物理化学学报 >> 2008, Vol. 24 >> Issue (07): 1192-1198.doi: 10.3866/PKU.WHXB20080713

研究论文 上一篇    下一篇

不同硅铝比β沸石的理化性质及烃类催化裂化活性

李强; 窦涛; 霍全; 徐庆虎; 巩雁军; 潘惠芳   

  1. 中国石油大学(北京)化工学院CNPC催化重点实验室, 北京 102249; 太原理工大学精细化工研究所, 太原 030042
  • 收稿日期:2008-01-03 修回日期:2008-03-13 发布日期:2008-07-04
  • 通讯作者: 窦涛 E-mail:doutao@cup.edu.cn

Physicochemical Properties and Activities of Hydrocarbon Catalytic Cracking of β-Zeolite with Different Silica-Alumina Ratios

LI Qiang; DOU Tao; HUO Quan; XU Qing-Hu; GONG Yan-Jun; PAN Hui-Fang   

  1. CNPC Key Laboratory of Catalysis, China University of Petroleum, Beijing 102249, P. R. China; Institute of Special Chemical, Taiyuan University of Technology, Taiyuan 030042, P. R. China
  • Received:2008-01-03 Revised:2008-03-13 Published:2008-07-04
  • Contact: DOU Tao E-mail:doutao@cup.edu.cn

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摘要： 采用润湿态固相转化方法按照投料硅铝摩尔比(n(SiO2)/n(Al2O3))分别为30、60、150、300、500和纯硅时合成了β沸石, 化学法和X射线荧光(XRF)测定产物的硅铝比和反应初始凝胶基本一致. 利用X射线衍射(XRD)、红外光谱(FT-IR)、扫描电镜(SEM)、氨程序升温脱附(NH3-TPD)和低温N2吸附对系列样品的物相、水热稳定性、晶体形貌、酸性以及表面积和孔体积做了系统的表征. 并将该系列样品作为活性组分添加剂, 以高岭土为基质分别制备烃类裂化催化剂, 对其催化裂化性能进行了评价. 结果表明, 不同硅铝比β沸石添加到裂化催化剂均可以提高其裂化活性, 改善催化剂的抗积炭性能, 硅铝比为150的β沸石催化剂在保持较高裂化活性的前提下, 汽油收率最高, 抗积炭性能也较好, 是优选的裂化催化材料.

关键词: 硅铝比, β沸石, 理化性质, 催化裂化

Abstract: High-crystallized β-zeolites with different silica-alumina molar ratios were successfully synthesized in extremely dense aqueous system using tetraethylammonium hydroxide (TEAOH) as template and solid silica gel as silica source, respectively. The silica-alumina molar ratios in the initial gels were 30, 60, 150, 300, 500, and pure silica, respectively, which were consistent with those in so-prepared samples determined by chemical method and XRF analysis. Subsequently, the physicochemical properties of samples were characterized by XRD, FT-IR, SEM, NH3-TPD, and N2-adsorption analysis. The results showed that the extent of dealumination was changed obviously and the acid content was decreased significantly in the low silica β-zeolite with highest aluminium content after hydrothermal treatment. The high silica or pure silica β-zeolites could not display higher hydrothermal stability partly due to their small grain sizes. After hydrothermal treatment, the medium silica-alumina ratio zeolite beta could remain higher acid amount and showed better hydrothermal stability. The effect of β-zeolites with different n(SiO2)/n(Al2O3) ratios as an active additive on cracking performance has been investigated. It was found that β-zeolite could increase the activity of cracking catalyst and improve the performance of resistance to carbon deposition. As β-zeolite with n(SiO2)/n(Al2O3) molar ratio of 150 was added, the cracking catalyst exhibited the higher cracking gasoline yield and lower carbon deposition.

Key words: Silica-alumina ratio, β-Zeolite, Physicochemical property, Catalytic cracking