Improvement of fuel properties of used palm oil derived biodiesel with butyl ferulate as an additive

Abstract

The present study addresses the significant utility of Used Palm oil Methyl Ester (UPOME) and enhancing the capabilities by adding butyl ferulate. This phenolic antioxidant ester was synthesized using Rhizopus nevius lipase immobilised onto cuttlebone. The butyl ferulate synthesis was monitored in RP-HPLC and confirmed via GC-MS. Concurrently, UPOME was prepared using KOH as the catalyst from the used palm oil. The UPOME was fortified with ferulic acid and butyl ferulate, separately at various concentrations and subjected to thermal oxidation at 110 °C. Biodiesel prepared were estimated for oxidative stability by pattern variations deciphered from the excitation-emission matrix profile. Similarly, the induction period (IP) of the prepared biodiesels was analysed in Rancimate. The addition of the butyl ferulate at 600 ppm in UPOME was able to reduce 80% of the hydroperoxide formation whereas the free ferulic acid showed Stokes shift at the same condition and concentration. Comparatively, 3.5 fold escalation in IP was observed in UPOME with 1000 ppm butyl ferulate than the free ferulic acid. Emission characteristics depicted a significant reduction in NOx (4.7%), CO (27.8%), CO2 (8.3%) and Unburned Hydrocarbons (5.7%) when fuelled B20 with 1000 ppm BF in Compression Ignition engine.