JPS6052140B2 - Manufacturing method of ethylene glycol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for the catalytic production of ethylene glycol from synthesis gas, a mixture of carbon monoxide and hydrogen.

Ethylene glycol is an extremely important chemical product industrially as a raw material for polyester fibers, a raw material for organic solvents, and a non-volatile antifreeze.

Traditionally, ethylene glycol has been produced by the oxidation reaction of ethylene.

In recent years, as a method for producing ethylene glycol, a technology has been developed that uses synthesis gas, which is a cheaper and more abundant raw material than ethylene, as a raw material. For example, JP 53-311n, JP 55-43821, JP 53-15047, JP 50-32118.
No., Special Publication No. 56-40131, Special Publication No. 55-5497
No., Special Publication No. 55-33694, Special Publication No. 55-3369
No. 7, JP-A-51-125203, JP-A-56-10
No. 894, JP 56-40698, JP 52-4
No. 28, Japanese Patent Publication No. 52-4281, Special Publication No. 56-40
No. 132, JP-A-53-121714, JP-A-54-
No. 71098, JP-A-54-48703, JP-A-54
-92903, JP-A-54-16415, JP-A-5
4-122211, JP 55-9065, JP 53-10888, JP 56-75498, JP 57-128645, JP 57-130941, and JP 57 -13094 Wani publications and U.S. Patent Nos. 4,013,700 and 4,199,520,
No. 4,133,776, No. 4,151,192, 4,1
No. 53,623, No. 4,225, No. 5 (to), No. 4,199
, No. 521, No. 4,190,598, and No. 4,211,
As described in the specifications of No. 7m, a method of reacting carbon monoxide and hydrogen using a rhodium catalyst under high temperature and high pressure conditions is well known. However, the methods of the prior art exemplified above have not yet achieved catalytic activity commensurate with the use of expensive rhodium, so it is difficult to adopt them as a method for implementing them on an industrial scale. I have a problem.

The present inventors took the above circumstances into consideration and, as a result of intensive studies to increase the activity of the rhodium catalyst, arrived at the present invention.

That is, the present invention provides a method for producing ethylene glycol by reacting carbon monoxide and hydrogen in a liquid phase, in which rhodium and the general formula -PRl, R2, R3 (wherein the group R1 is a primary represents an alkyl group, the group R2 represents a secondary alkyl group, a tertiary alkyl group or a cycloalkyl group, and the group R3 represents a primary alkyl group, a secondary alkyl group, a tertiary alkyl group or a cycloalkyl group (represents) table. The gist of this invention is a method for producing ethylene glycol, which is characterized in that it uses a trialkylphosphine prepared by the method described above.

According to the method of the present invention, it is possible to produce ethylene glycol at a high level of yield that could not be achieved with conventional catalyst systems. The present invention will be explained in more detail below. The raw material gases used in the present invention, ie, carbon monoxide and hydrogen, are not particularly limited, and may contain some amount of inert gas such as nitrogen gas or carbon dioxide.

The volume ratio of hydrogen and carbon monoxide is usually 1/10 to 10/1.
The composition is preferably in the range of 1/5 to 5/1. In the present invention, it is first necessary to contain rhodium as a catalyst component.

As the feeding form of the rhodium component, any rhodium metal or rhodium compound capable of forming a rhodium-carbonyl compound in the reaction zone can be used. Specific examples of rhodium compounds include o-valent compounds such as dirhodium octacarbonyl; monovalent complex compounds such as acetylacetonatobis(carbonyl)rhodium, bromotris(pyridine)rhodium, and chlorotris(triphenylbosphin)rhodium; Rhodium salts such as rhodium chloride, rhodium nitrate, and rhodium acetate; oxides such as rhodium trihydroxide; trivalent complex compounds such as tris(acetylacetone) rhodium; cluster compounds such as tetrarhodium dodecacarbonyl and hexalodium-xadecacarbonyl; rhodium Examples include anion complexes such as tetracarbonyl anion and carbidehexalodium pentadecacarbonyl dianion. The amount of rhodium used is the concentration in the reaction solution, and is usually 0.000 rhodium atoms per liter of reaction solution.
It ranges from 1 to 100 gram atoms, preferably from 0.001 to 10 gram atoms.

The present invention also requires the use of a specific trialkylphosphine that acts as a reaction promoter as a catalyst component.

This is thought to have the function of coordinating with rhodium, the main catalyst, and controlling its electronic state. Although the details of the mechanism are not necessarily clear, it is assumed that, for example, the electron donating ability of trialkylphosphine plays an important role. In fact, even when rhodium-phosphine catalysts are used, the selectivity to ethylene glycol varies greatly depending on the type of phosphine. Therefore, in the present invention, in order to achieve a high level of ethylene glycol yield, phosphines, especially common phosphines, are used. AR1R2R3
[However, the group R1 represents a primary alkyl group, and the group R2 represents a secondary alkyl group, a tertiary alkyl group, or a cycloalkyl group (hereinafter collectively referred to as "α monobranched alkyl group"), The group R3 represents a primary alkyl group or an α-monobranched alkyl group]. In this case, it is understood that as a result of the electronic interaction between the alkyl groups in the trialkylphosphine molecule, the physical property constant of the electron donating ability described above is adjusted to a desired state, and the suitable properties as a promoter are exhibited. be done. Specific examples of trialkylphosphines used in the present invention include di-1s0-propylethylphosphine,
1s0-propyl-n-butylphosphine, 1s0-propyl-n-butylphosphine,
-Butyl-methylphosphine, di-t-butyl-ethylphosphine, di-t-butyl-n-propylphosphine, di-t-butyl-n-butylphosphine, dicyclopentyl-ethylphosphine, dicyclopentyl-n-propylphosphine, dicyclopentyl -n-butylphosphine, dicyclohexy-methylphosphine, dicyclohexy-ethylphosphine, dicyclohexy-n
-Butylphosphine, diadamantyl-ethylphosphine, diadamantyl-n-butylphosphine, dinorborny-ethylphosphine, dinorborny-n-butylphosphine, IsO-propyl-t-butyl-n-butylphosphine, t-butyl-cyclohexy-ethylphosphine one primary alkyl group and two α-
Trialkylphosphine having a branched alkyl group; Is
O-propyl-diethylphosphine, IsO-propyl-n-butylphosphine, IsO-propyl-ethyl-n-butylphosphine, t-butyl-diethylphosphine, t-butyl-n-butylphosphine, cyclopentyl-diethylphosphine, cyclopentyl-n-butylphosphine Propylphosphine, cyclopentyl-ethyl-n-butylphosphine, cyclohexyl-diethylphosphine, cyclohexyl-n-octylphosphine, adamantyl-diethylphosphine, adamantyl-n-butylphosphine, norbornyl-diethylphosphine, norbornyl-n-butylphosphine Trialkylphosphines having two primary alkyl groups and one α monobranched alkyl group such as -butylphosphine are mentioned.

The amount of trialkylphosphine used is usually 0.2 to 1,000 mol, preferably 0.2 to 500 mol, more preferably 0.2 to 100 mol, per gram atom of rhodium.
mol, more preferably in the range of 0.5 to 10 mol.

The present invention can be carried out in the absence of a solvent, that is, the reaction raw materials and catalyst components themselves can be used as a solvent, but a solvent can also be used. Examples of such solvents include ethers such as diethyl ether, anisole, tetrahydrofuran, ethylene glycol dimethyl ether, and dioxane; ketones such as acetone, methyl ethyl ketone, and acetophenone; methanol, ethanol,
Alcohols such as n-butanol, benzyl alcohol, phenol, ethylene glycol, diethylene glycol; Carboxylic acids such as formic acid, acetic acid, propionic acid, toluic acid; Esters such as methyl acetate, n-butyl acetate, benzyl benzoate; benzene, Aromatic hydrocarbons such as toluene, ethylbenzene, 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; N,N-dimethylformamide, N,
Carboxylic acid amides such as N-dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoric acid triamide, N,
Amides of inorganic acids such as N,N'',N''-tetraethylsulfamide;N,N''-dimethylimidazolidone, N,
Ureas such as N,N'',N'-tetramethylurea; Sulfones such as dimethylsulfone and tetramethylenesulfone;
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 and ethylene Examples include carbonate esters such as carbonate and carbonate. Among the above solvents, it is preferable to use aprotic polar solvents, such as amides, ureas, sulfones, sulfoxides, lactones, polyethers, nitriles, and carbonate esters. Particularly preferred are aprotic polar solvents having a dielectric constant of 20 or more. The reaction of the present invention can be carried out in either a homogeneous system or a heterogeneous suspension system.

The reaction temperature is usually 100 to 300°C, but a more preferable temperature range is about 100 to 250°C. The reaction pressure is usually 50k9/Clt or higher, preferably 150 to 600k9/a.
It is about l. The method of the present invention can be carried out in any batch, semi-continuous or continuous reaction mode.
Oxygen-containing compounds produced by the reaction, ie, ethylene glycol, methanol, ethanol, etc., can be separated by conventional separation methods such as distillation. Furthermore, the distillation residue can be recycled and reused as a reaction catalyst liquid. EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

The amount of product produced was expressed as a turnover number (MOl/g-AtOmRh-Hr), which indicates the number of moles of product produced per rhodium atom position and unit reaction time. Example 1 A Hastelloy C autoclave with an internal volume of 35 cc was charged with 0.
Acetylacetona, tobis(carbonyl)rhodium [Rh(CO)2(Aca
c)], di(t-butyl)n-butylphosphine 0.1
Charge 10ml of N-methylpyrrolidinone and 10ml of N-methylpyrrolidinone, and add 30ml of equidissolved mixed gas of carbon monoxide and hydrogen at room temperature.
Filled with 0k9/CTl.

The initial pressure of the reactor was 485 kg/Cd when the temperature of the autoclave was raised to 240°C. After continuing the reaction for 2 hours, the autoclave was cooled and the contents were taken out and analyzed by gas chromatography. As a result, 22.3 m01/g-AtOmRh-H
R-3 ethylene glycol and 10.8rr101/g
It was confirmed that methanol of -AtOmRhIhr was produced. Example 2 The reaction was carried out in the same manner as in Example 1, except that N,N''-dimethylimidazolidinone was used instead of N-methylpyrrolidinone as the solvent. As a result, 20.6n101/g-AtOmRhIhr. Ethylene glycol and 13.4m01/~g-AtO
It was confirmed that mRh●Hr methanol was produced. Comparative Example 1 The reaction was carried out in the same manner as in Example 2 without using di(t-butyl)n-butylphosphine, and as a result, 1
It was confirmed that 2.3 m01/g-AtOnlRh-Hr of ethylene glycol and 8.6 m01/g-AtOmRh●Hr of methanol were produced.

Examples 3 to 4 Examples - except that the amount of di(t-butyl)n-butylphosphine used was changed as shown in Table 1.
Table 1 shows the results of the reaction conducted in the same manner as in 2.

Examples 5 to 7 In place of di(t-butyl)n-butylphosphine
The reaction was carried out in the same manner as in Example 2, except that the phosphine shown in Example 2 was used and the reaction temperature and amount of phosphine used were partially changed as shown in Table 2. The results are shown in Table 2.

Examples 8 to 9 The reaction was carried out in the same manner as in Example 1, except that the phosphines shown in Table 3 were used instead of di(t-butyl)n-butylphosphine, and the reaction temperature was 230'C. .

The results are shown in Table-3. Comparative Example 2 The reaction was carried out in the same manner as in Example-1 except that di(t-butyl)n-butylphosphine was not used and the reaction temperature was 230°C. As a result, 7.63n101/g-A
tOmRh●Hr of ethylene glycol and 5.78m
It was confirmed that methanol of 01/g-AtOmRhlIhr was produced.

Example 10 In a Hastelloy C autoclave with an internal volume of 35 cc, 0.
Acetylacetonatobis(carbonyl)rhodium [Rh(CO)2(Acac)] containing 6mm01 of rhodium
], di(t-butyl)n-butylphosphine 0.6n1
m01 and N,N″-dimethylimidazolidinone 4m
1 and then filled with an equal volume mixed gas of carbon monoxide and hydrogen up to 300k9/C7lf at room temperature.

The initial value of the reaction pressure when the autoclave temperature was raised to 230°C was 480k9/Clt. 5 more
The reaction was started by adding an equal volume mixed gas of carbon monoxide and hydrogen to 20k9/Clt. When the pressure drops to 500kg/cl, add gas to 520k9/C.
The reaction was continued for 1 hour while repeatedly returning to IL. The autoclave was cooled and the contents were taken out and analyzed by gas chromatography. As a result, the turnover number was 12.85 m01/g-AtOmRh●
Hr ethylene glycol and Q9.2 lmOl/g-
It was confirmed that methanol of AtOmRh●Hr was produced. The space-time yield of ethylene glycol reached 120 g/l-Hr based on the charged solvent. [In the rhodium-cesium benzoate-N-methylmorpholine-sulfolane (solvent) system, which is a known typical rhodium catalyst system, ethylene glycol vacancies are eliminated even when high pressure of 1030 kg/d and high temperature conditions of 260°C are used. The hourly yield is 1
Only 18g/11Hr. (Jose, El Vidal (
JOse, L., Vicial), and W. E. Walker, Inorganic Chemistry, Kanmaki 89
Example 11 The amount of rhodium used was 0.9rT1m01, and the amount of di(t-butyl)n-butylphosphine was 0.9111m
The reaction was carried out in the same manner as in Example 10 except that 0I was used. As a result, 9.39rn01/g-AtOmRhIh
r ethylene glycol and 19.98 n101/g-
It was confirmed that methanol of AtOmRh●Hr was produced.

Claims (1)

[Claims] 1. In a method for producing ethylene glycol by reacting carbon monoxide and hydrogen in a liquid phase, rhodium and general formula PR_1R_2R_3 (in the formula, group R_1
represents a primary alkyl group, the group R_2 represents a secondary alkyl group, a tertiary alkyl group, or a cycloalkyl group, and the group R_3 represents a primary alkyl group, a secondary alkyl group,
A method for producing ethylene glycol, which uses a trialkylphosphine represented by a tertiary alkyl group or a cycloalkyl group.