JPS58135830A - Preparation of ethanol - Google Patents

Abstract

PURPOSE:To prepare ethanol, easily, in high selectivity, by reacting methanol, CO and H2 using a catalyst containing Co, Fe and /or Ni and an alkyl phosphine as active components. CONSTITUTION:Ethanol is prepared by pressing a mixed gas of H2 and CO (the molar ratio of H2/CO is 1:2-3:1) under 150-450kg/cm<2> into a solvent preferably toluene, n-octane, cyclohexane, etc. containing methanol, a Co compound such as dicobalt octacarbonyl, an Ni compound such as nickel chloride, nickel iodide, etc. and/or an Fe compound such as ferrous chloride, and an alkyl phosphine such as tri-n-butyl phosphine, and reacting the components together at 200- 260 deg.C. The atomic ratios of Co:(Ni and/or Fe):(P in the alkyl phosphine) are 1: (0.05-0.4):(0.5-1.5). The reaction system may contain iodine provided that the atomic ratio of I/Co is <=0.1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for selectively producing ethanol from methanol, carbon oxide and hydrogen. Method G for producing ethanol by reacting in the presence of 41m1@s
1-149213 is known.

However, in this method, in addition to the target ethanol, many byproducts such as dimethyl ether, methyl ethyl ether, diethyl ether, acetaldehyde, dimethoxyethane, acetic acid, methyl acetate, ethyl acetate, methyl formate, and other compounds of Cs or higher are simultaneously produced. However, it has drawbacks such as low selectivity to free ethanol and a complicated process for separating ethanol from the reaction product.

Furthermore, in recent years, a method using inexpensive iron or nickel as a cocatalyst for a cobalt catalyst in the presence of iodide has been developed.
No. 4-1157!50. This method uses an iron-copal F carbonyl anchor as a catalyst, and the atomic ratio of iron and cobalt to the number of moles of iodide is 0.5!1~100s.
This is a method in which the reaction is carried out in the presence of Ii8 iodide. However, this method has many high-boiling point products that cannot be detected by gas chromatography analysis, and the selectivity to ethanol is not necessarily high. Also, British Patent No. 2,056,7
59 uses a catalyst combining cobalt and ruthenium or osmium in the presence of a tertiary phosphine as a promoter, with a molar ratio of iodide (copal) ranging from 311 to 1!10.
A method is disclosed in which the reaction is carried out in the presence of iocide of iron or nickel instead of ruthenium or osmium.
It is also stated that group metals are also used. however,
According to the inventor's study, in the presence of a large amount of iocide as described in the claims, when iron or nickel is used as a cocatalyst instead of ruthenium or osmium, acetaldehyde and dimeFxyethane The generation increases,
Extremely low free ethanol content.

The present invention solves this problem and provides a method for producing ethanol with low by-products and high selectivity. This is a method of reacting in the presence of a catalyst containing iron and/or nickel and (2) alkyl phosphine as active ingredients. Although the presence of iodine is not required in the present invention, the atomic ratio of iodine/cobalt is 0.1 or less. If it is, the selectivity to ethanol will not be affected much.

Copal used in this Jitsumeiwa study includes cobalt carbonyl such as dicobalt octacarbonyl and cobalt hydride tetracarbonyl, as well as inorganic copal such as cobalt hydroxide, cobalt carbonate - basic cobalt carbonate, and cobalt halide. Various cobalt compounds that produce cobalt carbonyl in the reaction system are used, such as organic cobalt compounds such as 1111 salt, cobalt heptane, and cobalt acetylacetonate.However, cobalt iodide is used. If this is the case, it is necessary to use other ancient copper compounds to keep the iodine to cobalt atomic ratio below 0.1. The amount of cobalt compound used is 1 to 300 in terms of cobalt atoms per 1 mole of methanol. atoms, preferably 5 to 10
011 atoms. If the amount is less than this range, the reaction will proceed, but the reaction will be slow (0).If the amount is more than this range, there will be no adverse effects, but it will not be economical.

As nickel or iron in the present invention, any compound containing nickel or iron can be used, and if kept, inorganic nickel or iron compounds such as hydroxides, carbonates, halides, organic nickel such as nickel acetate or iron acetate, etc. can be used. These include acid salts, nitschelokene, ferrocene, nickel or iron-7cetylacetonate F-added organic nickel or iron compounds, nickel or iron carbonyl, and the like.

The amount of nickel, iron, or their compounds used is 0.1 to 100 nickel or iron atoms per 1 mole of methanol.
9 atoms, preferably 1 to 30 wII atoms. however,
When using nickel iodide or iron iodide, the atomic ratio of iodine to cobalt must be 0.1 or less.

Examples of the alkyl phosphine in the present invention include tri-n-butyl, phosphine t)liphenylphosphine, Lely/4-latolylphosphine, F-lycyclohexylphosphine, 1.4-bisF-liphenylphosphinobutane, 1.6 - Pisdolphenylphosphinohexane etc. can be used ◎ The amount of alkylphosphine used is per mole of methanol,
It is 2 to 600 milligram atoms, preferably 10 to 200 milligram atoms. If the amount is less than this range, the effect of suppressing by-products of ethers and esters will be small, and if it is more than this range, the methanol reaction rate and ethanol selectivity will decrease, which is not preferable.

Cobalt nickel or iron that can suitably carry out the present invention
The atomic ratio of phosphorus is 110.01-0°5+0.1-2, preferably 110.05-.0°4io, s-1.5. Outside this range, the lifetime of ethers, esters, and high-boiling products increases, which is not preferable.

The method of the present invention can be carried out without the use of a solvent in 41 (although it can be carried out in the presence of an inert solvent that does not affect the reaction KI). Examples of hydrocarbons that can use esters include aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as hexane and octane, and alicyclic hydrocarbons such as cyclohexane. Examples of solvents used include diethyl ether, diisopropyl ether, dioquinone, and tetrahydro-7rane.As ester solvents, methyl acetate, ethyl acetate, and the like are used.

*The amount of m used is 0 to 5 mol, preferably 0 to 2 mol, per 1 mol of methanol. If the amount is more than that, there will be no problem with the reaction, but the space-time yield will be small, which is not practical.

The reaction temperature varies depending on the catalyst system used and other reaction conditions, but is generally 150'C to 300'C, preferably 20
Although the reaction proceeds at temperatures below 0, which is 0'C to 260C, the reaction rate becomes slower.

Above this range, the number of related organisms increases, which is not desirable.

The reaction pressure should be at least 50&C#/cyn2, above 1.
1ha 41HC squid, practically 150-450#/
A range of cIa2 is preferred. - The molar ratio of carbon 8 hydrogen oxides ranges from 4:1 to 1t4, preferably from 2:1 to 1@3. Carbon monoxide and hydrogen for the reaction Kfl include:
For example, inert gases such as argon, nitrogen, carbon dioxide, methane, and ethane may be mixed into the reaction, but in this case, the partial pressures of carbon monoxide and hydrogen must correspond to the above pressure range. There is.

The method of the present invention can be carried out either batchwise or continuously.According to the present invention, ethanol can be selectively produced from methanol, -carbon oxide, and hydrogen.In the following examples and comparative examples: The methanol conversion rate, the ethanol selectivity, the actual methanol conversion rate, and the realizable ethanol selectivity are defined as follows.

, 1 Methanol reaction rate (%) Methanol charged, molar Selectivity to each product (%) ≧ Actual methanol conversion rate (%) =・ Methanol charged, molar Realizable ethanol selectivity (%) = ] Note 1 ) Dimethoxyethane, methyl ester, and other methanol components that are recovered by harmful birds through hydrolysis.

Note 2) Refers to free ethanol and ethanol that can be easily recovered by hydrogenation or hydrolysis of acetofludehyde, dimethoxyethane, ethyl ester, etc.

Example 1 Methanol 10f (0,5121 mol), dicobalt octacarbonyl 2f (0,0058 mol), and nickel chloride 0.5% (0,0021 mol)% were placed in a stainless steel noodle-type autoclave with an internal volume of 100 mm. Li-butylphosphine 3P (0,0148 mol) was charged, and then a mixed gas of hydrogen and carbon monoxide (H2/C
Press fit Hifu 1) 200I141/cH1 into O mo, and
The reaction was carried out at 30°C for 3 hours.

After the reaction, the autoclave was cooled and residual gas was purged, and the reaction product liquid was analyzed using an internal standard method using gas chromatography.

As a result, the methanol reaction rate was 26.6%, the free ethanol selectivity was 67.7%, and the selectivity to other components was 1.0% for methyl formate and 1% for methyl ethyl ether.
．． 9%, methyl acetate 2.5%, dimethoxyethane 1.
It was 6%. This is the actual methanol conversion rate 25.8
%, achievable ethanol selectivity 73.8
%.

, 1m! ! Example 2 Example IK) A reaction was carried out by adding 10 mF (0,1084 mol) of toluene. As a result, methanol reaction rate
25.2%, the selectivity to free ethanol was 77.4%, and the selectivity to other components was 2.5%.
%, methyl ethyl ether 1.8%, methyl acetate 0
6% and dimethoxyethane 1.1%.

This is a realizable selectivity to ethanol of 84.1% at an actual methanol reaction rate of 24.2%. ◎ Comparative Examples 1 to 4 In a toluene solvent, dicobalt octacarbonyl, nickel chloride, Tori-butylphosphine were In coexistence 1 of one or two selected from among them, the reaction was carried out under the same conditions as in Example 2. No. 111jK showed the results, but dicobalt octacarbonyl, nickel chloride, tri-phthylphosphine It can be seen that when the five components do not coexist, there are many byproducts such as ethers and chills, and the selectivity of free ethanol and realizable ethanol is low. Examples 3 to 5 Methanol 10 (0, 5121 mol), dicobalt octacarbonyl 2t (0,o.

58 mol), Tory Peng-butylphosphine 3) (0,
The reaction was carried out in the same manner as in Example 2, in which a predetermined amount of nickel iodide, nickel 7cetyl 7cetonate, or ferrous monochloride was impregnated as a cocatalyst. Ta. The results are shown in Table 2. O Example 6 Example 5 Ki 1 element o, 1sP (o, oo.

5 mol) was added thereto, and the reaction was carried out at 1 Hz. As a result, the ratio to 1 methanol was 23.6%, the selectivity to free ethanol was 70.1%, and the selectivity to other components was 0.8% for methyl formate, 6.0% for methyl ethyl ether,
Methyl acetate was 2.1% and dimethoxyethane was 4.6%. This is a realizable ethanol selectivity of 79.3% at an actual methanol conversion rate of 22.8%.

Comparative Example 5 Example 6 except that 0.62 (0,0024 mol) of iodine was used, the reaction temperature was 200°C, and the reaction time was IHr.
I did it in the same way. This is because the atomic ratio of quartz to cobalt is 0.5, which is outside the scope of the present invention. ◎As a result,
The methanol reaction rate was 55.5%, the selectivity to free ethanol was 46.0%, and the selectivity to other components was 4.1% for acetaldehyde, 0.4% for methyl formate, 5.7% for methyl ethyl ether, and 5.7% for acetic acid. Methyl 6.0%,
Dimethoxyethane was 17.7%. This is a realizable ethanol selectivity of 75.2% at an actual methanol conversion rate of 28.5%.

Comparative Example 6 Cobalt iodide instead of dicobalt octacarbonyl
Using 1f (0,0032 mol), the reaction temperature was 200°C.
The reaction was carried out in the same manner as in Example 3 except that the reaction time was changed to IHr. This means that the atomic ratio of iodine to cobalt is 2.
and is outside the scope of this invention. As a result, methanol reaction rate 64. s%, the selectivity to free ethanol is 2%, and the selectivity to other components is acetaldehyde 4
4.5%, methyl ethyl ether 0.2%, methyl acetate 6.0%, and dimethoxyethane 26.7%.When the atomic ratio of iodine to cobalt becomes large, 7cetofludehyde and dimethoxyethane become the main products. Example 0
6-8 Kn-octane, cyclohexane instead of toluene solvent
Example 2 except using dioxane or methyl acetate solvent
The reaction was carried out in the same manner as in Table 5. The results are shown in Table 5.

Claims (1)

[Claims] Methanol, - carbon oxide and hydrogen, C1) Kobal)
, (2) iron and/or nickel, and (3) furkylphosphine, in the presence of a catalyst as active ingredients. A method for producing ethanol.