Diethyl ether, flame combustion

Diethyl ether is a very low-boiling, highly flammable liquid => open flames or sparks from light switches can cause explosive combustion of mixture of diethyl ether and air. 

Particularly important compounds have been studied by flame combustion calorimetry. Methane [92-94], ethanol [95], diethyl ether [96], carbon monoxide [92,93,97], hydrochloric acid [98], and water [93,97,99] are representative examples. With a few exceptions (HC1, H2O, D2O [100], SO2 [101], cyanogen [102,103], and some lower chloroalkanes [104,105]), measurements by flame combustion calorimetry have been limited to substances of general formula CaHbOc. 

G. Pilcher, H. A. Skinner, A. S. Pell, A. E. Pope. Measurements of Heats of Combustion by Flame Calorimetry. Part 1. Diethyl Ether, Ethyl Vinyl Ether and Divinyl Ether. Trans. Faraday Soc. 1963, 59, 316-330. 

B Reactions of compounds with oxygen with the development of flames are called combustions. In addition, flameless reactions of organic compounds with oxygen are known. They are referred to as autoxidations. Of the autoxidations, only those that take place via sufficiently stable radical intermediates can deliver pure compounds and at the same time appealing yields. Preparatively valuable autoxidations are therefore limited to substitution reactions of hydrogen atoms that are bound to tertiary, allylic, or ben-zylic carbon atoms. An example can be found in Figure 1.27. Unintentional autoxidations can unfortunately occur at the O—Cprtm—H of ethers such as diethyl ether or tetrahydrofuran (THF) (Figure 1.28). 

The ignition di am for diethyl ether—oxygen mixtures has been determined [68] and the slow combustion has been studied in some detail. The low temperature oxidation becomes appreciable at 120 °C and Lemay and Ouellet [69], working at 160—175 °C which was below the lower limit of cool flame for in their pyrex reaction vessel, observed an initial pressure drop during which oxygen was consumed by a zero-order process with an activation energy of about 50 kcal. mole. Peroxides... 

Vovelle et al. [83] showed that the cool-flame region for diethyl ether was considerably extended by the addition of di-tert-butyl peroxide. The products of the normal combustion, cool flames and two-stage ignition were all examined [84] and found to include carbon monoxide and dioxide, water, acetaldehyde, methanol and methane, ethylene and acetylene. 

Heated flat-flame burners also have been used for the stabilization of cool-flame and two-stage ignitions. These systems were pioneered by Agnew et al. [76], and a definitive study of the spatially resolved chemistry of diethyl ether combustion has been reported [77]. Ballinger and Ryason [78] have described this type of burner in detail and have reported the relative behaviour of some n-alkanes, PRF fuel mixtures, and the effect of anti-knock additives. 

EXPLOSION and FIRE CONCERNS flammable NFPA rating Health 2, Flammability 3, Reactivity 3 dangerous fire hazard when exposed to heat, flame or oxidizers explosive in vapor form flashback along vapor trail may occur shock-sensitive explosive closed containers may rupture violently on heating forms explosive mixtures with combustible materials can be desensitized by the addition of 1-2% propane, butane, chloroform, dimethyl ether, or diethyl ether heating to decomposition emits toxic fumes of oxides of nitrogen use water spray, dry chemical, foam, or carbon dioxide for firefighting purposes. 

Properties Colorless si. vise, liq., nearly odorless very sol. in diethyl ether sol. in ethanol, toluene, water misc. with oxygenated soivs. m.w. 134.18 dens. 1.023 vapor pressure 1 mm (73.8 C) b.p. 233 C flash pt. (OC) 124 C ref. index 1.4410 Toxicology LD50 (oral, rat) 14,850 mg/kg, (IP, mouse) 10 g/kg, (IV, rat) 5800 mg/kg, (skin, rabbit) > 20 ml/kg mildly toxic by ing. primary skin and eye irritant may cause somnolence, tremors, kidney/ureter/blad-der changes mutagenic data TSCA listed Precaution Combustible when exposed to heat and flame can react vigorously with oxidizing materials... 

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