Various operational conditions were experimentally simulated on a laboratory and pilot plant scale. Relevant operational changes were executed and the effects on the process documented. The experiments focused on extreme situations of the biogas process, aimed at registering the individual reactions through measurable parameters and, if possible, incorporate the findings into the simulation program developed by the project partner Helmut Schmidt University Hamburg.
The results have clearly demonstrated the stepwise reaction that leads to biogas production, which characterizes the direct correlation between acids concentration and biogas production. The data density of the online measurements allowed the minute-exact identification of the shift from one preferred metabolic pathway to another.
In addition, further correlations could be presented, which are currently not shown in the standard models such as ADM1. The stoichiometric distribution of metabolic products is approximately correct, a thermodynamic consideration is also relevant in the more extreme cases of the anaerobic digestion process.
 Batstone, D. J.; Keller, I.; Angelidaki, I.; Kalyuzhnyi, S. V.; Pavlostathis, S. G.; Rozzi, A.; Sanders, W. T. M.; Siegrist, H.; Vavilin, V. A. (2002) The IWA Anaerobic Digestion Model No 1 (ADM1), Water Science and Technology Vol. 45, Nr. 10, pp. 65-73