JPS6153339B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a process for the direct production of lower aliphatic alcohols, in particular ethylene glycol and methanol, from a mixture of carbon monoxide and hydrogen (hereinafter referred to as syngas) in the liquid phase. Ethylene glycol is a raw material for polyester fibers,
It is an industrially important chemical product as an organic solvent raw material or a non-volatile antifreeze, and is currently generally manufactured by using ethylene as a raw material and subjecting it to an oxidation reaction and a hydration reaction. On the other hand, methanol is a basic chemical widely used as formalin, acetic acid, dimethyl phthalate, methacrylic acid, or a solvent, and is currently produced by reacting synthesis gas in the gas phase at high temperature and pressure. In recent years, methods have been proposed for directly producing lower aliphatic alcohols in the liquid phase using synthesis gas as a raw material. Regarding such a method, a catalyst containing rhodium or a catalyst containing Ru is known. Many methods using catalysts containing rhodium have already been proposed, such as JP-A-51-36403;
JP-A-51-32506 or JP-A-51-63110 describes an alkali metal salt, quaternary ammonium salt or bis(tertiary phosphine) as a promoter.
It is stated that the addition of iminium salts is effective. Also, JP-A-48-68509, JP-A-52-
No. 42809 and JP-A-52-42810 describe the addition of organic nitrogen or oxygen ligands. Furthermore, in JP-A-55-9065, phosphine oxide is used as a promoter. In addition, methods using rhodium as a catalyst include JP-A-50-32117, JP-A No. 32118, and JP-A No. 32118.
No. 51-32507, No. 88902, No. 125203, Japanese Unexamined Patent Publication No. 1973
-42808, JP-A No. 53-108889, JP-A No. 12714, JP-A No. 12714,
124204, JP-A No. 16415, JP-A No. 48703, JP-A No.
No. 71098, No. 92903, No. 122211, Japanese Unexamined Patent Publication No. 1983-
75498, JP-A-57-128645, JP-A No. 130941, JP-A No.
It is described in the specification of No. 130942, etc. However, even with these methods, the activity and selectivity of the catalyst are still insufficient, and the recycling of the catalyst is difficult, so that they have not been commercially implemented. Examples of catalysts containing ruthenium include JP-A-55-115834, JP-A-56-100728, and JP-A-56-100728.
No. 51426, JP-A-57-109735, JP-A No. 123128, JP-A No.
Although it is described in the specification of No. 130937 or No. 130939, the activity is insufficient in these as well.
Furthermore, the selectivity for ethylene glycol is low. Furthermore, regarding the method of carrying out the reaction in the coexistence of rhodium and ruthenium, for example,
12396, 57-128644, 57-123128, 58-
No. 118527, No. 58-118528, No. 58-121227, etc., but these also have insufficient activity and low selectivity for ethylene glycol. The present inventors conducted intensive studies to overcome the above-mentioned drawbacks of known catalysts. As a result, the activity for producing lower aliphatic alcohols was significantly improved by using appropriate phosphines as co-catalysts in the coexistence of rhodium and ruthenium. The present invention was achieved by discovering that the selectivity of ethylene glycol can be increased, and moreover, surprisingly, by coexisting an organic amine as a second cocatalyst, the lower aliphatic alcohol producing activity can be further improved. . That is, the present invention uses a compound of the general formula
PR ₁ R ₂ R ₃ (Here, R ₁ , R ₂ , and R ₃ represent the same or different primary alkyl group, secondary alkyl group, tertiary alkyl group, or cycloalkyl group) A method for producing an aliphatic alcohol characterized by coexisting with a tertiary alkylphosphine represented by The present invention provides a method for producing aliphatic alcohols characterized by coexistence of aliphatic alcohols. In the process according to the invention, rhodium compounds and ruthenium compounds are used as catalysts. The rhodium and ruthenium compounds that can be used are
Any form may be used as long as it forms a rhodium carbonyl complex and a ruthenium carbonyl complex in a high-pressure reaction system, such as carbonyl compounds,
Examples include coordination compounds and salts such as acetylacetonate salts, carboxylates, oxides, hydroxides, halides, nitrates, and phosphates. It is also possible to use metallic rhodium and metallic ruthenium, which are known to transform into rhodium carbonyl complexes and ruthenium carbonyl complexes under the present reaction conditions. Specific examples of rhodium compounds include rhodium oxide (), tetrarhodium dodecacarbonyl, dirhodium octacarbonyl, hexalodium hexadecacarbonyl, rhodium formate (), rhodium acetate (), rhodium propionate (), rhodium butyrate () , rhodium valerate (), rhodium naphthenate (), rhodium dicarbonylacetylacetonate, rhodium tris (acetylacetonate), rhodium nitrate (), and the like. Ruthenium compounds include triruthenium dodecacarbonyl, ruthenium tris(acetylacetonate), tetrahydridetetraruthenium dodecacarbonyl, dichlorotricarbonylruthenium dimer, dicarbonylbis(allyl)ruthenium, dicarbonyl(methyl)(cyclopentadienyl) ) Ruthenium, Ruthenocene,
Examples include ruthenium oxide (), ruthenium chloride (), ruthenium bromide (), ruthenium nitrate (), and ruthenium acetate (). The amounts of rhodium and ruthenium compounds used as catalysts can vary within a wide range, but generally from 0.001 to 1 g atoms of metal per 1 part of reaction medium are suitable as a sum of rhodium and ruthenium compounds. There is no particular restriction on the ratio of the rhodium compound and ruthenium compound used as a catalyst, but
The ratio of the ruthenium compound to the sum of the ruthenium compound and the rhodium compound (Ru/Ru+Rh) is preferably 0.1 to 0.9. The use of ruthenium compounds is useful for stabilizing the catalyst and reducing loss of expensive rhodium compounds. It is very important in the process of the invention to use a phosphine with a suitable structure as a cocatalyst. By coexisting an appropriate phosphine, the activity of the catalyst can be significantly improved, and the selectivity of ethylene glycol can be increased. Furthermore, by using such a phosphine, the stability of the catalyst is improved, and the formation of metallic precipitates, which is a problem when using a rhodium-based catalyst, can be suppressed. Phosphines having a suitable structure include the general formula PR ₁ R ₂ R ₃ (where R ₁ , R ₂ , R ₃ are the same or different primary alkyl groups, secondary alkyl groups or tertiary alkyl groups). A tertiary alkylphosphine represented by a tertiary alkyl group or a cycloalkyl group is used. Specific examples of the tertiary alkyl phosphine used include triisopropylphosphine,
Tri-tert-butylphosphine, tri-sec-butylphosphine, tricyclohexylphosphine, tricyclopentylphosphine, diisopropyltert-butylphosphine, diisopropyl
sec-butylphosphine, diisopropylcyclohexylphosphine, 1-tert-butylisopropylphosphine, di-tert-butyl sec-butylphosphine, di-tert-butylcyclohexylphosphine, di-sec-butylisopropylphosphine, di -sec-butyl tert-butylphosphine, 1-sec-butylcyclohexylphosphine, dicyclohexylisopropylphosphine,
dicyclohexyl tert-butylphosphine, dicyclohexyl sec-butylphosphine, tritert
-amylphosphine, tri(methyl-tert-butyl)phosphine, tri(dimethylisopropyl)
Phosphine, tri(pentamethylethyl)phosphine, tris(1-bicyclo[2.2.2]octyl)phosphine, tris(1-bicyclo[2.2.1]pentyl)phosphine, trimethylphosphine, triethylphosphine , Tory-n
-Propylphosphine, tri-n-butylphosphine, triisobutylphosphine, tri-n-hexylphosphine, tris(2-ethylhexyl)phosphine, di-n-butyl-isobutylphosphine, di-tert-butyl- n-butylphosphine, di-iso-propyl-n-butylphosphine, di-tert-butyl-n-propylphosphine, tert-butyl-di-n-butylphosphine,
Examples include tert-butyl-di-n-propylphosphine. There is no particular restriction on the amount of these alkylphosphine used, but the ratio of the number of gram molecules of the tertiary alkylphosphine to the sum (M) of the number of gram atoms of each of the rhodium compound and the ruthenium compound (P/M ratio ) is suitably in the range of 0.01 to 1000, more preferably 0.1 to 100. Furthermore, in the method of the present invention, an organic amine can be used as the second co-catalyst, and by coexisting the second co-catalyst, the activity of the catalyst can be further improved. Specific examples of organic amines that can be used include imidazole, N-methylimidazole,
N-ethylimidazole, benzimidazole,
N-methylbenzimidazole, 1,2-dimethylimidazole, 1,5,6-trimethylimidazole, 4-dimethylaminopyridine, 2-hydroxypyridine, pyridine, N-methylpyrrolidine, N-methylpiperidine, 2-aminopyridine, Triethylamine, tributylamine, pyrrolidine, 2,2'-dipyridyl, aniline, N/N
-dimethylaniline, pyrrole, triidine,
Examples include 1,8-phenanthroline, 1,4-diazabicyclo[2,2,2]octane, and morpholine. The amount of the second co-catalyst to be used may be within the range of 0.1 to 1000 as a ratio to the sum of the number of grams of atoms of each of the rhodium compound and the ruthenium compound (second co-catalyst/Ru + Rh), and the type of the second co-catalyst Depending on the situation, it can also be used as a solvent. Preferably, the process according to the invention is carried out using a solvent. Examples of such solvents include ethers such as diethyl ether, anisole, tetrahydrofuran, ethylene glycol dimethyl ethyl, and dioxane, ketones such as acetone, methyl ethyl ketone, and acetophenone, methanol, ethanol, n-butanol, benzyl alcohol, phenol, Alcohols such as ethylene glycol and diethylene glycol, carboxylic acids such as formic acid, acetic acid, propionic acid and toluic acid, esters such as methyl acetate, n-butyl acetate and benzyl benzoate, benzene, toluene, ethylbenzene,
Aromatic hydrocarbons such as tetralin, n-hexane,
Aliphatic hydrocarbons such as n-octane and cyclohexane, halogenated hydrocarbons such as dichloromethane, trichloroethane and chlorobenzene, nitro compounds such as nitromethane and nitrobenzene, triethylamine, tri-n-butylamine, benzyldimethylamine, pyridine, α-picoline, Tertiary amines such as 2-hydroxypyridine, carboxylic acid amides such as N.N.-dimethylformamide, N.N.-dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoric triamide, N.N.
Other amides such as N'/N'-tetraethylsulfamide, ureas such as N/N'-dimethylimidazolidone, N/N/N/N-tetramethylurea, dimethylsulfone, tetramethylenesulfone, etc. Sulfones, sulfoxides such as dimethyl sulfoxide and diphenyl sulfoxide, lactones such as γ-butyrolactone and ε-caprolactone, polyethers such as tetraglyme and 18-crown-6, nitriles such as acetonitrile and benzonitrile, dimethyl carbonate , carbonate esters such as ethylene carbonate, etc. Using the above-mentioned solvents, the reaction can be carried out in either a homogeneous system or a heterogeneous suspension system. The molar ratio of carbon monoxide to hydrogen in the synthesis gas used as feedstock is generally in the range of 1/10 to 10/1. Further, there is no problem even if an inert gas such as nitrogen, methane, carbon dioxide, etc. is mixed in. The reaction pressure, expressed as the sum of carbon monoxide partial pressure and hydrogen partial pressure, is preferably in the range of 100 to 3000 Kg/cm ² , more preferably 150 to 1000 Kg/cm ² . The reaction temperature is preferably in the range of 100 to 350°C, more preferably in the range of 150 to 300°C. The method of the present invention can be carried out either continuously or batchwise. Products such as ethylene glycol and methanol can be easily separated from the reaction solution by known separation operations (eg, distillation, extraction, etc.). The catalyst in the residual liquid from which the product has been separated can be subjected to various regeneration treatments or recycled to the reaction system without any special treatment. Hereinafter, it will be explained in more detail with examples,
The present invention is not limited to these. In addition, the following abbreviations are used in the examples. EG: Ethylene glycol MeOH: Methanol Example 1 After replacing the inside of a Hastelloy-C autoclave with an internal volume of 30 c.c. with nitrogen, 0.025 mmol of tetrarhodium dodecacarbonyl (Rh ₄ (CO) ₁₂ ), triruthenium dodeca Carbonyl ( _Ru3 (CO) ₁₂ )
0.033mmol, triisopropylphosphine 0.4m
mol and 1.0 m of 4-N・N-dimethylaminopyridine
mol and N-methylpyrrolidone 7.5ml as solvent
was charged, and then an equal volume mixed gas of carbon monoxide and hydrogen was charged to 350 kg/cm ² at room temperature. The temperature of the autoclave was heated to 240°C, and the reaction was continued for 2 hours. The reaction pressure at this time was 500 Kg/cm ² . After the reaction was completed, the autoclave was cooled to room temperature, most of the gas was slowly released, the pressure was returned to normal pressure, the reaction mixture was taken out, and the product was analyzed using a gas chromatograph.
As turnover number, 24.9mol/g-atom
Rh/hr ethylene glycol and 15.0mol/g-at
om Rh·hr methanol was produced. Comparative Example 1 Triisopropylphosphine and 4-N・N
- Example 1 without addition of dimethylaminopyridine
The results of repeating the experiment were as follows. EG 1.1mol/g-atom Rh・hr MeOH 1.3mol/g-atom Rh・hr Examples 2 to 4 Using the same reactor as Example 1, experiments were conducted under the preparation and reaction conditions shown in Table 1. The results shown in Table 1 were obtained. In either case, no precipitation of the metal used as a catalyst was observed.

[Table] Examples 5 to 8 Rh ₄ (CO) ₁₂ 0.025 m in the same reactor as Example 1
mol, 0.033 mmol of Ru ₃ (CO) ₁₂ , 0.2 mmol of phosphine and 4-N·N-dimethylaminopyridine described in the table were charged, and the same reaction as in Example 1 was carried out to obtain the results shown in Table 2.

【table】

[Table] Examples 9 to 17 Rh ₄ (CO) ₁₂ 0.025 m in the same reactor as in Example 1
mol, Ru ₃ (CO) ₁₂ 0.033 mmol, iPr ₃ P0.2 mmol,
and 0.2 mmol of various amines were charged, and the reaction was carried out in the same manner as in Example 1 to obtain the results shown in Table 3.

[Table] Examples 18-27 Rh ₄ (CO) ₁₂ 0.025m in the same reactor as Example 1
mol, Ru ₃ (CO) ₁₂ 0.033 mmol, the phosphine listed in Table 3, and 7.5 ml of the solvent were charged, and the reaction was carried out in the same manner as in Example 1 to obtain the results shown in Table 4.

[Table] Example 28 Rh ₄ (CO) ₁₂ 0.025m in the same reactor as Example 1
mol, Ru ₃ (CO) ₁₂ 0.067 mmol, tri-iso-propylphosphine 0.3 mmol, and N-methylpyrrolidone 7.5 ml were charged, and the reaction was carried out in the same manner as in Example 1. As a result, the turnover number was 13.5 mol/
g-atom Rh/hr ethylene glycol and
Methanol of 13.5 mol/g-atom Rh·hr was produced.

Claims (1)

[Claims] 1 In producing aliphatic alcohols by reacting carbon monoxide and hydrogen in a liquid phase in the coexistence of a rhodium compound and a ruthenium compound, a compound of the general formula PR ₁ R ₂ R ₃ ( Here, R ₁ , R ₂ and R ₃ are the same or different primary alkyl groups,
Represents a secondary alkyl group, tertiary alkyl group or cycloalkyl group. ) A method for producing an aliphatic alcohol, which comprises coexisting a tertiary alkyl phosphine represented by: 2 In producing aliphatic alcohols by reacting carbon monoxide and hydrogen in a liquid phase in the coexistence of a rhodium compound and a ruthenium compound, the general formula PR ₁ R ₂ R ₃ (herein, R ₁ , R ₂ and R ₃ are the same or different primary alkyl groups,
Represents a secondary alkyl group, tertiary alkyl group or cycloalkyl group. ) A method for producing aliphatic alcohols, which comprises coexisting a tertiary alkyl phosphine represented by the following formula, and further adding an organic amine as a second co-catalyst.