Thermodynamic modeling of clathrate hydrate stability conditions in methane + ۱-methylpiperidine/۲-methylpiperidine + water system

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, ۲,۲-dimethylbutane, etc. However, some sH clathrate hydrate formers are soluble in water such as ۱-methylpiperidine, ۲-methylpiperidine, ۳-methylpiperidine, ۴-methylpiperidine, and hexamethyleneimine. In this study, Chen-Guo and Mehta-Sloan models were used to model sH hydrate stability conditions for ۱-methylpiperidine / ۲-methylpiperidine with methane as a help gas. The aqueous phase behavior containing ۱-methylpiperidine / ۲-methylpiperidine is modeled using the NRTL activity coefficient model. Although both Chen-Guo and Mehta-Sloan models show errors of less than ۱%, Mehta-Sloan model results are in a better agreement with the experimental data with ۰.۱۰% average absolute error in comparison with Chen-Guo model results with ۰.۳۸% average absolute error for ۱-methylpiperidine while there is not much difference for ۲-metylpiperidine when using both models in which %AAD for both models are approximately the same, i.e. ۰.۷۹%.

کلیدواژه ها:

Clathrate Hydrate ، Structure H (sH) ، Water-Soluble Hydrate Former ، ۱-Methylpiperidine