RESUMO: Na produção de biodiesel a partir de pinhão manso (Jatropha curcas), são gerados resíduos na forma de casca (epicarpo) e de torta. Uma das alternativas de uso desses resíduos é a produção de energia. Neste sentido, objetivou-se, com o presente trabalho, analisar o potencial energético da casca e da torta de J. curcas, caracterizando-os in natura e transformados em carvão vegetal. Foram avaliados o teor de umidade, de acordo com Vital (1997); a densidade do granel; a composição química imediata, segundo a norma ABNT NBR 8112/86 e o rendimento gravimétrico em carvão. O epicarpo apresentou teor de umidade de 18,9%, densidade do granel de 100kg/m 3 , teor de materiais voláteis de 72,6%, teor de carbono fi xo de 13%, teor de cinza de 14,4% e poder calorífi co superior de 3.641kcal/kg. Carbonizado o epicarpo produziu 38,1% de carvão vegetal, com 29% de material volátil, 45% de carbono fi xo, 25% de cinza e poder calorífi co superior de 3.954kcal/kg. A torta apresentou teor de umidade, em base seca, de 2,41%, densidade do granel de 601kg/m 3 , teor de materiais voláteis de 77,84%, teor de carbono fi xo 14,21%, teor de cinza de 7,95% e poder calorífi co superior de 5.122kcal/kg. Com a carbonização da torta, obteve-se 32% de carvão vegetal com 18,27% de materiais voláteis, 71,29% de carbono fi xo, 10,43% de cinza e poder calorífi co superior de 6.234kcal/kg. Os elevados teores de cinzas, tanto para a casca quanto para a torta, estão relacionados aos altos teores de constituintes minerais presentes nas suas respectivas estruturas anatômicas.Palavras chaves: Resíduos, bioenergia, carbonização. ENERGY POTENTIAL OF BIOMASS AND CHARCOAL OFJatropha curcas PEEL AND PIE INTRODUÇÃOEstima-se que o Brasil tenha mais de 200 espécies oleaginosas com potencial para a produção de biodiesel (BELTRÃO, 2006) e uma destas espécies é o pinhão manso (Jatropha curcas L.). O pinhão manso é uma planta oleaginosa da família Euphorbiacea que pode ser cultivada em solos pouco férteis e de clima desfavorável, como o Semi-Árido nordestino. Segundo Purcino e Drummond (1986), o cultivo de tal espécie é interessante nas pequenas propriedades, que fazem uso da mão-de-obra familiar disponível, além de ser uma cultura perene, segundo Peixoto (1973), que pode ser utilizada na conservação do solo.Segundo Peixoto (1973), o fruto do pinhão manso é composto de 53 a 62% de sementes (endocarpo + albúmen) e de 38 a 47% de epicarpo (casca). Penha et al. (2009) mencionam que as sementes dessa oleaginosa possuem um albúmen com até 60,8% de óleo. Devido às suas características, o pinhão-manso passou a ser considerado uma opção agrícola viável para a obtenção de biodiesel, pois produz, no mínimo, duas toneladas de óleo por hectare (CARNIELLI, 2003).

The purpose of this study was to evaluate the wettability and surface roughness of 11 Amazonian hardwoods. Surface roughness was evaluated by a profilometer, while wettability was measured by a goniometer. Distillated water and phenol-formaldehyde were employed to study wood wettability. A 10-μL drop was placed on the wood surface and the contact angle was measured every 2 seconds for 120 seconds. The Virola michelii and Trattinnickia burserifolia wood specimens analyzed presented different roughness values according to the surface evaluated, radial or tangential. Regarding wettability, Virola michelii wood showed the lowest water contact angle on the tangential surface, while the radial surface presented better wettability for phenol-formaldehyde. The wettability of the species studied was not clearly affected by surface roughness, which depends on wood density.

The paper aimed at studying the potential of two nondestructive methods to estimate the wood mechanical properties and mass loss due to thermal treatments. In this study, a low-density tropical hardwood species Simarouba amara (marupá) was used. Forty small beams with dimensions of (25 × 25 × 400) mm (width × thickness × length) were cut from this species. Initially, the beams were nondestructively tested using stress wave and ultrasound methods. Stress wave velocity (Swv), ultrasound velocity (V LL), dynamic modulus of elasticity (E d) and stiffness coefficient (C LL) were longitudinally determined. Afterwards, the beams were thermally treated using a chamber without air circulation under atmospheric pressure. Two schedules were tested: 160 ºC for 180 minutes and 200 ºC for 70 minutes. Mass loss (ML) due to thermal treatment was calculated and the thermally treated material was again nondestructively evaluated. Afterwards, modulus of rupture (f m), modulus of elasticity (E M) and parallel compression strength (f c,0) of treated material were assessed. Backward linear multiple regression analysis was run in order to estimate these properties. Parameters investigated through nondestructive testing (before and after treatment) and derivative variables were used as independent variables, totaling 12 variables. For both treatment schedules, all parameters related to nondestructive techniques were affected by the thermal treatment, thus acoustic velocities and stiffness values were improved. It was found that all evaluated properties of treated material could be modeled at a reasonable level (R 2 = 0.392 to 0.874) depending on the nondestructive method and treatment schedule used. Nevertheless, ultrasound method fitted the most suitable models for a large number of properties. The utilization of variables from both methods together yielded better models whose R 2 value ranged from 0.466 (f m) to 0.941 (E M). It was found that the most important nondestructive variables which entered into the models were: Swv before and after treatment, V LL after treatment, E d before treatment and C LL after treatment. Finally, it could be concluded that stress wave and ultrasound nondestructive methods presented great potential to evaluate properties of thermally treated wood material.