Effect of hydrotreating in biodiesel on the growth of deposits in the combustion chamber as a solution for the deposits reduction in the usage of biodiesel

The usage of biodiesel has been encouraged by government based on the issuance of The Regulation of Minister of Energy and Mineral Resources No. 12/2015 on the supply, utilization, and administration of biofuels as other alternative fuels. This regulation sets mandatory biodiesel mixture by 30 percent for national energy consumption by 2025. But the usage of biodiesel with a larger percentage in diesel engines still leaves some problems with the decline of biodiesel fuel quality and the formation of deposits in combustion chamber and injectors. The purpose of this study is to compare biodiesel fuel (B20) with Hydrotreated Biodiesel (HBD) in an experiment by using fuel droplet method on a plate to observe the characteristics and mechanism of deposit formation. Plates are heated in few temperature variations in a sealed test rig so that the conditions are similar to the engine real conditions. Deposit growth of Hydrotreated Biodiesel as known as Hydrotreated Vegetable Oil (HVO) less better than Fatty Acid Methyl Ester (FAME). It may occurred because the lubricity of HVO is very low due to the absence of sulfur and oxygen compounds in the fuel, that causes oxidation that can lead to deposits in the combustion chamber.