Jafarsadegh Moghaddas

Abstract The catalytic cracking of atmospheric gasoil over protonic HZSM-5 zeolite (SiO₂/Al₂O₃ = 33.3) was studied in a fixed-bed reactor. The effects of temperature (500, 550, and 600 °C) and catalyst loading (0.1, 0.3, and 0.5 g) on conversion of gasoil and selectivity of ethylene and propylene were thoroughly investigated. Both ethylene and propylene selectivities increased with rising temperature at all catalyst loadings, whereas the propylene-to-ethylene (P/E) ratio declined.

This study applies the unreacted shrinking core model (USCM) to elucidate the interaction between metal amine salt and ammonia gas. The governing equations of the model were numerically solved to describe non-catalytic gas-solid reactions. The model considered the effects of diffusion resistance through the product layer and the chemical reaction. The experimental data were compared with the model, and the results confirmed the validity of the USCM model.