METHOD OF PREPARING CARBAMIDO-FORMALDEHYDE CONCENTRATE Russian patent published in 1999 - IPC

FIELD: chemical industry. SUBSTANCE: described is carbamido-formaldehyde concentrate of certain composition by chemisorption of formaldehyde containing gases resulting from oxidative dehydrogenation of methanol on iron-molybdenum catalyst with aqueous carbamide solution in alkaline medium. Aqueous carbamide solution is 50-65% aqueous carbamide solution containing 0.05-2.0% of amine, and process is carried out in three-section column to obtain carbamide-formaldehyde concentrate with controllable content of uronic and triazine derivatives. This content is reached by varying pH values of medium, amine content in carbamide solution and formaldehyde to carbamide molar ratio in middle and lower column sections. EFFECT: optimization of process of synthesis of carbamido-formaldehyde concentrate having improved technical characteristics. 4 ex, 1 tbl