Systematic Investigation of Solid Residues From Three German Biomass Power Plants

Residues from three waste wood combustion plants in Germany - two grate combustion plants and one fluidized bed combustion plant - were investigated. Chemical and mineralogical characterization showed similar findings to literature data about MSWI residues. Especially element partitioning and mineralogical composition are comparable. Nevertheless, high carbon concentrations in cyclone and fly ashes show that burnout in waste wood combustion especially with grate combustion technique is poorer than in MSWI combustion. Waste wood combustion bottom ashes consist mainly of
quartz, silicates and carbonates, whereas in cyclone and fly ashes sulfates, chlorides and fluorides prevail. Evaluation for possible utilization path using characterization and leaching tests on fresh and stored bottom ashes were not satisfying due to high solubility of Cr, Pb and Zn.