High-pressure Physical Properties Research Articles

ライスオイルの高圧物性に関する研究

In order to estimate the lubricating performance of rice bran oil, the experiments of high pressure viscosity and high pressure density have been carried out, and such high pressure physical properties as pressure viscosity coefficient and bulk modulus were grasped. Based on the experimental results including the measurement value of wax crystallization temperature at atmospheric pressure, phase transition diagram of test oil was made, and the phase transition behavior of test oil was compared with other vegetable oils. As a result, the pressure viscosity coefficient of the rice bran oil at the test temperature range from 293K to 333K showed higher value in comparison with other vegetable oils. The relation between bulk modulus and pressure was different depending on the test temperature. In addition, it was found that the rice bran oil has a similar solid-liquid phase transition properties to such vegetable oil as soybean oil in which the composition ratio of unsaturated fatty acids resembles.

The High-Pressure Physical Property of Gas With CO2 in the Changshen Gas Reservoir

The natural gas in Changshen gas reservoir has high CO2 content. There are no conventional methods to calculate the physical parameters of natural gas. In view of this specificity, the physical parameters are determined and analyzed by PVT laboratory experiments. Experimental studies show that, below 20 MPa, the compressibility factor, volume factor, density, and isothermal compressibility have strong sensitivity to pressure, but the steam content contributes little and the absolute viscosity maintains strong pressure sensitivity. The compressibility factor, density, absolute viscosity, and steam content increase violently stronger than volume factor with the increase of CO2, and the isothermal compressibility is not sensitive to CO2. The variations of the high-pressure physical properties of Changshen gas reservoir depend on pressure and CO2 content, which should be considered in the reservoir development.

First-principles study of high-pressure physical properties of α-Ti2Zr

The structure, elastic constant, Debey temperature and electron distribution of α-Ti2Zr under high pressure are presented by using first-principles pseudopotential method based on density functional theory in this paper. The calculated structural parameters at zero pressure are in agreement with experimental values. The elastic constants and their pressure dependence are calculated using the static finite strain technique. We obtain the bulk modulus, Young’s modulus and Poisson’s ratio for α-Ti2Zr. The G and B at zero pressure are 101.2 and 35.6 GPa, respectively. The G/B value is relatively small and decreases with pressure increasing, showing that the α-Ti2Zr is rather ductile. The Debye temperature Θ=321.7 K is obtained by the average sound velocity based on elastic constants. We investigate anisotropies of the compressional wave and two shear waves. The acoustic velocities are obtained from elastic constants by solving Christoffel equation. The results indicate the strong anisotropy for α-Ti2Zr. Moreover, the pressure dependence of s→d electron transfer indicates that β-Ti2Zr will occur under high pressure.

High-Pressure Viscosity of Soybean-Oil-Based Biodiesel Blends with Ultra-Low-Sulfur Diesel Fuel

Current and future injector designs for diesel engines approach pressures of greater than 100 MPa. However, the high-pressure physical properties, such as viscosity, of biodiesel blends with diesel...

Paraffin Deposition Test and Phase State Simulation for Dalaoba Condensate Gas Reservoir

The condensate gas reservoir of paraffin in Dalaoba is a kind of special and complex gas reservoir.High content of paraffin for condensate gas reservoir in Dalaoba and the deposition of paraffin seriously affect the production and safety to bring about greater economic loss.The method with combination of laser method and on-line filtering method for PVT high-pressure physical property shall be employed,and the simulated deposition method for paraffin precipitation phase state shall be established,therefore,the deviation between the simulated prediction results and experimental value for the paraffin precipitation point in Dalaoba is between 0.2°C~3.5°C to meet the precision requirement on engineering computation.

High-Pressure Viscosity of Biodiesel from Soybean, Canola, and Coconut Oils

Current and future injector designs for diesel engines approach pressures of greater than 100 MPa. However, the high-pressure physical properties, such as viscosity, of biologically derived diesel fuel (biodiesel) are nearly absent in the literature. This study focuses on the viscosity of biodiesel samples, fatty acid methyl esters (FAMEs), derived from soybean oil, soybean oil from Vistive soybeans, canola oil, recycled canola oil that has been used in cooking and frying, and coconut oil from 283.15 to 373.15 K and pressures up to 131 MPa. Petroleum-derived diesel (ultra-low sulfur, number 2 diesel) has also been investigated to compare to the biodiesel samples. The viscosity of the samples increases linearly with pressure until approximately 35 MPa, followed by a higher order response to pressure. Except for coconut-oil-derived biodiesel, the biodiesel samples have viscosities that are greater than petroleum-derived diesel at both ambient and elevated pressures. However, at lower temperatures and high pressures, the diesel and biodiesel samples become more similar. The viscosity of the biodiesel samples with pressure can increase nearly 300% over the pressure range investigated over their respective ambient-pressure viscosity; number 2 diesel increases up to ∼400% over similar pressures. The biodiesel samples at 283.15 K were found to experience pressure-induced cloud points (solid−liquid equilibrium) from 70 to 100 MPa, which significantly increases their viscosity. The Tait−Litovitz equation was found to correlate the data very well over the large range of both temperature and pressure.

2802 植物油脂系生分解性潤滑油のトライボロジー特性と高圧物性(S65 サステイナブル・トライボロジー)

Vegetable oils are made from crop resources such as rapeseed and soybean. They are expected as an alternative material for lubricants of fossil resource due to sustainable circulation. On the other hand, the application of biodegradable lubricants for machines used outdoors, like construction machinery and agricultural implements and machinery etc., is expanding because it is environmental friendly. The biodegradable lubricants based on vegetable oil have already been put to practical use. In this paper, we report tribological characteristics and high-pressure physical properties of various vegetable oils.

Tailoring sphere density for high pressure physical property measurements on liquids

We present a new method of tailoring the density of a sphere for use as a probe in high pressure-temperature physical property experiments on liquids. The method consists of a composite sphere made of an inner, high density, metallic, spherical core and an exterior, low density, refractory, spherical shell or mantle. Micromechanical techniques are used to fabricate the composite sphere. We describe a relatively simple mechanical device that can grind hemispherical recesses as small as 200 μm in diameter in sapphire and as small as 500 μm in diameter in ruby hemispheres. Examples of composite spheres made with a Pt or WC core and Al2O3 shell used in metallic liquids pressurized to 16 GPa and 1900 K are shown.