JPS6155419B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalyst for the hydrogenation reaction of alkylene oxide and a method for producing the same. Specifically, the present invention relates to a catalyst for producing a corresponding alkanol by hydrogenating an alkylene oxide having 2 to 5 carbon atoms in a liquid phase in the presence of hydrogen, and a method for producing the same.

It has been known that alkylene oxides having 2 to 5 carbon atoms, such as ethylene oxide and propylene oxide, are reduced to corresponding alkanols by a hydrogenation catalyst in the presence of hydrogen. For example, in German Patent No. 563,625, 80
It is stated that ethanol can be obtained by hydrogenation reaction at ℃.

However, when alkylene oxide is in the liquid phase,
No catalyst has yet been found that can be used industrially and stably at a high level for hydrogenation reactions at temperatures of 50 to 250° C. under hydrogen pressures of normal pressure to 200 kg/cm ² G. For example, the Raney-Nickel type catalyst used in general liquid phase hydrogenation reactions shows quite high activity in this type of reaction, but at the same time, a large amount of alkylene oxide polymer is produced due to side reactions, which weakens the catalyst. It has been found that poisoning leads to a significant decrease in activity and a decrease in the yield of the target product, alkanol. Furthermore, nickel-diatomaceous earth catalysts, which are generally used in industrial hydrogenation reactions, not only have a low selectivity for the alkanol produced, but also have a low selectivity when used as a fixed-bed catalyst in the liquid phase.
Since this catalyst is a molded product, its physical durability is extremely poor, and it begins to disintegrate after several days to several tens of days of continuous operation, making it unsuitable for use as a catalyst for liquid phase applications. The same applies to the catalyst in the above German patent.

On the other hand, as a supported hydrogenation catalyst with relatively high mechanical strength, a shaped gamma (γ)-alumina support is impregnated with metal salts of nickel, copper, and manganese, which become metal oxides by thermal decomposition, and is supported in air. Among them, a catalyst which is calcined at a high temperature of 250 to 500°C, preferably about 375° to 425°C, and then reduced in a hydrogen stream has been reported (see the specification of Japanese Patent Publication No. 15997/1983). If such a manufacturing process is carried out, a catalyst with high strength will certainly be obtained. However, γ-
It has been found that when alumina is used as a carrier in the liquid phase hydrogenation reaction of alkylene oxides, it gradually loses its activity due to the formation of by-products such as polymers, similar to the Raney type catalyst mentioned above. It is.

In view of the current situation, the present inventors have hereby proposed a method that exhibits stable and high activity in the reaction of alkylene oxide and hydrogen to produce the corresponding alkanol in the liquid phase, and has excellent physical durability.
The present invention was completed by developing a catalyst that has a long life and enables long-term production on an industrial scale.

That is, the present invention is a catalyst for hydrogenating alkylene oxide in the liquid phase, which is made by supporting nickel, copper, and chromium in the form of metals or oxides on an α-alumina carrier. Approximately 2 to 20% by weight in terms of element, preferably approximately 3 to 12% by weight, copper approximately 0.05% in terms of element
-3% by weight, preferably about 0.1-2% by weight, and more preferably about 0.05-3% by weight, preferably about 0.1-2% by weight of chromium in terms of element, and more preferably is the finished catalyst
The catalyst has a BET specific surface area adjusted to a range of about 2 to 30 m ² /g. In addition, a preferred α-alumina carrier has a bulk density of about 0.6 to 1.5 g/cc and a water absorption rate of 15 to 1.5 g/cc.
60% and a BET specific surface area in the range from 0.01 to 10 m ² /g is used. α here
-Alumina carrier is mainly composed of α-alumina, which maintains sufficient physical stability under the above reaction conditions and is itself inert to the reaction, and is generally used as a binder for the carrier. Although there is no particular problem even if small amounts of oxides such as silicon, alkali metals, and alkaline earth metals used as oxides are contained, it is not preferable that active alumina components such as γ-alumina are contained. As mentioned above, because of its activity, it polymerizes alkylene oxide, and the polymer poisons the catalyst. The carrier may be in various shapes such as pellets, granules, and spheres.

In the catalyst of the present invention, all three elements, nickel, copper, and chromium, are essential, and a highly active catalyst cannot be obtained with nickel alone or a combination of nickel-copper or nickel-chromium.
Furthermore, supporting a metal in an amount exceeding the above-mentioned limit does not contribute to improving the activity at all, and may even adversely affect the selectivity of alkanol.
On the other hand, if the amount of metal supported is below the limit range, the activity will be significantly reduced.

The catalyst of the present invention is produced as follows.
The above α-alumina support is immersed in an aqueous medium in which nickel, copper and chromium compounds are dissolved, and the required amount is supported at 50-150°C, preferably 100-150°C.
Dry at 120℃, then dry at about 250~450℃
C., preferably in the temperature range of 270 DEG to 330 DEG C., with hydrogen or hydrogen-containing gas to obtain the finished catalyst.
In this case, the drying treatment must be performed at a temperature of 150° C. or lower, and heat treatment at temperatures exceeding 200° C. must be avoided in air or in a nitrogen stream. This is because, for example, if the force calcining process in air at 300°C is reduced, the specific surface area of the catalyst will be smaller and the hydrogenation activity will be significantly lower than that of the catalyst produced by the method of the present invention. Because it was discovered.

As the nickel, copper, and chromium compounds, water-soluble salts such as nitrates, acetates, and formates are preferably used, and nitrates with high solubility are particularly advantageous. This is because it is easiest to adjust the concentration for supporting the desired amount of each metal on the α-alumina support. Reduction treatment with hydrogen gas is performed using hydrogen gas.
Although it is preferable to use 100% hydrogen, it may also be performed using a hydrogen-containing gas diluted with an inert gas such as nitrogen or methane. In order to achieve the amount of metal supported within the above-mentioned limits, it is usually sufficient to carry out the above-mentioned impregnation, drying and reduction operations once, but in some cases they may be repeated several times.

The catalyst produced by the above method of the present invention has excellent hydrogenation activity and mechanical strength, and can be used as a catalyst for general continuous liquid phase hydrogenation reactions. In addition, it exhibits particularly stable and excellent activity selectivity, and enables long-term continuous production on an industrial scale, which has not been possible in the past.

The hydrogenation reaction of alkylene oxide using the catalyst of the present invention is carried out at a temperature of about 50 to 250°C, preferably about 80 to 250°C.
The reaction can be carried out at 200° C. and at a hydrogen pressure of normal pressure to 200 Kg/cm ² G, preferably about 20 to 100 Kg/cm ² G. The solvent used as a raw material diluent for this reaction is not particularly limited as long as it does not participate in the reaction, and various solvents such as dioxane, tetrahydrofuran, ethers consisting of low-paying alkyl groups having 1 to 8 carbon atoms, benzene, and cyclohexane can be used. From among them, an appropriate selection is made taking into account the difficulty of recovering and separating the product from the product.

In addition to alkanol as the main product, the products of this reaction include some glycol ethers as by-products, and trace amounts of glycols and decomposed gases such as methane and ethane are also detected.

The following examples further illustrate the excellent properties of the catalyst according to the invention and illustrate its preparation as well as the hydrogenation reaction of alkylene oxides. All percentages are by weight unless otherwise indicated.

Example 1 α-alumina carrier made into pellets (bulk specific gravity
1.3, water absorption rate 24%, BET specific surface area 3m ² /g) 2.5
was heated at 100°C in a rotary blender and degassed. On the other hand, Ni(NO ₃ ) ₂・6H ₂ O892g, Cu
(NO ₃ ) ₂・3H ₂ O34g, Cr(NO ₃ ) ₃・9H ₂ O69g
A solution obtained by adding 190 ml of water and dissolving it by heating was added, and impregnation and drying were performed by keeping the mixture at 100° C. and mixing by rotating for one and a half hours. This catalyst was immediately reduced at 305° C. for 6 hours by flowing pure hydrogen at 0.15 N/hour per gram of catalyst at normal pressure. The metal content of this catalyst was 5.1% nickel, 0.25% copper, and 0.25% chromium. The BET specific surface area of the catalyst is 8
m ² /g.

75 g of dioxane, 25 g (0.57 mol) of ethylene oxide, and 10 ml (13.7 mol) of the above catalyst were placed in a stainless steel autoclave with an internal volume of 0.5 and equipped with an electromagnetic stirrer.
g) was charged, the pressure was adjusted to 70 Kg/cm ² G with hydrogen gas, and the reaction was carried out at 120° C. for 2 hours. Analysis of the reaction product liquid showed that the conversion rate of ethylene oxide was 98% and the ethanol selectivity was 90%. As for by-products other than ethanol, mono-, di-, and triethylene glycol ethyl ether produced by the reaction between ethanol and raw material ethylene oxide have a total selectivity of 6%, ethylene glycols have a selectivity of 2%, and ethylene oxide polymer has only a trace. Other decomposed gases (methane, ethane, etc.) were also observed.

Here, the conversion rate and selectivity are defined as follows.

Conversion rate = Number of moles of alkylene oxide introduced - Number of moles of unreacted alkylene oxide / Number of moles of alkylene oxide introduced × 100 Selectivity = Number of moles of alkylene oxide converted to the product / Consumed in the reaction Number of moles of total alkylene oxide x 10
0 Example 2 725 ml (990 g) of the same catalyst obtained in Example 1
Continuous experiments were carried out on the alkanol production reaction between ethylene oxide and hydrogen using ethylene oxide as a fixed bed catalyst.
A raw material containing 25% ethylene oxide using dioxane as a diluent was supplied at a feed rate (SV) of 2.0 g (raw material)/ml (catalyst) at 130°C under a hydrogen pressure of 50 Kg/cm ² G, and hydrogen was fed in parallel with this. The reaction was carried out by supplying 180 N/hour. Analysis of the composition of the produced liquid and gas at the reactor outlet revealed that the initial conversion rate of ethylene oxide was 99% and the selectivity of each product was as follows.

Ethanol 89% Glycol ethers 7% Ethylene glycols 2% Cracking gas 1% Ethylene oxide polymer 1% Even if this reaction was continued under the same conditions for about 3 months, there was no change in the activity or selectivity of the catalyst, and the catalyst itself The physical appearance of the material was not contaminated with polymer, and no crushing or pulverization occurred.

Example 3 For 120 ml of spherical α-alumina carrier (bulk specific gravity 1.0, water absorption rate 35%, BET specific surface area 5 m ² /g),
Ni (NO ₃ ) ₂・6H ₂ O42.8g, Cu (NO ₃ ) ₂・3H ₂ O1.6
The catalyst was impregnated with a solution prepared by adding 15 ml of water to 3.3 g of Cr(NO ₃ ) ₃ ·9H ₂ O and dissolving it under heating, followed by drying and reduction under the same conditions as in Example 1 to obtain a catalyst. The metal content of this catalyst is 6.4% nickel, 0.3% copper, and 0.3% chromium.
%, and the BET specific surface area was 9.5 m ² /g.

10 ml (10.7 g) of this catalyst was taken and reacted in an autoclave under the same reaction conditions as in Example 1.
The conversion rate of ethylene oxide was 98% and the ethanol selectivity was 88%.

Example 4 For 300 ml of the same carrier used in Example 1,
Ni (NO ₃ ) ₂・6H ₂ O107.0g, Cu (NO ₃ ) ₂・
A solution prepared by adding 24 ml of water to 8.2 g of 3H ₂ O and 8.3 g of Cr(NO ₃ ) ₃ ·9H ₂ O and dissolving them under heating was impregnated, dried, and then reduced at 270° C. for 6 hours. The metal content of this catalyst is 5.0% nickel, 0.5% copper, and 0.3% chromium.
%, and the BET specific surface area was 8.5 m ² /g.

10 ml (10.7 g) of this catalyst was taken and reacted in an autoclave under the same reaction conditions as in Example 1. The ethylene oxide conversion rate was 97% and the ethanol selectivity was 88%.

Example 5 Using the same carrier as used in Example 1, the same impregnation, drying and reduction operations were repeated twice to obtain a catalyst. The content of each metal in this catalyst is nickel 10.0%,
The content was 0.5% copper and 0.5% chromium, and the BET specific surface area of the catalyst was 13 m ² /g.

10 ml (14.4 g) of this catalyst was taken and reacted in an autoclave under the same reaction conditions as in Example 1. The ethylene oxide conversion rate was 99% and the ethanol selectivity was 91%.

Example 6 For a spherical α-alumina carrier (bulk specific gravity 0.92, water absorption rate 27%, BET specific surface area 0.3 m ² /g) 2.5,
Ni (NO ₃ ) ₂・6H ₂ O714g, Cu (NO ₃ ) ₂・3H ₂ O27.2
A solution prepared by adding 152 ml of water to 55.2 g of Cr(NO ₃ ) ₃ ·9H ₂ O and dissolving it under heating was impregnated and dried in the same manner as in Example 1, and then hydrogen was added at 0.3 N/h per 1 g of catalyst. It was reduced by circulation at 295°C for 6 hours. This operation was repeated twice to obtain the final catalyst.
The metal content of this catalyst is nickel 10.9%, copper
0.54% and chromium 0.54%. BET specific surface area is
It was 7.5m ² /g.

Using 725 ml of this catalyst as a fixed bed catalyst, Example 2
The reaction was carried out under the same reaction conditions. At a conversion rate of ethylene oxide of 97%, the selectivity of each product was as follows.

Ethanol 90% Glycol ether 7% Ethylene glycol 2% Others 1% Even if this reaction was carried out under the same conditions for about 3 consecutive months, there was no change in the activity or selectivity of the catalyst, and no change was observed in the physical appearance of the catalyst. I couldn't help it.

Claims (1)

[Claims] 1. A catalyst for hydrogenating alkylene oxide in a liquid phase, which comprises nickel, copper and chromium supported in the form of metals or oxides on an α-alumina carrier. 2 Approximately 2 to 20 nickels per finished catalyst in elemental terms
2. The catalyst according to claim 1, wherein copper is supported in an amount of about 0.05 to 3% by weight in terms of element, and further chromium is supported in an amount of about 0.05 to 3% by weight in terms of element. 3 Approximately 3 to 12 nickels per finished catalyst in elemental terms
The catalyst according to claim 1, wherein copper is supported in an amount of about 0.1 to 2% by weight in terms of element, and further chromium is supported in an amount of about 0.1 to 2% by weight in terms of element. 4. The catalyst according to claim 1, having a BET specific surface area in the range of about 2 to 30 m ² /g. 5 Bulk density is approximately 0.6 to 1.5 g/cc, water absorption rate is approximately 15 to 60
% and a BET specific surface area of approximately 0.01 to 10 m ² /g. 6. Nickel, copper, and chromium compounds are impregnated and supported on an α-alumina carrier, dried at 50 to 150°C, and then reduced with hydrogen or hydrogen-containing gas at a temperature range of approximately 250 to 450°C. A method for producing a catalyst for liquid phase hydrogenation of alkylene oxide.