Influence of gas-phase reactions on catalytic reforming of isooctane
Influence of gas-phase reactions on catalytic reforming of isooctane
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DOI：
10.1016/j.proci.2010.05.050
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发表时间：
2011
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影响因子：
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通讯作者：
Torsten Kaltschmitt;L. Maier;M. Hartmann;C. Hauck;O. Deutschmann
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文献类型：
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作者：
Torsten Kaltschmitt;L. Maier;M. Hartmann;C. Hauck;O. Deutschmann
通过实验和数值模拟研究了在短接触时间和高温条件下，气相反应在异辛烷催化部分氧化(CPOX)中的意义，以加深对车载物流燃料CPOX产氢的理解。对焦炭前体的形成给予了特别关注。以进口C/O摩尔比为1.1的Rg涂层整体柱上异辛烷的环氧化反应为参考，对二维流场进行了描述，并结合了详细的表面和气相反应机理。结果表明，催化剂在无氧催化区结焦和结焦前驱体的形成。以富氧操作的环氧氯丙烷(C/O=1.0−1.6)的产品组成为入口组分，在推流反应器中进行了873~1173K温度范围内气相均相转化的研究。气相转化由两个详细的反应机理模拟。结果表明，大部分副产物和烟尘前体物质来自未转化的燃料，而不是来自额外添加的碳氢化合物，如乙烯。这两种机制都很好地预测了实验观察到的气相组成的所有趋势，无论是在轴向反应器中还是在不同的入口组成中。在CPOX实验中，碳烟前体的量随着燃料进料量的增加而增加，对应于CPOX实验中C/O比的增加。
The significance of gas-phase reactions in catalytic partial oxidation (CPOX) of isooctane at short contact times and high temperatures is studied experimentally and numerically to gain further understanding of hydrogen production by CPOX of logistic fuels for on-board applications. Special attention is given to the formation of coke precursors. CPOX of isooctane over a rhodium coated monolith with a molar inlet C/O ratio of 1.1 is used as reference case for a two-dimensional flow field description coupled with detailed surface and gas-phase reaction mechanisms. The results reveal catalyst coking and formation of coke precursors in the oxygen-free catalyst zone. Taking the product composition of the rich operated CPOX reactors (C/O=1.0−1.6) as inlet composition, homogeneous conversion in the gas-phase is studied in the temperature range from 873 to 1173K in a plug flow reactor. Conversion in the gas-phase is modeled by two detailed reaction mechanisms. Results show that most of the by-products and soot precursor species arise from unconverted fuel and not from additionally added hydrocarbons like ethylene. Both mechanisms well-predict all experimentally observed trends in gas-phase composition, both in axial reactor profiles and for different inlet compositions. The amount of soot precursors raises with increasing fuel feed corresponding to an increasing C/O ratio in CPOX experiments.