Abstract Toluene as a model tar compound was used to study the effect of atmosphere on carbon deposition during biomass tar reforming. A novel Ni-loaded on lignite char (Ni/LC) and commercial Ni/Al2O3 was employed for stability evaluation in a thermogravimetric analyzer. The mechanism of coke formation under N2, H2 and steam with different steam/carbon (S/C) ratio were investigated during 5 h test. Nickel particle growth is the main reasons responsible for the deactivation of Ni-based catalysts for tar reforming. Steam remarkably suppressed the carbon deposition on Ni/Al2O3, especially in a high S/C ratio. Ni/Al2O3 exhibited high activity and stability for 5 h operation in S/C ratio of 2. H2 significantly promoted the carbon deposition on Ni/Al2O3 and caused the catalyst deactivation within 0.5 h. Ni/LC exhibited great resistance to coke deposition under inert and H2 reforming of toluene. The catalysts before and after catalytic cracking were characterized by X-ray diffraction and transmission electron microscopy to investigate the behavior of carbon deposition. Except for H2 reforming, an obvious change of the Ni crystallite size (NCS) can be found after reforming for 5 h under all conditions used in this study. The NCS in Ni/LC was significantly increased with increasing time and S/C ratio, which should be partly responsible for the deactivation of the Ni/LC.

中文翻译：

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在甲苯作为生物质焦油模型化合物重整过程中，气氛对 Ni/Al 2 O 3 和负载 Ni 对褐煤焦炭沉积的影响

摘要 以甲苯为模型焦油化合物，研究了大气对生物质焦油重整过程中积碳的影响。在热重分析仪中采用了一种新型的负载镍的褐煤炭 (Ni/LC) 和商业 Ni/Al2O3 进行稳定性评估。在 5 h 的试验中研究了 N2、H2 和不同蒸汽/碳 (S/C) 比的蒸汽下的焦炭形成机制。镍颗粒生长是导致用于焦油重整的镍基催化剂失活的主要原因。蒸汽显着抑制了 Ni/Al2O3 上的碳沉积，尤其是在高 S/C 比下。Ni/Al2O3 在 S/C 比为 2 的条件下运行 5 小时后表现出高活性和稳定性。H2 显着促进了 Ni/Al2O3 上的积碳，并在 0.5 小时内导致催化剂失活。Ni/LC 在甲苯的惰性和 H2 重整下表现出很强的抗焦炭沉积能力。通过X射线衍射和透射电子显微镜对催化裂化前后的催化剂进行表征，以研究碳沉积行为。除了 H2 重整，在本研究中使用的所有条件下重整 5 小时后，可以发现 Ni 微晶尺寸 (NCS) 的明显变化。Ni/LC 中的 NCS 随着时间和 S/C 比的增加而显着增加，这应该是 Ni/LC 失活的部分原因。在本研究中使用的所有条件下重整 5 小时后，可以发现 Ni 微晶尺寸 (NCS) 的明显变化。Ni/LC 中的 NCS 随着时间和 S/C 比的增加而显着增加，这应该是 Ni/LC 失活的部分原因。在本研究中使用的所有条件下重整 5 小时后，可以发现 Ni 微晶尺寸 (NCS) 的明显变化。Ni/LC 中的 NCS 随着时间和 S/C 比的增加而显着增加，这应该是 Ni/LC 失活的部分原因。