Anaerobic Digester Tank: Design and Operation for Stable Biogas An anaerobic digester tank is a sealed vessel where microbes break down organic waste into biogas at 35-38°C mesophilic temperature over a 20-40 day retention. The acidic, methane-rich slurry demands an inert lining rated for 30-50 years. Engineered by Shijiazhuang Zhengzhong Technology Co., Ltd. (Center Enamel) to AWWA D103-09 and ISO 28765, capacities span 500-50,000 m3. What an Anaerobic Digester Tank Is An