Page 392 - Advances in Eco-Fuels for a Sustainable Environment

346 Advances in Eco-Fuels for a Sustainable Environment

0.175Nm friction torque. Fig. 12.6 demonstrates better tribological behavior by the
ecofuel with a significant reduction of COF within the minimal friction torque range.
The results revealed that the B20 ecofuel reduces about 30% friction torque compared
to diesel, which implies lower frictional energy loss and minimum wear on the metal
surfaces contributing to sustainable engine durability and improved engine reliability
compared to fossil fuel.

12.3.3 Wear characteristics

Table 12.3 summarized the mean WSD of the stationary balls measured by a scanning
optical microscope. The results reveal that the higher WSD was found for diesel com-
pared to ecofuel under the same test conditions. Table 12.3 shows that the mean WSD
2
and wear surface were found to be 0.630mm and 0.31mm for diesel, respectively. On
2
the other hand, B20 ecofuel demonstrates about 0.59mm WSD and 0.21mm wear
surface, which is about 6.35% and 32.35% lower than diesel, respectively. This could
be due to the higher content of aliphatic acid (C n H 2n+1 COOH) in the ecofuel blend
enhancing the lubricating properties to reduce friction and wear by creating a thin
lubricating film between the metal surfaces. This has already been supported by many
researchers such as Habibullah, Masjuki [7], Fazal, Haseeb [11], and Syahrullail, Wira
[24]. In addition, the longer carbon chain length of the ecofuel contributes to the thick-
ening of the lubricating film, which creates a more protected surface area on the metal
contact surface, as reported by Havet, Blouet [25]. The literature reported some key
operating conditions such as speed, load, temperature, oil composition, etc., that play a
vital role on WSD, as reported by Maleque, Masjuki [26]. For instance, Fazal, Haseeb
[11] experimented with palm biodiesel at constant temperature and load but for vary-
ing speeds from 600rpm to 1500rpm. They identified that WSD increases with
increased speed but decreases for higher biodiesel blend proportions. Hu, Du [27] also
reported that the oil components such as the presence of mono and diglycerides and
free fatty acids in the ecofuel enhance the lubricity of the fuel. In addition, Fazal,
Haseeb [11] and Geller and Goodrum [28] have pointed out that the higher DU
and longer CCL can play an important role to enhance l the ubrication properties
of the fuel.

Table 12.3 Summary of wear characteristics of the tested fuels

Diesel B20 ecofuel
Major Minor Mean Major Minor Mean
WSD WSD WSD Area WSD WSD WSD Area
Tested
2 2
mm mm mm mm mm mm mm mm
balls
Ball 1 0.65 0.64 0.64 0.32 0.62 0.59 0.60 0.24
Ball 2 0.68 0.66 0.67 0.35 0.63 0.60 0.61 0.20
Ball 3 0.60 0.56 0.58 0.26 0.57 0.55 0.56 0.19
Mean WSD ¼ 0.63mm Mean WSD ¼ 0.59mm