Article
Chemistry, Physical
Gaurav Vishwakarma, Bijesh K. Malla, K. S. S. V. Prasad Reddy, Jyotirmoy Ghosh, Soham Chowdhury, Sharma S. R. K. C. Yamijala, Sandeep K. Reddy, Rajnish Kumar, Thalappil Pradeep
Summary: Restricted migration limits chemical transformations within interstellar and cometary ices. We found that CO2 can migrate from clathrate hydrate cages to amorphous solid water in the presence of tetrahydrofuran under ultrahigh vacuum and cryogenic conditions. This migration may create a more conducive environment for chemical transformations in interstellar environments.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Gaurav Vishwakarma, Bijesh K. Malla, K. S. S. V. Prasad Reddy, Jyotirmoy Ghosh, Soham Chowdhury, Sharma S. R. K. C. Yamijala, Sandeep K. Reddy, Rajnish Kumar, Thalappil Pradeep
Summary: Restricted migration of CO2 from clathrate hydrate cages to amorphous solid water matrix was observed in the presence of tetrahydrofuran (THF) under ultrahigh vacuum and cryogenic conditions. This cage-matrix exchange may create a more conducive environment for chemical transformations in interstellar environments.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
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
Yingmei Wang, Aili Niu, Wenze Jiao, Ji Chen, Peng Zhang, Jinping Li
Summary: Carbon dioxide hydrate formation rate is improved by using different accelerator systems. The combination of nanographite-TBAB and SDS-TBAB shows better performance in reducing the nucleation time. TBAB shows the best nucleation amount, formation rate, and conversion rate among the single acceleration systems.
Article
Thermodynamics
Hassan Pahlavanzadeh, Sepideh Nouri, Mahnaz Aghajanloo, Amir H. Mohammadi, Samira Mohammadi
Summary: In this study, the dissociation conditions of CO2 + water systems in the absence/presence of MgCl2 + THF aqueous solutions at different concentrations were investigated experimentally and thermodynamically. The results showed that MgCl2 acted as an inhibitor while THF acted as a promoter. The equilibrium curve shifted towards the left in the presence of MgCl2, especially at high pressures. A thermodynamic model using the Peng-Robinson equation of state and the UNIQUAC activity coefficient model was developed and found to predict the equilibrium conditions reasonably well.
FLUID PHASE EQUILIBRIA
(2023)
Article
Energy & Fuels
Meku Maruyama, Shun Kao, Hitoshi Kiyokawa, Satoshi Takeya, Ryo Ohmura
Summary: In this study, clathrate-hydrate-based continuous CO2 capture was experimentally investigated, and it was found that the CO2 concentration rate and recovery ratio were lower compared to pre-combustion systems. However, it was revealed that improving the geometry of mixing impellers could enhance the CO2 recovery ratio for continuous operation.
Article
Energy & Fuels
Namrata Gaikwad, Gaurav Bhattacharjee, Jitendra S. Sangwai, Rajnish Kumar, Praveen Linga
Summary: This study investigates the kinetics and morphology of hydrate crystal growth in gas-water and gas-liquid hydrocarbon-water systems using different additives. The addition of tryptophan significantly enhances gas uptake and hydrate formation rate. In the gas-liquid hydrocarbon-water system, the presence of water-insoluble Cyclo-O hinders mass transfer between gas and bulk water phase, resulting in cloudlike hydrate formation.
Article
Energy & Fuels
Andrea Rossi, Michele Ciulla, Valentino Canale, Marco Zannotti, Marco Minicucci, Pietro Di Profio, Rita Giovannetti
Summary: The structural characterization of gas hydrates prepared in different environments was investigated using Raman spectroscopy and scanning electron microscopy (SEM). The study revealed that the surrounding environment affects the structure and replacement performance of gas hydrates.
Article
Chemistry, Physical
Satoshi Takeya, Akihiro Hachikubo, Hirotoshi Sakagami, Hirotsugu Minami, Satoshi Yamashita, Masayoshi Takahashi, Keiichi Hirano, Kazuyuki Hyodo, Akio Yoneyama
Summary: Understanding the dissolution processes of natural methane (CH4) hydrates is crucial for assessing the amount of methane released into seawater from unconventional natural gas resources. High-resolution experiments have successfully visualized the spatial relationships between methane hydrates and seawater, revealing that dissociation of methane hydrates leads to the formation of microbubbles.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Engineering, Chemical
Amir Mohammad Javidani, Hassan Pahlavanzadeh, Ali Eslamimanesh, Abolfazl Mohammadi
Summary: Hydrate-based desalination is a cost-effective technique for producing fresh water, but the kinetics of hydrate formation in saline water is relatively low. This study investigates the kinetics of an R410a refrigerant hydrate in the presence of various concentrations of CaCl2 and the effect of cyclopentane addition on hydrate formation kinetics. The results show that lower concentrations of CaCl2 have no significant effect on hydrate formation, while higher concentrations lead to a decline in kinetic parameters. Additionally, the presence of cyclopentane improves the kinetics of hydrate formation.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Engineering, Chemical
Zengqi Liu, Shuting Zhang, Yingying Liu, Qiang Sun, Zhen Xu, Aixian Liu, Yiwei Wang, Xuqiang Guo
Summary: This study evaluated the Peq of CH4-CO2 gas mixtures with different TBAB solutions at different temperatures by considering the effects of multiple solute interactions and the deformation of D-cages. The proposed model can accurately predict Peq by incorporating the effects of gas dissolution, the presence of electrolytes, and the deformation of D-cages. It provides a quantitative description of these effects on Peq values for corresponding systems.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Energy & Fuels
Beatrice Castellani
Summary: A countermeasure to global warming is the removal of high CO2 amounts from the atmosphere and storing it in stable carbon storage sites. CO2 storage as clathrate hydrates in marine environments is an innovative approach that shows potential. This article discusses the positioning of direct hydrate-based CO2 storage among traditional geological options and the development of a reliable, stable, durable, efficient, and environmentally friendly hydrate-based CO2 storage pathway.
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, Multidisciplinary
Sirisha Nallakukkala, Hani Abulkhair, Abdulmohsen Alsaiari, Iqbal Ahmad, Eydhah Almatrafi, Omar Bamaga, Bhajan Lal, Azmi Mohd Shariff
Summary: This study analyzed the suitability of methane, carbon dioxide, and propane for hydrate formation, and concluded that CO2-C3H8 is the preferred hydrate former for hydrate-based desalination.
Article
Energy & Fuels
Yanhong Wang, Jinfeng Lu, Jing Qi, Xuemei Lang, Shuanshi Fan, Chi Yu, Gang Li
Summary: This study utilized HCFC-141b as an additive to capture CO2, enhancing the kinetics difference in methane and carbon dioxide hydrate formation, effectively reducing energy consumption and improving separation efficiency.
Article
Energy & Fuels
Meku Maruyama, Shun Kao, Hitoshi Kiyokawa, Satoshi Takeya, Ryo Ohmura
Summary: In this study, clathrate-hydrate-based continuous CO2 capture was experimentally investigated, and it was found that the CO2 concentration rate and recovery ratio were lower compared to pre-combustion systems. However, it was revealed that improving the geometry of mixing impellers could enhance the CO2 recovery ratio for continuous operation.
Article
Chemistry, Organic
Hiroto Miyabe, Mizuha Ujita, Masaki Nishio, Toyotaka Nakae, Tsukasa Usuki, Minako Ikeya, Chika Nishimoto, Suguru Ito, Mineyuki Hattori, Satoshi Takeya, Shigenobu Hayashi, Daisuke Saito, Masako Kato, Hiroshi Nishihara, Teppei Yamada, Yoshinori Yamanoi
Summary: A series of octamethyltetrasilanes with different donor and acceptor groups were prepared and their optical properties were studied. Two compounds showed dual emission behavior in solution and reversible photoluminescent change under mechanical and thermal stimuli in the solid state.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Satoshi Takeya, Daisuke Yahagi, Akihiro Hachikubo
Summary: The crystallographic structure and dissociation kinetics of thermodynamically unstable structure I carbon monoxide (CO) hydrate were investigated, along with the dissociation of binary gas hydrates involving CO and other gases. The phase transition of ice formed by CO hydrate dissociation was found to be crucial for the kinetic stability of the hydrate.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Engineering, Chemical
Akari Gibo, Seiya Nakao, Sayaka Shiraishi, Satoshi Takeya, Shigeo Tomura, Ryo Ohmura, Keita Yasuda
Summary: A dual functional methodology for seawater desalination and salt manufacture using carbon dioxide clathrate hydrate was proposed in this study, demonstrated by visual observation of clathrate hydrate formation and salt precipitation along with PXRD analysis.
Article
Chemistry, Physical
Yong Chen, Satoshi Takeya, Amadeu K. Sum
Summary: This study reports the observation of a hidden clathrate structure, the tetragonal structure (TS-I), in gas hydrates. The TS-I forms as a cocrystal when two or more sI crystal grains with different growth directions come into contact or when the growth of an sI crystal encounters geometrical frustration. The results imply that TS-I may play an important role in the combination and/or transition between sI and sII.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Thermodynamics
Akihiro Hachikubo, Go Fuseya, Emi Sugimori, Satoshi Takeya
Summary: In this study, the pressure dependence of the hydration number of argon hydrate and the equilibrium pressure at different temperatures were measured. The hydration number of argon hydrate decreased with increasing formation pressure and approached the value of the ideal hydration number of sII hydrate. The results of both measurements were consistent with each other.
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2022)
Article
Multidisciplinary Sciences
Yong Chen, Satoshi Takeya, Amadeu K. Sum
Summary: Clathrate hydrates are ordered structures stabilized by hydrophobic interactions between water and guest molecules. In this study, an alternative method is proposed to understand the complex structures of clathrate hydrates, revealing the diverse crystalline hydrogen-bonded networks that can be formed. The topological dual relations between clathrate hydrate networks and tetrahedrally close-packed structures provide insights into their nucleation, phase transition, and co-existence mechanisms. Molecular dynamics simulations are employed to explore the intrinsic structural relationships of clathrate hydrates and other unrelated ordered materials.
NATURE COMMUNICATIONS
(2023)
Article
Thermodynamics
Akihiro Hachikubo, Kaede Takizawa, Satoshi Takeya
Summary: The stable isotope fractionation between nitrogen gas and hydrate phases during nitrogen hydrate formation was investigated. It was found that nitrogen hydrate was slightly more susceptible to 14N15N inclusion, indicating a slightly lower equilibrium pressure for 14N15N hydrate compared to 14N2 hydrate.
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2023)
Article
Chemistry, Physical
Satoshi Takeya, Hiroshi Fujihisa, Saman Alavi, Ryo Ohmura
Summary: We report a thermally induced phase transition of cubic structure II hydrates of tetrahydropyran (THP) and CO2 below about 140 K. The phase transition was characterized by powder X-ray diffraction measurements at variable temperatures. A dynamical ordering of the CO2 guests in small pentagonal dodecahedral 512 host water cages, not previously observed in the simple CO2 hydrate, occurs simultaneously with the symmetry lowering transition from a cubic structure II to a tetragonal unit cell.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Review
Chemistry, Multidisciplinary
Akio Yoneyama, Daiko Takamatsu, Thet-Thet Lwin, Shigehito Yamada, Tetsuya Takakuwa, Kazuyuki Hyodo, Keiichi Hirano, Satoshi Takeya
Summary: Crystal-based X-ray interferometry (CXI) detects X-ray phase shifts with the highest sensitivity among the X-ray phase-detecting methods. Phase-contrast X-ray imaging (PCXI) using CXI has the highest density resolution and has been widely applied in various fields. Novel imaging methods have also been developed to take advantage of CXI's high sensitivity, such as visualization of the effective atomic number and the three-dimensional temperature. This article reviews the principles, history, and potential applications of PCXI and CXI systems.
APPLIED SCIENCES-BASEL
(2023)
Article
Materials Science, Multidisciplinary
Sol Geo Lim, Jong-Won Lee, Hiroshi Fujihisa, Chang Yeop Oh, Jiyeong Jang, Dohyun Moon, Satoshi Takeya, Michihiro Muraoka, Yoshitaka Yamamoto, Ji-Ho Yoon
Summary: Researchers have successfully synthesized a hydroquinone clathrate structure that can stably capture neon gas at room temperature and atmospheric pressure, and release it at high temperatures. The structure allows for encapsulation of neon gas in the one-dimensional channels of the clathrate framework, with inter-cage migration through the hexagonal entrance. This study has important implications for the storage and controlled release of noble gases in solid materials.
COMMUNICATIONS MATERIALS
(2023)
Article
Energy & Fuels
Takashi Morimoto, Rikuto Suzuki, Sho Kuromatsu, Takeshi Watanabe, Shinji Koh, Satoshi Takeya, Takaaki Inada, Hiroyuki Kumano
Summary: The addition of Zn-ZnO to TBAB aqueous solution was found to significantly promote nucleation of TBAB hydrate. However, the nucleation-promoting mechanism of Zn-ZnO is still unclear.
GAS SCIENCE AND ENGINEERING
(2023)
Article
Chemistry, Physical
Yoshiharu Suzuki, Satoshi Takeya
Summary: Metastable forms of ice and their crystal growth are crucial in various areas. This study investigates the effects of solute on the crystal growth of ice in dilute solution and reveals the inhibitory effect of trehalose on ice crystal growth, which results in easier sublimation of ice.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Sanehiro Muromachi, Masato Kida, Masato Morimoto, Shogo Yamane, Satoshi Takeya
Summary: This paper investigates the manipulation of the structure and properties of semiclathrate hydrates. By adjusting the alkyl side chain length of quaternary ammonium salts, the structure and relevant properties of the hydrates can be modified.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Sanehiro Muromachi, Satoshi Takeya, Saman Alavi, John A. Ripmeester
Summary: The crystal structure of tetra-n-butylammonium chloride (TBAC) + CO2 semiclathrate hydrate, known for its high CO2 selectivity, was studied using single crystal X-ray diffraction. The study revealed that the CO2 gas occupies dodecahedral (D) cages along with water and chloride ions. Different types of D cages were observed, with the ratio of D-L:D-M:D-N as 2:2:1. The CO2 molecules were found in distorted D-M and D-N cages, while chloride ions were partially present in D-M cages. The spatial distribution of CO2 in the cages was limited due to the distortion of D-M and D-N cages. The study also highlighted the superior CO2 capture preference of TBAC hydrate.