BIODIESEL FUEL FROM ANIMAL FAT - ANCILLARY STUDIES ON TRANSESTERIFICATION OF BEEF TALLOW

Transesterification of beef tallow was investigated. The solubility of ethanol in beef tallow was much higher than that of methanol. At 100 degrees C the solubility of methanol was 19% (w/w). The solubility of ethanol in beef tallow reached 100% (w/w) at about 68 degrees C. For t he distribution of methanol between beef tallow methyl esters (BTME) a nd glycerol, the percentage of total methanol in the glycerol phase wa s higher than that in the fatty acid methyl ester (FAME) phase in a si mulated system at room temperature. At 65-80 degrees C, however, the p ercentage of total methanol in FAME (60% (w/w)) was higher than that i n glycerol (40% (w/w)) in a 90:10 (w/w) blend of FAME and glycerol. Th is coincided with the methanol distribution in the transesterified pro duct. The process for making beef tallow methyl esters should recover methanol using vacuum distillation, separate the ester and glycerol ph ases, and then wash the beef tallow methyl esters with warm water. At neutral pH, the separation of ester and glycerol and water washing was easier because it reduced emulsion formation.