Passivation method of isodewaxing catalyst and production method of lubricant base oil

Abstract

The invention relates to a passivation method of an isomerization dewaxing catalyst and a production method of lubricant base oil, and the passivation method comprises the following steps: (1) injecting carrying oil containing a vulcanizing agent and hydrogen into a reactor at a first reaction temperature to carry out first passivation treatment on the reduced isomerization dewaxing catalyst; (2) after the first passivating treatment is completed, injecting carrying oil containing a vulcanizing agent and hydrogen into the reactor at a second reaction temperature to continuously carry out second passivating treatment on the isodewaxing catalyst, so as to obtain a passivated catalyst; wherein the second reaction temperature is 40-80 DEG C higher than the first reaction temperature; by means of sulfur injection step-by-step passivation treatment, the selectivity of the catalyst is improved, and the yield of the base oil can be improved by 3% or above.

Description

Technical Field

[0001] The invention belongs to the field of petrochemical industry and relates to a passivation method of an isomerization dewaxing catalyst used for producing lubricating oil base oil and a production method of lubricating oil base oil. Background Art

[0002] How to improve the selectivity of isodewaxing catalysts is one of the issues that researchers in the field of petrochemicals are concerned about. Isodewaxing catalysts are mainly composed of precious metals and molecular sieves. They are different from conventional catalytic hydrocracking catalysts. The catalyst systems of the two are different. The latter is sulfurized to obtain catalytic activity, while the metal hydrogenation and acid cracking functions of isodewaxing catalysts are very strong. After the catalyst is hydrogen activated, the initial activity is high, and it is easy to deposit carbon, which reduces the selectivity of the catalyst. Conventional sulfurization is easy to cause permanent poisoning of precious metals.

[0003] The current methods for catalyst passivation are: 1) Do not add passivators, rely on the chemical reaction of the raw materials to gradually deposit carbon and reduce the initial activity of the catalyst; 2) Add compounds that can produce ammonia to passivate the acidic sites of the catalyst; 3) Add compounds that can produce sulfur and ammonia at the same time to passivate the entire catalyst.

[0004] For example, CN 103789008A discloses a method for starting a hydrocracking unit, wherein the passivation method proposed is to introduce nitrogen-containing light distillate oil when the catalyst bed temperature is about 245°C, and when the bed temperature rises to 290°C, replace it with nitrogen-containing heavy distillate oil, and rely on the generated ammonia to passivate the acid sites of the catalyst. However, since the nitrogen in the distillate oil reacts chemically with hydrogen to generate ammonia, the ammonia is adsorbed on the acid sites of the catalyst, inhibiting the initial activity of the catalyst, and the nitrogen content in the distillate oil is unstable, affecting the passivation effect.

[0005] CN 109957419 A discloses a start-up method of a hydrocracking process, in which after the catalyst is sulfurized, gaseous nitrides such as pyridine and quinoline are introduced to passivate at 420°C-550°C. The start-up method adopts high-temperature passivation. However, after the catalyst is sulfurized, gaseous nitrides such as pyridine and quinoline are introduced to passivate at 420°C-550°C. The start-up method adopts high-temperature passivation, and the passivating agent used is highly toxic and easily pollutes the environment.

[0006] CN 103059969 A discloses a start-up passivation method for a hydrocracking catalyst, wherein the refined raw oil in the method is high-nitrogen oil, and the high-fraction gas generated after refining is used to passivate the cracking agent, and no passivating agent needs to be introduced. Since the refined raw oil used is high-nitrogen oil, the high-fraction gas generated after refining is used to passivate the cracking agent, and no passivating agent needs to be introduced, but nitrogen-containing compounds are easily strongly adsorbed on the acid center of the hydrocatalytic catalyst, and are easily polycondensed at high temperature to form carbon deposit precursors.

[0007] CN105647574A discloses a method for producing lubricating base oil from a high wax content raw material, wherein a pretreatment solution is first mixed with an isomeric dewaxing catalyst for pretreatment to obtain a pretreated isomeric dewaxing catalyst, and then the pretreated isomeric dewaxing catalyst is loaded into a reactor for hydrogen activation, and finally the raw oil and hydrogen are contacted with the activated isomeric dewaxing catalyst to perform an isomeric dewaxing reaction. Since the pretreatment solution is first mixed with the isomeric dewaxing catalyst for pretreatment, the pretreatment solution contains sulfur compounds and nitrogen compounds, and a chemical reaction occurs in a hydrogen atmosphere, the metal active site is shielded by sulfur, and the acidic site is adsorbed by ammonia, which reduces the initial activity of the catalyst, the passivating agent consumption is large, the hydrogen sulfide concentration is high, and the equipment is easily corroded, and the catalyst needs to be pretreated, which is costly. Summary of the invention

[0008] The purpose of the present invention is to provide a method for passivating an isomerization dewaxing catalyst and a method for producing a lubricating oil base oil, which adopts step-by-step sulfur injection passivation, uses a single passivating agent, has a small addition amount, and has a good passivation effect.

[0009] To achieve one aspect of the above-mentioned invention object, the present invention adopts the following technical solution:

[0010] A passivation method for an isomerization dewaxing catalyst, wherein the isomerization dewaxing catalyst is a noble metal molecular sieve catalyst used for catalytic production of lubricating oil base oil, wherein the active component is a noble metal and the carrier is a carrier containing a ten-membered ring molecular sieve; the passivation method comprises the following steps:

[0011] (1) injecting a carrier oil containing a sulfiding agent and hydrogen into a reactor at a first reaction temperature to perform a first passivation treatment on the reduced isomerization dewaxing catalyst; wherein the first reaction temperature is 180-250° C., the reaction time is 1-8 hours, and the volume concentration of hydrogen sulfide in the tail gas discharged from the reactor is controlled to be 10-40 ppm;

[0012] (2) After the first passivation treatment is completed, at a second reaction temperature, a carrier oil containing a sulfiding agent and hydrogen are injected into the reactor to continue the second passivation treatment of the isodewaxing catalyst to obtain a passivated catalyst; wherein the second reaction temperature is 40-80° C. higher than the first reaction temperature, the reaction time is 1-5 hours, and the volume concentration of hydrogen sulfide in the exhaust gas discharged from the reactor is controlled to be 40-100 ppm.

[0013] In the present invention, the vulcanizing agent may be a commonly used vulcanizing agent in the art, such as dimethyl disulfide and / or carbon disulfide. As is well known in the art, the vulcanizing agent may also be other dimethyl sulfide, dimethyl disulfide or thiol compounds.

[0014] In the present invention, the carrier oil can be a solvent oil commonly used in the art, which is well known in the art, such as one or more of light white oil, coal direct liquefaction diesel, Fischer-Tropsch diesel with a distillation range of 300-390°C, Fischer-Tropsch hydrocracking oil and petroleum-based diesel.

[0015] In the present invention, the isodewaxing catalyst used for catalytic production of lubricating oil base oil has a carrier that is a ten-membered ring molecular sieve well known in the art, such as ZSM-48, and of course it can also be one or more of ZSM-22, ZSM-23 and ZSM-35 as well known in the art; the active component of the isodewaxing catalyst is a precious metal, preferably Pd and / or Pt.

[0016] In a preferred embodiment of the present invention, the reactor is a fixed bed reactor. When performing the first passivation treatment and the second passivation treatment, the carrier oil is mixed with hydrogen before being injected into the reactor and then injected from the top of the reactor; after the reaction, the tail gas is discharged from the top outlet of the reactor and the carrier oil is discharged from the bottom.

[0017] Preferably, when the carrier oil is mixed with hydrogen, the volume ratio of hydrogen to oil can be 500-1000:1, such as 600:1 or 800:1; and when the first passivation treatment and the second passivation treatment are performed, the tail gas discharged from the top is reused as circulating hydrogen to be mixed with the carrier oil. It is understood in the art that in actual operation, in order to ensure the hydrogen concentration during mixing, a small amount of tail gas is discharged to introduce fresh hydrogen to maintain the hydrogen volume concentration in the tail gas not less than 85%, such as 90%.

[0018] In the present invention, in order to improve the selectivity of the catalyst after passivation, when the first passivation treatment is carried out, the volume concentration of hydrogen sulfide in the exhaust gas is controlled to be 10-40ppm, such as 20 or 30ppm. If it is too low, the sulfur injection rate will be too slow and the efficiency will be low. When the second passivation treatment is carried out, the volume concentration of hydrogen sulfide in the exhaust gas is controlled to be 40-100ppm, such as 50, 60 or 80ppm. By combining the first passivation treatment with a higher temperature and a lower hydrogen sulfide concentration in the exhaust gas with the second passivation treatment with a lower temperature and a higher hydrogen sulfide concentration in the exhaust gas, a better passivation effect is achieved.

[0019] When the concentration is too high, the rate of injecting the sulfiding agent into the reactor is reduced; that is, when the volume concentration of hydrogen sulfide in the exhaust gas is higher than the upper limit of the corresponding control range during the first or second passivation treatment, the rate of the sulfiding agent entering the reactor is reduced;

[0020] When the concentration is too low, the rate of injecting the sulfiding agent into the reactor is increased; that is, when the first or second passivation treatment is performed, when the volume concentration of hydrogen sulfide in the exhaust gas is lower than the lower limit of the corresponding control range, the rate of the sulfiding agent entering the reactor is increased.

[0021] In step (1) of the present invention, at the first reaction temperature, a carrier oil containing a sulfiding agent and hydrogen are injected into the reactor to perform a first passivation treatment on the reduced isomerization dewaxing catalyst. When a fixed bed reactor is used, the carrier oil is continuously injected. Of course, it is understandable that at this time, the oil phase and tail gas will also be continuously discharged from the reactor.

[0022] Preferably, when performing the first passivation treatment, the reaction temperature is 190-230°C, such as 200 or 220°C.

[0023] Preferably, during the first passivation treatment, the reaction pressure is 2.5-6.5 MPa, preferably 3-6 MPa, such as 4 or 5 MPa.

[0024] Preferably, when the first passivation treatment is performed, the reaction time is 2-6 hours, such as 2-5 hours, 3 hours or 4 hours, that is, the time for continuously injecting the carrier oil containing the sulfidizing agent when the first passivation treatment is performed.

[0025] In the present invention, during the first passivation treatment, the concentration of the sulfiding agent in the carrier oil can be 0.01-0.1wt%, preferably 0.02-0.08wt%, such as 0.03wt%, 0.04wt%, 0.05wt%, 0.6wt% or 0.07wt%; during the second passivation treatment, the concentration of the sulfiding agent in the carrier oil can be 0.01-0.06wt%, preferably 0.01-0.05wt%, such as 0.02wt%, 0.03wt% or 0.04wt%; preferably, the concentration of the sulfiding agent in the carrier oil during the second passivation treatment can be 40%-80% of the concentration of the sulfiding agent in the carrier oil during the first passivation treatment, such as 50%, 60% or 70%.

[0026] In step (2) of the present invention, at a second reaction temperature, a carrier oil containing a sulfiding agent and hydrogen are injected into the reactor to continue the second passivation treatment of the isodewaxing catalyst to obtain a passivated catalyst; wherein the second reaction temperature is 40-80°C higher than the first reaction temperature, such as 50, 60 or 70°C; preferably, the second reaction temperature is 230-300°C, and more preferably 240-260°C, such as 250 or 280°C.

[0027] Preferably, when the second passivation treatment is performed, the reaction pressure is 2.5-6.5 MPa, preferably 3-6 MPa, such as 4 or 5 MPa, for example, the same as the first passivation treatment.

[0028] Preferably, when the second passivation treatment is performed, the reaction time is 2-4 hours, such as 3 hours.

[0029] In the present invention, the isodewaxing catalyst needs to be reduced before passivation, that is, hydrogen is used to convert the active components in the catalyst from an oxidized state to a reduced state to improve the catalyst activity, such as introducing hydrogen at 240°C for activation for 5-10 hours. The specific activation process is well known in the art and will not be repeated here.

[0030] To achieve another aspect of the above-mentioned invention object, the present invention adopts the following technical solution:

[0031] A method for producing a lubricating oil base oil, comprising:

[0032] a. Deactivate the isomerization dewaxing catalyst using the deactivation method described in any one of claims 1 to 9;

[0033] b. cooling the passivated catalyst obtained in step (2), and then purging the passivated catalyst with hydrogen to remove residual sulfur;

[0034] c. contacting the catalyst obtained in step b with a carrier oil without a sulfiding agent and hydrogen, heating the reactor, and then replacing the carrier oil in the reactor with a waxy feedstock oil to carry out a hydroisomerization reaction to produce a lubricating oil base oil.

[0035] In step b of the present invention, hydrogen is used to cool and purge the catalyst bed after passivation in step (2), for example, to 120-180° C., such as 150° C., to remove residual sulfur and reduce subsequent adverse effects.

[0036] In step c of the present invention, the carrier oil and hydrogen are mixed and injected into the reactor, and the temperature is increased, for example, after the temperature is increased to 280-340° C., such as 300° C., the carrier oil is switched to waxy feedstock oil to perform a hydroisomerization reaction to obtain a lubricating oil base oil; the specific hydroisomerization reaction is well known in the art. In some embodiments, the reaction temperature is 320-340° C., the pressure is 3-5 MPa, such as 3.5 MPa, and the mass space velocity is 0.6-1.2 h -1 For example, 1h -1 , hydrogen-oil volume ratio 500-1000:1, such as 600:1 or 800:1.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] The present invention performs sulfur injection passivation treatment on the isomerization dewaxing after reduction in two steps, and adopts different reaction passivation conditions and sulfurizing agent dosages in the two steps, so that the catalyst is not afraid of sulfur and the yield of the base oil can be improved.

[0039] In addition, in the passivation process of the present invention, nitrogen-containing compounds may not be used at all, and only a sulfiding agent may be used for passivation, which is simple to operate and low in cost. The passivation method of the present invention reduces the influence of passivation on the activity and stability of the catalyst, while reducing the carbon deposition amount of the isomerization dewaxing catalyst, improving the selectivity of the catalyst, and the base oil yield can be increased by more than 3%, with obvious effects. DETAILED DESCRIPTION

[0040] The present invention is further described below in conjunction with the embodiments, but the present invention is not limited to the listed embodiments, but also includes equivalent improvements and modifications of the technical solutions defined in the claims attached to the patent application of the present invention.

[0041] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values, such as values ​​of ±10% of the endpoint values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0042] Unless otherwise specified, all relevant reagents in the following examples / comparative examples are of analytical grade.

[0043] The hydroisomerization catalyst for preparing lubricating oil base oil in the present invention is a precious metal molecular sieve catalyst, which is known in the art. The precious metal includes Pd and / or Pt, etc., and the content of the precious metal element is 0.1-0.5wt% such as 0.2wt%, 0.3wt% or 0.4wt%; the carrier includes a ten-membered ring molecular sieve and an alumina binder, and the ten-membered ring molecular sieve is selected from one or more of ZSM-22, ZSM-23, ZSM-48 and ZSM-35, and the mass fraction of the ten-membered ring molecular sieve in the catalyst is 60-90wt%, such as 65wt%, 75wt% or 85wt%.

[0044] The isodewaxing catalyst is first reduced with hydrogen, and precious metal oxides such as platinum oxide are reduced to elemental platinum. The catalyst has high hydrogenation activity and cracking activity. Studies have found that directly feeding waxy crude oil is prone to cracking and carbon deposition, and requires passivation treatment.

[0045] The oxidized hydroisomerization catalyst C1 was prepared by referring to the preparation method of Example 1 in CN110642266B; at the same time, according to the preparation method of Example 1 in CN110642266B, the Pt therein was replaced with Pd of the same mass to obtain the oxidized hydroisomerization catalyst C2.

[0046] The passivated catalyst was evaluated in situ in a fixed bed reactor. The waxy feedstock oil used was wax oil from Fischer-Tropsch refining. The relevant parameters are shown in Table 1.

[0047] Catalyst evaluation conditions: Hydroisomerization reaction temperature 320-340°C, pressure 3.5MPa, mass space velocity 1h -1 , hydrogen to oil volume ratio 600:1. The product oil is cut using a true boiling point distiller, the pour point of the total product represents the activity of the catalyst, and the yield of fractions above 300°C represents the selectivity of the catalyst.

[0048] Yield = mass of distillate oil above 300°C in the product / mass of raw oil * 100%.

[0049] Example 1

[0050] 100g of oxidized isomerization dewaxing catalyst C1 was placed in a fixed bed reactor. After nitrogen displacement of the reactor was qualified at 3.5MPa, hydrogen was introduced and the temperature was raised to 240°C. The temperature was kept constant for 5 hours to obtain the reduced C1 catalyst.

[0051] Injecting a carrier oil containing a sulfiding agent into the reactor to perform a first passivation treatment on the reduced isomerization dewaxing catalyst, the treatment temperature is 210°C, the pressure is 3.5MPa, and the treatment time is 3h; wherein the sulfiding agent is dimethyl disulfide, the concentration in the carrier oil is 0.04wt%, the carrier oil is Fischer-Tropsch diesel, the hydrogen-to-oil ratio is 800:1, and the initial mass space velocity is 1.0h -1 , the tail gas is circulated and the volume content of hydrogen sulfide in the exhaust gas is controlled to be 10-40ppm;

[0052] After the first passivation treatment is completed, a carrier oil containing a sulfiding agent is injected into the reactor to continue the second passivation treatment on the isomerization dewaxing catalyst, the treatment temperature is 250°C, the pressure is 3.5MPa, and the treatment time is 3h to obtain a passivated catalyst; wherein the sulfiding agent is dimethyl disulfide, the concentration in the carrier oil is 0.02wt%, and the carrier oil is Fischer-Tropsch diesel; the hydrogen-to-oil ratio is 800:1, and the initial mass space velocity is 1.0h -1 , the tail gas is circulated and the volume content of hydrogen sulfide in the exhaust gas is controlled to be 40-100ppm;

[0053] After the passivation, the temperature was lowered and hydrogen was purged to remove residual hydrogen sulfide. Fischer-Tropsch diesel and hydrogen were introduced, the temperature was raised, and Fischer-Tropsch refined wax oil was switched for catalyst evaluation. The results are shown in Table 2.

[0054] Example 2

[0055] 100g of oxidized isomerization dewaxing catalyst C1 was placed in a fixed bed reactor. After nitrogen displacement of the reactor was qualified at 5MPa, hydrogen was introduced and the temperature was raised to 240°C. The temperature was kept constant for 5 hours to obtain the reduced C1 catalyst.

[0056] Injecting a carrier oil containing a sulfiding agent into the reactor to perform a first passivation treatment on the reduced isomerization dewaxing catalyst, the treatment temperature is 230°C, the pressure is 5MPa, and the treatment time is 6h; wherein the sulfiding agent is dimethyl disulfide, the concentration in the carrier oil is 0.02wt%, the carrier oil is Fischer-Tropsch diesel, the hydrogen-to-oil ratio is 800:1, and the initial mass space velocity is 1.0h -1 , the tail gas is circulated and the volume content of hydrogen sulfide in the exhaust gas is controlled to be 10-40ppm;

[0057] After the first passivation treatment is completed, a carrier oil containing a sulfiding agent is injected into the reactor to continue the second passivation treatment on the isomerization dewaxing catalyst, the treatment temperature is 280°C, the pressure is 5MPa, and the treatment time is 2h to obtain a passivated catalyst; wherein the sulfiding agent is dimethyl disulfide, the concentration in the carrier oil is 0.01wt%, and the carrier oil is Fischer-Tropsch diesel; the hydrogen-to-oil ratio is 800:1, and the initial mass space velocity is 1.0h -1 , the tail gas is circulated and the volume content of hydrogen sulfide in the exhaust gas is controlled to be 40-100ppm;

[0058] After the passivation, the temperature was lowered and hydrogen was purged to remove residual hydrogen sulfide. Fischer-Tropsch diesel and hydrogen were introduced, the temperature was raised, and Fischer-Tropsch refined wax oil was switched for catalyst evaluation. The results are shown in Table 2.

[0059] Example 3

[0060] 100g of oxidized isomerization dewaxing catalyst C1 was placed in a fixed bed reactor. After nitrogen displacement of the reactor was qualified at 3MPa, hydrogen was introduced and the temperature was raised to 240°C. The temperature was kept constant for 5 hours to obtain the reduced C1 catalyst.

[0061] Injecting a carrier oil containing a sulfiding agent into the reactor to perform a first passivation treatment on the reduced isomerization dewaxing catalyst, the treatment temperature is 190°C, the pressure is 3MPa, and the treatment time is 2h; wherein the sulfiding agent is CS2, the concentration in the carrier oil is 0.08wt%, the carrier oil is Fischer-Tropsch diesel, the hydrogen-to-oil ratio is 800:1, and the initial mass space velocity is 1.0h -1 , the tail gas is circulated and the volume content of hydrogen sulfide in the exhaust gas is controlled to be 10-40ppm;

[0062] After the first passivation treatment is completed, a carrier oil containing a sulfiding agent is injected into the reactor to continue the second passivation treatment on the isomerization dewaxing catalyst, the treatment temperature is 230°C, the pressure is 3MPa, and the treatment time is 4h to obtain a passivated catalyst; wherein the sulfiding agent is CS2, the concentration in the carrier oil is 0.05wt%, and the carrier oil is Fischer-Tropsch diesel; the hydrogen-to-oil ratio is 800:1, and the initial mass space velocity is 1.0h -1 , the tail gas is circulated and the volume content of hydrogen sulfide in the exhaust gas is controlled to be 10-40ppm;

[0063] After the passivation, the temperature was lowered and hydrogen was purged to remove residual hydrogen sulfide. Fischer-Tropsch diesel and hydrogen were introduced, the temperature was raised, and Fischer-Tropsch refined wax oil was switched for catalyst evaluation. The results are shown in Table 2.

[0064] Example 4

[0065] 100g of oxidized isomerization dewaxing catalyst C2 was placed in a fixed bed reactor. After nitrogen displacement of the reactor was qualified at 6MPa, hydrogen was introduced and the temperature was raised to 240°C. The temperature was kept constant for 5 hours to obtain the reduced C2 catalyst.

[0066] The first part of the carrier oil containing the sulfiding agent is injected into the reactor to perform the first passivation treatment on the reduced isomerization dewaxing catalyst, the treatment temperature is 250°C, the pressure is 6MPa, and the treatment time is 1h; wherein the sulfiding agent is CS2, the concentration in the carrier oil is 0.06wt%, the carrier oil is Fischer-Tropsch diesel, the hydrogen-to-oil ratio is 800:1, and the initial mass space velocity is 1.0h -1 , the tail gas is circulated and the volume content of hydrogen sulfide in the exhaust gas is controlled to be 10-40ppm;

[0067] After the first part of the carrier oil is injected, the second part of the carrier oil containing the sulfiding agent is injected into the reactor to continue the second passivation treatment of the isomerization dewaxing catalyst, the treatment temperature is 290°C, the pressure is 3MPa, and the treatment time is 5h to obtain a passivated catalyst; wherein the sulfiding agent is CS2, the concentration in the carrier oil is 0.04wt%, and the carrier oil is Fischer-Tropsch diesel; the hydrogen-to-oil ratio is 600:1, and the initial mass space velocity is 1.0h -1 , the tail gas is circulated and the volume content of hydrogen sulfide in the exhaust gas is controlled to be 40-100ppm;

[0068] After the passivation, the temperature was lowered and hydrogen was purged to remove residual hydrogen sulfide, Fischer-Tropsch diesel was added, the temperature was raised, and Fischer-Tropsch refined wax oil was switched for catalyst evaluation. The results are shown in Table 2.

[0069] Comparative Example 1

[0070] 100 g of oxidized isomerization dewaxing catalyst C1 was placed in a fixed bed reactor. After the reactor was replaced with nitrogen at 3.5 MPa and qualified, hydrogen was introduced and the temperature was raised to 240°C. The temperature was kept constant for 5 hours. After the reduction was completed, Fischer-Tropsch refined wax oil was added and the temperature was raised to start catalyst evaluation. The results are shown in Table 2.

[0071] Comparative Example 2

[0072] The difference from Example 1 is that the passivation treatment is a one-step passivation treatment: after reduction, a carrier oil containing a sulfiding agent is injected into the reactor to perform a passivation treatment on the reduced isomerization dewaxing catalyst, the treatment temperature is 210° C., and the treatment time is 6 hours; wherein the tail gas is circulated and the volume content of hydrogen sulfide in the discharged tail gas is controlled to be 10-40 ppm;

[0073] The rest is the same as in Example 1.

[0074] After the passivation, the temperature was lowered and hydrogen was purged to remove residual hydrogen sulfide. Fischer-Tropsch diesel and hydrogen were introduced, the temperature was raised, and Fischer-Tropsch refined wax oil was switched for catalyst evaluation. The results are shown in Table 2.

[0075] Comparative Example 3

[0076] The difference from Example 1 is that the passivation treatment is a one-step passivation treatment: after reduction, a carrier oil containing a sulfiding agent is injected into the reactor to continue the passivation treatment of the isomerization dewaxing catalyst, the treatment temperature is 250° C., the treatment time is 6 hours, and a passivated catalyst is obtained; wherein the tail gas is circulated and the volume content of hydrogen sulfide in the discharged tail gas is controlled to be 40-100 ppm;

[0077] The rest is the same as in Example 1.

[0078] After the passivation, the temperature was lowered and hydrogen was purged to remove residual hydrogen sulfide. Fischer-Tropsch diesel and hydrogen were introduced, the temperature was raised, and Fischer-Tropsch refined wax oil was switched for catalyst evaluation. The results are shown in Table 2.

[0079] Table 1 Refined wax properties

[0080] project Numeric Density, g / cm3 0.82 Distillation range (D2887) / ℃ IBP / 5% 293 / 354 10％ / 30％ 376 / 408 50％ / 70％ 428 / 450 90％ / 95％ 475 / 493 99.5％ 550

[0081] Table 2 Experimental results

[0082]

[0083] It can be seen from Table 2 that after the passivation treatment of the present invention, the base oil yield is significantly improved, and is increased by more than 3% at the same pour point.

Claims

1. A method for passivating an isomerization dewaxing catalyst, wherein the isomerization dewaxing catalyst is a noble metal molecular sieve catalyst used for catalytic production of lubricating oil base oil, wherein the active component is a noble metal and the carrier is a carrier containing a ten-membered ring molecular sieve; characterized in that: The passivation method comprises the following steps: (1) injecting a carrier oil containing a sulfiding agent and hydrogen into a reactor at a first reaction temperature to perform a first passivation treatment on the reduced isomerization dewaxing catalyst; wherein the first reaction temperature is 180-250° C., the reaction time is 1-8 hours, and the volume concentration of hydrogen sulfide in the tail gas discharged from the reactor is controlled to be 10-40 ppm; (2) After the first passivation treatment is completed, at a second reaction temperature, a carrier oil containing a sulfiding agent and hydrogen are injected into the reactor to continue the second passivation treatment of the isodewaxing catalyst to obtain a passivated catalyst; wherein the second reaction temperature is 40-80° C. higher than the first reaction temperature, the reaction time is 1-5 hours, and the volume concentration of hydrogen sulfide in the exhaust gas discharged from the reactor is controlled to be 40-100 ppm.

2. The passivation method according to claim 1, characterized in that: The reactor is a fixed bed reactor. When performing the first passivation treatment and the second passivation treatment, the carrying oil is mixed with hydrogen before being injected into the reactor, and then injected from the top of the reactor. After the reaction, the tail gas is discharged from the top outlet of the reactor, and the carrying oil is discharged from the bottom.

3. The passivation method according to claim 2, characterized in that: When the carrier oil is mixed with hydrogen, the volume ratio of hydrogen to oil is 500-1000:1; Furthermore, when the first passivation treatment and the second passivation treatment are performed, the tail gas discharged from the top is reused as circulating hydrogen.

4. The passivation method according to any of the preceding claims, characterized in that During the first passivation treatment and the second passivation treatment, when the volume concentration of hydrogen sulfide in the tail gas is too high, reducing the rate of injecting the sulfiding agent into the reactor; When the volume concentration of hydrogen sulfide in the tail gas is too low, the rate of injecting the sulfiding agent into the reactor is increased.

5. The passivation method according to any of the preceding claims, characterized in that When the first passivation treatment is performed, the reaction temperature is 190-230° C.; the reaction pressure is 2.5-6.5 MPa, preferably 3-6 MPa; and the reaction time is 2-6 hours.

6. The passivation method according to any of the preceding claims, characterized in that When the second passivation treatment is performed, the reaction temperature is 230-300° C., preferably 240-260° C.; the reaction pressure is 2.5-6.5 MPa, preferably 3-6 MPa; and the reaction time is 2-4 hours.

7. A passivation method according to any one of the preceding claims, characterised in that The vulcanizing agent includes one or more of dimethyl sulfide, dimethyl disulfide, a mercaptan compound and carbon disulfide; The carrier oil is one or more of light white oil, coal direct liquefaction diesel, Fischer-Tropsch diesel with a distillation range of 300-390° C., Fischer-Tropsch hydrocracking oil and petroleum-based diesel.

8. The passivation method according to any of the preceding claims, characterized in that During the first passivation treatment, the concentration of the sulfiding agent in the carrier oil is 0.01-0.1wt%; during the second passivation treatment, the concentration of the sulfiding agent in the carrier oil can be 0.01-0.06wt%; preferably, the concentration of the sulfiding agent in the carrier oil during the second passivation treatment is 40%-80% of the concentration of the sulfiding agent in the carrier oil during the first passivation treatment.

9. The passivation method according to any of the preceding claims, characterized in that The noble metal element is selected from Pd and / or Pt; The ten-membered ring molecule is selected from one or more of ZSM-22, ZSM-23, ZSM-48 and ZSM-35.

10. A method for producing a lubricating oil base oil, comprising: a. Deactivate the isomerization dewaxing catalyst using the deactivation method described in any one of claims 1 to 9; b. cooling the passivated catalyst obtained in step (2), and then purging the passivated catalyst with hydrogen to remove residual sulfur; c. contacting the catalyst obtained in step b with a carrier oil without a sulfiding agent and hydrogen, heating the reactor, and then replacing the carrier oil in the reactor with a waxy feedstock oil to carry out a hydroisomerization reaction to produce a lubricating oil base oil.

Images