Pyrolysis of olive pomace and copyrolysis of olive pomace with refuse derived fuel

Abstract

Pyrolysis of olive pomace and copyrolysis of olive pomace with RDF blends were investigated by TGA. To see the effect of heating rate on pyrolysis behavior and kinetic parameters of olive pomace, TG and DTG curves were obtained at three different heating rates (10, 20, and 30°C min−1) between 20°C and 800°C. The results showed that activation energy decreased as the heating rate was increased. In the pyrolysis profile of olive pomace, weight loss was observed almost in one stage where two peaks overlapped between temperatures 170–372°C, having a highest peak at 342°C. In the case of olive pomace‐RDF blends, copyrolysis experiments were conducted under N2 atmosphere at a heating rate of 10°C min−1 from 20°C to 800°C. The pyrolysis profile of the blends presented three peaks (except moisture removal) meaning three consecutive reactions: cellulose‐hemicellulose decomposition, plastics decomposition and CaCO3 decomposition. Lignin decomposition comprised all the stages. Because of its high activation energy, using olive pomace alone in the pyrolysis reaction required a high temperature operation or long reaction time in the reactor. Blending it with RDF decreased the activation energy, decreased the peak temperatures, increased the number of pyrolysis stages (decomposition of plastics and inorganic carbonate based additives), and increased the time required for higher conversion rates. RDF which had a high ash content and low calorific value was found as more useful as a fuel when it was blended with olive pomace. Lower activation energies observed in the relevant decomposition stages indicated that the reaction became faster upon blending. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 649–656, 2014