Abstract

• Hydrothermal treatment is one of the environmentally friendly methods for the conversion of biomass into valuable end products such as biofuel, hydrochar and biochar. In this research work, hydrothermal treatment of grass (Pennisetum hordeorides Lam.) was carried out at 100C to 140 ˚C for 20 min to 40 min as the preliminary step to provide bioenergy products such as bioethanol and biochar. The maximum reducing sugar content of liquid fraction, 43.46 mg/mL was achieved after hydrothermal treatment at 110 ˚C for 30 min and further yeast fermentation of reducing sugar was accomplished to obtain 2% by volume of bioethanol. Carbonization of solid residue after hydrothermal treatment was conducted for biochar at different temperatures (300 C, 400 C and 500 C) and times (0.5 hr, 1 hr, 2 hr, 4 hr, 8 hr). Characterization of grass such as cellulose, hemicellulose, and lignin contents before and after hydrothermal treatment was conducted. High heating value (HHV) and energy densification were evaluated for energy values of biochar. The maximum HHV (26.78 MJ/kg) and energy densification (1.28) had resulted for the carbonization temperature of 500 C for 2 hr. The changes in surface morphology and functional groups in raw grass, HTG and biochar were observed by Scanning Electron Microscopy (SEM) and by Fourier Transform Infrared Spectroscopy (FTIR).