T HE INCREASE in fuel demand consumption led to search about alternative fuels. Screw press was used to extract oil from roselle seeds at a temperature of 45 °C and motor speed of 30 rpm. Biodiesel was produced from roselle oil. Biodiesel blends were prepared from diesel and roselle biodiesel in volume percentages of 10 and 20 %. The experiments were run at engine load variations from start to full load. Thermal efficiency for roselle methyl ester blends was higher than diesel oil. Biodiesel blends achieved lower specific fuel consumptions of roselle methyl ester blends about diesel fuel. CO and HC emissions for biodiesel blends were decreased of diesel fuel. Biodiesel blends showed higher NOx emissions for biodiesel blends about diesel fuel. Roselle rmethyl ester blends up to 20% percentage are used as alternative fuels because performance and emissions were improved compared to diesel fuel.

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Increase of fossil fuel consumption rates, depletion of conventional fuel, harmful exhaust emissions increase and global warming. This concludes to search for alternative fuels. This study was performed to produce a suitable alternative fuel. The produced oil from non-edible jatropha seeds becomes researcher's interest because of the higher price of edible vegetable oils. Design, manufacturing, and testing of an efficient system to produce the oil from Egyptian jatropha seeds was carried out. This hydraulic press squeezes jatropha seeds to produce the oil. It is designed to obtain the maximum oil yield. Physical and chemical parameters such as specific gravity, kinematic viscosity, calorific value, flash number and cetane number of the extracted oils were measured. Time of oil extracted from jatropha seeds is 720 minutes at a yield of 11%. The extracted Jatropha oil gave light color because of its low FFA of 5%. The density and viscosity of the extracted oil decreased as the temperature increases. The flash point of the oil is higher than diesel oil. Calorific value of the produced jatropha oil was 39201 kJ/kg. Jatropha biodiesel oxidation instability increased for hydraulic extraction due to its content of oleic and linoleic acids.

Bench-scale refining of crude colour-fixed cottonseed oil was carried out using equipment and conditions similar 10 those ;it a local factory. Ethanolamine at 2 ~ 3"" level resulted in 55---62", reduction in the oil colour, and 24-26 o?; reduction in the refining loss over the factory treated oil. Sodium silicate at 0.14-0.47',, level resulted in about 50% reduction in oil colour and 24-440., reduction in the refining loss. A two-step treatment, first with caustic soda lye then with either additives. and miscella relining using ethanolamine as an additive, resulted in superior oil colour, yet the refining losses were high.

The purpose of this research is to study the influence of extraction methods (solvent, soxhlet, screw and hydraulic) on the properties of jatropha oil. This study was established to use the exhaust heat recovery to preheat the extracted oil. The free fatty acid, and the properties of jatropha oils extracted using various methods were determined. The oil yields are 19, 11, 25 and 20% for screw, hydraulic, Soxhlet and solvent extraction processes, respectively. Free fatty acids were 2.7, 5, 17.6 and 21.1% for the oils extracted using the screw press, hydraulic, solvent and soxhlet methods, respectively. Linoleic, oleic, palmitic, and stearic fatty are the major fatty acids in the extracted oils. Measured calorific values of jatropha oil extracted following soxhlet, solvent, screw and hydraulic processes methods were 39135, 38808, 39128, 39201 and 38789 kJ/kg, respectively. For jatropha oil extracted by soxhlet, solvent, screw, hydraulic, and biodiesel methods, the evaluated cetane numbers were 37.53, 37.62, 37.83, 39.12, and 42.62, respectively. Effect of oil preheating on density and viscosity was investigated. As the temperature of the oil increased, the density and viscosity of the oil decrease.