Utilization of spelt wheat hull as a renewable energy source by pelleting

Abstract

Spelt wheat is an old crop, which is regaining its popularity with arisen interest for organic food. This crop is characterized by its hard hull, which must be removed in Spelt processing and utilization for food. Agricultural waste, such as spelt hull, which falls in the category of biomass, can be considered as renewable energy source and be used for energy generation. The percentage of waste in form of hull can rise up to 30%. In order to achieve better conversion of biomass to energy, it is necessary to conduct a pre-treatment of the raw material. In this study, pelleting was used as a pre-treatment of raw material. Production of quality biomass pellets requires preparation of raw material, which implies milling and conditioning. Main goal of this study was to determine physical and chemical properties of pellets made from spelt hull, as well as specific energy consumption during pelletizing process in dependence of form of added water during conditioning process. Spelt hull proved to be good raw material for production of fuel pellets, with some minor aberrations in comparison to the fuel pellet standards (ÖNORM M 7135, DIN 51731, SS 187120). Since these standards are manly for wood, and wood-residue pellets, lower criteria could be applied for agricultural biomass pellets, such as spelt pellets. Steam conditioning did cause some reduction in energy consumption for pelleting of spelt hull, but from this study, it can be concluded that adding water as a preparation method can also be used, without significant looses in pellet quality and with savings in energy consumption for pellet production.