ATR Reactor Setup Influence of Preheating the Reactants

In order to establish the influence of preheating of the reactants on the ATR reactor performance, catalytic activity tests were carried out with and without preheating the reactants. For the tests performed with air and water preheating, two heat exchangers were integrated in the previous version of ATR reactor. 

The first step is relevant to the start-up phase, which in this particular case we chose to extend for up to 1 h in order to verify the reactor stability also in these conditions, where water is not present and while there is a higher oxygen concentration in the feed gas with respect to the ATR conditions. By lowering the 02 CH4 ratio, the H2 concentration at the reactor outlet increases, approaching the value expected by thermodynamic evaluation and CH4 conversion is still complete. A further decrease in the 02 CH4 feed ratio to values lower than 1.16 corresponds to an abrupt decrease in temperature in the lower section and a simultaneous temperature increase in the catalytic reforming section. 

These results can be explained by considering that at this 02 CH4 ratio the homogeneous combustion reaction is not favored and consequently the feed mixture reacts in the catalytic section where the heat developed by the exothermic reactions is responsible for the remarkable temperature increase. 

By lowering the x value at 0.84, the average temperature in the catalytic section is lowered by about 100 °C whereas the H2 concentration increases up to about 30 vol.%. In the next step, by lowering the xvalue to 0.71, a dramatic effect on CH4 conversion is observed. In fact, the new value is lower than 90%. The observed temperature profile along the catalytic bed (a higher value at the catalyst inlet and a decrease along the 

It must be evidenced that the reactor performance is stable under all investigated operating conditions. 

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