(437c) Use of a Nanoscale Catalyst and Supercritical Reaction Medium in Fuel Production Via Fischer-Tropsch Synthesis

Fischer-Tropsch Synthesis (FTS) is surface-catalyzed polymerization reaction which produces hydrocarbons, oxygenates, heat, water, and CO₂ from syngas, a mixture of hydrogen and carbon monoxide. While FTS produces many of the compounds in liquid transportation fuels, the additional production of light gas, heavy wax, and a large amount of waste heat make the economics of large scale fuel production challenging. This research aimed to improve the reaction in two ways. First, a nanoscale iron-based carbon-supported catalyst was utilized. Nanoscale catalysts have high surface area, which translates to higher FT activity. The carbon nanotube support has high thermal stability and chemical resistance. Additionally, the use of a carbon support eliminates some of the difficulties in reduction often seen with iron nanoparticles on oxidic supports and is typically thought to increase selectivity to olefins. Secondly, the reaction was conducted in a supercritical hexane reaction medium. Such a medium has been shown to improve product selectivity and activity maintenance by alleviating some of the heat and mass transfer challenges of the reaction. The simultaneous use of both the nanoscale catalyst and supercritical fluid reaction media yielded an active, stable catalyst with relatively high selectivity towards valuable hydrocarbon and oxygenate products.