结构助剂SiO_2、Al_2O_3对铁基催化剂浆态床F-T合成性能的影响  

Effect of SiO_2 and Al_2O_3 on performances of iron-based catalysts for slurry Fischer-Tropsch synthesis

作　　者：万海军[1] 吴宝山[1] 李廷真[1] 陶智超[1] 安霞[1] 相宏伟[1] 李永旺[1] 

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室

出　　处：《燃料化学学报》2007年第5期589-594,共6页Journal of Fuel Chemistry and Technology

基　　金：国家杰出青年基金(20625620);国家自然科学基金(重大项目;20590361)

摘　　要：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微球状Fe/Cu/K/SiO2和Fe/Cu/K/Al2O3催化剂,研究SiO2和Al2O3作为结构助剂对铁基催化剂吸附行为、炭化行为及F-T合成反应性能的影响。表征结果表明,与Al2O3相比较,SiO2抑制了H2的吸附,但促进了CO的吸附,有利于催化剂的炭化。催化剂在260℃、1.5MPa、H2/CO=0.67和2 000h-1下的浆态床F-T合成反应评价表明,Fe/Cu/K/SiO2催化剂具有较高的F-T合成活性、高的水煤气变换反应(WGS)活性,且其烃产物选择性明显向高炭数方向偏移,而Fe/Cu/K/Al2O3催化剂则表现出较低的F-T合成活性、低的水煤气变换反应(WGS)活性和高的轻质烃选择性。但Fe/Cu/K/AlO催化剂比Fe/Cu/K/SiO催化剂具有更好的运行稳定性。Two spherical iron-based catalysts(Fe/Cu/K/SiO2 and Fe/Cu/K/Al2O3) were prepared by the combination of coprecipitation and spray drying method for the application of slurry Fischer-Tropsch synthesis(FTS).The effects of SiO2 and Al2O3 on the reduction and the carburization behaviors of iron-based catalysts were studied using temperature-programmed desorption(TPD) in H2 and CO,isothermal reduction in syngas,and Mssbauer-effect spectroscopy(MES).The results indicate that SiO2 suppresses the H2 adsorption,facilitates the CO adsorption,and the carburization as compared with Al2O3.The FTS performances of the catalysts were evaluated in a slurry reactor under the industrial relevant reaction conditions of 260 ℃,1.5 MPa,H2/CO = 0.67,and a space velocity of 2 000 h-1.This indicates that SiO2-supported catalyst has higher FTS activity,higher water-gas shift reaction(WGS) reactivity,and higher selectivities to heavy hydrocarbons.Furthermore,the run stability of Al2O3 supported,iron-based catalyst is better than SiO2 supported catalyst.

关 键 词：F-T合成 铁基催化剂 SIO2 AL2O3 烃选择性 

分 类 号：TQ529.2[化学工程—煤化学工程]