A comparative study of steam gasification and combustion methods for landfill stale waste (LSW) treatment

Landfill stale waste (LSW) poses considerable environmental issues, especially concerning methane emissions and the ecosystem contamination. This research investigates the potential for energy recovery and the emission profiles of LSW combustibles via steam gasification at various temperatures (700, 750, 800, and 850 °C) and combustion at 850 °C, utilizing a fixed-bed reactor and TG-DSC analysis. Our findings indicate that steam gasification conducted at 850 °C yields a high-quality syngas with a hydrogen concentration of 46.9%, which greatly increased efficiency. Conversely, combustion occurring at the same temperature leads to total oxidation, yet it produces increased emissions of nitrogen oxides (NO_x) and sulphur dioxide (SO₂). Significantly, NO_x emissions resulting from steam gasification are approximately 75% lower compared to those produced by combustion. Although SO₂ emissions are slightly higher in gasification, the overall environmental impact is lower. This research highlights that steam gasification can be applied as an effective method for treating LSW combustibles, providing enhanced energy recovery and reduced emissions and thereby promoting sustainable waste management practices.