Kinetics of Methane Hydrate Formation in an Aqueous Solution with and without Kinetic Promoter (SDS) by Spray Reactor

Abstract

Hydrate formation apparatus reported so far was mainly concentrated in stirred-tank batch environments. It was difficult to produce the high gas storage hydrate efficiently. Some nonstirred technology has been attracting more attention by researchers. This work proposed a new apparatus for hydrate formation by spraying water into a gaseous phase with a fine nozzle. It can get sufficient contact surface area for gas-liquid reaction. Methane hydrate formation experiments have been conducted using pure water and sodium dodecyl sulfate (SDS) aqueous solution for comparison at 277.15 K. The experiments were conducted at 7.0 and 6.0 MPa, respectively. Kinetics of methane hydrate formation have been investigated by methane consumption per mole of water and reaction rate. The mechanism of hydrate formation and kinetics property by spraying atomization were studied with the theory of crystal chemistry.

Methane Hydrate Formation and Dissociation in Synperonic PE/F127, CTAB, and SDS Surfactant Solutions

“…Gas consumption was also plotted in terms of moles of methane per mole of water in Figures –. The same ratio is also listed for the data reported in the literature ,,− ,− in Table S1 as Supporting Information. A strict comparison cannot be achieved since each experiment was performed at different driving forces but both sets of data are similar or in the same magnitude order.…”

“…It has been determined that the induction time decreases with SDS in methane hydrates. − This effect was ascribed to the increase on contact area using 300 ppm of SDS at 277.15 K, 6.0 and 7.0 MPa, and the reduction of methane mole fraction in the aqueous phase at 274.15 K and 4.2 MPa. , Also, a nonsignificant but systematic decreasing was observed on induction time as the surfactant concentration increased at 6 MPa . Opposite variations on this stage were observed with different SDS concentrations.…”

“…These are usually water soluble and are dosed at low concentrations ranging from 0.1 to 1.0 wt % . Several authors have analyzed multiple effects of surfactants on gas hydrates in depth. − SDS is one of the most studied additives on methane hydrates in a wide range of pressure and concentration because this anionic additive has an effective promotion activity.…”

Chemical Affinity Modeling of Methane Hydrate Formation and Dissociation in the Presence of Surfactants

“…Surfactants (i.e., water soluble) have been utilized for both improving and inhibiting hydrate formation and dissociation . Several researchers have investigated numerous effects of additives on the formation and dissociation of hydrates. ,,− Sodium dodecylsulfate (SDS) is a widely used surfactant to investigate methane hydrate formation and dissociation because of its promoting activity, such as a decrease in induction time and an increase in formation rate. − ,,, Kalogerakis et al compared the effect of anionic and non-ionic surfactants in a stirred cell, reporting a greater increase in methane hydrate formation rate with an anionic surfactant (SDS). Hydrate growth on the reactor wall was attributed to a more water-wet wall due to the anionic surfactant solution.…”

“…3,4,6−16 Sodium dodecylsulfate (SDS) is a widely used surfactant to investigate methane hydrate formation and dissociation because of its promoting activity, such as a decrease in induction time and an increase in formation rate. [6][7][8]11,17,18 Kalogerakis et al 19 compared the effect of anionic and non-ionic surfactants in a stirred cell, reporting a greater increase in methane hydrate formation rate with an anionic surfactant (SDS). Hydrate growth on the reactor wall was attributed to a more water-wet wall due to the anionic surfactant solution.…”