High-Temperature Short-Contact-Time Supersonic Nozzle Chemistry of Light Aliphatic Hydrocarbons
High-Temperature Short-Contact-Time Supersonic Nozzle Chemistry of Light Aliphatic Hydrocarbons
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轻质脂肪烃的高温短接触时间超声喷嘴化学
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
G. A. Somorjai
中科院分区：
文献类型：
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作者：
L. Romm;G. A. Somorjai
用镍、钼、铁、钯和石英制成的喷嘴在900- 1150 ℃的喷嘴温度下从C2（乙烷、乙炔）和C1（甲烷）反应物生产长链烃CmHn（m≥3，n≤m）。热解和膨胀到超声分子束的组合被证明是非常有效的轻质脂肪烃转化为较重的低聚物。在Tnozzle = 1000 ℃时，乙烷转化率接近100%，而在Tnozzle = 1100- 1150 ℃时，甲烷转化率达到70%。喷嘴中的接触时间在1-100 ms的范围内，使得能够至少同时进行动力学和热力学控制。主要产品为乙炔和苯及其同系物。在产品分布中也检测到自由基。反应机制涉及自由基的形成，并可能在喷嘴表面发生耦合反应，然后解吸为气相并膨胀为超声束。
Nozzles fabricated variously from nickel, molybdenum, iron, palladium, and quartz were utilized to produce longer-chain hydrocarbons CmHn (m≥3, n≤m) from C2 (ethane, acetylene) and C1 (methane) reactants at nozzle temperatures in the range 900-1150C. A combination of pyrolysis and expansion to a supersonic molecular beam is shown to be very effective in the conversion of light aliphatic hydrocarbons to heavier oligomers. The conversion of ethane is close to 100% at Tnozzle = 1000C, while that of methane reaches 70% at Tnozzle = 1100-1150C. The contact time in the nozzle is in the range 1-100 ms enabling at least simultaneous kinetic and thermodynamic control. Major products are acetylene and benzene and its homologues. Free radicals are also detected in the product distribution. The reaction mechanism involves formation of free radicals and, possibly, coupling reactions at the nozzle surface followed by desorption to the gas phase and expansion to a supersonic beam.