Processes and catalysts for production of light olefins

Patent metadata

Field	Value
Publication number	US-9656928-B2
Application number	US-201414538993-A
Country	US
Kind code	B2
Filing date	Nov 12, 2014
Priority date	Nov 12, 2014
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

A novel process and a novel catalyst for the production of light olefins. 1-butene is cracked in the presence of an acid- or base-modified silicalite-1 catalyst bed, wherein the modified silicalite-1 has a Si/Al ratio of greater than 1000. The modification procedures described herein increase the selectivity of the silicalite-1 catalyst toward light olefins such as ethylene and propylene. The catalytic cracking of 1-butene may be carried out in a fixed bed reactor or a fluidized bed reactor.

First claim

The invention claimed is:

1. A process of producing ethylene and propylene, comprising:
treating silicalite-1 crystals to at least one of acid washing and base treatment to produce modified silicalite-1 crystals; and
contacting 1-butene in a reactor with the modified silicalite-1 crystals to catalytically crack the 1-butene to form a mixture comprising ethylene and propylene;
wherein the modified silicalite-1 crystals have an average particle size of 0.02 mm to 1.0 mm in diameter, an MFI framework, and a Si/Al ratio of greater than 1000.

2. The process of claim 1 , wherein the catalytic cracking is carried out in the presence of an inert gas.

3. The process of claim 1 , wherein the catalytic cracking is carried out at a reactor temperature within the range of 450° C. to 750° C.

4. The process of claim 1 , wherein the catalytic cracking is carried out with an on-stream time of 1 to 5 hours.

5. The process of claim 1 , wherein the catalytic cracking is carried out at a hydrocarbon partial pressure within the range of 5 psia to 50 psia.

6. The process of claim 1 , wherein the catalytic cracking is carried out at a gas hourly space velocity of 600 h −1 to 10000 h −1 .

7. The process of claim 1 , wherein the reactor is selected from the group consisting of a fluidized bed reactor and a fixed bed reactor.

8. The process of claim 1 , wherein the silicalite-1 crystals are calcinated before and/or after acid washing or base treatment.

9. The process of claim 1 , wherein the process produces at least 50 wt. % total ethylene and propylene based on the total weight of the 1-butene.

10. The process of claim 1 , wherein the process produces ethylene and propylene in a ratio of ethylene to propylene of 1:2 to 1:3.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Al-Khattaf Sulaiman Saleh
• Palani Arudra
• Aitani Abdullah Mohammed

Classifications

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J2235/15

  X-ray diffraction · CPC title

• B01J35/70

  characterised by their crystalline properties, e.g. semi-crystalline (catalysts comprising carbon B01J21/18; molecular sieves B01J29/00) · CPC title

• C07C2529/035

  Crystalline silica polymorphs, e.g. silicalites · CPC title

• C07C11/04

  Ethene · CPC title