Performance of a Co-Ni catalyst for propane reforming under low steam-to-carbon ratios
Performance of a Co-Ni catalyst for propane reforming under low steam-to-carbon ratios
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DOI：
10.1016/j.cej.2004.03.005
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发表时间：
2004-09
影响因子：
15.1
通讯作者：
K. Hardiman;Tan T. Ying;A. Adesina;E. Kennedy;B. Dlugogorski
中科院分区：
文献类型：
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作者：
K. Hardiman;Tan T. Ying;A. Adesina;E. Kennedy;B. Dlugogorski
虽然用于合成气生产的烃的催化蒸汽重整通常在过量的蒸汽/碳比（S：C>3）下进行，但是由于焦化而导致的在线催化剂失活总是影响重整器性能。因此，有必要获得碳沉积和纯蒸汽重整活性之间耦合的定量关系，以制定最佳的重整-再生器策略。由于蒸汽重整的动力学信息通常是在无碳条件下收集的，因此焦炭对速率参数的影响尚未完全了解。本研究针对采购两个蒸汽重整和失活动力学常数同时从瞬态反应数据的条件下，低的水碳比在流化床反应器进料丙烷和采用氧化铝负载的Co-Ni催化剂。双因素方差分析统计处理证实了温度和S：C比对焦化动力学的强交互作用。虽然蒸汽重整动力学常数表现出Arrhenius依赖于温度，失活速率系数的特征在于由一个负的活化能，因为碳沉积增加，随着温度降低的范围内检查（773- 873 K）。这是证实了总有机碳（TOC）分析，XRD数据和程序升温氧化（TPO）的结果所使用的催化剂。TPO光谱证明了两种类型的碳质池与不同的C：H比为1和6的形成-表明焦炭的形成通过表面CHx物种的脱氢聚合反应进行萘化合物。
Although the catalytic steam reforming of hydrocarbon for synthesis gas production is often carried out with excess steam-to-carbon ratio (S:C>3), on-line catalyst deactivation due to coking invariably affects reformer performance. It is therefore necessary to obtain quantitative relation on the coupling between carbon deposition and pure steam reforming activity in order to develop optimal reformer-regenerator policy. Since kinetic information on steam reforming is often collected under carbon-free conditions, the effect of coke on the rate parameters is not fully understood. This investigation addresses the procurement of both steam reforming and deactivation kinetic constants simultaneously from transient reaction data under conditions of low steam-to-carbon ratio in a fluidised bed reactor fed with propane and employing an alumina-supported Co-Ni catalyst. Two-way ANOVA statistical treatment confirmed strong interaction between temperature and S:C ratio on the coking dynamics. Although the steam reforming kinetic constant exhibited Arrhenius dependency on temperature, the deactivation rate coefficient is characterised by a negative activation energy since carbon deposition increased with decreasing temperature in the range examined (773–873K). This was corroborated by total organic carbon (TOC) analysis, XRD data and temperature-programmed oxidation (TPO) results of the used catalysts. The TPO spectra evidenced the formation of two types of carbonaceous pools with different C:H ratios of 1 and 6—an indication that coke formation proceeded via dehydropolymerisation of surface CHxspecies to naphthalenic compounds.