An efficient catalysts grading technology for hydrocracking light cycle
oil to high-octane gasoline
Abstract
Naphthalene and tetralin hydrocracking behaviors were investigated over
NiMo and CoMo catalysts. The results showed that CoMo catalyst with high
concentration of S-edges could hydrosaturate more naphthalene to
tetralin but exhibit lower yield of high-value light aromatics (carbon
numbers less than 10) than NiMo catalyst. NiMo catalyst with high
concentration of Mo-edges also presented a higher selectivity to convert
naphthalene to cylanes than CoMo catalyst. Subsequently, the naphthalene
and LCO hydrocracking performances were also investigated over different
catalysts systems. It showed that the naphthalene hydrocracking
conversion and the yield of light aromatics for CoMo-AY/NiMo-AY grading
catalysts were higher than NiMo-AY/CoMo-AY grading catalysts at same
condition. A stepwise reaction principle was proposed to explain the
high-efficiency of CoMo-AY/NiMo-AY grading catalysts. Finally, the LCO
hydrocracking evaluation results confirmed that CoMo-AY/NiMo-AY
catalysts grading system with low carbon deposition and high stability
was more efficient to convert LCO to high-octane gasoline.