**5. Feedstock used for the production of biodiesel**

The feedstock is one of the key factor that plays vital role in the economics of the biodiesel technology. More than 350 oil-bearing crops have been identified as a potential feedstock for the production of biodiesel. The feedstock should fulfill two main requirements (i) large production scale (ii) low production cost [59]. The feedstock availability for the production of biodiesel depends upon the geographical location, local soil conditions, regional climate and agricultural practices of any country. The suitability of feedstock depends upon various factors such as oil yield per hectare, production cost, oil content of the seeds and relevant product properties of the oil. It has been found that, the cost of the feedstock is about 75% of overall production cost of biodiesel [60]. Therefore, selection of cheapest feedstock is a major problem and high relevant to the biodiesel industry. Biodiesel feedstocks are generally categorized into four classes as shown (**Figure 11**).
