JPH11279090A - Production of methanol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain methanol in a high yield, by reacting carbon monoxide with hydrogen in the presence of a metal alkoxide and Raney copper containing a specific amount of copper. SOLUTION: Carbon monoxide is reacted with hydrogen in the presence of (A) a metal alkoxide (e.g. potassium methoxide or the like) and (B) Raney copper (a copper catalyst consisting of a substantially zero-valent copper) having 80.0-99.9 wt.% copper content in a solvent at temperature of 40-200 deg.C under pressure of 120 kg/cm<2> -G. The used amount of the component A is preferably 0.01-100 times as much as the component B. Methanol or a mixed solvent of metal is preferable as the solvent for the reaction. preferably the used amount of the component A is 0.01-10 wt.% based on the solvent and that of the component B is 0.5-80 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel method for producing methanol. Methanol is an inexpensive and highly versatile useful compound as an intermediate material for various chemical products, and itself as a solvent, fuel for automobiles, and fuel for thermal power generation.

[0002]

2. Description of the Related Art A method for producing methanol from carbon monoxide and hydrogen, a so-called gas phase method, has been industrially practiced for a long time. For example, in 1913, BASF, Germany, used a catalyst mainly composed of oxides such as Cr and Zn,
300 ° C. or higher, the possibility of producing an oxygen-containing compound containing methanol from a water gas under the conditions of 100 atm or more is shown.
Thereafter, the production of so-called high-pressure methanol was started in various countries. In 1959, ICI of the United Kingdom
Against the background of a high-level desulfurization technology of synthesis gas, a reaction is carried out using a catalyst containing CuO as a main component at a lower temperature and lower pressure, that is, at a temperature of 200 ° C. to 300 ° C. and 50 to 150 atm. A method for producing low-pressure methanol has been developed. Since then, catalysts and processes have been improved. At present, most of the industrial production methods of methanol are carried out by a low-pressure method at a reaction temperature of 200 ° C. and a reaction pressure of about 100 atm. Copper chromite is used in such a gas phase, low temperature, low pressure method. In addition, there is a report using a Raney copper-zinc catalyst as a copper catalyst for producing methanol in the gas phase. For example, J. Catal., 80, 1-13 (1983) and J.Ca
tal., 80, 14-24 (1983) discloses a Raney copper-zinc catalyst obtained by developing a master alloy containing 50% by weight of aluminum, 30-36% by weight of copper, and 14-20% by weight of zinc. And a gas-phase methanol synthesis method from carbon monoxide or carbon dioxide and hydrogen. Among them, the Raney copper catalyst to which zinc is added increases the specific surface area of the catalyst,
It reports an increase in activity.

[0003] For example, Japanese Patent Application Laid-Open No. 7-197110 discloses a method of melting a copper alloy comprising 30 to 60% by weight of copper, 0.5 to 25% by weight of zinc, 0.5 to 10% by weight of chromium and aluminum. A continuous methanol synthesis method is disclosed using a Raney copper alloy with a controlled particle size, obtained by dropping and scattering the liquid on a high-speed rotating disk, and the physical properties such as the particle size distribution of the catalyst are also 120 hours after the reaction. Report no change.

[0004] However, in the methanol production process by the gas phase method, there is a problem that it is difficult to increase the size of the methanol to provide a large amount of methanol at a low cost because of a problem such as heat removal. .

The reaction of methanol synthesis from carbon monoxide and hydrogen is an exothermic reaction and has an equilibrium as shown in the following equation. CO + 2H ₂ → CH ₃ OH ΔH ₂₉₈ = -21.7 kcal / mol

Accordingly, the lower the temperature and the higher the reaction conditions, the more advantageous for methanol synthesis. A catalyst that is more active at lower temperatures is advantageous in that it significantly improves the conversion of the source gas and eliminates the need to recycle unreacted gas to the reaction system. Further, a catalyst having a high methanol production activity at a pressure lower than the synthesis gas production pressure is industrially extremely advantageous in that it does not need to be pressurized when introducing a raw material synthesis gas into a methanol reactor. In addition, low-temperature liquid-phase methanol synthesis has attracted attention in recent years, since performing the reaction in the liquid phase also exerts an effect on heat removal, which is a problem of the gas phase method.

The prior art of this low temperature liquid phase methanol synthesis method will be described below.

Low temperature and low pressure, for example, below 160 ° C.,
Some catalysts are known as low-temperature, low-pressure active catalysts having a certain level of activity under reaction conditions of 0 atm or less. Among them, a copper or nickel catalyst is known as a highly active catalyst. However, it is known that the use of a nickel catalyst produces extremely toxic nickel carbonyl, which is extremely difficult to handle.

As the copper catalyst, for example, Japanese Patent Publication No. Sho 63
JP-A-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. . The publication specifically shows monovalent and divalent compounds as copper compounds.

[0010] Furthermore, Japanese Patent Publication No. 6-2686 (WO8
6/03190), in the presence of a copper catalyst prepared by the Adkins method and a catalyst composed of an alkali metal alkoxide, the liquid reaction medium in the reactor is more than pure methanol at the same temperature in addition to methanol and methyl formate. A method is disclosed 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 low dielectric constant. It is described that as a copper catalyst, copper chromite obtained by pre-hydrogen reduction of a thermal decomposition product of ammonium bichromate is most preferable.

A report on a similar copper chromium-based catalyst is disclosed in Appl. Catal., 103, 105-122 (1993). Among them, the use of copper chromite catalyst and potassium methoxide (or sodium methoxide) in methanol synthesis using carbon monoxide and hydrogen reduces the reaction temperature by about 100 ° C. as compared with the conventional gas phase method, and recycles gas. The amount is reported to be significantly lower.

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

As far as the present inventors have verified, none of the low-temperature liquid phase methanol synthesis catalysts can be said to have sufficient activity, and for example, copper chromite catalyst such as copper chromite has a valence of copper. In the catalyst, the surface copper oxide becomes metallic copper by reduction, and the activity is severely degraded.
For example, carbonyl compounds and the like have problems such as difficulty in handling, and are still insufficient for industrial implementation.

[0014] Further, it has been found that the use of metal alkoxide is essential for producing methanol under low temperature and low pressure reaction conditions, but the metal alkoxide used is converted to formate during the reaction and is lost. Furthermore, it has been found that the conversion amount increases with an increase in the metal alkoxide. As a result, it was found that the economical efficiency was greatly impaired unless the amount of the metal alkoxide used was much smaller than that known in the prior art.

On the other hand, the use of methanol as a solvent has a great advantage in that the process of separating the solvent and the product can be omitted. However, any of the low-temperature liquid-phase methanol synthesis catalysts has low activity in the product methanol solvent, and even when used in other solvents, the activity is reduced by sequentially generated methanol. Therefore, at present, there is a strong demand for a catalyst which has little catalyst degradation under low-temperature and low-pressure reaction conditions in the presence of methanol and has high activity even at a low concentration of metal alkoxide.

[0016]

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly active, long-lived catalyst for producing methanol from carbon monoxide and hydrogen under low-temperature, low-pressure reaction conditions in the presence of a solvent. It is to be.

[0017]

DISCLOSURE OF THE INVENTION The present inventors have conducted intensive studies on a catalyst which can obtain high activity by batch and flow reactions under a high concentration of methanol and a low concentration of metal alkoxide. By using a copper catalyst, it has been found that methanol is produced at a specifically high rate among copper-based catalysts. Furthermore, when a Raney copper catalyst containing calcium was used, it was found that the catalyst activity was high, the catalyst activity was hardly deteriorated, and stable catalyst activity could be maintained, and the present invention was completed.

That is, the present invention provides a method for reacting carbon monoxide with hydrogen in a solvent in the presence of a metal alkoxide and Raney copper having a copper content in the range of 80.0 to 99.9% by weight. This is a characteristic method for producing methanol.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The Raney copper used in the method of the present invention is a copper catalyst containing essentially zero-valent copper as a main component, and is obtained by developing a master alloy containing copper or aluminum with an aqueous alkali solution or the like. It is a catalyst. As the mother alloy, any mother alloy such as a lump obtained by pulverization or a granular one can be used. The Raney copper used preferably contains calcium in addition to copper and aluminum. If the content of calcium is lower than 0.01% by weight, a sufficient effect may not be obtained. On the other hand, if the content is more than 20% by weight, the content of the copper component exhibiting catalytic activity decreases, which may not be preferable. Therefore, it is preferably in the range of 0.01 to 20% by weight, more preferably in the range of 0.05 to 15% by weight, and still more preferably in the range of 0.1 to 10% by weight.

Further, the Raney copper used is copper,
In addition to aluminum and calcium, Group VIIIA metals such as iron, cobalt and nickel, and VII such as manganese and rhenium
Group A metals, Group VIA metals such as chromium and molybdenum, Group VA metals such as vanadium and niobium, Group IVA metals such as titanium and zirconium, Group IB metals such as gold and silver, zinc,
A group IIB metal such as cadmium can be used even if added. It is also effective to add these fourth metals in combination. The addition amount of these fourth metals is not particularly limited, but is usually used in the range of 0.01 to 20% by weight. Further, the use of Raney copper other than these does not limit the present invention.

The Raney copper used in the present invention is obtained by developing a mother alloy, and a known method can be used for the developing method. For example, the aqueous alkali solution used for developing the master alloy may be an aqueous solution of sodium or potassium hydroxide or carbonate. In consideration of economy, an aqueous solution of caustic soda is preferred. The amount of the alkali used is usually 1 to 2 with respect to 1 mol of aluminum in the alloy.
Use 0 times mole. Preferably it is in the range of 1.5 to 15 moles, more preferably in the range of 2 to 10 moles. Next, the concentration of the alkaline aqueous solution used for developing the master alloy is
It can be used in the range of 10 to 40% by weight. If the concentration is less than 10% by weight, the development is insufficient and sufficient catalytic activity cannot be obtained. The developing temperature and the aging temperature of the mother alloy vary depending on the type of alkali used, but can usually be used in the range of 20 to 100 ° C. If the temperature is lower than 20 ° C., the elution rate of aluminum decreases, and the development is insufficient and sufficient activity cannot be obtained. Further, the feeding speed of the master alloy varies depending on the amount of the developed mother alloy, but it is preferable to feed the master alloy in a range of 0.5 to 1 hour under stirring conditions. If the charging time is short, the deployment proceeds rapidly, and it becomes difficult to control the deployment temperature. On the other hand, charging over a long time is not preferable because the catalyst becomes uneven. Further, the aging time of Raney copper varies depending on the type of alkali used, but is preferably in the range of 0.5 to 6 hours.
If the time is shorter than 0.5 hour, sufficient activity cannot be obtained due to insufficient elution of aluminum. On the other hand, when the time is longer than 6 hours, the reaction is terminated and is meaningless. The copper content in the Raney copper catalyst obtained by such an operation method is usually in the range of 80.0 to 99.9% by weight, and more preferably in the range of 90.0 to 99.9% by weight. . 8
If the amount is outside the range of 0.0 to 99.9% by weight, the catalytic activity may not be sufficiently obtained. The specific surface area (BET
Method), Raney copper with a high surface area is good, usually 5 m ² /
g or more are used.

The amount of Raney copper used in the method of the present invention is determined based on the amount of the solvent. It is sufficient to use a small amount of Raney copper, but if it is too large, stirring becomes insufficient and the activity is rather reduced. Therefore, the amount of Raney copper used is in the range of 0.5 to 80 wt%, preferably 1 to 70 wt%, based on the solvent.

The metal alkoxide used in the present invention is:
Alkali metals such as Li, Na and K, Mg, Ca, Sr
At least one selected from alkaline earth metals such as
It is an alkoxide of more than one kind of metal. Among them, K and Na are preferable as the metal. Alkoxides having 1 to 10 carbon atoms are used. Of these, methoxide, ethoxide, propoxide, and butoxide are preferred. Further, methoxide is preferred. Further, metal alkoxide obtained by previously reacting a metal hydride (hydride) and an alcohol can also be used.

The amount of metal alkoxide used in the method of the present invention is based on the amount of Raney copper and the amount of solvent.
It is determined as appropriate. With respect to Raney copper, if the amount of the metal alkoxide used is small, a sufficient catalytic effect cannot be obtained, and if it is too large, it may be inhibited. Therefore, the amount of the metal alkoxide used is in the range of 0.01 to 100 times the weight of Raney copper, preferably in the range of 0.1 to 30 times, and more preferably in the range of 0.1 to 10 times. . Also, with respect to the solvent, if the amount of metal alkoxide used is large,
In addition to insufficient stirring, the amount of alkoxide lost during the reaction increases, which is economically undesirable. On the other hand, if the amount is small, sufficient catalytic activity cannot be obtained. Therefore, the amount of metal alkoxide used is
The range of 0.01 to 10% by weight is preferred.

As the solvent used in the present invention, methanol or a mixed solvent of methanol is used. The second solvent used in the methanol mixed solvent is not particularly limited, but is usually dioxane, tetrahydrofuran, diethyl ether, ethers such as diphenyl ether,
Glymes such as monoglyme, diglyme and triglyme; esters such as methyl acetate and ethyl propionate; alcohols having 6 or less carbon atoms such as ethanol, propanol and hexanol; hexane, benzene, decalin and chlorobenzene Preferred are hydrocarbons and halogenated hydrocarbons. Also, aprotic polar solvents such as dimethylformamide and N-methylpyrrolidone can be used. Among them, ethers such as dioxane and tetrahydrofuran are preferable in terms of activity. The ratio of methanol in the solvent is not particularly limited, but even at a concentration of 5% by weight or more, it can be used without a decrease in activity. In view of process aspects such as separation from products, it is particularly preferable to use only methanol.

The Raney copper and metal alkoxide used in the method of the present invention are effective as a catalyst for synthesizing methanol, even if they are used in a mixture beforehand or if they are successively added as they are to a solvent. it can.

In the present invention, a catalyst having excellent methanol activity even at a low temperature of 160 ° C. or less is used, but the reaction can be carried out in a temperature range of 40 to 200 ° C. If the reaction temperature exceeds 200 ° C., the conversion will be significantly reduced. On the other hand, when the reaction temperature is lower than 40 ° C., the reaction rate is small and not practical. Preferably 60
~ 180 ° C. More preferably 80 to 16
It is in the range of 0 ° C. However, the method of the present invention is not limited to a temperature other than the above, in consideration of the overall economic efficiency including the recovery of the reaction heat.

The raw material carbon monoxide and hydrogen can be used even if they contain nitrogen or carbon dioxide, but it is preferable that the amount of carbon dioxide is small. In some cases, it is desirable to remove trace amounts of sulfur compounds and water before starting the methanol synthesis reaction.
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 relative to carbon monoxide is greater than the stoichiometric ratio of 2, the selectivity of methanol is improved, but if it is further increased, excess hydrogen remains unused 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 more
Although the methanol activity increases, a practical pressure for supplying the synthesis gas to the reactor without increasing the pressure is 120.
kg / cm ² -G or less is preferred. However, implementation at higher pressures is also within the scope of the present invention.

In the method of the present invention, as an embodiment, the effect is exhibited in both a batch reaction and a flow reaction.

[0032]

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

1. Example 1 Catalyst activity and catalyst life test by a flow reaction test Example 1 90 g of Raney copper alloy powder manufactured by Kishida Chemical Co., Ltd. was weighed in a container, and poured into 556 g of a 24% by weight aqueous sodium hydroxide solution sealed with nitrogen while stirring little by little. Liquid temperature 55
The development was performed over 1 hour while maintaining the temperature at ± 2 ° C. After the completion of the charging, the mixture was further kept at 45 ° C. for 1 hour, aged sufficiently, and washed with distilled water previously deoxidized in batch. P of the supernatant
The well was washed until H became 8.7-9.0. Then
After solvent replacement with dehydrated methanol, the mixture was air-dried in nitrogen. Thus, 43 g of a Raney copper catalyst was obtained. As a result of analyzing the obtained catalyst, it was found to be 98.5% by weight of copper and 0.99% by weight of aluminum. Its specific surface area is 15.9 m ² / g.
Met.

In the reaction, 37.2 g of the Raney copper catalyst described above and 80 ml of a methanol solution of 2% by weight potassium methoxide were charged into a flow-type reactor having an inner volume of 260 ml in nitrogen, and CO / H ₂ = 1/2 (mol) at room temperature. Is supplied at a constant pressure of 50 kg / cm ² -G and a temperature of 120 ° C.
To perform a continuous reaction. Meanwhile, a methanol solution of 2% by weight potassium methoxide was continuously supplied to the reactor at a rate of 15 ml / hr. Further, a part of the supply gas was withdrawn as an unreacted gas, and the reaction liquid was also withdrawn at regular intervals to keep the liquid level constant. Analysis showed that the CO conversion was 97.9.
%, A reaction result of 94.4% methanol selectivity,
A stable activity for 75 hours was obtained. During that time, the average of the methanol yield [STY (Space time yield)] based on the solvent was 160 g-MeOH / l / hr.

Further, the appearance of the used catalyst changed from black to reddish brown, and as a result of analysis of the catalyst, the BET specific surface area was slightly reduced to 10.9 m ² / g.

Example 2 The method described in JP-A-1-172366 and the like
That is, a master alloy was prepared by a “rotating water atomizing method”. First, 100 g of a copper-aluminum alloy (CuAl = 50/50) was heated to about 1,000 ° C. in a high frequency heating and melting furnace.
And dissolved. Next, it was added and dissolved so that the metal calcium content was 1.2% by weight with respect to the alloy. This molten alloy is injected into rotating water, quenched and solidified, and Cu
-An Al-Ca alloy was obtained.

90 g of the thus-obtained Raney copper alloy powder containing calcium was weighed in a container, and poured into 556 g of a 24% by weight aqueous sodium hydroxide solution sealed with nitrogen while stirring little by little. The development was performed over 1 hour while maintaining the temperature. After the end of charging, further at 45 ° C for 1
The mixture was aged for a long period of time, and washed in batches using distilled water previously deoxygenated. The pH of the supernatant is 8.7 to 9.0
Washed well until Next, the solvent was replaced with dehydrated methanol, followed by air drying in nitrogen. Thus, 43 g of a Raney copper catalyst containing calcium was obtained. As a result of analyzing the obtained catalyst, 97.5% by weight of copper and 1.01% of aluminum were obtained.
% By weight and 1.0% by weight of calcium. Its specific surface area was 25.8 m ² / g.

The reaction was carried out in the same manner as in Example 1 except that 37.2 g of the Raney copper catalyst was used.

As a result of the analysis, a reaction result with a CO conversion of 98.1% and a methanol selectivity of 96.5% was obtained, and a stable activity for 75 hours was obtained. In the meantime, the average of the solvent-based methanol yield [STY (Space time yield)] was 17
0 g-MeOH / l / h.

Further, the appearance of the catalyst after use was not changed (black), and the BET specific surface area was 25.25 as a result of catalyst analysis.
It was 3 m ² / g.

Comparative Example 1 A reaction was carried out in the same manner as in Example 1 except that a commercially available copper chromite catalyst (manufactured by Nissan Gardler) was used instead of the Raney copper catalyst. Maximum activity 58g-Me in 10 hours of reaction
Although OH / l / hr was shown, the activity gradually decreased thereafter, and a stable result was not obtained. Therefore, the reaction was stopped in 25 hours. Furthermore, in this reaction, precipitation of a copper mirror due to reduction of copper during the reaction was confirmed after the reaction.

Example 3 Example 1 except that the amount of the Raney copper catalyst charged was 50 g.
As a result, a reaction result with a CO conversion of 98.3% and a methanol selectivity of 95.5% was obtained. The average STY was 225 g-MeOH / l / hr.

Example 4 The reaction was carried out under the same reaction conditions as in Example 1 except that sodium methoxide was used instead of potassium methoxide. As a result, the CO conversion was 97.1% and the methanol selectivity was 94.3%. Was obtained. The average STY was 148 g-MeOH / l / hr.

Example 5 The procedure was repeated, except that the concentration of potassium methoxide was changed to 2% by weight.
The reaction was carried out under the same reaction conditions as in Example 1 except that the amount was changed to 5% by weight. As a result, a reaction result with a CO conversion of 94.8% and a methanol selectivity of 93.1% was obtained. Also, the average STY
Was 135 g-MeOH / l / hr.

2. Catalyst activity test by batch reaction Example 6 1 g of Raney copper catalyst obtained by the method of Example 1, potassium methoxide
2.1 g (30 mmol) of oxide, 20 m of methanol
l into an autoclave, CO / H at room temperature _Two= 1 /
2 (molar ratio) synthesis gas, temperature 120 ° C, pressure
50kg / cm^TwoThe reaction was performed with -G. Pressure is about 45 minutes
9kg / cm^Two−G
Response has ended. As a result of the analysis, the STY based on the solvent used was
198 g-MeOH / l / hr.

Example 7 Example 2 was repeated in place of the Raney copper catalyst obtained by the method of Example 1.
The reaction was carried out under the same reaction conditions as in Example 6, except that 1 g of the Raney copper catalyst containing calcium obtained by the method described in 1) was used. After confirming that the pressure had dropped to 8.5 kg / cm ² -G in about 45 minutes, the reaction was terminated.

As a result of the analysis, the STY based on the charged solvent was
205 g-MeOH / l / h.

Example 8 2.1 g (30 mmol) of potassium methoxide
The reaction was carried out under the same reaction conditions as in Example 6 except that the amount was changed to 0.14 g (2 mmol). After confirming that the pressure had dropped to 10.5 kg / cm ² -G in about 45 minutes, the reaction was terminated. As a result of analysis, S based on the solvent used
TY was 178 g-MeOH / l / hr.

Example 9 A reaction was carried out under the same reaction conditions as in Example 6, except that tetrahydrofuran was used instead of methanol. After confirming that the pressure had dropped to 8 kg / cm ² -G in about 45 minutes, the reaction was terminated. As a result of the analysis, the STY based on the charged solvent was 212 g-MeOH / l / hr.

Example 10 A reaction was carried out under the same reaction conditions as in Example 6, except that a solvent mixture of 5% by weight of methanol and 95% by weight of dioxane was used instead of methanol. After confirming that the pressure dropped to 8.5 kg / cm ² -G in about 45 minutes,
The reaction was completed. As a result of analysis, STY based on solvent used
Was 189 g-MeOH / l / hr.

Example 11 The amount of the 24% by weight aqueous sodium hydroxide solution used for developing the mother alloy was changed to 228 g instead of 556 g. as a result,
The copper content of the obtained Raney copper catalyst was 90% by weight. The reaction was carried out under the same reaction conditions as in Example 6 except that the thus obtained Raney copper catalyst was used. As a result of the analysis,
STY based on the charged solvent is 173 g-MeOH / l / h.
r.

Example 12 In Example 2, 100 g of a copper-aluminum alloy (Cu / Al = 50/50) was melted at about 1,000 ° C. in a high-frequency heating and melting furnace. Next, it was added and dissolved so that the metal calcium content was 17% by weight with respect to the alloy. This molten alloy was injected into rotating water, rapidly cooled and solidified to obtain a Cu-Al-Ca alloy.

The obtained alloy was alkali-developed in the same manner as in Example 2 to obtain 83.1% by weight of copper and 0.9% of aluminum.
42.5 g of a Raney copper catalyst containing 8% by weight and 15.0% by weight of calcium was obtained. The specific surface area is 32.3 m ²
/ G.

An experiment was carried out in the same manner as in Example 6 except that a Raney copper catalyst containing calcium obtained by the above-mentioned method was used for the reaction.

As a result of the analysis, the STY based on the solvent used was 2
13 g-MeOH / l / h. In addition, there was no change in the appearance of the catalyst after use (black).
The ET specific surface area was 30.9 m ² / g.

Example 13 In Example 2, 100 g of a copper-aluminum alloy (Cu / Al = 50/50) was melted at about 1,000 ° C. in a high-frequency heating and melting furnace. Next, it was added and dissolved so that the content of metallic calcium was 0.01% by weight with respect to the alloy. This molten alloy was injected into rotating water, rapidly cooled and solidified to obtain a Cu-Al-Ca alloy.

The obtained alloy was alkali-developed in the same manner as in Example 2 to obtain 99.1% by weight of copper and 0.7% of aluminum.
42 g of a Raney copper catalyst of 8% by weight and 0.0008% by weight of calcium were obtained. Its specific surface area is 17.0 m ² / g
Met.

An experiment was conducted in the same manner as in Example 6 except that the Raney copper catalyst containing calcium obtained by the above-mentioned method was used for the reaction.

As a result of the analysis, the STY based on the charged solvent was 1
98 g-MeOH / l / h. Further, the appearance of the catalyst after use changed from black to reddish brown, and as a result of catalyst analysis, the BET specific surface area was slightly reduced to 12.9 m ² / g.

Comparative Example 2 1 g of CuCl (1 g) was used in place of the Raney copper catalyst.
The reaction was carried out under the same reaction conditions as in Example 6 except that the solvent was changed to tetrahydrofuran instead of methanol at 0 mmol). After confirming that the pressure had decreased to 19 kg / cm ² -G in about 60 minutes, the reaction was terminated. As a result of the analysis, the STY based on the charged solvent was 78 g-MeOH / l /
hr. Furthermore, in this reaction, precipitation of a copper mirror due to reduction of copper during the reaction was confirmed after the reaction.

Comparative Example 3 A copper chromite catalyst 1 was used in place of the Raney copper catalyst.
The reaction was carried out under the same reaction conditions as in Example 8 except that the amount was changed to g. As a result, little pressure absorption was recognized, and almost no methanol activity was obtained. Furthermore, in this reaction, precipitation of a copper mirror due to reduction of copper during the reaction was confirmed after the reaction.

Comparative Example 4 1 g of CuCl (1 g) was used in place of the Raney copper catalyst.
The reaction was carried out under the same reaction conditions as in Example 8 except that the amount was changed to 0 mmol). As a result, almost no methanol activity was obtained with only slight pressure absorption. Furthermore, in this reaction, precipitation of a copper mirror due to reduction of copper during the reaction was confirmed after the reaction.

COMPARATIVE EXAMPLE 5 The method described in US Pat. No. 4,623,634, ie, molybdenum hexacarbonyl (Mo
The reaction was carried out under the same reaction conditions as in Example 8, except that 2.6 g (10 mmol) of (CO) ₆ ) was used in place of the Raney copper catalyst. As a result of analysis, STY based on solvent used
Was 56 g-MeOH / l / hr. Also, a large amount of molybdenum hexacarbonyl was attached to the upper part of the autoclave.

Comparative Example 6 1 g of CuCl (1 g) was used in place of the Raney copper catalyst.
0 mmol), and the reaction was carried out under the same reaction conditions as in Example 6 except that a mixed solvent of 5% by weight of methanol and 95% by weight of dioxane was used instead of methanol.
As a result of the analysis, the STY based on the solvent used was 32 g-MeO
H / l / hr.

Reference Example 1 A 24% by weight aqueous solution of caustic soda 55 used for developing a mother alloy
Instead of 6 g, it was 228 g of a 15% by weight aqueous sodium hydroxide solution. As a result, the aluminum content in the obtained Raney copper catalyst was 25% by weight. The reaction was carried out under the same reaction conditions as in Example 6 except that the thus obtained Raney copper catalyst was used. As a result of the analysis, the STY based on the charged solvent was 88 g-MeOH / l / hr.

Comparative Example 7 Raney copper-zinc-chromium (manufactured by Nikko Rica Co., 77.6% by weight, aluminum 8.4% by weight, aluminum 10.4% by weight, zinc 10.4% by weight, chromium 3) was used in place of the Raney copper catalyst. The reaction was carried out under the same reaction conditions as in Example 6 except that the amount was changed to 0.6% by weight. As a result, little pressure absorption was observed, and almost no methanol activity was obtained.

Comparative Example 8 The reaction was carried out under the same reaction conditions as in Example 6 except that the Raney copper catalyst was replaced by a copper powder (Mitsui Metals, 1050Y, specific surface area: 1.29 m ² / g). As a result, methanol activity was hardly obtained at a level where slight pressure absorption was observed.

Tables 1 and 2 summarize the results obtained in the above Examples and Comparative Examples.

[0069]

[Table 1]

* 1 98.5% by weight of copper, 0.99 of aluminum
% By weight * 2 97.5% by weight of copper, 1.01% by weight of aluminum, 1.0% by weight of calcium * 3 STYmax: maximum STY (g-MeOH / l / h), STYav: average STY (g-MeOH / l / h), COconv. : CO conversion (%),
MeOHsel .: Selectivity of methanol (%) Conditions: temperature 120 ° C., pressure 50 kg / cm ² -G, H ₂ /
CO = 2

[0071]

[Table 2]

* 1 98.5% by weight of copper, 0.99 of aluminum
% By weight * 2 97.5% by weight of copper, 1.01% by weight of aluminum, 1.0% by weight of calcium * 3 90.0% by weight of copper * 4 83.1% by weight of copper, 0.98% by weight of aluminum, 15.0% by weight of calcium * 5 99.1% by weight of copper, 0.78% by weight of aluminum %, Calcium 0.008% by weight * 6 Copper 75.0% by weight, aluminum 25.0% by weight * 7 Copper 77.6% by weight, aluminum 8.4% by weight, zinc 1
0.4 wt%, chromium 3.6 wt% * 8 THF: tetrahydrofuran Conditions: temperature 120 ° C, pressure 50 kg / cm ² -G, H ₂
/ CO = 2

[0073]

According to the present invention, in a method for producing methanol from carbon monoxide and hydrogen, in producing methanol continuously from carbon monoxide and hydrogen in the presence of a solvent, Raney copper and metal alkoxide are mixed. By performing the reaction as a catalyst, under low-temperature, low-pressure reaction conditions, even at a low metal alkoxide concentration, a methanol activity (compared as STY) far superior to that of a known catalyst was obtained.
Over time, stable results were obtained.

As a result, it is not necessary to recycle the unreacted synthesis gas to the reaction system, and the methanol synthesis reaction can be carried out even at a lower pressure than in the synthesis gas production step. This is an industrially advantageous production method, such as the absence of any.

Continued on the front page (72) Inventor Kenji Fujiwara 1-2-1, Waki, Waki-machi, Kuga-gun, Yamaguchi Prefecture Inside Mitsui Chemicals, Inc. (72) Inventor Takeshi Omatsuzawa 6-1-2, Waki, Waki-cho, Kuga-gun, Yamaguchi Prefecture No. Mitsui Chemicals, Inc. (72) Inventor Kenichi Yamamoto 4-4-2-301 Kuba, Otake City, Hiroshima Prefecture

Claims (9)

[Claims] 1. A metal alkoxide and a copper content of 8
A method for producing methanol, comprising reacting carbon monoxide and hydrogen in a solvent in the presence of Raney copper in the range of 0.0 to 99.9% by weight. 2. The method according to claim 1, wherein the Raney copper contains calcium. 3. The calcium content in Raney copper is 0.
3. The method according to claim 2, wherein the amount is in the range of from 01 to 20% by weight. 4. The method according to claim 1, wherein the metal alkoxide is an alkali metal alkoxide or an alkaline earth metal alkoxide. 5. The method according to claim 4, wherein the metal alkoxide is potassium methoxide or sodium methoxide. 6. The method according to claim 1, wherein the solvent is methanol or an organic solvent containing 5% by weight or more of methanol. 7. The method according to claim 1, wherein the concentration of the metal alkoxide is 0.01 to 10% by weight based on the solvent. 8. The method according to claim 1, wherein the reaction is carried out at 60 to 180 ° C.
The method described in. 9. The method according to claim 1, wherein the reaction is performed at 10 to 120 atm.