JPS6168318A - Synthesizing method of crystalline aluminosilicate - Google Patents

Abstract

PURPOSE:To synthesize high-silica crystalline aluminosilicate easily and inexpensively by heating an aq. mixture contg. a silica source, an alumina source and an alkali metal source under the coexistence with lower cyanoalkane or lower cyanoalkene. CONSTITUTION:Crystalline aluminosilicate is synthesized by heating an aq. mixture contg. a silica source such as sodium silicate, an alumina source such as sodium aluminate and an alkali metal source such as sodium hydroxide at about 100-250 deg.C under the coexistence with at least one kind of compd. of lower cyanoalkane such as acetonitrile and propionitrile or lower cyanoalkene such as acrylonitrile and methacrylonitrile. The preferable composition of the above-mentioned aq. mixture is shown as follows. The silica source vs. the alumina source is 10-1,000, water vs. the silica source is 10-100, the alkali metal source vs. the silica source is 0.001-10, A vs. the silica source is 0.01-10 (but the silica source is shown by SiO2 g-mol, the alumina source by Al2O3 g-mol, the alkali metal source by alkali metal g-atom, water by g-mol and A by g-mol of lower cyanoalkane or the like).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for synthesizing crystalline aluminosilicate, particularly high-silica crystalline aluminosilicate, which is advantageous as a catalyst in industrial fields such as chemistry and petroleum refining.

(Prior art) ZSM as a known high silica crystalline aluminosilicate
-5 is mentioned (Special Publication No. 46-10064) ZSM
-5 is useful as a catalyst for gasoline synthesis from methanol, ethylbenzene synthesis, etc., and is hydrothermally synthesized in the coexistence of a tetrapropylammonium salt. As a method for synthesizing high-silica zeolites such as ZSM-5, organic sulfur (
JP-A-54-137500), alcohol (JP-A-54-137500), alcohol (JP-A-54-137500
2-43800), cyclic ether (JP-A-56-140)
023) or amino alcohol (JP-A-57-781)
8) is also disclosed.

(Problems to be Solved by the Invention) Known methods for synthesizing high-silica crystalline aluminosilicate require expensive chemicals such as tetrapropylammonium salts, or can only be synthesized under extremely limited conditions. There have been problems such as difficulty in large-scale industrial synthesis, difficulty in synthesizing with good reproducibility, and difficulty in synthesizing crystalline aluminosilicate with a high degree of crystallinity.

(Means for Solving the Problems) As a result of intensive study on a method for economically industrially producing crystalline aluminosilicate, particularly high-silica crystalline aluminosilicate with a high degree of crystallinity, the present inventors found that silica sources, alumina A ZSM-5 type high silica crystalline alumino acid having a high degree of crystallinity is obtained by heating an aqueous mixture containing an alkali metal source and an alkali metal source in the coexistence of at least one compound selected from lower cyanoalkanes and lower cyanoalkenes. We have discovered a method to synthesize silicates.

That is, the present invention provides crystallinity, which is characterized by heating an aqueous mixture containing a silica source, an alumina source, and an alkali metal source in the coexistence of at least one compound selected from lower cyanoalkanes and lower cyanoalkenes. A method for synthesizing aluminosilicate is provided.

As the silica source, alumina source, and alkali metal source used in the present invention, those normally used in the synthesis of zeolite (crystalline aluminosilicate) can be used. As the silica source, sodium silicate, water glass, silica gel, silicic anhydride, etc. can be used. As the alumina source, sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum hydroxide, alumina, etc. can be used. As the alkali metal source, sodium hydroxide, sodium silicate, water glass, sodium aluminate, potassium hydroxide, etc. are used, and sodium compounds are preferred.

The lower cyanoalkanes and lower cyanoalkenes used in the present invention are cyanoalkanes and cyanoalkenes having 2 to 4 carbon atoms, and the lower cyanoalkanes are preferably acetonitrile and propionitrile, and the cyanoalkenes are preferably acrylonitrile. , methacrylonitrile are preferred.

The composition of the silica source, alumina source, water, and at least one compound selected from lower cyanoalkanes and lower cyanoalkenes in the aqueous mixture used in the method of the present invention is preferably within the following range expressed in molar ratio. be.

, (However, the silica source is expressed in terms of silica (SiO□) gram moles, the alumina source is expressed in terms of alumina (AlzO:+) gram moles, and the alkali metal source is expressed in terms of alkali metal gram atoms.) Silica source / alumina source = 10 to 1000
Water/silica source = 10-100 Alkali metal source/silica source = 0.001-10 A/silica source = 0.01-10 (A is gram moles of at least one compound selected from lower cyanoalkanes and lower cyanoalkenes) ) More preferable composition ranges are shown below.

Silica source/Alumina iJ? 20-200 water/silica source =
15-50 Alkali metal source/silica source = 0.05-IA/silica source = 0.1-5 At least one compound selected from lower cyanoalkanes and lower cyanoalkenes (hereinafter referred to as lower cyanoalkanes) in the method of the present invention An aqueous mixture containing a silica source, an alumina source, and an alkali metal source (abbreviated as carbonized hydrocarbon)
The preparation of the aqueous mixture (hereinafter abbreviated as aqueous mixture) will be exemplified below.

The water containing the silica source, the alumina source and the lower cyanide carbon are mixed with stirring. Adjust the hydrogen ion concentration by adding acid or alkali as necessary.

The preferred range of hydrogen ion concentration and pH is IO to 13. The alkali metal source is added together with the silica source and/or the alumina source, or when adjusting the hydrogen ion concentration. 100 to 25% of the aqueous mixture in a pressure vessel
Heat to 0°C, preferably 110 to 180°C. At this time, heating may be performed while stirring. The heating time depends on the heating temperature; the higher the heating temperature, the shorter the heating time; the lower the heating temperature, the longer the heating time, and is usually preferably 10 to 200 hours, but heating for more than 200 hours is also acceptable.

One of the effects of the present invention is that fine, high-crystallinity crystalline aluminosilicate can be easily synthesized. When observed using a scanning electron microscope, fine crystalline aluminosilicate is mainly columnar or hexagonal plate-shaped crystals. A crystalline aluminosilicate with an average short diameter of 1 micron or less. To synthesize fine crystalline aluminosilicate, heating with strong stirring is desirable.

As a heating method for synthesizing fine crystalline aluminosilicate, first stage 110 to 140°C1 second stage 155
Two-step heating to ~180°C is preferred. In the case of two-stage heating, the first stage heating time is preferably 30 to 140 hours.

The X-ray diffraction pattern of the crystalline aluminosilicate synthesized by the method of the present invention is as shown in Table 1.
The pattern is similar to .

Table 1 (X-ray source; CuKα) In the method of the invention, if desired, an oxide source such as titanium, vanadium, chromium, manganese, iron, zinc, gallium, boron, etc. can be used together with or instead of an alumina source. These foreign element-containing zeolites can be synthesized in addition to aqueous mixtures.

The crystalline aluminosilicate synthesized by the method of the present invention can be ion-exchanged with various metal cations by a known method to form crystalline aluminosilicate containing various metal cations into a mold.

The crystalline aluminosilicate synthesized by the method of the present invention can be molded into various shapes using a known binder if necessary.

The crystalline aluminosilicate synthesized by the method of the present invention can be used as a highly active catalyst in various known reactions in which ZSM-5 type crystalline aluminosilicate is effective as a catalyst. Examples of the above reactions include alcohol synthesis by hydration of olefins and hydrogenolysis of heavy oils. As catalysts for these reactions, fine crystalline aluminosilicates synthesized by the method of the present invention are particularly preferred.

(Effects of the Invention) The present invention provides a method for economically synthesizing a ZSM-5 type high-silica crystalline aluminosilicate using an inexpensive cyanoalkane or cyanoalkene. Furthermore, the present invention provides a method for synthesizing a highly crystalline, preferably finely crystalline aluminosilicate useful as a highly active catalyst for olefin hydration reactions and the like.

(Examples) Next, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

Example 1 145 g of sodium silicate (water glass No. 3) and 68 g of water
(Liquid A). 5.2 g of aluminum sulfate and 2.4 g of concentrated sulfuric acid were dissolved in 40 g of water (liquid B).

8 g of acetonitrile was dissolved in 80 g of water (liquid C) A
The liquid was mixed with liquids B and C while being strongly stirred, and the resulting gel-like aqueous mixture was charged into an autoclave with an internal volume of 500 cc, and heated to 120°C for 3 days while stirring at a circumferential speed of 1.5 m/sec. The mixture was heated to 160° C. for 1 day while stirring at the same circumferential speed.

The crystalline aluminosilicate was collected using a centrifuge, washed with water, and then dried at 120°C. The composition of the obtained crystalline aluminosilicate is 0,9 N az O-A I2
0 s '50 S i O'z (anhydrous base)
Met. A fluorescent X-ray spectrometer and a high frequency inductively coupled optical emission spectrometer (ICP) were used for the compositional analysis. The X-ray diffraction pattern of the obtained crystalline aluminosilicate is shown in FIG.

It is an X-ray diffraction pattern similar to ZSM-5 zeolite. According to observation using a scanning electron microscope, as shown in FIG. 2, it was a hexagonal plate-shaped crystal with a minor axis of 0.3 to 0.5 microns.

Example 2 36 g of sodium silicate (water glass No. 3), 2.6 g of aluminum sulfate, 0.6 g of sulfuric acid, and 2.2 g of propionitrile.
A solution of 5 g in 47 g of water was mixed with stirring. This aqueous mixture was charged into a 100 cc micro bomb and heated to 1.55° C. for 7 days.

The obtained crystalline aluminosilicate was collected using a centrifuge, washed with water, and dried. Silica/alumina (molar ratio) is 2
8. The X-ray diffraction pattern showed a similar pattern to Z SM-5.

Example 3 A crystalline aluminosilicate was synthesized by using 2.6 g of acrylonitrile instead of propionitrile and using the same conditions as in Example 2 except for the same conditions.

The X-ray diffraction pattern of the synthesized crystalline aluminosilicate showed a pattern similar to ZSM-5. According to observation using a scanning electron microscope, it was a hexagonal plate-shaped crystal with a minor axis of 2 to 3 microns.

Example 4 The crystalline aluminosilicate synthesized in Example 1 was immersed in an aqueous ammonium chloride solution according to a conventional method to convert the sodium ion type to the ammonium ion type, and after drying,
A proton-type crystalline aluminosilicate was prepared by combustion at 00°C.

Reference Example Using the proton-type crystalline aluminosilicate prepared in Example 4 as a catalyst, 2-methyl-
2-Propertool was synthesized.

30g of imbutene, 50g of water, 10g of catalyst, internal volume: 15
The mixture was placed in a stainless steel autoclave which had been previously purged with nitrogen at a temperature of 0-1, and kept in a water bath maintained at 70°C for 60 minutes with shaking. The autoclave was then taken out from the water bath, and after cooling, the autoclave valve was developed to distill isobutyne, and the remaining aqueous phase was analyzed using a gas chromatograph. The aqueous phase contained 24.5% by weight of 2-methyl-2-propatol, and no other products were detected.

[Brief explanation of the drawing]

FIG. 1 is a powder X-ray diffraction diagram of crystalline aluminosilicate synthesized according to Example 1 of the present invention. The horizontal axis represents the diffraction angle 2θ (degrees), and the X-ray source used was α-rays from copper. FIG. 2 is a scanning electron micrograph showing the crystal structure of the crystalline aluminosilicate synthesized according to Example 1 of the present invention. Figure 2

Claims (1)

[Claims] (1) An aqueous mixture containing a silica source, an alumina source, and an alkali metal source is heated in the coexistence of at least one compound selected from lower cyanoalkanes and lower cyanoalkenes. A method for synthesizing crystalline aluminosilicate. (2) The method according to claim 1, wherein the composition of the aqueous mixture is within the following range. Silica source/Alumina source = 10-1000 Water/Silica source = 10-100 Alkali metal source/Silica source = 0.001-10A/Silica source = 0.01-10 [However, the silica source is calculated in terms of gram moles of silica (SiO_2) , the alumina source is expressed in terms of gram moles of alumina (Al_2O_3), the alkali metal source is expressed in terms of alkali metal gram atoms, water is expressed in gram moles, and A represents the sum of gram moles of at least one compound selected from lower cyanoalkanes and lower cyanoalkenes. (3) The method according to claim 1 or 2, wherein the lower cyanoalkane is acetonitrile or propionitrile. (4) The method according to claim 1 or 2, wherein the lower sialalkene is acrylonitrile or methacrylonitrile.