Study Of Spent FCC Catalyst To Remove The Trace Olefins In Aromatics

Great attention has been paid to find an effective routine to the reuse and treat the spent FCC catalyst for the toxic metal V, Ni and Co that deposited on the surface will lead to the pollution of air, soil and water. In this research, with the ultrasonic and proper chemical methods, the spent FCC catalyst was calcined and washed in kinds of solutions in order to remove the coke and the contaminating metals on the surface of the catalyst so as to recover its surface properties and chemical activity. experiments showed that the spent FCC washed with 5% oxalic acid and 10% citric acid and then calcined at 550℃showed best performance in remove the trace olefins in aromatics. Comprised with the catalyst washing with magnetic stirring, the catalyst washed in the ultrasonic reactor showed better activity in the reaction. The treated spent FCC catalyst modified with compound A showed much better activity than that of catalyst without modification. The mixed-based catalyst prepare with the spent FCC catalyst treated with 5% oxalic acid and 10% citric acid and active clay showed greatest olefin conversion with the loading content of at 7% and 10%, the olefin conversion after 120mins' reaction was above 80%. BET showed that the pretreatment process expanded the mesoporous properties of the spent catalyst; XRD indicated that the pretreatment did not change the structure of catalyst; FT-IR illustrated that the modification process greatly increased the amount of L acid and the total acid and the more L acid the catalyst possessed, the higher activity it would show. ICP showed that the removal rate of Ni, Co, V was 85.7%, 61.9% and51.3% correspondingly.