Recovery of formic acid by distillation

US4551208A · kind A · utility

Assignee

• BASF SE

Inventors

• Kaspar Bott · Mannheim, DE
• Gerd Kaibel · Lampertheim, DE
• Horst Hartmann · Dresden, DE
• Rudolf Irnich · Worms, DE
• Horst Buelow · Bischofswerda, DE

Key dates

• Filing date: May 25, 1984
• Grant date: Nov 5, 1985
• Expiry date: May 25, 2004

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C51/44
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Formic acid is recovered, by distillation, from its mixtures with solvents of the general formula I ##STR1## where R.sup.1 is hydrogen, methyl, ethyl or vinyl and R.sup.2 and R.sup.3 are each alkyl, cycloalkyl, aryl or aralkyl, or R.sup.2 and R.sup.3 together form a 1,4- or 1,5-alkylene group, in each case of not more than 8 carbon atoms, with the provisos that the sum of the number of carbon atoms in R.sup.2 and R.sup.3 is 7 to 14 and that only one of these radicals is aryl, by a method in which the distillation is carried out in the presence of a carboxamide II which is selected from the group consisting of formamide, acetamide, propionamide and the same compounds substituted by N-methyl or N,N-dimethyl, and which has a boiling point lower than that of the solvent I.