Rapid and high capacity methane storage in clathrate hydrates using surfactant dry solution

Abstract

Surfactant dry solution (DS) was prepared by mixing sodium dodecyl sulfate (SDS) solution, hydrophobic silica nanoparticles and air in a high speed blender. Flour-like SDS-DS combines the advantages of dispersed dry water and active SDS solution. Methane storage in clathrate hydrates using SDS-DS was investigated in a stainless steel vessel without stirring under the condition of 5.0 MPa and 273.2 K. The results demonstrated that highly dispersed SDS-DS could significantly enhance formation kinetics and storage capacity of methane hydrate. SDS-DS exhibited about the same methane storage capacity (172.96 m 3 •m-3) as dry water, but faster storage rates than dry water. Compared to SDS solution, SDS-DS had similar storage rates (7.44 m 3 •m-3 •min-1) and higher methane storage capacity under the relative low pressure. However, the aggregation of partial SDS-DS powders destroyed its original dispersive property after hydrate dissociation.

Influence of compressing pressure on macro void formation of carbon monolith for methane adsorption

“…The states before and after adsorption are indicated by numeric subscripts 1 and 2 [19,[21][22][23][24][25][26][27], respectively. All gravimetric and volumetric storage capacities for methane of the carbon monoliths used were obtained at 293 K and 3.5 MPa and listed in Table 5.…”

“…Their specific surface area (BET) was from 1115 to 1460 m 2 /g, micropore volumes were from 0.54 to 0.65 cm 3 /g, and mesopore volumes were from 0.14 to 0.29 cm 3 /g, respectively. The samples used here were the PMAC1/2-3-x series, which are activated with mass ratio of ½ as the anthracite to potassium hydroxide, so then obtained activated carbon powders shaped with binder percent of 3 and compressing under variable pressure (10,25,45, 55 and 65 MPa) for making carbon monolith. This result implies that the compression destroys or reduces large internal pores inside the monolith and eventually its volume was reduced as expected.…”

“…Coin-type carbon monoliths for ANG application were fabricated from the PMAC series carbon powders using CMC as a binder. In fabricating the carbon monoliths, different binder contents (3, 5, and 10 wt.%) and compressing pressures (10,25,45, 55 and 65 MPa) were employed in order to elucidate the effect of preparation conditions on physical characteristics of the carbon monoliths. The corresponding amounts of activated carbon and binder were first thoroughly mixed in water and then the water present in the slurry was removed by heating.…”

“…J. Chem., 18 (44), 2017, [24][25][26][27][28][29][30][31][32][33][34][35] For example, PMAC1/2-3-65 sample represents the activated carbon prepared with mass ratio of ½ as the anthracite to potassium hydroxide, so then prepared activated carbon shaped with binder percent of 3 and compressing under pressure of 65 MPa. Porous texture characterization: The porous textures of the prepared carbon monoliths were characterized using nitrogen adsorption and desorption isotherm data measured at 77 K (Micromeritics ASAP 2020, USA).…”

Improved Methane Hydrate Formation and Dissociation with Nanosphere-Based Fixed Surfactants As Promoters

“…17−19 With the reaction solution dispersed in the nano/microstructures, gas hydrate formation could be improved efficiently. In addition, the reaction solutions were also used in the form of dry water to enhance gas hydrate formation, 20,21 in which the water existed as micro droplets, as a result, a very rapid hydrate formation and high storage capacity were achieved. However, the hydrate dissociation might result in the aggregation of the dry water powders and therefore led to poor recycling performance of dry water in gas hydrate formation.…”