Development of Fe Fischer-Tropsch catalysts for slurry bubble column reactors

The effect of two binder systems - a silica-based system and a silica-kaoli n-clay-phosphate-based system - on a doubly promoted Fischer-Tropsch (FT) s ynthesis iron catalyst (100Fe/5Cu/4.2K) was studied. The catalysts were pre pared by coprecipitation, followed by binder addition and spray drying at 2 70 degrees C in a 1 m diameter, 2 m tall spray dryer. The binder silica con tent was varied from 0 to 20 wt.%. A catalyst with 12 wt.% binder silica wa s found to have the highest attrition resistance. The FT activity and selec tivity of this catalyst are better than a Ruhrchemie catalyst at 270 degree s C and 1.48 MPa. The addition of precipitated silica or kaolin to catalyst s containing 10-12 wt.% binder silica decreases attrition resistance and in creases methane selectivity. Based on the experience gained, a catalyst has been successfully spray dried in 500 g quantity. This catalyst showed 95% CO conversion over 125 h of testing at 270 degrees C, 1.48 MPa, and 2 NL/g- cat/h and had less than 4% methane selectivity. Its attrition resistance wa s one of the highest among the catalysts tested. (C) 2000 Elsevier Science B.V. All rights reserved.