Evaluating the viability of biogas as a sustainable transport fuel in Nigeria: Policy gaps, analytical insights, and strategic roadmap

The transport industry in Nigeria is still mainly dependent on fossil fuels making the industry very costly to operate, energy insecure, and increasing greenhouse gas emissions. Its contribution to the transport sector is insignificant despite having an estimated 19billion m 3 of annual biogas potential in the form of agricultural and other organic residues. This paper analyses the feasibility of upgraded biogas (biomethane) as a renewable transport fuel in rural Nigeria based on secondary data, a comparative analysis, and the modelling of the cost and emission. Based on the 3m 3 /day of biogas that was upgraded to 1.8m 3 /day of biomethane, a payback period of 9.8 years of operation, an internal rate of return of 6 9, and a reduction of CO₂ emission by 85–90 % over diesel was simulated. The results show that although biomethane is currently uneconomical to produce, it is a technically and environmental viable alternative mode of transportation in the rural areas. Policy alignment, fiscal incentives, and modular upgrading infrastructure are the recommendations of the study that can speed up the process of changing Nigeria to a low-carbon, energy-secure transport system. • Nigeria's transport sector remains highly dependent on fossil fuels. • Biomethane offers 85–90 % lower CO₂ emissions than diesel or petrol. • A 3 m 3 /day upgraded biogas plant yields ∼1.8 m 3 biomethane daily. • Despite higher fuel cost, policy incentives can improve biomethane viability. • Integrating digestate reuse enhances circular economy and rural resilience.