JPS61215339A - 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 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 catalyst such as tetrarhodium dodecacarbonium at 50-350 deg.C under 1-2,000kg/ cm2G pressure for 0.1-20hr preferably in a solvent adding an organic phosphorus compound of formula (R<1> and R<2> are 3-12C alkylene wherein the C atom bonded to P is secondary or tertiary; R<3> is 1-4C alkyl; n is 0 or 1) such as di-tert-butyl(trimethylsilylmethyl)phosphinone, etc., as a reaction accelerator to the reaction system. The molar ratio of the organic phosphorus compound to the Rh atom is 0.1-500.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field Ethylene glycol can be produced rapidly and with high selectivity and high yield.

BACKGROUND OF THE INVENTION Ethylene glycol has traditionally been produced by an oxidation reaction of ethylene. In recent years, due to factors such as the soaring price of ethylene, production technology from synthetic gas, which is a cheaper raw material, is being developed.

For example, Special Publications No. 53-31122, No. 55-43821,
53-15047, JP 50-32118, JP 56-40131, JP 55-5497, JP 55-336
94, 55-33697, JP 51°-12520
3, 'Special Publication No. 56-108094, No. 54-48703
, 54-92903, 54-16415, 54-
As disclosed in the specifications of No. 122211, No. 90598, No. 4211719, and No. 4302547, a method is known in which a rhodium catalyst is used and synthesis gas is reacted at high temperature and high pressure.

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

The present inventors have conducted intensive studies to increase the production rate and selectivity of ethylene glycol per unit rhodium atom in a method of forming an ethylene glycol structure using a rhodium-containing compound catalyst. When an organic phosphorus compound containing 03
-12 and the carbon bonded to the phosphorus atom is a secondary or tertiary alkyl group, R3 is a C1-4 alkyl group, and n is 0 or 1). The present invention provides a method for producing ethylene glycol, characterized in that the reaction is carried out by adding t-addition.

Detailed Description of the Invention The rhodium-containing compound used in the method of the present invention is not particularly limited, but includes, for example, metallic rhodium, rhodium oxides, hydroxides, inorganic acid salts, organic acid salts, or complex compounds. can be exemplified. More specifically,
Dirhodium trioxide, rhodium dioxide, rhodium hydroxide,
rhodium oxalate, rhodium nitrate, rhodium sulfate, rhodium trisacetylacetonate, rhodium acetate, propylammonium) dodecalhodium tridecacal(η-nclopentadienyl) rhodium, (η
-cyclobentadienyl) (η-cyclooctadiene)
Examples include rhodium and rhodocene.

The amount of rhodium compound used is 1Xl0-6 to 10 per liter of reaction solution as the concentration of rhodium atoms in the reaction solution.
0 gram atom, preferably lXl0-5 to 10 gram atom.

The organic phosphorus compound used in the method of the present invention is a compound having a structure represented by the following general formula (I).

(However, R1 and R2 are the same or different C3-12 alkyl groups in which the carbon bonded to the phosphorus atom is secondary or tertiary, R3 is a C1-4 alkyl group, and n is 0 or 1 respectively).

ru group, cyclopentyl group, cyclohexyl group, sil group,
These include sec-butyl group, tertiary-butyl group, isobutyl group, and the like.

Furthermore, specific examples of these organic phosphorus compounds include =]nprovir(trimethylsilyl)phosphine, methyl)phosphine, di-tert-butyl(trimethylsilylmethyl)phosphine, dicyclopentyl(1-'J-n-7
'Tylsilylmethyl)phosphine, dicyclooctyl(
Examples include triethylsilylmethyl)phosphine.

These organic phosphorus compounds can be used alone or in combination of two or more.

The amount of these organic phosphorus compounds used varies depending on the type, but generally, an acidic substance such as a boronic acid can be added to the rhodium atom used in the reaction system. By adding these compounds, the effect of adding the organic phosphorus compound, that is, aromatic amines such as ethylamine, tributylamine, and tricyclohexy; pyridines such as pyridine, 4-dimethylaminopyridine, and 2-hydroxypyridine; 1.1 .4.4-Tetramethylethylenediamine, 1.1,8.8-tetramethylhexamethylenediamine, aliphatic polyamines such as 1.8-diazabicyclo(5,4,0) to undecene-7, 1-methylimidazole , imidazoles such as 1-methylbenzimidazole, and the like. Examples of carboxylic acids include aliphatic carboxylic acids such as formic acid, acetic acid, and trichloroacetic acid, and aromatic carboxylic acids such as benzoic acid and 3-fluorobenzoic acid.

The preferable addition amount range of the above-mentioned tertiary amines and carboxylic acids depends on the compound to be added, but in general, it is o and i to SOO times the rhodium compound used, and more preferably 0.5 to Any material may be used as long as it dissolves additives, etc., and those described below can be used. Ethers such as ester, tetraethylene glycol dimethyl ether, acetone, diethyl ketone,
Ketones such as acetophenone, phenols such as phenol and methoxyphenol, methyl acetate, ethyl acetate,
Esters such as ethylene glycol diacetate and γ-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
- Substituted ureas such as urea, N,N-dimethylimidazolidinone, phosphoric acid triamides such as hexamethylphosphoric acid triamide and tripiperidinophosphine oxide, nitriles such as benzene, toluene, xylene, and tetrandinitrile; These include dimethyl carbonate, ethylene carbonate, and other carbonate esters.

1:.

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#/ad
G, preferably 30-1,000 A11/cj
G.

More preferably, it is in the range of 50 to soo#/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 20 as a molar ratio of carbon monoxide to hydrogen gas.
, preferably in the range of 0.1 to 1°. The reaction temperature is usually 50 to 350°C, preferably 100 to 30°C.
It is in the range of 0°C. Furthermore, the reaction time is usually 0.1~
A time period of 20 hours is used, preferably a range of 0.3 to 10 hours.

The process can be carried out batchwise, semi-continuously or continuously.

”■11 Examples 1-2 The reactor is s o o # / cj G (gauge pressure)
As a real atom, it can withstand up to 0.4 mIJ g atom),
0.8 mmol each of the organic phosphorus compounds shown in Table 1, and N,N-dimethylimidazolidinone = 7 as a solvent.
．． After charging 5 d 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 reaction was continued at room temperature until the pressure reached 37 tcg/dG (gauge pressure). The mixed gas was sealed in the vessel.

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. When the reaction was carried out while maintaining this temperature for 1 hour, 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 was quantitatively analyzed by gas chromatography. Comparative Example 1 Example J1 except that no organic phosphorus compound was added. ;
The reaction was carried out in the same manner as above, and the resulting reaction solution was analyzed, and the results are shown in Table 1.

(Leaving space below) Examples 3 to 5 In Example 1, 0.8 μIJ mole of each of the compounds shown in Table 2 was used as the organic phosphorus compound, and 1,1.8.8-tetramethyl was used as the second additive. The reaction was carried out in the same manner as in Example 1, except that 0.8 mmol of hexamethylene diamine was added to each reaction system. The results are shown in Table 2.

(The following is a blank space) 11 However, [From the above-mentioned experimental examples, it is clear that according to the method of the present invention, the desired ethylene glycol can be produced at a high production rate and in high yield with high selectivity.'

Claims (1)

[Claims] (1) In the method of producing ethylene glycol by reacting carbon monoxide and hydrogen under heat and pressure conditions in the presence of a rhodium-containing compound catalyst, the reaction system includes general formulas, ▲mathematical formulas, chemical formulas, tables, etc.▼ (However, R^1 and R^2 are the same or different C_3_~_
1_2 and the carbon bonded to the phosphorus atom is secondary or tertiary
ethylene glycol is produced by adding and reacting an organic phosphorus compound represented by R^3 is an alkyl group of C_1_ to_4, and n is 0 or 1, respectively. Method.