New Apparatus for Low-Temperature Investigations:  Measurements of the Multiphase Equilibrium of Mixtures Containing Methane, Ethane, Propane, Butane, Methanol, and Carbon Dioxide

Abstract

A new experimental apparatus has been developed to measure vapor− liquid equilibria (VLE) and vapor−liquid−liquid equilibria (VLLE) for multicomponent systems containing light hydrocarbons, carbon dioxide, methanol, and water at low temperatures. These systems are particularly difficult to investigate experimentally because of the polarity contrast existing between the polar and nonpolar components. In such systems, the phase equilibrium leads to a heterogeneous distribution of the different components into the different phases. Nevertheless, such systems are frequently met in refining processes and in gas treatment. Consequently, it is very important to investigate them experimentally in order to improve the engineering processes. In the present study, we describe a new apparatus which allows to investigate fluid phase equilibrium at low temperature. The experimental setup is presented in detail and the experimental procedures to reach and measure vapor−liquid and vapor−liquid−liquid equilibrium are explained. This equipment has been tested on the methanol−ethane binary system.