Pressure and temperature conditions for methane hydrate dissociation in sodium chloride solutions.

Maekawa, Tatsuo; Itoh, Sadahiko; Sakata, Susumu; Igari, Shun-ichiro; Imai, Noboru

doi:10.2343/geochemj.29.325

Cited by 73 publications

(43 citation statements)

References 8 publications

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“…Outside the polar permafrost region, methane hydrates are stable below 300 m b.s.l. (below sea level) and at ocean temperatures of nearly 0 • C (Maekawa et al, 1995). The carbonate precipitation sequesters additional amounts of CO 2 , prevents the ocean water from acidifying and ultimately improves the CO 2 absorption by ocean water from the atmosphere.…”

Section: Carbon Storage As Organic and Inorganic Marine Debris And Asmentioning

confidence: 99%

Climate engineering by mimicking natural dust climate control: the iron salt aerosol method

et al. 2017

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Abstract. Power stations, ships and air traffic are among the most potent greenhouse gas emitters and are primarily responsible for global warming. Iron salt aerosols (ISAs), composed partly of iron and chloride, exert a cooling effect on climate in several ways. This article aims firstly to examine all direct and indirect natural climate cooling mechanisms driven by ISA tropospheric aerosol particles, showing their cooperation and interaction within the different environmental compartments. Secondly, it looks at a proposal to enhance the cooling effects of ISA in order to reach the optimistic target of the Paris climate agreement to limit the global temperature increase between 1.5 and 2 • C.Mineral dust played an important role during the glacial periods; by using mineral dust as a natural analogue tool and by mimicking the same method used in nature, the proposed ISA method might be able to reduce and stop climate warming. The first estimations made in this article show that by doubling the current natural iron emissions by ISA into the troposphere, i.e., by about 0.3 Tg Fe yr −1 , artificial ISA would enable the prevention or even reversal of global warming. The ISA method proposed integrates technical and economically feasible tools.

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Section: Carbon Storage As Organic and Inorganic Marine Debris And Asmentioning

confidence: 99%

Climate engineering by mimicking natural dust climate control: the iron salt aerosol method

et al. 2017

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“…In spite of uncertainties and natural variability in these parameters, apparent thermal gradients calculated from BSR depths can provide insights into subsurface temperature structure and indirectly into patterns of fluid flow [e.g., Yamano et al, 1982;Bangs et al, 1993;Yuan et al, 1996;Pecher et al, 1996;Zwart et al, 1996]. We calculated the apparent thermal gradient assuming hydrostatic pressure, a sediment P wave velocity of 1.73 km/s (measured by interval velocity analysis; Figure 7), a seafloor temperature of 2.5°C (as was measured near the escarpment during ROV dives; Figure 8), and the phase boundary for pure methane hydrate in water of 3.5% salinity (as determined experimentally by Maekawa et al [1995]). …”

Section: Fluid Flow Inferred From Variations In Bsr Depth and Seafloomentioning

confidence: 99%

Seismic and seafloor evidence for free gas, gas hydrates, and fluid seeps on the transform margin offshore Cape Mendocino

et al. 2003

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[1] Seismic data and seafloor samples indicate the presence of free gas, gas hydrate, and fluid seeps south of the Gorda Escarpment, a topographic feature that marks the eastern end of the Gorda/Pacific transform plate boundary southwest of Cape Mendocino, California. In spite of high sedimentation rates and high biological productivity, direct or indirect indicators of gas hydrate presence had not previously been recognized in this region, or along transform margins in general. Gas is indicated by a bottom simulating reflection (BSR) observed near the Gorda Escarpment, by ''bright spots'' and ''gas curtains'' scattered throughout the sedimentary basin to the south, and by d C and d18 O isotopes of carbonates, which are similar to those recovered from other hydrate-bearing regions. The BSR reflection coefficient of À0.13 ± 0.04 and interval velocities as low as 1.38 km/s indicate that free gas is present beneath the BSR. Local shallowing of the BSR toward the north facing Gorda Escarpment and beneath a channel near the crest suggests fluid flow toward the seafloor. Integrating these various observations, we suggest a scenario in which methane is formed in thick Miocene and Pliocene deposits of organicrich sediments that fill the marginal basin south of the transform fault. Dissolved and free gas migrates toward the escarpment along stratigraphic horizons, resulting in hydrate formation and in channels, slumps and chemosynthetic communities on the face of the escarpment. We conclude that the BSR appears where hydrate-bearing sediments are uplifted because of current triple junction tectonics.

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“…Experimental data in presence of 15 mass% of NaCl from: this work (• ). Experimental data in presence of 20 mass% of NaCl from: Maekawa et al, 1995 (◆), Maekawa and Imai, 1999 (▲) and this work. Experimental data for methane hydrate (distilled water) from: Blanc and Tournier-Lasserve, 1990 (■), Ross and Tocyzylkin, 1992 (■ ■), and Nixdorf and Oellrich, 1997 (■).…”

mentioning

confidence: 99%

“…Methane hydrate dissociation conditions in the presence of NaCl. Experimental data in presence of 10 mass% of NaCl from: Kabayashi et al, 1951 (• •), Maekawa et al, 1995 (◆) and Maekawa and Imai, 1999 (▲). Experimental data in presence of 15 mass% of NaCl from: this work (• ).…”

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confidence: 99%

Methane and Water Phase Equilibria in the Presence of Single and Mixed Electrolyte Solutions Using the Cubic-Plus-Association Equation of State

Haghighi

Chapoy

Tohidi

2008

Oil & Gas Science and Technology - Rev. IFP

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Résumé -Application de l'équation d'état Cubic-Plus-Association pour la prédiction des équilibres entre phases pour les systèmes contenant du méthane et de l'eau en présence d'électrolyte(s) -Les hydrates de méthane ont été largement présentés comme une potentielle nouvelle source d'énergie. Les hydrates à l'état naturel peuvent se former dans diverses roches ou sédiments si les conditions appropriées de pression et température en présence d'eau et de méthane sont réunies. Toutefois, la salinité des eaux de formation peut connaître d'importantes variations, et ces changements modifient la zone de stabilité des hydrates. En outre, l'eau de gisement produite avec les fluides de réservoir peut contenir diverses quantités de sels, pouvant prévenir la formation d'hydrates. Par conséquent, il est essentiel d'obtenir une meilleure compréhension de l'effet des sels sur la stabilité des hydrates. Dans cette communication, de nouvelles données expérimentales de dissociation d'hydrates de méthane en présence de solutions aqueuses contenant différentes concentrations de NaCl, KCl et de MgCl 2 ont été réalisées. Les nouvelles données ont été mesurées en utilisant une méthode à volume constant. La précision et la fiabilité des mesures expérimentales ont été démontrées en comparant les mesures avec les données de la littérature. Une approche thermodynamique dans lequel l'équation d'état CPA est combinée avec une modification du terme électrostatique proposé par Debye-Hückel a été employée pour modéliser les équilibres entre phases. Les conditions de formation d'hydrates sont modélisées par la théorie développée par van der Waals et Platteeuw. Pour modéliser en milieux poreux les équilibres entre phases d'hydrate, l'effet de la pression capillaire a été pris en compte. Les prédictions du modèle développé ont été validées par rapport à des données expérimentales indépendantes et les données obtenues dans ce travail. Un bon accord entre les prédictions et les données expérimentales a été observé, confirmant la fiabilité du modèle développé. Abstract -Methane and Water Phase Equilibria in the Presence of Single and Mixed Electrolyte

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Pressure and temperature conditions for methane hydrate dissociation in sodium chloride solutions.

Cited by 73 publications

References 8 publications

Climate engineering by mimicking natural dust climate control: the iron salt aerosol method

Climate engineering by mimicking natural dust climate control: the iron salt aerosol method

Seismic and seafloor evidence for free gas, gas hydrates, and fluid seeps on the transform margin offshore Cape Mendocino

Methane and Water Phase Equilibria in the Presence of Single and Mixed Electrolyte Solutions Using the Cubic-Plus-Association Equation of State

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