Production and Characterization of Recycled Carbon from Phenol Resin Waste Using Supercritical Methanol

Abstract

In this work, a recycling method for phenol resin (Bakelite) waste using supercritical methanol was investigated. Phenol resin is manufactured by the condensation reaction between phenol and formaldehyde to form insoluble and infusible three-dimensional reticulate structures. For this reason, these resins are mostly buried or incinerated as waste, and only a small percentage is reused as filler materials. In terms of reducing environmental pollution and improving waste management, the development of recycling technologies for phenol resin waste is necessary. In this study, phenol resin waste was treated with supercritical methanol over the 553.15–703.15 K temperature range and at pressures up to 20.6 MPa. As a result of this treatment, waste was decomposed into phenol and carbon particles. Carbon particles began from at temperatures and pressures above 603.15 K and 13.9 MPa, respectively. The sizes of the carbon particles obtained in this manner ranged from 1 to $4~\upmu \hbox {m}$ and decreased with increasing temperature and pressure. These carbon particles had identical chemical and crystal structures and crystallinities to amorphous carbon. This recycled carbon can be used for the same purposes as existing amorphous carbon.