Influence of dimethyl ether addition on the oxidation of acetylene in the absence and presence of NO

Dimethyl ether (DME) is a promising diesel fuel additive for reducing soot and NOx emissions, because of its interesting properties and the possibility of a renewable production. An experimental and modeling study of the oxidation of acetylene (C2H2, considered as an important soot precursor) and DME mixtures has been performed under well-controlled flow reactor conditions. The influence of temperature, air excess ratio (λ) and presence of NO on the oxidation process has been analyzed. Under fuel-rich conditions, the presence of DME in these mixtures modifies the radical pool delaying the acetylene consumption. C2H2 and DME, and the radicals generated in their conversion, interact with NO achieving different levels of NO concentration diminution depending upon the operating conditions. Under fuel-lean conditions, the presence of DME in the mixtures increases the NO diminution, whereas for the other values of λ considered, the maximum NO decrease reached is lower than that obtained in the case of pure acetylene.