Page 385 - Advances in Eco-Fuels for a Sustainable Environment

340 Advances in Eco-Fuels for a Sustainable Environment

for each test. The three balls were placed into the cup using tweezers, and the cup was
filled with 10mL of the fuel sample being tested, which comes to about 3mm over the
stationary balls. During the test, the axial load of 40kg was applied to the stationary
balls by the loading arm according to the ASTM D4172 standard method. The friction
torque (FT) was measured by the calibrated torque arm, which is assembled with a
friction-recording device. This test was conducted at a nominal 75°C temperature that
was controlled between 75 and 80°C during the study using a thermostated bath. After
completion of the test, the stationary balls were cleaned to laboratory standards.
A high-resolution microscopy was performed on these balls using a high-resolution
optical microscope in accordance with the ASTM D4172 standard. Finally, SEM/
EDX analysis was conducted to evaluate the metal surface morphology of the tested
balls. The coefficient of friction was calculated using Eq. (12.1).
The coefficient of friction can be calculated by Eq. (12.1).

p ffiffiffi
Torque kg mmÞ 6
ð
Coefficient of friction COFÞ, μ ¼
ð
ð
3 Load kgÞ Distance mmÞ
ð
p ffiffiffi
T 6
¼ (12.1)
3Wr c
where T is friction torque in kg-mm, W is applied a load in kg, and r c is the distance in
mm from the center of the lower ball contact surface to the axis of rotation. The value
of r c ¼3.67mm was measured for the test setup.
For wear debris analysis, a scanning electron microscope (SEM) was used to
observe debris on filter paper. Then the metal surface morphology of the tested balls
was obtained using an energy dispersive X-ray (EDX) analysis. The focal point on the
surface of the ball was adjusted to obtain a better quality of image for analysis. The
WSD was calculated from the mean value of the wear diameter obtained from the
image. The images from the SEM/EDX test were analyzed to obtain wear on the metal
surface as they indicate the corrosive behavior of the tested fuels. The assessment of
the parameters mentioned above could help to improve engine durability as well as the
durability and total lifetime of the engine. The uncertainty analysis found that the
overall uncertainty related to wear and friction is about 3.68% for this experiment.
The test was repeated three times to minimize the error of the results.

12.3 Results and discussions

12.3.1 Physiochemical properties of the fuel

The physiochemical properties of the experimented ecofuel and its blend were deter-
mined using ASTM and EN standards. The key fuel properties such as density, kine-
matic viscosity, flash point, lubricity, etc., are presented in Table 12.2. The higher
3
density of the pure Tamanu ecofuel was found to be 889kg/m whereas the diesel
3 3
and B20 ecofuel blend densities are 832kg/m and 843.4kg/m at the 15°C temper-
ature, respectively. Another key physical property of the fuel that has a direct