Errors in the Determination of Kinetic Parameters

The determination of the chemical reaction rate is based on measurements of the concentrations, temperature and flow rates. Experimental errors in the measurements of these quantities are inevitable. 

The importance of correct and accurate temperature measurement follows immediately from a consideration of the reaction rate sensitivity with respect to temperature, as considered in Chapter 2. Although the temperature measurements themselves may be rather accurate, the error of a few degrees due to an incorrect position of the thermocouple can be crucial. Such errors may arise, for example, if the outlet bed temperature is measured at some distance from the outlet or in the reactor exit tube. 

To elucidate the significance of the accuracy of concentration and flow rate measurements, two ideal situations in the reactor which are usually assumed to occur in the experimental data collection are considered  

If the resistances to heat and mass transfer can be neglected, Equation S.3S or 5.36 is used for the determination of the kinetic parameters when an ideal mixing model holds, whereas Equation 5.42 or Equations 5.43 and 5.44 are used when a plug flow model is valid. For the sake of simplicity a first-order reaction is considered. The governing equations used for the determination of the chemical reaction constant are 

Jackson, R. (1977) Transport in Porous Catalysts. Amsterdam Elsevier. 

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E. Gileadi, G. Stoner, andJ. O M. Bockris,/. Electrochem. Soc. 113 585 (1966). Calculation of errors in the determination of kinetic parameters arising from potential sweep rates that are too high. 

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