Physical and Energy Characteristics, Compression Strength and Chemical Modification of Charcoal Produced from Sixteen Tropical Woods in Costa Rica

Charcoal production from woody species from fast-growth plantations has gained importance in a variety of uses. The objective of the present work is to determine the density, compression resistance, moisture content (MC), gross calorific value (GCV), ash and volatile content, chemical modification by Fourier-transform infrared spectroscopy (FTIR) spectrum and thermogravimetric degradation of charcoal produced by pyrolysis at 450°C from sixteen tropical woods from fast-growth plantations in Costa Rica. The results showed values of MC of 2.65–7.72%, density of 0.15–0.39 g/cm³, compression strength of 19.07–82.92 kg/cm², ash content of 0.26–7.98%, GCV of 32.10–24.29 MJ/kg, volatile matter of 22.45–33.34%, fixed carbon of 60.36–68.91%, carbon of 78.51–69.43%, hydrogen of 4.15–3.55%, oxygen of 17.25–26.56%, O/C ratio of 0.17–0.29 and H/C ratio of 0.56–0.64. FTIR spectrum evidenced the presence of OH, CH2, C = O, C-O-C groups, common in pyrolyzed biomass. TGA analysis showed two types of behavior, which differ in that one group presents two peaks between 200°C and 800°C. The multivariate analysis by principal components (PC) applied to charcoal characteristics measured in sixteen species showed that the variations of these characteristics can be explained up to 99% and four groups were established.