Abstract In this work, we investigated the deactivation of a commercial ZSM-5 based catalyst during ex situ catalytic fast pyrolysis (CFP). The experimental runs were carried out in a novel cascade dual fluidized bed reactor system where thermal pyrolysis of biomass was carried out in the first reactor, while ex situ catalytic conversion of the pyrolysis vapours was carried out in the second reactor. Consecutive reaction-regeneration cycles were realised using the same catalyst batch in order to evaluate catalyst deactivation over time. A comparison between in situ and ex situ CFP revealed that in contrast to what was observed in the case of in situ CFP, no accumulation of biomass-derived metals on the catalyst was observed during ex situ CFP. Both acidity and surface area were less affected compared to in situ CFP and the catalyst maintained higher activity. Product distribution and composition exhibited some variation over time which was attributed to the accumulation of biomass ash in the pyrolysis reactor and not to the poisoning of the catalyst bed. These results clearly demonstrated that ex situ CFP is an effective way to avoid catalyst poisoning during the CFP of biomass and to prolong catalyst lifetime.

中文翻译：

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级联热催化反应器系统中生物质异位催化快速热解过程中的催化剂失活、灰分积累和生物油脱氧

摘要 在这项工作中，我们研究了商业 ZSM-5 基催化剂在异位催化快速热解 (CFP) 过程中的失活。实验运行是在一个新型的级联双流化床反应器系统中进行的，其中生物质的热解在第一个反应器中进行，而热解蒸汽的异位催化转化在第二个反应器中进行。使用相同的催化剂批次实现连续的反应-再生循环，以评估催化剂随时间的失活。原位和非原位 CFP 之间的比较表明，与在原位 CFP 的情况下观察到的情况相反，在非原位 CFP 期间未观察到生物质衍生金属在催化剂上的积累。与原位 CFP 相比，酸度和表面积的影响较小，并且催化剂保持较高的活性。产品分布和组成随着时间的推移表现出一些变化，这归因于热解反应器中生物质灰的积累，而不是催化剂床的中毒。这些结果清楚地表明，异位 CFP 是避免生物质 CFP 期间催化剂中毒和延长催化剂寿命的有效方法。