Oxidation stability of blends of Jatropha biodiesel with diesel

Biodiesel, an ecofriendly and renewable fuel substitute for diesel has been receiving the attention of researchers around the world. Due to heavy import of edible oil, the production of biodiesel from edible oil resources in India is not advisable. Therefore it is necessary to explore non-edible seed oils, like Jatropha curcas (J. curcas) and Pongamia for biodiesel production. The oxidation stability of biodiesel from J. curcas oil (JCO) is very poor and therefore an idea is given to increase the oxidation stability of biodiesel by blending it with petro-diesel. J. curcas biodiesel (JCB), when blended with petro diesel leads to a composition having efficient and improved oxidation stability. The results have shown that blending of JCB with diesel with less than 20% (v/v) would not need any antioxidants but at the same time, need large storage space. Similarly, if the amount of diesel is decreased in the blend, it will require the addition of antioxidant but in lesser amount compared to pure JCB. For the purpose five antioxidants were used namely butylated hydroxytoluene (BHT), tert-butyl hydroquinone (TBHQ), butylated hydroxyanisole (BHA), propyl gallate (PG), and pyrogallol (PY). A B30 blend (30% JCB in the blend of JCB and petro-diesel) has been tested for the same purpose. PY is found to be the best antioxidant among all five antioxidants used. The optimum amount of antioxidant (PY) for pure biodiesel tested for the present experiment is around 100 ppm while it is around 50 ppm for B30 blend to maintain the international specification of oxidation stability.