Method for production of methyl methacrylate by oxidative esterification using a heterogeneous catalyst

Patent metadata

Field	Value
Publication number	US-10865179-B2
Application number	US-201816648286-A
Country	US
Kind code	B2
Filing date	Sep 12, 2018
Priority date	Sep 19, 2017
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

A method for preparing methyl methacrylate from methacrolein and methanol. The method comprises contacting a mixture comprising methacrolein, methanol and oxygen with a heterogeneous catalyst comprising a support and a noble metal, wherein oxygen concentration at a reactor outlet is from 1 to 7.5 mol % and wherein pH at a reactor outlet is no greater than 7.5.

First claim

The invention claimed is:

1. A method for preparing methyl methacrylate from methacrolein and methanol; said method comprising contacting in a reactor a mixture comprising methacrolein, methanol and oxygen with a heterogeneous catalyst comprising a support and a noble metal, wherein the noble metal comprises gold, wherein the catalyst has an average diameter of at least 300 microns, wherein oxygen concentration at a reactor outlet is from 1 to 7.5 mol % and wherein pH at a reactor outlet is no greater than 7.5.

2. The method of claim 1 in which the reactor is an axial flow reactor having a liquid-phase superficial velocity of 0.5 to 20 mm/s and an average partial pressure of oxygen greater than 50 kPa.

3. The method of claim 2 in which the catalyst has an average diameter from 400 microns to 10 mm.

4. The method of claim 3 in which the catalyst is contained in a catalyst bed which is at a temperature from 40 to 120° C.

5. The method of claim 4 in which pH in the reactor is from 3 to 7.2.

6. The method of claim 5 in which oxygen concentration at a reactor outlet is from 1.6 to 6 mol %.

7. The method of claim 1 in which the support is selected from the group consisting of γ-, δ-, or θ-alumina, silica, magnesia, titania, zirconia, hafnia, vanadia, niobium oxide, tantalum oxide, ceria, yttria, lanthanum oxide and combinations thereof.

8. The method of claim 7 in which methanol and methacrolein are fed to a reactor containing the catalyst bed in a molar ratio from 1:1 to 10:1, respectively.

9. The method of claim 8 in which at least 90 wt % of the noble metal is in the outer 70% of catalyst volume.

Assignees

• Dow Global Technologies Llc
• Rohm & Haas

Inventors

• Herron Jeffrey
• Arriola Daniel J
• Blaylock D Wayne
• Lee Wen-Sheng
• Sussman Victor
• Hickman Daniel A
• Limbach Kirk W

Classifications

• B01J23/66

  Silver or gold · CPC title

• B01J35/397

  Egg shell like · CPC title

• B01J23/63

  with rare earths or actinides · CPC title

• B01J35/40

  characterised by dimensions, e.g. grain size (in a colloidal state B01J35/23; crystallite size B01J35/77) · CPC title

• C07C67/40 Primary

  by oxidation of primary alcohols · CPC title