Fecha de publicación: 08/12/2022 Fuente: WIPO (eseential oils OR extracts) The present invention improves monomer yield. This monomer production system has: a dissolution unit in which a polyester solution is stored; a first reaction unit to which the polyester solution and a reaction solvent are introduced, and which depolymerizes the polyester in the polyester solution and extracts a first depolymerized polyester, which contains the depolymerized polyester, to the reaction solvent; a second reaction unit which further depolymerizes the first depolymerized polyester, and generates a second depolymerized polyester, which is the further depolymerized first depolymerized polyester; a separation unit for separating the reaction solvent in which the second depolymerized polyester is dissolved into the reaction solvent, a monomer derived from carboxylic acid, a monomer of an alcohol component, and a residual substance containing an oligomer, which is a component other than the reaction solvent, the monomer derived from carboxylic acid or the monomer of an alcohol component; and an introduction pipe through which the monomer derived from carboxylic acid and the residual substance are introduced to the dissolution unit.