Journal of Chemical and Engineering Data, Vol.50, No.2, 673-676, 2005
Measurements of the speed of sound for mixtures of methane plus butane with a particular focus on the critical state
The speed of sound in binary mixtures of methane + butane has been measured in the subcritical, nearcritical, and supercritical regions as a function of pressure at 311 K. The measurements were based on an acoustic pulse technique using a high-pressure vessel equipped with two 1-MHz transducers to generate and receive the ultrasonic wave. The results showed that the speed of sound decreased with decreasing pressure for mixtures in the subcritical region, whereas it passed through a minimum in the supercritical region.