本文借助COMSOL套裝軟體，以數值模擬方式探討固定床捕碳劑吸附反應器提升溫度均勻性之研究，討論在不同材質、加裝不同數量導熱鰭片、反應管內部或外部加熱的反應器，改善內部溫度均勻性以提升CaO吸附CO2之性能及降低所需之能耗。利用各種不同條件，使反應管內部溫度分布更均勻，讓CaO捕碳劑可以發揮其最大效益，並將吸附之所需成本—單位加熱量(W)、吸附時間及總能耗一併討論。數值模擬結果顯示，在加熱管定溫為973K的情況下，入口氣體溫度為600K時，若將一般之反應圓管直徑由1吋放大到4吋時，管長由250 (mm)放大到500 (mm)，則管內最大溫差會變大，管內平均溫度下降，若考量體積大小的單位CO2吸附量結果，吸附效率將剩48%。而在反應器中加入不同數量導熱鰭片裝置，可以有效的提升管內平均溫度，並減小最大溫差。數值模擬結果得知，裝入不同數量導熱裝置，其最理想內管半徑會隨材質、鰭片數及內外部加熱方法而有所不同。若數值模擬分析下的能耗，鰭片數愈多，吸附效益愈佳；若是數值模擬固定反應管吸附平均轉化率，鰭片數愈多，所需能耗愈小，此關鍵在於吸附時間的差異。

關鍵字： 氧化鈣吸附、固定床、均溫設計

The paper is to design a uniform temperature distribution in a scale-up fixed bed reactors with different materials, inserting numerous internal heat conducting device and different heating methods by numerical simulation of COMSOL software. The performance of CaO sorbents, some of capture efficiency including energy consumption can be improved due to improvement of temperature uniformity. In fact, all of our efforts are to achieve a cost reduction. The simulation result demonstrates that the performance of absorption is only 48% at 973K for the original design as the diameter of the reaction tube is increased from 1 inch to 4 inches, and the length of the tube is changed from 250 (mm) to 500 (mm). The reactor can be effectively improved by adding numerous internal heat conducting device because the temperature distribution in reactor becomes more uniform. The results also show that the best internal radius will vary with the material, the number of fins and internal or external heating method. The numerical simulation method shows adding more axial fins in reactors can decrease unit energy consumption. Last but not least, the numerical simulation method demonstrate that adding more axial fins in reactors can decrease total energy consumption.in the condition of fixing average conversion ,and the key point is time of absorption.

Keywords : Calcium oxide absorption, Fixed bed, Uniform temperature design.

摘要 I
Abstract II
致謝 III
第一章、前言 1
1.1、研究背景 1
1.2、研究目的 3
第二章、文獻回顧 4
2.1、二氧化碳捕獲分離技術 4
2.2、鈣鎂捕碳劑 7
2.3、改質氧化鈣 10
2.4、水合反應 13
2.5、二氧化碳捕獲反應器 18
2.5.1、流體化床 18
2.5.2、固定床 19
2.6、理論再生能耗 20
2.7、CaO吸附反應 23
第三章、數值模型模擬 26
3.1、模擬軟體介紹 26
3.2、模型幾何參數設定 26
3.3、模型分析 28
3.3.1、模擬進行之物理假設 29
3.3.2、統御方程式及數值方法 30
3.3.3、化學動力學 31
3.3.4、模擬參數設定 32
3.3.5、邊界條件 34

3.4、模擬分析數值方法說明 35
3.5、模擬分析目標 37
3.5.1、暫態模擬分析 37
3.5.2、穩態模擬分析 37
3.5.3、模擬分析實施步驟 38
3.5.4、反應器尺寸對CO2吸附性能的影響 39
3.5.5、探討加裝內部加熱零件之最理想管內半徑(最佳Ri) 40
3.5.6、不同材質、導熱鰭片，以及加熱方式對CO2吸附性能的影響 41
第四章、結果與討論 42
4.1、反應器尺寸對CO2吸附性能的影響 43
4.2、探討加裝內部加熱零件之最理想管內半徑(最佳Ri) 45
4.3、不同材質、導熱鰭片，以及加熱方式對CO2吸附性能的影響 55
4.3.1、入口氣體溫度300K，3 ~ 6軸向鰭片管狀反應器，材質為不鏽鋼或 56
4.3.2、入口氣體溫度850K，3 ~ 6軸向鰭片管狀反應器，材質為不鏽鋼或 62
4.3.3、平均轉化率X = 0.65，入口氣體溫度850K，3 ~ 6軸向鰭片管狀反應器，材質為不鏽鋼或銅之暫態吸附能耗比較 68
第五章、結論 72
5.1、結論 72
5.2、未來展望 74
參考文獻 75

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