JPH0959189A - Method for producing methanol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain in an industrially advantageous way the subject methanol exhibiting excellent methanol activity even under low-temperature and low- pressure reaction conditions, by reaction between carbon monoxide and hydrogen in the presence of a catalyst consisting of a combination of a copper compound plus metal alkoxide with active carbon. SOLUTION: The objective methanol is obtained by reaction between carbon monoxide and hydrogen in a solvent in the presence of a catalyst composed of (A) a copper compound, (B) a metal alkoxide and (C) active carbon pref. at 40-200 deg.C under a pressure of <=50atm. It is preferable that the component A be a cuprous halide (e.g. cuprous chloride) and the amount of the component C to be used is 0.1-10wt. times that of the component A, and it is recommended that the component B be a 1-10C alkoxide of a metal such as Na or K (specifically, e.g. sodium methoxide).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel method for producing methanol. Methanol is an inexpensive and highly versatile compound as an intermediate raw material for various chemical products and as a solvent, a fuel for automobiles, and a fuel for thermal power generation.

[0002]

2. Description of the Related Art A method for producing methanol from carbon monoxide and hydrogen has been used industrially for a long time. For example, in 1913, BASF, Germany,
Using a catalyst mainly composed of an oxide such as 300 ° C. or more,
The possibility of producing oxygen-containing compounds containing methanol from water gas under the conditions of 100 atm or more was shown, and thereafter, so-called high-pressure methanol production methods were started in various countries. 1
In 959, the company ICI of the United Kingdom made use of CuO-based catalysts at a lower temperature and lower pressure, that is, 200 ° C.
A so-called low-pressure process for producing methanol has been developed in which the reaction is carried out at 300 ° C. and 50 to 150 atm. Since then, catalysts and processes have been improved. At present, most of industrial production methods of methanol use a copper-based catalyst and are carried out by a low pressure method at a reaction temperature of 200 ° C. and a reaction pressure of about 100 atm.

The reaction of methanol synthesis from carbon monoxide and hydrogen is an exothermic reaction as shown in the following equation. CO + 2H ₂ → CH ₃ OH ΔH ₂₉₈ = -21.
7 kcal / mol Therefore, the lower the reaction temperature and the higher the pressure, the more advantageous for methanol synthesis. Catalysts that are highly active at lower temperatures have the advantage of not needing to recycle unreacted gas to the reaction system by significantly improving the conversion rate of the raw material gas. A catalyst showing a high methanol production activity is industrially extremely advantageous in that it is not necessary to pressurize when introducing a raw material synthesis gas into a methanol reactor.

Low temperature and low pressure, eg below 160 ° C., 50
Low temperature with some activity under reaction conditions below atmospheric pressure
Several catalysts are known as low-pressure active catalysts. Among them, a copper or nickel catalyst is known as a highly active catalyst. However, it is known that nickel carbonyl, which is extremely toxic, is generated when a nickel catalyst is used, and its handling is extremely difficult. For example, JP-B-63-51130 discloses a method of synthesizing an oxygen-containing organic compound by reacting carbon monoxide and hydrogen with a copper compound other than copper oxide and sodium alkoxide or potassium alkoxide as a catalyst. Is disclosed.

For example, Japanese Patent Publication No. 6-2686 (WO86 /
03190), the liquid reaction medium in the reactor, in addition to methanol and methyl formate, has a lower dielectric constant than that of pure methanol at the same temperature in the presence of a catalyst consisting of a copper catalyst prepared by the Adkin method, an alkali metal alkoxide. A method for producing methanol from carbon monoxide and hydrogen in a liquid phase using at least 50% by volume of a non-polar organic solvent having a constant number is disclosed.

Further, Appl. Catal. , 10
3,105-122 (1993), in a methanol synthesis with carbon monoxide and hydrogen, a copper chromite catalyst,
When potassium methoxide (or sodium methoxide) is used, the reaction temperature is about 10 compared to the conventional method.
It is reported that the amount of recycled gas will be significantly reduced by lowering the temperature by 0 ° C.

Also, for example, US Pat. No. 4,992,4
No. 80, No. 4,935,395 describes Cu, N.
A method for producing methanol from synthesis gas using a homogeneous catalyst using a carbonyl compound of a metal selected from i, Pd, Co, Ru, Mo and Fe and alkoxide as a catalyst is disclosed.

[0008]

As far as the inventors of the present invention have verified, there is a problem that the activity of each catalyst is not sufficient, the activity is severely deteriorated, or the handling is difficult. It has been confirmed that it is still insufficient for industrial implementation. Therefore, under the present circumstances, there is a strong demand for a catalyst having higher activity under the reaction conditions of low temperature and low pressure.

An object of the present invention is to provide a novel production method using a highly active catalyst for producing methanol from carbon monoxide and hydrogen under reaction conditions of low temperature and low pressure.

[0010]

Means for Solving the Problems The inventors of the present invention have made earnest studies on a catalyst which is industrially advantageous and can obtain high activity at a low temperature of 160 ° C. or lower and a low pressure of 50 atm or lower. It was found that methanol is produced with high activity by coexisting with activated carbon, and the present invention has been completed.

That is, the present invention comprises (1) a copper compound, (2) a metal alkoxide and (3) activated carbon in the production of an oxygen-containing compound from carbon monoxide and hydrogen in the presence of a solvent and in the presence of a solvent. The method for producing methanol is characterized by using a catalyst as described above.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The copper compound used in the method of the present invention is specifically copper chloride (I, II), copper bromide (I, II), copper iodide (I, II), or copper sulfate. Copper sulfamate,
Inorganic copper salts derived from mineral acids such as copper phosphate, copper carbonate, hydrogen halide, sulfuric acid, phosphoric acid, copper acetate, copper formate, copper oxalate, copper oleate, copper stearate, Examples thereof include copper naphthenate, copper benzoate, copper citrate, and copper carboxylates such as copper tartrate. Further, copper acetylacetonate, copper alkoxide, copper (I) cyanide, copper thiocyanate, copper carbonyl, and Raney copper can also be used. Copper oxide can also be used. further,
The above-mentioned copper compounds supported on silica or alumina can also be used. However, use of other than these copper compounds does not limit the present invention.

When using these copper compounds as a catalyst, among these copper compounds, a copper compound containing monovalent copper as the copper is more preferable than divalent copper because high activity can be obtained. However, even a divalent copper compound can be preferably used as long as it is a copper that is easily reduced to monovalent by carbon monoxide or hydrogen under the reaction conditions. Examples of such divalent copper compounds include copper (II) carbonate, copper (II) acetate, copper acetylacetonate (II), and copper (II) chloride.

The amount of the copper compound used in the present invention is
It is appropriately determined depending on the amount of the solvent used. In the case of a copper compound supported on a carrier, the amount used means the total weight including the weight of the carrier. A small amount of the copper compound is sufficient, but if it is too large, the activity is rather lowered. Therefore, the amount of copper compound used is 0.5 to 50 wt% with respect to the solvent.
Range, and preferably in the range of 1 to 30 wt%.

The activated carbon used in the method of the present invention includes, as its raw materials, charcoal, coconut shell, lignin and the like for plant-based ones, and petroleum pitch, coal pitch, coke, leek coal and lignite for mineral-based ones. Lignite, peat, petroleum distillation residue,
Examples of other materials such as coal tar include natural fibers such as rayon and synthetic materials such as phenol and acrylic resin. The present invention is not limited even if activated carbon made of a raw material other than these is used. Further, any form such as powdered coal, crushed coal, and granular coal can be used. However, since impurities such as chlorine and sulfur may become poisonous substances of the catalyst of the present invention, it is preferable that the proportion of impurities is low. Also, steam activation before use,
It is preferable to activate by either method of chemical activation. Furthermore, the activated carbon used preferably has a large BET specific surface area. Generally, activated carbon made from coconut shell has a large surface area and is preferably used. In addition, even if using raw materials other than coconut shell, it is specially processed,
Those having a high surface area are also preferably used.
The surface area is 300 m ² / g or more, preferably 50
The range is 0 m ² / g or more, more preferably 1000 m ² / g or more.

Specifically, as such activated carbon, "Maxsorb" manufactured by Kansai Thermochemical Co., Ltd., which has been specially processed, is used.
(Trade name) and “M-30” (trade name) manufactured by Osaka Gas Co., Ltd., and “Shirasagi C ₂ X” manufactured by Takeda Pharmaceutical Co., Ltd. manufactured from plant-based raw materials such as coconut shells ( (Trade name), "Star Coal W-YC" (trade name) manufactured by Kita Kasei Kogyo Co., Ltd., and "Kuraray Coal BP-25" (trade name) manufactured by Kuraray Chemical Co., Ltd. manufactured from phenolic resin as a raw material. ), "CPG" manufactured by Toyo Calgon Co., Ltd. manufactured from mineral raw materials, "Tsurumi Coal 4GV" (trade name) manufactured by Tsurumi Coal, "PG3" manufactured by Cataler Industry Co., Ltd., and the like. To be

In the method of the present invention, the amount of activated carbon used is appropriately determined with respect to the amount of copper compound used. The larger the amount of the activated carbon used, the more the activity is improved, but practically, it is in the range of 0.1 to 10 times, preferably 0.2 to 5 times the weight of the copper compound.

The metal alkoxide used in the present invention is
It is an alkoxide of a metal selected from Li, Na and K. Among these, Na and K are preferable as the metal, and K is most preferable. Also, alkoxide has 1 to 1 carbon atoms.
Zero alkoxides are used. Among these, methoxide, ethoxide, propoxide and butoxide derived from alcohol are preferable.

In the method of the present invention, the amount of metal alkoxide used is appropriately determined with respect to the amount of copper compound used. If the amount of the metal alkoxide used is too small, the catalytic effect cannot be sufficiently obtained, and if it is too large, the reaction is hindered, which is not preferable. Therefore, the amount of metal alkoxide used is in the range of 0.1 to 30 times, preferably 0.3 to 10 times the weight of the copper compound.

The solvent used in the present invention is not particularly limited, but includes ethers such as dioxane, tetrahydrofuran, diethyl ether and diphenyl ether, glymes such as glyme, diglyme and triglyme, methyl acetate and ethyl propionate. Such esters, alcohols having 6 or more carbon atoms such as hexanol and heptanol, hydrocarbons such as hexane, benzene, decalin and chlorobenzene, and halogenated hydrocarbons are preferably used. Also, dimethylformamide,
An aprotic polar solvent such as N-methylpyrrolidone can also be used. Among these, ethers and glymes are particularly preferable.

(1) a copper compound used in the method of the present invention,
The metal alkoxide (2) and the activated carbon (3) are effective as a catalyst for synthesizing methanol even if they are used by mixing them in advance, or when they are sequentially added to the solvent as they are, and any method can be used.

In the present invention, a catalyst having excellent methanol activity even at a low temperature of 160 ° C. or lower is used, but the reaction can be carried out in the temperature range of 40 to 200 ° C. If the reaction temperature exceeds 200 ° C., the conversion will be significantly reduced. On the other hand, if the reaction temperature is lower than 40 ° C., the reaction rate is small and not practical. Preferably, it is in the range of 60 to 180 ° C. More preferably, it is in the range of 80 to 160 ° C. However, the method of the present invention is not limited to a higher temperature in consideration of overall economic efficiency including recovery of reaction heat and the like.

Although carbon monoxide and hydrogen as raw materials can be used even if they contain nitrogen and carbon dioxide, it is preferable that the amount of carbon dioxide is small. In some cases, it is desirable to remove sulfur compounds and water to trace amounts before starting the reaction of methanol synthesis.
The mixing ratio of carbon monoxide and hydrogen is in the range of 1: 0.5 to 1: 5. If the amount of hydrogen used with respect to carbon monoxide is larger than the stoichiometric ratio of 2, the selectivity of methanol improves, but if it is further increased, excess hydrogen remains unutilized and is uneconomical. Therefore, practically 1: 1.5-
A range of 1: 2.5 is preferred.

In the method of the present invention, the higher the reaction pressure, the higher the methanol activity. However, as a practical pressure for supplying the synthesis gas to the reactor without increasing the pressure, it is 50 kg.
/ Cm ² −G or less is preferable. However, implementation at higher pressures is also included in the scope of the present invention.

[0026]

The present invention will be described in more detail with reference to the following examples.

Example 1 Cuprous chloride (CuCl) 1 g (10 mmol), activated carbon A (trade name: MaxSorb, manufactured by Kansai Thermochemical Co., Ltd., BE
T specific surface area: 3000 m ² / g) 0.5 g, sodium methoxide 1.6 g (30 mmol), dioxane 20 ml were charged into an autoclave, and CO / H ₂ = 1/2 at room temperature.
A synthesis gas (molar ratio) was injected under pressure up to 50 kg / cm ² -G, and a reaction was carried out at a reaction temperature of 120 ° C. for 3 hours. As a result of the analysis, a reaction result with a CO conversion of 95% and a methanol selectivity of 99% or more was obtained. Absorption of pressure is completed in about 30 minutes,
The solvent-based yield [STY (Space time yield)] is 1 when the reaction time is the time when this pressure drop is observed.
It was 75 g-MeOH / l / hr.

Example 2 The same as Example 1 except that the activated carbon A was changed to 0.5 g of activated carbon B (trade name: M-30, manufactured by Osaka Gas Co., Ltd., BET specific surface area: 3000 m ^{2 /} g). As a result of the reaction, a reaction result with a CO conversion rate of 93% was obtained. Also, STY is 165g
It was / l / hr.

Example 3 Commercially available copper-chromium catalyst (trade name: G-99c (Cu: Cr:
Mn: Ba = 36: 32: 2.2: 2.4), Nissan Gardler Catalyst Co., Ltd.
1 g (made as 5.7 mmol as Cu), 2.1 g (40 mmol) of sodium methoxide, and 1 part of activated carbon A.
g, triglyme 20ml into an autoclave,
As a result of carrying out the reaction under the same reaction conditions as in Example 1, a reaction result with a CO conversion of 93% was obtained. Also, STY is 15
It was 5 g / l / hr.

Example 4 1.4 g (10 mmol) of copper (I) bromide (CuBr),
Activated carbon C (Product name: Shirasagi C ₂ X, Takeda Pharmaceutical Co., Ltd.)
Made, BET specific surface area: 1200 m ² / g) 0.5 g, sodium methoxide 1.6 g (30 mmol), dioxane 20
Charge ml to autoclave, CO / H ₂ = 1/2
(Mole ratio) of synthetic gas was injected up to 40 kg / cm ² -G, and the reaction was carried out at a reaction temperature of 150 ° C. for 3 hours. As a result of the analysis, a reaction result with a CO conversion rate of 90% was obtained. Also, S
TY was 130 g / l / hr.

Example 5 Copper sulfate (CuSO ₄ ) 1.6 g (10 mmol), activated carbon B 0.5 g, potassium methoxide 2.1 g (30 m)
mol) and 20 ml of dioxane were charged into an autoclave and 50 k of a synthesis gas of CO / H ₂ = 1/2 (molar ratio) was charged.
The mixture was pressed into g / cm ² -G and reacted at a reaction temperature of 160 ° C. for 3 hours. As a result of the analysis, a reaction result with a CO conversion rate of 91% was obtained. The STY was 86 g / l / hr. As a result of analyzing the catalyst solution after this reaction, the presence of monovalent copper was confirmed.

Example 6 1.8 g (10 mmo) of copper acetate (Cu (OAc) ₂ ).
l), activated carbon B 0.5 g, potassium methoxide 2.1
g (30 mmol) and 20 ml of dioxane were charged into an autoclave and the reaction was carried out in the same manner as in Example 1. As a result, C
A reaction result with an O conversion of 90% was obtained. The STY was 85 g / l / hr. As a result of analyzing the catalyst solution after this reaction, the presence of monovalent copper was confirmed.

Example 7 Copper acetylacetonate (Cu (acac) ₂ ) 2.6
g (10 mmol), activated carbon D (trade name: CPG, manufactured by Toyo Calgon Co., Ltd., BET specific surface area: 1000 m ² / g)
7 g, potassium methoxide 2.1 g (30 mmo
l) and 20 g of triglyme were charged into an autoclave and the reaction was performed at 110 ° C. in the same manner as in Example 1. As a result, a reaction result with a CO conversion of 91% was obtained. Also,
The STY was 85 g / l / hr. As a result of analyzing the catalyst solution after this reaction, the presence of monovalent copper was confirmed.

Example 8 1.3 g (10 mmol) of cupric chloride (CuCl ₂ ),
Activated carbon E (trade name: Kuraray Coal BP-25, manufactured by Kuraray Chemical Co., Ltd., BET specific surface area: 1200 m ^{2 /} g) 0.5
g, sodium ethoxide 2.0 g (30 mmo
l), 20 ml of dioxane was charged into the autoclave,
As a result of carrying out the reaction in the same manner as in Example 1, the CO conversion was 90%.
The reaction result of was obtained. Also, STY is 88g / l / h
r.

Comparative Example 1 1 g (10 mmol) of cuprous chloride (CuCl), 1.6 g (30 mmol) of sodium methoxide and 20 ml of dioxane were charged into an autoclave, and CO / H was added at room temperature.
₂ = 1/2 (molar ratio) of synthetic gas at 50 kg / cm ² -G
Then, the mixture was pressed into the flask and reacted at a reaction temperature of 120 ° C. for 3 hours.
As a result of the analysis, the CO conversion rate was 80%. Also, STY
Was 78 g-MeOH / l / hr.

Comparative Example 2 Commercially available copper-chromium catalyst (trade name: G-99c (Cu: Cr:
Mn: Ba = 36: 32: 2.2: 2.4), Nissan Gardler Catalyst Co., Ltd.
1 g (manufactured by Co., Ltd.) (5.7 mmol as Cu) and 20 ml of triglyme were charged into an autoclave and reacted under the same reaction conditions as in Comparative Example 1, as a result, a CO conversion rate of 78% was obtained. The STY was 68 g / l / hr.

[0037]

According to the present invention, in a method for producing methanol from carbon monoxide and hydrogen, a copper compound and a metal alkoxide compound are allowed to react in the presence of a solvent with an active carbon as a catalyst to give 160 Below ℃,
Even under a reaction condition of 50 atm or less, it showed far superior methanol activity (compared to STY) than the known catalyst, and a carbon monoxide conversion rate of 90% or more was obtained. As a result, it is not necessary to recycle unreacted synthesis gas to the reaction system, and since the methanol synthesis reaction can be performed at a lower pressure than the synthesis gas manufacturing process, it is not necessary to pressurize the synthesis gas as a raw material. This is an industrially advantageous manufacturing method.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C07C 29/154 C07C 29/154 // C07B 61/00 300 C07B 61/00 300 (72) Inventor Mitsuo Tanaka 1-6 Takasago, Takaishi-shi, Osaka Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Kenji Fujiwara 1-6 Takasago, Takaishi-shi, Osaka Mitsui Toatsu Chemical Co., Ltd.

Claims (5)

[Claims] 1. In producing an oxygen-containing compound from carbon monoxide and hydrogen in the presence of a solvent, (1) a copper compound,
A method for producing methanol, which comprises using a catalyst composed of (2) metal alkoxide and (3) activated carbon. 2. The production method according to claim 1, wherein the copper compound is a copper compound containing monovalent copper. 3. The production method according to claim 1, wherein the copper compound is a monovalent copper halide. 4. The amount of activated carbon used is 0.
It is 1-10 times, The manufacturing method of any one of Claims 1-3. 5. A reaction temperature of 40 to 200 ° C. and a reaction pressure of 50.
The production method according to claim 1, wherein the reaction is performed at atmospheric pressure or less.