(532a) The Effect of Precursor Salt, Reduction Promoter, and Drying Rate On the Performance of Iron Fischer-Tropsch Catalysts Prepared By Solvent Deficient Precipitation (SDP)

The Fischer-Tropsch (FT) process has been a valuable means of producing liquid hydrocarbons and fuels since its invention over 90 years ago. This process continues to draw significant interest in light of current environmental and energy concerns. The development of better - more active, selective, and stable - FT catalysts is an area of ongoing research.

The work presented in this paper will discuss three important variables that have an impact on the performance of iron FT catalysts prepared by solvent deficient precipitation (SDP), a novel dry-mix preparation method that produces Fe FT catalysts in a significantly shorter time than it takes to prepare standard precipitated catalysts. The FT performance (activity/selectivity, physical and chemical properties) of unsupported Fe-Cu-K-SiO₂ catalysts made from 4 different iron precursor salts: 1) iron nitrate, 2) iron citrate, 3) iron oxylate, and 4) iron sulfate – will be compared and discussed. Secondly, we examine the use of manganese instead of copper as a promoter for enhancing reduction of the Fe during preparation. Thirdly, we look at the effect of drying temperature on the performance of a series of six catalysts made from the nitrate salt.  Each catalyst was first dried at 60^oC, and then ramped to 80,100,115, 130, or 150˚C. It was found that the catalyst dried at 60/130^oC had significantly higher activity, lower methane make, and better overall performance than the other catalysts.