Waste Manag Res. 2013 Oct;31(10):1002-11. doi: 10.1177/0734242X13492004.
Landfilling is the most common and cost-effective waste disposal method, and it is widely applied throughout the world. In developing countries in Asia there is currently a trend towards constructing sanitary landfills with gas recovery systems, not only as a solution to the waste problem and the associated local environmental pollution, but also to generate revenues through carbon markets and from the sale of electricity. This article presents a quantitative assessment of climate co-benefits from landfill gas (LFG) to energy projects, based on the case of Bangkok Metropolitan Administration, Thailand. Life cycle assessment was used for estimating net greenhouse gas (GHG) emissions, considering the whole lifespan of the landfill. The assessment found that the total GHG mitigation of the Bangkok project would be 471,763 tonnes (t) of carbon dioxide (CO(2))-equivalents (eq) over its 10-year LFG recovery period.This amount is equivalent to only 12% of the methane (CH(4)) generated over the whole lifespan of the landfill. An alternative scenario was devised to analyse possible improvement options for GHG mitigation through LFG-to-energy recovery projects. This scenario assumes that LFG recovery would commence in the second year of landfill operation and gas extraction continues throughout the 20-year peak production period. In this scenario, GHG mitigation potential amounted to 1,639,450 tCO(2)-eq during the 20-year project period, which is equivalent to 43% of the CH(4) generated throughout the life cycle. The results indicate that with careful planning, there is a high potential for improving the efficiency of existing LFG recovery projects which would enhance climate co-benefits, as well as economic benefits. However, the study also shows that even improved gas recovery systems have fairly low recovery rates and, in consequence, that emissions of GHG from such landfills sites are still considerable.
填埋是最常见和最具成本效益的废物处理方法，在世界范围内得到广泛应用。在亚洲的发展中国家，目前有一种趋势是建造带有气体回收系统的卫生填埋场，这不仅是解决废物问题和相关的当地环境污染的一种方法，也是通过碳市场和出售电力来产生收入的一种方法。本文以泰国曼谷都市区管理局为例，对垃圾填埋气（LFG）到能源项目的气候协同效益进行了定量评估。生命周期评估用于估算净温室气体（GHG）排放，考虑了垃圾填埋场的整个生命周期。评估发现，曼谷项目的总 GHG 减排量将在其 10 年的 LFG 回收期内达到 471763 吨二氧化碳（CO2）当量（eq）。这一数量仅相当于整个填埋场生命周期中产生的甲烷（CH4）的 12%。设计了一个替代方案来分析通过 LFG 到能源回收项目实现 GHG 减排的可能改进方案。该方案假设 LFG 回收将在垃圾填埋场运营的第二年开始，并且气体提取将在 20 年的高峰期持续进行。在这种情况下，20 年项目期间的 GHG 减排潜力达到 1639450 吨二氧化碳（CO2）当量，相当于整个生命周期中产生的 CH4 的 43%。结果表明，通过精心规划，提高现有 LFG 回收项目效率的潜力很大，这将提高气候协同效益和经济效益。然而，该研究还表明，即使是改进的气体回收系统也只有相当低的回收率，因此，这些垃圾填埋场的温室气体排放仍然相当可观。
