Process for preparation of di- and polyamines of the diphenylmethane series

US10689322B2 · kind B2 · utility

Assignee

• Covestro Deutschland AG · DE

Inventors

• Thomas Knauf · Dormagen, DE
• Stefan Wershofen · Mönchengladbach, DE
• Klaus-Gerd Gruner · Duisburg, DE
• Volker Hartjes · Duisburg, DE

Key dates

• Filing date: Jun 22, 2015
• Grant date: Jun 23, 2020
• Expiry date: Jun 22, 2035

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/582
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for preparing di- and polyamines of the diphenylmethane series (MDA), a system for producing MDA and a process for operating a system for preparing MDA. The invention enables optimization of production standstills during operation of the MDA process with respect to time expenditure and optionally also with respect to energy and material consumption by means of a so-called recirculation mode for individual system components. During interruption of the process or interruption of the operation of individual system components, formaldehyde is not introduced into the reaction and the system components that are not affected by a revision, repair, or cleaning measure are operated in so-called recirculation mode. This enables, among other things, that only the affected system component can be put in standstill during the time period of the measure, which is advantageous in terms of productivity and economy of the process as well as in terms of the quality of the products produced.