FIELD: performing exothermic reactions between propylene and ethyl benzene hydroperoxide for forming propylene oxide with the use of solid heterogeneous catalyst. SUBSTANCE: reactor is divided into several separate zones; each zone has layer of solid epoxidation catalyst. Conditions of exothermic reactions are maintained at such level that liquid phase is maintained in entire reactor without considerable vapor generation. Cold flow is fed to reactor which is preliminarily heated to temperature of reaction through separate indirect heat exchange with reaction liquid from different zones of reactor. Reaction liquid from last reaction zone is subjected to reducing of pressure for forming gas0vapor mixture at reduced temperature; this gas-vapor is preheated by indirect heat exchange with reaction liquid from at least one zone of reactor. EFFECT: considerable reduction of cost for assembly and operation of system at hydroperoxide conversion of 98% and selectivity of conversion of propylene to propylene oxide of about 99%. 4 cl, 1 dwg, 1 tbl
