This Article investigates the decomposition of benzene (as a model tar) over finely dispersed char particles continuously distributed into a packed bed. Fragmented char particles and benzene plus a gasification agent (H₂O or CO₂) were supplied into a ceramic reactor that was heated electrically. The supplied char particles were retained in the reactor by a bed of alumina grains. Woody char as well as iron-doped and potassium-doped woody char were used. The influence of the gasification agent, char concentration, char weight time (proportional to the instant char mass present in the bed), and bed temperature (600–1050 °C) was investigated. Increasing the char concentration and char weight time increased benzene conversions for all tested chars. At similar char weight times, the benzene conversion increased with temperature, whereas the iron- and potassium-doped char did not affect the specific conversion. At similar char concentrations, changing the gasification agent from CO₂ to steam as well as using doped char led to decreased benzene conversions. This can be explained by accelerated char gasification reactions and thus a diminished char mass in the packed bed. Furthermore, benzene conversion rates were enhanced in the presence of CO₂ as compared to steam. As the temperature was increased from 950 to 1050 °C, the benzene conversions were slightly reduced. This was interpreted as a combined effect of the enhanced benzene conversion rates and reduced char weight times. The highest benzene conversions achieved in the experiments were approximately 80% at 950–1000 °C using CO₂ as gasification agent and supplying approximately 20–30 g N m^–3 undoped woody char.

中文翻译：

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连续填充木质焦炭颗粒的填充氧化铝床中的苯转化率

本文研究了连续分布在填充床中的细分散炭颗粒上苯（作为模型焦油）的分解。碎片状的炭颗粒和苯以及气化剂（H ₂ O或CO ₂）被供给到电加热的陶瓷反应器中。所提供的炭颗粒通过氧化铝颗粒床保留在反应器中。使用了木质焦炭以及掺杂铁和钾的木质焦炭。考察了气化剂，炭浓度，炭重量时间（与床中存在的瞬时炭量成正比）和床温度（600-1050°C）的影响。炭浓度和炭重量时间的增加会增加所有测试炭的苯转化率。在相似的焦炭重量时间，苯转化率随温度增加，而铁和钾掺杂的焦炭不影响比转化率。在类似的炭浓度下，将气化剂从CO ₂换成蒸汽以及使用掺杂的炭导致苯转化率降低。这可以通过加速的焦炭气化反应来解释，从而可以减少填充床中的焦炭质量。此外，与蒸汽相比，在存在CO ₂的情况下提高了苯的转化率。随着温度从950°C升高到1050°C，苯的转化率略有降低。这被解释为苯转化率提高和炭重时间缩短的综合作用。在实验中，使用CO ₂作为气化剂并提供约20–30 g N m ^–3的未掺杂木炭，在950–1000°C的实验中，最高的苯转化率约为80％。