Reaction from integral reactor experiments

Reaction Rate Equations from Integral Reactor Experiments... 

These equations also lead to a constant value for k, which confirms that the reaction has second-order kinetices. Peterson [2] has discussed further aspects of differential versus integral fitting of data from batch reactor experiments. 

From a few well chosen experiments in an integral reactor of technical dimensions with side-stream analysis both reaction schemes and the effective heat transfer and kinetic parameters of a reaction model for propylene oxidation could be deduced, from which valuable information for both catalyst development and optimization of the reaction conditions could be obtained. 

The data used for parameter estimation were from experiments wth very short gas residence times and generally low conversions. In order to check the validity of the derived expressions, we also carried out experiments at higher residence times. The proposed model reaction rate expressions eq.8, 9 and 10 were used to predict the integral reactor behavior under the following assumptions ... 

The evaluation of the experiments in both reactors was based on the mechanism of the oxidation. The concentration profiles measured in the integral reactor, as well as the finite slope in the origin of the concentration-residence time curves from the loop reactor, reveal that, the xylene is converted by simultaneous reactions to the products phthalicanhydride, phthalide, toluylaldehyde, CO and CO2. The distinct maximum of the phthalide- and tolualdehyde -concentration curve indicates that these are intermediate products which are converted mainly to phthalicanhydride in a consecutive step. From the decrease of the PSA-concentration at high residence times it may be concluded that, this species oxidize to CO, CO2, as well as water and to a lower extend, to MSA. For the evaluation of the ex-... 

Since the process may be carried out under the same temperature conditions as those in industry, a complete set of data may be evaluated from the experiment. The overall heat of reaction (300 kj kg-1) is obtained through integration of the heat release rate over time. The maximum heat release rate of 18 Wkg"1 is reached after 3.6 hours at a temperature of 53 °C. The specific heat capacity (1.7 kj kg 1 l< ) is calculated from the steps in heat released rate at the beginning and end of the temperature program. As an example, we consider a cooling failure at 3 hours. The reactor temperature is 47 °C and the thermal conversion is 0.35. Thus, the temperature after cooling failure can be calculated as... 

A reactor-reaction model has been presented. The reaction model predicted well the result of integral experiments which were conducted using the same catalyst under different operating conditions. The methane conversion increased with increasing residence time while the C2 selectivity decreased with increasing residence time from i = 0.05 to 0.6 sec. 

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