To fulfill the ever increasing energy demand, the world is overexploiting fossil fuel resources owing to environmental consequences that enforce the global shift toward renewable energy. Ethanol is emerging as a key biofuel; however, its production generates large volumes of stillage. Stillage is a nutrient‐rich effluent posing serious environmental risks if unmanaged. This article explores the evolving biological approaches, such as anaerobic digestion (AD), microbial fuel cells (MFCs), and lipid‐producing microbes for stillage‐to‐energy conversion. Based on the literature survey, the use of two‐stage AD (TSAD) processes significantly enhances bioenergy production, achieving a 20%–30% increase in energy recovery. In addition, nutrient‐balanced co‐digestion has been shown to be highly effective, achieving chemical oxygen demand (COD) removal of around 90%. While these processes offer dual benefits, including waste treatment and renewable energy production simultaneously, challenges remain in optimizing performance and implementation at a large scale. Integrating life cycle assessment (LCA) provides a sustainability framework to guide decision‐making and policy support. This review provides a timely reflection on the potential and research gap of microbe‐assisted stillage‐to‐energy solutions, aiming for a cleaner circular bioeconomy.
Bhatia et al. (Thu,) studied this question.