Characterization of Palm Biodiesel Deposit on The Locomotive Engine Fuel Filters: Composition, Physical, Chemical Properties

High ratio biodiesel blend fuel has become mandatory for all sectors including road and non-road vehicles since 2016. All stakeholders of biofuel in Indonesia had conducted a specified investigation through road tests 40,000 km to evaluate the high biodiesel effect on performance, emissions, and engine components. An improvement in fuel properties of biodiesel FAME has also been stated in the new fuel standard. Moreover, the recommendation for proper high biodiesel ratio handling and storage also socialized to all stakeholders. However, shorter fuel filter mileage and fuel degradation for long storing still remain issues for the implementation of biodiesel in Indonesia. An assessment of biodiesel in a locomotive in Indonesia was conducted through a rail test conducted for 6 months with a coal train in Sumatera Island with a blend ratio of 20% by volume (B20) and pure diesel fuel (B0) as a reference. The purpose of this rail test was to investigate the effect of B20 on various factors at railway application. This paper is presented a detailed analysis of the deposits formed in the used main and used twin filters of the locomotive for one maintenance period. An analysis of morphology, elemental analysis, and its physical and chemical properties was done by using a digital microscope, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and gas chromatography-mass spectrometry (GC-MS), respectively. An analysis showed that B20 had more deposits on the main filter compared with B0, while it had fewer deposits on the twin filter. Deposit in both of main and twin filters for B20 was identified mostly from hydrocarbons and fatty acid methyl esters. Analysis results also recommended that the fuel filter mileage of B20 was still possible to be prolonged with the current fuel filter standard by considering to deposit formation for both B0 and B20 still under tolerance level.