Solid‐liquid‐vapor phase behavior of the methane‐carbon dioxide system

Abstract

Abstract The phase behavior of the methane‐carbon dioxide system has been determined experimentally along the solid‐liquid‐vapor locus. Pressure‐temperature measurements were made along this locus from the triple point of carbon dioxide to −284°F. Compositions of the vapor phase along the solid‐liquid‐vapor locus were determined with sampling techniques over a composition range of 0.1 to 12% carbon dioxide. Liquid‐phase compositions were obtained from crystal‐point determinations on eleven methane‐carbon dioxide mixtures ranging from 0.16 to 20% carbon dioxide. With the pressure‐temperature for the solid‐liquid‐vapor locus as the termination locus of the dew and bubble data of Donnelly and Katz (2), consistent liquid‐ and vapor‐phase compositions were obtained over the remaining concentration range. Changes in the pressure‐temperature relationship of the solid‐liquid‐vapor locus caused by using a methane stock containing 0.56 mole % nitrogen are also reported.