Prediction of CH4 and CO2 hydrate phase equilibrium and cage occupancy from ab initio intermolecular potentials

Sun, Rui; Duan, Zhenhao

doi:10.1016/j.gca.2005.05.012

Cited by 178 publications

(132 citation statements)

References 105 publications

(213 reference statements)

Supporting

Mentioning

123

Contrasting

Order By: Relevance

“…Sun and Duan (2005) compiled a large set of experimental data from the literature concerning pressure-temperature equilibria for CO 2 and CH 4 hydrates. The shaded region in Fig.…”

Section: Pressure and Temperature Sensitivitymentioning

confidence: 99%

“…2 Table 1 for other parameters. The shaded region bounds the region in which CO2 and/or CH4 hydrates are likely to develop (after Sun and Duan, 2005). …”

Section: Pressure and Temperature Sensitivitymentioning

confidence: 99%

“…sub-sea, JTC may cause hydrate formations where initial reservoir pressures are as high as 6 MPa. But at such low temperatures, high pressures also become a concern for hydrate formation (Sun and Duan, 2005).…”

Section: Pressure and Temperature Sensitivitymentioning

confidence: 99%

See 2 more Smart Citations

Analytical solution for Joule–Thomson cooling during CO2 geo-sequestration in depleted oil and gas reservoirs

Mathias

Gluyas

Oldenburg

et al. 2010

International Journal of Greenhouse Gas Control

View full text Add to dashboard Cite

Mathematical tools are needed to screen out sites where Joule Thomson cooling is a prohibitive factor for CO 2 geosequestration and to design approaches to mitigate the effect. In this paper, a simple analytical solution is developed by invoking steady-state flow and constant thermophysical properties. The analytical solution allows fast evaluation of spatiotemporal temperature fields, resulting from constant-rate CO 2 injection. The applicability of the analytical solution is demonstrated by comparison with non-isothermal simulation results from the reservoir simulator TOUGH2. Analysis confirms that for an injection rate of 3 kgs−1 (0.1MTyr−1) into moderately warm(>40°C) and permeable formations(>10 −14 m 2 (10 mD)), JTC is unlikely to be a problem for initial reservoir pressures as low as2 MPa (290 psi).

show abstract

“…Sun and Duan (2005) compiled a large set of experimental data from the literature concerning pressure-temperature equilibria for CO 2 and CH 4 hydrates. The shaded region in Fig.…”

Section: Pressure and Temperature Sensitivitymentioning

confidence: 99%

“…2 Table 1 for other parameters. The shaded region bounds the region in which CO2 and/or CH4 hydrates are likely to develop (after Sun and Duan, 2005). …”

Section: Pressure and Temperature Sensitivitymentioning

confidence: 99%

See 1 more Smart Citation

Analytical solution for Joule–Thomson cooling during CO2 geo-sequestration in depleted oil and gas reservoirs

Mathias

Gluyas

Oldenburg

et al. 2010

International Journal of Greenhouse Gas Control

View full text Add to dashboard Cite

show abstract

“…Thus, modifications on the model were required to better predict the formation condition of CO 2 hydrate in aqueous electrolyte solution. To predict both phase equilibria and cage occupancy of methane hydrate and carbon dioxide hydrate in gas-water binary systems Sun and Duan (2005) proposed a model using atomic site-site potentials to account for the angle-dependent molecular interactions with parameters directly from ab initio calculation results. This model could predict the phase equilibria of CH 4 hydrate and CO 2 hydrate in binary systems over a wide temperature-pressure range with accuracy close to experiment.…”

Section: Electrolytesmentioning

confidence: 99%

“…Many researchers used thermodynamic models for computational prediction methods for the hydrate forming conditions (John et al, 1985;Ng and Robinson, 1976;Parrish and Prausnitz , 1972;Tse and Bishnoi , 1994;Van der Waals and Platteeuw , 1959). Sun and Duan (2005) presented an improved model for the prediction of phase equilibria and cage occupancy of CH 4 and CO 2 hydrate in binary systems over a wide temperaturepressure range with accuracy close to experiment. More recently the application of advanced thermodynamic modelling to CO 2 -rich systems was presented by Tohidi et al (2012).…”

Section: Adisasmito Et Almentioning

confidence: 99%

Kinetics of the formation of CO2 hydrates in the presence of sodium halides and hydrophobic fumed silica nanoparticles

Farhang¹

View full text Add to dashboard Cite

CO 2 capture by trapping the greenhouse gas in clathrates hydrates is proving to be one of the promising options for long term carbon storage. This technology is desirable as it can be deposited in the deep ocean where the suitable pressure and temperature is ready without any extra cost. To date, this method has mostly been of academic interest because the formation of gas hydrates is very slow and requires lots of energy and resources. It is important therefore to develop an efficient and economical process to be able to apply this method at an industrial scale. Scientists and researchers have been looking for suitable additives to accelerate the formation of CO 2 hydrate. To meet these objectives numerous additives have previously been tested and several were found to be suitable hydrate promoters. The mechanism for the formation of gas hydrates in the presence of additives is not clear yet. Understanding this mechanism would help us to select and synthesise the most suitable and cost effective additive.In this thesis, two groups of chemicals i.e. salt and hydrophobic particles were added to the hydrate formation reactor and examined. Initially sodium halides were tested for their effect on the kinetics of the formation of CO 2 hydrates in an isochoric system. The effect of different anion types and concentrations was investigated by directly measuring pressure and temperature changes in the reactor and evaluating maximum CO 2 uptake, conversion, storage capacity, induction time, and hydrate growth rate. The results indicated that sodium halides at a concentration of 50 mM (mmol/L) increase CO 2 consumption and conversion to hydrates. In addition, sodium iodide and sodium bromide in a range of concentrations between 50 and 250 mM significantly increased the hydrate formation kinetics. Measurements of the surface potential of CO 2 hydrates formed in the presence of sodium halides showed negative charge on hydrates with the highest zeta potential observed at the concentration of 50 mM. The findings of this part of the research led us to propose a mechanism for the formation of CO 2 hydrates in the presence of sodium halides.The second group of additives extensively investigated in the current research were hydrophobic nano-particles. Two types of hydrophobic fumed silica were studied.iii They produced two types of particle stabilised systems when mixed with water (i.e. silica foam and dry water). The influence of particle hydrophobicity and concentration on hydrate formation kinetics was established by monitoring gas consumption, CO 2 conversion and induction time. The morphology, microstructure, and pore characteristics were elucidated by cryogenic scanning electron microscopy (cryo-SEM), and the elemental distribution and composition were determined by X-ray energy dispersive spectroscopy (EDS). The results indicated that the promoting effect of hydrophobic fumed silica was dependent on the particle hydrophobicity and on the weight ratio of silica to water. The kinetics of CO 2 hydrate formation were ...

show abstract

Salinity‐buffered methane hydrate formation and dissociation in gas‐rich systems

et al. 2015

View full text Add to dashboard Cite

Methane hydrate formation and dissociation are buffered by salinity in a closed system. During hydrate formation, salt excluded from hydrate increases salinity, drives the system to three-phase (gas, water, and hydrate phases) equilibrium, and limits further hydrate formation and dissociation. We developed a zero-dimensional local thermodynamic equilibrium-based model to explain this concept. We demonstrated this concept by forming and melting methane hydrate from a partially brine-saturated sand sample in a controlled laboratory experiment by holding pressure constant (6.94 MPa) and changing temperature stepwise. The modeled methane gas consumptions and hydrate saturations agreed well with the experimental measurements after hydrate nucleation. Hydrate dissociation occurred synchronously with temperature increase. The exception to this behavior is that substantial subcooling (6.4°C in this study) was observed for hydrate nucleation. X-ray computed tomography scanning images showed that core-scale hydrate distribution was heterogeneous. This implied core-scale water and salt transport induced by hydrate formation. Bulk resistivity increased sharply with initial hydrate formation and then decreased as the hydrate ripened. This study reproduced the salinity-buffered hydrate behavior interpreted for natural gas-rich hydrate systems by allowing methane gas to freely enter/leave the sample in response to volume changes associated with hydrate formation and dissociation. It provides insights into observations made at the core scale and log scale of salinity elevation to three-phase equilibrium in natural hydrate systems.

show abstract

Prediction of CH4 and CO2 hydrate phase equilibrium and cage occupancy from ab initio intermolecular potentials

Cited by 178 publications

References 105 publications

Analytical solution for Joule–Thomson cooling during CO2 geo-sequestration in depleted oil and gas reservoirs

Analytical solution for Joule–Thomson cooling during CO2 geo-sequestration in depleted oil and gas reservoirs

Kinetics of the formation of CO2 hydrates in the presence of sodium halides and hydrophobic fumed silica nanoparticles

Salinity‐buffered methane hydrate formation and dissociation in gas‐rich systems

Contact Info

Product

Resources

About