Butadiene extraction process

Patent metadata

Field	Value
Publication number	US-9409837-B2
Application number	US-201314034822-A
Country	US
Kind code	B2
Filing date	Sep 24, 2013
Priority date	Oct 4, 2012
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

A process for recovering butadiene from a C 4 fraction is disclosed. The process may include: contacting a mixed C 4 stream comprising butane, butene, and butadiene, with a solvent comprising an organic solvent and water in a butadiene pre-absorber column to recover an overheads fraction comprising at least a portion of the butane, butene, and water, and a first bottoms fraction comprising the organic solvent, butadiene, and at least a portion of the butene; and feeding the first bottoms fraction to a butadiene extraction unit to recover a butene fraction, a crude butadiene fraction, and a solvent fraction.

First claim

What is claimed:

1. A process for recovering 1,3-butadiene from a C 4 fraction, comprising:
feeding a hydrocarbon fraction containing butanes, butenes, 1,2-butadiene, 1,3-butadiene, C 4 acetylenes, C 3 acetylenes, and C 5+ hydrocarbons to a butadiene extraction unit;
recovering from the butadiene extraction unit a 1,3-butadiene fraction, a C 3 acetylene fraction, a C 4 acetylene fraction, one or more fractions comprising the butanes and butenes, and a fraction comprising the 1,2-butadiene and the C 5+ hydrocarbons;
selectively hydrogenating at least one of the C 3 acetylene fraction and the C 4 acetylene fraction to produce a hydrogenated effluent comprising olefins, dienes, and oligomer byproducts;
feeding the hydrogenated effluent and the fraction comprising the 1,2-butadiene and the C 5+ hydrocarbons to a separator to recover a heavies fraction comprising the C 5+ hydrocarbons and the oligomer byproducts and a lights fraction comprising the olefins, dienes, and 1,2-butadiene; and
feeding the lights fraction to the butadiene extraction unit.

2. The process of claim 1 , wherein the C 4 acetylene fraction comprises C 4 acetylenes and 1,2-butadiene.

3. The process of claim 2 , wherein an amount of 1,2-butadiene in the C 4 acetylene fraction is approximately equal to an amount of the 1,2-butadiene in the feed hydrocarbon fraction.

4. The process of claim 2 , wherein the C 4 acetylene fraction is fed to the selectively hydrogenating step, and wherein an amount of 1,2-butadiene consumed via the selectively hydrogenating is approximately equal to an amount of the 1,2-butadiene in the feed hydrocarbon fraction.

5. The process of claim 1 , wherein vinylcyclohexene is produced in the butadiene extraction unit or is present in the feed hydrocarbon fraction, the process further comprising:
recovering a fraction comprising the vinylcyclohexene from the butadiene extraction unit; and
feeding the vinylcyclohexene fraction to the separator, wherein the vinylcyclohexene is recovered from the separator in the heavies fraction.

6. The process of claim 1 , further comprising:
feeding at least a portion of the hydrocarbon fraction to the separator as a reflux;
vaporizing at least a portion of the hydrocarbon fraction fed to the separator;
recovering the vaporized portion with the lights fraction for feed to the butadiene extraction unit.

7. The process of claim 6 , wherein the reflux comprises only the hydrocarbon fraction or a portion thereof and wherein the lights fraction is recovered as a vapor phase fed to the butadiene extraction unit.

8. The process of claim 1 , further comprising:
vaporizing a portion of the feed hydrocarbon fraction in a vaporization system;
recovering a vapor fraction from the vaporization system;
recovering a liquid fraction from the vaporization system;
feeding the recovered liquid fraction to the separator as a reflux.

9. The process of claim 8 , further comprising:
vaporizing at least a portion of the liquid fraction fed to the separator; and
recovering the vaporized portion with the lights fraction for feed to the butadiene extraction unit.

10. The process of claim 1 , wherein the fraction comprising 1,2-butadiene and C 5+ hydrocarbons further comprises at least one of N-methylpyrrolidone (NMP) and tertiary butyl catechol (TBC).

11. The process of claim 1 , wherein the butadiene extraction unit comprises one or more of the following:
a pre-absorber;
a pre-fractionation column;
a feed scrubber/stripper system
a main wash column;
a rectifier;
an afterwash column;
an acetylene fractionator;
a butadiene fractionator;
an acetylene washer;
a solvent purification system; and
a degasser and cooling column.

12. A process for recovering 1,3-butadiene from a C 4 fraction, comprising:
feeding a hydrocarbon fraction containing butanes, butenes, 1,2-butadiene, 1,3-butadiene, C 4 acetylenes, C 3 acetylenes, and C 5+ hydrocarbons to a vaporization system;
recovering a vapor fraction from the vaporization system;
recovering a liquid fraction from the vaporization system;
feeding the recovered vapor fraction to a butadiene extraction unit;
recovering from the butadiene extraction unit a 1,3-butadiene fraction, a C 3 acetylene fraction, a C 4 acetylene fraction, one or more fractions comprising the butanes and butenes, and a fraction comprising the 1,2-butadiene and the C 5+ hydrocarbons;
selectively hydrogenating at least one of the C 3 acetylene fraction and the C 4 acetylene fraction to produce a hydrogenated effluent comprising olefins, dienes, and oligomer byproducts;
feeding the hydrogenated effluent and the fraction comprising the 1,2-butadiene and the C 5+ hydrocarbons to a separator to recover a heavies fraction comprising the C 5+ hydrocarbons and the oligomer byproducts and a lights fraction comprising the olefins, dienes, and 1,2-butadiene;
feeding the recovered liquid fraction to the separator as a reflux; and
feeding the lights fraction to the butadiene extraction unit.

13. The process of claim 12 , wherein the C 4 acetylene fraction comprises C 4 acetylenes and 1,2-butadiene.

14. The process of claim 13 , wherein an amount of 1,2-butadiene in the C 4 acetylene fraction is approximately equal to an amount of the 1,2-butadiene in the feed hydrocarbon fraction.

15. The process of claim 13 , wherein an amount of 1,2-butadiene consumed via the selectively hydrogenating is approximately equal to an amount of the 1,2-butadiene in the feed hydrocarbon fraction.

16. The process of claim 12 , wherein vinylcyclohene is produced in the butadiene extraction unit or is present in the feed hydrocarbon fraction, the process further comprising:
recovering a fraction comprising the vinylcyclohexene from the butadiene extraction unit; and
feeding the vinylcyclohexene fraction to the separator, wherein the vinylcyclohexene is recovered from the separator in the heavies fraction.

Assignees

• Lummus Technology Inc

Inventors

• Brummer Robert John
• Schwint Kevin John
• Dwyer Thomas Alexander

Classifications

• B01D11/0492

  Applications, solvents used · CPC title

• C07C5/09 Primary

  to carbon-to-carbon double bonds · CPC title

• C07C7/005 Primary

  Processes comprising at least two steps in series · CPC title

• C07C7/167

  for removal of compounds containing a triple carbon-to-carbon bond · CPC title

• C07C7/10

  by extraction, i.e. purification or separation of liquid hydrocarbons with the aid of liquids · CPC title