2. Non-edible oil merits as biodiesel feedstock

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 South-East Asia.

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