Dynamic Simulation of Adiabatic Catalytic Fixed-Bed Tubular Reactors: A Simple Approximate Modeling Approach

https://doi.org/10.22146/ajche.49713

Wiwut Tanthapanichakoon(1*), Shinichi Koda(2), Burin Khemthong(3)

(1) 
(2) 
(3) 
(*) Corresponding Author

Abstract


Fixed-bed tubular reactors are used widely in chemical process industries, for example, selective hydrogenation of acetylene to ethylene in a naphtha cracking plant. A dynamic model is required when the effect of large fluctuations with time in influent stream (temperature, pressure, flow rate, and/or composition) on the reactor performance is to be investigated or automatically controlled. To predict approximate dynamic behavior of adiabatic selective acetylene hydrogenation reactors, we proposed a simple 1-dimensional model based on residence time distribution (RTD) effect to represent the cases of plug flow without/with axial dispersion. By modeling the nonideal flow regimes as a number of CSTRs (completely stirred tank reactors) in series to give not only equivalent RTD effect but also theoretically the same dynamic behavior in the case of isothermal first-order reactions, the obtained simple dynamic model consists of a set of nonlinear ODEs (ordinary differential equations), which can simultaneously be integrated using Excel VBA (Visual BASIC Applications) and 4th-order Runge-Kutta algorithm. The effects of reactor inlet temperature, axial dispersion, and flow rate deviation on the dynamic behavior of the system were investigated. In addition, comparison of the simulated effects of flow rate deviation was made between two industrial-size reactors.

Keywords: Dynamic simulation, 1-D model, Adiabatic reactor, Acetylene hydrogenation, Fixed-bed reactor, Axial dispersion effect


Keywords


Dynamic simulation, 1-D model, Adiabatic reactor, Acetylene hydrogenation, Fixed-bed reactor, Axial dispersion effect

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References

1. Bos, A.N.R. et al. (1993). “A kinetic study of the hydrogenation of ethyne and ethene on a commercial Pd/Al2O3 catalyst”, Chem. Eng. Process: Process Intensif. 32, 53–63.
2. Gobbo, R. et al. (2004). “Modeling, simulation, and optimization of a front- end system for acetylene hydrogenation reactors”, Braz. J. Chem. Eng. 21, 545–556.

3. Levenspiel, O. (1972). Chemical Reaction Engineering, John Wiley & Sons.

4. Mostoufi, N. et al. (2005). “Simulation of an acetylene hydrogenation reactor”, Int. J. Chem. Reactor Eng. 3, article A14.
5. Schbib, N.S. et al. (1994). “Dynamics and control of an industrial front-end acetylene converter”, Comput. Chem. Eng. 18, S355–S359.
6. Schbib, N.S. et al. (1996). “Kinetics of Front-End Acetylene Hydrogenation in Ethylene Production”, Ind. Eng. Chem. Res. 35, 1496-1505.
7. Westerterp, K. R. et al. (2002). “Selective hydrogenation of acetylene in an ethylene stream in an adiabatic reactor”, Chem. Eng. Tech 25, 529-539.



DOI: https://doi.org/10.22146/ajche.49713

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