Studies on Biomass Torrefaction for Energy Densification of the Fuel

Abstract

Torrefaction of selected biomass materials was successfully carried out using in-house developed indirectly heated fixed bed reactor (FBR) at varied temperature (200–300 °C) with a heating rate of 10 °C/min for 60 min. Commercially available sawdust pellets (6 mm diameter) were selected for preliminary studies for which the highest energy density around 12875 MJ/m3 was obtained at 250 °C. For comparison, the torrefaction cum pelletization was further performed on powdered sawdust, rice straw, and cotton stalk biomass materials (0.6 mm). The maximum energy density was observed for the pelleted–torrefied sawdust which was 14080 MJ/m3 followed by pelleted–torrefied cotton stalk which showed 9450 MJ/m3 and then pelleted–torrefied rice straw of which 6545 MJ/m3 energy density was obtained. Our preliminary observations indicate that torrefaction cum pelletization is the best way to improve the energy density of biomass materials than pelletization cum torrefaction.