Pyrolysis of sludge and biomass residues

Abstract The thermochemical conversion processes for sludge and biomass residues are briefly reviewed, focusing on the advantages of pyrolysis. The pyrolysis process is described, and the effects of the parameters affecting the pyrolysis products are discussed, considering also synergetic effects between different operating conditions. Pyrolysis kinetics is explained, describing in detail several isoconversional kinetic models, such as those of Friedman, Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS), and Vyazovkin, and the distributed activation energy model (DAEM). Pyrolysis measurements of sewage sludge, conducted in a thermogravimetric analyzer, are employed to determine the pyrolysis kinetic parameters, that is, the preexponential factor and the activation energy, applying the different kinetic models studied. Finally, the main characteristics of the reactors available to hold biomass pyrolysis reactions are examined.