Clathrate Hydrates E-Book
336,99 €
Mehr erfahren.
- Herausgeber: Wiley-VCH GmbH
- Kategorie: Wissenschaft und neue Technologien
- Sprache: Englisch
Clathrate Hydrates
All-inclusive reference on clathrate hydrates from a molecular perspective
Clathrate hydrates are crystalline water-based inclusion compounds many of which form at high pressures and low temperatures. Molecular science has provided the foundation for many areas of modern hydrate research and applications ranging from desalination processes to flow assurance in oil and gas pipelines.
Clathrate Hydrates provides detailed information on the molecular science aspects of hydrate research, covering the structural, compositional, spectroscopic, thermodynamic, and mechanical properties of clathrate hydrates as well as simulation methods and selected engineering applications. Edited and authored by recognized leaders in the field, this comprehensive resource introduces readers to clathrate hydrates and reviews the state-of-the-art of the field. In-depth chapters address different areas of specialization such as characterization of clathrate hydrates using NMR spectroscopy, infrared and Raman spectroscopy, and X-ray and neutron diffraction and scattering.
- Highlights recent developments in clathrate hydrate research and applications such as natural gas recovery, desalination, and gas separation
- Reviews various molecular simulation methods for characterizing clathrate hydrates, including quantum mechanical calculations and Monte Carlo results
- Contains tables of known guest molecules, summaries of structural and physical properties, and different classes of clathrate hydrate phase equilibria
- Introduces unconventional guest-host interactions, related non-hydrate clathrates, and space-filling cages using the Frank-Kasper approach
- Covers the molecular motion of guest and host molecules and the relationship between cage geometry and guest dynamics
- Presents the rate and mechanisms of hydrate formation and decomposition from both macroscopic and microscopic points
Clathrate Hydrates: Molecular Science and Characterization is an indispensable reference for materials scientists, physical chemists, chemical engineers, geochemists, and graduate students in relevant areas of science and engineering.
Sie lesen das E-Book in den Legimi-Apps auf:
Seitenzahl: 1634
Veröffentlichungsjahr: 2022
Ähnliche
Table of Contents
Cover
Title Page
Copyright
Dedication
Volume 1
Preface
Scope
1 An Introduction to Clathrate Hydrate Science
1.1 Introduction
1.2 Selected Highlights of Clathrate Hydrate Science Research Up to the Present
1.3 Clathrate Hydrate Research at the NRC Canada
1.4 Contributors to NRC Clathrate Hydrate Research
1.5 Review Articles and Books on Clathrate Hydrates
1.6 Conference Proceedings
2 An Introduction to Clathrate Hydrates
2.1 Introduction
2.2 The First Gas Hydrates
2.3 The Phase Rule
2.4 de Forcrand and Villard – Career Gas Hydrate Researchers
2.5 Nikitin and von Stackelberg
2.6 Solving the Gas Hydrate Puzzle
2.7 Clathrate Hydrate Science – A New Era
2.8 Clathrate Hydrates in Engineering
2.9 Clathrate Hydrates in Nature
2.10 Summary and Observations
References
Notes
3 Classification of Clathrate Hydrates
3.1 Introduction
3.2 Hydrates as Clathrates
3.3 Clathrate and Related Hydrates – Guest Chemistry
3.4 The Canonical Clathrate Hydrates
3.5 Phase Equilibria
3.6 Tabulation of Hydrate Properties
3.7 Summary
References
4 Synthesis of Clathrate Hydrates
4.1 Introduction
4.2 General Considerations in the Synthesis of Clathrate Hydrates
4.3 Synthesis of Hydrates with Water‐Soluble Guests Near Ambient Conditions
4.4 Synthesis of Hydrates of Guests with Low Solubility in Water
4.5 Synthesis of Clathrate Hydrates of Strongly Hydrated or Reactive Guests
4.6 Pure Hydrates – Kinetic and Thermodynamic Control
4.7 High‐Pressure Reactors
4.8 Synthesis of Single Crystals
4.9 Summary
References
5 Structures of Canonical Clathrate Hydrates
5.1 Introduction
5.2 The Canonical Clathrate Hydrates
5.3 Some General Structural Considerations
References
6 Structures of Noncanonical Clathrates and Related Hydrates
6.1 Introduction
6.2 Amine Hydrates
6.3 Ionic Clathrate Hydrates
References
7 Thermodynamics and Statistical Mechanics of Clathrate Hydrates
7.1 Introduction
7.2 Clathrate Hydration Numbers and Cage Occupancies
7.3 Enthalpy of Dissociation of Hydrate Phases
7.4 Statistical Mechanics of Clathrate Hydrates: The van der Waals–Platteeuw Solid Solution Model for Clathrate Hydrate Formation
7.5 Application of the van der Waals–Platteeuw Theory to Determining Hydrate Equilibrium Composition
7.6 Computational Predictions of Hydrate Dissociation Pressures Using the van der Waals–Platteeuw Theory
7.7 Extensions of the van der Waals–Platteeuw Theory
7.8 Other Thermodynamic Topics
7.9 Conclusions
References
Volume 2
8 Molecular Simulations of Clathrate Hydrates
8.1 Introduction
8.2 Molecular Simulations
8.3 Structural Characterization of Clathrate Hydrates with Simulations
8.4 Dynamic Characterizations of Guest Motion in Cages
8.5 Simulations of Clathrate Hydrates
8.6 Ab Initio Quantum Mechanical Calculations of Clathrate Hydrates
8.7 Conclusions and Outlook
References
9 X‐ray and Neutron Diffraction and Scattering of Clathrate Hydrates
9.1 Introduction
9.2 Crystallography and X‐ray Diffraction
9.3 Instrumentation
9.4 Structural Characterization with Diffraction Methods
9.5 Neutron Diffraction or Elastic Neutron Scattering
9.6 Inelastic Neutron Scattering
9.7 Inelastic X‐ray Scattering
9.8 Summary
References
10 Characterization of Clathrate Hydrates Using Nuclear Magnetic Resonance Spectroscopy
10.1 Introduction
10.2 NMR Interactions
10.3 Experimental Aspects of NMR Spectroscopy
10.4 The Development of NMR Techniques Over Time
10.5 NMR Powder Line Shapes in Clathrate Hydrates
References
11 Specialized Methods of Nuclear Magnetic Resonance Spectroscopy and Magnetic Resonance Imaging Applied to Characterization of Clathrate Hydrates
11.1 Introduction
11.2 13C MAS NMR in Compositional and Structural Analysis of Gas Hydrates
11.3 129Xe NMR Applications: Other Topics
11.4 Ionic Hydrates
11.5 Clathrate Hydrates and Magnetic Resonance Imaging
References
12 Reorientation and Diffusion in Clathrate Hydrates
12.1 Introduction
12.2 Early Work on Clathrates/Inclusion Compounds
12.3 Dynamics
12.4 Water Dynamics in Ice and Clathrate Hydrates
12.5 Guest Motions
12.6 Summary
References
13 IR and Raman Spectroscopy of Clathrate Hydrates
13.1 Fundamentals and Quantification
13.2 IR Spectroscopy of Clathrate Hydrates
13.3 Raman Spectroscopy of Clathrate Hydrates
13.4 Conclusions
Appendix 3A Raman Peaks of Clathrate Hydrate Guests
References
14 Kinetics of Clathrate Hydrate Processes
14.1 Introduction
14.2 Experimental Measurement of Hydrate Process Rates
14.3 Modeling the Kinetics of Hydrate Nucleation
14.4 Hydrate Phase Transformations
14.5 Metastability
14.6 Kinetic Modifiers
14.7 Molecular Simulations of Clathrate Hydrate Nucleation and Growth
14.8 Concluding Remarks
References
15 Mechanical and Thermal Transport Properties of Clathrate Hydrates
15.1 Introduction
15.2 Theoretical Background
15.3 Mechanical Properties: Acoustic Velocity and Elastic Constants
15.4 Thermal Expansion
15.5 Transport Properties: Thermal Conductivity
15.6 Molecular Dynamics Simulations of Thermal Properties of Clathrate Hydrates
15.7 Summary
References
16 Applications of Clathrate (Gas) Hydrates
16.1 Introduction
16.2 Flow Assurance in Oil and Gas Pipelines
16.3 Natural Gas Energy Recovery from the Earth's Hydrates
16.4 Desalination
16.5 Concentration of Wastewater and Aqueous Organic Solutions
16.6 Storage and Transportation of Natural Gas, Hydrogen, and Other Materials
16.7 Gas Separations
16.8 Conclusions
References
Index
Wiley End User License Agreement
List of Tables
Chapter 2
Table 2.1 Molecules found by de Forcrand to form double hydrates with H
2
S [1...
Table 2.2 De Forcrand's hydrate compositions obtained using calorimetric dat...
Chapter 3
Table 3.1 The clathrate hydrates according to guest type.
Table 3.2 Clathrate crystal structure nomenclature, past and present.
Table 3.3 The convex polyhedra found in the canonical clathrate hydrates (se...
Table 3.4 Chemical categories of neutral guest species which form the canoni...
Table 3.5 A list of CS‐I (sI), CS‐II (sII), and other canonical simple clath...
Table 3.6 Double hydrates of CS‐II structure, listing only guests that do no...
Table 3.7 The HS‐III hydrates formed from the large cage guest molecules occ...
Chapter 5
Table 5.1 Structures of the canonical clathrate hydrates with neutral guest ...
Table 5.2 Canonical clathrate hydrate structures from single‐crystal X‐ray d...
Table 5.3 Canonical clathrate hydrate structures from powder X‐ray/neutron d...
Table 5.4 Properties of the cages, stoichiometry, and framework density in c...
Table 5.5 Geometric characterization of cage types for the main clathrate hy...
Table 5.6 Geometry and symmetry of unit cells, cages, and water oxygen atom ...
Table 5.7 Maximum guest van der Waals diameter,
D
max
, volume of the guest mol...
Table 5.8 Lattice constants for binary HS‐III clathrate hydrates with methan...
Table 5.9 Geometry and symmetry characterization of unit cells and cages for...
Table 5.10 Related clathrate hydrate, clathrasil (silica clathrates), and me...
Chapter 6
Table 6.1 Melting point temperatures and crystallographic data of semi‐clath...
Table 6.2 Single‐crystal structures of ionic clathrate hydrates (the salt hy...
Table 6.3 Additional salt hydrate structures.
Table 6.4 Structural information on TBAB hydrates from different literature ...
Table 6.5 Single‐crystal diffraction structures of salt hydrates containing ...
Table 6.6 Structural details for the hydrate of (1.67 choline hydroxide)·(te...
Table 6.7 Ionic clathrate hydrates of monobasic acids.
Table 6.8 The structure of higher hydrates of the basic (Me)
4
N
+
OH
−
Table 6.9 Heterogeneous framework ionic clathrates containing Si and/or Al.
Chapter 7
Table 7.1 Composition (hydration numbers) and cage occupancies of clathrate ...
Table 7.2 Experimentally measured enthalpy of dissociation per stoichiometri...
Table 7.3 The cage occupancies at 0 °C and the reference pressure
P
0
and Lang...
Table 7.4 The reported values of Δ
μ
W
and Δ
H
W
between ice and empty clat...
Table 7.5 The fractional coordinates, symmetry multiplicity, and occupancy o...
Table 7.6 A compilation of Kihara potential parameters used in the methane c...
Table 7.7 Hydrate decomposition conditions for various guests with related s...
Table 7.8 Encagement enthalpies (kJ·mol
−1
) per guest molecule in clath...
Table 7.9 Enthalpy of sublimation for solid guest and enthalpy of conversion...
Chapter 8
Table 8.1 Intermolecular parameters for the intermolecular electrostatic and...
Table 8.2 Predicted ice melting points, methane hydrate lattice constants at...
Table 8.3 The spherical harmonics for
l
= 3 that are used in the local order ...
Table 8.4 A partial list of classical molecular dynamics, Monte Carlo, ab in...
Table 8.5 Computed enthalpy of formation, Δ
H
form
,
per stoichiometric unit (k...
Table 8.6 Computed encagement enthalpies per guest molecule (kJ mol
−1
)...
Table 8.7 Zero‐point energies (in parentheses) and low‐lying states of
para
a...
Chapter 9
Table 9.1 The seven space‐filling crystal systems defined based on the symme...
Table 9.2 The 48 general points generated by the symmetry operations of the ...
Table 9.3 A summary of elastic properties of CS‐I (MH‐I), HS‐III (MH‐II), an...
Chapter 10
Table 10.1 Structural parameters, shielding tensor, and spin–rotation tensor...
Table 10.2 Experimental
129
Xe NMR isotropic chemical shifts and anisotropy co...
Table 10.3 Calculated
129
Xe isotropic chemical shifts and anisotropy componen...
Table 10.4 Experimental NMR isotropic chemical shifts and anisotropy compone...
Table 10.5
2
H NMR line shape parameters for guests in clathrate hydrates.
Table 10.6
129
Xe and
131
Xe NMR parameters of Xe in CS‐I and CS‐II clathrate hydra...
Chapter 11
Table 11.1
13
C isotropic chemical shifts (ppm) of methane in various cages of cla...
Table 11.2 Assignment of
13
C NMR signals from gas hydrates recovered from Bar...
Table 11.3
T
1
and
T
CP
/
T
1
ρ
relaxation data at 173 K for HS‐III TBME‐CH
4
and C...
Chapter 12
Table 12.1 Hydrate cages,
13
C chemical shift data for encaged
13
CO
2
.
Table 12.2 Water molecule relaxation times and activation energies from diel...
Table 12.3 Water molecule relaxation times and activation energies from diel...
Table 12.4 Information on water dynamics in CS‐I ethylene oxide and CS‐II TH...
Table 12.5 Summary of dynamic properties of spherical top guest molecules in...
Table 12.6
2
H nuclear quadrupole coupling constants of static solid molecules (mi...
Table 12.7 Molecular length, dipole moment, order parameter, and tilt angle ...
Table 12.8 Reorientational activation energies from dielectrics and
1
H NMR fo...
Table 12.9 Reorientational activation energies for guest molecules in CS‐I h...
Table 12.10 Barrier height and molecular size parameters for the rotation of...
Table 12.11 Classification of guests according to guest motional behavior.
Chapter 13
Table 13.1 Average Raman peak positions (cm
−1
) for C–H stretching mode...
Table 13.2 Comparison of geometric parameters of guest molecules estimated b...
Table 13.A.1 Reported Raman peak shifts (cm
−1
) of C–H stretching mode ...
Table 13.A.2
Peak Raman shifts (cm
−1
) of hydrocarbons in clathrate hydrate...
Table 13.A.3 Peak Raman shifts (cm
−1
) of other gases in clathrate hydr...
Chapter 14
Table 14.1 The measured homogenous nucleation temperatures of ice and some c...
Chapter 15
Table 15.1 Longitudinal frequency shift, ν, and longitudinal acoustic veloci...
Table 15.2 Summary of experimental and theoretically predicted elastic modul...
Table 15.3 Summary of selected thermal conductivity data for clathrate hydra...
Table 15.4 Exponents of the power laws describing thermal conductivities of ...
Chapter 16
Table 16.1 Defined hydrate catastrophic indexes (HCIs) for different experim...
Table 16.2 SNG technology compared with CNG and LNG.
List of Illustrations
Chapter 1
Figure 1.1 National Research Council of Canada Building M‐12 on the NRC Mont...
Figure 1.2 (a) Donald Davidson observing a clathrate hydrate sample; (b) Wil...
Figure 1.3 (a) S. K. Garg at the controls of the Bruker 1.4 T SXP spectromet...
Figure 1.4 Clathrate group, Division of Chemistry, National Research Council...
Figure 1.5 National Research Council Canada building at 100 Sussex Drive, Ot...
Chapter 2
Figure 2.1 Pioneers of clathrate science from the early 1800s. From left to ...
Figure 2.2 Cailletet apparatus [40] showing the hand‐driven hydraulic pumps ...
Figure 2.3 Pioneers of clathrate science in the late 1800s and early 1900s. ...
Figure 2.4 The phase diagram of SO
2
and water mixture showing the stability ...
Figure 2.5 De Forcrand's results showing (a) octahedral and related crystall...
Figure 2.6 Villard's apparatus for hydrate formation and characterization. O...
Figure 2.7 von Stackelberg's characterization of the stoichiometry of hydrat...
Figure 2.8 Pioneers of clathrate science in the mid‐1900s. From left to righ...
Figure 2.9 (a) The body‐centered cubic arrangement of the dodecahedral cages...
Figure 2.10 Pioneers of clathrate science in the mid‐1900s. Top row, George ...
Figure 2.11 The number of publications related to gas (clathrate) hydrates b...
Chapter 3
Figure 3.1 The structure of several inclusion compounds with zero‐, one‐, or...
Figure 3.2 The polyhedral cages found in clathrate hydrate phases along with...
Figure 3.3 Guest size–structure relationships for CS‐I, CS‐II, and HS‐III cl...
Figure 3.4 The phase equilibrium of the CO
2
–H
2
O system over a large pressure...
Figure 3.5 The
i
1
category
P
–
T
phase diagram of methane hydrate shown in two...
Figure 3.6 The
T
–
X
phase diagram for tetrahydrofuran (THF). The mole fractio...
Figure 3.7 The variation of the
T
–weight % THF phase diagram under isobaric ...
Figure 3.8 (a) The
P
–
T
phase diagram of DME‐H
2
O showing the six quadruple po...
Figure 3.9 (a) A partial phase diagram for the Xe–neohexane–water system. (b...
Chapter 4
Figure 4.1 Cady's apparatus for synthesizing gas hydrates at 0 °C. Water and...
Figure 4.2 Schematic diagram of apparatus for the deposition of amorphous ic...
Figure 4.3 (a) A schematic diagram of the semi‐batch experimental setup desi...
Figure 4.4 Schematic of apparatus for the continuous formation of methane hy...
Figure 4.5 Schematic of the experimental apparatus utilizing a bubble column...
Figure 4.6 Schematic of spray reactor for hydrate production along with a te...
Figure 4.7 (a) The setup of Australia's CSIRO flow loop for hydrate formatio...
Figure 4.8 THF clathrate hydrate growth apparatus for observing (a) macrosco...
Figure 4.9 (a) High‐pressure cell for optical and Raman spectroscopic observ...
Chapter 5
Figure 5.1 The polygons in the CS‐I, CS‐II, and HS‐III hydrate phases along ...
Figure 5.2 Two views of the unit cell structures of the (a) CS‐I, (b) CS‐II,...
Figure 5.3 The variation of the CS‐II lattice constant as a function of the ...
Figure 5.4 (a) The spherical THF distribution in the large cage of CS‐II dou...
Figure 5.5 (a) Methylcyclohexane–methane HS‐III double hydrate, showing two ...
Figure 5.6 (a) Ethane molecules in the small and large cages of the CS‐I hyd...
Figure 5.7 (a) The two disordered positions of the ethylene oxide guest mole...
Figure 5.8 (a) The single‐crystal X‐ray structure of the CS‐II THF+CH
3
OH cla...
Figure 5.9 Hydrogen bonding between cage water molecules and (a) CO
2
, (b) pi...
Figure 5.10 Adjacent D and T cages for: (a) the pure CS‐I Cl
2
clathrate hydr...
Figure 5.11 View with full symmetry for the distribution of the 2‐propanol m...
Figure 5.12 (a) Detailed structure of HS‐III′ (sH′) hydrate showing the alte...
Figure 5.13 The (a) TS‐I hydrate phase (bromine) showing the D (gray), T (gr...
Figure 5.14 (a) The structure HS‐I unit cell seen in two views. The relation...
Figure 5.15 (a) The truncated octahedral Voronoi cell of an atom in the body...
Figure 5.16 Frank–Kasper normal coordination polyhedra with 12 (two views), ...
Figure 5.17 (a) The Frank
–
Kasper A‐15 (
β
‐tungsten) structure squa...
Figure 5.18 (a) The Kagomé net oriented in the {111} direction used to const...
Figure 5.19 (a) The Kagomé net used to construct the hexagonal Frank
–
K...
Figure 5.20 (a) The Kagomé‐patterned net used to construct the tetragonal Fr...
Figure 5.21 (a) The hexagonal unit cell of the Frank
–
Kasper
μ
‐
...
Figure 5.22 The Schlegel diagrams for the cages seen in the CS‐I, CS‐II, TS‐...
Figure 5.23 The layered structure of the CS‐II clathrate hydrates showing th...
Figure 5.24 The stacking pattern of the HS‐II and hexagonal
phase. See tex...
Chapter 6
Figure 6.1 Cages in amine semi‐clathrate structures in (a) trimethylamine, (...
Figure 6.2 The cages observed in the five structures of the tert‐butylamine ...
Figure 6.3 The cages in the three cyclo‐butylamine (cBA) semi‐hydrate struct...
Figure 6.4 Combined cages observed in salt hydrates. (a) The 5
40
6
4
‐hedron (T
Figure 6.5 The T
4
cage in TBAB·38H
2
O along with adjacent D
A
(light gray) and...
Figure 6.6 (a) The layered structure of choline hydroxide·(
n
‐Pr)
4
N hydrate, ...
Figure 6.7 Strong acid hydrates of (a) the cubic
hydrate of HPF
6
·HF·5H
2
O (...
Figure 6.8 The tetragonal
I
4
/mcm
unit cell of the Cs[(CH
3
)
4
N]
2
(OH)
3
·14H
2
O hy...
Figure 6.9 The heterogeneous hydrate structures, (a) [(CH
3
)
4
N]
4
[Si
4
Al
4
O
12
(OH...
Figure 6.10 (a) The variation of the CS‐I Xe clathrate hydrate and CS‐II THF...
Chapter 7
Figure 7.1 Cady's apparatus for measuring the hydration number of gas hydrat...
Figure 7.2 The pressure dependence of the hydration number for the clathrate...
Figure 7.3 A schematic diagram of the Tian–Calvet heat flow calorimeter used...
Figure 7.4 The dependence of the (a) hydration number
n
and (b) the cage occ...
Figure 7.5 The first
129
Xe NMR hydrate spectrum recorded was for the xenon d...
Figure 7.6 The
13
C CP/MAS NMR spectra at –80 °C for the
13
C enhanced methane...
Figure 7.7 Solid‐state MAS
13
C NMR spectra of complex natural gas hydrate. S...
Figure 7.8 The Raman spectra of CH
4
in the CS‐I clathrate hydrate (with H
2
O ...
Figure 7.9 The temperature–composition phase diagram for ethylene oxide hydr...
Figure 7.10 (a) Pairs of
σ
* and
ε
/
k
parameters from the Kihara pot...
Figure 7.11 Contours of equal average deviation of 82 experimental hydrate p...
Figure 7.12 (a) Schematic representation of multilayers first shell model us...
Figure 7.13 The equilibrium pressure–temperature three‐phase diagram of pure...
Figure 7.14 (a) The three‐phase equilibrium line of CS‐I methane hydrate (bl...
Figure 7.15 The three‐ or four‐phase equilibrium boundary lines plotted as l...
Figure 7.16 The three‐ or four‐phase equilibrium boundary lines plotted as l...
Chapter 8
Figure 8.1 (a) The structure of 3,3‐dimethyl‐2‐butanone (pinacolone) illustr...
Figure 8.2 The methane C–water OW RDF for the small (S) D cages and large (L...
Figure 8.3 The RDFs of the alcohol guest hydroxyl group atoms (O
H
and H
O
) wi...
Figure 8.4 Experimental and molecular dynamics predicted values of the (a) c...
Figure 8.5 The angular distribution of CO
2
guests in T cages of the CS‐I cla...
Figure 8.6 The unit cell of CS‐I methane clathrate hydrate. Water molecule
j
Figure 8.7 (a) The initial configuration of a methane clathrate hydrate phas...
Figure 8.8 (a) The distribution of the coherence order for liquid water, cub...
Figure 8.9 (a) The Bjerrum L‐ and D‐defects in a hydrogen bonded lattice, wh...
Figure 8.10 (a) Velocity autocorrelation function for methane carbon, the CS...
Figure 8.11 Decreases in the overall system temperature in NVE simulations o...
Figure 8.12 One‐dimensional cuts through the potential energy surfaces for H
Figure 8.13 Three‐dimensional wavefunction isosurfaces of
p
‐H
2
in the CS‐II ...
Figure 8.14 Three‐dimensional isosurfaces of
para
‐H
2
in the CS‐II clathrate ...
Chapter 9
Figure 9.1 Examples of Miller indices (
hkl
) for illustrated planes in a two‐...
Figure 9.2 (a) Schematic representation of the Debye–Scherrer geometry for p...
Figure 9.3 Diffraction pattern for a powder sample of CS‐I xenon hydrate rec...
Figure 9.4 (a) Single‐crystal diffractometer geometry showing the three rota...
Figure 9.5 The simulated powder X‐ray diffraction patterns based on single‐c...
Figure 9.6 Neutron powder diffraction pattern of CS‐II Kr clathrate hydrate....
Figure 9.7 HS‐III
tert
‐butyl methyl ether (TBME) + CH
4
binary clathrate hydr...
Figure 9.8 (a)
In situ
powder X‐ray diffraction profiles, using Cu K
α
r...
Figure 9.9 Neutron scattering length density map of the (001) plane as obtai...
Figure 9.10 Charge density difference distribution changes of the Xe atom fo...
Figure 9.11 Distortions in the electron distribution around oxygen atoms for...
Figure 9.12 Energy‐dispersive X‐ray diffraction results for (a) single‐cryst...
Figure 9.13 (a) The orthorhombic MH‐III methane hydrate inclusion compound o...
Figure 9.14 Paris–Edinburgh cell of the type used in the discovery of the hi...
Figure 9.15 Pressure–volume data for the sequential transformation of the me...
Figure 9.16 Result of Rietveld analysis of neutron diffraction on HS‐III met...
Figure 9.17 Schematic of a triple‐axis spectrometer employed for neutron dif...
Figure 9.18 (a) Incoherent inelastic neutron scattering (IINS) characterizat...
Figure 9.19 IINS data showing the low‐frequency‐coupled modes for a Xe guest...
Figure 9.20 Inelastic X‐ray spectra of methane hydrate at selected scatterin...
Figure 9.21 (a) Schematic of NRIXS facility at the Advanced Photon Source (A...
Figure 9.22 Representative QENS spectrum of methyl fluoride clathrate hydrat...
Figure 9.23 A schematic drawing of the Compton scattering spectrometer. The ...
Figure 9.24 (a) Experimental Compton profiles
J
(
p
z
) as a function of momentu...
Chapter 10
Figure 10.1 (a) Ellipsoidal representation of a shielding tensor indicating ...
Figure 10.2 Dipolar Pake doublet powder pattern for a homonuclear ½–½ spin p...
Figure 10.3 Conceptual ellipsoid and corresponding NMR line shape for
2
H in ...
Figure 10.4 Calculated second‐order powder patterns for the central transiti...
Figure 10.5 After application of a short duration 90° pulse which rotates th...
Figure 10.6 (a) Simple single 90° pulse NMR experiment. After the pulse, the...
Figure 10.7 Comparison of low‐temperature
19
F derivative line shapes of soli...
Figure 10.8 Line shapes of H
2
molecules in H
2
–D
2
O sII clathrate as a functio...
Figure 10.9
1
H NMR derivative line shapes of (left) THF‐d
8
·15.2H
2
O at 93 K a...
Figure 10.10
1
H NMR spectrum of isolated H
2
O molecules in a D
2
O matrix of lo...
Figure 10.11
129
Xe NMR spectra of CS‐I Xe hydrate showing broadened features...
Figure 10.12 Static
1
H‐decoupled CP
129
Xe NMR spectra at 77 K of hydrates CS...
Figure 10.13 (a) MAS and static
129
Xe NMR spectra of HS‐III Xe/methyl cycloh...
Figure 10.14
129
Xe NMR spectra at 77 K of (a) CS‐I Xe hydrate and (b) CS‐II ...
Figure 10.15
129
Xe CP NMR of metastable Xenon HS‐I hydrate containing a smal...
Figure 10.16
129
Xe spectra of mixed hydrates of Xe/DME (dimethyl ether) Top:...
Figure 10.17 Static
77
Se CP NMR spectra of H
2
Se CS‐I hydrate at three temper...
Figure 10.18 The top spectrum shows the dynamically averaged
13
C CSA line sh...
Figure 10.19
2
H NMR line shape of static D
2
O in THF·17D
2
O CS‐II hydrate at 3...
Figure 10.20
2
H NMR line shapes of D
2
S in D
2
O CS‐I hydrate. 240 K: broad sta...
Figure 10.21
2
H NMR line shapes of CS‐I hydrates of cyclopropane‐C
3
D
6
(left)...
Figure 10.22
2
H NMR spectra of double hydrates with H
2
S and large deuterated...
Figure 10.23 Static second‐order central transition
17
O NMR line shapes of D
Figure 10.24
131
Xe spin‐echo NMR spectra of a static sample of CS‐I xenon hy...
Figure 10.25
83
Kr NMR static spectra of krypton CS‐II hydrates obtained at
T
Figure 10.26 Stationary
33
S NMR spectrum of CS‐I H
2
S hydrate obtained at
T
=...
Figure 10.27
33
S NMR spectrum of stationary powder of SO
2
CS‐I hydrate obtai...
Chapter 11
Figure 11.1
13
C HP DEC MAS of synthetic CS‐I methane hydrate (a) and natural...
Figure 11.2 (a)
13
C HPDEC MAS NMR spectra of CS‐I hydrate prepared from CH
4
/...
Figure 11.3 Signal intensities in
13
C CP MAS NMR spectra as a function of co...
Figure 11.4
13
C CP MAS and
13
C HPDEC MAS spectra of CS‐II mixed iso‐butane/C...
Figure 11.5 Cross‐polarization with (a) contact time 400 μs, (b) contact tim...
Figure 11.6 Signal intensity dependencies on the contact time for this HS‐II...
Figure 11.7
13
C HPDEC MAS (a) and
13
C CP MAS (b) NMR at 193 K of ice + metha...
Figure 11.8 (a) Time‐resolved
13
C MAS NMR of CS‐I methane hydrate dissociati...
Figure 11.9
129
Xe NMR spectra at 77 K of the reaction product of CS‐I hydrat...
Figure 11.10 Time development of the
129
Xe NMR spectrum after exposure of a ...
Figure 11.11 Time dependence of the hyperpolarized
129
Xe spectra following i...
Figure 11.12
129
Xe NMR spectra at 77 K of a sample produced by co‐deposition...
Figure 11.13
129
Xe MAS NMR spectra at 183 K of the CS‐I Xe hydrates and CS‐I...
Figure 11.14
19
F spectra of HAsF
6
·HF·5H
2
O: (a) solid at 298 K, (b) liquid at...
Figure 11.15
2
H NMR line shapes of (CH
3
)
4
NOD·5D
2
O: Multiple sites in the sta...
Figure 11.16 (a) Spatial encoding with magnetic field gradients. (b) Slice s...
Figure 11.17 The schematics of a setup for
in situ
NMR micro‐imaging in gas ...
Figure 11.18
1
H micro‐imaging data for CO
2
hydrate formation in silica gel p...
Figure 11.19 Left panel (in green): Magnetic resonance images of methane and...
Chapter 12
Figure 12.1 (a) Low‐temperature permittivity,
ε
′, and loss,
ε
″, cu...
Figure 12.2 Dielectric absorption associated with reorientation of THF guest...
Figure 12.3 Line shape or spin–spin relaxation time (
T
2
) and spin–lattice re...
Figure 12.4 Dynamic averaging effects on the
2
H NMR line shape of
2
H atoms i...
Figure 12.5 (a)
13
C NMR spectra for
13
CO
2
CS‐I hydrate (top), and a CS‐II do...
Figure 12.6 Coordinate system used in the motional averaging calculation. Th...
Figure 12.7 (a) Schematic picture of the formation of a Bjerrum defect pair ...
Figure 12.8 (a) Arrhenius plots of dielectric relaxation times of water mole...
Figure 12.9 (a) Static
17
O NMR
1
H decoupled spin‐echo spectra of the central...
Figure 12.10 The 12 possible orientations of a water molecule on any one par...
Figure 12.11 (a) Temperature dependence of the second moment of proton absor...
Figure 12.12
2
H solid echo spectra of THF‐h
8
·17D
2
O as a function of temperat...
Figure 12.13 The large cage (T, 5
12
6
2
) of CS‐I hydrate. The left side shows ...
Figure 12.14
13
C NMR static line shapes of
13
C‐enriched CO
2
hydrate at 238 (...
Figure 12.15 Change of
19
F line shape of SF
6
deuteriohydrate in the region o...
Figure 12.16 (a) Second moment or mean square line width, as a function of t...
Figure 12.17 Models for the dynamic state of the CO
2
molecule encaged in the...
Figure 12.18 (a) Calculated
13
C line shapes for CO
2
hydrate at 77 K (dashed ...
Figure 12.19 Results of calculations for CO
2
guests in the CS‐I large cages:...
Figure 12.20 Second moment of the
1
H resonance of THF⋅17D
2
O as a function of...
Figure 12.21 Solid‐echo spectra of TDF·17H
2
O recorded for an interpulse dela...
Figure 12.22 Effective
2
H quadrupole coupling frequencies of deuterated CS‐I...
Figure 12.23 (a) The prochiral TMO molecule (with one labeled hydrogen atom,...
Figure 12.24 (a) Time development of the
129
Xe NMR spectrum after exposure o...
Figure 12.25 (a) Temperature dependence of the
13
C NMR spectrum of the doubl...
Figure 12.26
1
H NMR experimental (below) and calculated (above) line shapes ...
Figure 12.27
1
H spin–lattice relaxation times as a function of inverse tempe...
Figure 12.28 A summary of the changes in guest line shape at different tempe...
Chapter 13
Figure 13.1 Representation of the excitation of molecular states resulting i...
Figure 13.2 Schematic of Raman spectrum of carbon tetrachloride (CCl
4
) showi...
Figure 13.3 Comparison of IR and Raman spectra for (a) liquid water and (b) ...
Figure 13.4 Comparison of water Raman spectrum in the liquid, ice, and hydra...
Figure 13.5 Schematic diagram of (a) the attenuated total reflection (ATR) m...
Figure 13.6 (a) Schematic of a pressure cell suitable for Raman studies at p...
Figure 13.7 C–H stretching mode of CH
4
molecules in the vapor phase (2917.6 ...
Figure 13.8 C–H stretching mode of CH
4
molecules in natural and synthetic hy...
Figure 13.9 The position of a guest molecule ABC in a cage where the C atom ...
Figure 13.10 Variation in Raman peak position shift with intramolecular equi...
Figure 13.11 Schematic diagram of an
in situ
Raman spectroscopic observation...
Figure 13.12 (A) The O–H stretching mode of the CS‐II (a) and CS‐I (b) CH
4
c...
Figure 13.13 Structural changes of gas hydrates under high pressure, in term...
Figure 13.14 Raman vibrational spectra of H
2
in known clathrate‐hydrate envi...
Chapter 14
Figure 14.1 (a) The moles of methane gas consumed as a function of time in a...
Figure 14.2 The pressure drop during the hydrate formation from ice exposed ...
Figure 14.3 Typical isothermal differential scanning calorimetry experiments...
Figure 14.4 Raman spectra of methane in transition from dissolved methane to...
Figure 14.5 A typical kinetic run on the formation of methane hydrate from p...
Figure 14.6 Time dependence (
t
in minutes) of methane hydrate formation for ...
Figure 14.7 The formation kinetics of CO
2
hydrate at 275 K and 58 bar as det...
Figure 14.8 (a) The reactor for synthesis of methane hydrate in a water‐satu...
Figure 14.9 (a) A schematic representation of the chemical potential of the ...
Figure 14.10 (a) The negative
r
3
dependence of the volume free energy and th...
Figure 14.11 (a) The contributions of the exponential terms from Eq. (14.8) ...
Figure 14.12 (a) A spherical cap solid crystal phase nucleus (clathrate hydr...
Figure 14.13 (a) Schematic plots of the free energy of heterogeneous and hom...
Figure 14.14 (a) A schematic model of the steps involved with hydrate format...
Figure 14.15 (a) The simultaneous DSC scans for the cooling (blue) followed ...
Figure 14.16 Methane gas consumption, as an indicator of hydrate formation, ...
Figure 14.17 (a) A schematic representation of the shrinking core model for ...
Figure 14.18 (a) The nucleation (black dots) of phase
β
into the phase
Figure 14.19 (a) Integrated intensity of the
129
Xe NMR spectral lines for th...
Figure 14.20 (a) Pressure drop for the reaction of powdered ice with Xe gas ...
Figure 14.21 A schematic representation of the relation between crystal morp...
Figure 14.22 (a) Sequential video graphs of the growth of methane hydrate cr...
Figure 14.23 Optical images of hydrate single crystals showing different cry...
Figure 14.24 The cages where the Miller index planes cut through the CS‐I an...
Figure 14.25 The depressurization (vertical) and heating (horizontal) routes...
Figure 14.26 Ice coating formed at 220 K and 60 kPa on the CS‐I CO
2
clathrat...
Figure 14.27 The two models of growth inhibition are very similar except for...
Figure 14.28 Simple model of melting and freezing inhibition operating throu...
Figure 14.29 Mechanism of step pinning by adsorbed KHI polymer clumps on a h...
Figure 14.30 The partial encapsulation of a hydrophobic pendant methyl group...
Figure 14.31 The DSC scans of the decomposition of natural gas hydrate for a...
Figure 14.32 Molecular dynamics simulations of growth and decay of hydrate n...
Figure 14.33 Molecular dynamics simulations of the mechanism of homogeneous ...
Figure 14.34 Simulations the process of hydrate nucleation, the formation of...
Figure 14.35 A representation of the multiscale approach for laboratory and ...
Chapter 15
Figure 15.1 (a) A schematic representation of the Brillouin scattering spect...
Figure 15.2 (a) Experimental Brillouin scattering data for polycrystalline x...
Figure 15.3 (a) Acoustic longitudinal velocities of clathrate hydrates at 0 ...
Figure 15.4 Single crystal of methane hydrate grown in diamond anvil cell....
Figure 15.5 (a) Pressure dependence of the longitudinal (LA) and transverse ...
Figure 15.6 The pressure dependence of elastic moduli,
c
11
,
c
12
,
c
44
and bul...
Figure 15.7 (a) Elastic moduli for argon and methane hydrate as a function o...
Figure 15.8 The temperature dependence of the ice, CS‐I methane clathrate, a...
Figure 15.9 The constant pressure thermal expansion of the lattice parameter...
Figure 15.10 Temperature dependence for the
a
(top) and
c
(bottom) unit cell...
Figure 15.11 (a) Thermal conductivity of CS‐II tetrahydrofuran hydrate betwe...
Figure 15.12 Thermal conductivity measurement results for tetrahydrofuran hy...
Figure 15.13 (a) The “reversal” of the thermal conductivity at
T
< 100 K and...
Figure 15.14 Schematic representation of the phonon scattering process in th...
Chapter 16
Figure 16.1 Methane hydrate formation in the presence of different weight pe...
Figure 16.2 The interaction of the winter flounder AFP (wf‐AFP) with empty h...
Figure 16.3 Hydrate growth along the vessel wall and receding gas/water inte...
Figure 16.4 Map showing gas hydrate accumulations in the earth.
Figure 16.5 Experimental conditions for methane and carbon dioxide hydrate f...
Figure 16.6 Timeline of progress on the use of hydrates for water desalinati...
Figure 16.7 Schematic of the prototype for the seawater desalination process...
Figure 16.8 Dissociation temperatures for different hydrate structures at 0....
Figure 16.9 Block flow diagram of a facility for the production and storage ...
Figure 16.10 Hydrate phase equilibrium for THF‐H
2
‐water.
Figure 16.11 Hydrogen storage capacity at different aqueous THF concentratio...
Figure 16.12 H
2
storage capacities with semi‐clathrates.
Figure 16.13 Post‐combustion capture with hydrates: the CO
2
separation step ...
Figure 16.14 Pre‐combustion capture with hydrates: The CO
2
separation step f...
Figure 16.15 Temperature (
T
) composition (
w
) diagram of the semi‐clathrate h...
Figure 16.16 Partial phase diagram for a CO
2
/H
2
(39.2/60.8 mol%) fuel gas mi...
Figure 16.17 Hydrate phase equilibrium for the fuel gas mixture with or with...
Figure 16.18 Comparison of CO
2
capacity of HBGS process with conventional so...
Guide
Cover
Table of Contents
Title Page
Copyright
Dedication
Preface
Begin Reading
Index
Wiley End User License Agreement
Pages
iii
iv
v
xiii
xiv
xv
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
193
194
195
196
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
219
220
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
467
468
469
470
471
472
473
474
475
476
478
477
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
550
548
549
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
783
784
785
786
787
788
789
790
791
792
Clathrate Hydrates
Molecular Science and Characterization
Volume 1
Edited by
John A. RipmeesterSaman Alavi
Clathrate Hydrates
Molecular Science and Characterization
Volume 2
Edited by
John A. RipmeesterSaman Alavi
Editors
Dr. John A. RipmeesterNational Research Council of Canada100 Sussex Dr.K1A 0R6 NKCanada
Dr. Saman AlaviUniversity of OttawaDepartment of Chemistry and Biomolecular SciencesSTEM Complex, 150 Louis‐Pasteur Pvt.Ottawa, ON, K1N 6N5Canada
Cover Images: © Structure illustration provided by Dr. Satoshi Takeya; inset image © metamorworks/Shutterstock
All books published by WILEY‐VCH are carefully produced. Nevertheless, authors, editors, and publisher do not warrant the information contained in these books, including this book, to be free of errors. Readers are advised to keep in mind that statements, data, illustrations, procedural details or other items may inadvertently be inaccurate.
Library of Congress Card No.: applied for
British Library Cataloguing‐in‐Publication Data A catalogue record for this book is available from the British Library.
Bibliographic information published by the Deutsche Nationalbibliothek
The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data are available on the Internet at <http://dnb.d-nb.de>.
© 2022 WILEY‐VCH GmbH, Boschstr. 12, 69469 Weinheim, Germany
All rights reserved (including those of translation into other languages). No part of this book may be reproduced in any form – by photoprinting, microfilm, or any other means – nor transmitted or translated into a machine language without written permission from the publishers. Registered names, trademarks, etc. used in this book, even when not specifically marked as such, are not to be considered unprotected by law.
Print ISBN: 978‐3‐527‐33984‐6ePDF ISBN: 978‐3‐527‐69508‐9ePub ISBN: 978‐3‐527‐69506‐5oBook ISBN: 978‐3‐527‐69505‐8
To my wife Beth and daughters Heather and Wendy who put up with my science‐oriented adventures that sometimes got in the way of family time, to the memory of my parents, John and Thea, who, while raising their recently emigrated family, encouraged me to pursue higher education.
To my wife Dorothy for her support and patience during my never‐ending scientific activities, to my mother Zari for her encouragement on our path to higher education, and to the memory of my father Mohammad who motivated me to become a chemist.
Preface
Scope
Why write this book? A number of reasons come to mind. Today, a vast number of publications on clathrate hydrates continue to appear in journals dealing with the many different, often non‐overlapping areas of hydrate research. Increasingly, these studies focus especially on engineering and geological aspects, as well as potential applications. Molecular science has provided the fundamental underpinnings for much of this work; however, the earlier work has become more difficult to find, and there have not been major comprehensive monographs or books focused on scientific aspects of these substances for some 40 years. It is to fill this gap that preparation of this book was undertaken. We also feel there are a number of misconceptions or questionable approaches that have propagated over the years, and this book provides an opportunity to revisit some of these points.
The 150 years that it took for the first observed phenomenon of gas hydrates to be properly explained make for a fascinating story of the intertwining of the then current hydrate science, advances in technology, and the evolution of chemical concepts. After an Introduction and summary of the “classical period,” the book presents 16 chapters outlining hydrate science in different areas of specialization (see below). Each chapter provides a short summary of the respective methodology and is written with an emphasis on the experience of the authors with significant feedback from the editors and the other chapter authors. The book also provides comprehensive tabulated information on the structural, compositional, spectroscopic, thermodynamic properties, and molecular simulations of clathrate hydrates. With this information gathered in one place, it will be a valuable resource for both experienced researchers, and researchers and graduate students of science and engineering just starting their studies of these fascinating substances. The authors have aimed at making each chapter as comprehensive as possible, but in a work of this scope, valuable work will inevitably not be discussed.
A summary of the chapter contents follows.
Chapter 1 reports the major highlights in the development of clathrate hydrate knowledge and then highlights contributions of the National Research Council of Canada group where the authors of this volume have worked or which they were in close collaboration.
Chapter 2 gives a more detailed historical outline of the study of clathrate hydrates from the classical period up to 1970 when the hydrate crystallographic structure became known and the statistical mechanical model of clathrate hydrates was developed. We surveyed some of the primary literature of this period to clarify some of the historical aspects of these substances discovered by the early researchers.
Chapters 3 and 4 introduce the different hydrate cages made of hydrogen‐bonded water molecules and discuss the classification of clathrate hydrates as part of the larger family of supramolecular compounds, and their techniques of synthesis, respectively. Hydrates are presented as solid solutions with their stability being a lattice property. Comprehensive tables are presented of the known guest molecules, and summaries of their structural and physical properties are given in this chapter. The different classes of clathrate hydrate phase equilibria are presented.
Chapters 5 and 6 discuss structural aspects of clathrate hydrates, semi‐clathrates, and salt hydrates. The importance of unconventional guest–host interactions like hydrogen and halogen bonding is introduced. Different ways of looking at hydrate structures based on layered structures and space filling cages using the Frank–Kasper approach are presented, and related non‐hydrate clathrates are introduced.
Chapter 7 introduces thermodynamics and statistical mechanics of clathrate hydrates with discussion of calorimetric methods and the van der Waals–Platteeuw theory and some of its extensions. Many recent engineering applications and extensions are not directly discussed as they are discussed in Chapter 16 or are beyond the scope considered for this book. Tables of hydrate composition and thermochemical information are presented.
Chapter 8 gives a summary of the application of molecular simulation methods to study clathrate hydrate properties. Methods of characterizing structural and dynamic properties of clathrate hydrates are discussed. Most of the emphasis is on classical molecular dynamics and Monte Carlo results, but quantum mechanical calculations of confinement effects for small molecules such as hydrogen and methane in the clathrate hydrate cages are also reviewed. A table is given for systems studied to date using molecular simulation methods.
Chapters 9, 10, 11, and 13 discuss X‐ray and neutron diffraction and scattering, general and specialized NMR methods and IR/Raman methods for studying clathrate hydrates, respectively. The techniques are briefly introduced, and the often complementary information they provide on clathrate hydrates are described. The use of these methods in unraveling the structure and dynamics of guest–lattice interactions is summarized.
Chapter 12 presents information, mainly from dielectrics and solid‐state NMR, on the molecular motion of guest and host molecules. The relationship between cage geometry and guest dynamics is introduced, as is the effect of guest–host hydrogen bonding on water molecule dynamics.
Chapter 14 presents the rate and mechanisms of hydrate formation and decomposition from both macroscopic (process) and microscopic (mechanism) points of view. Classical nucleation theory introduces a number of key parameters that are pertinent to both homo‐ and heterogeneous nucleation mechanisms of hydrate formation. Emphasis is placed on hydrate processes as phase changes occurring in the presence of mass and temperature gradients rather than chemical reactions occurring in isotropic and isothermal systems. The various factors that modify kinetics of hydrate formation are introduced and discussed from results gathered from both experimental and molecular simulations. The hydrate memory effect and possible mechanisms of kinetic hydrate inhibition (using both polymeric substances and antifreeze proteins) are discussed in this chapter.
Chapter 15 deals with mechanical properties of clathrate hydrates, including acoustic velocity, elastic constants, thermal expansion, and thermal conductivity. Experimental and theoretical backgrounds for the study of these properties are given. Some anomalous effects seen in the temperature dependence of the thermal conductivity of hydrate phases, but absent in ice, are discussed in detail in this chapter.
Chapter 16 presents with selected potential applications of clathrate hydrate compounds, including flow assurance, natural gas recovery, desalination, concentration of aqueous solutions, and the storage of natural gas, hydrogen, and gas separation. This chapter is meant to be an overview of some applications, which will be well studied in the near future.
The authors' work described in this book has contributions from many colleagues, staff, and students at the National Research Council of Canada who are named in Chapter 1. The contributions of these individuals are gratefully acknowledged. The work described would not have been possible without the material support of the National Research Council of Canada from ∼1960 to 2011. As in any field, the progress in clathrate hydrate research is the result of collaboration and contributions from researchers in many countries. We hope to have given proper representation of contributions from researchers from all parts of the world. We apologize for any omissions, which are the result of the limited scope of some of the discussions in this book.
We would like to acknowledge the contributions of Donald Davidson (1925–1986) of the National Research Council of Canada as one of the pioneers in modern hydrate research in Canada. Don (i) initiated a multi‐technique approach to studying gas hydrates; (ii) provided mentorship to generations of hydrate researchers at the NRC; and (iii) wrote a number of monographs and book chapters, which are exemplary for their clarity and are still useful today. At the time, the National Research Council was a fertile multidisciplinary environment where cutting‐edge dielectric, NMR, single‐crystal X‐ray crystallographic, and simulation techniques were being developed, and almost immediately being used in understanding these substances. After Don's passing, this tradition was maintained at the NRC.
The editors would like to thank the authors of the chapters in this book for their contributions and their patience with our numerous requests for editorial changes. We would particularly like to thank Christopher I. Ratcliffe, Amadeu K. Sum, Peter Englezos, and Dennis D. Klug who also commented extensively on chapters other than their own.
We would like to thank our wives Beth and Dorothy for support and dealing with the seemingly unending demands on our time while we worked on this book. We thankfully acknowledge their indirect, but important contributions in getting this book project completed.
1An Introduction to Clathrate Hydrate Science
John A. Ripmeester1, Saman Alavi1, 2, and Christopher I. Ratcliffe1
1 National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada
2 University of Ottawa, Department of Chemistry and Biomolecular Science, STEM Complex, 150 Louis‐Pasteur Pvt., Ottawa, ON, K1N 6N5, Canada
1.1 Introduction
The first intersection of clathrate hydrates and human endeavor took place in the late 1700s. A number of researchers (natural philosophers) working on the solubility of newly discovered airs (gases) observed unexpected ice‐like solids formed above the freezing point of ice when certain gases were passed into cold water or when such a solution was frozen. Davy identified these solids as two‐component water–gas compounds and named them “gas hydrates.” After some 140 years and much research, these solids were shown to be clathrates, materials where small molecules (guests) are trapped in an ice‐like lattice (host) consisting of hydrogen‐bonded water cages. During the time between initial discovery and final identification, gas hydrates confounded researchers by having a number of properties that countered concepts derived from mainstream chemistry. For instance, the hydrates were non‐stoichiometric, the water‐to‐gas ratios were not small whole numbers, and they decomposed upon heating or depressurization to give back the unchanged starting materials. The lack of chemical bonds between the water and the gas in the hydrates suggested that these were not real chemical compounds and in fact were the first examples of “chemistry beyond the molecule” – supramolecular compounds.
From phase equilibrium studies, we now know that when many gases and water are in contact under appropriate pressure (P) and temperature (T) conditions, a solid hydrate will form. The gas hydrates store gases, including natural gas, very efficiently with one volume of solid hydrate storing some 160 volumes of gas at standard temperature and pressure (STP). Since a number of gas hydrates are found naturally, this class of materials can be taken to be an unusual type of mineral. There are many sites in the geosphere where natural gas and water are in contact under the conditions required to form gas hydrate. Locations where this occurs are in sediments offshore of continental margins, under permafrost, and in some deep freshwater lakes.
Well before the discovery of natural gas hydrate in the geosphere, oil and gas engineers encountered blocked natural gas pipelines during cold weather operation which was initially attributed to ice formation from moisture in wet gas. Knowledge of earlier work on solid methane hydrate led Hammerschmidt in the 1930s to the correct explanation for the pipeline blocks – they were made of solid methane hydrate rather than ice. Since then, during the exploration, production and transport phases of hydrocarbon resources, blockage by natural gas hydrate formation has become a well‐known hazard, resulting in possible serious damage and loss of life, for example in the Deepwater Horizon oil spill of 2010. Much research has been carried out to prevent or manage hydrate formation in pipelines. Other problems related to gas hydrates have been identified, including marine geohazards, such as submarine landslides, and sudden gas releases from hydrate formations.
Because of the vast amounts of trapped natural gas in hydrate form globally, gas hydrates have been evaluated to be a significant unconventional natural gas resource. Hydrate deposits have been mapped in many locations around the world, usually using geotechnical methods that depend on the location of unexpected solid hydrate–liquid water interfaces which act as seismic reflectors. Test wells for gas production have been drilled in the Mackenzie Delta, Canada (Mallik 2L38), Alaska, the Nankai trough offshore Japan, and offshore China. Many problems have been encountered in producing gas from hydrate reservoirs, including the development of the best techniques for destabilizing the solid hydrate and capturing the resulting gas. Some hydrate deposits, often associated with hydrocarbon seeps or vents, exist as outcrops on the seafloor. Whereas most of the methane in hydrate reservoirs is of biogenic origin, hydrates associated with seeps or hot vents are formed from thermally altered hydrocarbons originally residing in deeper reservoirs. Some hydrate outcrops are home to specialized biological ecosystems where microbes feed on hydrocarbons and these in turn become a food source for “ice‐worms.”
Besides the marine and terrestrial natural gas hydrates, there are gas hydrates of air (mainly N2 and O2
