Revisiting Reaction Network Modeling of Thermal Cracking of Hydrocarbons

Thermal cracking of hydrocarbons is an industrially important process to produce products with better economic value. Although substantial literature exists on the thermal cracking of hydrocarbons, there is considerable disparity in the proposed mechanisms and kinetic parameters. A better understanding of the complex cracking reactions network becomes important to maximize the returns by producing the products in demand, mostly C2–C4 olefins. In this work, we propose an improved molecular reaction scheme(s) for the thermal cracking of C2–C7 linear hydrocarbons and establish a set of improved and unified kinetic parameters. Starting with a reaction network scheme for ethane cracking, the kinetic model and parameters are extended up to heptane cracking. The model accuracy was improved in a stepwise manner by using multiple data sets of ethane, propane, and butane cracking. The improved reaction scheme and unified kinetic parameters fit the major product profiles of cracking of individual light alkanes, from ethane to heptane, as well as mixtures of these hydrocarbons within a 10% relative error, and have the potential of representing kinetics of reactions involving a complex feed like naphtha. The molecular reaction mechanism is validated against industrial data available in the literature.