JP4519378B2 - Heavy oil hydrodesulfurization catalyst, method for producing the same, and hydrodesulfurization method for heavy oil using the same - Google Patents

Description

【００５２】
【表２】

【００５３】
以上の実施例１〜７および比較例１〜３と比較例５で得た触媒の水素化脱硫活性を、原料油にＡＲを用いて、下記に示す方法で評価した。
（水素化脱硫活性の評価方法）
ライトガスオイルとＶＧＯで触媒を予備硫化処理した後、下記の運転条件下、初期劣化（コーク劣化）が落ち着いた７００時間後の生成油に含まれる硫黄濃度を測定し、以下に示す計算式〔式１〕により反応速度定数を求めることで評価した。
原料油ならびに生成油の硫黄濃度の分析はニューリー（株）社製、Ｘ線硫黄分析計（ＲＸ−６１０ＳＡ）で求めた。なお、反応速度定数が高いほど、触媒の水素化脱硫活性が優れていることを示す。
評価結果を比較例１の反応速度定数を１００とした場合の相対値で表３に示す。また反応終了後、反応に用いた触媒をソックスレー抽出し、乾燥させた後、（株）柳本株式会社製、ＣＨＮ分析計（ＭＴ-５）を用い、触媒上に析出したコーク量を測定した。結果を併せて表３に示す。
【００５４】
＜脱硫化活性評価の条件１＞
[原料油：常圧残油]
原油：アラビアンライト
密度：０．９７１３ｇ／ｃｍ³（１５℃）
硫黄分：３．４２質量％
ニッケル、バナジウム分：計５０質量ｐｐｍ
蒸留性状：５容量％（留出温度３６７℃）、４０容量％（留出温度５０６℃）、５０容量％（留出温度５３７℃）
[反応速度測定装置]
固定床高圧流通式反応装置
[反応条件]
反応温度：３８０℃
液空間速度：０．４ｈ^-1
水素分圧：１０．３ＭＰａ
水素／油比：１６９０Ｎｍ³／ｋｌ
【００５５】
〔数式１〕
反応速度定数＝[(１/生成油の硫黄濃度)−(１/原料油の硫黄濃度)]×液空間速度
【００５６】
【表３】

【００５７】
次に実施例８、実施例９および比較例４で得た触媒の水素化脱硫活性を、原料油にＶＧＯを用いて、下記に示す条件で評価した。始めにライトガスオイルで予備硫化処理を行い、下記の運転条件下、４００℃で３００時間、強制劣化させた後、３６０℃に降温し、生成油に含まれる硫黄濃度を測定した。
そして各々の触媒は、以下に示す計算式〔式２〕により反応速度定数を求め評価した。評価結果を比較例４の触媒の水素化脱硫活性を１００とした場合の相対値で表４に示す。また反応終了後、反応に用いた触媒をソックスレー抽出し、乾燥させた後、ＣＨＮ分析を行うことで触媒上に析出したコーク量を測定した。結果を併せて表４に示す。
【００５８】
＜脱硫化活性評価の条件２＞

[装置]
固定床高圧流通式反応装置
[反応条件]
反応温度：４００℃および３６０℃
液空間速度：０．７ｈ^-1
水素分圧：４．９ＭＰａ
水素／油比：４２０Ｎｍ³／ｋｌ
【００５９】
〔式２〕：
反応速度定数＝[(１/生成油の硫黄濃度^1/2)−(１/原料油の硫黄濃度^1/2)]×液空間速度
【００６０】
【表４】

【００６１】
表３および表４に示される結果から、本発明の水素化脱硫触媒はコークの析出が多く、活性が高いことが分かる。
一方、リチウムを含まず、しかも１００〜２００ＫＪ/ｍｏｌのアンモニア吸着熱を発する酸点を過剰に含む比較例１および４の触媒は、コークの析出が多く活性が低い。リチウムを過剰に含み酸点が少ない比較例２の触媒は活性がかなり低い。リチウムを混練法、共沈法により担持した比較例３および５の触媒は触媒上の酸性質を制御できず、コークの析出が多いと共に活性が著しく低い。
【００６２】
【発明の効果】
種々の重質油留分の水素化脱硫処理において、本発明の水素化脱硫触媒を用いることにより、コーク劣化による触媒活性の低下を抑制し、重質油留分中の硫黄化合物を長期間にわたり、高い効率で除去することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum gas oil (hereinafter referred to as VGO) fraction obtained by an indirect desulfurization apparatus, or an atmospheric residue (hereinafter referred to as AR) fraction and a vacuum residue (hereinafter referred to as VR) fraction obtained from a direct desulfurization apparatus. In hydrodesulfurization of heavy oil hydrodesulfurization catalyst capable of suppressing coke degradation and removing sulfur compounds in the heavy oil fraction over a long period of time with high efficiency, such hydrodesulfurization The present invention relates to a method for producing a catalyst and a method for hydrodesulfurization of heavy oil using such a hydrodesulfurization catalyst.
[0002]
[Prior art]
A large amount of sulfur compounds are contained in heavy oils such as AR obtained by treating crude oil with an atmospheric distillation apparatus and VGO, VR obtained by further treating AR with a vacuum distillation apparatus. When these heavy oils are used as fuel without being desulfurized, sulfur oxides (SOx) are discharged into the atmosphere.
[0003]
Therefore, conventionally, hydrodesulfurization treatment of heavy oil fractions by indirect desulfurization equipment and direct desulfurization equipment has been incorporated as one of the processes for producing various petroleum products from crude oil, and sulfur compounds can be removed.
Hydrodesulfurization catalysts aimed at removing sulfur compounds in heavy oils have molybdenum, tungsten, group VIII cobalt and nickel as active active ingredients in the periodic table Group VIA, which are alumina, magnesia. Those supported on an inorganic oxide carrier such as silica and titania have been developed.
[0004]
However, heavy oils contain asphaltenes that impede hydrodesulfurization reactions, organometallic compounds that reduce catalytic activity, and macromolecules rich in aromaticity, and the hydrodesulfurization activity of the above-described catalysts over a long period of time. It is difficult to maintain.
[0005]
Several proposals have been made for methods for improving the hydrodesulfurization performance of catalysts. For example, in JP-A-4-265158, hydrodesulfurization performance is improved by adding phosphorus to the catalyst. In JP-A-58-14645, etc., zeolite is added to an alumina carrier to improve hydrodesulfurization performance.
[0006]
In the hydrodesulfurization treatment of heavy oil, the catalyst causes deterioration over time, so it is important to improve the desulfurization performance and suppress the deterioration. Factors for catalyst deterioration include firstly due to metal components such as nickel and vanadium in heavy oil (metal deterioration), and secondly due to coke deposition on the catalyst (coke deterioration).
[0007]
In JP-A-7-256106, when hydrocracking is carried out using a catalyst in which a hydrogenation active metal is supported on a carrier containing lithium oxide, an excellent addition rate can be obtained without increasing the precipitate. However, further improvement is required from the viewpoint of desulfurization activity.
[0008]
Japanese Patent Application Laid-Open No. 2000-8050 proposes a catalyst in which an alkali metal or alkaline earth metal is added to a catalyst carrier having a total Brested acid amount of 50 μmol / g or more by TPD measurement, and a hydrogenation active metal is supported. This method also requires further improvement from the viewpoint of suppressing coke deterioration.
[0009]
[Problems to be solved by the invention]
The object of the present invention is that in hydrodesulfurization treatment such as VGO by indirect desulfurization equipment and AR by direct desulfurization equipment, there is little decrease in catalytic activity due to coke deterioration, and the sulfur compounds in the heavy oil fraction are used for a long period of time. To provide a hydrodesulfurization catalyst that can be removed with high efficiency, and to provide a method for producing the hydrodesulfurization catalyst, and a hydrodesulfurization method for heavy oil using the hydrodesulfurization catalyst. .
[0010]
[Means for solving the problems]
According to the present invention, a catalyst having the following constitution, a production method thereof, and a catalytic hydrodesulfurization method are provided to achieve the object of the present invention.
1. 8 to 25% by mass of at least one metal selected from Group VIA of the periodic table, 1 to 8% by mass of at least one metal selected from Group VIII of the periodic table, and 0.05 to 0 of lithium. .8% by mass (both expressed in terms of oxide based on the catalyst) supported on an alumina carrier,
It has an acid point that generates heat of adsorption of ammonia of 100 to 200 KJ / mol measured by a microcalorimetry method in a range of 270 to 380 μmol per gram of catalyst , and the lithium is supported on the alumina support by an impregnation method. A hydrodesulfurization catalyst characterized by having a specific surface area of 180 to 330 m ² / g, a pore volume of 0.4 to 0.7 ml / g, and an average pore diameter of 7 to 11 nm .
2. 2. The hydrodesulfurization catalyst according to 1 above, wherein the metal of Group VIA of the periodic table is molybdenum or tungsten, and the metal of Group VIII of the periodic table is cobalt or nickel.
3 . A heavy oil containing a sulfur compound under reaction conditions of a hydrogen partial pressure of 4 to 18 MPa, a temperature of 320 to 410 ° C., and a liquid space velocity of 0.1 to 4.0 h ⁻¹ is combined with the catalyst according to the above 1 or 2. A method for hydrodesulfurization of heavy oil, characterized in that they are brought into contact with each other.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The catalyst of the present invention is a catalyst in which alumina is used as a carrier, a Group VIA metal and a Group VIII metal are supported as active metals, and lithium is supported by an impregnation method. Sulfur compounds in quality oil can be removed with high efficiency over a long period of time.
[0012]
The manufacturing method of the alumina support | carrier used for the catalyst of this invention is not specifically limited, A normal method is employable. That is, by neutralizing a water-soluble aluminum compound such as aluminum sulfate, nitrate or chloride with a base such as ammonia, or neutralizing an alkali metal aluminate with an acidic aluminum salt or acid, etc. The produced aluminum hydrogel or hydrosol can be produced by applying a general formulation such as washing, aging, molding, drying, and baking.
[0013]
In order to obtain an alumina carrier having structural properties suitable as a catalyst carrier, it is only necessary to appropriately adjust the pH, concentration, time, temperature, etc. of these chemicals by adding a precipitating agent or a neutralizing agent. For example, if the pH at the time of gel formation is performed on the acidic side, the specific surface area increases. In the present invention, it is preferable that the pH is about 4 to 8 and the temperature is about 15 to 90 ° C.
[0014]
After the gel is formed, aging, cleaning and removing impurities, and dehydration drying are performed. The aging is preferably performed at a pH of 4 to 9 and a temperature of about 15 to 90 ° C. for about 1 to 25 hours. Outside these ranges, not only is it difficult to remove impurities in the alumina gel after aging, but the surface area of the alumina gel is reduced.
The dehydration drying is performed by adjusting the water content without applying heat to the alumina gel. For example, it is dehydrated and dried by a method such as natural filtration at about 15 to 90 ° C. and about 0.01 to 2 MPa, suction filtration, pressure filtration, etc., so that the water content after dehydration drying is about 60 to 90% by mass. It is preferable to make it. By adjusting the water content without applying extra heat to the alumina gel, the surface structure of the alumina can be controlled, and the hydrodesulfurization activity of the catalyst can be improved.
[0015]
The carrier is formed after dehydration and drying. The molding method is not particularly limited, and a general method such as extrusion molding, tableting molding, or granulation in oil can be used. The pore volume and pore distribution, which are structural properties of alumina, can also be controlled by adjusting the pressure and speed during molding.
[0016]
The shape of the alumina support is preferably a cylindrical, trilobal, quadrilobal, dumbbell, or ring pellet in consideration of the distribution of the heavy oil fraction catalyst layer. A shape with a small pressure loss (pressure difference) is selected. Similarly, the pellet diameter is desirably in the range of 1/10 to 1/36 inch so that the pressure loss does not increase before and after the catalyst layer under the reaction conditions. In addition, a pellet diameter is represented by the long diameter of the cross section of the thickest part except what the shape of a pellet is a cylinder.
[0017]
After molding, the alumina support can be obtained by drying at room temperature to about 150 ° C. for about 3 to 24 hours, followed by firing at about 200 to 600 ° C. for about 3 to 24 hours.
[0018]
The catalyst of the present invention is one in which at least one metal selected from Group VIA, at least one metal selected from Group VIII and lithium, and, if necessary, a phosphorus compound are supported.
[0019]
As the Group VIA metal described above, chromium, molybdenum or tungsten is used, but molybdenum or tungsten is preferred. These Group VIA metals can be used in combination of two or more. Various compounds of these Group VIA metals can be used. Specific examples of the molybdenum compound include molybdenum oxide, ammonium molybdate, molybdenum condensed acid salt, etc., but molybdenum oxide, ammonium molybdate, and molybdophosphoric acid are preferable. Specific examples of the tungsten compound include tungsten oxide, ammonium tungstate, and tungsten condensed acid salt. Tungsten oxide, ammonium tungstate, and tungstophosphoric acid are preferable.
These compounds can be used alone or in combination of two or more. Of course, a molybdenum compound and a tungsten compound can be used in combination.
[0020]
The group VIII metal is preferably nickel or cobalt. Moreover, nickel and cobalt can also be used together. Various compounds of these Group VIII metals can be used. Specific examples of the nickel compound include nickel nitrate, nickel sulfate, nickel carbonate, nickel acetate, nickel oxalate, nickel chloride and the like, and nickel nitrate, nickel carbonate, and nickel acetate are preferable. Specific examples of the cobalt compound include cobalt nitrate, cobalt sulfate, cobalt carbonate, cobalt acetate, cobalt oxalate, and cobalt chloride, but cobalt nitrate, cobalt carbonate, and cobalt acetate are preferable.
These compounds can be used alone or in combination of two or more. Of course, a nickel compound and a cobalt compound can be used in combination.
[0021]
Various types of lithium can be used. Specific examples include lithium hydroxide, lithium nitrate, lithium oxalate, lithium sulfate, lithium chloride, lithium carbonate, and lithium acetate, with lithium hydroxide, lithium nitrate, and lithium acetate being preferred.
[0022]
In addition to the Group VIA metal, Group VIII metal, and lithium described above, phosphorus may be added in order to improve the dispersibility of the active metal. Various compounds can be used as the phosphorus compound. Specific examples include orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, and tetraphosphoric acid, but orthophosphoric acid is preferred.
[0023]
The amount of the Group VIA metal supported is 8 to 25% by mass, preferably 12 to 22% by mass, and particularly preferably 12 to 20% by mass in terms of oxide based on the catalyst. The amount of the Group VIII metal supported is 1 to 8% by mass, preferably 2 to 5% by mass, expressed in terms of oxide based on the catalyst.
[0024]
The amount of lithium supported is 0.05 to 0.8% by mass, preferably 0.07 to 0.7, particularly preferably 0.1 to 0.4, expressed in terms of oxide based on the catalyst. . When the loading is within this range, the desired acid properties and acid amount can be controlled, and a catalyst in which coke deterioration hardly occurs while maintaining high activity can be obtained. If the amount of lithium supported is reduced too much, the desired acid properties and the amount of acid cannot be controlled, resulting in coke deterioration. Moreover, if it increases too much, even the acid point required for catalyst activity will be controlled, and catalyst activity will fall.
[0025]
Regarding the amount of metal supported, “display in terms of oxide based on the catalyst” means that the mass of all metal species contained in the catalyst is calculated as the oxide of each metal, and the total mass is calculated for each metal. It means to display by the value divided by the oxide mass. Aluminum was trivalent, molybdenum was hexavalent, nickel and cobalt were bivalent, and lithium was monovalent metal.
The metal loading was measured by dissolving the catalyst in a mixed acid and then analyzing it by ICP spectroscopy (inductively coupled high-frequency plasma spectroscopy) and displaying it in terms of catalyst-based metal oxide.
[0026]
In addition, phosphorus can be added to the catalyst of the present invention as needed in order to highly disperse the active metal. In this case, the amount of phosphorus supported is preferably 0.5 to 6% by mass, more preferably 2 to 5% by mass in terms of oxide based on the catalyst. Here, phosphorus was calculated as a pentavalent metal. The loading of phosphorus has the effect of enhancing the dispersibility of the active metal and improving the catalytic activity. When the amount of phosphorus supported is larger than the above range, the pore volume is reduced and the catalytic activity is lowered, which is not preferable.
[0027]
In the catalyst of the present invention, various preparation methods such as an impregnation method, a coprecipitation method, a kneading method, a deposition method, and an ion exchange method can be adopted as a method for supporting the Group VIA metal and the Group VIII metal.
On the other hand, the desulfurization activity and coke deterioration of the prepared catalyst are greatly affected by the lithium loading method. The impregnation method is preferable because the acid amount and acid properties on the catalyst surface can be efficiently controlled.
The active metal and lithium may be supported in any order. That is, the active metal and lithium may be supported simultaneously, or the active metal may be supported after the lithium is supported and then dried and fired to form a metal oxide. Alternatively, lithium may be supported after the active metal is supported and dried and fired to form a metal oxide.
Particularly preferred is a method in which both of the active metal and lithium are supported by the impregnation method. In this case, the active metal and lithium may be impregnated simultaneously or individually. When impregnating individually, the impregnation order may be impregnated with lithium first, dried and fired to obtain a metal oxide, and then impregnated with active metal, or impregnated with active metal first and dried. -After baking to form a metal oxide, it may be impregnated with lithium.
[0028]
After supporting the metal, drying and firing are performed. The drying method and conditions are not particularly limited. For example, the usual conditions employed in these methods are employed, such as ordinary air drying, hot air drying, and heat drying. After drying, firing is performed, but the method is not particularly limited. For example, an electric furnace, a muffle furnace, etc. are used and the method of baking for about 2 to 10 hours at about 400-650 degreeC under air circulation is mentioned.
[0029]
The catalyst of the present invention has an acid point that generates an ammonia adsorption heat of 100 to 200 KJ / mol by a microcalorimetric method, 270 to 380 μmol / g, preferably 290 to 380 μmol / g, more preferably 310 per gram of the catalyst. It is in the range of ˜380 μmol / g.
The heat of adsorption generated when ammonia is adsorbed on the acid sites on the catalyst surface varies depending on the acid properties of the acid sites. A catalyst having an acid point with an adsorption heat of 100 to 200 KJ / mol in the above range has sufficient activity in the hydrodesulfurization reaction of heavy oil and has very little deterioration over time. If the acid point is less than 270 μmol / g, the catalytic activity is not sufficient, and if it exceeds 380 μmol / g, the desired coke deterioration cannot be suppressed, such being undesirable.
In order to better control the amount of the acid sites, the supported amount of lithium is 0.05 to 0.8% by mass in terms of oxide based on the catalyst, and the lithium impregnation method. in you carrying.
[0030]
In the microcalorimetry method, a predetermined amount of a sample (here a catalyst) is filled in an adsorption tube, ammonia gas is introduced at a predetermined amount with a certain amount of pulse, and adsorbed on the sample, and the heat of adsorption generated during this adsorption. Is a method of measuring acid strength and acid amount. Here, the heat of adsorption corresponds to the acid strength, and the adsorption amount (introduction amount) corresponds to the acid amount.
In the present invention, the measurement conditions of the microcalorimetry method in which the measurement was performed are as follows.
That is, as a measuring device, a high temperature thermal measurement surface analysis device CSA-450G manufactured by Tokyo Riko Co., Ltd. was used, and the catalyst (sample) was vacuum dried at 400 ° C. for 4 hours, and then the temperature of the thermostatic bath was set to 150 ° C. Then, ammonia gas was introduced and the heat of adsorption was measured using a Tian-Calvet calorimeter.
[0031]
The catalyst of the present invention is not particularly limited in specific surface area, pore volume, and average pore diameter, but in order to efficiently remove sulfur content in heavy oil, the specific surface area should be 100 to 500 m ² / g. Preferably, 180 to 330 m ² / g is more preferable. The pore volume is preferably 0.3 to 0.8 ml / g, more preferably 0.4 to 0.7 ml / g. The average pore diameter is preferably 5 to 13 nm, more preferably 7 to 11 nm.
[0032]
In order to perform the catalytic hydrotreating of heavy oil using the hydrodesulfurization catalyst of the present invention, for example, the catalyst of the present invention is charged into a reactor such as an indirect desulfurization apparatus or a direct desulfurization apparatus, and the raw material is supplied to the reactor. By introducing heavy oil as oil, desulfurization treatment can be performed under conditions of high temperature and high pressure hydrogen partial pressure. A preferred embodiment is a so-called fixed bed flow reaction system. The catalyst is maintained in the reactor as a fixed bed, a preliminary sulfidation treatment is performed, and most of the supported metal components are converted to sulfides, and then the feedstock is passed downward from above the fixed bed. The catalyst may be charged in a single reactor or in each of a plurality of reactors connected in series. In particular, when the feedstock is AR or VR, the feedstock contains a high concentration of metal such as nickel and vanadium, so a catalyst layer having a demetallizing function is combined in the previous stage (upper layer) of the desulfurization catalyst layer. It is particularly preferred to use a multistage reactor.
[0033]
The reaction conditions for catalytic hydrodesulfurization of the VGO fraction, the AR fraction, the VR fraction, etc. using the catalyst of the present invention are preferably a hydrogen partial pressure of 4 to 18 MPa, a feed oil temperature of 320 to 410 ° C., a liquid Contact with the catalyst according to the invention under conditions in the space velocity range of 0.1 to 4.0 h ⁻¹ .
[0034]
When the above raw material oil is hydrotreated under the above reaction conditions, the catalyst of the present invention is less deteriorated with time than conventional catalysts, and can produce low sulfur heavy oil over a long period of time.
In addition, the catalyst of this invention can be used also as a catalyst for desulfurization of a light oil fraction other than a VGO fraction, an AR fraction, and a VR fraction.
[0035]
【Example】
EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
[0036]
[Preparation of catalyst]
Example 1
In 26 g of ion-exchanged water, 7.8 g of molybdophosphoric acid, 1.9 g of nickel carbonate, 1.5 g of orthophosphoric acid, and 0.18 g of lithium nitrate were dissolved. All of this aqueous solution was dropped into 30 g of alumina pellets having a surface area of 330 m ² / g in an eggplant-shaped flask, allowed to stand at room temperature for 1 hour, air-dried, and then at 500 ° C. under air circulation using a muffle furnace. Calcination was performed to obtain catalyst (1). As a result of elemental analysis by ICP spectroscopy, the composition (mass%) in oxide conversion display based on the catalyst was as follows.
NiO / MoO ₃ / P ₂ O ₅ / Li ₂ O = 3/15/3 / 0.1
[0037]
Example 2
Catalyst (2) was obtained in the same manner as in Example 1 except that the amount of lithium nitrate was changed to 0.35 g. Moreover, the catalyst composition (mass%) calculated | required by the same analysis method as Example 1 was as follows.
NiO / MoO ₃ / P ₂ O ₅ / Li ₂ O = 3/15/3 / 0.2
[0038]
Example 3
A catalyst (3) was obtained in the same manner as in Example 1 except that the amount of lithium nitrate was changed to 0.70 g. Moreover, the catalyst composition (mass%) calculated | required by the same analysis method as Example 1 was as follows.
NiO / MoO ₃ / P ₂ O ₅ / Li ₂ O = 3/15/3 / 0.4
[0039]
Example 4
Catalyst (4) was obtained in the same manner as in Example 1 except that the amount of lithium nitrate was changed to 1.1 g.
Moreover, the catalyst composition (mass%) calculated | required by the same analysis method as Example 1 was as follows.
NiO / MoO ₃ / P ₂ O ₅ / Li ₂ O = 3/15/3 / 0.7
[0040]
Example 5
First, 7.8 g of molybdophosphoric acid, 1.9 g of nickel carbonate, and 1.5 g of orthophosphoric acid were dissolved in 26 g of ion-exchanged water, and all of this aqueous solution was dropped into 30 g of alumina pellets used in Example 1 in an eggplant type flask. Then, it left still at room temperature for 1 hour, and after air-drying, it baked at 500 degreeC under the air circulation using the muffle furnace, and obtained the catalyst A. Next, 0.18 g of lithium nitrate was dissolved in 24 g of ion-exchanged water, and all of this aqueous solution was added dropwise to the catalyst A in an eggplant-shaped flask, allowed to stand at room temperature for 1 hour, air-dried, and then used in a muffle furnace. The catalyst was calcined at 500 ° C. under air flow to obtain catalyst (5). Moreover, the catalyst composition (mass%) calculated | required by the same analysis method as Example 1 was as follows.
NiO / MoO ₃ / P ₂ O ₅ / Li ₂ O = 3/15/3 / 0.1
[0041]
Example 6
First, 0.18 g of lithium nitrate was dissolved in 26 g of ion-exchanged water, and all of this aqueous solution was dropped into 30 g of alumina pellets used in Example 1 in an eggplant-shaped flask, and then allowed to stand at room temperature for 1 hour. After air drying, calcination was carried out at 500 ° C. under air flow using a muffle furnace to obtain Catalyst B. Next, 7.8 g of molybdophosphoric acid, 1.9 g of nickel carbonate, and 1.5 g of orthophosphoric acid were dissolved in 24 g of ion-exchanged water, and all of this aqueous solution was added dropwise to the catalyst B in an eggplant type flask. The mixture was allowed to stand for air, air-dried, and then calcined at 500 ° C. in an air stream using a muffle furnace to obtain catalyst (6).
Moreover, the catalyst composition (mass%) calculated | required by the same analysis method as Example 1 was as follows.
NiO / MoO ₃ / P ₂ O ₅ / Li ₂ O = 3/15/3 / 0.1
[0042]
Example 7
Catalyst 7 was obtained in the same manner as in Example 1, except that 0.11 g of lithium hydroxide was used instead of 0.18 g of lithium nitrate.
Moreover, the catalyst composition (mass%) calculated | required by the same analysis method as Example 1 was as follows.
NiO / MoO ₃ / P ₂ O ₅ / Li ₂ O = 3/15/3 / 0.1
[0043]
Example 8
In 24 g of ion-exchanged water, 9.1 g of molybdophosphoric acid, 1.9 g of cobalt carbonate, 1.5 g of orthophosphoric acid, and 0.18 g of lithium nitrate were dissolved. All of this aqueous solution was dropped into 30 g of alumina pellets having a surface area of 320 m ² / g in an eggplant-shaped flask, allowed to stand at room temperature for 1 hour, air-dried, and then air-circulated using a muffle furnace at 500 ° C. Calcination was performed to obtain catalyst (8). Moreover, the catalyst composition (mass%) calculated | required by the same analysis method as Example 1 was as follows.
CoO / MoO ₃ / P ₂ O ₅ / Li ₂ O = 3/17/3 / 0.1
[0044]
Example 9
Catalyst 9 was obtained in the same manner as in Example 8 except that the amount of lithium nitrate was 1.1 g.
Moreover, the catalyst composition (mass%) calculated | required by the same analysis method as Example 1 was as follows.
CoO / MoO ₃ / P ₂ O ₅ / Li ₂ O = 3/17/3 / 0.7
[0045]
Comparative Example 1
Catalyst {circle around (1)} was obtained in the same manner as in Example 1, except that no lithium nitrate was added. The catalyst composition (mass%) obtained by the same analysis method as in Example 1 was as follows.
NiO / MoO ₃ / P ₂ O ₅ = 3/15/3
[0046]
Comparative Example 2
Catalyst (2) 'was obtained in the same manner as in Example 1, except that the amount of molybdophosphoric acid was 8.0 g, the amount of nickel carbonate was 2.0 g, and the amount of lithium nitrate was 3.6 g. Moreover, the catalyst composition (mass%) calculated | required by the same analysis method as Example 1 was as follows.
NiO / MoO ₃ / P ₂ O ₅ / Li ₂ O = 3/15/3/2
[0047]
Comparative Example 3
Lithium nitrate was added to the alumina gel, and both were uniformly kneaded, then dried and fired to obtain a lithium-containing alumina carrier. An aqueous solution (using 26 g of ion-exchanged water as a solvent) in which 7.8 g of molybdophosphoric acid, 1.9 g of nickel carbonate and 1.5 g of orthophosphoric acid were dissolved in 30 g of this carrier was added dropwise in an eggplant type flask, and then at room temperature. The mixture was allowed to stand for air, air-dried, and then calcined at 500 ° C. under air flow using a muffle furnace to obtain a lithium kneading method catalyst (3).
Moreover, the catalyst composition (mass%) calculated | required by the same analysis method as Example 1 was as follows.
NiO / MoO ₃ / P ₂ O ₅ / Li ₂ O = 3/15/3 / 0.1
[0048]
Comparative Example 4
Catalyst (4) 'was obtained in the same manner as in Example 8 except that lithium nitrate was not added. The catalyst composition (mass%) obtained by the same analysis method as in Example 1 was as follows.
CoO / MoO ₃ / P ₂ O ₅ = 3/17/3
[0049]
Comparative Example 5
Ammonium hydroxide was added to an aqueous solution of aluminum nitrate and lithium nitrate to form a precipitate. This precipitate was sufficiently washed with water, filtered, dried and fired to obtain a lithium-containing alumina carrier. An aqueous solution (using 26 g of ion-exchanged water as a solvent) in which 7.8 g of molybdophosphoric acid, 1.9 g of nickel carbonate and 1.5 g of orthophosphoric acid were dissolved in 30 g of this carrier was added dropwise in an eggplant type flask, and then at room temperature. The mixture was allowed to stand for air, air-dried, and then calcined at 500 ° C. under air flow using a muffle furnace to obtain a lithium coprecipitation catalyst (5). Moreover, the catalyst composition (mass%) calculated | required by the same analysis method as Example 1 was as follows.
NiO / MoO ₃ / P ₂ O ₅ / Li ₂ O = 3/15/3 / 0.1
[0050]
[Catalyst properties]
The chemical properties of the catalysts obtained in Examples 1 to 9 and Comparative Examples 1 to 4 are shown in Table 1, and the amount of acid sites that generate 100-200 KJ / mol ammonia adsorption heat (catalyst measured by the microcalorimetry method). Table 2 shows the structural properties of the catalyst per 1 g).
[0051]
[Table 1]

[0052]
[Table 2]

[0053]
The hydrodesulfurization activity of the catalysts obtained in Examples 1 to 7 and Comparative Examples 1 to 3 and Comparative Example 5 was evaluated by the following method using AR as the raw material oil.
(Method for evaluating hydrodesulfurization activity)
After presulfiding the catalyst with light gas oil and VGO, the sulfur concentration contained in the product oil 700 hours after the initial deterioration (coke deterioration) was settled under the following operating conditions was measured. Evaluation was made by determining the reaction rate constant according to equation (1).
The analysis of the sulfur concentration of the raw material oil and the product oil was obtained with an X-ray sulfur analyzer (RX-610SA) manufactured by Newly Corporation. In addition, it shows that the hydrodesulfurization activity of a catalyst is excellent, so that reaction rate constant is high.
The evaluation results are shown in Table 3 as relative values when the reaction rate constant of Comparative Example 1 is 100. After completion of the reaction, the catalyst used for the reaction was subjected to Soxhlet extraction and dried, and then the amount of coke deposited on the catalyst was measured using a CHN analyzer (MT-5) manufactured by Yanagimoto Co., Ltd. The results are also shown in Table 3.
[0054]
<Condition 1 for desulfurization activity evaluation>
[Raw material: Normal pressure residue]
Crude oil: Arabian light density: 0.9713 g / cm ³ (15 ° C)
Sulfur content: 3.42 mass%
Nickel, vanadium content: 50 mass ppm in total
Distillation properties: 5% by volume (distillation temperature 367 ° C.), 40% by volume (distillation temperature 506 ° C.), 50% by volume (distillation temperature 537 ° C.)
[Reaction rate measuring device]
Fixed bed high pressure flow reactor
[Reaction conditions]
Reaction temperature: 380 ° C
Liquid space velocity: 0.4h ^-1
Hydrogen partial pressure: 10.3 MPa
Hydrogen / oil ratio: 1690 Nm ³ / kl
[0055]
[Formula 1]
Reaction rate constant = [(1 / Sulfur concentration of product oil) − (1 / Sulfur concentration of feed oil)] × Liquid space velocity
[Table 3]

[0057]
Next, the hydrodesulfurization activity of the catalysts obtained in Example 8, Example 9 and Comparative Example 4 was evaluated using the VGO as the feedstock under the following conditions. First, a preliminary sulfidation treatment was performed with light gas oil. After forced degradation at 400 ° C. for 300 hours under the following operating conditions, the temperature was lowered to 360 ° C., and the concentration of sulfur contained in the product oil was measured.
Each catalyst was evaluated by obtaining a reaction rate constant by the following formula [Formula 2]. The evaluation results are shown in Table 4 as relative values when the hydrodesulfurization activity of the catalyst of Comparative Example 4 is defined as 100. Further, after the reaction was completed, the catalyst used in the reaction was subjected to Soxhlet extraction, dried, and then subjected to CHN analysis to measure the amount of coke deposited on the catalyst. The results are also shown in Table 4.
[0058]
<Condition 2 for desulfurization activity evaluation>

[apparatus]
Fixed bed high pressure flow reactor
[Reaction conditions]
Reaction temperature: 400 ° C and 360 ° C
Liquid space velocity: 0.7h ^-1
Hydrogen partial pressure: 4.9 MPa
Hydrogen / oil ratio: 420 Nm ³ / kl
[0059]
[Formula 2]:
Reaction rate constant = [(1 / sulfur concentration of the produced oil ^1/2 ) − (1 / sulphur concentration of the feedstock ^1/2 )] × liquid space velocity
[Table 4]

[0061]
From the results shown in Table 3 and Table 4, it can be seen that the hydrodesulfurization catalyst of the present invention has high coke precipitation and high activity.
On the other hand, the catalysts of Comparative Examples 1 and 4 that do not contain lithium and that contain an excessive amount of acid sites that generate an ammonia adsorption heat of 100 to 200 KJ / mol have high coke deposition and low activity. The catalyst of Comparative Example 2 containing an excessive amount of lithium and having a low acid point has a considerably low activity. The catalysts of Comparative Examples 3 and 5 in which lithium is supported by a kneading method or a coprecipitation method cannot control the acid properties on the catalyst, have a large amount of coke deposition and a very low activity.
[0062]
【The invention's effect】
By using the hydrodesulfurization catalyst of the present invention in the hydrodesulfurization treatment of various heavy oil fractions, it is possible to suppress a decrease in catalytic activity due to coke degradation, and to prevent sulfur compounds in the heavy oil fractions over a long period. Can be removed with high efficiency.

Claims (3)

8 to 25% by mass of at least one metal selected from Group VIA of the periodic table, 1 to 8% by mass of at least one metal selected from Group VIII of the periodic table, and 0.05 to 0 of lithium. .8% by mass (both expressed in terms of oxide based on the catalyst) supported on an alumina carrier,
It has an acid point that generates heat of adsorption of ammonia of 100 to 200 KJ / mol measured by a microcalorimetry method in a range of 270 to 380 μmol per gram of catalyst , and the lithium is supported on the alumina support by an impregnation method. A hydrodesulfurization catalyst characterized by having a specific surface area of 180 to 330 m ² / g, a pore volume of 0.4 to 0.7 ml / g, and an average pore diameter of 7 to 11 nm .   The hydrodesulfurization catalyst according to claim 1, wherein the Group VIA metal of the periodic table is molybdenum or tungsten, and the Group VIII metal of the periodic table is cobalt or nickel. The catalyst according to claim 1 or 2 , wherein a heavy oil containing a sulfur compound under reaction conditions of a hydrogen partial pressure of 4 to 18 MPa, a temperature of 320 to 410 ° C, and a liquid space velocity of 0.1 to 4.0 h ^-1 is used. A hydrodesulfurization method for heavy oil, characterized in that it is brought into contact with the oil.