Fluidized-bed cracking of butene to form propylene and ethylene

Patent metadata

Field	Value
Publication number	US-10112190-B2
Application number	US-201815996458-A
Country	US
Kind code	B2
Filing date	Jun 2, 2018
Priority date	Jan 10, 2017
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

A method of producing propylene and ethylene from a butene-containing hydrocarbon stream by cracking olefin compounds in the butene-containing hydrocarbon stream in the presence of a core-shell ZSM catalyst, wherein the core-shell ZSM catalyst comprises a ZSM-5 core and a silica shell disposed thereon. Various embodiments of the method of producing propylene and ethylene, and the method of making the core-shell ZSM catalyst are also provided.

First claim

The invention claimed is:

1. A fluidized-bed method of cracking butene to form propylene and ethylene, comprising:
contacting a butene-containing hydrocarbon stream with a core-shell ZSM catalyst in a fluidized-bed reactor to form a product stream comprising propylene and ethylene,
wherein at least 50 wt % of the butene-containing hydrocarbon stream is butene. and
wherein the core-shell ZSM catalyst comprises:
a ZSM-5 core, and
a silica shell having a thickness in the range of 0.5 to 50 μm, which covers at least a portion of a surface of the ZSM-5 core.

2. The method of claim 1 , wherein the silica shell has a thickness in the range of 0.5 to 30 μm.

3. The method of claim 1 , wherein the core-shell ZSM catalyst is dispersed in a silica and/or an alumina binder.

4. The method of claim 1 , wherein a weight percent of the silica shell in the core-shell ZSM catalyst is within the range of 4 to 75 wt %, with the weight percent being relative to the total weight of the core-shell ZSM catalyst.

5. The method of claim 1 , wherein the core-shell ZSM catalyst has an acidity of less than 0.1 mmol/g.

6. The method of claim 1 , wherein at least 50 wt % of the product stream is propylene and ethylene.

7. The method of claim 1 , wherein a propylene-to-ethylene weight ratio of the product stream is within the range of 0.2 to 4.

8. The method of claim 1 , further comprising:
treating the core-shell ZSM catalyst with nitrogen at a temperature in the range of 400 to 700° C. prior to the contacting.

9. The method of claim 1 , further comprising:
mixing the butene-containing hydrocarbon stream with nitrogen to form a gaseous mixture prior to the contacting, wherein a partial pressure of the butene-containing hydrocarbon stream in the gaseous mixture is within the range of 5 to 50 psi.

10. The method of claim 1 , wherein the butene-containing hydrocarbon stream is contacted with the core-shell ZSM catalyst at a temperature in the range of 400 to 700° C. and a space velocity in the range of 800 to 10,000 −1 .

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Al-Khattaf Sulaiman
• Arudra Palani
• Abdalla Amr

Classifications

• C07C4/06

  Catalytic processes {(C07C4/025 takes precedence)} · CPC title

• B01J37/0221

  of particles · CPC title

• B01J21/08

  Silica · CPC title

• C07C2529/40

  of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11 · CPC title

• B01J29/40

  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 title