Cold Soak Filtration:Palm Oil based BiodieselPalm Oil-based Biodiesel
By Haiying Tang
National Biofuels Energy LaboratoryNextEnergy/Wayne State University
Detroit MI 48202Detroit, MI 48202
Cold Flow Properties: a current pissue with biodiesel
Insolubles formation in biodiesel blends may have serious implicationsASTM Standard Test Method: Determination of contamination of biodiesel blend by cold soak laboratorybiodiesel blend by cold soak laboratory filtration
300 mL of biodiesel Soaked at 4.4°C (40°F) for 16 hours,Soaked at 4.4 C (40 F) for 16 hours,Allowed to warm to 20-22°C (68-72°F), and vacuum filtered through a single 0.7 μm glass fiber filter.The filtration time in seconds it reported.
Canola Soy Animal Fat Soy Soy-dist Palm Soy
Results: Time to FilterSampleB100
Time for Equilibration (min)
Sample Temperature before filter ( oF)
Vacuum,(Inches Hg)
Time to Filter (Second)
1A 80 70 22.5 126
1B 95 70 22.5 130
2A 80 69 22.5 96
2B 90 69 22.5 96
3A 150 71 22.5 222
3B 160 71 22.5 222
4A 75 71 22.5 830
4B 72 71 22.5 825Soy
5A 90 70 22.5 101
5B 100 72 22.5 105
6A 265 72 22.5 6900Palm6B 360 73 22.5 829
7A 90 71 22.5 105
7B 100 72 22.5 100
Cold Soak Filtration ExperimentalCold Soak Filtration Experimental
Samples: ULSD, B2, B5, B10, B20, B50, B70, and B100300 mL volume
Storage Temperature and Time4 ºC for 24 hr-15 ºC for 24 hr23 ºC for 24 hr (Control)23 C for 24 hr (Control)Allow to come to room temperature without external heating
FilterVacuum pump: ~68 kpa0.7 μm glass fiber filter
ResultsThe time to filter
Filtration system from ASTM D4625-04
The time to filterThe insoluble mass
Insoluble Formation above Cloud Point
25
30
35
ppm
) SBO-B20
Insolubles were observed above cloud point for biodiesel blends
- Storage temperature
Biodiesel-Soybean oil 0
5
10
15
20
Prec
ipita
tes
(p- Storage time- Blending levels - Feedstock
30
35
40
45
in)
23 ºC
4 ºC
Minus 15 ºC
Control 1 hr 2 hr 4 hr 6 hr 8 hr 12 hr 24 hr 72 hr 1 week 2 weeks
Storage Time
10
15
20
25
Tim
e to
filte
r (m
20
30
40
50
cipi
tate
s (p
pm) SBO-B100
0
5
0% 20% 40% 60% 80% 100%
Biodiesel Concentration 0
10
0 0.5 hr 1 hr 2 hr 4 hr 8 hr 20 hr 24 hr 72 hr 1 week 2 weeks
Storage Time
Prec
Soy-, Cottonseed-, and Poultry fat-and Poultry fatbased biodiesel and their blendsResults
Much higher solvency ff t t 4 ºCeffect at 4 ºC,
compared to the 23 ºC for SBO-based biodiesel.CSO d PF b dCSO- and PF- basedbiodiesel had lower insolubles levels than the SBO based biodiesel;the SBO-based biodiesel;The difference may be attributed to the presence of naturallypresence of naturally occurring levels of sterol glucosides in the feedstocks.
Physical Properties Of Palm oil (PO-)based biodieselPhysical Properties Of Palm oil (PO-)based biodiesel
ASTM ASTM SBO CSO PF YG PO ULSDmethod specif
ication a
SBO CSO PF YG PO ULSD
Viscosity, 40 ºC 2
D 445 1.9-6.0 4.336 4.221 4.386 4.552 4.523 2.154(mm2/s)
Acid number (mg KOH/g)
D 664 0.5 max 0.215 0.262 0.298 0.515 0.249 0.005
Free glycerin (mass D 6584 0 020 0 006 0 001 0 001 0 000Free glycerin (mass %)
D 6584 0.020 0.006 0.001 0.001 0.000 -
Total glycerin (mass %)
D 6584 0.24 0.177 0.186 0.143 0.016 -
Clo d point (ºC) D 2500 Report 3 6 7 13 16 25Cloud point (ºC) D 2500 Report 3 6 7 13 16 -25Pour point (ºC) D 97 -3 0 3 0 12 -36
Cold filter plugging D 6371 -3 3 2 -3 12 -26p gg gpoint (ºC)
3 3 2 3 12 26
Oxidative stabilityInduction Period (hr)
EN 14112 3minimum 3.52 6.57 0.67 2.25 11.1 -
FAME CompositionFAME Composition
FA (%) SBO Distilled SBO
CSO PF YG PO
C14:0 0 0 0.76 1.04 0.14 0.60C16:0 14.1 16.02 24.74 21.82 16.12 47.24C16:1 0 7 0 56 0 37 3 71 0 02 0 00C16:1 0.7 0.56 0.37 3.71 0.02 0.00C18:0 5.15 5.37 2.68 7.61 3.96 3.04C18:1 25.29 26.51 18.45 36.59 31.43 40.82C18:2 48.7 46.31 52.99 27.02 46.05 8.15C18:3 6.08 5.23 0 1.78 2.28 0.15∑SFA (%) 19 2 21 39 28 2 30 9 20 22 50 88∑SFA (%) 19.2 21.39 28.2 30.9 20.22 50.88∑UFA (%) 80.8 78.61 71.8 69.1 79.78 49.12
Cloud Point, Pour Point, and Cold Filter Plugging Point
Palm oil -based Biodiesel
20 CPPP
0
10
o C
)
PPCFPPPoly. (CP)Poly. (PP)
20
-10
empe
ratu
re (o
-30
-20
Te
-400% 20% 40% 60% 80% 100%
Biodiesel Concentration
Physical Appearance (at 23 ºC for 24 hr)
Physical Appearance (at 4 ºC for 24 hr, come back to RT)
Effect of Temperature onEffect of Temperature on Time to Filter
Palm oil-based Biodiesel
90 23 ºC
60
70
80
min
)
4 ºC
30
40
50
60
me
to fi
lter (
0
10
20
30
Tim
00% 20% 40% 60% 80% 100%
Biodiesel Concentration (%)
Effect of Temperature on Insoluble MassPalm oil-based biodiesel
120023 ºC
800
1000
(ppm
)
23 C
4 ºC
400
600
ecip
itate
s (
0
200
Pr
0% 20% 40% 60% 80% 100%Biodiesel Concentration (%)
Soybean Vs. Palm oil-based Biodiesel and its blends
SBO-based Biodiesel
20
25
30
35
s (p
pm)
SBO: 23 ºCSBO: 4 ºCSBO: -15 ºC
25
30
35
40
45
filter
(min
)
23 ºC
4 ºC
Minus 15 ºCSBO-based biodiesel
0
5
10
15
20
0% 20% 40% 60% 80% 100%
Prec
ipita
tes
0
5
10
15
20
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Tim
e to
f
Biodiesel ConcentrationBiodiesel Concentration
Palm oil-based Biodiesel
80
90 23 ºC
4 ºC
Palm oil-based biodiesel
120023 ºC
4 ºC
20
30
40
50
60
70
Tim
e to
filte
r (m
in)
200
400
600
800
1000
Pre
cipi
tate
s (p
pm)
4 ºC
0
10
0% 20% 40% 60% 80% 100%Biodiesel Concentration (%)
0
200
0% 20% 40% 60% 80% 100%Biodiesel Concentration (%)
Nature of the Insolubles FTIR
Possibility
Stetyl glycosidesStetyl glycosides
Monoglycerides, diglycerides, triglycerides of total glycerinof total glycerin
Dimers, trimers, tetramers of oxidative products
GC-FIDproducts
Solvency effect when blend with ULSD
FTIR Spectrum: Palm Oil–based Biodiesel
PO-based B100
A
Insoluble from PO-based B100
Monoolein Standard
-COO
-OH-CH2 -CH2
C-O-C
o oo e Sta da d
4000.0 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 650.0cm-1
OHSteryl Glucosides Standard
2918.281176.55
1045.01
FTIR Spectrum: Insoluble from Palm Oil-based Biodiesel
2850.86
1469.06
1391.45
720.79
3307.39
2915.83 Insoluble from PO-based B100
A
1729.43
1176.22
1046.99
2850.16
1739.061469.70
1392.08
719.64
3296.87
1392.08
Monoolein Standard
4000.0 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 650.0cm-1
GC-FID Chromatography: Palm oil-based BiodieselFAME
160
180
C16:0ISTD2
120
140
C16:0
80
100
C 18M
60
80
glycerol
ISTD1C 18Mono
C16 Mono
20
40 Diglycerides
00 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
triglycerides
GC-FID Chromatography : Insoluble from PO-B100
450
ISTD2350
400
S
C16 Mono
250
300
C18150
200
S
C18 Mono
50
100
ISTD1
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
GC-FID ChromatographyC16:0
Diglycerides
ISTD2C18 MonoStandard
glycerolISTD1
S
triglycerides
Steryl Glucoside StandardSG
C16 Mono
Insoluble from PO-B100
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
SummaryThere is different insoluble formation on palm with soy-based biodiesel in cold soak test
For PO based biodiesel the filtration time andFor PO-based biodiesel, the filtration time and insoluble mass was linear as a function of biodiesel concentrationSolvency of ULSD has a significant influence onSolvency of ULSD has a significant influence on insolubles formation of SBO-based biodeisel
Insolubles from SBO-based biodiesel are due to sterol glucosides However Insolubleto sterol glucosides. However, Insoluble formed from Palm oil based –biodiesel can be attributed to monoglycerides.
