Masato Kida

National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan

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Publications (53)111.79 Total impact

  • Yusuke Jin · Masato Kida · Jiro Nagao
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    ABSTRACT: The phase equilibrium conditions for krypton (Kr)-tetra-n-butylammonium bromide (TBAB)-water systems were determined using an isochoric method. The pressure and temperature ranges were (0.06 to 1.0) MPa and (280 to 290) K, respectively, and TBAB solutions had TBAB molar fractions, xTBAB, of 0.0062, 0.0138, 0.0234, and 0.0359. A second order transition of the TBAB hydrate was observed in all the Kr-TBAB-water systems. In the region at lower pressure than the phase transition point, the Kr-TBAB-water systems with low concentration (xTBAB = 0.0062 and 0.0138) and high concentration (xTBAB = 0.0234 and 0.0359) prefer to form TBAB·38H2O and TBAB·26H2O hydrates, respectively. However, a new TBAB hydrate was observed as a stable crystal structure in the higher pressure regions. Raman spectrum of the new TBAB hydrate shows band shapes remarkably similar to that of pure TBAB·38H2O with the crystalline space group Pmma in the frequency ranges of the lattice for C-C stretching, C-H bending, the C-H stretching bands of the -CH2 groups of TBA+ molecules, and the O-H stretching modes of water molecules, excluding the C-H stretching bands of the CH3 groups of TBA+ molecules.
    No preview · Article · Nov 2015 · Journal of Chemical & Engineering Data
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    ABSTRACT: Solid-state 13C NMR and powder X-ray diffraction measurements were conducted on mixed gas hydrates including methane and butane (i-butane and n-butane) to investigate the effect of guest composition in the hydrate lattice on the lattice parameters and density. The guest molecules were quantitatively analyzed by 13C NMR spectroscopic techniques without the influence of uncaged components. The 13C NMR measurements showed that the large cages in the structure II hydrate framework were almost fully occupied by methane and butane. Furthermore, small cage occupancies decreased with increasing butane composition as butane molecules preferentially occupied the large cages of structure II. The powder X-ray diffraction profiles showed that the lattice constant of structure II hydrate crystals increased with increasing butane composition, suggesting that the variation in guest distribution in the methane-butane systems contributes to the lattice expansion. The hydrate densities were estimated using the lattice parameters from the powder X-ray diffraction profiles and cage occupancies from 13C NMR spectra, and the results obtained suggested that the lattice expansion contributes to lowering the hydrate density. The resultant structural properties of the mixed gas hydrates will be useful for designing novel gas hydrate technologies.
    No preview · Article · Sep 2015 · Chemical Engineering Science
  • Motoi Oshima · Masato Kida · Yusuke Jin · Jiro Nagao
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    ABSTRACT: The thermal properties of {tetra-n-butylammonium bromide + tetra-n-butylammonium chloride (TBAB + TBAC)} mixed semiclathrate hydrates prepared from aqueous solutions were investigated by dissociation temperature measurements and differential scanning calorimetry (DSC). The maximum dissociation temperature of the mixed hydrate crystals at 0.1 MPa is 288.5 K for xTBAB = 0.2 {mole fraction of TBAB to (TBAB + TBAC)}, which is higher than that of the pure hydrates {T = (285.5 and 288.2) K for TBAB and TBAC hydrates, respectively}. In addition, the dissociation enthalpies of the mixed hydrates are higher than those of the pure hydrates {(5.55 ± 0.06) kJ × mol-1 H2O for pure TBAB hydrate and (5.30 ± 0.05) kJ × mol-1 H2O for pure TBAC hydrate}, with a maximum of (5.95 ± 0.12) kJ × mol-1 H2O recorded at approximately xTBAB = 0.4. It was therefore suggested that the crystal distortion in (TBAB + TBAC) mixed hydrates, caused by replacing water molecules by both bromide and chloride anions, was smaller than that observed for each pure hydrate. Consequently, the hydration numbers in the mixed hydrates were hypothesized to be slightly higher than those of the pure hydrates.
    No preview · Article · Jul 2015 · The Journal of Chemical Thermodynamics
  • Masato Kida · Mizuho Watanabe · Yusuke Jin · Jiro Nagao
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    ABSTRACT: In this study, we measured the hydrate equilibrium conditions for simple methane, ethane, propane, and krypton hydrates formed from liquid/solid deuterium oxide in order to understand the effect of deuterium replacement in the host framework on the gas hydrate equilibrium conditions. We obtained the equilibrium conditions by recording pressure and temperature for gas hydrate formation and dissociation under deuterium oxide-rich conditions in the pressure range of (0.142 to 5.49) MPa and the temperature range of (263.4 to 282.3) K. The hydrate equilibrium pressure for deuterium oxide systems at a fixed temperature decreases in the order of methane, krypton, ethane, and propane. The hydrate equilibrium temperatures for all liquid deuterium oxide systems increase compared with those for its usual liquid water systems at fixed pressure. The deuterium isotopic effect of host water molecules on hydrate equilibrium temperatures for the three phases including liquid water at a fixed pressure becomes greater in the order of methane, ethane, krypton, and propane. The hydrate equilibrium conditions for all solid deuterium oxide systems are approximately consistent with those for its usual liquid water systems. The gas hydrate crystals formed from deuterium oxide were characterized by 13C NMR spectroscopy.
    No preview · Article · May 2015 · Journal of Chemical & Engineering Data
  • Masato Kida · Mizuho Watanabe · Yusuke Jin · Jiro Nagao
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    ABSTRACT: In this report, we describe the effects of ice on the restriction of methane diffusion during the dissociation of pressurized methane hydrate grains using two deuterium-labelling approaches with D2O. Direct measurements of the dissociation behaviors of the methane hydrate samples labelled by a temperature ramping method at temperatures of 253.0–293.0 K were carried out. The deuterium-labelling approaches demonstrated that water molecules in the host framework of methane hydrate predominantly contribute to ice formation, which restricts methane release from the decomposing hydrate framework more than ice coexisting with methane hydrate. The shielding effect of ice in intimate contact with methane hydrate particles on methane diffusion during the decomposition of the hydrate framework depends on the ratio of preexisting ice in the methane hydrate sample.
    No preview · Article · May 2015 · Japanese Journal of Applied Physics
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    ABSTRACT: The ionic clathrate hydrate of tetra-n-butylammonium (TBA) acrylate was characterized using single-crystal X-ray diffraction, elemental analysis, and nuclear magnetic resonance (NMR) spectroscopy. The crystal structure of TBA acrylate was Jeffrey's type III and tetragonal P42/n, with a 33.076(7) × 33.076(7) × 12.170(2) Å3 unit cell. The volume of the unit cell was 13315(5) Å3, which is almost twice that of the ideal structure. The TBA cation was disordered and located in two types of fused cages. Although the acrylate anion was located in a pentagonal dodecahedral cage neighboring the TBA cation, there is a residual acrylate anion that could be around the other TBA cation in the unit cell. Solid-state 13C NMR spectra showed that the TBA cation was clearly disordered at 173 K, but not at 239 K. NMR peaks from the acrylate anion were not observed at either temperature. This is probably because of the strong restriction on the acrylate anion by hydrogen bonding with the lattice water. Some of the characteristics of the anion and cation of the ionic guest incorporated in the hydrate structure have yet to be defined. Further research is needed to clarify complexation of the ionic clathrate hydrate and the ionic guest, and the resulting structure.
    No preview · Article · Apr 2015 · Canadian Journal of Chemistry
  • Yusuke Jin · Masato Kida · Jiro Nagao
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    ABSTRACT: In this study, we characterized structure H (sH) clathrate hydrates (hydrates) containing nitrogen (N2) and 2,2-dimethylbutane (neohexane, hereafter referred to as NH) molecules. Based on the powder X-ray diffraction profile, we estimated the unit cell dimensions of the sH hydrate of N2 + NH to be a = 1.22342(15) nm and c = 0.99906(17) nm at 153 K. The c axis of this hydrate was slightly shorter (i.e., 0.00584 nm) than that of CH4 + NH, whereas we observed no difference in the a axis between these two hydrates. We successfully observed a symmetric N–N stretching (N–N vibration) Raman peak with two bumps, and determined that the N–N vibrational mode in the 512 and 435663 cages occurred at approximately 2323.8 and 2323.3 cm−1, respectively. We found the cage occupancy ratio of the 435663/512 cages (θM/θS) of the sH hydrate of N2 + NH to be approximately 1.30. From a comparison of the N–N vibrational modes in the 512, 435663, 51262, and 51264 cages of the sI, sII, and sH hydrates, we determined that N2 molecules in the distorted 435663 cages experience more attractive guest-host interaction than those in spherical 51264 cages, whereas the guest/cage diameter ratio of 435663 cages is larger than that of 51264 cages. We determined the L1–L2–H–V four-phase equilibrium pressure–temperature conditions in the N2–NH–water system in the temperature range of 274.36–280.71 K. Using the Clausius–Clapeyron equation, we estimated the dissociation enthalpies of the sH hydrates of N2 + NH to be 388.4 and 395.9 kJ·mol−1 (per one molar of N2 molecules) in the experimental temperature range.
    No preview · Article · Apr 2015 · The Journal of Physical Chemistry C
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    ABSTRACT: Effective and absolute permeability are among the most important factors affecting the productivity of hydrate-bearing sediments during gas recovery operations. In this study, effective and absolute permeability have been measured using natural sediment cores obtained from a methane hydrate reservoir in the Eastern Nankai Trough off the shore of Japan. The cores were recovered under pressure and shaped cylindrically with liquid nitrogen spray after rapid pressure release. The cylindrical core was inserted into a core holder for flooding tests in order to apply a near in situ effective stress. The effective permeability of water in the hydrate-bearing sandy sediment was 47millidarcies (md) with a hydrate saturation of 70%. After hydrate dissociation, the absolute permeability was estimated to be 840md. Other test results showed that the absolute permeability of the hydrate-free sediments was estimated to be tens of microdarcies for clayey sediments, tens of md for silty sediments, and up to 1.5darcy for sandy sediments. Absolute permeability showed a strong correlation with sediment grain size in log-log plots. In addition, the effective permeability of hydrate-bearing sandy sediments and the absolute permeability of hydrate-free sandy sediments correlated with the effective porosity. We compared measured data to other experimental data using pressure cores recovered from the same well and wireline pressure tests from a well near the coring well. The results are consistent with each other. At this location, we found that the effective permeability for hydrate-bearing sandy sediments was in the range of 1-100md, which was 2-3 orders of magnitude higher than conventional estimates. Finally, the change of permeability, potentially caused by depressurization-induced gas production, was analyzed. It was found that the high effective stress owing to depressurization and freshwater generation originating from hydrate dissociation caused reduction in absolute permeability.
    No preview · Article · Mar 2015 · Marine and Petroleum Geology
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    ABSTRACT: Bulk sediment mineralogy was measured from a gas hydrate-bearing Middle Pleistocene deepwater turbidite interval at the offshore production test site of the Eastern Nankai Trough area. We used a cores recovered from a 60-m-long section of the borehole to obtain samples for analysis of mineral and organic contents to ascertain the sediment mineralogy of the gas hydrate reservoir. Powder X-ray diffraction analysis, ignition loss test, and field-emission scanning electronic microscopy revealed the following: (i) ten bulk minerals vary in concentration and most of them have good exponential correlation with median grain size; (ii) the upper muddy section is dominated by coccolith-rich hemipelagites, whereas the middle and lower sections are characterized by relatively coccolith-poor, probably humic-rich alterations of sand and mud; and (iii) the common occurrence of authigenic gypsum, siderite, and framboidal pyrite indicates early diagenesis in anoxic and high salinity conditions probably associated with gas hydrate formation in some degree. Such mineralogical data can provide useful information on evaluation of thermal properties, geomechanical characteristics, effective permeability, and early diagenetic mechanism to characterize and exploit gas hydrate reservoirs.
    No preview · Article · Mar 2015 · Marine and Petroleum Geology
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    ABSTRACT: This study describes the chemical and crystallographic properties of natural gas hydrates recovered from a methane production test site in the eastern Nankai Trough. Gases released from the hydrate-bearing sediments contain methane as the main hydrocarbon component. The hydrate-bound gas includes small amounts of ethane and heavier hydrocarbons (less than ∼300 ppm). Concentrations of minor hydrocarbon components decrease in sediment cores recovered from shallower subseafloor depths. Molecular and isotopic analyses suggest a microbial origin for the natural gas distributed at this site. The 13C NMR and Raman spectra provide evidence that methane molecules are encaged in two distinct polyhedral cages of the structure I hydrate with a hydration number of 6.1. The powder X-ray diffraction profile shows that the crystal type of the gas hydrate is structure I (sI), with lattice constants estimated at 1.1841(2) nm at 83 K. At widely varying temperatures, the lattice constants of the pore-space natural gas hydrate crystals agree well with those of massive natural gas hydrate and artificial methane hydrate, suggesting that the mode of hydrate occurrence does not significantly affect the physical dimensions of the crystal lattice. The small amounts of ethane and heavier hydrocarbons that form sI hydrate have no influence on the lattice expansion of the pore-space hydrate. The density of the natural gas hydrate crystals in the hydrate-bearing sediment sample is estimated at 0.95 g/cm3 at 83 K.
    No preview · Article · Mar 2015 · Marine and Petroleum Geology
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    ABSTRACT: Sediment cores containing methane hydrate were obtained under pressure from the Eastern Nankai Trough offshore Japan, and they have been analyzed to investigate the relationship between compressional wave velocity (P-wave velocity), methane hydrate saturation, and pore space hydrate morphology. P-wave velocities of pressure cores were measured at near in-situ pressures, thus preventing hydrate dissociation. After the measurement of P-wave velocity, the cores were cut, under pressure, into separate P-wave velocity intervals. Each core interval was depressurized while measuring the evolved gas volume to quantify methane hydrate saturation. The results show that P-wave velocity correlates well with hydrate saturation; the P-wave velocity varied from less than 1700 m/s in the hydrate-free section to greater than 2300 m/s in the section with the highest hydrate saturation of 72%. The measured P-wave velocities were correctly reproduced by the sediment frame component model by adjusting model parameters such as sand-clay ratio and effective stress. It was found that all core data plotted within the model predictions assuming zero effective stress and assuming in situ effective stress. This may indicate that the cores were in the process of relaxing from their in situ effective stress at the time of measurement. By using pressure cores and pressure core analysis technology, the relationship between P-wave velocity and methane hydrate saturation has been directly obtained nondestructively. The observed relationship in high-resolution core-scale specimens enables estimation of the hydrate morphology and is expected to be more accurate than cross-plot data in well logging.
    No preview · Article · Mar 2015 · Marine and Petroleum Geology
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    ABSTRACT: Gas hydrate-bearing sediments from the eastern Nankai Trough, Japan, are characterized in terms of their lithology, interpreted processes and paleoenvironments of deposition, and various geometric parameters of their grain size distribution. These data are used to determine the relative influence of each characteristic on gas hydrate saturation within the sedimentary column. Four lithologies have been identified in a single turbidite sequence that can be attributed to hyperpycnal flow deposits, Tc or Td divisions of a turbidite sequence, a Te division of a turbidite sequence, and hemipelagic mud. Facies association indicates that the sediment core can be vertically divided into units that are characteristic of three depositional environments: a lowermost channel-fill turbidite sequence, an intervening sheet-like turbidite sequence, and an uppermost basin floor sequence. The channel-fill turbidite and sheet-like turbidite sequences are the best hydrate reservoirs, as evidenced by the high levels of gas hydrate contained within them. The relationships between gas hydrate saturation and the grain size distribution parameters of median grain size, sand content, and skewness show that the latter can be useful tools with which to assess the quality of the gas hydrate reservoir in the eastern Nankai Trough area. This result provides useful criteria for assessing reservoir quality in the eastern Nankai Trough area.
    No preview · Article · Feb 2015 · Marine and Petroleum Geology
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    ABSTRACT: The study of mechanical properties of marine sediments is essential for the prediction of the occurrence of geohazards (e.g., subsea landslides and seafloor subsidence) and the design of submarine structures for offshore industry. In this study, triaxial compression tests of gas-hydrate-bearing sandy sediments and clayey-silty sediments were conducted. The sediments were recovered by pressure coring in the Eastern Nankai Trough, the area of the first Japanese offshore production test. Soil index properties were measured and revealed porosity of 40% to 50%, with porosity decreasing gradually with greater depth below the seafloor. The mean particle size was less than 10 μm for clayey-silty sediments and approximately 100 μm for sandy sediments. Permeability, estimated by a consolidation process of triaxial testing and with X-ray diffraction analysis, depended on the content of fines, which consisted chiefly of mica, kaolinite, and smectite. The results of undrained compression tests for clayey-silty sediments showed positive excess pore pressure under all test conditions. This mechanical behavior indicates that the core samples are normally consolidated sediments. Drained compression tests showed that the strength and stiffness of sandy sediments increase with hydrate saturation. Furthermore, the volumetric strain of hydrate-bearing sediments changed from compression to dilative. This result was obtained for hydrate saturation values (Sh) of more than 70%. The shear strength of hydrate-bearing turbidite sediments of the Eastern Nankai Trough is shown to be a function of the confining pressure.
    No preview · Article · Feb 2015 · Marine and Petroleum Geology
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    ABSTRACT: Geomechanical and geotechnical properties are essential for evaluating the stability of deep seabed and subsea production systems for gas hydrate extraction from marine sediments. In this study, natural gas hydrate-bearing sediment was subjected to triaxial compression tests (shearing) using a newly developed triaxial testing system (TACTT) to investigate the geomechanical behavior of sediments recovered from below the seafloor in the eastern Nankai Trough, where the first Japanese offshore production test was conducted in 2013. The sediments were recovered using a hybrid pressure coring system, with pressure cores cut using onboard pressure core analysis tools. The pressure cores were subsequently transferred to our shore-based laboratory and subsampled using pressure core non-destructive analysis tools (PNATS) for the TACTT system. Pressure and temperature conditions were maintained within the hydrate stability boundary during coring and laboratory testing. An image processing technique was used to capture deformation of the sediment sample within the transparent acrylic test cell, and digital photographs were obtained for each 0.1% strain level experienced by the sample during the triaxial compression test. Analysis of the digitized images showed that sediments with 63% hydrate saturation exhibited brittle failure, whereas hydrate-free sediments exhibited ductile failure. The increase in shear strength with increasing hydrate saturation in natural gas hydrates is in agreement with previous data from sediments containing synthetic gas hydrates.
    No preview · Article · Feb 2015 · Marine and Petroleum Geology
  • Yusuke Jin · Masato Kida · Jiro Nagao
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    ABSTRACT: Phase equilibrium pressure–temperature (pT) boundaries of structure-H clathrate hydrates (sH hydrates) with rare gas (Kr and Xe)-bromide large molecule guest substances (LMGSs: bromocyclohexane, BrCH and bromocyclopentane, BrCP) were measured. The phase boundaries for the sH hydrates in the Kr–LMGS–water systems shifted to lower pressures than those for the pure Kr hydrate in the temperature range of (273.2 to 279.3) K. In this study, sH hydrate formation was not confirmed in the Xe–BrCP–water system, but sH hydrates were found in the Xe–BrCH–water system. At temperatures below 277 K, equilibrium conditions were observed at lower pressures for the Xe–BrCH–water system than for the pure Xe hydrate. However, the equilibrium pT curve for the Xe–BrCH–water system crossed over the equilibrium pT curve for the Xe hydrate at around 277 K. Intersections between the equilibrium pT curves for the Xe hydrates and the sH hydrates (Xe + LMGS) have also been found in Xe–methylcyclohexane–water systems. Using the Kr–and Xe–bromide LMGS–water systems showed that the sH hydrate phase stabilities are strongly related to the encaptured LMGS.
    No preview · Article · Apr 2014 · Journal of Chemical & Engineering Data
  • Masato Kida · Mizuho Watanabe · Yusuke Jin · Jiro Nagao
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    ABSTRACT: Elucidating the mechanisms of self-preservation and control of dissociation of gas hydrates is crucial for developing technologies facilitating highstability and long-term storage of natural gas using gas hydrate crystals. Direct measurements of the dissociation behavior of pressurized and nonpressurized methane hydrate grains in a temperature ramping test were conducted. We revealed that a pressurized process is effective for enhancing self-preservation and that it is useful to store methane gas while maintaining a submillimeter-sized hydrate material under high temperature conditions.
    No preview · Article · Jan 2014 · Japanese Journal of Applied Physics
  • Yusuke Jin · Masato Kida · Jiro Nagao
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    ABSTRACT: This study characterized new structure H (sH) clathrate hydrates with bromide large-molecule guest substances (LMGSs) bromocyclopentane (BrCP) and bromocyclohexane (BrCH), using powder X-ray diffraction (PXRD) and Raman spectroscopy. The lattice parameters of sH hydrates with (CH4 + BrCP) and (CH4 + BrCH) were determined from their PXRD profiles. On the basis of their Raman spectra, the M-cage to S-cage occupancy ratio (435663 and 512 cages, respectively), θM/θS, was estimated to be approximately 1.3, and the Raman shift of the symmetric C–H vibrational modes of CH4 in S- and M-cages was 2911.1 and 2909.1 cm–1, respectively. The phase-equilibrium conditions of sH hydrates with (CH4 + BrCP) and (CH4 + BrCH) were determined by an isochoric method. A comparison between the equilibria of sH hydrates with BrCP and BrCH and those with other typical nonpolar and polar LMGSs (methylcyclopentane, MCP; methylcyclohexane, MCH; neohexane, NH; and tert-butyl methyl ether, TBME) at the same temperature revealed that the equilibrium pressure increased in the order NH < MCH < BrCH < TBME MCP < BrCP. The phase stabilities of sH hydrates can be determined by not only molecular geometry but also their polar properties, which affect guest–host interactions.
    No preview · Article · Oct 2013 · The Journal of Physical Chemistry C
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    ABSTRACT: The solid-state 13C NMR spectra of various guest hydrocarbons (methane, ethane, propane, adamantane) of clathrate hydrates were measured to elucidate local structural environments around hydrocarbon molecules isolated in guest-host frameworks of clathrate hydrates. Results show that, depending on the cage environment, trends in the 13C chemical shift and in the line width change as a function of temperature. Shielding around the carbons of the guest normal alkanes in looser cage environments tends to decrease with increasing temperature, although shielding in tighter cage environments tends to increase continuously with increasing temperature. Furthermore, the 13C NMR line widths suggest that the local structures, because of the reorientation of the guest alkanes in structure II, are more averaged than those in structure I. Differences between structures I and II tend to be remarkably large in the lower temperature range examined in this study. The 13C NMR spectra of adamantane guest molecules in structure H hydrate show that the local structures around adamantane guests trapped in structure H hydrate cages are averaged at the same level as the phase α solid adamantane.
    No preview · Article · Apr 2013 · The Journal of Physical Chemistry A
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    ABSTRACT: Thermal measurements and hydrate mapping in the vicinity of the K-2 mud volcano in Lake Baikal have revealed a particular type of association of thermal anomalies (29–121 mW m–2) near hydrate-forming layers. Detailed coring within K-2 showed that hydrates are restricted to two distinct zones at sub-bottom depths exceeding 70–300 cm. Temperature data from stations with hydrate recovery and degassing features all display low thermal gradients. Otherwise, the thermal gradients within the mud volcano are generally increased. These findings imply a more complicated thermal regime than often assumed for mud volcanoes, with important roles for both fluids and hydrates. The coexistence of neighbouring low and high thermal anomalies is interpreted to result from discharging and recharging fluid activity, rather than hydrate thermodynamics. It is suggested that hydrates play a key role in controlling the fluid circulation pattern at an early stage. At a later stage, the inflow of undersaturated lake water would favour the dissolution of structure I hydrates and the formation of structure II hydrates, the latter having been observed on top of structure I hydrates in the K-2 mud volcano.
    Full-text · Article · Dec 2012 · Geo-Marine Letters
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    ABSTRACT: This study reports measurements of the Raman spectra of Lake Baikal gas hydrates and estimations of the hydration number of methane-rich samples. The hydration number of gas hydrates retrieved from the southern Baikal Basin (crystallographic structure I) was approx. 6.1. Consistent with previous results, the Raman spectra of gas hydrates retrieved from the Kukuy K-2 mud volcano in the central Baikal Basin indicated the existence of crystallographic structures I and II. Measurements of the dissociation heat of Lake Baikal gas hydrates by calorimetry (from the decomposition of gas hydrates to gas and water), employing the hydration number, revealed values of 53.7–55.5 kJ mol–1 for the southern basin samples (structure I), and of 54.3–55.5 kJ mol–1 for the structure I hydrates and 62.8–64.2 kJ mol–1 for the structure II hydrates from the Kukuy K-2 mud volcano.
    No preview · Article · Dec 2012 · Geo-Marine Letters