Light Alkenes Preparation by the Gas Phase Oxidative Cracking or Catalytic Oxidative Cracking of High Hydrocarbons

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• 作者：Xuebin Liu ; Wenzhao Li ; Haiou Zhu ; Qingjie Ge ; Yanxin Chen and Hengyong Xu
• 关键词：light alkenes ; gas phase oxidative cracking ; catalytic oxidative cracking ; high hydrocarbons ; hydrogen addition
• 刊名：Catalysis Letters
• 出版年：2004
• 出版时间：2004
• 年：2004
• 卷：94
• 期：1/2
• 页码：31-36
• 全文大小：143 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Catalysis
  Physical Chemistry
  Industrial Chemistry and Chemical Engineering
  Pharmacy
  
• 出版者：Springer Netherlands
• ISSN：1572-879X

文摘

The preparation of light alkenes by the gas phase oxidative cracking (GOC) or catalytic oxidative cracking (COC) of model high hydrocarbons (hexane, cyclohexane, isooctane and decane in the GOC process and hexane in the COC process) was investigated in this paper. The selection for the feed in the GOC process was flexible. Excellent conversion of hydrocarbons (over 85%) and high yield of light alkenes (about 50%) were obtained in the GOC of various hydrocarbons including cyclohexane at 750°C. In the GOC process, the utilization ratio of the carbon resources was high; CO dominated the produced CO_X (the selectivity to CO₂ was always below 1%); and the total selectivity to light alkenes and CO was near or over 70%. In the COC of hexane over three typical catalysts (HZSM-5, 10% La₂O₃/HZSM-5 and 0.25% Li/MgO), the selectivity to CO_X was hard to decrease and the conversion of hexane and yield of light alkenes could not compete with those in the GOC process. With the addition of H₂ in the feed, the selectivity to CO_X was reduced below 5% over 0.1% Pt/HZSM-5 or 0.1% Pt/MgAl₂O₄ catalyst. The latter catalyst was superior to the former catalyst due to its perfect performance at high temperature, and with the latter, excellent selectivity to light alkenes (70%) and the conversion of hexane (92%) were achieved at 850°C (a yield of light alkenes of 64%, correspondingly).