2011 International Conference on Alternative Energy in Developing Countries and Emerging Economies
- 73 -
Performance and Emission of Small Diesel
Engine Using Diesel-Crude Palm Oil-Water
Emulsion as Fuel
K. Narkpakdee
*
and T. Kiatsiriroat
**
.
*
Graduate School, Chiang Mai University,
(Thailand)
**
Department of Mechanical Engineering, Faculty of Engineering Chiang Mai University,
(Thailand)
Abstract--
Diesel and crude palm oil(CPO)
emulsion was drop-in replaced of diesel oil in a
small diesel engine to test the engine performance
and emission. In the study, the compositions of
diesel/CPO/water of 95/0/5, 90/0/10, 90/5/5, 85/5/10,
85/10/5 and 80/10/10 by volume were used in a four-
stroke single cylinder diesel engine having a pre-
combustion chamber. The engine speed was in a
range of 1000
–
2000 rpm.
From the results, it could be found that the
torque and the engine power for the emulsion of
90/5/5 were close to those of from the diesel oil but
the performance were poorer when the percentages
of CPO and water were increased. The specific fuel
consumption of the emulsified oil with the
composition of 90/5/5 was quite close to that of the
diesel oil at low engine speed and higher
consumption was needed with higher amount of
CPO and water in the emulsion due to lower
heating value in the emulsion. The emissions
in
terms of CO, NOx and black smoke for the
emulsified oil could be reduced significantly.
Index Terms
—
Palm
–
Diesel Emulsion, Diesel engine
performance, Emission
I. N
OMENCLATURE
T
Torque
(N m)
F
Force (N)
N
Engine Speed (rpm)
P
Power (kW)
m
f
’
mass rate of fuel consumption
(g/hr).
sfc
Specific fuel consumption (g/kW- hr)
II.
I
NTRODUCTION
Vegetable oil could be blended with diesel oil in a
proper composition and it could be used to run diesel
engine. In Thailand, there were some studies reported
the results of diesel oil directly blended with crude
palm oil (CPO) for running in diesel engines.
The
compostion of CPO should not exceed 20 % by volume
_____________________
This work was supported by the Commission on Higher Education
Thailand and the facilities from Rajamangala University of
Technology Lanna and the Graduate School, Chiang Mai University.
and the recommended one was 10 % by volume [1].
However, since the chemical and physical properties of
the vegetable oil are quite different from those of the
diesel, especially the viscosity which is 9-10 times of
the diesel oil then the atomization of the fuel droplets
and the fuel volatility are poorer than those of the
diesel oil which results in poorer combustion
performance.
One technique to reduce the blended fuel viscosity
is to mix water into the fuel in a form of emulsion.
Cherng-Yuan Lin and Kuo-Hua Wang [2] studied a
small single cylinder diesel engine performance when
diesel/water emulsion was used as fuel. Span-80 was a
surfactant for the emulsion. The engine power was less
than that with the diesel oil and the performance was
poorer with the percentage of water in the emulsion but
the quality of the exhaust gas is better. The engine
could not operate when the amount of water
reached 20
% by volume.
Abu-Zaid [3] also used diesel/water
emulsion with water compositions of 0, 5, 10, 15 and
20 % by volume to run a 659 cc direct injection diesel
engine.
Span 80 and Tween 80 were surfactants to
form the emulsion. More complete combustion was
found for the emulsified oil than that for the diesel oil
and the temperature of the exhaust gas was lower. The
torque and the engine power from the emulsified oil
were slightly different from that from the diesel oil but
the specific fuel consumption was higher with the
amount of water composition. Cherng-Yuan Lin and
Hsiu-An Lin[4] used an emulsified oil from diesel
blended with trans-estered biodiesel from soybean.
Span 80 and Tween 80 were surfactants. The
emulsified oil was taken as fuel in a 4 cylinders, 4
strokes direct ignition diesel engine. Since the heating
value of the emulsified oil was lower than that of the
standard diesel oil, therefore, the specific fuel
consumption of the emulsified oil was higher but CO
and NOx in the exhaust gas were lower.
In this study, diesel oil and crude palm oil(CPO) in
a form of emulsion with compositions of
diesel/CPO/water of 95/0/5, 90/0/10, 90/5/5, 85/5/10,
85/10/5 and 80/10/10 by volume were taken as fuels in
a four-stroke single cylinder diesel engine having a
pre-combustion chamber. The engine speed was taken
in a range of 1000
–
2000 rpm. The engine
performances and the emissions were considered.
III. E
XPERIMENTAL TEST
