Abstract
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•General phase study of CO2-alkane mixtures.•Available thermodynamic data is described for mixtures of CO2 with light alkanes.•S-V, L-V, and S-L-V locus for cryogenic CO2 capture from natural gas are discussed.•Simulated phase data for CO2 mixtures by different simulators are discussed.•Challenges with the available thermodynamic data for CO2 mixtures are discussed.
The increasing global energy demand has compelled the researchers to utilize the undeveloped contaminated natural gas (N.G) reservoirs. However, due to the emissions standards established by environmental regulatory authorities, N.G treatment has become more crucial. Amongst the established CO2 separation strategies, the cryogenic CO2 removal techniques are promising due to environmentally friendliness, high N.G purification, low footprint values, no chemical reaction involved and capable of handling N.G with high CO2 content. Design and operation of a cryogenic process require accurate thermodynamic knowledge along with the understanding of the phase behavior of CO2 with light alkanes to make the process cost–effective. Furthermore, the study of frosting and liquefaction behavior of CO2 or CO2–alkanes mixture is significant for the energy minimization and smooth operation of the cryogenic CO2 removal from N.G. This paper provides a critical review of the available experimental and predicted thermodynamic data for CO2–alkanes mixtures at different conditions. The significance of pressure–temperature (PT), pressure–composition (P–xy), and temperature–composition (T–xy) phase diagrams for CO2–alkane mixtures are discussed in this paper. This paper also describes the use of the equation of states (EoS) for predicting the thermodynamic phase behavior of the CO2 mixtures. This review will help the researchers in designing more efficient, economical, and sustainable cryogenic CO2 capture processes.