Evaluation of Biofuel Energy Potential of Barks from Some Conifer Species in Türkiye

Abstract

Fuel characteristics were evaluated for bark from four coniferous tree species native to Türkiye (Calabrian pine, Black pine, Scotch pine, and Taurus cedar). Bark samples from varying elevations and age groups were analyzed through calorific value (kcal/kg), ash content (%), volatile organic compounds (VOC, %), sulfur emissions (SO_2, %), elemental ash composition, Fourier transform infrared (FT-IR) spectroscopy, and principal component analysis (PCA). All calorific values were determined on oven-dried samples. Calabrian pine had the highest higher heating value on a dry basis at 5044 kcal/kg, along with the lowest value for ash (1.55%), while Scotch pine exhibited the lowest energy value (4518 kcal/kg). Black pine, which had the highest ash content (3.84%), appeared less suitable as a fuel source. Sulphur emissions across all species were marginal (0.005% to 0.04%). Ash content increased with altitude in Calabrian pine, while the opposite trend was observed in larch. PCA results showed interspecific variations in mineral composition and combustion traits. In conclusion, Calabrian pine and Taurus cedar bark show strong potential as renewable and cost-effective biomass energy sources due to their favorable calorific and ash properties. However, environmental factors such as altitude remain determining factors in biomass fuel performance.