MODELING AND EXPERIMENTAL-VERIFICATION OF PHYSICAL AND CHEMICAL PROCESSES DURING PYROLYSIS OF A REFUSE-DERIVED FUEL

A model for refuse-derived fuel (RDF) conventional pyrolysis in a fixe d-bed reactor is presented. The model investigates the influence of th e heat- and mass-transfer processes on the pyrolysis product yields. S olid degradation reactions have been modeled by assuming that the inte ractions between the main RDF components during pyrolysis are negligib le and that the RDF pyrolysis behavior may be considered as the sum of the separate behaviors of ''primary reacting species''. The model acc ounts for conductive and convective heat transfer within the solid mat rix and secondary tar-cracking-reactions, as well as for variability i n physical properties and in the void fraction of the pyrolyzing mater ial. Quite good agreement was found between model results and experime ntal data obtained for conventional pyrolysis of a RDF in a laboratory -scale fixed-bed reactor, The model is able to predict the temperature transients, the rate of gas generation, and the product final yields during conventional pyrolysis of RDF.