Formic Acid → Methyl formate

Example 1 was carried out in laboratory plant 1. By means of metering pumps, 1760 g/h of methyl formate as stream (1a) and 849 g/h of water as stream (1c) were metered into the stirred vessel A1. Stream (1c) was taken off from the mixing vessel X and was composed of fresh water via stream (1b) and recycle water from the distillation apparatus B2 via stream (3c). Stream (1b) was selected so that the sum of stream (1b) and stream (3c) gave the desired stream (1c). The stirred vessel A1 was operated at 110° C. and 1.3 MPa abs. The output was introduced into tube reactor A2 which was likewise operated at 110° C. and 1.3 MPa abs. The output from tube reactor A2 was introduced into tube reactor A3. 1964 g/h of tri-n-hexylamine were fed via stream (8a) into the latter. The output from tube reactor A3 was introduced into tube reactor A4. A further 1661 g/h of tri-n-hexylamine were fed via stream (8b) into the latter. Streams (8a) and (8b) were taken off from the vessel Y which served to distribute tri-n-hexylamine recirculated via stream (8) over the two tube reactors A3 and A4. Tube reactor A3 was operated at 115° C. and 1.3 MPa abs, and tube reactor A4 was operated at 110° C. and 1.3 MPa abs. A product mixture comprising 58.4% by weight of tri-n-hexylamine, 16.4% by weight of formic acid, 12.3% by weight of methanol, 7.8% by weight of water and 6.9% by weight of methyl formate was obtained as stream (2).