TY - JOUR
T1 - Investigation of the K-Mg-Ca Sulfate System as Part of Monitoring Problematic Phase Formations in Renewable-Energy Power Plants
AU - Tesfaye, Fiseha
AU - Lindberg, Daniel
AU - Moroz, Mykola
AU - Hupa, Leena
N1 - Open access
PY - 2020/10/15
Y1 - 2020/10/15
N2 - Besides the widely applied hydropower, wind farms and solar energy, biomass and municipal and industrial waste are increasingly becoming important sources of renewable energy. Nevertheless, fouling, slagging and corrosion associated with the combustion processes of these renewable sources are costly and threaten the long-term operation of power plants. During a high-temperature biomass combustion, alkali metals in the biomass fuel and the ash fusion behavior are the two major contributors to slagging. Ash deposits on superheater tubes that reduce thermal efficiency are often composed of complex combinations of sulfates and chlorides of Ca, Mg, Na, and K. However, thermodynamic databases involving all the sulfates and chlorides that would favor a better understanding and control of the problems in combustion processes related to fouling, slagging and corrosion are not complete. In the present work, thermodynamic properties including solubility limits of some phases and phase mixtures in the K2SO4-(Mg,Ca)SO4 system were reviewed and experimentally investigated. Based on the new and revised thermochemical data, binary phase diagrams of the K2SO4-CaSO4 and K2SO4-MgSO4 systems above 400 °C, which are of interest in the combustion processes of renewable-energy power plants, were optimized.
AB - Besides the widely applied hydropower, wind farms and solar energy, biomass and municipal and industrial waste are increasingly becoming important sources of renewable energy. Nevertheless, fouling, slagging and corrosion associated with the combustion processes of these renewable sources are costly and threaten the long-term operation of power plants. During a high-temperature biomass combustion, alkali metals in the biomass fuel and the ash fusion behavior are the two major contributors to slagging. Ash deposits on superheater tubes that reduce thermal efficiency are often composed of complex combinations of sulfates and chlorides of Ca, Mg, Na, and K. However, thermodynamic databases involving all the sulfates and chlorides that would favor a better understanding and control of the problems in combustion processes related to fouling, slagging and corrosion are not complete. In the present work, thermodynamic properties including solubility limits of some phases and phase mixtures in the K2SO4-(Mg,Ca)SO4 system were reviewed and experimentally investigated. Based on the new and revised thermochemical data, binary phase diagrams of the K2SO4-CaSO4 and K2SO4-MgSO4 systems above 400 °C, which are of interest in the combustion processes of renewable-energy power plants, were optimized.
KW - Sulfates
KW - Thermodynamic modeling
KW - Superheater tubes
KW - High-temperature processes
KW - Slagging and fouling management
U2 - 10.3390/en13205366
DO - 10.3390/en13205366
M3 - Article
SN - 1996-1073
VL - 13
SP - 5366
JO - Energies
JF - Energies
IS - 20
M1 - 5366
ER -