Production of isoprene from iso-butanol

Patent metadata

Field	Value
Publication number	US-9233891-B2
Application number	US-201514789244-A
Country	US
Kind code	B2
Filing date	Jul 1, 2015
Priority date	Sep 24, 2010
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

A process to make isoprene may include providing a reaction zone containing an acidic aqueous solution. The process may include introducing, continuously or intermittently, in the reaction zone a mixture containing isobutanol and an aqueous solution of formaldehyde. The process may include operating the reaction zone at conditions effective to dehydrate isobutanol to iso-butene, and produce isoprene by reaction of formaldehyde and iso-butene, while distilling away a mixture containing produced isoprene and water.

First claim

The invention claimed is:

1. A process comprising:
a) providing a reaction zone comprising an acidic aqueous solution;
b) introducing, continuously or intermittently, in said reaction zone a mixture comprising (i) isobutanol and an aqueous solution of formaldehyde;
c) operating said reaction zone at conditions effective to dehydrate isobutanol to iso-butene and produce isoprene by reaction of formaldehyde and iso-butene while distilling away a mixture comprising produced isoprene and water from the reaction zone to the outside of the reaction zone.

2. The process according to claim 1 , wherein isobutanol provides 10% or more of the iso-butene for the isoprene synthesis.

3. The process according to claim 1 , wherein isobutanol provides 50% to 100% of the iso-butene for the isoprene synthesis.

4. The process according to claim 1 , wherein isobutanol provides 100% of the iso-butene for the isoprene synthesis.

5. The process according to claim 1 , wherein the mixture further comprises an iso-butene precursor that is an ether, and wherein the reaction zone is operated at conditions effective to decompose the iso-butene precursor to iso-butene, dehydrate the isobutanol to iso-butene, and produce isoprene by reaction of formaldehyde and iso-butene while distilling away the mixture comprising produced isoprene and water from the reaction zone to the outside of the reaction zone.

6. The process according to claim 5 , wherein the ether is ethyl-t-butyl ether, di-isobutyl-ether, di-t-butyl-ether, or ethyl-t-butyl ether.

7. The process according to claim 1 , wherein the mixture further comprises iso-butene, and wherein the reaction zone is operated at conditions effective to dehydrate the isobutanol to iso-butene and produce isoprene by reaction of formaldehyde and iso-butene while distilling away the mixture comprising produced isoprene, water, unreacted starting materials and other low boiling point components from this reaction zone to the outside of the reaction zone.

8. The process according to claim 1 , wherein the reaction zone pressure is from 7 to 18 bars gauge.

9. The process according to claim 1 , wherein the reaction zone temperature is from 140 to 240° C.

10. The process according to claim 1 , wherein a molar ratio of t-butyl-moiety sent as fresh feed to the reaction zone to formaldehyde sent as fresh feed to the reaction zone is from 0.5 to 2.

11. The process according to claim 1 , wherein a molar ratio of t-butyl-moiety to formaldehyde in the reaction zone is from 1 to 18.

12. The process according to claim 1 , wherein the mixture further comprises an iso-butene precursor that is an ether, wherein the mixture further comprises iso-butene, and wherein the reaction zone is operated at conditions effective to decompose the iso-butene precursor to iso-butene, dehydrate the isobutanol to iso-butene, and produce isoprene by reaction of formaldehyde and iso-butene while distilling away the mixture comprising produced isoprene and water from the reaction zone to the outside of the reaction zone.

13. The process according to claim 12 , wherein the ether is ethyl-t-butyl ether, di-isobutyl-ether, di-t-butyl-ether, or ethyl-t-butyl ether.

14. A process comprising:
a) providing a reaction zone comprising an acidic aqueous solution;
b) introducing, continuously or intermittently, in said reaction zone a mixture comprising (i) isobutanol and an aqueous solution of formaldehyde;
c) operating said reaction zone at conditions effective to dehydrate isobutanol to iso-butene and produce isoprene by reaction of formaldehyde and iso-butene while distilling away a mixture comprising produced isoprene and water from the reaction zone to the outside of the reaction zone, wherein under the reaction conditions in the reaction zone the iso-butanol acts as solvent to improve solubility of iso-butene and enhance the presence of t-butyl-carbocations in the aqueous phase.

Assignees

• Total Res & Technology Feluy

Inventors

• Vermeiren Walter
• Gonzalez Jose C

Classifications

• C07C1/24

  by elimination of water · CPC title

• C07C2/867 Primary

  the non-hydrocarbon is an aldehyde or a ketone · CPC title

• C07D301/02

  Synthesis of the oxirane ring · CPC title

• C07C1/22

  by reduction · CPC title