| 초록 |
ε-Fe2C is known as one of active phases in Fischer-Tropsch synthesis (FTS) and ε-Fe2C has high stability and low CO2 selectivity in FTS. However, epsilon carbide phases have less information about effects of chemical promoter on FTS performance than another active phase χ-Fe5C2. In this study, potassium was used as chemical promoter for the activated carbon (AC)-supported iron catalysts to improve FTS activity in reaction which conducted at 250 ℃. The effects of K promotion on formation of epsilon carbide and FTS performance were investigated. Through identical syngas pretreatment on catalysts which had different K contents, we synthesized catalysts having ε-Fe2C as their main active phase and identified iron phases with XRD and SAED methods. It was found that K enhanced degree of carburization of the catalysts from their XRD data. After the pretreatment step, FTS activity test was conducted with the catalysts. Through preliminary test runs, it was confirmed that FTS activity, C5+ selectivity, and olefins ratio were increased as K content increased. Fresh, pretreated and spent catalysts were analyzed by XRD and SAED methods for identifying iron species. |
