Production of Pelletized Fuel from Biodiesel-Production Wastes: Oil Palm Fronds and Crude Glycerin

Biomass from agricultural residue is regarded as an important source of renewable energy in Thailand due to tremendous annual production. One of the country’s largest and most available crop residues is obtained from oil palm plantations. The residue is mainly used for biodiesel feedstock. Thus, this study was aimed to investigate the potential of using oil palm fronds to produce pelletized fuel. To improve the calorific property of the fuel, crude glycerin obtained from biodiesel-processing production was combined with ground fronds as a biomass binder. The glycerin content, ranging from 19 to 45% (by weight), enhanced the heating value of the oil palm fronds from 17.2 MJ/kg (no addition of glycerin) to 17.8-20.4 MJ/kg. The fuel properties, which were examined by the proximate and ultimate analyses, comply with the quality demands of pelletized fuel suggested by the European Biomass Industry Association. Although the combustion ash content was found to be higher than the criterion, the ash chemical composition was found to be suitable for being used as a cement-replacement material. The result of preconditioning the crude glycerin with pH adjustment indicated that the preconditioning did not appear to have the effect on the fuel quality of the palm frond pellets.