METHOD FOR PREPARING CARBAMIDE-FORMALDEHYDE CONCENTRATE Russian patent published in 2004 - IPC

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for preparing carbamide-formaldehyde concentrate used for manufacturing synthetic binding resins. Method is carried out by hemosorption of formaldehyde prepared by oxidative dehydrogenation of methanol on silver catalyst with carbamide solution with additions of ammonia water in column of plate type (hemosorber). Hemosorber is refluxed with formaldehyde aqueous solution from above that is prepared in condensation of steam-gaseous mixture in outlet of the main column and additional absorption column. Hemosorption process is carried out in the mole ratio formaldehyde to carbamide = (2.0-2.5):1 at middle part of absorber, at pH 5.0-6.5 and temperature of steam-gaseous mixture in outlet 85-95 C. Part of ready product from the sorption column vat is recovered on its upper plate.

EFFECT: enhanced quality of ready product, improved ecological indices of process.

3 cl, 1 dwg