Effects of oxygenate and aromatic content on engine-out aldehyde emissions from pure, binary, and ternary mixtures of ethanol, toluene, and iso-octane

Abstract

<div class="section abstract"><div class="htmlview paragraph">Sustainable fuel components, such as ethanol, can be blended into gasoline to help reduce fossil fuel consumption. Aldehydes are both observed emissions and major intermediates in the oxidation of gasoline/ethanol fuel mixtures and are solely attributed to the fuel’s alcohol content.</div><div class="htmlview paragraph">This study aims to evaluate the direct impact of toluene, iso-octane, and ethanol on engine-out formaldehyde and acetalde hyde emissions. A single-cylinder direct injection spark ignition engine was run at low speed and load conditions with varying equivalence ratios. The emissions are measured using a FTIR.</div><div class="htmlview paragraph">The aldehyde emissions from pure ethanol are ten- and five- times greater than pure toluene and iso-octane, respectively. Greater formaldehyde than acetaldehyde is found for iso-octane and toluene and vice versa for ethanol. The addition of 25 %vol of toluene to ethanol halves the average aldehyde emissions due to toluene suppressing effects. In the ternary mixtures with fixed ethanol content, the higher toluene concentration mixture led to lower average aldehyde emissions.</div></div>