(443c) Modeling of Fischer-Tropsch Fuels Production From Polygeneration Facilities

The interest in Fischer-Tropsch fuel production is a consequence of stringent environmental regulations, technological developments and changes in fossil energy reserves. It is a potential answer to satisfy many of our future energy needs. The use of FT technology for biomass conversion to synthetic hydrocarbons may offer a promising and carbon neutral alternative to conventional diesel, kerosene and gasoline. FT-liquids are free of sulphur and can be matched directly with conventional fuel markets. Generic process simulation models of gas-phase Fischer-Tropsch Synthesis (FTS) and supercritical phase Fischer-Tropsch Synthesis (SC-FTS) processes were developed based on previous and ongoing work at Auburn University. The models have been developed using data available in the open literature and their performance is currently being validated against the latest experimental data. Synthesis gas production from steam reforming is included in the model. The downstream processing results in two products, i.e. a gasoline and a jet fuel similar to JP-5, including paraffin, olefin and oxygenate products. The product distribution is obtained using the Anderson-Schulz-Flory (ASF) distribution for gas-phase model. In supercritical phase, the product distribution is much more narrow compared to traditional gas-phase FTS due to the vapor-like transport properties and liquid-like thermal properties in the supercritical phase. A hydrocracking reactor is added to convert the heavier compounds back into fuel range products. Using experimental data generated within the Consortium for Fossil Fuel Science (CFFS), models have been developed for analysis of the supercritical water reforming (SCWR) process. The high-pressure hydrogen produced from supercritical water reforming of biomass is intended for injection in the SC-FTS process during the cracking/isomerization step and will be included in the model as well. In addition, the light fraction from gas-phase model is converted to synthesis gas and recycled to the FTS reactor by steam reforming. Economic and environmental analysis was performed through quantifying the level of environmental impact using EPA's WAR algorithm. In this way, experimental and theoretical efforts can supplement each other, providing direction for further experimental efforts.