Method for preparing formic acid

The invention discloses a method for preparing formic acid, and belongs to the technical field of compound preparation. The method for preparing formic acid comprises the following steps: mixing diformate, an organic solvent and a copper catalyst, and then decomposing to obtain an organic solvent containing formic acid and formate, wherein the boiling point of the organic solvent is at least 20 DEG C lower than the boiling point of the formic acid; and rectifying the organic solvent containing formic acid at 40-50 DEG C, and then continuously rectifying at 60-80 DEG C to obtain formic acid. According to the method, the rectification difficulty in the anhydrous formic acid preparation process is reduced. 本发明公开一种制备甲酸的方法，属于化合物制备技术领域。该制备甲酸的方法，包括以下步骤：将二甲酸盐、有机溶剂和铜催化剂混合，之后分解得到含有甲酸的有机溶剂和甲酸盐；所述有机溶剂的沸点低于所述甲酸的沸点至少20℃；将所述含有甲酸的有机溶剂在40-50℃下进行精馏，之后继续在60-80℃下进行精馏得到甲酸。该方法降低了制备无水甲酸过程中的精馏难度。