652f Slurry Phase Fischer-Tropsch Synthesis Catalyzed by Nano-Sized Iron: Effect of Particle Size

Devinder Mahajan1, Nathan Hould2, Jonathan Fletcher3, Sheena Joseph2, and Philipp Gütlich4. (1) Energy Sciences & Technology, Brookhaven National Laboratory, Building 815, Upton, NY 11973, (2) Chemical & Molecualr Engineering, SUNY at Stony Brook, 314 Old Engineering, Stony Brook, NY 11794, (3) Chemical and Molecular Engineering, Stony Brook University, 314 Old Engineering, Stony Brook, NY 11794, (4) Insitut fur Anorganische Chemie und Analytische Chemie, Universität Mainz, Staudingerweg-9, Mainz, D-55099, Germany

Fischer-Tropsch (F-T) synthesis remains one of the most researched topics to monetize remote natural gas. As petroleum price rises to unprecedented levels due to constrained global petroleum supply, the economics of transportation fuels produced via F-T technology is beyond the breakeven point. Several F-T plants are now in various stages of construction worldwide though the overall process efficiency remains an issue.

We are systematically investigating the nanosizing effect of traditional F-T catalysts with a goal to enhance space-time-yield (STY) and product selectivity. We previously reported results of a study in which the F-T activity of two nanosized α-Fe2O3 based materials, NANACAT (3 nm) and BASF (20-80 nm), were compared to that obtained with a supported micron-sized (32.5 μm) α-Fe2O3 UCI catalyst in slurry phase with natural gas-derived synthesis gas (H2/CO ~ 2/1) (Mahajan et al., Energy & Fuels, 17, 1210-21 (2003)). We are now following the activity and particle size data as these relate to changes with temperature (493 K, 513 K, and 543 K) during the F-T reaction with these catalyst systems. The TEM and Mössbauer data will be discussed and its implication in designing an F-T synthesis process based on nanosized Fe catalyst will be discussed.