Binary system

About: Binary system is a research topic. Over the lifetime, 5788 publications have been published within this topic receiving 97882 citations.

Vapor-liquid equilibria of triglycerides-methanol mixtures and their influence on the biodiesel synthesis under supercritical conditions of methanol

Abstract: The non-catalytic synthesis of biodiesel (fatty acids methyl esters) from triglycerides and methanol proceeds at elevated pressures above 100 bar and tem- peratures above 523 K. Kinetic investigations of the system revealed an unusual be- havior of the reaction rate constant with increasing temperature and pressure. In or- der to explain this phenomenon, the phase behavior of the triglycerides-methanol mixture was investigated. The phase equilibria of the binary system sunflower oil-methanol were measured at different temperatures between 473 and 503 K, and a range of pressures between 10 and 56 bar. The experimental data were correlated using the Peng-Robinson, Soave-Redlich-Kwong and Redlich-Kwong-Aspen equa- tions of state and different mixing rules. The best results were obtained with the RK-ASPEN equation of state and the Van der Waals mixing rule (VdW), which were then used to calculate the distribution of the phases at pressures and temperatures usual for the non-catalytic synthesis of biodiesel under high pressures. The obtained data indicated a strong influence of the phase equilibria on the reaction kinetics.

Bubble-point pressures of the binary system carbon dioxide+linalool

Abstract: A synthetic method was used to investigate high-pressure vapor–liquid equilibria of the binary system carbon dioxide+linalool. The bubble points of this system were measured at carbon dioxide mole fractions from 0.2 up to 0.993 and within temperature and pressure ranges of 283–371 K and 1.4–14.7 MPa, respectively. Critical points of this binary system were also determined experimentally for a carbon dioxide mole fraction range from 0.93 up to 0.993. The results were correlated by the Stryjek–Vera modified version of the Peng–Robinson equation of state using one-fluid van der Waals mixing rules with both one and two interaction parameters.

The mass ratio and formation mechanisms of Herbig Ae/Be star binary systems

Abstract: We present B- and R-band spectroastrometry of a sample of 45 Herbig Ae/Be (HAe/Be) stars in order to study their binary properties. All but one of the targets known to be binary systems with a separation of ∼0.1–2.0 arcsec are detected by a distinctive spectroastrometric signature. Some objects in the sample exhibit spectroastrometric features that do not appear attributable to a binary system. We find that these may be due to light reflected from dusty haloes or material entrained in winds. We present eight new binary detections and four detections of an unknown component in previously discovered binary systems. The data confirm previous reports that HAe/Be stars have a high binary fraction, 74 ± 6 per cent in the sample presented here. We use a spectroastrometric deconvolution technique to separate the spatially unresolved binary spectra into the individual constituent spectra. The separated spectra allow us to ascertain the spectral type of the individual binary components, which in turn allows the mass ratio of these systems to be determined. In addition, we appraise the method used and the effects of contaminant sources of flux. We find that the distribution of system mass ratios is inconsistent with random pairing from the initial mass function, and that this appears robust despite a detection bias. Instead, the mass ratio distribution is broadly consistent with the scenario of binary formation via disc fragmentation.