Sustainable Biodiesel Production Pathways in Nigeria: A Review of Feedstock Options, Production Methods and Engine Performance

Nigeria's energy sector for transportation currently uses petroleum diesel, which has resulted in the increase of greenhouse gases, air pollution, and energy insecurity in the country. The use of the more environmentally friendly biodiesel will thus offer the country an alternative for diversification, job creation, and environmental enhancement. The paper aims to critically examine the recent developments in the available processes for the production of biodiesel, with specific reference to the Nigerian situation, as well as successful international programs implemented in Brazil, India, Indonesia, the EU, and the US. The paper will examine the available feedstock, which can be categorized into four major categories, namely waste cooking oils, non-edible oils, microalgae, and animal fats, and evaluate the availability, yield, and sustainability of each of the available feedstocks for the production of biodiesel. The available conversion processes, such as trans-esterification, hydrotreated vegetable oil (HVO), and the emerging thermochemical processes, will also be examined. The performance characteristics of the engine and the emission impact are also discussed, including combustion efficiency, the balance between the formation of NOx and PM, and fuel compatibility in compression ignition engines. Case studies in different countries have proven that feedstock diversification, policy consistency, and technology integration are important in the scale-up of biodiesel technology. Research gaps have also been identified in Nigeria, including feedstock logistics, catalyst optimization, and environmental impact assessment. The study has also recommended the development of an adaptive national strategy that includes the integration of the circular economy concept, feedstock valorization, and regional cooperation in the development of sustainable biodiesel in Nigeria.