Evaluation method for guard catalyst

Abstract

To provide an evaluation method for a guard catalyst that enables evaluation under conditions closer to an actual machine and that has high reproducibility of evaluation results.SOLUTION: An evaluation method for a guard catalyst for a direct desulfurization reaction comprises supplying one or both of an atmospheric distillation residual oil and a vacuum distillation residual oil to a guard catalyst layer formed in a fixed bed flow type reactor. A temperature of the guard catalyst layer is 100°C or higher, the guard catalyst comprises an inorganic oxide, and a ratio of a particle diameter of the guard catalyst to an inner diameter of the fixed bed flow type reactor is 2 to 30%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for evaluating a guard catalyst. [Background technology]

[0002] Due to the decline in demand for heavy oil, there is a demand for technology that can efficiently convert atmospheric distillation residue oil, which is the main heavy oil base material obtained by processing crude oil in an atmospheric distillation unit, and vacuum distillation residue oil, which is obtained by processing the atmospheric distillation residue oil in a vacuum distillation unit, into light fractions with high added value.

[0003] As a technology for converting heavy oil base materials into light fractions, a process is known in which feedstock oils such as atmospheric distillation residue oil or a mixture of atmospheric distillation residue oil and vacuum distillation residue oil are treated in a fluid catalytic cracking unit to produce light fractions such as gasoline, kerosene, and diesel.

[0004] The sulfur content of the feedstock oil processed in the fluid catalytic cracking unit must be reduced to a certain level in order to satisfy the specifications for the target light fraction and to protect the fluid catalytic cracking catalyst. Therefore, the atmospheric distillation residue oil and the mixed oil are hydrotreated using a hydrotreating catalyst before being processed in the fluid catalytic cracking unit.

[0005] To convert more heavy oil basestocks into light fractions, it is necessary to increase the processing volume of the feedstock, especially the vacuum distillation residue. However, these feedstocks contain impurities such as residual carbon and metals, which accumulate on the hydrotreating catalyst and clog the pores, reducing the activity of the hydrotreating catalyst. Furthermore, the feedstock generates uneven flow and pressure differentials within the reactor, hindering stable operation.

[0006] For this reason, in hydrotreating, a guard catalyst is used at the inlet side of the reactor to capture these impurities. A demetallization catalyst is also used downstream of the guard catalyst. The guard catalyst primarily captures solid metals and residual carbon contained in the feedstock. The demetallization catalyst primarily captures metals dissolved in the feedstock.

[0007] Incidentally, when operating an actual hydrotreating plant, the guard catalyst, demetallization catalyst, and hydrotreating catalyst may be changed, and reaction conditions such as feedstock, pressure, and temperature may be changed. In such cases, it is risky to examine the changed reaction conditions in the actual plant, and it is therefore desirable to examine these changed conditions using a small-scale catalyst performance evaluation device (bench-scale device) that simulates the actual plant. Furthermore, when a catalyst-related reaction malfunction occurs, it is inefficient to analyze the cause of the malfunction using the actual plant, and it is therefore desirable to analyze the cause of the malfunction in a shorter time using bench-scale equipment.

[0008] For the above-mentioned demetallization catalysts and hydrotreating catalysts, various catalyst evaluation methods using bench-scale equipment simulating actual equipment have been proposed. On the other hand, for guard catalysts, no catalyst evaluation method using bench-scale equipment simulating actual equipment has been established. These catalysts are used as molded bodies, but guard catalysts are larger than demetallization catalysts and hydrotreating catalysts, making it difficult to evaluate them directly using bench-scale equipment.

[0009] In Patent Document 1, 100 g of powdered iron oxide, which had been dried in advance at 400°C for 1 hour, was suspended in 9 L of commercially available kerosene, and this suspension was passed through an acrylic perforated plate into a guard catalyst layer filled in an acrylic cylinder at a rate of 5 L / min for 2 minutes to evaluate the iron oxide capture ability of the guard catalyst layer. This method of evaluating guard catalysts at room temperature using a simulated liquid is known as the cold flow method. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 2024-18466 Summary of the Invention [Problem to be solved by the invention]

[0011] The cold flow method described in Patent Document 1 is a method for evaluating guard catalysts under conditions that are significantly different from the reaction conditions of actual plants, such as feedstock oil, pressure, non-supply of hydrogen, and temperature. In other words, the cold flow method does not use the feedstock oil actually used in actual plants, and therefore does not reproduce the impurity deposition that occurs in actual plants. Furthermore, while the blockage of guard catalyst pores by deposits is accelerated by heat, the cold flow method, which evaluates at low temperatures, makes it difficult to reproduce the blockage of pores that occurs in actual plants. Furthermore, the cold flow method simply physically adsorbs impurities in the simulated liquid onto the catalyst, and is unable to reproduce the deposition of impurities resulting from the reaction of the feedstock. In particular, guard catalysts deposit impurities such as residual carbon and metals, as well as coke produced by the reaction, but the cold flow method cannot evaluate the impact of this coke deposition.

[0012] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a method for evaluating a guard catalyst that enables evaluation under conditions closer to those of an actual device and that provides highly reproducible evaluation results. [Means for solving the problem]

[0013] In order to solve the above problems, the present invention has the following aspects. [1] A method for evaluating a guard catalyst for a direct desulfurization reaction, the method comprising supplying either atmospheric bottom oil or vacuum bottom oil, or both, to a guard catalyst layer formed in a fixed-bed flow reactor, the temperature of the guard catalyst layer being 100°C or higher, the guard catalyst containing an inorganic oxide, and the ratio of the particle size of the guard catalyst to the inner diameter of the fixed-bed flow reactor being 2 to 30%. [2] The guard catalyst evaluation method according to [1], wherein the guard catalyst is a guard catalyst in which a hydrogenation active component is supported on the inorganic oxide. [3] The method for evaluating a guard catalyst according to [1] or [2], wherein a demetallization catalyst layer is further formed downstream of the guard catalyst layer in the fixed-bed flow reactor. [4] The method for evaluating a guard catalyst according to any one of [1] to [3], wherein the guard catalyst has a particle size of 1 to 4 mm. [5] The method for evaluating a guard catalyst according to any one of [1] to [4], wherein the guard catalyst layer has a packed volume of 5 to 60 mL. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a method for evaluating a guard catalyst, which allows evaluation under conditions closer to those of an actual device and provides highly reproducible evaluation results. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a graph showing the relationship between the amount of metal deposition and the natural logarithm of the desulfurization reaction rate constant in the evaluation of the guard catalysts of Examples 1 and 2. [Figure 2] FIG. 1 is a graph showing the change in differential pressure over time in the evaluation of the guard catalysts of Examples 1 and 2. DETAILED DESCRIPTION OF THE INVENTION

[0016] The following describes in detail the embodiments of the present invention. However, the following description is an example of an embodiment of the present invention, and the present invention is not limited to these contents and can be modified and implemented within the scope of its gist.

[0017] <Definition> The definitions of terms used in this specification are as follows. "Atmospheric residue" refers to the residue obtained by treating crude oil in an atmospheric distillation unit. Properties of atmospheric residue include, for example, a density at 15°C of 0.78 to 1.15 g / mL, a sulfur content of 0.05 to 5 mass%, a nickel content (elemental equivalent) of 1 to 100 mass ppm, a vanadium content (elemental equivalent) of 1 to 200 mass ppm, an iron content (elemental equivalent) of 1 to 100 mass ppm, an asphaltene content of 0.1 to 10 mass%, and a carbon residue content of 1 to 30 mass%. "Vacuum distillation bottoms" are bottoms obtained by treating atmospheric distillation bottoms in a vacuum distillation apparatus. Properties of vacuum distillation bottoms include, for example, a density at 15°C of 0.78 to 1.15 g / mL, a sulfur content of 0.05 to 7 mass%, a nickel content (elemental equivalent) of 1 to 200 mass ppm, a vanadium content (elemental equivalent) of 1 to 400 mass ppm, an iron content (elemental equivalent) of 1 to 200 mass ppm, an asphaltene content of 0.1 to 15 mass%, and a carbon residue content of 1 to 30 mass%.

[0018] The density at 15°C can be measured in accordance with JIS K 2249-1 (2011) "Crude oil and petroleum products - Determination of density - Part 1: Vibration method." The sulfur content can be measured in accordance with JIS K 2541-4 (2003) "Crude oil and petroleum products - Sulfur content test method, Part 4: Radiation excitation method." Nickel, vanadium, and iron contents can be measured in accordance with the Japan Petroleum Institute standard JPI-5S-62-2000 "Method for Metal Analysis of Petroleum Products (ICP Atomic Emission Spectroscopy)." The asphaltene content can be measured by adding toluene to a sample, filtering the sample through a cellulose filter, and recovering the toluene-insoluble content, which is then measured as the asphaltene content. The carbon residue can be measured in accordance with JIS K 2270-2 "Crude petroleum and petroleum products - Determination of carbon residue - Part 2: Micro method."

[0019] The specific surface area of ​​the catalyst can be measured by the BET method using nitrogen adsorption. The pore volume and average pore diameter of the catalyst can be measured by mercury intrusion porosimetry. The composition of the catalyst can be measured by dissolving the catalyst and then subjecting it to ICP emission spectrometry. The particle size of the guard catalyst can be measured with a vernier caliper, etc. The particle size may also be controlled by sieving.

[0020] <Guard catalyst evaluation method> The guard catalyst evaluation method of this embodiment is a method for evaluating a guard catalyst for a direct desulfurization reaction. The guard catalyst evaluation method is carried out by supplying either or both of atmospheric distillation bottom oil and vacuum distillation bottom oil to a guard catalyst layer formed in a fixed-bed flow reactor (hereinafter also simply referred to as "reactor"), and the temperature of the guard catalyst layer is 100°C or higher. The guard catalyst contains an inorganic oxide. The ratio of the particle size of the guard catalyst to the inner diameter of the fixed-bed flow reactor is 2 to 30%.

[0021] <Guard catalyst> The ratio of the particle size of the guard catalyst to the inner diameter of the reactor is 2 to 30%, preferably 3 to 25%, and more preferably 4 to 20%. When the ratio is equal to or greater than the lower limit, the generation of a pressure difference between the reactor inlet and the reactor outlet is easily suppressed, and when the ratio is equal to or less than the upper limit, the guard catalyst is easily packed uniformly, improving the reproducibility of the evaluation results.

[0022] When the cross-sectional shape of the reactor is a perfect circle, the inner diameter of the reactor means the diameter of the perfect circle. When the cross-sectional shape of the reactor is other than a perfect circle, for example, the inner diameter is calculated by dividing the cross-sectional area by S (cm 2 ), then (4S / π) 1 / 2 The cross-sectional shape of the reactor is preferably approximately circular, more preferably a perfect circle.

[0023] The reactor may contain guard catalysts whose particle size ratio to the inner diameter of the reactor is less than 2% or more than 30%. However, the content of guard catalysts whose particle size ratio to the inner diameter of the reactor is less than 2% or more than 30% is preferably 5% by mass or less, more preferably 2% by mass or less, and still more preferably 0.5% by mass or less, of the total mass of guard catalysts packed in the reactor. It is also preferable that the guard catalyst does not contain a guard catalyst having a particle size ratio of more than 50% relative to the inner diameter of the reactor.

[0024] The particle size of the guard catalyst is preferably 1 to 4 mm, more preferably 1 to 3.5 mm, and even more preferably 1 to 3 mm. When the particle size of the guard catalyst is equal to or larger than the lower limit, the generation of a pressure difference between the reactor inlet and the reactor outlet is easily suppressed, whereas when the particle size of the guard catalyst is equal to or smaller than the upper limit, the guard catalyst is easily packed uniformly, improving the reproducibility of the evaluation results. The particle size of the guard catalyst can be adjusted by crushing the molded guard catalyst and sieving it. As the crushing method, any method known in the art can be used.

[0025] Guard catalysts are used in actual reactors as molded bodies. The major axis of molded guard catalysts is usually 5 mm or more. The major axis of molded guard catalysts is larger than the inner diameter of bench-scale reactors. Therefore, molded guard catalysts may not be able to be directly loaded into bench-scale reactors. Furthermore, the present inventors have found that even if molded guard catalysts can be directly loaded into reactors, it is difficult to achieve uniform loading, which results in a problem of poor reproducibility in the evaluation of molded guard catalysts. The present inventors have found that by using guard catalysts whose particle size ratio to the inner diameter of the reactor falls within the above-mentioned range, it is possible to reproducibly evaluate guard catalysts on a bench scale that simulates an actual reactor.

[0026] (inorganic oxides) The inorganic oxide may be any inorganic oxide known in the art. Examples include metal oxides such as silica, alumina, boria, magnesia, titania, zinc oxide, and phosphorus oxide. However, oxides of metals in Groups 6, 9, and 10 of the long-form periodic table (described below) are not considered inorganic oxides but are considered hydrogenation-active components. Although boron and silicon are generally considered to be semimetallic elements, they are treated as metals in this specification. The inorganic oxide may be a mixture or composite oxide of the above metal oxides. Furthermore, the inorganic oxide may be a crystalline inorganic oxide such as zeolites, such as α-alumina, β-alumina, γ-alumina, and δ-alumina, or a non-crystalline inorganic oxide such as amorphous silica.

[0027] The inorganic oxide is preferably alumina, and more preferably γ-alumina because of its large specific surface area. The content of alumina relative to the total mass of the inorganic oxide is preferably 80 to 100 mass%, more preferably 85 to 100 mass%, and even more preferably 90 to 100 mass%.

[0028] When the inorganic oxide is mainly composed of alumina, the inorganic oxide may contain either or both of zinc and phosphorus in addition to alumina. When the inorganic oxide contains zinc oxide, the content of zinc oxide (ZnO) relative to the total mass of the inorganic oxide is preferably 0.01 to 15 mass%, more preferably 0.01 to 12 mass%, and even more preferably 0.01 to 10 mass%. When the inorganic oxide contains phosphorus oxide, the content of phosphorus oxide (P2O5) relative to the total mass of the inorganic oxide is preferably 0.01 to 10 mass%, more preferably 0.01 to 8 mass%, and even more preferably 0.01 to 5 mass%.

[0029] (hydrogenation active ingredient) The guard catalyst may consist solely of the inorganic oxide, or may contain both the inorganic oxide and a hydrogenation active component. The hydrogenation active component is preferably supported on an inorganic oxide. In the case of a guard catalyst containing an inorganic oxide and a hydrogenation active component, the guard catalyst not only captures solid metals (hereinafter also referred to as "scale"), residual carbon, coke, and the like contained in the feedstock, but also has demetallization and hydrotreating capabilities. The use of such a guard catalyst can further protect the demetallization catalyst and hydrotreating catalyst packed downstream of the guard catalyst layer, thereby extending the life of these catalysts. However, the hydrogenation active component is not essential for the guard catalyst to function. Even when the guard catalyst does not contain a hydrogenation active component, coke is still formed due to the acid sites of the inorganic oxide.

[0030] Examples of the hydrogenation active component include metals of Group 6, Group 9, and Group 10 in the long form periodic table. When the guard catalyst contains a hydrogenation active component, it preferably contains a metal of Group 6 and either or both of a metal of Group 9 and a metal of Group 10.

[0031] Examples of Group 6 metals include molybdenum, tungsten, and chromium, and among these, molybdenum is preferred because it has a high hydrotreating activity per unit mass. The Group 6 metal may be in the form of a simple metal or a metal compound. Among these, a metal compound is preferred, and an oxide or sulfide is more preferred. The Group 6 metal may form a composite oxide or composite sulfide with other elements contained in the guard catalyst. When the guard catalyst contains a Group 6 metal, the content of the Group 6 metal relative to the total mass of the guard catalyst is preferably 0.01 to 35 mass% and more preferably 1 to 30 mass% in terms of oxide (e.g., MoO3). When the substance containing a Group 6 metal is calculated as an oxide, the Group 6 metal is calculated as a hexavalent metal. The guard catalyst may contain only one type of Group 6 metal compound, or two or more types.

[0032] Examples of Group 9 metals and Group 10 metals include nickel, palladium, platinum, cobalt, rhodium, and iridium, among which nickel and cobalt are preferred, with nickel being more preferred, as they have high hydrogenation ability and low catalyst preparation costs. The guard catalyst may contain only a Group 9 metal, only a Group 10 metal, or both a Group 9 metal and a Group 10 metal. The Group 9 metals and Group 10 metals may be in the form of simple metals or metal compounds. Among these, metal compounds are preferred, and oxides and sulfides are more preferred. The Group 9 metals and Group 10 metals may form composite oxides or composite sulfides with other elements contained in the guard catalyst. When the guard catalyst contains a Group 9 metal or a Group 10 metal, the total content of the Group 9 metal and the Group 10 metal relative to the total mass of the guard catalyst is preferably 0.01 to 18 mass%, more preferably 1 to 15 mass%, calculated as an oxide (e.g., NiO). When the Group 9 metal or the Group 10 metal is calculated as an oxide, the Group 9 metal or the Group 10 metal is calculated as a divalent metal. The guard catalyst may contain only one type of Group 9 compound or two or more types of Group 10 compounds.

[0033] (Properties of guard catalyst) The specific surface area of ​​the guard catalyst is 80 to 300 m 2 / g, and 100 to 300m 2 / g, and more preferably 100 to 280m 2 / g is more preferred. When the specific surface area of ​​the guard catalyst is equal to or greater than the lower limit, the ability to capture scale, residual carbon, coke, etc. is improved. When the specific surface area of ​​the guard catalyst is equal to or less than the upper limit, the average pore size tends to be large, improving the ability to capture relatively large scale, etc.

[0034] The pore volume of the guard catalyst is preferably 0.4 to 1.0 mL / g, more preferably 0.45 to 1.0 mL / g, and even more preferably 0.5 to 0.9 mL / g. When the pore volume of the guard catalyst is equal to or greater than the lower limit, the ability to capture relatively large scales, etc. is improved. When the pore volume of the guard catalyst is equal to or less than the upper limit, the specific surface area tends to be large, and the ability to capture scales, residual carbon, coke, etc. is improved.

[0035] The average pore diameter of the guard catalyst is preferably 7 to 50 nm, more preferably 7 to 40 nm, and even more preferably 8 to 30 nm. When the average pore diameter of the guard catalyst is equal to or greater than the lower limit, the ability to capture relatively large scales, etc. is improved. When the average pore diameter of the guard catalyst is equal to or less than the upper limit, the specific surface area tends to be large, and the ability to capture scales, residual carbon, coke, etc. is improved.

[0036] <Evaluation conditions> The guard catalyst of this embodiment is evaluated by supplying a feedstock to a guard catalyst layer formed in a fixed-bed flow reactor. The feedstock includes either atmospheric residue or vacuum residue, or both. The temperature of the guard catalyst layer is 100°C or higher. It is preferable to supply hydrogen in addition to the feedstock.

[0037] As other evaluation conditions, it is preferable to use the feedstock oil used in the actual equipment, and to set the conditions to those assumed for the actual equipment. The guard catalyst of this embodiment is preferably evaluated on a scale smaller than that of the actual equipment. By performing the evaluation on such a small scale, the guard catalyst can be evaluated more efficiently.

[0038] (Reactor, packing configuration, etc.) The internal volume of the reactor is preferably 10 to 10,000 mL, more preferably 20 to 7,000 mL, and even more preferably 50 to 5,000 mL. When the internal volume of the reactor is equal to or greater than the lower limit, the amount of guard catalyst packed can be ensured, improving the reproducibility of evaluation results. When the internal volume of the reactor is equal to or less than the upper limit, the guard catalyst can be evaluated more efficiently. The inner diameter of the reactor is preferably 5 to 100 mm, more preferably 5 to 70 mm, and even more preferably 10 to 50 mm. When the inner diameter of the reactor is equal to or greater than the lower limit, the guard catalyst can be easily packed, and accordingly, the guard catalyst can be easily packed uniformly, improving the reproducibility of the evaluation results. When the inner diameter of the reactor is equal to or less than the upper limit, the guard catalyst can be evaluated more efficiently.

[0039] The packed volume of the guard catalyst layer is preferably 5 to 6000 mL, more preferably 10 to 3000 mL, and even more preferably 10 to 2000 mL. When the packed volume of the guard catalyst layer is equal to or greater than the lower limit, the reproducibility of the evaluation results is improved. When the packed volume of the guard catalyst layer is equal to or less than the upper limit, the guard catalyst can be evaluated more efficiently. When a plurality of guard catalyst layers are packed, the above-mentioned packed volume means the total packed volume of all the guard catalyst layers.

[0040] The ratio of the packed volume of the guard catalyst layer to the internal volume of the reactor is preferably 1 to 80%, more preferably 2 to 60%, and even more preferably 2 to 50%. When this ratio is equal to or greater than the lower limit, the reproducibility of the evaluation results is improved. When this ratio is equal to or less than the upper limit, the guard catalyst can be evaluated more efficiently.

[0041] As described above, it is preferable to evaluate guard catalysts using a small-scale bench-scale apparatus. In the case of a bench-scale apparatus, the amount of guard catalyst to be evaluated, the amount of feedstock oil used, the amount of energy used, and the like can be reduced. Furthermore, a large installation space is not required, installation costs can be reduced, and evaluation procedures are simple. The reactor used in such a bench-scale apparatus has an internal volume of, for example, 10 to 200 mL, and an inner diameter of, for example, 5 to 20 mm. When using a reactor in such a bench-scale apparatus, it is particularly preferable that the packed volume of the guard catalyst layer is 5 to 60 mL. According to the guard catalyst evaluation method of this embodiment, highly reproducible evaluation is possible even using such a small-scale, convenient-scale device.

[0042] The packing configuration in the guard catalyst evaluation method may be such that a guard catalyst layer is packed into the reactor. To achieve reaction conditions closer to those of an actual reactor, it is preferable to form a demetallization catalyst layer downstream of the guard catalyst layer and perform the evaluation. A hydrotreating catalyst layer may be formed downstream of the demetallization catalyst layer. The packing configuration is not limited to the above configuration, as long as it conforms to the packing configuration of an actual reactor. For example, a first demetallization catalyst layer may be formed downstream of a first guard catalyst layer, a second guard catalyst layer may be formed downstream of the first demetallization catalyst layer, and a second demetallization catalyst layer may be formed downstream of the second guard catalyst layer.

[0043] (demetallization catalyst, hydrotreating catalyst) Examples of demetallization catalysts and hydrotreating catalysts include catalysts in which the above-mentioned hydrogenation active components are supported on inorganic oxides. Catalysts known in the art can be used as demetallization catalysts and hydrotreating catalysts. Examples of such demetallization catalysts include the first-stage catalysts described in JP 2010-248476 A, WO 2015 / 053087 A, WO 2015 / 046316 A, and WO 2015 / 046323 A. Examples of hydrotreating catalysts include the middle-stage catalysts and second-stage catalysts described in WO 2015 / 046323 A, WO 2015 / 053087 A, and JP 2010-248476 A.

[0044] (Physical properties of demetallization catalyst) The specific surface area of ​​the demetallization catalyst is 80 to 300 m 2 / g, and 100 to 300m 2 / g, and more preferably 100 to 280m 2 / g is more preferred. When the specific surface area of ​​the demetallization catalyst is equal to or greater than the lower limit, the demetallization activity is likely to be improved. When the specific surface area of ​​the demetallization catalyst is equal to or less than the upper limit, the average pore diameter is likely to be large, the metal resistance performance is unlikely to be reduced, and the diffusibility of nickel, vanadium, etc. within the pores can be maintained, which makes it easy to improve the demetallization activity.

[0045] The pore volume of the demetallization catalyst is preferably 0.4 to 1.0 mL / g, more preferably 0.45 to 1.0 mL / g, and even more preferably 0.5 to 0.9 mL / g. When the pore volume of the demetallization catalyst is equal to or greater than the lower limit, the metal resistance is less likely to decrease, and the diffusibility of nickel and vanadium within the pores can be maintained, which tends to improve the demetallization activity.When the pore volume of the demetallization catalyst is equal to or less than the upper limit, the specific surface area tends to increase, which tends to improve the demetallization activity.

[0046] The average pore diameter of the demetallization catalyst is preferably 7 to 50 nm, more preferably 7 to 40 nm, and even more preferably 8 to 30 nm. When the average pore diameter of the demetallization catalyst is equal to or greater than the lower limit, the metal resistance is less likely to decrease, and the diffusibility of nickel and vanadium within the pores can be maintained, which tends to improve the demetallization activity.When the average pore diameter of the demetallization catalyst is equal to or less than the upper limit, the specific surface area tends to increase, which tends to improve the demetallization activity.

[0047] In order to increase the effective number of pores that satisfy the above average pore diameter and pore volume, the pore size distribution of the demetallization catalyst is such that the ratio of the volume of pores having pore diameters within ±1.5 nm of the average pore diameter to the total pore volume is preferably 15 to 50% or more, more preferably 20 to 50%. When this ratio is within this range, the number of pores that are not useful for the demetallization reaction of nickel and vanadium is small, and demetallization activity is likely to be improved.

[0048] (Methods of producing guard catalysts, demetallization catalysts, and hydrotreating catalysts) The guard catalyst, demetallization catalyst, and hydrotreating catalyst can be produced by methods known in the art. For example, an inorganic oxide is shaped into a molded inorganic oxide body. The molded inorganic oxide body may be calcined as needed. A compound containing a hydrogenation active component is supported on the molded inorganic oxide body. Examples of the supporting method include known methods such as impregnation, coprecipitation, kneading, deposition, and ion exchange. The support thus obtained may be calcined as needed. Examples of methods for producing guard catalysts, demetallization catalysts, and hydrotreating catalysts include the methods described in JP-A-2010-248476, WO-A-2015 / 053087, WO-A-2015 / 046316, and WO-A-2015 / 046323.

[0049] (raw oil) The feedstock oil used in the evaluation of the guard catalyst of this embodiment is either or both of atmospheric distillation residual oil and vacuum distillation residual oil. In addition to atmospheric distillation residual oil and vacuum distillation residual oil, the feedstock oil of this embodiment may also include heavy extract, which is a particularly heavy oil component among the oil components extracted and removed by solvent extraction of lubricating base oil such as hydrocracked heavy oil, fluid catalytic cracking residual oil, thermal cracking heavy oil, thermal cracking light oil, and de-sludge oil. The total content of atmospheric distillation residue and vacuum distillation residue relative to the total volume of the feedstock is preferably 50 to 100% by volume, more preferably 60 to 100% by volume, and even more preferably 70 to 100% by volume.

[0050] The density of the feedstock oil at 15°C is preferably 0.78 to 1.15 g / mL, more preferably 0.82 to 1.1 g / mL, and even more preferably 0.84 to 1.06 g / mL.

[0051] The sulfur content of the feedstock oil is preferably, for example, 0.05 to 7 mass %. The nickel content (in elemental terms) of the feedstock oil is preferably, for example, 1 to 200 ppm by mass. The vanadium content (in elemental terms) of the feedstock oil is preferably, for example, 1 to 400 ppm by mass. The iron content (in elemental terms) of the feedstock oil is preferably, for example, 1 to 200 ppm by mass.

[0052] The asphaltene content of the feedstock oil is preferably, for example, 0.1 to 15 mass %. The residual carbon content of the feedstock oil is preferably, for example, 1 to 30 mass %.

[0053] (Reaction conditions) The reaction temperature (temperature of the guard catalyst layer) is 100°C or higher, preferably 280 to 420°C, more preferably 320 to 420°C, and even more preferably 350 to 420°C. If the reaction temperature is above the lower limit of the above range, the blockage of the guard catalyst pores by deposits in an actual machine is likely to be reproduced. In addition, the deposition of impurities derived from the reaction of the feedstock oil, such as coke, is likely to be reproduced. The upper limit of the reaction temperature is set based on the maximum temperature at which the equipment is used in the actual machine.

[0054] The pressure (hydrogen partial pressure) is preferably 3 to 20 MPa, more preferably 4 to 17.5 MPa, and even more preferably 5 to 15 MPa. If the hydrogen partial pressure is equal to or higher than the lower limit of the range, the deposition of impurities derived from the reaction of the feedstock oil, such as coke, is likely to occur. The upper limit of the hydrogen partial pressure is set based on the maximum operating temperature of the equipment in the actual plant.

[0055] The liquid hourly space velocity for the guard catalyst layer is 0.01 to 10 h -1 It is preferable that the time is 0.01 to 5 hours. -1 It is more preferable that the time is 0.01 to 3 hours. -1 The above-mentioned range of the liquid hourly space velocity is set based on the actual equipment.

[0056] When a demetallization catalyst layer is formed in addition to the guard catalyst layer, the liquid hourly space velocity relative to the total volume of the guard catalyst layer and the demetallization catalyst layer is 0.01 to 5 h -1 It is preferable that the time is 0.01 to 3 hours. -1 It is more preferable that the time is 0.01 to 2 hours. -1 The above-mentioned range of the liquid hourly space velocity is set based on the actual equipment.

[0057] Hydrogen / feed oil ratio is 50 to 3000 Nm 3 / kL is preferred, and 100 to 2500 Nm 3 / kL is more preferable, and 200 to 2000Nm 3 / kL is more preferable. 3means the volume of hydrogen converted into standard conditions. The above hydrogen / feed oil ratio range is set based on the actual plant.

[0058] When the guard catalyst contains a hydrogenation-active component, it is preferable to activate it by sulfurization in the reactor before starting the reaction. This sulfurization is generally carried out at 200 to 400°C, preferably 250 to 350°C, under a hydrogen atmosphere with atmospheric or higher hydrogen partial pressure, using a petroleum distillate containing sulfur compounds to which a sulfurizing agent such as dimethyl disulfide or carbon disulfide has been added, or hydrogen sulfide. [Example]

[0059] The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0060] <Catalyst analysis method> (specific surface area) The surface area was measured by the BET method using nitrogen adsorption. The nitrogen adsorption device used was a surface area measuring device (BELSORP-mini II) manufactured by Microtrack Bell Co., Ltd.

[0061] (pore volume, average pore diameter) The pore volume and average pore diameter were measured by mercury intrusion porosimetry using a porosimeter (AutoPore IV, manufactured by Micromeritics). Mercury intrusion porosimetry is based on the law of capillary action. In the case of mercury and a cylindrical pore, this law is expressed as follows: The volume of mercury that penetrates into the pore is measured as a function of the applied pressure P. The surface tension of the mercury in the catalyst pore is set to 484 dyne / cm, and the contact angle is set to 130°. D=-(1 / P)4γcosθ In the formula, D is the pore diameter, P is the applied pressure, γ is the surface tension, and θ is the contact angle. Pore ​​volume is the total volume of mercury that has entered the pores per gram of catalyst or support. Average pore diameter is the average value of D calculated as a function of P. The pore size distribution is the calculated distribution of D as a function of P.

[0062] The specific measurement procedure for the mercury intrusion method is as follows. (1) Turn on the vacuum heating degassing device and set the temperature at 400°C and the vacuum level at 5 x 10 -2 Check that the temperature is below Torr. (2) Place the empty sample burette in a vacuum heating degasser. (3) Vacuum level is 5 x 10 -2 After confirming that the pressure has dropped to Torr or less, the sample burette is removed from the vacuum heating degasser with its cock closed, and after cooling, its weight is measured. (4) Place the sample (catalyst or carrier) in the sample buret. (5) Place the sample burette in a vacuum heating degasser until the vacuum reaches 5 x 10 -2 Torr or less and maintain the pressure for at least one hour. (6) Remove the sample burette containing the sample from the vacuum heating degasser, cool it, and then measure its weight to determine the sample weight. (7) Place the sample in the AutoPore IV cell. (8) Measured using AutoPore IV.

[0063] (composition) The content of each element in the catalyst was confirmed to be the ratio based on the amount of raw material charged by elemental analysis using an inductively coupled plasma emission spectrometer (iCAP 6000: manufactured by Thermo Scientific). The amount of each element was determined by the absolute calibration curve method.

[0064] The specific measurement procedure for elemental analysis is as follows. (1) 0.05 g of the catalyst, 1 mL of hydrochloric acid (50% by mass), one drop of hydrofluoric acid, and 1 mL of pure water were placed in a Uniseal and heated to dissolve. (2) After dissolution, the solution was transferred to a polypropylene measuring flask (50 mL), and pure water was added to the flask to make a total volume of 50 mL. (3) This solution was measured using the inductively coupled plasma emission spectrometer.

[0065] <Reaction method> A mixed oil of atmospheric distillation residue and vacuum distillation residue having the properties shown in Table 1 was passed as a feedstock through a reactor packed with the catalysts of Examples 1 and 2 described below, and the guard catalyst was evaluated. Specifically, the catalyst packed in the reactor was first pretreated under the following conditions. Next, a mixed fluid of the feedstock and hydrogen-containing gas was introduced from the top (inlet) of the reactor, and the reaction was allowed to proceed under the conditions shown in Table 2. The mixed fluid of the product oil and gas was discharged from the bottom of the reactor, and the product oil was separated in a gas-liquid separator. The density of the feedstock oil in Table 1 is the density at 15° C. The density, sulfur content, nickel content, vanadium content, iron content, asphaltene content, and residual carbon content of the feedstock oil at 15° C. were determined by the methods described above. The liquid hourly space velocity in Table 2 is the liquid hourly space velocity for the entire catalyst layer packed in the reactor. The reaction temperature was 380°C until the 16th day, then increased by 5°C to 385°C until the 23rd day, then increased by 5°C to 390°C until the 30th day, then increased by 5°C to 395°C until the 47th day, and then increased by 2°C to 397°C.

[0066] Catalyst pretreatment conditions: dried at 120°C for 3 hours under normal pressure. The catalyst was pre-sulfided using vacuum diesel fuel at a hydrogen partial pressure of 10.3 MPa and 370°C for 12 hours, after which the feedstock oil for activity evaluation was used.

[0067] [Table 1]

[0068] [Table 2]

[0069] <Analysis of reaction results> (hydrotreating (desulfurization) activity) The hydrotreating (desulfurization) activity was analyzed by the following method: The reactor was operated under the above conditions, and the product oil was sampled every other day from the start of operation, and the desulfurization reaction rate constant was calculated using the following equation 1. Desulfurization reaction rate constant (Ks) = [1 / S P -1 / S F 〕×(LHSV) Equation 1 In the formula 1, S F is the sulfur content in the feedstock oil, S P represents the sulfur content in the produced oil, and LHSV represents the liquid hourly space velocity. P This is the constant of the reaction rate equation that obtains a second-order reaction order with respect to the reduction in the amount of sulfur dioxide (CO₂). A higher reaction rate constant indicates higher catalytic activity. The sulfur content of the feedstock oil and the sulfur content of the product oil were measured using the method described above.

[0070] (Amount of metal deposited) The amount of metal deposition in the catalyst layer was analyzed as follows: The reactor was operated under the above conditions, and the product oil was sampled every other day from the start of operation, and the amount of metal deposition in the catalyst layer was calculated using the following formula. Amount of metal deposited = WHSV×24×(M F -M P ) Equation 2 In the above formula 2, M F is the total content of nickel and vanadium in the feedstock oil, M P represents the total content of nickel and vanadium in the produced oil, and WHSV represents the weight hourly space velocity. The nickel and vanadium contents in the feed oil and the nickel and vanadium contents in the produced oil were measured by the methods described above.

[0071] (differential pressure) The differential pressure in the reactor was calculated every other day using the following formula 3. Differential pressure = Feedstock tank supply pressure - Pressure inside the equipment Equation 3

[0072] <Guard catalyst> Guard Catalyst A: Guard catalyst A was a catalyst in which molybdenum and nickel were supported as hydrogenation active components on a zinc-supported alumina carrier. The composition and physical properties of guard catalyst A are shown in Table 3. The content of the composition in Table 3 means the content of each element in oxide equivalent relative to the total mass of the guard catalyst. Guard catalyst A was a circular extruded body with a diameter of 6.0 mm. The body was crushed and sieved to separate particles that passed through a sieve with 2 mm openings but did not pass through a sieve with 1.18 mm openings. In other words, the particle size was adjusted to be greater than 1.18 mm and not greater than 2 mm.

[0073] Guard Catalyst B: Guard catalyst B was a catalyst with a smaller amount of hydrogenation active component supported than guard catalyst A. Guard catalyst B was a spherical molded body with a diameter of 5.0 mm. The molded body was crushed and sieved to separate particles that passed through a sieve with 2 mm openings but did not pass through a sieve with 1.18 mm openings. In other words, the particle size was adjusted to be greater than 1.18 mm and not greater than 2 mm.

[0074] <Demetallization catalyst> Demetallization catalyst A: Demetallization catalyst A was a catalyst in which molybdenum and nickel were supported as hydrogenation active components on a zinc-supported alumina carrier. The composition and physical properties of demetallization catalyst A are shown in Table 3. Demetallization catalyst B was a four-lobe extruded body with a major axis of 1.4 mm and a minor axis of 1.2 mm. The body was used as is without being crushed.

[0075] [Table 3]

[0076] [Example 1] A high-pressure flow reactor with an inner diameter of 14.3 mm, height of 732 mm, and volume of 100 mL was packed with guard catalyst A, demetallization catalyst A, guard catalyst A, and demetallization catalyst A in this order from the reactor inlet. The packed volume ratio of guard catalyst A:demetallization catalyst A:guard catalyst A:demetallization catalyst A from the reactor inlet was 16:8:9.5:66.5. The total packed volume of these catalysts was 50 mL. The ratio of the particle size of guard catalyst A to the inner diameter of the reactor was greater than 8.3% and less than or equal to 14%. The reaction was carried out according to the reaction method described above. To confirm reproducibility, the reaction was carried out twice with the same packing configuration. Figure 1 shows a graph with the metal deposition amount on the horizontal axis and the natural logarithm of the desulfurization reaction rate constant on the vertical axis. Figure 2 shows the change in differential pressure over time. In Figures 1 and 2, Example 1-1 shows the results of the first reaction, and Example 1-2 shows the results of the second reaction.

[0077] [Example 2] A high-pressure flow reactor with an inner diameter of 14.3 mm, height of 732 mm, and volume of 100 mL was packed with guard catalyst B, demetallization catalyst A, guard catalyst A, and demetallization catalyst A in this order from the reactor inlet. The volumetric packing ratio of guard catalyst B:demetallization catalyst A:guard catalyst A:demetallization catalyst A from the reactor inlet was 21.3:2.7:9.9:66.1. The total packing volume of these catalysts was 50 mL. The particle size ratio of guard catalyst A and guard catalyst B to the inner diameter of the reactor was greater than 8.3% and less than or equal to 14%. The reaction was carried out according to the reaction method described above. To confirm reproducibility, the reaction was carried out twice with the same packing configuration. Figure 1 shows a graph with the metal deposition amount on the horizontal axis and the natural logarithm of the desulfurization reaction rate constant on the vertical axis. Figure 2 shows the change in differential pressure over time. In Figures 1 and 2, Example 2-1 shows the results of the first reaction, and Example 2-2 shows the results of the second reaction.

[0078] As shown in Figure 1, the reproducibility of the two reaction results in Example 1 and the two reaction results in Example 2 was very high. The vertical axis in Figure 1 represents hydrotreating activity, and the change in this hydrotreating activity over time essentially depends on the ability of the guard catalyst to capture impurities in the feed oil and coke produced by the reaction, and the demetallization performance of the demetallization catalyst. 2, the reproducibility of the change in differential pressure over time was very high in the two reactions in Example 1 and the two reactions in Example 2. This change in differential pressure over time also depends substantially on the ability of the guard catalyst to capture impurities in the feed oil and coke produced by the reaction, and on the demetallization performance of the demetallization catalyst. In Examples 1 and 2, a demetallization catalyst was also used, and the evaluation results of Examples 1 and 2 are the results of evaluation of the guard catalyst and the demetallization catalyst. In other words, this is a complex system that is more difficult to achieve reproducibility than when evaluating the guard catalyst alone. Therefore, the high reproducibility of the evaluation results of the guard catalyst and the demetallization catalyst means that the reproducibility is also high when evaluating the guard catalyst alone. [Industrial Applicability]

[0079] The method of the present invention for evaluating guard catalysts for direct desulfurization reactions is useful because it allows evaluation under conditions closer to those of an actual plant and the evaluation results are highly reproducible.

Claims

1. A method for evaluating a guard catalyst for a direct desulfurization reaction, comprising: The process is carried out by supplying either or both of atmospheric distillation residue and vacuum distillation residue to a guard catalyst layer formed in a fixed-bed flow reactor, the temperature of the guard catalyst layer is 100°C or higher, the guard catalyst comprises an inorganic oxide; The method for evaluating a guard catalyst, wherein the ratio of the particle size of the guard catalyst to the inner diameter of the fixed-bed flow reactor is 2 to 30%.

2. 2. The method for evaluating a guard catalyst according to claim 1, wherein the guard catalyst is a guard catalyst in which a hydrogenation active component is supported on the inorganic oxide.

3. 3. The method for evaluating a guard catalyst according to claim 1, wherein a demetallization catalyst layer is further formed downstream of the guard catalyst layer in the fixed-bed flow reactor.

4. 3. The guard catalyst evaluation method according to claim 1, wherein the guard catalyst has a particle size of 1 to 4 mm.

5. 3. The method for evaluating a guard catalyst according to claim 1, wherein the guard catalyst layer has a packed volume of 5 to 60 mL.

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