METHOD OF PREPARING FORMIC ACID Russian patent published in 1998 - IPC

FIELD: chemical industry. SUBSTANCE: formic acid is prepared by hydrolysis of methyl formate continuously at 80-100 C in reactor filled with highly acidic sulphocationite. Reaction product is admitted into column operating at reduced pressure of 0.2-0.5 bar, and from column still is removed aqueous formic acid solution which is further subjected at two-stage rectification at two different pressures, first at higher pressure or up to 2.5-2.8 bar and then at lower pressure up to 0.5 bar. Process efficiency is increased and formic acid is prepared with concentration of at least 86 wt %. EFFECT: more efficient preparation method. 1 dwg, 1 tbl