Chemical and Energetic Properties of Seven Species of the Fabaceae Family

Abstract

In this work, the chemical compositions and energetic properties of the wood and bark of seven Fabaceae species were determined to evaluate their dendroenergetic potential. Chemical composition, elemental, proximate and heating value analyses were conducted. In addition, an ash microanalysis was performed. The obtained results varied as follows: cellulose (from 20.21% in Parkinsonia aculeate bark to 58.83% in Albizia plurijuga sapwood), hemicelluloses (from 8.81% in Eysenhardia polystacya heartwood to 23.71% in Pakinsonia aculeate wood), lignin (from 12.88% in wood to 26.53% in bark of Parkinsonia aculeate), extractives (from 11.68% in sapwood to 36.17% in bark of Eysenhardia polystacya), carbon (from 42.4% in Albizia plurijuga bark to 49.5% in Eysenhardtia polystacya heartwood), hydrogen (from 6.4% in Eysenhardtia polystacya bark to 7.3% in Albizia plurijuga sapwood), oxygen (from 42.3% in Prosopis laevigata bark to 50.5% in Acacia pennatula bark), nitrogen (from 0.11% in Albizia plurijuga heartwood to 1.64% in Prosopis laevigata bark), sulfur (from 0.04% in Prosopis laevigata heartwood to 0.14% in Acacia farnesiana wood, Erythina caralloides bark, and Prosopis laevigata bark), ash (from 0.76% in Eysenhardtia polystacya heartwood to 11.49% in Acacia plurijuga bark), volatile material (from 70.08% in Eysenhardtia polystacya bark to 91.75% in Albizia plurijuga sapwood), fixed carbon (from 6.97% in Albizia plurijuga sapwood to 23.44% in Prosopis laevigata bark), and calorific value (from 17.36 MJ·kg-1 in Acacia pennatula bark to 21.23 MJ·kg-1 in Prosopis laevigata bark). The most abundant chemical elements in wood ash and bark ash are listed here: Ca˃K˃P˃Mg˃Na. According to the obtained results, the wood and bark of the seven Fabaceae species could be used to produce solid biofuels for local use. Additionally, highlighting the high concentrations of extractives was important, especially in the bark samples, which could be a potential source of phytochemicals.