Aerobic municipal landfill treatment, reduction of greenhouse gases, selective adsorption of carbon dioxide

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Municipal solid wastes (MSW) in landfills, if left untreated undergo a slow anaerobic digestion process producing methane gas. Methane (CH4) and CO2 are the major greenhouse gases (GHG). Methane traps 25 times more thermal energy in the atmosphere than CO2. On the other hand, municipal solid waste can be considered as a renewable alternative fuel. Landfill gases in an anaerobic process usually consist of CH4(~50%), CO2(~40%), nitrogen(~5%), oxygen (~1%) and 0.5% other trace components. Globally, urban solid waste landfills account for ~14% of anthropogenic methane. Capturing methane before it is released into the atmosphere or reducing its production by aeration of the landfill improves the climate. The main objective of this research and development project is to reduce greenhouse gas (GHG), and in particular, methane emissions from the Wood Buffalo Landfill located in Fort McMurray, Alberta; using an aerobic municipal solid waste (MSW) treatment process. In order to minimize the impact of the landfill gases, the gases will be collected and transferred to the gas separation and purification unit, where CH4 and CO2 and other gas molecules such as H2S, water vapor, ammonia and volatile organic compounds (VOCs) will be separated and purified. A pressure swing adsorption (PSA) and/or temperature swing adsorption (TSA) technique using different porous adsorbents such as zeolitic materials will be used to separate the landfill gas stream. The purified CO2 will be used for different processes including growing algae, whereas the purified biomethane can be used as a sustainable source of renewable fuel. The impact of the aerobic process on leachate generation and its quality as well as the developing a process in which the leachate will be treated before entering the groundwater streams will also be studied. Highly selective natural zeolites will be considered for removal of toxic elements (e.g. heavy metals, ammonia, VOCs, etc.) from MSW landfill leachate. Another potential outcome of the present aerobic treatment process is developing a high quality and eco-friendly compost deploying the Canadian natural and modified zeolites during the course of landfill mining.