ABSTRACT
Motor gasoline is a mixture of primarily naphtha-range hydrocarbon molecules from C5 to C12 blended together to meet a tight range of physical specifications on volatility, distillation temperature profile, and sulfur, aromatics, and olefin content. With widespread automobile use, gasoline demand increased dramatically, and many new technologies were developed to address the volume requirements. Octane number is a measure of a gasoline’s ability to resist knocking as it burns in the combustion chamber. The distillation curve of gasoline is comprised of three segments: the front-end volatility, the midrange volatility, and the tail-end volatility. Vapor lock and hot fuel handling problems occur when excessive gasoline vapor accumulates somewhere in the fuel system and reduces or interrupts the fuel supply to the engine. Gasoline volatility in the US is specified using six vapor pressure/distillation classes and six vapor–liquid ratio classes. Several components of gasoline are limited by specifications to deliver certain performance and environmental objectives.
