| Summary: | 碩士 === 國立臺北科技大學 === 化學工程研究所 === 104 === This study examined the optimation of a cycling system for biodiesel production. The cycling system was divided into three stages. In the first stage, the high acid value of palm sludge oil as a feedstock was esterified by glycerol via high-temperature esterification to produce the glycerides. The optimal operation conditions of the high-temperature esterification were as follows: the molar ratio of glycerol to free fatty acids of 9:10, the reaction temperature of 250 °C, the reaction pressure of 250 mmHg and the acid value below 0.5 mg KOH/g while the reaction time was over 180 min. It is noted that the high-temperature esterification was controlled by temperatue and pressure in the absence of catalyst; therefore, the products of glycerides can be used directly to the next stage of transesterification without sepratation process for catalyst. In the second stage, the esterifed oils were trans-esterifed by potassium phosphate and certain amount of methanol to produce fatty acid methyl esters (FAMEs). The potassium phosphate can be recovered by filtration and then used as fertilizer. The optimal conditions of transesterification were the methanol/oil molar ratio of 2.5, the catalyst dosages of 2% wcat/woil, the reaction temperature of 65 °C, the rotating speed of 500 rpm, and reaction time of 120 min, resulting in both the yield and the ester content of FAMEs above 94%. For establishing a cycling system, the byproduct glycerol in the second stage of transesterification would be recycled and used in the first stage. Therefore, the three stage focused on the recovery and purification to form crude glycerol and examined the properties of biodiesel via the high-temperature esterification of crude glycerol. In summary, the on-site recovery and reuse of biodiesel-derived glycerol for a cycling system of biodiesel production would satisfy the concept of cleaner production for the development of a sustainable society.
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