Page 134 - Biofuels Refining and Performance

Raw Materials to Produce Low-Cost Biodiesel 117

Figure 4.7 Pongamia pinnata (L.)
Pierre. (Photo courtesy of the Food
and Agricultural Organization of
the United Nations[www.fao.org].)

All parts of the plant have also been analyzed for its reported medical
importance. Several scientists have investigated and guaranteed
karanja oil as a potential source of biodiesel [78]. Most researchers have
conducted the transesterification of P. pinnata oil by using methanol and
potassium hydroxide catalysts [90–92]. Meher et al. [90] found that
using a methanol–oil molar ratio of 12:1 produced maximum yield of
biodiesel (97%), while Vivek and Gupta [91] stated the optimum ratio
was 8–10:1. In both cases, the optimal temperature was around 65 C,
with a reaction time of 180 min [90] and 30–40 min [91]. Vivek and Gupta
used 1.5% w/w of catalyst (KOH), while Meher et al. used 2% w/w solid
basic Li/CaO catalyst [93]. Due to the high FFA (free fatty acid) content,
some researchers have proposed esterification with H SO prior to trans-
4
2
esterification with NaOH [94, 95]. In all cases, karanja oil has shown a
feasibility to be used as a raw material to produce biodiesel, saving
large quantities of edible vegetable oils. Diesel engine performance tests
were carried out with karanja methyl ester (KME) and its blend with
diesel fuel from 20% to 80% by volume [92]. Results have revealed a
reduction in exhaust emissions together with an increase in torque,
brake power, thermal efficiency, and reduction in brake-specific fuel
consumption, while using the blends of karanja-esterified oil (20–40%),
compared to straight diesel fuel.

4.2.7 Linseed oil
Crop description. Linum usitatissimum L.—commonly known as lin-
seed, flaxseed, lint bells, or winterlien—belongs to the family Linaceae
(see Fig. 4.8). This annual herb can grow up to 60 cm in height in most
temperate and tropical regions. This plant is native to West Asia and the
Mediterranean [96]. The seeds contain 30–40% oil, including palmitic