Chapter 12: Green Anti-knock Agents for Enhancement of Gasoline Performance

Anti-knock agents are added to gasoline to increase its octane number and to reduce engine knocking. Engine knocking is a pinging noise that occurs when the fuel–air mixture in the combustion chamber detonates prematurely. This can cause damage to the engine parts and reduce its efficiency. Earlier, lead compounds were widely used as anti-knock agents in gasoline, but have been phased out owing to their negative effects on human health and the environment. Therefore, various alternative compounds have been introduced as anti-knock agents, including aromatic hydrocarbons, fuel oxygenates and organometallic compounds. Green gasoline itself can act as an anti-knock agent if used in appropriate proportions in petroleum gasoline blends. The use of these compounds is subject to regulations, which vary depending on the country and its specific legislation.