Page 189 - Biofuels Refining and Performance

172 Chapter Six

Performance of various blends. Performances of blends of degummed
vegetable oil with diesel are shown in Figs. 6.3 and 6.4. The 20% blends
of jatropha, karanja, and putranjiva oils with diesel gave quite satis-
factory performance related to BSFC and brake thermal efficiency ( ).
bt
Beyond the 20% blends, the cetane numbers and viscosities of the blends
were not so effective.
Comparison of the performance of blends. As per Figs. 6.5 and 6.6, engine
performance using jatropha and karanja oils was better than diesel but
the use of putranjiva oil gave reverse results at all loads, although the
results were more or less the same. Degummed karanja oil blends gave
better performance, but at high loads, the performance of jatropha oil
blends was better in comparison to the performance of karanja oil blends.
The performance data showed that all three vegetable oils could be used
as alternative fuels for diesel engines.

Effect of loads on emissions of vegetable oil blends and comparison. As per
Figs. 6.7 and 6.8, it is interesting to note that for the karanja, jatropha,
and putranjiva oils, in every case, smoke and particulates decreased,
which was very favorable in terms of their environmental impact on
human beings. The rate of increase in smoke and particulate generation
with the load of jatropha oil, in comparison to karanja and putranjiva

500 Diesel
10% blend
20% blend
450
30% blend
40% blend
400
BSFC (kg/kWh) 350

300

250

200
Karanja Jatropha Putranjiva
Oils
Figure 6.3 Brake specific fuel consumption versus vegetable oils and diesel
blends at 1200 rpm, 45 bTDC, 20 compression ratio, and 1.4-kW brake power.