PVTxy properties of CO₂ mixtures relevant for CO₂ capture, transport and storage: Review of available experimental data and theoretical models

The knowledge about pressure-volume-temperature-composition (PVTxy) properties plays an important role in the design and operation of many processes involved in CO₂ capture and storage (CCS) systems. A literature survey was conducted on both the available experimental data and the theoretical models associated with the thermodynamic properties of CO₂ mixtures within the operation window of CCS. Some gaps were identified between available experimental data and requirements of the system design and operation. The major concerns are: for the vapour-liquidequilibrium, there are no data about CO₂/COS and few data about the CO₂/N2O4 mixture. For the volume property, there are no published experimental data for CO₂/O₂, CO₂/CO, CO₂/N2O4, CO₂/COS and CO₂/NH₃ and the liquid volume of CO₂/H₂. The experimental data available for multi-component CO₂ mixtures are also scarce. Many equations of state are available for thermodynamic calculations of CO₂ mixtures. The cubic equations of state have the simplest structure and are capable of giving reasonable results for the PVTxy properties. More complex equations of state such as Lee-Kesler, SAFT and GERG typically give better results for the volume property, but not necessarily for the vapourliquid equilibrium. None of the equations of state evaluated in the literature show any clear advantage
in CCS applications for the calculation of all PVTxy properties. A reference equation of state for CCS should thus be a future goal. Copyright © 2011 Elsevier Ltd All rights reserved.