Optimize reactor system

Therefore, in the first place the process synthesis should solve a structural problem, the configuration of the optimal reactor system. Then detailed design and refinement can follow. If there are several candidates close to optimum, these could be assembled in a superstructure and submitted to structural optimisation. 

The internal reforming of CH4 by CQzin SOFC system was performed over an ESC (electrolyte st rported cell) prepared with Ni based anode catalysts. Figure 5 diows the performance of voltage and power density with current density over various ESC (Ni based anodes I YSZ (LaSr)Mn03) at SOOC when CH4 and CO2 were used as reactants. To improve the contact between single cell and collector, different types of SOFC reactor were used [5]. In the optimized reactor (C), it was found fliat die opai-... 

Operating conditions. Optimization variables such as batch cycle time and total amount of reactants have fixed values for a given batch reactor system. However, variables such as temperature, pressure, feed addition rates and product takeoff rates are dynamic variables that change through the batch cycle time. The values of these variables form a profile for each variable across the batch cycle time. 

Reactor systems that can be described by a yield matrix are potential candidates for the application of linear programming. In these situations, each reactant is known to produce a certain distribution of products. When multiple reactants are employed, it is desirable to optimize the amounts of each reactant so that the products satisfy flow and demand constraints. Linear programming has become widely adopted in scheduling production in olefin units and catalytic crackers. In this example, we illustrate the use of linear programming to optimize the operation of a thermal cracker sketched in Figure E 14.1. 

Optimisation may be used, for example, to minimise the cost of reactor operation or to maximise conversion. Having set up a mathematical model of a reactor system, it is only necessary to define a cost or profit function and then to minimise or maximise this by variation of the operational parameters, such as temperature, feed flow rate or coolant flow rate. The extremum can then be found either manually by trial and error or by the use of numerical optimisation algorithms. The first method is easily applied with MADONNA, or with any other simulation software, if only one operational parameter is allowed to vary at any one time. If two or more parameters are to be optimised this method becomes extremely cumbersome. To handle such problems, MADONNA has a built-in optimisation algorithm for the minimisation of a user-defined objective function. This can be activated by the OPTIMIZE command from the Parameter menu. In MADONNA the use of parametric plots for a single variable optimisation is easy and straight-forward. It often suffices to identify optimal conditions, as shown in Case A below. 

SELCONT - Optimized Selectivity in a Semi-Continuous Reactor System... 

The books by T. Kailath [Unear Systems, 1980, Prentice-Hall) and H. Kwakernaak and R. Sivan Linear Optimal Control Systems, 1972, Wiley) can be consulted for detailed information. A recent paper by MacGregor, et al. ( State Estimation For Polymerization Reactors, 1986IFAC Symposium, Bournemouth, U.K.) discusses some of the problems of applying state estimators to chemical engineering systems. 

Both digester systems exhibit extremely low levels of detectable cellulase activities (exoglucanase, endoglucanase, and -glucosidase) when compared to industrial saccharifying processes (See Table III) in which the hydrolysis of cellulose in the feedstock is optimized with respect to enzyme loading. Therefore, the data indicate the level of improvement that may be made to attain maximum rates for cellulose hydrolysis in the anaerobic reactor system. 

Reaction kinetics describes what influences the reaction and how fast it takes place. Knowledge of kinetic parameters, such as reaction order n and reaction rate constant k, helps us to assess the feasibility of using ozonation to treat waters and to design an appropriate reactor system. It can help us to understand how a reaction can be influenced, so that a treatment process can be optimized. Kinetic parameters are also necessary for use in scientific models, with which we further improve our understanding of the chemical processes we are studying. 

Gas-Solid Heterogeneous Reaction Mixtures. Gas-solid heterogeneous reaction mixtures may be advantageously irradiated in annular (immersion-type) photochemical reactors. Again, the content of solid particles is limiting the size and the productivity of the reactor system. This is of particular importance when the solid support is used to specifically adsorb substrates or products of the photochemical reaction the first to enhance specificity of radical substitution reactions [20], the latter to reach better photostability and to ensure optimal purity. 

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