本篇論文主要在探討化工程序中觸媒填充床應用於甲醛的製造程序，依據稀釋觸媒填充密度可以降低反應器熱點溫度的想法，分析各種不同的稀釋密度與稀釋段長度所造成的影響，選擇較好的設計方式，並與工業界常使用的觸媒填充床作比較。
首先選擇適當的數學模式，本系統為高放熱氣相反應，其數學模式為一複雜的非線性偏微分方程組，在模擬過程中，應用正交排列法將偏微分方程式簡化成常微分方成組，此數值方法對於模擬的正確性與模擬時間皆有相當好的表現。之後對兩種反應器作穩態與動態的分析，作為控制策略安排上的考量與資訊。在控制策略上以達到最佳產率為主要目標，使用反應器溫度分布預測出最佳產率的方向，藉由控制熱點溫度達到最佳化產率的目的，最後比較兩種反應器在不同擾動下，反應器熱點溫度與產率的變化。

This work studied the control design for catalytic packed-bed reactor in Formaldehyde production, based on the idea that the diluting the catalyst will lower the hot spot of the reactor, analysis on the effect of catalyst dilution and dilution zone was carried out and a comparison was made with the packed-bed reactor used in industry.

The first step was to determine the mathematical model; this is a highly exothermic reaction represented by a set of complex partial differential equation; By way of orthogonal collocation, the partial differential equations are transformed into a set of ordinary differential equation, this method prove to be accurate and requires a short cpu time. Thereafter, steady state and dynamic state analysis for two reactors were carried out, and the control strategies were based on the information obtained. The objective is to find the maximum product, the optimal direction was predicted by the temperature profile, and optimal productivity was obtained by control of hot spots. Finally, a comparison of the effect of disturbances on the hot spot temperature and productivity of the reactors are made.

參考文獻：
1. Chen C. Y. and Sun C. C. 1991, Runaway detection for nonlinear inferential control system in packed bed reactors, Journal of the Chinese Institute of Chemical Engineers, Vol.22, No.4, pp219-229.
2. Chou Y. S. 1992, Analysis and robust controller design for an ethylene oxide catalytic fixed bed reactor, Journal of the Chinese Institute of Chemical Engineers, Vol.23, No.5, pp303-314.
3. Chen C. Y. and Sun C. C. 1988, Estimation of unmeasured output variables in packed bed reactors, Journal of the Chinese Institute of Chemical Engineers, Vol.19, No.5, pp291-301.
4. Crider J. E. and Foss A. S. 1966, Computational studies of transients in packed tubular chemical reactors, AIChE Journal, Vol.12, No.3, pp514-522.
5. Dente M. and Collina A. 1966, Verifica di un reattore tubolare per la ossidazione del metanolo a formaldeide, La Chimica e L’industria, Vol.48, No.6, pp581-588.
6. Finlayson B. A.1980, Nonlinear analysis in chemical engineering, McGraw-Hill Inc., New York.
7. Hansen K. 1971, Analysis of transient models for catalytic tubular reactors by orthogonal collocation, Chemical Engineering Science, Vol.26, pp1555-1569.
8. Kulkarni M. S. and Dudukovic M. P. 1996, Dynamics of gas phase and solid phase reactions in fixed bed reactors, Chemical Engineering Science, Vol.51, No.11, pp3083-3088.
9. Kulkarni M. S. and Dudukovic M. P. 1998, Periodic operation of asymmetric bidirectional fixed-bed reactors with temperature limitations, Industrial & Engineering Chemistry Research, Vol.37, No.3, pp770-780.
10. Liou C. T. and Chou Y. S. 1983, Sensitivity of transport parameters on adiabatic catalytic fixed bed reactor, Journal of the Chinese Institute of Chemical Engineers, Vol.14, pp447-456.
11. Liu S.L. and Amundson N.R.1963, Stability of adiabatic packed bed reactors, Industrial & Engineering Chemistry Research, Vol.2, No.3, pp183-189.
12. Lordanidis A. A. 2002, Mathematical modeling of catalytic fixed bed reactors, Ph.D. Thesis, University of Twente, The Netherlands.
13. McGreavy C. and Naim H. 1977, Reduced dynamic model of a fixed bed reactor, Canadian Journal Chemical Engineering Vol.55, pp326-332.
14. McGreavy C. and Creswell D. L. 1969, Lumped parameter approximation to a general model for Catalytic Reactors, Canadian Journal Chemical Engineering, Vol.47, pp583-589.
15. Quina M. J. and Quinta F. R. 2000, Start-up and wrong-way behavior in a tubular reactor: dilution effect of the catalytic bed, Chemical Engineering Science, Vol.55, pp3885-3897.
16. Van Doesburg H. and De Jong W. 1976, Transient behaviour of an adiabatic fixed-bed reactor methanator I, Chemical Engineering Science, Vol.31, pp45-51.
17. Windes L.C. and Schwedock M. J. 1989, Steady state and dynamic modeling of a packed bed reactor for the partial oxidation of methanol to formaldehyde, Chemical Engineering Communications, Vol.78, pp 1-43.
18. Windes L. C. and Ray W. H. 1992, A control scheme for packed bed reactors having a changing catalyst activity profile II: On-line optimizing control, Journal of Process Control, Vol.2, No.1, pp43-53.
19. Wu W. and Huang M.Y. 2003, Nonlinear inferential control for an exothermic packed bed reactor: geometric approaches, Chemical Engineering Science, Vol.58, pp2023-2034.