Eng. Hasan Abo Hashish (Master)

Bio oil extraction method has an effect on oil yield and extraction time. Extraction methods also have effects on the physical and chemical properties of oil. Oil physical and chemical properties have effects on engine performance and emissions. This led to design, manufacturing and testing a continuous system to produce bio oil. The optimum speed and preheating temperature of our screw press to get improved properties of extraction oil, minimum extraction time and minimum motor power was studied. The present screw press is specially designed on laboratory scale.

The influence of different motors speeds of 20, 60, 100 and 140 rpm and preheating temperatures 50, 75, 100 and 125°C on oil extraction yield were investigated. This is concerned with the efficient production of biodiesel from jatropha seeds. An efficient screw press for continuous production of biodiesel was designed and operated. The effects of many parameters which affect the oil yield from the screw press were studied in order to determine the optimum operating conditions for maximum yield. Physical and chemical properties of oil such as viscosity, density, calorific value, flash point and Cetane number were considered in this study for the selected extraction techniques . V

Four extraction methods were considered and thoroughly studied, namely, screw press, hydraulic press, Soxhlet and solvent. Screw press was designed, manufactured and tested on the laboratory scale to produce oil at an extraction temperature of 100°C and screw speed of 60 rpm. Hydraulic press was designed and manufactured in the present work, and solvent extraction methods were used to extract oil at room temperature. Soxhlet use petroleum ether at an extraction temperature of 70°C. The extraction temperature and extraction time were studied for the four considered processes. Effect of temperature on oil density and viscosity for the extraction processes were investigated. The effect of extraction methods on fatty acid compositions for jatropha oil was measured. Higher extraction temperatures with long extraction time result in darker color oil. Temperature has effects on viscosity and density of extracted oil by different processes. Method of extraction has an effect on free fatty acid (FFA) composition .

A single cylinder diesel engine (DEUTZ F1L511) has been employed as the test engine in the present work. For the experimental setup, the engine was equipped with all the necessary instruments to measure different engine parameters. AC generator of maximum electric power output of 4.5 kW has been coupled directly to the test engine to determine the engine brake power. In this case, an external controllable electric load bank with variable loads. The loads from 0 to full load by step 0.5 kW as (0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, and 4.5). The engine performance and exhaust emissions were tested when burning using diesel, biodiesel, preheated biodiesel at 40°C utilizing the engine exhaust, jatropha and preheated jatropha oil at 90°C by exhaust heat.

The results of performance parameters and exhaust emission are based on the study are thermal efficiency, specific fuel consumption, exhaust VI gas temperature, volumetric efficiency, air fuel ratio and CO, CO2, HC, NOx emissions and O2 concentration.

The results show that extraction of jatropha oil by screw press is more efficient in producing jatropha yield than other methods. There is a limiting minimum extraction temperature for reducing free fatty acid percentage in the produced oil. An extraction temperature of 75 or 100°C at a motor speed of 20 or 60 rpm give the maximum jatropha extraction yield. These conditions also are related to lower motor power and torque. Screw press extraction method is the optimum process because of its higher yield, good acceptable properties, continuity and lower price compared to other methods. It is therefore a suitable method for commercial production of biodiesel. Preheated jatropha oil at 90°C by exhaust has the best properties. Specific fuel consumption of preheated jatropha oil at 90°C by exhaust is the same as diesel oil. Thermal efficiency increased for preheated jatropha oil compared to diesel oil. The exhaust gas temperature for diesel oil is higher than preheated jatropha oil by about 41%. Volumetric Efficiency is decreased for preheated jatropha oil in comparison with diesel oil.