Reactivity of Fluid Catalytic Cracking feedstocks as a function of reactive hydrogen content

Detailed feedstock composition analysis is a reasonable support for predicting product yields and quality parameters from the chemistry involved in FCC processing. Nonetheless, given the huge number of individual hydrocarbons present in common FCC feedstocks, it is necessary to lump them in Hydrocarbon Types (HT). In order to understand the interactions during FCC processing between these different hydrocarbon types and its relationship to yield and quality of end products, it is necessary to consider relative content and reactivity of these carbon families in the raw material. Hydrogen content of each hydrocarbon is a good measure of the cracking performance of this hydrocarbon. As hydrogen content increases in a molecule, the yields to LPG and gasoline increase. In this article, based on HT identification and refinery-measured feedstock properties, an estimation of reactivity for any feedstock is obtained. Two types of hydrogen, which are commonly part of the same molecule were defined as refractory (nonreactive) and reactive. Based on these types of hydrogen, a Reactivity Factor (RF) was introduced and defined as a relative index that measures cracking potential of FCC feedstocks. The described approach to classify FCC feedstocks, will be useful in future developing of correlations predicting yields and quality of end products.