Sequestration of Landfill Gas Emissions Using Basic Oxygen Furnace Slag

Fugitive methane (CH4) and carbon dioxide (CO2) emissions from organic waste decomposition at municipal solid waste (MSW) landfills, commonly known as landfill gas (LFG), constitute one of the major anthropogenic sources of greenhouse gas (GHG) emissions to the atmosphere (US EPA). In recent years, biocovers involving the addition of organic-rich amendments to landfill cover soils have promoted microbial oxidation of CH4 to CO2, thereby reducing CH4 emissions from landfill. Although the CH4 emissions are controlled, a considerable amount of CO2 that is still emitted into the atmosphere as a result of microbial oxidation of CH4 in landfill covers as well as the CO2 prevailing from MSW decomposition. Complementing the CH4 oxidizing biocover with CO2 sequestration is considered to have the ability to result in a “zero-emission” landfill. Accordingly, carbon capture and storage (CCS) techniques using alkaline industrial by-products such as basic oxygen furnace (BOF) slag adds an important dimension to potentially sustainable solutions to the challenge of landfill gas emission. The main research objective was to deduct the capacity of BOF slag to capture CO2 from a synthetic LFG mixture and learn the mechanisms involved in carbonation with respect to two main parameters effecting CO2 sequestration by BOF slag: moisture and particle size.