Graphical solution of equations for stirred-tank reactors in series

The tanks-in-series model (TIS) is a popular model to describe the residence time distribution (RTD) of non-ideal continuously stirred tank reactors (CSTRs) with limited back-mixing. In this work, the TIS model was generalised to a cascade of n CSTRs with non-integer non-negative n. The resulting model describes non-ideal back-mixing with n > 1. However, the most interesting feature of the n-CSTR model is the ability to describe short recirculation times (bypassing) with n < 1 without the need of complex reactor networks. The n-CSTR model is the only model that connects the three fundamental RTDs occurring in reactor modelling by variation of a single shape parameter n: The unit impulse at n→0, the exponential RTD of an ideal CSTR at n = 1, and the delayed impulse of an ideal plug flow reactor at n→∞. The n-CSTR model can be used as a stand-alone model or as part of a reactor network. The bypassing material fraction for the regime n < 1 was analysed. Finally, a Fourier analysis of the n-CSTR was performed to predict the ability of a unit operation to filter out upstream fluctuations and to model the response to upstream set point changes.

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Optimal design on an economic basis for continuous stirred tank reactors in series using michaelis-menten kinetics for ping-pong reactions

The Canadian Journal of Chemical Engineering ◽

10.1002/cjce.5450660127 ◽

1988 ◽

Vol 66 (1) ◽

pp. 168-172 ◽

Cited By ~ 19

Author(s):

F. Xavier Malcata

Keyword(s):

Optimal Design ◽

Stirred Tank ◽

Stirred Tank Reactors ◽

Economic Basis ◽

Ping Pong ◽

In Series ◽

Continuous Stirred Tank ◽

Continuous Stirred Tank Reactors

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Hydrodynamic Characteristics Assessment and Modeling of a Novel Membrane-Aerated Reactor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.516-517.763 ◽

2012 ◽

Vol 516-517 ◽

pp. 763-768 ◽

Cited By ~ 1

Author(s):

Rong Chang Wang ◽

Shuang Lin Dai ◽

Yun Fei Tang ◽

Jian Fu Zhao

Keyword(s):

Residence Time ◽

Scale Up ◽

Stirred Tank ◽

Circulation Rate ◽

Hydrodynamic Characteristics ◽

Recirculation Flow ◽

Stirred Tank Reactors ◽

In Series ◽

Circulation Velocity

The research study is aimed at the characterization of the hydrodynamics of a novel membrane-aerated reactor. Hydrodynamics was determined by means of impulse tracer trials in clean reactor and calculating residence time distribution (RTD) curves at different recirculation flow rates and hydraulic retention time. Thus the typical RTD curves were analyzed to calculate the average residence time, the dimensionless variance, the number of stirred tank reactors in series, and the dispersion number.The results showed that the hydraulic characteristics in the membrane-aerated reactor was essentially correlated with circulation rate. With the circulation velocity increasing, the number of stirred tank reactors in series decreased gradually, approaching to 1, while the dispersion number increased up to 0.2. It was concluded that the flow patterns within the membrane-aerated reactor are perfectly mixed under all the conditions tested. A simple correlation between the Reynolds number and the mixing was developed which can be used for design and scale-up purposes.

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