Boosting the Octane Rating of Petrol: A Review of the Trends and Impacts on the Environment

Abstract

An important quality of petrol (also called motor spirit or gasoline) is its octane rating (number) which is a measure of how resistant petrol is to the abnormal combustion phenomenon known as knocking (detonation or pinging). Petrol with low octane rating will burn uncontrollably in motor engine resulting loss of power, fuel wastage, and ultimately total engine failure. At the design level, increasing the octane number of petrol meant that the engine compression ratio could be raised to maximized power output. Straight-run motor spirit is characterized by low octane number and was only suitable for the earlier engines with low compression ratios. Latter demands for more powerful engines call for increase in compression ratios of the latter designed engines. The challenge however, was that these latter engines could not run on low quality petrol (with low octane rating). Various additives were sought to boost the octane rating of petrol, and more recently refinery reconfiguration is being given much attention. This work peruses the trends towards boosting the octane quality of petrol, highlighting the impacts of these trends to the sustainability of the environment.