Measurements of methane hydrate equilibrium in systems inhibited with NaCl and methanol

Methane hydrate phase equilibria for systems containing NaCl, KCl, and NH 4 Cl

“…After complete melting of the hydrate, there are only the base line and sharp signals from thermal lag due to temperature change. The heat flow curve returns to the baseline [4,32] after complete hydrate melting. Therefore, the way to determine the equilibrium temperature for hydrate containing salts is to find the temperature when the heat flow curve start to return to the baseline.…”

“…In addition, the hydrate equilibrium conditions in the presence of inhibitors were also measured through DSC method [14,22]. However, Lafond et al [4] pointed out the potential problems of the DSC method for inhibited systems, and introduced a novel technique for measuring hydrate equilibrium conditions in the presence of inhibitors. Compared with the isochoric method with two cycles approach, the DSC method is a less time-consuming technique.…”

“…Studies on the chemical and physical properties of hydrates receive considerable attention because hydrates are considered an energy resource for natural gas and are one of main factors for pipeline blockage in oil and gas transportation [1][2][3][4]. Fossil fuels is the primary source for energy and as the outlook for continued demands for energy resources increases [5], there is increased interest in the exploration and production of oil and gas reservoirs in harsher environments in terms of pressure, temperature, and fluid chemistry.…”

Accurate measurement of phase equilibria and dissociation enthalpies of HFC-134a hydrates in the presence of NaCl for potential application in desalination

“…This continuous and gradual change in salinity during the dissociation process results in a broader endothermic peak, which makes it difficult to determine the accurate T onset of the HFC-134a hydrates in the presence of NaCl. In addition, the heat flow curve during the hydrate dissociation can fluctuate due to the localized inhomogeneity caused by the limitation of the mass transfer [39,40]. To overcome the influence of the salinity change on the T onset , the stepwise method can be used for salt-containing systems.…”

Inhibition effect of 1-ethyl-3-methylimidazolium chloride on methane hydrate equilibrium

“…The experimental data of offset temperatures (determined at the heating rate of 0.05 K/min) for the dissociation of methane hydrates in the presence of ethanol are in good agreement with the literature data measured by using isochoric method [24; 25], as listed in table 2. In addition, the stepwise differential scanning calorimetry scheme proposed by Lafond et al [26] was also performed. Our experimental results (determined from the offset temperature) of dissociation conditions of methane hydrates in the presence of EMIM-Cl are consistent with that of the stepwise heating scheme [26] within the experimental uncertainty + 0.1 K. Table 3 reports the dissociating temperatures of methane hydrates in pure water in the pressure ranging from 5.00 to 35.00 MPa measured by the HP µDSC in this study.…”