Potential of solid residues from power plants as thermochemical energy storage materials

Due to large amounts of solid residue of oil shales produced every year by thermal processing, new ways of utilizing them are constantly investigated. As the main components of oil shale ash are calcium, magnesium and silica, the material has potential for different areas. In this paper, we investigated the possibility and potential of utilizing Estonian oil shale ash, rich in CaO, for thermochemical energy storage material. The investigated samples included the sources of main ash flow—bottom and electrostatic precipitator ash from two power plants utilizing circulating fluidized bed combustion technology. The ash from the economizer was also analysed as a comparison. The samples were characterized through elemental and chemical analysis and XRF and subjected to thermal analysis in either mixtures or pure environments of N₂ and/or CO₂.