Kinetic study of different biomass pyrolysis and oxygen-enriched combustion

Abstract

Global warming and the GHG effect have forced the reduction of the energetic dependence on fossil fuels. Because of that, research focusing on biomass properties, characteristics and energetic conversion has increased in the last decades. The present study was carried out in terms of determination of kinetic parameters, focusing on two different energetic conversion processes: pyrolysis, carried out under nitrogen atmosphere, and oxygen-enriched combustion, using an atmosphere of air enriched with 30% oxygen. Three different lignocellulosic bio-mass samples were used. Thermogravimetric analysis was performed using four different heating rates in order to carry out a kinetic analysis using model free methods (Friedman, Kissinger-Akahira-Sunose, and Flynn-Wall-Ozawa). The results showed that oxygen-enriched combustion produced a more complete reaction with low char values and activation energy values greater than pyrolysis values. Among the kinetic methods, Friedman reported the most different values, acceptable for pyrolysis process but not so much for oxygen-enriched combustion.