- 學位論文
毫米尺寸同向型液珠流體系統之高通量轉酯化反應
High-Throughput Transesterification by Millimeter-Sized Co-Flowing Droplet-Based Fluidic Systems
摘要
本研究將同向型 (co-flowing) 流道之液珠式流體技術應用於轉酯化反應中產製生質柴油，改善生質柴油產業於傳統製程上耗能、費時的問題。液珠式微流體系統具有高表面積體積比之特性，大幅增加兩不互溶流體之反應界面，提高化學反應速率。基於此優勢基礎上，將微觀系統的特點引入巨觀系統中，設計一毫米尺度流道晶片，利用同向型流道結構穩定生成液珠產製生質柴油，不但可以保有微系統中快速反應的優點，更可以改善微系統產量不足的缺點。毫米尺寸的母模製作僅需使用CNC工具機進行刻製，不需使用昂貴的微機電製程。 實驗分析以大豆油與甲醇作為反應物，利用同向型流道將甲醇包覆於大豆油中生成甲醇液珠，進行轉酯化反應。於反應時間1分鐘、催化劑NaOH濃度1 wt% (相對於大豆油)、醇油體積比1、反應溫度23 ℃之條件下進行實驗，反應轉化率可達到87%。將反應溫度提升至55 ℃，其於條件相同下，更可達到95%之轉化率，若是要達成99%以上的完全轉化，則須將反應時間延長至6分鐘。使用毫米尺度流體晶片的另一項優勢是，未來可將生質柴油後端的分離與純化整合於同一個晶片上成為一套系統，前端通入原料，後端即可輸出成品，更具商業化之價值。本研究提出毫米尺度液珠流體系統生質柴油產製晶片的構想，可應用於社區型的家用廢棄食用油回收轉化，做為地區型小型能源產置中心，符合分散式能源的世界潮流。
並列摘要
In this research, the biodiesel fuel production by transesterification of oils was taken place in a millimeter-sized, co-flowing droplet-based fluid channel. By using this chip, we solved the main disadvantages of the traditional biodiesel production method, such as high energy and time consumption. The large surface to volume ratio of the droplet-based device increased the material interface of two immiscible fluids and significantly enhanced the reaction rate of soybean oil and methanol. The millimeter-sized channel not only keeps the advantage of microfluidic system (rapid reaction) but also improved the disadvantage of microsystem (low output). Without using MEMS process, the presented chip was fabricated by CNC machining. In our co-flowing chip, the methanol droplet was generated and surrounded by soybean oil. The conversion of oil attained 87% at 23 ℃ with residence time 1 min when the volume ratio of methanol to oil was 1 and the concentration of NaOH catalyst was 1.0 wt% (based on the methanol weight); At the same conditions, the conversion attained 95% at 55 ℃ with residence time 6 min. Compare to previous work (including traditional methods and microsystem), our droplet-based biodiesel transesterification system has greater efficiency and consumes less energy during the reaction. Based on this study, we can integrate the whole biodiesel production process in one chip, including transesterification, separation and purification. This biodiesel production concept is convenient for household use such as to convert cooking oil to biodiesel which is conformed to the requirements of the rend of distributed energy (cheap and medium production).