毕业论文-生物柴油.doc

摘 要 本文主要对利用废食用油制备生物柴油的预酯化—酯交换工艺进行了研究。通过预酯化的单因素实验，考察了乙醇用量、催化剂浓硫酸用量、反应时间及反应温度对酯化率的影响趋势。通过酯交换的单因素实验，考察了乙醇用量、催化剂氢氧化钾用量、反应时间和反应温度对粗生物柴油产率的影响趋势，确定了利用废食用油制备生物柴油的最佳工艺条件。 预酯化的实验结果表明，其最佳工艺条件为：乙醇用量为80 mL、催化剂浓硫酸用量为1 g、反应时间为3 h、反应温度为70 ℃。酯交换的实验结果表明，其最佳工艺条件为：乙醇用量为60 mL、催化剂氢氧化钾用量1 g、反应时间为40 min、反应温度为70 ℃。在此条件下可使50 mL废食用油的酸值由40.27 mgKOH/g降到1.52 mgKOH/g，粗生物柴油的产率可达到93.71%，达到了预期的效果。采用预酯化—酯交换工艺，利用废食用油制备生物柴油，具有产率高、成本低的优点，在废食用油资源化方面前景广阔。 关键词：废食用油,生物柴油,预酯化,酯交换,酸值 Abstract Waste cooking oil are used to produce biodiesels by pre-esterification and transesterification have been studied in this study. Through single factor experiment of pre-esterification, ethanol dosage, catalyst sulfuric acid dosage, reaction temperature and reaction time on the esterification rate of trends is determined. Through single factor experiment of transesterification, ethanol dosage, catalyst potassium hydroxide dosage, reaction temperature and reaction time on the the productivity of crude biodiesel of trends was determined, and identify the optimum conditions of waste cooking oil used to produce biodiesels. The experimental results of pre-esterification show that the pre-esterification optimum conditions: ethanol join amount of 80 mL, catalyst concentrated sulfuric acid join amount of 1 g, the best reaction time is 3 h, the optimum reaction temperature is 70 ℃. The experimental results of transesterification show that the transesterification optimum conditions: ethanol join amount of 60 mL, catalyst potassium hydroxide join amount of 1 g, the best reaction time was 40 min, the optimum reaction temperature is 70 ℃. Under this condition, the acid value of 50 mL waste cooking oil decline from 40.27 mgKOH / g to 1.52 mgKOH / g, crude biodiesel yield up to 93.71%, and reached the desired goal. Waste cooking oil are used to produce biodiesels by pre-esterification and transesterification with the advantage of high yield and low cost, in aspect of waste cooking oil resources with broad prospects. Key words: Waste c