METHOD OF PRODUCING ISOPRENE Russian patent published in 2012 - IPC C07C11/18 C07C2/86 C07C1/20 C07C7/00 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing isoprene via liquid-phase reaction of formaldehyde and isobutylene and/or substances which are sources thereof, for example, 4,4-dimethyl-1,3-dioxane and trimethyl carbinol, in the presence of an aqueous solution of an acid catalyst at high temperature and pressure, while extracting a vapour-liquid stream of reaction products and water from the reaction zone, which is then separated, cooled, condensed and split into aqueous and oily layers, followed by extraction of isoprene and recirculation of the aqueous solution of acid catalyst into the process, characterised by that 1-10% of the recirculated aqueous solution of acid catalyst is mixed at temperature 40-80°C and weight ratio (0.01-0.1):1 with 4,4-dimethyl-1,3-dioxane and trimethyl carbinol in a vessel, from where the solution is output, said solution containing the acid catalyst, 4,4-dimethyl-1,3-dioxane and trimethyl carbinol, which is fed into the isoprene synthesis reaction zone, and precipitated salts which are output from the process.

EFFECT: use of the present method enables to carry out the process with higher selectivity and efficiency and, consequently, improves cost-performance ratio of the process.

3 cl, 4 ex, 1 tbl, 1 dwg