Zeolite production method

Patent metadata

Field	Value
Publication number	US-10669157-B2
Application number	US-201715492318-A
Country	US
Kind code	B2
Filing date	Apr 20, 2017
Priority date	Jul 1, 2010
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

Disclosed is a method for readily and inexpensively producing zeolite without using an organic structure-directing agent (organic SDA). Specifically disclosed is a method whereby a gel containing a silica source, an alumina source, an alkaline source and water is reacted with zeolite seed crystals, to produce a zeolite with the same kind of skeletal structure as the zeolite. The gel used is a gel of a composition whereby, when a zeolite is synthesized from this gel only, the synthesized zeolite comprises at least one of the kinds of composite building units of the target zeolite.

First claim

The invention claimed is:

1. A method of producing a zeolite comprising:
reacting a gel and zeolite seed crystals to produce a zeolite having the same kind of skeletal structure as the zeolite seed crystals;
wherein:
the gel comprises a silica source, an alumina source, an alkali source and water;
the gel is capable of synthesizing a zeolite without the use of the zeolite seed crystals, wherein the zeolite synthesized without the use of the zeolite seed crystals comprises one or more building units of zeolite;
the zeolite seed crystals comprise one or more composite building units of zeolite;
the zeolite seed crystals and the zeolite synthesized without the use of zeolite seed crystals comprise at least one equivalent composite building unit of zeolite;
wherein the reacting step occurs without the use of an organic structure-directing agent; and
wherein the zeolite produced is MEL zeolite, MSE zeolite, or MTW zeolite.

2. The method of producing a zeolite according to claim 1 ,
wherein the zeolite synthesized without the use of zeolite seed crystals has a different kind of skeletal structure as the zeolite seed crystals.

3. The method of producing a zeolite according to claim 2 ,
wherein the zeolite produced is MEL zeolite,
MEL zeolite is used as the zeolite seed crystals, and
the gel has a composition which forms a mordenite zeolite, when the zeolite is synthesized from the gel without the use of the zeolite seed crystals.

4. The method of producing a zeolite according to claim 3 ,
wherein a gel having a composition shown in the following (a) or (b) is used as the gel,
SiO 2 /Al 2 O 3 =40 to 200,
Na 2 O/SiO 2 =0.24 to 0.4,
H 2 O/SiO 2 =10 to 50,  (a)

SiO 2 /Al 2 O 3 =10 to 40,
Na 2 O/SiO 2 =0.05 to 0.25,
H 2 O/SiO 2 =5 to 50  (b).

5. The method of producing a zeolite according to claim 4 ,
wherein, as a post treatment, dealumination of the zeolite is carried out by mixing the zeolite and an aqueous solution of citric acid or a salt thereof, and heating a mixed aqueous solution under an autogenous pressure.

6. The method of producing a zeolite according to claim 3 ,
wherein, as a post treatment, dealumination of the zeolite is carried out by mixing the zeolite and an aqueous solution of citric acid or a salt thereof, and heating a mixed aqueous solution under an autogenous pressure.

7. The method of producing a zeolite according to claim 2 ,
wherein the zeolite produced is MSE zeolite,
MSE zeolite is used as the zeolite seed crystals, and
the gel has a composition which forms a mordenite zeolite, when the zeolite is synthesized from the gel without the use of the zeolite seed crystals.

8. The method of producing a zeolite according to claim 7 ,
wherein a gel having a composition shown in the following (a) or (b) is used as the gel,
SiO 2 /Al 2 O 3 =40 to 200,
(Na 2 O+K 2 O)/SiO 2 =0.24 to 0.4,
K 2 O/(Na 2 O+K 2 O)=0 to 0.7,
H 2 O/SiO 2 =10 to 50,  (a)

SiO 2 /Al 2 O 3 =10 to 40,
(Na 2 O+K 2 O)/SiO 2 =0.05 to 0.25,
K 2 O/(Na 2 O+K 2 O)=0 to 0.7,
H 2 O/SiO 2 =5 to 50  (b).

9. The method of producing a zeolite according to claim 7 ,
wherein, as a post treatment, dealumination of the zeolite is carried out by mixing the zeolite and an aqueous solution of citric acid or a salt thereof, and heating a mixed aqueous solution under an autogenous pressure.

10. The method of producing a zeolite according to claim 2 ,
wherein the zeolite produced is MTW zeolite,
MTW zeolite is used as the zeolite seed crystals, and
the gel has a composition which forms an MFI zeolite, when the zeolite is synthesized from the gel without the use of the zeolite seed crystals.

11. The method of producing a zeolite according to claim 10 ,
wherein a gel having a composition shown below is used as the gel,
SiO 2 /Al 2 O 3 =10 to 150,
Na 2 O/SiO 2 =0.075 to 0.23,
H 2 O/SiO 2 =5 to 50.

12. The method of producing a zeolite according to claim 2 ,
wherein, as a post treatment, dealumination of the zeolite is carried out by mixing the zeolite and an aqueous solution of citric acid or a salt thereof, and heating a mixed aqueous solution under an autogenous pressure.

13. The method of producing a zeolite according to claim 1 ,
wherein, as a post treatment, dealumination of the zeolite is carried out by mixing the zeolite and an aqueous solution of citric acid or a salt thereof, and heating a mixed aqueous solution under an autogenous pressure.

14. A method of producing a zeolite comprising:
reacting a gel and zeolite seed crystals to produce a zeolite having the same kind of skeletal structure as the zeolite seed crystals;
wherein:
the gel comprises a silica source, an alumina source, an alkali source and water;
the gel is capable of synthesizing a zeolite without the use of the zeolite seed crystals, wherein the zeolite synthesized without the use of the zeolite seed crystals comprises one or more building units of zeolite;
the zeolite seed crystals comprise one or more composite building units of zeolite;
the zeolite seed crystals and the zeolite synthesized without the use of zeolite seed crystals comprise at least one equivalent composite building unit of zeolite;
wherein the reacting step occurs without the use of an organic structure-directing agent;
wherein the zeolite produced is MFI zeolite; and
wherein a gel having a composition shown in the following (a) or (b) is used as the gel,
SiO 2 /Al 2 O 3 =40 to 200,
Na 2 O/SiO 2 =0.24 to 0.4,
H 2 O/SiO 2 =10 to 25,  (a)

SiO 2 /Al 2 O 3 =10 to 40,
Na 2 O/SiO 2 =0.05 to 0.25,
H 2 O/SiO 2 =5 to 25  (b).

15. The method of producing a zeolite according to claim 14 ,
wherein, as a post treatment, dealumination of the zeolite is carried out by mixing the zeolite and an aqueous solution of citric acid or a salt thereof, and heating a mixed aqueous solution under an autogenous pressure.

Assignees

• Unizeo Co Ltd
• Univ Tokyo
• Mitsui Mining & Smelting Co

Inventors

• Itabashi Keiji
• Okubo Tatsuya
• Kamimura Yoshihiro
• Elangovan Shanmugam Palani

Classifications

• B01J29/7007

  Zeolite Beta · CPC title

• C01B39/36

  Pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11 · CPC title

• C01B39/38

  Type ZSM-5 · CPC title

• C01B39/42

  Type ZSM-12 · CPC title

• C01B39/026

  After-treatment · CPC title