物理化学学报 >> 2011, Vol. 27 >> Issue (08): 1947-1955.doi: 10.3866/PKU.WHXB20110837

催化和表面科学 上一篇    下一篇

一种可作为FCC基质的新型改性镁铝尖晶石材料

许孝玲, 李春义, 山红红   

  1. 中国石油大学(华东)化学化工学院, 重质油国家重点实验室, 山东 青岛 266555
  • 收稿日期:2011-03-30 修回日期:2011-05-24 发布日期:2011-07-19
  • 通讯作者: 李春义 E-mail:chyli@upc.edu.cn
  • 基金资助:

    国家教育部创新基金资助项目

Novel Modified Magnesium-Aluminate Spinels as Potential FCC Matrix Components

XU Xiao-Ling, LI Chun-Yi, SHAN Hong-Hong   

  1. State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao 266555, Shandong Province, P. R. China
  • Received:2011-03-30 Revised:2011-05-24 Published:2011-07-19
  • Contact: LI Chun-Yi E-mail:chyli@upc.edu.cn
  • Supported by:

    The project was supported by the Creation Group Foundation of the Ministry of Education of China.

摘要:

镁铝尖晶石作为硫转移剂被广泛应用于流体催化裂化(FCC)过程中, 可降低再生烟气中的SO2排放. 通过将镁铝尖晶石和Y分子筛纳米簇溶液混合在酸性条件下再次晶化的方法改性镁铝尖晶石, 改性后尖晶石的酸性明显提高. 改性尖晶石材料的酸性和碱性可通过改变体系的pH值得以调节. 实验表明, 此改性方法可以将分子筛的结构单元引入到尖晶石中, 从而使尖晶石的微孔比表面、酸性和水热稳定性明显提高. 与原尖晶石相比, 改性尖晶石裂化减压瓦斯油(VGO)的活性和产物选择性均得到改善, 同时还保留了部分碱性活性位, 仍具有一定的脱硫活性. 改性尖晶石裂化VGO的反应性能优于高岭土, 同时以改性尖晶石作为部分基质的FCC催化剂的反应性能也优于以高岭土为主要基质的FCC催化剂.

关键词: 镁铝尖晶石, Y分子筛纳米簇, 硫转移, 催化裂化, 水热稳定性

Abstract:

Modified magnesium-aluminate spinels (MgAl2O4) were prepared by recrystallizing a mixture of MgAl2O4 and zeolite Y nanoclusters in acidic medium to improve the acidity of MgAl2O4, which was commonly used as a sulfur transfer agent in fluid catalytic cracking (FCC) units. The acidity and basicity of these samples can be tuned by varying the pH value of the synthesis system. From the characterization and catalytic cracking tests the introduction of zeolitic building units into the spinels contributed to the increased microporosity, acidity, and hydrothermal stability. The catalytic results indicate that the activities and the product selectivities of the modified spinels for vacuum gas oil (VGO) cracking improved remarkably compared to the parent spinel. These samples exhibited even better performance than Kaolin clay for VGO cracking while retaining a part of the basic sites for oxidative SO2 uptake. Moreover, the FCC catalyst prepared using the modified spinel as a partial matrix, after equilibration, also gave superior catalytic behavior compared to a reference FCC catalyst with Kaolin clay as the main matrix.

Key words: Magnesium-aluminate spinel, Zeolite Y nanocluster, Sulfur transfer, Catalytic cracking, Hydrothermal stability

MSC2000: 

  • O643