Intensification kinetics effects

Kinetic effects. As a first example of limitation, the previous sections demonstrated that homogeneous reactions cannot be intensified by geometric structuring since they are not scale dependent Nevertheless, their characteristic times can be accelerated, since they depend on a kinetic constant and on the reactant concentration. As a result, intensification of homogeneous reactions requires either a temperature increase (when additional selectivity or thermal sensitivity problems do not prevent this possibility) or a concentration increase. 

There are several reasons for carrying out the reactions at supercritical conditions. Naturally, some of the reasons are coupled. Nevertheless, they, in general, relate to favorable transport properties, unique solvency characteristics, favorable kinetic considerations, and their sensitivity to operating conditions (manipulated variables). These unique properties lead to opportunities in process synthesis, process intensification, and controllability. These advantages, coupled with the environmentally friendly nature of these processes, make reactions in supercritical fluids attractive. The effect of these properties on opportunities for these favorable reaction environments is summarized in Table 1. 

Hence, the stated above results have shown, that the fractal conception of chemical reactions kinetic describes quantitatively kinetics of solid-phase imidization process at different temperatures. This description is given only within the firamewoik of reaction physical aspects and does not affect its chemical aspects. The effective initial concentration of reagents at imidization temperature growth is due to physical cause also - by reagents diffusion intensification in solid-phase state. 

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