Formation and dissociation studies for optimizing the uptake of methane by methane hydrates

Modelling of hydrate formation kinetics: State-of-the-art and future directions

“…In perfect agreement with this reasoning, Giavarini et al (2003) verified an almost immediate formation of propane hydrate from melting ice (T op = 1 • C, P op = 4 bar) but a much slower process (13.3 t nuc (h) 18) when liquid water was employed in the reactor (T op =2 • C, P op =3.6.4.8 bar). Similar trends of an effect Table 2 Induction time for methane hydrates formed from water with different previous treatments (Vysniauskas and Bishnoi, 1983) of the thermal history of water upon the nucleation time were reported by many authors (Schroeter et al, 1983;Monfort and Nzihou, 1993;Parent and Bishnoi, 1996;Moudrakovski et al, 2001;Link et al, 2003;Lee et al, 2005a,b;Servio and Englezos, 2003;Linga et al, 2007), characterising what has been known as the memory effect in hydrate nucleation. Zatsepina et al (2004), in particular, verified that even the addition of small amounts (5-35%) of thawed water into distilled water was already enough to bring about a substantial drop in the value of t nuc .…”

“…The performance of eight different surfactants (SDS, dodecyl trimethyl ammonium chloride, dodecylamine, dodecylamine HCl, sodium oleate, sodium lauric acid, Superfloc 16 ᭨ and Superfloc 84 ᭨ ) as methane hydrate promoters was compared by Link et al (2003). The adopted response variable was the methane uptake by the hydrate, expressed as a percentage of the maximum theoretical value, and its maximum value reached 97.3% for SDS.…”

“…The adopted response variable was the methane uptake by the hydrate, expressed as a percentage of the maximum theoretical value, and its maximum value reached 97.3% for SDS. It ought to be emphasised that, in their comparison, Link et al (2003) kept the concentration of all surfactants fixed and equal to the critical micellar concentration (CMC) of SDS reported by Zhong and Rogers (2000), namely 0.205.0.220 kg/m 3 , even though a more appropriate comparison should adopt, for each surfactant, its respective CMC.…”

Sorptive storage of natural gas onto dry and wet phillipsite: Study of dynamics, storage and delivery

“…An optimum value of water contents was clearly evidenced: at low water content, the formation pressure of hydrate is rather high, and hence higher pressures must be reached for storing larger amount of methane. Conversely, at high water content, formation of hydrate pressures are close to the bulk water hydrate pressure (31.8 bars), but the diffusion of gaseous methane throughout the pores network is drastically hindered, and only a low amount of methane stored [9]. The amount of methane stored at 80 bars as a function of the water content was concluded and existence of an optimum amount of water was found to be at 350 g water.…”

Different Mechanism Effect between Gas-Solid and Liquid-Solid Interface on the Three-Phase Coexistence Hydrate System Dissociation in Seawater: A Molecular Dynamics Simulation Study

“…The availability of methane in hydrates makes hydrates a key future energetic resource, whose exploitation represents a technical challenge. Studies that were conducted earlier by other researchers aimed in establishing efficient ways for exploration of gas hydrates [1][2][3][4] with a broad range of laboratory experiments [5][6][7][8][9][10][11][12][13][14] and field scale simulations [15][16][17][18]. However, the microscopic mechanism study of hydrate dissociation and its production process faces a great limitation with the available conventional methods.…”