JPH0156057B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new process for the production of ethylene glycol and ethylene glycol derivatives from synthesis gas using a new catalyst system that improves the selectivity and yield to ethylene glycol. More specifically, the present invention provides a catalyst consisting of ruthenium, rhodium and manganese carbonyl compounds dispersed in a low melting point quaternary phosphonium compound dissolved in an N-lower-alkyl or N-cycloalkylpyrrolidone solvent, and carbon monoxide and hydrogen. An object of the present invention is to provide a new and improved method for producing a mixture of ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methanol, and ethanol in which the yield is improved by contacting the mixture with the mixture. Ethylene glycol is a chemical that has found widespread use in industry. It is used, for example, in the production of plasticizers for vinyl polymers or as a component of polyester fibers and antifreeze compositions. In view of its many uses, there is a need to find new and more economical ways to produce it. A proposed method for producing ethylene glycol involves the reaction of carbon monoxide with hydrogen in the presence of various catalyst systems. Generally, a mixture of carbon monoxide and hydrogen, known as synthesis gas or syngas, is reacted at high temperature and pressure in the presence of the proposed catalyst. For example, Belgian patent no.
No. 793,086 and US Pat. No. 3,940,432 describe the co-synthesis of ethylene glycol and methanol using rhodium complex catalysts. US Patent No.
No. 3,833,634 describes the use of various other metals as catalysts, but only rhodium and cobalt are effective in the production of ethylene glycol, with typical yields of ethylene glycol ranging from 58 parts to 9.8 parts. It has been shown that U.S. Pat. No. 3,989,799 discloses a series of carbonyl mixed metal salts useful as catalysts in the production of oxygenated compounds by the reaction of carbon monoxide and hydrogen. There is no report on selectivity for specific compounds such as ethylene glycol, nor is there any mention of the use of quaternary "onium" salts. US Pat. No. 4,013,700 discloses a method for preparing polyhydric alcohols and their ether and ester derivatives in the presence of quaternary phosphonium cations and rhodium carbonyl complexes. This system produces ethylene glycol in moderate yield, as shown by the yield of 4.2 g or less. U.S. Pat. No. 4,265,828 discloses that a catalyst system consisting of a mixture of CO and H ₂ and a ruthenium compound dispersed in a low melting point quaternary phosphonium or ammonium base or salt is heated at a temperature of at least 150° C. under a pressure of greater than 500 psi (3.5 MPa). A method for producing ethylene glycol is disclosed which comprises heating at a temperature of . The maximum yield of ethylene glycol obtained by this method was 17.6% by weight. U.S. Pat. No. 4,315,994 discloses the use of a bimetallic catalyst system consisting of acetylacetonatoruthenium () and acetylacetonatrodium () dispersed in a low melting point quaternary onium base or salt at temperatures of at least 150°C. The production of alkylene glycols and their ethers is disclosed. The highest reported selectivity to ethylene glycol was 18.5% by weight. Many of these methods are limited by the nature and activity of the catalyst system. Many catalysts provide very mediocre selectivity to the desired glycol, have limited solubility, and/or are expensive to manufacture. It would be a significant advance in the art if processes for producing ethylene glycol and monohydric alcohols were improved to produce ethylene glycol in higher yields and selectivities. The objective of obtaining ethylene glycol in these higher yields and selectivities was to combine a mixture of carbon monoxide and hydrogen with N-lower-alkyl or N-
A catalyst consisting of a ruthenium carbonyl compound, a rhodium carbonyl compound and a manganese carbonyl compound dispersed in a low melting point quaternary phosphonium salt dissolved in a cycloalkylpyrrolidone solvent.
It has been found that this can be achieved by the process of the invention, which consists of contacting at a temperature of ~350<0>C and a pressure of from 5 to 75 MPa. This process produces ethylene glycol and glycol derivatives including ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, methanol and ethanol. Surprisingly, by using this novel catalyst system, higher yields and selectivities can be achieved in the production of ethylene glycol, which is traditionally obtained from syngas in the relevant synthesis process. It was found that it could be synthesized in a higher yield than previously. The process of the invention, as far as the formation of the target ethylene glycol is concerned, can be illustrated by the following formula: Typical yields of ethylene glycol are 10-40% by weight of the total liquid product. The ruthenium carbonyl compounds used in the catalyst used in the present invention include simple carbonyl compounds such as triruthenium dodecacarbonyl;
Hydroxycarbonyl compounds such as H ₂ Ru (CO) ₁₃ or H ₄ Ru (CO) _{12 ,} or tricarbonylruthenium chloride () dimer, |Ru(CO) ₃ Cl ₂ | ₂
There are substituted carbonyl compounds such as A preferred ruthenium compound is triruthenium dodecacarbonyl. Suitable rhodium carbonyl compounds include simple carbonyls and hydrocarbonyls such as tetrarhodium dodecacarbonyl and hexalhodium hexadecacarbonyl, chlorodicarbonyl rhodium() dimer, and most preferably dicarbonyl (acetylacetate). Nato) Rhodium (). The manganese carbonyl compound used in the catalyst composition is preferably a compound having one manganese atom with three separate carbonyl groups and an unsaturated hydrocarbon group, such as those having the formula: YMn(CO) ₃ (formula where Y is an unsaturated aliphatic or alicyclic hydrocarbon group containing 2 to 16 carbon atoms, such as allyl, cyclopentadienyl, cyclohexadienyl, methylcyclopentadienyl, phenylcyclopentadienyl; is an alkyl or aryl substituted alicyclic group such as dienyl or butylcyclohexadienyl). Examples of these are:
Among them, allylmanganesetricarbonyl, cyclohexadienylmanganesetricarbonyl, butadienylmanganesetricarbonyl, cyclohexenylmanganesetricarbonyl, and methylcyclopentenylmanganesecarbonyl are mentioned. Particularly preferred manganese carbonyl compounds include:
Mention may be made of allylmanganese tricarbonyl, cyclopentadienyl manganese tricarbonyl and methylcyclopentadienyl manganese tricarbonyl. The ruthenium, rhodium and manganese carbonyl compounds are first dispersed in a low melting point quaternary borophonium base or salt. The quaternary phosphonium base or salt selected should have a relatively low melting point, ie, should have a melting point below the reaction temperature. Usually the quaternary phosphonium compounds used have a melting point below 180°C, preferably 150°C.
It has a melting point below. Suitable quaternary phosphonium salts have the formula: [In the formula, R ₁ , R ₂ , R ₃ and R ₄ are organic groups (especially aliphatic hydrocarbon groups bonded to a phosphorus atom),
X is an anion, preferably a chloride or bromide ion. Preferred organic groups include alkyls having 1 to 20 carbon atoms, which are straight or branched, such as methyl, ethyl, n-butyl, isobutyl, octyl, 2-ethylhexyl and dodecyl. Tetraethylphosphonium bromide and tetrabutylphosphonium bromide are typical examples in commercial production today. corresponding fourth
Bophonium acetate, benzoate and butyrate are also satisfactory. Specific examples of suitable quaternary phosphonium salts include:
Tetrabutylphosphonium bromide, tetraheptylphosphonium bromide, tetrabutylphosphonium acetate, tetrabutylphosphonium benzoate, tetrabutylphosphonium butyrate, octylphosphonium acetate, tetrahexylphosphonium acetate and tetraoctylphosphonium bromide. Preferred quaternary salts are generally tetraalkylphosphonium salts containing alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, butyl, amyl, hexyl and isobutyl. Tetrabutylphosphonium bromide is most preferred. The dispersion of the ruthenium carbonyl compound, rhodium carbonyl compound and manganese carbonyl compound in the quaternary phosphonium compound is then treated with N
-(Cyclohexyl)-2-pyrrolidone, N-
Dissolved in N-lower-alkyl or N-cycloalkylpyrrolidone solvents such as (isopropyl)-2-pyrrolidone or N-methyl-2-pyrrolidone. The amounts of ruthenium, rhodium and manganese carbonyl compounds used in the process of the invention can vary within a wide range. The process is carried out in the presence of a catalytically effective amount of each compound to produce the desired product in reasonable yield. The reaction is carried out with ruthenium and rhodium carbonyl compounds in an amount of 1 x 10 ^-6 % by weight or less, based on the total weight of the reaction mixture.
This can be carried out using a combination with a manganese carbonyl compound in an amount of about 10 ^-6 % by weight or less. The upper concentration limit is constrained by various factors, including catalyst cost, partial pressures of carbon monoxide and hydrogen, and operating temperature. The total concentration of the ruthenium carbonyl compound and the rhodium carbonyl compound is 1×10 ^-6 to the total weight of the reaction mixture.
20% by weight, preferably 1×10 ^-5 to 10% by weight, and the concentration of the manganese carbonyl compound is 1×10 ^-6 to 20
% by weight, preferably from 1 x 10 ^-5 to 10% by weight, is usually desirable for the practice of this invention. The preferred atomic ratio of ruthenium, rhodium and manganese is 10:1:1
~10:100:100. Most preferably, a relatively high ratio of ruthenium to rhodium is used. Particularly high yields and selectivities of ethylene glycol are obtained when the five aforementioned components of the catalyst system are combined on a molar basis as follows. i.e. ruthenium carbonyl compound 0.1
~4 mol, rhodium carbonyl compound 0.1-4 mol, manganese carbonyl compound 0.1-4 mol, quaternary phosphonium compound 10-60 mol and solvent 0.1
~60 moles. The temperatures used in the process of the invention can vary over a wide range depending on experimental factors including catalyst type, pressure and other variables. The operable range is 150-350°C. even narrower range
150-275°C represents a particularly preferred temperature range. The pressure used may also vary over a considerable range, but is often between 2.5 and 200 MPa.
The preferred operating range varies from about 5 to 75 MPa, but pressures above 75 MPa also provide useful yields of the target product. The pressures referred to herein refer to the total pressure produced by all reactants, but substantially due to carbon monoxide and hydrogen. Initially, the relative amounts of carbon monoxide and hydrogen present in the synthesis gas mixture can vary, and these amounts may be varied over a wide range. in general,
The molar ratio of CO: _H2 is between 20:1 and 1:20, preferably between 5:1 and 1:5, but ratios outside these ranges may also be used with good results.
Particularly in continuous operation, but also in batch processes, carbon monoxide-hydrogen gaseous mixtures can be used up to 50% by volume.
It may be used in conjunction with one or more of the following other gases: These other gases include one or more inert gases such as nitrogen, argon, and neon, or which gases may be reactive or non-reactive under the carbon monoxide hydrogenation conditions. Examples include hydrocarbons such as carbon dioxide, methane, ethane, propane, etc., ethers such as dimethyl ether, methyl ethyl ether and diethyl ether, and alkanols such as methanol. The desired reaction product, ethylene glycol, is produced in significant amounts, typically 10-40% by weight. Lower monohydric alcohols such as methanol and ethanol are also produced in significant amounts. Other derivatives such as acetic acid and ethylene glycol ethers are also formed in small amounts. Ethylene glycol, monohydric alcohols and other by-products can be recovered from the reaction mixture by conventional means such as fractional distillation under vacuum. The novel process of the invention can be carried out in a batch, semi-continuous or continuous process. The catalyst may be initially introduced into the reaction zone in batches, or it may be introduced into such zone continuously or intermittently during the synthetic reaction. The operating conditions can be adjusted to optimize the formation of the desired ethylene glycol product, which can be recovered by methods known to those skilled in the art, such as distillation, fractionation, or extraction. The fraction enriched in catalyst components is then recycled to the reaction zone, if desired.
Further product is then formed. The target product, ethylene glycol, was identified herein by one or more of the following analytical methods. i.e., typically gas-liquid chromatography (g/c), gas chromatography/infrared spectroscopy (CG/IR), nuclear magnetic resonance (NMR) analysis and elemental analysis, or a combination of these techniques. be. Analyzes are generally parts by weight, percentages are weight %, all temperatures are in degrees Celsius, and all pressures are in megapascals (MPa). The following example is provided to illustrate the method of the invention. Example 1 (Comparative Example) This example uses no solvent. Triruthenium dodecacarbonyl (0.213 g, 0.33 mmol), dicarbonyl(acetylacetonato) rhodium() (0.258 g, 1.0 mmol), tetrabutylphosphonium bromide (5.0 g, 14.7 mmol) and methylcyclopentadienylmangantri The mixture of carbonyl (0.055 g, 0.25 mmol) was transferred to a 550 ml pressure cooker equipped with a heating source and stirring means. The reactor was sealed, flushed with H ₂ /CO (1:1), then flushed with H ₂ /CO (1:1).
The pressure was increased to 20.8 MPa. While rocking the reaction mixture
Heated to 220℃ and increased the pressure to 36.7MPa with H ₂ /CO (1:1) added from a large capacity surge tank.
Then, the increment added from the surge tank was 36.7MPa.
maintained. The reactor was held at this temperature for 5 hours. After cooling, excess gas was vented and a dark red liquid product (10.4 g) was collected and then analyzed. Typical data for a distillate based on a solvent-free basis are shown below: 31.4% Methanol 12.1% Ethanol 3.6% Ethylene glycol monomethyl ether 1.1% Ethylene glycol monoethyl ether 29.2% Ethylene glycol The analytical results for a typical gas sample are: It was hot on the street. 48.8% Hydrogen 2.1% Carbon Dioxide 0.3% Methane 49.9% Carbon Monoxide The increase in liquid yield is 4.9 g or 88.2 in yield.
It was %. The calculated yield of ethylene glycol is 23
It was millimole hot. The calculated total yield of ethylene glycol product was 26 mmol. Example 2 Example 2 was carried out exactly as Example 1 except that a solvent was added. A clear improvement in the yield of ethylene glycol was observed. The reaction mixture consisted of triruthenium dodecacarbonyl (0.213 g,
0.33 mmol), dicarbonylacetylacetonatrodium (), (0.258 g, 1.0 mmol), tetrabutylphosphonium bromide (5.0 g, 14.7 mmol) and methylcyclopentadienylmanganese tricarbonyl (0.055 g, 0.25 mmol). include. This was processed exactly as in Example 1. After cooling, excess gas was vented and a dark red liquid product (16.0 g) was collected and then analyzed. 34.3% Methanol 10.4% Ethanol 1.9% Ethylene Glycol Monomethyl Ether 0.3% Ethylene Glycol Monoethyl Ether 33.7% Ethylene Glycol The analysis results for a typical gas sample were as follows. 47.6% Hydrogen 4.6% Carbon Dioxide 0.5% Methane 46.7% Carbon Monoxide The increase in liquid yield is 5.5 g or 99.5 in yield.
% (without solvent). The calculated yield of ethylene glycol was 27 mmol. The calculated total yield of ethylene glycol product was 29 mmol. Examples 3 and 4 demonstrate the effectiveness of catalyst precursors with high ruthenium to rhodium molar ratios. Example 4 contains a manganese component while Example 3 does not. When the molar ratio of ruthenium to rhodium is increased,
The weight increased and the yield of ethylene glycol product increased. Example 3 (Comparative Example) The procedure used in Example 3 uses a large amount of triruthenium dodecacarbonyl (0.852 g, 1.33 mmol) and a smaller amount of dicarbonylacetylacetonatrodium () (0.200 g, 0.78 mmol). , and tetrabutylphosphonium bromide (10.0
Example 1 was exactly as in Example 1, except that 5.0 g of 1-cyclohexyl-2-pyrrolidone was dissolved in 5.0 g of 1-cyclohexyl-2-pyrrolidone. After cooling, excess gas was vented and a dark red liquid product (25.8 g) was collected and then analyzed. Typical data for a distillate based on a solvent-free basis are shown below: 34.7% Methanol 18.6% Ethanol 5.4% Ethylene glycol monomethyl ether 0.4% Ethylene glycol monoethyl ether 21.7% Ethylene glycol The analytical results for a typical gas sample are: It was hot on the street. 46.6% Hydrogen 5.3% Carbon dioxide 1.5% Methane 45.1% Carbon monoxide Liquid yield increased by 9.7g or 88.2% yield
(solvent-free). The calculated yield of ethylene glycol was 29 mmol. The calculated total yield of ethylene glycol product was 35 mmol. Example 4 Triruthenium dodecacarbonyl (0.852g,
1.33 mmol), dicarbonyl(acetylacetonato)rhodium () (0.200 g, 0.78 mmol),
Tetrabutylphosphonium bromide (10.0 g, 29.4 mmol) and methylcyclopentadienylmanganese tricarbonyl (0.218 g, 1.0 mmol)
It was dissolved in 5.0 g of 1-cyclohexyl-2-pyrrolidone and then treated as in Examples 1-3. After cooling, excess gas was vented and a dark red liquid product (27.2 g) was collected and then analyzed. Typical data for a distillate based on a solvent-free basis are shown below: 38.5% Methanol 17.7% Ethanol 4.6% Ethylene Glycol Monomethyl Ether 1.7% Ethylene Glycol Monoethyl Ether 19.5% Ethylene Glycol The analytical results for a typical gas sample are: It was hot on the street. 42.9% Hydrogen 6.8% Carbon Dioxide 2.2% Methane 47.2% Carbon Monoxide Increase in liquid yield is 10.9g or 97.0% yield
(solvent-free). The calculated yield of ethylene glycol was 34 mmol. The calculated total yield of ethylene glycol product was 43 mmol. The following table summarizes the results for each example. 【table】

Claims (1)

[Claims] 1. A method for producing an ethylene glycol-containing mixture by contacting a mixture of carbon monoxide and hydrogen with a ruthenium-containing catalyst at a temperature of 150 to 350°C and under a pressure of 2.5 to 200 MPa. and that the catalyst consists of a ruthenium carbonyl compound, a rhodium carbonyl compound and a manganese carbonyl compound dispersed in a low melting point quaternary phosphonium compound and dissolved in an N-lower-alkyl or N-cycloalkylpyrrolidone solvent. How to characterize it. 2. Claim 1, wherein the ruthenium carbonyl compound is triruthenium dodecacarbonyl.
The method described in section. 3. The method according to claim 1 or 2, wherein the rhodium carbonyl compound is dicarbonyl(acetylacetonato)rhodium(). 4 Claims in which the manganese carbonyl compound is a compound represented by the formula: YMn(Co) ₃ (wherein Y is an unsaturated fatty acid or alicyclic hydrocarbon having 2 to 16 carbon atoms) 1st to 3rd
The method described in any one of paragraphs. 5. The method according to any one of claims 1 to 4, wherein the fourth phosphonium compound is tetrabutylphosphonium bromide. 6. According to any one of claims 1 to 5, the solvent is N-(cyclohexyl)-2-pyrrolidone-, N-(isopropyl)-2-pyrrolidone, or N-methyl-2-pyrrolidone. the method of.