Multifunctional biodiesels could be synthesized from soapstocks such as palm oil, rice bran oil, and soy bean oil. Firstly, methyl ester of soapstocks could be prepared by reacting with methanol in the present of sulfuric acid to yield 96-98% of products. Finally, the nitration reaction was carried out to give 92-95% yield. Their structures were characterized by FT-IR, 1H-, and 13C-NMR. The multifunctional biodiesels could be easily blended with base diesel fuel. These compounds could rise in cetane number to 1.6, 2.0, 2.2, 2.3 and 3.9 units for multifunctional biodiesel from palm oil soapstock and 6.8, 7.7, 7.9, 12.3 and 13.4 units for multifunctional biodiesel from soy bean oil soapstock and 3.6, 3.7, 4.5, 8.5 and 8.7 units for multifunctional biodiesel from rice bran oil soapstock at the concentrations of 0.50%, 1.0%, 2.0%, 5.0% and 10.0% by weight, respectively. For lubricity performances, these multifunctional biodiesels were investigated by using high frequency reciprocating rig machine. All samples at concentration of 5% by weight could provide mean wear scar diameter of multifunctional biodiesel from palm oil soapstock less than 460 microm. In the view of cetane number and lubricity performance, the multifunctional biodiesel from palm oil soapstock was the best additive for diesel fuel.
