Energy Properties of 22 Timber Species from Oaxaca, Mexico

The potential use of forest species as fuels depends on their energy quality. However, in rural communities in developing countries, fuelwood is still an energy source without any technical study evaluating its energetic characteristics. Therefore, this study aimed to analyze the energetic characteristics of 22 forest species from four communities in the state of Oaxaca, Mexico. The basic wood density, proximal analysis, and high heating value were evaluated. As a result of the analysis, the fuel number (FN) is proposed as a measure of the energy quality of biomass fuels in the form of firewood. FN considers the basic wood density, the fixed carbon, and the high heating value of each species. Wood basic density ranged from 0.472 g·cm-1 for Pinus pseudostrobus to 0.814 g·cm-3 for Dodonaea viscosa, fixed carbon ranged from 4.74% to 21.27% for Liquidambar styraciflua and Quercus rugosa, respectively, and high heating value from 18.33 MJ·kg-1 to 22.07 MJ·kg-1 for Liquidambar styraciflua and Pinus leiophylla, respectively. Classifying wood according to FN, in decreasing order, Quercus rugosa stands out as the best wood (66.97%), followed by Liquidambar styraciflua (39.52%). Regarding the fuel value index, the nine pine species showed the highest values (27.32 to 77.76). The FN provides a measure of the quality of biomass fuels in the form of firewood, and can be evaluated by easily measured variables.