Title : Kinetics of catalytic hydrogenation of propene Investigations based on graph theory
Abstract:
The kinetics of heterogeneous catalytic reactions is the topic of theoretical and practical importance. Theoretical aspects are concerned with determination of the process run, stages, limitations etc., while in practical applications kinetic experiments were applied to assist reactor design and scaling up of various processes. Both directions overlap and in many articles are discussed simultaneously. The most often applied method is to find a single step having the strongest influence on the process rate. This step is selected from a sequence of elementary steps. In the literature, there are present a lot of works that present successful application of the concept, however in many instances failed attempts are reported - the kinetic equations are of not sufficient precision, as for the gas phase hydrogenation of propene process. In this work, we present a procedure based on graph theory and completed with statistical analysis that helps to obtain a high precision kinetic equation for the mentioned process. The method substantially differs from rate determining step approach. On the basis of the catalytic cycle proposed, the general form of the kinetic equation is derived without any additional assumptions. It allows considering all possible interactions between the reagents and the species. The most promising variant, that is a linear catalytic mechanism, was developed and tested. Statistical analysis allows simplifying the equation to obtain the form that includes only statistically significant variables. For the considered process, the kinetic equation obtained characterizes of the large precision confirmed by values of statistical indicators and the criterion. The residual sum of squares is more than 15% less than for the best equation founded in literature. The form of kinetic equation is not previously reported in literature and rather cannot be derived on the basis of classical approaches.
