Patent ID: 6713649
Filing Date: 2004-03-30
Classification: C07C

Abstract:
A process for the preparation of formic acid, comprising the following steps:a) hydrolysis of methyl formate to give a mixture of water, formic acid, methanol and excess methyl formate; b) removal of the methanol and excess methyl formate from form the mixture of water, formic acid, methanol and excess methyl formate by distillation to give aqueous formic acid; c) extraction of the aqueous formic acid with at least one formic acid ester selected from the group consisting of ethylene glycol diformate, diethylene glycol diformate, propane-1,2-diol diformate, propane-2,3-diol diformate, dipropylene glycol diformate, butane-2,3-diol diformate, butane-1,4-diol diformate, benzyl formate, cyclohexyl formate, 2-phenylformate, and 2-ethylhexylformate, to give a mixture of said at least one formic acid ester and formic acid under distillation conditions in an extractive distillation column; d) separation of said at least one formic acid ester and formic acid by distillation.