Reaction Mechanism Analysis Using Periodic Temperature Forcing

Periodic forcing of the input variables such as pressure has been employed to optimize the selectivity or understand the kinetics of chemical reactions when there is a nonlinear relationship between the reaction rate(s) and the controlled variable. The relationship between the reaction rate constant and the temperatures is also nonlinear. However, temperature control is difficult to implement and hence only a few studies on periodic temperature forcing have been reported. With the advent of microreactors, there is a potential to implement periodic forcing of temperatures during a reaction. In this report, the results of numerical simulations of the effect of periodic forcing of temperatures at various frequencies for a select set of reaction mechanisms are presented. The results are also compared with the analytical solutions in limiting cases. In the study of reaction mechanisms, distinguishability between candidate mechanisms is an important factor. In many cases, the results of isothermal reactions will not be able to differentiate between two mechanisms. We illustrate an example where periodic temperature forcing at various frequencies can help differentiate between candidate mechanisms.