| The density, kinematic viscosity, acid value, sulfur content and oxidation stability of seventeen kinds of biodiesel feedstock oils were determined and analyzed. The results showed that the densities (20℃)of the oils were 0.89-0.93 g/cm3 and they decreased with temperature rising; all the kinematic viscosities were higher than 30 mm2/s, in which swill-cooked dirty oil reached 62.64 mm2/s; sulfur contents were relatively low, while sesame oil was especially high, reaching 201.48 mg/L; acid values had significant difference among the oils with the highest of swill-cooked dirty oil (164.47 mgKOH/g) and the lowest of soybean oil (1.31 mgKOH/g), and the acid values of Jatropha curcas
L. seed oil and rubber seed oil were 5.58 and 5.53 times of their fresh oils after storage for 720 d; the oxidation stability of castor seed oil was the best with induction period reaching 39.10 h, while that of swill-cooked dirty oil was the worst with 1.07 h of the induction period, and the induction period of Jatropha curcas L. seed oil shortened from 15.90 h to 5.24 h after storage for two years. |
