2.1. Non-edible oil crops in South-East Asia

Jatropha (Jatropha curcas) was not the only prominent non-edible oil crop. Other crops such as karanja (Pongamia pinnata), polanga (Calophyllum inophyllum), and neem (Azadirachta indica) were also found to be promising as alternative biodiesel feedstocks [11]. Rubber (Hevea brasiliensis) and mahua (Madhuca indica) have also shown potential and needs to be explored as biodiesel feedstock (Figure 1). The oil from the seed of these plants (Figure 2) has been considered as a waste material as it is non-edible; hence, they have the significant potential for biodiesel production.

2.1.1. Jatropha (Jatropha curcas L.)

Jatropha curcas L., a member of the family Euphorbiaceae, is a large drought-resistant multipurpose shrub with several attributes and considerable potential, and has evoked interest all over the tropics as a potential biofuel crop [12]. The lifespan of this perennial bush is more than 50 years, and it can grow on marginal soils with low nutrient content [12, 13]. Seed

Figure 2. Seeds of six different species of non-edible vegetable oils as renewable sources for biodiesel.

Figure 1. Six different species of non-edible vegetable oils as renewable sources for biodiesel.

Non-Edible Vegetable Oils as Renewable Resources for Biodiesel Production: South-East Asia Perspective

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Non-Edible Vegetable Oils as Renewable Resources for Biodiesel Production: South-East Asia Perspective http://dx.doi.org/10.5772/intechopen.73304 203

Figure 1. Six different species of non-edible vegetable oils as renewable sources for biodiesel.

Figure 2. Seeds of six different species of non-edible vegetable oils as renewable sources for biodiesel.

#### 2.1.1. Jatropha (Jatropha curcas L.)

higher demand for food and energy. Utilizing non-edible oils as a biodiesel feedstock assists the sustainability of biodiesel production and minimizes the impact directly on food supply [1].

Deforestation and destruction of ecosystem due to urbanization and plantation expansion is a big issue in utilizing edible oil as biodiesel feedstock. Furthermore, the boundary line between food and fuel is blurred since both the fields are competing for the same resources. Debating over food versus fuel is still a dilemma. There are large surplus of food crops in developed countries. However, millions of people in developing countries still face the scarcity of food. Conversion of food crops such as palm oil, coconut oil, corn, soybean, and sugarcane to biodiesel could lead to serious food shortage. Countries in South-East Asia fall in the tropical belt and have many species of crops both edible as well as non-edible ones. Developing biodiesel production based on non-edible oil is one of the scenarios for fuel security without interfering with the food supply. This is especially true for palm oil which makes up about onethird of vegetable oil as biodiesel feedstock and has become the hottest environmental topic in

High price of high quality refined edible oil makes them not feasible as tent to uneconomic for developing countries like India due to high production cost of methyl or ethyl ester from the edible oil. The cost is about four times higher compared to the cost of diesel [4]. Valuable nutrient elements in edible oil such as essential amino acids, β-carotene, α-carotene, vitamin-E, lycopene, tocotrienols, and carotenoids will be neglected, if this oil is converted to fuel.

Non-edible crops can grow in waste and unproductive land which may be helpful for reclaiming the land [1, 5, 6]. Furthermore, non-edible oils may contain toxic substances such as triterpenoids and strong odor in neem oil, and furanoflavones, furanoflavonols, chromenoflavones, flavones, and furanodiketones in karanja oil [7]. Rubber seed oil contains cyanogenic glucoside that yields poisonous prussic acid (HCN) due to enzymatic reaction [8]. Jatropha oil contains toxic phorbol esters (0.03–3.4%) [9] or curcain [10], depending on the variety. Hence, it

Jatropha (Jatropha curcas) was not the only prominent non-edible oil crop. Other crops such as karanja (Pongamia pinnata), polanga (Calophyllum inophyllum), and neem (Azadirachta indica) were also found to be promising as alternative biodiesel feedstocks [11]. Rubber (Hevea brasiliensis) and mahua (Madhuca indica) have also shown potential and needs to be explored as biodiesel feedstock (Figure 1). The oil from the seed of these plants (Figure 2) has been considered as a waste material as it is non-edible; hence, they have the significant potential for

is better to exploit these non-edible oils as feedstocks for biodiesel production.

2.1. Non-edible oil crops in South-East Asia

biodiesel production.

2. Non-edible oil merits as biodiesel feedstock

South-East Asia.

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Jatropha curcas L., a member of the family Euphorbiaceae, is a large drought-resistant multipurpose shrub with several attributes and considerable potential, and has evoked interest all over the tropics as a potential biofuel crop [12]. The lifespan of this perennial bush is more than 50 years, and it can grow on marginal soils with low nutrient content [12, 13]. Seed production is from 0.2 kg to more than 2 kg per plant [5]. The average weight per 1000 seeds is about 500–800 g, which is equivalent to 1333 seeds per kg. The seed coats constitute about 35– 40% of the total seeds. The oil content in seeds ranges from 35 to 40% and the kernels 55–60% (www.jartropha.org) [14]. Many investigations have been done on the composition and content of the jatropha seeds [15]. Optimal seed yield in good condition area is around 5 t dry seed ha<sup>1</sup> y<sup>1</sup> [16]. Seed oil contain 22.50% saturated fatty acid (16.00% palmitic acid, 6.50% stearic acid) and 78.70% unsaturated fatty acid (43.50% oleic acid, 34.40% linoleic acid, 0.80% linolenic acid) [6].

seeds is about 300–500 kg/ha/year [24]. Rubber seed kernels (50–60% of seed) contain 40–50% of pale yellow oil [25–27]. Rubber seed oil does not contain any unusual fatty acids, but is rich in polyunsaturated fatty acids C18:2 and C18:3 that make up 52% of its total fatty acid composition [28]. Rubber seed oil contains 18.90% saturated fatty acid (10.20% palmitic acid, 8.70% stearic acid) and 80.50% unsaturated fatty acid (24.60% oleic acid, 39.605 linoleic acid,

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Madhuca indica is a member of the family Sapotaceae and is commonly known as Butter Tree. Mahua oil is obtained from the seed kernel. The tree is medium to large and found in Asia. Average productivity of mahua seed is about 1.6 kg/tree [30]. The seeds contain 30–40% fatty oil, which is non-edible and used in the manufacture of various products such as soap and glycerin. It contains 31.80% saturated fatty acid (17.80% palmitic acid, 14.00% stearic acid) and

Characteristics of vegetable fats and oils depend on the length and degree of un-saturation of the fatty alkyl chains. Thus, the fatty acid plays an important role in determining biodiesel characteristics. Amount of each fatty acid, chain length, and number of double bond present in the hydrocarbon chain influences the biodiesel properties [31]. The stability of biodiesel also depends on the feedstock properties used for biodiesel production. The most abundant fatty acids in the oil samples were oleic, linoleic, linolenic, palmitic, and stearic fatty acid. Oleic acid comprises of a major portion of the total fatty acid irrespective of non-edible oil summarized in Table 1. All oils have high unsaturated fatty acids (up to 80%) which mean they have good low

Properties Jatropha Karanja Polanga Rubber Mahua Neem Diesel

Palmitic (C16:0) 16.0 11.7 12.0 10.2 17.8 14.9 — Stearic (C18:0) 6.5 7.5 12.9 8.7 14.0 14.4 — Total 22.5 19.2 24.9 18.9 31.8 29.3 —

Oleic (C18:1) 43.5 51.6 34.1 24.6 46.3 61.9 — Linoleic (C18:2) 34.4 16.5 38.3 39.6 17.9 7.5 — Linolenic (C18:3) 0.80 2.7 0.30 16.3 — —— Total 78.7 70.8 72.4 80.5 64.2 69.4 — Cetane number 52.3 55.8 57.3 — 40 57.8 46 Oilseed content, %w 55 33 65 40–50 50 44.5 — FFA %w 14 2.5 22 17 20 — — Specific gravity 0.92 0.91 0.90 0.91 — — 0.84

64.20% unsaturated fatty acid (46.30% oleic acid, 17.90% linoleic acid) [11].

16.30% linolenic acid) [29].

Saturated fatty acid

Unsaturated fatty acid

2.1.6. Mahua (Madhuca indica)

3. Characteristic of non-edible oils
