Lindorfer H, Braun R, Kirchmayr R
BOKU - University of Natural Resources and Applied Life Sciences, Vienna, Department for Agrobiotechnology, IFA-TulIn, Institute for Environmental Biotechnology, Konrad Lorenz Str. 20, 3430 Tulln, Austria.
Water Sci Technol. 2006;53(8):159-66. doi: 10.2166/wst.2006.246.
With the increasing application of energy crops in agricultural biogas plants and increasing digester volumes, the phenomenon of self-heating in anaerobic digesters appeared in some cases. Until now this development was just known from aerobic systems. To obtain an idea of the thermodynamics inside an anaerobic digester, a detailed analysis of all heat fluxes in a full-scale agricultural biogas plant was carried out. Several experiments were realised to quantify the influences of different internal and external energy sources. To estimate the impact of self-heating in anaerobic systems, data of other full-scale agricultural biogas plants in Austria were collected. Alternatives to the cooling of the digesters are discussed based on individual experiences of several plants. A connection between carbohydrate-rich substrates, especially with high starch contents, and the self-heating could be shown. From the results it can be assumed that the anaerobic digestion of most energy crops is exothermic, which is in contrast to the current thermodynamic belief.
随着能源作物在农业沼气厂中的应用不断增加以及消化池容积的增大，厌氧消化池中出现了自热现象。到目前为止，这种现象仅在好氧系统中出现过。为了了解厌氧消化池内部的热力学情况，对一座大型农业沼气厂中的所有热通量进行了详细分析。开展了多项实验以量化不同内部和外部能源的影响。为评估厌氧系统中自热的影响，收集了奥地利其他大型农业沼气厂的数据。基于多家工厂的个别经验，讨论了消化池冷却的替代方案。结果表明富含碳水化合物的底物，尤其是淀粉含量高的底物与自热之间存在关联。从结果可以推测，大多数能源作物的厌氧消化是放热的，这与当前的热力学观点相反。
