Biodiesel effects on fuel filter; assessment of clogging characteristics

Material compatibility is still one of the serious problems in the application of biodiesel on diesel engine. One of the main causes of the problem is related to the flow-ability and filterability of biodiesel. Due to its physical and flow properties, biodiesel potentially caused a blockage in the filter higher than petro-diesel. The profile and mechanism of filter clogging or blockage due to the use of to biodiesel and the blends are investigated in the present work. Typical fuel oil filter used is a cartridge with media made from porous synthetic materials. Biodiesel used in this work is palm oil-based which is applied purely and in the blends of petro-diesel with composition of 20:80 (B20). It was tested in on boiler fuel system. Fuel passed on the system through the filter with a contact time of 3500 hours. The filter media is also observed by immersing it in B20 and B100 in the same time period. The result showed that the filter contacted to biodiesel was clogged faster than diesel oil (B0). On endoscopy microscope image, the filter media surface was clearly degraded. It shown that the pores of filter media are mostly covered by oil sludge. The filter blocking tendency (FBT) value is used to predict filter clogging time limit. In this work, the use of B20 performing FBT in ranges from 1.51-1.84, whereas the use of B100 ranges of 1.58-2.42 in a contact period of 3500 hours. The premature blockage was occurred in filter media contacted to B100, and a filter replacement is then required to conduct before 8 months. There is a significant relationship between the moisture content of biodiesel on the rate and characteristics of the filter clogging.