Manfredi Simone, Niskanen Antti, Christensen Thomas H
Department of Environmental Engineering - Technical University of Denmark, DTU-Building 115, DK-2800 Kgs. Lyngby, Denmark.
Waste Manag. 2009 May;29(5):1588-94. doi: 10.1016/j.wasman.2008.10.005. Epub 2008 Dec 9.
The current landfill gas (LFG) management (based on flaring and utilization for heat generation of the collected gas) and three potential future gas management options (LFG flaring, heat generation and combined heat and power generation) for the Old Ammässuo landfill (Espoo, Finland) were evaluated by life-cycle assessment modeling. The evaluation accounts for all resource utilization and emissions to the environment related to the gas generation and management for a life-cycle time horizon of 100 yr. The assessment criteria comprise standard impact categories (global warming, photo-chemical ozone formation, stratospheric ozone depletion, acidification and nutrient enrichment) and toxicity-related impact categories (human toxicity via soil, via water and via air, eco-toxicity in soil and in water chronic). The results of the life-cycle impact assessment show that disperse emissions of LFG from the landfill surface determine the highest potential impacts in terms of global warming, stratospheric ozone depletion, and human toxicity via soil. Conversely, the impact potentials estimated for other categories are numerically-negative when the collected LFG is utilized for energy generation, demonstrating that net environmental savings can be obtained. Such savings are proportional to the amount of gas utilized for energy generation and the gas energy recovery efficiency achieved, which thus have to be regarded as key parameters. As a result, the overall best performance is found for the heat generation option - as it has the highest LFG utilization/energy recovery rates - whereas the worst performance is estimated for the LFG flaring option, as no LFG is here utilized for energy generation. Therefore, to reduce the environmental burdens caused by the current gas management strategy, more LFG should be used for energy generation. This inherently requires a superior LFG capture rate that, in addition, would reduce fugitive emissions of LFG from the landfill surface, bringing further environmental benefits.
通过生命周期评估模型，对芬兰埃斯波市旧阿马苏奥垃圾填埋场目前的填埋气（LFG）管理（基于对收集到的气体进行燃烧和用于发电供热）以及三种潜在的未来气体管理方案（LFG燃烧、发电供热以及热电联产）进行了评估。该评估考虑了在100年的生命周期时间范围内，与气体产生和管理相关的所有资源利用情况以及对环境的排放。评估标准包括标准影响类别（全球变暖、光化学臭氧形成、平流层臭氧消耗、酸化和营养物富集）以及与毒性相关的影响类别（通过土壤、水和空气对人类的毒性、土壤和水中的生态毒性慢性影响）。生命周期影响评估结果表明，垃圾填埋场表面LFG的分散排放决定了在全球变暖、平流层臭氧消耗以及通过土壤对人类的毒性方面具有最高的潜在影响。相反，当收集到的LFG用于能源生产时，对其他类别的潜在影响估计在数值上为负，这表明可以实现净环境效益。这种效益与用于能源生产的气体量以及实现的气体能量回收效率成正比，因此必须将其视为关键参数。结果发现，发电供热方案的整体性能最佳，因为它具有最高的LFG利用率/能量回收率，而LFG燃烧方案的性能最差，因为在此方案中没有LFG用于能源生产。因此，为了减轻当前气体管理策略造成的环境负担，应将更多的LFG用于能源生产。这本质上需要更高的LFG捕获率，此外，这还将减少垃圾填埋场表面LFG的无组织排放，带来进一步的环境效益。
