Effects of blending bagasse with an aluminosilicate-based additive on bagasse ash properties

Abstract

Bagasse, an abundant form of agricultural waste obtained via sugarcane processing in Southeast Asia, is increasingly usedas fuel in biomass plants. However, the ash generated via bagasse combustion, particularly at high alkali contents, can causesignificant slagging and fouling in boilers and combustors. In this study, an aluminosilicate-based fuel additive was used tochange the properties of ash and mitigate these problems. The ash generated from bagasse combustion exhibited a highpotassium oxide content of 18.38 % and a relatively low alumina content, which is expected to result in ash with a low meltingtemperature. The potassium oxide and calcium oxide contents decreased significantly, whereas the alumina content increasedas the additive blend ratio was increased. Four predictive indices, which were calculated from the chemical compositionsof the ash, indicated that blending with the additive mitigates ash-related problems compared with those associated withthe combustion of bagasse alone. Potassium sulfate was found to be the main mineral phase in the ash of the non-blendedsample. Conversely, the additive-blended samples showed higher contents of kalsilite, lomonosovite, and mutinaite, which areminerals with high melting temperatures. Therefore, blending an aluminosilicate-based additive with bagasse can mitigateash-related problems in boilers and combustors.