Experimental investigations on tetrahydrofuran – methane – water system: Rapid methane gas storage in hydrates

Abstract

This study reports methane (CH4) gas storage capacity along with TetraHydroFuran (THF) as guest molecules in mixed hydrates. This process has been studied in two reactors of 100 and 400 mL capacity, having 4.5 and 7.5 cm internal diameter respectively, in non-stirred configuration. Experiments were conducted in each reactor at constant initial gas pressure (7.5 MPa) and by increasing the height of the solution from 1 to 8 cm, resulting in volume scale-up factor of 5. The total CH4 gas uptake (moles) passes through a maximum at around 50% volume of the reactor indicating a transition from gas-rich to solution rich conditions. Observed variations in gas uptake are within ±20% of the maximum, upon different solution volume from 35% to 70% of reactor’s volume. Another set of experiments were conducted keeping the amount of the solution constant and increasing gas pressure in the range of 0.5–11.0 MPa. The gas uptake increased upon an increase in the gas pressure, but this is at least 40% less compared to the theoretical estimate. The stirring of solution or addition of promoter (Sodium Dodecyl Sulfate, SDS) is also not effective in increasing the gas consumption. Kinetics of gas uptake, in both stirred and non-stirred conditions, are quicker and 90% of gas consumption occurs in an hour after the hydrate nucleation event.

Enrichment of gas storage in clathrate hydrates by optimizing the molar liquid water–gas ratio

“…8 Natural hydrates are ascertained to be a future energy source if used with feasible technology and will have economic value. 9 The synthetic hydrates provide multifaceted applications such as storage media for greenhouse gases, [10][11][12][13][14][15][16] carbon dioxide capture from fuel gas, 17 methane recovery from coal mine gas, 18,19 desalination, [20][21][22] cold storage, [23][24][25][26][27] and gas transportation. 12,28 Because of their structural properties and selectivity, this process slowly escalates to address various food technology issues.…”

“…52 Thermodynamic promoters such as tetrahydrofuran, cyclopentane, tetra-n-butyl ammonium bromide, and epoxycyclopentane increase the hydrate stability conditions to higher temperatures. 11,[53][54][55][56][57][58][59][60] The use of packed beds, porous materials, nanoparticles, dry water, foams, and hydrogels proved to accelerate the growth kinetics and higher gas uptake by increasing the surface area. Studies report that the micelle formation and the decreased surface tension offer higher gas water interaction and enhance mass transfer.…”

“…The operating conditions are chosen since a higher driving force offers a faster reaction rate and enhances the yield. 11,72,74 The gas is introduced at 298 K. As the reactor temperature decreases, the gas linearly decreases. Once the phase equilibrium boundary is crossed, a steep reduction in the pressure is observed.…”

Cyclic methane hydrate production stimulated with CO2 and N2

“…That is, the negative rhythm is the most preferred scheme for CH 4 production, but the least preferred one for CO 2 storage. The parameter values of hydrate kinetics are taken from bulk phase systems in this paper because these values are less accessible in porous media [46][47][48]. Besides, the measurement of the hydrate formation kinetic constant is much more difficult, which also exhibits a weak correlation to the temperature [49,50]; thus, there is great uncertainty.…”

Intensification of Gas Hydrate Formation Processes by Renewal of Interfacial Area between Phases

“…This study analyses gas hydrate synthesis technology that will guarantee its transportation and long-term storage. According to many researchers [12][13][14][15], storage of natural gas in clathrate hydrates offers the best storage method, explained by the relative convenience of natural gas recovery at minimal cost compared to conventional storage methods [16][17][18][19][20][21]. The works [22,23] present comprehensive data on managing gases in a hydrated state.…”