Page 128 - Biofuels Refining and Performance

Raw Materials to Produce Low-Cost Biodiesel 111

Figure 4.2 Salvadora angustifolia. (Photo courtesy of Dr. Kazuo Yamasaki
[http://pharm1.pharmazie.uni-greifswald.de/gallery/gal-salv.htm].)

Main uses. The fruits are sweet and edible. The seed cake contains
12% protein and is suitable for livestock fodder. The wood is used for
building purposes. It is also an important source of fuelwood. The fat in
seeds can be used for making soap and candles. The leaves and fruits
are used in medicine to relieve cough, rheumatism, and fever. The tree
contributes to erosion control in fragile areas [50]. Some authors have
carried out systematic studies on the lubrication properties of biodiesel
from S. oleoides and its blends. Biodiesel was prepared by base-catalyzed
transesterification using methanol. Results indicate that addition of
biodiesel improves the lubricity and reduces wear scar diameter even
at a 5% blend [51].

4.2.2 Castor oil
Crop description. Ricinus communis L., commonly known as the castor-
oil plant, belongs to the family Euphorbiaceae (see Fig. 4.3). This peren-
nial tree or shrub can reach up to 12 m high in tropical or subtropical
climates, but it remains 3 m tall in temperate places. Native to Central
Africa, it is being cultivated in many hot climates. The oil contains up
to 90% ricinoleic acid, which is not suitable for nutritional purposes
due to its laxative effect [52]. This hydroxycarboxylic acid is responsi-
ble for the extremely high viscosity of castor oil, amounting to almost a
hundred times the value observed for other fatty materials [53].