Knocking, in gasoline engine

Use To extend spark plug life, to control deposit-induced knocking in gasoline engines. 

Product characterization aims at defining their end-use properties by means of conventional standard measurements related as well as possible — and in any case, being the object of a large consensus— to end-use properties. We cite for example that octane numbers are supposed to represent the resistance of gasoline to knocking in ignition engines. 

Gasoline with too low an octane number can cause knocking in the engine of a car, when the fuel ignites too easily and burns in an uncontrolled manner. Knocking lowers fuel efficiency, and it can damage the engine. 

Uses Standard in testing knock of gasoline engines and for octane rating determinations anesthetic solvent organic synthesis. 

It is known that a small amount of lead tetraethyl is effective as an anti-knock agent in gasoline engines. This effect is due to the inhibition of the gas-phase reaction by the lead or lead oxide derived from the lead tetraethyl.l o.si] The inhibitory action of lead compounds on hydrocarbon combustion is largely exerted in the gaseous phase of the combustion zone. 

OTHER COMMENTS used as a standard in testing knock of gasoline engines (i.e., for determining octane rating) pure normal-heptane has an octane number of zero other uses include anesthetics, organic synthesis, preparation of laboratory reagents, and use as a solvent. 

Chemical additives first entered the industry in the first decade of the centuiy. These additives sewed a number of uses. For example, they lessened the capacity of gasoline to vaporize out of the gas tank or to polymerize (i.e., produce gummy residues) in the engine. In the early 1920s, the most important application for these substances was to eliminate knocking. Tetraethylead (TEL) was the first major gasoline additive to be commercialized for this purpose. 

Once gasoline is refined, chemicals ore added to reduce knocking and prevent the formation of gum in the engine. 

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