Gasoline autoignition temperature

Group D gases, but hexane or gasoline, owing to their lower autoignition temperatures. For Group C tests, ethylene can be used for all test stages. 

MTBE and related ethers are used to add octane to gasoline. MTBE also adds oxygen to the gasoline, which allows for more efficient combustion, and therefore less carbon monoxide and unbumed hydrocarbon in the exhaust emissions A relined grade of MTBE is used in the solvents and pharmaceutical industries. Its higher autoignition temperature and narrower flammability range also make it relatively safer to use compared to other ethers. 

The autoignition temperature of ethanol is significantly higher than that of gasoline or diesel fuel. This should make ethanol less susceptible to ignition when spilled on hot surfaces such as engine exhaust manifolds. 

Unlike its homologue, diethyl ether, DIPE has a comparatively high autoignition temperature. Indeed, it can be blended into motor gasoline as an octane improver. Hence precautions are not required to avoid a vapour explosion due to contact with hot surfaces. 

The low toxicity of DME is comparable to that of liquid propane. Comparatively, methanol is toxic upon skin contact and ingestion. Dimethyl ether has a higher autoignition temperature and lower flammability limit than gasoline [61], however. 

Auto Ignition This is the temperature at which materials burn without a source of ignition. Gasoline autoignites at 450°F. Asphalt autoignites at 320°F methane at 1000°F. The heavier the hydrocarbon, the lower the autoignition temperature. Iron sulfide (pyrophorric iron) burns at room temperature when it is dry. 

The engine was the first to incorporate compression ignition of alcohols (7). Low cetane fuels can autoignite, however, provided the in-cylinder temperature is high enough and fuel injection correcdy timed. This compression ignition works for methanol as well as ethanol and gasoline. 

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