Patent ID: 6841700

Claim:
A process for obtaining anhydrous or substantially anhydrous formic acid, in which i) methyl formate is subjected to hydrolysis, ii) methanol and excess methyl formate are distilled off from the resultant hydrolysis mixture, iii) the bottom product from distillation ii), which comprises formic acid and water, is extracted in a liquid—liquid extraction with an extractant which principally takes up the formic acid, iv) the resultant extract phase, comprising formic acid, extractant and some of the water, is subjected to distillation, v) the top product obtained in this distillation, which comprises water and some of the formic acid, is fed back into the lower part of the distillation device in step ii), vi) the bottom product from distillation step iv), which comprises predominantly extractant and formic acid, is separated by distillation into anhydrous or substantially anhydrous formic acid and the extractant, and vii) the extractant leaving step vi) is fed back into the process, which comprises feeding methanol-containing methyl formate into the distillation device for carrying out step ii) before the hydrolysis of the methyl formate (step i)), where the corresponding feed point for the methanol-containing methyl formate in the distillation device is located above the removal point for methanol an below the removal point for methyl formate, and methyl format with a reduced methanol content is obtained at the removal point for methyl formate and is subsequently fed to step i).