正癸烷在Pt/ZSM-5上的催化燃烧及气相产物特性

Catalytic Combustion and Gaseous Products Characteristics of n-Decane on Pt/ZSM-5

关键词:  烃燃料  点火  催化燃烧  催化裂解  气相产物  当量比

Key words:  Hydrocarbon fuel  Ignition  Catalytic combustion  Catalytic cracking  Gaseous products  Equivalence ratio

摘要:

催化燃烧能提高航空煤油的燃烧效率，其生成的小分子气体也对后期的航空煤油点火燃烧特性起重要作用。以航空煤油一元替代燃料正癸烷为对象，研究了催化燃烧及其气相产物特性，在Pt/ZSM-5和石英砂上进行了催化/无催化燃烧的对比实验，分析了温度（100~600℃）、当量比（Φ=0.6，1.0，2.0）和催化剂（Pt/ZSM-5）对正癸烷转化率和气相产物特性的影响。研究发现：Pt催化条件下，正癸烷的燃烧启动温度降低约110℃。催化反应在200℃左右就可以实现较高转化率：Φ=0.6~1.0时，转化率在75%以上。催化反应产物中的CO显著减少，正癸烷转化率和完全氧化程度提高。Φ=0.6~2.0时，CO₂始终是最主要产物。低温下（<150℃）正癸烷催化裂解生成丁烯的反应对催化反应启动有重要影响。烃类气相产物由C3，C4大分子向C1，C2小分子转化和气相氧化产物由CO₂向CO转化则是富燃高温（>500℃）下正癸烷催化反应的两个重要特征。

Abstract:

Catalytic combustion can improve the combustion efficiency of aviation kerosene， and the small molecule gas generated by catalytic combustion plays an important role in the ignition and combustion characteristics of aviation kerosene in the later stage. As an alternative fuel of aviation kerosene， n-decane was taken as the research object. The characteristics of catalytic combustion and its gaseous products were studied. The comparative experiments of catalytic/non-catalytic combustion on Pt/ZSM-5 and quartz were performed. The effects of temperature （100~600℃）， equivalent ratio （Φ=0.6， 1.0， 2.0） and catalyst （Pt/ZSM-5） on n-decane conversion and gaseous products characteristics were analyzed in the experiment. On the Pt catalysis conditions， the light-off temperatures of n-decane are reduced by about 110℃. The catalytic reaction achieves high conversion at about 200℃： when Φ=0.6~1.0， the conversion is above 75%. Furthermore， the CO content is reduced significantly in catalytic reaction and the conversion of n-decane and the degree of complete oxidation increased. In the range of Φ=0.6~2.0， CO₂ is the main gaseous product. The reaction of catalytic cracking of n-decane to butene at low temperature （<150℃） has an important effect on the start of the catalytic reaction. On the fuel-rich conditions， the transformation of hydrocarbon gaseous products from C3， C4 macromolecules to C1， C2 micromolecules and the gaseous oxidation products from CO₂ to CO are two important characteristics of the n-decane catalytic reaction at high temperature （>500℃）.