Vapour-liquid equilibrium data for the carbon dioxide (CO2) + carbon monoxide (CO) system

Abstract

In carbon capture, utilization and storage (CCUS), a thorough understanding of thermophysical behaviour of the candidate fluid is an essential requirement for accurate design and optimised operation of the processes. In this communication, vapour liquid equilibrium data (VLE) of the binary mixtures of CO+CO2 are presented. A static-analytic method was used to obtain VLE data at six isotherms (253.15, 261.45, 273.00, 283.05, 293.05, 298.15) K and pressures up to 12 MPa. The standard uncertainties of the measured temperature and pressure were estimated to be 0.1 K, 0.005 MPa, respectively. Also, the standard uncertainty of the measured molar composition of each phase is found to be less than 1.1%. The measured experimental results are then compared with some predictive thermodynamic equations of state (EoS) (i.e. the Peng Robinson (PR-78) with classical or Wong-Sandler mixing rules, the GERG, and EoS-CG without an with a specific departure function) and available data in the literature. A sound agreement is observed between the results of this work and some of the VLE data published in the open literature. Furthermore, for all isotherms, the best agreement is observed between experimental results and predicted VLE data from the PR-EoS with the Wong-Sandler mixing rules and the EoS-CG with a specific departure function. However, a significant deviation is found between measured results and VLE data calculated using the GERG-EoS.

Henry’s Law Constants and Vapor–Liquid Distribution Coefficients of Noncondensable Gases Dissolved in Carbon Dioxide

“…There is generally good consistency in the trends for isotherms obtained from different publications. Some of the data sets obtained by different authors at the same temperatures match with each other very well [e.g., the measurements by Coquelet et al and Løvseth et al for Ar (Figure d), by Souza et al Westman et al, and Chapoy et al for CO, except for a small number of outliers in Westman et al’s data at 253.152 and 298.166 K (Figure e,f), and by Pteropoulou et al and Xu et al for CH 4 at 293 K (Figure h)]. The low dilution limit is particularly well resolved for H 2 (Figure b) and also for N 2 and Ar (Figure a,d, respectively).…”

“…The relative standard uncertainty of the fugacity coefficient u (ϕ V∞ )/ϕ V∞ was calculated based on eq . The uncertainties u ( y )/ y and u ( x )/ x were either taken from the experimental studies ,, or estimated as a ratio of the reported absolute experimental uncertainties divided by the smallest measured mole fraction. The uncertainty u ( x ) by Wei et al was estimated to be 0.0005 based on the data reported to four significant figures.…”

“…The pertinent experimental database was compiled based on most recent and most accurate measurements at small dilutions (x < 0.1) 5 and temperatures between the triple point (216.59 K) to the critical point of CO 2 (304.13 K). To ensure more complete coverage and better resolution of the temperature range, data from various sources were utilized, as, for example, in the case of the CO 2 −N 2 mixture for which we used the data from Westman et al 23 and Fandinõ et al, 22 the CO 2 −Ar mixture represented by the measurements from Løvseth et al 24 and Coquelet et al, 43 and the CO 2 −CO mixtures for which we combined the data from studies by Westman et al, 28 Chapoy et al, 30 and Souza et al 29 For CH 4 , the Pxy data from recent experimental campaigns were found to be rather limited. In particular, Legoix et al 25 have reported the bubble point data but did not include the dew point measurements, while the study by Peropoulou et al 26 has only covered temperatures above 293 K. To expand our database for CH 4 to low temperatures, we have also included historical data identified in the recent literature reviews.…”

“…Some of the data sets obtained by different authors at the same temperatures match with each other very well [e.g., the measurements by Coquelet et al 43 and Løvseth et al 24 for Ar Table 1. Values of the Henry Constants (H) and the Vapor−Liquid Distribution Coefficients at Infinite Dilution (K ∞ ) Derived from the Literature Pxy Data for the Six Gas Solutes at Various Temperatures (T) and Calculated at the Critical Point of the CO 2 Solvent Where ∞ K cr = 1 and H cr Is Obtained from eq 10 a gas reference (Figure 1d), by Souza et al 29 Westman et al, 28 and Chapoy et al 30 for CO, except for a small number of outliers in Westman et al's 28 data at 253.152 and 298.166 K (Figure 1e,f), and by Pteropoulou et al 26 and Xu et al 42 for CH 4 at 293 K (Figure 1h)]. The low dilution limit is particularly well resolved for H 2 (Figure 1b) and also for N 2 and Ar (Figure 1a,d, respectively).…”

“…To obtain accurate and complete Pxy data covering a wide range of vapor and liquid mole fractions, several studies were performed in the past 15 years, resulting in the new measurements for CO 2 binary mixtures with H 2 , N 2 , Ar, CH 4 , , O 2 , and CO. − In the present work, the results of these studies, particularly reporting the data on noncondensable components at small dilutions (below ca. 10% mol/mol), formed the basis for determining Henry’s law constants for gases dissolved in CO 2 .…”