Gasoline By Guillermo Maxi

Raw Materials  A mixture of liquid hydrocarbons with four to twelve carbon atoms.  Typically heptane (C 7 H 14 ), octane (C 8 H 18 ), and nonane (C 9 H 18 ).  These hydrocarbons are refined from crude petroleum and classify into three groups: paraffins, olefins, and aromatics  Modern gasoline fuels includes antivarnishing agents, detergents, and oxidation and rust inhibitors.

Distilling Process  Heat up crude oil until it boils or vaporizes.  The vapors are separated into fractions or groups of hydrocarbons with differing condensation points.  In a refinery's fractionating tower, hot oil vapors pass upward, becoming cooler as they rise. The heavier fractions condense near the bottom of the tower.  Gasoline condenses near the top.

Cracking Processes  Originally, Thermal cracking consisted of applying high pressure and intense heat to break complex hydrocarbons into lighter compounds.  Catalytic Cracking implements a catalyst which speeds up chemical reactions. However, it doesn’t required high pressures.  Gasoline having high octane number will burn more smoothly in engines.

Properties  It’s dyed, flammable, and has distinctive odor.  Gasolines are blended from hundreds of hydrocarbons, and different combinations are produced to meet the needs of different engines and to prevent engine knock.  A high octane number produces less knocking. Regular gasoline generally has an octane number of 87 and premium gasoline between 91 to 94.

Altering Properties  More volatile mixtures improve cold-weather starting, while less volatile mixtures are produced for warm-weather periods in order to forestall vapor lock.  Tetraethyl lead used to be added to gasoline in order to reduce engine knock. It is a toxic substance and damages catalyst. It is banned.  Combining gasoline with ethanol or methanol formed gasohol. It reduces hydrocarbon emissions but releases formaldehyde which is carcinogen.

Work Citied  Trench, C. J. (2014). Gasoline. The New Book of Knowledge. Retrieved August 27, 2014, from Grolier Online h&type=0ta  Volti, R. Gasoline. In Science online. Retrieved from &SingleRecord=True  "Gasoline." UXL Science. U*X*L, Student Resources in Context. Web. 27 Aug  "Oil refining." UXL Science. U*X*L, Student Resources in Context. Web. 27 Aug