JPS59146924A - Production of synthetic crystalline aluminosilicate zeolite - Google Patents

Abstract

PURPOSE:To obtain a synthetic crystalline aluminosilicate zeolite having a high salic ratio (molar ratio between silica and alumina) by maintaining a mixture incorporated with a prescribed ratio of Na2O, SiO2, H2O and Al2O3 at a prescribed temp. and forming a crystal. CONSTITUTION:A reactive mixture contg., by molar ratio, 0.13 Na2O/SiO2, 45.9 H2O/SiO2, and 40-100 SiO2/Al2O3 is prepd. The reactive mixture is maintained at 190 deg.C to form the crystal of aluminosilicate zeolite. The formed crystal is separated and recovered. The synthetic crystalline aluminosilicate zeolite having >=40 salic ratio is thus obtd. without using an org. salt as an alkali source.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a synthetic crystalline aluminosilicate zeolite with a high capane ratio (meaning the molar ratio of silica to alumina; the same applies hereinafter), and more specifically relates to a method for producing a synthetic crystalline aluminosilicate zeolite with a high capane ratio (the molar ratio of silica to alumina). The present invention relates to a method for producing synthetic crystalline aluminosilicate zeolites with a capan ratio of 40 or more using classical sodium hydroxide or sodium salts without using any organic bases.

Generally, synthetic zeolite can be prepared by a method in which a four-component reaction mixture consisting of alkali, silica, alumina, and water is maintained under predetermined conditions to generate crystals. Various synthetic crystalline zeolites obtained by this method are widely used industrially as adsorbents, catalysts, and catalyst carriers.

By the way, among synthetic crystalline zeolites, those with a high Si/Ron ratio have a highly active catalytic ability for the Taratzkink reaction, alkylation reaction, and isomerization reaction of hydrocarbons, compared to those with a low Si/Ron ratio. However, since it has excellent heat resistance and acid resistance, when synthetic crystalline zeolite is used industrially, it is said that one with a high Si/Ron ratio is preferable. Under these circumstances, research has continued in the industry with the aim of developing synthetic crystalline zeolites with a high carbon ratio, and as a result of this research, organic bases such as tetrapropylammonium hydroxide have been used as alkali sources for zeolide synthesis. A method using but,
This synthetic method is not always successful because the organic base used as a raw material is relatively expensive.

As a result of repeated studies on a method for producing synthetic crystalline aluminosilicate zeolite with a high silicon-9 ratio without using an organic base, the present inventors have determined that the composition of the reaction mixture is strictly specified, and that It has been discovered that synthetic crystalline aluminosilicate zeolites with a high silicon-to-carbon ratio can be produced without the use of organic bases by maintaining the zeolite at a very narrow constant temperature.

The method for producing synthetic crystalline aluminosilicate zeolite according to the present invention consists of four components: a sodium source (alkali source), a silica source, an alumina source, and water, and the molar ratio of oxides is Na2O/5in2=0. .13 H20/8102=45.90 Sin2/Al□O,=40.0 to 100.0 was prepared, and the reaction mixture was heated for 1 hour until crystals of aluminosilicate zeolite were formed.
It is characterized by maintaining the temperature at 90°C and separating and collecting the generated crystals.

In producing the synthetic crystalline aluminosilicate zeolite of the present invention, commonly used silica sol, silica gel, water glass, etc. can be used as the silica source, and alumina gel, alumina sol, aluminic acid, etc. can be used as the alumina source. Common substances such as soda and aluminum salts can be used. And the alkaline source is water-soluble
IJum salt or sodium hydroxide is used.

According to the present invention, a reaction mixture is first prepared using the above-mentioned silica source, alumina source, alkali source, and water, and the composition of the reaction mixture maintains the above-mentioned oxide molar ratio. is necessary, and if it deviates from this, the desired synthetic crystalline aluminosilicate zeolite cannot be obtained.

The reaction mixture is reacted at a temperature and time sufficient to form a synthetic crystalline aluminosilicate zeolite, and the reaction temperature is generally 190°C and the reaction time is in the range of 24 to 48 hours. be. This reaction is preferably carried out under pressure, but autogenous pressure is sufficient.

The crystalline product thus obtained is filtered off, washed with water and separated from the reaction medium. Furthermore, the crystals can be dried and calcined if necessary. For example, drying at 110°C for 3 to 24 hours, and baking at 200°C to 1000°C.
, preferably at a temperature in the range of 400°C to 800°C.

The synthetic crystalline aluminosilicate zeolite of the present invention is produced by converting at least a portion of the synthetic form of sodium cations into hydrogen, hydrogen precursors, and metals from Groups 1 to 2 of the Periodic Table of the Elements. The cation selected can still be ion-exchanged with a cation mixture.

The method of the present invention will be described in detail below with reference to Examples.

Example 1 21.75g of 1.3742.9 sodium aluminate
Sodium hydroxide solution (10.45 wt% Na0H
) and 84.26 g of water, and 85.111 silica sol (20
wt% s i 02 ) solution with stirring to prepare a reaction mixture. The reaction mixture has the following composition in molar ratios:

5.33 Na2O・A120m ” 40.O5i0
2111836 H2O The reaction mixture was aged for 1 hour at room temperature with stirring, charged to an autoclave and heated to 190
After holding at autogenous pressure for 15 hours at 110°C, the resulting product was filtered, washed with water, and dried at 110°C for 16 hours.

The obtained product was crystalline based on its powder X-ray diffraction pattern.

Examples 2-4 1.0895 J of sodium aluminate was added to 23.2111
Sodium hydroxide solution (10.45 wt% NaOH)
and 79.41 F water, and 7
85.18# silica in 0.50.9 water, sol (2
0 wt% 5io2) solution with stirring to prepare a reaction mixture. The reaction mixture has the following composition in molar ratios:

6.67Na20 'Al20g'' 50.O510
2" 2295H20 This reaction mixture was aged for 1 hour at room temperature with stirring, then charged into an autoclave and heated to 190°C.
, after holding at autogenous pressure for 15 hours (Example 2), 24 hours (Example 3) and 48 hours (Example 4), respectively.
The resulting product was filtered off, washed with water and dried at 110°C for 16 hours.

The obtained products were all crystalline based on their powder X-ray diffraction patterns. However, a trace amount of quartz was present in the product produced in Example 4.

Examples 5-6 0.7640. ! 7 sodium aluminate at 24.89.
Sodium hydroxide solution (10,45vrt%Na0
H) and 77.94 g of water, and 6B, 49. ji+ underwater 85.181! was added to a silica sol (20 wt% 5 lots) solution with stirring to prepare a reaction mixture. The reaction mixture has the following composition in molar ratios:

9.33Na20"Al20g"70.08i02'3
213H20 This reaction mixture was aged for 1 hour at room temperature with stirring, then charged into an autoclave at 190°C and autogenous pressure for 15 hours (Example 5) and 24 hours (Example 6).
After each hold, the resulting product was filtered off, washed with water and dried at 110° C. for 16 hours.

The obtained products were all crystalline based on their powder X-ray diffraction patterns.

Example 7 0.5198.9 of sodium aluminate is dissolved in a solution consisting of 26.15 p of sodium hydroxide solution (10.45 wt% NaOH) and 78.62 p of water and 67
．． 85.18 in 70p water. li+ silica sol (2
0 wj% 5102) solution with stirring to prepare a reaction mixture. The reaction mixture has the following composition in molar ratios:

13.33Na20・A120B-100,08101
・4590H10 This reaction mixture was aged for 1 hour with stirring at room temperature, charged into an autoclave, and kept at 190°C and autogenous pressure for 15 hours.The obtained product was filtered, washed with water, and aged at 110°C for 16 hours. Dry for an hour.

The obtained product was crystalline based on its powder xIO, p-component diagram.

Claims (1)

[Claims] 1. The composition expressed in molar ratio of oxides is Na, O/
8102 = 0.13 H20/5i02 = 45.90 show /AI, Os = 40.0-100.0 The reaction mixture was held at a temperature of 190 °C for the time until crystals of aluminosilicate zeolite were formed. A method for producing synthetic crystalline aluminosilicate zeolite, which comprises separating and recovering the crystals produced.