METHOD OF CLEANING GASES TO REMOVE FORMALDEHYDE Russian patent published in 2004 - IPC

FIELD: polymer materials. SUBSTANCE: invention is intended for use in production of urea-formaldehyde press materials by bringing reactants into contact with chemisorbent, more particularly sawdust modified by aqueous solution of urea and phosphoric acid at weight ratio (0,5-1):(0.25-1) and 90-95 C for 0.5-1 h and thermally treated for 1 h at 140-150 C. Weight ratio of solid phase to liquid phase is 1:(4.5-5.4). As modifying substances, urea is also utilized together with nitric acid at 1:1 weight ratio. EFFECT: excluded emission of formaldehyde and reduced cost due to low price of sorption materials having important sorption capacity. 2 cl, 1 tbl, 2 ex