Electrolyte Cubic Square-Well Equation of State, eCSW EoS, based upon the Helmholtz free energy consists of the one non-electrolyte term and the two electrolyte terms. The non-electrolyte term is cubic square-well equation of state (CSW EoS) and the two electrolyte contributions consist of a Born energy and the mean spherical approximation terms. In this work, eCSW EoS is coupled with the van der Waals-Platteuw model and applied to predict the hydrate dissociation pressures of the methane+ ionic liquid+ water systems. Ferthermore, the adjustable paramers of the imidazolium based ionic liquid solutions calculated by using experimental data in litreture.A good agreement between the results of the model with the experimental data indicates the reliability of this model to predict the hydrate equilibrium conditions.
Gas or Clathrate hydrates are non-stoichiometric compounds in which the guest molecules with desirable size and shape are trapped inside the water molecules network so that no chemical bonding is formed among water and gas molecules . In gas processing and transmission gas pipelines, gas hydrates are undesirable since it causes blockage of pipelines . Therefore, various methods can be applied to reduce risk of hydrate formation including operating outside the hydrate stability zone, removing/reducing both free water and vaporized water, and injecting inhibitors . One kind of inhibitors which can be applied to prevent hydrate blockages in oil and gas industries is thermodynamic inhibitors. The aforementioned inhibitors including alcohols, glycols and inorganic salts effectively shift hydrate equilibrium phase boundary to the lower temperatures and higher pressures. these inhibitors reduce water activity and lead to prevent gas hydrates formation. Ionic liquids are a type of green electrolytes with low melting points and are composed of complex ionic species that have specific characteristics including low volatility (low vapor pressure) and good thermal stability . Some studies have been carried out to represent ionic liquids as the new group of inhibitors because of their specific chemical behavior . Several investigations have been accomplished to model and predict gas hydrate formation conditions in the presence of the thermodynamic inhibitors . Most of these thermodynamic models are composed of van der Waals-Platteuw model for solid phase and also equation of states for fluid phases.
Publisher : 2nd National Iranian Conference on Gas Hydrate (NICGH)
By : A. Haghtalab , M. Zare1, A. N. Ahmadi , K. Nazari ,G. Khatinzadeh
File Information: English Language/ 12 Page / size: 0.99 KB
سال : 1392
ناشر : دومین کنفرانس ملی هیدرات گاز (NICGH)
کاری از : حق طلب, محمد زارع, علی ناصر احمدی , ناظری ,خاتین زاده
اطلاعات فایل : زبان انگلیسی / 12 صفحه / حجم : KB 0.99