The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 13, 2018
Filed:
Nov. 16, 2015
Steffen Krill, Muehltal, DE;
Rudolf Burghardt, Darmstadt, DE;
Melanie Raczek, Darmstadt, DE;
Torsten Balduf, Pfungstadt, DE;
Steffen Krill, Muehltal, DE;
Rudolf Burghardt, Darmstadt, DE;
Melanie Raczek, Darmstadt, DE;
Torsten Balduf, Pfungstadt, DE;
Evonik Röhm GmbH, Darmstadt, DE;
Abstract
The present invention relates to an optimized process for preparing methacrylic acid, wherein methacrolein is prepared in a first stage from propionaldehyde and formaldehyde by means of a Mannich reaction and oxidized in a second stage to methacrylic acid. More particularly, the present invention relates to the reduction in the amounts of catalyst to be used in the first stage, especially to the reduction in the amounts of acid to be used here, by virtue of the additional installation of recycling streams suitable for the purpose.