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In this study the pH levels of aluminum oxide (Al2O3), silicon dioxide (SiO2), and zinc oxide (ZnO) nanoparticles dispersed in propylene glycol and water mixture were measured in the temperature range of 0°C to 90°C. The volumetric concentration of nanoparticles in these fluids ranged from 0 to 10% for different nanofluids. The average particle sizes (APS) considered were from 10 nm to 70 nm. The pH measuring apparatus and the measurement procedure were validated by measuring the pH of a calibration fluid, whose properties are known accurately. The measured pH values agreed within less than ±0.5% with the published data reported by the manufacturer. Following the validation, the pH values of different nanofluids were measured. The measurements showed that pH of nanofluids decreased with an increase in temperature and increased with an increase in particle volumetric concentration. For the same nanofluid at a fixed volumetric concentration, the pH was found to be higher for larger particle sizes. From the experimental data, empirical models were developed for three nanofluids to express the pH as functions of temperature, volumetric concentration, and the size of the nanoparticles. [ABSTRACT FROM AUTHOR]

The feasibility of transporting gas-to-liquids (GTL) products (natural gas chemically converted to liquid hydrocarbons) through an existing oil pipeline—the Trans Alaska Pipeline System (TAPS)—for bringing value to Alaska's vast stranded natural gas resources is currently being investigated. As part of this major project, the phase behavior measurement and modeling of GTL and Alaska North Slope crude (ANSC) oil blends have been carried out. The saturation pressures for various types of GTL and ANSC oil blends were measured in a conventional windows based PVT apparatus. The phase behavior of GTL and ANSC oil blends were also modeled by the Peng-Robinson and Soave-Redlich-Kwong equations-of-state. The measured and modeled saturation pressures were found to be in close agreement. The results also indicated that the GTL and ANSC oil blends would always exist as single-phase liquid under the current TAPS operating conditions. [ABSTRACT FROM AUTHOR]

As part of a major project on studying the transportation of gas-to-liquids (GTL) through the existing Trans Alaska Pipeline System (TAPS), the density and viscosity of GTL and the Alaskan North Slope Crude (ANSC) and their blends were measured. All density and viscosity measurements were performed, using the Anton–Paar vibrating tube densitometer and a cone and plate viscometer respectively, at temperatures ranging from 20 oC to 60 °C at atmospheric pressure. The accuracy of the measured data has been ascertained. In addition to the density and viscosity data, other data reported for GTL and ANSC include compositions. Finally, generalized dens ty and viscosity correlations for the measured data are presented. [ABSTRACT FROM AUTHOR]