以催化裂化废催化剂为原料合成NaY分子筛的研究

Synthesis of NaY Zeolite Using Fluid Catalytic Cracking Waste Catalyst

针对催化裂化(FCC)废催化剂的回收利用问题,提出了一种废催化剂再利用的方法,即以FCC废催化剂为铝源,合成时只补充部分硅源,采用自制的高效NaY沸石导向剂,水热合成NaY分子筛。同时,以普通的化工原料合成了对比试样Y型分子筛。讨论了不同的FCC废催化剂预处理方式对合成产物性能的影响,发现以经过碱熔活化处理的废催化剂为原料合成的Y分子筛拥有更高的结晶度和纯度。采用X射线衍射、热分析、程序升温脱附法(NH3-TPD)和N2静态容量吸附法对结晶产物和对比样品的晶体结构,热稳定性、酸性质、比表面积以及孔分布进行了表征。结果显示,以FCC废催化剂为原料完全可以合成出与普通原料性能接近的NaY分子筛。其BET比表面积可以达到615m2.g-1,孔体积可达0.38cm3.g-1,孔径集中在0.51nm左右。

A method for reclaiming Fluid Catalytic Cracking（FCC） waste catalyst was proposed. FCC waste catalyst was used as raw material for the synthesis of NaY zeolite from silica gel, sodium hydroxide and the directing（nucleation） agent via the hydrothermal method. For comparison purposes, the reference NaY zeolite was prepared using common industrial chemicals. The effect of FCC waste catalyst pretreatment on the performance of NaY zeolite was studied. It is found that Y zeolite synthesized using alkali activated FCC catalyst possesses high crystallinity and purity. Selected sample was characterized by XRD, N2 adsorption-desorption techniques, TG-DTA method and temperature-programmed desorption of ammonium（NH3-TPD）. The results indicate that the NaY zeolite has similar performances to the reference zeolite and its surface area and pore volume can reach 615 m^2.g^-1 and 0.38 cm^3.g^-1, respectively.