MOISTURE AND INORGANIC SUBSTANCE CONTENT IN PINE TIMBER PRODUCTS FOR USE IN PELLETS AND BRIQUETTES

The forest industry in the municipal seat of Nuevo San Juan Parangaricutiro and the Indigenous Community of Nuevo San Juan Parangaricutiro, located in Michoacan state, Mexico, generates 1,232 m(3).year(-1) of underutilized pine sawdust and shavings. The sawdust and shavings of Pinus leiophylla Sch. Et Cham., P. montezumae Lamb. and P. pseudostrobus Lindl were subjected to physicochemical analyzes to determine if they meet the requirements for pellet and briquette production. The moisture, ash, and inorganic element contents in the byproducts were determined using international standards. Moisture content in ash was 51.5 +/- 1.9 %, and 53.7 +/- 0.1 % in shavings; these values exceeded the maximum allowable. Ash content in sawdust and shavings was 0.26 +/- 0.03 % and 0.34 +/- 0.03 %, respectively. For the three species evaluated, the average percentage of calcium, potassium, magnesium, phosphorus, sulfur, silicon, iron, aluminum and sodium in sawdust was 47.1 +/- 2.8, 26.0 +/- 2.5, 13.5 +/- 0.4, 5.0 +/- 0.4, 3.2 +/- 0.4, 2.3 +/- 0.8, 1.0 +/- 0.1, 1.3 +/- 0.4 and 1.4 +/- 0.3, respectively, while the average percentage was 43.2 +/- 7.0, 16.5 +/- 3.0, 10.1 +/- 4.8, 4.0 +/- 0.6, 1.8 +/- 0.2, 3.6 +/- 0.3, 1.0 +/- 0.6, 1.1 +/- 0.1 and 1.0 +/- 0.6 in shavings, respectively. Arsenic was only found in the shavings (17.1 +/- 17.1). Based on the results, sawdust is the most suitable byproduct for pellet and briquette production.