Theoretical Analysis of Heat Integration in a Periodically Operated Cascade of Catalytic Fixed‐Bed Reactors

Abstract

Forced periodic operation can lead to improved reaction processes. Such operation is studied for the example of the application of a cascade of connected adiabatic fixed-bed reactors to perform catalytic total oxidation. It is shown that the periodic operation of the configuration considered allows an autothermal operation. The concept can outperform classical reverse-flow operation concerning the reduction of slips of unconverted feed. A simple model based on the assumption of a hypothetical countercurrent of the solid phase is derived and compared with a standard dynamical model of the reactor cascade. By evaluation of steady state profiles and application of bifurcation theory, it is demonstrated that the reduced model describes the limiting case for an infinitely segmented cascade and allows assessment of important properties of the periodic process. It permits a fast and detailed analysis of limit point bifurcations, which result in curves enclosing the region of desired ignited states of the reactor. Using singularity analysis further helps to understand the influence of secondary parameters and to identify operational limits. Copyright © 2009 John Wiley & Sons, Inc. All Rights Reserved. [accessed November 25, 2009

Dynamics and control of loop reactors - a review

“…The domain around V sw /V th =1 is the domain with the highest potential for heat recuperation as was shown in numerous studies (e.g. [1,37,45]). extinguished (E).…”

“…The singularities expected in a loop reactor were characterized [45,46] by plotting the domain of frozen rotating patterns in the plane of the inlet temperature vs the switching velocity (V sw /V th , denoted as Flow rate ratio γ in Fig. 5).…”

A Mathematical Study on the System of Partial Differential Equations Describing Reverse-Flow Reactor

“…When RFR works, complex and characteristic phenomena are experimentally-observed, see [14,15,16] and references therein. They are also observed in numerical simulations with the aid of mathematical models, see [7,10,11,14,15,16,17] and references therein. According to numerical simulations by Budhi et al, complicated and sensitive asymptotic behavior of solutions can be observed, see [2].…”

Temperature and conversion patterns in a network of catalytic reactors for methanol synthesis with different switch strategies

“…each simulation, the switching time has been step-wise increased and the previously computed solution has been employed as initial condition for the following simulation. We note that the number of periods needed for the NTW to achieve regime conditions increases dramatically as the points S i are approached (Zahn et al, 2009). It must be also stressed that, although not reported in Fig.…”

“…In the context of catalytic combustion of volatile organic compounds, Haynes and Caram (1994) compared, for example, the performances of a NTW of two reactors with those of the reverse-flow-reactor, while Brinkmann et al (1999) analyzed the performance of a network of three reactors. Several studies of NTWs of three or more reactors have been also performed focusing on the analysis of complex reactor dynamics Altimari et al, 2006;Zahn et al, 2009). Velardi and Barresi (2002) and Sheinman and Sheintuch (2009) analyzed the performance of a NTW of catalytic reactors where methanol synthesis process takes place.…”