Biomass vs coal ashes: resource or environmental issue?

This works is focused on the characterization of different kind of fly ashes coming from combustion of coal and different types of biomass, with the goal of understanding the differences between each other in terms of chemical and mineralogical composition, grain size and micro-structure. A set of samples coming from gasification plants, biomass combustion (forest chips, grapevine pruning, thistles, olive-tree pruning) and coal power plants are analyzed. The bulk analysis of samples is made by means of Energy Dispersive X-ray Spectrometry (EDS) for chemical characterization, X-Ray Powder Diffraction (XRPD) treated with Rietveld method for quantitative mineralogical characterization, and thermogravimetric measurements for determining the amount of volatile components. Back Scattered Electrons (BSE) images of sections, integrated with further EDS point analyses, allowed to characterize the internal structure of the particles within the ashes. Preliminary results of the analyses, which are run within the framework of a wider research project, are presented.