Diethyl ether autoignition temperature

There is a good correlation between autoignition temperatures and octane or cetane numbers in motor fuels. Thus, toluene and diisopropyl ether make attractive additives for petrol while the low autoignition temperature of glycol ethers, diethyl ethers and some normal paraffins show them to have high cetane numbers and to be useful as cold start improvers for diesel compression/ignition engines. 

Molecular sieves, activated alumina and calcium chloride dry diethyl ether very satisfactorily but the hrst two are difficult to regenerate given the low temperatures demanded to avoid autoignition and the need to avoid the use of air. A number of other chemicals are suitable (Chapter 7) provided that they are not harmful to the subsequent use of the diethyl ether. Pervaporation is also a suitable way of drying diethyl ether down to 0.1% w/w water. 

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. 

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