Ru助剂对Co/SiO_2/HZSM-5催化剂合成航空燃油类烃的影响

以中孔硅胶和微孔HZSM-5分子筛为复合载体,添加Ru制备了钴基催化剂,考察了Ru添加量(1%~4%,质量分数)对催化剂结构和固定床费托合成航空燃油类烃的影响。实验结果表明,制备的复合载体催化剂有一定的微孔和中孔结构,Ru的添加有利于Co分散,Ru促进的催化剂低温还原过程提高了催化剂在150~750℃的还原度和CO转化率,复合载体中HZSM-5分子筛利用其微孔结构,提高了异构烃的收率。当Ru负载量为1%时,CO转化率达到62.8%,航空燃油类烃的收率达到37.7%,包括约10.9%的异构烃。Ru负载量超过2%时,增强的催化剂CO加氢活性和CH4选择性,导致合成产物向低碳烃方向偏移。

Ru modified Co/SiO2/HZSM-5 catalysts for jet fuel-range hydrocarbons synthesis

Selective synthesis of jet fuel-range hydrocarbons (C_8~18) was investigated in a fixed-bed reactor over Ru modified cobalt-based catalysts, supported on mesoporous SiO₂ and microporous HZSM-5. The effect of Ru adding amount (1%~4%) and the textual and structural properties of the catalysts on Fischer-Tropsch synthesis(FTS) performance were studied. The results showed that the tailor-made Ru-Co/SiO₂/HZSM-5 catalysts maintained both meso-and micro-pores. Co dispersion and reducibility at 150~750 ℃ were enhanced with the increase of Ru amount, which resulted in the increase of CO conversion. In the same time, the yield of iso-paraffins was enhanced due to the existence of microporous structure of HZSM-5. Thus CO conversion of 62.8% and yield of jet fuel-range hydrocarbons (C_8~18) of 37.7%, including 10.9% of iso-paraffins, were achieved over 1% Ru modified Co/SiO₂/HZSM-5. The FTS product distribution shifted to low-carbon hydrocarbons when Ru amount was higher than 2% due to the increased CO hydrogenation rate and CH₄ selectivity.