Research topic III

For the sake of the environment: Evaluation of the reuse potential of the ash accumulating during biomass combustion

Biomass combustion produces various types of ash, including bottom ash and fly ash. Bottom ash is collected below the boiler and is a coarse-grained material. The fine-grained fly ash is removed from the hot flue gases by air pollution control devices, such as electrostatic precipitators, cyclones, and bag filters. Unlike bottom ash, which is commonly used (after tests) as fertilizer, fly ash cannot be used for this purpose because it may contain a higher concentrations of heavy metals. Currently, it is essentially disposed of in landfills. To optimize the whole material cycle, the BIOCOMBUST project is searching for alternatives to disposal. Specifically, we explore the potential of using the fly ashes from biomass combustion as a secondary raw material, for example as a CO₂-neutral clinker substitute in the cement industry. For this purpose, we investigate the fly ashes in detail with regard to their physical, chemical and toxicological properties.

Research topic I        Research topic II        Research topic III