Development of a High-Pressure Capillary-Tube Viscometer and Its Application to Methane, Propane, and Their Mixtures in the Gaseous and Liquid Regions

A versatile absolute capillary-tube viscometer has been developed and applied to measure the viscosity of methane, propane, and four selected mixtures of the two from 100 (6.8 atm) to 8000 psia (544.4 atm) and temperatures from 40° (4.44°C) to 280°F (137.78°C). The reproducibility of the data, excluding the critical regions, was 0.25%. The data for the pure components are critically compared with values available in the literature. Within the experimental limits of this study, it has been found that, for each pure component and mixture studied, the residual viscosity, the viscosity at some pressure and temperature less the dilute-gas viscosity at that temperature, is a unique and continuous function of the density.