* *大如何泄漏必须抵消积极作用?* *在一个大概的估计…沼气替代天然气。为简单起见我们假设1:1置换,一摩尔甲烷的沼气*替换一摩尔的天然气。这也意味着,一摩尔的甲烷,“保存”1摩尔的二氧化碳。甲烷是密集的25倍cliamte改变比二氧化碳。如果泄漏100/25 = 4%,积极影响将被抵消。影响气体泄漏的因素,从最大的到最小的影响(这是大部分来自记忆):*底物的保留时间不透气系统,根据保留时间消化器,digestate可能仍有10%左右的总沼气潜力,当digestate存储是开放和荷尔蒙替代疗法是短暂的。之后的一个迭代的德国rennewable能源法律指定150天气密系统中的保留时间因为这个原因&我认为这是合理的对许多基质。*泄漏箔屋顶-箔屋顶是常见的大型坦克,尤其是连接屋顶箔/蒸煮器是一种常见的泄漏。(本研究从植物中发现泄漏率)[1]0至20 Nm³/ h(平均5 - 10海里³/ h),但可能没有给出尺寸的植物约500 Nm³/ h沼气生产。 * Methane slip - I don't have numbers to go by, but I think 0.5-1% of gas slip (unburnt gas in the exhaust) in IC motors is common. This regardless of wether you burn natural gas or biogas, AFAIK. * Manure storage - some wastes will ferment on their own, esp. manure. * Everything else - IMO the art of building gas pipes etc. is pretty well developed, if proper procedures are followed and proper materials used leakages from pipes should be neglible. In summary, the methane loss of biogas plants may well be above the 4% cutoff point I mentioned above, or well below, depending on plant design and quality of building. However, as you pointed out in comments to your question, you need to also look at what would happen to the feedstock without biogasification. Manure would ferment (but not as completely) in an open pit and emit gasses. Municipal wastes would be either incinerated (likely with additional fuel because of the high moisture content), composted or landfilled (landfilled wastes also ferment and produce biogas, if this goes to the atmosphere, is flared or used productivly depends on the site). I have worked in landfill supervision and design of biogas plants. At this point, I lack good numbers to really compare biogasification to other disposal paths. Having worked in landfill supervision and design of biogas plants, I have more trust in a properly designed biogas plant to keep methane out of the atmosphere than in a typically, well maintained landfill. But I'm sure you can find shoddy biogas plants that leak, for the same amount of input, worse than some landfills! Likewise, [I'm still looking for hard numbers of fuel usage for incineration of biowastes][2], so I can't offer a good comparison here. So IMO, while biogas from energy crops is highly questionable, biogasification of wastes is a net benefit if done properly. *biogas is anything between 50 and 70% methane, the rest CO2 and traces. [1]: https://publikationen.sachsen.de/bdb/artikel/15246/documents/18428 [2]: http://sustainability.stackexchange.com/questions/4772/co-firing-fossil-fuels-use-in-waste-incineration