Rare earth-containing high-silica zeolite having penta-sil type structure and process for the same

• US 5,232,675 A
• Filed: 01/14/1992
• Issued: 08/03/1993
• Est. Priority Date: 02/28/1991
• Status: Expired due to Term

• Current Assignee: China Petrochemical Corporation, Research Institute of Petroleum Processing Sinopec
• Original Assignee: China Petrochemical Corporation, Research Institute of Petroleum Processing Sinopec
• Inventors: Fu, Wei, Zhang, Shugin, Zhou, Meng, Shu, Xingtian, He, Mingyuan, Shi, Zhicheng
• Primary Examiner(s): MCFARLANE, ANTHONY R
• Application Number:
  US07/820,385
• Time in Patent Office: 567 Days
• Field of Search: 502/65, 502/64, 502/79, 423/328, 423/328.1, 423/328.2, 423/329.11, 423/330.11, 423/332, 423/709, 423/718
• US Class Current: 423/328.2
• CPC Class Codes: B01J 2229/36 Steaming
• CPC Class Codes: B01J 2229/40 Special temperature treatment, i.e. other than just for template removal
• CPC Class Codes: B01J 2229/42 Addition of matrix or binder particles
• CPC Class Codes: B01J 29/088 Y-type faujasite
• CPC Class Codes: B01J 29/40 of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
• CPC Class Codes: C01B 39/36 Pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11

Abstract

The present invention discloses a rare earth-containing high-silica zeolite having penta-sil type structure and process for the same. The anhydrous composition of the high-silica zeolite of the present invention (based on the mole ratio of oxides) can be defined by the formula

xRE.sub.2 O.sub.3 yNa.sub.2 OAl.sub.2 O.sub.3 zSiO.sub.2

in which X=0.01-0.30, y=0.4-1.0, and z=20-60. The high-silica zeolite of the present invention is an useful active component for catalysts.

Claims

1. A synthetic crystalline aluminosilicate zeolite having an anhydrous chemical composition (based on moles of oxides) of formula:

space="preserve" listing-type="equation">xRE.sub.2 O.sub.3 yNa.sub.2 OAl.sub.2 O.sub.3 zSIO.sub.2

wherein

x=0.01-0.30, y=0.4-1.0, z=20-60;

said zeolite having the structure of a pentasil and a X-ray diffraction pattern listed in Table 1, and its normal hexane adsorption/cyclohexane adsorption ratio being 2-4 times higher than that of H-ZSM-5 zeolite.

2. A zeolite according to claim 1, wherein the composition of said zeolite is formed through the reaction of rare earth-containing faujasite seeds with the gel system comprising water glass, aluminum salt, inorganic acid and water.

3. A zeolite according to claim 1, wherein the rare earth-containing faujasite seed is REY, REHY, or REX.

4. A zeolite according to claim 3, wherein the rare earth-containing faujasite seed contains 2-27% rare earth elements and less than 7.0% sodium (both based on the weight of oxides).

5. A process for synthesizing a crystalline aluminosilicate zeolite having an anhydrous chemical composition based on moles of oxides of the formula:

space="preserve" listing-type="equation">xRE.sub.2 O.sub.3 yNa.sub.2 OAl.sub.2 O.sub.3 zSIO.sub.2

wherein

x=0.01-0.30, y=0.4-1.0, z=20-60,

said zeolite having the structure of a pentasil and an X-ray diffraction pattern listed in Table 1, and its normal hexane adsorption/cyclohexane adsorption ratio being 2-4 times higher than that of H-ZSM-5 zeolite, said process comprising the steps of dispersing rare earth-containing faujasite seed in a gel system comprising water glass, aluminum salt, inorganic acid and water, with oxide mole ratio SiO₂ /Al₂ O₃ =30-120, Na₂ O/Al₂ O₃ =2-15, and H₂ O/SiO₂ =20-100 and crystallizing at a temperature of 130°

-200°

C. for 12-60 hours followed by filtrating, washing, and drying.

6. A process according to claim 5, wherein said seed is REY, REHY, or REX, containing rare earth element 2-27% and sodium less than 7.0% (both based on the weight of oxides).

7. A process according to claim 5, wherein the amount of the seed used satisfies the mole ratio of RE₂ O₃ (present in the seed) and Al₂ O₃ (in said gel system) in the range of 0.01-0.40.

8. A process according to claim 5, wherein said aluminum salt is Al₂ (SO₄)₃, AlCl₃, AlPO₄, Al₂ (HPO₄)₃, or Al(H₂ PO₄)₃.

9. A process according to claim 8, wherein said aluminum salt is AlPO₄.

10. A process according to claim 9, wherein said aluminum salt is AlPO₄ gel.

11. A process according to claim 5, wherein said inorganic acid is phosphoric acid, sulfuric acid, hydrochloric acid, or nitric acid.

12. A process according to claim 5, wherein the amount of said inorganic acid used is sufficient to produce a PH value of the system in the range of 10-12.

13. A process according to claim 5, wherein the temperature of said crystallization proceeds at 160°

-190°

C. for 16-30 hours.