吸热型碳氢燃料裂解引发剂筛选及引发机理分析

筛选可溶性添加剂替代多相催化剂, 达到促进吸热型碳氢燃料裂解、提高燃料热沉以及燃烧性能的目的. 采用考察裂解气相产物气体流量的方法进行实验. 测试了10种添加剂在500～650 ℃范围内对正庚烷裂解效果的影响. 研究发现, 三乙胺、2,6-二叔丁基对甲酚(BHT)可促进正庚烷裂解, 其它添加剂均无显著效果. 在550 ℃时, 当三乙胺质量分数达到6%时, 实验总气体收率比计算总气体收率增加80%以上. 机理研究表明, 三乙胺的引发剂基团来源于C—N键的断裂. BHT的结构、性状与前者显著不同, 在550 ℃时, 当BHT质量分数为3.4%时体系的气体收率较之纯正庚烷裂解气体收率增加80%以上, BHT的引发基团主要是连接于叔丁基上的甲基发生脱离的结果

Screening Experiments for Initiators and Initiating Mechanism for the Cracking of the Endothermic Hydrocarbon Fuel

Initiators to promote the cracking of the endothermic hydrocarbon fuel were screened. The flow rate of gas products was measured by a water-displacement method. Triethylamine and butylated hydroxytoluene (BHT) were found to be effective on promoting the cracking of heptane at 500～650 ℃. For the triethylamine system, the experimental yield of total gas product could be 80% higher than that calculated by neglecting the interaction between triethylamine and heptane as the mass fraction of triethylamine reached 6% at 550 ℃. The accelerating mechanism was studied by gas chromatography-mass spectrometry (GC-MS). It was demonstrated that the accelerating effect originated mainly from the initiative release of CH₃CH₂• from triethylamine by the scission of the C—N bond. For BHT, the initiating radicals were mainly produced by the scission of the bond between the tert-butyl carbon atom and methyl radical.