Advancing sustainable energy: biohydrogen, biogas, and biohythane production from waste materials through life cycle analysis

The production of biofuels from waste materials presents a sustainable approach to generating biohydrogen, biogas, and biohythane while addressing waste management, renewable energy production, and nutrient recycling. This review examines recent biohydrogen and biogas production advancements from renewable resources, focusing on the environmental implications of various production methods. The primary aim is to evaluate the current state of technologies that convert diverse waste streams into biohydrogen and biogas via fermentation, emphasizing life cycle analysis (LCA). The review highlights critical pathways and processes for biofuel production and explores LCA studies to assess their environmental impact. However, comparing results from different studies is challenging due to variations in software, impact categories, system boundaries, functional units, and analytical approaches. Despite these challenges, fermentation-based production methods offer notable environmental benefits, including reduced carbon dioxide emissions, minimized ozone depletion, enhanced human health outcomes, lower ecotoxicity, and decreased reliance on fossil fuels. Integrating biohydrogen production with anaerobic digestion to produce biohythane also demonstrates the potential for greater energy efficiency and lower greenhouse gas emissions. Adopting energy strategies grounded in life cycle principles can significantly support the transition to renewable energy systems.