Development and Evaluation of a New Advanced Solid Bio-Fuel and Related Production Process

An advanced solid bio-fuel along with a suitable process for its production at industrial scale was developed and analyzed. This new product, similar in the shape to woody pellet, can be obtained not only by wood or woody material but also by uncontaminated agro-industrial vegetable wastes. It is characterized by high density, low mixture content, and good calorific value. All these desirable properties were obtained by compressing and heating the raw materials, previously chopped and mixed, at temperature significantly higher than that used for drying but smaller than that used for the pyrolysis of woody material. The compression and heating condition of biomass were set within the range that partial decomposition of a portion of the biomass and thermal hardening of hemicelluloses is induced, 115-230 °C and 8-25 MPa. The measured lower heating value of the new solid bio-fuel is in the range between 18 and 20 MJ/kg and its specific net renewable energy content is significantly higher than that of traditional woody pellet. This last result along with a number of environmental impacts of the new solid bio-fuel was quantified using an LCA methodology.