Process for purifying propylene oxide

Patent metadata

Field	Value
Publication number	US-10676451-B2
Application number	US-201716315345-A
Country	US
Kind code	B2
Filing date	Jul 19, 2017
Priority date	Jul 20, 2016
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

Disclosed is a process for purifying propylene oxide. A stream S0 containing propylene oxide, acetonitrile, water, and an organic compound containing one or more of acetone and propionaldehyde is provided. Propylene oxide is separated from S0 by subjecting S0 to distillation in a first distillation unit, obtaining a gaseous top stream S1c enriched in propylene oxide, a liquid bottom stream S1a enriched in acetonitrile and water, and a side stream S1b containing propylene oxide and enriched in the carbonyl compound; reacting the carbonyl compound in S1b with an organic compound containing an amino group to obtain a reaction product; separating propylene oxide from the reaction product in a second distillation unit, obtaining a gaseous top stream S3a enriched in propylene oxide and a liquid bottoms stream S3b enriched in the reaction product; and introducing stream S3a into the first distillation unit.

First claim

The invention claimed is:

1. A process for purifying propylene oxide, the process comprising
(i) providing a stream S 0 comprising propylene oxide, acetonitrile, water, and an organic compound comprising a carbonyl group —C(═O)—, wherein said organic compound comprising a carbonyl group —C(═O)— comprises one or more of acetone and propionaldehyde; and
(ii) separating propylene oxide from the stream S 0 by distillation by
(ii.1) subjecting the stream S 0 to distillation conditions in a first distillation unit, obtaining a gaseous top stream S 1 c which is enriched in propylene oxide compared to the stream S 0 , a liquid bottoms stream S 1 a which is enriched in acetonitrile and water compared to the stream S 0 , and a side stream S 1 b comprising propylene oxide which is enriched in the carbonyl compound compared to the stream S 0 ;
(ii.2) reacting the carbonyl compound comprised in the side stream S 1 b with an organic compound comprising an amino group —NH 2 obtaining a reaction product of the organic compound comprising a carbonyl group and the organic compound comprising an amino group;
(ii.3) separating propylene oxide from the reaction product of the organic compound comprising a carbonyl group and the organic compound comprising an amino group in a second distillation unit, obtaining a gaseous top stream S 3 a which is enriched in propylene oxide and a liquid bottoms stream S 3 b which is enriched in the reaction product of the organic compound comprising a carbonyl group and the organic compound comprising an amino group; and
(ii.4) introducing the top stream S 3 a which is enriched in propylene oxide propylene oxide into the first distillation unit.

2. A process for purifying propylene oxide, the process comprising
(i) providing a stream S 0 comprising propylene oxide, acetonitrile, water, and an organic compound comprising a carbonyl group —C(═O)—, wherein said organic compound comprising a carbonyl group —C(═O)— comprises one or more of acetone and propionaldehyde; and
(ii) separating propylene oxide from the stream S 0 by distillation by
(ii.1) subjecting the stream S 0 to distillation conditions in a first distillation unit, obtaining a gaseous top stream S 1 c which is enriched in propylene oxide compared to the stream S 0 , a liquid bottoms stream S 1 a which is enriched in acetonitrile and water compared to the stream S 0 , and a side stream S 1 b comprising propylene oxide which is enriched in the carbonyl compound compared to the stream S 0 ;
(ii.2) admixing the side stream S 1 b with an organic compound comprising an amino group —NH 2 and reacting the organic compound comprising a carbonyl group with the organic compound comprising an amino group, obtaining a stream S 2 comprising propylene oxide and a reaction product of the organic compound comprising a carbonyl group and the organic compound comprising an amino group;
(ii.3) subjecting the stream S 2 to distillation conditions in a second distillation unit, obtaining a gaseous top stream S 3 a which is enriched in propylene oxide compared to the stream S 2 , and a liquid bottoms stream S 3 b which is enriched in the reaction product of the organic compound comprising a carbonyl group and the organic compound comprising an amino group compared to the stream S 2 ; and
(ii.4) introducing the stream S 3 a into the first distillation unit.

3. A process for purifying propylene oxide, the process comprising
(i) providing a stream S 0 comprising propylene oxide, acetonitrile, water, and an organic compound comprising a carbonyl group —C(═O)—, wherein said organic compound comprising a carbonyl group —C(═O)— comprises one or more of acetone and propionaldehyde; and
(ii) separating propylene oxide from the stream S 0 by distillation by
(ii.1) subjecting the stream S 0 to distillation conditions in a first distillation unit, obtaining a gaseous top stream S 1 c which is enriched in propylene oxide compared to the stream S 0 , a liquid bottoms stream S 1 a which is enriched in acetonitrile and water compared to the stream S 0 , and a side stream S 1 b comprising propylene oxide which is enriched in the carbonyl compound compared to the stream S 0 ;
(ii.2) subjecting the side stream S 1 b to distillation conditions in a second distillation unit and adding an organic compound comprising an amino group —NH 2 to the second distillation unit, and reacting the organic compound comprising a carbonyl group with the organic compound comprising an amino group, obtaining a reaction product of the organic compound comprising a carbonyl group and the organic compound comprising an amino group, and obtaining a gaseous top stream S 3 a which is enriched in propylene oxide compared to the stream S 1 b , and a liquid bottoms stream S 3 b which is enriched in the reaction product of the organic compound comprising a carbonyl group and the organic compound comprising an amino group compared to the stream S 1 b ; and
(ii.3) introducing the stream S 3 a into the first distillation unit.

4. The process of claim 1 , wherein the organic compound comprising a carbonyl group —C(═O)— comprised in the stream S 0 further comprises one or more of acetaldehyde, formaldehyde, butyraldehyde, isobutyraldehyde, 2-butanon, 1-pentanal, 2-pentanon, 3-pentanon, and 2-methylpentanone.

5. The process of claim 1 , wherein at least 95 weight % of the stream S 0 consist of propylene oxide, acetonitrile, water, and the organic compound comprising a carbonyl group.

6. The process of claim 1 , wherein the stream S 0 is obtained by a process comprising
(a) providing a liquid feed stream comprising propene, hydrogen peroxide, water, and acetonitrile;
(b) passing the liquid feed stream provided in (a) into an epoxidation zone comprising an epoxidation catalyst comprising a titanium zeolite, and subjecting the liquid feed stream to epoxidation reaction conditions in the epoxidation zone, obtaining a reaction mixture comprising propene, propylene oxide, water, acetonitrile, and the organic compound comprising a carbonyl group;
(c) removing an effluent stream from the epoxidation zone, the effluent stream comprising propylene oxide, water, acetonitrile, propene, and the organic compound comprising a carbonyl group;
(d) separating propene from the effluent stream by distillation by subjecting the effluent stream to distillation conditions in a distillation unit, obtaining a gaseous stream which is enriched in propene compared to the effluent stream subjected to distillation conditions, and a liquid bottoms stream which is enriched in propylene oxide, water, acetonitrile and the organic compound comprising a carbonyl group compared to the effluent stream subjected to distillation conditions;
wherein said liquid bottoms stream obtained in (d) is the stream S 0 .

7. The process of claim 1 , wherein said providing (i) comprises
(a) providing a liquid feed stream comprising propene, hydrogen peroxide, water, and acetonitrile;
(b) passing the liquid feed stream provided in (a) into an epoxidation zone comprising an epoxidation catalyst comprising a titanium zeolite, and subjecting the liquid feed stream to epoxidation reaction conditions in the epoxidation zone, obtaining a reaction mixture comprising propene, propylene oxide, water, acetonitrile, and the organic compound comprising a carbonyl group;
(c) removing an effluent stream from the epoxidation zone, the effluent stream comprising propylene oxide, water, acetonitrile, propene, and the organic compound comprising a carbonyl group;
(d) separating propene from the effluent stream by distillation by subjecting the effluent stream to distillation conditions in a distillation unit, obtaining a gaseous stream which is enri

Assignees

• Basf Se
• Dow Global Technologies Llc

Inventors

• Teles Joaquim Henrique
• Kramp Marvin
• Mueller Christian
• Woerz Nicolai Tonio
• Metzen Bernd
• Keller Tobias
• Riedel Dominic
• Schelling Heiner
• Weber Markus
• Urbanczyk Daniel
• Parvulescu Andrei-Nicolae
• Wegerle Ulrike
• Mueller Ulrich
• Weidenbach Meinolf
• Witzl Werner J

Classifications

• C07D301/32 Primary

  Separation; Purification · CPC title

• C07D303/04

  containing only hydrogen and carbon atoms in addition to the ring oxygen atoms · CPC title

• B01D3/143

  by two or more of a fractionation, separation or rectification step · CPC title

• Y02P20/582

  Recycling of unreacted starting or intermediate materials · CPC title