Biolubricant from spent bleaching earth oil through propylene glycol ester synthesis

摘要

An ester type biolubricant, propylene glycol ester, has been synthesized from spent bleaching earth oil (SBEO). First, SBEO was pretreated to remove coloring materials via adsorption using activated carbon, to reduce FFA (free fatty acid) via esterification using acid catalyst, to separate glycerol via transesterification using methanol, and to produce FAME (fatty acid methyl ester) or biodiesel. The transesterification process of the treated SBEO, using methanol and KOH as base catalyst at molar ratio 1:6 (SBEO:methanol) produced FAME with 99.21% yield. Then, FAME was reacted with propylene glycol to produce propylene glycol ester (biolubricant). The transesterification process of the FAME with propylene glycol produced propylene glycol ester biolubricant with 92% yield. The biolubricant gave flash point 252°C and pour point -7°C.