Physico-chemical upgrading of agroresidues as solid biofuels

Two types of agroresidues, wheat straw and olive kernels, which are considered to be of premium importance for electricity production through combustion or gasification, were studied with respect to upgrading them by use of the pretreatment techniques of fractionation, leaching and both combined. Both the pretreated and the untreated samples were analyzed in order to determine the effect of the pretreatment on the ash and the ash chemistry of the pretreated samples compared with the untreated samples. The ash behaviour of the untreated and the pretreated samples was characterized by simple sintering tests performed in a laboratory muffle furnace, whereas a number of the thermally treated samples were further characterized with the use of SEM-EDX techniques.