摘要
研究了固定床反应器中合成气制低碳烯烃熔铁催化剂的反应性能，考察了不同母体相组成和助催化剂对熔铁催化剂活性、低碳烯烃选择性的影响，通过TG-DTG、CO2-TPD等表征手段分析了母体相组成对熔铁催化剂的还原行为、表面酸碱性的影响。结果表明，当催化剂母体中n（Fe^2＋）／n（Fe^3＋）为1左右时，熔铁催化剂的表面碱性最强，有利于提高低碳烯烃选择性；考察助催化剂发现，稀土氧化物M2O3的加入能显著提高低碳烯烃选择性，在n（Hn）：n（CO）=1．6、2．0MPa、310℃、GHSV=11400h^-1的条件下，CO的转化率达73．8％，低碳烃烯烷摩尔比n（C2^=-C4^n）/n（C2°-C4°）达5．12，即在气态烃中低碳烯烃选择性达83．7％。正交实验分析结果表明，在所考察的5种助催化剂中，V2O5和MoO3的加入会降低低碳烯烃选择性；其它助催化剂没有显著影响。
Fischer-Tropsch synthesis （FTS） reaction on the fused-iron catalyst was studied in a fixed bed reactor. The effects of iron oxide precursors and promoters on the activity of the catalyst and the selectivity to C2-C4 light olefins were investigated. The reduction behavior and the surface acidity and basicity of the catalysts were characterized by TG-DTG and CO2-TPD. The experimental results showed that when n （Fe^2＋）/n （Fe^3＋） in the iron oxide precursors was about 1, the prepared fused-iron catalyst had the highest surface basicity, which helped to improve the selectivity of light olefins. The addition of promoter M2O3 highly increased the selectivity of olefins in C2-C4 to 83.7% [n （olefin）：n （paraffin） of 5.12] with a CO conversion of 73.0% at the conditions of n（H2）/ n （CO）=1.6, p=2.0 MPa, T=310℃ and GHSV=11400h^-1. The result of the orthogonal test showed that VO05 and MoO3 reduced the selectivity to olefins in C2-C4 and the effects of other promoters were not observed.
出处
《天然气化工—C1化学与化工》
CAS
CSCD
北大核心
2011年第5期28-32,共5页
Natural Gas Chemical Industry
