Autoignition mechanism of dimethyl ether-air mixtures in the presence of atomic iron

摘要

The search for reactive additives capable of reducing the combustibility of dimethyl ether is an important problem due to the widening use of ether as an alternative environmentally friendly motor fuel. This paper presents a numerical study of the autoignition chemistry of mixtures of dimethyl ether with air in the presence of atomic iron. Atomic iron, which is an effective inhibitor of premixed laminar hydrocarbon flames, was found to shorten the induction period. However, the additive affects only the first stage of the induction period. The mechanism of promotion of the low-temperature oxidation of dimethyl ether-air mixtures by atomic iron is the formation of hydroxyls in reactions involving iron compounds. Since the additive hardly changes the duration of the second stage of the induction period, it can be suggested that OH radicals play an insignificant role in the low-temperature oxidation of dimethyl ether at this stage.