nickel chloride.

16. The hydrocracking method according to claim 11, wherein: The aqueous solution containing the compound of the Group VIII metal and the compound of the Group VIB metal further contains an organic additive, and the organic additive is selected from organic acids and organic amines; The molar ratio of the organic additive to the metal element of Group VIII is 0.1-10.

17. The hydrocracking method according to claim 16, wherein: The molar ratio of the organic additive to the metal element of Group VIII calculated as the element is 0.4-8.

18. The hydrocracking method according to claim 11, wherein: In step S1, the impregnation conditions include: an impregnation temperature of 5-150°C and an impregnation time of 0.5-12 hours; In step S2, the conditions of the first drying treatment include: a drying temperature of 50-300°C; a drying time of 1-12 hours; the conditions of the first calcination include: a calcination temperature of 360-700°C; a calcination time of 0.2-12 hours.

19. The hydrocracking method according to claim 18, wherein: In step S2, the conditions of the first drying treatment include: a drying temperature of 100-250°C; a drying time of 2-8 hours; and the conditions of the first calcination include: a calcination time of 1-10 hours.

20. The hydrocracking method according to claim 19, wherein: In step S2, the conditions of the first drying treatment include: a drying temperature of 110-180°C.

21. The hydrocracking method according to claim 1, wherein: In step SS2, the amount of the nitric acid solution is 0.5-4 mL per 100 g of the first mixed powder or the second mixed powder.

22. The hydrocracking method according to claim 1, wherein: In step SS1, the weight ratio of the pseudo-thin alumina, the amorphous silica-alumina, the Y-type molecular sieve and the sesbania powder is 25-75:15-55:0.5-40:2-4; or The weight ratio of the pseudo-alumina, the amorphous silica-alumina, the Y-type molecular sieve, the methyl cellulose and the sesbania powder is 25-75:15-55:0.5-40:0.1-3:2-4.

23. The hydrocracking method according to claim 1, wherein: The content of SiO2 in the pseudo-thin diatomite is less than 0.1wt%, the content of Fe2O3 is less than 0.01wt%, the content of Na2O is less than 0.15wt%, the content of water is less than 3wt%, and the loss on ignition is 32-38%; the pore volume of the pseudo-thin diatomite is 0.60-1.1mL / g, and the specific surface area is 220-310m 2 / g; The characteristics of the amorphous silicon aluminum oxide include: SiO2 content of 15-55%, Al2O3 content of 45-85%, and bulk density of 250-450g / L; The mass concentration of the nitric acid solution is 0.3-3%.

24. The hydrocracking method according to claim 1, wherein: In step SS2, the mixing conditions include: temperature of 10-40° C., time of 1-10 minutes; In step SS3, the second drying conditions include: temperature of 80-250°C; time of 1-12 hours; the second calcination conditions include: temperature of 300-650°C; time of 1-8 hours; air flow rate of 20-50L / h.

25. The hydrocracking method according to claim 24, wherein: In step SS3, the second drying conditions include: a temperature of 110-200° C.; the second calcination conditions include: a time of 2-6 hours.

26. The hydrocracking method according to claim 1, wherein: The hydrogenation conditions include: temperature of 200-650°C; hydrogen partial pressure of 3-24 MPa; liquid hourly volume space velocity of heavy distillate oil raw material of 0.1-50h -1 .

27. The hydrocracking method according to claim 26, wherein: The hydrogenation conditions include: temperature of 300-510°C; hydrogen partial pressure of 4-10 MPa; liquid hourly volume space velocity of heavy distillate oil raw material of 2-40h -1 .

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