以天然凹凸棒石为原料合成Fe/Ti-ZSM-5沸石分子筛及其催化裂化性能

Synthesis and catalytic cracking performance of Fe/Ti-ZSM-5 zeolite from attapulgite mineral

以天然凹凸棒石为硅源、铁源和钛源, 一步合成了Fe/Ti-ZSM-5分子筛. X射线衍射、扫描电镜和N2吸附等温线测定结果表明, 所合成的样品具有良好的结晶度和较大的比表面积; NH3程序升温脱附和H2程序升温还原结果表明, 该样品具有强的酸性和氧化还原性能. 更为重要的是, 与常规方法制备的ZSM-5沸石相比, Fe/Ti-ZSM-5在催化裂解原料油(LGO, 加拿大)的测试中, 丙烯的产率提高0.21%, 总轻烯烃的产率提高0.33%. 由此可见, Fe与Ti物种在ZSM-5沸石分子筛中的存在有利于提高轻烯烃的产率,有望在石油炼制过程中提高烯烃产率.

Fe/Ti‐ZSM‐5 zeolite was synthesized successfully from treated attapulgite（ATP）.This mineral consists of amorphous silica containing Fe and Ti species.X‐ray diffraction patterns,scanning electron microscopy images,and nitrogen sorption isotherms indicate that the sample has a typical MFI structure,high crystallinity,and large specific surface area.Temperature‐programmed desorption of ammonia and H2 temperature‐programmed reduction indicates that the Fe/Ti‐ZSM‐5 zeolite is strongly acidic and has superior redox properties.More importantly,compared with conventional ZSM‐5 zeolite,Fe/Ti‐ZSM‐5 performs well,resulting in an increase in yield of 0.21% propylene and 0.33% total light olefins in the catalytic cracking of Canadian LGO（light gas oil）.These results suggest that the presence of Fe and Ti species in ZSM‐5 zeolite is favorable for enhancing light olefin yields,which is potentially important for oil refining in the future.