Production of anhydrous or substantially anhydrous formic acid

US4326073A · kind A · utility

Assignee

• BASF SE

Inventors

• Dieter Wolf · Darmstadt, DE
• Rudolf Schmidt · Giengen an der Brenz, DE
• Ulrich Block · Ludwigshafen, DE
• Hartmut Schoenmakers · Heidelberg, DE
• Kaspar Bott · Mannheim, DE
• Gerd Kaibel · Lampertheim, DE

Key dates

• Filing date: Mar 18, 1980
• Grant date: Apr 20, 1982
• Expiry date: Mar 18, 2000

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C51/48
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Anhydrous or substantially anhydrous formic acid is obtained by hydrolysis of methyl formate, in a process wherein PA1 (a) methyl formate is hydrolyzed, PA1 (b) the methanol and excess methyl formate are distilled from the hydrolysis mixture obtained, PA1 (c) the bottom product of distillation (b), consisting of formic acid and water, is extracted, in a liquid-liquid extraction, with an extractant which in the main takes up the formic acid, PA1 (d) the resulting extract phase, consisting of formic acid, the extractant and a part of the water, is subjected to distillation, PA1 (e) the top product obtained from this distillation and consisting of all or part of the water introduced into the distillation, and part of the formic acid, is recycled, as vapor, into the lower part of the distillation column of stage (b), PA1 (f) the bottom product of distillation stage (d), consisting of the extractant, with or without part of the water, and the greater part of the formic acid, is separated by distillation into anhydrous or substantially anhydrous formic acid and the extractant, and PA1 (g) the extractant leaving stage (f) is recycled to the process.