Firing up anaerobic digestion – a high-res temperature assay

Biogas as a renewable energy source is becoming increasingly important because it offers significant advantages: It can be stored and used on demand, its production is independent of climate, time of day, and geographical conditions. Additionally, a wide variety of organic substrates can be used as feedstocks, which channels different waste streams into energy recovery and helps reduce overall waste volumes. Despite these advantages, operators of biogas plants face challenges: fluctuating feed-in tariffs, inconsistent political support, and intense competition for suitable substrates complicate their work. Therefore, research aimed at optimizing plants and processes is crucial for the stability and efficiency, as well as the future, of biogas technology. This project specifically investigates the impact of temperature on biogas production. The temperature range between 34 and 61 C is divided into several smaller temperature steps and thoroughly studied. Three different microbial communities, originating from different operational environments, are used and compared. Two central aspects are the focus of the study: the systems resilience to temperature fluctuations and its stability under irregular or extreme feeding conditions. To capture the full range of temperature effects, both physicochemical and microbiological aspects of the biogas process are examined. The studies include measuring biogas quantity and quality, routine checks such as pH and acidity levels, as well as analyzing microbial communities and their metabolic products. The goal is to better understand the microbial communities in the reactor and their responses to temperature changes and feeding rhythms. This approach is innovative because, until now, research has typically focused on well-known temperature ranges of approximately 37 C or 55 C. The intermediate temperature range has been largely neglected, even though some large plants already use it. This research aims to fill this gap and provide new insights into the stability and efficiency of biogas plants. The experiments are conducted under the leadership of Priv.-Doz. Dr. Sabine Podmirseg and a team of experienced microbiologists specializing in biogas research and molecular microbiology. They are supported by national and international experts in the field. Through this research project, the scientists make a significant contribution to the further development of biogas as a sustainable energy source.