Catalytic reactors design strategy

Effect of catalytic reactor design on plantwide control strategy Application to VAM plant... 

Effect of Catalytic Reactor Design on Plantwide Control Strategy... 

The mass balance with homogeneous one-dimensional diffusion and irreversible nth-order chemical reaction provides basic information for the spatial dependence of reactant molar density within a catalytic pellet. Since this problem is based on one isolated pellet, the molar density profile can be obtained for any type of chemical kinetics. Of course, analytical solutions are available only when the rate law conforms to simple zeroth- or first-order kinetics. Numerical techniques are required to solve the mass balance when the kinetics are more complex. The rationale for developing a correlation between the effectiveness factor and intrapellet Damkohler number is based on the fact that the reactor design engineer does not want to consider details of the interplay between diffusion and chemical reaction in each catalytic pellet when these pellets are packed in a large-scale reactor. The strategy is formulated as follows ... 

For first-order irreversible chemical kinetics in a packed catalytic tubular reactor (i.e., n = 1), ideal design strategies are justified if the relative difference... 

Among the different heterogenization strategies, the entrapping of catalysts in membranes or, in general, the use of a catalyst confined by a membrane in the reactor, offers new possibility for the design of new catalytic processes. 

The case study of vinyl acetate synthesis emphasises the benefits of an integrated process design and plantwide control strategy based on the analysis of the Reactor / Separation / Recycles structure. The core is the chemical reactor, whose behaviour in recycle depends on the kinetics and selectivity of the catalyst, as well as on safety and technological constraints. Moreover, the recycle policy depends on the reaction mechanism of the catalytic reaction. 

A quantitative strategy is discussed herein to design isothermal packed catalytic tubular reactors. The dimensionless mass transfer equation with unsteady-state convection, diffusion, and multiple chemical reactions represents the fundamental starting point to accomplish this task. Previous analysis of mass transfer rate processes indicates that the dimensionless molar density of component i in the mixture I must satisfy (i.e., see equation 10-11) ... 

Gorgiin et al. presented the developments of observers for fuel processing reactors such as a partial oxidation reformer, tvater-gas shift and preferential oxidation cleanup reactors [454]. Simplified models tvere used for the observer design. The principle of an observer-based control strategy is to run a simplified reactor model in the controller sofiware. Model parameters are then permanently adopted by measurements during the control process. For each reaction, vhich vas considered in one of the reactors, one measurement vas used to adopt the models. With catalytic partial oxidation and preferential oxidation the reactor temperature and one species... 

To sum up, a systematic effort has been made in this book to review the recent advances made in evolving novel catalytic approaches to make chemical processes greener and enviromnentally sustainable. It has also highlighted the importance of novel separation processes to achieve sharper product cuts and the use of well-designed multiphase reactors for enhanced process performance. It has imequivocally stressed the need for chemists and chemical engineers to adopt irmovative PI strategies to reduce the envirorunental burden of line and specialty chemical processes. 

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