Devolatilization Behavior and Pyrolysis Kinetics of Potential Tunisian Biomass Fuels

Biomass thermochemical conversion is complex and requires a good understanding of the thermal decomposition process. This process may be identified using mass loss kinetics which are useful for the design of proper equipment used for biomass conversion. This work aims to determine devolatilization kinetic parameters characterizing four Tunisian biomass species: industrial by product (Pine Sawdust), agro-industrial by product (Olive Solid Waste), agricultural residue (Date Palm Trunk) and seaweed (Posidonia Oceanica) using data from non-isothermal thermogravimetry and the Coats and Redfern calculation method. Decomposition TG and DTG data were analyzed by applying 10 kinetic models including processes governed by nuclei growth, surface nucleation followed by geometric, diffusion and chemical reaction models. Obtained results show that biomass pyrolysis is represented by two successive steps: (i) devolatilization stage characterized by high weight loss rate, which is well described by diffusional, surface nucleation followed by geometric and first order chemical reaction models. (ii) char formation stage characterized by low weight loss rate, which is well described by second order and third order chemical reaction models. (c) 2014 American Institute of Chemical Engineers Environ Prog, 33: 1452-1458, 2014