Page 73 - Biofuels Refining and Performance

56 Chapter Two

calorific value [8]. About 14% of the oil supplied in the world market is
palm oil, yielding an average 3.4 ton/(ha
yr) of oil [9]. Individual palm
seeds, however, are capable of producing much higher yields. The extrac-
tion of palm kernel oil increases fuel oil yields by 10%. Current culti-
vation is mostly in lowland humid tropics such as Malaysia, West Africa,
and Indonesia. While the conditions to grow coconut palms are similar to
oil palms, the yield potential of coconut palms has not yet been devel-
oped to that potential. Soybeans and peanuts are annual leguminous
crops that are used as sources of both oil and protein. Soybeans thrive
best in subtropical climates. The individual varieties differ greatly in
terms of their reaction to the length of a day and normally can be grown
in a limited geographical area. Peanut cultivation requires an ambient
temperature for growth, as less than optimal temperatures are known
to result in poor yields. Due to its deep root system, it is relatively resist-
ant to drought. It is also a suitable crop for mixed cultivation along
with oil palms and corn. In terms of calorific value of seed, oil plants such
as Simmondsia chinensis, Pittosporium resinifreum, Ricinus communis,
Jatropha curcas, and Cucurbita foetidissima are found to be ideal.
Buffalo gourd (Cucurbita foetidissima), a desert-adapted plant, pro-
duces high-quality oil and fermented starch. The oil has a high ratio of
unsaturated to saturated fatty acids. Crude protein and fat content in
the whole seeds is 32.9% and 33%, respectively [8]. With a seed yield of
3000 kg/ha and estimated 16% hydrocarbon, about 35 barrels of crude
oil could be produced per hectare, in addition to carbohydrate from
roots, forage from vines, and protein-rich oil cakes. Jojoba (Simmondsia
chinensis) is a shrub that grows naturally in the United States and
Mexico. Its seeds contain about 50% of oil by weight and does not
decrease with long-term storage. The oil is remarkably resistant to
degradation by bacteria, probably because it cannot cleave and metab-
olize the long-chain esters it contains (mostly hydrocarbons containing
38–44 carbon atoms). Jojoba oil has potential uses as a fuel and chem-
ical feedstock, and can also be used as a replacement for vegetable oils
in foods, hair oils, and cosmetics since it does not become rancid.
Additionally, it can be used as a source of long-chain alcohols for
antifoaming agents and lubricants. The hydrogenated oil is a white,
hard crystalline wax and has potential uses in preparation of floor and
automobile waxes, waxing fruit, impregnating paper containers, and
manufacturing of carbon paper and candles. Physic nut (Jatropha
curcas), a tropical American species, is a large shrub, or a small tree.
The seeds yield 46–58% oil of kernel weight and 30–40% of seed weight.
In trade, this oil is called curcas oil. All parts of the plant exude sticky,
opalescent, acidic, and astringent latex, containing resinous substances.
The bark of this plant is a rich source of tannin (31%) and also yields a
dark-blue dye. Now Jatropha oil, a semidrying oil, is in high demand