METHOD OF UNINTERRUPTED PRODUCTION OF FORMALIN AND CARBAMIDE-FORMALDEHYDE CONCENTRATE Russian patent published in 2008 - IPC C07C47/04 C07C47/55 C07C45/29 C08G12/12 

FIELD: chemistry.

SUBSTANCE: invention pertains to the method of uninterrupted production of formalin and carbamide-formaldehyde concentrate. The method involves catalytic dehydrogenation of methanol with formation of formaldehyde-containing contact gases, in which there is separation of part of the formaldehyde in form of formalin, supply of contact gases for chemisorption of formaldehyde by a water solution of carbamide, obtaining of carbamide-formaldehyde concentrate with calculated molar ratios of formaldehyde to carbamide of (4.5-5.2):1. Separation of part of the contact gases in form of formalin is made by cooling the contact gases of dehydrogenation of methanol to temperature lower than the dew point of 50-80°C. The resulting condensate is removed in form of formalin, and the remaining part of contact gases is taken for chemisorption.

EFFECT: method increases quality and stabilisation of the mixture of formalin and carbamide-formaldehyde concentrate and simplifies the process.

1 dwg, 4 ex