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Enthalpy of Combustion of Fuels as a Function of Distillate Cut: Application of an Advanced Distillation Curve Method



Thomas J. Bruno, Beverly L. Smith


In previous work, several significant improvements in the measurement of distillation curves for complex fluids were introduced. The modifications to the classical measurement provide for (1) temperature and volume measurement(s) of low uncertainty, (2) temperature control based upon fluid behavior, and most important, (3) a composition-explicit data channel in addition to the temperature-volume relationship that usually comprises the measurement. This latter modification was achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, during the measurement of the distillation curve. In this paper we utilize the composition-explicit information to characterize distillate cuts in terms of available energy content. This is critical information in the study of real fuels. The measure we use for the fluid energy content is heat of combustion for each component in each distillate fraction. As a test system, we present the distillation cuts of two prepared mixtures of n-decane + n-tetradecane. Then, as a further illustration of the approach, we present an analysis of distillate fractions of a 91 ROM gasoline, and a 91 ROM gasoline with 15 percent methanol (vol/vol) added.
Energy and Fuels


boiling curve, complex fluids, distillation curve, gasoline, heat of combustion, hydrocarbons, methanol
Created August 5, 2006, Updated January 27, 2020