PREDICTION OF HYDRATE FORMATION TEMPERATURES OF SOUR GASES USING CPA EoS

The aim objective of this study is prediction of hydrate dissociation temperatures using CPA (Cubic-Plus-Association) and and compare with SRK (Soave-Redlich-Kwong) EoS (equation of state) for sour gases. For this purpose, the solid solution theory of van der Waals-Platteeuw has been used to estimate the water chemical potential in hydrate phase. In this modeling, 20 experimental data points of methane-hydrogen sulfide and 57 experimental data for methane-hydrogen sulfide-carbon dioxide hydrate dissociations points have been extracted from literature. The results show that average absolute deviation, AAD, between calculated and experimental temperatures is 1.30 K for methane-hydrogen sulfide system for SRK EoS and it is 1.10 K for CPA EoS. Also for methane-hydrogen sulfide-carbon dioxide system AAD is 0.80 and 0.76 K for SRK and CPA EoS, respectively.