Biogas from Zoo Animal Waste: ATEX Safety Distance Modelling at Madrid Zoo Aquarium

Abstract

The rising cost of traditional energy sources is forcing us to seek alternatives that enable energy self-sufficiency. At the Madrid Zoo Aquarium (Spain), the production of biomethane through the anaerobic digestion of organic waste is being considered, improving environmental management and achieving a competitive advantage in the energy management process. This opportunity also carries with it the possibility of explosions, fires or polluting environments, which requires the establishment of preventive measures to minimize these risks. To respond to this type of contingency, this study develops both empirical equation and charts that allow the establishment of dangerous distances that must be considered due to the presence of flammable gases escaping into the atmosphere and the duration of the danger, taking into account the influence of environmental conditions and dilution. Different risk situations are considered, both during the operation of the facility and during the cleaning and maintenance of tanks and equipment, as well as in the management of waste generated at the end of treatment. © 2025 by the authors.