نمایش همه 4 نتیجه
Experimental Study and Modeling of Methane Hydrate Formation Induction Time in the Presence of Ionic Liquids
Gas hydrate formatioرایگان!
Gas hydrate formation has been referred as unfavorable phenomenon since it leads to blockage of pipelines. To prevent formation of these compounds, several methods are normally pursued including system heating, depressurization, water removal, and use of gas hydrate formation inhibitors. The latter technique may be the most practical method for this purpose. Two types of inhibitors are generally used in the industry: thermodynamic inhibitors and kinetic ones. Thermodynamic inhibitors (such as ethylene glycol and methanol) shift the hydrate-liquid-vapor- (HLV) equilibrium curve to lower temperature and higher-pressure conditions. Kinetic inhibitors (such as PVP, PVCap) delay the hydrate nucleation and growth rates. There are some evidences that ionic liquids have dual inhibition effects. In this communication, we use three ionic liquids including (BMIM-BF4), (BMIM-DCA), and (TEACL). Methane hydrate formation induction time in the presence of different concentrations of these three ionic liquids is kinetically investigated in this work. Consequently, the effects of initial pressure and ionic liquids concentration on the induction time can be evaluated. In addition, a three parameter semi-empirical model is developed on the basis of chemical kinetics theory. Finally, it is shown that the proposed semi-empirical model has a good accuracy in comparison with the experimental data
Induction time of Methane Hydrate formation in the presence of electrolyte solutions of sodium chloride and sodium sulfate
Devising methods toرایگان!
Devising methods to prevent hydrate formation is of the important issues in natural gas industry. Since a great deal of money is annually spent on using hydrate inhibitors, identification of new inhibitors with higher degrees of efficacy is economically justifiable. Bearing in mind the significant ole of hydrate inhibitors in prevention of natural gas pipelines’ getting blocked, the present study attempts to investigate two ompounds of NaCl and Na2SO4 as inhibitors of hydrate methane’s formation so as to respond to “what is the inhibitive kinetic impact of lectrolyte compounds of NaCl and Na2SO4 on the formation of methane hydrate?” To do so, this study measures the induction time of ethane ydrate crystals in the presence of electrolyte solutions of NaCl and Na2SO4 and compares the results obtained with the state lacking such inhibitors
Investigating and Modeling the Thermo-Dynamic Impact of Sodium Chloride and Sodium Sulfate on Prevention of the Formation of Methane Hydrate
Devising methods toرایگان!
Devising methods to prevent hydrate formation is of the important issues in natural gas industry. Since a great deal of money is annually spent n using hydrate inhibitors, identification of new inhibitors with higher degrees of efficacy is economically justifiable.The present article attempts to nvestigate two compounds of NaCl and Na2SO4 as inhibitors of hydrate methane’s formation so as to respond to “what is the inhibitive thermo- ynamic impact of electrolyte compounds of NaCl and Na2SO4 on the formation of methane hydrate?”. To do so, this study not only measures the equilibrium temperature and pressure of methane hydrate formation in the presence of electrolyte solutions of NaCl and Na2SO4 and mpares the results obtained with the state lacking such inhibitors, but it also assesses the regression and mathematical modeling are utilized within a basic virtual environment in order to propose a model for prediction of thermo-dynamic equilibrium temperature and pressure of methane hydrate formation
Investigation of Six Imidazolium-Based Ionic Liquids as Thermo-Kinetic Inhibitors for Methane Hydrate by Molecular Dynamics Simulation
The thermo-kinetic iرایگان!
The thermo-kinetic inhibition mechanism of six imidazolium-based ionic liquids (ILs) on methane clathrate hydrate formation and growth is studied in this work using classical molecular dynamics (MD) simulation. The ionic liquids investigated include 1-(2,3-dihydroxypropyl)-3-methylimidazoliumbis(fluorosulfonyl)imide ([C3(OH)2mim][f2N]), 1-(2-hydroxyethyl)-3-methylimidazolium bis(fluorosulfonyl)imide ([C2OHmim][f2N]), 1- ethyl-3-methylimidazolium tetrafluoroborate ([C2mim][BF4]), 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]), 1-butyl-3-methylimidazolium acetate ([C4mim][OAc]) and 1-ethyl-3-methylimidazolium ethylsulfate ([C2mim][EtSO4]). Simulations showed that [C2OHmim][f2N] and [C3(OH)2mim][f2N] are strongly hydrated compared to other ILs because of hydrogen bonding between OH groups of the cation and water molecules. They also exhibit high diffusion rates towards crystal surface and bond to it through strong intermolecular interactions. As a result, these two ILs are stronger thermo-kinetic inhibitors for formation and growth of methane hydrates compared to other ILs studied in this work as well as conventional inhibitors like methanol and NaCl. The simulations also revealed that cations of [C3(OH)2mim][f2N] and [C2OHmim][f2N] show that the presence of ions near the hydrate crystal causes hindrance for water and guest molecules adsorbing on the hydrate surface, which inhibits the growth of hydrate crystals. In addition, it is shown that [C3(OH)2mim][f2N] and [C2OHmim][f2N] are more likely to inhibit hydrate formation