Modern automotive fuels are composed of a blend of base fuel, various types of blending components, and additives. These additions serve to enhance fuel performance, particularly by preventing pre-ignition, also known as ‘engine knock,’ during combustion in the engine. While numerous blending components and additives help raise the fuel’s octane number, and thus prevent engine knock, not all of them have equal effects on human health, the environment, and the durability of the engine.
In light of these concerns, Sustainable Fuels conducted a literature review to investigate the impact of nitrogen-based octane boosters. This review reveals that nitrogen-containing octane boosters are acutely toxic or harmful, often irritating to the eyes and/or skin or sensitizing, and cause damage to organs, often targeting the blood system. Their impact on the environment is critical as well, as the use of such octane boosters results in an additional release of nitrogen during fuel combustion, leading to higher-end levels of NOx, greenhouse gases, poorer air quality, and well-known toxicity to man and the environment.
Moreover, they are much less effective anti-knock agents than organometallic substances and must therefore be used at higher concentrations for satisfactory knock suppression. A number of studies indicate damaging effects on internal combustion vehicle engines resulting from their use, including pre-ignition, shortened induction period, and an increase in deposits (gum, tar, sludge). These factors collectively lead to reduced efficiency and potential engine failure.
The existing human health, environmental and technical data suggest that aniline-type nitrogen-containing octane boosters show lower performance than metal-based octane boosters, have an unfavorable human health and environment profile, and are detrimental to air quality and vehicle engines. Hence Sustainable Fuels recommends for existing and future nitrogen-containing octane boosters to only be allowed to be blended into fuels if they successfully pass a properly designed screening that considers both their efficacy and their safety for man and the environment. Find out more here.