FIELD: organic chemistry, chemical technology. SUBSTANCE: caprolactam is synthesized by depolymerization of polymers containing the repeating link -[N(H)-(CH2)5-C(O)-]- or from mixtures consisting of 50-99 wt.% of polymer or thermoplastic formed material with the same repeating link and involving also 0.01-50 wt.% of additions taken among the group including inorganic filling agents, organic or inorganic pigments and dyes; 0-10 wt.% of organic and/or inorganic additions; 0-40 wt.% of polyamide free polymers and 0-20 wt.% of polyamides, exception for polycaprolactam and copolyamides synthesized from caprolactam. Depolymerization is carried out in the presence of the base in two in-line depolymerization reactors under decreased pressure. The base is added to dehydrated raw before depolymerization stage carrying out. Device used for realization of method proposed consists of melting unit connected with the base mixing unit and polymer fusion to which depolymerization reactors D1 and D2 are connected in-line. EFFECT: increased yield of caprolactam, use of caprolactam-containing wastes. 6 cl, 1 tbl, 1 dwg, 5 ex
