Electronic Theses and Dissertation

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Nowadays, the amount of waste cooking oil (WCO) continues to increase. Unfortunately, much of this waste is improperly disposed of, harming the environment. Utilizing WCO as biodiesel feedstock offers a solution to reduce the impact of this waste on the environment, creating a more cost-effective and environmentally friendly fuel. Moreover, the catalyst plays a crucial role in facilitating the biodiesel production reaction. In order to decrease the costs associated with catalysts in biodiesel production, one potential approach is to utilize heterogeneous or solid catalysts derived from easily accessible waste biomass products, such as fruit peel waste. By utilizing waste-derived biomass materials for catalyst development, the process becomes more cost-effective and sustainable. The utilization of fruit peel wastes for catalyst development has gained popularity in recent times due to the abundance of waste resources and the desire to mitigate disposal challenges. In the present study, jackfruit (Artocarpus heterophyllus) peel waste (JPW) has been chosen and developed as a heterogeneous catalyst for biodiesel synthesis. The prepared catalyst has been characterized and it is showed the presence of significant components such as potassium (K), calcium (Ca), and magnesium (Mg) in the catalyst, which play a significant role in the synthesis of biodiesel. Furthermore, response surface methodology (RSM) with a centered composite design type has been applied to examine the best conditions of the transesterification process. The optimization process shows the optimum conditions were achieved for biodiesel synthesis with an oil-to-methanol molar ratio of 1:9, a catalyst weight of 12 % (w/w), a reaction time of 105 minutes, and a constant reaction temperature of 65 °C, yielding a methyl ester content of 98.88%. Additionally, reusability studies were conducted to assess the stability of the prepared catalysts. The results indicated that the JPW catalyst can be utilized for up to three cycles, with the highest yield observed at 93.33%. Moreover, the fuel properties of the waste cooking oil (WCO) biodiesel were investigated, and it was found that the physicochemical properties of the WCO biodiesel comply with the requirements outlined in ASTM D 6751. Moreover, an experimental study of tested fuels using a single-cylinder direct injection diesel engine has been conducted, to evaluate engine performance and exhaust emissions. The BSFC demonstrated an average decrease of 16.67-22.69% with the rise in engine speed. Conversely, BTE exhibited an average increase of 16.67% as engine speed increased. Moreover, engine torque experienced a slight decrease initially, followed by a significant decrease at high speeds. In contrast, BP exhibited a proportional increase with the rise in engine speed. Meanwhile, it was observed that CO emissions exhibited a significant reduction, averaging 6.11-48.63% across all speeds, when compared to pure diesel. Conversely, CO2 and NO emissions showed an overall increase, although some reductions were noted for certain fuel samples. Additionally, as engine speed increased, a downward trend in HC emissions was observed. While an increase in smoke opacity was generally observed in this study, a slight decrease was noted for certain fuel samples within the engine speed range of 1800 to 2400 rpm