Application of the Advanced Distillation Curve Method to Fuels for Advanced Combustion Engine Gasolines

Abstract

Incremental but fundamental changes are currently being made to fuel composition and combustion strategies to diversify energy feedstocks, decrease pollution, and increase engine efficiency. The increase in parameter space (by having many variables in play simultaneously) makes it difficult at best to propose strategic changes to engine and fuel design by use of conventional build-and-test methodology. To make changes in the most time-and cost-effective manner, it is imperative that new computational tools and surrogate fuels are developed. Currently, sets of fuels are being characterized by industry groups, such as the Coordinating Research Council (CRC) and other entities, so that researchers in different laboratories have access to fuels with consistent properties. In this work, six gasolines (FACE A, C, F, G, I, and J) are characterized by the advanced distillation curve (ADC) method to determine the composition and enthalpy of combustion in various distillate volume fractions. Tracking the composition and enthalpy of distillate fractions provides valuable information for determining structure property relationships, and moreover, it provides the basis for the development of equations of state that can describe the thermodynamic properties of these complex mixtures and lead to development of surrogate fuels composed of major hydrocarbon classes found in target fuels. ■ INTRODUCTIONIncremental but fundamental changes are currently being made to fuel composition and combustion strategies, enabling engines to accept diversified energy feedstocks, decrease pollution, and increase efficiency. To make changes in the most time-and cost-effective manner, the design and development of surrogate fuels is of utmost importance to computational studies, experimental design, and thermophysical property modeling. 1−3 Surrogate blends with a limited number of components can more readily provide insight into property effects on mixing, vaporization, and combustion, which lead to improvements in engine efficiency, decreased emissions, and enhanced performance. 4−9 Indeed, both theoretical and experimental studies of surrogates (frequently blends of components, such as n-heptane and isooctane) have been conducted comparing the properties of proposed surrogates to those of gasoline. 10−18 In addition, surrogate fuels have value as time invariant references, by allowing for direct comparisons of results from different laboratories using the same surrogate fuel. This approach avoids the temporal differences in the composition of individual refinery streams, which are blended together to make finished fuels, because commercial fuels and even reference fuels tend to vary over time. 3 Despite this variability, one of the best options for researchers looking for fuel consistency is the use of reference fuel sets characterized by industry groups, such as the Coordinating Research Council (CRC) Fuels for Advanced Combustion Engines (FACE) group. 19 The FACE group is composed of volunteers from industry, government, and academia, who wo...

Advances in rapid compression machine studies of low- and intermediate-temperature autoignition phenomena

“…Full-boiling range fuels are liquid fuels that consist of a diverse mix of hydrocarbon species which cover a wide range of molecular weights and isomeric structures. The distillation curves for such fuels span a large range of temperature where the difference between initial and final boiling points can be on the order of 100 to 200 K [450,451]. Gasoline, jet fuel, and diesel are included within this classification.…”

The influence of chemical composition on ignition delay times of gasoline fractions

“…The six types of classification based on ASTM D2789 standard are paraffins, monocycloparaffins, dicycloparaffins, alkylbenzenes, indanes and tetralines (grouped together), and naphthalenes. As many of the gasolines in our study contains olefins and classification in this work is based on PIONA (paraffins, iso-paraffins, olefins, naphthenes, and aromatics) a direct comparison between our results and the results in Burger et al [31] was not performed. It was also explicitly stated in [31] that a direct quantitative comparison of the results based on ASTM D2789 method to other classification methods was not always possible.…”

“…As many of the gasolines in our study contains olefins and classification in this work is based on PIONA (paraffins, iso-paraffins, olefins, naphthenes, and aromatics) a direct comparison between our results and the results in Burger et al [31] was not performed. It was also explicitly stated in [31] that a direct quantitative comparison of the results based on ASTM D2789 method to other classification methods was not always possible. However, the ignition quality of the gasoline fractions were not obtained in their study.…”

“…The diesel used in Hetzel's experiments [30] had a CN of 55 and was separated into 12 equal fractions. Recently, Burger et al [31] measured the enthalpy of combustion and hydrocarbon family types (using mass spectrometric classification technique) of FACE gasoline fractions. Fuels for advanced combustion engines (FACE) gasolines are research grade fuels with specific target properties viz., RON and OS, such that various laboratories could evaluate fuels with consistent composition and properties set forth by the Coordinating Research Council (CRC) [32].…”

“…Fuels for advanced combustion engines (FACE) gasolines are research grade fuels with specific target properties viz., RON and OS, such that various laboratories could evaluate fuels with consistent composition and properties set forth by the Coordinating Research Council (CRC) [32]. Classification of hydrocarbon family types in Burger et al [31] was based on ASTM D2789 standard [31,33], which characterizes different components in a hydrocarbon mixture into six types. The six types of classification based on ASTM D2789 standard are paraffins, monocycloparaffins, dicycloparaffins, alkylbenzenes, indanes and tetralines (grouped together), and naphthalenes.…”