Article
Thermodynamics
Jia Song, Zhi-Gao Sun, Rong Li, Meng-Ling Dai
Summary: The equilibrium conditions of the CO2 + HFE254 or cyclopentanone + water system are determined by the isometric method. Cyclopentanone promotes CO2 hydrate formation and is a thermodynamic accelerator, while HFE254 does not affect the equilibrium pressure of CO2 hydrate. The hydrate dissociation temperature of the CO2 + cyclopentanone system increases with pressure, but decreases when pressure is above 3.2 MPa, forming a mixed hydrate of structure I and structure II.
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2021)
Article
Multidisciplinary Sciences
Emile Jules Beckwee, Geert Watson, Maarten Houlleberghs, Daniel Arenas Esteban, Sara Bals, Pascal Van Der Voort, Eric Breynaert, Johan Martens, Gino Baron, Joeri F. M. Denayer
Summary: This study reports a new type of periodic mesoporous organosilica (PMO) nanotubes, referred to as hollow ring PMO (HR-PMO), capable of promoting methane clathrate hydrate formation under mild working conditions and at high water loading. The HR-PMO nanotubes exhibit a steep single-stepped isotherm and a noticeably high methane storage capacity. Supported by ex situ cryo-electron tomography and x-ray diffraction, the findings suggest that HR-PMO nanotubes promote clathrate hydrate nucleation and growth by distributing and confining water in the mesopores of their outer wall, central channels, and external surface. These results highlight the potential application of organosilica materials for pressure-based storage of biomethane in confined clathrate hydrates.
Article
Engineering, Chemical
Tongling Jing, Chuanqi Tao, Yanbin Wang, Huan Miao, Mingyu Xi, Xingchen Zhao, Haiyang Fu
Summary: This study investigates methane adsorption in coal under high temperature and high pressure conditions and quantitatively analyzes the change in energy during the adsorption process. The results show that the adsorption capacity of coal is influenced by the degree of coal metamorphism, pressure, and temperature. The adsorption potential and adsorption capacity are important parameters for quantitatively characterizing the ease and capacity of adsorption. Additionally, the impact of pressure and temperature on adsorption varies at different depths.
Article
Energy & Fuels
Dnyaneshwar R. Bhawangirkar, Vishnu Chandrasekharan Nair, Siddhant Kumar Prasad, Jitendra S. Sangwai
Summary: The study investigated methane hydrate formation and dissociation in the presence of different concentrations of Krishna-Godavari basin sediment samples, revealing thermodynamic and kinetic characteristics. The inhibition effect during methane hydrate formation increased with sediment concentration, while stable temperature range during dissociation also increased. This research contributes to a better understanding of the KG basin reservoir and future methane gas exploration.
Article
Energy & Fuels
Lijuan Huang, Zongfa Li, Yu Wang, Liang Zhang, Yuliang Su, Zhe Zhang, Shaoran Ren
Summary: The research conducted explosion experiments on methane and air mixtures in a closed chamber at elevated pressure and temperature situations, providing useful data on the dependency of explosion risk parameters on pressure, temperature and gas concentration. The experimental results show that explosion pressure increases with initial pressure but slightly declines at elevated temperatures, while pressure rise rate and deflagration index increase at high pressures but lower at higher temperatures.
Article
Energy & Fuels
Pengfei Wang, Ying Teng
Summary: The heterogeneous distribution of hydrate in the experiment leads to local low temperature, which has a significant impact on the hydrate dissociation process. The methane production in the experiment is lower than the simulation, and the high water saturation in the Class 2 sample affects gas flow.
Article
Chemistry, Physical
Hideki Tanaka, Masakazu Matsumoto, Takuma Yagasaki
Summary: This study proposes substitution schemes for methane-carbon dioxide (CH4-CO2) hydrates and investigates the advantages and efficiencies of the substitution under three-phase and two-phase coexistence conditions. The study finds that although substitution is feasible in three-phase coexistence, its working window in temperature-pressure space is narrower compared to the two-phase coexistence condition. It also suggests a significant endothermic substitution in the medium pressure range.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Environmental Sciences
Fengyi Mi, Zhongjin He, Guosheng Jiang, Fulong Ning
Summary: This study investigates the formation of CH4 hydrates in clay nanopores under the influence of marine environmental factors such as seawater salinity, pressure, and temperature. The results reveal that high salinity hinders diffusion, high pressure promotes diffusion, and high temperature causes phase separation.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Chemistry, Physical
Rongtao Yan, Hongfei Yu, Dehuan Yang, Yuancheng Wu, Hao Tang
Summary: This paper investigates the isotropic compression characteristics of methane hydrate-bearing soil (MHBS), showing that the hydrate saturation, temperature, and pore pressure conditions have significant influences on the compressibility and strength of MHBS.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Multidisciplinary Sciences
Hirokazu Kadobayashi, Satoka Ohnishi, Hiroaki Ohfuji, Yoshitaka Yamamoto, Michihiro Muraoka, Suguru Yoshida, Naohisa Hirao, Saori Kawaguchi-Imada, Hisako Hirai
Summary: Research has shown that in the C-O-H system, the process of methane molecule dissociation and polymerization to produce heavier hydrocarbons while releasing hydrogen to ultimately form diamond occurs at milder temperatures and pressures due to the influence of water, indicating that diamond formation can also potentially take place in the upper parts of the icy mantles of giant icy planets.
SCIENTIFIC REPORTS
(2021)
Article
Energy & Fuels
Jyoti Shanker Pandey, Stian Almenningen, Nicolas von Solms, Geir Ersland
Summary: The study investigates the effectiveness of combined pressure depletion and thermal stimulation to produce CH4 gas from CH4 gas hydrates under permafrost conditions. It was found that the rate of CH4 gas production is affected by hydrate saturation and initial distribution, and that thermal stimulation can enhance gas production by melting metastable hydrate and surrounding ice cover. These results provide important insights into understanding and predicting the impact of global warming on the dissociation of permafrost-affected gas hydrates.
Article
Energy & Fuels
Mengdi Pan, Manja Luzi-Helbing, Judith M. Schicks
Summary: Natural gas hydrates are crystalline solids composed of water and gas molecules. The structure and composition of these hydrates vary depending on the source of the gas. Recent studies have reported the existence of coexisting hydrate phases with different structures and compositions in natural gas hydrate reservoirs. Raman spectroscopy analysis showed fluctuations in cage occupancy and composition within individual crystals, but no evidence of coexisting phases. Experimental results indicated that coexisting phases may form when an initial methane hydrate phase reacts with a mixture.
Article
Geosciences, Multidisciplinary
Alexey Portnov, Peter B. Flemings, Kehua You, Kevin Meazell, Michael R. Hudec, Dallas B. Dunlap
Summary: Rapid sedimentation leads to temperature reduction, pore pressure increase, and expansion of the gas hydrate stability zone. Through one-dimensional models and two-dimensional simulations, researchers found that rapid burial decreases the geothermal gradient and develops overpressure, resulting in changes in the thickness of the gas hydrate stability zone, potentially leading to an underestimation of carbon storage.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Chemistry, Physical
Zhengxiao Xu, Zhaomin Li, Shiti Cui, Binfei Li, Qifeng Zhang, Lei Zheng, Maen M. Husein
Summary: Foam flooding is an effective tertiary recovery method for oil and gas reservoirs, but it is highly sensitive to reservoir temperature and pressure. This study investigated the formation and collapse of water-based foam stabilized by a mixed ionic and nonionic surfactant system under typical reservoir conditions. Results showed that the foam had the highest comprehensive value under low temperature and high pressure. Increasing temperature led to larger and fewer gas bubbles, while increasing pressure decreased bubble size and increased their number. Understanding the variation of foam properties with temperature and pressure is crucial for the successful application of foam flooding.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Energy & Fuels
Myungchul Park, Younghoon Sohn, Hyunho Kim, Ki-Heum Park, Mincheol Ryu, Yutaek Seo
Summary: The performance of Luvicap EG was investigated with varying pH conditions and the addition of MEG. Results showed that Luvicap deteriorated at high pH conditions, while MEG effectively slowed down the growth rate for acid and neutral solutions. Under high pH and high impeller speed, Luvicap EG performed well with an enhanced effect by the addition of MEG.
Article
Chemistry, Physical
Hirokazu Kadobayashi, Hisako Hirai, Hiroaki Ohfuji, Michika Ohtake, Michihiro Muraoka, Suguru Yoshida, Yoshitaka Yamamoto
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Energy & Fuels
Michihiro Muraoka, Yoshitaka Yamamoto, Norio Tenma
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2020)
Article
Chemistry, Multidisciplinary
Michihiro Muraoka, Malcolm A. Kelland, Yoshitaka Yamamoto, Norio Tenma
CRYSTAL GROWTH & DESIGN
(2020)
Article
Spectroscopy
Hirokazu Kadobayashi, Hisako Hirai, Keita Suzuki, Hiroaki Ohfuji, Michihiro Muraoka, Suguru Yoshida, Yoshitaka Yamamoto
JOURNAL OF RAMAN SPECTROSCOPY
(2020)
Article
Multidisciplinary Sciences
Hirokazu Kadobayashi, Satoka Ohnishi, Hiroaki Ohfuji, Yoshitaka Yamamoto, Michihiro Muraoka, Suguru Yoshida, Naohisa Hirao, Saori Kawaguchi-Imada, Hisako Hirai
Summary: Research has shown that in the C-O-H system, the process of methane molecule dissociation and polymerization to produce heavier hydrocarbons while releasing hydrogen to ultimately form diamond occurs at milder temperatures and pressures due to the influence of water, indicating that diamond formation can also potentially take place in the upper parts of the icy mantles of giant icy planets.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Multidisciplinary
Michihiro Muraoka, Malcolm A. Kelland, Yoshitaka Yamamoto, Kiyofumi Suzuki
Summary: A study was conducted to evaluate the impact of various hydrate crystal growth inhibitors on THF hydrate, revealing different effects of inhibitors at varying growth rates, leading to different degrees of inhibition on sII gas hydrate.
CRYSTAL GROWTH & DESIGN
(2021)
Article
Engineering, Environmental
Sol Geo Lim, Jiyeong Jang, Jong-Won Lee, Minjun Cha, Jeasung Park, Michihiro Muraoka, Yoshitaka Yamamoto, Dohyun Moon, Ji-Ho Yoon
Summary: The study evaluates the potential feasibility of using hydroquinone clathrate formed from CO2N2O gas mixtures for storage and recovery of GHGs. The results show that the clathrates have high gas storage capacity, lack selectivity for CO2 or N2O, and can serve as a novel technology for GHG storage and recovery.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Hiroshi Fukui, Hirokazu Kadobayashi, Hirotaka Abe, Ryunosuke Takahashi, Hiroki Wadati, Naohisa Hirao
Summary: The lattice volume of ice VIII was measured in different pressure-temperature pathways, and it was found that the volume depends on the pathway, suggesting that deviatoric stress results in a larger volume. Dense ice is in the ice VIII phase with a molar volume of 6.56 cm(3) and in a high-pressure phase with a molar volume of 6.45 cm(3) at 10 K. The pressure can be estimated as 57.0 & PLUSMN; 3.4 and 60.4 & PLUSMN; 3.6 GPa, respectively.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Geosciences, Multidisciplinary
Jun Yoneda, Yusuke Jin, Michihiro Muraoka, Motoi Oshima, Kiyofumi Suzuki, William F. Waite, Peter B. Flemings
Summary: The study quantified the petrophysical and geomechanical properties of methane hydrate-bearing sediments in the Gulf of Mexico using pressure-core analysis tools. The results provide a foundation for understanding the natural hydrate system and predicting gas production behavior for future resource development.
Article
Astronomy & Astrophysics
M. Muraoka, J. Yoneda, Y. Jin, T. Hattori, T. Imai, K. Suzuki
Summary: This study aims to develop a thermal property estimation model for determining the thermal properties of methane hydrate (MH)-bearing sediments, as direct measurement of thermal properties of general MH reservoirs is difficult. By improving existing models and using a single-sided transient plane source method, we measured the thermal property values of pressure core samples from the Nankai Trough of Japan and estimated their thermal conductivity. The de Vries model agreement well with the measured thermal conductivity values before and after MH dissociation, while the random distribution model shows increasing discrepancy as gas saturation increases.
EARTH AND SPACE SCIENCE
(2023)
Article
Chemistry, Inorganic & Nuclear
Ryosuke Taniai, Tsubasa Endo, Takuya Kanetomo, Atsushi Okazawa, Hirokazu Kadobayashi, Saori I. Kawaguchi, Masaya Enomoto
Summary: A mixed-valence iron(ii,iii) coordination polymer shows thermal hysteresis and a shift in the ferromagnetic phase transition temperature with increasing pressure. High-pressure powder X-ray diffraction and Fe-57 Mossbauer spectroscopy studies suggest that this unique magnetic behavior is caused by pressure-induced high transition entropy.
DALTON TRANSACTIONS
(2023)
Proceedings Paper
Chemistry, Physical
Hirokazu Kadobayashi, Hisako Hirai, Kenji Machita, Hiroaki Ohfuji, Michihiro Muraoka, Suguru Yoshida, Yoshitaka Yamamoto
27TH AIRAPT INTERNATIONAL CONFERENCE ON HIGH PRESSURE SCIENCE AND TECHNOLOGY
(2020)
Correction
Chemistry, Physical
Satoshi Takeya, Michihiro Muraoka, Sanehiro Muromachi, Kazuyuki Hyodo, Akio Yoneyama
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Satoshi Takeya, Michihiro Muraoka, Sanehiro Muromachi, Kazuyuki Hyodo, Akio Yoneyama
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2020)
