EVALUATION OF Coffea arabica L. WOOD QUALITY AS A SOURCE OF BIOENERGY

Abstract

This work aimed to evaluate, through principal component analysis, the quality of Coffea arabica L. wood obtained from different growth systems and varieties as a source of bioenergy. Wood from three different growth systems (natural, conventional and organic) and two different varieties (Mundo Novo and Catuaí) were used, totalizing six treatments. The contents of elementary components (C, H, N, S and O), ash, lignin, total extractives and holocellulose, basic density, the higher heating value, the lower heating value, as well as the lower and higher volumetric heating values of the analyzed woods were quantified. Principal components multivariate statistical analyses were conducted. The scores of the principal components of interest were determined as a way to divide the woods into groups. Group I was composed by the wood from the organic coffee “Mundo Novo” and natural “Mundo Novo”; Group II by the organic “Catuaí”, and Group III by the wood from convencional “Mundo Novo”, natural “Catuaí” and convencional “Catuaí”. Wood residues from the species Coffea arabica L. showed great potential for energetic use, especially the woods from the conventional systems and the “Catuaí” Variety. Woods from  Group III stood out, due to the high volumetric heating values , basic density, lignin content and higher heating value. However, the woods of this group showed high nitrogen content.