| 摘要 |
The invention provides a process for the preparation of formic acid by hydrolyzing methyl formate with water at high temperature and pressure in the presence of a formic acid catalyst. Methanol is also formed. The reesterification of the reaction products to methyl formate (a reaction favored by high temperatures) is minimized by flashing the reaction product at relatively low pressure and temperature and thereafter distilling the residual liquid. Thus procedure separates the methyl alcohol from the formic acid with a minimum contact time and at a low temperature which does not favor the reesterification reaction. High purity formic acid may be obtained by subjecting the bottom from the vacuum distillation of further distillation.
<??>In a preferred embodiment of the invention, prior to the main hydrolysis, the methyl formate is partially hydrolyzed to form the small amount of formic acid needed to accelerate the main hydrolysis step. Accordingly, the necessary formic acid catalyst is formed in situ, thus eliminating the need to add formic acid or to recycle product formic acid. |
