Process for purification propylene oxide

• US 20050082159A1
• Filed: 02/07/2003
• Published: 04/21/2005
• Est. Priority Date: 02/15/2002
• Status: Abandoned Application

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Sumitomo Chemical Company Limited
• Inventors: Nakayama, Toshio, Shinohara, Koji, Oku, Noriaki
• Application Number:
  US10/504,425
• Publication Number:
  US 20050082159A1
• Time in Patent Office: Days
• US Class Current: 203/68
• CPC Class Codes: C07D 301/32 Separation; Purification

Abstract

A process for purifying propylene oxide, which comprises using a liquid reaction mixture containing propylene oxide, and water, hydrocarbons and oxygen-containing organic compounds as impurities obtained by reacting cumene hydroperoxide with propylene, as a liquid raw material, and separating and recovering propylene oxide from the liquid raw material, wherein the process comprises the following steps: first step; a step of subjecting the liquid raw material to extractive distillation using a hydrocarbon of 7 to 10 carbons as an extractant to separate into the overhead stream containing most of water and the oxygen-containing impurities and the bottom stream containing propylene oxide, the hydrocarbons and the extractant, second step; a step of subjecting the bottom stream to extractive distillation using a hydrocarbon of 7 to 10 carbons as an extractant to separate into the overhead containing propylene oxide and the bottom stream containing hydrocarbons and the extractant, and third step; subjecting the extractant used in the first step and/or second step to distillation to purify the extractant, wherein the bottom temperature of the distillation column or extractive distillation column in each of the steps is 130° C. or lower.

Claims

1. A process for purifying propylene oxide, which comprises:

using a liquid reaction mixture containing propylene oxide, and water, hydrocarbons and oxygen-containing organic compounds as impurities obtained by reacting cumene hydroperoxide with propylene, as a liquid raw material, and

separating and recovering propylene oxide from the liquid raw material, wherein the process comprises the following steps;

first step;

a step of subjecting the liquid raw material to extractive distillation using a hydrocarbon of 7 to 10 carbons as an extractant to separate into the overhead stream containing most of water and the oxygen-containing impurities and the bottom stream containing propylene oxide, the hydrocarbons and the extractant,

second step;

a step of subjecting the bottom stream to extractive distillation using a hydrocarbon of 7 to 10 carbons as an extractant to separate into the overhead containing propylene oxide and the bottom stream containing hydrocarbons and the extractant, and

third step;

subjecting the extractant used in the first step and/or second step to distillation to purify the extractant,

wherein the bottom temperature of the distillation column or extractive distillation column in each of the steps is 130°

C. or lower.

2. The process according to claim 1, wherein the bottom temperature is 120°

C. or lower.