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Characterization of Groundnut Oil-based Biodiesel to Assess the Feasibilityfor Power GenerationT. Eeveraa; P. Balamuruganb; S. Chittibabua

a Department of Biotechnology, Periyar Maniammai University, Thanjavur, TamilNadu, India b

Department of Electrical Engineering, Periyar Maniammai University, Thanjavur, TamilNadu, India

Online publication date: 29 April 2011

To cite this Article Eevera, T. , Balamurugan, P. and Chittibabu, S.(2011) 'Characterization of Groundnut Oil-basedBiodiesel to Assess the Feasibility for Power Generation', Energy Sources, Part A: Recovery, Utilization, andEnvironmental Effects, 33: 14, 1354 — 1364To link to this Article: DOI: 10.1080/15567030903330884URL: http://dx.doi.org/10.1080/15567030903330884

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Energy Sources, Part A, 33:1354–1364, 2011

Copyright © Taylor & Francis Group, LLC

ISSN: 1556-7036 print/1556-7230 online

DOI: 10.1080/15567030903330884

Characterization of Groundnut Oil-based Biodiesel

to Assess the Feasibility for Power Generation

T. EEVERA,2 P. BALAMURUGAN,1 and S. CHITTIBABU2

1Department of Electrical Engineering, Periyar Maniammai University,

Thanjavur, TamilNadu, India2Department of Biotechnology, Periyar Maniammai University, Thanjavur,

TamilNadu, India

Abstract Methyl ester production from groundnut oil was optimized. The optimumcatalyst concentration, amount of ethanol used per liter of oil, reaction time, and

temperature was found. This groundnut oil-derived biodiesel was tested in a directinjection, naturally aspirated, single-cylinder diesel engine. The diesel engine was

operated from no load to full load condition. Effect of this biodiesel on engine pa-rameters, namely: fuel consumption, electrical efficiency, lower heating value, higher

heating value, and engine speed was examined, and also the physical and chemicalproperties, such as specific gravity, moisture content, refractive index, acid value;

iodine number, saponification value, and peroxide value of the methyl esters used inthis study were estimated. Based on electrical efficiency, the methyl esters obtained

from groundnut oil were found to be a good alternate fuel in internal combustionengines with electrical generators.

Keywords biodiesel, electrical efficiency, fuel consumption, higher heating value,lower heating value, speed regulation, transesterification, voltage regulation

1. Introduction

Petroleum-derived fuels have been the major source of the world’s energy. However,

environmental concerns, in addition to the ozone depletion concerns, have pushed the

world towards searching for alternative energy sources with particular emphasis on those

of a renewable nature. Future projections indicate that the only feasible option is the

production of synthetic fuels derived from non-petroleum sources (Tashtoush et al.,

2004). One of the promising alternative energy sources is biomass. It is renewable

and widely available with much less sulfur and nitrogen compared to fossil fuels, thus

making it more environmentally friendly. In recent years, research has been directed

to explore plants oils and fats as sustainable energy sources (Martini and Shell, 1998).

The primary problem with straight vegetable oil and animal fat as fuels in an internal

combustion engine is their high viscosity. It is known that fuels with high viscosity cause

several serious problems on engine performance and operation (Yahya and Marley, 1994;

Address correspondence to Dr. T. Eevera, Department of Biotechnology, Periyar ManiammaiUniversity, Thanjavur, TamilNadu 613 403, India. E-mail: [email protected]

1354

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Groundnut Oil-based Biodiesel for Power Generation 1355

Goering et al., 1987). Among the methods that had been widely investigated to reduce

the viscosity of vegetable oils and animal fat was chemically transforming these two into

their corresponding esters. Biodiesel had been found suitable for use as a fuel in diesel

engines (Harrington, 1986).

The commission white paper European policy predicts that by the year 2010, the CO2

emission from transport will have risen to about 1,113 million tons annually (Gvindonas

and Stasys, 2006), with the main responsibility resting on road transport, which accounts

for 84% of the transport-related CO2 emission. Most studies on biodiesel reported that

emission of carbon dioxide (CO2), total particulate matter, and carbon monoxide (CO)

were reduced with biodiesel while the oxides of nitrogen (NOx) increased. However,

biodiesel does not contain sulfur; catalytic converter technology is more effective at

countering NOx emissions. Moreover, biodiesel degrades quickly in the environment and

is non-toxic. The U.S. Environmental Protection Agency and Food & Drug Adminis-

tration verified biodiesel as a clean alternative fuel or additional fuel (Lin et al., 2006).

Additionally, the U.S. Congress has passed legislation allowing Federal and State fleet

managers to meet the Energy Policy Act (EPACT) alternative fuel vehicle acquisition

requirements by using biodiesel added to conventional diesel at a blend of 20% and

higher.

Based on the arguments presented above, this study was carried out and was intended

as a comparative study of plant oil-based methyl esters as a replacement for diesel fuel

taking into account the traditional and more recent developments in the utilization of

alternative fuels in diesel engines. The main objective of the study was to optimize the

transesterification process of groundnut oil-based biodiesel production, the engine per-

formance, and power generation potential of groundnut oil-derived biodiesel, in addition

to physical and chemical characterization.

2. Materials and Methods

Groundnut oil was used in this experimental study. The oil was filtered by cloth mainly

to remove the dirt and other inert materials. Under agitation, the raw oil was heated

up to near the boiling point to remove the water contaminant present in the oil. It was

allowed to cool down under room temperature. The above treated oil was heated up to a

desired temperature on a hot plate. A fixed amount of freshly prepared sodium hydroxide-

methanol solution was added into the oil, taking this moment as the starting time of the

reaction. When the reaction reached the preset reaction time, heating and stirring were

stopped. The products of reaction were allowed to settle overnight. During settling, two

distinct liquid phases were formed: the crude ester phase at the top and the glycerol

phase at the bottom. The crude ester phase separated from the bottom glycerol phase

was then washed by cold or warm de-ionized water several times until the washed water

became clear. The excess methanol and water in the ester phase were then removed by

evaporation under atmospheric conditions. After that, the weight of the ester was taken

for product yield calculation.

The reaction was investigated step by step. The optimal value of each parameter

involved in the process was determined while the rest of the parameters were kept con-

stant. After each optimal value was attained, this value was adopted for the optimization

of the next parameter.

Physical and chemical properties of methyl esters were estimated (Hodl, 1994;

Demirbas, 1998) under laboratory conditions. The cetane number (CN) and higher heating

values (HHV) were calculated (Mohibbe Azam et al., 2005; Demirbas, 1998) from the


1356 T. Eevera et al.

following equation by using the estimated saponification value (SV) and iodine value

(IV):

CN D 46:3 C 5458=SV � 0:225 � IV; (1)

HHV D 49:43 � Œ0:041.SV/ C 0:015.IV/�: (2)

The engine used in all test runs was a diesel engine model IS4722, single stroke,

natural cooling, direct injection, with a specification of single phase, 5 KVA, 220 V, 22

A, 1,500 RPM. The engine was originally designed and optimized to operate on diesel

fuel. To establish the baseline data, the engine was operated with diesel at different

load conditions. Similarly, a test run was performed for the biodiesel at different load

conditions. Each test run was started by a 15-min start-up period to attain steady state

conditions and minimize any residuals from the previous fuel. From the different test

run, data were collected related to fuel consumption at different load conditions, voltage

regulation at no load (V0) to full load (V ) condition, and speed regulation at no load (N0)

to full load (N ) condition, mainly to calculate voltage and speed regulation based on the

formula given below:

Voltage regulation .%/ D .V0 � V /=V � 100; (3)

Speed regulation .%/ D .N0 � N /=N � 100: (4)

A simulation has been carried out based on the fuel consumption, higher heating

value, and fuel density value recorded from the test run using HOMER, micro power

optimization software developed by the National Renewable Energy Lab (Golden, CO),

to find out specific fuel consumption, annual fuel consumption, and electrical efficiency

of the engine based on the load pattern given in Figure 1. It simulates the operation of a

system by making energy balance calculations for each of the 8,760 h in a year. For each

hour, the electric demand in the hour had been compared to the energy that the system

could supply in that hour. The size and shape of the load profile was used to vary from

day to day in reality. To make the load data realistic, a noise input was added to the

hourly and daily data. For this simulation, 10% hourly variation and 5% daily variation

in the load profile was added.

Figure 1. Load profile with respect to time.



3. Result and Discussion

3.1. Effect of Catalyst Concentration

The effect of sodium hydroxide concentration on the transesterification process was

investigated with its concentration varying from 0.5 to 2.5 wt% (based on the weight

of raw oil). The operation conditions during the whole reaction process were fixed

at the optimal level: reaction temperature of 55ıC, reaction time of 90 min, and 180

ml of methanol per liter of oil. As the sodium hydroxide concentration increased, the

conversion of triglyceride, as well as the ester content, also increased. Insufficient amounts

of sodium hydroxide resulted in incomplete conversion of triglycerides into the esters

as indicated from its lower ester content. The ester content reached an optimal value

when the sodium hydroxide concentration reached 1.5 wt%, and further increases in the

catalyst concentration resulted in ester production amount being decreased as shown in

Figure 2. A large amount of soap was observed in an excess amount of sodium hydroxide

added experiments. This is because the addition of excess alkaline catalyst caused more

triglyceride participation in the saponification reaction with sodium hydroxide resulting

in the production of a larger amount of soap and reduction of the ester yield.

3.2. Effect of Reaction Time

The transesterification reaction was conducted at 55ıC; an excess amount of alcohol (180

ml per liter of oil) and optimal sodium hydroxide concentration of 1.5 wt% was used.

The changes in methyl ester yield with different reaction times were studied. The ester

content increased with a reaction time from 15 min onwards and reached a maximum at

a reaction time of 90 min at 55ıC, and then remained relatively constant with increasing

further the reaction time (Figure 2). The results indicated that an extension of the reaction

time from 90 min to 150 min had no significant effect on the conversion of triglycerides

but leads to a reduction in the product yield. This is because a longer reaction enhanced

the hydrolysis of esters (reverse reaction of transesterification), resulting in loss of esters

as well as causing more fatty acids to form soap.

Figure 2. Effect of catalyst concentration and reaction time on transesterification process.



3.3. Effect of Methanol Amount

The transesterification of groundnut oil was conducted with different amounts of methanol

in the range of 120 ml to 240 ml per liter of oil. The optimized catalyst concentration

and reaction time, as obtained in the above sections, were adopted. Maximum ester

content was obtained at a methanol amount of 180 ml (Figure 3). Moreover, it was

observed that for a high alcohol amount, added set up required a longer time for the

subsequent separation stage since separation of the ester layer from the water layer

became more difficult with the addition of a large amount of methanol. This is due to the

fact that methanol, with one polar hydroxyl group, can work as an emulsifier that enhances

emulsion. Therefore, increasing the alcohol amount to oil is another important parameter

affecting the biodiesel yield and biodiesel purity, apart from catalyst concentration and

reaction time. This result is in line with the report of many investigations based on neat

vegetable oils (Leung and Guo, 2006; Zhang et al., 2003; Freedman et al., 1984).

3.4. Effect of Reaction Temperature

The transesterification reaction was carried out under the optimal conditions obtained

in the previous section (i.e., 180 ml of methanol and 1.5 wt% sodium hydroxide). The

experiments were conducted at temperatures ranging from 40 to 60ıC at 5ıC intervals.

The effect of reaction time was shown in Figure 4. Experimental results showed that the

transesterification reaction could proceed within the temperature range studied but the

reaction time to complete the reaction varied significantly with reaction temperatures.

It can be seen that a high product yield could be achieved at 50ıC. If the temperature

increases to above 55ıC, the product yield started to decrease. The reason for this is that

a higher temperature accelerates the side saponification reaction of triglycerides.

3.5. Methyl Ester Chemical and Physical Property

Fuel properties like specific gravity, moisture content, refractive index, acid value, iodine

Figure 3. Effect of methanol on methyl ester yield.



Figure 4. Optimization of reaction temperature.

value (IV), saponification value (SV), and peroxide value were estimated. The cetane

number (CN) and higher heating values (HHV) of methyl ester were calculated based on

the estimated SV and IV listed in Tables 1 and 2.

Cetane number is the ability of fuel to ignite quickly after being injected. Better

ignition quality of the fuel is always associated with a higher CN value. For this, differ-

ent countries/organizations have specified different minimum values of cetane number.

Table 1

Physical property of groundnut oil-based methyl esters

Properties Groundnut oil–biodiesel

Specific gravity 0.878

Moisture content (wt%) 0.45

Viscosity (�10�6 N � s/m2) 16.62

Refractive index 1.4494

Table 2

Chemical characteristics of groundnut oil-based methyl esters

Properties Groundnut oil–biodiesel

Acid value (AV) 0.2

Saponification value (SV) 187

Iodine value (IV) 111

Peroxide value (PV) 19.21

Higher heating value (HHV), kJ/kg 39.048

Cetane number 50.51



Biodiesel standards of the USA (ASTM D 6751), Germany (DIN 51606), and European

Organization (EN14214) have set this value as 47, 49, and 51, respectively. The groundnut

oil-based methyl esters have a cetane number of 50.51, which was well above the U.S.

and German standards but marginally complying with European standards.

Another important criterion for selection of methyl esters is its degree of unsaturation,

which is measured as iodine value. A higher degree of unsaturation, methyl esters

are not suitable for biodiesel. At high temperatures commonly found in an internal

combustion engine, the process can get accelerated and the engine can quickly become

gummed up with the polymerized methyl esters. To use biodiesel as fuel for IC engines,

the lowest limit of iodine value should be around 115 as per standards. The iodine

value of groundnut oil-based biodiesel met the standard specification. Generally, methyl

esters with higher CN are favored for use as biodiesel. However, with an increase of

CN, IV decreases, which means the degree of unsaturation decreases. This situation

will lead to the solidification of methyl esters at higher temperatures. To avoid this

situation, the upper limit of CN (65) has been specified in the U.S. biodiesel standard

(ASTM PS 121-99). The biodiesel under study can be used both in cold and hot

climates.

3.6. Engine Performance and Power Generation

Feasibility Assessment

From the test run, fuel consumption was recorded at a different load condition in terms

of liter per hour (Table 3) for the test fuel in comparison with diesel.

A simulation has been carried out based on the fuel consumption, higher heating

value, and fuel density in value recorded from the test run using HOMER, a micro power

optimization software developed by National Renewable Energy Lab (Golden, CO), to

find out specific fuel consumption, annual fuel consumption, and electrical efficiency of

the engine based on the load pattern given in Figure 1.

From the simulation studies, the following information related to engine performance

and power generation related properties like electrical efficiency. Specific fuel usage and

annual fuel consumption were estimated for biodiesel under study and compared with

diesel.

Figure 5 shows the specific fuel consumption for groundnut oil-based biodiesel;

this result revealed that biodiesel was an oxygenated fuel that can increase combustion

efficiency in diesel engines. One hundred percent biodiesel resulted in incomplete com-

bustion in the diesel-engine generator and impeded the release of energy from the fuel.

Hence, diesel engines need to be modified to cope with 100% biodiesel (Lin et al.,

2006).

Table 3

Fuel consumption (liter/h) at different load condition

Load in kW

Name of the fuel 0.5 1.0 2.0 3.0 4.0 5.0

Groundnut 0.35 0.80 1.50 2.10 2.80 3.22

Diesel 0.30 0.60 1.10 1.50 2.00 2.30



Figure 5. Fuel consumption for groundnut oil derived biofuel and diesel.

The comparison of groundnut oil-based biodiesel with diesel is shown in Figure 6.

Because of higher lower heating value, the amount of fuel required to generate 1 KWh

power is lower in the above-mentioned oil-based methyl esters.

The higher values of lower heating value and lower volume of specific fuel con-

sumption leads to an increase in the electrical efficiency and is shown in Figure 7.

Speed regulation (Figure 8) and voltage regulation (Figure 9) data of the biofuel

under study showed that the fuel could be used in the already existing diesel engine like

that of diesel.

The fuel required for one year for the given load profile was also calculated through

the simulation (Figure 10).

Even though the plant oil-based methyl esters yield lower electrical efficiency when

compared to diesel, it could be mixed with the diesel to prolong its availability and also

the problems of unexploited fallow lands and unemployed laborers could be solved at

the same time by cultivating edible and non-edible oil yielding plants used to produce

vegetable oil-based biodiesel.

Figure 6. Lower heating values of different fuels.



Figure 7. Mean electrical efficiency of different biofuels.

Figure 8. Voltage regulation of biofuels and diesel.

4. Conclusion

From the results, it was clearly shown that the groundnut oil-based methyl esters can be

produced without major complications. The speed and voltage regulation of the biodiesel

under study was similar to diesel. The electrical efficiency of methyl ester obtained from

groundnut oil was comparable with diesel. Groundnut oil-derived biodiesel can be mixed

very well with diesel and used in diesel engines-based electrical generators without any

modifications to minimize the production cost of electricity generation.

Acknowledgment

The authors wish to thank the Department of Science and Technology, Government of

India for funding under the Young Scientist scheme (SR/FTP/ETA-012/2009).



Figure 9. Speed regulation of biofuels and diesel.

Figure 10. Annual fuel consumption.

References

Biodiesel standard. 1994. DIN V51606, Germany.

Biodiesel standard. 2003. EN14214, European Standards Organization.

Biodiesel standard. 1999. ASTM D6751, USA.

Biodiesel standard. 1999. ASTM PS 121, USA.

Demirbas, A. 1998. Fuel properties and calculation of higher heating values of vegetable oils. Fuel

77:1117–1120.

Freedman, B., Pryde, E. H., and Mounts, T. L. 1984. Variables affecting the yield of fatty esters

from transesterified vegetable oils. JAOCS 61:1638–1643.

Goering, C., Schrock, M., Kaufman, K., Hanna, M., Harris, F., and Merely, E. 1987. Evaluation

of vegetable oils as fuel in diesel engines. Fuel Proc. Technol. 76:91–103.



Gvindonas, L., and Stasys, S. 2006. The effect of rapeseed oil methyl esters on direct injection

Diesel engine performance and exhaust emission. Energy Convers. Manage. 47:1954–1967.

Harrington, K. J. 1986. Chemical and physical properties of vegetable oil esters and their effect

on diesel fuel performance. Biomass 9:1–17.

Hodl, P. 1994. Handbook of Analytical Methods for Fatty Acid Methyl Esters Used as Biodiesel

Fuel Substitutes. Vienna: Research Institute for Chemistry and Technology.

Leung, D. Y. C., and Guo, Y. 2006. Transesterification of neat and used frying oil: Optimization

for biodiesel production. Fuel Proc. Technol. 87:883–890.

Lin, Y.-C., Lee, W.-J., and Hou, H.-C. 2006. PAH emission and energy efficiency of palm-biodiesel

blends fueled on diesel generator. Atmos. Environ. 40:3930–3940.

Martini, N., and Shell, J. S. 1998. Plant Oils as Fuels—Present State of Science and Future

Development. Berlin: Springer, p. 276.

Mohibbe Azam, M., Waris, A., and Nahar, N. M. 2005. Prospects and potential of fatty acid methyl

esters of some non-traditional seed oils for use as biodiesel in India. Biomass & Bioenergy

29:293–302.

Tashtoush, G., Al-Widyan, M., and Al-Jarrah, M. 2004. Experimental study on evaluation and

optimization of conversion of waste animal fat into biodiesel. Energy Convers. Manage.

45:2697–2711.

Yahya, A., and Marley, S. 1994. Performance and exhaust emissions of a CI engine operating

on ester fuels at increased injection pressure and advanced timing. Biomass & Bioenergy

6:297–319.

Zhang, Y., Dube, M. A., Mclean, D. D., and Kates, M. 2003. Biodiesel production from waste

cooking oil: 2. Economic assessment and sensitivity analysis. Biores. Technol. 90:229–240.


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