Recently, the main advantage of polycarbonate over other types of plastic is unbeatable strength combined with light weight, temperature resistance, impact resistance, etc. Therefore, polycarbonate is a versatile, tough plastic used for a variety of applications, from bulletproof windows to compact disks. The main polycarbonate material is produced by the reaction of bisphenol A and toxic phosgene. However non-phosgene polycarbonate production process can be started with green manufacturing process of diphenyl carbonate (DPC) without phosgene. In this work, to provide a green process design data for optimum separation of DPC, MPC, DMC and phenol etc. that occurs in the synthetic process of DPC, ternary liquid-liquid equilibrium (LLE) for the DPC contained systems and binary solid-liquid equilibrium (SLE) were determined and correlated with activity coefficient models.