Kinetic models for pyrolysis and combustion of sewage sludge

R. RODRIGUEZ, D. GAUTHIER, S. UDAQUIOLA, G. MAZZA, O. MARTINEZ, AND G. FLAMANT

New Brunswick, Canada

Congreso; IWA SPECIALISTS CONFERENCES: MOVING FORWARD WASTEWATER BIOSOLIDS SUSTAINABILITY; 2007

Université de Moncton, New Brunswick, Canada

Abstract: Thermogravimetric analyses were carried out on dry samples of sewage sludge from San Juan, Argentina in inert and oxidative atmosphere. Three peaks can be observed in all differential thermogravimetric curves during the organic matter decomposition. Different reaction schemes were set up in order to explain the experimental data. The pyrolysis phenomenon can be schemed by three parallel reactions or by a reaction with formation of one intermediate solid that decomposes later, and other reaction parallel to the first. In order to interpret the combustion phenomenon, the first and second schemes consider that the sewage sludge is formed by three fractions; the third scheme supposes that the sludge is formed by only two fractions. The first scheme of combustion considers that all fractions decompose with formation of char whereas the second scheme proposes that one fraction is oxidized without previous decomposition. The third scheme supposes only two fractions that decompose forming char. The simulations fit correctly the experimental data for the first two schemes only, and the fit is better with the second scheme.