Promoted stable combustion of alcohol-based fuel accompanied by inhibition of Leidenfrost effect in a wide temperature range

Highlights: • Self-propagating oxidation heat release along with in-situ radical generation is proposed to inhibit the Leidenfrost effect. • The negative temperature behavior is found in the ethanol-based fuel ignition at lower temperatures. • MDEB/E10/n-D90 could combust stably and completely without NTC behavior. • Low-temperature (125 °C) and fast ignition (27 ms) of ethanol-based fuel is realized. Combustion of bio-alcohols helps alleviate energy crisis and environmental pollution. However, the Leidenfrost effect (LE) of alcohols triggered by the adiabatic vapor layer greatly reduces the heat transfer efficiency, which makes alcohols exhibit a long ignition delay time (IDT) at low temperatures, hindering energy efficiency and clean combustion. Here, we first develop a scalable strategy to inhibit LE via self-propagating oxidation heat release and concomitant in-situ active radical generation. Reliable ignition and stable combustion of alcohol-based fuels are achieved in a wide temperature range by using a reactive organometallic compound methoxydiethylborane (MDEB). The theoretically released heat of MDEB self-oxidation is two orders of magnitude greater than the evaporation latent heat of ethanol or n-decane by thermodynamic calculation. Experiments show that the flammable temperature limits of MDEB/ethanol and MDEB/ethanol/n-decane are extended to 225 and 125 °C, which dropped by 370 and 465 °C, respectively. Moreover, the IDT of MDEB/ethanol/n-decane hybrid fuel significantly decreases to 27 ms. The 100% ignition achievement and disappearance of negative temperature behavior highlight the reliable start-up in the Liedenfrost region. This work thus provides a promising tool for promoting the ignition reliability and combustion stability of alcohols for ICEs at low temperatures, as well as pollutant control.