Characterization of a lab-scale platinum filament pyrolyzer for studying the fast devolatilization of solid fuels Enrico Biagini a, * , Federica Lippi b , Leonardo Tognotti b a Consorzio Pisa Ricerche, Divisione Energia e Ambiente, Lungarno Mediceo, 16, Pisa, Italy b Department of Chemical Engineering, University of Pisa, via Diotisalvi, 2, Pisa, Italy Received 15 February 2006; received in revised form 30 May 2006; accepted 1 June 2006 Available online 30 June 2006 Abstract Platinum filament pyrolyzers achieve very high temperature and heating rate and can provide useful parameters for practical appli- cations in combustion, pyrolysis and gasification processes. The critical use of an experimental instrument is necessary to provide reliable data. In this work, a commercial pyrolyzer (CDS Pyroprobe 2000) is characterized to obtain a correspondence between the nominal and the effective operating conditions. This is the basis for the modeling estimation of the effective thermal history of the sample during each experimental run. The experimental results obtained performing the devolatilization of coals, biomass and waste fuels using the pyrolyzer are compared with those obtained in a conventional thermogravimetric balance, to evaluate the effects of extremely different operating conditions. The amount of volatile released programming the most severe thermal conditions using the pyrolyzer (thus in conditions more similar to large-scale plants) differs significantly from that of thermogravimetric runs. Global kinetics are obtained fitting the exper- imental results and using the thermal history of the sample from the model results. They depend strongly on the conditions used for the devolatilization. Global kinetics obtained in the thermogravimetric balance runs (low heating rate) overestimate the rate of devolatiliza- tion in the pyrolyzer (high heating rate). Ó 2006 Elsevier Ltd. All rights reserved. Keywords: Pyrolysis; Biomass; Alternative fuels 1. Introduction Biomass and waste fuels are of current interest for replacing coals in energy production. They represent a renewable energy source, most of them reduce the atmo- spheric CO 2 level and give low emissions of SO 2 , NO x and heavy metals. Moreover, energy can be recovered from residues and wastes. The extreme variety of these fuels and their heterogeneous properties require a fundamental investigation, in order to remark the differences respect to coals and define the most important characteristics for applications in large scale plants. The devolatilization is the first step in all thermal pro- cesses (combustion, pyrolysis, gasification) and is crucial for alternative fuels, having a very high volatile matter con- tent. The development of experimental procedures for the study of these fuels on a laboratory scale is indispensable to provide useful data for practical applications. The com- parison of results obtained in a wide range of temperature and heating rate, even using different experimental equip- ment, allows the effect of heat and mass transfer on the devolatilization to be evaluated [1–3]. Conventional thermogravimetric (TG) balances operate at relatively low temperature and heating rate. So that parameters obtained this way give only a preliminary or comparative characterization, but can be hardly applicable to practical processes, which operate at high temperature and heating rate. Vice versa, advanced pyrolyzers (fila- ment, Curie-point, microfurnace and wire-mesh types) allow rapid and reproducible runs to be performed at high final temperature. The small amount of the sample used in 0016-2361/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.fuel.2006.06.002 * Corresponding author. Tel.: +39 050511250; fax: +39 050511266. E-mail address: e.biagini@ing.unipi.it (E. Biagini). www.fuelfirst.com Fuel 85 (2006) 2408–2418