JPH10272360A - Method for producing fluidized catalyst for methanol synthesis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the slurry property, heighten the strength, and increase the productivity, by granulating a slurry composition containing a pectic substance in a specified amount relatively to the solid matter of respective catalyst components together with the catalyst components, in the case of producing a fluid catalyst for methanol synthesis and containing copper, zinc, and zirconium compounds as main components. SOLUTION: To produce the fluid catalyst for methanol synthesis, which contains copper zinc, and zirconium compounds as main component and is to be used for methanol synthesis process, the slurry property is improved by granulating the slurry composition containing a pectic substance in 0.1-5 wt.% relatively to the solid matter of respective catalyst components together with these catalyst components and the heat resistance of the catalyst produced from the slurry is improved. The pectic substance is polysaccharide existing in higher plants in nature and produced by extraction from peels of citrus fruits and apple residue. The fluidized catalyst may contain 30-70 wt.% (based on oxide standard of respective metal compounds) of zirconium and further magnesium and/or aluminum compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an improvement in a method for producing a fluidized catalyst for methanol synthesis, and more particularly, to a methanol synthesis reaction condition under which the strength and productivity of the catalyst can be increased and high-quality energy can be recovered. The present invention relates to a method for efficiently producing a usable fluid catalyst for methanol synthesis having excellent heat resistance.

[0002]

2. Description of the Related Art Recently, in the methanol synthesis process, technical improvements have been made for the purpose of increasing the size and reducing the unit energy consumption in order to promote cost reduction. As one of the technological improvements of such a methanol synthesis process, the development of a synthesis reaction using a fluid catalyst has been carried out.
For example, JP-A-60-84142, JP-A-60-1
06534, JP-A-60-12040,
JP-A-63-209754, JP-A-63-3154
No. 1, JP-A-7-39756 and the like disclose a fluidized catalyst for methanol synthesis and a method for producing the same. On the other hand, the fluidized bed catalytic reactor promotes the rapid transfer of the heat of reaction and enhances the efficiency of recovering the heat of reaction, so that the reaction rate of methanol synthesis can be increased, and it is advantageous for increasing the size of the reactor. In addition, it has the advantage that the heat of reaction can be effectively recovered and the energy consumption can be reduced. The catalyst used in such a fluidized bed catalytic reactor is:
Performance with excellent activity, strength and heat resistance is required. Further, since the amount of the catalyst is large for use in a large-sized apparatus, the productivity of the catalyst is also an extremely important factor.

[0003] Fluid catalysts are usually spherical powders,
As a granulation method for obtaining this, a spray drying method, an oil dropping method, or the like is employed. In the production of such a fluidized catalyst, a catalyst component (hereinafter, sometimes referred to as a raw material cake) is slurried into a granulated raw material. The properties of the granulation slurry generally include the constituent components, the composition and the It depends on the preparation method. The strength of the fluidized catalyst is greatly affected by various conditions at the time of granulation. Therefore, it is particularly important to control the properties of the slurry in the step of slurrying the raw material cake, that is, the slurry concentration and the slurry fluidity. In general, the higher the slurry concentration (solids concentration), the better the abrasion resistance and the strength of the catalyst, and the higher the productivity per hour, and the better the catalyst from an industrial point of view. Therefore, catalyst development for satisfying such conditions is being actively conducted. As described above, the higher the slurry concentration is, the more advantageous it is. On the other hand, if the slurry concentration is high, the fluidity becomes poor, and the operability at the time of spray drying,
That is, it is not possible to smoothly transfer the slurry and the like, which causes an undesirable situation that the productivity of the catalyst is reduced. Therefore, improvement in fluidity under a high slurry concentration is required. As such an improvement, see, for example,
JP-A-39756 proposes adding a trace amount of sodium to a catalyst component.

On the other hand, as described above, in a fluidized bed catalytic reactor, the recovery rate of the reaction heat is high, and the reaction heat can be effectively recovered. Is achieved. When recovering such reaction heat, it is usually recovered as steam, and the recovered steam is used in various ways as an energy source. Therefore, it goes without saying that the recovered steam is more advantageous at a higher temperature, that is, at a higher pressure. Thus, in order to recover high-energy steam, the fluidized-bed catalytic reactor is inevitably operated at a high reaction temperature. Therefore, since the catalyst used in this fluidized bed catalytic reactor is used at a high temperature, it is strongly required to have excellent heat resistance as well as activity and abrasion resistance. This heat resistance is also an important factor that affects durability. However, as proposed in the above-mentioned Japanese Patent Application Laid-Open No. 7-39756, in a catalyst prepared by a slurry property reforming method in which sodium is added, although the strength and productivity of the catalyst are improved, a high quality is obtained. It has been found that the performance is not always sufficient under the synthesis reaction conditions under which the energy can be recovered.

[0005]

SUMMARY OF THE INVENTION Under the above circumstances, the present invention can improve the properties of a slurry, improve the strength and productivity, and can suitably recover a high-quality energy even under methanol synthesis reaction conditions. An object of the present invention is to provide a method for efficiently producing a usable fluid catalyst for methanol synthesis having excellent heat resistance.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies on the improvement of the slurry properties. As a result, the slurry properties were improved by adding pectin at a specific ratio during the preparation of the slurry. It has been found that the above object can be achieved. The present invention has been completed based on such findings. That is, in the present invention, when producing a fluidized catalyst for methanol synthesis containing copper, zinc and zirconium compounds as main components, 0.1 to 5% by weight of pectic substance based on the solid content is contained together with each catalyst component. The present invention provides a method for producing a fluidized catalyst for methanol synthesis, comprising granulating a slurry composition to be produced.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The fluidized catalyst obtained by the method of the present invention comprises a copper, zinc and zirconium compound as a main component and, if necessary, a magnesium and / or aluminum compound, and contains carbon monoxide and / or Alternatively, it is a fluid catalyst for synthesizing methanol from a synthesis gas containing carbon dioxide and hydrogen as main components. The method of the present invention is characterized in that pectic substances are added to a slurry used in the granulation step in the preparation of the catalyst, and the pectic substances are polysaccharides present in higher plants in nature. It is industrially manufactured by extracting from citrus peel, apple refuse and the like. This is known to become a negatively charged hydrocolloid when dispersed in water, and is known to move in a complicated manner depending on the surrounding conditions. Since this pectic substance is a polysaccharide, that is, a carbohydrate derivative, it does not contain any element that adversely affects the methanol synthesis reaction.

In the present invention, by adding such a pectic substance in the preparation of a slurry during granulation of a fluidized catalyst, the properties of the slurry are improved and the heat resistance of the obtained catalyst is improved. The method for preparing the raw material cake and the method for granulation in the present invention are not particularly limited, and the methods used in the conventional preparation of a fluidized catalyst for methanol synthesis can be applied. That is, usually, first, a raw material cake is produced by a precipitation reaction of a catalyst component, a pectic substance is added to this to form a slurry as described above, and then the slurry is granulated by spray drying or the like, whereby a fluidized catalyst is produced. Is obtained. In the present invention, the proportions of the copper, zinc and zirconium compounds, which are the main components of the raw material cake, are not particularly limited. For example, the proportion of copper and zinc is 0.5: 1 to 20: 1 in atomic ratio. The range is preferable, and particularly the range of 0.8: 1 to 15: 1 is preferable. Also,
The content of zirconium in the catalyst component is preferably in the range of 30 to 70% by weight based on the oxide of each metal compound. If necessary, compounds such as aluminum, boron, chromium, magnesium, and silicon can be contained as auxiliary components, and among these, it is preferable to contain aluminum and / or magnesium compounds. When an aluminum compound is contained, the content is preferably in the range of 0.5 to 10% by weight, particularly preferably 1 to 5% by weight, based on the oxide of each metal compound. When a magnesium compound is contained, the content is preferably such that the amount of magnesium atoms is in the range of 10 to 60% based on the total amount of zinc and magnesium atoms.

[0009] The pectin added as a slurry property modifier when making such a raw material cake into a slurry is not particularly limited with respect to its origin, and pectin extracted and produced from various natural products is used as it is. Can be used. The amount of addition is in the range of 0.1 to 5% by weight based on the solid content of the raw material cake in the slurry. This amount is 0.
If it is less than 1% by weight, the effect of improving the slurry properties and the effect of improving the heat resistance of the catalyst cannot be sufficiently exhibited, and the object of the present invention cannot be achieved. On the other hand, if it exceeds 5% by weight, the effect is not improved for the amount, but the heat resistance tends to decrease, and it is economically disadvantageous. From the viewpoint of the effect of improving the slurry properties, the effect of improving the heat resistance of the catalyst, and the balance of economic efficiency, the particularly preferred amount of the pectin is 0.2 to 4% by weight based on the solid content of the raw material cake in the slurry. %
Range. Thus, by the addition of pectin,
Without using an alkali such as a sodium-based material, the viscosity of the slurry is reduced, so that when the slurry concentration suitable for granulation is high, the slurry concentration can be increased by about 5% by weight or more. In the present invention, the concentration of this slurry is usually in the range of 15 to 30% by weight. In this manner, the catalyst obtained by granulating the slurry whose properties have been modified is reduced in the content of fine powder having a particle size of 20 μm or less, which is unsuitable as a fluidized catalyst. Not only the abrasion property is improved, but also the heat resistance is particularly improved as compared with the conventional alkali-added catalyst.

The granules thus prepared can be used as they are, but are usually used after firing. This baking treatment is generally performed under an air atmosphere at 250.degree.
This is performed at a temperature of about 500 ° C. At this time, the added pectic substance is oxidized and removed, but when the amount of addition is large and the generation of heat of oxidation reaction is expected to be large, the temperature is slowly raised to the target firing temperature, or once maintained at a temperature lower than the target temperature. For example, it is desirable to oxidize slowly so as not to cause a rapid oxidation reaction. The catalyst calcined in this way is usually used for methanol synthesis after reduction treatment. This reduction treatment method is not particularly limited, and a conventionally known method can be used. The reaction conditions for synthesizing methanol using the fluidized catalyst obtained by the method of the present invention include the concentration of hydrogen in the raw material gas, the concentration of carbon monoxide and carbon dioxide, and the content of copper in the catalyst. In general, the reaction pressure is about ²⁰ to 300 kg / cm ² , preferably about 30 to 300 kg / cm ^2.
２００200 kg / cm ² and the reaction temperature is 150-35.
The temperature is about 0 ° C, preferably 200 to 300 ° C. Also,
Gas hourly space velocity (GHSV) is 1000 to 80000h
It is important to set the gas linear velocity at about r ^-1 so that the catalyst particles can sufficiently flow. The fluidized catalyst obtained by the method of the present invention can be used not only in a gas phase fluidized bed reactor but also in a liquid phase fluidized bed reactor. Further, this catalyst can be used as a fixed bed catalyst by changing the particle shape, and can also be used for other reactions such as a liquid phase hydrogenation reaction and a methanol reforming reaction.

[0011]

Next, the present invention will be described in more detail with reference to Examples, Comparative Examples and Test Examples, but the present invention is not limited to these Examples. In the production of catalysts in Examples and Comparative Examples, ion-exchanged water was used.
The slurry concentration (solid content concentration) was determined by measuring the water content with an infrared moisture meter to determine the solid content concentration. Example 1 62 kg of copper nitrate (trihydrate) was dissolved in 390 liters of water and kept at 40 ° C. Next, ammonium bicarbonate 44.
After dissolving 6 kg in 460 liters of water and adjusting the temperature to 40 ° C., the copper nitrate solution was added with stirring to prepare a copper slurry. On the other hand, a zinc oxide slurry (temperature: 40 ° C.) prepared by adding 7 kg of zinc oxide obtained by thermally decomposing basic zinc carbonate at 300 ° C. to 100 liters of water was added to the copper slurry, and carbon dioxide gas was added. Blowing was performed at a flow rate of 1.5 m ³ / hr for 2 hours. At this time, after a lapse of 60 minutes at a liquid temperature of 40 ° C., the temperature was raised to 80 ° C. and maintained for 30 minutes. After completion of the reaction, the mixture was cooled to 50 ° C., and alumina sol (containing 10% by weight of Al ₂ O ₃ ) was added to the copper-zinc compound slurry.
A slurry in which 6 kg was dispersed in 100 liters of water was added to prepare a copper-zinc-aluminum compound slurry.

To this copper-zinc-aluminum compound slurry, 110 kg of an aqueous solution of zirconyl oxynitrate (containing 25% by weight of ZrO ₂ ) dissolved in 240 liters of water (liquid temperature of 40 ° C.), and 38.8 kg of ammonium hydrogencarbonate in water A liquid dissolved in 500 liters (liquid temperature 40 ° C.) was added simultaneously with stirring and kept at a temperature of 40 ° C. for 30 minutes. Then, at that temperature, a basic magnesium carbonate slurry prepared from magnesium nitrate and sodium carbonate was added so that magnesium atoms became 33.5% of the total amount of magnesium and zinc atoms, and the mixture was added for 30 minutes. Held. Thereafter, the mixture was filtered and washed to obtain about 210 kg of a raw material cake composed of a copper-zinc-zirconium-aluminum-magnesium compound. The water content of this raw material cake was 69% by weight. The contents of sodium and ammonia in the solid content of this cake were 0.002% by weight and 0.008% by weight, respectively. This raw material cake 20k
Then, pectin (derived from lemon) was added to the g in an amount of 1.0% by weight based on the solid content to prepare a slurry that could be supplied to a spray dryer. The slurry concentration (solids concentration) is 20.
It was 5% by weight. This slurry was spray-dried to obtain a spherical powder having an average particle size of 60 μm. This was fired at 380 ° C. This is designated as catalyst A.

Example 2 In Example 1, the amount of pectin added was based on the solid content.
The procedure was performed in the same manner as in Example 1 except that the content was 0.2% by weight. This is designated as catalyst B. The concentration (solid content) of the slurry prepared by adding pectin was 17.1% by weight. Example 3 In Example 1, the amount of pectin added was based on the solid content.
The procedure was performed in the same manner as in Example 1 except that the content was 0.5% by weight. This is designated as catalyst C. The concentration (solid content) of the slurry prepared by adding pectin was 20.0% by weight. Example 4 In Example 1, the amount of pectin added was based on the solid content.
It carried out similarly to Example 1 except having set it to 4.0 weight%. This is designated as catalyst D. The concentration (solid content) of the slurry prepared by adding pectin was 20.8% by weight. Comparative example 1 It carried out like Example 1 except not adding pectin. This is designated as catalyst E. The slurry concentration (solid content concentration) at this time was 14.
It was 0% by weight.

Example 5 A raw material cake was prepared in accordance with Example 1 of JP-A-7-39756. 62 kg of copper nitrate (trihydrate) in 39
It was dissolved in 0 liter and kept at 40 ° C. Next, 28.7 kg of sodium carbonate was dissolved in 460 liters of water,
Then, the above-mentioned copper nitrate solution was added under stirring to prepare a copper slurry. On the other hand, a zinc oxide slurry prepared by adding 7 kg of zinc oxide obtained by pyrolyzing basic zinc carbonate at 300 ° C. to 100 liters of water was added to the copper slurry, and carbon dioxide gas was added at 1.5 m ³ / hr. At a flow rate of 2 hours. At this time, after a lapse of 60 minutes at a liquid temperature of 40 ° C., 7
The temperature was raised to 0 ° C. and maintained for 30 minutes. After completion of the reaction, 50 ° C
After cooling to an aqueous solution of zirconyl oxynitrate (containing 25% by weight of ZrO ₂ )
Liquid obtained by dissolving 110 kg in 240 liters of water (liquid temperature 50
C.) and a solution prepared by dissolving 24.8 kg of sodium carbonate in 500 liters of water (solution temperature: 50 ° C.) were added with stirring, and kept at that temperature for 30 minutes. Thereafter, the cake was filtered and washed to obtain a cake composed of a copper-zinc-zirconium compound. The water content of this cake was 68.2% by weight. Using this cake, according to Example 5 of JP-A-7-39756,
A catalyst comprising copper, zinc, zirconium and aluminum was prepared as follows. Using the above cake,
When preparing the slurry, alumina sol (# 200 manufactured by Nissan Chemical Co., Ltd.)
In order to be 2.5% by weight based on the oxide of each metal compound,
In addition, pectin was added so as to be 1.0% by weight based on the solid content of the cake, to prepare a slurry that could be supplied to the spray dryer. At this time, the slurry concentration (solid content concentration) was 27.5% by weight. Next, this slurry is
A catalyst was prepared in the same manner as in Example 1. This is designated as catalyst F.

Comparative Example 2 A catalyst was prepared according to Example 5 of JP-A-7-39756. That is, a slurry was prepared using the cake obtained in Example 5 of the present invention. In preparing this slurry, alumina sol (# 200 manufactured by Nissan Chemical Industries, Ltd.)
And sodium hydroxide such that the aluminum content in the catalyst is 2.5% by weight based on the oxide of each metal compound, and the sodium content is 0.4% by weight based on the oxide of each metal compound. Added. The slurry concentration (solid content concentration) at this time was 27.0% by weight. This is designated as catalyst G. Comparative Example 3 According to Comparative Example 1 of JP-A-7-39756, copper
A cake composed of a zinc-zirconium compound was prepared.
The sodium content in this cake was 0.008% by weight based on the oxide of each metal compound. Using this cake, except that pectin was not added, in the same manner as in Example 5 of the present invention, alumina sol was added to obtain a slurry that could be supplied to a spray drier composed of a copper-zinc-zirconium-aluminum compound. Prepared. The concentration (solid content concentration) of this slurry was 13.0% by weight. Next, this was treated in the same manner as in Example 1 to prepare a catalyst. This is designated as catalyst H.

Test Examples 1 to 8 Activity test 100 ml of each of the catalysts A to H prepared in Examples 1 to 5 and Comparative Examples 1 to 3 was reacted with a stainless steel reaction having an inner diameter of 30 mm provided with a sintered metal filter below. The vessel was filled. Nitrogen gas was introduced through a filter at the bottom of the reactor, and the temperature was maintained at 140 ° C. Next, the nitrogen gas is gradually replaced with hydrogen gas, and after all of them, 240
C., and kept for 3 hours to reduce the catalyst. Thereafter, the temperature was lowered, and 67.3 mol% of hydrogen, 24.1 mol% of carbon monoxide, 6.6 mol% of carbon dioxide, 1.5 mol% of methane and nitrogen
The activity test was performed by switching to synthesis gas consisting of 0.5 mol%. The reaction conditions are as follows. Reaction temperature 260 ° C. Reaction pressure 70 kg / cm ² Gas hourly space velocity (GHSV) 20000 hr ⁻¹ Also, in order to know the catalyst life (heat resistance), the reaction temperature was raised to 360 ° C., and methanol synthesis was performed for 10 hours. After that, the catalyst activity when the reaction temperature was set to 260 ° C. again, and the reaction temperature was again raised to 360 ° C., and methanol synthesis was performed for 10 hours (total 20 hours). And the catalyst activity was measured. Table 1 shows the methanol concentration in the reaction tube outlet gas in each case.

[0017]

[Table 1]

Test Examples 9 to 16 Abrasion test Catalysts A to H obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were placed in a glass reactor having an inner diameter of 25 mm equipped with a filter at the bottom.
Each 100 ml was filled, nitrogen gas was introduced through a filter at the bottom of the reactor, and the temperature was maintained at 140 ° C.
Next, the nitrogen gas was gradually replaced with hydrogen gas, and after replacing the entire amount, the temperature was raised to 240 ° C., and the temperature was held for 3 hours to perform reduction. After the reduction was completed, the temperature was lowered and replaced with nitrogen gas to obtain a sample for a wear test. Next, this sample was collected with a diameter of 0.
A stainless steel plate having a small hole of 4 mm and having an inner thickness of 27 mm and filled with 50 g was filled with a nitrogen gas-substituted glass tube. An exhaust pipe provided with a cylindrical filter paper was inserted into the upper part of the glass tube so that the catalyst powder would not be scattered. After a nitrogen gas was spouted from the small hole at the bottom at a rate of 510 liter / hr for 1 hour, the nitrogen gas was stopped, and a small amount of air was gradually flowed for 15 hours to oxidize the catalyst.

After the completion of the oxidation, the entire amount of the catalyst was taken out, and the particle size distribution was measured with a sonic hand shifter (SW-20 manufactured by Tsutsui Rikakiki), and the wear rate was determined by the following equation. AR (−20) = [(AB) / C] × 100 (% by weight)
・ Hr ^-1 ) AR (−44) = [(FG) / H] × 100 (% by weight)
・ Hr ^-1 ) AR (−20) = wear rate determined from a change in particle ratio of 20 μm or less (weight% · hr ⁻¹ ) AR (−44) = wear rate determined from a change in particle ratio of 44 μm or less ( wt% · hr ^-1) a: 2 occupying in the oxidation catalyst particles recovered after the abrasion test
Ratio of particles of 0 μm or less (% by weight) B: Ratio of particles of 20 μm or less in catalyst particles for abrasion test (% by weight) C: Ratio of particles exceeding 20 μm in catalyst particles for abrasion test (% by weight) F: 4 in the oxidation catalyst particles recovered after the abrasion test
Ratio of particles of 4 μm or less (% by weight) G: Ratio of particles of 44 μm or less in catalyst particles for abrasion test (% by weight) H: Ratio of particles exceeding 44 μm in catalyst particles for abrasion test (% by weight) Table 2 shows the results of the wear test.

[0020]

[Table 2]

[0021]

According to the method of the present invention, the properties of the slurry during the granulation of the catalyst are improved, the productivity of the catalyst is enhanced, and the catalyst for methanol synthesis having high strength and excellent heat resistance is efficiently produced. can get. This catalyst can be suitably used even under methanol synthesis reaction conditions where high-quality energy can be recovered. Therefore, the method of the present invention has great industrial significance in practical use.

──────────────────────────────────────────────────の Continuation of front page (51) Int.Cl. ⁶ Identification symbol FI C08B 37/06 C08B 37/06 // C07B 61/00 300 C07B 61/00 300 C08L 5/06 C08L 5/06 (72) Invention Person Koji Yamagami 182 Niigata, Niigata City, Niigata Niigata Research Institute, Niigata Research Laboratory Mitsubishi Gas Chemical Co., Ltd. ) Inventor Toshiyasu Watanabe 182 Niigata, Niigata City, Niigata Prefecture Niigata Research Institute Niigata Research Laboratory Mitsubishi Gas Chemical Co., Ltd. (72) Inventor Satoru Hida, 182 Niigata, Tayuhama, Niigata-shi, Niigata Pref.

Claims (3)

[Claims] In producing a fluidized catalyst for methanol synthesis containing copper, zinc and zirconium compounds as main components, each catalyst component contains 0.1 to 5% by weight of pectic substance with respect to the solid content. A method for producing a fluidized catalyst for methanol synthesis, comprising granulating a slurry composition. 2. The process for producing a fluidized catalyst for methanol synthesis according to claim 1, wherein the fluidized catalyst for methanol synthesis contains 30 to 70% by weight of zirconium based on the oxide of each metal compound. 3. The method for producing a fluidized catalyst for methanol synthesis according to claim 1, wherein the fluidized catalyst for methanol synthesis further contains a magnesium and / or aluminum compound.