JPS6144832A - Production of ethylene glycol - Google Patents

Abstract

PURPOSE:To accelerate the reaction for the production of the titled compound from synthetic gas which is available abundantly at a lower cost than ethylene, using a catalyst containing rhodium and trialkylphosphine, by adding an aliphatic polybasic carboxylic acid to the reaction system. CONSTITUTION:Ethylene glycol useful as a raw material of polyester fiber, etc. is produced by reacting carbon monoxide with hydrogen in liquid phase at a volume ratio of preferably 1/5-5/1 in the presence of a catalyst containing 0.001- 1g-atom of rhodium per 1l of the reaction solution and 0.5-100mol, preferably 0.8-10mol of trialkylphosphine based on 1g-atom of rhodium. In the above process, preferably 0.5-100mol of an about 2-20C aliphatic polybasic carboxylic acid based on 1g-atom of rhodium, is added to the reaction system to improve the activity of the above catalyst and to obtain the objective compound in high yield unattainable by conventional catalyst system.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a process for producing ethylene glycol 'ftM from synthesis gas, ie 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 melting, or a non-volatile antifreeze solution.

[Conventional technology]

Conventionally, 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, Tokko Sho Jr J-31/-22, Tokko Sho zs-
airai issue, special public show 1! No.-110147, JP-A-1
0-72111, special public Shoj/a-da θ/J1, special public Shojj-j19, special public Shojj-Jj4? Da issue, Tokko Akira! J-33697, Tokko Shoj/-/-2j Ko03, Tokko Sho! Goichi 1019ft, special public showj6-4106
No. 9r, JP-A No. 72-412r09, JP-A-Sho! --u
srio issue, special public Akira! 6-ftO13,2, Japanese Patent Application Publication No. 1973
3-7λ/7/da issue, Tokukai Sho! Darts No. 1091, Tokukai@za-atri 0J No., Toku Tokukai Sho! 4-lij? r number,
Tokukai Akira! Riichi person number 134776, name /j/, /9ko number,
given name/! 46 pieces No. 3, 4 g, 2.24 No. 30, %/?
5jj, 2/issue, %/? 4jtr issue, name, 2/ to 7/9
No., and name 30shi! As described in the specifications of the Dak issue, using a rhodium catalyst, under high temperature and high pressure conditions, -
A well-known method is to react carbon oxide with hydrogen.

[Problem that the invention seeks to solve]

However, in the prior art methods exemplified above,
Since catalytic activity sufficient to justify the use of expensive rhodium twice has not yet been achieved, there have been problems such as difficulty in adopting the method on an industrial scale.

[Means for solving problems]

The inventors of the present invention have arrived at the present invention as a result of intensive studies to increase the active gold content of rhodium catalysts in consideration of the above problems.

That is, the present invention provides a method for embroidering ethylene glycol by reacting carbon monoxide and hydrogen in a liquid phase in the presence of a catalyst containing rhodium and trialkylphosphine. The gist of this invention is a method for producing ethylene glycol, characterized by the presence of and.

This will be explained in more detail below.

The raw material gases used in the present invention, ie, carbon monoxide and water, are not particularly limited, and may contain a small amount of kiln waste gas or inert gas such as carbon dioxide. The volume ratio of hydrogen to backoxidizing element is usually 1/1O.
It is preferable to use gold having a composition in the range of 75 to 5/1.

In the present invention, rhodium and trialkylphosphine are present as catalyst components.

As the supply form of the rhodium component, it is possible to use rhodium metal or a rhodium compound capable of forming a rhodium carbonyl compound in the reaction zone. Specific examples of the rhodium compound include θ-valent compounds such as dirhodium octacarbonyl; monovalent @1 arsenic compounds such as acetylacetonatodicarbonyl rhodium and chlorodicarbonyl rhodium timer; pdium trichloride, nitrate @v= Salts of dium, etc.: Oxides such as rhodium trihydroxide Nidris (acetylacetonato) Trivalent complex compounds such as rhodium; Clusters such as tetrarhodium dodecacarbonyl, hexalodium hexadecacarbonyl; rhodium tetracarbonyl anion, to carbide Examples include anion rings such as xalodium bentadecacarbonyl dianion.

The amount of rhodium used is usually in the range of 0.000/~/Q gram atom, preferably θ, 0θ/~/gram atom, assuming 11 degrees in the reaction solution.

i9. The above trialkylphosphines include trimethylphosphine, triethylphosphine, tri-n-propylphosphine, tri-n-butylphosphine, tri-n
- Straight chain alkyl phosphine such as amylphosphine, tri-n-octylphosphine, tri-1@o-butylphosphine, tris(,2-ethylhexyl)phosphine, tri-490-solpylphosphine, tri-θec-
Branched alkyl phosphines such as butylphosphine and tri-t-butylphosphine; cyclic alkylphosphines such as nitricyclopentylphosphine and tridichloro\xylphosphine; and the like.

The amount of the above-mentioned trialkylphosphine used is rhodium 7.
0.2 to 10 θ mol, preferably r, ;, ', ' to 100 mol, more preferably θ, per gram atom
It is in the range of r to 10 moles.

The method of the present invention further uses an aliphatic polycarboxylic acid group which acts as a reaction accelerator.

As these aliphatic polycarboxylic acids, those having about 2 to -2Q carbon atoms are usually used.

Specific examples of the aliphatic polycarboxylic acids include oxalic acid,
Malonic acid, methylmalonic acid, ethylmalonic acid 11 ethylmethylmalonic acid: IJs, succinic acid, glutaric acid, β-ethylglutaric acid, β,! - Saturated aliphatic polycarboxylic acids such as diamic tylpropyl glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, hexadecanedioic acid; /, / - Schiff 0 butane dicarboxylic acid! L Q10-/, 3-cyclobutanedicarboxylic acid% tran! I-/ml-cyclobutanedicarboxylic acid, i,i-Schiff tetrapropanedicarboxylic acid, /, /
-cyclohexanedicarboxylic acid, /, /-7 clobentanedicarboxylic acid, C18-7, cocyclopentanedicarboxylic acid, trans-/, 2-cyclopentunedicarboxylic acid%018-/J-cyclopentanedicarboxylic acid,
trana-7,3-cyclopentanedicarbone i
Examples thereof include aliphatic polycarboxylic acids containing a hydroxy group or an oxo-so group, such as 11, /, J, and 4t-3-oxoglutaric acid.

The amount of aliphatic polycarboxylic acid used is usually rhodium 7.
0 for gram atom. /-200 mol, preferably in the range of 0.001 to 100 mol.

The present invention is carried out in the absence of a solvent (1), i.e., the reaction raw materials and catalyst components themselves are used as the solvent. Alcohols such as tanol, benzyl alcohol, phenol, 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, tetralin, etc.; aliphatic hydrocarbons such as n-hexane, n-octane, Schiftetrahexane; halogenated hydrocarbons such as dichloromethane, tricloethane, chlorobenzene;
Nonito i compounds such as nitrobenzene: N,N-dimethylformamide, H,N-dimethylacetamide, N-
Carboxylic acid amide such as methylpyrrolidone, hexamethylphosphoric acid triamide, N, N, N', N'-
Amides such as tetraethylsulfamide; Ureas such as N,M'-dimethylimidazolitone, N,N,N',N'-tetramethylurea; Sulfones such as dimethylsulfone and tetramethylenesulfonv; dimethylsulfoxide; , nitriles such as nzoethryl, carbonic acid esters such as ethylene carbonate, and the like.

Among the above solvents, it is preferable to use aptic polar solvents, such as thiamides, 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 either in a homogeneous system or in a heterogeneous suspension system. The reaction temperature is usually 10
Although a condition of θ to 300°C is adopted, a preferable temperature range is about 0 to -25θ°C. The reaction pressure is usually soicg/d or more, but preferably λ! θ~ri! It is about Okg/cd. The method of the present invention can be carried out in any of the batch, continuous, or continuous reaction formats. The dead oxygen compounds produced by the reaction, ie, ethylene glycol, methanol, 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.

〔Example〕

EXAMPLES The present invention will be explained in more detail below using 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 in units of rhodium atoms and turnover number (moA/g-atomRh-hr), which indicates the number of moles of product produced per unit reaction time.

Example-/Inner volume 3! In the OC Hastelloy 0# autoclave, θ
,/mg-atom of rhodium (Rh(CO)2(
a(laC)), tri-180-propylphosphine θ,/mmol and adipic acid 0. / mmol and N,N''-dimethylimidazolidinone/ad, and then - an equal volume mixed gas of carbon oxide and hydrogen at room temperature.
It was filled up to θotcg7cit. The initial value of the reaction pressure when the autoclave temperature was raised to 1 and 2.2θ°C was 4t7o1cg/crl. After continuing the reaction for 4 hours, the autoclave was cooled and the contents were poured out and analyzed by gas chromatography.
77.0jm04/g-atom Rh-hr of ethylene glycol and t3. a,z m027g-a
It was confirmed that methanol of tom Rh5hr was produced.

Examples 2 and Comparative Examples Reactions were carried out in the same manner as in Example 1, except that the aliphatic polycarboxylic carbon 1 [-] shown in Figure 1 was used in place of coadipic acid. The results are shown in Table-7.

Table −l*)! J-1so-propylphosphine'! The reaction was carried out without addition.

Example-j F except that tri-180-propylphosphine was changed to tricyclohexylphosphine! Example-7 and fin? What is the result of the reaction? , ≦3moz7g-ato
m Rh-hr ethylene glycol, 2j, θj'
m027g-atom Rh#hr was found to be producing 1Mu.

Comparative Example-3 Example- except that adipic acid was not added! As a result of carrying out the reaction in the same manner as , g, j' 9 m027g-a
ZO7ll Rh -hr's ethylene glycol and /2J! It was confirmed that methanol of mol/g-atom nh@hr was produced.

〔effect〕

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 using conventional catalyst threads.

Claims (1)

[Claims] (1) In a method for producing ethylene glycol by reacting carbon monoxide and hydrogen in a liquid phase in the presence of a catalyst containing rhodium and trialkylphosphine, it is possible to include an aliphatic polycarboxylic acid in the reaction system. Characteristic method for producing ethylene glycol.