Vacuum gas oil hydrotreating catalyst, method for producing vacuum gas oil hydrotreating catalyst, and method for hydrotreating vacuum gas oil

Abstract

The present invention relates to a hydroprocessing catalyst for a heavy hydrocarbon oil, the hydroprocessing catalyst comprising phosphorus- and zinc-containing alumina that serves as a support and at least one metal selected from group-6 metals on the periodic table and cobalt both supported on the support, in which the phosphorus- and zinc-containing alumina contains phosphorus in an amount of 0.1 to 4% by mass in terms of oxide content relative to the amount of the support and also contains zinc in an amount of 1 to 8% by mass in terms of oxide content relative to the amount of the support, the at least one metal is supported on the support in an amount of 8 to 30% by mass in terms of oxide content relative to the amount of the catalyst, and cobalt is supported on the support in an amount of 2 to 8% by mass in terms of oxide content relative to the amount of the catalyst.

Description

[Technical Field]

[0001] The present invention provides vacuum diesel a hydrotreating catalyst according to the present invention; vacuum diesel A method for producing the hydrotreating catalyst of vacuum diesel The present invention relates to a hydrotreating method. This application claims priority based on Japanese Patent Application No. 2020-056301, filed on March 26, 2020, the contents of which are incorporated herein by reference. [Background technology]

[0002] The oil fractions obtained by distillation or cracking of crude oil generally contain sulfur compounds, and when these oils are used as fuel, sulfur oxides and the like are generated due to these sulfur compounds. Therefore, the process of producing petroleum products from crude oil includes a hydrotreating step to remove the sulfur compounds.

[0003] Vacuum gas oil, which is a distillate obtained by further vacuum distilling the atmospheric residue obtained by processing crude oil in an atmospheric distillation unit, also contains high concentrations of sulfur compounds. For this reason, vacuum gas oil is hydrotreated in an indirect desulfurization unit.

[0004] To improve the efficiency of hydrotreating in indirect desulfurization units, hydrotreating catalysts have been developed. Hydrotreating catalysts that use Group 6 metals and cobalt as active species and support these active species on an inorganic oxide support primarily composed of alumina have been developed.

[0005] Patent Document 1 discloses a vacuum gas oil hydrotreating catalyst containing molybdenum, cobalt, and phosphorus. The state of alumina constituting the carrier in the hydrotreating catalyst is 27 When analyzed using Al-NMR, the proportion of area intensity attributable to tetrahedral Al in the coordination structure of Al atoms is 30% or more of the total, and the external surface area of ​​the catalyst is 3500 mm 2 / ml or more, the hydrotreating activity is improved. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-74075 Summary of the Invention [Problem to be solved by the invention]

[0007] In recent years, there has been an increasing demand for bottomless processes, and heavy hydrocarbon oils are hydrotreated and then processed in a fluid catalytic cracker to produce gasoline and middle distillates such as kerosene and diesel. The sulfur content of the feedstock oil supplied to the fluid catalytic cracker must be reduced to a certain level or below in order to protect the fluid catalytic cracking catalyst, and therefore, heavy hydrocarbon oils that are difficult to desulfurize must be hydrotreated. Therefore, there is a demand for hydrotreating catalysts that have high hydrotreating activity for heavy hydrocarbon oils and whose activity is not easily reduced. However, the hydrotreating activity and catalyst life of the hydrotreating catalyst described in Patent Document 1 are insufficient.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heavy hydrocarbon oil hydrotreating catalyst that has high activity for hydrotreating heavy hydrocarbon oil and is resistant to deterioration in activity, a method for producing the heavy hydrocarbon oil hydrotreating catalyst, and a heavy hydrocarbon oil hydrotreating method that uses the heavy hydrocarbon oil hydrotreating catalyst. [Means for solving the problem]

[0009] As a result of intensive research conducted by the present inventors to achieve the above object, they found that by using a catalyst for hydrotreating heavy hydrocarbon oils in which phosphorus- and zinc-containing alumina containing specific amounts of phosphorus and zinc is used as a support and specific amounts of at least one metal selected from Group 6 metals of the periodic table and cobalt are supported on the phosphorus- and zinc-containing alumina support, the hydrotreating activity for heavy hydrocarbon oils is high and the activity is less likely to decrease, and they have completed the present invention.

[0010] That is, the present invention relates to the following heavy hydrocarbon oil hydrotreating catalyst, method for producing heavy hydrocarbon oil hydrotreating catalyst, and method for hydrotreating heavy hydrocarbon oil. [1] A phosphorus-zinc-containing alumina carrier containing 0.1 to 4 mass% of phosphorus in oxide equivalent, based on the carrier, and 1 to 8 mass% of zinc in oxide equivalent, based on the carrier; The catalyst for hydrotreating heavy hydrocarbon oils comprises a carrier on which at least one metal selected from Group 6 of the periodic table is supported in an amount of 8 to 30 mass % (oxide equivalent) based on the catalyst, and cobalt in an amount of 2 to 8 mass % (oxide equivalent) based on the catalyst. [2] A method for producing a catalyst for hydrotreating heavy hydrocarbon oil, comprising a step of supporting at least one metal selected from Group 6 of the periodic table on a phosphorus- and zinc-containing alumina support, the alumina support containing phosphorus in an amount of 0.1 to 4 mass % in terms of oxide, based on the support, and zinc in an amount of 1 to 8 mass % in terms of oxide, based on the support, in such a manner that the metals contained are 8 to 30 mass % in terms of oxide, based on the catalyst, and cobalt in an amount of 2 to 8 mass % in terms of oxide, based on the catalyst. [3] Hydrogen / oil ratio 100-1000Nm 3 / kL, hydrogen partial pressure 3.5-10MPa, 330-430℃, liquid hourly space velocity 0.2-2hr -1 A method for producing hydrotreated heavy hydrocarbon oil, comprising contacting the heavy hydrocarbon oil with the hydrotreating catalyst for heavy hydrocarbon oil according to [1]. [4] Hydrogen / oil ratio 100-1000Nm 3 / kL, hydrogen partial pressure 3.5-10MPa, 330-430℃, liquid hourly space velocity 0.2-2hr -1 A method for hydrotreating heavy hydrocarbon oils, comprising contacting the heavy hydrocarbon oils with the catalyst for hydrotreating heavy hydrocarbon oils according to [1]. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a catalyst for hydrotreating heavy hydrocarbon oils that has high activity for hydrotreating heavy hydrocarbon oils and is resistant to deterioration in activity, a method for producing the catalyst for hydrotreating heavy hydrocarbon oils, and a method for hydrotreating heavy hydrocarbon oils using the catalyst for hydrotreating heavy hydrocarbon oils. DETAILED DESCRIPTION OF THE INVENTION

[0012] 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.

[0013] <Heavy hydrocarbon oil hydrotreating catalyst> The heavy hydrocarbon oil hydrotreating catalyst of this embodiment (hereinafter sometimes simply referred to as "hydrotreating catalyst") uses a phosphorus-zinc-containing alumina support containing 0.1 to 4 mass % of phosphorus, calculated as oxide, based on the support, and 1 to 8 mass % of zinc, calculated as oxide, based on the support, and supports at least one metal selected from Group 6 of the periodic table in an amount of 8 to 30 mass % of oxide, based on the catalyst, and cobalt in an amount of 2 to 8 mass % of oxide, based on the catalyst, on the support. In this specification, "Group 6 metals of the periodic table" (hereinafter sometimes referred to as "Group 6 metals") refers to Group 6 metals in the long-form periodic table. In this specification, the Group 6 metals and cobalt are collectively referred to as "hydrogenation active components."

[0014] This paper explains about phosphorus-zinc-containing alumina carriers containing phosphorus and zinc. The main component of the support of the hydrotreating catalyst of this embodiment is alumina. Various types of alumina can be used, such as α-alumina, β-alumina, γ-alumina, and δ-alumina. Alumina that is porous and has a high specific surface area is preferred, and γ-alumina is more preferred. The purity of the alumina is preferably 98% by mass or more, and more preferably 99% by mass or more. Impurities in alumina include SO4 2- , Cl - , Fe2O3, Na2O, etc. It is preferable that the amount of these impurities is as small as possible. The total content of impurities relative to the total mass of alumina is preferably 2 mass% or less, and more preferably 1 mass% or less. For each component, SO42- is 1.5 mass% or less, Cl - , Fe2O3, and Na2O are each preferably 0.1 mass % or less.

[0015] The alumina used as the support for the hydrotreating catalyst of this embodiment may be a composite alumina obtained by compounding at least one oxide selected from zeolite, boria, silica, and zirconia. The composite alumina refers to a mixture or composite oxide of alumina and at least one oxide selected from zeolite, boria, silica, and zirconia. The content of alumina relative to the total mass of the composite alumina is preferably 92 to 99.9 mass%, more preferably 95 to 98 mass%. The content of at least one oxide selected from zeolite, boria, silica, and zirconia relative to the total mass of the composite alumina is preferably 0.1 to 8 mass%, more preferably 2 to 5 mass%. As the above-mentioned composite components, zeolite, boria, silica, and zirconia, those generally used as carrier components for this type of catalyst can be used.

[0016] The support of the hydrotreating catalyst of this embodiment is a phosphorus-zinc-containing alumina support in which phosphorus and zinc are further contained in an alumina support (including a composite alumina support). Phosphorus and zinc are added as components to improve the quality of active sites in order to increase the hydrotreating activity and residual carbon removal activity per amount of hydrotreating active component. Phosphorus and zinc play a role in precisely creating highly active hydrogenation active component-sulfur phases such as CoMoS and CoWS. Furthermore, the inclusion of phosphorus and zinc prevents the activity of the hydrotreating catalyst from decreasing.

[0017] The zinc content in the support of the hydrotreating catalyst of this embodiment is 1 to 8 mass % in terms of oxide, based on the support, preferably 1 to 6 mass %, more preferably 1 to 5 mass %, and even more preferably 1 mass % or more but less than 4 mass %. When the zinc content is at least the lower limit of the above range, the sulfidity of the Group 6 metal can be sufficiently improved. In addition, a decrease in the activity of the hydrotreating catalyst is suppressed. When the zinc content is at most the upper limit of the above range, a decrease in pore volume and specific surface area is unlikely to occur, the Group 6 metal is sufficiently dispersed, and the sulfidity of cobalt is unlikely to decrease.

[0018] The phosphorus content in the support of the hydrotreating catalyst of this embodiment is 0.1 to 4 mass %, preferably 0.5 to 2 mass %, calculated as oxide based on the support. When the phosphorus content is equal to or greater than the lower limit of the above range, the sulfidity of the Group 6 metal can be sufficiently improved. Furthermore, a decrease in the activity of the hydrotreating catalyst is suppressed. When the phosphorus content is equal to or less than the upper limit of the above range, a decrease in pore volume and specific surface area is unlikely to occur, and the Group 6 metal is sufficiently dispersed, thereby fully achieving the effect of adding phosphorus.

[0019] In this specification, with regard to the phosphorus and zinc contents, "based on the support, in oxide equivalent" means the ratio of the mass of phosphorus oxide and the mass of zinc oxide to the total mass of all elements contained in the support calculated as their respective oxides. The mass of phosphorus oxide is calculated in terms of diphosphorus pentoxide (PO), and the mass of zinc oxide is calculated in terms of zinc oxide (ZnO). In this specification, the mass of an element contained in a support or a hydrotreating catalyst can be measured by inductively coupled plasma atomic emission spectrometry.

[0020] The hydrotreating catalyst of this embodiment contains phosphorus and zinc, which is thought to mitigate the interaction between the Group 6 metal or cobalt and the support, facilitating the sulfurization of the Group 6 metal and cobalt. On the other hand, if the interaction between the Group 6 metal or cobalt and the support becomes too weak, aggregation of the hydrogenation active component occurs, so precise control is required for the addition of phosphorus and zinc. In the hydrotreating catalyst of this embodiment, the precisely controlled addition of phosphorus and zinc is thought to maintain a highly dispersed state of the hydrogenation active component-sulfur phase, such as the CoMoS phase or CoWS phase, while also optimizing the structural morphology, such as the number of layers.

[0021] The phosphorus- and zinc-containing alumina support of the hydrotreating catalyst of this embodiment preferably has the following physical property values.

[0022] The specific surface area of ​​the phosphorus- and zinc-containing alumina support is 200 to 400 m, as measured by the nitrogen adsorption method (BET method). 2 / g is preferred, and 250 to 360m 2 / g is more preferable. When the specific surface area is equal to or greater than the lower limit of the above range, the hydrogenation active component is sufficiently dispersed, resulting in high hydrotreating activity. When the specific surface area is equal to or less than the upper limit of the above range, the support has a sufficiently large pore diameter, resulting in a sufficiently large pore diameter of the hydrotreating catalyst. As a result, sulfur compounds are sufficiently diffused into the catalyst pores, resulting in high hydrotreating activity. In other words, when the specific surface area is within the above range, the hydrotreating active component is well dispersed and a hydrotreating catalyst having a sufficiently large pore diameter can be obtained.

[0023] The average pore size of the phosphorus- and zinc-containing alumina support in the pore size distribution measured by mercury intrusion porosimetry is preferably 4 to 12 nm, more preferably 6 to 8 nm. When the average pore size is within this range, the support has a sufficient surface area within the pores, and sulfur compounds diffuse sufficiently into the catalyst pores, resulting in high hydrotreating activity.

[0024] The pore volume of the phosphorus- and zinc-containing alumina support, as measured by mercury intrusion porosimetry, is preferably 0.5 to 0.9 mL / g, more preferably 0.55 to 0.8 mL / g. When the pore volume is above the lower limit of the above range, a sufficient amount of solvent can penetrate into the pores when preparing the catalyst using a conventional impregnation method. A sufficient amount of solvent allows the hydrogenation-active component to dissolve well in the solvent, improving the dispersibility of the hydrogenation-active component and resulting in a highly active catalyst. While adding a large amount of acid such as nitric acid can increase the solubility of the hydrogenation-active component, adding too much acid reduces the surface area of ​​the support, which is the main cause of reduced hydrotreating activity. When the pore volume is below the upper limit of the above range, the specific surface area is sufficiently large, improving the dispersibility of the hydrogenation-active component. In other words, when the pore volume is within the above range, the support has a sufficient specific surface area and can accommodate a sufficient amount of solvent within the pore volume, resulting in both good solubility and dispersibility of the hydrogenation-active component and further improving hydrotreating activity.

[0025] The hydrotreating catalyst of this embodiment is a catalyst in which a Group 6 metal and cobalt are supported as hydrogenation active components on the phosphorus- and zinc-containing alumina support.

[0026] The zinc content in the hydrotreating catalyst of this embodiment is preferably 0.5 to 7 mass %, more preferably 0.7 to 6.5 mass %, and even more preferably 1 to 6 mass %, calculated as oxide based on the catalyst. When the zinc content is at least the lower limit of the above range, the sulfidity of the Group 6 metal can be sufficiently improved. Furthermore, a decrease in the activity of the hydrotreating catalyst is suppressed. When the zinc content is at most the upper limit of the above range, a decrease in pore volume and specific surface area is unlikely to occur, the Group 6 metal is sufficiently dispersed, and the sulfidity of cobalt is unlikely to decrease.

[0027] The phosphorus content in the hydrotreating catalyst of this embodiment is preferably 0.5 to 8 mass %, more preferably 0.5 to 4.5 mass %, and even more preferably more than 3.6 mass % but not more than 4.5 mass %, calculated as oxide based on the catalyst. When the phosphorus content is equal to or greater than the lower limit of the above range, the sulfidity of the Group 6 metal can be sufficiently improved. Furthermore, a decrease in the activity of the hydrotreating catalyst is suppressed. When the phosphorus content is equal to or less than the upper limit of the above range, a decrease in pore volume and specific surface area is unlikely to occur, and the Group 6 metal is sufficiently dispersed, thereby fully achieving the effect of adding phosphorus.

[0028] In this specification, with regard to the phosphorus and zinc contents, "on a catalyst basis, in oxide equivalent" means the ratio of the mass of phosphorus oxide and the mass of zinc oxide to the total mass of all elements contained in the catalyst calculated as their respective oxides. The mass of phosphorus oxide is calculated in terms of diphosphorus pentoxide (PO), and the mass of zinc oxide is calculated in terms of zinc oxide (ZnO).

[0029] Examples of Group 6 metals include molybdenum (Mo), tungsten (W), and chromium (Cr), and among these, molybdenum is preferred because of its high hydrotreating activity per unit mass. The Group 6 metal to be supported may be one type only, or two or more types may be used in combination. The amount of Group 6 metal supported on the phosphorus- and zinc-containing alumina support is 8 to 30 mass %, preferably 10 to 25 mass %, calculated as oxide based on the catalyst. When the amount of Group 6 metal supported is equal to or greater than the lower limit of the above range, it is sufficient to realize the effects attributable to the Group 6 metal. When the amount of Group 6 metal supported is equal to or less than the upper limit of the above range, the Group 6 metal is less likely to aggregate and is sufficiently dispersed. In other words, the amount of Group 6 metal supported does not exceed the amount that can be efficiently dispersed, and the catalyst surface area does not decrease significantly, thereby improving catalytic activity.

[0030] The amount of cobalt supported on the phosphorus- and zinc-containing alumina support is 2 to 8 mass %, preferably 2.5 to 5 mass %, calculated as oxide based on the catalyst. When the amount of cobalt supported is equal to or greater than the lower limit of the above range, sufficient active sites attributable to cobalt can be obtained. When the amount of cobalt supported is equal to or less than the upper limit of the above range, the cobalt is less likely to aggregate and is sufficiently dispersed.

[0031] Hydrotreating reactions include desulfurization reactions, hydrogenation reactions other than desulfurization reactions, and the like. When hydrotreating reactions are performed in a reactor with a low hydrogen partial pressure with the main purpose of desulfurization reactions, the progress of hydrogenation reactions other than desulfurization reactions consumes hydrogen in the reactor, making coking more likely to occur. By including cobalt in the hydrotreating catalyst of this embodiment, hydrogenation reactions other than desulfurization reactions can be suppressed, thereby suppressing the occurrence of coking. As a result, the activity of the hydrotreating catalyst is suppressed from decreasing over time.

[0032] Here, with regard to the amounts of Group 6 metals and cobalt supported, "on a catalyst basis, in oxide equivalent" means the ratio of the mass of each metal oxide to the total mass of all elements contained in the catalyst calculated as their respective oxides. The masses of Group 6 metals and cobalt oxides are calculated by converting the Group 6 metals into hexavalent oxides (e.g., MoO3 for Mo) and cobalt into divalent oxides (CoO).

[0033] In terms of the amounts of the Group 6 metal and cobalt components supported, the optimum mass ratio of the Group 6 metal, which is a hydrogenation active component, to cobalt is preferably 0.14 to 0.3, expressed as [mass of cobalt oxide] / [mass of cobalt oxide+mass of Group 6 metal oxide]. When the ratio of the mass of cobalt oxide to the total mass of the Group 6 metal oxide and cobalt oxide is equal to or greater than the lower limit of the above range, hydrogenation active component-sulfur phases such as CoMoS phases and CoWS phases, which are thought to be active sites for hydrotreating reactions, are sufficiently formed, resulting in high hydrotreating activity.When the ratio of the mass of cobalt oxide to the total mass of the Group 6 metal oxide and cobalt oxide is equal to or less than the upper limit of the above range, metal species not involved in hydrotreating activity (CoS species and Co spinel species incorporated into the lattice of the support) are less likely to be formed, resulting in high hydrotreating activity.

[0034] The hydrotreating catalyst contains SO4 derived from the alumina contained in the carrier. 2- , Cl - The amount of these impurities is preferably as small as possible, and the total amount of impurities relative to the total mass of the hydrotreating catalyst is preferably 2% by mass or less, more preferably 1% by mass or less. 2- is 1.5 mass% or less, Cl - , Fe2O3, and Na2O are each preferably 0.1 mass % or less.

[0035] The hydrotreating catalyst of this embodiment preferably has the following physical property values ​​in order to enhance the hydrotreating activity for heavy hydrocarbon oils.

[0036] The specific surface area of ​​the hydrotreating catalyst of this embodiment is 150 to 300 m as measured by the BET method. 2 / g is preferred, and 190 to 250m 2 / g is more preferable. When the specific surface area is equal to or greater than the lower limit of the above range, the hydrotreating active component is sufficiently dispersed, resulting in high hydrotreating activity. When the specific surface area is equal to or less than the upper limit of the above range, the hydrotreating catalyst has a sufficiently large pore diameter. Therefore, the sulfur compounds are sufficiently diffused into the catalyst pores, resulting in high hydrotreating activity. That is, when the specific surface area is within the above range, it is possible to improve both the dispersibility of the hydrotreating active component and the diffusibility of the sulfur compounds into the catalyst pores during hydrotreating.

[0037] The hydrotreating catalyst of this embodiment preferably has an average pore diameter of 5 to 20 nm, more preferably 7 to 11 nm, in the pore distribution measured by mercury intrusion porosimetry. When the average pore diameter is within this range, the catalyst has a sufficient surface area within the pores (i.e., the effective surface area of ​​the catalyst), while enhancing the diffusibility of sulfur compounds into the catalyst pores, thereby further improving the hydrotreating activity.

[0038] The pore volume of the hydrotreating catalyst of this embodiment, as measured by mercury intrusion porosimetry, is preferably 0.45 to 0.8 mL / g, more preferably 0.45 to 0.7 mL / g. When the pore volume is equal to or greater than the lower limit of the above range, sulfur compounds are sufficiently diffused within the catalyst pores during hydrotreating, improving hydrotreating activity. When the pore volume is equal to or less than the upper limit of the above range, the specific surface area of ​​the catalyst can be prevented from becoming extremely small. When the pore volume is within the above range, both the dispersibility of the hydrotreating active component and the diffusibility of sulfur compounds into the catalyst pores during hydrotreating can be improved.

[0039] In order to increase the effective number of pores that satisfy the above-mentioned average pore diameter and pore volume, the pore size distribution of the hydrotreating catalyst of this embodiment 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 65% ​​or more, more preferably 70% or more.

[0040] Furthermore, the distribution state of the hydrogenation active component in the hydrotreating catalyst of this embodiment is preferably a uniform type in which the hydrogenation active component is uniformly distributed in the catalyst.

[0041] <Method for producing a catalyst for hydrotreating heavy hydrocarbon oil> The method for producing a heavy hydrocarbon oil hydrotreating catalyst of this embodiment includes a step of supporting at least one metal selected from Group 6 of the periodic table on a phosphorus- and zinc-containing alumina support containing 0.1 to 4 mass % of phosphorus, calculated as oxide, based on the support, and 1 to 8 mass % of zinc, calculated as oxide, based on the support, in an amount of 8 to 30 mass % of metal selected from Group 6 of the periodic table, calculated as oxide, based on the catalyst, and 2 to 8 mass % of cobalt, calculated as oxide, based on the catalyst.

[0042] The phosphorus- and zinc-containing alumina support can be prepared, for example, by the steps of preparing an alumina gel, adding a phosphorus compound and a zinc compound to the alumina gel so that the phosphorus content is 0.1 to 4 mass % in oxide equivalents based on the support, and the zinc content is 1 to 8 mass % in oxide equivalents based on the support, and kneading the mixture, molding the resulting mixture, and drying and firing the molded product.

[0043] To obtain the phosphorus- and zinc-containing alumina support used in the hydrotreating catalyst of this embodiment, first, an alumina gel is obtained by a conventional method. Any alumina raw material can be used as long as it contains aluminum, but aluminum salts such as aluminum sulfate, aluminum nitrate, etc. These alumina raw materials are usually provided as aqueous solutions, and although there are no particular limitations on their concentration, it is preferably 2 to 50 mass %, more preferably 5 to 40 mass %, based on the total mass of the aqueous solution.

[0044] For example, alumina gel is prepared by first mixing an aqueous sulfuric acid solution, sodium aluminate, and aluminum hydroxide in a stirring vessel to prepare a slurry. The resulting slurry is then subjected to a rotary cylindrical continuous vacuum filter to remove water and washed with pure water to obtain alumina gel.

[0045] The resulting alumina gel was then added to the filtrate with SO4 2- , Na + After washing until no trace of alumina can be detected, the alumina gel is mixed with pure water to form a uniform slurry. The resulting alumina gel slurry is dehydrated until the water content relative to the total mass of the slurry is 60 to 90 mass % to obtain a cake.

[0046] In the manufacturing method of this embodiment, it is preferable to dehydrate the alumina gel slurry using a filter press. A filter press is a device that filters a slurry by applying compressed air or pump pressure, and is generally called a filter press. Filter presses are classified into plate-frame and concave-plate types. A plate-frame type filter press has filter plates and filter frames alternately clamped between end plates, and the slurry is filtered by being forced into the filter frames. The filter plates have grooves that serve as filtrate flow paths, and a filter cloth is stretched over the filter frames. On the other hand, a concave-plate type filter press has filter cloth and concave-plate type filter plates arranged alternately and clamped between the end plates to form a filter chamber (Reference: Chemical Engineering Handbook, p. 715).

[0047] As described above, in the production method of this embodiment, the moisture adjustment when preparing the alumina used for the carrier is carried out using the above-mentioned filter press. By dehydrating using the filter press, the surface condition of the alumina carrier can be improved, and the sulfidity of the hydrogenation active component can be increased. The dehydration step using the filter press is preferably carried out after at least one of the above-mentioned step of preparing the alumina gel and the step of kneading the phosphorus compound and the zinc compound described below, or may be carried out after both steps. In particular, it is more preferable to carry out the dehydration step after preparing the alumina gel and before kneading the phosphorus compound and the zinc compound.

[0048] In addition to the above-described method, other methods for preparing alumina gel include a method of neutralizing an aqueous solution containing an alumina raw material with a neutralizing agent such as sodium aluminate, aluminic acid, or ammonia, and a method of mixing the aqueous solution with a precipitating agent such as hexanemethylenetetramine or calcium carbonate. The amount of the neutralizing agent used is not particularly limited, but is preferably 30 to 70 mass % based on the total amount of the aqueous solution containing the alumina raw material and the neutralizing agent.The amount of the precipitating agent used is not particularly limited, but is preferably 30 to 70 mass % based on the total amount of the aqueous solution containing the alumina raw material and the precipitating agent.

[0049] When composite alumina is prepared by combining an oxide such as zeolite as a support for a hydrotreating catalyst, first, an alumina gel is prepared by a conventional method, and the obtained alumina gel is aged, washed, dehydrated and dried, and the moisture content is adjusted, and then the process is carried out before adding the phosphorus compound and zinc. As a composite method, alumina can be combined with an oxide such as zeolite by a coprecipitation method, a kneading method, or the like. The composite alumina gel is then aged, washed, dehydrated and dried, and the moisture content is adjusted. It is also preferable to use a press filter for dehydration in the final dehydration step before molding the composite alumina gel.

[0050] As the zinc compound to be added to the support of the hydrotreating catalyst of this embodiment, various compounds can be used, and examples thereof include zinc oxide, zinc nitrate, zinc sulfate, zinc carbonate, zinc chloride, zinc acetate, zinc hydroxide, and zinc oxalate. Of these, zinc oxide, zinc nitrate, and zinc sulfate are preferred, and zinc oxide is particularly preferred.

[0051] Various compounds can be used as the phosphorus compound to be added to the support of the hydrotreating catalyst of this embodiment, such as orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, and tetraphosphoric acid, with orthophosphoric acid being preferred.

[0052] A phosphorus compound and a zinc compound are added to the alumina gel obtained above by kneading. Specifically, a phosphorus compound and a zinc compound heated to 15 to 90°C are added to a water-adjusted alumina gel heated to 50 to 90°C. Then, the mixture is kneaded and stirred using a heated kneader or the like to obtain a kneaded mixture of the alumina gel, the phosphorus compound, and the zinc compound. As described above, dehydration using a press filter may be performed after kneading and stirring the alumina gel, the phosphorus compound, and the zinc compound. The phosphorus compound may be added directly, or a phosphorus solution (or suspension) in which the phosphorus compound is dissolved (or suspended) in a solvent may be added.

[0053] The resulting kneaded product is then molded, dried, and calcined to obtain a phosphorus- and zinc-containing alumina carrier. The molding of the kneaded product can be carried out by various molding methods, such as extrusion molding and pressure molding. The drying temperature for drying the resulting molded product is preferably 15 to 150°C, more preferably 80 to 120°C. The drying time is preferably 30 minutes or longer. The calcination temperature can be appropriately set as needed, but for example, to obtain γ-alumina, the calcination temperature is preferably 450°C or higher, more preferably 480 to 600°C. The calcination time is preferably 2 hours or longer, more preferably 3 to 12 hours.

[0054] The zinc compound and the phosphorus compound may be added to the alumina support by a method other than kneading, and may be supported on the alumina support by a method other than kneading. Methods for supporting the zinc compound and the phosphorus compound on the alumina support by a method other than kneading include known methods such as impregnation, coprecipitation, deposition, and ion exchange. Examples of impregnation methods include an evaporation-to-dryness method in which the alumina support is immersed in an impregnation solution in excess of the total pore volume of the alumina support and then the solvent is completely dried to support the components; an equilibrium adsorption method in which the alumina support is immersed in an impregnation solution in excess of the total pore volume of the alumina support and then subjected to solid-liquid separation such as filtration to obtain a catalyst carrying the components; and a pore-filling method in which the alumina support is impregnated with an impregnation solution in an amount approximately equal to the total pore volume of the alumina support and then the solvent is completely dried to support the components. The method for impregnating the alumina support with the zinc compound and the phosphorus compound may be a one-step impregnation method in which the components are simultaneously impregnated, or a two-step impregnation method in which the components are individually impregnated.

[0055] When zinc compounds and phosphorus compounds are supported by the above impregnation method or the like, moisture is generally removed to a certain extent (so that the LOI (loss on ignition) is 50% or less) in a nitrogen stream, air stream, or vacuum at room temperature to 80°C, followed by drying in an air stream at 80 to 150°C for 10 minutes to 10 hours in a drying furnace, followed by calcination in an air stream at 300 to 700°C, more preferably 500 to 650°C, for 10 minutes to 10 hours, more preferably 3 to 6 hours.

[0056] The zinc compound and phosphorus compound may be supported on the alumina carrier in their entirety by the kneading method, or in their entirety by the impregnation method or the like, or in their entirety by the kneading method or the like.

[0057] The phosphorus- and zinc-containing alumina support thus obtained is then loaded with a Group 6 metal and cobalt.

[0058] In the hydrotreating catalyst of this embodiment, the raw material compound of the Group 6 metal to be supported on the phosphorus- and zinc-containing alumina support is preferably a molybdenum compound, such as molybdenum trioxide, molybdophosphoric acid, ammonium molybdate, or molybdic acid, with molybdophosphoric acid, molybdenum trioxide, and ammonium molybdate being preferred.

[0059] In the hydrotreating catalyst of this embodiment, examples of the raw material compound of cobalt to be supported on the phosphorus- and zinc-containing alumina support include cobalt carbonate, cobalt acetate, cobalt nitrate, cobalt sulfate, and cobalt chloride, with cobalt carbonate and cobalt acetate being preferred, and cobalt carbonate being more preferred.

[0060] Methods for supporting a Group 6 metal or cobalt on a phosphorus- and zinc-containing alumina support may be known methods such as impregnation, coprecipitation, kneading, deposition, ion exchange, etc. Examples of impregnation methods include an evaporation-to-dryness method in which a phosphorus- and zinc-containing alumina support is immersed in an impregnation solution in excess of the total pore volume of the phosphorus- and zinc-containing alumina support and then the solvent is completely dried to support the hydrogenation-active component; an equilibrium adsorption method in which a phosphorus- and zinc-containing alumina support is immersed in an impregnation solution in excess of the total pore volume of the phosphorus- and zinc-containing alumina support and then a solid-liquid separation such as filtration is performed to obtain a catalyst supporting the hydrogenation-active component; and a pore-filling method in which a phosphorus- and zinc-containing alumina support is impregnated with an impregnation solution in an amount approximately equal to the total pore volume of the phosphorus- and zinc-containing alumina support and then the solvent is completely dried to support the hydrogenation-active component. The method for impregnating the phosphorus- and zinc-containing alumina support with the raw material compound of the Group 6 metal and the raw material compound of cobalt may be a one-step impregnation method in which these components are simultaneously impregnated, or a two-step impregnation method in which these components are individually impregnated.

[0061] Specific methods for supporting the Group 6 metal, cobalt, on the phosphorus- and zinc-containing alumina support include the following methods. An impregnation solution containing a raw compound of a Group 6 metal and a raw compound of cobalt is prepared. During preparation, heating (30 to 100°C) or the addition of an acid (nitric acid, phosphoric acid, or an organic acid (citric acid, acetic acid, malic acid, tartaric acid, etc.)) may be performed to promote dissolution of these compounds. That is, in this embodiment, when the Group 6 metal and cobalt are supported on the phosphorus-zinc-alumina support, phosphorus may be separately supported in addition to the phosphorus contained in the phosphorus-zinc-alumina support.

[0062] Examples of phosphorus compounds that can be added separately when supporting a Group 6 metal, cobalt, on a phosphorus-zinc alumina support include phosphorus-containing raw material compounds for hydrogenation active components such as molybdophosphoric acid, orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, and tetraphosphoric acid, with orthophosphoric acid being preferred. Supporting phosphorus separately when supporting a Group 6 metal, cobalt, on a phosphorus-zinc alumina support can improve the dispersibility of the hydrogenation active component.

[0063] Next, the prepared impregnation solution is gradually added to the phosphorus- and zinc-containing alumina support so as to be uniformly impregnated. The impregnation time is preferably 1 minute to 5 hours, more preferably 5 minutes to 3 hours. The impregnation temperature is preferably 5 to 100°C, more preferably 10 to 80°C. There are no particular restrictions on the impregnation atmosphere, but air, nitrogen, and vacuum are each suitable.

[0064] The ratio of the mass of phosphorus kneaded into the support in terms of oxide to the mass of the Group 6 metal in terms of oxide is preferably 0.25 or less. If it is 0.25 or less, the surface area and pore volume of the catalyst are not reduced, and a decrease in catalytic activity is suppressed. Furthermore, the amount of acid does not increase, and carbon deposition can be prevented, thereby suppressing activity deterioration.

[0065] When molybdenum is used as the Group 6 metal, the ratio of the mass of phosphorus mixed with the support in terms of oxide to the mass of molybdenum in terms of oxide is preferably 0.01 to 1.5, more preferably 0.05 to 1.0. When the ratio of the mass of phosphorus mixed with the support in terms of oxide to the mass of molybdenum in terms of oxide is within the above range, cobalt and molybdenum can be naturally integrated.

[0066] In the method for producing a hydrotreating catalyst of this embodiment, after loading a raw compound of a Group 6 metal and a raw compound of cobalt, the impregnated body is first dehydrated to a certain extent (so that the LOI (loss on ignition) is 50% or less) at 15 to 80°C in a nitrogen stream, an air stream, or in a vacuum. The resulting material is then dried in a drying furnace in an air stream at 80 to 150°C for 10 minutes to 10 hours. The resulting material is then calcined in a calcining furnace in an air stream. The calcination temperature is preferably 300 to 700°C, more preferably 500 to 650°C. The calcination time is preferably 10 minutes to 10 hours, more preferably 3 hours or longer.

[0067] Examples of phosphorus contained in the hydrotreating catalyst of this embodiment include the phosphorus compound, phosphorus oxide (PO) produced by the calcination, and a composite oxide of phosphorus and at least one element selected from the group consisting of aluminum, zinc, a Group 6 metal, and cobalt.

[0068] Examples of zinc contained in the hydrotreating catalyst of this embodiment include the zinc compound, zinc oxide (ZnO) produced by the calcination, and a composite oxide of zinc and at least one element selected from the group consisting of aluminum, phosphorus, Group 6 metals, and cobalt.

[0069] Examples of the Group 6 metal contained in the hydrotreating catalyst of this embodiment include raw material compounds of the Group 6 metal, oxides produced by the calcination (specific example: MoO), and composite oxides of a Group 6 metal and at least one element selected from the group consisting of aluminum, zinc, phosphorus, and cobalt.

[0070] Examples of cobalt contained in the hydrotreating catalyst of this embodiment include the raw material compound of cobalt, the oxide produced by the calcination (specific example: CoO), and a composite oxide of cobalt and at least one element selected from the group consisting of aluminum, zinc, phosphorus, and Group 6 metals.

[0071] The hydrotreating catalyst of this embodiment prepared as described above preferably has a Group 6 metal sulfidity of 84 mol % or more, more preferably 86 mol % or more, as determined by XPS quantitative analysis and represented by the following formula: Group 6 metal sulfidity=[(M6(IV) / M6)×100] [wherein M6(IV) is the molar amount of Group 6 metal sulfide in the sulfurized catalyst, and M6 is the molar amount of all Group 6 metal elements in the sulfurized catalyst] Here, the Group 6 metal sulfidity in the XPS quantitative analysis results means the ratio (molar ratio) of the amount of Group 6 metal sulfide (M6(IV)) in the sulfurized catalyst to the total amount of Group 6 metal elements (M6). For example, when molybdenum is used as the Group 6 metal in the catalyst, the molybdenum sulfidity [(Mo(IV) / Mo)×100] obtained by XPS quantitative analysis means the ratio (molar ratio) of the amount of molybdenum disulfide (molar amount) to the total amount of molybdenum in the sulfurized catalyst. The molybdenum sulfidity is preferably 84 mol% or more, and more preferably 86 mol% or more. The amount (molar amount) of Group 6 metal sulfide in the sulfurized catalyst can be obtained by heating the catalyst of the present invention at a rate of 5°C / min under a flow of 50 ml / min of a mixed gas of H2S and H2 (the content of H2S relative to the total volume of the mixed gas is 4.8% by volume), treating it at 300°C for 10 minutes to sulfurize it, purging it with high-purity helium gas for 10 minutes, and then performing XPS measurement while evacuated to a vacuum.

[0072] Furthermore, in the catalyst of the present invention, the cobalt sulfidity as a result of XPS quantitative analysis, which is represented by the following formula, is preferably 60 mol % or more, more preferably 65 mol % or more. Cobalt sulfidity = [(amount of cobalt sulfide / amount of cobalt element) x 100] Here, the cobalt sulfidity in the results of XPS quantitative analysis means the ratio (molar ratio) of the amount (molar amount) of cobalt sulfide to the amount (molar amount) of cobalt element in the sulfided catalyst. That is, the cobalt sulfidity [(CoS / Co)×100] in the XPS quantitative analysis results means the ratio (molar ratio) of the amount of cobalt monosulfide to the total amount of cobalt in the sulfided catalyst. The cobalt sulfidity is preferably 60 mol% or more, and more preferably 65 mol% or more.

[0073] <Method for producing hydrotreated heavy hydrocarbon oil (hydrotreating method for heavy hydrocarbon oil)> The method for producing hydrotreated heavy hydrocarbon oil of this embodiment is carried out in a water / oil ratio of 100 to 1000 Nm 3 / kL, hydrogen partial pressure 3.5-10MPa, reaction temperature 330-430℃, liquid hourly space velocity (hereinafter referred to as LHSV) 0.2-2hr -1The hydrotreating catalyst of the present invention is brought into contact with a heavy hydrocarbon oil containing sulfur compounds under the above conditions to carry out hydrotreating, thereby reducing the sulfur content in the heavy hydrocarbon oil and producing a hydrotreated heavy hydrocarbon oil. In the hydrotreating method for heavy hydrocarbon oil of this embodiment, the water / oil ratio is 100 to 1000 Nm 3 / kL, hydrogen partial pressure 3.5-10MPa, reaction temperature 330-430℃, liquid hourly space velocity 0.2-2hr -1 The present invention provides a method for hydrotreating heavy hydrocarbon oils, which comprises contacting the hydrotreating catalyst of the present invention with heavy hydrocarbon oils containing sulfur compounds.

[0074] Hydrogen / oil ratio is 100 to 1000 Nm 3 / kL, and 175 to 925 Nm 3 / kL, more preferably 250 to 850 Nm 3 / kL is more preferable. The hydrogen partial pressure is preferably 3.5 to 10 MPa, and more preferably 4 to 9 MPa. When the hydrogen partial pressure is equal to or higher than the lower limit of the above range, the hydrogenation reaction is likely to proceed. The reaction temperature is preferably 330 to 430°C, more preferably 350 to 410°C. When the reaction temperature is equal to or higher than the lower limit of the above range, the catalytic activity can be fully exerted. When the reaction temperature is equal to or lower than the upper limit of the above range, the thermal cracking of the heavy hydrocarbon oil proceeds appropriately, while catalyst deterioration is unlikely to occur. By reaction temperature is meant the average temperature of the catalyst bed. LHSV is 0.2 to 2 hours -1 It is preferable that the time is 0.5 to 2 hours. -1 It is more preferable that:

[0075] Heavy hydrocarbon oils to be subjected to the method for producing hydrotreated heavy hydrocarbon oil (hydrotreating method for heavy hydrocarbon oil) of this embodiment include vacuum gas oil obtained by further vacuum distilling atmospheric distillation residue obtained by atmospheric distillation of crude oil in an atmospheric distillation unit in a vacuum distillation unit, atmospheric heavy oil obtained by atmospheric distillation of crude oil in an atmospheric distillation unit, heavy extracts which are particularly heavy oil components among the oil components extracted and removed by solvent extraction of lubricating base oil such as hydrocracked heavy oil, atmospheric distillation residue, fluid catalytic cracking residue, thermal cracking heavy oil, and scraped oil, among which vacuum gas oil, heavy extract, fluid catalytic cracking residue, and thermal cracking heavy oil are preferred, and vacuum gas oil is particularly preferred. Hydrogenolysis catalysts for hydrocarbon oils contain active hydrogenation components, but it is common technical knowledge in the field that catalyst components other than the active hydrogenation components must be separately studied and optimized for each type of hydrocarbon oil. For example, when a hydrotreatment catalyst for so-called residual oils, such as atmospheric distillation residual oil or vacuum distillation residual oil, is used as a hydrotreatment catalyst for distillate oils such as vacuum gas oil, the molecules of vacuum gas oil are small relative to the catalyst pore size of the hydrotreatment catalyst for residues, which tends to lead to diffusion-limited reaction, making it difficult to obtain catalytic effects. Furthermore, when a hydrotreatment catalyst for relatively light oils, such as atmospheric distillation gas oil, is used as a hydrotreatment catalyst for relatively heavy oils, such as vacuum gas oil, uncalcined catalysts are often used for hydrotreatment of relatively light oils, and therefore activity is likely to deteriorate in high-temperature environments such as those used in the hydrotreatment of vacuum gas oil. Examples of catalyst components other than the hydrogenation active component include the specific surface area of ​​the carrier, physical properties such as pore structure, the hydrogenation active component, and the types and contents of components (phosphorus, zinc, etc.) contained in the hydrotreating catalyst other than alumina.

[0076] The density of the heavy hydrocarbon oil to be subjected to the method for producing hydrotreated heavy hydrocarbon oil of this embodiment (hydrotreating method for heavy hydrocarbon oil) is 0.91 to 1.10 g / cm 3 is preferred, and 0.95 to 1.05 g / cm 3 The sulfur content is preferably 2 to 6 mass %, more preferably 2 to 5 mass %. The nickel content is preferably 3 ppm or less, the vanadium content is preferably 3 ppm or less, and the asphaltene content is preferably 0.1 mass % or less.

[0077] The density of the hydrogenated heavy hydrocarbon oil produced by the method for producing hydrotreated heavy hydrocarbon oil of this embodiment (hydrotreating method for heavy hydrocarbon oil) is 0.87 to 0.95 g / cm 3 is preferable, and 0.88 to 0.94 g / cm 3 The sulfur content is preferably 1.0 to 3.5 mass %, more preferably 1.2 to 3.4 mass %.

[0078] The hydrotreating catalyst of this embodiment may be activated by sulfiding in a reactor before use (i.e., before carrying out the hydrotreating method of this embodiment). This sulfiding is generally carried out at 200 to 400°C, preferably 250 to 350°C, in a hydrogen atmosphere at atmospheric or higher hydrogen partial pressure, by flowing a petroleum distillate containing sulfur compounds, to which a sulfiding agent such as dimethyl disulfide or carbon disulfide has been added, or hydrogen sulfide, through the hydrotreating catalyst.

[0079] Examples of zinc, phosphorus, Group 6 metal, and cobalt contained in the catalyst of this embodiment after the sulfurization treatment include zinc sulfide, phosphorus sulfide, sulfides of Group 6 metals, and cobalt sulfide. Further examples include composite sulfides of two or more elements selected from the group consisting of zinc, phosphorus, Group 6 metals, cobalt, and aluminum.

[0080] By hydrotreating heavy hydrocarbon oil using the hydrotreating catalyst of this embodiment, the hydrotreating proceeds sufficiently and it becomes possible to reduce the sulfur compounds in the heavy hydrocarbon oil over a long period of time.

[0081] To carry out the hydrotreating method of this embodiment on a commercial scale, a fixed-bed, moving-bed, or fluidized-bed catalyst layer of the hydrotreating catalyst of this embodiment may be formed in a reactor, a feedstock oil may be introduced into this reactor, and hydrotreating may be carried out under the conditions described above. Most commonly, a fixed-bed catalyst layer is formed in the reactor, and the feedstock oil is introduced into the upper part of the reactor, passes through the fixed bed from top to bottom, and the product is discharged from the bottom of the reactor; alternatively, the feedstock oil is introduced into the lower part of the reactor, passes through the fixed bed from bottom to top, and the product is discharged from the top of the reactor.

[0082] The hydrotreating method of this embodiment may be a single-stage hydrotreating method in which the hydrotreating catalyst of this embodiment is packed into a single reactor, or may be a multi-stage continuous hydrotreating method in which the hydrotreating catalyst of this embodiment is packed into several reactors. [Example]

[0083] 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.

[0084] <Physical and chemical properties of catalyst and carrier> [1] Analysis of physical properties (specific surface area, pore volume, average pore diameter, and pore distribution) a) Measurement method and equipment used: The specific surface area was measured by the BET method using nitrogen adsorption. The nitrogen adsorption device used was a surface area measuring device (Belsorp 28) manufactured by Nippon Bell Co., Ltd. The pore volume, average pore diameter, and pore distribution were measured by mercury intrusion porosimetry. The mercury intrusion apparatus used was a porosimeter (MICROMERITICS AUTO-PORE 9200, manufactured by Shimadzu Corporation).

[0085] b) Mercury porosimetry measurement principle: 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 assumed to be 484 dyne / cm, and the contact angle is assumed to be 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. Pore ​​size distribution is the distribution of D calculated as a function of P.

[0086] c) Measurement procedure: 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 containing the sample 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 AUTO-PORE 9200 cell. 8) Measure using AUTO-PORE 9200.

[0087] [2-1] Analysis of chemical composition a) Analysis method and equipment used: Metal analysis of the support and catalyst was performed using an inductively coupled plasma emission spectrometry (ICPS-2000: Shimadzu Corporation). 2- The analysis was carried out using a sulfur analyzer (S632, manufactured by LECO). Metal quantification was performed using the absolute calibration curve method.

[0088] b) Measurement procedure: 1) 0.05 g of catalyst or carrier, 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 ICPS-2000 or S632.

[0089] <Hydrotreatment of heavy hydrocarbon oil> Hydrotreatment of vacuum gas oil having the following properties was carried out in the following manner. First, a catalyst was packed into a high-pressure flow reactor to form a fixed-bed catalyst layer, and pretreatment was carried out under the following conditions. Next, a mixed fluid of feed oil heated to the reaction temperature and hydrogen-containing gas was introduced from the top of the reactor, and hydrogenation reactions consisting of desulfurization and cracking reactions were carried out under the following conditions. 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.

[0090] Catalyst pretreatment conditions: drying 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.

[0091] Reaction conditions: Pressure (hydrogen partial pressure): 4.9 MPa Liquid space velocity ;0.95hr -1 Hydrogen / oil ratio: 240Nm 3 / kL Reaction temperature: set so that the sulfur content in the resulting oil is 0.28% by mass

[0092] Feedstock properties: Oil type: Vacuum gas oil (Arabian heavy, Das blend) Density (15℃); 0.9295g / cm 3 Sulfur content: 2.72% by mass Nitrogen content: 0.092% by mass Residual carbon content: 0.81% by mass

[0093] [Manufacturing Example 1] 1.5 L of a 12% by mass aqueous solution of sulfuric acid was added to 100 L of pure water in a stirring vessel, heated to 95°C, and then vigorously stirred with a stirring blade for 5 minutes. 3.9 L of sodium aluminate with an alumina concentration of 70 g / L was added to prepare aluminum hydroxide, which was then stirred with a stirring blade for 24 hours. The resulting slurry was placed in a filter and filtered to remove water. The resulting gel was then dissolved in pure water and spun to form a filtrate containing SO4 2- , Na + The gel was washed until no traces of fluorine were detected. The washed gel was then mixed with pure water to form a homogeneous slurry, which was then placed in a compression filter. The slurry was then sandwiched between filter plates via a filter cloth, and the filter plates were squeezed to dehydrate. Filtration was discontinued when the moisture content of the cake reached 80%. The cake was placed in a heated kneader (set temperature 80°C) and thoroughly kneaded to homogenize it. After that, phosphoric acid and zinc oxide were added, and the mixture was further kneaded to homogenize it. The resulting cake was placed in an extrusion molding machine and extruded into a four-leaf shape with a major axis of 1.3 mm and a minor axis of 1.1 mm. The molded product was dried and then calcined at 600°C for 4 hours to obtain a phosphorus- and zinc-containing alumina support (support A). Table 1 shows the phosphorus and zinc contents of the carrier A calculated as oxides, the specific surface area, the pore volume, and the average pore diameter.

[0094] [Manufacturing Example 2] An alumina carrier (carrier B) was obtained in the same manner as in Production Example 2, except that phosphoric acid and zinc oxide were not added. Table 1 shows the phosphorus and zinc contents of carrier B calculated as oxides, specific surface area, pore volume, and average pore diameter.

[0095] [Table 1]

[0096] [Example 1] 50.00 g of Carrier A produced in Production Example 1 was placed in an eggplant-shaped flask, and a solution of 5.5114 g of cobalt carbonate, 19.0187 g of molybdophosphoric acid, and 1.9418 g of orthophosphoric acid dissolved in 40.5 g of ion-exchanged water was added thereto using a pipette. The mixture was immersed at 25°C for 1 hour, then air-dried in a nitrogen stream, dried in a muffle furnace at 120°C for 1 hour, and then calcined at 500°C for 4 hours to obtain Catalyst A. The contents of phosphorus, zinc, cobalt, and molybdenum in Catalyst A calculated on an oxide basis, and the SO4 2- The contents of Na2O and Fe2O3, the specific surface area, the pore volume, the average pore diameter, and the ratio of the volume of pores having a pore diameter within ±1.5 nm of the average pore diameter to the total pore volume are shown in Table 2. Note that "pore distribution" in Table 2 means "the ratio of the volume of pores having a pore diameter within ±1.5 nm of the average pore diameter to the total pore volume." Using catalyst A, heavy hydrocarbon oil was hydrotreated by adjusting the reaction temperature so that the sulfur content in the product oil would be 0.28 mass%. Table 3 shows the reaction temperatures from 1 day to 17 days after the start of the reaction.

[0097] [Comparative Example 1] Catalyst B was obtained in the same manner as in Example 1, except that carrier B was used instead of carrier A. Table 2 shows the catalyst-based, oxide-equivalent contents of phosphorus, zinc, cobalt, and molybdenum for catalyst B, the specific surface area, pore volume, average pore diameter, and the ratio of the volume of pores having pore diameters within the average pore diameter ±1.5 nm to the total pore volume. Using catalyst B, heavy hydrocarbon oil was hydrotreated by adjusting the reaction temperature so that the sulfur content in the product oil would be 0.28 mass%. Table 3 shows the reaction temperatures from 1 day to 12 days after the start of the reaction.

[0098] Comparative Example 2 60.00 g of Carrier A produced in Production Example 1 was placed in an eggplant-shaped flask, and a solution of 11.1 g of nickel nitrate hexahydrate, 10.5 g of ammonium molybdate tetrahydrate, and 13.8 g of citric acid monohydrate dissolved in 36.1 g of ion-exchanged water was added thereto using a pipette. The mixture was immersed at 25°C for 1 hour, then air-dried in a nitrogen stream, dried in a muffle furnace at 120°C for 1 hour, and calcined at 300°C for 1 hour and then at 500°C for 4 hours to obtain Catalyst C. The contents of phosphorus, zinc, nickel, and molybdenum in Catalyst C calculated as oxides, and SO4 2- Table 2 shows the contents of Na2O and Fe2O3, the specific surface area, the pore volume, the average pore diameter, and the ratio of the volume of pores having a pore diameter of the average pore diameter ±1.5 nm to the total pore volume. Using catalyst C, the reaction temperature was adjusted so that the sulfur content in the product oil would be 0.28 mass%, and heavy hydrocarbon oil was hydrotreated. Table 3 shows the reaction temperatures from 1 day to 17 days after the start of the reaction.

[0099] [Table 2]

[0100] [Table 3]

[0101] As shown in Table 3, the hydrotreating catalyst of Example 1 of the present invention had a lower reaction temperature at the initial stage of the reaction than the zinc-free hydrotreating catalyst of Comparative Example 1, and there was no need to increase the reaction temperature even 17 days after the start of the reaction. In other words, it was found that the hydrotreating catalyst of Example 1 had higher hydrotreating activity and was less likely to lose activity than the hydrogenation catalyst of Comparative Example 1. Furthermore, the hydrotreating catalyst of Example 1 of the present invention had a lower reaction temperature at the beginning of the reaction than the hydrotreating catalyst of Comparative Example 2, which did not contain cobalt, and there was no need to increase the reaction temperature even 17 days after the start of the reaction. The reaction temperature at the beginning of the reaction was thought to be largely due to the fact that the hydrotreating catalyst of Example 1 carried a larger amount of molybdenum than the hydrotreating catalyst of Comparative Example 2. On the other hand, the increase in reaction temperature was thought to be due to the fact that the hydrotreating catalyst of Comparative Example 2 carried nickel instead of cobalt. [Industrial Applicability]

[0102] The catalyst for hydrotreating heavy hydrocarbon oil according to the present invention is useful because it can be used to reduce the sulfur content in heavy hydrocarbon oil.

Claims

1. a phosphorus- and zinc-containing alumina carrier containing 0.1 to 4 mass % of phosphorus, calculated as oxide, based on the carrier, and 1 to 8 mass % of zinc, calculated as oxide, based on the carrier; The vacuum gas oil hydrotreating catalyst comprises a carrier on which at least one metal selected from Group 6 of the periodic table is supported in an amount of 8 to 30 mass % in terms of oxide, based on the catalyst, and cobalt in an amount of 2 to 8 mass % in terms of oxide, based on the catalyst.

2. The method for producing a vacuum gas oil hydrotreating catalyst includes a step of supporting at least one metal selected from Group 6 of the periodic table on a phosphorus- and zinc-containing alumina support, the alumina support containing phosphorus in an amount of 0.1 to 4 mass % in terms of oxide, based on the support, and zinc in an amount of 1 to 8 mass % in terms of oxide, based on the support, so that the metal contains 8 to 30 mass % in terms of oxide, based on the catalyst, and cobalt in an amount of 2 to 8 mass % in terms of oxide, based on the catalyst.

3. Hydrogen / oil ratio 100 to 1000 Nm ３ / kL, hydrogen partial pressure 3.5-10 MPa, 330-430°C, liquid hourly space velocity 0.2-2 hr －１ 2. A method for hydrotreating vacuum gas oil, comprising contacting the vacuum gas oil with the vacuum gas oil hydrotreating catalyst according to claim 1.

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