Propylene via metathesis with low or no ethylene

Patent metadata

Field	Value
Publication number	US-9422209-B2
Application number	US-201314024986-A
Country	US
Kind code	B2
Filing date	Sep 12, 2013
Priority date	Sep 14, 2012
Publication date	Aug 23, 2016
Grant date	Aug 23, 2016

Abstract

A process for producing propylene is disclosed, including: fractionating a mixed C4 hydrocarbon stream to recover a first fraction comprising isobutene and a second fraction comprising 2-butene; contacting the first fraction with a first metathesis catalyst in a first metathesis reaction zone; recovering an effluent from the first metathesis reaction zone comprising at least one of ethylene, propylene, unreacted isobutene, C5 olefins, and C6 olefins; contacting the second fraction and the ethylene in the effluent with a second metathesis catalyst in a second metathesis reaction zone; recovering an effluent from the second reaction zone comprising at least one of unreacted ethylene, propylene, unreacted 2-butene, fractionating the effluent from the first metathesis reaction zone and the effluent from the second metathesis reaction zone to recover an ethylene fraction, a propylene fraction, one or more C4 fractions, and a fraction comprising at least one of C5 and C6 olefins.

First claim

What is claimed:

1. A process for the production of propylene from a mixed C4 hydrocarbon stream comprising isobutene, 1-butene, and 2-butene, the process comprising:
concurrently:
fractionating the mixed C4 hydrocarbon stream and
isomerizing a portion of the 2-butene to form 1-butene
to recover a first fraction comprising isobutene and 1-butene and a second fraction comprising 2-butene;

contacting at least a portion of the first fraction with a first metathesis catalyst in a first metathesis reaction zone;
recovering an effluent from the first metathesis reaction zone comprising at least one of ethylene, propylene, unreacted isobutene, C5 olefins, and C6 olefins;
contacting at least a portion of the second fraction and ethylene with a second metathesis catalyst in a second metathesis reaction zone;
recovering an effluent from the second reaction zone comprising at least one of unreacted ethylene, propylene, unreacted 2-butene,
fractionating the effluent from the first metathesis reaction zone and the effluent from the second metathesis reaction zone to recover an ethylene fraction, a propylene fraction, one or more C4 fractions, and a fraction comprising at least one of C5 and C6 olefins.

2. The process of claim 1 , further comprising feeding the ethylene fraction to the second metathesis reaction zone as the at least a portion of the ethylene in the effluent from the first metathesis reaction zone.

3. The process of claim 1 , further comprising recycling the one or more C4 fractions to at least one of the first metathesis reaction zone and the second metathesis reaction zone.

4. The process of claim 1 , wherein the first fraction further comprises isobutane, the process further comprising:
fractionating the first fraction to recover an isobutane fraction and a fraction comprising isobutene and 1-butene; and
feeding the fraction comprising isobutene and 1-butene to the first metathesis reaction zone as the at least a portion of the first fraction.

5. A process for the production of propylene, comprising:
fractionating a mixed C4 hydrocarbon stream to recover a first fraction comprising isobutene and 1-butene and a second fraction comprising 2-butene;
feeding a portion of the second fraction to an isomerization reaction zone containing an isomerization catalyst;
contacting the 2-butene with the isomerization catalyst to convert at least a portion of the 2-butene to 1-butene;
recovering an effluent from the isomerization reaction zone comprising the 1-butene and any unreacted 2-butene; and
feeding the effluent from the isomerization reaction zone to the fractionating a mixed C4 stream;
contacting at least a portion of the first fraction with a first metathesis catalyst in a first metathesis reaction zone;
recovering an effluent from the first metathesis reaction zone comprising at least one of ethylene, propylene, unreacted isobutene, unreacted 1-butene, C5 olefins, and C6 olefins;
fractionating the effluent from the first metathesis reaction zone to recover a fraction comprising ethylene and propylene, a fraction comprising any unreacted isobutene and any unreacted 1-butene, and a fraction comprising any C5 and C6 olefins;
contacting a remaining portion of the second fraction and ethylene with a second metathesis catalyst in a second metathesis reaction zone;
recovering an effluent from the second metathesis reaction zone comprising at least one of unreacted ethylene, propylene, and unreacted 2-butene,
fractionating the effluent from the second metathesis reaction zone and the fraction comprising ethylene and propylene to recover an ethylene fraction, a propylene fraction, a C4 fraction, and a fraction comprising at least one of C5 and C6 olefins;
feeding at least a portion of the ethylene fraction to the second metathesis reaction zone as the ethylene;
feeding at least a portion of the C4 fraction to the second metathesis reaction zone; and
feeding at least a portion of the fraction comprising any unreacted isobutene and any unreacted 1-butene to the first metathesis reaction zone.

6. The process of claim 5 , wherein the first fraction further comprises isobutane, the process further comprising:
fractionating the first fraction to recover an isobutane fraction and a fraction comprising isobutene and 1-butene; and
feeding the fraction comprising isobutene and 1-butene to the first metathesis reaction zone as the at least a portion of the first fraction.

7. A process for the production of propylene, comprising:
feeding a mixed C4 hydrocarbon stream comprising 1-butene, 2-butene, and isobutene to a catalytic distillation reactor system;
concurrently in the catalytic distillation reactor system:
isomerizing at least a portion of the 2-butene to form 1-butene;
fractionating the mixed C4 hydrocarbon stream to recover a first fraction comprising isobutene and 1-butene and a second fraction comprising 2-butene; and

contacting at least a portion of the first fraction with a first metathesis catalyst in a first metathesis reaction zone;
recovering an effluent from the first metathesis reaction zone comprising at least one of ethylene, propylene, unreacted isobutene, C5 olefins, and C6 olefins;
contacting at least a portion of the second fraction and at least a portion of the ethylene in the effluent with a second metathesis catalyst in a second metathesis reaction zone;
recovering an effluent from the second reaction zone comprising at least one of unreacted ethylene, propylene, unreacted 2-butene,
fractionating the effluent from the first metathesis reaction zone and the effluent from the second metathesis reaction zone to recover an ethylene fraction, a propylene fraction, one or more C4 fractions, and a fraction comprising at least one of C5 and C6 olefins.

8. The process of claim 7 , wherein the first fraction further comprises isobutane, the process further comprising:
fractionating the first fraction to recover an isobutane fraction and a fraction comprising isobutene and 1-butene; and
feeding the fraction comprising isobutene and 1-butene to the first metathesis reaction zone as the at least a portion of the first fraction.

9. A process for the production of propylene, comprising:
fractionating a mixed C4 hydrocarbon stream to recover a first fraction comprising isobutene and a second fraction comprising 2-butene;
feeding a portion of the second fraction to an isomerization reaction zone to convert 2-butene to 1-butene, recovering an effluent from the isomerization reaction zone, and feeding the effluent from the isomerization reaction zone to the fractionating a mixed C4 stream;
contacting at least a portion of the first fraction with a first metathesis catalyst in a first metathesis reaction zone;
recovering an effluent from the first metathesis reaction zone comprising at least one of ethylene, propylene, unreacted isobutene, C5 olefins, and C6 olefins;
contacting at least a portion of the second fraction and at least a portion of the ethylene in the effluent with a second metathesis catalyst in a second metathesis reaction zone;
recovering an effluent from the second reaction zone comprising at least one of unreacted ethylene, propylene, unreacted 2-butene,
fractionating the effluent from the first metathesis reaction zone and the effluent from the second metathesis reaction zone to recover an ethylene fraction, a propylene fraction, one or more C4 fractions, and a fraction comprising at least one of C5 and C6 olefins.

10. The process of claim 9 , further comprising feeding the ethylene fraction to the second metathesis reaction zone as the at least a portion of the ethylene in the effluent from the first metathesis reaction zone.

11

Assignees

• Lummus Technology Inc

Inventors

• Stanley Stephen J
• Gartside Robert J
• Chellppannair Thulusidas

Classifications

• C07C2523/24

  Chromium, molybdenum or tungsten · CPC title

• C07C2523/32

  Manganese, technetium or rhenium · CPC title

• C07C11/04

  Ethene · CPC title

• C07C11/06

  Propene · CPC title

• C07C6/04 Primary

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