Heat capacities and acoustic virial coefficients for a synthetic coal mine methane mixture by speed of sound measurements at T = (273.16 and 250.00) K

Abstract

Measurements of speed of sound for a synthetic coal mine methane mixture of ten components are reported. Data were obtained using a spherical resonator for two isotherms T = (273.16 and 250.00) K and pressures up to 8 MPa. The uncertainty study is detailed and the total uncertainty of the speed of sound is no worse than 0.01%. Heat capacities and acoustic virial coefficients were obtained through said measurements. Results are compared with the GERG-2008 equation of state.

Comparison of GERG-2008 and simpler EoS models in calculation of phase equilibrium and physical properties of natural gas related systems

“…Dauber and Span [7], [8] applied GERG-2008 to simulation of liquefied natural gas process and made comparison with cubic EoSs including SRK and PR. Recently, Perez-Sanz et al [9] measured the speed of sound for a synthetic coal mine methane as well as second virial acoustic coefficient, adiabatic coefficient and heat capacity. They validated their measurements by comparing their results with GERG-2008 predictions, where they found good agreement between GERG-2008 and experimental measurements for speed of sound, heat capacity and adiabatic coefficient.…”

Speed of sound and phase equilibria for (CO2 + C3H8) mixtures

“…Typical acoustic pressure levels of (1 to 20) mPa are generated, which produce signal amplitudes between (10 to 200) μV. More information about the design of acoustic transducers and acquisition instrumentation and procedures used for determination of the resonance acoustic signal were described elsewhere [25][26][27].…”

Speeds of sound for (CH4 + He) mixtures from p = (0.5 to 20) MPa at T = (273.16 to 375) K

“…No speed of sound data were found in the literature for binary mixtures of methane with helium, although high quality speed of sound measurements have been performed for pure methane [11][12][13][14] and pure helium [15]. The setup of this research has also been used successfully in previous works [16][17] and [18] for other binary and natural gas-like mixtures.…”

“…The biggest contribution to this term is due to the uncertainty of the radius calibration from acoustic measurements in argon, which comes from the 200 parts in 10 6 (0.02 %) expanded uncertainty of argon EoS. Expressions for the uncertainty calculus are detailed in [17].…”