Comparison of CO{sub 2} - sources for fuel synthesis

As it has been estimated in several publications, e.g., the combustion of fossil fuels contribute with about 50 % to the global warming due to the increasing concentration of atmospheric CO{sub 2}. Short term strategies for the reduction of the CO{sub 2}-emissions are energy saving and efficient utilization. But as a successful long term strategy to stabilize the atmospheric CO{sub 2}-content only the substitution of fossil fuels by renewable energy sources can be accepted. The potential of renewable energy sources is by several magnitudes higher than any estimated future world energy demand. Unfortunately, large renewable energy sources are almost located far away of the main energy consumption areas, e.g. in desert regions, mountains or over the oceans. If there is no realistic possibility to join an electric grid, renewable energy must be transported by energy carriers. For the intercontinental transport of energy as well as for energy storage, the generation of chemical energy carriers is the best alternative. Possible alternatives are hydrogen or liquid carbonaceous energy carriers.