Production of tert-butyl esters of ethylenically unsaturated carboxylic acids

US10301252B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Catharina Horstmann · Ludwigshafen, DE
• Claus Hechler · Mannheim, DE
• Gregor Grackiewicz · Ludwigshafen am Rhein, DE
• Bernd Schall · Ludwigshafen am Rhein, DE

Key dates

• Filing date: Nov 28, 2016
• Grant date: May 28, 2019
• Expiry date: Nov 28, 2036

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/10
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for continuously preparing the tert-butyl ester of an ethylenically unsaturated carboxylic acid, by a) reacting an ethylenically unsaturated carboxylic acid with isobutene in the presence of an acidic catalyst to give an esterification mixture; b) removing the acidic catalyst; c) removing low-boiling components; and d) supplying a tert-butyl ester-comprising liquid to a distillation apparatus and subjecting it to purifying distillation in the distillation apparatus, where d1) in the distillation apparatus the tert-butyl ester-comprising liquid is separated into a tert-butyl ester-comprising gaseous top product and a carboxylic acid-comprising liquid bottom product; d2) the tert-butyl ester-comprising gaseous top product is at least partly condensed and the condensate is recycled partly as reflux to the distillation apparatus; d3) the carboxylic acid-comprising liquid bottom product is recycled at least partly to step a); d4) carboxylic acid-comprising liquid bottom product is drawn off and passed to a heater; a superheated, liquid recycle stream is taken from the heater; and the superheated recycle stream is let down into the distillation apparatus; and d5) at least in th…