Iodine-based catalyst for reductive dehydroxylation of vicinal polyols to olefins

Patent metadata

Field	Value
Publication number	US-9505672-B2
Application number	US-201214364693-A
Country	US
Kind code	B2
Filing date	Dec 5, 2012
Priority date	Dec 15, 2011
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

Olefins are produced by the reductive dehydroxylation of vicinal polyols or esters thereof, or a combination thereof, in a liquid reaction medium, under a hydrogen atmosphere, at a temperature from 50° C. to 250° C., in the presence of a halogen-based, preferably iodine-based, catalyst. Examples of the catalyst, which may be included independently or generated in situ, are iodine (I 2 ), hydroiodic acid (HI), iodic acid (HIO 3 ), lithium iodide (LiI), and combinations thereof.

First claim

The invention claimed is:

1. A process for preparing an olefin comprising:
subjecting a material to a reductive dehydroxylation in presence of an iodine-based catalyst, a liquid reaction medium, and 0.1 wt % to 100 wt % gaseous hydrogen to form an olefin;
performing the reductive dehydroxylation under conditions comprising a hydrogen pressure ranging from 1 psig to 2000 psig, a temperature ranging from 50° C. to 250° C., and a ratio of moles of the material to moles of iodine atoms in the iodine-based catalyst ranging from 4:1 to 27:1;
wherein the material is selected from the group consisting of a vicinal polyol, an ester of a vicinal polyol, and combinations thereof; and
wherein the iodine-based catalyst is selected from the group consisting of iodine (I 2 ), hydroiodic acid (HI), lithium iodide (LiI), and combinations thereof.

2. The process of claim 1 , wherein the hydrogen pressure is from 50 psig to 500 psig.

3. The process of claim 1 , wherein the temperature ranges from 100° C. to 210° C.

4. The process of claim 1 , wherein the ratio of moles of the material to moles of the iodine atoms ranges from 4:1 to 8:1.

5. The process of claim 1 , wherein the gaseous hydrogen is part of a mixture that further includes at least one additional gas selected from carbon monoxide, carbon dioxide, nitrogen, methane, and combinations thereof.

6. The process of claim 1 , wherein the reductive dehydroxylation is conducted as a two-step process comprising a first step and a second step,
wherein the first step comprises a partial dehydroxylation under conditions including a first hydrogen pressure ranging from 1 psig to 50 psig and a first temperature ranging from 50° C. to 120° C., and;
wherein the second step comprises continuing the dehydroxylation from the first step to completion under conditions including a second hydrogen pressure ranging from 1 psig to 50 psig and a second temperature ranging from 180° C. to 210° C.

Assignees

• Dow Global Technologies Llc

Inventors

• Deshpande Raj
• Davis Paul
• Pandey Vandana
• Kore Nitin
• Briggs John R

Classifications

• C07C1/24 Primary

  by elimination of water · CPC title

• C07C11/04

  Ethene · CPC title

• C07C2527/06

  Halogens; Compounds thereof · CPC title

• B01J27/08

  Halides · CPC title

• C07C11/06

  Propene · CPC title