PROCESS FOR PRODUCING FORMALIN OR UREA-FORMALDEHYDE SOLUTION Russian patent published in 2006 - IPC C07C47/04 C07C47/55 C07C45/29 C08G12/12 

FIELD: industrial organic synthesis.

SUBSTANCE: process comprises providing alcohol-water-gas mixture via evaporation of water-methanol mixture, combining the latter with air and emission gas, catalytic dehydrogenation of methanol on silver catalyst at elevated temperature followed either absorption of formaldehyde from reaction gases or chemisorption thereof from indicated gases with urea solution in column to produce and recover formalin in case of absorption or urea-formaldehyde solution in case of chemisorption. Into absorption/chemisorption stage, preheated emission gas is supplied in weight proportion to methanol (0.25-6,8):1. Generally, emission gas is preheated to 50-130°C.

EFFECT: increased concentration of produced formalin or urea-formaldehyde solution, widened concentration control range, simplified equipment, and reduced fire risk.

2 cl, 1 dwg, 4 ex