| dc.description.abstract | Biodiesel has developed as a plant-based fuel alternative over the last
20 years and is now a substitute for fossil diesel oil. Compared to fossil diesel,
palm oil biodiesel offers advantages in terms of emissions, toxicity,
biodegradability, engine lubrication, and contribution to national energy security.
Although palm biodiesel has good quality, its oxidative stability is still lower
than that of fossil diesel. This is due to the content of polyunsaturated fatty acids,
which ranges from 9-12%, significantly affecting oxidative stability. To improve
this stability, methyl esters of polyunsaturated fatty acids need to be removed
through a liquid-liquid extraction process using a silver nitrate (AgNO3) solution.
The extraction process is carried out with various concentrations of AgNO3 (1
M and 5 M), methanol content in the solution (10%-v, 25%-v, and 50%-v), and
the biodiesel to AgNO3 ratio (1:1 and 1:2) at a temperature of 25- 35°C for 3
hours, followed by the separation of extract and raffinate for 45 minutes. The
research results show that the induction period for all variations experienced a
decrease compared to biodiesel before extraction. However, GC-MS analysis and
iodine number indicated a reduction in polyunsaturated fatty acid methyl esters
after the extraction process. The best results in the extraction process were
obtained with the variation of 1 M, 10%-v methanol, and a 1:1 ratio, with an
induction period of 15.26 hours, polyunsaturated fatty acid methyl ester
composition of 0.08%, and iodine number of 49.76 g iodine/100g. | en_US |
