Advanced utilisation options for biomass gasification fl y ash

Abstract

The objective of this work was to search sustainable methods for the direct utilisation of the fly ash generated in a 150 kWth fluidised-bed pilot plant using Orujillo waste, a by-product from olive oil industry. An extensive characterization was made over raw ashes generated in the process. Existing (combustion) fly ash utilisation methods were found not to be directly applicable to these gasification ashes because of the high concentrations of unburned carbon and harmful soluble compounds. Further utilisation options for management of these ashes were identified. Two utilisation paths are investigated in detail in this work: the use of ash in the manufacture of gypsum wallboards and bricks with isolation properties. These utilisation options are based on lowcost preparation methods using ash in significant proportion, yielding a considerable high-value product. They represent promising new applications with high market potential. Dedicated tests to assess these two utilisation options are issued and from this the potential application of these routes is discussed. Keyboards: gasification; pilot plant; waste disposal