Page 122 - Advances in Eco-Fuels for a Sustainable Environment

94 Advances in Eco-Fuels for a Sustainable Environment

oil is more viable than soy oil in the world market, the production of biodiesel from
peanut oil is not economically viable [12]. The work carried out by Kaya et al. [18]
shows that an optimized conversion of 89% has been obtained from peanut oil at 60°C
for a methanol to oil molar ratio of 6:1 and using 0.5% (wt of oil) NaOH as a catalyst.
Some of the properties of peanut oil methyl esters include a kinematic viscosity of
2
4.42mm /s, a calorific value of 40.1MJ/kg, a cetane number of 53.59, a cloud point
of 0°C, and a pour point of 8°C [18].

Palm oil (Elaeis guineensis)
One of the most economically suitable as an alternative biodiesel source among all the
conventional edible biodiesel feedstocks is palm (Elaeis guineensis). It is famous and
extensively cultivated among all the plant families. It is grown in all tropical areas
where the weather is hot and humid; countries such as Malaysia and Indonesia are
ideal for the cultivation of palm [21]. A palm tree can yield average oil 3–4 times
higher than any other conventional feedstocks employed in the biodiesel production
such as rapeseed or sunflower [22]. The massive production of biodiesel from palm oil
permits it to be used in the production of biodiesel, even though it is edible. The palm
fruit consists of an outer pulp and two or three kernels. The pulp of the fruit forms the
source of crude palm oil and the kernels form the source of palm kernel oil. The palm
oil requires extra methanol transesterification before it can be used as biodiesel
because it has high levels of fatty acids and this increases the cost of the production
somewhat. The fatty acids found in palm oil are myristic acid (0.5–2wt%), palmitic
acid (32–45wt%), stearic acid (2–7wt%), oleic acid (38–52wt%), and linoleic
acid (5–11wt%). The fatty acid profile of palm kernel oil shows the presence of sat-
urated fatty acids such as caprylic acid (3–5wt%), capric acid (3–7wt%), lauric
acid (40–52wt%), myristic acid (14–18wt%), palmitic acid (7–9wt%), stearic acid
(1–3wt%), and unsaturated fatty acids such as oleic acid (11–19wt%) and linoleic
acid (0.5–2wt%) [12]. As per the work carried out by Mootabadi et al. [23], an opti-
mum conversion of 95.2% palm oil to methyl esters has been obtained in a reaction
time of 60min using a BaO catalyst via the ultrasound-assisted transesterification
process. Some of the properties of palm oil methyl esters include a kinematic viscosity
2
of 4.61mm /s, a flash point of 140.5°C, and an acid value of 0.40mgKOH/g [21].

Sunflower oil (Helianthus annuus)
Sunflower (Helianthus annuus L.) with high oil content is one of the most prominent
oilseed crops used in the production of biodiesel. Sunflower belongs to the family
Compositae. The total oil content in sunflower is 25%–35%. Sunflower oil has high
amounts of unsaturated fatty acids. Approximately 70wt% of sunflower oil is lin-
oleic acid and is highly susceptible to lipid oxidation [24]. The other fatty acids
in sunflower oil are myristic acid (1wt%), palmitic acid (3–6wt%), stearic acid
(1–3wt%), arachidic acid (0.5–4wt%), oleic acid (14–35wt%), and linolenic acid
(<1.5%) [12]. Antolin et al. [25] obtained a methyl ester yield of 96% from sun-
flower oil at a reaction temperature of 70°C for a methanol to oil molar ratio of
3:1 using 0.28% (wt of oil) KOH as a catalyst. The physical properties exhibited