The impact that anthropogenic CO 2 is having on the environment has been thoroughly documented over the last 20 years. Many different technologies have been proposed to reduce its impact on global warming such as geological sequestration. However, an interesting and attractive alternative would be the recycling of the gas into energy-rich molecules. Iron rather than cobalt catalysts, based on the Fischer-Tropsch technology, have shown the greatest promise in converting CO 2 to value-added hydrocarbons. The addition of co-catalysts is, however, essential to fine tune the product distribution to the more desired alkene products. The role that both the promoter and support play on the catalyst's activity is reviewed.

The hydrogenation of CO 2 using a traditional Fischer-Tropsch Co-Pt/Al 2 O 3 catalyst for the production of valuable hydrocarbon materials is investigated. The ability to direct product distribution was measured as a function of different feed gas ratios of H 2 and CO 2 (3:1, 2:1, and 1:1) as well as operating pressures (ranging from 450 to 150 psig). As the feed gas ratio was changed from 3:1 to 2:1 and 1:1, the production distribution shifted from methane toward higher chain hydrocarbons. This change in feed gas ratio is believed to lower the methanation ability of Co in favor of chain growth, with possibly two different active sites for methane and C 2 -C 4 products. Furthermore, with decreasing pressure, the methane conversion drops slightly in favor of C 2 -C 4 paraffins. Even though under certain reaction conditions product distribution can be shifted slightly away from the formation of methane, the catalyst studied behaves like a methanation catalyst in the hydrogenation of CO 2 .

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A novel, robust, and innovative electrolytic cation exchange process has been used to efficiently extract large quantities of CO2 in the form of bicarbonate and carbonate from natural seawater, and to simultaneously produce H2 gas in quantities and ratios intended for possible future production of hydrocarbons. This indirect approach acidifies seawater by using the protons electrolytically produced by electrolysis at the anode. Electrons concurrently produced with these protons are subsequently consumed at the cathode forming hydrogen gas. The ability to degas and recover 92% [CO2]T from natural seawater was demonstrated. The potential detrimental effects of mineral deposits on the module’s electrode surfaces were successfully mitigated by cyclically changing the module electrode’s polarity. This feasibility study marks the first time that CO2 has been successfully extracted on a continuous basis from natural seawater. In addition, there is no energy or economic penalty to extract CO2 from the seawater matrix, above the energy needed to produce hydrogen.