FIELD: chemistry.
SUBSTANCE: present invention relates to a method of processing by-products of synthesis of 4,4-dimethyl-1,3-dioxane formed from isobutylene and formaldehyde and / or substances which are sources thereof, when decomposed on an aluminosilicate catalyst in the presence of water vapor at temperature of 400–480 °C. Method is characterized by that before decomposition, by-products of synthesis step of 4,4-dimethyl-1,3-dioxane are mixed with demineralized water and aqueous layer of condensate of reaction mass of liquid phase synthesis of isoprene in ratio of HBP : demineralized water : aqueous layer of condensate of reaction mass of liquid-phase isoprene synthesis equal to 1:(0.1–0.28):(0.01–0.06) respectively, obtained mixture is hydrolyzed at temperature of 100–155 °C and pressure from atmospheric to 1.0 MPa with subsequent evaporation of obtained hydrolyzate in water vapor flow at temperature of 190–250 °C and pressure of 0.2–1.0 MPa, formed gas is fed for catalytic decomposition.
EFFECT: increase of total output of useful products, reduction of coke content, increase of heavy residue conversion.
1 cl, 2 ex
