Journal of Fundamentals of Renewable Energy and Applications
Open Access
ISSN: 2090-4541
ISSN: 2090-4541
Ralph-Uwe Dietrich, D H Konig, F G Albrecht and A Worner
German Aerospace Centre (DLR)-Institute of Engineering Thermodynamics, Germany
Posters & Accepted Abstracts: J Fundam Renewable Energy Appl
Liquid fuels will remain the fuel of choice for air and cargo transport for the coming decades. Synthetic fuels produced by the Power-to-Liquid (PtL) route are a promising alternative to generation bio-fuels. Electrolysis-based hydrogen together with carbon monoxide is converted by Fisher-Tropsch synthesis (FTS) to liquid hydrocarbons. Sustainable hydrogen can be derived from water electrolysis using renewable power. Sustainable carbon monoxide sources are biomass or air-based carbon dioxide. Using â�?�?unavoidableâ�? industrial CO2 from steel or cement production shall reduce the societyâ�?�?s carbon footprint as well. For technoeconomic assessment the Biomass-to-Liquid and PtL process routes have been modeled in process simulation software. Furthermore, a combined process concept called Power+Biomass-to-Liquid is developed and presented. Efficiency, cost and realistic quantities of synthetic fuels production are compared for different process routes and feed-stocks. Renewable synthetic fuels can be produced at a cost of 1.50 to 4.50 â�?¬/l, depending on the feedstock, process route, equipment cost and plant scale. Hydrogen generation is the most significant cost factor, drawing the attention towards the renewable power generation cost as well as the electrolyzer type, efficiency and investment cost. Biomass respectively CO2 availability limits the plant size or will add additional feedstock transport efforts. The overall energetic efficiency from power to chemical energy (LHV) stored in liquid fuel can reach 60% for optimal conditions and unit operations. Operating water electrolysis with fluctuating power requires an electrolyzer oversize as well as hydrogen storage capacities. A sustainable pathway for the production of synthetic liquid fuels is able to absorb huge amounts of renewable excess power. Economic implication compared to present cost of fossil based fuels will be quantified.
Email: ralph-uwe.dietrich@dlr.de