| 摘要 |
The invention relates to a method for producing formic acid by hydrogenation of carbon dioxide in the presence of a catalyst which contains an element of the 8th, 9th or 10th group of the periodic system, a tertiary amine and a polar solvent, at a pressure of 0.2 to 30 MPa abs and a temperature of 20 to 200°C, thereby producing two liquid phases, and separation of the two liquid phases. The liquid phase (B) enriched by the tertiary amine is returned to the hydrogenation reactor and the formic acid/amine addition product from the liquid phase (A) enriched by the formic acid/amine addition product and the polar solvent is thermally separated into free formic acid and free tertiary amine in a distillation unit and the tertiary amine released during separation and the polar solvent are returned to the hydrogenation reactor. |
