Evolução das estruturas turbostratica e porosa de materiais carbonosos obtidos por tratamento termico do Pinus elliottii entre 600C e 2600C

AUTOR(ES)
DATA DE PUBLICAÇÃO

1991

RESUMO

Pine wood samples of Pinus elliottii were heal treated in a range of temperatures from 600 ºC to 2600 ºC. In inert atmosphere. The charcoals, the subject of this research work, were then obtained. It was assumed that this material behaves according to the granular structure model proposed by Emmerich and that it exhibits a porous structure made up of micro, meso and macropores, according to Kalliat, Kwak and Schmidt?s model. High angle X-ray diffraction, small angle X-ray scattering and carbon dioxide adsorption techniques were used in order to obtain the data relating to the behavior of the turbostratic microcrystallites (Warren?s theory), the characteristic parameters of the porous structure, the fractal dimensions of the surface of the pores and the specific surface area of the micropores which, then, were analyzed as a function of the temperatures of the thermal treatment of the charcoals. It was then concluded that the charcoals studied could be considered highly porous, the evolution of the porous structure is strongly related to the dynamics of the growth of the microcrystallites and that the fractal dimensions of the macropores decreases when the influence of the micropores is taken into account. It was concluded, too, that the growing of the specific surface areas of the micropores, obtained through the gaseous adsorption technique, up to the temperature where the volatilization activity is relevant, is due to the increase in the number of channels, which allows the adsorbate to reach not only the new micropores created but also others already present and of larger sizes

ASSUNTO(S)

energia da biomassa carvão vegetal

ACESSO AO ARTIGO

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