COMPARISON OF DIESEL ENGINE CHARACTERISTICS USING PURE PLANT OIL (PPO) FROM COCONUT, PALM, AND PHYSIC NUT

• Main Author: Hartanto, Yuda
• Format: Theses
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/41586
• Institution: Institut Teknologi Bandung

Diesel engine can be operated on either pure plant oil (PPO) oil or biodiesel. In biodiesel process, it will increase cost production due to many stages of processes, while PPO shows an opposite condition. There are several potential resources in Indonesia: coconut, palm, and physic nut, because these are tropical plants and also has a vast majority of quantity. Engine was running in 17 hours endurance test with various operating conditions. This experiment was using 815cc single cylinder, direct injection, four strokes diesel engine. Maximum power of the engine is 9,7kW with compresion ratio 20. Engine was connected to 5kW electric generator, which water heaters role as loads. Test fuels are including pure coconut oil (PCO), pure palm oil (PPaO), pure jatropha oil (PJO), and diesel fuel as a datum. Each PPO blends with diesel fuel with composition 50%-volume. Characteristics of PPO are high viscosity, low volatility, and low energy content. As a result, PCO has higher BSFC (10%) before endurance test in comparison with diesel fuel, also PPaO (13%) and PJO (27%) show a similar condition. Surprisingly, after endurance test all PPO have BSFC almost similar with diesel fuel because decreasing of engine components friction. On the other hand, PPO produce less complete combustion than diesel fuel because bad spray characteristic. It is evident that low CO2 emission and high UHC, CO, O2, and opacity emissions. The drawbacks are phosporus content, unsaturated fatty acid content, and low combustion quality of PPO, which leads to higher engine deposit than diesel fuel. Phosporus content has major responsibility of deposit growth. In comparison with diesel fuel, PCO, PPaO, and PJO result more engine deposits than diesel fuel, which accounts for 139,7%, 232,9%, and 288,9% respectively. PPO gives well antiwear property on plunger and injector. Evidently, using of PPO has a lower wear than diesel fuel does. Fatty acids content in PPO give those results. PCO has the best antiwear property among test fuels, whereas the worst is PJO. The difference of carbon chainlength causing each PPO has antiwear property differently.