Análise econômica de dois sistemas de descascamento de madeira de eucalipto / Economic analysis of two systems of descascamento of eucalyptus wood

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

The objective of this work was to analyze the two systems of the eucalyptus wood peeling, utilized by the Brazilian forest companies, with the purpose to identify the most advantageous in the economical point of view. The evaluated systems were the fixed system, composed by a barrel of industrial peeling, and a mobile, composed by an agricultural tractor modified with a rotor peeling with rotative knives. Also were evaluated three alternatives of the use of the peel. The part of the study referring to the collect of the volume data and the laboratorial analyzes of the samples were realized by the COPENER FLORESTAL LTDA; situated in the northeast region from Bahia. The specimen utilized to the study was the hybrid Eucalyptus urophilla x Eucalyptus gradis. The sampled was made in two cutting pieces, choose aleatory, where were identified 13 diameters classes, were abated and cube two trees of each specimen, one in each cutting piece, in a total of 26 trees. In each of these trees, were removed peel rings in positions of 0, 25, 50, 75 and 100% of the commercial summit, to determine the humidity texts, nutrients, the calorific power and the density. In other stage, was sent a questionnaire to the companies, approaching the main questions about the wood peeling. With the data of the rigorous cube, laboratorial analyses and the questionnaire, were obtained the follow estimatives: total volume of the trunk: 489,02 m3/ha; peel volume: 49,42 m3/ha; peel perceptual: 10,1%; peel density: 270 kg/m3; biomaterial: 13,6 t/ha; humidity: 59,58%; calorific power: 3550 kcal/kg; transportation cost: R$ 0,0356 /m3/Km; shipment and discharge cost: R$1,38/m3; mobile peeling cost of R$4,65/ m3 and fixed of R$2,00/ m3; exploitation capacity of the organic compound: 60% of the volume; productive capacity in electrical energy :500 kwh/ m3 ; tannin texts: 14,7%; and quantity of nutrients in 30 kg of peel: N = 97,17 g, P = 8,60 g, K = 85,72 g, Ca = 754,96 g and MG = 88,00 g. These values facilitate the estimate the necessary quantity of fertilizer to replacement, such as: ammonium sulphate = 486,00 g; super phosphate simple= 218,89 g; potassium chloride = 36,21 g; and dolomitic calcareous (Ca and Mg) = 3523,33 g, resulting in increment of R$0,46/ m3 in the wood cost. Regarding to the operational parts of the system was observed that the mobile peeling could promote a decrease in the transport cost, shipment and discharge, in the same perceptual of the peel volume. However, the mobile peeling cost is elevated, doing that, in the economic point of view, for the studied conditions, this system stays in disadvantage. To the observed peel perceptual, the transportation distance that compares the both systems in cost is 255 Km. The alternative uses showed, in 30 kg of peel, revenue values of R$10,24, in electric energy and R$6,20 to the tannins extraction. The observed results facilitated to conclude that: by the current situation, the fixed system is economically more advantageous than the mobile system to a space of 100 Km, took as reference. The determinant factor of this situation is the mobile peeling cost that is superior to the fixed one. Inferior distances to the compared distance favors the fixed system, while the superiors favors the mobile system; and the alternatives of the use of the peel showed revenues that could amortize part of the cost of the wood.

ASSUNTO(S)

descascamento manejo florestal economic analysis eucalyptus wood peeling alternative uses avaliação econômica usos alternativos

ACESSO AO ARTIGO

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