A catalyst grading method

Abstract

The present invention provides a catalyst grading method, which includes a catalytic reaction unit; in the catalytic reaction unit, along the material flow direction, the total acid content of the catalyst increases first and then decreases; the molar content ratio of the Brönsted acid in the catalyst increases first and then decreases; in the logistics direction, the catalytic reaction unit sequentially includes an adjacent first catalyst layer and a second catalyst layer, in the first catalyst layer, the content of weak acid is greater than the content of medium-strong acid; in the second catalyst layer, the content of weak acid is less than the content of medium-strong acid. The catalyst grading method of the present invention can improve the catalytic effect by grading the catalyst, thereby improving the yield of the base oil, improving the viscosity index of the base oil, and reducing the pour point and cloud point of the base oil.

Description

Technical Field

[0001] The invention relates to the technical field of catalysts, and in particular to a catalyst grading method. Background Art

[0002] Lubricating oil can reduce mechanical failures caused by friction and wear between mechanical parts. Therefore, with the rapid development of modern mechanical equipment and the automotive industry, the market demand for lubricating oil base oil has increased year by year. Converting paraffin oil into lubricating oil can achieve high added value of paraffin oil and bring huge economic benefits. Generally, the industry mainly uses hydroisomerization technology to isomerize the long-chain alkane molecules in paraffin oil into isoalkane molecules with branched structures. This technology can improve the low-temperature flow properties of the oil while retaining the viscosity index of the oil.

[0003] In the prior art, the research on isomerization dewaxing technology mainly focuses on the research on catalysts and their preparation processes. Although the catalysts and their preparation processes can directly affect the effect of isomerization dewaxing technology, the preparation process of the catalyst is relatively complicated, and the research on new catalysts tends to consume a lot of manpower and material resources. Therefore, it is necessary to grade the existing catalysts to improve the effect of isomerization dewaxing technology. Summary of the invention

[0004] The invention provides a catalyst grading method. By grading the catalyst, the catalytic effect can be improved, thereby increasing the yield of the base oil and improving the viscosity index, pour point and cloud point of the base oil.

[0005] The present invention provides a catalyst grading method, which comprises a catalytic reaction unit; in the catalytic reaction unit, along the material flow direction, the total acid content of the catalyst increases first and then decreases; The molar content ratio of acid increases first and then decreases;

[0006] In the material flow direction, the catalytic reaction unit includes adjacent first catalyst layer and second catalyst layer in sequence, in which the content of weak acid is greater than that of medium-strong acid; in the second catalyst layer, the content of weak acid is less than that of medium-strong acid.

[0007] The catalyst grading method as described above, wherein, in the catalytic reaction unit, along the material flow direction, further comprises a third catalyst layer disposed after the second catalyst layer;

[0008] The total acid amount of the catalyst in the second catalyst layer is greater than the total acid amount of the catalyst in the first catalyst layer and / or the total acid amount of the catalyst in the third catalyst layer;

[0009] The second catalyst layer The molar content of the acid is greater than that of the first catalyst layer. The molar content of the acid and / or the third catalyst layer The molar content of acid;

[0010] In the third catalyst layer, the content of weak acid is less than that of medium-strong acid.

[0011] The catalyst grading method as described above, wherein in the catalytic reaction unit, in at least one catalyst layer, The molar content of the acid is 5-60%.

[0012] In the catalyst grading method as described above, in the catalytic reaction unit, in at least one catalyst layer, the total acid content of the catalyst is 50-300 μmol / g; preferably, the total acid content of the catalyst is 100-300 μmol / g.

[0013] The catalyst grading method as described above, wherein in the catalytic reaction unit, in at least one catalyst layer, the weak acid content of the catalyst is 10-150 μmol / g; preferably, the weak acid content of the catalyst is 20-100 μmol / g; and / or,

[0014] In the catalytic reaction unit, in at least one catalyst layer, the catalyst has a medium-strong acid content of 5-250 μmol / g; preferably, the catalyst has a medium-strong acid content of 10-220 μmol / g.

[0015] The catalyst grading method as described above, further comprises: a protective agent unit located before the catalytic reaction unit along the material flow direction.

[0016] The catalyst grading method as described above, wherein in the protective agent unit, along the material flow direction, the active metal content in the protective agent gradually increases or remains unchanged; and / or,

[0017] In the protective agent unit, along the material flow direction, the pore volume between the protective agents decreases and the specific surface area of ​​the protective agents increases.

[0018] The catalyst grading method as described above, wherein in the protective agent unit, a first protective agent layer and a second protective agent layer are sequentially included along the material flow direction;

[0019] The active metal content of the protective agent in the first protective agent layer is less than or equal to the active metal content of the protective agent in the second protective agent layer.

[0020] The catalyst grading method as described above, wherein the volume percentage of the protective agent is 2-20% based on the total volume of the protective agent and the catalyst; and / or,

[0021] Based on the total volume of the protective agent and the catalyst, the volume percentage of the catalyst is 80-98%.

[0022] In the catalyst grading method as described above, the mass percentage of active metal in the protective agent is less than or equal to 5%.

[0023] The present invention provides a catalyst grading method. The catalysts are graded according to their acidity, which can effectively improve the catalytic effect, thereby increasing the yield of base oil and the viscosity index of the base oil, reducing the low-temperature performance of the pour point and cloud point of the base oil, and effectively improving the quality of the base oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present invention or related technologies. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 A graph showing a change trend of the total acid content of the catalyst along the material flow direction in the catalytic reaction unit in some embodiments of the present invention;

[0026] Figure 2 This is a trend diagram of the total acid content of the catalyst along the material flow direction in the catalytic reaction unit in other embodiments of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The present invention provides a catalyst grading method, which includes a catalytic reaction unit; in the catalytic reaction unit, along the material flow direction, the total acid content of the catalyst increases first and then decreases; The molar content ratio of acid increases first and then decreases;

[0029] In the material flow direction, the catalytic reaction unit includes adjacent first and second catalyst layers in sequence. In the first catalyst layer, the content of weak acid is greater than that of medium-strong acid; in the second catalyst layer, the content of weak acid is less than that of medium-strong acid.

[0030] The catalyst of the present invention can be a catalyst commonly used in the art. In some embodiments, the catalyst can contain a molecular sieve of a ten-member topology structure, and the molecular sieve can be one or more of ZSM-5, SAPO-11, ZSM-22, ZSM-35, ZSM-23, ZSM-48 and SAPO-41. In some embodiments, the catalyst can also contain an amorphous inorganic porous material, and the amorphous inorganic porous material can be selected from at least one of aluminum oxide, zirconium oxide and titanium oxide or one or more of its composite oxides (aluminum oxide-silicon dioxide, aluminum oxide-zirconium oxide, zirconium oxide-titania, aluminum oxide-titania).

[0031] In the present invention, the mass percentage of the molecular sieve can be 40-80% based on the total mass of the catalyst, and further, the mass percentage of the molecular sieve can be 55-75% based on the total mass of the catalyst. The mass percentage of the amorphous inorganic porous material can be 19-59.9% based on the total mass of the catalyst, and further, the mass percentage of the amorphous porous material can be 25-50% based on the total mass of the catalyst.

[0032] In the catalyst of the present invention, the active metal may be selected from one or more of Pt, Pd, Ru and Ni, and further, the active metal may be selected from Pt and / or Pd. In some embodiments, the mass percentage of the active metal is 0.1% to 1.0% based on the total mass of the catalyst, and further, the mass percentage of the active metal is 0.2% to 0.5% based on the total mass of the catalyst.

[0033] The catalytic reaction unit of the present invention can 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 catalysts with different acid amounts prepared from different types of molecular sieves.

[0034] In the present invention, the material can be selected from one or more of hydrocracking tail oil, paraffin-based wax oil, naphthenic wax oil, intermediate-based wax oil, wax oil or wax paste.

[0035] In the catalyst grading method of the present invention, the material can be mixed with hydrogen and then enter the catalytic reaction unit for reaction. The reaction product 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.

[0036] The reaction pressure is 6-15 MPa, the reaction temperature is 300-400° C., the volume space velocity is 0.5-3.0, and the hydrogen-to-oil volume ratio is 100-1000:1.

[0037] In the present invention, the acid types in the catalyst 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, and 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, and the stronger the ability to accept electron pairs, the stronger the acidity.

[0038] 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.

[0039] 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.

[0040] It can be understood that in the present invention, the weak acid content in the catalyst that contacts the material first is greater than the medium-strong acid content, and the weak acid content in the catalyst that contacts the material later is less than the medium-strong acid content. 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.

[0041] Figure 1 The total acid content of the catalyst in the catalytic reaction unit along the material flow direction in some embodiments of the present invention is a trend diagram. Figure 1 As shown, in the present invention, along the material flow direction, the total acid content of the catalyst can change in a gradient, first increasing and then decreasing. Figure 2 FIG. 1 is a graph showing the change trend of the total acid content of the catalyst along the material flow direction in the catalytic reaction unit in some other embodiments of the present invention. Figure 2 As shown, in the present invention, along the material flow direction, the total acid amount of the catalyst can be gradually increased and then gradually decreased.

[0042] 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.

[0043] In some embodiments of the present invention, in the catalytic reaction unit, along the material flow direction, a third catalyst layer is further included after the second catalyst layer;

[0044] The total acid amount of the catalyst in the second catalyst layer is greater than the total acid amount of the catalyst in the first catalyst layer and / or the total acid amount of the catalyst in the third catalyst layer;

[0045] The second catalyst layer The molar content of the acid is greater than that of the first catalyst layer. The molar content of the acid and / or the third catalyst layer The molar content of acid;

[0046] In the third catalyst layer, the content of the weak acid is less than that of the medium-strong acid.

[0047] It can be understood that the catalytic reaction unit of the present invention may include a first catalyst layer, a second catalyst layer and a third catalyst layer in sequence along the material flow direction.

[0048] It is understood that in the present invention, the total acid amount of the catalyst in the first catalyst layer and the total acid amount of the catalyst in the third catalyst layer 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 layer 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.

[0049] 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.

[0050] In the present invention, the amount of acid in the catalytic reaction unit 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.

[0051] In some embodiments of the present invention, in the catalytic reaction unit, in at least one catalyst layer, The molar content of the acid is 5-60%. Further, in the catalytic reaction unit, at least one catalyst layer, The molar content of the acid is 10-50%.

[0052] In some embodiments of the present invention, in the catalytic reaction unit, in at least one catalyst layer, the total acid amount of the catalyst is 50-300 mmol / g. Further, in the catalytic reaction unit, in at least one catalyst layer, the total acid amount of the catalyst is 100-300 μmol / g.

[0053] In some embodiments of the present invention, in the catalytic reaction unit, in at least one catalyst layer, the weak acid content of the catalyst is 10-150 μmol / g; and / or,

[0054] In the catalytic reaction unit, in at least one catalyst layer, the catalyst has a medium-strong acid content of 5-250 μmol / g.

[0055] Further, in the catalytic reaction unit, in at least one catalyst layer, the weak acid content of the catalyst is 20-100 μmol / g; and / or,

[0056] In the catalytic reaction unit, in at least one catalyst layer, the catalyst has a medium-strong acid content of 10-220 μmol / g.

[0057] In some embodiments of the present invention, the catalyst grading method further includes: a protective agent unit located before the catalytic reaction unit along the material flow direction.

[0058] It can be understood that the catalyst grading method of the present invention further includes: allowing the material to flow through the protective agent unit to remove impurities first, and then allowing the impurity-removed material to flow through the catalyst reaction unit to perform a catalytic reaction.

[0059] The present invention can convert the material into base oil to a greater extent by first removing impurities from the material and then performing a 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.

[0060] In some embodiments of the present invention, in the protective agent unit, along the material flow direction, the active metal content in the protective agent gradually increases or remains unchanged.

[0061] In the present invention, 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 nickel, cobalt, molybdenum and tungsten.

[0062] In the present invention, more than two protective agents may be arranged in the protective agent unit, 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.

[0063] In the present invention, the pore volume can adsorb inorganic impurities, and the larger the pore volume, the stronger the adsorption capacity.

[0064] 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.

[0065] Exemplarily, in the protective agent unit, a first protective agent layer and a second protective agent layer are sequentially included along the material flow direction;

[0066] The active metal content of the protective agent in the first protective agent layer is less than or equal to the active metal content of the protective agent in the second protective agent layer.

[0067] In the present invention, the content of the protective agent in the protective agent unit and the content of the active metal in the protective agent can be further selected to better remove impurities in the material, improve the catalytic efficiency, and improve the yield and quality of the base oil.

[0068] In some embodiments of the present invention, the volume percentage of the protective agent is 2-20% based on the total volume of the protective agent and the catalyst.

[0069] It can be understood that, based on the total volume of the protective agent and the catalyst, the volume percentage of the catalyst is 80-98%.

[0070] Furthermore, based on the total volume of the protective agent and the catalyst, the volume percentage of the protective agent is 5-15%, and the volume percentage of the catalyst is 85-95%.

[0071] In some embodiments of the present invention, the mass percentage of active metal in the protective agent is less than or equal to 5%.

[0072] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0073] Examples 1-3, Comparative Examples 1-3

[0074] The grading methods of the catalysts of Examples 1-3 and Comparative Examples 1-3 are shown in Table 1;

[0075] Table 1

[0076]

[0077]

[0078]

[0079] Test Example 1

[0080] According to the catalyst grading method in Table 1, under the hydrogenation process conditions shown in Table 2, the feedstock oils shown in Table 3 were catalytically treated to obtain catalytic products, the catalytic products were subjected to boiling point cutting to obtain base oils with a fraction greater than 300°C, and the properties of the base oils were analyzed. The results are shown in Table 4.

[0081] Table 2

[0082] Isogeneous dewaxing reactor temperature, ℃ 370 Reaction pressure, MPa 12 <![CDATA[Liquid hourly space velocity, h -1 > 1.2 Hydrogen to oil volume ratio 500

[0083] Table 3

[0084]

[0085] Table 4

[0086]

[0087]

[0088] It can be seen from Table 4 that, relative to Comparative Examples 1 to 3, the grading method of the catalyst in Examples 1 to 3 of the present invention can improve the yield of the base oil, and can effectively reduce the pour point and cloud point performance indicators of the base oil, the viscosity index of the base oil is higher, and the sulfur and nitrogen contents in the product are lower, which can effectively improve the quality of the base oil.

[0089] Test Example 2

[0090] According to the catalyst grading method in Table 1, under the hydrogenation conditions shown in Table 5, the feedstock oils shown in Table 6 were catalytically treated to obtain catalytic products, the catalytic products were subjected to actual boiling point cutting to obtain base oils with a fraction greater than 300°C, and the properties of the base oils were analyzed. The results are shown in Table 7.

[0091] Table 5

[0092] Isogeneous dewaxing reactor temperature, ℃ 350 Reaction pressure, MPa 8 <![CDATA[Liquid hourly space velocity, h -1 > 1.5 Hydrogen to oil volume ratio 400

[0093] Table 6

[0094]

[0095]

[0096] Table 7

[0097]

[0098] It can be seen from Table 7 that, compared with Comparative Examples 1 to 3, the catalyst grading method in Examples 1 to 3 of the present invention has a higher yield for producing base oil, lower sulfur and nitrogen contents, and can effectively reduce the low temperature performance (pour point and cloud point) index of the base oil, and the viscosity index of the base oil is higher, which can effectively improve the quality of the base oil.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A catalyst grading method, characterized in that: The method comprises a catalytic reaction unit; in the catalytic reaction unit, along the material flow direction, the total acid amount of the catalyst increases first and then decreases; the molar content ratio of the Brönsted acid in the catalyst increases first and then decreases; In the material flow direction, the catalytic reaction unit includes a first catalyst layer and a second catalyst layer adjacent to each other in sequence, wherein the content of weak acid in the first catalyst layer is greater than that of medium-strong acid; and the content of weak acid in the second catalyst layer is less than that of medium-strong acid; It also includes: a protective agent unit located before the catalytic reaction unit along the material flow direction; In the protective agent unit, the active metal content in the protective agent increases or remains unchanged along the material flow direction; and / or, In the protective agent unit, along the material flow direction, the pore volume between the protective agents decreases and the specific surface area of ​​the protective agents increases.

2. The catalyst grading method according to claim 1, characterized in that: In the catalytic reaction unit, along the material flow direction, a third catalyst layer is also included after the second catalyst layer; The total acid amount of the catalyst in the second catalyst layer is greater than the total acid amount of the catalyst in the first catalyst layer and / or the total acid amount of the catalyst in the third catalyst layer; The molar content of the Brönsted acid in the second catalyst layer is greater than the molar content of the Brönsted acid in the first catalyst layer and / or the molar content of the Brönsted acid in the third catalyst layer; In the third catalyst layer, the content of weak acid is less than that of medium-strong acid.

3. The catalyst grading method according to claim 1, characterized in that: In the catalytic reaction unit, in at least one catalyst layer, the molar content of Brönsted acid is 5-60%.

4. The catalyst grading method according to claim 1, characterized in that: In the catalytic reaction unit, in at least one catalyst layer, the total acid content of the catalyst is 50-300 μmol / g.

5. The catalyst grading method according to claim 4, characterized in that: The total acid amount of the catalyst is 100-300 μmol / g.

6. The catalyst grading method according to any one of claims 1 to 4, characterized in that: In the catalytic reaction unit, in at least one catalyst layer, the weak acid content of the catalyst is 10-150 μmol / g; and / or, In the catalytic reaction unit, in at least one catalyst layer, the catalyst has a medium-strong acid content of 5-250 μmol / g.

7. The catalyst grading method according to claim 6, characterized in that: The weak acid content of the catalyst is 20-100 μmol / g; and / or, The catalyst has a medium-strong acid content of 10-220 μmol / g.

8. The catalyst grading method according to claim 7, characterized in that: In the protective agent unit, a first protective agent layer and a second protective agent layer are sequentially included along the material flow direction; The active metal content of the protective agent in the first protective agent layer is less than or equal to the active metal content of the protective agent in the second protective agent layer.

9. The catalyst grading method according to claim 7, characterized in that: Based on the total volume of the protective agent and the catalyst, the volume percentage of the protective agent is 2-20%; and / or, Based on the total volume of the protective agent and the catalyst, the volume percentage of the catalyst is 80-98%.

10. The catalyst grading method according to any one of claims 7 to 9, characterized in that: The mass percentage of active metal in the protective agent is less than or equal to 5%.

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