JPS6256786B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a catalyst for the nuclear hydrogenation of aromatic hydrocarbons, and more particularly to an aromatic hydrocarbon catalyst containing alumina, nickel oxide, and one or more selected from oxides of alkali metals, alkaline earth metals, and zinc in specific proportions. Concerning hydrogen nuclear hydrogenation catalysts. Conventionally, various catalysts have been known as catalysts for the nuclear hydrogenation of aromatic hydrocarbons, including Raney catalysts, palladium, platinum, and other noble metal catalysts, but they not only lack sufficient catalytic performance but also lack handling and economic efficiency. Many of them have drawbacks in terms of aspects, and they are not necessarily satisfactory as catalysts for nuclear hydrogenation of aromatic hydrocarbons. Furthermore, in the past, it was generally believed that alkali metals and alkaline earth metals had no promoter effect in the nuclear hydrogenation reaction of aromatic hydrocarbons using a nickel catalyst; for example, in the nuclear hydrogenation reaction of toluene. It has been reported that when an alkali is added to the nickel-silica catalyst in the reaction, the activity decreases rapidly [Industrial Chemistry]
68 , 1835 (1965)] and a report that in the hydrogenation reaction of benzene, adding barium carbonate to a nickel catalyst using iron oxide as a carrier reduces its activity [Catalyst Engineering Course 6 , Catalytic Reaction (1) Hydrogenation, 240 1967 Published in September 2017]. Therefore, the special public official
Publication No. 25368 proposes a fluoride of sodium, magnesium, calcium, strontium, and barium combined with nickel and diatomaceous earth as a catalyst for nuclear hydrogenation of aromatic hydrocarbons. In this case, relatively large amounts of nickel and fluoride are required to be supported, 2 to 60% by weight and 2 to 80% by weight, respectively.
It could not necessarily be said that it was an effective catalyst. The present invention has been made to solve these drawbacks, and an object of the present invention is to provide a catalyst for nuclear hydrogenation of aromatic hydrocarbons that has excellent catalytic performance and has advantages in terms of handling and economy. . As a result of extensive research in line with this objective, the present inventors have found that by adding one or more selected from alkali metals, alumina earth metals, and zinc oxides to an alumina-nickel catalyst, The present invention was achieved based on the discovery that the surface area of nickel metal is increased, which means that the degree of dispersion of nickel metal is increased. That is, the present invention is characterized in that it consists of 100 parts by weight of alumina, 5 to 20 parts by weight of nickel oxide, and 0.3 to 9 parts by weight of one or more selected from oxides of alkali metals, alkaline earth metals, and zinc. This catalyst has high activity and is also excellent in handling and economy. In the present invention, the content of nickel is
The amount is 5 to 20 parts by weight as nickel oxide per 100 parts by weight. In catalysts containing more than 20 parts by weight of nickel oxide, alkali metals, alkaline earth metals,
An increase in the surface area of nickel metal cannot be expected by adding one or more selected from zinc oxides, and if the amount is less than 5 parts by weight, the catalyst activity will be poor. In addition, one or more oxides selected from oxides of alkali metals, alkaline earth metals, and zinc are preferably lithium oxide, sodium oxide, potassium oxide, cesium oxide, magnesium oxide, calcium oxide, strontium oxide, barium oxide, and zinc oxide. More preferably, it is barium oxide. As the supported amount of alkali metal, alkaline earth metal, and zinc oxides increases, the nuclear hydrogenation activity increases, reaching a maximum value when the content is around 1 to 2 parts by weight relative to 100 parts by weight of alumina, and after that, the hydrogenation activity increases. is gradually decreasing. Therefore, these oxides are contained in an amount of 0.3 to 9 parts by weight, preferably 0.4 to 6 parts by weight, and more preferably 0.4 to 6 parts by weight, based on 100 parts by weight of alumina.
It is carried in an amount of 0.5 to 4 parts by weight. If the amount supported on the alkali is less than 0.3 parts by weight, the catalyst activity will be low and it will not be effective. In addition, if the amount exceeds 9 parts by weight, the catalyst activity will be low, and furthermore, if a solution of barium sulfate, barium hydroxide, etc. is used, the desired amount cannot be supported at once due to its low solubility. The carrying operation must be repeated several times and is not practical. Nickel oxide and oxides of alkali metals, alkaline earth metals, and zinc can be supported on the alumina carrier by adding appropriate aqueous solutions of these metal components, and well-known impregnation methods and kneading methods can be applied. Suitable aqueous solutions include, for example, nitrates and hydroxides of nickel nitrate, alkali metals, alkaline earth metals, and zinc. Regardless of which of these production methods is used, the catalyst of the present invention has improved activity compared to conventional catalysts made of alumina and nickel oxide. Among them, the method to obtain a more active catalyst is to support nickel oxide on alumina.
The impregnation method is used, and more preferably the impregnation method is also used when supporting oxides of alkali metals, alkaline earth metals, and zinc.To make a catalyst only by the impregnation method, the following steps are required. There is a method. (1) Add a solution of alkali metal salt etc. to alumina,
After thermal decomposition to support an oxide such as an alkali metal, a nickel salt solution is added and nickel oxide is supported in the same manner. (2) A mixed solution of a solution of an alkali metal salt etc. and a nickel salt solution is prepared. (3) A method in which oxides such as alkali metals and nickel oxide are supported on alumina at the same time; and (3) a method in which nickel oxide is supported first and then oxides such as alkali metals are supported. Although possible, method (1) is particularly preferred in the present invention. Further, it is preferable that the nickel salt solution, alkali metal salt, etc. solution be supported on alumina in the form of an acidic liquid, as this will help improve the catalytic activity. Examples of aromatic hydrocarbons for which the catalyst of the present invention can be used include benzene, toluene, ethylbenzene, xylene, diphenylmethane, naphthalene, and phenol. The reaction conditions for this nuclear hydrogenation of aromatic hydrocarbons are usually carried out in the gas phase, and the reaction temperature is 80 to 350°C, preferably 100 to 250°C. W/F is 1 to 100 g-cat hr/mo, preferably 3 to 70 g-cat h ₂ /mo. The molar ratio of aromatic hydrocarbon to hydrogen is 1:3-15, preferably 1:3-10. Since the catalyst of the present invention as described above significantly improves the catalytic activity, it is very effectively used in the nuclear hydrogenation reaction of aromatic hydrocarbons. The present invention will be specifically described below based on Examples and Comparative Examples. Comparative example 1 Molded alumina carrier (water absorption rate 0.75cc/g)
Put 100g into a 500c.c. beaker, shake the carrier and add 2.53mo/nickel nitrate solution (PH
1.7) Impregnated with 75 c.c. dropwise at room temperature. To ensure uniform loading, leave it at room temperature for 12 hours.
Thereafter, it was dried in a dryer using a conventional method and calcined in air at 500°C for 3 hours in an electric furnace to obtain catalyst A. The activity of this catalyst A in the benzene nuclear hydrogenation reaction was tested under normal pressure using a conventional fixed bed flow reactor. Catalyst A was packed in a Pyrex glass reaction tube with an inner diameter of 14 mm and subjected to hydrogen reduction at 500°C for 3 hours, H ₂ /C ₆ H ₆ = 3 (molar ratio),
Benzene was supplied using a microfeeder at a reaction temperature of 140°C, and hydrogen activity (benzene disappearance rate) was measured. The results are shown in Table 1. Example 1 100g of alumina carrier used in Comparative Example 1 was added to 500c.c.
0.26 mo/
The carrier was impregnated with 75 c.c. of barium nitrate solution (PH4.9) dropwise at room temperature. After that, dry it in a dryer using the usual method, and then dry it in a Matsufuru oven for 800
C. for 3 hours to support barium oxide on the alumina support. 100 g of this barium oxide-supported alumina carrier was impregnated with 75 c.c. of a 2.53 mo/nickel nitrate solution (PH 1.7) dropwise. After standing still for 12 hours, dry in the usual manner and heat in the air at 500 °C in an electric furnace.
C. for 3 hours to obtain catalyst B. Hydrogen activity of this catalyst B (benzene disappearance rate)
was measured in the same manner as in Comparative Example 1. The results are shown in Table 1. Examples 2 to 9 In Example 1, lithium oxide, sodium oxide, potassium oxide, cesium oxide, magnesium oxide, calcium oxide,
Catalysts C ₁ to _{C 8} were obtained in the same manner as in Example 1 except that strontium oxide and zinc oxide were supported. The hydrogen activity (benzene disappearance rate) of this catalyst (C ₁ to C ₈ ) was measured in the same manner as in Comparative Example 1. The results are shown in Table 1. Example 10 100 g of the catalyst A prepared in Comparative Example 1 was placed in a 500 c.c. beaker, and 75 c.c. of 0.26 mo/barium nitrate solution (PH4.9) was added dropwise at room temperature while shaking and impregnating the beaker. After standing at room temperature for 12 hours, it was dried by a conventional method and calcined in air at 500° C. for 3 hours in an electric furnace to obtain catalyst D. Hydrogen activity of this catalyst D (benzene disappearance rate)
was measured in the same manner as in Comparative Example 1. The results are shown in Table 1. Example 11 500 g of γ-alumina powder was placed in a stirrer kneader, and a small amount of pure water was added. Separately, 25.6 g of barium nitrate was dissolved in 500 c.c. of pure water, and this was added little by little to the alumina while stirring. This paste was heated while being kneaded to adjust the water content to about 20% by weight, molded using a screw extruder, dried and fired at 800°C for 3 hours to prepare barium oxide-supported alumina. Catalyst E was prepared by impregnating this barium oxide-supported alumina carrier (water absorption rate: 0.75 cc/g) with a nickel nitrate solution in the same manner as in Example 1, followed by drying and calcining. Hydrogen activity of this catalyst E (benzene disappearance rate)
was measured in the same manner as in Comparative Example 1. The results are shown in Table 1. Example 12 500 g of γ-alumina powder was placed in a stirring kneader, and a small amount of pure water was added. Then barium nitrate
25.6g of 500c.c. solution and nickel nitrate 2.53mo/
75 c.c. of the solution was added little by little to the above alumina while stirring. This paste was heated while being kneaded to adjust the water content to about 20% by weight, molded using a screw type extrusion molding machine, dried and calcined at 500°C for 3 hours to prepare catalyst F. Hydrogen activity of this catalyst F (benzene disappearance rate)
was measured in the same manner as in Comparative Example 1. The results are shown in Table 1. Example 13 Same alumina carrier 100 as used in Comparative Example 1
g was placed in a 500 c.c. beaker, and 75 c.c. of a 0.26 mo/barium hydroxide solution was added dropwise to the carrier in the same manner as in Example 1 to impregnate it. Thereafter, it was dried in a dryer using a conventional method, and then calcined in a Matsufuru furnace at 800°C for 3 hours to support barium oxide on the alumina support. Alumina carrier supporting this barium oxide
100 g of the carrier was impregnated with 75 c.c. of a 2.53 mo/nickel nitrate solution by dropping it onto the carrier. After leaving it for 12 hours, dry it by the usual method and heat it in the air at 500 °C in an electric furnace.
C. for 3 hours to prepare catalyst G. Hydrogen activity of this catalyst G (benzene disappearance rate)
was measured in the same manner as in Comparative Example 1. The results are shown in Table 1.

[Table] Examples 14 to 16 The concentration of the barium nitrate solution in Example 1 was changed to make the barium oxide content relative to the weight of alumina 0.6% by weight, 1.5% by weight, and further 0.39mo
/ barium nitrate solution 150c.c. on alumina carrier
By impregnating 100 g in two portions, catalysts each having a barium oxide content of 9% by weight were obtained. Catalyst HIJ was obtained by supporting these catalysts on nickel oxide in the same manner as in Example 1. The hydrogen activity (disappearance rate of benzene) of this catalyst HIJ was measured in the same manner as in Comparative Example 1, and the dissipation rate of toluene was also measured.
Shown in the figure. In addition, catalyst A of Comparative Example 1, Example 1
The benzene and toluene disappearance rates of catalyst B are also shown.

[Table] Example 17 When the nuclear hydrogenation reaction of benzene was carried out using the catalyst I obtained in Example 16, 145
Catalytic activity (benzene disappearance rate) remains unchanged even after time elapses.
3.4×10 ^-3 benzene mo/catalyst g. The min value was maintained and there was no change at all. As shown in the above examples and comparative examples,
The catalyst of the present invention, which contains alumina, nickel oxide, and oxides of alkali metals, alkaline earth metals, and zinc in specific proportions, has higher catalytic activity than conventional catalysts made of alumina and nickel oxide. It is excellent. In addition, in the catalyst of the present invention, especially one using barium oxide as the oxide has excellent catalytic activity. Furthermore, as a supporting method, an impregnation method is preferable, and in particular, a catalyst obtained by impregnating the catalyst with an alkali metal, an alkaline earth metal, a zinc salt, and a nickel salt in this order is most excellent. Furthermore, the catalyst of the present invention has good durability as shown in Example 17.

[Brief explanation of the drawing]

Figures 1 and 2 respectively show the
It is a graph showing the relationship between the content of BaO, the rate of disappearance of benzene, and the rate of disappearance of toluene with respect to the weight of Al ₂ O ₃ .

Claims (1)

[Claims] 1 100 parts by weight of alumina and 5 to 20 parts by weight of nickel oxide
1. A catalyst for the hydrogenation of aromatic hydrocarbons, comprising: 1 part by weight, and 0.3 to 9 parts by weight of one or more selected from oxides of alkali metals, alkaline earth metals, and zinc. 2. The aromatic hydrocarbon nuclear hydrogenation catalyst according to claim 1, wherein the oxide is barium oxide. 3. The aromatic hydrocarbon hydrogenation catalyst according to claim 1 or 2, wherein the content of the oxide is 0.4 to 6 parts by weight. 4. The aromatic hydrocarbon nuclear hydrogenation catalyst according to claim 1, 2 or 3, wherein the nickel oxide and oxide are supported on alumina by an impregnation method. 5. Claim 4, wherein the nickel salt solution and the alkali metal, alkaline earth metal, and zinc salt solutions used when supporting nickel oxide and oxides on alumina by an impregnation method are acidic liquids. catalyst for the nuclear hydrogenation of aromatic hydrocarbons.