Preparing formic acid, comprises e.g. reacting a reaction mixture comprising carbon dioxide, hydrogen, polar solvent and tertiary amine in presence of cationic complex catalyst into hydrogenation mixture including formic acid-amine-adduct

摘要

Preparing formic acid, comprises (a) reacting a reaction mixture comprising carbon dioxide, hydrogen, a polar solvent and a tertiary amine of (Ia) in the presence of a cationic complex catalyst, in a hydrogenation reactor (I) to obtain a hydrogenation mixture containing a formic acid-amine-adduct (A1) of (II), and (b) processing the hydrogenation mixture comprising (b1) separating the polar solvent from the hydrogenation mixture to obtain a distillate containing a formic acid-amine-adduct (A2), and (b2) splitting the formic acid-amine-adduct (A2) to obtain tertiary amine and formic acid. Preparing formic acid, comprises (a) reacting a reaction mixture comprising carbon dioxide, hydrogen, at least one polar solvent and at least one tertiary amine of the formula (NR 1>R 2>R 3>) (Ia) in the presence of at least one cationic complex catalyst, which contains at least one element from groups 8, 9 and 10, in a hydrogenation reactor (I) to obtain a hydrogenation mixture containing at least one polar solvent, at least one cationic catalyst and at least one formic acid-amine-adduct (A1) of formula (NR 1>R 2>R 3>x x 1HCOOH) (II), and (b) processing the hydrogenation mixture comprising (b1) separating at least one polar solvent from the hydrogenation mixture in a distillation apparatus (II) to obtain a distillate containing at least one polar solvent and a bottom mixture comprising at least one formic acid-amine-adduct (A2), and (b2) splitting at least one formic acid-amine-adduct (A2) contained in the bottom mixture, in a thermal cracking unit (III) to obtain at least one tertiary amine and formic acid, where the cationic complex catalyst is immobilized before processing the hydrogenation mixture in the step (b) by at least one carrier material having acidic functional groups, which is insoluble in the hydrogenation mixture. Either R 1>-R 3>(1-16C) aliphatic, (1-16C) araliphatic or (1-16C) aromatic group (all optionally branched or cyclic, and C of all groups are optionally substituted by -N- or -O-); or 2 or 3 of R 1>-R 3>chain containing at least 4 atoms; and x 10.4-5.