Upgrading fuel property of Bagasse, Cane leaves, and Eucalyptus-wood Residues via torrefaction Pretreatment

Abstract

The biomass torrefaction process was experimental designed and statistically analyzed with response surface methodology. There were two independent factors; temperature (250-300ºC) and time (30-60 min), and three response variables; heating value, weight loss percentage and energy yield. Results showed that torrefied biomass has higher heating value, weight loss of biomass during torrefaction increased and energy yield decreased according to the severity factor of the torrefaction process. Torrefied biomass had the lower molar ratio of H/C and O/C and had more thermal stability with improved fuel properties than of the raw biomass.  Proposed equations based on the anova analysis and response surface methodology were estimated for the optimum condition of each biomass torrefaction; bagasse, cane leaves and eucalyptus wood residue. Torrefied biomass producing at the optimum condition was palletized using gluten as a binder at 5%wt. of biomass. The produced torrefied pellet met the general standard of THIALAND; the L/D dimension, the pellet density, the energy density, and the strength was about 3.22 to 3.88, 0.34 to 0.27 g/cm³, 8,927.10  to 25,071.74 MJ/m³, and 41.20 to 73.03 N respectively. Cane leaves-torrefied pellet to have the highest combustion efficiency than bagasse torrefied-pellet and eucalyptus torrefied-pellet.