EFFECT OF THERMAL DEGRADATION ON
PALM FATTY ESTER (PFAE) OIL MIXED
WITH MINERAL (MO) OIL
BY:
Mohd Izzat Bin Abd Ghani
Supervised by: Assoc. Prof. Dr. Hidayat Bin Zainuddin
Panel 1 : Dr Zawani Bte Saharudin
No Tel : 01137758434
Panel 2 ; Dr. Farhan bin Hanafi
Email:
mhdizzat@yahoo.com
This presentation will discuss :
INTRODUCTION
LITERATURE REVIEW
PROBLEM STATEMENT
OBJECTIVES
SCOPES
RESEARCH METHODOLOGY
RESULT AND DISCUSSION
CONCLUSION
Introduction
■ A transformer is the backbone of energy distribution throughout the nation
■ Transmit one voltage level to another
■ Average life of 30-50 years
■ Highly expensive
3
INTRODUCTION
Generally, mineral-based insulating oil is used in transformer due to
excellent properties namely as adequate dielectric strength, low
viscosity, good operating in cold-climate temperature, cheaper and
readily available




Non-renewable resource
Non-biodegradable
Corrosive
Flammable
Insulating liquid serves three main functions [1]:
1) Serves as an excellent heat transfer medium
2) To insulate electrically, also in combination with solid materials
3) To act as transformer health diagnostic agent
LITERATURE REVIEW
NEI oil slowing
degradation rates
Paraffinic low
viscosity and
thermal
transferability
Naphthenic
hampered by
inflammability
1890s
The use of first petroleumbased MO oil. Two type MO
oil were introduced
Paraffinic and Naphthenic.
Paraffinic produced
unsoluble sludge which
reduced viscosity and
thermal transferability.
Naphthenic greater
viscosity but hampered by
inflammability [2]
2002
Mcshane et al. Study
the aging rate of kraft
paper in NEI oil it was
found the kraft paper
in NEI having Slower
degradation rates
compared to MO oil
[4]
1990s
The beginning
research for MO
oil alternative.
Introduction of
Natural ester
(NEI) (i.e Canola,
Corn ,Cottonseed
) oil to overcome
the shortcoming
of MO oil [3]
NEI oil has better
breakdown
voltage, flash
point but low
oxidation stability
2008
Takaaki Kanoh et al.
Developed vegetable
based insulating oil,
Palm Fatty Acid Ester
(PFAE)
has a higher dielectric
breakdown voltage,
higher flash
point, and less viscosity
compared to MO oil
2006
Mcshane et. al.
Highlighted the
major
disadvantages of
NEI oil is
susceptibility to
oxidation and
higher pour point
[5]
77 %
biodegradable in
28 days with
outstanding
oxidation
stability
2016
S.N.Norhan et al
Conducted research
2012
on dielectric
Kano et al study the
strength of blended
Palm Fatty Acid Ester oil by mixing PFAE
(PFAE). It was found
oil with MO oil at
that PFAE oil having
ratio 20/80. It was
outstanding oxidation found that the
stability and 77 %
dielectric strength of
biodegradable in just the blended oil is
28 days compared to comparable to NEI
MO
oil which is higher
than MO oil.
2011
N. Azis et al
reviewed on NEI oil.
Oxidation is one of
the ageing
mechanism may
weakening the
glycosidic bond and
accelerates ageing
process
2014
Takaaki Kanoh et al
Study insulation
paper ageing in
PFAE oil. It was
discovered that the
water in paper
insulation is more
readily migrates into
insulating oil
Dielectric
strength
improved in MOPFAE oil,
moisture readily
migrates into
PFAE oil
PROBLEM STATEMENTS
1
2
3
Environmental issues becomes more concern. Few issues
concerning with mineral oil such as it has poor biodegradability and
could contaminate the environment if a spillage occurs.
Recently blended oil consist of MO oil and PFAE oil (MO-PFAE oil) has
been introduced. None of previous research study the performance of
the blended oil under thermal degradation .
Lack of study related on the effect of thermal degradation on the
moisture, total acid number (TAN) and tensile strength in the
blended insulating oil.
OBJECTIVES
1
2
To evaluate the ageing effect under thermal degradation on
the moisture content, acidity and tensile strength
•To investigate the correlation between tensile strength
with moisture content and acidity.
SCOPES
1
2
3
The ratio of PFAE to MO oil is at 20/80,
The accelerated aging process is only affected by thermal
aging at 130 °C, 150 °C and 170 °C in the present of
metal catalyst and kraft paper.
The aging hours is only 300 hours.
METHODOLOGY
FIRST STAGE :PREPARATION & TEST INSULATING OIL
MO oil / PFAE oil
1.Filtering
Filtering process
Moisture removal
Check
1.Moisture
2. TAN
2.Moisture removal
Measurement moisture content ASTM D1533
MO oil / PFAE oil
Filtering process
Moisture removal
Check
1.Moisture
2. TAN
.
Blending/mixing oil
Measurement of Total acid number (TAN)
ASTM D974
MO oil / PFAE oil
Filtering process
Sample oil
Moisture removal
No
Check
1.Moisture
2. TAN
Yes
Blending/mixing oil
Blending 20% PFAE oil + 80% MO oil
MO oil / PFAE oil
1
2
Oil samples were prepared in a 500 mL beaker
with ratio of 80% MO and 20% PFAE.
Filtering process
Moisture removal
The mixing process was performed using a hot
plate magnetic stirrer at the temperature and
speed of 90°C and 550 rpm respectively for an
hour.
No
Check
1.Moisture
2. TAN
Blending/mixing oil
3
Then, the oils sample is left in a room
temperature for 24 hours.
Check
1.Moisture
2. TAN
PREPARATION & TEST PAPER INSULATION (KRAFT
PAPER).
1
2
Kraft paper is cut into strips into 15 mm x 250 mm size
Dry the kraft paper in ventilated oven 105 °C ± 5
ISO 1924-2
ASTM D 2413 – 99 / BS
EN 60641
Accelerated Thermal Aging setting
• Settings used for the accelerated
thermal ageing tests:
• Type of oven: Vacuum oven
• Temperature setting: 130°C, 150°C,
170 °C
• Duration of ageing: 300 hours
• Volume of oil sample: 1000 ml
• Ratio of paper/pressboard to oil: 2:10
• Metal catalyst: Copper, iron, zinc,
aluminium
RESULT AND DISCUSSION
PFAE , MO-PFAE and
MO oil increased by
548.17%, 343.35% and
11.85% respectively
MO and MO-PFAE
oil further
decreased by
70.14% ,28.5%,
MO-PFAE
higher than
MO, PFAE oil
15.67 %,and
6.16%
respectively
PFAE , MO and MO-PFAE
oil further decreased by
26%, 41.2% and 45.46%
No linear
correlation
was found
Tensile strength of the
MO-PFAE oil impoved by
15.67 % compared to MO
oil despite the moisture
has increased by 142.17%
after blended.
Moderate & high correlation
was found between Tensile
strength and TAN but unable
to verify the type of acids
degrading the insulation paper.
CONCLUSION
Throughout this study the moisture content, acidity and tensile strength has been conducted according to test method
ASTM D 1533, D974 and ISO 1924-2 it was found that;
1.Blended oil (MO-PFAE) does increase the water saturation limits compared to pure MO but moisture content from
kraft paper is not readily migrates into MO-PFAE oil compared to PFAE oil and MO oil.
2.The rates acidity increase in MO-PFAE exhibits similar to PFAE oil which increase faster as the aging temperature rises.
3.-Tensile strength of MO-PFAE does improved by 15.67 % despite huge increase in moisture content.
-Significantly slowing the decreasing rate of of tensile strength at 170 C
4.No correlation was found between tensile strength and moisture content.
5.The tensile strength and acidity was found the be highly correlated but further studies needed
to verify the types of acid which degrades the insulation paper.
THANK YOU
REFERENCE
[1] CIGRE Working Group A2.37, Transformer Reliability Survey, (2015) 1–122.
[2] S.H. Choi, C.S. Huh, The Lightning Impulse Properties and Breakdown Voltage of Natural Ester Fluids Near the Pour Point, J. Electr. Eng. Technol. 8 (2013) 524–529. doi:10.5370/JEET.2013.8.3.524
[3] C. P. McShane, G. Gauger, and J. Luksich, “Fire Resistant Natural Ester Dielectric Fluid and Novel Insulation System for Its Use”, IEEE/PES Transmission & Distribution Conf., 1999, New Orleans, USA
[4] C. P. McShane, K. J. Rapp, J. L. Corkran, G. A. Gauger, and J. Luksich, “Aging of kraft paper in natural ester dielectric fluid,” IEEE Int. Conf. Conduct. Break. Dielectr. Liq. ICDL, no. March, pp. 173–177, 2002.
[5] C. P. McShane, K. J. Rapp, J. L. Corkran, G. A. Gauger, and J. Luksich, “Aging of kraft paper in natural ester dielectric fluid,” IEEE Int. Conf. Conduct. Break. Dielectr. Liq. ICDL, no. March, pp. 173–177, 2002.
[6] C. Patrick McShane, J. Corkran, K. Rapp, and J. Luksich, “Natural ester dielectric fluid development,” Proc. IEEE Power Eng. Soc. Transm. Distrib. Conf., pp. 18–22, 2006.
[7] T. Kanoh et al., “Analyses of electro-chemical characteristics of palm fatty acid esters as insulating oil,”
2008 IEEE Int. Conf. Dielectr. Liq. ICDL 2008, no. 1, pp. 2–5, 2008
.
[8] N. Azis and Z. D. Wang, “ACID GENERATION STUDY OF NATURAL ESTER,” pp. 1–6, 2011.
[9] T. Kano, T. Suzuki, R. Oba, A. Kanetani, and H. Koide, “Study on the oxidative stability of palm fatty acid ester (PFAE) as an insulating oil for transformers,” Conf. Rec. IEEE Int. Symp. Electr. Insul., pp. 22–25, 2012..
[10] T. Suzuki, T. Kano, A. Kanetani, S. Hatada, and F. Kurihara, “Comparative study of the insulation paper aging in palm fatty acid ester (PFAE) and mineral oil,” Proc. 2014 IEEE 18th Int. Conf. Dielectr. Liq. ICDL 2014, p
7–10, 2014..
[11] S. N. Norhan, H. Zainuddin, S. A. Ghani, and I. S. Chairul, “Dielectric breakdown performance of mineral oil and palm fatty acid ester oil mixture blended using ultrasonic homogenizer,”
PECON 2016 - 2016 IEEE 6th Int. Conf. Power Energy, Conf. Proceeding, pp. 322–326, 2017.