Passivation of vanadium in an equilibrium FCC catalyst at short contact-times

Autor:	Elisabeth M. Myhrvold, Trond Myrstad, Michael Stöcker, Elisabeth Tangstad, Ivar M. Dahl, Anne Andersen
Rok vydání:	2006
Předmět:	Nickel Hydrogen Transition metal Passivation Chemistry Process Chemistry and Technology Inorganic chemistry chemistry.chemical_element Vanadium Coke Fluid catalytic cracking Catalysis
Zdroj:	Applied Catalysis A: General. 313:35-40
ISSN:	0926-860X
Popis:	An equilibrium FCC (ECAT) sample containing 2800 ppm vanadium and 2500 ppm nickel was characterized by ESR and ESCA, and tested in a microactivity test (MAT) to study the effect of reductive pretreatments at elevated temperatures. From ESR and ESCA studies, it is found that the vanadium of the ECAT sample consists of V 4+ converting to a considerable part of V 3+ after a treatment with 5% H 2 in N 2 between 650 and 750 °C. Approximately, 40% of the vanadium exists as V 3+ after such a treatment at 700–750 °C. The reductive procedure led to an increase in the gasoline yield and a reduction in the coke yield in MAT when processing an atmospheric residue from the North Sea at 524 °C. It is shown that it is sufficient with a reduction/passivation time as short as 3 min in hydrogen at 689 °C to obtain a significant effect on the gasoline and coke yields. The results indicate that the main part of the observed reduction occurs in the outer layer of the particle at such short reduction times.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c246ffba47cebe023fd32727ffbaf572 https://doi.org/10.1016/j.apcata.2006.07.001 Zobrazit plný text záznamu Full Text from ScienceDirect