	US 11,866,387 B2
	Process for producing methacrylic acid or methacrylic acid esters
Alexander May, Seeheim-Jugenheim (DE); Steffen Krill, Muehltal (DE); Marcel Treskow, Mobile, AL (US); Diego Carambia, Jose C. Paz (AR); and Gabriel Avella, San Isidro (AR)
Assigned to Röhm GmbH, Darmstadt (DE)
Appl. No. 17/266,735
Filed by Röhm GmbH, Darmstadt (DE)
PCT Filed Jul. 11, 2019, PCT No. PCT/EP2019/068644 § 371(c)(1), (2) Date Feb. 8, 2021, PCT Pub. No. WO2020/030374, PCT Pub. Date Feb. 13, 2020.
Claims priority of application No. 18188458 (EP), filed on Aug. 10, 2018.
Prior Publication US 2021/0317064 A1, Oct. 14, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. C07C 67/39 (2006.01); B01J 23/38 (2006.01); B01J 35/02 (2006.01); C07C 45/75 (2006.01); C07C 45/83 (2006.01); C07C 51/25 (2006.01); B82Y 30/00 (2011.01); B82Y 40/00 (2011.01)

CPC C07C 67/39 (2013.01) [B01J 23/38 (2013.01); B01J 35/023 (2013.01); C07C 45/75 (2013.01); C07C 45/83 (2013.01); C07C 51/252 (2013.01); B82Y 30/00 (2013.01); B82Y 40/00 (2013.01)]

14 Claims

1. A process for producing methacrylic acid or a methacrylic acid ester, comprising:

a) producing acrolein from a raw material comprising glycerol, wherein the raw material is evaporated and thereafter converted in the presence of a heterogeneous catalyst and a co-feed gas comprising at least one of the components selected from the group consisting of hydrogen, oxygen, and water,

b) reacting the acrolein of process step a) with hydrogen to produce propanal,

c) reacting the propanal of process step b) with formaldehyde to produce methacrolein, and

d) oxidizing the methacrolein in the presence of an oxygen containing gas to the methacrylic acid or in the presence of an alcohol to the methacrylic acid ester,

wherein process step d) is carried out in a liquid phase at a pressure of from 1 to 100 bar, and in the presence of a heterogeneous noble-metal-comprising catalyst comprising a metal and/or a metal oxide, and

wherein the propanal produced in process step b) before being condensed in the presence of formaldehyde in process step c), is purified from hydroxyl acetone.