Novel thermodynamic early warning method for anaerobic digestion failure of energy crops
Novel thermodynamic early warning method for anaerobic digestion failure of energy crops
复制标题
能源作物厌氧消化失败热力学预警新方法
DOI：
10.1016/j.biortech.2020.123440
复制
发表时间：
2020
影响因子：
11.4
通讯作者：
Sun Yongming
中科院分区：
文献类型：
--
作者：
Xiao Fan;Li Ying;Sun Yongming
为了研究厌氧消化过程的热力学计算是否可以应用于不稳定厌氧消化的早期预警，一组饲喂能源作物（杂交狼尾草）的半连续消化池通过逐步增加有机负荷率进行操作，直到发生过载。在此过程中定期监测沼气产量和含量、pH、碱度、挥发性脂肪酸以及甲烷/二氧化碳（CH 4/CO 2）和挥发性脂肪酸/碱度比等传统预警指标。根据 Nernst 和 Van’t Hoff 方程计算了戊酸、丁酸和丙酸产甲烷阶段的吉布斯自由能变化 (Δ G)。结果表明，三个互养产甲烷阶段的ΔG可以作为不稳定厌氧消化的预警指标，最多可以提前21天指示厌氧消化失败（停止产生沼气），即比其他指标提前1-8天。
To investigate whether thermodynamic calculations of anaerobic digestion processes can be applied to the early warning for unstable anaerobic digestion, a group of semi-continuous digesters fed with an energy crop (Hybrid Pennisetum) were operated via a step-wise increase in the organic load rates until overload occurred. Traditional early warning indicators, such as biogas production and content, pH, alkalinity, and volatile fatty acids as well as the methane/carbon dioxide (CH 4/CO 2) and volatile fatty acid/alkalinity ratios, were regularly monitored during the process. The Gibbs free energy changes (Δ G) of the methanogenesis phases of valerate, butyrate, and propionate were calculated based on Nernst and Van’t Hoff equations. The results demonstrate that Δ G of the three syntrophic methanogenesis phases can be used as an early warning indicator for unstable anaerobic digestion, indicating anaerobic digestion failure (ceased biogas production) up to 21 days in advance, that is, 1–8 days earlier than some other indicators.