High Concentrated Formic Acid is produced from weak Formic Acid using Pfaudler HoFA processes.
The Pfaudler Dual Pressure HoFA process takes advantage of the pressure dependence of the azeotropic composition of formic acid.
Up to 100% formic acid is produced at low pressure conditions by rectification. Therefore, the azeotropic mixture received is then reconcentrated at higher pressure conditions and recycled to the high concentration step.
Alternatively, azeotropic acid can be recycled to the formic acid production process for reconcentration.