JPS61215337A - Production of ethylene glycol - Google Patents

Abstract

PURPOSE:To produce the titled compound in high rate of production, selectivity and yield under relatively moderate condition, by reacting CO with H2 under high temperature and pressure condition in the presence of a Rh-containing compound catalyst using a specific organic phosphorus compound as a reaction accelerator. CONSTITUTION:The objective compound can be produced by reacting CO with H2 at a molar ratio (CO/H2) of 0.05-20 in the presence of a Rh-containing compound catalyst such as tetrarhodium dodecacarbonium at 50-350 deg.C under 1-2,000kg/cm<2>G pressure for 0.1-20hr preferably in a solvent adding an organic phosphorus compound comprising the 9-substituted-9-phosphabicyclo[3.3.1]nonane of formula I (R is 1-20C alkyl or cycloalkyl) and/or the 9-substituted phosphabicyclo[4.2.1]nonane of formula II as a reaction accelerator to the reaction system. The atomic ratio of the P atom of the organic phosphorus compound to the Rh atom is 0.1-500.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for producing ethylene glycol.

According to the method of the present invention, ethylene glycol can be produced at a high selectivity and at a high production rate under relatively mild conditions using carbon monoxide and hydrogen.

≦ffi Ethylene glycol has conventionally been produced by an oxidation reaction of ethylene. In recent years, due to factors such as the soaring price of ethylene, techniques for producing carbon monoxide and hydrogen from synthesis gas, which are cheaper raw materials, are being developed.

For example, %'j: Showa 53-31122, Showa 55-4382
1, 53-15047, JP-A-50-3294, 5
6-40698, JP-A-52-42809, JP-A-52-4
2810. Special Publication No. 56-40132, Japanese Patent Publication No. 53-12
1714, 54-71094, 54-48703,
54-92903, 130941 and 57-13
0942 Koji No. 25530, Koji No. 4199521
As disclosed in the specifications of No. 4190598, No. 4211719, and No. 4302547, there is a known method of reacting synthesis gas at high temperature and high pressure using a rhodium catalyst. .

In these known technologies, rhodium catalysts still have low activity in terms of production rate of ethylene glycol per unit catalyst amount, and there is still no practical way to produce ethylene glycol on an industrial scale using expensive rhodium catalysts. Not enough.

Summary of the Invention As a result of intensive studies to increase the production rate and selectivity of ethylene glycol per unit rhodium atom in a method for producing ethylene glycol using a rhodium catalyst, the present inventors have developed an organic phosphorus compound having a specific structure. ,
That is, 9-alkyl-9-phosphabicyclo(3,3,
1) Nonane and an organic phosphorus compound represented by general formula (I) and/or general formula (II) (wherein R is an alkyl group of 01 to 20 or a cycloargyl group) are added to the reaction system to carry out the reaction. The present invention provides a method for producing ethylene glycol.

The rhodium-containing compound as a catalyst used in the method of the present invention is not particularly limited, but includes, for example, metal rhodium, rhodium oxides, hydroxides, inorganic acid salts, Examples include organic acid salts and complex compounds. More specifically, dirhodium trioxide, rhodium dioxide, rhodium hydroxide, nium)hequinalodium pentadecacarbonyl, dicarbonyl(η-cyclopentadienyl)rhodium, (l-cyclopentadienyl)(17- Examples include rhodium and rhodocene.

The usage noise of the rhodium-containing compound is I x 10- per liter of reaction solution as # degrees of rhodium atoms in the reaction solution.
' to 100 gram atoms, preferably 1 x 10 to 10 gram atoms.

The organic phosphorus compound used as a reaction accelerator in the present invention has a structure represented by the following general formulas (I) and (TI).

(Here, R represents an alkyl group or cycloalkyl group having 1 to 20 carbon atoms) The organic phosphorus compound of the above general formula (1) is a 9-substituted 3,29-phosphabicyclo(3,3,1 Nonane, general formula (
The organic compound 9218 (ii) is called 9-substituted-9-phosphabicyclo[4,2゜1]nonane, and the specific series of substituents R include methyl group and ethyl group. , 1-propyl group, 2-propyl group, 1-butyl group, 2-butyl group, 2-methyl-1-propyl group, tert-butyl group, 1-nee-pentyl group, 1-methyl-1-butyl group alkyl groups such as neopentyl group, ■-hexyl group, 1-octyl group, 1-decyl group, 1-dodecyl group, 1-eicosyl group, cyclopentyl group, cyclohexyl group, cyclooctyl group, cyclodecyl group, cyclododecyl group Examples include cycloalkyl groups such as.

The above-mentioned organic phosphorus compound can be used alone or in combination with the compound represented by the general formula (I) and the compound represented by the general formula ([), but it can increase the production rate and selectivity of the target ethylene glycol. To do this, the general formula (
Preference is given to using the organophosphorus compounds represented by 1) alone or in mixtures of these compounds.

The amount of these organic phosphorus compounds used varies depending on the compound, but it is necessary that the atomic ratio of phosphorus atoms to rhodium atoms used be in the range of 0.1 to 500, more preferably 0.5 to 300. Although it is desirable, the reaction solvent may be any solvent that can dissolve the rhodium heavy compound catalyst and the organic phosphorus compound as the reaction promoter.
You can use the ones listed below.

For example, ethers such as diethyl ether, tetrahydrofuran, dioxane, diethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether, ketones such as acetone, diethyl ketone, and acetophenone, 7 enols such as phenol and methoxyphenol, methyl acetate, ethyl acetate, and ethylene glycol. Esters such as diacetate and r-butyrolactone, sulfones such as sulfolane and dimethylsulfone, sulfoxides such as dimethylsulfoxide and diethylsulfoxide,
N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidinone, N-isopropylpyrrolidinone, N-methyl-2-pyridone amide, Nl, he, 8-TI'771 no V urea, Substituted ureas such as N,N-dimethylimidazolidinone, hexamethylphosphoric triamide 1, tri- or alicyclic hydrocarbons,
These include nitro compounds such as nitromethane and nitrobenzene, nitriles such as acetonyl-IJ2 and benzonitrile, and carbonic acid esters such as dimethyl carbonate and ethylene carbonate.

In the method of the present invention, the reaction is carried out under heated and pressurized conditions. The reaction pressure is usually 1 to 2,000 storage/mG,
Preferably ii30 to 1,000/dG.

More preferably, it is in the range of 50 to 60 (1#/iG).

At this time, the ratio of carbon monoxide and hydrogen supplied to the reaction system as raw material gas for ethylene glycol production is usually 0.05 to 2 as a molar ratio of carbon monoxide to hydrogen gas.
0, preferably o, i to 10. The reaction temperature is usually 50 to 350°C, preferably 100 to 350°C.
It is in the range of 00°C. Furthermore, the reaction time is usually 0.1
A range of ˜20 hours is used, preferably 0.3 to 10 hours.

Kenpo can be practiced batchwise, semi-continuously or continuously.

Examples 1 to 10 of "11" A method was adopted in which this was rotated from the outside by magnetic induction.

Under an argon gas atmosphere, 18.7 milligrams of sodium dodecalponyl (0.1 milligram atoms as a rhodium atom) was added to the reactor, an organic phosphorus compound shown in Table 1, and 7 N,N-dimethylimidazolidinone as a solvent. After charging .5d and sealing the reactor, the gas in the reaction system was replaced several times with an equimolar mixed gas of carbon monoxide and hydrogen, and the mixture was heated to 370Af, 'J (gauge pressure) at room temperature.
The mixed gas was sealed in the reactor until the temperature reached . This reactor was stirred by external magnetic induction rotation and heated using an electric furnace until the temperature of the reaction solution reached 220°C. This temperature is 2
When the reaction was carried out for a certain period of time, absorption of gas was observed over time. The maximum pressure reached at 220°C and the pressure at the end of the reaction are shown in Table 1 as maximum pressure - minimum pressure.

After the reaction was completed, the reactor was rapidly cooled to room temperature, and unreacted gas was purged to obtain a homogeneous reaction solution. This is 1-Pr = isopropyl group, n-Bu: first fluor group, Cartl
= cyclohexyl group, CsH* = cyclopentyl group, respectively.

Effects of the Invention From the above experimental examples, it is clear that according to the method of the present invention, the desired ethylene glycol can be produced in good yield at a high production rate and high selectivity under relatively mild conditions.

Claims (1)

[Claims] (1) In a method for producing ethylene glycol by reacting carbon monoxide and hydrogen under heated and pressurized conditions in the presence of a rhodium-containing compound catalyst, general formula (I) and/or general formula (II) is added to the reaction system. , ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) (However, R is an alkyl group or cycloalkyl group of C_1_ to_2_0) A method for producing ethylene glycol, which comprises adding the expressed organic phosphorus compound to carry out the reaction.