JP2641941B2 - Alcohol production - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an alcohol, and more particularly, to a method for producing a corresponding alcohol under a low-temperature and low-pressure condition with high yield and high selectivity using a novel highly active catalyst. Related to the method of manufacturing at a rate.

[Conventional technology and its problems]

Many methods for producing aliphatic alcohols, alicyclic alcohols, or aromatic alcohols by hydrogenating carboxylic acids or carboxylic acid esters have been disclosed since the 1930s.

Here, copper catalysts have been mainly proposed as catalysts used for hydrogenation of carboxylic acid esters, particularly hydrogenation of fatty acid esters, but copper-chromium catalysts are generally industrially awarded. ing. However, although the copper-chromium catalyst is excellent in the performance as a catalyst, it has a very serious problem in terms of wastewater during the production of the catalyst or disposal of the used catalyst. In addition, in the production of higher aliphatic alcohols, which require severe reaction conditions in the hydrogenation of carboxylic acid esters, high-temperature and high-pressure reaction conditions of 250 to 300 ° C. and 200 to 300 atm are required, so that capital investment or There are many problems in maintenance and the like. Furthermore, since it is a high-temperature reaction, generation of a side reaction product is inevitable, and it is apparent that it is not preferable from the viewpoint of energy saving.

For this reason, there has been a demand for the development of a technique capable of hydrogenating a carboxylic acid ester at low temperature or low pressure.

For example, attempts to hydrogenate higher fatty acid esters at low temperatures or low pressures have been made for a long time,
In many cases, the purpose is achieved by using a large amount of a copper-chromium catalyst.

Adkins et al. [J. Amer. Chem. Soc., 70 , 3121 (194
8)] is for hydrogenating methyl laurate in a liquid phase suspension bed reaction system,
It has been reported that lauryl alcohol can be obtained at a low temperature of 150 ° C using parts by weight and an extremely large amount of copper-chromium catalyst, but the hydrogen pressure is extremely high at 340 atm and a large amount of catalyst is used. The reaction time is long despite doing. Also, Ueno et al. [Industrial Chemistry Magazine, Vol. 38, 1105
P. (1935); the same magazine, Vol. 48, p. 18 (1945)] shows that in the hydrogenation of various fatty acid esters, 100
It has been reported that aliphatic alcohols can be obtained at low hydrogen pressures (initial charging pressure at room temperature) of 10 to 25 atm using 10 parts by weight of copper-chromium catalyst per part by weight. At 270 to 300 ° C., so that the yield of unsaponifiable substances accompanying side reactions is high, and the yield of alcohol is as low as 30 to 60%.

Japanese Patent Application Laid-Open No. 60-38333 discloses the use of copper-chromium as one component of a catalyst and the adoption of a fixed bed reaction system, whereby 218 ° C., 60 ° C.
Although hydrogenation of methyl laurate has been attempted under the reaction condition of bar, there is a problem that the liquid hourly space velocity (LHSV) is 0.2 and the productivity is very low.

On the other hand, catalysts that do not contain harmful chromium are also being developed. For example, [Industrial Chemical Magazine, Vol. 53, p. 74 (1950
Year)], hydrogenation of sperm whale oil is carried out by a liquid-phase suspension bed reaction method using a copper-zinc catalyst supported on diatomaceous earth. The reaction conditions are 280 to 290 ° C and 110 atm (at room temperature). Initial charge). In German Patent 2613226, hydrogenation of higher fatty acid methyl is carried out by a gas phase fixed bed reaction method using a copper-zinc solid catalyst. The reaction conditions in this case are relatively low at 230 to 240 ° C., but high pressure conditions of 250 atm are employed. In JP-A-54-32191, higher fatty acid methyl is hydrogenated under the reaction conditions of 300 ° C. and 95 atm (initial pressure of charging at room temperature) in a liquid phase suspension bed system using a copper-molybdenum-zinc catalyst. And employs very harsh reaction conditions. Also, Japanese Patent Publication No. 60-45940
In No. 2, hydrogenation of methyl laurate was carried out at 250 ° C and 204 atm in a liquid-phase suspension bed reaction method using a very large amount of a cobalt-zinc-copper catalyst of 22 parts by weight based on the ester. However, the reaction conditions are not sufficiently relaxed.

JP-A-61-56139 attempts to hydrogenate higher fatty acid esters using a nickel-based catalyst in a fixed-bed reaction system under a low pressure condition of 50 bar.
° C and the alcohol yield is very low at 40% or less.

Further, a catalyst containing at least one of magnesium, lanthanide metal and actinide metal in addition to copper as a catalyst component has been proposed (JP-A-62-63533).

Further, the present inventors have previously described a composite oxide of copper oxide and at least one metal oxide selected from zinc, yttrium and thorium, wherein the composite oxide contains 20 to 90 as copper oxide. A catalyst obtained by reduction of a catalyst precursor containing parts by weight was proposed (JP-A-63-141937).

However, none of these methods using a copper-chromium-based catalyst and a catalyst containing no harmful chromium have sufficient activity of the catalyst, and a catalyst having higher activity has been demanded.

[Means for solving the problem]

The present inventors have conducted intensive studies in order to impart even more excellent activity to the catalyst used in the production of alcohol, and as a result, a catalyst having a specific catalyst component and an extremely high activity that has never been seen before. The present invention has been completed.

That is, the present invention relates to (a) copper oxide and (b) a IIa group element, II
A composite metal oxide composed of an oxide of one or more metals selected from the group Ib, lanthanide and actinide elements, wherein (a) / (b) is 91/9 by weight.
99 (a) + on the titanium oxide and / or hydroxide carrier (c).
(B) 有機 / (c) (weight ratio) = 15/85 to 65/35 in the presence of a catalyst obtained by reducing a catalyst precursor supported or contained, and converting the organic carboxylic acid ester with hydrogen An object of the present invention is to provide a method for producing alcohol, which is characterized by catalytic reduction.

In the catalyst according to the present invention, the composition of the catalyst precursor before reduction activation is one kind selected from (a) copper oxide and (b) a IIa group element, a IIIb group element, a lanthanide element and an actinide element. A composite metal oxide composed of the above metal oxides, wherein (a) / (b) is in a ratio of 91/9 to 99/1 by weight and (c) ) {(A) + (b)} /
(C) (weight ratio) = 15 / 85-65 / 35, preferably 20 / 80-6
It is supported or contained at a ratio of 0/40, and specifically exhibits high activity only when it is within this composition range.

The method for producing the catalyst precursor composition according to the present invention is not particularly limited, and is prepared by a known method. For example, a precipitant is added to a mixed aqueous solution containing each metal salt, or in the presence of a supporting component, titanium oxide and / or hydroxide,
A method in which a precipitate obtained by a coprecipitation method in which a precipitant is added to a metal salt aqueous solution that can be a catalyst component other than the carrier component is washed with water, dried and calcined, or on a titanium oxide and / or hydroxide as a carrier component. A method in which a metal salt that can be a catalyst component other than the carrier component is impregnated from an aqueous solution and then dried and calcined, or calcined after uniformly mixing compounds such as oxides, hydroxides, and carbonates thereof. It is prepared by a method such as

The metal salt used in the above precipitation method and impregnation method can be used as long as it is water-soluble. For example, copper, IIa
As metal salts of group III elements, group IIIb elements, lanthanide elements or actinide elements, generally sulfates, nitrates,
Ammonium complexes, acetates, oxalates, acetylacetonate salts and oxides, and sulfates as titanium metal salts are used.

Examples of the titanium oxide and / or hydroxide used in the present invention include titanium oxide such as TiO ₂ (titania), TiO and Ti ₂ O ₃ , metatitanic acid (TiO (OH) ₂ ), and titanic acid (Ti (O
H) ₄ ) or a mixture thereof, and the higher the surface area, the better. These carriers are prepared by hydrolysis of sulfates, chlorides, oxalates and alkoxides, or by precipitation from aqueous sulfate solutions.

Group IIa element used in the present invention is Be, Mg, Ca, Sr, Ba, R
a, III b group element Sc, Y, lanthanide element La, C
e, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, actinide element is Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk , Cf, Es, Fm, Md,
No and Lr are used, and these may be used alone or in combination of two or more.

As a precipitant used in the precipitation method, an aqueous alkali solution such as ammonia, urea, ammonium carbonate, sodium carbonate, sodium hydrogen carbonate, sodium hydroxide, or potassium hydroxide is used.

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

For the catalyst precursor thus obtained, graphite, a fatty acid salt, starch, mineral oil, talc, bentonite, an alkali metal salt, an alkaline earth salt, etc. for improving the catalyst strength and the like within a range not impairing the effects of the present invention. A trace component may be added.

Next, when hydrogenating the carboxylic acid ester, reduction activation of the catalyst is required. When reducing and activating the catalyst precursor, a gas phase reduction method or a hydrocarbon such as liquid paraffin,
Any of the liquid phase reduction methods performed in a solvent such as dioxane, aliphatic alcohol or fatty acid ester may be used. For example, when reducing using hydrogen gas, 100
The reaction is preferably carried out at a temperature of from 800 to 800 ° C., preferably from 150 to 500 ° C., until water formation is no longer observed or hydrogen absorption is no longer observed. In particular, when the reduction is carried out in a solvent, it is desirable to carry out the reduction at a temperature of 150 to 350 ° C. until hydrogen absorption is not observed. Furthermore, there is no problem even if a normal activation method is used in which the catalyst precursor is heated and reduced in a hydrogen atmosphere in an ester as a hydrogenation raw material, and is subjected to the reaction as it is.

As a reducing agent used for reducing the catalyst precursor, there are carbon monoxide, ammonia, hydrazine, formaldehyde and lower alcohols such as methanol in addition to the above-mentioned hydrogen, and these reducing agents are used alone or in a mixed state. You may. Also, nitrogen, helium,
It may be used in a state diluted with an inert gas such as argon or in the presence of a small amount of water vapor.

Examples of the carboxylic acid ester subjected to the hydrogenation reaction using the catalyst obtained from the catalyst precursor of the present invention include lower or higher alcohol esters of alicyclic carboxylic acids, aromatic carboxylic acids and aliphatic carboxylic acids. In these, the carboxylic acid moiety is reduced by hydrogenation to the corresponding alcohol. For example, an ester of a straight-chain or branched-chain saturated or unsaturated fatty acid having 1 or more carbon atoms and an alcohol, and an ester of an alicyclic carboxylic acid or an aromatic carboxylic acid and an alcohol are exemplified. The alcohol portion constituting the carboxylic acid ester is not particularly limited. Examples of such carboxylic esters include formate, acetate, caproate, caprylate, undecenoate, laurate, myristate, palmitate, stearate, isostearate, and oleate. Oxalate, maleate, adipate, sebacate, cyclohexanecarboxylate, benzoate, phthalate and the like.

In hydrogenating the carboxylic acid ester, any one of a suspension bed reaction system, a fixed bed reaction system, and a fluidized bed reaction system is employed depending on the shape of the catalyst.

For example, when a suspension bed reaction method is adopted, a powder catalyst is used. Although a solvent can be used for the reaction, it is preferable to perform the reaction without a solvent in consideration of productivity. As the solvent, those which do not adversely affect the reaction of alcohol, dioxane, hydrocarbon or the like are selected. In this case, the catalyst amount is 0.1
To 20% by weight, but can be arbitrarily selected according to the reaction temperature or reaction pressure within a range where a practical reaction rate can be obtained. The reaction temperature is from 160 to 350 ° C, preferably from 180 to 280 ° C. Reaction pressure is 1 ~ 350kg /
cm ² , preferably 30 to 300 kg / cm ² .

When a fixed bed reaction system is adopted, a catalyst which is shaped for a purpose is used. The reaction temperature is 130-300 ° C,
Preferably it is 160 to 270 ° C. The reaction pressure is between 0.1 and 300 kg / cm ² . Here, the liquid hourly space velocity (LHSV) is arbitrarily determined according to the reaction conditions, but is preferably in the range of 0.5 to 5 in consideration of productivity or reactivity.

〔The invention's effect〕

By using the highly active catalyst obtained according to the present invention, the organic carboxylic acid ester can be catalytically reduced with hydrogen at a practical reaction rate even under low temperature and low pressure conditions to achieve high yield and high selectivity. Alcohol can be produced. Further, since the catalyst of the present invention does not contain harmful atoms such as chromium, it is highly safe for human bodies and the environment.

〔Example〕

Hereinafter, the present invention will be described in more detail by examples,
The present invention is not limited to these examples.

Example 1 Catalyst preparation: A catalyst containing a group IIIb element yttrium (Y) was prepared by the following method.

Titanium oxide produced from titanium sulfate (anatase type)
And 10% by weight of mixed aqueous solution of copper nitrate and yttrium nitrate
Was stirred and mixed at 98 ° C. to obtain a slurry having a pH of 9. The precipitate is separated from this slurry by filtration, washed thoroughly with water, dried, and then dried at 450 ° C. for 2 hours.
By firing for a time, a composite oxide of titanium oxide-supported copper oxide-yttrium oxide was obtained. The composite oxide thus obtained was represented by the following weight composition.

CuO: Y ₂ O ₃ : TiO ₂ = 47.5%: 2.5%: 50.0% (95.0%: 5.0%) where the weight composition of the copper oxide and the yttrium oxide is shown in parentheses.

Evaluation of catalytic activity: 150 g of fatty acid methyl ester having an alkyl composition having 8 to 18 carbon atoms (saponification value: SV = 258; acid value: AV = 0.06) and 3.75 g of catalyst precursor prepared as described above (for ester) (2.5% by weight) was charged into a rotary stirring type 0.5 autoclave, and the catalyst was activated for reduction under a hydrogen pressure of 10 kg / cm ² (gauge pressure), a temperature of 200 ° C. and a flow of hydrogen for 2 hours. After the temperature was raised to 230 ° C, the hydrogen pressure was raised to 120 kg / cm ² and the stirring speed was 800
The reaction was started at rpm and a hydrogen flow rate of 5 / min.

The comparison of the activity of the catalyst was performed using the first-order reaction rate constant per 1 g of the catalyst precursor.

Comparative Examples 1 to 3 Titanium oxide-supported copper oxide or a copper oxide-yttrium oxide catalyst precursor was obtained according to the preparation method described in Example 1 except that the composition of yttrium oxide was changed. Using these catalyst precursors, hydrogenation of fatty acid methyl esters was carried out in accordance with the catalyst activity evaluation method described in Example 1.

Comparative Examples 4 and 5 According to the preparation method described in Example 1 without using a titanium oxide carrier, two types of catalyst precursors having different ratios of copper oxide / yttrium oxide in the composition range of the prior art were obtained. Using these catalyst precursors, hydrogenation of fatty acid methyl esters was carried out in accordance with the catalyst activity evaluation method described in Example 1.

Comparative Example 6 Example 1 was repeated except that an alumina carrier (γ-Al ₂ O ₃ ) was used instead of the titanium oxide carrier in Example 1.
A catalyst precursor was obtained according to the preparation method described in (1). Using this catalyst precursor, the fatty acid methyl ester was hydrogenated according to the catalytic activity evaluation method described in Example 1.

Example 2 and Comparative Example 7 A catalyst precursor in which the weight composition of copper oxide and yttrium oxide was 95: 5 was obtained in accordance with the preparation method described in Example 1, except that the composition of the titanium oxide support was changed. Using these catalyst precursors, aliphatic methyl esters were hydrogenated according to the catalyst activity evaluation method described in Example 1. However, the catalyst concentration is 5.
0% by weight.

Examples 3 to 8 In place of Y which is a IIIb group element, M which is a IIa group element
For g, Ca, Ba, La and Ce as lanthanide elements, and Th as actinide element, a catalyst precursor was obtained according to the preparation method described in Example 1 using nitrate of each element. Using these catalyst precursors, hydrogenation of fatty acid methyl esters was carried out in accordance with the catalyst activity evaluation method described in Example 1.

The results obtained in Examples 1 to 8 and Comparative Examples 1 to 7 and the weight ratios of the components (a), (b), and (c) are shown in Table 1.
It was shown to.

The activity comparison of the catalyst was represented by a first-order reaction rate constant k [Hr ⁻¹ · gr ⁻¹ ] per 1 g of the catalyst precursor. The larger the value, the higher the reaction rate.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C07C 31/125 9155-4H C07C 31/125

Claims (1)

(57) [Claims] (1) Copper oxide (a) and (b) a group IIa element, IIIb
A composite metal oxide composed of an oxide of one or more metals selected from group III elements, lanthanide elements and actinide elements, wherein (a) / (b) is 91/9 to 99 by weight.
/ 1 and the composite metal oxide is added to the (c) titanium oxide and / or hydroxide carrier by {(a) + (b)} /
(C) Catalytic reduction of an organic carboxylic acid ester with hydrogen in the presence of a catalyst obtained by reducing a catalyst precursor supported or contained at a weight ratio of 15/85 to 65/35. Characteristic method for producing alcohol.