The Effect of Fuel Filter Pore Size on B20 Fuel Filter Clogging at Low-Temperature Condition

One of the crucial problems in B20 implementation is fuel filter clogging problem, due to the presence of some glyceride impurities in biodiesel. The existence of monoglyceride in B20 fuel, even in a very low amount, could cause the formation of a precipitate, especially at low-temperature conditions. The accumulated precipitate could accelerate fuel filter clogging. To anticipate the problem, the precipitate formed in the B20 fuel based on the monoglyceride content in biodiesel should be tested using different pore sizes of fuel filter. This research was conducted by applying a modified CSFT method of ASTM D7501 for the precipitation test at 20°C using fuel filter pore sizes of 0.8, 3, 5 and 8 microns, respectively. Monopalmitin was added to biodiesel with low monoglyceride content to vary monoglyceride content so that each had approximate monoglyceride content of 0.623% and 0.824%, respectively. Each biodiesel sample with varied monoglyceride content was then blended with petroleum diesel fuel to produce B20 fuel samples. Each sample in the 100 ml separating funnel was separately soaked at 20°C for 21 days, then filtered, washed with petrol-ether, vacuum-dried, and weighed for constant amount of precipitate retained on the filter. The result showed that the wider the filter pore size was, the less the precipitate amount could be maintained on the filter.