Page 125 - Advances in Eco-Fuels for a Sustainable Environment

Prospective ecofuel feedstocks for sustainable production 97

acid (1.2wt%), palmitic acid (18–25wt%), stearic acid (1–2.5wt%), oleic acid
(17–38wt%), linoleic acid (45–55wt%), and palmitoleic acid (1–2wt%) [12].
Chattopadhyay et al. [33] stated that the maximum conversion of cottonseed oil to
biodiesel obtained has been 80% at a reaction temperature of 37°C for a methanol
to oil molar ratio of 15:1 in a reaction time of 4h using 0.5% (wt of oil) enzyme
(lipase) catalyst and 5% water concentration. Some of the physical properties
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exhibited by cottonseed oil biodiesel include a kinematic viscosity of 10mm /s, a flash
point of 130°C, and a calorific value of 38.6MJ/kg [33].

Passion fruit seed oil (Passiflora edulis)
Passion fruit (Passiflora edulis) is grown in tropical climatic regions and is native to
South America. Passion fruit is considered a potential source of biodiesel and is
widely grown in Brazil. After the extraction of juice from the fruit, the seeds are usu-
ally discarded. The oil content of the seed is 18.5–28.3wt%. The passion fruit seed oil
consists of saturated and unsaturated fatty acids such as palmitic acid (8.8–11.0wt%),
stearic acid (2.2–3.1wt%), oleic acid (13.6–16.9wt%), linolenic acid (0.3–0.4wt%),
and linoleic acid (67.8–74.3wt%) [12]. According to work carried out by Farias et al.
[34], the conversion of 95.8% of passion fruit oil to biodiesel has been obtained for a
methanol to oil molar ratio of 9:1 and 1% (wt of oil) KOH catalyst. Some of the prop-
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erties of passion fruit oil biodiesel include a kinematic viscosity of 3.7mm /s, an acid
value of 0.27mgKOH/g, a pour point of 5°C, and a cloud point of 4°C [34].

Moringa oil (Moringa oleifera)
Moringa (Moringa oleifera) is an oilseed tree belonging to the Moringaceae family
and it grows 5–10m in height. Moringa is distributed in the Philippines, Cambodia,
and Central and North America; it is indigenous to sub-Himalayan regions of north-
west India, Africa, Arabia, Southeast Asia, the Pacific and Caribbean Islands, and
South America. M. oleifera, which are fast-growing and drought-tolerant, can tolerate
poor soil, a wide rainfall range (25 to 300+cm per year), and soil pH from 5.0 to 9.0.
The oil content in a fully matured and dried seed is between 33 and 41wt%. Because
Moringa oil contains 7.1wt% of behenic acid, it is commercially known as “ben oil” or
“behen oil” [35]. The fatty acid profile shows that Moringa oil contains palmitic acid
(6.5wt%), stearic acid (6wt%), oleic acid (72.2wt%), linoleic acid (1.0wt%), and
arachidic acid (4.0wt%) [12]. Rashid et al. [36] found that maximum conversion
of moringa oil to its corresponding methyl esters obtained was 94.30% for a methanol
to oil ratio of 6.4:1 at a reaction temperature of 55°C in a reaction time of around
70min and using 0.80% (wt of oil) KOH catalyst. Some of the properties displayed
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by moringa oil biodiesel include a kinematic viscosity of 4.80mm /s, a cetane number
of 67.0, an acid value of 0.38mgKOH/g, a flash point of 162°C, a cloud point of 18°C,
and a pour point of 17°C [36].

4.2.1.3 Nonedible oils
The following are the commonly used nonedible oils for the production of biodiesel.