JP4891937B2 - Method for producing regenerated hydrotreating catalyst and method for producing petroleum product - Google Patents

Description

  The present invention relates to a method for producing a regenerated hydrotreating catalyst for treating a distillate petroleum fraction and a method for producing a petroleum product.

  Crude oil contains sulfur-containing compounds, nitrogen-containing compounds, oxygen-containing compounds, etc. as impurities, and petroleum products obtained from crude oil through a process such as distillation have hydrogenation activity for each fraction in the presence of hydrogen. The content of these impurities is reduced by a process called a hydrotreating process which is brought into contact with a catalyst. In particular, desulfurization for reducing the content of sulfur-containing compounds is well known. Recently, from the viewpoint of reducing environmental impact, regulations on the content of impurities, including sulfur-containing compounds in petroleum products, and the demand for reduction have become more stringent. Many so-called “sulfur-free” petroleum products are produced. Has been.

  The hydrotreating catalyst used for the hydrotreating of petroleum is exchanged because its activity decreases due to the deposition of coke and sulfur when used for a certain period of time. In particular, the above-mentioned “sulfur-free” has been demanded, and in the hydrotreating equipment for fractions such as kerosene, light oil and vacuum gas oil, a high hydrotreating capacity is required. This has led to increased costs and increased catalyst waste.

As a countermeasure against this, some of these facilities use a regenerated catalyst obtained by regenerating a used hydroprocessing catalyst (see, for example, Patent Documents 1 and 2).
JP 52-68890 A JP-A-5-123586

  In using the regenerated catalyst, if the activity of the hydrotreating catalyst can be maintained even if the hydrotreating process and the regenerating process are repeated several times, the regenerated hydrotreating catalyst (hereinafter referred to as “regenerated hydrotreating process”). The advantage of the use of “catalyst” or simply “regenerated catalyst”) is even greater. However, in the case of the conventional regeneration process, even if the activity can be recovered from the viewpoint of coke deposition, which is one of the causes of the decrease in the activity of the hydrotreating catalyst, the regeneration process itself reduces the activity of the catalyst. I might let you. In addition, since the catalyst activity after regeneration differs depending on the use history before regeneration of the catalyst, the regeneration treatment method, and the like, the regeneration catalyst, particularly the regeneration catalyst after regeneration multiple times, does not always have a stable and sufficient activity. If it is found that the activity is low after the regenerated catalyst is charged into the hydrotreating equipment and the hydrotreating operation is started, it is necessary to reduce the processing speed of the raw material oil, which is a serious problem.

  For the reasons described above, the adoption of regenerated catalyst is actually not being used particularly in hydroprocessing facilities with insufficient processing capacity. In addition, when the regenerated catalyst is used, a prior activity evaluation is required. However, the method of performing the activity evaluation by carrying out a hydrotreating reaction using a test facility requires a long period of time, and thus is not practical.

  The present invention has been made in view of such circumstances, and a method for simply producing a regenerated hydrotreating catalyst having sufficient activity, and a regenerated hydrotreating catalyst obtained by the production method are used. It aims at providing the manufacturing method of petroleum products.

  In order to solve the above-mentioned problems, the present invention regenerates a used hydroprocessing catalyst containing at least one selected from the group consisting of Group 6 metals and Group 8 to 10 metals in the periodic table. A first step, a second step of observing the regenerated catalyst obtained in the first step with a transmission electron microscope and determining whether the catalyst is reused, and a second step And a third step of recovering a catalyst determined to be suitable for reuse, and a method for producing a regenerated hydrotreating catalyst for treating a distillate petroleum fraction.

  In the second step, it is preferable to determine that it is appropriate to reuse the catalyst when observation with a transmission electron microscope is performed and a metal aggregate of 100 nm or more is not observed.

  In the second step, a sample having a thickness of 30 nm to 200 nm is prepared from the regenerated catalyst obtained in the first step using a focused ion beam, and the sample is observed with a transmission electron microscope. Preferably it is done.

  In addition, the hydrotreating catalyst is an inorganic carrier containing aluminum oxide, based on the total catalyst mass, at least one selected from Group 6 metals of the Periodic Table, 10 to 30% by mass, and Periodic Tables 8 to 8 A catalyst obtained by supporting 1 to 7% by mass of at least one selected from Group 10 metals is preferred.

  Furthermore, in the hydrotreating catalyst, at least one selected from Group 6 metals of the periodic table is molybdenum, and at least one selected from Group 8 to 10 metals of the periodic table is cobalt and / or nickel. It is preferable.

  The present invention also provides a fourth step for producing a regenerated hydrotreating catalyst by the method for producing a regenerated hydrotreating catalyst of the present invention, and a regenerated hydrotreating catalyst obtained in the fourth step. And a fifth step of hydrotreating a distillate petroleum fraction using the above-described method.

The operating conditions of the fifth step are preferably a hydrogen partial pressure of 3 to 13 MPa, an LHSV of 0.05 to 5 h ⁻¹ , a reaction temperature of 200 ° C. to 410 ° C., and a hydrogen / oil ratio of 100 to 8000 SCF / BBL.

  Moreover, it is preferable that the distillation temperature by the distillation test of the distillate petroleum fraction used for the manufacturing method of the petroleum product of this invention is 130-700 degreeC.

  The method for producing a regenerated hydrotreating catalyst of the present invention has an effect that a regenerated hydrotreating catalyst having sufficient activity can be easily produced. In addition, the petroleum product production method of the present invention has an effect that a highly practical production process using a regenerated hydrotreating catalyst having sufficient activity and a low cost can be realized, thereby reducing costs. It is very useful in terms of reducing the amount of waste discharged and increasing the efficiency of hydrotreating distillate oil fractions.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

(Hydroprocessing catalyst)
The hydrotreating catalyst used in the present invention contains at least one selected from the group consisting of Group 6 metals and Groups 8 to 10 metals of the periodic table. The Periodic Table Group 6 metal is preferably molybdenum, tungsten, or chromium, more preferably molybdenum or tungsten, and particularly preferably molybdenum. As said group 8-10 metal of a periodic table, iron, cobalt, and nickel are preferable, cobalt and nickel are more preferable, and cobalt is especially preferable. These metals may be used alone or in combination of two or more. When two or more selected from the group consisting of Group 6 metals and Group 8 to 10 metals in the periodic table are used, molybdenum-cobalt, molybdenum-nickel, tungsten-nickel, molybdenum-cobalt-nickel, tungsten-cobalt -Nickel etc. are preferably used. Here, the periodic table is a long-period type periodic table defined by the International Union of Pure and Applied Chemistry (IUPAC).

  The hydrotreating catalyst according to the present invention is preferably one in which the active metal is supported on an inorganic carrier containing aluminum oxide. Preferred examples of the inorganic carrier containing aluminum oxide include alumina, alumina-silica, alumina-boria, alumina-titania, alumina-zirconia, alumina-magnesia, alumina-silica-zirconia, alumina-silica-titania, and various types. Examples include a carrier in which a porous inorganic compound such as various clay minerals such as zeolite, ceviolite, and montmorillonite is added to alumina, among which alumina is particularly preferable.

  The catalyst for hydrotreating according to the present invention has an inorganic carrier containing aluminum oxide, 10 to 30% by mass selected from Group 6 metals of the periodic table, based on the total catalyst mass, A catalyst obtained by supporting 1 to 7% by mass of at least one selected from Group 8 to 10 metals is preferred.

  The precursor of the active metal species used when the active metal is supported on the inorganic carrier is not limited, but an inorganic salt of the metal, an organic metal compound, or the like is used, and a water-soluble inorganic salt is preferably used. In the supporting step, it is preferable to support using a solution of these active metal precursors, preferably an aqueous solution. As the supporting operation, for example, a known method such as an immersion method, an impregnation method, a coprecipitation method, or the like is preferably employed.

  The carrier on which the active metal precursor is supported is preferably dried and then calcined in the presence of oxygen, and the active metal species is once converted to an oxide. Further, before the hydrotreating of the distillate petroleum fraction, the active metal is preferably converted into a sulfide by a sulfiding treatment called presulfiding.

  The shape of the hydrotreating catalyst according to the present invention may be powder, but is preferably formed into particles. The molded catalyst may be obtained by supporting the active metal on the molded inorganic carrier, or may be obtained by molding the active metal after supporting the powdered inorganic carrier. Good. Various methods can be used for molding, such as a method in which the powdered inorganic carrier or the inorganic carrier carrying the active metal is molded by compression, a small amount of water, an acid aqueous solution, etc. are added and kneaded, and this is extruded. A method of cutting and the like is preferably employed. Further, at the time of molding, a binder made of an inorganic oxide may be added to the inorganic carrier for the purpose of improving moldability and / or mechanical strength of the molded catalyst. The shape of the molded catalyst particles is not limited, but may be, for example, a spherical shape, a cylindrical shape, a pellet shape, or a modified cylindrical shape such as a three-leaf type cross section. The shaped catalyst particles are excellent in handling properties compared to a powdered catalyst, and have the effect of reducing the pressure loss of the oil to be treated during the hydrotreating of the distillate petroleum fraction.

(Regeneration process)
The hydrotreating catalyst that has been used for a certain period of time in the hydrotreating equipment of the distillate petroleum fraction and whose activity has fallen below a certain level is subjected to a regeneration treatment in the first step of the present invention. Although the equipment for performing the regeneration treatment is not particularly limited, it is preferably carried out in equipment different from the hydrotreating equipment for the distillate petroleum fraction. That is, instead of performing the regeneration process with the catalyst in the reactor of the hydrotreating equipment of the distillate petroleum fraction, the catalyst is extracted from the reactor, and the extracted catalyst is used for the regeneration process. It is preferable to move to an equipment and perform a regeneration process using the equipment.

  Although the form for performing the regeneration treatment of the used catalyst used in the first step of the present invention is not limited, the catalyst pulverized from the used catalyst and, in some cases, fillers other than the catalyst are removed by sieving. And a step of removing oil adhering to the used catalyst (deoiling step), a step of removing coke deposited on the used catalyst, a sulfur component (regeneration step), and the like. preferable.

  Among these, in the deoiling step, a method of volatilizing the oil by heating the used catalyst to a temperature of about 300 to 400 ° C. in an atmosphere where oxygen is not substantially present, for example, a nitrogen atmosphere is preferably employed. The The deoiling step may be performed by a method of washing oil with light hydrocarbons or a method of removing oil by steaming.

  In the regeneration step, the used catalyst is 300 to 700 ° C., preferably 320 to 550 ° C., more preferably 330 to 450 ° C. in an atmosphere where molecular oxygen exists, for example, in the air, particularly in the air stream. Particularly preferably, a method of oxidizing and removing the deposited coke, sulfur, etc. by heating to a temperature of 340 to 400 ° C. is preferably employed. When the heating temperature is lower than the lower limit temperature, the removal of substances having reduced catalytic activity such as coke and sulfur content tends not to proceed efficiently. On the other hand, when the heating temperature exceeds the upper limit temperature, the activity of the obtained regenerated catalyst tends to decrease due to aggregation of active metal in the catalyst or formation of a composite metal oxide.

(Analysis / judgment process)
After the regeneration process is performed in the first step, a part of the hydrotreating catalyst (regenerated catalyst) provided for the regeneration process is extracted. In the second step, the extracted regenerated catalyst is observed with a transmission electron microscope (TEM) to determine whether the catalyst is reused. The determination as to whether or not the catalyst can be reused can be made based on, for example, a criterion of whether the decrease in activity is within an allowable range in comparison with the hydrotreating catalyst before use. That is, the activity of the catalyst is separately evaluated by a hydrotreating reaction test using the regenerated catalyst, and the correlation between the result and the result of TEM observation of the regenerated catalyst is grasped in advance. It is possible to predict the degree of activity from the observation result, and thereby it is possible to determine whether or not the regenerated catalyst should be recovered and reused.

  The thickness of the sample used for TEM observation is important. If the thickness is too thick, the electron beam cannot be transmitted, and the state of dispersion / aggregation of the active metal in the catalyst cannot be observed. For this reason, the thickness of the TEM observation sample is preferably 200 nm or less, more preferably 150 nm or less, still more preferably 120 nm or less, and particularly preferably 80 nm or less. The thickness of the TEM observation sample is preferably 30 nm or more. When the thickness is less than 30 nm, the sample tends to be easily broken and difficult to handle, or a damage layer due to ion collision described later tends to remain. When the thickness of the sample satisfies the above conditions, it is possible to easily and reliably determine the presence or absence of metal aggregation in the observation field.

  The preparation of the sample having the thickness for TEM observation is preferably performed by a method of physically or mechanically cutting and polishing the catalyst particles. Examples of this method include an ultrathin section method, a sputtering / thinning method, and a focused ion beam method. The catalyst particles for hydrotreating according to the present invention are fragile and are a composite composed of a support and an active metal having different hardness and sputtering efficiency. The focused ion beam method (FIB) is particularly preferable from the viewpoint that a sample for TEM observation having the above thickness can be produced reliably and in a state where the tissue is held from a specific portion of such catalyst particles. By applying a focused ion beam (FIB) / transmission electron microscope (TEM), information on the active metal species in the target regenerated catalyst, especially information on the dispersion / aggregation state of the active metal species can be obtained. These pieces of information are closely related to the hydrotreating activity of the regenerated catalyst, and from these pieces of information, it is determined whether the regenerated catalyst is hydrotreated, and therefore, whether the regenerated catalyst is reused or reused for hydrotreating. It is possible to determine.

An example of a method for preparing a sample for TEM observation by FIB will be described below. Typical conditions for FIB irradiation are as follows.
Ion source: Ga
Accelerating voltage: Roughing 40kV, Finishing 10kV
Deposit: Tungsten

  When a sample for TEM observation is collected from the surface portion of the catalyst particles by FIB, a deposit (tungsten) as a protective film is previously formed on the catalyst particle surface by vapor deposition when irradiating the catalyst surface with FIB. Next, while observing with a scanning ion microscope, sputtering is performed by irradiating focused Ga ions to the peripheral portion of the region where the catalyst particle surface deposit is formed (the portion where the catalyst particle surface is exposed). By this sputtering, a raised portion is formed on the surface of the catalyst particle, and then sputtering is performed by irradiating the bottom of the raised portion with Ga ions, and the raised portion is separated from the catalyst particle and collected as a sample. A series of these operations is called “rough machining”. In the case of rough machining, Ga ions are high energy, so that a damage layer is formed by collision of Ga ions in the portion irradiated with the beam. The damaged layer can be removed in the finishing process described later, but when selecting the size of the sample for TEM observation formed with a thickness of about 20 nm on the surface layer portion of the side surface of the collected raised portion, It is desirable to consider the thickness. The collected sample may be subjected to a finishing process described later as it is, but the collected sample may be further subjected to roughing.

  The sampling position of the sample for TEM observation from the catalyst particles is preferably two locations, the central portion and the surface portion of the catalyst particles. Here, the “center portion” is the surface of a virtual particle (hereinafter referred to as “virtual particle A”) whose similarity is reduced so that the ratio to the total volume of the catalyst particle becomes 13% by volume with the center of gravity of the catalyst particle as the center. An inner region is meant, and the “surface part” means a region between the surface of the catalyst particles and the surface of the virtual particles A (region occupying 87% by volume with respect to the total volume of the catalyst particles). .

  Furthermore, the central portion is a region located inside virtual particles (hereinafter referred to as “virtual particles B”) that are similarly reduced with the center of gravity of the catalyst particles as the center so that the ratio to the total volume of the catalyst is 2% by volume. It is more preferable that On the other hand, the surface portion is a virtual particle (hereinafter referred to as “virtual particle C”) that is similar and reduced so that the ratio to the total volume of the catalyst is 42% by volume centered on the surface of the catalyst particle and the center of gravity of the catalyst particle. It is more preferable that it is a region between them (region occupying 58% by volume with respect to the total volume of the catalyst particles). Furthermore, a sample for TEM observation may be collected from a region between the surface of the virtual particle B and the surface of the virtual particle C (region occupying 40% by volume with respect to the entire catalyst particle).

When a sample for TEM observation is collected from the central part of the catalyst particles, the catalyst particles are first cut so that the central part of the catalyst particles is exposed. Cutting can be performed with a sharp blade or the like under visual observation or observation with a magnifier or an optical microscope. Then, a deposit as a protective film is formed at the central portion on the cut surface, and it is preferable to form and collect a sample by FIB in the same manner as in the case of collecting a sample from the above-mentioned catalyst particle surface portion. .

  Next, with respect to the sample after rough processing, the acceleration voltage is made as low as possible (preferably the lowest voltage), and sputtering by Ga ion irradiation is performed over time (finishing processing). Thereby, it is possible to further reduce the thickness of the sample while suppressing the formation of a further damaged layer, and it is possible to obtain a sample suitable for TEM observation. Note that the damaged layer formed during the roughing process is removed during the finishing process.

The sample obtained in this way is observed with a TEM to determine the suitability of catalyst reuse. Typical conditions for TEM observation are as follows.
(TEM measurement conditions)
Electron gun: LaB6
Accelerating voltage: 200kV
Shooting magnification: 10,000 to 500,000 times

  The suitability of catalyst reuse is preferably determined based on the presence or absence of active metal aggregates contained in the catalyst or the size of the active metal aggregates. Moreover, it is preferable that the visual field of TEM observation shall be 10 or more fields selected arbitrarily. Particularly preferably, TEM observation is performed for 10 fields of view, and when active metal aggregates having a maximum length of 100 nm or more are not observed, “in comparison with the hydrotreating catalyst before use, the range of decrease in activity is From the viewpoint that it is within the allowable range when it is used, it is determined that it can be recovered and reused in the next step. On the other hand, active metal aggregates having a maximum length of 100 nm or more are observed. In the case where the regenerated catalyst is used, from the viewpoint that “the range of the decrease in activity is out of the allowable range for use in reuse in comparison with the hydrotreating catalyst before use”, It is determined that it cannot be collected and reused in the process.

(Catalyst recovery process)
In the second step, the regenerated catalyst determined that “the range of decrease in activity is within the allowable range for reuse” (that is, “reusability is suitable”) is recovered in the third step, Transported and filled into hydrotreating facilities for petroleum. On the other hand, the regenerated catalyst determined in the second step as “the range of the decrease in activity is out of the allowable range for use in reuse” (that is, “unsuitable for reuse”) is discarded.

  In addition, the 4th process in the manufacturing method of the petroleum product of this invention is a process of manufacturing the catalyst for regenerated hydrogenation processes with the manufacturing method of the regenerated hydrogenation catalyst of this invention, The said 1st-3rd process Is included. Since aspects of the hydrotreating catalyst, the regeneration process, the analysis / judgment process, the catalyst recovery process, and the like in the method for producing a petroleum product of the present invention are the same as those described above, redundant descriptions are omitted here.

(Hydrogenation process)
In the hydrotreating step of the distillate petroleum fraction, which is the fifth step of the present invention, before the hydrotreating reaction, the regenerated catalyst charged in the equipment is treated with a sulfur compound called presulfidation. The active metal species is preferably a metal sulfide.

Although it does not specifically limit as conditions for preliminary sulfidation, a sulfur compound is added to the feed oil used for the hydrotreating of the distillate petroleum fraction, this is temperature 200-380 degreeC, LHSV1-2h- ¹ and a pressure is hydrogenation. It is preferable to continuously contact the regenerated catalyst under the same conditions as in the treatment operation and for a treatment time of 48 hours or longer. Although it does not limit as a sulfur compound added to the said raw material oil, Dimethyl disulfide (DMDS), hydrogen sulfide, etc. are preferable, and it is preferable to add these about 1 mass% with respect to the mass of a raw material oil with respect to raw material oil.

  The operating conditions in the hydrotreating step of the distillate petroleum fraction that is the fifth step are not particularly limited, but for the purpose of maintaining a state where the active metal species of the catalyst is a sulfide, a sulfur compound such as DMDS is used as a raw material. Although a small amount may be added to the oil, it is usually preferable not to add a sulfur compound because it is possible to maintain a sulfide state by the sulfur compound already contained in the raw material oil.

The hydrogen partial pressure at the reactor inlet in the hydrotreating step is preferably 3 to 13 MPa, more preferably 3.5 to 12 MPa, and particularly preferably 4 to 11 MPa. When the hydrogen partial pressure is less than 3 MPa, coke formation on the catalyst becomes intense and the catalyst life tends to be shortened. On the other hand, when the hydrogen partial pressure exceeds 13 MPa, there is a concern that the construction cost of the reactor, peripheral equipment, and the like will increase and the economy will be lost.

LHSV in the hydrotreatment step is preferably 0.05～5H ^-1, more preferably 0.1～4.5H ^-1, particularly preferably may be in the range of 0.2~4h ^-1. When LHSV is less than 0.05 h ⁻¹ , there is a concern that the construction cost of the reactor becomes excessive and the economic efficiency is lost. On the other hand, when LHSV exceeds 5h- ¹ , there is a concern that the hydrogenation treatment of the raw material oil is not sufficiently achieved.

  The hydrogenation reaction temperature in the hydrotreating step is preferably 200 ° C to 410 ° C, more preferably 220 ° C to 400 ° C, and particularly preferably 250 ° C to 395 ° C. When the reaction temperature is lower than 200 ° C., the hydrogenation treatment of the raw material oil tends not to be sufficiently achieved. On the other hand, when the reaction temperature exceeds 410 ° C., the generation of a gas component as a by-product increases, which is not desirable because the yield of the target refined oil decreases.

  The hydrogen / oil ratio in the hydrotreating step is preferably 100 to 8000 SCF / BBL, more preferably 120 to 7000 SCF / BBL, and particularly preferably 150 to 6000 SCF / BBL. When the hydrogen / oil ratio is less than 100 SCF / BBL, coke formation on the catalyst proceeds at the reactor outlet, and the catalyst life tends to be shortened. On the other hand, when the hydrogen / oil ratio exceeds 8000 SCF / BBL, there is a concern that the construction cost of the recycle compressor becomes excessive and the economic efficiency is lost.

  The reaction type in the hydrotreating step is not particularly limited, but usually, it can be selected from various processes such as a fixed bed and a moving bed, but a fixed bed is preferable. The reactor is preferably tower-shaped.

  As the feedstock to be subjected to the hydrotreating of the distillate petroleum fraction of the present invention, the distillation temperature by distillation test is preferably 130 to 700 ° C, more preferably 140 to 680 ° C, and particularly preferably 150 to 660 ° C. Those in the range are used. When a feed oil having a distillation temperature lower than 130 ° C. is used, the hydrotreating reaction becomes a reaction in the gas phase, and the above-mentioned catalyst tends not to exhibit sufficient performance. On the other hand, when a feedstock having a distillation temperature exceeding 700 ° C. is used, the content of poisonous substances with respect to the catalyst such as heavy metals contained in the feedstock is increased, and the life of the catalyst is greatly reduced. The other properties of the distillate petroleum fraction used as the feedstock are not particularly limited, but typical properties include specific gravity (15/4 ° C.) 0.8200 to 0.9700, sulfur content 1.0 to It is 4.0 mass%.

  The sulfur content in the present invention is the sulfur content measured in accordance with “6. Radiation excitation method” of “Crude oil and petroleum products—Sulfur content test method” prescribed in JIS K2541-1992. means. Moreover, the distillation test in this application means what is performed based on "6. Vacuum distillation test method" of "Petroleum product-Distillation test method" prescribed | regulated to JISK2254.

Further, as a means for directly evaluating the hydrotreating activity of the regenerated catalyst, a desulfurization rate constant under the same operating conditions can be given. The desulfurization rate constant is defined by the following equation.
Desulfurization rate constant = LHSV × (1 / produced oil sulfur content−1 / raw oil sulfur content)

However, since the activity of the new catalyst differs depending on the manufacturer, production unit, etc., the activity of the regenerated catalyst obtained by regenerating after using the hydrotreating catalyst is relative to the activity standard of the corresponding new catalyst. It is considered appropriate to evaluate based on specific activity. Therefore, the activity of the regenerated catalyst is evaluated based on the specific activity defined by the following equation.
Specific activity = desulfurization rate constant of regenerated catalyst / desulfurization rate constant of new catalyst

  EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited at all by these examples. In the following examples and comparative examples, the “center part” means a virtual particle (similar to the above-mentioned virtual particle) with the center of gravity of the catalyst particle being reduced and the ratio to the total volume of the catalyst being 2% by volume. It means the region located inside B). In addition, the “surface portion” refers to virtual particles (the virtual particles C described above) that are reduced in size so that the ratio to the total volume of the catalyst is 42% by volume centering on the surface of the catalyst particles and the center of gravity of the catalyst particles. (Area occupying 58% by volume with respect to the total volume of the catalyst particles).

[Example 1]
(Regenerative hydrogenation catalyst)
A catalyst in which molybdenum and cobalt are supported on an alumina carrier as active metals, and a regenerated catalyst 1 obtained by regenerating a hydrotreating catalyst used for two years in a kerosene hydrotreating facility as shown in Table 1 was used. .

(TEM observation of regenerated hydrotreating catalyst)
Next, the regenerated catalyst 1 was subjected to the above-described roughing and finishing using FIB, and a sample (thickness: 100 nm) for TEM observation was produced. The sample was collected at two locations, a central region and a surface region. The FIB conditions are shown below.
Ion source: Ga
Accelerating voltage: Roughing 40kV, Finishing 10kV
Deposit: Tungsten

Next, each of the TEM observation samples collected from the central portion and the surface portion was subjected to TEM observation in 10 visual fields to determine the presence or absence of active metal aggregates. The conditions for TEM observation are shown below. In this example, no metal aggregates of 100 nm or more were detected in any of the samples collected from the central part and the surface part.
(TEM measurement conditions)
Electron gun: LaB6
Accelerating voltage: 200kV
Shooting magnification: 10,000 to 500,000 times

(Hydrogenation reaction)
The filled with regenerated catalyst 1 in a fixed bed continuous flow reactor, it was pre-sulfurization of the catalyst. To a fraction corresponding to kerosene having the properties shown in Table 1, 1% by mass of DMDS was added based on the mass of the fraction, and this was continuously fed to the catalyst for 48 hours. Then, hydrotreating reaction was performed under the conditions described in Table 1, using a fraction corresponding to kerosene having the properties described in Table 1 as a raw material oil. The desulfurization rate constant was determined from the sulfur content in the product oil. In addition, the same reaction was performed using a new catalyst corresponding to the regenerated catalyst 1 to obtain a desulfurization rate constant, and the specific activity of the regenerated catalyst 1 was calculated therefrom. The results are shown in Table 1.

[Example 2]
(Regenerative hydrogenation catalyst)
A catalyst in which molybdenum and cobalt as active metals are supported on an alumina carrier, as shown in Table 1, a regenerated catalyst 2 was used which was regenerated from a hydrotreating catalyst used for 2 years in a gas oil hydrotreating facility. .

(TEM observation of regenerated hydrotreating catalyst)
As a result of TEM observation of the regenerated catalyst 2 in the same manner as in Example 1, no metal aggregates were detected.

(Hydrogenation reaction)
A hydrotreating reaction was carried out in the same manner as in Example 1 except that a fraction corresponding to light oil having the properties shown in Table 1 was used as the raw material oil and the conditions shown in Table 1 were used. The results of specific activity are shown in Table 1.

[Example 3]
(Regenerative hydrogenation catalyst)
A catalyst in which molybdenum and cobalt as active metals are supported on an alumina carrier, as shown in Table 1, using a regenerated catalyst 3 that has been regenerated from a hydrotreating catalyst that has been used for one year in a vacuum gas oil hydrotreating facility. did.

(TEM observation of regenerated hydrotreating catalyst)
As a result of TEM observation of the regenerated catalyst 3 in the same manner as in Example 1, no metal aggregates were detected.

(Hydrogenation reaction)
A hydrotreating reaction was carried out in the same manner as in Example 1 except that the fraction corresponding to the vacuum gas oil having the properties shown in Table 1 was used as the raw material oil and the conditions shown in Table 1 were used. The results of specific activity are shown in Table 1.

[Comparative Examples 1-3]
(Regenerative hydrogenation catalyst)
Catalysts having molybdenum and cobalt as active metals supported on an alumina carrier, each having a history of regenerated catalysts 4 to 6 shown in Table 1, were used.

(TEM observation of regenerated hydrotreating catalyst)
As a result of TEM observation of each of the regenerated catalysts 4 to 6 in the same manner as in Example 1, a metal aggregate of 100 nm or more was detected.

(Hydrogenation reaction)
A hydrotreating reaction was performed in the same manner as in Example 1 except that each fraction having the properties shown in Table 1 was used as the raw material oil and the conditions shown in Table 1 were used. The results of specific activity are shown in Table 1.

From the results of Table 1, according to the method of the present invention, the activity of the regenerated catalyst was determined by simple TEM observation, and “the range of the decrease in activity is within the allowable range for reuse” (that is, “recycling is It can be seen that by recovering and using the regenerated catalyst determined to be “appropriate”), an activity of about 93% or more in comparison with the new catalyst is maintained (Examples 1 to 3). On the other hand, in Comparative Examples 1 to 3, the raw material oil corresponding to Examples 1 to 3 was hydrotreated, but in either case, the activity relative to the new catalyst was about 89% or less, and the activity decreased. Is big.

Claims (8)

A first step of regenerating a spent hydrotreating catalyst containing at least one selected from the group consisting of Group 6 metals and Groups 8-10 metals of the periodic table;
A second step of observing the regenerated catalyst obtained in the first step with a transmission electron microscope and determining whether the catalyst is reused;
A third step of recovering the catalyst determined to be suitable for reuse in the second step;
A method for producing a regenerated hydrotreating catalyst for treating a distillate petroleum fraction.   2. The catalyst according to claim 1, wherein in the second step, observation with a transmission electron microscope is performed, and when a metal aggregate of 100 nm or more is not seen, it is determined that reuse of the catalyst is appropriate. A method for producing a catalyst for regenerated hydrogenation.   In the second step, using a focused ion beam, a sample having a thickness of 30 nm to 200 nm is prepared from the regenerated catalyst obtained in the first step, and the sample is observed with a transmission electron microscope. The method for producing a regenerative hydrotreating catalyst according to claim 1, wherein:   The hydrotreating catalyst is an inorganic carrier containing aluminum oxide, 10 to 30% by mass selected from Group 6 metals of the periodic table based on the total catalyst mass, and 8 to 10 of the periodic table. The catalyst for regenerated hydroprocessing according to any one of claims 1 to 3, wherein the catalyst is obtained by supporting 1 to 7% by mass of at least one selected from group metals. Production method.   In the hydrotreating catalyst, at least one selected from Group 6 metals of the periodic table is molybdenum, and at least one selected from Group 8 to 10 metals of the periodic table is cobalt and / or nickel. The method for producing a regenerated hydrotreating catalyst according to any one of claims 1 to 4, wherein: A fourth step of producing a regenerated hydrotreating catalyst by the method for producing a regenerated hydrotreating catalyst according to any one of claims 1 to 5,
A fifth step of hydrotreating a distillate petroleum fraction using the regenerated hydrotreating catalyst obtained in the fourth step;
A method for producing a petroleum product, comprising: The operating conditions of the fifth step are: hydrogen partial pressure 3-13 MPa, LHSV 0.05-5 h ⁻¹ , reaction temperature 200 ° C.-410 ° C., hydrogen / oil ratio 100-8000 SCF / BBL, The method for producing a petroleum product according to claim 6.   The method for producing a petroleum product according to claim 6 or 7, wherein the distillation petroleum fraction has a distillation temperature of 130 to 700 ° C according to a distillation test thereof.