Abstract
In Japan, the demand for woody biomass as a source of energy is increasing with current growing of the market size for this source of energy. When woody biomass is used as a source of energy, it is important to consider that the energy balance between the input to produce wood fuel and the output obtained from wood fuel along with the cost of comminuting woody biomass is important. The purpose of this study is to investigate the effects of dimension and species of wood materials on the energy and cost of wood chip production. We measured the power consumption and calculated the energy consumption per dry mass when test specimens such as Sugi (Chamaecyparis obtusa), Karamatsu (Larix kaempferi), and Kunugi (Quercus acutissima) of various widths and thicknesses were comminuted by a disc chipper. Additionally, the productivity of chipper comminuting, and the cost per dry mass of chip production were calculated. The power consumption was in the range from 6.5 kW to 46.9 kW, and it increased when the dimension and density of the test specimens were increased. However, the energy consumption of dry mass was in the range from 45.3 MJ/t to 96.4 MJ/t and it had a tendency to decrease when the dimensions and densities of the test specimens were increased. The comminuting cost was in the range from 632 yen/t to 7,611 yen/t, and it had a tendency to decrease when the dimensions and densities of the test specimens were increased. Additionally, the cost was strongly affected by productivity and was lower when productivity was high. These facts indicate that reduction of energy consumption and cost during woody biomass comminution can be achieved by using materials whose mass is large and by increasing productivity.
