RETRACTED: Optimizing two‐stage anaerobic digestion for circular economy: bioenergy production and waste valorization
Sumit Sharma, Pradeep Kumar Meena, Chitresh Nayak, Lokesh Singh, Sagar Shelare, Chandrika S Wagle
Abstract
Abstract This study explores the two‐stage anaerobic digestion (TSAD) process as a sustainable approach to converting organic waste into valuable resources within a circular economy framework. The primary focus is developing a closed‐loop system that enables effective digestate management and integrates energy production, specifically hydrogen (H 2 ) and methane (CH 4 ). Results show that TSAD efficiency improves significantly through pre‐treatment techniques and co‐digestion strategies. Pre‐treatment enhances the breakdown of organic matter, making it more accessible to microbes. Co‐digestion helps maintain optimal carbon‐to‐nitrogen ratios, nutrient levels, pH, and moisture content. These strategies enhance digestion performance without additional water or mineral supplements. The study also evaluates digestate processing for nutrient recovery and biochar production, promoting complete resource utilization. TSAD is not just a biochemical process; it operates as a sequential biorefinery with the potential for large‐scale implementation. However, key challenges remain. Energy consumption, environmental impact, and economic viability must be addressed. The costs associated with feedstock transportation, storage, pre‐treatment, and digestate handling remain significant. Advancements are needed to improve the overall sustainability and practicality of TSAD systems.