Iron-catalyzed hydrogenation of carbon dioxide to hydrocarbons/fuels in condensed phase

Nowadays chemical storage technologies achieve an increasing interest. With their help the energy of the excess electricity from wind and solar plants can be converted to hydrogen via water electrolysis. To store higher quantities of electrical energy it is useful to convert this hydrogen to hydrocarbons with carbon dioxide. Here we present an advanced reaction concept for the hydrogenation of carbon dioxide under supercritical conditions. Compared to the corresponding gas phase carbon dioxide based Fischer-Tropsch reaction several advantages are expected. The insolubility of water in supercritical carbon dioxide is used to shift the chemical equilibrium of the reverse water-gas shift reaction to the benefit of the carbon monoxide to produce hydrocarbons via the Fischer-Tropsch synthesis in the second step of the two-stage reaction. Furthermore the good solubility of waxes in supercritical carbon dioxide prevent blockage of the catalyst pore system. It could be shown that iron-based catalysts with different copper, aluminum and potassium content reach high carbon dioxide conversion in this reaction.