نمایش همه 4 نتیجه
Effect of Additives on Gas Hydrate Formation and Stability
This study examinesرایگان!
This study examines the effects of two additive including hydroxyethyl cellulose (HEC) and sodium dodecyl sulfate (SDS) for increasing stability and gas content of natural gas hydrates. SDS can used as a hydrate promoter and HEC as a stabilizer. A high-pressure reactor in a laboratory- scale is used for to measure hydrate formation rate and stability. Hydrate stability tests were performed at temperature of -5 °C and pressure 15 bar. Induction time was obtained around 40 minutes at an optimum value of SDS
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
Kinetic investigation of methane hydrate in the presence of Imidazolium Based Ionic Liquid solutions
Methane hydrate formرایگان!
Methane hydrate formation experiments in the presence of the various imidazolilium based ionic liquid solutions with 0.5wt% concentration including 1-buthyl-3-methylimidazolium methyl sulfate ([BMIM][MeSO4]) , 1-ethyl-3-methylimidazolium hydrogen sulfate ([EMIM][HSO4]), 1- ethyl-3-methylimidazolium ethyl sulfate ([EMIM][EtSO4]), 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) and 1-(2- hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([OH-EMIM][BF4]) were conducted in a high pressure reactor at the same temperature. The induction time, gas consumption and temperature were measured.The results of experiments were indicated that [EMIM][EtSO4] and [BMIM][MeSO4] had the kinetic inhibiton effects meanwhile the other ionic liquids could be able to apply as the kinetic promoters