ARTICLE pubs.acs.org/IECR
Fatty Acid Alkyl Esters as Solvents: Evaluation of the Kauri-Butanol Value. Comparison to Hydrocarbons, Dimethyl Diesters, and Other Oxygenates Gerhard Knothe* and Kevin R. Steidley National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, Peoria, Illinois 61604, United States ABSTRACT: Esters, most commonly methyl esters, of vegetable oils or animal fats or other lipid feedstocks have found increasing use as an alternative diesel fuel known as biodiesel. However, biodiesel also has good solvent properties, a feature rendered additionally attractive by its biodegradability, low toxicity, and low content of volatile organic compounds. The kauri-butanol (KB) value is a parameter used for describing the solvent strength of a liquid. In this work, the KB values of individual fatty acid alkyl esters were determined. The KB values of fatty esters depend on chain length, including the alcohol moiety, and unsaturation, a phenomenon observed similarly in hydrocarbons. The KB values of fatty acid methyl esters range from well over 100 for short-chain esters to the 40-60 range for C18 esters with a maximum being attained for methyl esters of C4-C5 acids. For the sake of comparison, the KB values of dimethyl diesters and hydrocarbons (alkanes) were also determined as well as those of some standard solvents. Compounds with eight carbons were selected to compare the influence of various functional groups on solvent strength as documented by the KB value. KB values can be determined with good accuracy by reducing the amount of KB solution from 20 to 5 g, thus using correspondingly less solvent sample.
’ INTRODUCTION The depletion of the world’s petroleum reserves as well as environmental and economic concerns have caused an everintensifying search for renewable, domestically produced, and environmentally friendly fuels. In this context, biodiesel,1,2 defined as the monoalkyl esters of vegetable oils or animal fats,3 although it can be obtained from other triacylglycerol feedstocks such as used cooking oils or, potentially, algae, plays a prominent role as an alternative to conventional petroleumderived diesel fuel (petrodiesel). Biodiesel, for which standards have been developed,3,4 is obtained by transesterifying vegetable oils or other materials largely comprised of triacylglycerols with monohydric alcohols, most commonly methanol, to give the corresponding monoalkyl esters.1,2 Other advantages of biodiesel include a positive energy balance, low or no sulfur content, no aromatics content, high flash point, inherent lubricity, reduction of most regulated exhaust emissions, miscibility with petrodiesel in all blend ratios, and compatibility with the existing fuel distribution infrastructure. Technical challenges facing biodiesel include reduction of NOx exhaust emissions, oxidative stability, and cold flow properties. The economics of biodiesel have made it often dependent on incentives in the form of subsidies, tax reductions, or other regulations to be competitive with petrodiesel. Therefore, it is of interest to investigate other potential applications where biodiesel may be technically and economically competitive, helping to secure additional markets and providing economic stability to this product. Besides overall favorable properties as transportation fuel, biodiesel has numerous other potential uses, although none of them can compete with fuel in terms of volume. These uses include heating oil,5,6 power generation,7 lubricants,8 plasticizers,9 high boiling absorbents for cleaning of gaseous industrial emissions,10 and various solvent applications. This article not subject to U.S. Copyright. Published 2011 by the American Chemical Society
Some solvent applications of biodiesel include use as a polymerization solvent11,12 and an alternative to organic solvents in liquid-liquid extractions.13 An interesting solvent-related application of vegetable oil methyl esters is the remediation of spills of petroleum in the environment such as the cleaning of contaminated shores.14-19 Low content of volatile organic compounds (VOC), high flash point, low toxicity, and biodegradability render biodiesel/vegetable oil esters additionally attractive as solvents. The general properties of methyl soyate have been compared with those of conventional solvents,20 and the physicochemical properties of methyl soyate as a solvent in liquid-liquid separations have been reported.21 Several technical application notes or brochures refer to the use of biodiesel as a solvent with kauri-butanol (KB) values being reported.22,23 A study on the KB value of biodiesel derived from various feedstocks (canola, corn, soybean, and sunflower oils) exists.24 The KB value, for whose determination the standard ASTM D1133 exists,25 measures the solvent power of hydrocarbon solvents, although KB values have also been determined for other classes of compounds with some values given in reference works.26,27 The KB value has been also stated to be primarily a measure of solvent aromaticity28 with a sequence aliphatic hydrocarbons < naphthenic hydrocarbons < aromatic hydrocarbons. Higher KB value indicates stronger solvency.25 Determination of the KB value is accomplished by “titrating” the KB solution until it attains turbidity as defined in ASTM D1133.25 When the KB value was being developed, heptane and toluene were chosen as primary standards for the sake of Received: November 16, 2010 Accepted: February 3, 2011 Revised: January 26, 2011 Published: February 28, 2011 4177
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Table 1. Kauri-Butanol Values Given in the Literature sample
KB value
reference
cyclopentane
53.4
27
cyclohexane
55-56
27
terpene solvents
>58, >500
27
pentane
26
27
hexane
29-30
27
heptane
30
27
pentanes (isopentane and n-pentane)
25-27
30
hexanes heptanes
29.3 29.5-30.4
30 30
toluene
105
27
xylene
98
27
ethylbenzene
96
27
D-limonene
68
31
turpentine
61
31
R-pinene
52
27
dimethyl ether vinyl chloride
91 60
26 26
dichloromethane
136
31
1,1,2,2-tetrachloroethylene
90
31
1,1,1-trichloroethane
124
31
1,1,2-trichlorofluoroethane
32
31
mixed amyl chlorides
71
27
o-chlorotoluene
110
27
pine oil
>500
27
reproducibility, one reason being to accommodate the varying grades of the kauri gum.29 Toluene has been assigned a KB value of 105 in ASTM D1133. The KB value of the soybean oil methyl esters in technical commercial literature appears to be in the range 56-61.22,23 An overview article on the use of methyl soyate as an alternative solvent gives its KB value as 58.20 This contrasts with a publication24 in which the KB values of methyl and ethyl esters of some vegetable oils were mostly in the range high 70s to low 80s, with ethyl esters showing lower KB values. KB values of some other solvents, mostly hydrocarbons, or other materials have been reported and span a wide range of values. They are included in Table 1, which lists KB values from various literature sources.26,27,30,31 Solubility parameters with theoretical basis have been developed, notably the Hildebrand solubility parameter and the Hansen solubility parameters (HSP).26,28,32 The Hildebrand parameter δ is defined by the square root of the cohesive energy density δ ¼ ðE=V Þ1=2
ð1Þ
where E = heat of vaporization and V = molar volume. An approximately linear relationship exists between the Hildebrand parameter and the KB number for hydrocarbons with KB > 35, which is [see ref 26 and references therein] δ=MPa1=2 ¼ 0:04KB þ 14:2
ð2Þ
A different relationship which includes a correction for molecular size applies to aliphatic hydrocarbons with KB < 35. However, the Hildebrand parameter does not always yield acceptable or useful results32 and thus HSP have been developed in which the
solubility parameter consists of several parts, namely dispersion (δD), hydrogen bonding (δH), and polarity (dipole-dipole forces; δP). The heats of vaporization of various fatty compounds have been determined by various experimental methods33-35 and calculated or predicted.36-38 As V can easily be obtained from the molecular weight and density of a compound, δ is then easily determinable. The HSP of saturated C10, C12, C14, C16, and C18 fatty acid methyl esters as well as those of methyl oleate and methyl linoleate determined by a group contribution method have been reported.39 A comprehensive compilation of KB values of oxygenated compounds is not available in the literature to the best of our knowledge. In light of this, the significance of “green” or oxygenated solvents, and since the KB values (as are other properties) of mixtures such as vegetable oil esters (biodiesel) are determined by the aggregate of the properties of the individual components, the KB values of neat esters are reported here. To further assess the effect of the methyl ester moiety, dimethyl esters are also evaluated here. A variety of C8 compounds are reported to compare the influence of different oxygenated moieties. Some common oxygenated solvents are also included.
’ EXPERIMENTAL SECTION All straight-chain esters (methyl, ethyl, n-propyl, n-butyl) were purchased from NuChek-Prep, Inc. (Elysian, MN, USA) and were of purity >99%. Hydrocarbons and dimethyl diesters were purchased from Sigma-Aldrich (St. Louis, MO) with stated purities of >98% or 99%. Random purity checks of some samples by nuclear magnetic resonance spectroscopy (NMR; Bruker (Billerica, MA, USA) Avance 500 spectrometer operating at 500 MHz for 1H NMR with CDCl3 as solvent) and/or gas chromatography-mass spectrometry (GC-MS; Agilent Technologies (Palo Alto, CA, USA) 6890 gas chromatograph coupled to an Agilent Technologies 5973 mass selective detector at 70 eV, HP-5 capillary column) confirmed the purities. Biodiesel (methyl soyate) was obtained from Ag Environmental Products, Lenexa, KS, USA, and ultralow sulfur diesel (ULSD) fuel was provided by Chevron. Standardized kauri-butanol solution conforming to the standard ASTM D1133 was obtained from Chemical Service Laboratories (Dallas, TX, USA). The A factor of this solution as given by the vendor was 104.9 (acceptable range 100-110), and the B factor was 37.0. The A factor conforms to the KB value of toluene generally given as 105,25 and the B factor is determined using a 75:25 heptane:toluene mixture. Kauri-butanol values were determined according to the standard ASTM D1133. However, instead of 20 mL of KB solution, in most cases 5 mL was used as this scale was shown to suffice. Although ASTM D1133 calls for reporting KB values to the nearest 0.5 KB value, we report KB values to the nearest 0.1. ’ RESULTS AND DISCUSSION Scale of KB Value Determination. The standard ASTM D113325 for determining the KB value calls for using 20 g of KB solution. For solvents with high KB values, this leads to significant consumption. During the course of this work it was determined that the use of 5 g KB solution suffices for determining KB values. For this purpose, the equation given for calculating 4178
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Table 4. Kauri-Butanol Values of Fatty Esters and Acidsa
Table 2. Effect of Assay Scale on Kauri-Butanol Value Determination sample
sampleb
mL used
KB value
scale of KB solution (g)
mL used
KB value
toluene
20
104.9
105.0
soybean oil (refined)
toluene toluene
10 5
53.1 26
106.2 104.1
neat fatty acid esters methyl formate
6.4
29.1
heptane:toluene 75:25
20
38.5
41.4
methyl acetate
16.5
67.8
heptane:toluene 75:25
10
19.2
41.3
methyl propionate
36.0
142.4
heptane:toluene 75:25
5
9.7
41.7
methyl butyrate
45.0
176.9
hexane
20
27.6
31.0
hexane
10
13.9
31.2
methyl valerate methyl caproate
44.8 31.6
176.1 125.6
methyl soyate
14.3
59.3
3.8
19.1
hexane
5
6.9
31.0
methyl octanoatec
122.6
121.9
heptane heptane
20 5
25.0 6.3
28.5 28.7
methyl decanoate
23.9
96.1
methyl laurate
18.9
77.0
hexadecane
20
15.6
19.5
methyl myristate
15.4
63.5
hexadecane
5
3.9
19.5
methyl oleated
12.4
52.1
methyl oleate
20
49.0
51.5
methyl linoleate
14.0
58.2
methyl oleate
5
12.4
52.1
acetone
20
75.0
76.4
ethyl oleate propyl oleate
11.6 12.0
49.0 50.5
acetone
5
18.7
76.2
butyl oleate
9.8
42.1
triolein
3.0
16.1
Table 3. Kauri-Butanol Values of Hydrocarbons sample
a
fatty acids
mL used
KB value
ULSD
6.9
31.0
hexaneb hexanec
27.6 13.9
31.0 31.2
hexane
6.9
31.0
25.0
28.5
octane
6.0
27.6
decane
5.6
26.0
dodecane
4.9
23.3
tetradecane
4.2
20.7
hexadecaneb 1-octene
15.6 7.9
19.5 34.8
1-tetradecene
5.2
24.5
1-octadecene
4.1
20.3
cyclopentane
13.0
54.4
cyclohexane
12.5
52.4
methylcyclohexane
11.3
47.8
xylenes (mixture)
25.6
96.9
p-xylene
24.4
98.0
heptaneb
>682
86.4
335.4
1% oleic acid in methyl oleate 1% monolein in methyl oleate
12.6 12.6
52.8 52.8
1:1 methyl oleate:methyl linoleate
13.3
55.5
a
For 5 g scale of KB solution. b As boiling points are of interest for solvent applications, some boiling points are as follows:40 methyl formate, 31.7 °C; methyl acetate, 56.9 °C; methyl propionate, 79.8 °C; methyl butyrate, 102.8 °C; methyl valerate, 127.4 °C; methyl caproate, 149.5 °C; methyl octanoate, 192.9 °C; methyl decanoate, 224 °C; methyl laurate, 267 °C; methyl palmitate, 417 °C; methyl stearate, 443 °C; methyl oleate, 218.5 °C (at 20 mmHg). c For 20 mL scale. d Value also in Table 2.
For 5 g scale of KB solution. b For 20 mL scale (see also Table 1). c For 10 mL scale.
the KB value in ASTM D113325 ð3Þ
in which A = toluene (mL) required to titrate 20 g of KB solution, B = heptane-toluene blend (mL) required to titrate 20 g of KB solution, and C = solvent (mL) under test required to titrate 20 g of KB solution (Section 8) is modified to KB ¼ ½65ð4C - BÞ=ðA - BÞ þ 40
>177
oleic acid mixtures
a
KB ¼ ½65ðC - BÞ=ðA - BÞ þ 40
octanoic acid
ð4Þ
when only 5 g of KB solution is used (with experimental A and B values relative to 20 g of KB solution) but still 20 mL of toluene and heptane-toluene blend is used to determine A and B. If only
5 g KB solutions are used to determine A and B and 5 g KB solutions are used for determining the KB value, then eq 3 can be used unmodified. Table 2 contains KB values of some samples determined with 5 and 20 g KB solutions. The values are nearly identical. Therefore, additional determinations of the KB value were carried out with 5 g KB solution. Determining the KB values of many components of biodiesel or other materials is affected by the specification that it be determined between 20 and 30 °C, a temperature at which some common biodiesel components, for example methyl palmitate and methyl stearate, are solids. Higher temperatures can be problematic as the volatility of many solvents influences the KB determination (boiling points of some compounds studied here are contained as footnotes in Tables 4 and 5). Hydrocarbons. For the sake of verification of prior literature and comparison to the oxygenated compounds studied here, the KB values of several hydrocarbons were determined (Table 3). Regarding the influence of compound structure, the results confirm that KB values decrease with increasing chain length. Cyclic hydrocarbons such as cyclopentane and cyclohexane exhibit higher KB values than straight-chain alkanes as noted in 4179
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Table 5. Kauri-Butanol Values of Dimethyl Diestersa sampleb
mL used
KB value
dimethyl malonate (C3)
3.8
19.1
dimethyl succinate (C4)
7.1
31.8
dimethyl glutarate (C5)
10.8
45.9
dimethyl adipate (C6)
14.8
61.3
dimethyl pimelate (C7)
20.2
81.9
dimethyl suberate (C8)
30.6
106.8
dimethyl azelate (C9)
31
123.3
a
For 5 g scale of KB solution. b Boiling points of the compounds are as follows:40 dimethyl malonate, 181.4 °C; dimethyl succinate, 196.4 °C; dimethyl glutarate, 214 °C; dimethyl adipate, 115 °C (at 13 mmHg); dimethyl pimelate, 120 °C (at 10 mmHg); dimethyl suberate, 268 °C; dimethyl azelate 156 °C (at 20 mmHg).
Figure 1. Kauri-butanol values of saturated methyl esters.
prior literature.31 Aromatic hydrocarbons possess even higher KB values than the corresponding alicyclic compounds, as also noted previously.31 Corresponding to this observation, substitution of CH3 for H in the ring compounds leads to a decrease of the KB value (methylcyclohexane vs cyclohexane, xylene vs toluene). A double bond in a straight-chain hydrocarbon slightly increases the KB value (1-octene vs octane and 1-tetradecene vs tetradecane; also Table 3). The KB value of a sample of ULSD fuel was determined to be slightly higher than that of most alkanes, likely resulting from ULSD being a mixture of hydrocarbons containing other classes of compounds such as cyclic compounds besides straight-chain alkanes. Methyl Esters: Influence of Chain Length and Functional Groups. The KB values of fatty compounds are listed in Table 4. Figure 1 visualizes the values obtained for the methyl esters of saturated fatty compounds. Methyl soyate and methyl oleate are in the range 55-60, coinciding with other reports21 but in contrast to a publication on the KB values of biodiesel derived from a variety of sources in which the KB values were reported to be considerably higher, namely high 70s to low 80s for methyl esters of canola, corn, soybean, and sunflower oils.24 Other sources also report a KB value of methyl soyate (biodiesel) in the range 56-58 as discussed in the Introduction. Vegetable oils
themselves have low KB values as shown by the values for refined soybean oil and triolein (also Table 4). The KB value of neat methyl esters increases with decreasing chain length, reaching a maximum at C4-C5 length of the acid chain, and then decreasing again at even shorter chain lengths (Table 4 and Figure 1). That decreasing chain length (up to a certain chain length) leads to higher KB values was reported previously for a mixture of vegetable oil methyl esters.24 Similarly, increasing the size of the alcohol moiety in fatty esters leads to a decrease of the KB value (methyl oleate vs ethyl oleate vs propyl oleate vs butyl oleate, Table 4), confirming the previous observation made for vegetable oil methyl, ethyl, propyl, and butyl esters.24 Higher KB values were observed for refined oils.24 Increasing unsaturation apparently leads to higher KB values as shown for methyl oleate vs methyl linoleate, an observation also reported previously for mixtures of vegetable oil methyl esters.24 On the other hand, triacylglycerols are the oxygenated organic compounds with the lowest KB values identified in the course of this work and, to the best of our knowledge, in other literature so far as shown by the KB values for soybean oil and triolein (Table 4). However, free fatty acids exhibit KB values significantly greater than the corresponding methyl esters (Table 4). Adding 1% oleic acid to methyl oleate, however, does not significantly affect the KB value (Table 4). Similarly, 1% of monoolein added to methyl oleate also did not significantly affect the KB value. A 1:1 mixture of methyl oleate:methyl linoleate showed a value approximately corresponding to this mixing ratio, confirming that the KB value of vegetable oil methyl esters likely is proportional to the fatty acid profile. Dimethyl Diesters. The KB values of dimethyl diesters (Table 5) contrast those of hydrocarbons. For the dimethyl diesters with three to nine carbon atoms in the chain in which both ends of the chain are terminated by ester groups, the KB value increases continuously with increasing chain length. An investigation into greater chain lengths is largely precluded by the melting points of the dimethyl diesters exceeding the prescribed temperature range for determination of the KB value. Other Oxygenated Compounds. To further investigate the effect of oxygenated moieties, some C8 compounds were selected. The presence of oxygen usually imparts higher KB values (Table 6). Of the compounds in Table 6, dibutyl ether has the lowest KB value while the compounds with carbonyl moieties have considerably higher values. In comparison to the two C8 ketones, 2- and 3-octanone, studied here, acetone has a considerably lower KB value. The effect of increasing chain length on the KB value is most pronounced for alcohols (Table 6). Indeed, butanol is used for the KB solution because of the infinite solubility of the kauri resin in butanol, but methanol possesses a KB value only in the range of alkanes. It is of interest to compare the KB values of some common organic solvents noted for their high solvency (also Table 6). Both tetrahydrofuran (THF) and dimethyl sulfoxide (DMSO) have high KB values, with the KB value of THF not being finally determinable due to the high dilution when large amounts of sample solvent are used. This effect is observed in a similar fashion for other samples, for example, 1- and 2-propanol. In comparison to THF, cyclopentane has a KB value of approximately 54, showing the effect of replacing one CH2 moiety with oxygen in increasing solvent power. The solvency-enhancing effect of oxygen may be more pronounced for cyclic compounds as, for example, the methyl esters studied in comparison exhibit a much lower increase in KB value versus straight-chain 4180
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Table 6. Kauri-Butanol Values of Other Oxygenated Organic Compoundsa sample
mL used
KB value
alcohols methanol ethanol
7.5 20.8
33.3 84.2
1-propanol
>150
>580
2-propanol
>150
>580
compounds being largely responsible for greater KB values of oxygenated compounds versus straight-chain hydrocarbons. The differences are even greater for oxygenated cyclic compounds versus cyclic hydrocarbons.
’ AUTHOR INFORMATION Corresponding Author
*Tel.: (309) 681-6112. Fax: (309) 681-6524. E-mail: gerhard.
[email protected].
solvents acetone
18.7
DMSOb
120
THF
>150
water C8 compounds
0.5
76.2 464.1 >579 6.5
2-octanone
160
617.2
3-octanone
>87.2
>338.5
octanal
>200
dibutyl ether
14.9
>770.4 61.6
other methyl benzoate a
80
’ DISCLOSURE Product names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.
310.9
b
For 5 g scale of KB solution. DMSO determination is difficult. KB value is therefore subject to change upon further tests.
hydrocarbons. This observation is further confirmed by a comparison of the KB values of dibutyl ether versus those of hydrocarbons of comparable chain length (octane, decane; Tables 3 and 6). However, it may be noted that if the oxygen is bound in the form of a carbonyl to a hydrocarbon chain (see values for C8 compounds in Table 6), a greater increase in KB values occurs. Relation to Solubility Parameters. The KB value is a straightforward assessment of solubility related to a specific material, the kauri resin. As, however, countless other materials are affected by the nature of a solvent, solubility parameters, especially the HSP, take more aspects into account. It is worthwhile to briefly consider the KB value in relation to solubility parameters. The HSP, δD (16.45-16.58), but especially δP (1.45-2.4) and δH (4.61-5.85), of fatty compounds decrease with increasing chain length39 in the C10-C18 range. The HSPs are higher for methyl linoleate than for methyl oleate.39 These observations generally correspond to those made here for KB values. However, the high KB values for free fatty acids do not correspond with smaller differences in HSP for free fatty acids (17, 2.8, and 6.2 for oleic acid; 15.1, 3.3, and 8.2 for octanoic acid) given in the literature.32
’ SUMMARY AND CONCLUSIONS While the present results underscore the suitability of fatty acid alkyl esters for solvent applications, they also imply that saturated methyl esters with three to eight carbon atoms in the chain may be most suitable for such applications. Investigating whether this would hold for practical tests and applications such as cleaning contaminated shores or using as solvent in paints is, however, beyond the scope of this work. Solubility parameters of such compounds are likely slightly greater than those reported previously for longer-chain compounds. The KB values of oxygenated compounds show a strong dependence on structure, with carbonyl oxygen in straight-chain
’ REFERENCES (1) Knothe, G., Krahl, J., Van Gerpen, J., Eds.; The Biodiesel Handbook; AOCS Press: Champaign, IL, USA, 2005. (2) Mittelbach, M; Remschmidt, C. Biodiesel—The Comprehensive Handbook. M. Mittelbach: Graz, Austria, 2004. (3) American Society for Testing and Materials (ASTM). D6751 Standard Specification for Biodiesel Fuel (B100) Blend Stock for Distillate Fuels; ASTM: West Conshohocken, PA, USA. (4) European Committee for Standardization (CEN). EN 14214 Automotive Fuels—Fatty Acid Methyl Esters (FAME) for Diesel Engines— Requirements and Test Methods; CEN: Brussels, Belgium. (5) Staat, F.; Vallet, E. Vegetable Oil Methyl Ester as a Diesel Substitute. Chem. Ind. (London) 1994, 863–865. (6) Mushrush, G.; Beal, E. J.; Spencer, G.; Wynne, J. H.; Lloyd, C. L.; Hughes, J. M.; Walls, C. L.; Hardy, D. R. An Environmentally Benign Soybean Derived Fuel as a Blending Stock or Replacement for Home Heating Oil. J. Environ. Sci. Health 2001, A36, 613–622. (7) C-etinkaya, M.; Karaosmanoglu, F. A New Application Area for Used Cooking Oil Originated Biodiesel: Generators. Energy Fuels 2005, 19 (2), 645–652. (8) Wichmann, H.; Bahadir, M. Bio-based Ester Oils for Use as Lubricants in Metal Working. Clean 2007, 35 (1), 49–51. (9) Wehlmann, J. Use of Esterified Rapeseed Oil as Plasticizer in Plastics Processing. Fett/Lipid 1999, 101, 249–256. (10) Bay, K.; Wanko, H.; Ulrich, J. Biodiesel—High-Boiling Absorbent for Gas Purification (Biodiesel Hoch siedendes Absorbens f€ur die Gasreinigung). Chem. Ing. Tech. 2004, 76, 328–333. (11) Salehpour, S.; Dube, M. A. Biodiesel: A Green Polymerization Solvent. Green Chem. 2008, 10 (3), 321–326. (12) Salehpour, S.; Dube, M. A.; Murphy, M. Solution Polymerization of Styrene Using Biodiesel as a Solvent: Effect of Biodiesel Feedstock. Can. J. Chem. Eng. 2009, 87 (1), 129–135. (13) Spear, S. K.; Griffin, S. T.; Granger, K. S.; Huddleston, J. G.; Rogers, R. D. Renewable Plant-Based Soybean Oil Methyl Esters as Alternatives to Organic Solvents. Green Chem. 2007, 9 (9), 1008– 1015. (14) Miller, N. J.; Mudge, S. M. The Effect of Biodiesel on the Rate of Removal and Weathering Characteristics of Crude Oil Within Artificial Sand Columns. Spill Sci. Technol. Bull. 1997, 4, 17–33. (15) Mudge, S. M.; Pereira, G. Stimulating the Biodegradation of Crude Oil with Biodiesel Preliminary Results. Spill Sci. Technol. Bull. 1999, 5, 353–355. (16) Obbard, J. P.; Ng, K. L.; Xu, R. Bioremediation of Petroleum Contaminated Beach Sediments: Use of Crude Palm Oil and Fatty Acids to Enhance Indigenous Biodegradation. Water, Air Soil Pollut. 2004, 157 (1-4), 149–161. 4181
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Industrial & Engineering Chemistry Research (17) Pereira, M. G.; Mudge, S. M. Cleaning Oiled Shores: Laboratory Experiments Testing the Potential Use of Vegetable Oil Biodiesels. Chemosphere 2004, 54, 297–304. lvarez, P.; Vila, J.; Garrido-Fernandez, J. M.; Gri(18) Fernandez-A foll, M.; Lema, J. M. Trials of Bioremediation on a Beach Affected by the Heavy Oil Spill of the Prestige. J. Hazard. Mater. 2006, 137, 1523–1531. (19) DeMello, J. A.; Carmichael, C. A.; Peacock, E. E.; Nelson, R. K.; Arey, J. S.; Reddy, C. M. Biodegradation and Environmental Behavior of Biodiesel Mixtures in the Sea: An Initial Study. Mar. Pollut. Bull. 2007, 54 (7), 894–904. (20) Wildes, S. Methyl Soyate: A New Green Solvent. Chem. Health Saf. 2002, 9, 24–26. (21) Srinivas, K.; Potts, T. M.; King, J. W. Characterization of solvent properties of methyl soyate by inverse gas chromatography and solubility parameters. Green Chem. 2009, 10, 1581–1588. (22) http://www.soygold.com. (23) http://www.soynewuses.org/downloads/Tech_Solvents.pdf. (24) Hu, J.; Du, Z.; Tang, Z.; Min, E. Study on the Solvent Power of a New Green Solvent: Biodiesel. Ind. Eng. Chem. Res. 2004, 43, 7928– 7931. (25) American Society for Testing and Materials (ASTM). D113309 Standard Test Method for Kauri-Butanol Value of Hydrocarbon Solvents; ASTM: West Conshohocken, PA, USA. (26) Barton, A. F. M. Handbook of Solubility Parameters and Other Cohesion Parameters, 2nd ed.; CRC Press: Boca Raton, FL, USA, 1991; pp 286-293. (27) Flick, E. W. Industrial Solvents Handbook, 5th ed.; William Andrew Publishing: Norwich, NY, USA, 1999. As Handbook of Solvents, 5th ed.; Noyes Data Corp.: Westwood, NJ, USA , Pentagon Pres: New Delhi, India, and Jaico Publishing House: Mumbai, India, 2001. (28) Senichev, V. Yu.; Tereshatov, V. V. General Principles Governing Dissolution of Materials in Solvents. In Handbook of Solvents; Wypych, G., Ed.; ChemTec Publishing: Toronto, Canada, and William Andrew Publishing: New York, 2002; pp 101-124. (29) Beard, L. C.; Shipp, V. L.; Spelshouse, W. E. Standardization of Kauri Butanol Test for Paint and Lacquer Thinners. Ind. Eng. Chem., Anal. Ed. 1933, 5, 307–9. (30) http://solvents.conocophillips.com/EN/products/documents/ ProductTypicals62004.pdf. (31) http://ezychem.com/2172#0. (32) Hansen, C. M. Hansen Solubility Parameters. A User’s Handbook. 2nd ed.; CRC Press: Boca Raton, FL, USA, 2007. (33) van Genderen, A. C. G.; van Miltenburg, J. C.; Blok, J. G.; van Bommel, M. J.; van Ekeren, P. J.; van den Berg, G. J. K.; Oonk, H. A. J. Liquid-Vapour Equilibria of the Methyl Esters of Alkanoic Acids: Vapour Pressures as a Function of Temperature and Standard Thermodynamic Function Changes. Fluid Phase Equilib. 2002, 202, 109–120. (34) Chickos, J. S.; Zaho, H.; Nichols, G. The Vaporization Enthalpies and Vapor Pressures of Fatty Acid Methyl Esters C18, C21 to C23, and C25 to C29 by Correlation-Gas Chromatography. Thermochim. Acta 2004, 424, 111–121. (35) Lipkind, D.; Kapustin, Y.; Umnahanant, P.; Chickos, J. S. The Vaporization Enthalpies and Vapor Pressures of a Series of Unsaturated Fatty Acid Methyl Esters by Correlation Gas Chromatography. Thermochim. Acta 2007, 456, 94–101. (36) Castellon-Elizondo, E.; Lutz, G.; Mata-Segreda, J. F. The SoftSolid Model for Liquids. Application to Biodiesel and Other Materials of Technological Interest. J. Phys. Org. Chem. 2006, 19, 744–747. (37) Mulero, A.; Cachadi~na, I.; Parra, M. I. Comparison of Corresponding-States-Based Correlations for the Prediction of the Vaporization Enthalpy of Fluids. Ind. Eng. Chem. Res. 2008, 47, 7903–7916. (38) Ceriani, R.; Gani, R.; Meirelles, A. J. A. Prediction of Heat Capacities and Heats of Vaporization of Organic Liquids by Group Contribution Methods. Fluid Phase Equilib. 2009, 283, 49–55. (39) Medina-Gonzalez, Y.; de Caro, P.; Thiebaud-Roux, S.; LacazeDufaure, C. Fatty Acid Methyl Esters as Biosolvents of Epoxy Resins: A Physicochemical Study. J. Solution Chem. 2007, 36, 437–446.
ARTICLE
(40) Handbook of Chemistry and Physics, 88th ed.; Lide, D. R., Ed.-inChief; CRC Press: Boca Raton, FL, USA, 2007-2008.
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