Viscosity Measurements and Predictions for Natural Gas

Abstract

A vibrating-wire viscometer of very high precision was used to measure the viscosity of methane and of two natural gases. The experimental data were, in general, taken at temperatures of 260, 280, 300, and 320 K and at pressures up to 20 MPa, and additionally in the case of methane at temperatures of 340 and 360 K and at pressures up to 29 MPa. The estimated uncertainty is ±0.3 and ±0.5% for methane and the natural gases, respectively. The new experimental data for methane were used together with zero-density or low-density viscosity values from this study and from the literature to develop a viscosity equation for natural gas composed of two contributions. The mixing rule of Wilke [J. Chem. Phys. 18: 517 1950] was applied for the zero-density viscosity part which is based on zero-density correlations for twelve components (methane, nitrogen, carbon dioxide, ethane, propane, n-and isobutane, n-and isopentane, n-hexane, n-heptane, and n-octane) and agrees with the values derived from experiment within ±0.3%. The density dependence of the residual viscosity part was correlated with methane data only, neglecting any temperature dependence, whereas the composition dependence is characterized by a pseudo-critical viscosity value. For methane the agreement between the correlated and experimental data is within ±0.5%. The values predicted with the correlation and the experimental data agree within ±1% for both the high calorific, H, natural gas and the low calorific, L, natural gas.

Rarefied Natural Gas Transport

“…1, we then verify the present formulas (1)-(4). The calculated results compare very well with the data listed in Friend et al (1989) and Schley et al (2004) (see Johnston & McCloskey, 1940;Clarke & Smith, 1969;Haberman & John, 1980;Sonntag et al, 1998;GPSA, 1998;Ivings et al, 2003).…”

“…Then you can use the formulas and the properties to present further properties of other hydrocarbons, such as ethane, propane, butane, etc., to calculate further physical properties of natural gases in most common operating states, and to conduct further analyses of theoretical and experimental researches. Various tests have been conducted to determine  , k , p c , and  of methane at different working pressures or temperatures (Mann & Dickins 1931;Johnston & McCloskey 1940;Clarke & Smith, 1969;Jansoone et al, 1970;Vennix et al, 1970;Younglove, 1974;Gammon & Douslin, 1976;Kerley, 1980;Kurumov et al, 1988;Friend et al, 1989;Jin et al, 1992;Pátek & Klomfar, 2002;Hurly et al, 2003;Schley et al, 2004;Viswanathan, 2007). Except for density, temperature was found to be a relatively important factor in the gaseous state.…”

“…Natural gas (or simply gas), made up of around 82.0-89.6 mol% methane, 0.9-9.8 mol% nitrogen, 3.4-9.4 mol% ethane, 0.6-4.7 mol% propane, 0.1-1.7 mol% n-butane, and other gases (GPSA, 1998;Ivings et al, 2003;Schley et al, 2004), is a gaseous fossil fuel that has methane as its primary compound and is moved primarily by pipeline. It is desirable to understand the physical properties in rarefied natural gas transport and the corresponding behavior in pipelines.…”

Documentation and assessment of the transport property model for mixtures implemented in NIST REFPROP (version 8.0)

“…Comparisons with a ternary refrigerant mixture R32/R125/R134A measured by Laesecke et al [28] are presented in Table 4 Langelandsvik et al [68] samples with the deviations increasing as the pressure increases at the lowest temperatures. It was noted in the Langelandsvik et al [68] manuscript that there are unexplained differences between the measurements of Schley et al [65] and the work of Langelandsvik et al [68]. The REFPROP program is in better agreement with the measurements of Schley et al [65].…”

Review on Natural Gas Thermopysical Property Measurement Techniques

“…Schley al. [48] measured viscosity of methane and two natural gases up to 29 MPa with a ±0.3 % and ±0.5 % estimated uncertainties for methane and gas mixtures, respectively. Likewise, vibrating-wire viscometers are considered as quasi-primary measurement methods [43].…”