Reactor strategy

Keywords Biofilm, Bioreactor, Kinetics, Modeling, Reactor strategy Contents... 

J B Infers, P Lodder, G.D Enoch, Modelling of selective catalytic denox reactors—strategy for replacing deactivated catalyst elements, Chem. Eng Technol. 74 192 (1991). 

There are many articles and textbooks available for further information about fermentation processes and bioreactor engineering. " The technology continues to be an area of study to improve production of pharmaceuticals, specialty chemicals, antibodies, and food products. Choosing the correct cell type and reactor strategy is of utmost importance. This choice also effects the downstream processing or separation sequence used to purify the product thus, a systems approach to fermentation is extremely valuable. 

Figure 6. Examples of two-stage reactor strategies for metol-ion removal, showing the overall and individual fractional conversions.

Int. Symp. on Nucl. Fuel Cycle and Reactor Strategy, IAEA, Vienna,... 

INTERNATIONAL ATOMIC ENERGY AGENCY. Nuclear Fuel Cycle and Reactor Strategies Adjusting to New Realities . IAEA Proceedings Series. STI/PUB/1026. 1997 Vienna, Austria. 

The FBR is being developed as a future alternative to light water reactors in Japan. The shift from LWRs to FBRs, which is expected to start around 2030, is the reactor strategy in the "Long-term Plan for the Development and Application of Nuclear Power" established by the Japan Atomic Energy Commission (JAEC). 

Most processes are catalyzed where catalysts for the reaction are known. The strategy will be to choose the catalyst, if one is to be used, and the ideal characteristics and operating conditions needed for the reaction system. Decisions must be made in terms of reactor... 

Figure 11 shows a system for controlling the water dow to a chemical reactor. The dow is measured by a differential pressure (DP) device. The controller decides on an appropriate control strategy and the control valve manipulates the dow of coolant. The procedure to determine the overall failure rate, the failure probabiUty, and the reUabiUty of the system, assuming a one-year operating period, is outlined hereia. 

Fig. 17. Examples of selective control strategy (a) reactor hot spot (b) level override (c) prioritized and (d) constraint controls, where...

Product Recovery. Comparison of the electrochemical cell to a chemical reactor shows the electrochemical cell to have two general features that impact product recovery. CeU product is usuaUy Uquid, can be aqueous, and is likely to contain electrolyte. In addition, there is a second product from the counter electrode, even if this is only a gas. Electrolyte conservation and purity are usual requirements. Because product separation from the starting material may be difficult, use of reaction to completion is desirable ceUs would be mn batch or plug flow. The water balance over the whole flow sheet needs to be considered, especiaUy for divided ceUs where membranes transport a number of moles of water per Earaday. At the inception of a proposed electroorganic process, the product recovery and refining should be included in the evaluation to determine tme viabUity. Thus early ceU work needs to be carried out with the preferred electrolyte/solvent and conversion. The economic aspects of product recovery strategies have been discussed (89). Some process flow sheets are also available (61). 

Regulatory Control For most batch processes, the discrete logic reqmrements overshadow the continuous control requirements. For many batch processes, the continuous control can be provided by simple loops for flow, pressure, level, and temperature. However, very sophisticated advanced control techniques are occasionally apphed. As temperature control is especially critical in reactors, the simple feedback approach is replaced by model-based strategies that rival if not exceed the sophistication of advanced control loops in continuous plants. 

Additional discussion regarding reactor design strategies is covered in Section 3.1 on minimization (as an inherently safer design strategy), and in Section 4.4 on Design and Construction. 

Verwijs, J. W., H. van den Berg, and K. R. Westerterp (1996). "Startup Strategy Design and Safeguarding of Industrial Adiabatic Tubular Reactor Systems. AIChE Journal 42, 2 (February), 503-15. 

Balakrishna, S. and Biegler, L.T., 1992b. Targeting strategies for the synthesis and energy integration of non-isothermal reactor networks. Industrial and Engineering Chemistry Research, 31(9), 2152. 

In this short initial communication we wish to describe a general purpose continuous-flow stirred-tank reactor (CSTR) system which incorporates a digital computer for supervisory control purposes and which has been constructed for use with radical and other polymerization processes. The performance of the system has been tested by attempting to control the MWD of the product from free-radically initiated solution polymerizations of methyl methacrylate (MMA) using oscillatory feed-forward control strategies for the reagent feeds. This reaction has been selected for study because of the ease of experimentation which it affords and because the theoretical aspects of the control of MWD in radical polymerizations has attracted much attention in the scientific literature. 

Another strategy would involve design of the reactor vessel for a pressure rating in excess of any likely emergency system pressure. This assumes we can adequately predict all possible worst case situations, which is doubtful. 

The strategies explored and defined in the various examples presented open a way for wider application of microwave chemistry in industry. The most important problem for chemists today (in particular, drug discovery chemists) is to scale-up microwave chemistry reactions for a large variety of synthetic reactions with minimal optimization of the procedures for scale-up. At the moment, there is a growing demand from industry to scale-up microwave-assisted chemical reactions, which is pushing the major suppliers of microwave reactors to develop new systems. In the next few years, these new systems will evolve to enable reproducible and routine kilogram-scale microwave-assisted synthesis. 

Startup and Shutdown Strategies. In addition to safe operation, the usual goal of a reactor startup is to minimize production of off-specification material. This can sometimes be accomplished perfectly. 

I., Mikkola, J.-P., and Salmi, T. (2004) The development of monolith reactors general strategy with a case study. Chem. Eng. Sci., 59, 5629-5635. 

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