Användning av plasmaförgasning för framställning av syntetiskt jetbränsle

Sammanfattning: Using plasma gasification to create synthetic jet fuel is a relative new method that could be a suitable option to make the aviation industry more sustainable. Bromma Airport in Stockholm has been used as a potential case to sustain the flights with this type of fuel. Plasma gasification is the process of dissolving organic material into its elemental particles at very high temperatures. Since no oxygen is supplied, no combustion takes place and therefore no emissions are released. The slag created of the non-organic material can be used as a construction material. The product produced is a gas rich in energy, which can be processed in a Fischer-Tropsch reactor into liquid fuel after cleaning. The need of a plant on Bromma Airport has been identified, and a suitable location in the southern part of the airfield has been found. Estimated area needed for the plant is 10 300 m2 . The feedstock for the process is waste from the forest industry, so called grot. To remove the bio waste from the land has a positive effect on the regrowth of the forest, and the feedstock arrives to the plant in the shape of woodchip. In order to produce the airport’s yearly need of jet fuel of 52 300 m3 , a total of 229 700 tonne woodchip is needed. That corresponds to a truck arriving at the plant every 33rd minute within 12 hours per day every day the plant is operating. Positive effects of using the produced fuel is a more clean combustion in the jet engines, less wear-and-tear on the turbine blades, and lower Sulphur content in the airplane’s exhaust gas. Since the energy density of the produced fuel is lower than the standard jet fuel, a larger volume is needed in order to reach the same amount of energy. The technology of the plasma gasification in the plant is based on that of Solena Fuels, where a carbon catalytic bed distributes the heat evenly from the six plasma torches that are needed. The plasma torches have a total power need of 127 800 MWh/year. In a suggestion to lower the need of electricy, a Rankine cycle can deliver 21 556 MWh/year to the process. The Fischer-Tropsch process is carried out using a coboltbased catalyst, and with the use of micro-channels the efficiency between gas and liquid fuel can be improved.