METHOD OF PRODUCING CARBAMIDE-FORMALDEHYDE CONCENTRATE Russian patent published in 2013 - IPC C08G12/12 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing carbamide-formaldehyde concentrate. The method involves oxidative dehydrogenation of methanol to formaldehyde on a silver or iron-molybdenum catalyst in one or more flow- or deck-type reactors, as well as chemisorption and absorption of formaldehyde-containing gas in two series-arranged towers. For chemisorption in the first tower, 50-65% aqueous carbamide solution is used. The gas coming out of the chemisorption tower is divided into two portions, where the smaller portion is fed for catalytic after burning and the larger portion is fed into the lower section of the second tower for absorption of formaldehyde with demineralised water. The solution of methylene glycol formed in the second tower is taken for mixing with carbamide solution in a flow mixer to obtain a pre-condensate which is fed into the upper section of the first tower.

EFFECT: invention increases efficiency of production and prevents formation of hard-to-dissolve products.

1 dwg, 1 ex