Patent Number: 6,252,109

Title: Method for the recovery of formic acid

Abstract: The invention relates to a method for removing chemically bound formic acid from a material containing the same, in the presence of free formic acid. The method is characterized in that chemically bound formic acid is allowed to react to free formic acid at a normal pressure, at a temperature of less than C., the initial contact free formic acid being about 3 to 20%. The reaction time is typically 0.5 to 4 hours. The material to be treated may be, for instance, material, obtained from a formic-acid-based pulp cooking process, containing cellulose and/or lignin.

Inventors: Rousu; Pasi Petteri (Oulu, FI), Anttila; Juha Rainer (Oulu, FI), Rousu; Esa Juhani (Oulu, FI)

Assignee: Chempolis Oy

International Classification: C07C 51/09 (20060101); D21C 11/00 (20060101); D21C 3/20 (20060101); D21C 3/00 (20060101); C07C 051/00 ()

Expiration Date: 06/26/2018