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研究生:張松節
研究生(外文):Song-Jay Chang
論文名稱:含浸條件對金屬在球型載體上分佈之影響
論文名稱(外文):EFFECT OF IMPREGNATION CONDITIONS ON FINAL METAL DISTRIBUTION INSIDE A SPHERICAL SUPPORT
指導教授:洪賑城
指導教授(外文):Jan-Chen Hong
學位類別:碩士
校院名稱:大同大學
系所名稱:化學工程研究所
學門:工程學門
學類:化學工程學類
論文種類:學術論文
論文出版年:2003
畢業學年度:91
語文別:英文
論文頁數:92
中文關鍵詞:含浸條件球型載體模擬觸媒
外文關鍵詞:impregnation conditionspherical supportsimulationcatalyst
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本研究室推導出一個在球型載體上製備非均勻觸媒之含浸及乾燥過程的數學模式。含浸模式(硝酸鎳及檸檬酸之共含浸),包含了四個偏微分方程式;而乾燥模式,則包含了五個偏微分方程式和一個常微分方程式。我們藉著變數變換的方法將移動邊界的含浸過程轉換成固定邊界,並且將數學模式中之偏微分方程式藉由正交配置法(Orthogonal Collocation)轉換成常微分方程式,再用Gear Method 解之。為了製備理想金屬分佈之觸媒,我們發展了一個最佳化的程式去找尋出最佳的含浸條件(含浸濃度、共含浸物濃度、含浸時間),而此程式則使用GRG2(Generalized reduced gradient method)找最佳化條件。
在電腦模擬中所使用的參數皆為本研究室早期研究的實驗數據。由模擬結果得到下列結論:當含浸時間或含浸物濃度增加時,載體觸媒內的金屬分佈會向球體中心移動。同時,琪最大值亦會增加。再者,硝酸鎳在載體上之覆蓋率及最大值會隨著檸檬酸濃度的增加而變大。最佳化問題結果顯示我們可以求出整體最大值,而且,此為一多極大值之問題,然而,整體最大值落在一個極小的長方體中。

A mathematical model of dry-impregnation and drying for preparing non-uniform catalyst in a spherical support has been developed. The model for dry-impregnation, which was used for co-impregnation of nickel nitrate and citric acid, consists four simultaneous PDE’s, while the model for drying consists five PDE’s and one ODE. The dry-impregnation model is a moving-boundary problem which has been transformed to a fixed-boundary one by change of variables. The simultaneous PDE’s in the mathematical model have been transformed to a series of ODE’s by orthogonal collocation. Gear’s method was used to solve the ODE’s. To prepare a catalyst with desired metal distribution, an optimization problem was set up to search for the best impregnation conditions including impregnation time and bulk concentrations of nickel nitrate and citric acid. Generalized reduced gradient method was used to find the optimal.
The parameters used in computer simulation are experimental data obtained previously in this research group. Simulation results show that, as impregnation time or Ni concentration increases, the metal distribution moves toward the center of the pellet. In the meantime, the value of the maximum increases. Both the maximum value and the average amount of the nickel nitrate become larger with increasing acid concentration. Results of the optimization problem show that a global maximum can be obtained, and the problem is a multi-optimum one, however, the global optimum is located in a small cuboid.

ACKNOWLEDGEMENTS
ABSTRACT
CHINESE ABSTRACT
TABLE OF CONTENTES
LIST OF TABLES
LIST OF FIGURES
NOTATION
CHAPTER 1 INTRODUCTION
1.1 Previous Study
1.2 Objective of This Study
CHAPTER 2 MATHEMATICAL MODEL
2.1 Co-impregnation Model in Spherical Support
2.2 Drying Model in Spherical Support
2.3 Dimensionless Transform for Co-impregnation Model
2.4 Dimensionless Transform for Drying Model
2.5 Change of Variable for Co-Impregnation Model
2.6 Penetration Velocity Model
2.7 Determination of Temperature — Dependent Parameters
in Drying Model
CHAPTER 3 NUMERICAL METHODS
3.1 Orthogonal Collocation Method for Co-impregnation in Spherical Support
3.2 Orthogonal Collocation Method for Drying in Spherical Support
CHAPTER 4 MODEL PARAMETERS AND OPTIMIZATION PROBLEM
4.1 Model Parameters
4.2 Optimization Problem
CHAPTER 5 RESULTS AND DISCUSSION
5.1 Results of Computer Simulation
CHAPTER 6 CONCLUSIONS
REFERENCES

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4. Huang, K. C., “Simulation of Dynamic Behaviors of Catalyst Drying by Orthogonal Collocation,” Master Thesis, Tatung University, Taipei, Taiwan (2001).
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11. Tsai, Y. T., “A Non-Isothermal Mathematical Model for Catalyst Drying,” Master Thesis, Tatung Institute of Technology, Taipei, Taiwan (1995)
12. Stewart, W. E. and J. Villadsen, AIChE., 15, 28 (1953).
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15. Leon, S. L. and A. D. Waren, “GRG2 User Guide,” University of Texas at Austin, Texas (1989).
16.“IMSL Computational Technology Toolkit,” 593, Visual Numerics, Inc (1997).

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