摘要
负氢离子转移反应(htr)是重要的催化裂化基元反应之一。利用单事件微动力学模型对脂肪烃催化裂化的评估结果,从分子层面论述了htr反应的自催化特性。结果表明:原料中1-辛烯的存在提高了正碳离子活性中心覆盖率,尤其在原料转化率低的情况下,进而产生了更高的htr反应速率。htr反应速率不受原料中烯烃加入的影响,生成叔正碳离子的htr反应速率比生成仲正碳离子的速率快近5个数量级。对裂化反应机理比率(CMR)和反应链长(CL)的考察结果表明:当原料为纯烷烃时,两者的数值相近;当原料中加入烯烃时,CMR会受到明显影响,而CL几乎保持恒定。
Hydride transfer（htr） is generally recognized as one of the most important elementary reactions in catalytic cracking. Using Single Event Micro Kinetics （SEMK） in the assessment of the catalytic cracking of aliphatics, the autocatalytic character of hydride transfer was addressed at the molecular level. The results showed that the presence of 1 octene in the feedstock resulted in the enhanced acid site coverage, in particular at lower feed conversions and, consequently, in higher hydride transfer rates. Irrespective of the co feeding ofolefins, hydride transfer rates towards tertiary carbenium ions were almost 5 orders of magnitude higher than those towards secondary ones. The investigation of the Cracking Mechanism Ratio （CMR） and the reaction cycle Chain Length （CL） reveals that both CMR and CL adopt similar values when a pure paraffin feed is processed. However, while CMR was strongly affected by the addition of olefins in the feedstock, CL remained practically constant.
出处
《华东理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2013年第4期390-398,共9页
Journal of East China University of Science and Technology
基金
国家公派(CSC)联合培养博士生项目
