JP3812101B2 - Method for producing aldehydes and / or alcohols - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing aldehydes and / or alcohols. Specifically, the present invention relates to a method for producing aldehydes and / or alcohols in a gas phase with a high yield using a highly active catalyst when reducing carboxylic acid or a derivative thereof with molecular hydrogen.
[0002]
[Prior art]
Alcohols and aldehydes are useful compounds as organic synthetic intermediates. Various methods for producing alcohols or aldehydes are known, but a method for producing aldehydes and / or alcohols by reducing carboxylic acid with molecular hydrogen is considered to be the most desirable method. However, this method has been considered technically difficult.
[0003]
Various patents are known so far for the method of catalytic hydrogenation of carboxylic acids. Among them, in the case of producing aldehydes, generally, a method of reacting in a gas phase using metal oxides as a catalyst has been proposed. Among these various metal oxides, it has been reported that when a catalyst mainly composed of zirconium oxide is used, high aldehyde selectivity can be achieved. (See JP-A-60-152434, JP-A-60-243037, JP-A-61-115043). However, when these various metal oxides were used as catalysts, the reaction temperatures were all as high as around 350 ° C. Therefore, it is difficult to carry out the reaction using a thermally unstable raw material carboxylic acid or a derivative thereof. In addition, since a part of the product is decomposed into hydrocarbons due to heat, the selectivity of aldehyde and / or alcohol to be obtained is greatly reduced, which is not a preferable method.
In addition, a method for hydrogenating carboxylic acid in the gas phase using a catalyst in which ruthenium and tin are supported on a support such as silica and alumina has been reported (Japanese Patent Publication No. 7-68155). In this case, it is reported that the reaction proceeds at a low temperature of about 250 ° C. under atmospheric pressure in a gas phase reaction, but the selectivity of aldehyde is insufficient and the production of hydrogenated products and the like is frequent. I can't stand it.
[0004]
In addition, a reaction in which a carboxylic acid is directly hydrogenated with molecular hydrogen to produce an alcohol is also known. For example, JP-A-7-227541 discloses a reaction in which a carboxylic acid is hydrogenated in a liquid phase using a catalyst obtained by supporting ruthenium and tin oxide as active components on a carrier. Lett. 30, 297, 1995 report a method of hydrogenating a carboxylic acid derivative in a liquid phase using a SnO ₂ and Al ₂ O ₃ kneading catalyst (SnO ₂ in the support is 4 to 57% by weight). These require high pressure for the reaction, and the reaction is mainly carried out in the liquid phase. For this reason, a reactor for high-pressure reaction is required, and there are problems in terms of cost and safety, and in addition, since it is a liquid phase reaction, elution of catalyst components occurs and the catalyst life is shortened. It was.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of such circumstances, and in a gas phase reaction, carboxylic acids are directly hydrogenated in the vicinity of normal pressure to produce industrially useful aldehydes and / or alcohols with high selectivity. It aims to provide a method.
[0006]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have found that when a catalyst obtained by loading ruthenium on a tin oxide support is used, the carbon dioxide has a very high selectivity at a pressure near normal pressure, at a relatively low temperature. The inventors have found that aldehydes and / or alcohols can be obtained from acids or their derivatives, and have led to the present invention. That is, the gist of the present invention is characterized in that a carboxylic acid or a derivative thereof is reduced in a gas phase by molecular hydrogen in the presence of a catalyst in which a ruthenium component is supported on a support mainly composed of tin oxide. In the process for producing aldehydes and / or alcohols.
[0007]
Hereinafter, the present invention will be described in detail.
The starting materials for the process of the present invention are aliphatic, alicyclic, aromatic and heterocyclic carboxylic acids or their derivatives.
Specific examples of the aliphatic carboxylic acid include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, hexanoic acid, heptanoic acid, octanoic acid, 2-ethylhexanoic acid, nonanoic acid, Decanoic acid, undecanoic acid, lauric acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, stearic acid, isostearic acid, nonadecanoic acid, tricosanoic acid, tetracosanoic acid, acrylic acid, methacrylic acid, 10-undecenoic acid, 9-octadecene Examples thereof include saturated or unsaturated carboxylic acids having 2 to 24 carbon atoms such as acid, oleic acid, and 11-eicosenoic acid. Further, polycarboxylic acids such as oxalic acid, malonic acid, diethylmalonic acid, succinic acid, maleic acid, glutaric acid, adipic acid, decanedioic acid, octadecanedioic acid and the like can also be used.
[0008]
Examples of the alicyclic carboxylic acid include cyclopentane carboxylic acid, cyclohexane carboxylic acid, 1,4-cyclohexane dicarboxylic acid, and the like.
The aliphatic carboxylic acid or alicyclic carboxylic acid may have a group inert to the reaction as a substituent. Examples of such a substituent include an aryl group, O, S, N, and the like. And a heterocyclic group, an ether group, an alkoxy group, and the like. Specific examples include phenylacetic acid, cinnamic acid, glycolic acid and the like.
[0009]
The aromatic carboxylic acid used in the present invention can be represented by the general formula Ar- (COOH) n. (In the formula, n is 1 or 2, and Ar represents an aryl group which may have a substituent). Examples of the aryl group represented by Ar usually include a phenyl group, a naphthyl group, and an anthryl group. Examples of the substituent that the aryl group may have include an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, A halogen atom, a hydroxy group, a formyl group, an acyl group, an aryl group, etc. are mentioned. Specific examples of the compound include benzoic acid, toluic acid, dimethylbenzoic acid, cyclohexylbenzoic acid, cumic acid, t-butylbenzoic acid, phenylbenzoic acid, anisic acid, phenoxybenzoic acid, chlorobenzoic acid, and fluorobenzoic acid. And carboxylic acids such as hydroxybenzoic acid, acetylbenzoic acid, naphthoic acid, naphthalenedicarboxylic acids and anthracenecarboxylic acid. Moreover, phthalic acid etc. can also be used.
[0010]
The heterocyclic ring constituting the starting heterocyclic carboxylic acid used in the present invention has at least one N, S, or O atom in the ring, specifically, a pyrrole ring, Furan ring, thiophene ring, oxazole ring, thiazole ring, oxazoline ring, imidazole ring, imidazoline ring, pyrazole ring, pyran ring, thiopyran ring, pyridine ring, quinoline ring, oxazine ring, thiazine ring, pyrimidine ring, pyrazine ring, triazine ring , Azepine ring, oxepin ring and the like. Specific examples include nicotinic acid, furan carboxylic acid, and thiazole carboxylic acid. In addition, the heterocyclic carboxylic acid may have a group inert to the reaction as a substituent. Examples of such a substituent include a heterocyclic group containing an atom such as an aryl group, O, S, and N. A cyclic group, an ether group, an alkoxy group, etc. are mentioned.
[0011]
As the starting material of the present invention, derivatives of the above carboxylic acids such as esters and acid anhydrides can also be used. As the ester, any of aliphatic, alicyclic, aromatic ester and the like may be used. Specifically, methyl ester, ethyl ester, n-butyl ester, isobutyl ester, octyl ester of carboxylic acid exemplified above, There are cyclohexyl ester, phenyl ester and the like, and in the case of polycarboxylic acid, it may be a half ester or an ester with a plurality of alcohols. The anhydride may be a homo anhydride or a hetero anhydride. As the derivative of the aromatic carboxylic acid or heterocyclic carboxylic acid, a lower alkyl ester is preferable.
Among the carboxylic acids and derivatives thereof, as starting materials for the method of the present invention, alicyclic carboxylic acids, aromatic carboxylic acids, heterocyclic carboxylic acids or derivatives thereof are preferably used, especially aromatic carboxylic acids or These derivatives are preferred.
[0012]
The catalyst used in the present invention is characterized in that a ruthenium component is supported on a support containing tin oxide. In particular, it is characterized by using a carrier mainly composed of tin oxide. The main component means that the proportion of tin oxide in the carrier used for the catalyst exceeds 50% by weight. The proportion of tin oxide in the support used for the catalyst is desirably 60% to 100%, more preferably 80% to 100%. Thus, by using the support mainly containing tin oxide, the high selectivity of the product which is a feature of the present invention can be exhibited. As the tin oxide, either stannous oxide (II) or stannic oxide (IV) can be used, but stannic oxide is preferable. In addition to tin oxide, the support may contain one or more compounds selected from oxides of various metals. Examples of these metals include aluminum, titanium, silicon, zirconium, vanadium, chromium, molybdenum, tungsten, manganese, rhenium, iron, copper, bismuth, nickel, cobalt, antimony, and lanthanoids.
[0013]
Further, ruthenium is supported as a catalyst component on the carrier mainly containing tin oxide, but one or more components other than ruthenium may be further supported. Examples of other components include Group 8 metals such as platinum, rhodium, and palladium, chromium, silver, copper, rhenium, alkali metals, alkaline earth metals, and lanthanoids.
[0014]
As the ruthenium compound as a catalyst raw material used in the present invention, mineral salts of ruthenium such as nitric acid, sulfuric acid and hydrochloric acid are generally used, but organic acid salts such as acetic acid, hydroxides, oxides or complex salts are also used. can do. Specifically, for example, ruthenium nitrate, ruthenium sulfate, ruthenium chloride, ruthenium bromide, ruthenium iodide, ruthenium hydroxide, ruthenium oxide, potassium ruthenate, ruthenium alkoxide, ammonium oxydecachlorodiruthenate, pentachloroaquartenium Ammonium acetate, ammonium ruthenate, potassium oxydecachlorodiruthenate, potassium pentachloroaquaruthenate, potassium perruthenate, nitrosylruthenium nitrate, sodium oxydecachlorodiruthenate, hexaammineruthenium chloride, pentaamminechlororuthenium Chloride, hexaammineruthenium bromide, dodecacarbonyltriruthenium, hexacarbonyltetrachlorodiruthenium, tricarbonyltri Rollo ruthenate cesium tris (acetylacetonato) ruthenium, tricarbonyl bis (triphenylphosphine) ruthenium, dichloro-tris (triphenylphosphine) ruthenium and the like.
[0015]
The method for preparing the catalyst of the present invention is not particularly limited, and for example, it can be prepared by a known method such as a coprecipitation method or an impregnation method. When the impregnation method is used, for example, a method in which a compound containing a ruthenium component as described above is dissolved in water, for example, water to form a solution, and the carrier is immersed in the solution so that the ruthenium component is supported on the carrier. is there. Further, when a component other than ruthenium is included as a catalyst component, its production method is not particularly limited, and even if a plurality of components are simultaneously supported, each component is individually supported, You may carry | support by the method of combining the method.
[0016]
In the catalyst of the present invention, the amount of ruthenium supported on 100 parts by weight of tin oxide used as a carrier is preferably 0.01 to 20 parts by weight as ruthenium metal. The amount is preferably 0.1 to 10 parts by weight, more preferably 1 to 8 parts by weight. When the amount of ruthenium supported is too small, the activity of the catalyst is lowered and the productivity is deteriorated. If the amount of ruthenium supported is too large, the dispersibility of ruthenium may be reduced, and ruthenium having poor dispersibility may cause problems such as the production of many undesirable hydrocarbon products.
[0017]
After the catalyst component is supported on the carrier, it is dried by any method. The drying method is not limited, but for example, drying by air drying, heating drying in a muffle furnace, drying under a temperature condition of 100 ° C. to 150 ° C. under an inert gas stream, drying under reduced pressure, etc. The method is mentioned. After drying, firing or reduction treatment is performed as necessary. When performing a baking process, it is normally performed in the temperature range of 100 to 600 degreeC, Preferably, it is the range of 200 to 400 degreeC.
[0018]
Moreover, it is desirable to activate the catalyst by performing a reduction treatment. A known liquid phase reduction method or gas phase reduction method is employed as the reduction treatment method. In the case of the gas phase reduction method, the reaction is usually performed in a temperature range of 100 ° C to 600 ° C, preferably in a range of 300 ° C to 500 ° C. Examples of the liquid phase reduction method include a formalin reduction method, a hydrazine reduction method, and a lithium aluminum hydride reduction method. Note that the catalyst is not sufficiently activated under the conditions where the temperature of the reduction treatment is too low or the treatment time is too short, so that an expected effect may not be sufficiently exhibited. The details of the structure of the catalyst after the reduction treatment are unclear, but under reducing conditions such that the catalyst is fully activated, substantially noble metal components such as ruthenium are reduced to metal. It is estimated that.
[0019]
The reduction reaction of the carboxylic acid of the present invention is carried out in the gas phase using molecular hydrogen using the catalyst thus obtained. By using the catalyst according to the present invention, the hydrogenation of the carboxylic acid occurs under a relatively low temperature condition at a pressure near normal pressure without using the high pressure condition, and the aldehyde and / or alcohol is obtained with high selectivity. I can do it. The proportion of aldehyde and / or alcohol produced varies depending on the raw materials and reaction conditions. The produced alcohol reacts with a carboxylic acid produced from a carboxylic acid or a carboxylic acid derivative, which is a raw material, to form a carboxylic acid ester. Alcohols and / or aldehydes can be produced. Therefore, in this invention, the carboxylic acid ester produced | generated by the hydrogenation reaction of carboxylic acid is also considered as a reaction product (active ingredient). Further, when a polycarboxylic acid or derivative thereof is used as a starting material, polyaldehyde, hydroxyaldehyde, polyol, aldehyde carboxylic acid or ester thereof, hydroxycarboxylic acid or ester thereof, lactone, or the like is produced. It varies depending on the reaction conditions.
[0020]
In the reduction reaction in the present invention, the reaction pressure may be carried out in the vicinity of normal pressure, but it may be in a pressurized state. It can be carried out between normal pressure and 100 kg / cm ² . Preferably it is carried out between 1 and 50 kg / cm ² .
The temperature of the hydrogenation reaction is selected from 100 ° C to 500 ° C, preferably 150 ° C to 400 ° C, more preferably 200 ° C to 300 ° C.
[0021]
As the reaction method of the reduction reaction of the present invention, the reaction is preferably carried out under a hydrogen stream using the above-mentioned catalyst as a fixed bed catalyst. In this case, the concentration of the carboxylic acid or its derivative in the feedstock is 20 in the gas phase. (Volume)% or less, preferably 0.01 to 10 (Volume)%. If this concentration is too dilute, the efficiency of the reaction will be poor. On the other hand, if the concentration is too high, a higher reaction temperature will be required to promote the reaction, resulting in poor selectivity and shortened catalyst life. May occur.
The hydrogen used may contain a gas that does not adversely affect some reaction, such as nitrogen or water vapor.
The alcohols and / or aldehydes produced by the reaction are separated and purified by a known method such as distillation, or are supplied to the subsequent steps as a mixture.
[0022]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to description of a following example, unless the summary is exceeded. In the following examples, “%” indicates “wt%”.
[0023]
[Catalyst Preparation Example 1]
(Preparation of Ru 2.0% / SnO ₂ )
In a 100 ml flask, 0.68 g of RuCl ₃ .3H ₂ O was weighed, 10 ml of water was further added and dissolved, and then 13.0 g of SnO ₂ was added as a carrier and stirred well. The obtained slurry was dried at 50 ° C. and 25 mmHg with a rotary vacuum drier to remove solvent water, and then baked at 150 ° C. for 30 minutes in a nitrogen atmosphere. The obtained solid was tableted with a tableting machine and then pulverized to adjust the size to 10 to 20 mesh. Thereafter, reduction treatment was performed at 250 ° C. for 30 minutes under a hydrogen stream to obtain a catalyst. The ratio of tin oxide in the carrier of the obtained catalyst was 100%, and the ratio of ruthenium to tin oxide was 2.0%.
[0024]
[Catalyst Preparation Comparative Example 1]
(Preparation of 2.0% Ru / 5.0% Sn / SiO ₂ catalyst)
The flask 100ml, RuCl ₃ · 3H ₂ O and 0.45g, SnCl ₂ · 2H ₂ O was 0.83g weighed, further water 10cc and conc. After 2 ml of HCl aqueous solution was added and dissolved, 8.1 g of SiO ₂ (trade name: Caractect Q-10, 10 to 20 mesh) was added as a carrier and shaken well. The obtained slurry was dried at 50 ° C. and 25 mmHg with a rotary vacuum drier to remove solvent water, and then baked at 150 ° C. in a nitrogen atmosphere. Thereafter, treatment was performed at 300 ° C. under a hydrogen stream to obtain a catalyst. The catalyst support obtained was 100% SiO ₂ , the ratio of ruthenium to the support was 2.0%, and the ratio of tin was 5.0%.
[0025]
Example 1
(Hydrogenation reaction of benzoic acid with Ru 2.0% / SnO ₂ )
5 ml of the catalyst obtained in Catalyst Preparation Example 1 was charged into a glass tube reactor having a diameter of 1.5 cm, benzoic acid was fed at 3.3 mmol / hr, and hydrogen was supplied at a space velocity of GHSV = 1250 hr ^−1. The hydrogenation reaction of benzoic acid was carried out at a pressure and a reaction temperature of 250 ° C. As a result of analyzing the reaction product, the conversion of benzoic acid was 77.4%, benzaldehyde selectivity was 91.3%, benzyl alcohol selectivity was 0.9%, benzyl benzoate selectivity was 3.0%, and toluene selectivity was 4.8. %Met. The total selectivity of the active ingredients benzaldehyde, benzyl alcohol and benzyl benzoate was 92.5%.
[0026]
Comparative Example 1
(Hydrogenation reaction of benzoic acid with 2.0% Ru / 5.0% Sn / SiO ₂ )
Using 5 ml of the catalyst obtained in Catalyst Preparation Comparative Example 1, the reaction was conducted under the same conditions as in Example 1. As a result, the conversion of benzoic acid was 82.3%, benzaldehyde selectivity was 30.1%, benzyl alcohol selectivity was 27.9%, benzyl benzoate selectivity was 16.9%, and toluene selectivity was 25.1%. The total selectivity of the active ingredients benzaldehyde, benzyl alcohol and benzyl benzoate was 74.9%.
[0027]
Example 2
(Hydrogenation reaction of benzoic acid with Ru 10.0% / SnO ₂ )
In the same manner as in Example 1, a catalyst having 10% ruthenium supported on a stannic oxide support was prepared. Using 5 ml of this catalyst, the reaction was carried out under the same conditions as in Example 1. As a result, the conversion of benzoic acid was 61.5%, benzaldehyde selectivity was 81.1%, benzyl alcohol selectivity was 4.1%, benzyl benzoate selectivity was 9.9%, and toluene selectivity was 4.8%. The total selectivity of the active ingredients benzaldehyde, benzyl alcohol and benzyl benzoate was 95.1%.
[0028]
Example 3
(Hydrogenation reaction of lauric acid with Ru 2.0% / SnO ₂ )
The reaction was carried out under the same conditions as in Example 1 except that 5 ml of the catalyst produced based on Example 1 was used, lauric acid was supplied at 4.2 mmol / hr as a raw material, and the reaction temperature was 270 ° C. The conversion of lauric acid was 72.0%, the lauryl aldehyde selectivity was 53.3%, and the lauryl alcohol selectivity was 2.8%.
[0029]
【The invention's effect】
According to the method of the present invention, carboxylic acid and / or alcohol can be obtained with high selectivity by carrying out a hydrogenation reaction of carboxylic acid using a catalyst having stannic oxide as a carrier. For example, when benzoic acid is used as the carboxylic acid, the total selectivity of the active ingredients is 90% or more, and the selectivity of aldehyde is particularly improved. In the case of an aliphatic carboxylic acid such as lauric acid, an aldehyde can be obtained with high selectivity.

Claims (7)

Aldehydes and / or alcohols characterized in that carboxylic acids or their derivatives are reduced in the gas phase with molecular hydrogen in the presence of a catalyst having a ruthenium component supported on a support mainly composed of tin oxide. Manufacturing method. The method for producing aldehydes and / or alcohols according to claim 1, wherein a catalyst having a tin oxide ratio of 60 to 100% by weight in the support is used. The method for producing aldehydes and / or alcohols according to claim 2, wherein a catalyst having a tin oxide ratio of 80 to 100% in the carrier is used. The aldehydes according to any one of claims 1 to 3, wherein a catalyst in which ruthenium is 0.01 to 20 parts by weight as a ruthenium metal with respect to 100 parts by weight of tin oxide in the catalyst is used. / Or production method of alcohols. The method for producing aldehydes and / or alcohols according to any one of claims 1 to 4, wherein the carboxylic acid is an aromatic carboxylic acid. A hydrogenation catalyst for producing aldehydes and / or alcohols by reducing a carboxylic acid or a derivative thereof in a gas phase with molecular hydrogen, and a carrier containing 60 to 100% by weight of tin oxide, A hydrogenation catalyst carrying a ruthenium component. The hydrogenation catalyst according to claim 6, wherein ruthenium is 0.01 to 20 parts by weight as ruthenium metal with respect to 100 parts by weight of tin oxide.