Zeolite SSZ-57 having enhanced large pore selectvity

Patent metadata

Field	Value
Publication number	US-9718051-B2
Application number	US-201414189556-A
Country	US
Kind code	B2
Filing date	Feb 25, 2014
Priority date	Feb 28, 2013
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

The present invention is directed to an alumino-borosilicate SSZ-57 zeolite having enhanced large pore selectivity. The alumino-borosilicate SSZ-57 zeolite of the present invention is characterized as having substantially all of its aluminum atoms located within regions of the zeolite structure which form the 12 ring channels.

First claim

What is claimed is:

1. An alumino-borosilicate SSZ-57 zeolite having a SiO 2 /B 2 O 3 ratio of at least 150,
wherein the zeolite is characterized as having substantially all of its aluminum atoms located within regions of the zeolite structure which form the 12 ring channels, and
wherein the zeolite has a Constraint Index of between 0.3 and 1.0, inclusive, at 316° C. and 40 minutes on-stream when the zeolite is subject to a 50/50 feed of n-hexane and 3-methylpentane.

2. The zeolite of claim 1 , wherein the zeolite produces an iso-C 4 /n-C 4 ratio of 2.5 to 4.5, inclusive, during a Constraint Index test at 316° C. and 40 minutes on-stream, when the zeolite is subject to a 50/50 feed of n-hexane and 3-methylpentane.

3. The zeolite of claim 1 , wherein the zeolite has a composition as described as follows:

SiO 2 /B 2 O 3
at least 50

SiO 2 /Al 2 O 3
at least 150.

4. An alumino-borosilicate SSZ-57 zeolite having a SiO2/B2O3 ratio of at least 150, wherein the zeolite is characterized as having substantially all of its aluminum atoms located within regions of the zeolite structure which form the 12 ring channels, made by a method comprising the steps of:
(a) preparing a reaction mixture containing: (1) at least one source of silicon oxide; (2) at least one source of boron oxide; (3) at least one source of an element selected from Groups 1 and 2 of the Periodic Table; (4) hydroxide ions; (5) a structure directing agent selected from the group consisting of an N-butyl-N-cyclohexylpyrrolidinium cation, an N-propyl-N-cycloheptylpyrrolidinium cation, an N-butyl-N-cyclooctylpyrrolidinium cation, and mixtures thereof; and (6) water;
(b) maintaining the reaction mixture under crystallization conditions sufficient to form crystals of borosilicate SSZ-57;
(c) subjecting the borosilicate SSZ-57 crystals to calcination conditions; and
(d) replacing at least a portion of the boron in the 12-ring channels of framework of the calcined borosilicate SSZ-57 with aluminum to provide an alumino-borosilicate SSZ-57characterized as having substantially all of its aluminum atoms located within regions of the zeolite structure which form the 12 ring channels; and
wherein the zeolite has a Constraint Index of between 0.3 and 1.0, inclusive, at 316° C. and 40 minutes on-stream when the zeolite is subject to a 50/50 feed of n-hexane and 3-methylpentane.

5. The zeolite of claim 4 , wherein the zeolite produces an iso-C 4 /n-C 4 ratio of 2.5 to 4.5, inclusive, during a Constraint Index test at 316° C. and 40 minutes on-stream, when the zeolite is subject to a 50/50 feed of n-hexane and 3-methylpentane.

6. The zeolite of claim 4 , wherein the zeolite has a composition as described as follows:

SiO 2 /B 2 O 3
at least 50

SiO 2 /Al 2 O 3
at least 150.

7. A method for making an alumino-borosilicate SSZ-57 zeolite having a SiO2/B2O3 ratio of at least 150, wherein the zeolite is characterized as having substantially all of its aluminum atoms located within regions of the zeolite structure which form the 12 ring channels, comprising the steps of:
(a) preparing a reaction mixture containing: (1) at least one source of silicon oxide; (2) at least one source of boron oxide; (3) at least one source of an element selected from Groups 1 and 2 of the Periodic Table; (4) hydroxide ions; (5) a structure directing agent selected from the group consisting of an N-butyl-N-cyclohexylpyrrolidinium cation, an N-propyl-N-cycloheptylpyrrolidinium cation, an N-butyl-N-cyclooctylpyrrolidinium cation, and mixtures thereof; and (6) water;
(b) maintaining the reaction mixture under crystallization conditions sufficient to form crystals of borosilicate SSZ-57;
(c) subjecting the borosilicate SSZ-57 crystals to calcination conditions; and
(d) replacing at least a portion of the boron in the 12-ring channels of framework of the calcined borosilicate SSZ-57 with aluminum to provide an alumino-borosilicate SSZ-57characterized as having substantially all of its aluminum atoms located within regions of the zeolite structure which form the 12 ring channels.

8. The method of claim 7 , wherein the step of replacing at least a portion of the boron in the 12-ring channels of framework of the calcined borosilicate SSZ-57 with aluminum to provide an alumino-borosilicate SSZ-57 comprises subjecting the zeolite to an amount of aluminum nitrate nonahydrate for a time and at a temperature sufficient to affect a replacement of an amount of boron in the 12-ring channel framework of the calcined borosilicate SSZ-57 with an amount of aluminum sufficient to yield an alumino-borosilicate SSZ-57 having enhanced large pore selectivity.

9. The method of claim 8 , wherein the zeolite has a Constraint Index of between 0.3and 1.0, inclusive, at 316° C. and 40 minutes on-stream when the zeolite is subject to a 50/50 feed of n-hexane and 3-methylpentane.

10. The method of claim 8 , wherein the zeolite produces an iso-C 4 /n-C 4 ratio of 2.5 to 4.5, inclusive, during a Constraint Index test at 316° C. and 40 minutes on-stream, when the zeolite is subject to a 50/50 feed of n-hexane and 3-methylpentane.

Assignees

• Chevron Usa Inc

Inventors

• Zones Stacey Ian
• Chen Cong-Yan
• Benin Annabelle

Classifications

• C01B39/026

  After-treatment · CPC title

• C01B39/36

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

• B01J29/86 Primary

  Borosilicates; Aluminoborosilicates {(B01J29/005 takes precedence)} · CPC title

• B01J2229/183

  in framework positions · CPC title

• C01B39/023

  Preparation of physical mixtures or intergrowth products of zeolites chosen from group C01B39/04 or two or more of groups C01B39/14 - C01B39/48 · CPC title