Alkaline and Acidic Biodiesel Production from oily Seeds of Terebinth (Pistacia terebinthus) plant and Physicochemical Properties of the Biodiesels

The objective of the paper is to evaluate the physicochemical properties of the biodiesel produced by alkaline and acidic transesterifications of seed oil of wild Terebinth (Pistacia terebinthus) plant from Şirnak province. The terebinth tree is widely distributed in Şirnak province and its oily seeds are consumed mostly as a snack by local people. Transesterification is the process of exchanging the alkyl groups of an oil or fat with the methyl groups from short-chain alcohols (methanol) in the presence of an acidic, alkaline or enzymatic catalyst. The results of alkaline and acidic biodiesels from terebinth oil is as follow: the kinematic viscosity of alkaline biodiesel was found to be 4.88 mm2/s (40 °C), density was 0.8644 g/cm3 (15°C), the flashpoint was 134°C, calorific value was 38.250 (kJ/kg), cetane number was 41 and a water content was < 250 mg/kg; the acidic biodiesel had a kinematic viscosity of 5.14 mm2/s (40 °C), the density of 0.8907 g/cm3 (15 °C), a flashpoint of 195°C, calorific value of 36.300 (kJ/kg), cetane number of 34, and the water content of < 250 mg/kg. In conclusion, the analysis indicated that biodiesel can be produced from terebinth oil by two methods and the results showed that the physicochemical properties of the biodiesels were as good as previously released biodiesel qualities, however, alkaline biodiesel was much qualified than acidic biodiesel.