摘要或動機

因國際原油價格上漲，因此對研究及發展具潛力的生質柴油引起高度興趣。傳統以加熱方式在適當觸媒下將低碳數醇類與油脂轉酯化生成生質柴油。但以強鹼為觸媒使用過量會讓部分反應轉為皂化。而利用微波，使微波腔在極短的時間內產生電場，使具有電偶極的分子朝向電場方向迅速排列而產生轉動，快速地增加分子間的碰撞頻率而加速反應，但不破壞分子結構。也嘗試利用超音波來生產生質柴油。試驗方法為利用SD-22
柴油引擎測試所生產的生質柴油，並收集廢氣檢驗，評估其污染性。實驗後發現，微波能將一般加熱所需的60 分鐘大幅縮短至4 分鐘，甲醇溶液能生產較多的生質柴油。其中1.40%氫氧化鉀甲醇溶液且油與醇莫耳比1：9
效果較佳。氫氧化鉀甲醇溶液0.80%且油與醇莫耳比1：5 效果亦佳。製成的生質柴油能讓引擎發動，廢氣處理後經分光光度計檢驗氮氧化物，生質柴油確實能有效減少氮氧化物污染。



Due to the fact that the price of international crude oil raises , people look for
alternative energy resources actively. Therefore, I have great interests in doing
researching and developing the biodiesel through many ways. The traditional way
is to transesterify the low carbon alcohols and fats with the suitable catalysts
by means of generally heating. However, the overuse of strong bases as catalysts
may turn the experiment result into saponification reaction. This study made good
use of the microwave to generate electric fields in the microwave cavity in an extremely
short time. Owing to the effect electric fields exerted, the molecules with electric
dipole momentum rearranged to rotate rapidly .Consequently, the frequency of collision
among the molecules increased without destroying the molecule structures. Also,
I applied SD-22 diesel engine to test the produced biodiesel and examined the collected
exhaust to evaluate its pollutant. According to the results of these experiments,
the conclusion was as following: the microwave could shorten the Transesterification
reaction time from 60 minutes to 4 minutes. The methanol solution could produce
more biodiesel than the ethanol solution. Besides, the 1.40 wt ％ Potassium hydroxide
solution with the molar ratio of oil and methanol 1:9 had the best efficiency in
producing biodiesel. On the other hand , the 0.80 wt ％ Sodium hydroxide solution
with the molar ratio of oil and methanol 1:5 also had the great efficiency. All
the biodiesel we produced enabled the diesel engine to run smoothly. The exhaust
inspected from the examination of Spectrophotometer resulted that the biodiesel
did less NOx pollution to the environment indeed.