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Hydrogen produced from regenerative sources has the potential to be a sustainable substitute for fossil fuels. A hydrogen internal combustion engine has good combustion characteristics, such as higher flame propagation velocity, shorter quenching distance, and higher thermal conductivity compared with hydrocarbon fuel. However, storing hydrogen is problematic since the energy density is low. Hydrogen can be chemically stored as a hydrocarbon fuel. In particular, an organic hydride can easily generate hydrogen through use of a catalyst. Additionally, it has an advantage in hydrogen transportation due to its liquid form at room temperature and pressure. We examined the application of an organic hydride in a spark ignition (SI) engine. We used methylcyclohexane (MCH) as an organic hydride from which hydrogen and toluene (TOL) can be reformed. First, the theoretical thermal efficiency was examined when hydrogen and TOL were supplied to an SI engine.

A new 0W-20 gasoline engine oil was developed to improve fuel economy over ILSAC GF-2 5W-20 gasoline engine oils and to meet ILSAC GF-3 requirements. The main improvements made were to viscosity and friction modifiers. Viscosity at 80°C was adjusted to obtain better fuel economy than with 5W-20 oil in the Japanese 10-15 mode test. Therefore, low-temperature viscosity decreased to 0W and high-temperature high-shear viscosity exceeds 2.6 mPa?s. Friction modifiers and other additives were investigated to find the lowest friction characteristics. The resulting formulation shows more than a 2.0% fuel economy gain in the Japanese 10-15 mode test and the new oil has been certified as meeting ILSAC GF-3 requirements.

The internal combustion engines waste large amounts of heat energy, which account for 60% of the fuel energy. If this heat energy could be converted to the output power of engines, their thermal efficiency could be improved. The thermal efficiency of the Otto cycle increases as the compression ratio and the ratio of specific heat increase. If high octane number fuel is used in engines, their thermal efficiency could be improved. Moreover, thermal efficiency could be improved further if fuel could be combusted in dilute condition. Therefore, exhaust heat recovery, high compression combustion, and lean combustion are important methods of improving the thermal efficiency of SI engines. These three methods could be combined by using hydrous ethanol as fuel. Exhaust heat can be recovered by the steam reforming of hydrous ethanol. The reformed gas including hydrogen can be combusted in dilute condition. In addition, it is cooled by directly injecting hydrous ethanol into the engine.