Co-hydrothermal carbonization of styrofoam and sawdust: fuel properties evaluation and effect of water recirculation on hydrochar properties

Abstract

The goal of this research was to create a co-hydrochar (Co-HC) from styrofoam (SF) and sawdust (SD) using a co-hydrothermal carbonization (co-HTC) method and to investigate the physicochemical features of co-hydrochar. At various temperatures (180°C, 200°C, 220°C), the co-HTC procedure was carried out. The impact of process water recirculation during co-HTC at 200°C was also examined. TGA test was used to study the pyrolysis behavior of the co-hydrochar and the results showed that the Co-HC improved physicochemical properties, low O/C and H/C ratios, and high heating value (HHV) of 28.89 MJ/kg, making it suitable for use as a solid fuel. The results also indicated that recirculation of process water promoted dehydration and decarboxylation, increased Co-HC yield percent (73.85%), and significantly guided the Co-HC's HHV (29.84 MJ/kg). The current investigation discovered that hydrochar generation from a mixture of SF and SD is promising and the recirculation of process water was an environmentally friendly approach for generating solid energy.