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Modeling phase equilibria for acid gas mixtures using the CPA equation of state. I. Mixtures with H 2 S
Author(s) -
Tsivintzelis Ioannis,
Kontogeorgis Georgios M.,
Michelsen Michael L.,
Stenby Erling H.
Publication year - 2010
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.12207
Subject(s) - ternary operation , thermodynamics , solvation , chemistry , equation of state , binary number , methanol , ternary numeral system , polar , combining rules , flory–huggins solution theory , group contribution method , phase (matter) , phase equilibrium , organic chemistry , molecule , mathematics , physics , polymer , arithmetic , astronomy , computer science , programming language
The Cubic‐Plus‐Association (CPA) equation of state is applied to a large variety of mixtures containing H 2 S, which are of interest in the oil and gas industry. Binary H 2 S mixtures with alkanes, CO 2 , water, methanol, and glycols are first considered. The interactions of H 2 S with polar compounds (water, methanol, and glycols) are modeled assuming presence or not of cross‐association interactions. Such interactions are accounted for using either a combining rule or a cross‐solvation energy obtained from spectroscopic data. Using the parameters obtained from the binary systems, one ternary and three quaternary mixtures are considered. It is shown that overall excellent correlation for binary mixtures and satisfactory prediction results for multicomponent systems are obtained. There are significant differences between the various modeling approaches and the best results are obtained when cross association is explicitly accounted for, especially using the cross‐association energy from independent experimental studies rather than from combining rules. © 2010 American Institute of Chemical Engineers AIChE J, 2010