Cu助剂的加入方式对铁基催化剂F-T合成性能的影响

Effect of incorporation manner of Cu promoter on Fischer-Tropsch synthesis performances over iron-based catalysts

  • 摘要: 采用不同的沉淀方式与喷雾干燥成型技术相结合的方法制备了系列微球状FeCuK/SiO2催化剂,结合H2-TPR和Mssbauer谱等表征手段,研究Cu助剂的加入方式对铁基催化剂物相结构、还原和碳化行为以及F-T合成性能的影响。催化剂在浆态床反应器中以接近F-T合成实际工况条件 (250℃、1.5MPa、H2/CO=0.67和2.0L/gcat-h) 进行评价。结果表明,以共沉淀方式加入Cu助剂与铁氧化物相相互作用强,因而促进了催化剂的还原和碳化,提高了催化剂的活性。而以分别沉淀方式加入Cu助剂抑制催化剂的还原和碳化,降低反应活性。四种方式加入Cu助剂均使铁基催化剂在500h运行实验中表现出良好的稳定性。与其他加入方式的Cu相比,共沉淀Cu提高了重质烃的选择性,对含氧化合物的生成有一定抑制作用。

     

    Abstract: A series of spherical FeCuK/SiO2 catalysts for slurry Fischer-Tropsch synthesis (FTS) were prepared by the spray drying method. The effects of incorporation manner of Cu on the crystallite structure, the reduction and carburization behaviors were studied by H2 temperature-programmed reduction (H2-TPR) and Mssbauer spectroscopy. The catalytic performances were evaluated in a slurry reactor under the industrial relevant reaction conditions of 250℃, 1.5MPa, H2/CO=0.67 and a space velocity of 2.0L/gcat-h. The result indicated that the coprecipitated Cu was well dispersed in iron phase, which promoted the reduction, carburization of the catalyst and the catalytic activity. The addition of respective precipitated Cu suppressed the reduction and carburization of the catalyst. All catalysts were stable during 500h on stream. For the hydrocarbon selectivity, the addition of the coprecipitated Cu increased the selectivities of heavy hydrocarbons and olefins, and restrained the formation of oxygenates, compared with others.

     

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