Selection of Corymbia and Eucalyptus clones for firewood supply for thermal and electrical energy generation

In Brazil, thermal and electric power generation from wood chips and agroforestry residues has expanded in regions favored by biomass availability and transportation logistics. Globally, wood stands out as a strategic renewable source, with potential for integration into cogeneration systems to enhance energy efficiency. The development and selection of new genotypes that meet the requirements for forest productivity and wood quality are important strategies for companies aiming to ensure a wood supply for bioenergy. The primary objective of this study was to investigate the differences in energy potential of new Corymbia and Eucalyptus clones intended for direct combustion in thermal and electrical energy cogeneration systems. We utilized the Scott-Knott hierarchical cluster analysis to classify the genetic materials based on the similarity of the evaluated properties. The study analyzed 16 genotypes of Corymbia spp., Eucalyptus spp., and their hybrids. In each treatment, corresponding to a genotype, three trees were harvested at 81 months of age with a medium diameter, spaced 6 m x 1,5 m totaling 48 sample units. We determined the basic and energy densities, elemental chemical composition, higher, lower, and useful heating values, and available energy. Among the Eucalyptus genus, clone 2 Eucalyptus cloeziana (gympie messmate) excelled in basic and energy densities, and useful heating value. Within the Corymbia hybrids and across all genetic materials evaluated, clone 4 exhibited the best performance in providing quality wood to meet the needs of bioenergy projects intended for thermal and electrical energy cogeneration systems. This superiority is attributed to its high basic and energy densities, available energy, and useful heating value, coupled with the best results in the combined analysis of average annual increase and wood dry weight increase.