Abstract
This research presents strategies to mitigate combustion-related CO₂ emissions from petrol utilisation in Nigeria through a what-if exergy analysis within the period of 2000–2019. Five scenarios were considered and evaluated, including a Business-as-Usual (BaU) case, which served as the baseline. In the BaU scenario, fossil fuel was used for both automobile and local standby electricity generation. Subsequently, the following key performance parameters were used to determine the best choice of the optional scenarios: exergy efficiency, sustainability index, improvement potential and CO₂ emissions. These were analysed for all petrol-consuming sub-sectors. The optimal scenario involved limiting the use of petrol to transportation while adopting higher thermal efficiencies obtainable in efficiency-conscious regions. Compared to the BaU scenario, this best-case approach resulted in an annual average exergy efficiency improvement of 100.06%, a 19.08% increase in the sustainability index, a 71.70% reduction in improvement potential and a 59.89% decrease in annual CO₂ emissions.

Key words: Carbon dioxide Mitigation, Exergy Efficiency, Petrol, Electricity Generators, Transportation, GHG, Sustainability Index, Improvement Potential