JPH0236135A - Production of alcohol - Google Patents

Abstract

PURPOSE:To obtain an alcohol by hydrogenating a carboxylic ester in the presence of a catalyst prepared by reduction of a compound metal oxide containing CuO, ZnO, MoO3 and/or WO3 or containing an alkaline (earth) metal oxide, iron family metal oxide, etc., other than the above-mentioned oxides. CONSTITUTION:A carboxylic ester is reacted with hydrogen under 50-300kg/cm2 hydrogen pressure at 150-300 deg.C in the presence of a catalyst prepared by reduction of a compound metal oxide represented by formula I (AO is MoO3 and/or WO3, a is 55-75wt.%; b is 25-45wt.%; c is 0.1-10wt.%) or formula II [BO is oxide of alkaline (earth) metal, iron family metal, etc.; a', b' and c' are respectively synonymous with a, b and c; d' is 0.1-8wt.%] to prepare an alcohol. The above-mentioned catalyst has durability against poisoning by trace impurities in the raw materials or heat deterioration in a high-activity state. The catalyst is prepared by the coprecipitation method, etc., where a precipitant is added to an aqueous mixture solution of respective metal salts.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method for producing alcohol, and more specifically to a method for producing a carboxylic acid ester using a catalyst obtained by reducing a composite metal oxide having a specific composition. It relates to a method for hydrogenating and producing the corresponding alcohols.

[Prior Art and Problems to be Solved by the Invention] Many methods have been disclosed since the 1930s for producing aliphatic alcohols, alicyclic alcohols, or aromatic alcohols by hydrogenating carboxylic acids or carboxylic acid esters. It's coming. However, most of the industrial methods for hydrogenating carboxylic acid esters to produce the corresponding alcohols use copper-chromium catalysts under reaction conditions at low temperatures and high pressures. This is not only an economic disadvantage due to the harsh reaction conditions, but also a disadvantage in terms of the use of chromium, and there is a call for the development of a chromium-free catalyst to replace the copper-chromium catalyst. There is.

Several attempts have been made to obtain the corresponding alcohol by hydrogenating carboxylic acid esters using a copper-zinc composite oxide catalyst as a catalyst to replace the copper-chromium catalyst; Oxide catalysts are generally inferior to copper-chromium catalysts in terms of poisoning due to impurities in the raw material ester and thermal stability of the catalyst, and are insufficient in terms of catalyst durability.

(Means for Solving the Problems) Therefore, the present inventors developed a method for hydrogenating a carboxylic acid ester to produce a corresponding alcohol using a copper-zinc composite oxide catalyst having high activity and high catalyst durability. As a result of intensive research to find out, we were able to obtain the knowledge that the following catalysts are suitable for the purpose.

That is, the following formula (I) or (II) (I) (CuO), (Zr+0)JAO').

^0: Mo01 and/or WO.

a: 55-75% by weight b: 25-45% by weight c: 0.1-10% (H) (Cub)-・(ZnO)b・(AO)-・
(BO': Ja・AO: Moot and/or -〇.

BO: Oxide of one or more metals selected from alkali metals, alkaline earth metals, and iron group metals a": 55 to 75% by weight b': 25 to 45% by weight c': 0.1 to 10% by weight % d': 0.1 to 8% by weight The catalyst obtained by reducing the composite metal oxide is poisoned by trace impurities in the raw material ester, which was insufficient with conventionally known copper-zinc catalysts. Alternatively, the present invention was completed by obtaining the result that the catalyst has a high degree of durability while maintaining high activity against thermal deterioration.

That is, the present invention provides a method for producing alcohol, which comprises bringing a carboxylic acid ester into contact with hydrogen in the presence of a catalyst obtained by reducing a composite metal oxide represented by the above formula (I) or (II). It provides:

Several attempts have been made to improve catalyst durability by adding a third metal component to a copper-zinc composite oxide catalyst. For example, [Industrial Chemistry Journal, Vol. 53, 7
4 (1950)] reported that in the hydrogenation reaction of Mamatzkola barley, the durability of the catalyst was improved by adding a small amount of chromium oxide to a copper oxide-zinc oxide catalyst supported on diatomaceous earth. However, in this case, the use of chromium is disadvantageous in practice.

JP-A-53-133594 discloses that a coprecipitated cobalt-zinc-copper oxide catalyst is superior in stability to a coprecipitated copper-zinc oxide catalyst in the hydrogenation reaction of polyglycolate to ethylene glycol. Although it is stated,
Despite using a large amount of catalyst, high activity has not been obtained.

Furthermore, in JP-A No. 54-32191, a hydrogenation reaction of coconut fatty acid methyl ester was conducted using a copper oxide-copper molybdate-zinc oxide catalyst, which is one of the above-mentioned composite metal oxides disclosed by the present inventors. However, as the reaction is carried out at high temperatures, sufficient activity is not obtained.
Furthermore, there is no mention of catalyst durability.

In any of the above production methods, in the method of hydrogenating a higher fatty acid ester to produce the corresponding higher aliphatic alcohol, high activity is achieved against poisoning by trace impurities in the raw material ester or thermal deterioration of the catalyst. Up to now, there has been no known example of a copper-zinc-based composite oxide catalyst that maintains its properties and has a high degree of durability. Here, in the specification of German Patent DE 3443277^1, "in the copper-zinc catalyst, Fe, C0. Ni, Ru, Rh, Pd,
Os, [r.

■He group elements such as pt, Cr, M0. - such as V
If 0.1% or more of group IA elements, elements such as Tc+Ag, Re+Au, and ca, or elements with atomic numbers of 80 or higher such as Ilg and Pb are present, side reactions such as hydrogenolysis may occur, or they may become catalyst poisons. Catalytic activity is lost. When considering the statement ``, by adding a third component to the copper-zinc composite oxide catalyst, a high degree of catalyst durability during alcohol production can be achieved while maintaining the original high activity of the copper-zinc catalyst. I never expected it to be possible.

The method for producing the catalyst composition according to the present invention is not particularly limited, and it can be prepared by a known method. For example, a catalyst precursor obtained by drying and calcining a precipitate obtained by a coprecipitation method in which a precipitant is added to a mixed aqueous solution of each metal salt constituting a composite metal oxide, or each oxide or hydroxide. , a catalyst precursor obtained by uniformly mixing and calcining compounds such as carbonates, carboxylates, metal alcoholades, or nitrates, and further adding other remaining components to at least one or more metal oxides constituting the catalyst precursor. It is prepared by a method in which a catalyst precursor obtained by impregnating and supporting, drying, and firing is reduced with a reducing substance.

The compound composition of the composite metal oxide that is the catalyst precursor is 55 to 75% by weight as copper oxide, 25 to 45% by weight as zinc oxide, and 0% as molybdic acid and/or tungstic acid.
01 to 10% by weight, preferably 0.3 to 2% by weight.

Furthermore, the fourth catalyst component, an oxide of one or more metals selected from alkali metals, alkaline earth metals, and iron group metals, is added to zero.
．． It can also contain 1-8%. Here, the oxide of one or more metals selected from alkali metals, alkaline earth metals, and iron group metals, which is the fourth catalyst component, includes sodium oxide, calcium oxide, cobalt oxide, potassium oxide,
Examples include cesium oxide, magnesium oxide, barium oxide, iron oxide, and nickel oxide.

When preparing a composite metal oxide, which is a catalyst precursor, by a co-precipitation method, any metal salt can be used as long as it is water-soluble; however, for boat fishing, sulfates, nitrates,
Ammonium complex salts, acetates or chlorides are used. Furthermore, as water-soluble salts of tungstic acid compounds and molybdic acid compounds, in addition to sodium salts, ammonium salts such as ammonium paratungstate and ammonium baramolybdate can be used.

Furthermore, the water-soluble metal salts described above can also be used when preparing by impregnation method.

Such catalyst precursors may include known catalysts such as diatomaceous earth, alumina, silica gel, silica-alumina, magnesia, calcia, zirconia, titania, chromia, zinc oxide, yttrium oxide, thorium oxide, etc., to the extent that activity or selectivity is not significantly impaired. There is no problem in using it after reducing it while it is supported on a carrier or in a state where it is homogeneously mixed with the carrier. Further, when supporting the catalyst precursor on the above-mentioned carrier, examples include a method of supporting the catalyst precursor by a coprecipitation method, a method of supporting the catalyst precursor by impregnating it with an aqueous solution of a metal salt as a catalyst component, and the like. Although the supported amount is not particularly limited, it is preferably 10 to 200% of the carrier weight.

In addition, graphite, fatty acid salts, starch, Fh oil, talc, bentonite, alkali metal salts, alkaline earth metal salts, etc. may be used to improve the strength of the catalyst, within a range that does not impair the effects of the present invention.
A trace amount of a third component may be added.

When preparing a metal composite oxide, which is a catalyst precursor, by a coprecipitation method, it is important to select the preparation pH and calcination temperature. For example, it is desirable that the preparation pH be 2 to 11 and the firing temperature be 300 to 600°C.

Next, when reducing the catalyst precursor with a reducing substance, either a gas phase reduction method or a liquid phase reduction method performed in a solvent such as a hydrocarbon such as liquid paraffin, dioxane, an aliphatic alcohol, or a fatty acid ester is used. May be used. For example, when reducing using hydrogen gas, 100 to 800
'C1 It is preferable to carry out the reaction at a temperature of preferably 150 to 500° C. until water generation is no longer observed or hydrogen absorption is no longer observed. In particular, when reduction is carried out in a solvent, it is desirable to carry out the reduction until no hydrogen absorption is observed at a temperature of 150 to 350°C. There is no problem in using the usual activation method of heating, reducing, and directly subjecting to the reaction.

In addition to the aforementioned hydrogen, the reducing substances used to reduce the catalyst precursor include carbon monoxide, ammonia, hydrazine, formaldehyde, and lower alcohols such as methanol, and these reducing substances may be used alone or in combination. May be used in any condition. Further, it may be used diluted with an inert gas such as nitrogen, helium, or argon, or in the presence of a small amount of water vapor.

In the method of the present invention, it is possible to use a solvent when hydrogenating a carboxylic acid ester, for example, by a liquid phase suspended bed reaction method, but in consideration of productivity, the reaction may be carried out without a solvent. is desirable. As the solvent, one is selected that does not adversely affect the reaction of alcohol, dioxane, hydrocarbon, or the like.

The amount of catalyst is 0.1 per 100 parts by weight of carboxylic acid ester.
-20 In-fft parts is preferred, but it can be arbitrarily selected within a range that provides a practical reaction rate depending on the reaction temperature or reaction pressure.

The reaction temperature is generally selected to be 150 to 300'C. Hydrogen pressure is 1 to 350 kg/cm2, but 5
It is preferable to conduct the reaction at 0 to 300 kg/cmz from the viewpoint of alcohol yield and reaction rate.

Furthermore, by forming the catalyst of the present invention into granules, tablets, cylinders, etc., it becomes possible to hydrogenate carboxylic acid esters in a fixed bed reaction system or even in a fluidized bed reaction system.

Both the carboxylic acid moiety and the alcohol moiety of the carboxylic acid esters to be hydrogenated according to the present invention may be aliphatic, aromatic or alicyclic compounds, and may form a lactone within the molecule. Further, the molecule may have another functional group such as a double bond or a hydroxyl group.

Furthermore, carboxylic acid esters derived from naturally occurring substrates such as soybean oil, sunflower oil, bean oil, coconut oil, palm oil, palm kernel oil and beef tallow are preferably used in the process of the invention.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these Examples.

Example 1 (Sodium tungstate, impregnation method) (]
) Catalyst Preparation After heating a mixed aqueous solution of copper nitrate and zinc nitrate to 90 to 100°C in which the weight ratio of copper oxide and zinc oxide is 7:3, a 10% by weight aqueous sodium carbonate solution was added as a precipitant. By gradual addition, a slurry having a pH of about 9 was obtained. The precipitate was filtered from this slurry and thoroughly washed with water to obtain a precipitate cake in which the weight ratio of copper oxide to zinc oxide was 7:3.

Next, 71.1 mg of sodium tungstate dihydrate
An amount equivalent to 10 g of the above precipitate cake after firing was added to an aqueous solution prepared by dissolving 500 °C in distilled water, and after stirring thoroughly, the water was evaporated to dryness and dried at 110 ° C. Copper oxide-zinc oxide-sodium tungstate (Cu deposited ZnO: W(
h: Na, 0=69.5: 29.8: 0.5
5:0.15 (weight ratio)) composite metal oxide was obtained. The obtained catalyst precursor is designated as A.

(2) Catalyst durability evaluation 7.5 g of the above catalyst precursor A and 150 g of methyl laurate
0.5! In a rotating stirring autoclave, hydrogen pressure 100
kg/co+2 and a temperature of 200°C for 5 hours. At this time, water produced by reduction of the catalyst was removed from the system by blowing hydrogen at 30 minute intervals. After completion of the reduction, a reduced catalyst was obtained from the resulting slurry by centrifugation.

Coconut fatty acid methyl ester (saponification value (SV) = 253.
9) Charge 150 g and the entire amount of the reduction catalyst into a 0.51 rotation stirring autoclave, and set the hydrogen pressure to lo.

kg/cm”, temperature 240°C, stirring speed 800 rpm
It reacted for 1 hour. The resultant alcohol and catalyst were separated by centrifuging the reaction mixture. The saponification value of the product alcohol was measured and found to be 107.5. Using the entire amount of the recovered catalyst, the reduction reaction of coconut fatty acid methyl ester was repeated nine times according to the same reaction method as above, and the saponification value of the product alcohol was measured. The results obtained are shown in Table 1.

Table 1 In the reaction in this example, the rate of decrease in saponification value per minute of reaction time is used as a measure of catalyst activity. That is, it is expressed as =2.44/min.

In addition, 1. The slope of the straight line obtained by displaying the results in Table 1 on a graph with the saponification value decreasing rate on the vertical axis and the number of collections on the horizontal axis is used as a measure of catalyst durability, and the smaller the slope of the straight line, the more , indicating good catalyst durability. A straight line graph obtained by plotting the results in Table 1 above is shown in FIG.

Example 2 (Copper tungstate, kneading method) An amount equivalent to 10 g after firing of the precipitation cake in which the weight ratio of copper oxide and zinc oxide of Example 1 was 7:3 to 100 mg of copper tungstate prepared separately. After adding and kneading thoroughly, 110°
It was dried at 4.50°C and fired at 4.50°C for 2 hours. The obtained catalyst precursor is designated as B. B was reduced according to the method of Example 1, and its activity and durability were evaluated.

The results are shown in Table 2.

Example 3 (1-lium molybdate, impregnation method) A catalyst precursor was prepared by the impregnation method in the same manner as in Example 1, using sodium molybdate dihydrate 168.1a+g instead of sodium tungstate dihydrate. Body C was obtained. C was reduced according to the method of Example 1, and the activity and durability were evaluated.

The results are shown in Table 2.

Example 4 (Copper molybdate, kneading method) A catalyst precursor was obtained by the kneading method in the same manner as in Example 2, using 100 mg of copper molybdate prepared separately instead of copper tungstate. D was reduced according to the method of Example 1, and its activity and durability were evaluated.

The results are shown in Table 2.

Example 5 (Calcium tungstate, kneading method) Catalyst precursor E was obtained by the cross-wire method in the same manner as in Example 2, using 100 mg of separately prepared calcium tungstate instead of copper tungstate.

E was reduced according to the method of Example 1, and its activity and durability were evaluated.

The results are shown in Table 2.

Example 6 (Cobalt molybdate, kneading method) Catalyst precursor F was obtained by the kneading method in the same manner as in Example 2, using 100 mg of separately prepared cobalt molybdate instead of copper tungstate. F was reduced according to the method of Example 1,
Activity and durability were evaluated.

The results are shown in Table 2.

Comparative Example 1 (No Additives) The precipitation cake of Example 1 in which the weight ratio of copper oxide and zinc oxide was 7:3 was dried at 110°C and further calcined at 450"C for 2 hours to prepare catalyst precursor G. G was reduced according to the method of Example 1, and the activity and durability were evaluated.

The results are shown in Table 2.

Comparative Example 2 Weight ratio of copper oxide, zinc oxide and cobalt oxide is 66
．． After heating a mixed aqueous solution of copper nitrate, zinc nitrate, and cobalt nitrate with a ratio of 5:28.5:5 to 90 to 100°C, a 10% by weight aqueous solution of lium carbonate as a precipitant was gradually added. By doing so, a slurry having a pH of about -9 was obtained. The precipitate was filtered from this slurry and thoroughly washed with water to obtain a precipitate cake in which the weight ratio of copper oxide, zinc oxide, and cobalt oxide was 66.5:28.5:5. This cake was dried at 110℃ and further dried at 450℃.
It was fired for 2 hours at ``C''.

The obtained catalyst precursor is designated as H. H was reduced according to the method of Example 1, and activity and durability were evaluated.

The results are shown in Table 2.

From the comparison of the results shown in Table 2, M0. - The excellent catalyst durability of the added catalyst is evident.

Furthermore, regarding the recovered catalysts of Example 1.4 and Comparative Example 1, Cu
Table 3 shows the results of measuring the X-ray average particle diameter and BET surface area.

The mixture was added to a 300 ml aqueous solution of 204 mg (Table 3) and thoroughly stirred, and the water was evaporated to dryness, dried at 110°C, and further calcined at 450°C. The obtained catalyst precursor is designated as I. After reducing (2) according to the method of Example 1 to obtain a reduction catalyst, the reduction reaction of coconut fatty acid methyl ester was repeated 8 times in the same manner as in Example 1, and the saponification value of the product alcohol was measured.

The measurement results are shown in Table 4.

Further, Table 5 shows the composition of catalyst precursor I and the evaluation results of catalyst durability.

Table 4 As is clear from Table 3, M0. The W-added catalyst has a small increase in Cu particle size and a small decrease in surface area due to the reaction, and is thermally stabilized.

Example 7 18.28 g of copper adipate (7 g as copper oxide weighed after firing) and 7.72 g of zinc adipate (3 g as zinc oxide weighed after firing) were compared with newly prepared ammonium paratungstate (as tungsten oxide). Example 3 Copper adipate and zinc adipate of Example 7 were thoroughly kneaded and then calcined at 450'C. The resulting catalyst precursor was designated as J. J was reduced according to the method of Example 1 to improve activity and durability. The results are shown in Table 5.

Table 5 Table 7 also shows the evaluation results of comparing the activity and durability of the catalyst obtained with the catalyst precursor with Example 1.

Table 6 Comparative example 4 A commercially available copper-chromium catalyst is used as a catalyst precursor.

After obtaining a reduction catalyst by reducing K according to the method of Example 1, the reduction reaction of coconut fatty acid methyl ester was repeated 9 times in the same manner as in Example 1 except that the reaction temperature was changed from 240'C to 275°C. The saponification value of the product alcohol was measured. The measurement results are shown in Table 6.

As is clear from Table 7, the catalyst obtained from catalyst precursor A has the same activity and durability as the copper chromium catalyst under reaction temperature conditions lower by 35°C.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the number of times the catalyst was recovered and the saponification value decreasing rate of Example 1.

Claims (1)

[Claims] The following formula (I) or (II) (I) [CuO)_a [ZnO]_b [AO]_cA
O: MoO_3 and/or WO_3 a: 55-75% by weight b: 25-45% by weight c: 0.1-10% by weight (II) [CuO]_a_'[ZnO]_b_' [AO]
___c_′ [BO]_d_′AO: MoO_3 and/or WO_3 BO: Oxide of one or more metals selected from alkali metals, alkaline earth metals, and iron group metals a': 55 to 75% by weight b': 25 -45% by weight c': 0.1-10% by weight d': 0.1-8% by weight Contacting the carboxylic acid ester with hydrogen in the presence of a catalyst obtained by reduction of a composite metal oxide. A method for producing alcohol characterized by: