Mn助剂加入方式对铁基催化剂F-T合成性能的影响

采用连续共沉淀与喷雾干燥成型技术相结合的方法制备了系列微球状Fe/Mn/K催化剂，结合H2 DTG、CO TPR、Mossbauer谱等表征手段，研究了Mn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Mn助剂具有较强的Fe Mn相互作用，从而抑制了催化剂的还原和碳化，降低了催化剂的活性，提高了催化剂的稳定性。而以部分共沉淀和黏结剂方式加入Mn助剂促进了催化剂的还原和碳化，提高了反应活性加速了催化剂的失活。与共沉淀Mn相比，部分共沉淀和黏结剂Mn提高了重质烃和烯烃的选择性，同时抑制了有机含氧化合物的生成。

Effect of incorporation manner of Mn promoter on the performances of iron-based catalysts in Fischer-Tropsch synthesis

A series of spherical iron based (Fe/Mn/K) catalysts were prepared by the combination of co precipitation and spray drying method; the influences of incorporation manner of Mn promoter on their crystallite structure, reduction and carburization behaviors and performances in Fischer Tropsch synthesis were investigated though H2 differential thermo gravimetric analysis (H2-DTG), CO temperature programmed reduction (CO-TPR), Mossbauer spectroscopy as well as catalytic tests. The catalysts were evaluated in a slurry reactor under the industrially relevant reaction conditions of 250℃, 1.5MPa, H2/CO = 0.67 and a space velocity of 2.0L/gcat-h. The results illustrated that the addition of precipitated Mn brings on stronger Fe-Mn interaction than other incorporation manners; this may suppress the reduction and carburization of the catalyst, decrease the catalytic activity but enhance the catalytic stability. The addition of partial precipitated and binder Mn promotes the reduction and carburization of the catalyst, improves the catalytic activity but speeds up the catalyst deactivation. Compared with the precipitated Mn promoted catalyst, the addition of partial precipitated and binder Mn can enhance the selectivity of heavy hydrocarbons and olefins and restrain the formation of oxygenates.