Bubble-Point Measurements of <i>n</i>‑Butane + <i>n</i>‑Octane and <i>n</i>‑Butane + <i>n-</i>Nonane Binary Mixtures

Abstract

Mixtures of small gaseous hydrocarbons with longer chain hydrocarbons are of interest to the natural gas industry as well as other industries in which separations are critical. In particular, binary mixtures of <i>n-</i>nonane are of interest, because <i>n-</i>nonane was recently incorporated into the GERG-2008 equation of state, but there is little experimental vapor–liquid equilibrium (VLE) data available to support the equation. The bubble-point pressures of four compositions of each of the binary mixtures <i>n</i>-butane + <i>n</i>-octane and <i>n</i>-butane + <i>n-</i>nonane were measured over the temperature range of 270 to 370 K. The data and the expanded uncertainty (at a 95 % confidence level, <i>k</i> = 2) of each point are reported. Additionally, the data are compared to existing literature data for the <i>n-</i>butane + <i>n</i>-octane and the GERG-2008 equation for both systems. This is the first report of vapor–liquid equilibrium measurements on <i>n</i>-butane + <i>n-</i>nonane binary mixtures