[1]
[2]
4 Conclusions
This study showed that the liquidus temperatures
of DAG/DAG mixtures either follow a simple Vshape curve or change monotonically, both of
which fit well with values predicted by the NSS
model. The formation of molecular compounds
between different types of DAG was not observed.
According to previous studies, such eutectic or
monotectic behavior has also been commonly
observed in TAG/TAG mixtures. Similarly, the
liquidus curves of binary mixtures of different
types of acylglycerol, namely, DAG/MAG,
TAG/MAG, and DAG/TAG, were in good agreement
with the NSS model, with a few exceptions.
However, for TAG/MAG mixtures, concerns
remained regarding the reliability of the UNIFAC
(Dortmund) model for estimating the activity
coefficient. These results implied that each
[3]
[4]
[5]
L. Yu, I. Lee, E. G. Hammond, L. A. Johnson, J.
H. Van Gerpen. The influence of trace
components on the melting point of methyl
soyate. J. Am. Oil Chem. Soc., 1998, 75,
1821–1824.
H. Tang, R. C. De Guzman, S. O. Salley, K. Y. S.
Ng. Formation of insolubles in palm oil-,
yellow grease-, and soybean oil-based
biodiesel blends after cold soaking at 4 °c. J.
Am. Oil Chem. Soc., 2008, 85, 1173–1182.
G. M. Chupka, J. Yanowitz, G. Chiu, T. L.
Alleman, R. L. McCormick. Effect of
saturated monoglyceride polymorphism on
low-temperature performance of biodiesel.
Energy Fuels, 2011, 25, 398–405.
Y. Sugami, S. Yoshidomi, E. Minami, N. Shisa,
H. Hayashi, S. Saka. The effect of
monoglyceride polymorphism on cold-flow
properties of biodiesel model fuel. J. Am. Oil
Chem. Soc., 2017, 94, 1095–1100.
S. Yoshidomi, Y. Sugami, E. Minami, N. Shisa,
H. Hayashi, S. Saka. Predicting solid–liquid
equilibrium of fatty acid methyl ester and
monoglyceride mixtures as biodiesel model
fuels. J. Am. Oil Chem. Soc., 2017, 94, 1087–
A Self-archived copy in
Kyoto University Research Information Repository
https://repository.kulib.kyoto-u.ac.jp
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
1094.
I. Foubert, K. Dewettinck, D. Van de Walle, A.
J. Dijkstra, P. J. Quinn. Physical properties:
Structural and physical characteristics, in
Lipid Handb. with CD-ROM, (Eds: F.D.
Gunstone, J.L. Harwood, A.J. Dijkstra), CRC
Press, Boca Raton, 2007.
I. Paryanto, T. Prakoso, M. Gozan.
Determination of the upper limit of
monoglyceride content in biodiesel for B30
implementation based on the measurement
of the precipitate in a Biodiesel–Petrodiesel
fuel blend (BXX). Fuel, 2019, 258, 116104.
H. Imahara, E. Minami, S. Saka.
Thermodynamic study on cloud point of
biodiesel with its fatty acid composition.
Fuel, 2006, 85, 1666–1670.
R. O. Dunn. Crystallization behavior of fatty
acid methyl esters. J. Am. Oil Chem. Soc.,
2008, 85, 961–972.
J. C. A. Lopes, L. Boros, M. A. Kráhenbúhl, A.
J. A. Meirelles, J. L. Daridon, J. Pauly, I. M.
Marrucho, J. A. P. Coutinho. Prediction of
cloud points of biodiesel. Energy and Fuels,
2008, 22, 747–752.
R. O. Dunn. Correlating the Cloud Point of
Biodiesel to the Concentration and Melting
Properties of the Component Fatty Acid
Methyl Esters. Energy and Fuels, 2018, 32,
455–464.
L. Seniorita, E. Minami, Y. Yazawa, H.
Hayashi, S. Saka. Differential Scanning
Calorimetric Study of Solidification Behavior
of Monoacylglycerols to Investigate the
Cold-Flow Properties of Biodiesel. J. Am. Oil
Chem. Soc., 2019, 96, 979–987.
R. E. Timms. Phase behaviour of fats and
their mixtures. Prog. Lipid Res., 1984, 23, 1–
38.
L. Zhang, S. Ueno, K. Sato. Binary phase
behavior of saturated-unsaturated mixedacid triacylglycerols—A review. J. Oleo Sci.,
2018, 67, 679–687.
L. Seniorita, E. Minami, H. Kawamoto.
Solidification behavior of acylglycerols in
fatty acid methyl esters and effects on the
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
cold flow properties of biodiesel. J. Am. Oil
Chem. Soc., 2021, 98, 727–735.
J. M. Smith, H. C. Van Ness, M. M. Abbott.
Introduction to Chemical Engineering
Thermodynamics, McGraw-Hill Education,
New York, 2005.
J. Gmehling, J. Li, M. Schiller. A modified
UNIFAC model. 2. Present parameter matrix
and results for different thermodynamic
properties. Ind. Eng. Chem. Res., 1993, 32,
178–193.
J. M. Prausnitz, R. N. Lichtenthaler, E. G. de
Azevedo. Molecular Thermodynamics of
Fluid-Phase Equilibria, Prentice Hall PTR,
New Jersey, 1999.
J. Vereecken, W. Meeussen, I. Foubert, A.
Lesaffer, J. Wouters, K. Dewettinck.
Comparing the crystallization and
polymorphic behaviour of saturated and
unsaturated monoglycerides. Food Res. Int.,
2009, 42, 1415–1425.
K. Sato, T. Kuroda. Kinetics of melt
crystallization and transformation of
tripalmitin polymorphs. J. Am. Oil Chem. Soc.,
1987, 64, 124–127.
R. J. Craven, R. W. Lencki. Binary phase
behavior of diacid 1,3-diacylglycerols. J. Am.
Oil Chem. Soc., 2011, 88, 1125–1134.
Y. Xu, C. Dong. Phase behavior of binary
mixtures of three different 1,3diacylglycerols. Eur. J. Lipid Sci. Technol.,
2017, 119, 1–13.
L. Engström. Triglyceride systems forming
molecular compounds. Eur. J. Lipid Sci. Tech.,
1992, 94, 173–181.
Committee for Standardization Automotive
Fuels. Fatty Acid Methyl Esters (FAME) for
Biodiesel Engines - Requirements and Test
Methods (EN14214), European Committee
For Standardization CEN, 2008.
A. Holmgren, G. Lindblom, L. B. . Johansson.
Intramolecular hydrogen bonding in a
monoglyceride lipid studied by Fourier
transform infrared spectroscopy. J. Phys.
Chem., 1988, 92, 5639–5642.
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(b) DAG18:0/DAG16:0
(c) DAG18:1/TAG16:0
Mole fraction of DAG18:1
0.19
0.20
0.21
0.25
0.38
0.37
0.35
0.61
0.58
0.70
Heat flow
0.10
Heat flow
Heat flow
Exo.
(a) DAG18:0/DAG18:1
0.50
0.64
0.78
0.78
Endo.
Mole fraction
of DAG18:0
20
40
60
80
Temperature, C
Mole fraction
of DAG18:0
100 30 40 50 60 70 80 90 100 0
Temperature, C
0.77
0.89
20
40
60
80
Temperature, C
100
Fig. 1. DSC profiles at a heating rate of 10 °C/min for mixtures of (a) DAG18:0/DAG18:1, (b) DAG18:0/DAG16:0, and (c)
DAG18:1/TAG16:0 at various mole fractions. Filled and open triangles indicate the liquidus and solidus peaks, respectively.
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(a) DAG18:0/DAG12:0
(b) DAG18:0/DAG16:0
(c) DAG18:0/DAG18:1
90
90
90
80
70
NSS model
Experimental liquidus
60
Temperature, C
80
SS model
Temperature, C
Temperature, C
80
70
60
70
60
50
40
30
Experimental solidus
50
50
0.2 0.4 0.6 0.8
Mole fraction of DAG18:0
20
0.2 0.4 0.6 0.8
Mole fraction of DAG18:0
0.2 0.4 0.6 0.8
Mole fraction of DAG18:0
Fig. 2. Experimentally determined liquidus (filled circles) and solidus (open circles) temperatures of various DAG/DAG binary mixtures,
and theoretical liquidus curves calculated using the NSS (solid line) and SS (dashed line) models.
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(a) DAG12:0/MAG12:0
(b) DAG18:0/MAG18:0
(c) DAG18:1/MAG18:1
90
70
50
Experimental liquidus
NSS model
40
40
Temperature, C
Temperature, C
50
Temperature, C
SS model
60
80
70
30
20
Experimental solidus
30
0.2 0.4 0.6 0.8
Mole fraction of DAG12:0
(d) DAG18:0/MAG18:1
0.2 0.4 0.6 0.8
Mole fraction of DAG18:0
0.2 0.4 0.6 0.8
Mole fraction of DAG18:1
(e) DAG18:1/MAG16:0
70
90
80
CF model
60
Temperature, C
Temperature, C
10
60
70
60
50
50
40
30
40
30
20
0.2 0.4 0.6 0.8
Mole fraction of DAG18:0
0.2 0.4 0.6 0.8
Mole fraction of DAG18:1
Fig. 3. Experimentally determined liquidus (filled circles) and solidus (open circles) temperatures of various DAG/MAG binary
mixtures, and theoretical liquidus curves calculated using the NSS (solid line), SS (dashed line), and CF (dashed-dotted line) models.
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(a) TAG18:0/MAG18:0
(b) TAG18:0/MAG12:0
(c) TAG16:0/MAG18:1
70
90
90
80
NSS model
70
60
Experimental liquidus
60
Temperature, C
80
Temperature, C
Temperature, C
SS model
70
60
50
50
40
40
30
30
50
0.2 0.4 0.6 0.8
Mole fraction of TAG18:0
0.2 0.4 0.6 0.8
Mole fraction of TAG18:0
0.2 0.4 0.6 0.8
Mole fraction of TAG16:0
Fig. 4. Experimentally determined liquidus (filled circles) temperatures of various TAG/MAG binary mixtures, and theoretical liquidus
curves calculated using the NSS (solid line) and SS (dashed line) models.
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(a) DAG18:0/TAG16:0
(b) DAG12:0/TAG18:0
90
70
80
70
NSS model
Experimental liquidus
60
Temperature, C
SS model
Temperature, C
60
80
Temperature, C
(c) DAG18:1/TAG16:0
70
60
50
40
30
50
20
50
0.2 0.4 0.6 0.8
Mole fraction of DAG18:0
0.2 0.4 0.6 0.8
Mole fraction of DAG12:0
0.2 0.4 0.6 0.8
Mole fraction of DAG18:1
Fig. 5. Experimentally determined liquidus (filled circles) temperatures of various DAG/TAG binary mixtures, and theoretical liquidus
curves calculated using the NSS (solid line) and SS (dashed line) models.
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(a) DAG18:0/DAG18:1
(b) DAG18:0/MAG18:1
90
40
20
-120 0
Enthalpy, kJ/mol
Temperature, °
Liquidus
60
0.2
0.4
0.6
0.8
Mole fraction of DAG18:0
-90
E nthalpy at liquidus
-60
-30
70
50
30
-120 0
Enthalpy, kJ/mol
Temperature, °
80
0.6
0.8
Mole fraction of DAG18:0
-90
-60
-30
0.2
0.4
0.6
0.8
0.2
0.4
0.6
0.8
Mole fraction of DAG18:0
Mole fraction of DAG18:0
(c) TAG16:0/MAG18:1
(d) TAG16:0/DAG18:1
70
70
60
Temperature, °
Temperature, °
0.4
50
40
30
-120 0
0.2
0.4
0.6
0.8
Mole fraction of TAG16:0
-90
-60
-30
60
50
40
30
20
-120 0
Enthalpy, kJ/mol
Enthalpy, kJ/mol
0.2
0.2
0.4
0.6
0.8
Mole fraction of TAG16:0
-90
-60
-30
0.2
0.4
0.6
0.8
Mole fraction of TAG16:0
0.2
0.4
0.6
0.8
Mole fraction of TAG16:0
Fig. 6. Experimentally determined liquidus temperatures (filled circles) and enthalpies of melting at
liquidus (open circles) for various binary mixtures.
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Table 1. Pure materials used in this study and their supplier-guaranteed purities.
Name
Abbreviations
1-monolaurin
MAG12:0
1-monopalmitin
MAG16:0
1-monostearin
MAG18:0
1-monoolein
MAG18:1
1,3-dilaurin
DAG12:0
1,3-dipalmitin
DAG16:0
1,3-distearin
DAG18:0
1,3-diolein
DAG18:1
Tripalmitin
TAG16:0
Tristearin
TAG18:0
Manufacturer
Nu-Chek Prep, Inc., Elysian, MI
Olbracht Serdary Research Laboratories, Toronto, Canada
Purity, % (GC)
99
99
99
99
Nu-Chek Prep, Inc., Elysian, MI
99
99
99
Larodan Fine Chemicals AB, Solna, Sweden
Olbracht Serdary Research Laboratories, Toronto, Canada
99
99
99
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Table 2. Thermal properties of pure materials determined by DSC (10 °C/min) and the number of UNIFAC functional groups.
Crystal
type
CH3
CH2
CH
CH=CH
OH(p)
OH(s)
CH2COO
Melting
point (°C)
MAG12:0
11
44.8
Enthalpy
of fusion
(kJ mol-1)
22.4
MAG16:0
15
66.4
34.1
MAG18:0
17
74.2
39.2
MAG18:1
15
35.0
49.4
DAG12:0
β1
20
56.7
79.2
DAG16:0
β1
28
73.4
111.4
DAG18:0
β1
32
79.6
130.0
DAG18:1
β1
28
25.8
88.4
TAG16:0
41
63.3
132.4
TAG18:0
47
73.8
181.1
Component
Number of UNIFAC functional groups
...
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