Abstract To upgrade pyrolysis vapors derived from the catalytic fast pyrolysis (CFP) of Baiyinhua lignite (BYHL) in a drop tube reactor, various Co-loading (1, 3, 6 and 10 wt%) zeolites were prepared via wet impregnation. The effect of Co-loading and pyrolysis temperature ranged from 400 to 700 °C on product yields and tar properties were investigated in this work. The results showed that the product yield and the composition of pyrolysis tar were significantly affected by Co-modified HZSM-5 and parent HZSM-5 compared with no catalyst. Incorporation of metal-Co in HZSM-5 had an additional effect on the performance of the parent HZSM-5. The total content of benzene (B), toluene (T), ethylbenzene (E), xylene (X) and naphthalene (N) significantly increased and it reached 24.2 mg/g at Co-loading of 3 wt% (3Co-H-5) at 600 °C. 3Co-H-5 exhibited also a promising performance in lowering the oxygen content from 49.8% without a catalyst to 14.6% by GC–MS analysis. The deoxygenation mechanisms over metal-Co active centers and acid-catalyzed reactions, such as isomerization and cracking, over acid sites of HZSM-5 were speculated in this work. In addition, the temperature of 600 °C is not only appropriate for fast pyrolysis of lignite to obtain a higher pyrolysis tar, but also for catalytic pyrolysis to obtain BTEXN.

中文翻译：

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在共改性 HZSM-5 上褐煤热解蒸汽升级过程中增加轻芳烃产品

摘要 为了提高白银花褐煤 (BYHL) 在滴管反应器中催化快速热解 (CFP) 产生的热解蒸气，通过湿浸渍制备了各种共载量 (1, 3, 6 和 10 wt%) 沸石。在这项工作中研究了共负载和热解温度范围从 400 到 700 °C 对产品产率和焦油性质的影响。结果表明，与无催化剂相比，共改性HZSM-5和母体HZSM-5对产物收率和热解焦油组成有显着影响。在 HZSM-5 中加入金属钴对母体 HZSM-5 的性能有额外的影响。苯 (B)、甲苯 (T)、乙苯 (E)、二甲苯 (X) 和萘 (N) 的总含量显着增加，在共负载量为 3 wt% (3Co-H- 5) 在 600 °C。通过 GC-MS 分析，3Co-H-5 在将氧含量从没有催化剂的情况下的 49.8% 降低到 14.6% 方面也表现出有希望的性能。在这项工作中推测了金属-钴活性中心的脱氧机制和酸催化反应，如异构化和裂化，在 HZSM-5 的酸性位点上。此外，600℃的温度不仅适合褐煤快速热解获得较高的热解焦油，也适合催化热解获得BTEXN。