JPS6116734B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a porous body made of modified sepiolite. More specifically, the present invention involves treating natural sepiolite with a treatment step that includes a step of reacting an inorganic acid and an organic acid to increase the silica/magnesia (SiO ₂ /MgO) molar ratio in the sepiolite to 2 or more. The present invention relates to a method for producing porous modified sepiolite.

Sepiolite is a mineral commonly called sepiolite, which occurs naturally as hydrated magnesia silicate, but can also be synthesized from magnesium salts and silicates. Since this material is a porous material, it can be used as a catalyst carrier or adsorbent by taking advantage of its porosity, but naturally produced materials have a limit to their porosity and cannot be used as they are. However, depending on the purpose of use, the porous material is not necessarily sufficiently porous in many cases. In particular, when sepiolite is used as a catalyst carrier, it is necessary to make it porous and to adjust the specific surface area and pore volume.
Until now, no technical means have been known that can meet such demands.

The present inventors previously discovered that when water is added to natural sepiolite and kneaded, a modified product with significantly increased pore volume and specific surface area can be obtained, and based on this knowledge, sepiolite A method for manufacturing molded bodies was proposed (Japanese Patent Application No. 13018/1983).
However, since this method is based on physical rather than chemical means, there is a limit to how porous it can be made.
It was extremely difficult to obtain a fired product with a specific surface area of more than 300 m ² /g or a pore volume (>74 Å) of 0.9 cc/g or more.

According to the present invention, a method for producing a porous body made of sepiolite modified by chemical means rather than such physical means is provided. That is, according to the present invention, natural sepiolite is reacted with (a) an inorganic acid and/or an organic acid to form silica/magnesia (SiO ₂ /magnesia) in sepiolite.
MgO) step of increasing the molar ratio to 2 or more, (b) kneading and finally adjusting the moisture content to 80 to 350% by weight, and/or (c) firing step in any order. A method for producing porous modified sepiolite is provided, characterized in that it is treated in a combination of processing steps.

In the method of the present invention, the inorganic acid and/or organic acid treatment step (a) of sepiolite and the kneading and humidity conditioning treatment step (b) can be performed separately or simultaneously. Further, in the present invention, in order to obtain a molded article, molding steps can be combined by a conventional method as necessary.

The modified sepiolite according to the present invention is produced by making natural sepiolite utilize a reagent capable of reacting with magnesium as a magnesium desorbing agent. In this case, various substances that can react with magnesium are used as the magnesium desorbing agent, and specific examples thereof include, for example,
Inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, formic acid, acetic acid,
Organic acids such as oxalic acid and tartaric acid, ammonium hydrochloride,
Salts whose aqueous solutions are acidic (referred to as acidic salts in this application) such as ammonium sulfate and ammonium nitrate; and chelating agents such as ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and acetylacetone.

Although the reaction between sepiolite and the magnesium desorbing agent in the present invention depends on the type of desorbing agent, it is usually carried out in an aqueous medium or an aqueous medium prepared by adding another suitable organic solvent to water. In some cases, it is carried out in an organic solvent. The amount of these reaction media used is not particularly limited, but sepiolite dry matter
Preferably 100 parts by weight or more per 100 parts by weight
It is 300 parts by weight or more. Further, the amount of the magnesium desorbing agent used is 1.2 mol or more, preferably 1.5 mol or more, per 1 mol of magnesium in the sepiolite to be desorbed. Room temperature is sufficient for the reaction temperature, but since the rate of magnesium desorption from modified sepiolite changes depending on the reaction temperature, a heating temperature of 40 to 300°C, usually 50 to 150°C, may also be used. can.

The reaction between sepiolite and the magnesium desorbing agent in the present invention can be carried out using an acid or an acidic salt as the desorbing agent, but in this case, the pH of the solution is 5 or less, preferably PH
A range of 5 to 1 is used. Note that the reaction can be carried out even when the pH is 1 or lower, and in this case, the reaction time is shortened. Furthermore, when using a relatively weakly acidic desorbing agent such as an organic acid, it is preferable to lengthen the reaction time.

When sepiolite is reacted with a magnesium desorbing agent according to the present invention, the properties of the resulting modified sepiolite, such as the SiO ₂ /MgO ratio, specific surface area, and pore volume, vary depending on the specific reaction conditions used. Depending on the type and concentration of the desorbing agent,
Conditions such as reaction temperature and time are appropriately selected.

To preferably produce modified sepiolite according to the present invention, first, natural sepiolite ore is
After crushing into pieces of 15 mm or less, preferably about 8 to 50 meshes, they are dried at 100 to 200°C, usually 110 to 150°C. In this case, although sepiolite ore varies somewhat depending on the production area, it is generally Mg ₉ Si ₁₂ O ₃₀
It is represented by the composition formula (OH) _{10.6H 2} O. It is a fibrous magnesium silicate.

Next, this crushed sepiolite is immersed in an aqueous solution of a magnesium desorbing agent, the desorbing agent is reacted with the magnesium component in the sepiolite, and the magnesium component is extracted and removed from the sepiolite. After washing the modified sepiolite obtained in this way with water,
Dry and bake if necessary (e.g. 400-700℃)
and make it into a product.

The modified sepiolite according to the present invention has a silica/magnesia ratio that is higher than that of naturally produced sepiolite.
SiO ₂ /MgO is significantly increased. In other words, SiO ₂ /
The MgO ratio is about 1.3 in molar ratio, but the modified sepiolite according to the present invention has a high molar ratio of 1.3 or more, usually 1.5 to 50, and generally about 2 to 10. In the present invention, this molar ratio is 4
It is preferable to keep it at 8. Furthermore, the specific surface area and pore volume of the modified sepiolite in the present invention also vary greatly depending on the SiO ₂ /MgO ratio. The molar ratio of silica and magnesia (SiO ₂ /
Figure 2 shows the change in specific surface area of modified sepiolite with respect to MgO). In this case, modified sepiolite is obtained by treating natural sepiolite with hydrochloric acid and then firing it at 500°C.

In addition, in the drawings, double circled symbols indicate the SiO ₂ /MgO molar ratio and specific surface area of the raw material sepiolite. Further, according to the present invention, the modified sepiolite obtained as described above has general physical properties such as a specific surface area of 160 m ² /g or more and a specific pore volume of 0.6 cc/g after firing at 500°C.
g or more. Note that the specific surface area of the modified sepiolite after drying is usually 400 m ² /g or more.

In the present invention, the magnesium desorption step is combined with a kneading step using water as a medium to obtain a product with increased porosity. That is, sufficient water is added to the modified sepiolite obtained as described above, the mixture is kneaded, and the resulting kneaded product is dried or fired to obtain a product. Further, this kneading step does not necessarily need to be performed after the magnesium desorption step, and can be performed before the magnesium desorption step or simultaneously with the magnesium desorption step. In this case, the amount of water present during kneading is such that the final water content of sepiolite will be 80 to 350% by weight. Kneading means include ordinary kneaders, masticators, and molding machines (extruders, etc.)
is used. The kneading conditions are appropriately determined depending on the desired degree of porosity of the product and its intended use. This kneading achieves the effect of further improving the specific surface area and pore volume, as well as sharpening the pore distribution, and the more the kneading is done, the better the results will be.

The modified sepiolite according to the present invention can be used as a molded product in various shapes such as granules, pellets, and plates in addition to powder. There are various ways to make a molded body. For example, raw sepiolite is crushed, molded into a desired shape, and this molded body is subjected to magnesium removal treatment, and raw sepiolite is crushed and then water is added. Moisture (humidity control: sepiolite moisture content 80-350
(wt%), kneading, molding the obtained kneaded product, firing if necessary, and then subjecting it to magnesium desorption treatment. Modified sepiolite obtained by pulverizing raw material sepiolite and subjecting it to magnesium desorption treatment. A method of molding using Sepiolite as a molding material. After crushing the raw sepiolite and subjecting it to magnesium removal treatment, water is added to the obtained modified sepiolite to adjust the humidity (humidity adjustment: 80 to 350% by weight of sepiolite water content). , a method of kneading and molding the obtained kneaded product, and a method of pulverizing the raw material sepiolite, kneading the pulverized product at the same time as magnesium desorption treatment, and molding the obtained product. When producing a molded article of modified sepiolite according to the present invention, it is not necessary to add a molding aid, but the use of a molding aid is advantageous in order to obtain a molded article with high mechanical strength. As such molding aids, conventional inorganic or organic substances are applied, such as inorganic binders such as silica sol, alumina sol, alumina silica sol, bauxite, attapulgite, montmorillonite, and higher esters, higher alcohols, higher fatty acids, Organic binders such as salts thereof, starches, carboxymethylcellulose, polyvinyl alcohol, and polyacrylic acid may be used. The amount of these molding aids to be added varies depending on the type of molding aid used and is difficult to determine unambiguously, but in general, it is 0.5 parts by weight per 100 parts by weight of sepiolite on an anhydride basis. ~50 parts by weight, usually 1 to 20 parts by weight.

When the modified sepiolite molded body according to the present invention is produced by making the raw material sepiolite into a molded body in advance and then subjecting this to a magnesium desorption treatment under acidic conditions, the sepiolite molded body is produced by:
It tends to become powder under acidic conditions, so
It is necessary to take measures to prevent powdering in advance. As such a method, the raw material sepiolite or its molded product is heated at 200 to 1000°C.
Preferred methods include a method of firing at a temperature of 400 to 900°C, a method of using a molding aid, or a method of mildening the magnesium desorption treatment conditions.

Since the modified sepiolite according to the present invention has had its skeleton magnesium removed, it is extremely porous compared to natural sepiolite, and can be used for various purposes by utilizing its porosity. be done. For example, the modified sepiolite of the present invention can be used as a building material or a heat insulating material, and since it has extremely good moldability, it can be used as a molding aid when molding other inorganic materials. can do.

A particularly advantageous use of the modified sepiolite according to the invention is as a catalyst support. The modified sepiolite according to the present invention has significantly increased specific surface area and pore volume, and these properties can be adjusted to desired ranges by adjusting the SiO ₂ /MgO in the modified sepiolite.
It can be used as an optimal catalyst carrier for the applicable reaction. As a method for supporting the catalyst metal on the modified sepiolite of the present invention, a conventional method such as a dipping method can be adopted.In addition, in the modified sepiolite of the present invention, residual magnesium in the sepiolite can be exchanged with other metal ions. Therefore, an ion exchange method can also be adopted. To support metals by ion exchange method,
The modified sepiolite according to the present invention is brought into contact with an aqueous solution containing one or more desired metal ions at a pH of 7 or less. The metals supported on the modified sepiolite of the present invention include Cu, Ag, etc.
group metals, group b metals such as Zn, Cd, Hg, Sc,
Group A metals such as Y, La, Ce, Group B metals such as Ge, Sn, Pb, Group A metals such as Cr, Mo, W, Group A metals such as Mn, Re, and Fe, Co,
Group metals include Ni, Ru, Rh, Pb, Cs, Ir, and Pt. In addition, when obtaining modified sepiolite on which a metal is supported according to the present invention, the desired metal is supported in advance by an ion exchange method, and then other required metals are supported by a conventional method, so that the bonded metal can be obtained. Modified sepiolite supporting two or more metals can be obtained. The amount of metal that can be supported by ion exchange method is at most 4% by weight.
However, when using the immersion method, or when using the ion exchange method and the immersion method, it is possible to support an amount of metal as required. When used as a catalyst, the amount of metal supported is generally 40% by weight or less, usually 25% by weight or less. Further, the supported metal can take various forms such as oxides and metal salts in addition to the metal state.

The metal-supported modified sepiolite according to the present invention is used as a solid catalyst in various catalytic reactions. In this case, the characteristics of the modified sepiolite used as a support and the type of metal to be supported are selected depending on the type of target reaction. For example, a modified sepiolite with a SiO ₂ /MgO ratio of 2.5 to 6 according to the present invention is supported by replacing a part of magnesium with a metal such as Ni, Co, Fe, Cu, or Cr by an ion exchange method; Alternatively, one or more metals selected from group b, b, a, a, a, a, and a group metals of the periodic table can be supported on this, especially in the hydrogenation reaction of heavy oil. Effective as a catalyst for hydrodemetallization of heavy oil.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 MgO27.2%, _SiO2 62.8%, _{Al2O3 1.4} on dry basis
%, FeO ₃ 0.4% and crystal water and other 8.2%, and the specific surface area after firing at 500℃ for 2 hours is 140 m ² /
gr, pore volume 0.57 cc/gr (>75 Å) sepiolite ore was crushed into 10 to 8 meshes and then heated at 120℃ for 2 hours.
Dry for 100 hours and add 40 times the weight of 3N hydrochloric acid at room temperature.
A porous body was produced by soaking for a period of time. During immersion in this hydrochloric acid, intense bubbling was initially exhibited, but it soon stopped, and the resulting aqueous solution was initially colorless and gradually turned yellow. This is presumed to be due to the dissolution of Fe ³⁺ . Next, the sepiolite obtained by immersion for 100 hours was washed with pure water, dried at 120° C. for 2 hours, and further fired at 500° C. for 2 hours to obtain a modified sepiolite porous body. When this porous body was analyzed with an X-ray diffraction device, it was found that it only showed a broad peak at 2θ=18 to 28°, and the characteristic peaks of sepiolite had completely disappeared. Furthermore, when magnesium and silicon were analyzed using a fluorescent X-ray device, the SiO ₂ /MgO molar ratio (or Si/Mg atomic ratio) increased from approximately 2.0 in the raw material to 7.0, indicating that the main component of this porous material was approximately It was confirmed that it was silicic acid. Furthermore, the volume of pores with a diameter of 75 Å or more was determined to be 0.81 cc/gr using the mercury intrusion method.
Then, when the specific surface area is determined by the nitrogen adsorption method,
It was 228m ² /gr. From these results, it was found that the pore volume and specific surface area of the modified sepiolite porous material of the present invention were significantly increased by acid treatment. The dried product before firing had a specific surface area of 410 m ² /g and a pore volume of 0.57 cc/g.

Example 2 To the same sepiolite used in Example 1, about 40 times the weight of a 0.1 N nitric acid aqueous solution was added and immersed at room temperature for about 100 hours to remove the framework magnesium of the sepiolite. The obtained porous body was dried and fired in the same manner as in Example 1, and then used for analysis and measurement.

When this porous body was analyzed with an X-ray diffraction device, it was found from the peak positions and relative intensity ratios that it maintained almost the same structure as the raw material sepiolite. However, although the SiO ₂ /MgO molar ratio increased to 2.4 and the pore volume was 0.6 cc/gr (>75 Å), the specific surface area was 213 m ² /gr, which was significantly increased compared to the raw material. It was recognized that there was. In addition, the dry product before firing has a specific surface area of 405 m ² /g and a pore volume of
It showed 0.55cc/g.

Example 3 To the same sepiolite as in Example 1, about 40 times the weight of 1N hydrochloric acid was added and immersed at room temperature for about 10 hours to remove the skeleton magnesium of sepiolite. The obtained porous body was dried and fired in the same manner as in Example 1, and subjected to analysis and measurement. As a result, SiO ₂ /
Although the MgO molar ratio had increased to 5.0 and the pore volume was 0.64 cc/gr, the specific surface area was 32 m ² /gr, which was found to be significantly increased compared to the raw material. In addition, the dry product before firing has a specific surface area of 450 m ² /
g and pore volume of 0.60 cc/g.

Example 4 The porous body from which the magnesium of sepiolite obtained in Example 3 had been removed was kneaded with water to make it more porous by the following method.

First, the sepiolite porous material is finely ground to approximately 100 mesh or less, and the content is 5% as anhydrous alumina.
Add alumina sol so that
% by weight of water was added and thoroughly kneaded. After confirming that the pore volume was sufficiently large by sampling during the kneading process, the moisture content was adjusted to about 150% by weight. This humidity control product was extruded into a cylinder with a diameter of 1.0 mm, thoroughly air-dried, dried at 120°C for 2 hours, and further baked at 600°C for 3 hours. The porous body thus obtained had a specific surface area of 366 m ² /gr and a pore volume of 0.91 cc/gr. From this, after removing the framework magnesium of sepiolite,
It has been found that by further adding water and kneading, a porous material with significantly larger specific surface area and pore volume can be obtained.

Example 5 The same sepiolite as in Example 1 was molded in the same manner as in Example 4. However, silica sol is added instead of alumina sol as a binder.
Rotation was carried out at 500°C for 2 hours. The specific surface area of this material is
The pore volume was 178 m ² /gr and 0.72 cc/gr.

This molded body was immersed in 20 times its weight of anhydrous acetylacetone and kept at 60 to 80°C for about 2 hours to remove the skeleton magnesium in sepiolite. After thoroughly washing the obtained porous body with ethanol, it was heated to 600℃.
Baked for 1 hour. The specific surface area of this thing is 227
m ² /gr, and the pore volume (>75 Å) was 0.79 cc/gr. Furthermore, the Si/Mg atomic ratio was approximately 2.2 before the acetylacetone treatment, but increased to 2.6 after the treatment.

Examples 6, 7, 8 Porous bodies Cu, Ni, obtained in Example 3
and Cr were supported by ion exchange method. That is, metal support was carried out by adding 10 times the amount of 0.1 N metal nitrate aqueous solution to the porous material dried at 120°C and keeping it at room temperature for 5 hours, and after thoroughly washing with pure water, it was heated at 500°C for 2 hours. Baked for an hour. The amount of metal supported in the fired product was as follows.

Amount of metal supported Example 6 CuO 1.6% 〃 7 NiO 0.7% 〃 8 Cr ₂ O ₃ 1.1% Example 9 Molybdenum was added to the copper-supported porous body obtained in Example 6 by a normal dipping method to give 2.6 weight of MoO ₃ %
It was carried so that Using this metal-supported porous material, vanadium 130ppm, nickel 42ppm
and an atmospheric residual oil containing 2.62% sulfur was hydrodemetallized. The reaction is carried out using a normal high-pressure flow reactor.
The reaction was carried out at a hydrogen pressure of 140 Kg/cm ² , a liquid hourly space velocity of 1.0/hr, and a reaction temperature of 400°C.

The properties of the produced oil approximately 100 hours after the start of the reaction were as follows.

Vanadium 47ppm, Nickel 24ppm, Sulfur 1.91%.

Example 10 Using a catalyst in which 0.4% cobalt as CoO and 1.5% molybdenum as MoO ₃ were supported on the porous body obtained in Example 4 by a normal dipping method, 51 ppm of vanadium, 19 ppm of nickel, and A solvent deasphalted oil containing 2.42% sulfur was hydrodemetallized. Demetallization was carried out using the same equipment as in Example 9, hydrogen pressure 100 Kg/cm ² , liquid hourly space velocity 1.0/hr, reaction temperature.
It was carried out at 400℃.

The properties of the produced oil approximately 100 hours after the start of the reaction were as follows.

Vanadium, 0.1ppm, Nickel 0.7ppm, Sulfur 1.22%.

[Brief explanation of the drawing]

The drawing is a graph showing the relationship between specific surface area and SiO ₂ /MgO molar ratio in modified sepiolite according to the present invention.

Claims (1)

[Claims] 1 Natural sepiolite is treated with (a) an inorganic acid and/or an organic acid to form silica/magnesia (SiO ₂ /
1. A method for producing porous modified sepiolite, characterized in that the process comprises a step of increasing the MgO) molar ratio to 2 or more. 2 Natural sepiolite is reacted with (a) an inorganic acid and/or an organic acid to form silica/magnesia (SiO ₂ /
MgO) The process of increasing the molar ratio to 2 or more; (b) The process of kneading and finally adjusting the moisture content to 80 to 350% by weight, in any order. A method for producing characterized porous modified sepiolite. 3 Natural sepiolite is reacted with (a) an inorganic acid and/or an organic acid to form silica/magnesia (SiO ₂ /
1. A method for producing porous modified sepiolite, comprising a treatment step in which a step of increasing the MgO) molar ratio to 2 or more; and (c) a step of firing are combined in any order. 4 Natural sepiolite is reacted with (a) an inorganic acid and/or an organic acid to form silica/magnesia (SiO ₂ /
MgO) A process of increasing the molar ratio to 2 or more, (b) A process of kneading and finally adjusting the moisture content to 80 to 350% by weight, (c) A process of firing in any order. A method for producing porous modified sepiolite, the method comprising: