TY - JOUR
T1 - Vanadium and nickel deposition on FCC catalyst
T2 - Influence of residual catalyst acidity on catalytic products
AU - Etim, U. J.
AU - Bai, Peng
AU - Liu, Xiaohe
AU - Subhan, Fazle
AU - Ullah, Rooh
AU - Yan, Zifeng
N1 - Publisher Copyright:
© 2018 Elsevier Inc.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - The alteration of catalytic activity and selectivity of the cracking catalyst by porphyrinic metallic elements present in heavy crude oil fractions is a subject that requires serious attention. In this study, the effects of the two most deleterious of the metals (vanadium and nickel) and how they shift the product selectivity of the catalytic cracking are discussed, with a key focus on the catalytic behavior of the residual acidity consequent upon metal deactivation. Increasing loadings of vanadium and nickel were deposited on the FCC catalyst and subjected to a simulated FCC regeneration unit conditions. It is found that at loadings greater than 0.3 wt%, vanadium is 4–5 times as destructive as nickel on the crystalline structure of the catalyst. Catalytic evaluation results revealed correlations between residual surface acidity, catalyst activity and amount of coke formed on the catalyst at a constant catalyst-to-oil ratio (CTO). This result is in slight contrast with the widely reported enhanced coking activity of vanadium on FCC catalyst consequent upon dehydrogenation reaction. An alternative coke formation pathway based on the residual catalyst acidity is advanced for the observed coking behavior of high vanadium laden catalyst. In addition, a vanadium control measure relying on the acid-base chemistry and hydrothermal stability of a mixed-metal oxide is demonstrated as an effective method to limit the mobility of vanadium into the framework of the catalyst, the action that initiates vanadium deleterious effects. This study is expected to renew interest in the research on the coking behavior of metal poison catalysts.
AB - The alteration of catalytic activity and selectivity of the cracking catalyst by porphyrinic metallic elements present in heavy crude oil fractions is a subject that requires serious attention. In this study, the effects of the two most deleterious of the metals (vanadium and nickel) and how they shift the product selectivity of the catalytic cracking are discussed, with a key focus on the catalytic behavior of the residual acidity consequent upon metal deactivation. Increasing loadings of vanadium and nickel were deposited on the FCC catalyst and subjected to a simulated FCC regeneration unit conditions. It is found that at loadings greater than 0.3 wt%, vanadium is 4–5 times as destructive as nickel on the crystalline structure of the catalyst. Catalytic evaluation results revealed correlations between residual surface acidity, catalyst activity and amount of coke formed on the catalyst at a constant catalyst-to-oil ratio (CTO). This result is in slight contrast with the widely reported enhanced coking activity of vanadium on FCC catalyst consequent upon dehydrogenation reaction. An alternative coke formation pathway based on the residual catalyst acidity is advanced for the observed coking behavior of high vanadium laden catalyst. In addition, a vanadium control measure relying on the acid-base chemistry and hydrothermal stability of a mixed-metal oxide is demonstrated as an effective method to limit the mobility of vanadium into the framework of the catalyst, the action that initiates vanadium deleterious effects. This study is expected to renew interest in the research on the coking behavior of metal poison catalysts.
KW - Coke formation
KW - FCC catalyst
KW - Metal poisons
KW - Residual acidity
KW - Vanadium passivation
UR - http://www.scopus.com/inward/record.url?scp=85050001785&partnerID=8YFLogxK
U2 - 10.1016/j.micromeso.2018.07.011
DO - 10.1016/j.micromeso.2018.07.011
M3 - 文章
AN - SCOPUS:85050001785
SN - 1387-1811
VL - 273
SP - 276
EP - 285
JO - Microporous and Mesoporous Materials
JF - Microporous and Mesoporous Materials
ER -