Physical and chemical properties of timber by-products from Pinus leiophylla, P. montezumae and P. pseudostrobus for a bioenergetics use
This paper describes the chemical and physical properties of Pinus leiophylla, P. montezumae and P. Pseudostrobus timber by-products (wood chips, bark and wood-bark). The physical features determined were the initial moisture content, bulk density and calorific value whereas the determined chemical characteristics were pH, inorganic compounds, inorganic compounds microanalysis, extractives, lignin, and holocellulose. Such by-products were collected in the industrial complex at the Indigenous Community of Nuevo San Juan Parangaricutiro, located in Michoacán, México. The initial moisture content of the samples varied from 33.6 to 56%, while their bulk density ranged from 0.19 to 0.31 g.cm-3. The calorific value for the wood residues of the three different species of pines varied from 17.95 to 18.93 MJ.kg-1. Regarding their chemical characteristics, barks were more acid than woods, and in general, the inorganic content was lower in woods than in barks. According to the X-ray microanalysis, the major inorganic compounds found in ash were calcium, magnesium, and potassium. No heavy metals were detected at all. For the three pine species, extractives levels in barks were higher than in woods. Also, barks contained a higher concentration of lignin than woods. The highest holocellulose content was found in wood residues rather than in barks. It is concluded then that the three pine species timber by-products present physic and chemical properties that make them suitable for the production of solid biofuel.