A5013964420- Methane Hydrates and Related Phenomena
- CO2 Sequestration and Geologic Interactions
- Spacecraft and Cryogenic Technologies
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Inorganic Fluorides and Related Compounds
- Carbon Dioxide Capture Technologies
- Hydrocarbon exploration and reservoir analysis
- Crystallography and molecular interactions
- Atmospheric and Environmental Gas Dynamics
- Metal-Organic Frameworks: Synthesis and Applications
- Atmospheric Ozone and Climate
- Planetary Science and Exploration
- Phase Equilibria and Thermodynamics
- Geology and Paleoclimatology Research
- Coal and Coke Industries Research
- Thermodynamic properties of mixtures
- Chemical Thermodynamics and Molecular Structure
- Offshore Engineering and Technologies
- Chemical Synthesis and Characterization
- Phase Change Materials Research
- Freezing and Crystallization Processes
- Covalent Organic Framework Applications
- Astro and Planetary Science
- Adsorption and Cooling Systems
National Institute of Advanced Industrial Science and Technology
2015-2024
Yokohama National University
2024
University of British Columbia
2021
University of Tsukuba
2013-2020
Keio University
2008-2013
We report a new lattice structure of the ionic clathrate hydrate tetra-n-butylammonium bromide induced by guest CO2 molecules, which is found to provide high storage capacity. The was characterized set methods, including single crystal X-ray diffraction, NMR, and MD simulations.
The crystal structure of the semiclathrate hydrate tetra-<italic>n</italic>-butylphosphonium bromide is reported, and thermophysical property characterized by comparison with an analogous hydrate.
Ionic clathrate hydrates can selectively capture small gas molecules such as CO2, N2, CH4 and H2. We investigated CO2 + N2 mixed separation properties of ionic formed with tetra-n-butylammonium bromide (TBAB), chloride (TBAC), tetra-n-butylphosphonium (TBPB) (TBPC). The results showed that selectivity TBAC was remarkably higher than those the other despite less capacity hydrates. TBAB also irregularly high at a low pressure. X-ray diffraction Raman spectroscopic analyses clarified stably...
Methane trapped in the two distinct dodecahedral cages of ionic clathrate hydrate TBAB was studied by single crystal XRD and MD simulation. The relative CH4 occupancies over cage types were opposite to those CO2, which illustrates interplay between symmetry guest shape dynamics, thus gas selectivity.
This paper reports phase equilibrium measurements and crystal structure analysis on the ionic clathrate hydrate formed from tetra-n-butylphosphonium hydroxide (TBPOH). Phase temperatures were measured in mole fraction range of TBPOH aqueous solution 0.0072 to 0.0416. The highest hydrate–solution temperature was determined be 290.2 K at a 0.0340, which corresponds congruent composition. Single-crystal X-ray diffraction performed 288.7 K, chemical composition TBPOH·29.6H2O, is consistent with...
Non-destructive observations are useful for analyzing objects embedded in structures, but characterizations of low-density materials co-existing with liquid water or ice difficult, owing to insufficient contrast produced by X-ray computed tomography (CT). This study demonstrates the between absorption images clathrate hydrates and as a function energy using monochromatic X-rays. Quantitative characterization change CT resins indicates that measurements X-rays advantageous segmentation carbon...
Semiclathrate hydrates of tetra-n-butylammonium fluoride (TBAF) are potential CO2 capture media because they can at near ambient temperature under moderate pressure such as below 1 MPa. In addition to other semiclathrate hydrates, properties TBAF may vary with formation conditions aqueous composition and their complex hydrate structures. this study, we investigated for simulated flue gas, that is, + N2 by the gas separation test three different parameters each in mass fraction (wTBAF). The...
CO 2 capture preference of semiclathrate hydrate analyzed by single crystal XRD. Asymmetrically distorted cages preferentially .
Ionic clathrate hydrates are water-based materials that have unique properties, such as a wide range of melting temperatures and high gas capacities. In their structure, water molecules coordinate around ionic substances, which is regarded the actual hydration structure also linking hydrate clusters, giving insight into dynamics ions. This paper reports synthesis characterization tetra-n-butylammonium lactate (TBAL), anion biological organic material. Phase equilibrium measurements optical...
The superheated state of methane (CH4) hydrate that exists under the surface ice layer can persist for considerable lengths time, which showed promise as a method storing and transporting natural gas. This study extends this further by coating sI CH4 with one several sII hydrates, thus eliminating need defect-free continuous interface between hydrates. Gas crystals were kept intact above their dissociation temperature immersing them in liquid cyclopentane (CP), observed powder X-ray...
We report the experimental evidence for preservation of ozone (O(3)) encaged in a clathrate hydrate. Although is an unstable substance and apt to decay oxygen (O(2)), it may be preserved prolonged time if hydrate cavities form isolated molecules. This possibility was assessed using formed from + gas mixture coexisting with carbon tetrachloride or xenon. Each sample stored air-filled container at atmospheric pressure constant temperature range between -20 2 degrees C continually subjected...
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. crystal structure TBA Jeffrey’s type III tetragonal P4 2 /n, with a 33.076(7) × 12.170(2) Å 3 unit cell. volume the cell 13315(5) , which is almost twice that ideal structure. cation disordered located in two types fused cages. Although anion pentagonal dodecahedral cage neighboring cation, there...
This paper proposes an innovative CO2 enrichment system for crop production under a controlled greenhouse environment by means of tetra-n-butylammonium bromide (TBAB) + semi-clathrate hydrate (SC). In this system, is captured directly from exhaust gas combustion heater at night, which can be used stimulating photosynthesis crops in greenhouses during daytime. Although the capacity TBAB SC less than that hydrate, it shown store even moderate pressure conditions (<1.0 MPa) 283 K.
Introducing hydrophilic groups into carboxylates is a way to modify semiclathrate hydrate frameworks and change the properties of hydrates.
Semiclathrate hydrates are a crystalline host-guest material, which forms with water and ionic substances such as tetra-n-butylammonium (TBA) salts. Various anions can be used counter anion to the TBA cation, they modify thermodynamic properties of semiclathrate hydrates, critical for applications, example, cold energy storage gas separation. In this study, glycolate were newly synthesized. Measurements melting temperatures heat fusion crystal structure analysis performed. comparison other...
Developing highly efficient methane (CH4) hydrate storage methods and understanding the dissociation kinetics can contribute to advancing CH4 gas transport. The effects of tetrabutylammonium bromide (TBAB) (a thermodynamic promoter) addition on were evaluated microscopic scale using synchrotron x-ray computed tomography (CT) powder diffraction. Microscopic observations showed that a 5 wt. % TBAB solution facilitated nucleation owing initial growth semi-clathrate particles. crystals in +...