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

垃圾填埋场中的城市固体废物(MSW)如果未经处理，会经历缓慢的厌氧消化过程，产生甲烷气体。甲烷(CH4)和二氧化碳是主要的温室气体。甲烷在大气中捕获的热能是二氧化碳的25倍。另一方面，城市固体废物可以被认为是一种可再生的替代燃料。厌氧填埋气中含有甲烷(~50%)、二氧化碳(~40%)、氮气(~5%)、氧气(~1%)和其他0.5%的微量组分。在全球范围内，城市固体废物填埋场约占人为甲烷的14%。在甲烷被释放到大气中之前捕获甲烷，或者通过在垃圾填埋场通风来减少甲烷的产生，可以改善气候。该研究和开发项目的主要目标是使用好氧城市固体废物(MSW)处理工艺，减少温室气体(GHG)，特别是艾伯塔省麦克默里堡伍德布法罗垃圾填埋场的甲烷排放。为了尽量减少垃圾填埋气体的影响，这些气体将被收集并转移到气体分离和净化单元，在那里CH4和CO2以及其他气体分子，如硫化氢、水蒸气、氨和挥发性有机化合物(VOCs)将被分离和净化。采用变压吸附(PSA)和/或变温吸附(TSA)技术，使用不同的多孔吸附剂，如沸石材料，将垃圾填埋气分离。提纯的二氧化碳将用于不同的过程，包括培养藻类，而提纯的生物甲烷可以用作可持续的可再生燃料来源。还将研究好氧工艺对渗滤液产生及其质量的影响，以及开发一种工艺，在渗滤液进入地下水流之前对其进行处理。高选择性的天然沸石将被考虑用于去除有毒元素(如重金属、氨、挥发性有机化合物等)。来自MSW垃圾填埋场渗滤液。目前的好氧处理工艺的另一个潜在结果是在垃圾填埋场开采过程中使用加拿大天然沸石和改性沸石开发出高质量和环保的堆肥。

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.