Pyrolysis and wood by-products of species from the Brazilian semi-arid region

Abstract

The objective of this study was to analyze wood from ten species, endemic of the Brazilian semi-arid region, especially when subjected to pyrolysis and characterization of pyroligneous extract. In the wood, the total extractive, lignin and ash contents, the calorific value, and the elementary chemical composition (C, H, O, N, S) were analyzed. Samples were subjected to the flash pyrolysis process at a temperature of 500 C with a residence time of 5 minutes. The yields of charcoal, pyroligneous liquid, and non-condensing gases were determined. Pyroligneous liquid extracts were analyzed through gas chromatography (GC/MS) with the objective of detecting organic compounds. The wood of the Mimosa tenuiflora and Poincianella pyramidalis species was the most suitable for using biomass for energy purposes and to produce charcoal due to its high lignin content, charcoal yields and pyroligneous liquid. Oxygenated compounds, such as carboxylic acids, esters, ethers and ketones, as well as phenols, guaiacols and phenolic derivates were detected in the pyroligneous extracts.