Olefin conversion process

Patent metadata

Field	Value
Publication number	US-9809513-B2
Application number	US-201414548475-A
Country	US
Kind code	B2
Filing date	Nov 20, 2014
Priority date	Nov 20, 2013
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

Processes for the production of olefins are disclosed, which may include: contacting a hydrocarbon mixture comprising linear butenes with an isomerization catalyst to form an isomerization product comprising 2-butenes and 1-butenes; contacting the isomerization product with a first metathesis catalyst to form a first metathesis product comprising 2-pentene and propylene, as well as any unreacted C 4 olefins, and byproducts ethylene and 3-hexene; and fractionating the first metathesis product to form a C3− fraction and a C5 fraction comprising 2-pentene. The 2-pentene may then be advantageously used to produce high purity 1-butene, 3-hexene, 1-hexene, propylene, or other desired products.

First claim

What is claimed:

1. A process for the production of olefins, the process comprising:
(a) contacting a hydrocarbon mixture comprising linear butenes with an isomerization catalyst to form an isomerization product comprising 2-butenes and 1-butenes;
(b) contacting the isomerization product with a first metathesis catalyst to form a first metathesis product comprising 2-pentene and propylene, as well as any unreacted butenes, and byproducts ethylene and 3-hexene;
(c) fractionating the first metathesis product to form a C3− fraction comprising propylene and ethylene and a C5 fraction comprising 2-pentene; and
recycling the C3− fraction to step (a) or step (b).

2. The process of claim 1 , further comprising (d) contacting ethylene and the C5 fraction with a second metathesis catalyst, which may be the same or different than the first metathesis catalyst, to convert at least a portion of the 2-pentene and ethylene to propylene and 1-butene and form a second metathesis product comprising propylene and 1-butene.

3. The process of claim 2 , further comprising (e) fractionating the second metathesis product to form a propylene fraction and a 1-butene fraction.

4. The process of claim 3 , further comprising recycling the propylene fraction to at least one of step (a) and step (b).

5. The process of claim 3 , wherein the 1-butene fraction has a purity of at least 98 wt % 1-butene.

6. The process of claim 1 , further comprising (d) contacting the C5 fraction with a second metathesis catalyst, which may be the same or different than the first metathesis catalyst, to convert at least a portion of the 2-pentene to 2-butene and 3-hexene and form a second metathesis product comprising 2-butene and 3-hexene.

7. The process of claim 6 , further comprising (e) fractionating the second metathesis product to form a 2-butene fraction and a 3-hexene fraction.

8. The process of claim 7 , further comprising recycling the 2-butene fraction to step (a).

9. The process of claim 6 , wherein the 3-hexene fraction has a purity of at least 98 wt % 3-hexene.

10. The process of claim 8 , further comprising converting the 3-hexene fraction via isomerization to 1-hexene.

11. The process of claim 1 , further comprising converting the 2-pentene in the C5 fraction to isoprene.

12. The process of claim 1 , wherein the first metathesis product has a 2-pentene to 1-pentene ratio of greater than 100.

13. A process for the production of olefins, the process comprising:
feeding propylene and a mixed C4-olefin stream comprising a mixture of 1-butene and 2-butene to an isomerization/metathesis reactor including a first reaction zone comprising an isomerization catalyst and a second reaction zone comprising a first metathesis catalyst;
contacting the propylene and mixed C4-olefin stream with the isomerization catalyst in the first reaction zone to form an isomerization product comprising 2-butene and 1-butene;
contacting the isomerization product with the first metathesis catalyst in the second reaction zone to form a first metathesis product comprising 2-pentene, propylene, and byproducts ethylene and 3-hexene;
feeding the first metathesis product to a fractionation system;
fractionating the first metathesis product in the fractionation system to form at least one C3− fraction comprising propylene and ethylene and a C5 fraction comprising 2-pentene.

14. A process for the production of olefins, the process comprising:
feeding a mixed C4-olefin stream comprising a mixture of 1-butene and 2-butene to an isomerization/metathesis reactor including a first reaction zone comprising an isomerization catalyst and a second reaction zone comprising a first metathesis catalyst;
contacting the mixed C4-olefin stream with the isomerization catalyst in the first reaction zone to form an isomerization product comprising 2-butene and 1-butene;
contacting the isomerization product with the first metathesis catalyst in the second reaction zone to form a first metathesis product comprising 2-pentene, propylene, and byproducts ethylene and 3-hexene;
feeding the first metathesis product to a fractionation system;
fractionating the first metathesis product in the fractionation system to form at least one C3− fraction comprising propylene and ethylene and a C5 fraction comprising 2-pentene;
feeding ethylene and the C5 fraction to a metathesis reactor and contacting the ethylene and C5 fraction with a second metathesis catalyst, which may be the same or different than the first metathesis catalyst, to convert at least a portion of the ethylene and 2-pentene to propylene and 1-butene and recovering a second metathesis product comprising propylene and 1-butene;
fractionating the second metathesis product to recover a propylene fraction and a 1-butene fraction; and
feeding at least a portion of the propylene fraction to the isomerization/metathesis reactor.

15. A process for the production of olefins, the process comprising:
feeding a mixed C4-olefin stream comprising a mixture of 1-butene and 2-butene to an isomerization/metathesis reactor including a first reaction zone comprising an isomerization catalyst and a second reaction zone comprising a first metathesis catalyst;
contacting the mixed C4-olefin stream with the isomerization catalyst in the first reaction zone to form an isomerization product comprising 2-butene and 1-butene;
contacting the isomerization product with the first metathesis catalyst in the second reaction zone to form a first metathesis product comprising 2-pentene, propylene, and byproducts ethylene and 3-hexene;
feeding the first metathesis product to a fractionation system;
fractionating the first metathesis product in the fractionation system to form at least one C3− fraction comprising propylene and ethylene and a C5 fraction comprising 2-pentene;
recycling the C3− fraction to the isomerization/metathesis reactor;
feeding the C5 fraction to a metathesis reactor and contacting, in the absence of ethylene, the C5 fraction with a second metathesis catalyst, which may be the same or different than the first metathesis catalyst, to convert at least a portion of the 2-pentene to 2-butene and 3-hexane and recovering a second metathesis product comprising 2-butene and 3-hexene; and
fractionating the second metathesis product to recover a 2-butene fraction and a 3-hexene fraction.

16. A process for the production of olefins, the process comprising:
feeding a mixed C4-olefin stream comprising a mixture of 1-butene and 2-butene to an isomerization/metathesis reactor including a first reaction zone comprising an isomerization catalyst and a second reaction zone comprising a first metathesis catalyst;
contacting the mixed C4-olefin stream with the isomerization catalyst in the first reaction zone to form an isomerization product comprising 2-butene and 1-butene;
contacting the isomerization product with the first metathesis catalyst in the second reaction zone to form a first metathesis product comprising 2-pentene, propylene, and byproducts ethylene and 3-hexene;
feeding the first metathesis product to a fractionation system;
fractionating the first metathesis product in the fractionation system to form an ethylene fraction, a propylene fraction, a C4 fraction and a C5+ fraction comprising 2-pentene and 3-hexene;
feeding ethylene and the C5+ fraction to a metathesis reactor and contacting the ethylene and C5+ fraction with a second metathesis catalyst, which may be the same or different than the first metathesis catalyst, to convert at least a portion of the ethylene and 2-pentene to propylene and 1-butene and to convert at

Assignees

• Lummus Technology Inc

Inventors

• Choi Sukwon
• Ramachandran Bala

Classifications

• C07C2523/30

  Tungsten · CPC title

• C07C2521/10

  Magnesium; Oxides or hydroxides thereof · CPC title

• B01J8/0453

  the beds being superimposed one above the other · CPC title

• B01J2219/00006

  Large-scale industrial plants · CPC title

• B01J2208/025

  Two or more types of catalyst · CPC title