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Indonesia has planned for the implementation of B30 fuel in 2020, and as a consequence, a large-scale production of biodiesel from palm oil will be significantly increased in the country. In application as public transportation fuel, biodiesel quality and blending composition play an important role for the success of the implementation of B30 program. Indonesia consists of highlands and lowlands as urban areas that have different temperature regions varying from 12 - 35°C. Cold temperature could accelerate the formation of precipitate of B30 fuels. Samples of B30 fuels were made by blending biodiesel and/or hydrogenated vegetable oil (HVO) with Euro 3 and Euro 4 petro diesel fuels. The precipitate composed of monoglycerol and FAME. Precipitation of the chemicals was caused by their higher melting point that crystallized and the solvency effect of petro diesel in cold temperature.

Indonesia has implemented mandatory for utilization of high ratio biodiesel starting from B10 (10% of biodiesel and 90% of diesel fuel by volume) in 2013 then it gradually increased to B20 in 2016 and B30 in 2020. On the other hand, Indonesian Government will also strengthen vehicle emission regulation from Euro 2 to Euro4 in 2021. Therefore, B0 (low sulfur diesel fuel) and B100 (biodiesel) fuel properties as blended fuel for B30 must be improved to comply with Euro4 vehicle emission regulation. In this study various formulation of B30 were investigated, in which the B100 was varied from FAME (fatty Acid Methyl Ester), HVO (Hydrotreated Vegetable oil), and blend of FAME and HVO. The test was conducted under Euro4 vehicle technology to investigate their effect on emissions, fuel consumption and power. In this experiment, emission, fuel consumption and power were tested using UN-ECE R83-05 regulation, UN-ECE R101 and acceleration method respectively.

Water and diesel fuel emulsions containing 13% and 26% water by volume were investigated in a modern diesel engine with relatively early pilot injection, supercharging, and cooled EGR. The heat release from the pilot injection with water emulsions is retarded toward the top dead center due to the poor ignitability, which enables larger pilot and smaller main injection quantities. This characteristic results in improvements in the thermal efficiency due to the larger heat release near the top dead center and the smaller afterburning. With the 26% water emulsion, mild, smokeless, and very low NOx operation is possible at an optimum pilot injection quantity and 15% intake oxygen with EGR at or below 0.9 MPa IMEP, a condition where large smoke emissions are unavoidable with regular unblended diesel fuel. Heat transfer analysis with Woschni's equation did not show the decrease in cooling loss with the water emulsion fuels.

Combustion and exhaust gas emissions of alcohol and vegetable oil blends including a 20% ethanol + 40% 1-butanol + 40% vegetable oil blend and a 50% 1-butanol + 50% vegetable oil blend were examined in a single cylinder, four-stroke cycle, 0.83L direct injection diesel engine, with a supercharger and a common rail fuel injection system. A 50% diesel oil + 50% vegetable oil blend and regular unblended diesel fuel were used as reference fuels. The boost pressure was kept constant at 160 kPa (absolute pressure), and the cooled low pressure loop EGR was realized by mixing with a part of the exhaust gas. Pilot injection is effective to suppress rapid combustion due to the lower ignitability of the alcohol and vegetable oil blends. The effects of reductions in the intake oxygen concentration with cooled EGR and changes in the fuel injection pressure were investigated for the blended fuels.

Silent, clean, and efficient combustion was realized with emulsified blends of aqueous ethanol and diesel fuel in a DI diesel with pilot injection and cooled EGR. The pilot injection sufficiently suppressed the rapid combustion to acceptable levels. The thermal efficiency with the emulsified fuel improved as the heat release with the pilot injection was retarded to near top dead center, due to poor ignitability and also due to a reduction in afterburning. With the emulsified fuel containing 40 vol% ethanol and 10 vol% water (E40W10), the smokeless operation range can be considerably extended even under low fuel injection pressure or low intake oxygen content conditions.

Premixed diesel combustion modes including low temperature combustion and MK combustion are expected to realize smokeless and low NOx emissions. As ignition must be delayed until after the end of fuel injection to establish these combustion modes, methods for active ignition control are being actively pursued. It is reported that alcohols including methanol and ethanol strongly inhibit low temperature oxidation in HCCI combustion offering the possibility to control ignition with alcohol induction. In this research improvement of diesel combustion and emissions by ethanol intake port injection for the promotion of premixing of the in-cylinder injected diesel fuel, and by increased EGR for the reduction of combustion temperature.