Study on the reaction pathway selectivity in FCC process by using m-xylene as a probe molecule

A continuously flowing micro-reactor-GC system with a spontaneous multi-sampling device was set up to characterize the relative selectivity of bi-molecular reaction pathways and mono-molecular reaction pathways, denoted as R₁, in catalytic cracking process, in which m-xylene was used as the model molecule of raw material. The R₁ value determined by the new method can be well correlated with E-cat unit cell size and acid site density, and is consistent with the product distribution obtained from fixed fluidized bed reactor. The R₁ value can be used to estimate the quality of the cracking gasoline obtained in FCC process over the corresponding catalyst.