Systems and methods for producing propylene

Patent metadata

Field	Value
Publication number	US-9834497-B2
Application number	US-201615191009-A
Country	US
Kind code	B2
Filing date	Jun 23, 2016
Priority date	Jul 2, 2015
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

According to one or more embodiments described herein, a process for producing propylene, the process comprising at least partially metathesizing a first portion of a first stream to form a first metathesis-reaction product, at least partially cracking the first metathesis-reaction product to form a cracking-reaction product, the cracking reaction product comprising propylene and ethylene, at least partially separating ethylene from at least the cracking reaction product to form a first recycle stream, combining the first recycle stream with a second portion of the first stream to a form a mixed stream, and at least partially metathesizing the mixed stream to from a second metathesis-reaction product. In embodiments, the second metathesis-reaction product may comprise propylene, the first stream may comprise butene, and the first recycle stream may comprise ethylene.

First claim

What is claimed is:

1. A process for producing propylene, the process comprising:
at least partially metathesizing a first portion of a first stream to form a first metathesis-reaction product, the first stream comprising butene;
at least partially cracking the first metathesis-reaction product to form a cracking-reaction product, the cracking reaction product comprising propylene and ethylene;
at least partially separating ethylene from at least the cracking reaction product to form a first recycle stream, the first recycle stream comprising ethylene;
combining the first recycle stream with a second portion of the first stream to a form a mixed stream; and
at least partially metathesizing the mixed stream to form a second metathesis-reaction product, the second metathesis-reaction product comprising propylene.

2. The process of claim 1 , where the first stream comprises at least 10 wt. % butene.

3. The process of claim 1 , further comprising at least partially separating propylene from at least one of the cracking reaction product stream and the second metathesis-reaction product to form a product stream comprising at least 80 wt. % propylene.

4. The process of claim 1 , further comprising at least partially separating butene from at least one of the cracking-reaction product and the second metathesis-reaction product to form a second recycle stream comprising at least 10 wt. % butene.

5. The process of claim 4 , further comprising combining the second recycle stream with the first stream upstream of the first stream being partitioned into a first portion and a second portion.

6. The process of claim 4 , further comprising combining the second recycle stream with second portion of the first stream.

7. The process of claim 1 , where the first recycle stream comprises at least 80 wt. % ethylene.

8. The process of claim 1 , where in the first cracking-reaction product and the second metathesis reaction product are mixed prior to one or more separation processes.

9. The process of claim 8 , where the mixture of the first cracking-reaction product and the second metathesis reaction product comprises at least 10 wt. % propylene.

10. The process of claim 1 , where the first portion of the first stream is metathesized with a metathesis catalyst and the first metathesis-reaction product is cracked with a cracking catalyst.

11. The process of claim 10 , where the cracking catalyst is a mordenite framework inverted (MFI) structured silica catalyst.

12. The process of claim 10 , where the metathesis catalyst is a mesoporous silica catalyst impregnated with metal oxide.

13. A process for producing propylene, the process comprising:
introducing a first portion of a first stream comprising butene to a first reactor, where the first reactor comprises a first metathesis catalyst and a cracking catalyst, the first metathesis catalyst positioned generally upstream of the cracking catalyst;
at least partially metathesizing the first portion of the first stream with the first metathesis catalyst to form a first metathesis-reaction product;
at least partially cracking the first metathesis-reaction product with the cracking catalyst to produce a cracking-reaction product comprising propylene and ethylene;
passing the cracking-reaction product out of the first reactor in a cracking-reaction product stream;
combining a first recycle stream with a second portion of the first stream to a form a mixed stream and introducing the mixed stream to a second reactor, the second reactor comprising a second metathesis catalyst;
at least partially metathesizing the mixed stream with the second metathesis catalyst in the second reactor to produce a second metathesis-reaction product comprising propylene and passing the second metathesis-reaction product out of the second reactor in a second metathesis-reaction product stream;
at least partially separating ethylene from the cracking-reaction product stream, the second metathesis-reaction product stream, or a stream comprising a mixture of both, to form the first recycle stream; and
at least partially separating propylene from the cracking-reaction product stream, second metathesis-reaction product stream, or a stream comprising a mixture of both, to form a product stream comprising propylene.

14. The process of claim 13 , where the first stream comprises at least 10 wt. % butene.

15. The process of claim 13 , where in the cracking-reaction product and the second metathesis reaction product are mixed prior to one or more separation processes.

16. The process of claim 15 , where the mixture of the first cracking-reaction product and the second metathesis reaction product comprises at least 10 wt. % propylene.

17. The process of claim 13 , where a ratio of the mass flowrate of the first portion of the first stream and the second portion of the first stream is from 1:1 to 6:1.

18. The process of claim 13 , further comprising at least partially separating butene from at least one of the cracking-reaction product stream and the second metathesis-reaction product stream to form a second recycle stream comprising at least 10 wt. % butene.

19. A process for producing propylene, the process comprising:
introducing a first portion of a first stream comprising butene to a first reactor, where the first reactor comprises a first metathesis catalyst;
at least partially metathesizing the first portion of the first stream with the first metathesis catalyst to form a first metathesis-reaction product;
passing the first metathesis-reaction product to a second reactor, where the first reactor comprises a cracking catalyst;
at least partially cracking the first metathesis-reaction product with the cracking catalyst to produce a cracking-reaction product comprising propylene and ethylene;
passing the cracking-reaction product out of the second reactor in a cracking-reaction product stream;
combining an ethylene recycle stream with a second portion of the first stream comprising butene to a form a mixed stream and introducing the mixed stream to a third reactor, the third reactor comprising a second metathesis catalyst;
at least partially metathesizing the mixed stream with the second metathesis catalyst in the third reactor to produce a second metathesis-reaction product comprising propylene and passing the second metathesis-reaction product out of the third reactor in a second metathesis-reaction product stream;
at least partially separating ethylene from the cracking-reaction product stream, the second metathesis-reaction product stream, or a stream comprising a mixture of both, to form the ethylene recycle stream; and
at least partially separating propylene from the cracking-reaction product stream, the second metathesis-reaction product stream, or a stream comprising a mixture of both, to form a product stream comprising propylene.

20. The process of claim 19 , where the first stream comprises at least 10 wt. % butene.

21. The process of claim 19 , where the cracking-reaction product and the second metathesis reaction product are mixed prior to one or more separation processes.

22. The process of claim 21 , where the mixture of the cracking-reaction product and the second metathesis-reaction product comprises at least 10 wt. % propylene.

23. The process of claim 19 , further comprising at least partially separating butene from at least one of the cracking-reaction product stream and the second metathesis-reaction product stream to form a sys

Assignees

• Saudi Arabian Oil Co

Inventors

• Shaikh Sohel
• Jamal Aqil
• Zhang Zhonglin

Classifications

• C07C6/04 Primary

  at a carbon-to-carbon double bond · CPC title

• C07C2521/08

  Silica · CPC title

• C07C11/06

  Propene · CPC title

• C07C2523/30

  Tungsten · CPC title

• C07C2529/40

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