Dissociation processes of methane hydrate synthesized with glass beads were investigated using powder X-ray diffraction and calorimetry. Methane hydrate formed with coarse glass beads dissociated quickly at 150-200 K; in this temperature range methane hydrate dissociates at atmospheric pressure. In contrast, methane hydrate formed with glass beads less than a few microns in size showed very hig...

Isotopic fractionation of methane between gas and solid hydrate phases provides data regarding hydrate-forming environments, but the effect pressure on isotopic is not well understood. In this study, hydrates were synthesized in a cell, hydrogen isotope compositions residual hydrate-bound gases determined. The δ2H formed below freezing point water was 5.7–10.3‰ lower than that methane, indicati...

The observed moisture- and temperature dependent transformations of the dapsone (4,4'-diaminodiphenyl sulfone, DDS) 0. 33-hydrate were correlated to its structure and the number and strength of the water-DDS intermolecular interactions. A combination of characterization techniques was used, including thermal analysis (hot-stage microscopy, differential scanning calorimetry and thermogravimetric...

The LArge Reservoir Simulator (LARS) was developed to investigate various processes during gas hydrate formation and dissociation under simulated in situ conditions of relatively high pressure and low temperature (close to natural conditions). To monitor the spatial hydrate distribution during hydrate formation and the mobility of the free gas phase generated during hydrate dissociation, a cyli...

Concerns about the potential effects of rising carbon dioxide levels in the atmosphere have stimulated interest in a number of carbon dioxide sequestration studies. One suggestion is the sequestration of carbon dioxide as clathrate hydrates by injection of carbon dioxide into methane hydrate. Energy-supply research estimates indicate that natural gas hydrates in arctic and sub-seafloor formatio...

Geopressured reservoirs can serve as ample source of geothermal energy with temperatures as high as 140 0C. Salinities are typically high in these reservoirs due to the dissolution of surrounding salt domes. Cement retrogression can occur under these geopressured geothermal conditions resulting from calcium silicate hydrate [3CaO2SiO23H2O] phase in hydrated cement converting to alpha dicalciu...

In this article, the effect of sodium dodecyl sulfate (SDS) as an anionic surfactant on the thermodynamics, formation rate, formation kinetic, critical micellar concentration (CMC) and stability of methane hydrate was studied. A CMC of SDS and water solution for methane hydrate formation conditions in a batch process was measured at 450 ppm, where CMC was determined by hydrate induction time. I...

Researchers at DOE’s National Energy Technology Laboratory (NETL) have been investigating the formation of synthetic gas hydrates, with an emphasis on rapid and continuous hydrate formation techniques. The investigations focused on unconventional methods to reduce dissolution, induction, nucleation and crystallization times associated with natural and synthetic hydrates studies conducted in the...

Growth rate of a hydrate layer at the guest/liquid-water interface is analyzed considering the conjugate process of the mass-transfer and hydrate crystal growth. Hydrate-layer growth rate data in the literature are often compiled according to the system subcooling (∆T ≡ Teq − Tex, where Teq is the equilibrium dissociation temperature of the hydrate and Tex is the system temperature), suggesting...

The Krishna Godavari (KG) basin is rich in gas hydrate and exhibits an area of wide range of gas hydrate stability zone (GHSZ). In this region, we modeled the base of the gas hydrate stability zone (BGHSZ) utilizing in situ temperature measurements acquired during national gas hydrate program (NGHP) Expedition-01. The bottom simulation reflector (BSR) closely approximates the BGHSZ, and due to ...