In this paper, we propose the concept of utilizing the heat generated in Generation IV nuclear reactors to produce hydrogen and carbon from methane or natural gas by direct contact pyrolysis, a process that features zero greenhouse gas emissions. Methane or natural gas was bubbled through a bed of either low-melting-point metals (e.g., lead or tin), granular or catalytic materials (e.g., silicon carbide, α-alumina, NiMo/γ-alumina), or a mechanical mixture of molten metal and solid media. The methane conversions were found to be dependent upon the contact time between the methane and the heat transfer media, as well as on the methane bubble size. The most efficient systems used for the pyrolysis process were found to be the ones in which natural gas was bubbled through Mott porous metal filters, in a bed of either 4-in. Sn + SiC or Sn, with the product stream comprised of almost 80 and 70 vol % of hydrogen at 750 °C, respectively. The main advantage of this proposed system is the ease of buoyant separation of the generated carbon byproduct from the liquid heat transfer media. These experiments lay the groundwork for developing technical expertise in producing pure hydrogen cost-effectively by utilizing the heat energy contained in the liquid metal coolant in Generation IV nuclear reactors.

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Initiatives to limit carbon dioxide (COz) emissions have drawn considerable interest to integrated gasification combined-cycle (IGCC) power generation. This process can reduce CO 2production because of its higher efficiency, and it is amenable to CO/ capture, because CO 2 can be removed before combustion and the associated dilution with atmospheric nitrogen. This paper presents a process-design baseline that encompasses the IGCC system, CO 2 transport by pipeline, and land-based sequestering of CO 2 in geological reservoirs. The intent of this study is to provide the CO 2 budget, or an "equivalent CO2" budget, associated with each of the individual energy-cycle steps. Design capital and operating costs for the process are included in the full study but are not reported in the present paper. The value used for the "equivalent CO2" budget will be 1 kg CO2/kWh e. The base case is a 470-MW (at the busbar) IGCC system using an air-blown Kellogg Rust Westinghouse (KRW) agglomerating fluidized bed gasifier, U.S. Illinois #6 bituminous coal feed, and in-bed sulfur removal. Mining, feed preparation, and conversion result in a net electric power production of 461 MW, with a 0.830 kg/kWh e CO 2 release rate. In the CO 2 recovery case, the gasifier output is taken through water-gas shift and then to Selexol, a glycol-based absorber-stripper process that recovers CO 2 before it enters the combustion turbine. This process results in 350 MW at the busbar. A 500-km pipeline takes the recovered CO 2 to geological sequestering. The net electric power production in the recovery case is 320 MW, with a 0.234 kg/k_Vh e CO 2 release rate.

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This project emphasizes CO2-capture technologies combined with integrated gasification combined-cycle (IGCC) power systems, C02 transportation, and options for the long-term sequestration of C02. The intent is to quantify the C02 budget, or an "equivalent C02" budget, associated with each of the individual energycycle steps, in addition to process design capital and operating costs. The base case is a 458-MW (gross generation) IGCC system that uses an oxygen-blown Kellogg-Rust-Westinghouse (KRW) agglomerating fluidized-bed gasifier, bituminous coal feed, and low-pressure glycol sulfur removal, followed by Claus/SCOT treatment, to produce a saleable product. Mining, feed preparation, and conversion result in a *