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.

A high-precisioyumerical time step integratio'method is proposedfor a linear time-invariant structural dynamic system. Its numerical results are almost identical to the precise solution and are almost independentqf the time step size for a wide range of step sizes. Numerical examples illustrate this high precision.

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 .

No abstract

No abstract