Sustainable Hydrogen from Urinary Waste: useful Waste-to- Energy

This thesis investigates the potential of human urine as a sustainable feedstock for hydrogen generation, addressing global energy security, waste management challenges, and carbon emissions reduction. Hydrogen, as a cornerstone of the clean energy transition, faces production limitations due to the energy intensity and environmental impact of conventional methods. Urinary waste—abundant, nitrogen-rich, and ubiquitously generated to serve as a promising alternative which is abundant and mostly untapped, will offer decentralized resource recovery aligned with circular bioeconomy principles. This study employs a multi-faceted methodology, including: 1. Analysis of three hydrogen production pathways: Microbial Electrolysis Cells (MECs) leveraging electroactive bacteria (yielding up to 2.5 L H₂/m³/day), Urea electrolysis requiring only 0.37V (vs. 1.23V for water electrolysis), reducing energy input by 30%, and Aluminium-water reactions with potassium hydroxide (KOH), producing hydrogen and valorizable by-products (e.g., potassium aluminate), 2. Energy and efficiency quantification of aluminium-based urine reactions, emphasizing scalability and net energy balance, and 3. Case study of Nigeria, highlighting waste-to-energy (WtE) potential in regions with acute energy poverty and unmanaged waste. In line with clean transitioning, there is the need to facilitate the transition toward a more sustainable energy future in Nigeria. Key findings demonstrate that Urine’s high urea content (6.7% hydrogen by weight) enables efficient hydrogen extraction, with an average adult yielding ~0.77 kg H₂ annually. Advanced electrocatalysts (e.g., Ni–O–Ti sites) achieve 99% nitrogen selectivity in urea electrolysis, enhancing process viability. Waste-to-hydrogen (WtH) systems concurrently treat wastewater, reduce eutrophication risks, and recover nutrients (N, P, K) and purified water. Economic projections indicate a \$10 billion market for waste-derived hydrogen by 2030, driven by low feedstock costs and technological advances. This thesis stresses urine’s role as “liquid gold” for sustainable development, enabling decentralized energy access, circular resource loops, and progress toward net-zero emissions. Challenges—including catalyst durability, infrastructure for urine segregation, and socio-technical acceptance—are discussed, with recommendations for policy support and interdisciplinary innovation.