Inhibition Effects of Glucose on Clathrate
Hydrate (H-Lw-V) Equilibrium
by
Anthony Stephen Carbone
Department of Chemical Engineering
McGill University
Montreal, Quebec, Canada
May, 2011
A thesis submitted to McGill University in partial fulfillment of the
requirements of the degree of Masters of Engineering
© Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
Abstract
The three phase (H-Lw-V) equilibrium conditions for methane clathrate hydrates and
carbon dioxide clathrate hydrates in aqueous solution containing glucose were experimentally
determined. The glucose aqueous solutions varied between 10-30 wt% glucose, with the pressure
ranging from 3.4 to 7.8 MPa for the methane systems and 1.6 to 3.8 MPa for the carbon dioxide
systems. The experimental temperature for both hydrate systems in question ranged from 275.15
to 281.25 K.
Experimental results showed that systems containing glucose did in fact exhibit an
inhibiting effect on hydrate equilibrium conditions. This is shown by the equilibrium plots where
equilibrium curves of the glucose containing systems reside above (at higher pressures for equal
temperatures) the equilibrium curve of pure water. It was also found that as the glucose
concentration increased in the aqueous solution present, so did the degree of inhibition. All
systems containing glucose were also found to follow the same trend as the systems containing
pure water in terms of the apparent curvature of the equilibrium line. When compared to other
common thermodynamic hydrate inhibitors, only the 30 wt% glucose solution was able to exhibit
a level of hydrate inhibition at par with the others.
ii
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
Résumé
Les conditions d’équilibre pour les trois phases H-Lw-V ont été déterminées
expérimentalement pour des systèmes d’hydrates de méthane et d’hydrates de dioxyde de
carbone en présence d’une solution aqueuse de glucose. La concentration de la solution aqueuse
de glucose était variée entre 10-30 pourcentages massiques sous une gamme de température de
275.15 à 281.25 K. La gamme de pression résultante du système de méthane est 3.4 à 7.8 MPa,
et 1.6 à 3.8 MPa pour le système de dioxyde de carbone.
Les résultats des expériences avec les systèmes contenant le glucose ont démontré que le
glucose a un effet bloquant à propos de l’équilibre de la phase d’hydrate. Cela est évident après
une analyse des graphiques des données d’équilibre des systèmes contenant le glucose. La
courbe d’équilibre pour tous les systèmes contenant le glucose résident au dessus de la courbe
d’équilibre d’eau pure. Cela indique que pour la même température, les systèmes contenant le
glucose requièrent une pression plus élevée pour atteindre l’équilibre avec la phase d’hydrate. En
plus, les systèmes contenant le glucose suivent la même tendance que les systèmes contenant de
l’eau pure. En comparant les systèmes de glucose en question avec d’autres systèmes d’hydrates
contenant des bloquantes thermodynamiques populaires, il est possible de constater que
seulement la solution de glucose à 30 pour cent massique démontre un niveau bloquant
comparable.
iii
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
Acknowledgements
I would like to take this opportunity to thank all of the individuals who have helped me
throughout my studies and research, ultimately leading to the successful completion of my
masters degree in engineering. Without their help and support, my time as a graduate student
would not have been as fulfilling and enjoyable as it has been.
Firstly, I would like to sincerely thank my supervisor, Dr. Phillip Servio, for giving me
the opportunity to work under someone as talented as he is. I am extremely grateful for all of his
support, trust, and patience, as well as for his ability to motivate his students and elevate them to
be better researchers, and more importantly, better people. This dissertation, as well as the
journey it represents, would not have been the same without him.
Secondly, I would like to thank Dr. Servio’s hydrate research team, in particular Hallvard
Bruusgaard and Dany Posteraro. Mr. Bruusgaard took the time and had the patience to teach me
all I needed to know about the experimental set-up used throughout my masters degree, while
Mr. Posteraro was always there to lend a helping hand. Both of their friendships will not be
forgotten.
Thirdly, I would like to thank the technical staff as well as the administrative staff in the
chemical engineering department at McGill University who were always fast to act on anything
needing their attention.
Finally, I cannot end without giving a great big thank you to all of my family and friends
who have loved and supported me every step of the way. You are my inspiration to keep working
as hard as I do, and for that, I cannot thank you enough.
iv
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
Table of Contents
1.0
Introduction
1.1
Gas Hydrates
1.2
History of Gas Hydrates
1.3
Naturally Occurring Gas Hydrates
1.4
Hydrate Structure
1.5
Phase Equilibrium
1.6
Methane Hydrates
1.7
Carbon Dioxide Hydrates
1.8
Nucleation and Growth
1.9
Hydrates Inhibition
1.9.1 Antifreeze Proteins, Sugars, and Fatty Acids
1.10 Research Objectives
4
4
4
5
6
8
10
11
11
12
13
15
2.0
Materials and Methods
2.1
Experimental Set-Up
2.2
Materials
2.3
Experimental Procedure
2.4
Experimental Conditions
16
16
18
18
19
3.0
Results and Discussion
3.1
Methane Experiments
3.2
Carbon Dioxide Experiments
20
20
25
4.0
Conclusions and Recommendations
4.1
Conclusions
4.2
Recommendations
31
31
32
5.0
References
33
Publications
1
38
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
List of Figures
Figure 1: Structure I, structure II, and structure H cavities and unit cells (hydrate structures)
7
Figure 2: Sample three-phase equilibrium curve of a methane + butane system
9
Figure 3: Partial phase diagram for the methane-water system as published by Deaton
and Frost
10
Figure 4: Partial phase diagram for the carbon dioxide-water system as published by Deaton and
Frost
11
Figure 5: Proposed disaccharide core structure of the thermal hysteresis factor isolated from Upis
ceramboides
14
Figure 6: Experimental set-up
17
Figure 7: Measured equilibrium conditions of the water + glucose + methane system
(0 wt% glucose)
21
Figure 8: Measured equilibrium conditions of the water + glucose + methane system (various
glucose concentrations)
23
Figure 9: Measured and reported values of various methane hydrate systems in the presence
of a common thermodynamic hydrate inhibitor
24
Figure 10: Measured equilibrium conditions of the water + glucose + carbon dioxide
system (0wt% glucose)
26
Figure 11: Measured equilibrium conditions of the water + glucose + carbon dioxide
system (various glucose concentrations)
29
Figure 12: Measured and reported values of various carbon dioxide hydrate systems
in the presence of a common thermodynamic hydrate inhibitor
2
Master’s Thesis © Anthony Stephen Carbone, 2011
30
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
List of Tables
Table 1: Hydrate-liquid-vapour equilibrium data for the system CH4-0 wt% glucose/H20
20
Table 2: Hydrate-liquid-vapour equilibrium data for the system CH4-10 wt% glucose/H20
22
Table 3: Hydrate-liquid-vapour equilibrium data for the system CH4-20 wt% glucose/H20
22
Table 4: Hydrate-liquid-vapour equilibrium data for the system CH4-30 wt% glucose/H20
22
Table 5: Hydrate-liquid-vapour equilibrium data for the system CO2-0 wt% glucose/H20
25
Table 6: Hydrate-liquid-vapour equilibrium data for the system CO2-10 wt% glucose/H20
27
Table 7: Hydrate-liquid-vapour equilibrium data for the system CO2-20 wt% glucose/H20
27
Table 8: Hydrate-liquid-vapour equilibrium data for the system CO2-30 wt% glucose/H20
27
3
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
1.0 Introduction
1.1
Gas Hydrates
Gas hydrates are non-stoichiometric crystalline solids formed by water molecules in the
presence of gaseous or volatile liquid molecules at suitable temperatures and pressures. Under
appropriate hydrate forming conditions, water molecules become linked together through
hydrogen bonding, producing a cage-like structure stabilized by the presence of hydrate forming
gas molecules. Stabilization occurs through physical bonding of the present gas via weak van der
Waals forces. The formation of gas hydrates is thermodynamically unstable without the presence
of the guest gas molecules.
1.2
History of Gas Hydrates
Sir Humphry Davy was the first to discover gas hydrates. His discovery occurred in 1810,
with his results confirmed in 1823 by Michael Faraday [1]. Research in the field of gas hydrates
initially began as a purely academic pursuit, identifying which molecules possessed the
capability of forming hydrates, and under which temperature and pressure conditions these
hydrates existed. Since the 1930s, hydrates have gained industrial interest in the oil and gas
industry when it was discovered by Hammerschmidt that gas hydrate formation occurs in oil
pipelines, causing partial or total blockage of flow [2]. Due to these implications, a significant
portion of hydrate research is devoted to hydrate inhibition through the use of chemical, thermal,
mechanical and hydraulic inhibitors [3].
The oil and gas industry is continuously searching for hydrate inhibitors that will allow
oil and gas extraction in deeper waters without the threat of hydrate formation impeding
4
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
everyday operations [14]. As Kelland reported, low dosage hydrate inhibitors (LDHIs), which
are subdivided into anti-agglomerates (AAs) and kinetic hydrate inhibitors (KHIs), are a more
recent alternative technology to thermodynamic inhibitors which prevent gas hydrates from
plugging oil and gas production wells and pipelines [15]. AAs and KHIs are generally water
soluble polymers [14]. Other potential hydrate inhibitors include anti-freeze proteins (AFPs) and
anti-freeze glycoproteins (AFGPs), which are proteins that bind to the surface of ice nuclei, thus
acting as an inhibitor to ice formation. Recent work has shown that AFPs also inhibit hydrate
formation [14].
1.3
Naturally Occurring Gas Hydrates
Gas hydrates occur naturally around the world and can be found below the permafrost
zone and in subsea sediments in the Arctic, the Antarctic, and tropical and subtropical oceans [4].
These hydrates, composed mostly of methane, exist in very large quantities, making them a
potential alternative source of energy [5]. Estimates predict that global hydrate reserves contain
more than twice as much organic carbon than current global fossil fuel reserves [6]. Hydrates
formed with carbon dioxide are also currently being researched as a means of carbon dioxide
sequestration into the ocean, thus reducing the amount of carbon dioxide released into the
atmosphere, mitigating the effect of global warming [7].
One of the most recent technologies proposed with regards to gas hydrates is their
implementation in storage and transportation of gases. As suggested by Thomas and Dawe, who
have reviewed ways of transporting natural gas, gas hydrate gas storage and transportation is a
promising technology. As compared to Liquefied Natural Gas (LNG) or Compressed Natural
Gas (CNG), gas hydrates do not require cryogenic temperatures (-160 oC) or extremely high
5
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
pressures (200 bar) as they can be produced at normal temperatures (3 to 5 oC) and pressures (10
to 40 bar) [8]. Gudmundsson et al. have shown that hydrate based transportation technology is
appropriate for low to medium volumes (0.1 to 1 billion cubic meters) and short to medium
distances (100 to 5,000 km) [9].
The need for more fundamental research in the field of gas hydrates has been highlighted
by the growing interest in the field. The prospect of deep sea oil and gas extraction requires a
durable and inexpensive hydrate inhibitor to facilitate the extraction of these valuable resources.
1.4
Hydrate Structure
Gas hydrates take the form of different structures depending on the size of the guest
molecule present. To date, four hydrate structures have been observed: structure I (sI), structure
II (sII), structure H (sH), and tetragonal structure TS-I (only formed with Br2 guest molecule)
[10]. The figure below shows the three most common structures, along with their relative size
and potential guest molecules.
6
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
Figure 1: Structure I, structure II, and structure H cavities and unit cells (hydrate structures) (Image by Sloan
[11]).
Structure I hydrates are composed of 2 small cavities and 6 large cavities, leading to a
unit cell containing a total of 46 water molecules. The small and large cavities have an average
radius of 3.95 Å and 4.33 Å respectively [11]. Structure I hydrates form in the presence of guest
molecules smaller than propane, such as methane, ethane, and carbon dioxide, explaining why
this is the predominant structure found to occur naturally below the ocean floor. A body centered
cubic unit cell is typical of structure I hydrates [11].
Structure II hydrates contain 16 small cavities and 8 large cavities per unit cell, with a
total of 136 water molecules present [11]. The small and large cavities have an average radius of
3.91 Å and 4.73 Å respectively [11]. Structure II hydrates form in the presence of molecules
7
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
larger than those found in the formation of structure I hydrates, such as propane and iso-butane,
but smaller than pentane.
The structure H hydrate was discovered more recently by Ripmeester et al. [12]. Unlike
hydrates of structure sI and sII, structure H hydrates contain three different types of cavities, 3
small, 2 medium, and 1 large [11]. These cavities have average radii of 3.91 Å, 4.06 Å, and 5.71
Å respectively and due to their larger size, require larger guest molecules to ensure
thermodynamic stability. Hydrates of structure H contain 34 water molecules per unit cell [11].
1.5
Phase Equilibrium
Gas hydrates are often grown in stirred tank reactors or PVT cells (a cell where pressure,
temperature and volume are variable). These reactors are pressurized with a hydrate forming gas
or gas mixture which is consumed by the liquid water, leading to the formation of suspended
hydrate crystals.
8
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
Formation region
Decomposition region
Figure 2: Sample three-phase equilibrium curve of a methane + butane system [13].
The line presented in Figure 2 represents the three-phase equilibrium line between liquid
water, gas, and hydrate. Above the equilibrium line, in the formation region, hydrate and liquid
water is present, while below the equilibrium line, in the decomposition region, hydrate growth
or formation will not occur.
9
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
1.6
McGill University
Methane Hydrates
Deaton and Frost [36] were the first to publish equilibrium data about a methane hydrate
system in 1946. Their experimental method for determining such equilibrium data involved the
use of the isothermal pressure-search method, a method still employed today to determine
equilibrium data of various gas hydrate systems. Below is a plot of the data published by Deaton
and Frost for a methane hydrate system:
3
2.5
Methane Hydrate
and Liquid Water
p / MPa
2
1.5
Methane Gas
and Liquid Water
1
0.5
0
273
274
275
276
277
278
279
T/K
Figure 3: Partial phase diagram for the methane-water system as published by Deaton and Frost [1] (1946).
The curve separates the system conditions where methane hydrates can exits. Above the
curve, methane hydrates will nucleate and grow, whereas below the curve, hydrates cannot
nucleate and will decompose if present. On the curve itself, the methane hydrates are in
equilibrium with the system (allowing for the co-existence of methane gas, methane hydrates,
and water). At equilibrium, the hydrate growth rate is equal to the rate of hydrate decomposition,
allowing for no net apparent hydrate growth within the system.
10
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
1.7
McGill University
Carbon Dioxide Hydrates
In 1946, Deaton and Frost also published equilibrium results for the carbon dioxide (CO2)
hydrate system [36]. The same experimental method used to discover the methane hydrate
equilibrium data was also used for the CO2 hydrate system, with their experimental data plotted
below:
5
4.5
CO2 Hydrate
and Liquid Water
4
p / MPa
3.5
3
2.5
2
CO2 Gas
and Liquid Water
1.5
1
0.5
0
272
274
276
278
280
282
284
T/K
Figure 4: Partial phase diagram for the carbon dioxide-water system as published by Deaton and Frost [1]
(1946).
Once again, the pressure is plotted on the y-axis in MPa and the temperature on the x-axis
in K.
1.8
Nucleation and Growth
Hydrates are generated in a supersaturated aqueous solution of hydrate forming gas
dissolved in a bulk liquid phase (water). Like other crystal growth patterns, gas hydrate nuclei
are constantly forming and decomposing during the nucleation phase until a critical size or stable
hydrate nuclei is formed [21]. Critical radii for stable hydrate nucleation have been reported to be
11
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
between 15 nm to 50 µm [22]. The nucleation stage of hydrate growth is widely accepted as
being stochastic in nature, with factors such as driving force masking the unpredictability of the
system’s behaviour.
Vysniauskas and Bishnoi first assumed an Arrhenius-type dependence for the
temperature, pressure, water-gas interfacial area, and degree of supercooling on the reaction rate
constant [26]. The first to acknowledge hydrate growth as being crystalline in nature was
Englezos et. al. [23]. This model is based on crystallization and two-film theory. It describes the
growth of hydrate crystals in constantly stirred systems where agglomeration is assumed to be
negligible, using the reaction rate constant as the only adjustable parameter [23]. Skovborg and
Ramussen later proposed their own model based on the assumption that the transport of gas in
the gas phase to the liquid water phase is the rate determining step in the overall hydrate
formation process [24]. While there is some controversy regarding the rate determining step for
hydrate growth in a semi-batch stirred tank crystallizer, the most recent model of Bergeron and
Servio circumvents this ambiguity [25]. The Bergeron and Servio model relies on experimental
measurements of mole fractions of the hydrate forming gas in the bulk liquid phase to describe
hydrate growth, regardless of the rate determining step [25].
1.9
Hydrate Inhibition
The inhibition of hydrates in the oil and gas industry has traditionally been accomplished
by adding thermodynamic inhibitors such as methanol and glycol [17]. Thermodynamic
inhibitors are additives that change the hydrate’s thermodynamic forming conditions, thus
preventing hydrate growth under normal hydrate forming conditions [14]. One of the major
drawbacks of thermodynamic inhibitors is that they must be used in relatively large
12
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
concentrations (10-50 wt%) [14]. To circumvent this problem, low dosage hydrate inhibitors
(LDHIs) such as anti-agglomerates (AAs) and kinetic hydrate inhibitors (KHIs) have been
developed [15]. LDHIs are commonly water soluble polymers that are effective at concentrations
below 1 wt% [14]. AAs allow hydrates to form yet prevent them from accumulating into large,
uncontrollable masses while KHIs prevent hydrate formation by delaying their nucleation and
growth [14]. Nevertheless, the use of AAs and KHIs has been limited due to environmental
restrictions as a result of their lack of biodegradability [18].
1.9.1 Antifreeze Proteins, Sugars, and Fatty Acids
Antifreeze proteins (AFPs) and antifreeze glycoproteins (AFGPs) have recently been
under study as hydrate inhibitors due to their environmental compatibility. AFPs lower the
freezing point of ice, but do not affect its melting point; the difference between these two
temperatures is called thermal hysteresis [19]. The growth of the ice crystal is thus easily
controlled by keeping the system within the thermal hysteresis range. Zeng et. al. has concluded
that AFPs act on hydrate crystals via an adsorption-inhibition mechanism, as has been suggested
for the interaction of AFPs and ice, thus inhibiting hydrate formation and growth [20]. However,
protein denaturing is a major obstacle due to their natural limited shelf-life under ideal
conditions, and due to their quick unfolding outside of their narrow ideal operating condition
range. Therefore, finding a function, durable, cost-effective, and environmentally-friendly
hydrate inhibitor is currently a major priority for the oil and gas industry.
Chun et. al. have shown that simple sugars, like glucose and sucrose, have a substantial
inhibiting effect on a hydrate system [31]. Experiments were conducted on a CHClF2 (R22)
hydrate system in the presence of sucrose, glucose and lactic acid at concentrations of 20 and 40
13
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
wt%. The equilibrium hydrate dissociation results obtained by Chun et. al. show that the three
phase (H-Lw-V) systems containing sucrose and glucose are shifted from the equilibrium curve
of the pure R22-water system [31]. This shows that sucrose and glucose exhibit an inhibiting
effect.
Recently, xylomannan, a non-protein thermal hysteresis-producing antifreeze, has been
discovered in the freeze tolerant Alaskan beetle Upis cerambodies [28]. The thermal hysteresis
factor isolated from the Alaskan Upis bettle produced 3.7 +/- 0.3 oC of thermal hysteresis at
5mg/ml, comparable to that of the most active insect antifreeze proteins [28]. Compositional and
structural analyses indicate that this antifreeze contains a β-mannopyranosyl-(14) βxylyopyranose backbone and a possible fatty acid component (Figure 5).
Figure 5: Proposed disaccharide core structure of the thermal hysteresis factor isolated from Upis ceramboides
[28].
These antifreeze capabilities, coupled with stability of the sugar and (possible) fatty acid
chain, show great potential as the basis for future hydrate inhibitor development.
14
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
1.10
McGill University
Research Objectives
The objective of the research is to understand the effect of glucose on high pressure gas
hydrate systems, similar to those found in deep sea oil and gas pipelines. This objective stemmed
from the discovery of xylomannan, a non-protein thermal hysteresis-producing disaccharide
produced by the Alaskan Upis cerambodies [28]. Since xylomannan will be difficult to obtain in
useful quantities at the present time, another, more available simple sugar will be tested for its
antifreeze effects with regards to hydrate inhibition.
A methane gas hydrate system and a carbon dioxide gas hydrate system will be tested in
the presence of glucose at various concentrations. Equilibrium plots of these systems will be
produced based on the experimental data acquired.
15
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
2.0 Materials and Methods
2.1
Experimental Set-Up
All experiments were carried out in a Jefri-DBR Phase Behaviour System (Oilphase-
DBR-Schlumberger), as used by Beltran et. al. [35] to acquire data for Equilibrium Studies for
the System Methane + Carbon Dioxide + Neohexane +Water (Figure 6). The system contains a
high-pressure PVT cell built with a 20 cm tall glass cylinder (150 cm3 void volume) secured
between two full length viewing windows, inside a stainless steel frame. The full length viewing
windows allow for the constant monitoring of the contents of the reactor. An automated, highpressure, positive displacement pump (Oilphase-DBR-Schlumberger) [35] was used to regulate
the experimental pressure inside the reactor [35]. The fluid inside the pump comes into contact
with a floating stainless steel piston, which isolates the hydraulic fluid from the process side of
the cell. This allowes the piston to exert a pressure on the experimental contents without
contaminating the process side with the pump fluid. The high-pressure PVT cell is mounted
inside a temperature-regulated air bath by a bracket and horizontal shaft, attached to an electric
motor. The motor powers the shaft, allowing the cell to oscillate through sixty degrees about its
center of gravity, at a rate of forty oscillation cycles per minute [35].
16
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
Figure 6: Experimental set-up.
The pressure and temperature inside the high-pressure PVT cell was monitored using a
platinum RTD probe and a pressure transducer (both supplied with the phase behaviour system).
Using a coverage factor of k = 2 and assuming the corresponding standard uncertainty had a
normal distribution, each expanded uncertainty was estimated to be UT = 0.2 K and UP = 14 kPa,
for temperature and pressure respectively [35].
17
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
2.2
McGill University
Materials
The methane and carbon dioxide gases used during the equilibrium experiments were
both purchased from MEGS Specialty Gases with research grade purity specifications of
>99.995%. The D-(+)-Glucose used during these same experiments was purchased from SigmaAldrich Canada Ltd with a purity rating of ≥99.5 % (GC). For all experiments, the reverse
osmosis water was used as the base for the aqueous phase in the PVT cell.
2.3
Experimental Procedure
The process side of the PVT cell was loaded with 30 cm3 of 0 wt%, 10 wt%, 20 wt% and
30 wt% glucose solution, as required by each set of experiments. These solutions were prepared
using a Denver Instrument S-4002 top loading scale. Once these solutions were injected into the
process side of the PVT cell, the gas being used in the experiment was brought into contact with
the glucose mixture, then pressurized to a value just below the expected hydrate forming region
and left overnight to saturate and equilibrate. Agitation of the PVT cell began once all the
necessary chemicals were loaded into it. In order to induce hydrate crystallization, the positive
displacement pump was used to move the isolation piston forward, thus increasing the pressure
of the system above the equilibrium value for pure water. Once hydrates were formed, the
system was allowed to equilibrate (at least 2.5 hours) and pressure, temperature, system volume,
and hydrate presence in the bulk were monitored. The liquid (aqueous) + hydrate + gas
equilibrium conditions were measured using the isothermal pressure-search method [37, 38, 39].
This pressure search technique satisfies the phase rule for the systems in question . The system’s
pressure was decreased in steps of 0.05 MPa, allowing for the cell’s temperature to equilibrate
for one hour between each pressure decrease. In order to decrease the pressure in the cell, the
18
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
positive displacement pump was used to retract the isolation piston located within the PVT cell.
Care was taken to avoid large temperature fluctuations, maintaining the cell temperature within ±
0.4 K of the original value. As carried out by Beltran et. al. [35], this procedure was repeated
until visual confirmation of hydrate disappearance was achieved; the equilibrium temperature
and pressure conditions were then taken as the mean of the conditions at which the final hydrate
crystal was observed and the conditions at which the final hydrate crystal disappeared.
The estimated standard uncertainties were as follows: for temperature uT = 0.2 K, for
pressure uP = 0.03 MPa. Since the coverage factor used is k = 2 and assuming the corresponding
standard uncertainty had a normal distribution, each expanded uncertainty was estimated to be
UT = 0.4 K and UP = 0.06 MPa [35].
2.4
Experimental Conditions
All experiments were performed around the hydrate forming region in order to correctly
identify the equilibrium conditions of the hydrate systems in question. Temperatures commonly
experienced by underwater gas pipelines were chosen as a basis for data point acquisition due to
the isothermal pressure-search method being employed (temperature was set, pressure was
varied). Due to the isothermal nature of the procedure, temperature was not allowed to fluctuate
by more than 0.4 K. For both the methane and carbon dioxide systems, data points were acquired
at 2, 4, 6, and 8 K. Replicates of the endpoints were acquired for the methane/glucose system
while replicates for all four temperatures were acquired for the carbon dioxide/glucose system in
order to validate the accuracy of the results.
19
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
3.0 Results and Discussion
3.1
Methane Experiments
The accuracy of the data acquired using the previously described equipment was
confirmed through a comparison of equilibrium data obtained by Deaton and Frost [36] in a 0
wt% glucose system (Table 1). The data published by Deaton and Frost was within the
experimental uncertainty of the presented work within the same temperature range. This data is
presented in Table 1 as well as in Figure 7. It is used as a lower system boundary to show the
inhibition effect of the aqueous solutions used in this work. Note that an inhibition effect is
observed when hydrate equilibrium conditions are shifted to higher pressures and/or lower
temperatures due to the presence of inhibitor(s) in aqueous solution [16].
Table 1: Hydrate-liquid-vapour equilibrium data from this work. Temperature T, Pressure p, for the system CH40 wt% glucose/H20 under H-Lw-V equilibrium.
T/K
275.80
277.44
279.47
281.14
20
p / MPa
3.35
3.98
4.85
5.81
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
6.50
▬, 0 wt% glucose, this work;
X, 0 wt% glucose, Deaton and Frost [1];
6.00
p / Mpa
5.50
5.00
4.50
4.00
3.50
3.00
275
276
277
278
279
280
281
282
T/K
Figure 7: Measured equilibrium conditions of the water + glucose + methane system.
The experimental H-Lw-V hydrate equilibrium pressure and temperature conditions are
presented in Tables 1, 2, 3, and 4 based on their respective glucose concentrations, as well as in
Figure 8. It is observed in Figure 8 that systems containing glucose have equilibrium values
shifted above the pure water (0 wt% glucose) + methane system values. Also, as the glucose
concentration increases between systems, the respective equilibrium curves shift further above
the pure water + methane system equilibrium values. This indicates that glucose has an inhibiting
effect on methane hydrate systems and that as the concentration of glucose increases, so does the
degree of inhibition. There seems to be an exponential increase of inhibition as the glucose
concentration increases between systems, but due to a lack of detailed modelling, this claim
cannot be substantiated with any significant statistical data.
21
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
Table 2: Hydrate-liquid-vapour equilibrium data from this work. Temperature T, Pressure p, for the system CH410 wt% glucose/H20 under H-Lw-V equilibrium.
T/K
275.35
275.50
277.34
279.46
280.91
281.25
p / MPa
3.43
3.48
4.23
5.12
5.87
6.02
Table 3: Hydrate-liquid-vapour equilibrium data from this work. Temperature T, Pressure p, for the system CH420 wt% glucose/H20 under H-Lw-V equilibrium.
T/K
275.29
275.36
277.32
279.20
280.87
280.94
p / MPa
3.81
3.85
4.71
5.67
6.61
6.60
Table 4: Hydrate-liquid-vapour equilibrium data from this work. Temperature T, Pressure p, for the system CH430 wt% glucose/H20 under H-Lw-V equilibrium.
T/K
275.23
275.25
277.35
279.31
280.83
280.88
22
p / MPa
4.43
4.43
5.46
6.65
7.74
7.77
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
9
▬, 0 wt% glucose, this work
X, 0 wt% glucose, Deaton and Frost, 1946
♦, 10 wt% glucose
■, 20 wt% glucose
▲, 30 wt% glucose
8
p / Mpa
7
6
5
4
3
275
276
277
278
279
280
281
282
T/K
Figure 8: Measured equilibrium conditions of the water + glucose + methane system.
Experiments were not run for aqueous solutions containing more than 30 wt% glucose
since the maximum solubility of glucose in pure water within the temperature range used is
around 40 wt% glucose [40]. Therefore, in order to prevent glucose crystallization in the PVT
cell, a 30 wt% glucose aqueous solution was used as an upper boundary for data acquisition.
Figure 9 shows the relative inhibitive strength of glucose as compared to other simple
common thermodynamic inhibitors, methanol (CH3OH) [41] and magnesium sulphate (MgSO4)
[42]. A 30 wt% glucose solution shows a slightly stronger inhibitive action to hydrate formation
in comparison to methanol in low concentrations as well as to magnesium sulphate in
approximately equal proportions to glucose. When methanol is present at 35 wt% [41], it shows
a stronger inhibitive effect on hydrate formation than does glucose.
23
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
12
10
■, 30 wt% glucose, this work;
♦, 4.2 wt% CH3OH, [41];
▬, 28 wt% MgSO4, [42];
X, 35 wt% CH3OH, [41];
p / MPa
8
6
4
2
0
250.0
255.0
260.0
265.0
270.0
275.0
280.0
285.0
290.0
T/K
Figure 9: Measured equilibrium conditions of the water + glucose + methane system and reported equilibrium
conditions of the water + methanol + methane system, water + MgSO4 + methane system and water + methanol +
methane system.
24
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
3.2
McGill University
Carbon Dioxide Experiments
As was carried out in the methane experiments, after the PVT cell was cleaned out and
loaded with the new components required for the carbon dioxide experiments, the accuracy of
the measurements was again observed by confirming the data published by Deaton and Frost for
a 0 wt% glucose/H2O carbon dioxide hydrate system. These results are presented in Table 5 and
have been plotted in Figure 10.
Table 5: Hydrate-liquid-vapour equilibrium data from this work. Temperature T, Pressure p, for the system CO20 wt% glucose/H20 under H-Lw-V equilibrium.
T/K
275.37
277.49
279.21
280.98
275.24
277.16
279.13
281.10
p / MPa
1.61
2.05
2.47
3.16
1.55
1.92
2.43
3.23
Figure 10 compares the data acquired from my experimental set-up with the data
published by Deaton and Frost in 1946 [36]. This data lies in agreement with the data published,
thus proving the validity of future experiments with carbon dioxide. As in the methane
experiments, this data is used as the lower boundary for the carbon dioxide hydrate system due to
the lack of inhibiting glucose present. All future experimental results for systems containing a
glucose solution as the aqueous phase are expected to lie above the curve presented in Figure 10,
thus demonstrating glucose’s inhibiting effect on hydrate equilibrium.
25
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
5
▲, 0 wt% glucose, this work;
─, 0 wt% glucose, Deaton and
Frost [1];
4.5
4
p / MPa
3.5
3
2.5
2
1.5
1
0.5
0
272
274
276
278
280
282
284
T/K
Figure 10: Measured equilibrium conditions of the water + glucose + carbon dioxide system.
Experiments were then carried out with aqueous glucose solutions containing 10 wt%, 20
wt%, and 30 wt% glucose. The experimental data pertaining to these experiments are presented
in Tables 6, 7, and 8 respectively. A plot of this data (Figure 11) has been produced and will be
subsequently analyzed.
26
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
Table 6: Hydrate-liquid-vapour equilibrium data from this work. Temperature T, Pressure p, for the system CO210 wt% glucose/H20 under H-Lw-V equilibrium.
T/K
275.16
277.14
279.14
281.06
275.20
277.16
279.12
281.15
p / MPa
1.66
2.09
2.71
3.50
1.64
2.12
2.67
3.61
Table 7: Hydrate-liquid-vapour equilibrium data from this work. Temperature T, Pressure p, for the system CO220 wt% glucose/H20 under H-Lw-V equilibrium.
T/K
275.12
277.10
279.01
280.61
275.06
277.05
279.09
280.55
p / MPa
1.91
2.43
3.12
3.95
1.91
2.41
3.13
3.92
Table 8: Hydrate-liquid-vapour equilibrium data from this work. Temperature T, Pressure p, for the system CO230 wt% glucose/H20 under H-Lw-V equilibrium.
T/K
275.35
277.25
278.98
275.34
277.21
278.92
27
p / MPa
2.40
2.98
3.74
2.34
2.95
3.71
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
As predicted, all carbon dioxide hydrate experiments carried out in the presence of a
glucose aqueous solution did in fact reside above the pure water/carbon dioxide hydrate
equilibrium line (Figure 11), indicating that glucose does have a distinct inhibiting effect on
hydrate equilibrium in the presence of carbon dioxide. While the inhibitive effect of glucose is
relatively low at the 10 wt% concentration level, glucose does show a much stronger inhibitive
effect as its solution concentration increases. As was also experienced in the methane hydrate
system discussed previously in section 3.1, there seems to be an exponential increase in degree
of inhibition as the glucose concentration increases, but due to a lack of detailed modelling, this
claim cannot be substantiated with any significant statistical data.
Again, experiments were not run with aqueous solutions above 30 wt% glucose in order
to avoid crystallization in the PVT cell and experimental set-up tubing. A more detailed
explanation for this decision can be found in section 3.1.
It is important to note that there are no experimental values for hydrate equilibrium
around 281 K. This is due to the inability to form hydrates within the system at that temperature.
While it is not impossible to form carbon dioxide hydrates at 281 K, I was unable to induce
stable hydrate nucleation, possibly due to a lack of pressure. As was done for all other
experiments, the system was brought to a pressure above the assumed equilibrium point to
induce hydrate nucleation. Once hydrate growth began, the system was slowly brought down to a
pressure near the equilibrium point, where it was allowed to reach steady state before the
stepwise decreases in pressure commenced. At 281 K, the system was allowed to reach pressures
in excess of 10 MPa, far above the assumed equilibrium range of 4.9-5.2 MPa, yet hydrate
nucleation still did not occur.
28
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
5
▲, 0 wt% glucose, this work;
─, 0 wt% glucose, Deaton and
Frost;
X, 10 wt% glucose, this work;
4.5
4
*, 20 wt% glucose, this work;
♦, 30 wt% glucose, this work;
3.5
p / MPa
3
2.5
2
1.5
1
0.5
0
272
274
276
278
280
282
284
T/K
Figure 11: Measured equilibrium conditions of the water + glucose + carbon dioxide system.
The relative strength of glucose as an inhibitor in a carbon dioxide hydrate system is
shown in Figure 12. In this figure, glucose is compared to other thermodynamic inhibitors
commonly used in the oil and gas industry: alcohols and salts. The alcohols used in the
comparison are methanol and ethanol, while the salts used are sodium chloride and potassium
chloride.
From the figure, it is clear that the best performing inhibitor of those being compared is
the 10 wt% methanol (CH3OH) solution. The 30 wt% glucose solution tested seemed to have the
same relative inhibitive strength as the 10 wt% potassium chloride (KCl) solution and the 10
29
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
wt% ethanol (C2H5OH) solution, while displaying a stronger inhibitive strength than the 5 wt%
sodium chloride (NaCl) solution.
While the 30 wt% glucose solution does show the same inhibitive strength as some of the
other common thermodynamic inhibitors, it is being used in a higher concentration than the
others, making it a less effective inhibitor on a per mass basis.
4
▬, 30 wt% glucose, this work;
▲, 10 wt% CH3OH [43];
X, 10 wt% C2H5OH [43];
♦, 10 wt% KCl [44];
■, 5 wt% NaCl [44];
3.5
3
p / MPa
2.5
2
1.5
1
0.5
0
268
270
272
274
276
278
280
282
T/K
Figure 12: Measured equilibrium conditions of the water + glucose + carbon dioxide system and reported
equilibrium conditions of the water + methanol + carbon dioxide system, water + ethanol + carbon dioxide
system, water + potassium chloride + carbon dioxide system, and water + sodium chloride + carbon dioxide
system.
30
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
4.0 Conclusions and Recommendations
4.1
Conclusions
Experiments were conducted to measure the effect of aqueous D-(+)-glucose on hydrate
formation in the presence of methane and carbon dioxide. The accuracy of the equipment used
was verified by reproducing data for a pure water + methane system as well as a pure water +
carbon dioxide system found in the literature.
Experiments were conducted near the assumed hydrate equilibrium conditions of both the
methane and carbon dioxide systems. The experimental pressures ranged from 3.4 to 7.8 MPa for
the methane systems and 1.6 to 3.8 MPa for the carbon dioxide systems, with an experimental
temperature range of 275.15 to 281.25 K and glucose mass fractions of 0.1 to 0.3.
In both the methane and carbon dioxide systems, an inhibiting effect was observed at all
glucose concentrations. The inhibiting effect of the glucose was then perceived to increase as the
glucose concentration in the aqueous solution increased. All systems containing glucose were
also found to follow the same trend as the systems containing pure water in terms of the apparent
curvature of the equilibrium line.
In comparison to other thermodynamic hydrate inhibitors, glucose did not perform very
well on inhibition strength to mass fraction ratio. The 30 wt% glucose solution used was the only
solution of the three tested to yield a hydrate inhibition level at par with the other thermodynamic
inhibitors considered and employed in industry (10 wt% KCL, 5 wt% NaCl, 4-10 wt% methanol,
10 wt% ethanol). As seen in Figure 8, if methanol is present in the same mass fraction as
glucose, its inhibitive effects on hydrate equilibrium are much greater.
31
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
4.2
McGill University
Recommendations
Experimentation with sugars as thermodynamic inhibitors should be further pursued with
sugars of increasing complexity since they have been proven to be a viable hydrate inhibitor; one
that is readily available, thermally stable, environmentally friendly, and inexpensive when
compared to other types of synthetic hydrate inhibitors being used, such as anti-freeze proteins
and surfactants. Perhaps if sugars of longer length or containing side chains were employed,
greater inhibition could be achieved, and at lower sugar concentration.
Future studies on the equilibrium of hydrate systems in the presence of these sugars
should be carried out with gas mixtures that more closely duplicate the conditions present in
natural gas pipelines in terms of gas phase composition.
Morphology experiments can also be conducted for hydrates systems using sugars as an
inhibitor to get an insight as to how the sugar molecules interact with the hydrate cages. A better
understanding of the physical interaction between sugars and hydrates at the molecular level will
lead to a greater the ability to synthesize a very effective sugar molecule for hydrate inhibition.
32
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
5.0 References
1. Sloan, E.D., Clathrate Hydrates of Natural Gases. 1998, New York: Marcel Dekker Inc.
705.
2. Hammerschmidt EG. Formation of gas hydrates in natural gas transmission lines. Ind Eng
Chem, 1934. 26: p. 851–855.
3. Chatti, I., A. Delahaye, L. Fournaison, and J.-P. Petitet, Benefits and drawbacks of
clathrate hydrates: a review of their areas of interest. Energy Conversion and
Management, 2005. 46: p. 1333-1343.
4. Englezos, P., Clathrate Hydrates. Ind. Eng. Chem. Res., 1993. 32: p. 1251-1274.
5. Englezos, P., Lee, J. D., Gas Hydrates: A Cleaner Source of Energy and Opportunity for
Innovative Technologies. Korean J. Chem. Eng., 2005. 22: p. 671-681
6. Suess, E., G. Bohrmann, J. Greinert, and E. Lausch, Flammable Ice. Scientific American,
1999(November): p. 76-83.
7. Brewer, P.G., G. Friederich, E.T. Peltzer, and F.M.O. Jr., Direct experiments on the
ocean disposal of fossil fuel CO2. Science, 1999. 284: p. 943-945.
8. Thomas, S. and R.A. Dawe, Review of ways to transport natural gas energy from
countries which do not need the gas for domestic use. Energy, 2003. 28: p. 1461-1477.
9. Gudmundsson, J.S., Mork, M. and Graff, O.F., Hydrate Non-pipeline Technology, In
Proceedings of 4th International Conference on Gas Hydrates, Yokohama, May 19-23,
2002: p. 997-1002.
10. Goldschleger, I.U., Kerenskaya, G., Janda, K.C., Apkarian, V.A., Polymorphism in Br2
Clathrate Hydrates, The Journal of Physical Chemistry, 2008. 112: p. 787-789
33
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
11. Sloan, E.D., Fundamental principles and applications of natural gas hydrates, Nature,
2003. 426: p. 353-359
12. Ripmeester, J.A., Tse, J.S., Ratcliffe, C.I., Powell, B.M., A new clathrate hydrate
structure, Nature, 1987. 325: p. 135-136
13. Sloan, E.D., Gas Hydrates: Review of Physical/Chemical Properties, Energy & Fuels,
1998. 12: p. 191-196
14. Al-Adel, S., Dick, J.A.G., El-Ghafari, R., Servio, P., The effect of biological and
polymeric inhibitors on methane gas hydrate growth kinetics, Fluid Phase Equilibria,
2008. 267: p. 92-98
15. Kelland, M.A., History of the Development of Low Dosage Hydrate Inhibitors, Energy &
Fuels, 2006. 20: p. 825-847
16. Zeng, H., Wilson, L.D., Walker, V.L., Ripmeester, J.A., The inhibition of tetrahydrofuran
clathrate-hydrate formation with antifreeze protein, Can. J. Phys., 2003. 81: p. 17-24
17. Jensen, L., Ramlov, H., Thomsen, K., von Solms, N., Inhibition of Methane Hydrate
Formation by Ice-Structuring Proteins, Industrial & Engineering Chemistry Research,
Jan 14, 2010.
18. Del Villano, L., Kommedal, R., Kelland, M.A., Class of Kinetic Hydrate Inhibitors with
Good Biodegradability, Energy & Fuels, 2008. 22: p. 3143-3149
19. Hagiwara, Y., Sakurai, R., Nakanishi, R., Temperature of the solution of winter flounder
antifreeze protein near ice surfaces in a narrow space, Journal of Crystal Growth, 2010.
312: p. 314-322
34
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
20. Zeng, H., Wilson, L.D., Walker, V.K., Ripmeester, J.A., The inhibition of
tetrahydrofuran clathrate-hydrate formation with antifreeze protein, Canadian Journal of
Physics, 2003. 81: p. 17-24
21. Natarajan, V., Bishnoi, P.R., Kalogerakis, N., Induction phenomena in gas hydrate
nucleation, Chemical Engineering Science, 1994. 49(13): p. 2075-2087
22. Clarke, M.A., Bishnoi, P.R., Determination of the intrinsic rate constant and activation
energy of CO2 gas hydrate decomposition using in-situ particle size analysis, Chemical
Engineering Science, 2004. 59: p. 2983-2993
23. Englezos, P., Kalogerakis, N., Dholabhai, P.D., Bishnoi, P.R., Kinetics of formation of
methane hydrates and ethane gas hydrates, Chemical Engineering Science, 1987. 42(11):
p. 2648-2658
24. Skovborg, P., Rasmussen, P., A mass transport limited model for the growth of methane
and ethane gas hydrates, Chemical Engineering Science, 1994. 49(8): p. 1131-1143
25. Bergeron, S. Beltran, J.G., Servio, P., Reaction rate constant of methane clathrate
formation, Fuel, 2010. 89: p. 294-301
26. Vysniauskas, A., Bishnoi, P.R., Kinetics of ethane hydrate formation, Chemical
Engineering Science, 1985. 40(2): p. 299-303
27. Conrad, H., Lehmkuhler, F., Sternemann, C., Sakko, A., Paschek, D., Simonelli, L.,
Huotari, S., Feroughi, O., Tolan, M., Hamalainen, K., Tetrahydrofuran Clathrate Hydrate
Formation, Physical Review Letters, 2009. 103: p. 218301-1 to 218301-4
28. Walters, K.R., Serianni, A.S., Sformo, T., Barnes, B.M., Duman, J.G., A nonprotein
thermal hysteresis-producing xylomannan antifreeze in the freeze-tolerant Alaskan beetle
Upis cerambodies, PNAS, 2009. 106(48): p. 20210-20215
35
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
29. Bruusgaard, H., Lessard, L.D., Servio, P., Morphology Study of Structure I Methane
Hydrate Formation and Decomposition of Water Droplets in the Presence of Biological
Polymeric Kinetic Inhibitors, Crystal Growth & Design, 2009. 9(7): p. 3014-3023
30. Trebble, M.A., Bishnoi, P.R., Development of a new four-parameter cubic equation of
state, Fluid Phase Equilibria, 1987. 35: p. 1-18
31. Chun, M.K., Lee, H., Phase equilibria of R22 (CHClF2) hydrate system in the presence
of sucrose, glucose and lactic acid, Fluid Phase Equilibria, 1998. 150-151: p. 361-370
32. Bruusgaard, H, Beltran, J.G., Servio, P., Vapor-Liquid Water-Hydrate Equilibrium Data
for the System N2+CO2+H2O, J. Chem. Eng., 2008. 25: p. 2594-2597
33. Lee, S.-Y., Holder, G.D., A Generalized Model for Calculating Equilibrium States of Gas
Hydrates: Part II, Annals of the New York Academy of Sciences, Gas Hydrates:
Challenges for the Future, 2000. 912: p. 614-622
34. Van der Waals, J.H., Platteeuw, J.C., Clathrate Solutions, Advanced Chemical Physics,
1959. 2: p. 1-57
35. Beltran, J.G., Servio, P., Equilibrium Studies for the System Methane + Carbon Dioxide
+ Neohexane + Water, J. Chem. Eng. Data, 2008. 53: p. 1745-1749.
36. Sloan, E.D., Clathrate Hydrates of Natural Gases. 1998, New York: Marcel Dekker Inc.
37. Tohidi, B., Burgass, R.W., Danesh, A., Ostergaard, K.K., Todd, A.C., Improving the
Accuracy of Gas Hydrate Dissociation Point Measurements, Annals of the New York
Academy of Sciences, 2000. 912(Gas Hydrates): p. 924-931
38. Servio, P., Lagers, F., Peters, C., Englezos, P., Gas hydrate phase equilibrium in the
system methane-carbon dioxide-neohexane and water, Fluid Phase Equilibria, 1999. 158160: p. 795-800
36
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
39. Englezos, P., Ngan, Y.T., Effect of polyethylene oxide on gas hydrate phase equilibria,
Fluid Phase Equilibria, 1994. 92: p. 271-288
40. Alves, L.A., Almedia e Silve, J.B., Giulietti, M., Solubility of D-Glucose in Water and
Ethanol/Water Mixtures, J. Chem. Eng. Data, 2007. 52: p. 2166-2170.
41. Mohammadi, A.H., Richon, D., Phase Equilibria of Methane Hydrates in the Presence of
Methanol and/or Ethylene Glycol Aqueous Solutions, Ind. Eng. Chem. Res., 2010. 49: p.
925-928.
42. Porz, L.O., Clarke, M.A., Oellrich, L.R., Experimental Investigation of Methane
Hydrates Equilibrium Condition in the Presence of KNO3, MgSO4, CuSO4, J. Chem. Eng.
Data, 2010. 55: p. 262-266.
43. Maekawa, T., Equilibrium Conditions for Carbon Dioxide Hydrates in the Presence of
Aqueous Solutions of Alcohols, Glycols, and Glycerol, J. Chem. Eng. Data, 2010. 55: p.
1280-1284
44. Mohammadi, A.H., Afzal, W., Richon, D., Gas hydrates of methane, ethane, propane,
and carbon dioxide in the presence of single NaCl, KCl, and CaCl2 aqueous solutions:
Experimental measurements and predictions of dissociation conditions, J. Chem.
Thermodynamics, 2008. 40: p.1693-1697
37
Master’s Thesis © Anthony Stephen Carbone, 2011
Inhibition Effects of Glucose on Clathrate Hydrate (H-Lw-V) Equilibrium
McGill University
Publications
1. Bruusgaard, H., Carbone, A. & Servio, P., “H-Lw-V equilibrium measurements for the
CH4+C2H6+H2O hydrate forming system”, J. Chem.Eng. Data, 55 (9), 3680–
3683, 2010.
38
Master’s Thesis © Anthony Stephen Carbone, 2011