Clathrate polyhydrates of peralkylonium salts and their analogs

Dyadin, Yu. A.; Udachin, Konstantin A.

doi:10.1007/bf00753818

Cited by 119 publications

(154 citation statements)

References 80 publications

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“…relatively large (i.e. 5 K) [49] whereas the difference between 30.2 wt% TBPO (TBPO·28H 2 O) and 26.0 wt% TBPO (TBPO·34.5H 2 O) was rather small (less than 1 K) [45,46]. Moreover, the measured dissociation temperature of 5 wt% TBPO at ambient pressure was 276.2 K (with uncertainty of 0.5 K), whereas the corresponding temperature of 5 wt% TBAB was estimated by extrapolation to be 274.8 K or lower, depending on the hydrate type [40].…”

Section: Resultsmentioning

confidence: 99%

Phase equilibrium measurements for clathrate hydrates of flue gas (CO2+N2+O2) in the presence of tetra-n-butyl ammonium bromide or tri-n-butylphosphine oxide

Wang

2015

The Journal of Chemical Thermodynamics

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Please cite this article as: J. Du, L. Wang, Phase equilibrium measurements for clathrate hydrates of flue gas (CO 2 + N 2 + O 2 ) in the presence of tetra-n-butyl ammonium bromide or tri-n-butylphosphine oxide, J. Chem. Thermodynamics (2015), doi: http://dx.doi.org/10. 1016/j.jct.2015.04.023 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Abstract This paper reports the measured hydrate phase equilibria of simulated flue gas (12.6 vol% CO 2 , 80.5 vol% N 2 , 6.9 vol% O 2 ) in the presence of tetra-n-butyl ammonium bromide (TBAB) or tri-n-butylphosphine oxide (TBPO), at 0 wt%, 5 wt%, and 26 wt%, respectively. The measurements of the phase boundary between hydrate-liquid-vapor (H-L-V) phases and liquid-vapor (L-V) phases were performed within the temperature range (275.97 -293.99) K and pressure range (1.56 -18.78) MPa with using the isochoric step-heating pressure search method. It was found that addition of TBAB or TBPO allowed the incipient equilibrium hydrate formation conditions for the flue gas to become milder. Compared to TBAB, TBPO was largely more effective in reducing the phase equilibrium pressure.

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Section: Resultsmentioning

confidence: 99%

Phase equilibrium measurements for clathrate hydrates of flue gas (CO2+N2+O2) in the presence of tetra-n-butyl ammonium bromide or tri-n-butylphosphine oxide

Wang

2015

The Journal of Chemical Thermodynamics

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“…both covalent-ionic bonds (T--X: T = Si, AI; X = O) and hydrogen bonds (T--X...T: T = O; X= H) occur in the frameworks. These mixed (heterogeneous) tetrahedral network structures provide a link between two well known classes of host-guest compounds: zeolites and their related materials such as zeosiles and clathrasils (Liebau, Gies, Gunawardane & Marler, 1986;Meier & Olson, 1987;Smith, 1988), and clathrate hydrates and their related materials such as polyhydrates of alkylammonium salts and alkylamines (Jeffrey, 1984;Dyadin & Udachin, 1987;Mootz & St~iben, 1991). In these materials only covalent-ionic bonds or only hydrogen bonds connect the T atoms in their nonmixed (homogeneous) tetrahedral networks.…”

Section: M-{3}[{2r}[4mso20_x(oh)x]y[h20]_]{o}[h20] N With Mmentioning

confidence: 99%

“…2) might also occur above some temperature limit. Na[NMe417[SisO2o].54H20 is one member of a series of crystalline alkylammonium (alumino)silicate hydrates, [NR4],,,{ 3 }[{2r}[4MsO2o_~(OH) (Wiebcke, 1991) to be host-guest compounds with anionic three-dimensional (mainly) four-connected heterogeneous networks that are structurally related to both zeolite-type materials (Liebau et al, 1986;Meier & Olson, 1987;Smith, 1988) and clathrate hydrate-type materials (Jeffrey, 1984, Dyadin & Udachin, 1987Mootz & Stfiben, 1991 (Smith & Bennett, 1981) and zeolite-structure type AST (Meier & Olson, 1987), but this polyhydrate is another variant (tetragonal structure, space group /3,2m, Z = 2) of net No. 214.…”

Section: Non-centrosymmetric Arrangement? Considering Thementioning

confidence: 99%

Single-crystal X-ray diffraction and variable-temperature MAS NMR study on the heterogeneous network clathrate Na[N(CH₃)₄]₇[Si₈O₂₀].54H₂O

Wiebcke¹,

Koller²

1992

Acta Crystallogr Sect B

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2534 unique observed reflections. The host-guest compound consists of a three-dimensional fourconnected network composed of hydrogen-bonded oligomeric silicate anions with double four-ring structure, [SisO2o] s-, and H20 molecules. This mixed (heterogeneous) network has the topology of net No. 214 and zeolite-structure type AST. Orientationally disordered cationic guest species NMe~ are enclosed in large [46612] octadecahedral cages of

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“…Typical structures of semi-clathrate hydrates are tetragonal structure-I (TS-I), hexagonal structure-I (HS-I), and superlattice of cubic structure-I (SCS-I) in the TBA salts with theoretical structures being 10( 5 12 )Á16(5 30, 31 The structures of semi-clathrate hydrates depend on the anion species and on the formation conditions of temperature and concentration of the TBA salt. 32,33 In semi-clathrate hydrates, there is the possibility that an H 2 O molecule can occupy the (5 12 ) cage (S-cage).…”

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confidence: 99%

Hydrogen and carbon dioxide adsorption with tetra‐n‐butyl ammonium semi‐clathrate hydrates for gas separations

Komatsu¹,

Ota

Satō

et al. 2014

AIChE Journal

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Gas adsorption rates of H 2 , CO 2 , and H 2 -CO 2 gas mixture (H 2 /CO 2 5 3.4) with tetra-n-butyl ammonium salt (bromide, chloride, and fluoride) semi-clathrate hydrate particles were measured at 269 K to assess their properties for gas separation. Equilibrium gas occupancies in the S-cages of the particles were in order of (high to low) for hexagonal structure-I, tetragonal structure-I, and superlattice of cubic structure-I structures with the maximum fractional occupancy by CO 2 being about 40%. The CO 2 diffusion rate depended on the anion size of the salt, which is attributed to distortion of the S-cage that is close to the molecular size of CO 2 . Simulations of semi-clathrate hydrate particles with theory showed that H 2 /CO 2 selectivities could be as high as 36 (3.0 mol% TBAF) and that selectivities for an ideal membrane (3.3 mol% TBAF) could be >100 (269 K, 0.3-4.5 MPa). Semi-clathrate hydrates have wide application as separation media for gas mixtures.

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Clathrate polyhydrates of peralkylonium salts and their analogs

Cited by 119 publications

References 80 publications

Phase equilibrium measurements for clathrate hydrates of flue gas (CO2+N2+O2) in the presence of tetra-n-butyl ammonium bromide or tri-n-butylphosphine oxide

Phase equilibrium measurements for clathrate hydrates of flue gas (CO2+N2+O2) in the presence of tetra-n-butyl ammonium bromide or tri-n-butylphosphine oxide

Single-crystal X-ray diffraction and variable-temperature MAS NMR study on the heterogeneous network clathrate Na[N(CH₃)₄]₇[Si₈O₂₀].54H₂O

Hydrogen and carbon dioxide adsorption with tetra‐n‐butyl ammonium semi‐clathrate hydrates for gas separations

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Clathrate polyhydrates of peralkylonium salts and their analogs

Cited by 119 publications

References 80 publications

Phase equilibrium measurements for clathrate hydrates of flue gas (CO2+N2+O2) in the presence of tetra-n-butyl ammonium bromide or tri-n-butylphosphine oxide

Phase equilibrium measurements for clathrate hydrates of flue gas (CO2+N2+O2) in the presence of tetra-n-butyl ammonium bromide or tri-n-butylphosphine oxide

Single-crystal X-ray diffraction and variable-temperature MAS NMR study on the heterogeneous network clathrate Na[N(CH3)4]7[Si8O20].54H2O

Hydrogen and carbon dioxide adsorption with tetra‐n‐butyl ammonium semi‐clathrate hydrates for gas separations

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Single-crystal X-ray diffraction and variable-temperature MAS NMR study on the heterogeneous network clathrate Na[N(CH₃)₄]₇[Si₈O₂₀].54H₂O