Renewable Energy, Vol.147, 1139-1150, 2020
Biofuel quality analysis of fallen leaf pellets: Effect of moisture and glycerol contents as binders
The gardens from the University of Antioquia main campus (Colombia) produce similar to 2.8 tons of fallen leaves (FL) per month on a dry weight basis. A sample of this garden waste was pelletized (fallen leaves pellets, FLP). Accordingly, the physical and thermochemical properties of FLP were characterized for use as solid biofuel. The densification of FL was carried out with varying moisture (10, 15 and 20 wt%) and the glycerol contents (0, 5, and 10 wt%) as binders following a multifactorial statistical experimental design. In particular, the significant effect of the glycerol content on physical properties of FLP is noteworthy, as its increase influenced bulk density, which decreased from 524 to 380 kg/m(3). Furthermore, it was found that with the simultaneous increase of moisture and glycerol contents, tensile strength decreased by 10%, but the elastic behavior of pellets was elevated, leading to increases in their deformation capacity from 0.75 mm to 2.35 mm. This behavior can also be checked with superficial hardness of FLP, which decreased by up to 70% when the glycerol content increased. The fuel value index of FLP diminished by 15% with the glycerol content, while the volatile matter increased, leading to improve the reactivity of the pellets. (C) 2019 Elsevier Ltd. All rights reserved.
Keywords:Leaf litter residue;Garden waste;Densification;Binder;Pellets characterization;Sustainable university campus