Curricular Innovation Research in the Field of Renewable Energy Using the Example of Anaerobic Digestion and Methane Production

Abstract

In school and university education it is important to integrate current, innovative topics into curricula. Particularly in the field of education for sustainable development, there is a major need, based on the Sustainable Development Goals, to prepare the topics didactically, and to present them to school pupils at an early stage. This kind of research is known as "curricular innovation research". The production of biogas is an important topic as it is a source of renewable energy. More than 9000 biogas plants are currently in operation in Germany. It has been reported that no methane was measured in the state-of-the-art methods used in school experiments. A new experimental set-up was, therefore, developed to guarantee methane formation during these experiments, and to demonstrate the production of biogas in a hands-on way. Dried sugar beet was used as the substrate for biogas production. It was mixed with compost or garden soil which contains the microorganisms needed for biogas and methane production, and was used as the inoculum. A low-cost gas chromatograph served to measure the methane concentration in the biogas produced. In a first attempt to guarantee methane formation, sodium carbonate was added as a buffer to maintain the pH of the fermentation broth in the optimum range (7-8). Then, to avoid buffer addition, the optimum compost to sugar beet ratio was investigated in cooperation with the University of Hohenheim. Based on these results, methane formation was observed after 8 days, and methane concentrations up to 65 vol % were measured. Overall, this experiment constituted a hands-on way of demonstrating to school pupils the anaerobic digestion process through the production of biogas. This study also highlighted the major benefits of interdisciplinary cooperation in the field of curricular innovation research.