METHOD OF PRODUCING CARBAMIDE-FORMALDEHYDE CONCENTRATE Russian patent published in 2011 - IPC C08G12/00 C08G12/12 C07C47/52 C07C47/55 

FIELD: chemistry.

SUBSTANCE: method involves oxidative dehydrogenation of methanol to formaldehyde on an iron-molybdenum catalyst in one or more flow- or deck-type reactors, as well as chemisorption and absorption of formaldehyde-containing gas in two successively lying towers. During chemisorption in the first tower, the absorbent used is 50-65% aqueous solution of carbamide and carbamide-formaldehyde concentrate is obtained during chemisorption. Non-absorbed gas coming out of the chemisorption column is divided into two parts. The smaller part is taken for catalytic burning and the larger part is fed into the lower section of the absorber. Demineralised water is used during absorption in the second tower and the methylene glycol solution formed is fed into the upper section of the first tower.

EFFECT: avoiding formation of methane-containing waste water.

1 cl, 1 ex, 1 dwg