Low-Energy Pretreatment of Organic Waste Using a Vortex Layer Reactor: Effects on Biogas Production, Carbon Conversion, and Process Optimization
Annotatsiya
The sustainable management of agri-food waste is a key challenge in the context of the circular economy and energy transition. Anaerobic digestion is an effective method for converting organic waste into renewable energy; however, its efficiency is often limited by substrate properties, such as high lignin content, low biodegradability, and unfavorable C: N ratios. This study evaluates a low-energy pretreatment method based on a Vortex Layer Reactor (VLR, equivalent to the AVS-100 system) applied to slaughterhouse waste, swine manure, and spent mushroom substrate. The analysis included biogas yield, methane production, carbon conversion, process kinetics, and net energy efficiency. The results showed that pretreatment effectiveness depends on substrate type. No improvement was observed in slaughterhouse waste, with net energy efficiency decreasing by approximately 9%. In contrast, biogas yield increased by 14% for swine manure and 18% for spent mushroom substrate, with a maximum net energy gain of 17.6%. The process required only 2.16–3.6 kWh·Mg−1 (about 9 kWh·Mg−1 TS), significantly less than conventional methods. The findings indicate that pretreatment should be applied selectively, depending on substrate characteristics. This study supports decision-making in biogas plant management by integrating technological efficiency with energy and operational criteria.