Hydrothermal Synthesis Of Super-fine Zeolite Y With FCC Spent Catalyst

The environment problem can be aroused by the FCC spent catalyst. These fine powder can also result in the loss of resource due to its emission with flue gas. With using FCC spent catalyst fine as raw materials, the super-fine zeolite Y was prepared by in-situ hydro-thermal crystaliization method, which can achieve the efficient recycling of solid waste in FCC progress.In order to control the particle size of zeolite Y, the inorganic salts were introduced to the synthesis system and the other factors such as Si/Al ratio of precursor, alkalinity, crystallization temperature and time were tuned. The structure and properties of the sample were characterized by X-ray diffraction (XRD), temperature programmed desorption (TPD), scanning electron microscope (SEM) and Nitrogen adsorption-desorption. The results showed that the super-fine zeolite Y was synthesized by FCC spent catalyst fine with good thermal stability and high surface area. The main factor to affected the particle size of product was introduction amount of NaCl. The purity and relative crystallinity were affected by the Si-Al ratio of raw materials and alkalinity. The investigation showed that the physical structure and chemical properties of zeolites were significantly affected by its particle size. The smaller particle size of zeolite Y possesses, the greater outer surface area will be. While the thermal and hydrothermal stability are decreased with the decrease of particle size. In addition, the ratio of B and L acid sites can be controlled by the particle size.In order to get good active component of FCC, the effect of ion-exchange methods and conditions on the stability and hydrothermal stability were investigated. It showed that products could have optimum thermal and hydrothermal stability when the zeolites were firstly carried out an ion exchange, then taken hydrothermal treatment, and finally carried out two ion exchange. The catalyst still showed good activity and selectivity after hydrothermal treatment for 12h at 800oC.The catalytic performance of super-fine zeolite Y had been investigated with VGO as feed oil. Compared with the industrial catalyst, the super-fine zeolite Y as the active component of FCC catalyst had the higher light oil yield, conversion rate, and the higher desulfurating performance. In addition, the selectivity of light oil and the conversion rate were increased with the particle size of zeolite decreased. As the acid composition of hydrocracking catalyst, the super-fine zeolite Y showed a superior hydrocracking performance with naphthalene as model compound. The result also showed that the hydrogenation performance was decreased, while the cracking performance was increased with the particle size of zeolite decreased.