Methods of controlling polymorphism in organic-free synthesis of Na-zeolites and zeolite crystals formed therefrom

Patent metadata

Field	Value
Publication number	US-9714174-B2
Application number	US-201313946919-A
Country	US
Kind code	B2
Filing date	Jul 19, 2013
Priority date	Jul 19, 2012
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

Methods of controlling crystal polymorphism in organic-free synthesis of Na-Zeolites and the zeolite crystals formed using those methods are provided. The methods disclosed herein create certain types of zeolite crystals more efficiently than other previously known methods. The methods also create certain types of zeolite crystals in a form and concentration not previously disclosed. The methods disclosed herein generally comprise using solutions with varying ratios of silicon (Si), aluminum (Al), hydroxide (OH), and water. Some implementations of the invention disclosed include efficient methods of producing nearly pure cancrinite (CAN), methods of obtaining sodalite in solutions with a high Si/Al ratio, and a method of forming thin, platelet-like ANA crystals with a width of less than about 1 μm and a length of at least about 3 μm.

First claim

The invention claimed is:

1. A method of forming zeolite crystals having an ANA framework-type, comprising:
forming a zeolite growth solution comprising:
a Si/OH ratio of less than about 1; and
a Si/AI ratio of between about 6 to 1 and about 15 to 1; and

heating the zeolite growth solution to a temperature from about 180 degrees Celsius to about 220 degrees Celsius to form the zeolite crystals having an ANA framework-type.

2. A method of forming zeolite crystals having an ANA framework-type, comprising:
forming a zeolite growth solution containing water, an alumina source, a silica source, and a mineralizing agent; and
heating the zeolite growth solution to form the zeolite crystals having the ANA framework-type, wherein the zeolite growth solution is characterized by the following molar ratios:
a Si/OH ratio of less than about 1; and
a Si/Al ratio of between about 6 to 1 and about 15 to 1.

3. The method of claim 2 , wherein the alumina source is sodium aluminate, the silica source is colloidal silica, and the mineralizing agent is sodium hydroxide.

4. The method of claim 2 , wherein the heating is carried out at a temperature of at least about 180 degrees Celsius.

5. The method of claim 4 , wherein the temperature is from about 180 degrees Celsius to about 220 degrees Celsius.

6. The method of claim 2 , wherein the silica source is tetraethylorthosilicate (TEOS).

7. The method of claim 2 , wherein the heating is carried out for a period of 21 or more days.

8. The method of claim 2 , wherein the zeolite growth solution has a molar composition of 11NaOH:190H 2 O.

9. The method of claim 2 , wherein the zeolite growth solution is an organic-free solution.

10. A method of forming zeolite crystals having an ANA framework-type, comprising:
forming a zeolite growth solution containing water, an alumina source, a silica source, and a mineralizing agent; and
heating the zeolite growth solution to form the zeolite crystals having the ANA framework-type, wherein the zeolite growth solution is characterized by the following molar ratios:
a Si/OH ratio of less than about 1; and
a Si/Al ratio of at least about 6 to 1, wherein the heating is carried out for a period of 21 or more days.

Assignees

• Rimer Jeffrey D
• Maldonado Miguel
• Oleksiak Matthew D
• Univ Houston System

Inventors

• Rimer Jeffrey D
• Maldonado Miguel
• Oleksiak Matthew D

Classifications

• B01J29/70

  of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 · CPC title

• C01B39/52

  Sodalites · CPC title

• C01P2004/54

  Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension · CPC title

• C01B39/46 Primary

  Other types characterised by their X-ray diffraction pattern and their defined composition {(C01B39/023, C01B39/026, C01B39/06 take precedence)} · CPC title

• C01P2004/20

  extending in two dimensions, e.g. plate-like · CPC title