Autoignition characteristics of oxygenated gasolines

Abstract

Gasoline anti-knock quality, defined by the research and motor octane numbers (RON and MON), is important for increasing spark ignition (SI) engine efficiency. Gasoline knock resistance can be increased using a number of blending components. For over two decades, ethanol has become a popular anti-knock blending agent with gasoline fuels due to its production from bio-derived resources. This work explores the oxidation behavior of two oxygenated certification gasoline fuels and the variation of fuel reactivity with molecular composition. Ignition delay times of Haltermann (RON = 91) and Coryton (RON = 97.5) gasolines have been measured in a high-pressure shock tube and in a rapid compression machine at three pressures of 10, 20 and 40 bar, at equivalence ratios of φ = 0.45, 0.9 and 1.8, and in the temperature range of 650-1250 K. The results indicate that the effects of fuel octane number and fuel composition on ignition characteristics are strongest in the intermediate temperature (negative temperature coefficient) region. To simulate the reactivity of these gasolines, three kinds of surrogates, consisting of three, four and eight components, are proposed and compared with the gasoline ignition delay times. It is shown that more complex surrogate mixtures are needed to emulate the reactivity of gasoline with higher octane sensitivity (S = RON-MON). Detailed kinetic analyses are performed to illustrate the dependence of gasoline ignition delay times on fuel composition and, in particular, on ethanol content.

Ignition Study of an Oxygenated and High-Alkene Light Petroleum Fraction Produced from Automotive Shredder Residues

“…The studied fuel is comparable to a heavy naphtha, except for the last 10 vol %. The distillation curves of the different classes of fuels were published by Chang et al 30,31 provided by Haltermann and studied by Lee et al has a similar composition to the studied fuel, where some olefins are basically substituted by paraffins 43 (Table 1).…”

Effect of Thermoplastic Starch and Photocrosslinking on the Properties and Morphology of Electrospun Poly(ethylene‐co‐vinyl alcohol) Mats

“…Regular gasoline (Magna, 87 octane) was purchased from a service station in Mexico City. Gasoline, one of the most widely used light duty automotive fuels, is a complex mixture of relatively volatile hydrocarbons .…”

Chemical kinetic study of triptane (2,2,3-trimethylbutane) as an anti-knock additive

“…The RCM experiments for 2,2,3 trimethylbutane were carried out over a temperature range of 620-1015 K. Different temperatures at the end of compression are obtained by either varying initial temperature or diluent concentration/diluent gas type. In general, the uncertainty in measured ignition delay times is estimated to be less than 10% [46,47] .…”