Avaliação das características dendométricas, físicas, químicas e energéticas da Aroeira (Myracrodruon urundeuva Allemão) e da Leucena (Leucaena leucocephala (Lam.) R. de Wit).

Abstract

The Caatinga vegetation has important ecological, cultural and economic importance for the population which lives in this biome. This work aims to evaluate the dendrometric, physical, chemical and energy characteristics of aroeira (Myracrodruon urundeuva Allemão) and leucaena (Leucaena leucocephala (Lam.) R. de Wit). Suppression of five specimens of Myracrodruon urundeuva and Leucaena leucocephala following criteria phenological quality and health was conducted. The evaluated parameters were dendrometric DAP, total and commercial height, volume with bark and without bark. Average basic wood density was also assessed. Quantitative determinations of total extractives, lignin and holocellulose ash were made, in addition to the calorific value of wood. Carbonization was performed in duplicate using dry wood. Productivity of charcoal, pirolenhoso liquid and non-condensable gases were measured. Chemical analysis, determination of true density and bulk density was also performed. The experiment was arranged in a completely randomized design (DIC) and the means were compared by Tukey test at 5% probability. The species presented dendrometric parameters with average values of 10.00 and 14.08 cm for DAP; overall height 8.20 and 12.93 m; commercial height 4.90 and 10.07 m; volume with bark 0.032 and 0.104 m3; volume with bark 0.025 and 0.095 m3 for Myracrodruon urundeuva and Leucaena leucocephala respectively. The Myracrodruon urundeuva showed higher basic density (740.99 kg / m3) compared with Leucaena leucocephala (601.96 kg / m3). The ash content found on Myracrodruon urundeuva (1.08%) was higher than that of Leucaena leucocephala (0.66%). The extractives content (12.75 and 10.80%) and holocellulose (59.04 and 59.23%) for Myracrodruon urundeuva and Leucaena leucocephala were similar. The Leucaena leucocephala got higher total lignin content (29.31%) and the heating value of wood (4996.790 kcal / kg). The Myracrodruon urundeuva and Leucaena leucocephala showed similar performance, with 41.22% and 40.59% carbon, 22.07% and 26.45% and 36.71% condensate and 33.16% of non-condensable gases. The apparent density of Myracrodruon urundeuva (0.59 g / cm3) was higher than that of Leucaena leucocephala (0.39 g / cm3), but the species showed similar values for true density (1.21 g / cm3 and 1.11 g / cm3 respectively). Similarly, the gross calorific value did not differ between species, Myracrodruon urundeuva (6869.338 kcal / kg) and Leucaena leucocephala (6977.220 kcal / kg). The amount of released volatiles and ash produced was higher in Myracrodruon urundeuva with 33.87% and 3.79%.And the income fixed carbon was higher in Leucaena leucocephala (67.15%). Therefore, the wood of the two species showed good physical, chemical and energy characteristics, and we can therefore recommend the wood of Leucaena leucocephala for use for energy purposes, as this is an exotic species without operational restrictions and with excellent adaptability to semi-arid conditions. The species showed similar energy characteristics, and Leucaena leucocephala can be used for production and use of charcoal with the same efficiency of native species already known and used for the same purposes.