Study of biomass combustion wastes

• SEM images generally showed homogeneous finely divided structures after 550 °C burning.
• Wood pellets sample presented more than 35% of fly ashes (under 200 μm).
• None sample presented PM10 over 3%. PM2.5 were all negligible meaning low health risk.
• Some samples presented high deposition and corrosion risks. Alkali and Cl presence.

A number of widely referenced environmental and logistic advantages suggest biomass as an interesting feedstock to obtain energy in large quantities. One of the most important problems when using biomass is the amount of solid wastes produced, which causes deposition and corrosion phenomena (slagging and fouling) entailing energy efficiency decrement and maintenance problems.This work focuses on the study of ashes from eighteen different biomass samples, including energy crops, agricultural, industrial and forestry wastes and commercial fuels.Morphology (SEM) and grain size (PSD-LD) studies showed a homogeneous structure with low quantities of health risky fine particles for most samples after 550 °C burning.Compositional studies (EDXA, XRF) suggested that some of the studied samples, such as almond shell or rice husk, may respectively present high deposition and corrosion risks.