Moving heat around, chemically.Moving heat around, chemically Over long distances, a room-temperature gas mixture may carry heat more efficiently than a hot fluid, say researchers at the Sandia National Laboratories Sandia National Laboratories, which is managed and operated by the Sandia Corporation (a wholly owned subsidiary of Lockheed Martin Corporation), is a major United States Department of Energy research and development national laboratory with two locations, one in Albuquerque, New in Albuquerque, N.M. The Sandia team is investigating a technique, called thermochemical energy transport, that involves the use of reversible chemical reactions This is the 18th episode of television drama Men in Trees. It originally aired on June 25, 2007 on the TV2 network in New Zealand as a continuation of season 1. Recap Marin and Cash have a stew cook off, she admits his is better than hers. . These catalyst-driven reactions "trap" heat at its source and later release it at its destination. Normally, thermal energy thermal energy Internal energy of a system in thermodynamic equilibrium (see thermodynamics) by virtue of its temperature. A hot body has more thermal energy than a similar cold body, but a large tub of cold water may have more thermal energy than a cup of boiling moves from place to place as a hot liquid or gas flowing through a pipeline. The steam that drives a turbine generator, for instance, may be at a temperature close to 600 [deg.]C. The entire pipeline must be well insulated to ensure that as little heat as possible is lost during transport. Nevertheless, a considerable amount of energy still disappears. In contrast, a pipeline carrying a room-temperature fluid would suffer practically no heat losses, and the pipeline would not have to insulated. In the Sandia process, a mixture of carbon dioxide carbon dioxide, chemical compound, CO2, a colorless, odorless, tasteless gas that is about one and one-half times as dense as air under ordinary conditions of temperature and pressure. and methane is converted to carbon monoxide carbon monoxide, chemical compound, CO, a colorless, odorless, tasteless, extremely poisonous gas that is less dense than air under ordinary conditions. It is very slightly soluble in water and burns in air with a characteristic blue flame, producing carbon dioxide; and hydrogen. This process absorbs thermal energy, which is stored in the chemical bonds created by the reaction. The gases, now at 27[deg.]C, can then flow along pipes to their destination. There, the reverse reaction between carbon monoxide and hydrogen releases the stored chemical energy as heat. Alumina pellets coated with rhodium rhodium (rō`dēəm), metallic chemical element; symbol Rh; at. no. 45; at. wt. 102.9055; m.p. about 1,966°C;; b.p. 3,727±100°C;; sp. gr. 12.41 at 20°C;; valence +2, +3, +4, +5, or +6. serve as the catalyst. Because of this system's complexity and cost, it's unlikely to replace steam or hot-water heating systems used to warm buildings. However, it may be useful when thermal energy must be transported over hundreds of miles from large solar energy facilities or for the extraction of heat contained in molten rock buried several miles beneath the earth's surface. Initial experiments show that the concept works in the laboratory. Sandia is now preparing to do a field test on a larger, more realistic scale. |
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