Vol.4, No.9B, 85-88 (2013) Agricultural S ciences
http://dx.doi.org/10.4236/as.2013.49B015
Base-transesterification process for biodiesel fuel
production from spent frying oils
B. K . Abdalla1*, F. O. A. Oshaik2
1Karary University , Omdurman, Sudan; *Corresponding Author: [e-mail]
2Industrial Research and Consultancy Centre, Khartoum North, Sudan
Received August 2013
ABSTRACT
The concept of converting recycled oils to clean
biodiesel aims towards reducing the amount of
waste oils to be treated and lowering the cost of
biodiesel production. Samples of waste oils
were prepared from Spent Frying oil collected
from local hotels and restaurants in Khartoum,
Sudan. Selected methods to achieve maximum
yield of biodiesel using the waste feedstock were
presented and compared. Some properties of
the feedstock, such as free fatty acid content and
moisture content, were measured and eval uated.
Biodiesel yield recovery obtained, from Base-
transesterification proces s about 92%. Produced
Biodiesel specifications were also analyzed and
discussed in Base-transesterification process.
Kinematic viscosity of biodiesel was found to be
5.51 mm2·s−1 at 40˚C, the flash point was 174.2˚C
and Cetane No of 48.19. Biodiesel was characte-
rized by its physical and fuel properties ac-
cording to ASTM and DI N V 51606 s tandards.
Keywords: Base-Transesterification; Biodiesel;
Spent-Frying-Oil; Fuel
1. INTRODUCTION
The energy crises of 1979, which caused some alterna-
tive energy sources, were investigated; so Biodiesel was
introduced [1-3]. The use of vegetable oils is Soybean
oils and Sunflower oil as feed. Spent vegetable oil from
recycled fried oil was investigated to reduce pollution of
the environment [4-12]. In Sudan major vegetable oils
are produced from Peanut, Sunflower, Sesame and Cot-
tonseed oils. The consumption of Vegetable oils in Sudan
is about 260 ,000 t/y. The spent vegetable oils from frying
at Homes, Restaurants and Hotels are estimated to be
42,000 t/y.
Transesterification of a vegetable oil was conducted as
early as 1853, by sc ie ntist E. Duffy and J. Patrick. Rudolf
Diesel’s prime model ran on its own power for the first
time in Augsburg, Germany on August 10, 1893, has
been declared International Biodiesel Day. Diesel later
demonstrated his engine and received the “Grand Prix”
(highest prize) at the world fair in Paris, France in 1900.
This engine stood as an example of Diesel’s vision be-
cause it was powered by peanut oil. He believed that the
utilization of biomass fuel was the real future of his en-
gine. In 1912 speech, Rudolf Diesel said: the use of veg-
etable oil as engine fuels may seem insignificant today,
but such oils may become, in the course of time, as im-
portant as petroleum and the coal-tar products of the
present time. During the 1920 the diesel engine manu-
factures altered their engines to utilize the lo wer viscos i-
ty of the fossil fuel (petro diesel) rather than vegetable
oil, a biomass fuel. The petroleum industries were able to
make inroads in fuel market because their fuel was much
cheaper to produce than the biomass alternatives. The
result was, for many years, a near elimination of the
biomass fuel production infrastructure. Only recently there
have environmental impact concerns and a decreasing
cost differential made biomass fuels such as biodiesel, a
growing alternative.
The International Energy Outlook (IEO) 2007 refer-
ence case projects increased world consumption of mar-
keted energy from all sources over the 2004 to 2030 pe-
riod. Worldwide fuel liquids consumption, increase from
83 million barrels per day in 2004 to 118 million barrels
per day in 2030 [11-15]. Liquids fuels remain the most
important fuels for transportation. Transportation ac-
counts for 68% of the total projected increase in liquids
use between 2004 and 2030, the industrial accounts for
27% in world liquids demand. The objective of this work
is the management of spent frying oils.
2. MATERIALS AND METHODS
2.1. Material
2.1.1. Sampling
Spent frying oil which was produced after deep frying
of food was collected and used as feed stocks of biodie-

B. K. Abdalla, F. O. A. Oshaik / Agricultural Sciences 4 (2013) 85-88
86
sel production. Spent frying oil was classified to sample
(A).
2.1.2. Chemicals
• Alcohol (Methanol, Ethanol).
• Base catalyst (NaOH, KOH, K2CO3, etc).
• Acid catalyst (H2SO4).
• Drying salt (Na2SO4).
2.1.3. Equipments
• Stirrer hot plate,
• Oven,
• Filter,
• Condenser,
• Thermometer,
Gas chromatography mass spectrometer.
2.1.4. Equipments
• Stirrer hot plate,
• Oven,
• Filter,
• Condenser,
• Thermometer,
Gas chromatography mass spectrometer.
2.2. Methods of Samples Preparations
The sample was prepared by sedimentation the waste
oils, passed through thieve about (90 micron) to filtrate
the sample and the raw materials were analyzed to de-
termine the moisture content, density and free fatty acid
content.
Process of Biodiesel Fuel Production by
Base-Transesterification of Sample (A)
100 g of the sample (A) were weighted and placed on
a hot plate, in around bottom flask equipped with a
magnetic stirrer and a thermometer. The oil was stirred
and heated at (60˚C to 65˚C), freshly sodium meth oxide
solution was prepared by mixing (25 gm methanol with
0.5% of the sample NaOH) and added into the flask, the
mixture was heated and stirred for 1 hr, After this time,
the flask was removed from the hot-plate and the prod-
ucts of reaction were allowed to settle for several hours
to produce two distinct liquid phases. The top phase
(crude ester) was separated from bottom phase (glycerol)
by decantation, then washed for 3 times by a warm water
heated in 80˚C to remove the excess catalyst until the
wash water become clear. The ester phase was finally
dried at 100˚C for 30 minutes. The final product; biodie-
sel was obtained as a clear, light yellow liquid. F ig ure 1
shows the schematic block diagram of the biodiesel pro-
duction process.
• Theoretical calculation
Figure 1. Block diagram of biodiesel produced by base-tran-
sesterification process of sample (A).
100 gm waste oil + 25 gm methanol
0.5% NaOH
60C65 C−
→

100 gm biodiesel + 25 gm glycerol
• Mass balance:
100 gm waste oil + 25 gm methanol
0.5% NaOH
60C65 C−
→

92.2 gm biodiesel + 15.3 gm glycerol
Yield percentage of biodiesel recovery is about = 92.2%
From equation:
Input = output + losses
The losses = 100 – 92.2 = 7.8
7.8% the yield losses due to triglyceride saponification
and methyl ester dissolution in the glycerol phase.
Yield percentage of by product glycerol recovery is
about = 15.3% with efficiency about 61.2%.
2.3. Qualitative Analysis of Biodiesel Using Gas
Chromatograph-Mass
The GC serves to separate mixtures into component.
The separation is based upon the retention of the analyses
between two phases (the stationary liquid analyses be-
tween two phases (the stationary liquid phase and the
mobile gas phase). The interface directs the effluent of
the GC Colum into the mass spectrometer.
The mass spectrometer consists of three components:
1) Ion source ,
2) Mass filter or
3) Quadruple and Detector (continuous dynode elec-
tron multiplier).
All components of system are controlled via MS DOS
Chem. Station. The data software Includes programs to
calibrate MSD acquire data, process data and file man-
agement and Editing.
The gas chromatographic/mass spectral analyses were
carried out using Gas Chromatograph Mass Spectrometer
QP-2010-Shimadzu Instrument operating on EI (Electron
Impact) Mode, using the followed conditions:
Helium at 1 ml/min was used as the carrier gas. Room
temp: 26˚C and Humidity: 31%.
Physical and Chemical properties of biodiesel product
analyzed by (ASTM).
The American Society for Testing and Materials is an

B. K. Abdalla, F. O. A. Oshaik / Agricultural Sci ences 4 (2013) 85-88
87
international standards organization which has set the
property requirements, testing cr iteria and quality control
methods for biodiesel B100. This is known as ASTM.
Biodiesel was tested according to ASTM No: D1298,
D445, D92, D130, D976, and D524.
Environmental conditions: Temp: 19.9˚C and Pressure:
96.8 kPa.
3. RESULTS AND DISCUSSION
The analysis of the product showed, the results were
carried out with the objective to manage spent frying oil
to produce biodiesel, to help in disposal problems of
used fried oil and reduced contamination of water and
land resources. Tables 1 and 2 show the results of raw
materials and the biodi e s e l produce d, re specti ve l y.
ASTM and DIN standard which are 100˚C minimum,
copper strip corrosion rating is (1a) which is the same
with Din standard and suitable when comparing with
ASTM (3b max), also cetane No is about 48.19, it was
higher than the ASTM standard which is 40 minimum,
the viscosity @ 40˚C is 5.521 mm2/s , it was a good resu lt
to flow biodiesel, when comparing with ASTM standard
rang (1.9 - 6.0 mm2/s). Finally 10% distillation carbon
residue is about 1.191% was v. high and not acceptable,
by comparing with ASTM and Din standard.
Table 3 shows the comparison between Base-transes-
terification processes of biodiesel product properties with
ASTM and Din standard, which was found that the process
was suitable to produce pure biodiesel.
4. CONCLUSIONS AND
RECOMMENDATIONS
The methyl ester was prepared from spent frying oils
with methanol to produce biodiesel by base -transesteri -
fication process, and was successfully performed with a
maximu m biodiesel yield of 92 wt% and methyl ester
purity of 100%.
Table 1. Analysis results of raw materials (spent frying oils) of
sample (A).
Item Sample A
Moisture Content % 0.29
Density, g/cm3 0.92
Free Fatty Acid as Oleic Acid 0.48
Table 2. Yield results under select method conditions, of sam-
ple (A).
Parameter Biodiesel Produced by
Base-Transesterification
Biodiesel Yield wt% 92.2
Glycerol Y ield wt% 15.3
Table 3. Comparisons of biodiesel product properties with
ASTM and DIN V 51606 standard.
Item Base-transesterification
ASTM
standard
DIN V 51606
standard
Density, S.G @
15˚C g/ml 0.8873 - 0.875 - 0.900
Flash point (COC) 174.2˚C 100˚C min 100˚C min
Copper Strip
Corrosion Rating 1a 3b max 1
Cetane Index 48.190 40 min 49 min
Viscosity @
40˚C mm2/s 5.5211 1.9 - 6.0 3.5 - 5.0
10% distillation
Carbon Residue 1.19% 0.05% 0.30% max
Select methods and biodiesel yield may vary in terms
of the quality of r aw oils. T he f ue l proper ties of biod iesel
derived from spent frying oils, all met the ASTM stan-
dard and German Biodiesel Standard.
Production of biodiesel from waste cooking oils for
diesel substitute is particularly important because of the
decreasing trend of economical extracted oil reserves and
the environmental problems caused by the use of fossil
fuel. Waste cooking oil can be an important source for
biodiesel production in Sudan as there is large quantity
of waste cooking oil available. Use of waste cooking oil
helps to improve the biodiesel economics.
The results of the tests and calculations carried out
show that the techniques employed for the process are
possible to scale up this process for industrial use.
Assist the researchers to continue in this sector of al-
ternative biofuel.
REFERENCES
[1] Hideki, F., Akihiko, K. and Hideo, N. (2001) Biodiesel
fuel production by transesterification of oils. University
of Kobe, Kobe.
[2] Guo, Y., Leung, Y.C. and Koo, C.P. (2002) A clean bio-
diesel fuel produced from recycled oils and grease trap
oils. Department of Mechanical Engineering, University
of Hong Kong, Hong Kong.
[3] Zhang, Y., Dub, M.A., McLean, D.D. and Kates, M.
(2003) Biodiesel production from waste cooking oil: 1.
Process design and technological assessment. Department
of Chemical Engineering, University of Ottawa, Ottawa.
[4] Dan, A., Derek, M. and Bill, M. and Larry, S. (2003)
Industrial biodiesel plant design and engineering, practic-
al experience. International Palm Oil Conference, Putra-
jaya, Malaysia, 24-28 August 2003, 10p.
[5] Marina, E., Antonio, S., Boyan, K. and Peder, J. (2002)
Techno-economic analysis of biodiesel production in the
EU, a short summary for decision-makers. Report EUR
20279 EN.
[6] Patel, M.K. (2002-2003) Biodiesel from rapeseed oil and

B. K. Abdalla, F. O. A. Oshaik / Agricultural Sciences 4 (2013) 85-88
88
used frying oil, in European Union.
[7] Zach, C. (2005) Alternative fuels as a solution. History of
Alternative Fuel Development.
[8] Tao, B.Y. (2005) Biofuels for home heating oil. Depart-
ment of Agricultural and Biological Engineering, Univer-
sity of Purdue, West Lafayette.
[9] Van Gerpen, J., Shanks, B. and Pruszko, R. (2004) Biodie-
sel production technology. Iowa State University, Ames.
[10] Naveen, K. (2006) Moving toward sustainable energy
systems. University of Minnesota, Minneapolis.
[11] Lee, S., Speight, J.G. and Loyalka, S.K. (2007) Hand-
book of alternative fuel technologies. Taylor and Francis
Group, LLC, Boca Raton.
[12] Erhan, S.Z. (2005) Industrial uses of vegetable oils. Na-
tional Center for Agricultural Utilization Research, Agri-
cultural Research Service, United States.
[13] Chakrit, T. (2009) Biodiesel technology over view. Prince
of Songkla University, Songkhla, Thailand.
[14] Pornsiri, K. (2009) Feedstock with high free fatty acid
(FFA). Annul International Training Course (Biodiesel
Te chnology), PSU, Thailand.
[15] Chakrit, T. (2009) Biodiesel project, specialized research
and development center for alternative energy from palm
oil and oil crops. Faculty of Engineering, Prince of Song-
kla University, Songkhla, Thailand.