Page 282 - Biosystems Engineering

260 Cha pte r Ei g h t

Biodiesel (100% FAME)
Properties Putranjiva Karanja Jatropha Diesel
Viscosity in cSt (at 40°C) 5.81 5.81 5.42 5.03
Cetane number 40.2 35.6 41.0 46.3
Calorific value (kJ/kg) 3,9254 38,119 39,065 42,707
Pour point (°C) 2 5 2 –12
Specific gravity (at 25°C) 0.883 0.899 0.878 0.834
Flash point (°C) 152 190 171 78
Fire point (°C) 155 192 175 85
Carbon residue (%) 0.10 1.20 0.15 0.10

TABLE 8.1 Fuel Properties of Three Biodiesels and Diesel Fuel

When we compare the three oils, Jatropha shows better results in
specific gravity, viscosity, CN, and pour point, whereas putranjiva is
found to be better in calorific value, flash point, and carbon residue.

8.1.4 Measurement of Performance and Emission
To measure emissions, an automotive exhaust analyzer and a smoke
meter are generally used. Automotive exhaust analyzer functions
on the principle of the nondispersive infrared (NDIR) method. The
operational principle of the smoke meter analyzer is attenuation of
a LED pure green light beam. The Ricardo variable compression die-
sel engine is used to run with blends of (10, 30, 50, 70, and 100 per-
cent) transesterified oils, with diesel at different loads (0 to 2.7 kW),
constant injection times, constant speeds, and constant compression
ratios.
Ziejewski and Kaufman reported the results of an endurance
23
test using 25 to 75 percent alkali-refined sunflower oil with diesel and
25 to 75 percent of safflower oil with diesel on a volume basis. The
major problems experienced were premature injection, determination
of nozzle performance, and heavier carbon deposits in the grooves of
the piston ring. There was no significant problem with engine opera-
tion when a blend of safflower oil was used. That investigation
revealed that chemical differences between vegetable oil and diesel
had a very important influence on long-term engine performance.

8.1.5 Comparing the Effect of Loads on Biodiesel
Performance
24
Raheman and Phadatare carried out the experiments with different
oils and suggested that there were variations of the engine torque with