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Characteristics and Properties of Crude Oil and Its Products
Published in M.R. Riazi, Oil Spill Occurrence, Simulation, and Behavior, 2021
Density is defined as mass per unit volume, and it is shown by “d” or “ρ” and has the unit of kg/m3. Density is a function of both temperature and pressure; however, the effect of pressure on the density of liquids is much smaller than the effect of pressure on the density of gases. Usually the liquid density of oil at 1 atm and 20°C (shown by d20) is measured in laboratories and reported as a characterization parameter of oil. The specific volume is the reciprocal of density and represents volume of unit mass (v = 1/d). The molar volume is the volume of one mole of substance and has the unit of mol/m3 or lbmol/ft3 (V = M/d). Liquid densities are usually reported in terms of specific gravity (SG) which is the ratio of density to the density of water at the same temperature. In the petroleum industry the standard conditions are 60°F (15.5°C) and 1 atmosphere where the density of water is 0.999 g/cm3 and for a liquid petroleum fraction the specific gravity is defined as: SG(60°F/60°F) = density of liquid at 60°F in g/cm30.999 g/cm3
Energy Metrics
Published in John Andraos, Synthesis Green Metrics, 2018
Molar volume is the volume occupied by 1 mole of a substance under standard state conditions (25°C, 1 atm). Typical units are L/mol, cm3/mol, m3/mol, m3/kmol. The density of a substance is obtained when the molecular weight of a substance is divided by its molar volume. The liquid molar volume is calculated from the correlation equation for the liquid density of a substance at 298 K and 1 atm. If the substance is a solid at 298 K, the molar volume is calculated at its triple point temperature. If the substance is a gas at 298 K, the molar volume is calculated at its normal boiling point temperature.
Introduction and Definition of Terms
Published in David R. Gaskell, David E. Laughlin, Introduction to the Thermodynamics of Materials, 2017
where V, the molar volume of the gas, equals V′/n. The molar volume of an ideal gas at Standard Temperature Pressure (STP) is 22.414 liters.
Oxidation Characteristics and Corresponding Reaction Mechanism of Coal During the Spontaneous Combustion Latency
Published in Combustion Science and Technology, 2023
Xingguo Zhao, Guanglong Dai, Ruxiang Qin, Liang Zhou, Jinhu Li, Jinliang Li
In order to study the oxidation characteristics of coal during the SCL, isothermal oxidation experiments with different temperatures and different initial O2 volume fractions were carried out. The effects of oxidation products on oxidation characteristics were studied by repeated oxidation experiments. The experiment is terminated when the experimental gas concentration does not change or exceeds the range. The reaction rate of O2 can be expressed as .The production rate of CO and CO2 during the reaction can be expressed as and . In the formula: , and are the reaction rate of O2, the production rate of CO and CO2, respectively, mol/(kg·s). V is the volume of gas, L. is the volume fraction of O2, %. Vm is the molar volume of the gas, 22.4 L/mol. t is time, s. m is the mass of coal, kg. and are the slope of the straight line, 10−6/min.
Estimation of aqueous solubility of starch from various botanical sources using Flory Huggins theory approach
Published in Chemical Engineering Communications, 2021
Andri Cahyo Kumoro, Diah Susetyo Retnowati, Ratnawati Ratnawati, Marissa Widiyanti
In the solubility study, activities are frequently employed as an alternative to concentrations to counterbalance the deviations from thermodynamic ideality in the liquid phase. In order to facilitate this situation, several thermodynamic approaches have been used to predict the activity coefficient. For instance, the Flory Huggins theory has been successfully employed to estimate solubility of sugar in some cases (van der Sman 2013). For starch–water system where their molecules are highly asymmetric, mass or volume fraction based activity coefficient is much better scaled than mole fraction based activity coefficient especially due to extremely low mole fractions of high-molecular-weight starch dissolved in water (Lindvig et al. 2002). Therefore, volume fraction is preferable due to its temperature insensitivity (Holten-Andersen and Eng 1988). Volume fractions can be calculated from mass fraction solubility and molar volume of the respective components. The molar volume of water is 18.065 cm3/mol, whereas molar volume of starch is 108.27 cm3/mol (Benczedi et al. 1998).