Figure 2. Three-hole stopper at the top of the biogas reactor used in a school experiment

From

Energy Supply with Biogas – An Example of Curricula Innovation Research in the Field of Renewable Energy

Isabel Rubner, Linda Baur, Bettina Grau, Jörg Steinbrenner, Benedikt Hülsemann

World Journal of Chemical Education. 2023, 11(3), 38-44 doi:10.12691/wjce-11-3-4