Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Volatiles release and char combustion kinetics

Three groups of secondary fuels and coals were used during the experiments. Proximate and ultimate analyses, determination of heating values and ash characterisation were carried out. The devolatilisation and char combustion experiments were realised in a Thermogravimetric Analyser by Perkin Elmer (precision of temperature measurement +/-2 degrees Celsius, microbalance sensitivity <5μg).

Char samples were produced during the devolatilisation experiments in a fixed bed reactor. Based on the experimental results, the kinetic studies for both stages of the combustion process were accomplished. The fuel blends were tested under the same experimental conditions, i.e. particle size less than 250μm and low heating rate of 10degrees Celsius/min. The results showed that the main characteristics of the different secondary fuels were dependent on their chemical composition and especially the distribution of cellulose, hemicellulose and lignin.

The additive properties of the separate materials were valid when investigating the pyrolytic behavior of the fuel blends. Some interaction occurred in the high temperature region when testing the German lignite / paper sludge blend and this was attributed to the mineral matter effect. The experiments were replicated at least twice to determine their reproducibility, which was found to be very good.

Reported by

National Technical University of Athens
15780 Athens