Phase behavior of (CO2 + H2) and (CO2 + N2) at temperatures between (218.15 and 303.15) K at pressures up to 15 MPa. (May 2015)

• Record Type: Journal Article
• Authors: Fandiño, Olivia; Trusler, J.P. Martin; Vega-Maza, David
• Is Part Of: International journal of greenhouse gas control. Volume 36(2015:May)
• Page Start: 78
• Page End: 92
• Publication Date: 2015-05
• Subjects: Carbon capture -- Carbon dioxide -- Hydrogen -- Nitrogen -- Solid–vapor–liquid equilibrium -- Vapor–liquid equilibrium; Greenhouse gases -- Environmental aspects -- Periodicals; Air -- Purification -- Technological innovations -- Periodicals; Gaz à effet de serre -- Périodiques; Gaz à effet de serre -- Réduction -- Périodiques; Air -- Purification -- Technological innovations; Greenhouse gases -- Environmental aspects; Periodicals; 363.73874605
• DOI: 10.1016/j.ijggc.2015.02.018
• Languages: English
• ISSNs: 1750-5836

Abstract

Graphical abstract: Highlights: Measurements of vapor–liquid and solid–vapor–liquid equilibria. Mixtures of CO2 with H2 or N2 . Temperatures from 218 K to 303 K with pressures up to 15 MPa. Modeling with the Peng–Robinson equation of state. Applicable to low-temperature CO2 capture from syngas and pipeline transportation. Abstract: Vapor–liquid equilibrium data are reported for the binary systems (CO2 + H2 ) and (CO2 + N2 ) at temperatures between (218.15 and 303.15) K at pressures ranging from the vapor pressure of CO2 to approximately 15 MPa. These data were measured in a new analytical apparatus which is described in detail. The results are supported by a rigorous assessment of uncertainties and careful validation measurements. The new data help to resolve discrepancies between previous studies, especially for the (CO2 + H2 ) system. Experimental measurements of the three-phase solid–liquid–vapor locus are also reported for both binary systems. The vapor–liquid equilibrium data are modeled with the Peng–Robinson (PR) equation of state with two binary interaction parameters: one, a linear function of inverse temperature, applied to the unlike term in the PR attractive-energy parameter; and the other, taken to be constant, applied to the unlike term in the PR co-volume parameter. This model is able to fit the experimental data in a satisfactory way except in the critical region. We also report alternative binary parameter sets optimized for improved performance at either temperatures below 243 K or temperatures above 273 K. A simple predictive model for the three-phase locus is also presented and compared with the experimental data.