Simulation of chemical reactor

Shah, J. J. and R. O. Fox (1999). CFD simulation of chemical reactors Application of in situ adaptive tabulation to methane thermochlorination chemistry. Industrial Engineering Chemistry Research 38, 4200 4-212. 

However, for a basic design or a detailed simulation of chemical reactors, profiles of the concentrations and the temperature inside the catalyst pellet are not of primary interest, but rather the effective rates of production or disappearance of the reacting species and the effective heat release or consumption as well. Both are defined according to eqs 19 and 20 as averaged values, related to the pellet volume. ... 

Lindborg H (2007) Modeling and simulation of Chemical Reactor Flows. Dr ing Thesis, The Norwegian University of Science and Technology, Trondheim, In preparation... 

Holderith, J. Smirnov, N. I. (1 68). On some problems in the simulation of chemical reactors, Annales Univ. Scient. Bp. de R. Eotvos, Sec. Chimia, 10, 107-17. 

Keywords Simulation of chemical reactors Exothermic catalytic reaction Concentration profile Turbulent mass transfer diffusivity profile... 

Sporleder F (2011) Simulation of chemical reactors using the least-squares spectral element method. Ph.D. thesis, Norwegian University of Science and Technology (NTNU), Trondheim, Norway... 

A survey of the mathematical models for typical chemical reactors and reactions shows that several hydrodynamic and transfer coefficients (model parameters) must be known to simulate reactor behaviour. These model parameters are listed in Table 5.4-6 (see also Table 5.4-1 in Section 5.4.1). Regions of interfacial surface area for various gas-liquid reactors are shown in Fig. 5.4-15. Many correlations for transfer coefficients have been published in the literature (see the list of books and review papers at the beginning of this section). The coefficients can be evaluated from those correlations within an average accuracy of about 25%. This is usually sufficient for modelling of chemical reactors. Mathematical models of reactors arc often more sensitive to kinetic parameters. Experimental methods and procedures for parameters estimation are discussed in the subsequent section. 

Gunn, D. J. (1977) Inst. Chem. Eng., 4th Annual Research Meeting, Swansea, April. A sparse matrix technique for the calculation of Unear reactor-separator simulations of chemical plant. 

At some point in most processes, a detailed model of performance is needed to evaluate the effects of changing feedstocks, added capacity needs, changing costs of materials and operations, etc. For this, we need to solve the complete equations with detailed chemistry and reactor flow patterns. This is a problem of solving the R simultaneous equations for S chemical species, as we have discussed. However, the real process is seldom isothermal, and the flow pattern involves partial mixing. Therefore, in formulating a complete simulation, we need to add many additional complexities to the ideas developed thus far. We will consider each of these complexities in successive chapters temperature variations in Chapters 5 and 6, catalytic processes in Chapter 7, and nonideal flow patterns in Chapter 8. In Chapter 8 we will return to the issue of detailed modeling of chemical reactors, which include all these effects. 

Kuipers, Multiscale Modeling of Gas-Fluidized Beds Harry E.A. Van den Akker, The Details of Turbulent Mixing Process and their Simulation Rodney O. Fox, CFD Models for Analysis and Design of Chemical Reactors... 

The main aim of the methods described in this chapter is to obtain data for the design of chemical reactors, for the simulation of their operation behaviour, and, last but not least, to evaluate the influence of temperature and pressure on reaction rate. For this purpose, the techniques for measuring reaction rates at high pressures are presented. The details of the apparatus are mentioned in Chapter 4.3.4. 

Like the performance of chemical reactors, in which the transport and reactions of chemical species govern the outcome, the performance of electronic devices is determined by the transport, generation, and recombination of carriers. The main difference is that electronic devices involve charged species and electric fields, which are present only in specialized chemical reactors such as plasma reactors and electrochemical systems. Furthermore, electronic devices involve only two species, electrons and holes, whereas 10-100 species are encountered commonly in chemical reactors. In the same manner that species continuity balances are used to predict the performance of chemical reactors, continuity balances for electrons and holes may be used to simulate electronic devices. The basic continuity equation for electrons has the form... 

Zuflerey, B. (2006) Scale-down Approach Chemical Process Optimisation Using Reaction Calorimetry for the Experimental Simulation of Industrial Reactors Dynamics, EPFL, n°3464, Lausanne. 

Let us see if the trends observed by these simulations are justified in the light of our current knowledge of chemical reactors. The well known limit cases of zero and first order kinetics in a CSTR and a PFR suggest that... 

The heterogeneous reactors with supported porous catalysts are one of the driving forces of experimental research and simulations of chemically reactive systems in porous media. It is believed that the combination of theoretical methods and surface science approaches can shorten the time required for the development of a new catalyst and optimization of reaction conditions (Keil, 1996). The multiscale picture of heterogeneous catalytic processes has to be considered, with hydrodynamics and heat transfer playing an important role on the reactor (macro-)scale, significant mass transport resistances on the catalyst particle (meso-)scale and with reaction events restricted within the (micro-)scale on nanometer and sub-nanometer level (Lakatos, 2001 Mann, 1993 Tian et al., 2004). 

Sorensen, J. P., Simulation, Regression and Control of Chemical Reactors by Collocation Techniques, Doctoral Thesis, Danmarks tekniske Hpjskole, Lyngby (1982). 

---