Efficient dual-mode power generation with sustainable biogas and biodiesel blends in diesel generators

• Dual-fuel generator using biodiesel and biogas increased power output by up to 21.77%. • Liquid fuel consumption reduced by 31-35% with supplemental biogas. • Efficiency without biogas reached approximately 25% for biodiesel blends. • Peak liquid fuel savings of 72% observed with B100 biodiesel at 5 kW load. • Study supports renewable biofuels for sustainable distributed power generation. The increasing demand for renewable energy solutions has led to the exploration of sustainable biofuels like biogas and biodiesel for power generation. However, the combined use of these fuels in small-scale dual-fuel systems remains underexplored. This study aims to evaluate the performance of a dual-fuel diesel generator operating with waste-derived biodiesel and biogas. Biodiesel was synthesized from waste frying oil through transesterification, and biogas with a methane content of 63.5% was sourced from an agricultural digester. A 5 kVA diesel generator was modified for dual-fuel operation and tested under varying electrical loads and biodiesel blend ratios (B8, B20, B50, B80, and B100). Results revealed that dual-fuel operation increased power output by up to 21.77% compared to diesel-only mode and achieved liquid fuel savings of 28.74% to 31.08% across the blends. Efficiency in normal mode remained higher, peaking at 25.74% for B100. The findings demonstrate the feasibility of integrating biogas and biodiesel for small-scale power generation, offering a cost-effective and sustainable alternative for off-grid applications. Future research should address emissions analysis, biogas supply optimization, and scalability for broader implementation.