Page 446 - Advances in Eco-Fuels for a Sustainable Environment

Assessment of performance and emission behavior of novel annona 399

250

200
Diesel
EGT (°C) A20
150
A40
100
A60
50 A80
A100
0
0 1 2 3 4 5 6
BP(kW)

Fig. 14.4 Variation of EGT with BP for diesel and different proportions of AME diesel blends.

Fig. 14.4 shows the variation of EGT with brake power for different proportions of
AME blends and diesel. It is observed that the EGT increases with BP for all blends at
all loads. Among the different blends, A20 has a lower EGT than that of other blends.
The EGT for A20 is 208°C and for diesel is 199°C at maximum load. The marginal
increase in EGT for A20 is due to higher oxygen content in biodiesel improves the
combustion. This is also due to higher viscosity and poor volatility leading to late
burning and an increase in EGT. Further, the oxygen concentration in the fuel
increases with the biodiesel-diesel blend ratio, which enhances the combustion and
produces a higher temperature inside the combustion chamber, thereby increasing
the EGT.

14.3.4.1 HC emission

The HC emission in the exhaust is due to partially burned or unburned fuel inside the
combustion chamber. This is found due to wall wetting or flame quenching at the cyl-
inder lining and the escape of fuel particles in the crevice region.
Fig. 14.5 shows the variation of HC emissions with brake power for different pro-
portions of AME diesel blends and diesel. It is observed that the HC increases with
brake power for all blends at all loads. Among the different blends, A20 has a lower
HC than that of other blends. The HC emission for A20 is decreased by 27% than that
of diesel at maximum load. The HC emission is slightly higher in diesel fuel because
of poor oxygen supply and the combustion is incomplete and leads to an increase in
HC emission. The A20 blend has a lower HC emission than that of diesel because
AME contains a higher oxygen concentration and enhances combustion, which in turn
decreases the HC emissions. Even though oxygen concentration is higher for the other
biodiesel blends, HC emission is higher due to low calorific value and high viscosity
with increasing the blend ratio.