الفهرس 
Historical reviewOnly 14 pages are availabe for public view
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Abstract
The lack of energy resources and stringent environmental standards make energy efficiency combined with environmental protection one of the most important issues to be considered in marine industry and operation. The good diesel engine not only maintains specifications but also improves the quality of fuel consumption and produces the least possible emissions. Therefore, during simulation of the diesel engine, the different operating conditions should be taken into account.There has been great interest in the recent period in the application of natural gas to convert diesel engines from single fuel engines to dual-fuel engines. The chemical and physical specifications for natural gas is promising compared to fossil fuels. It has small density helps transport and storage. It is environmental friendly in terms of the percentage of gases emitted from the combustion process such as nitrogen oxides, sulfur oxides and particulate matters. As natural gas has high resistance against autoignition, introducing natural gas in the runway to form a flammable mixture with the use of the original injector to inject the pilot fuel, whether diesel fuel or a mixture of biofuel to verify the efficiency of combustion engine and the safety of combustion on the engine and the environment. Biofuel blends are under investigations and researches to be used as alternative fuel for internal combustion engines due to their sustainability and the ability of improving the properties through manufacturing and refining processes. First pure diesel oil was compared to biofuel blends as; Jatropha methyl ester JME B100, rapeseed methyl ester RME B100 and soybean methyl ester SME B100. Also, to study the effect of introducing different concentration of diesel oil with biofuel blend; Soybean methyl ester SME B40 and SME B20 were investigated as well. All the previous blends were studied as major fuel in the model. Secondly the previous mentioned blends were used as pilot fuel for dual fuel using natural gas as major fuel, where the natural gas is added in the air intake of the engine and the blends were used as pilot fuel for combustion. Maximum cylinder pressure is found to have slight variation across using different blends of biodiesel as pilot fuel compared to diesel oil. It was noted that the quantity of SOX emission was decreased obviously while comparing between diesel oil to biodiesel blends. NOx emissions were higher when compared to D.O. The net calorific value of the biodiesel is lower than that of diesel fuel.This may explain the increase in fuel consumption to achieve the same power. The results obtained are promising to allow usage of biofuel blends as an alternative source of energy also, using natural gas is very promising regarding environmental aspects.