TY - JOUR
T1 - Converting ash into reusable slag at lower carbon footprint
T2 - Vitrification of incineration bottom ash in MSW-fueled demonstration-scale slagging gasifier
AU - Heberlein, Stephan
AU - Chan, Wei Ping
AU - Hupa, Leena
AU - Zhao, Ya
AU - Lisak, Grzegorz
N1 - Publisher Copyright:
© 2024 Elsevier Ltd
PY - 2024/2
Y1 - 2024/2
N2 - Globally waste incineration is becoming the predominant treatment method of solid waste. The largest fraction of solid residue of this process is incineration bottom ash (IBA) requiring further treatment before applications such as in the construction industry become feasible. In this study, vitrification of IBA was conducted in a demonstration-scale high-temperature slagging gasification plant fueled with MSW and biomass charcoal as a green auxiliary fuel. High IBA co-feeding rates of up to 491 kg/h (equivalent to 107% of MSW feeding rate) were achieved during the trials. A highly leaching-resistant slag immobilizing heavy metals in the glass-like amorphous structure and recyclable iron-rich metal granules were generated in the process. The heavy metal migration into the solid by-product fractions depended on the IBA feeding rates and process conditions such as cold cap temperature, charcoal-to-ash ratio, and gasifier temperature profile. Slaked lime and activated carbon powder were used in a dry flue gas treatment and stack gas emissions were kept well below Singapore's regulatory limits. Steam from the hot flue gas was generated in a boiler to drive a steam turbine. The application of biomass charcoal instead of fossil fuels or electricity lead to a lower carbon footprint compared to alternative vitrification technologies. The overall results reveal promising application of high temperature slagging gasification process for commercial-scale vitrification of IBA.
AB - Globally waste incineration is becoming the predominant treatment method of solid waste. The largest fraction of solid residue of this process is incineration bottom ash (IBA) requiring further treatment before applications such as in the construction industry become feasible. In this study, vitrification of IBA was conducted in a demonstration-scale high-temperature slagging gasification plant fueled with MSW and biomass charcoal as a green auxiliary fuel. High IBA co-feeding rates of up to 491 kg/h (equivalent to 107% of MSW feeding rate) were achieved during the trials. A highly leaching-resistant slag immobilizing heavy metals in the glass-like amorphous structure and recyclable iron-rich metal granules were generated in the process. The heavy metal migration into the solid by-product fractions depended on the IBA feeding rates and process conditions such as cold cap temperature, charcoal-to-ash ratio, and gasifier temperature profile. Slaked lime and activated carbon powder were used in a dry flue gas treatment and stack gas emissions were kept well below Singapore's regulatory limits. Steam from the hot flue gas was generated in a boiler to drive a steam turbine. The application of biomass charcoal instead of fossil fuels or electricity lead to a lower carbon footprint compared to alternative vitrification technologies. The overall results reveal promising application of high temperature slagging gasification process for commercial-scale vitrification of IBA.
KW - Ash melting
KW - Carbon footprint analysis
KW - Heavy metal leaching
KW - Metal migration
KW - Stack gas emission analysis
UR - http://www.scopus.com/inward/record.url?scp=85182737399&partnerID=8YFLogxK
U2 - 10.1016/j.jenvman.2023.119967
DO - 10.1016/j.jenvman.2023.119967
M3 - Article
C2 - 38237332
AN - SCOPUS:85182737399
SN - 0301-4797
VL - 352
JO - Journal of Environmental Management
JF - Journal of Environmental Management
M1 - 119967
ER -