Correlation and prediction of biodiesel density for extended ranges of temperature and pressure

摘要: Abstract The knowledge of biodiesel density over large ranges temperature and pressure is important for predicting the behavior fuel injection combustion systems in diesel engines, optimization such systems. In this study, cottonseed oil was transesterified into its measured at temperatures between 288 K 358 K pressures 0.1 MPa 30 MPa, with expanded uncertainty estimated as ±1.6 kg m−3. Experimental pressure–volume–temperature (pVT) data used along literature relative to other 18 biodiesels, order build a database test correlation temperarure using Goharshadi–Morsali–Abbaspour equation state (GMA EoS). To our knowledge, first that measurements are presented under high pressures, GMA EoS model density. new tested allowed correlations within 0.2 kg m−3 corresponding average deviations 0.02%. From these results mechanical coefficients thermal expansivity, isothermal compressibility internal were calculated. spite their effect power injection, those properties rarely biodiesel, especially pressures. As remarkable result it found crossing point where isothermic curves cross. built develop two full predictive models valid up 373 K 130 MPa. One proposed methods (4PGMA) followed from EoS, (DU) derived observed linear relation degree unsaturation (DU), which depended FAMEs profile. deviation 4PGMA only about 2 kg m−3, 3 kg m−3 DU method limits application. These represent appreciable improvements context prediction when compared equations state.