Reactor non-isothermal

The temperature remains constant (isothermal reactor) if the heat of reaction is negligible (AHj 0). An isothermal condition can be maintained by removing the heat generated by an exothermic reaction or by adding the heat that is consumed by an endothermic reaction. The rate of any reaction is a strong function of temperature. Consider an nth-order 

Progression of temperature with time in a batch reactor. 

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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. 

The objectives of this presentation are to discuss the general behavior of non isothermal chain-addition polymerizations and copolymerizations and to propose dimensionless criteria for estimating non isothermal reactor performance, in particular thermal runaway and instability, and its effect upon polymer properties. Most of the results presented are based upon work (i"8), both theoretical and experimental, conducted in the author s laboratories at Stevens Institute of Technology. Analytical methods include a Semenov-type theoretical approach (1,2,9) as well as computer simulations similar to those used by Barkelew LS) ... 

There are several aspects of thermal sensitivity and instability which are important to consider in relation to reactor design. When an exothermic catalytic reaction occurs in a non-isothermal reactor, for example, a small change in coolant temperature may, under certain circumstances, produce undesirable hotspots or regions of high temperature within the reactor. Similarly, it is of central importance to determine whether or not there is likely to be any set of operating conditions which may cause thermal instability in the sense that the reaction may either become extinguished or continue at a higher temperature level as a result of fluctuations in the feed condition. We will briefly examine these problems. 

The critical condition and stability of exothermic chemical reaction in a non-isothermal reactor. Journal of Loss Prevention in the Process Industries, 10 (3), 141-50. 

Finally, chemical reactors can be classified according to the mode of heat removal. We can have either isothermal or non-isothermal reactors, a sub-category of which is adiabatic reactors. Often it is desirable to use the heat released by an exothermic reaction for an endothermic reaction, in order to achieve higher heat integration. 

C. Non-isothermal Reactor Models 1. Wall-catalyzed Reactions... 

Kokossis. A. C., and Floudas. C. A. "Synthesis of Non-isothermal Reactor Networks. Annual AIChE Meeting. Los Angeles, CA (1991). 

A schematic diagram of the two-reactor fixed-bed system is shown in Fig. 5. The primary reaction occurs in the reactor on the left while regeneration occurs on the right. Dashed lines indicate gas flow paths when the functions of the two reactors are reversed. Both gas and solid concentrations and temperatures (for non-isothermal reactors) are functions of time and axial position. 

Double-click on the FEMLAB 3.1 ECRE icon on your desktop. In the Model Navigator, select model denoted "4-Non-Isothermal Reactor 11" and press Documentation". This will open your web browser and display the documentation of this sped lie model. You can also review the detailed documentation for the whole scries of models listed on the left-hand side in the web browser window. Use chapter 2 in the online documentation to answ cr the questions below using the model 4-Non-Isothermai Reactor 11". Select the Model Navigator and press "OK" to open the model,... 

Unsta arty-State Non isothermal Reactor Design Ch... 

Skrzypek el al. (1985) studied the o-Xylene oxidation over a commercial V O ITiOx in fixed bed non-isothermal reactor. Kinetic measurements were made for the feed temperature range of 633-663 K and for a wide range of feed compositions. The reaction network is similar to that postulated by Yabrove and Ivanov (1980) with the exception that maleic anhydride is considered to be a final product. No formation of phthalide is reported from o-Xylene directly, and no combustion products from o-tolualdehyde and phthalide. 

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