Propylene oxide purification

• US 6,500,311 B1
• Filed: 09/21/2001
• Issued: 12/31/2002
• Est. Priority Date: 09/21/2001
• Status: Expired due to Fees

• Current Assignee: Lyondell Chemical Technology LP (Lyondellbasell Industries NV)
• Original Assignee: ARCO Chemical Technology, L.P. (Lyondellbasell Industries NV)
• Inventors: Sawyer, Gary A.
• Primary Examiner(s): Manoharan, Virginia
• Application Number:
  US09/957,591
• Time in Patent Office: 466 Days
• Field of Search: 203/43, 203/68, 203/70, 203/95, 203/44, 203/18, 203/DIG.23, 203/76, 203/79, 203/74, 203/14, 549/541, 549/538, 568/913
• US Class Current: 203/44
• CPC Class Codes: C07D 301/32 Separation; Purification

Abstract

A mixture of propylene oxide and methanol is separated by liquid/liquid extraction using water and a hydrocarbon such as n-octane as extractive solvents.

Claims

1. A process for the separation of a mixture of propylene oxide and methanol comprising fractionally distilling a mixture comprised of propylene oxide and methanol, recovering a distillate mixture comprised of propylene oxide and methanol which is concentrated in propylene oxide, contacting the mixture which is concentrated in propylene oxide with water and C₇-C₉ hydrocarbon extractive solvents in a liquid/liquid solvent extraction and separately recovering a stream comprised of the aqueous extractive solvent and methanol and a stream comprised of the extractive hydrocarbon solvent and propylene oxide.

2. The process of claim 1 wherein the hydrocarbon extractive solvent is octane.

3. The process of claim 1 wherein extracted propylene oxide and hydrocarbon solvent is subjected to an extractive distillation.