由於全球暖化現象造成氣候異常，推廣生質能源以降低石化燃料的需求，進而減少溫室氣體排放，是世界各國共同努力的目標。本研究以痲瘋樹籽油提煉生質柴油，其成本相對低廉，因痲瘋樹具有許多優點，例如：可於荒地種植、收成期達30-50年、油品佳且油量多等。 本研究利用兩階段製程於微波反應器內製備生質柴油，並使用均相鹼觸媒KOH來促進轉酯化效率。為避免痲瘋樹籽油中的游離脂肪酸和強鹼發生皂化反應，必須利用預酯化反應來降低原料油中的游離脂肪酸含量，使原料油的酸價低於1 mg KOH/g，利於鹼催化轉酯化反應。預酯化反應使用微波反應器，反應時間為2小時，反應溫度為70℃，甲醇用量為12 wt. %，硫酸用量為1 wt. %，在此操作條件下痲瘋樹籽油的酸價可低於1 mg KOH/g。本研究所得轉酯化反應的最佳反應條件為油：醇莫耳比為1：6、KOH用量為1 wt. %、攪拌速率為200 rpm、反應溫度為65℃，在此操作條件下，其反應時間為10秒、轉化率超過90%。比起傳統加熱須反應1小時，微波加熱反應要快得多。本研究亦設計一個連續式的微波反應器，其反應體積為3L，滯留時間為10秒，進料速率為18 L/min。此連續式製程在溫和的反應條件下具有良好的轉化率及選擇率。本研究將有助於相關之工業化設計。Biodiesel has attracted much attention due to energy crisis and CO2 issue. Using an efficient processing technology to prepare biodiesel from Jatropha seed oil is a competitive way to produce biodiesel. The biodiesel was obtained by transesterification reaction using KOH catalyst in this study. Since the side reactions occur when water and free fatty acids exist, a pretreatment is needed. The pre-esterification was used to reduce the amount of FFA. The optimum pre-esterification reaction conditions were 70℃, 12 wt.% methanol, 1 wt.% sulfuric acid, and 2 h reaction time. To accelerate the reaction rate of transesterification, microwave was used instead of conventional hot plate heating. The optimum reaction conditions in microwave batch reactor were the molar ratio of oil to methanol of 1: 6, 1 wt. % KOH, 200 rpm, and 65℃. The conversion of the oil was 90 % after 10 s reaction condition. The reaction rate in microwave reactor was much faster than that by the conventional heating method. The penetration length of microwave in Jatropha seed oil was calculated to be 27 cm. Therefore, it is difficult to operate in large batch reactors. This problem can be solved by using a continuous microwave reactor. A large scale process was developed using continuous microwave reactor. This process has high conversion and high selectivity in a very short reaction time under mild reaction conditions. The flow rate of oil was 18 L/min, and the reactor volume was 3 L.
