Review of Modern Approaches in the Development of Hybrid Biogas Systems

Biogas technologies play a main role in renewable energy; however, traditional biogas plants often fail to fully exploit the potential of raw materials, focusing solely on energy production. To enhance the efficiency of such systems, the development of hybrid biogas systems, which combine various technological processes, equipment, and energy sources, appears to be a promising approach. This study presents a review of modern engineering solutions in hybrid biogas systems based on patent analysis. A search and analysis of patent literature was conducted, covering the integration of anaerobic digestion with additional biomass treatment methods, biogas purification techniques, and combinations with other renewable energy sources (solar, wind, hydrogen, etc.). The key findings indicate that hybridization of biogas technologies significantly improves the performance and flexibility of biogas plants. Specifically, two-stage digestion increases biogas yield by 15–30%, CO2 methanation (power-to-methane) raises CH4 content up to 98%, and combined purification methods (membrane and adsorption) reduce methane losses to less than 1%. Furthermore, the integration of biogas plants with solar or wind energy systems reduces electricity production costs by 20–40%, while also ensuring more stable and predictable generation. The obtained data confirm that hybrid biogas systems enable the comprehensive utilization of organic waste while simultaneously generating energy and valuable by-products (biofertilizers, CO2 for industrial needs, etc.). The patent analysis, encompassing developments from various countries, highlights a strong global interest in hybrid biogas technologies. Many of the patents are already transitioning from prototype stages to practical implementation, confirming the high potential of hybrid biogas systems for the future of energy. The identified approaches and solutions can be practically applied to modernize existing biogas facilities and develop new, more efficient bioenergy complexes, paving the way for further industry advancement and the realization of clean energy through rational waste management.