JP3530937B2 - Catalyst for methanol synthesis - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a carbon oxide (CO
₂ and / or CO) for the synthesis of methanol by catalytic hydrogenation.

[0002]

2. Description of the Related Art Conventionally, a synthesis reaction of methanol from a mixed gas in which a synthetic gas (a mixed gas of CO and H ₂ ) is used as a main raw material and a small amount of CO ₂ is added is, for example, copper /
250 to 3 using a catalyst composed of zinc / aluminum oxide or a catalyst composed of copper / zinc / chromium oxide
It is carried out industrially under the conditions of 50 ° C and 50 to 150 atm (Catalyst Course Vol. 7, edited by The Catalyst Society, published by Kodansha (1
985)).

On the other hand, methanol synthesis using CO ₂ and hydrogen as main raw materials has recently been drawing attention from the viewpoint of recycling and recycling of carbon resources and global environmental problems. When a gas containing CO ₂ as a main component is reacted with hydrogen on a catalyst to synthesize methanol, the temperature lower than that used in the above-mentioned synthesis of methanol from the synthesis gas is considered due to the thermodynamic equilibrium of the reaction. It is necessary to carry out the reaction in. Further, in the methanol synthesis reaction on the copper-based catalyst, methanol is produced from CO ₂ and hydrogen in the raw material gas, but the reaction is inhibited by water (steam) produced together with the methanol (Appl.
ied Catalysis A: General 1
38 (1966) 311-318). The produced water reacts with CO in the raw material gas to produce CO ₂ and hydrogen, and again produces methanol.
The amount of water produced together with methanol is C in the raw material gas.
O ₂ / CO ratio increases with increasing. For these reasons, in order to synthesize methanol from a raw material gas having a high CO ₂ content, a synthesis gas is used as a main raw material and a raw material gas having a small CO ₂ content (raw material gas in the current methanol synthesis) is used for methanol synthesis. There is a need for a catalyst that is more highly active than the catalysts used and has excellent long-term durability.

Therefore, many attempts have been made so far to improve the performance of the catalyst by adding various compounds to the catalyst composed of oxides of copper / zinc / aluminum.
The present inventor has already developed a highly active catalyst which contains copper oxide, zinc oxide, aluminum oxide and silicon oxide as essential components and zirconium oxide and the like as optional components and has excellent long-term durability. Kaihei 10-309466).

However, subsequent studies by the present inventors have revealed that the catalyst according to the present invention has excellent durability, but there is room for further improvement.

[0006]

DISCLOSURE OF THE INVENTION The present invention is a further improvement and development of the above invention (Japanese Patent Laid-Open No. 10-309466), wherein when carbon oxide is reacted with hydrogen to synthesize methanol, The main purpose is to provide a catalyst having high activity and excellent durability especially for a long time.

[0007]

Means for Solving the Problems The present inventor has made diligent studies to improve the durability of the catalyst for methanol synthesis according to the above-mentioned invention, and as a result, the above-mentioned catalyst of the present invention was further oxidized. It has been found that a catalyst with cerium added can achieve that end.

That is, according to the present invention, firstly, copper oxide,
Zinc oxide, aluminum oxide, silicon oxide and cerium oxide are essential components, silicon oxide is derived from colloidal silica or dissolved silica in water, and the catalyst is 480 to 690.
There is provided a catalyst for synthesizing methanol, which has been subjected to a calcination treatment at ° C. Secondly, in the first invention, there is provided a methanol synthesis catalyst characterized by further containing zirconium oxide. Thirdly, in the first or second invention, there is provided a catalyst comprising a metal oxide containing copper oxide, zinc oxide, aluminum oxide, silicon oxide and cerium oxide as essential components and zirconium oxide as an optional component. When the total amount of the catalyst is 100% by weight, the content of each oxide is 20 to 60% by weight and 10 in the above order.
-50% by weight, 2-10% by weight, 0.30-0.9% by weight, 1-7% by weight, 0-40% by weight, the silicon oxide is derived from colloidal silica or dissolved silica in water, and a catalyst Provides a catalyst for methanol synthesis characterized by being subjected to a calcination treatment at 480 to 690 ° C.

[0009]

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

The methanol synthesis catalyst component of the present invention contains copper oxide, zinc oxide, aluminum oxide, silicon oxide (from colloidal silica or dissolved silica in water) and cerium oxide as essential components. It is effective to add an optional component such as zirconium oxide, gallium oxide, palladium oxide, or boron oxide, especially zirconium oxide, in order to improve the activity. Also,
Other substances may be included as long as the gist of the present invention is not impaired.

A feature of the catalyst of the present invention is that it has excellent durability, that is, its high catalytic activity is maintained for a long period of time, and is further superior to the catalyst of the invention described in JP-A-10-309466. It is to demonstrate durability. This is due to the action of the newly added cerium oxide. Although the content of the action of cerium oxide is not completely clear, the cerium oxide in cerium oxide can easily move between tetravalent and trivalent, so that the surface of the catalyst during the reaction can be It is speculated that it can be kept active. Even if lanthanum oxide, which is one of the rare earth elements like cerium, is added, the valence of lanthanum in lanthanum oxide remains trivalent,
The performance of the catalyst was not improved (see Comparative Example 2 below).

Further, in the present invention, as the silicon oxide, one derived from colloidal silica or water-dissolved silica is used. Even with the same silicon oxide, when it is produced by adding sodium silicate (water glass) or potassium silicate, for example, a catalyst having the desired effect cannot be obtained. In addition, colloidal silica and water-dissolved silica may be used in combination.

The proportion of each catalyst component is not particularly limited, but when the total amount of the catalyst is 100% by weight, the copper oxide content is 20%.
-60 wt% (preferably 30-50 wt%), zinc oxide 10-50 wt% (preferably 20-40 wt%), aluminum oxide 2-10 wt% (preferably 4-8 wt%), 0.3 to 0.9% by weight of silicon oxide,
1 to 7% by weight (preferably 2 to 6% by weight) of cerium oxide, and 0 to 40% by weight of optional components such as zirconium oxide.
(Preferably 10 to 30% by weight). By appropriately determining the composition in such a quantitative range according to the target reaction, it is possible to obtain the catalytic performance suitable for the reaction.

Further, the copper-based catalyst of the present invention is 480-69.
It is necessary to have been subjected to a baking treatment at 0 ° C. If the calcination temperature is lower than 480 ° C, the activity of the catalyst is insufficient and the durability is also insufficient. Even when the calcination temperature exceeds 690 ° C., it becomes negative in terms of catalytic activity and durability. Thus, the firing temperature is selected from the range of 480 to 690 ° C,
From the viewpoint of catalyst performance, it is higher than the above range of 52.
It is desirable to set the temperature to 0 to 680 ° C. A particularly preferable range is a higher temperature range of 560 to 670 ° C.

The catalyst of the present invention is disclosed in JP-A-10-30946.
It is easily manufactured by the method described in Japanese Patent Publication No. 6 or a method analogous thereto, and an example thereof is as follows. First, nitrate, sulfate, etc., which are optional components such as copper, zinc, aluminum, cerium, and preferably zirconium, are dissolved in water, and a predetermined amount of colloidal silica is added to prepare a mixed aqueous solution. On the other hand, sodium carbonate, sodium hydrogen carbonate, etc. are dissolved in water to obtain a precipitant aqueous solution. By mixing these two solutions,
A coprecipitate forms. This is filtered and washed,
The catalyst of the present invention composed of copper oxide, zinc oxide, aluminum oxide, silicon oxide, cerium oxide and preferably zirconium oxide is produced by drying and calcining at a predetermined temperature.

Raw materials for preparing any metal oxides such as copper oxide, zinc oxide, aluminum oxide, cerium oxide, and zirconium oxide, which are catalyst components, include water-soluble nitrates, sulfates, oxynitrates, and oxynitrates. Chlorides and the like can be used as appropriate. As the raw material of silicon oxide, as described above, one derived from colloidal silica or water-dissolved silica is used.

In the above catalyst production process, a basic compound such as sodium carbonate, sodium hydrogen carbonate or sodium hydroxide can be used as a precipitating agent for preparing a precipitate containing a catalyst component. Washing, filtration and drying of the precipitate can be performed by known methods.

The precipitate after drying has a temperature of 480 ° C to 690 ° C.
By performing the firing treatment in an oxygen atmosphere (usually in air) at (preferably 520 to 680 ° C.), the above-mentioned metal component becomes an oxide form.

The catalyst thus obtained is as it is,
Alternatively, it is used after being granulated or tableted by an appropriate method. The particle size and shape of the catalyst can be arbitrarily selected depending on the reaction system and the shape of the reactor.

The catalyst for synthesizing methanol of the present invention obtained as described above may be reduced with hydrogen to reduce the copper oxide component in the catalyst prior to use. However, even if this reduction is not performed, the reduction operation is not essential because it is naturally reduced during the methanol synthesis reaction using hydrogen as a part of the raw material.

The catalyst according to the present invention is useful both in the methanol synthesis reaction in the gas phase and in the methanol synthesis reaction carried out by suspending the catalyst in a liquid.

The reaction conditions for synthesizing methanol using the catalyst according to the present invention may differ depending on the concentrations of carbon oxide and hydrogen in the raw material gas, the content of catalyst components, etc., but the reaction temperature is 150 to 350 ° C. , The reaction pressure is 1 to 30 MPa
The range is suitable.

[0023]

EXAMPLES Hereinafter, the features of the present invention will be further clarified by giving examples.

Example 1 35.4 g of copper nitrate trihydrate and 25.5 zinc nitrate hexahydrate
g, aluminum nitrate nonahydrate 8.5 g, zirconium oxynitrate dihydrate 11.1 g, colloidal silica (manufactured by Nissan Chemical Industries, Ltd., Snowtex O, silica concentration 2)
0% by weight) 1.0 g and cerium nitrate hexahydrate 1.6
g in distilled water to prepare an aqueous solution of 300 ml.
It was a liquid. On the other hand, 36.5 g of anhydrous sodium carbonate was dissolved in distilled water to prepare a 300 ml aqueous solution, which was designated as solution B. The liquids A and B were simultaneously added dropwise to 800 ml of room temperature distilled water, which was well stirred at a rate of 8 ml / min, to obtain precipitates. The precipitate was aged at room temperature for 3 days, filtered and washed to remove sodium from the precipitate. After that, the precipitate is dried at 110 ° C., and in air,
It was calcined at 600 ° C. for 2 hours to obtain a catalyst. The composition of this catalyst was as follows: 45.1% by weight of copper oxide, 27.1% by weight of zinc oxide, 4.5% by weight of aluminum oxide, 19.8% by weight of zirconium oxide, 0.8% by weight of silicon oxide and cerium oxide (CeO). ₂ ) It was 2.7% by weight.

A reaction tube was filled with 1 ml of the obtained catalyst, and a mixed gas of helium and hydrogen (helium 90% by volume, hydrogen 1
(0% by volume) at 250 ° C. for 2 hours, and then a mixed gas of 22% by volume of CO ₂ , 3% by volume of CO and 75% by volume of H ₂ is passed through the catalyst layer. The mixed gas was reacted under conditions of a pressure of 5 MPa, a mixed gas flow rate of 167 ml / min, and a temperature of 250 ° C. The reaction product gas was analyzed by gas chromatography to examine the space-time yield of methanol. Reaction elapsed time 48 hours and 100
Table 1 shows the methanol space-time yield at 0 hours, and the catalytic activity stability (methanol space-time yield at the reaction elapsed time of 1000 hours / methanol space-time yield at the reaction elapsed time of 48 hours). Products other than methanol were mainly CO, and formation of trace amounts of methane, dimethyl ether, and methyl formate was observed.

Example 2 35.5 g of copper nitrate trihydrate and 25.6 of zinc nitrate hexahydrate
g, aluminum nitrate nonahydrate 8.6 g, zirconium oxynitrate dihydrate 10.1 g, colloidal silica (manufactured by Nissan Chemical Industries, Ltd., Snowtex O, silica concentration 2)
0% by weight) 1.0 g and cerium nitrate hexahydrate 2.7
g in distilled water to prepare an aqueous solution of 300 ml.
It was a liquid. On the other hand, 36.7 g of anhydrous sodium carbonate was dissolved in distilled water to prepare a 300 ml aqueous solution, which was designated as solution B. The liquids A and B were simultaneously added dropwise to 800 ml of room temperature distilled water, which was well stirred at a rate of 8 ml / min, to obtain precipitates. The precipitate was aged at room temperature for 3 days, filtered and washed to remove sodium from the precipitate. After that, the precipitate is dried at 110 ° C., and in air,
It was calcined at 600 ° C. for 2 hours to obtain a catalyst. The composition of this catalyst is as follows: copper oxide 45.2 wt%, zinc oxide 27.1 wt%, aluminum oxide 4.5 wt%, zirconium oxide 18.0 wt%, silicon oxide 0.8 wt% and cerium oxide (CeO). ₂ ) It was 4.4% by weight.

The reaction tube was filled with 1 ml of the obtained catalyst, and a methanol synthesis reaction was carried out in the same manner as in Example 1. The reaction product gas was analyzed by gas chromatography to examine the space-time yield of methanol. Reaction elapsed time 48 hours and 1
Table 1 shows the methanol space-time yield at 000 hours and the catalyst activity stability (methanol space-time yield at reaction elapsed time 1000 hours / methanol space-time yield at reaction elapsed time 48 hours). Products other than methanol are
Mainly CO, trace amounts of methane, dimethyl ether,
Formation of methyl formate was observed.

Comparative Example 1 35.1 g of copper nitrate trihydrate, zinc nitrate hexahydrate 25.3
g, aluminum nitrate nonahydrate 8.5 g, zirconium oxynitrate 12.5 g and colloidal silica (Nissan Chemical Co., Ltd., Snowtex O, silica concentration 20% by weight) 1.0 g are dissolved in distilled water, A 300 ml aqueous solution was prepared and designated as solution A. On the other hand, anhydrous sodium carbonate 3
6.3 g was dissolved in distilled water to prepare a 300 ml aqueous solution, which was designated as solution B. 8 ml each of solution A and solution B
A precipitate was obtained by simultaneously dropping it into 800 ml of room temperature distilled water that was well stirred at a speed of 1 / min. The precipitate was aged at room temperature for 3 days, filtered and washed to remove sodium from the precipitate. Then, the precipitate was dried at 110 ° C. and calcined in air at 600 ° C. for 2 hours to obtain a catalyst. The composition of this catalyst was 45.2% by weight of copper oxide, 27.0% by weight of zinc oxide, 4.5% by weight of aluminum oxide, 22.5% by weight of zirconium oxide and 0.8% by weight of silicon oxide.

1 ml of the obtained catalyst was filled in a reaction tube, and a methanol synthesis reaction was carried out in the same manner as in Example 1. The reaction product gas was analyzed by gas chromatography to examine the space-time yield of methanol. Reaction elapsed time 48 hours and 1
Table 1 shows the methanol space-time yield at 000 hours and the catalyst activity stability (methanol space-time yield at reaction elapsed time 1000 hours / methanol space-time yield at reaction elapsed time 48 hours). Products other than methanol are
Mainly CO, trace amounts of methane, dimethyl ether,
Formation of methyl formate was observed. From this result, it is clear that the activity stability of the catalyst to which cerium oxide is not added is lower than the activity stability of the cerium oxide-added catalyst.

Comparative Example 2 35.4 g of copper nitrate trihydrate and 25.5 zinc nitrate hexahydrate
g, aluminum nitrate nonahydrate 8.6 g, zirconium oxynitrate dihydrate 10.1 g, colloidal silica (manufactured by Nissan Chemical Industries, Ltd., Snowtex O, silica concentration 2)
0% by weight) and lanthanum nitrate hexahydrate 3.1
g in distilled water to prepare an aqueous solution of 300 ml.
It was a liquid. On the other hand, 36.7 g of anhydrous sodium carbonate was dissolved in distilled water to prepare a 300 ml aqueous solution, which was designated as solution B. The liquids A and B were simultaneously added dropwise to 800 ml of room temperature distilled water, which was well stirred at a rate of 8 ml / min, to obtain precipitates. The precipitate was aged at room temperature for 3 days, filtered and washed to remove sodium from the precipitate. After that, the precipitate is dried at 110 ° C., and in air,
It was calcined at 600 ° C. for 2 hours to obtain a catalyst. The composition of this catalyst is as follows: copper oxide 45.2% by weight, zinc oxide 27.1% by weight, aluminum oxide 4.5% by weight, zirconium oxide 18.0% by weight, silicon oxide 0.8% by weight and lanthanum oxide 4. It was 5% by weight.

1 ml of the obtained catalyst was filled in a reaction tube, and a methanol synthesis reaction was carried out in the same manner as in Example 1. The reaction product gas was analyzed by gas chromatography to examine the space-time yield of methanol. Reaction elapsed time 48 hours and 1
Table 1 shows the methanol space-time yield at 000 hours and the catalyst activity stability (methanol space-time yield at reaction elapsed time 1000 hours / methanol space-time yield at reaction elapsed time 48 hours). Products other than methanol are
Mainly CO, trace amounts of methane, dimethyl ether,
Formation of methyl formate was observed. From this result, it is clear that the stability of the catalytic activity is not improved in the catalyst to which lanthanum oxide is added.

Comparative Example 3 35.5 g of copper nitrate trihydrate and 25.6 of zinc nitrate hexahydrate
g, aluminum nitrate nonahydrate 8.6 g, zirconium oxynitrate dihydrate 10.1 g and cerium nitrate hexahydrate 2.7 g were dissolved in distilled water to prepare 300 ml of an aqueous solution, which was designated as solution A. . On the other hand, anhydrous sodium carbonate 36.
Dissolve 7 g in distilled water to prepare 300 ml aqueous solution,
It was designated as solution B. The liquids A and B were simultaneously added dropwise to 800 ml of room temperature distilled water, which was well stirred at a rate of 8 ml / min, to obtain precipitates. The precipitate was aged at room temperature for 3 days, filtered and washed to remove sodium from the precipitate. After that, the precipitate is dried at 110 ° C.,
It was calcined in air at 600 ° C. for 2 hours to obtain a catalyst. The composition of this catalyst was as follows: copper oxide 45.5% by weight, zinc oxide 27.
3% by weight, aluminum oxide 4.5% by weight, zirconium oxide 18.2% by weight and cerium oxide (CeO ₂ ).
It was 4.5% by weight.

The reaction tube was filled with 1 ml of the obtained catalyst, and a methanol synthesis reaction was carried out in the same manner as in Example 1. The reaction product gas was analyzed by gas chromatography to examine the space-time yield of methanol. Reaction elapsed time 48 hours and 1
Table 1 shows the methanol space-time yield at 000 hours and the catalyst activity stability (methanol space-time yield at reaction elapsed time 1000 hours / methanol space-time yield at reaction elapsed time 48 hours). Products other than methanol are
Mainly CO, trace amounts of methane, dimethyl ether,
Formation of methyl formate was observed. From this result, it is clear that the stability of the catalytic activity is extremely low in the catalyst to which silicon oxide is not added, as has been clarified in the existing invention (Japanese Patent Application No. 9-294097).

[0034]

[Table 1]

[0035]

The methanol synthesis catalyst of the present invention has excellent durability, that is, its high catalytic activity is maintained for a long period of time, and is even more durable than the catalyst described in JP-A-10-309466 previously proposed. Since it exhibits the above, it can be said to be a catalyst having high catalytic activity stability, which is extremely advantageous industrially.

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B01J 21/00-37/36 C07C 29 / 15,31 / 04 JISSTPLUS file (JOIS) WPI (DIALOG)

Claims (3)

(57) [Claims] 1. Copper oxide, zinc oxide, aluminum oxide,
A catalyst for methanol synthesis characterized in that silicon oxide and cerium oxide are essential components, silicon oxide is derived from colloidal silica or water-dissolved silica, and the catalyst has been subjected to a calcination treatment at 480 to 690 ° C. 2. The methanol synthesis catalyst according to claim 1, further comprising zirconium oxide. 3. Copper oxide, zinc oxide, aluminum oxide,
A catalyst composed of a metal oxide containing silicon oxide and cerium oxide as essential components and zirconium oxide as an optional component, wherein the content of each oxide is in the above order when the entire catalyst is 100% by weight. 20-60% by weight, 10-5
0% by weight, 2 to 10% by weight, 0.30 to 0.9% by weight,
1 to 7% by weight, 0 to 40% by weight, the silicon oxide is derived from colloidal silica or dissolved silica in water, and the catalyst has been subjected to a calcination treatment at 480 to 690 ° C. Or the catalyst for synthesizing methanol according to 2.