Production Test of Torrefied Woody Biomass Solid Fuel in an Original Small-scale Plant

Abstract

In this study, an original small-scale demonstration plant was manufactured to produce upgraded wood fuel by torrefaction. The plant consists of a rotary-kiln type oven and a ring-die type pelletizer, and they were optimized for torrefaction based on the commercial models. We succeeded in more than 240 h operation of the torrefaction oven and produced 2.3 t of torrefied chips from raw Japanese cedar chips without drying. The energy yield of the torrefied chips was more than double the energy yield of conventional charcoal chips. The average length of the torrefied pellets was 7.4 mm, which is shorter than the length of the normal wood pellets. In the combustion test using a cone calorimeter, no delay in ignition time and small decease in heat release rate were seen for torrefied pellets in comparison with the results of normal pellets.