Synthesis of ton framework type molecular sieves

Patent metadata

Field	Value
Publication number	US-11565943-B2
Application number	US-202117173712-A
Country	US
Kind code	B2
Filing date	Feb 11, 2021
Priority date	Feb 11, 2021
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

A method is disclosed making a molecular of TON framework type having unique properties. The method uses 1,3,4-trimethylimidazolium cations as a structure directing agent and a combined source of silicon and aluminum selected from alumina-coated silica and aluminosilicate zeolites. The obtained molecular sieve can be used in processes for dewaxing paraffinic hydrocarbon feedstocks.

First claim

The invention claimed is:

1. A method of synthesizing a molecular sieve having a TON framework, the method comprising:
(1) forming a reaction mixture comprising:
(a) a combined source of silicon and aluminum, where the combined source of silicon and aluminum is selected from the group consisting of an alumina-coated silica, an aluminosilicate zeolite having an FAU framework, and a mixture thereof;
(b) a structure directing agent (Q) comprising 1,3,4-trimethylimidazolium cations;
(c) a source of hydroxide ions;
(d) water; and
(e) seeds; and

(2) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the molecular sieve having a TON framework.

2. The method of claim 1 , wherein the reaction mixture has a composition, in terms of molar ratios, as follows:

SiO 2 /Al 2 O 3
 30 to 170

Q/SiO 2
0.03 to 0.50

OH/SiO 2
0.05 to 1.00

H 2 O/SiO 2
  5 to 100.

3. The method of claim 1 , wherein the reaction mixture has a composition, in terms of molar ratios, as follows:

SiO 2 /Al 2 O 3
 35 to 130

Q/SiO 2
0.04 to 0.30

OH/SiO 2
0.10 to 0.50

H 2 O/SiO 2
 10 to 50.

4. The method of claim 1 , wherein the aluminosilicate zeolite having an FAU framework is zeolite Y.

5. The method of claim 1 , wherein the source of hydroxide ions comprises an alkali metal hydroxide.

6. The method of claim 5 , wherein the alkali metal is lithium, sodium, potassium, or a mixture thereof.

7. The method of claim 6 , wherein a molar ratio of alkali metal cation/SiO 2 is in a range of from 0.1 to 1.0.

8. The method of claim 1 , wherein the seeds comprise a molecular sieve having a TON framework.

9. The method of claim 1 , wherein the reaction mixture comprises from 0.01 ppm by weight to 10,000 ppm by weight of the seeds.

10. The method of claim 1 , wherein the reaction mixture further comprises a separate source of silicon.

11. The method of claim 10 , wherein the separate source of silicon comprises colloidal silica, precipitated silica, fumed silica, an alkali metal silicate, a tetraalkyl orthosilicate, or a mixture thereof.

12. The method of claim 1 , wherein the crystallization conditions include a temperature of from 125° C. to 200° C. and a time of from 1 day to 10 days.

Assignees

• Chevron Usa Inc

Inventors

• Schmidt Joel Edward
• Ojo Adeola Florence

Classifications

• C10G2300/4012

  Pressure · CPC title

• C10G2300/4018

  Spatial velocity, e.g. LHSV, WHSV · CPC title

• C10G2300/4006

  Temperature · CPC title

• C01B39/48 Primary

  using at least one organic template directing agent · CPC title

• C01B39/02

  Crystalline aluminosilicate zeolites; Isomorphous compounds thereof; Direct preparation thereof; Preparation thereof starting from a reaction mixture containing a crystalline zeolite of another type, or from preformed reactants; After-treatment thereof · CPC title