Pirolise rapida de carvões minerais

AUTOR(ES)
DATA DE PUBLICAÇÃO

1990

RESUMO

The pyrolysis of national mineral coals was using termogravimetric analysis and by fast heating, comparing these results with those from coals United States and with a German lignite. The apparent activation energies obtanied with the thermogravimetric analysis gave very low values (between 25 and 54 kJ moI), showing a diffuslon controlled mechanism. Under fast heating conditions the values of the apparent activation energies obtained are higther (between 200 and 270 kJ moI) and increase with the rank of the coal, serving as a parameter for the classification. On the other hand, the apparent activation energies for the individual components are not dependent on the rank. Values of around 60 kJ mol for carbon dioxide 90 kJ mol for carbon monoxide and 140 kJ mol for methane are obtained. Chromatograms of the coals show peculiar characteristics which also serve to classify them, speclfically the relations CO2/CO and C2H4/C2H6. The relation between the carbon oxides can be correlated to the volatile content, allowing estimation of this value for unknown coals. Finally, an original structure model is proposed for the Candiota coal which is based on the information detailed in this work as well as literature information. This model is illustrative for low-rank coals but needs to be confirmed in future research on national coals.

ASSUNTO(S)

pirolise carvão

ACESSO AO ARTIGO

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