الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
As a result of the enormous demand for energy and the shortage of the fossil fuels, searching for alternative sources of energy is an urgent necessity. Biodiesel is a suitable substitute of petrodiesel. Biodiesel liquid fuel is sustainable, biodegradable, non-toxic, more environmentally friendly, has lower emissions and can be blended with petrodiesel. Biodiesel is produced by a homogeneous base-catalyzed (NaOH, or KOH) transestrification of vegetable oils and methanol (or ethanol). However, the production of biodiesel in Egypt faces many problems. The first problem is the high production cost due to the high price of the refined oil. This research addresses this problem by using waste frying oil (home domestic and Chipsy waste frying oils) to lower the production cost and avoid blockages of sewer pipes and the water pollution due to disposing the waste oil in sinks, rivers and seas. However, the major technical problem of using waste frying oil is its high content of free fatty acids ≥ 2%.These acids deplete the basic catalyst (NaOH, KOH) through a saponification reaction. Theresulting soap makes biodiesel production and separation difficult.The use of homogeneous acid-catalyzed (H2SO4) esterification will convert free fatty acids to biodiesel. Reducing the free fatty acid to 2% will prevent the saponification reaction and the undesirable effect of soap. This research investigated the use of several types of acidic heterogeneous catalysts (AMPS resin, amberlyst 36 wet, ferric sulfate, and cadmium sulfate)and comparing the esterification results to the traditional homogeneous esterification catalyst, H2SO4. The optimum % FFA conversion was recorded at operation condition of 6:1 methanol to oil molar ratio, 50 ºC, 300 rpm, for 120 min by using 3 % w/w AMPS resin. This resulted in nearly the same % conversion as the homogeneous 0.25 % H2SO4. However, AMPS resin is more expensive (825 LE/kg) than H2SO4 (27.17 LE/kg), which hinders the use of AMPS resin.The second problem is the corrosion and pollution generated as a result of using homogeneous catalysts. They also form water during esterification which slows the process. Water removal leads to additional costs. This research addresses this problem by using the lowest amounts of H2SO4 for the esterification process and by using effective and low cost heterogeneous catalysts in transesterification process, which can be separated easily. In addition, heterogeneous catalysts result in a higher biodiesel yield (from 95.5 – 98.99%) than homogeneous catalysts (79.3%).Several types of heterogeneous alkaline catalysts were prepared. These include Ca – Znmixed oxides, Ca – Mg mixed oxides, Acrylamide alkaline resin, phosphate rock and CaO commercial grade. While all the catalysts are effective, CaO and phosphate rock are the least expensive and hence were selected for this research. The next step was to determine the optimum operating condition for transesterification of esterified Chipsy waste frying oil using CaO and phosphate rock as heterogeneous catalysts.The biodiesel yield produced from using CaO (91.43%) was very close to that produced from using phosphate rock (90.9%). The optimum conditions for transesterification process are found to be 3:1 methanol to oil molar ratio, at 55 ºC, 300 rpm, with 3 % heterogeneous catalyst loading, and 30 min reaction time. By applying these conditions in a prototype for biodiesel production, CaO was very difficult to separate from biodiesel by forming emulsion.However, phosphate rock was better in separation and gave about 91 % actual biodiesel yield. iii To reduce petrodiesel consumption, the produced biodiesel was mixed with petrodiesel to produce B10 and B20 biodiesel blends. The physical and chemical properties of biodiesel,B10 and B20 were analyzed and the results confirmed the compatibility of these fuel blends for use in diesel engines. Moreover, biodiesel blends in most tests have improved the petrodiesel properties. Density was increased by (0.7 – 1.4%), viscosity was increased by (24.7 – 84.7%), and flash point was increased by (8.1 – 12.2%) and cloud point was decreased by (23 – 30%), pour point was decreased by (62 – 100%), sulfur content was decreased by (14– 24.6%) and ash content was decreased by 95%. The biodiesel blends calorific value (net,gross) and cetane index are very close to the petrodiesel. For the water content test, the results were within its acceptable ranges according to ASTM. The B10 and B20 blends were tested in a diesel engine. Biodiesel blends improved the petrodiesel performance in the diesel engine. Compared to petrodiesel, biodiesel blend decreased the fuel consumption by (3.5- 37.5%), decreased the brake specific fuel consumption (5- 10.7%), and increased the brake thermal efficiency by (1- 23.7%) The exhaust emissions produced from the B10 and B20 blends combustion were measured compared with petrodiesel. B10 and B20 blends reduced the emissions of HC by (8- 28%),CO by (6- 23.5%) and net emissions of CO2 by (3 to 16%). However the NOx emission produced from biodiesel blends combustion is increased from 4 to 9 ppm, which is consistent with other investigations.