Kinetic and reactor modeling will always be a fundamental step in the design of chemical processes. In this context, it has taken decades for kinetic models of petroleum refining processes to evolve with the intention of predicting the vast product distribution or at least part of it. The main problem with petroleum feedstocks arises from their complex composition and intricate structure at the molecular level. Depending on the boiling range, oil fractions may contain from a few hundred to a several thousands of different components. For modeling purposes, this implies a gigantic interconnected reaction network with a wide distribution of reactivities. Modeling of hydrocarbon conversion processes is consequently a challenging task due to its inherent high-level of complexity.