Thermodynamic modeling of clathrate hydrate stability conditions in methane + 1-methylpiperidine/2-methylpiperidine + water system

Document Type : Original Article


1 Faculty of Petroleum ,Gas and Petrochemical Engineering, Persian Gulf University, Bushehr, Iran

2 Faculty of Petroleum, Gas and Petrochemical Engineering, Persian Gulf University, Iran

3 Discipline of Chemical Engineering, School of Engineering, University of KwaZulu-Natal, Howard College Campus, King George V Avenue, Durban 4041, South Africa


There are three typical thermodynamic models to determine structure H (sH) hydrate stability conditions, i.e. van der Waals-Platteeuw based model developed by Mehta and Sloan, the Chen-Guo model introduced by Chen and Guo, and the Klauda-Sandler model applied by Sinehbaghizadeh et al. and other researchers. These thermodynamic models are typically used for water-immiscible or slightly soluble sH hydrate formers e.g. methylcyclopentane, methylcyclohexane, 2,2-dimethylbutane, etc. However, some sH clathrate hydrate formers are soluble in water such as 1-methylpiperidine, 2-methylpiperidine, 3-methylpiperidine, 4-methylpiperidine, and hexamethyleneimine. In this study, Chen-Guo and Mehta-Sloan models were used to model sH hydrate stability conditions for 1-methylpiperidine / 2-methylpiperidine with methane as a help gas. The aqueous phase behavior containing 1-methylpiperidine / 2-methylpiperidine is modeled using the NRTL activity coefficient model. Although both Chen-Guo and Mehta-Sloan models show errors of less than 1%, Mehta-Sloan model results are in a better agreement with the experimental data with 0.10% average absolute error in comparison with Chen-Guo model results with 0.38% average absolute error for 1-methylpiperidine while there is not much difference for 2-metylpiperidine when using both models in which %AAD for both models are approximately the same, i.e. 0.79%.