Process and apparatus for producing olefin

Patent metadata

Field	Value
Publication number	US-9309470-B2
Application number	US-200913119150-A
Country	US
Kind code	B2
Filing date	Sep 1, 2009
Priority date	Sep 17, 2008
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

The present invention provides a process for producing olefin having 3 or more carbon atoms from ethane stably in a simpler process. The present invention provides a method for producing olefin having a step of obtaining a cold fraction by cooling an ethane-cracked gas, which is obtained by thermal cracking of ethane in the presence of steam, to 600° C. or less; and a step of obtaining a catalytic cracking gas containing olefin having 3 or more carbon atoms by bringing the cold fraction into contact with a catalyst containing a medium pore diameter zeolite.

First claim

The invention claimed is:

1. A process for producing propylene comprising the steps of:
thermally cracking ethane in the presence of steam to obtain an effluent comprising ethylene;
cooling the effluent comprising ethylene to a temperature of 600° C. or less to obtain a cold fraction;
catalytically cracking the cold fraction in the presence of a catalyst comprising a zeolite to obtain a product gas comprising propylene, wherein an ethylene conversion rate in the catalytic cracking of the cold fraction is within a range of 45% to 85% by mass; and
separating and recovering said propylene,
wherein [1] the zeolite comprises ZSM-5 zeolite,
[2] silica to alumina ratio of the zeolite is within a range of 20 to 500, and
[3] temperature programmed desorption (TPD) acid amount of the zeolite is within a range of 20 to 500 μmol/g-zeolite.

2. A process for producing propylene comprising the steps of:
thermally cracking ethane in the presence of steam to obtain an effluent comprising ethylene;
cooling the effluent comprising ethylene to a temperature of 600° C. or less to obtain a cold fraction;
separating said cold fraction into a liquid-state heavy fraction and a cold gas fraction; and
catalytically cracking the cold gas fraction in the presence of a catalyst comprising a zeolite to obtain a product gas comprising propylene, wherein an ethylene conversion rate in the catalytic cracking of the cold gas fraction is within a range of 45% to 85% by mass,
wherein [1] the zeolite comprises ZSM-5 zeolite,
[2] silica to alumina ratio of the zeolite is within a range of 20 to 500, and
[3] temperature programmed desorption (TPD) acid amount of the zeolite is within a range of 20 to 500 μmol/g-zeolite.

3. The process according to claim 2 , further comprising the step of separating at least a part of aromatic hydrocarbons from the liquid-state heavy fraction.

4. The process according to claim 1 ,
wherein said step of catalytically cracking the cold fraction is conducted in a fluidized bed reactor, and further comprising:
removing continuously or intermittently a part of coked catalyst from the fluidized bed reactor and passing to a regenerator;
regenerating the coked catalyst with an oxygen-containing gas to produce a regenerated catalyst; and
recycling the regenerated catalyst to the fluidized bed reactor.

5. The process according to claim 1 , wherein said effluent comprising ethylene is cooled to from 300° C. to 600° C.

6. The process according to claim 1 , further comprising the steps of:
separating ethane from said product gas; and
recycling at least a part of said ethane to said step of thermally cracking ethane.

7. The process according to claim 1 , wherein the product gas comprising propylene is separated to obtain at least one of a C4 fraction or a gasoline fraction.

8. The process according to claim 7 , wherein at least a part of unreacted ethylene separated from the product gas is recycled to said step of catalytically cracking the cold fraction.

9. The process according to claim 7 , wherein the C4 fraction is separated to obtain i-butene and/or n-butene.

10. The process according to claim 7 , wherein the gasoline fraction is separated to obtain at least a part of aromatic hydrocarbons.

11. The process according to claim 2 ,
wherein said catalytically cracking of the cold gas fraction is conducted in a fluidized bed reactor, and further comprising:
removing continuously or intermittently a part of coked catalyst from the fluidized bed reactor and passing to a regenerator;
regenerating the coked catalyst with an oxygen-containing gas to produce a regenerated catalyst; and
recycling the regenerated catalyst to the fluidized bed reactor.

12. The process according to claim 2 , wherein said effluent comprising ethylene is cooled to from 300° C. to 600° C.

13. The process according to claim 2 , further comprising the steps of:
separating ethane from said product gas; and
recycling at least a part of said ethane to said step of thermally cracking ethane.

14. The process according to claim 2 , wherein the product gas further comprises a C4 fraction or a gasoline fraction.

15. The process according to claim 14 , wherein at least a part of unreacted ethylene separated from the product gas is recycled to said step of catalytically cracking the cold gas fraction.

16. The process according to claim 14 , wherein the C4 fraction is separated to obtain i-butene and/or n-butene.

17. The process according to claim 14 , wherein the gasoline fraction is separated to obtain at least a part of aromatic hydrocarbons.

Assignees

• Sekiguchi Mitsuhiro
• Tsunoda Takashi
• Asahi Kasei Chemicals Corp

Inventors

• Sekiguchi Mitsuhiro
• Tsunoda Takashi

Classifications

• C10G11/05

  Crystalline alumino-silicates, e.g. molecular sieves · CPC title

• C10G2400/22

  Higher olefins · 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

• B01J29/46

  Iron group metals or copper · CPC title

• C10G9/36

  with heated gases or vapours · CPC title