Comparative analysis of the chemical composition and biofuel properties of conifer cone residues from different species

This study aims to investigate the biofuel potential of cone residues from four coniferous species [Taurus cedar (Cedrus libani A. Rich.), Turkish red pine (Pinus brutia Ten.), Black pine (Pinus nigra subsp. pallasiana (Lamb.) Holmboe), and Scots pine (Pinus sylvestris L.)] from the Isparta region. Cone samples are materials that can be considered waste biomass after seed extraction and have the potential to serve as an alternative source for energy production due to their lignocellulosic structure. The study determined the calorific values, volatile matter, ash, sulphur content, and elemental composition of the samples, and also identified their characteristic functional groups using FT-IR analysis. According to the results obtained, the calorific values of pine cone samples ranged between 3954–5050 kcal/kg and were comparable to wood-based biomass. The volatile matter ratios of 58–64% and sulphur contents of 0.02–0.10% indicated that these materials are environmentally clean fuels. FT-IR analyses confirmed the presence of characteristic O–H, C–H, C=O, and C–O functional groups associated with the lignin, cellulose, and hemicellulose structure in all species. As a result, it has been determined that pine cones, particularly those from the Toros cedar and red pine, are suitable raw materials for biofuel production due to their high energy content and low ash and sulphur content. These findings indicate that pine cone residues can be utilized in renewable energy production, thereby contributing to sustainable forest management and waste biomass recovery.