US EPA

1225026 

Book/Book Chapter 

COMPARISON OF BIODIESELS PRODUCED FROM WASTE AND VIRGIN VEGETABLE OILS 

Hung, YS; Chen, YH; Shang, NC; Chang, CH; Lu, TL; Shie, JL; Chang, CY 

2010 

Zhonghua Minguo Huanjing Gongcheng Xuehui (Chinese Institute of Environment Engineering) 

20 

6 (Nov 2010) 

417-422 

In this study, a two-step process (acid catalyzed esterification followed by alkali catalyzed transesterification) was employed to convert waste vegetable oil (WVO), which showed the free fatty acids of 1.33 wt%, acid value of 2.66 mg KOH g super(-1), and the kinematic viscosity at 40 degree C of 39.5 mm super(2) s super(-1), into the biodiesel. The WVO biodiesel was synthesized under the following conditions: the methanol to oil molar ratio of 6, the H sub(2)SO sub(4) catalyst dosage of 0.5 wt% based on the oil weight, and the reaction temperature of 45 degree C for the acid catalyzed esterification; the methanol to oil molar ratio of 9, the KOH catalyst dosage of 2 wt% based on the oil weight, and the reaction temperature of 60 degree C for the alkali catalyzed transesterification. The acid values of the esterified WVO and the WVO biodiesel were determined as 1.42 and 0.18 mg KOH g super(-1), respectively. In addition, a single-step process (alkali catalyzed transesterification) was used to convert virgin vegetable oil (VVO) to biodiesel for comparison. These two oils were successfully converted to biodiesel while the ester contents of the WVO and VVO biodiesels were 98.8% and 99.3%, respectively. As a result, the WVO biodiesel had less polyunsarurated fatty acid methyl esters, higher kinematic viscosity, and lower oxidation stability compared to those of the VVO biodiesel. Furthermore, the fuel properties of two biodiesels can satisfy most biodiesel standards except the cold filter plug point and oxidation stability.