Page 383 - Advances in Eco-Fuels for a Sustainable Environment

338 Advances in Eco-Fuels for a Sustainable Environment

The investigation of ecofuel lubricating behavior is one of the interesting research
topics nowadays. Recently, many researchers have been working in this field to iden-
tify the effects of different parameters on the tribological characteristics of ecofuels.
For example, Mosarof and Kalam [4] and Mosarof and Kalam [12] investigated the
friction and wear characteristics of different ecofuels and their blends at different tem-
peratures and load conditions. Another investigation was done on ecofuel extracted
from Millettia pinnata and rice bran by Mosarof et al. [2], revealing that the lower
coefficient of friction of Millettia pinnata indicates better lubrication compared to rice
bran oil, which also demonstrated a lower wear scar diameter. In addition, an exper-
imental investigation of the corrosive behavior of palm ecofuel has been conducted by
Fazal and Haseeb [13] for long-term engine durability. They investigated the ecofuel
corrosive behavior of three different metals such as aluminum, copper, and stainless
steel for 50days at 80°C temperature. Their results revealed that ecofuel has an insig-
nificant effect on stainless steel. However, copper and aluminum were found to be
more susceptible to attack by the ecofuel compared to diesel. Therefore, the tribolog-
ical study of any new fuel including ecofuel or mineral oil is important to ensure sus-
tainability of engine durability.
There are many techniques available to investigate the tribological behavior of dif-
ferent ecofuels to evaluate key parameters such as coefficient of friction (COF), wear
scar diameter (WSD), wear debris, and metal surface morphology. The literature
reported that many researchers used a four-ball triobotester to analyze the tribological
behavior of different ecofuels [4, 7, 10]. This is also widely used in lubricant
manufacturing companies as well as research and development (R&D) of new lubri-
cants to characterize their friction and wear behavior. In addition, cylinder metal sur-
face morphology can be analyzed by an optical microscope and scanning electron
microscope (SEM) with energy dispersive X-ray spectroscopy (EDX) analysis.
In this study, a four-ball tribotester was used to perform the test of the ecofuel and
ULSD using the ASTM D4172 standard to investigate COF and WSD. Furthermore,
the wear debris was evaluated by a high-performance scanning electron microscope
(SEM) and wear scar surface morphology of the ball metals by energy dispersive
X-ray (EDX).

12.2 Methodology and associated theory

In this study, the tribological characteristic of Tamanu ecofuel were investigated and
compared with diesel. The experiment was conducted on the B20 blend, which was
prepared by mixing 20% vol. of Tamanu ecofuel and 80% vol. of diesel. The key
physiochemical fuel properties such as density, kinematic viscosity, flash point, oxi-
dation stability, ester content, cetane number, and iodine number were measured in
accordance with the ASTM and EN standards. The fuel properties were compared
with pure ecofuel, B20, and ULSD within the standard range. A four-ball test rig
(model TR-30H, DUCOM) was used to assess the tribological characteristics of
the tested fuels. All these tests were conducted in an external laboratory equipped with
appropriate testing equipment and tools under the supervision of an expert. Table 12.1