Thermochemical conversion of coal from Rio Turbio minefield with a sustainable energy plantation: on kinetics of co-pyrolysis

P. R. BONELLI; D. ZILLI; J. D. GONZALEZ; E. L. BUONOMO; A. L. CUKIERMAN

BUENOS AIRES, ARGENTINA

Congreso; XXII Interamerican Congress of Chemical Engineering, V Argentinean Congress of Chemical Engineering; 2006

ASOCIACION ARGENTINA DE INGENIEROS QUIMICOS, CONFEDERACION INTERAMERICANA DE INGENIERIA QUIMICA

Kinetics of co-pyrolysis of blends composed of equal proportions of the subbituminous coal from the Río Turbio minefield and stems from giant reed (Arundo donax L.), as representative biomass from sustainable energy plantations, is characterized accounting for the individual pyrolytic behavior and main physicochemical properties of both fuels. Non-isothermal thermogravimetric measurements for the blend and individual constituents, from ambient temperature up to 900 ºC under flowing nitrogen, and data modeling are performed. Coal pyrolysis begins at a higher temperature (~275 °C) and proceeds more gradually than the biomass, whereas the blend exhibits an intermediate pyrolytic behavior between those of the constituent fuels. A model which assumes variations in the activation energy with process evolution, through an increasing dependence on temperature and solid conversion, provides a suitable description of pyrolysis and co-pyrolysis results over the entire temperature range. The higher content of volatile matter of the biomass and differences in chemical structure between coal and biomass explain the pyrolytic behavior ascertained for the individual fuels and the blend. They are reflected in the estimated kinetic parameters.