High Silicon Nano-zeolite Catalytic Fcc Gasoline Olefin Reduction

In order to control the tail-gas pollution of fuels, pollution-producing and harmful materials in gasoline must be limited. In China, it is urgent to reduce the olefin content of FCC gasoline.This paper detailedly studies the adjusting of surface acidity by steaming and the influence of total acid and Lewiss acid sites to Bronsted acid sites ratio (CL/CB) on the performance of de-olefin catalyst. Catalytic performance of cobalt loaded and molybdenum loaded nano-HZSM-5 and Beta/ZSM-5 catalysts are also studied. Moreover, various samples of the scaled-up catalyst QG009 were evaluated. Besides, measure to slow down the deactivation of the catalyst is also investigated. The results are as follows:1) Total acid and CL/CB value of nano-HZSM-5 can be successfully adjusted by steaming. The stability of the de-olefin catalyst depends on the amount of total acid and strong acid, and on the value of CL/CB. Exceeded amount of total acid and strong acid, and low CL/CB value undergo the stability of de-olefin catalyst.2) Co loading increases total acid of nano-HZSM-5 and consequently enhances aromatization of the catalyst but is improper for de-olefin because it lack of stability. Mo loading decreases strong acid of nano-HZSM-5. Relatively good stability can be achieved by loading 1.41% Mo over nano-HZSM-5.3) The introduction of Beta zeolite into nano-ZSM-5 by synthesis can increase iso-paraffin of the product in model reactant converting but is hardly effective in real gasoline treatment.4) Scaled-up QG009 almost has the same adsorption ability, acidity, metal content and de-olefin performance as the experimental QG009. Shaping hardly has any influence on adsorption ability and reacting features of scaled-up QG009.5) De-olefin catalyst protector has the ability of getting rid of di-olefin in gasoline with high selectivity, and is able to slow down the deactivation of de-olefin catalyst.