A novel FCC catalyst synthesized via in situ overgrowth of NaY zeolite on kaolin microspheres for maximizing propylene yield

NaY/kaolin composite microspheres were synthesized by an in situ method using calcined kaolin microspheres as raw material. By mixing the modified NaY/kaolin composite microspheres and additive microspheres containing ZSM-5, a novel fluid catalytic cracking (FCC) catalyst for maximizing propylene yield in FCC unit was prepared. The catalyst was characterized by X-ray diffraction (XRD), temperature-programmed desorption of ammonium (NH₃-TPD), and N₂ adsorption–desorption techniques and tested in a bench FCC unit. The characterization results indicated that the catalyst has more meso- and macro-pores and more acid sites than the reference catalyst and thus can increase propylene yield by 1.27%.