Continuous process for the production and purification of acrylic acid

US7803969B2 · kind B2 · utility

Assignee

• Evonik Stockhausen GmbH · US

Inventors

• Stefan Nordhoff · Recklinghausen, DE
• Axel Kobus · Langen, DE
• Stefan Gross · Lörrach, DE
• Hans-Rolf Lausch · Alzenau, DE
• Torsten Balduf · Pfungstadt, DE
• Roland Fornika · Dülmen, DE
• Guenther Bub · Marl, DE

Key dates

• Filing date: Jan 14, 2002
• Grant date: Sep 28, 2010
• Expiry date: Jan 21, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C51/43
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a process for the purification of (meth)acrylic acid in a process stage that comprises the following process steps: a) (meth)acrylic acid is crystallized out from a mother liquor; b) crystallized (meth)acrylic acid is separated from the mother liquor; c) at least part of the separated (meth)acrylic acid crystals are melted; d) the melted part is at least partially recycled to the step a) or step b). The process according to the invention, the apparatus suitable for implementing the process, and the use of the apparatus according to the invention for the production of (meth)acrylic acid are characterized by a high purity of the thereby obtainable (meth)acrylic acid as well as by a high efficiency with regard to the achievable yield and necessary energy requirement.