Volume 11 Issue 3 ( September 2024)

Several studies on the use of elastomers in biodiesel have primarily focused on how the characteristics of elastomers change when exposed to biodiesel. However, information on the changes in biodiesel characteristics remains limited. This study examined the characteristics of B30 and B40 palm-based biodiesel blends during elastomer exposure. The elastomers were submerged in static B30 and B40 for 1007 hours at ambient temperature. Following 71, 167, 671, and 1007 immersion hours, the characteristics of the biodiesel blends, such as total acid number, water content, color, and oxidation stability, were analyzed. The results show that NBR has the most significant effect on the decline in the quality of B30 and B40, followed by EPDM. In contrast, fluoroelastomer has almost no significant effect. The total acid number of the biodiesel blends increased during NBR immersion. However, fuel immersed in EPDM and fluoroelastomer exhibited opposite trends. The water content characteristic generally increased over time during the 1007 immersion hours of the elastomers; the biodiesel blends observed a significant color change from 0.8 to >2.8 for NBR, 0.8 to 3.50 for EPDM during 71 immersion hours, then had a constant tendency up to 1007 immersion hours. The biodiesel's oxidation stability significantly decreased by 96% for NBR and 97% for EPDM during 71 hours of immersion. However, after 1007 immersion hours, oxidation stability increases, probably due to the absorption of biodiesel oxidation by- product by elastomers.

Keywords: palm-based biodiesel; characteristics; elastomers; immersion