An empirical correlation-based model to predict solid-fluid phase equilibria and phase separation of the ternary system CH4-CO2-H2S

A review on the solid–liquid–vapor phase equilibria of acid gases in methane

“…where T t and P t are the triple point temperature and pressure of CO 2 , respectively; and P Sub CO 2 is the sublimation pressure of solid CO 2 . Similar to the work of Ababneh and Al-Muhtaseb, 44 Yang et al 46 studied the SLVE behavior of this system by combining the PR EoS with Eqn 6 to find the fugacities of fluid and solid phases, receptively. They found that the optimum value for the interaction parameter k ij is 0.123, which is similar to the value found by Ababneh and Al-Muhtaseb.…”

“…However, there is an apparent deviation between the model predictions and experimental data at high temperatures, which could be explained by the fact the model assumes a presence of methane in the solid phase, even at higher temperatures; thus altering the model calculations for the other two phases. On the other hand, Ababneh and Al-Muhtaseb's model resulted in better predictions for the experimental data in the vapor phase as shown in 27 Donnelly and Katz 24 Ababneh & Al-Muhtaseb 44 2.14% Davis et al 27 Riva et al 2 1.94% Davis et al 27 Tang 50 1.98% Davis et al 27 Yokozeki 52 2.05% Davis et al Fig. 5, which could be attributed to their assumption that the solid phase consists of pure CO 2 , in agreement with experimental observations.…”

“…Overall, it was found that utilizing the PR EoS with k ij = 0.100 with laboratory data (symbols) 24,27 for the SLVE of the system CH 4 -CO 2 system. Comparisons are divided between two subfigures to avoid overcrowding: (A) 27,40,44,48,2,49 (B) [50][51][52]43 resulted in the least error of model estimations compared to the experimental data, 24,27 with an average absolute deviation (AAD) (as defined in Eqn 4) of 2.19%. Figure 4(A) shows their estimated SLVE locus as generated using the PR EoS against experimental data.…”

“…where v s is the molar volume of the solid phase and H sub is the enthalpy change at sublimation. Ababneh and Al-Muhtaseb 44 have been successful in predicting the distrbution of CH 4 and CO 2 between the three phase, where they assumed the solid phase to consist of pure CO 2 . Figure 5 shows their results comapred to the experimental data.…”

“…Model predictions (lines) compared to experimental data (symbols) 27 for the distribution of CH 4 CO 2 in the liquid and vapor phases. 44,52 Approach 2: Using EoS for vapor, liquid, and solid phases…”