Dehydration process

Patent metadata

Field	Value
Publication number	US-2016229779-A1
Application number	US-201414917114-A
Country	US
Kind code	A1
Filing date	Sep 18, 2014
Priority date	Oct 28, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

A process for preparing dry methacrolein, and a process for producing methyl methacrylate are disclosed.

First claim

1 . A process comprising p 1 (a) providing a first stream comprising water, methacrolein and, optionally, methanol to a phase separator, with the proviso that the first stream comprises at least 8 weight percent water;
(b) allowing the first stream to phase separate into an organic phase that comprises primarily methacrolein and an aqueous phase that comprises primarily water;
(c) distilling the organic phase in a dehydration column to produce a product stream comprising primarily methacrolein.

2 . The process of claim 1 wherein the first stream is primarily a liquid stream and comprises at least 10 weight percent water.

3 . The process of claim 1 wherein the product stream comprises less than 2 weight percent water based on the weight of the product stream.

4 . The process of claim 1 wherein the product stream comprises less than 1 weight percent water based on the weight of the product stream.

5 . The process of claim 1 wherein the product stream comprises less than 0.5 weight percent water based on the weight of the product stream.

6 . The process of claim 1 wherein the product stream is recovered as a side draw stream or as a bottoms stream of the dehydration column.

7 . The process of claim 1 wherein an overhead stream is taken from the dehydration column, and wherein the process further comprises (d) sending at least part of the dehydration column overhead stream to a phase separator.

8 . The process any of claim 1 wherein the product stream is recovered as a bottoms stream of the dehydration column.

9 . The process of any of claim 1 wherein the dehydration column is operated as a stripper.

10 . The process of any of claim 1 further comprising providing the product stream to a process comprising contacting methacrolein with methanol and an oxygen-containing gas in the presence of a catalyst under reaction conditions sufficient to produce MMA.

11 . The process of any of claim 1 wherein the first stream is prepared by converting propionaldehyde to methacrolein.

12 . The process of claim 11 wherein the propionaldehyde is produced, at least in part, by contacting ethylene with CO and H 2 in the presence of a hydroformylation catalyst under reaction conditions sufficient to produce the propionaldehyde.

13 . The process of claim 7 further comprising:
(e) distilling in a 2 nd distillation column the aqueous phase from the phase separator to produce (1) a 2 nd distillation column bottoms stream comprising primarily water and (2) a 2 nd distillation column overhead stream;
(f) sending at least part of the 2 nd distillation column overhead stream to a phase separator.

14 . A process for the preparation of MMA, the process comprising:
(1) contacting ethylene with CO and H 2 in the presence of a hydroformylation catalyst under reaction conditions sufficient to produce propionaldehyde; (2) contacting at least a portion of the propionaldehyde with formaldehyde in the presence of a catalyst to produce methacrolein, the methacrolein being in a first stream comprising water, the methacrolein and, optionally, methanol, with the proviso that the first stream comprises at least 10 weight percent water; (3) providing at least a portion of the first stream to a phase separator; (4) allowing at least a portion of the first stream to phase separate in the phase separator into an organic phase that comprises primarily methacrolein and an aqueous phase that comprises primarily water; (5) distilling at least a portion of the organic phase in a dehydration column to produce a product stream comprising primarily methacrolein, the product stream comprising less than 2 wt % water; and (6) providing at least a portion of the product stream to a process comprising contacting the methacrolein with methanol and an oxygen-containing gas in the presence of an oxidative esterification catalyst under reaction conditions sufficient to produce MMA.

15 . The process of claim 14 wherein the product stream comprises less than 0.5 weight percent water based on the weight of the product stream.

16 . The process of claim 1 wherein the organic phase is fed to the top half of the dehydration column, preferably to the top of the dehydration column.

Assignees

• Rohm & Haas

Inventors

• Hoy Iv Stacy W
• Kraptchetov Dmitri A
• Silvano Mark A

Classifications

• C07C47/22

  Acryaldehyde; Methacryaldehyde · CPC title

• C07C45/82

  by distillation · CPC title

• C07C45/80 Primary

  by liquid-liquid treatment · CPC title

• C07C45/505

  Asymmetric hydroformylation · CPC title

• C07C45/61

  by reactions not involving the formation of >C = O groups · CPC title