Base oil production method

Abstract

The invention discloses a base oil production method, which comprises the following steps: mixing a raw material with hydrogen, feeding the mixture into a grading filling hydroisomerization dewaxing reactor, sequentially flowing through a protective agent layer and a catalyst layer to carry out hydroisomerization reaction, obtaining a catalytic product, and carrying out boiling point cutting to obtain base oil with a fraction of more than 340 DEG C. Along the material flow direction, the total acid amount of the catalyst is firstly increased and then reduced, and the molar percentage content of # imgabs0 # acid in the total acid amount is firstly increased and then reduced; the reaction temperature of the protective agent layer is lower than that of the catalyst layer, and the reaction temperature in the catalyst layer is firstly increased and then kept or reduced. According to the method, the hydroisodewaxing reactor filled in a specific grading manner is used and matched with temperature setting of different areas to produce the base oil, so that the yield of the base oil is higher, the content of sulfur and nitrogen is lower, the low-temperature performance (pour point and cloud point) indexes of the base oil can be effectively reduced, the viscosity index of the base oil is higher, and the service life of the base oil is prolonged. The quality of the base oil is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of lubricating oil production, and in particular to a base oil production method. Background Art

[0002] The production of lubricating oil base oil is mainly obtained by solvent refining and hydroprocessing with petroleum distillate as raw materials. The base oil produced by the solvent refining process alone is basically not used due to poor stability and other reasons, but is used in combination with the hydroprocessing process. At present, the production of lubricating oil base oil by the hydroprocessing process mainly adopts technologies such as hydrotreating, hydrocatalytic dewaxing, hydroisomerization dewaxing, and hydrocracking / hydroisomerization dewaxing.

[0003] At present, the mainstream process technology for lubricating base oil production is hydroisomerization dewaxing, and its main process is: hydrotreating-hydrodewaxing-hydrogenation refining; most of the hydrotreating processes are aimed at hydrodesulfurization, denitrogenation, deoxygenation and hydrogenation saturation of some aromatics; the hydroisomerization dewaxing process is aimed at lowering the pour point and converting the wax molecules in the raw oil, which mainly includes isomerization dewaxing process and catalytic dewaxing process; the hydrorefining process is to remove impurities such as sulfur, nitrogen, oxygen, etc. remaining in the oil after dewaxing, and saturate olefins to improve the stability and color of the oil.

[0004] During the production process of lubricating base oil, the low temperature performance (pour point and cloud point) of the base oil is one of the important indicators. At the same time, the overall yield level of the base oil will directly affect the economic benefits of the lubricating oil production device. In the prior art, when producing base oil with low pour point and cloud point, the total base oil yield level is low; when the total base oil yield level is high, the pour point and cloud point temperature of the base oil are high. How to effectively reduce the pour point and cloud point of the base oil while ensuring that the total base oil yield remains at a high level is a problem that needs to be solved in this field.

[0005] CN102311785A discloses a method for producing lubricating base oil by hydrogenating cycloalkyl distillate oil. The lubricating base oil is produced by using a one-stage series hydrogenation process of hydrotreating-hydrogenation decondensation-hydrogenation supplementary refining with cycloalkyl distillate oil as raw material. The method successfully utilizes the characteristics of different catalysts to produce lubricating base oil with low pour point and good stability; however, due to the independent loading of various catalysts, the technology has a certain contradiction in the balance between the yield of lubricating oil fraction and the improvement of decondensation effect, which reduces the life of the hydrodecondensation catalyst.

[0006] CN1769380A discloses a production method for directly producing white oil from paraffin-based crude oil fractions or lubricating oil base oil. The process adopts a one-stage series process, through different catalyst grading, different catalyst combination loading, and integrates hydrogenation pre-refining, hydrodecondensation, and hydrogenation supplementary refining. The technical process is simple, easy to operate, and the conditions are mild. The catalyst has a strong ability to resist sulfur and nitrogen, and there is no strict restriction on the sulfur and nitrogen content of the raw oil; however, the temperature drop in the hydrodecondensation process and the temperature rise in the hydrogenation process are not fully utilized, the device has a large energy consumption, the hot spot temperature is high, and the operation cycle is limited.

[0007] CN1257107A discloses a method for producing high-quality low-condensation diesel from fraction oil. The method adopts a series process of hydrofining and hydrodecondensation, including two catalyst beds of hydrofining catalyst and hydrodecondensation catalyst, and the hydrodecondensation uses Ni / ZSM-5 catalyst; however, the temperature drop of the hydrodecondensation catalyst bed is large, the yield of diesel fraction and the improvement of decondensation effect are subject to certain restrictions, and the service life of the hydrodecondensation catalyst is reduced.

[0008] CN111073696A discloses a method for reducing the cloud point of a high-viscosity lubricating oil base oil. A first catalyst and a second catalyst are arranged in sequence from top to bottom in a reaction device; the first catalyst and the second catalyst are two different precious metal isomerization dewaxing catalysts; the lubricating oil base oil raw material flows through the first catalyst and the second catalyst in sequence from top to bottom, the reaction temperature of the lubricating oil base oil flowing through the second catalyst is lower than the reaction temperature of the first catalyst, and after hydrogenation and refining, the vacuum tower bottom product obtained by normal and vacuum distillation is a low-cloud point high-viscosity lubricating oil base oil; the defects of this technology or the shortcomings of the present invention are: although the method can produce a lubricating oil base oil with a low cloud point, the total base oil yield is not high, which reduces the production economy of the device.

[0009] CN101942336A discloses a method for producing a low cloud point high viscosity index lubricating oil base oil (including distillate oil, cracking tail oil, Fischer-Tropsch wax), using a high wax content heavy distillate oil with an initial boiling point of 300°C to 460°C, a wax content of ≥5%, a pour point of ≥-20°C, and a cloud point of ≥-5°C as a raw material, and in the presence of hydrogen, through a hydrogenation pre-refining-isomerization / asymmetric cracking-hydrogenation post-refining reaction process to produce a low pour point and low cloud point high viscosity index lubricating oil base oil, and co-produce high-quality naphtha and middle distillate oil. Although the method can produce a low cloud point lubricating oil heavy base oil, the total base oil yield is not high. Summary of the invention

[0010] In order to effectively reduce the pour point and cloud point of base oil while maintaining the total base oil yield at a relatively high level, the present invention provides a base oil production method, which adopts a hydroisomerization dewaxing process, wherein the raw material enters a graded and loaded hydroisomerization dewaxing reactor under a hydrogen atmosphere, contacts with a catalyst for a hydroisomerization reaction, and the reaction temperature of different regions is designed during the reaction, so that the normal alkanes with a high freezing point in the raw material are converted into lubricating oil base oil with a low pour point.

[0011] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0012] The present invention provides a graded loading hydroisomerization dewaxing reactor, wherein the base oil production method comprises the following steps:

[0013] After the raw material is mixed with hydrogen, it enters a graded hydroisomerization dewaxing reactor, flows through a protective agent layer and a catalyst layer in sequence to perform a hydroisomerization reaction to obtain a catalytic product;

[0014] Perform boiling point cutting on the catalytic product to obtain base oil with a fraction greater than 340° C.;

[0015] The protective agent layer is filled with a protective agent, and the catalyst layer is filled with a catalyst; the total acid content of the catalyst increases first and then decreases, and the catalyst The molar percentage content of acid in the total acid content first increases and then decreases.

[0016] The reaction temperature of the protective agent layer is lower than the reaction temperature of the catalyst layer, and the reaction temperature of the catalyst layer along the material flow direction first increases and then remains unchanged or decreases.

[0017] According to the base oil production method of the present invention, preferably, the catalyst comprises an active metal and a carrier; based on the total mass of the catalyst, the mass proportion of the active metal is 0.1% to 1.0%, more preferably 0.2% to 0.5%; the rest is the carrier.

[0018] According to the base oil production method of the present invention, preferably, the active metal in the catalyst is selected from at least one of Pt, Pd, Ru and Ni, more preferably Pt and / or Pd.

[0019] According to the base oil production method of the present invention, preferably, the carrier contains at least one molecular sieve with a ten-membered ring topology structure; more preferably, it further contains at least one amorphous inorganic porous material;

[0020] The molecular sieves include ZSM-5, SAPO-11, ZSM-22, ZSM-35, ZSM-23, ZSM-48, SAPO-41, etc.; the amorphous inorganic porous materials include alumina, silica, zirconia, titania and their composite oxides, and their composite oxides include alumina-silica, zirconia-silica, titania-silica, alumina-zirconia, zirconia-titania, alumina-titania, etc.

[0021] According to the base oil production method of the present invention, preferably, based on the total mass of the catalyst, the mass proportion of the molecular sieve is 40% to 80%, more preferably 55% to 75%; the mass proportion of the amorphous inorganic porous material is 19% to 59.9%, more preferably 25% to 50%.

[0022] In this field, the types of acids in catalysts are divided into: Acid and Lewis acid. Among them, Acid, also known as proton acid, is a type of acid defined using the Bronsted acid-base proton theory. The Bronsted acid-base theory calls substances that can donate protons acids. The stronger the ability to donate protons, the stronger the acidity. Lewis acid is a type of acid defined using the Lewis acid-base theory. The Lewis acid-base theory calls substances with empty orbitals that can accept electron pairs acids. The stronger the ability to accept electron pairs, the stronger the acidity.

[0023] The present invention can use pyridine infrared spectroscopy analysis (Py-IR) characterization method to determine the catalyst The molar content of acid and Lewis acid, among which pyridine is adsorbed on The acid center forms a pyridinium ion with an infrared characteristic absorption peak at 1530-1560cm -1 The corresponding molar amount is The molar amount of acid; pyridine is adsorbed on the Lewis acid center, and the infrared characteristic absorption peak is at 1440~1460cm -1 , the corresponding molar amount is the molar amount of Lewis acid. The molar content of acid refers to the ratio based on The total molar amount of acid and Lewis acid, The mole percentage of acid.

[0024] In the present invention, the acid in the catalyst is divided into weak acid, medium strong acid and strong acid according to the acid strength. Wherein, the content of weak acid refers to the molar content of weak acid, the content of medium strong acid refers to the molar content of medium strong acid, the content of strong acid refers to the molar content of strong acid, and the total acid content refers to the sum of the molar contents of weak acid, medium strong acid and strong acid. In some embodiments, the molar content and total acid content of acids of various strengths in the catalyst can be determined by ammonia temperature programmed desorption (NH3-TPD) method. On the NH3-TPD desorption diagram, the amount of ammonia desorbed between 100°C and 230°C corresponds to the amount of weak acid, the amount of ammonia desorbed between 230°C and 370°C corresponds to the amount of medium strong acid, and the amount of ammonia desorbed greater than 370°C corresponds to the amount of strong acid. The specific operation method may include: purging the catalyst sample with helium at 500°C for 1 hour and then cooling it to 60°C, introducing saturated ammonia vapor, and pulse adsorption five times to reach equilibrium; heating to 100°C and purging for 2 hours, and then program heating at a heating rate of 10°C / min to desorb ammonia to 650°C; absorbing the desorbed ammonia with hydrochloric acid solution, and then titrating the excess hydrochloric acid with sodium hydroxide solution, and defining the amount of weak acid, medium-strong acid, strong acid, and total acid of the catalyst according to the amount of hydrochloric acid consumed to absorb the ammonia.

[0025] According to the base oil production method of the present invention, preferably, the total acid amount of the catalyst is 50-300 μmol / g, more preferably 100-300 μmol / g; the content of weak acid is 10-150 μmol / g, more preferably 20-100 μmol / g; the content of medium-strong acid is 5-250 μmol / g, more preferably 10-220 μmol / g.

[0026] According to the base oil production method of the present invention, preferably, the catalyst The molar percentage of the acid to the total acid content is 5% to 50%.

[0027] According to the base oil production method of the present invention, preferably, along the material flow direction, the catalyst layer includes a first catalyst sub-layer and a second catalyst sub-layer adjacent to each other in sequence;

[0028] In the first catalyst sublayer, the content of weak acid is greater than that of medium-strong acid; in the second catalyst sublayer, the content of weak acid is less than that of medium-strong acid.

[0029] Specifically preferably, the total acid content of the first catalyst sublayer is 50-200 μmol / g, the weak acid content is 20-100 μmol / g, and the medium-strong acid content is 10-80 μmol / g. The molar content of the acid is 5% to 20%. More preferably, the total acid content is 50 to 150 μmol / g, the weak acid content is 30 to 100 μmol / g, and the medium-strong acid content is 10 to 60 μmol / g. The molar content of the acid is 5% to 15%;

[0030] The total acid content of the second catalyst sublayer is 150-300 μmol / g, the weak acid content is 30-100 μmol / g, and the medium-strong acid content is 120-200 μmol / g. The molar content of the acid is 20% to 50%; more preferably, the total acid content is 200 to 300 μmol / g, the weak acid content is 50 to 100 μmol / g, and the medium-strong acid content is 150 to 200 μmol / g. The molar content of the acid is 30% to 50%.

[0031] It can be understood that in the present invention, the content of weak acid in the catalyst that contacts the material first is greater than the content of medium-strong acid, and the content of weak acid in the catalyst that contacts the material later is less than the content of medium-strong acid. At the same time, the total acid content of the catalyst increases first and then decreases, and the catalyst The molar content of acid increases first and then decreases.

[0032] The present invention adjusts the number and strength of the acid sites of the catalyst (especially Acid), can effectively adjust the distribution of products and the yield of base oil.

[0033] According to the base oil production method of the present invention, preferably, along the material flow direction, the catalyst layer further includes a third catalyst sublayer disposed after the second catalyst sublayer;

[0034] With respect to the total acid amount of the catalyst, the second catalyst sublayer is greater than the first catalyst sublayer and / or the third catalyst sublayer;

[0035] About Catalyst The molar percentage content of acid in the total acid amount, the second catalyst sublayer is greater than the first catalyst sublayer and / or the third catalyst sublayer;

[0036] In the third catalyst sublayer, the content of weak acid is less than that of medium-strong acid.

[0037] Preferably, the total acid content of the third catalyst sublayer is 100-300 μmol / g, the weak acid content is 20-100 μmol / g, and the medium-strong acid content is 50-200 μmol / g. The molar content of the acid is 20% to 50%; more preferably, the total acid content is 100 to 250 μmol / g, the weak acid content is 20 to 80 μmol / g, and the medium-strong acid content is 80 to 200 μmol / g. The molar content of the acid is 25% to 50%.

[0038] According to the base oil production method of the present invention, preferably, the active metal content in the protective agent gradually increases or remains unchanged, and / or the pore volume of the protective agent decreases and the specific surface area increases.

[0039] According to the base oil production method of the present invention, preferably, based on the total volume of the protective agent and the catalyst, the volume percentage content of the protective agent is 2% to 20%; the volume percentage content of the catalyst is 80% to 98%. More preferably, the volume percentage content of the protective agent is 2% to 10%; the volume percentage content of the catalyst is 90% to 98%.

[0040] According to the base oil production method of the present invention, preferably, the pore volume of the protective agent is 0.4-0.8 mL / g, and the specific surface area is 50-200 m 2 / g.

[0041] According to the base oil production method of the present invention, preferably, the mass percentage content of active metal in the protective agent is 0-5%, and the rest is Al2O3 and / or Al2O3-SiO2.

[0042] According to the base oil production method of the present invention, preferably, the active metal in the protective agent is at least one selected from Co, Mo, Ni, and W.

[0043] According to the base oil production method of the present invention, preferably, along the material flow direction, the protective agent layer includes a first protective agent sub-layer and a second protective agent sub-layer adjacent to each other in sequence;

[0044] With respect to the active metal content of the protectant, the first protectant sublayer is less than or equal to the second protectant sublayer.

[0045] According to the base oil production method of the present invention, preferably, the active metal content of the protective agent in the first protective agent sublayer is 0-3wt%, and the active metal content of the protective agent in the second protective agent sublayer is 1wt%-5wt%.

[0046] According to the base oil production method of the present invention, preferably, the pore volume of the protective agent in the first protective agent sublayer is 0.7-0.8 mL / g, and the specific surface area is 80-130 m 2 / g; the pore volume of the protective agent in the second protective agent sublayer is 0.5 to 0.6 mL / g, and the specific surface area is 140 to 170 m 2 / g.

[0047] According to the base oil production method of the present invention, preferably, the raw material is selected from at least one of hydrocracking tail oil, paraffin wax oil, naphthenic wax oil, intermediate wax oil, wax oil or wax paste. The catalytic product can enter the supplementary refining reactor or directly enter the fractionation equipment for boiling point cutting to produce lubricating oil base oils of different viscosities.

[0048] According to the base oil production method of the present invention, preferably, the sulfur content in the raw material is ≤10 mg / g, and the nitrogen content is ≤5 mg / g; and the distillation range of the raw material is 300°C to 600°C.

[0049] According to the base oil production method of the present invention, preferably, in the hydroisomerization reaction, the hydrogen-oil volume ratio is 100-1000:1, the reaction pressure is 6-15 MPa, and the volume space velocity is 0.5-3.0 h -1 The reaction temperature of the protective agent layer is 300-350°C, and the reaction temperature of the catalyst layer is 330-400°C.

[0050] The inventors found in their research that when the isomerization dewaxing method is used to produce lubricating oil base, the hydroisomerization reaction and the hydrocracking reaction are parallel reaction processes, and the reaction temperature is directly related to the base oil yield and the service life of the catalyst. When the reaction temperature is high, the material conversion rate is high, and the cracking and hydroisomerization conversion depths of the materials will increase. Among them, the increase in the proportion of raw material cracking will increase the production of light oil products and cause the base yield to decrease; when the reaction temperature is low, the raw material conversion depth is low, and the generated base oil product condensation point and pour point do not meet the requirements. Therefore, in the process of producing lubricating oil base oil, there is an optimal reaction temperature distribution range and a maximum reaction temperature. The present invention finds that within the reaction temperature range, along the material flow direction, the reaction temperature of the reactor bed layer that first contacts the material should not be too high, otherwise the hydrocracking reaction rate and the catalyst coking process will be rapidly aggravated; along the material flow direction, the temperature of the middle bed layer area of ​​the reactor is gradually increased, so that the catalyst activity can be slowly released, the cracking depth can be effectively controlled and the depth of hydroisomerization can be guaranteed, and the catalyst coking can be avoided; the temperature of the lower bed layer area of ​​the reactor is kept unchanged or appropriately reduced, so that a small amount of unconverted material can be isomerized, and at the same time, the cracking depth of the oil product is not deepened, and the yield of light oil products is reduced, thereby ensuring the base oil yield.

[0051] The base oil production method provided by the present invention converts heavy wax oil into a lubricating base oil with low pour point and low cloud point through a protective agent layer and a catalyst layer under a hydrogen atmosphere, and produces the lubricating base oil with high yield. By loading the protective agent layer and the catalyst layer in the hydroisomerization dewaxing reactor, the acid content and acid strength in the catalyst layer are reasonably distributed, and the protective agent layer temperature and the catalyst layer temperature gradient increase along the material flow direction in the reactor, and the catalyst layer reaction temperature first increases and then remains unchanged or decreases, so as to control the excessive cracking of the oil product, so that the overall catalytic efficiency of the protective agent and the catalyst is improved, and the low temperature performance of the base oil is further reduced. Since the acid content and acid strength distribution in the catalyst layer are reasonably limited, the reaction temperature is reasonably distributed and controlled in the reactor, so that the cracking performance of the oil product is reduced, and the oil product is subjected to the hydroisomerization reaction to the maximum extent, thereby improving the yield of the base oil, and the viscosity index of the base oil can also be improved by using the method of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is a graph showing the variation trend of the total acid content of the catalyst in the catalyst layer along the material flow direction in some embodiments of the present invention.

[0053] Figure 2 This is a trend diagram of the total acid content of the catalyst in the catalyst layer along the material flow direction in other embodiments of the present invention. DETAILED DESCRIPTION

[0054] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0055] The base oil production method provided by the present invention uses a hydroisomerization dewaxing reactor with graded combination loading to reasonably distribute the acid content and acid distribution in the catalyst, and at the same time controls the reaction temperature in different areas. In the presence of hydrogen, heavy wax oil is converted into a lubricating oil base oil with a low pour point and low cloud point through a protective agent layer and a catalyst layer, and the lubricating oil base oil is produced with a high yield.

[0056] In the graded hydroisomerization dewaxing reactor of the present invention, along the material flow direction:

[0057] A protective agent layer and a catalyst layer are sequentially arranged in the hydroisomerization dewaxing reactor, wherein the protective agent layer is filled with a protective agent, and the catalyst layer is filled with a catalyst;

[0058] The total acid content of the catalyst increases first and then decreases, and the catalyst The molar percentage content of acid in the total acid content first increases and then decreases.

[0059] When the hydroisomerization dewaxing reactor is used for base oil production, the reaction temperature of the protective agent layer is lower than that of the catalyst layer, and in the catalyst layer, the temperature first rises and then remains unchanged or decreases, thereby avoiding the protective agent layer or the catalyst that first contacts the material from having an excessively high temperature, directly reacting with the oil product, aggravating the cracking of the oil product and the coking of the catalyst, reducing the light components of the product, and prolonging the service life of the catalyst.

[0060] Figure 1 This is a trend diagram of the total acid content of the catalyst in the catalyst layer along the material flow direction in some embodiments of the present invention. Along the material flow direction, the total acid content of the catalyst may change in a gradient, first increasing and then decreasing. Figure 2 This is a trend diagram of the total acid content of the catalyst in the catalyst layer along the material flow direction in other embodiments of the present invention. Along the material flow direction, the total acid content of the catalyst may gradually increase and then gradually decrease.

[0061] The present invention adjusts the number and strength of the acid sites of the catalyst (especially Acid), can effectively adjust the distribution of products and the yield of base oil.

[0062] Specifically, the catalyst comprises an active metal and a carrier. Based on the total mass of the catalyst, the mass percentage of the active metal is 0.1% to 1.0%, more preferably 0.2% to 0.5%; the rest is the carrier.

[0063] The active metal may be selected from at least one of Pt, Pd, Ru and Ni, more preferably Pt and / or Pd.

[0064] The carrier contains at least one molecular sieve with a ten-membered ring topology; the molecular sieve includes ZSM-5, SAPO-11, ZSM-22, ZSM-35, ZSM-23, ZSM-48, SAPO-41, etc.; more preferably, the carrier further contains at least one amorphous inorganic porous material, and the amorphous inorganic porous material includes Al2O3, SiO2, ZrO2, TiO2 and composite oxides thereof (Al2O3-SiO2, ZrO2-SiO2, TiO2-SiO2, Al2O3-ZrO2, ZrO2-TiO2, Al2O3-TiO2). Based on the total mass of the catalyst, the mass proportion of the molecular sieve is preferably 40% to 80%, more preferably 55% to 75%; the mass proportion of the amorphous inorganic porous material is 19% to 59.9%, more preferably 25% to 50%.

[0065] The catalyst layer of the present invention may be provided with catalysts with different acid amounts prepared from one type of molecular sieve, such as catalysts prepared from ZSM-22 molecular sieves with different acid amounts, or may be provided with catalysts with different acid amounts prepared from different types of molecular sieves.

[0066] Preferably, the total acid content of the catalyst is 50-300 μmol / g, more preferably 100-300 μmol / g; the weak acid content is 10-150 μmol / g, more preferably 20-100 μmol / g; the medium-strong acid content is 5-250 μmol / g, more preferably 10-220 μmol / g. The molar percentage of the acid to the total acid content is preferably 5% to 50%.

[0067] The above catalysts are graded and loaded in the catalyst layer. Along the material flow direction, the total acid content of the catalyst increases first and then decreases. The molar content of acid increases first and then decreases.

[0068] For example, in a preferred embodiment, along the material flow direction, the catalyst layer includes a first catalyst sub-layer and a second catalyst sub-layer that are adjacent to each other in sequence;

[0069] In the first catalyst sublayer, the content of weak acid is greater than that of medium-strong acid; in the second catalyst sublayer, the content of weak acid is less than that of medium-strong acid.

[0070] It can be understood that in the present invention, the content of weak acid in the catalyst that contacts the material first is greater than the content of medium-strong acid, and the content of weak acid in the catalyst that contacts the material later is less than the content of medium-strong acid. At the same time, the total acid content of the catalyst increases first and then decreases, and the catalyst The molar content of acid increases first and then decreases.

[0071] Preferably, the total acid content of the first catalyst sublayer is 50-200 μmol / g, the weak acid content is 20-100 μmol / g, and the medium-strong acid content is 10-80 μmol / g. The molar content of the acid is 5% to 20%. More preferably, the total acid content is 50 to 150 μmol / g, the weak acid content is 30 to 100 μmol / g, and the medium-strong acid content is 10 to 60 μmol / g. The molar content of the acid is 5% to 15%.

[0072] The total acid content of the second catalyst sublayer is 150-300 μmol / g, the weak acid content is 30-100 μmol / g, and the medium-strong acid content is 120-200 μmol / g. The molar content of the acid is 20% to 50%; more preferably, the total acid content is 200 to 300 μmol / g, the weak acid content is 50 to 100 μmol / g, and the medium-strong acid content is 150 to 200 μmol / g. The molar content of the acid is 30% to 50%.

[0073] By using the graded loading method of the catalyst layer of the present invention, the material can be mixed with hydrogen and then enter the catalytic reaction unit for reaction. The reaction products produced by the catalytic reaction unit can enter the supplementary refining reactor or directly enter the distillation equipment for base oil cutting to produce lubricating base oils of different viscosities.

[0074] In some embodiments of the present invention, along the material flow direction, the catalyst layer further preferably includes a third catalyst sublayer disposed after the second catalyst sublayer;

[0075] With respect to the total acid amount of the catalyst, the second catalyst sublayer is greater than the first catalyst sublayer and / or the third catalyst sublayer;

[0076] About Catalyst The molar percentage content of acid in the total acid amount, the second catalyst sublayer is greater than the first catalyst sublayer and / or the third catalyst sublayer;

[0077] In the third catalyst sublayer, the content of weak acid is less than that of medium-strong acid.

[0078] It can be understood that the catalyst layer of the present invention may include a first catalyst sub-layer, a second catalyst sub-layer and a third catalyst sub-layer in sequence along the material flow direction.

[0079] It can be understood that in the present invention, the total acid amount of the catalyst in the first catalyst sublayer and the total acid amount of the catalyst in the third catalyst sublayer can be the same or different, as long as the total acid amount of the catalyst can be increased first and then decreased along the material flow direction. The molar content of the acid and the third catalyst sublayer The molar content of the acid can be the same or different, as long as it can make the catalyst The molar content of the acid can be increased first and then decreased.

[0080] Preferably, the total acid content of the third catalyst sublayer is 100-300 μmol / g, the weak acid content is 20-100 μmol / g, and the medium-strong acid content is 50-200 μmol / g. The molar content of the acid is 20% to 50%; more preferably, the total acid content is 100 to 250 μmol / g, the weak acid content is 20 to 80 μmol / g, and the medium-strong acid content is 80 to 200 μmol / g. The molar content of the acid is 25% to 50%.

[0081] Through the above arrangement, the present invention can further improve the catalytic effect of the catalyst, increase the yield of the base oil, and improve the viscosity index, pour point and cloud point of the base oil.

[0082] In the present invention, the amount of acid in the catalyst layer can be further limited in order to further improve the catalytic efficiency of the catalyst and improve the yield, viscosity index, pour point and cloud point of the base oil.

[0083] In some embodiments of the present invention, in the catalyst layer, in at least one catalyst sublayer, The molar content of the acid is 5% to 50%. Further, in at least one catalyst sublayer, The molar content of the acid is 5% to 40%.

[0084] The catalyst of the present invention contains weak acid centers and medium-strong acid centers. In the catalyst layer, in at least one catalyst sublayer, the total acid amount of the catalyst is 50 to 300 μmol / g. Furthermore, in at least one catalyst sublayer, the total acid amount of the catalyst is 100 to 300 μmol / g.

[0085] In some embodiments of the present invention, in the catalyst layer, in at least one catalyst sublayer, the weak acid content of the catalyst is 10-150 μmol / g; and / or in at least one catalyst sublayer, the medium-strong acid content of the catalyst is 5-250 μmol / g.

[0086] Furthermore, in the catalyst layer, in at least one catalyst sublayer, the weak acid content of the catalyst is 20-100 μmol / g; and / or in at least one catalyst sublayer, the medium-strong acid content of the catalyst is 10-200 μmol / g.

[0087] In some embodiments of the present invention, in the protective agent layer in the hydroisomerization dewaxing reactor, the active metal content in the protective agent gradually increases or remains unchanged, and / or the pore volume of the protective agent decreases and the specific surface area increases.

[0088] In the hydroisomerization dewaxing reactor of the present invention, a protective agent layer is also provided before the catalyst layer. It is understood that the material first flows through the protective agent layer for impurity removal, and the impurity-removed material then flows through the catalyst layer for catalytic reaction. The present invention can convert the material into base oil to a greater extent by first removing impurities from the material and then carrying out the catalytic reaction, thereby improving the yield of the base oil, and can also reduce the impurity content in the base oil and improve the quality of the base oil.

[0089] Based on the total volume of the protective agent and the catalyst, the volume percentage content of the protective agent is preferably 2% to 20%, and the volume percentage content of the catalyst is 80% to 98%. More preferably, the volume percentage content of the protective agent is 2% to 10%, and the volume percentage content of the catalyst is 90% to 98%.

[0090] The active metal in the protective agent can remove organic impurities (desulfurization and denitrification). The higher the active metal content in the protective agent, the stronger the impurity removal ability of the protective agent (the stronger the desulfurization and denitrification ability). In the present invention, the active metal can be at least one of Co, Mo, Ni, and W. The mass percentage content of the active metal in the protective agent is 0-5%, and the rest is Al2O3 and / or Al2O3-SiO2.

[0091] The pore volume of the protective agent is preferably 0.4 to 0.8 mL / g, and the specific surface area is preferably 50 to 200 m 2 / g.

[0092] In the present invention, more than two protective agents may be arranged in the protective agent layer, and along the material flow direction, the pore volume between the protective agents gradually decreases or decreases in steps, and the specific surface area of ​​the protective agents gradually increases or increases in steps.

[0093] The pore volume between the protective agents can adsorb inorganic impurities. The larger the pore volume, the stronger the adsorption capacity.

[0094] The present invention grades the protective agent according to the impurity removal ability, which can improve the impurity removal effect of the protective agent, thereby improving the catalytic effect of the catalytic reaction and improving the yield and quality of the base oil.

[0095] Exemplarily, along the material flow direction, the protective agent layer includes a first protective agent sub-layer and a second protective agent sub-layer adjacent to each other in sequence;

[0096] With respect to the active metal content of the protectant, the first protectant sublayer is less than or equal to the second protectant sublayer.

[0097] For example, the active metal content of the protective agent in the first protective agent sublayer is 0-3wt%, the active metal content of the protective agent in the second protective agent sublayer is 1wt%-5wt%, the active metal in the protective agent is selected from one or a combination of Co, Mo, Ni, and W, and the rest of the protective agent except the active metal is an amorphous inorganic porous material. The amorphous inorganic porous material includes Al2O3, SiO2, ZrO2, TiO2 and their composite oxides (Al2O3-SiO2, ZrO2-SiO2, TiO2-SiO2, Al2O3-ZrO2, ZrO2-TiO2, Al2O3-TiO2), preferably alumina (Al2O3) and / or composite oxide amorphous silicon aluminum (Al2O3-SiO2).

[0098] Preferably, the pore volume and specific surface area of ​​the first protective agent sublayer are 0.7-0.8 mL / g and 80-130 m 2 / g; the pore volume and specific surface area of ​​the second protective agent sublayer are 0.5-0.6 mL / g and 140-170 m 2 / g.

[0099] The production of base oil using a hydroisomerization dewaxing reactor filled with any of the above graded configurations comprises the following steps:

[0100] After the raw material is mixed with hydrogen, it enters into any one of the above graded hydroisomerization dewaxing reactors and flows through the protective agent layer and the catalyst layer in sequence to perform hydroisomerization reaction to obtain a catalytic product;

[0101] The catalytic product is subjected to boiling point cutting to obtain a base oil with a fraction greater than 340° C.

[0102] The raw material can be selected from at least one of hydrocracking tail oil, paraffin wax oil, naphthenic wax oil, intermediate wax oil, wax oil or wax paste. Preferably, the sulfur content of the raw material is ≤10 mg / g, and the nitrogen content is ≤5 mg / g; the distillation range of the raw material is 300°C to 600°C.

[0103] In the production process, in the hydroisomerization reaction, the hydrogen-oil volume ratio is 100-1000:1, the reaction temperature is 300-400°C, the reaction pressure is 6-15MPa, and the volume space velocity is 0.5-3.0h -1 The reaction temperature of the protective agent layer is 300-350°C, and the reaction temperature of the catalyst layer is 330-400°C.

[0104] The reaction temperature of the protective agent layer is lower than that of the catalyst layer. In the catalyst layer, in the direction of the logistics, the reaction temperature first increases and then remains or decreases. More specifically, the reaction temperature of the first catalyst sublayer is lower than that of the second catalyst sublayer, and the reaction temperature of the third catalyst sublayer is not higher than that of the second catalyst sublayer.

[0105] For example, the test conditions used in the embodiment include: hydrogen-to-oil volume ratio of 500, protective agent layer temperature of 350°C, first catalyst sublayer reaction temperature of 360°C, second catalyst sublayer reaction temperature of 370°C, third catalyst sublayer reaction temperature of 365°C, reaction pressure of 12MPa, volume space velocity of 1.2h -1 .

[0106] For example, another test condition used in the embodiment includes: hydrogen-to-oil volume ratio of 500, protective agent layer temperature of 350°C, first catalyst sublayer reaction temperature of 360°C, second catalyst sublayer reaction temperature of 370°C, third catalyst sublayer reaction temperature of 370°C, reaction pressure of 12MPa, volume space velocity of 1.2h -1 .

[0107] Another test condition used in the embodiment includes: hydrogen-to-oil volume ratio of 400, protective agent layer temperature of 320°C, first catalyst sublayer reaction temperature of 330°C, second catalyst sublayer reaction temperature of 340°C, third catalyst sublayer reaction temperature of 335°C, reaction pressure of 8MPa, volume space velocity of 1.5h -1 .

[0108] Another test condition used in the embodiment includes: hydrogen-to-oil volume ratio of 400, protective agent layer temperature of 320°C, first catalyst sublayer reaction temperature of 330°C, second catalyst sublayer reaction temperature of 340°C, third catalyst sublayer reaction temperature of 340°C, reaction pressure of 8MPa, volume space velocity of 1.5h -1 .

[0109] The technical scheme of the present invention will be further described below in conjunction with specific embodiments. All numerical values ​​specified therein (such as temperature, time, concentration and weight, including the range of each thereof) can generally be appropriately changed by (+) or (-) approximate values ​​in increments of 0.1 or 1.0. All numerical values ​​specified can be understood as being preceded by the term "about".

[0110] Examples 1-3, Comparative Examples 1-3

[0111] The gradations of the catalyst layer and the protective agent layer in the hydroisomerization dewaxing reactor of Examples 1-3 and Comparative Examples 1-3 are shown in Table 1.

[0112] Table 1 Protective agent and catalyst properties and graded filling method

[0113]

[0114]

[0115]

[0116] Test Example 1

[0117] The hydroisomerization dewaxing reactor loaded with the protective agent and catalyst grade in Table 1 was used for the hydroisomerization reaction. The reaction pressure (hydrogen partial pressure) was 12 MPa and the total liquid hourly volume space velocity was 1.2 h -1 , the hydrogen-to-oil volume ratio is 500:1, and the reaction temperature process parameters of the two protective agent layers and the three catalyst layers in Table 1 are shown in Table 2. Comparative Example 4 uses the same graded filling method as Example 2 in Table 1, except that the reaction temperatures of the first protective agent sublayer, the second protective agent sublayer, the first catalyst sublayer, and the third catalyst sublayer, the reaction pressure (hydrogen partial pressure) of Comparative Example 4 is 12 MPa, and the total liquid hourly volume space velocity is 1.2 h -1 , the hydrogen-oil volume ratio is 500:1, and the reaction temperature process parameters are shown in Table 2.

[0118] The properties of the raw oil used are shown in Table 3. After the catalytic product is obtained, boiling point cutting is performed to obtain the base oil with a fraction greater than 340°C. The properties of the base oil are analyzed, and the results are shown in Table 4.

[0119] Table 2 Temperature in the reaction process / ℃

[0120] Bed Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 First Protectant Sublayer 350 350 350 370 370 370 380 Second Protectant Sublayer 350 350 350 370 370 370 380 First catalyst sublayer 360 360 365 370 370 370 380 Second catalyst sublayer 370 370 370 370 370 370 370 The third catalyst sublayer 365 370 360 370 370 370 370

[0121] Table 3 Raw material properties

[0122]

[0123] Table 4 Product properties and yield

[0124]

[0125] As can be seen from Table 4, relative to Comparative Examples 1 to 4, the protective agent and catalyst grading filling method of the hydroisomerization dewaxing reactor in Examples 1 to 3 of the present invention, as well as the defined protective agent layer and catalyst layer reaction temperatures, can be used. The efficient grading method can allow the material to be deeply isomerized and the cracking depth of the material to be controlled, which can effectively improve the yield of the base oil and effectively reduce the pour point and cloud point properties of the base oil. Controlling the reactor bed temperature can prevent the material from reacting too violently when initially contacting the protective agent and the catalyst, resulting in excessive cracking, excessive generation of light oil products, and reduced base oil yield. In addition, a high initial reaction temperature can also accelerate catalyst coking and affect the service life of the protective agent and the catalyst. At the same time, the base oil product obtained by the production method of the present invention has a higher viscosity index, and the sulfur and nitrogen contents in the product are lower, which can effectively improve the quality of the base oil.

[0126] Test Example 2

[0127] The hydroisomerization dewaxing reactor loaded with the protective agent and catalyst grade in Table 1 was used for the hydroisomerization reaction. The reaction pressure (hydrogen partial pressure) was 8 MPa and the total liquid hourly volume space velocity was 1.5 h -1 , the hydrogen-to-oil volume ratio is 400:1, and the reaction temperature process parameters of the two protective agent layers and the three catalyst layers in Table 1 are shown in Table 5. Comparative Example 5 uses the same graded filling method as Example 1 in Table 1, except that the reaction temperatures of the first protective agent sublayer, the second protective agent sublayer, the first catalyst sublayer and the third catalyst sublayer, the reaction pressure (hydrogen partial pressure) of Comparative Example 5 is 8MPa, and the total liquid hourly volume space velocity is 1.5h -1 , the hydrogen-oil volume ratio is 400:1, and the reaction temperature process parameters are shown in Table 5.

[0128] The properties of the raw oil used are shown in Table 6. After the catalytic product is obtained, the actual boiling point is cut to obtain the base oil with a fraction greater than 300°C. The properties of the base oil are analyzed, and the results are shown in Table 7.

[0129] Table 5 Temperature in the reaction process / ℃

[0130] Bed Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 5 First Protectant Sublayer 320 330 330 340 340 340 350 Second Protectant Sublayer 320 330 330 340 340 340 350 First catalyst sublayer 330 330 335 340 340 340 350 Second catalyst sublayer 340 340 340 340 340 340 340 The third catalyst sublayer 335 340 330 340 340 340 340

[0131] Table 6 Raw material properties

[0132]

[0133] Table 7 Product properties and yield

[0134]

[0135] It can be seen from Table 7 that, relative to Comparative Examples 1 to 3 and 5, the protective agent and catalyst grading and filling method of the hydroisomerization dewaxing reactor of Examples 1 to 3 of the present invention, as well as the defined reaction temperatures of the protective agent layer and the catalyst layer, can be used. The efficient grading method can allow the material to be deeply isomerized and the cracking depth of the material to be controlled, which can effectively improve the yield of the base oil and effectively reduce the pour point and cloud point properties of the base oil. Controlling the reactor bed temperature can prevent the material from reacting too violently when it initially contacts the protective agent and the catalyst, resulting in excessive cracking and the generation of too much light oil products, thereby reducing the base oil yield. In addition, a high initial reaction temperature can also accelerate catalyst coking and affect the service life of the protective agent and the catalyst. At the same time, the base oil product obtained by the production method of the present invention has a higher viscosity index and lower sulfur and nitrogen contents in the product, which can effectively improve the quality of the base oil.

[0136] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A method for producing a base oil, wherein: The base oil production method comprises the following steps: After the raw material is mixed with hydrogen, it enters a graded hydroisomerization dewaxing reactor, flows through a protective agent layer and a catalyst layer in sequence to perform a hydroisomerization reaction to obtain a catalytic product; Perform boiling point cutting on the catalytic product to obtain base oil with a fraction greater than 340° C.; The protective agent layer is filled with a protective agent, and the catalyst layer is filled with a catalyst; the total acid content of the catalyst increases first and then decreases, and the catalyst The molar percentage content of acid in the total acid content first increases and then decreases; The reaction temperature of the protective agent layer is lower than the reaction temperature of the catalyst layer, and the reaction temperature of the catalyst layer along the material flow direction first increases and then remains unchanged or decreases.

2. The base oil production method according to claim 1, wherein: Along the material flow direction, the catalyst layer includes a first catalyst sub-layer and a second catalyst sub-layer adjacent to each other in sequence; In the first catalyst sublayer, the content of weak acid is greater than that of medium-strong acid; in the second catalyst sublayer, the content of weak acid is less than that of medium-strong acid; The reaction temperature of the first catalyst sub-layer is lower than the reaction temperature of the second catalyst sub-layer.

3. The base oil production method according to claim 2, wherein: The total acid content of the first catalyst sublayer is 50-200 μmol / g, the weak acid content is 20-100 μmol / g, and the medium-strong acid content is 10-80 μmol / g. The molar content of the acid is 5% to 20%; The total acid content of the second catalyst sublayer is 150-300 μmol / g, the weak acid content is 30-100 μmol / g, and the medium-strong acid content is 120-200 μmol / g. The molar content of the acid is 20% to 50%.

4. The base oil production method according to claim 2, wherein: Along the material flow direction, the catalyst layer further includes a third catalyst sublayer arranged after the second catalyst sublayer; With respect to the total acid amount of the catalyst, the second catalyst sublayer is greater than the first catalyst sublayer and / or the third catalyst sublayer; About Catalyst The molar percentage content of acid in the total acid amount, the second catalyst sublayer is greater than the first catalyst sublayer and / or the third catalyst sublayer; In the third catalyst sublayer, the content of weak acid is less than the content of medium-strong acid; The reaction temperature of the first catalyst sublayer is lower than the reaction temperature of the second catalyst sublayer, and the reaction temperature of the third catalyst sublayer is not higher than the reaction temperature of the second catalyst sublayer.

5. The base oil production method according to claim 4, wherein: The total acid content of the third catalyst sublayer is 100-300 μmol / g, the weak acid content is 20-100 μmol / g, and the medium-strong acid content is 50-200 μmol / g. The molar content of the acid is 20% to 50%.

6. The base oil production method according to any one of claims 1 to 5, wherein: The active metal content in the protective agent gradually increases or remains unchanged, and / or the pore volume of the protective agent decreases and the specific surface area increases.

7. The base oil production method according to claim 6, wherein: Based on the total volume of the protective agent and the catalyst, the volume percentage content of the protective agent is 2% to 20%; and the volume percentage content of the catalyst is 80% to 98%.

8. The base oil production method according to claim 6, wherein: Along the material flow direction, the protective agent layer includes a first protective agent sub-layer and a second protective agent sub-layer adjacent to each other in sequence; The active metal content of the protective agent in the first protective agent sublayer is 0-3wt%, and the active metal content of the protective agent in the second protective agent sublayer is 1wt%-5wt%; The pore volume of the protective agent in the first protective agent sublayer is 0.7-0.8 mL / g, and the specific surface area is 80-130 m 2 / g; The pore volume of the protective agent in the second protective agent sublayer is 0.5-0.6 mL / g, and the specific surface area is 140-170 m 2 / g.

9. The base oil production method according to claim 1, wherein: The raw material is selected from at least one of hydrocracking tail oil, paraffin-based wax oil, naphthenic wax oil, intermediate-based wax oil, wax oil or wax paste.

10. The base oil production method according to claim 1, wherein: In the hydroisomerization reaction, the volume ratio of hydrogen to oil is 100-1000:1, the reaction pressure is 6-15 MPa, and the volume space velocity is 0.5-3.0 h -1 The reaction temperature of the protective agent layer is 300-350°C, and the reaction temperature of the catalyst layer is 330-400°C.

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