How we produce green gas
Biogas is produced in a digester through the four-stage process of biochemical anaerobic digestion: (1) hydrolysis, (2) acidogenesis, (3) acetogenesis, and (4) methanogenesis. During this process, carbohydrates, fats, and proteins are converted into methane (50–70%) and carbon dioxide (30–50%). Fermentation is complete once the substrate has passed through all stages, each characterized by a specific physiological microbial community. The key operational parameters are temperature and hydraulic retention time. Most agricultural biogas plants operate under mesophilic conditions (35–42°C / 95–108°F) with retention times ranging from 20 to 70 days, depending on the feedstock. A wide range of organic materials can be used, including manure, agricultural residues, organic waste, and energy crops. This flexibility enables the sustainable use of regional resources and reduces reliance on monocultures compared to other bioenergy technologies. To produce biomethane, raw biogas is upgraded by removing carbon dioxide and impurities, resulting in a high-purity renewable gas equivalent to natural gas. Biomethane can be injected into the gas grid, used as a vehicle fuel, or applied for power and heat generation. Modern fermentation technologies with optimized mixing and highly efficient insulation maximize substrate degradation while minimizing thermal energy demand. This increases methane yield and overall plant efficiency, positioning biomethane as a key solution for a renewable energy future.