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Enhanced durability of high-temperature desulfurization sorbents for moving-bed applications

Description: The objective of this contract was to identify and test fabrication methods and sorbent chemical compositions that enhance the long-term chemical reactivity and mechanical strength of zinc ferrite and other novel sorbents for moving-bed, high-temperature desulfurization of coal-derived gases. Desired properties to be enhanced for moving-bed sorbent materials are: (1) high chemical reactivity (sulfur absorption rate and total sulfur capacity), (2) high mechanical strength (pellet crush strength and attrition resistance), and (3) suitable pellet morphology (e.g., pellet size, shape, surface area, and average specific pore volume). In addition, it is desired to maintain the sorbent properties over extended cyclic use in moving- bed systems.
Date: August 1, 1991
Creator: Ayala, R.E.
Partner: UNT Libraries Government Documents Department

Rapid surface sampling and archival record system (RSSAR)

Description: Purpose is to develop a rapid surface (concrete, steel) contamination measurement system that will provide a ``quick-look`` indication of contamination areas, an archival record, and an automated analysis. A bulk sampling oven is also being developed. The sampling device consists of a sampling head, a quick look detector, and an archiving system (sorbent tube). The head thermally desorbs semi-volatiles, such as PCBs, oils, etc., from concrete and steel surfaces; the volatilized materials are passed through a quick-look detector. Sensitivity of the detector can be attenuated for various contaminant levels. Volatilized materials are trapped in a tube filled with adsorbent. The tubes are housed in a magazine which also archives information about sampling conditions. Analysis of the tubes can be done at a later date. The concrete sampling head is fitted with a tungsten-halogen lamp; in laboratory experiments it has extracted model contaminants by heating the top 4mm of the surface to 250 C within 100-200 s. The steel sampling head has been tested on different types of steels and has extracted model contaminants within 30 s. A mathematical model of heat and mass transport in concrete has been developed. Rate of contaminant removal is at maximum when the moisture content is about 100 kg/m{sup 3}. The system will be useful during decontamination and decommissioning operations.
Date: April 1, 1997
Creator: Barren, E.; Bracco, A. & Dorn, S.B.
Partner: UNT Libraries Government Documents Department

Rapid Surface Sampling and Archival Record (RSSAR) System. Topical report, October 1, 1993--December 31, 1994

Description: This report describes the results of Phase 1 efforts to develop a Rapid Surface Sampling and Archival Record (RSSAR) System for the detection of semivolatile organic contaminants on concrete, transite, and metal surfaces. The characterization of equipment and building surfaces for the presence of contaminants as part of building decontamination and decommissioning activities is an immensely large tacks of concern to both government and industry. Contaminated and clean materials must be clearly identified and segregated so that the clean materials can be recycled or reused, if possible, or disposed of more cheaply as nonhazardous waste. Characterization of building and equipment surfaces will be needed during initial investigations, during cleanup operations, and during the final confirmatory process, increasing the total number of samples well beyond that needed for initial characterization. This multiplicity of information places a premium on the ability to handle and track data as efficiently as possible. Aware of the shortcomings of traditional surface characterization technology, GE, with DOE support has undertaken a 12-month effort to complete Phase 1 of a proposed four-phase program to develop the RSSAR system. The objectives of this work are to provide instrumentation to cost-effectively sample concrete and steel surfaces, provide a quick-look indication for the presence or absence of contaminants, and collect samples for later, more detailed analysis in a readily accessible and addressable form. The Rapid Surface Sampling and Archival Record (RSSAR) System will be a modular instrument made up of several components: (1) sampling heads for concrete surfaces, steel surfaces, and bulk samples; (2) quick-look detectors for photoionization and ultraviolet; (3) multisample trapping module to trap and store vaporized contaminants in a manner suitable for subsequent detailed lab-based analyses.
Date: June 1, 1997
Partner: UNT Libraries Government Documents Department

Development and fabrication of a Bi-2223 racetrack coil for generator applications

Description: The development and fabrication of a layer-wound, epoxy-impregnated Bi-2223 high-temperature superconducting (HTS) racetrack coil which generates 40,000 ampere-turns of magnetomotive force (MMF) at 25 K is described. The coil was wound using Ag-sheathed Bi-2223 tape conductor laminated with copper foils for strength enhancement and insulated using a paper-wrap method. After epoxy impregnation, the coil was tested over a range of 16--25 K in a vacuum dewar using a closed-cycle helium refrigeration system. Descriptions of the tape lamination and insulation processing, the coil winding and impregnation, and the experimental test setup are given.
Date: December 31, 1996
Creator: Herd, K.G.; Salasoo, L.; Laskaris, E.T.; Ranze, R.A.; King, C.G.; Haldar, P. et al.
Partner: UNT Libraries Government Documents Department

Rapid surface sampling and archival record system

Description: A number of contamination sites exist in this country where the area and volume of material to be remediated is very large, approaching or exceeding 10{sup 6} M{sup 2} and 10{sup 6} M{sup 3}. Typically, only a small fraction of this material is actually contaminated. In such cases there is a strong economic motivation to test the material with a sufficient density of measurements to identify which portions are uncontaminated, so extensively they be left in place or be disposed of as uncontaminated waste. Unfortunately, since contamination often varies rapidly from position to position, this procedure can involve upwards of one million measurements per site. The situation is complicated further in many cases by the difficulties of sampling porous surfaces, such as concrete. For example, on concrete the standard wipe test provides results that are strongly operator- and surface condition-dependent. The results are not usually available real time, because the wipe samples are sent to a remote laboratory for analysis, entailing a delay of days to weeks between sampling and results. Further, the cost of analysis of a clean sample is usually the same as that of a contaminated sample; analysis of clean samples thereby increases the total analysis costs considerably. Another method for surface/sub surface characterization is to obtain a boring or a drilling. This method also involves the off-site analysis of the drilled material, incorporating the time and economic penalties described above. Other disadvantages of drilling techniques are disfiguration of the surface and distribution of contamination through byproduct dust. It is for the above reasons that we have chosen to develop thermal sampling methods for characterization of concrete, transite, and contaminated bulk debris. The sampling system we describe has been designed to greatly reduce the economic penalty posed by these difficulties.
Date: December 1, 1995
Creator: Barren, E.; Berdahl, D.R.; Penney, C.M. & Sheldon, R.B.
Partner: UNT Libraries Government Documents Department

Moving-bed sorbents

Description: The objective of this program is to develop mixed-metal oxide sorbent formulations that are suitable for moving-bed, high-temperature, desulfurization of coal gas. Work continues on zinc titanates formulations and Z-sorb III sorbent.
Date: December 1, 1995
Creator: Ayala, R.E.; Gupta, R.P. & Chuck, T.
Partner: UNT Libraries Government Documents Department

Advanced low-temperature sorbents

Description: A number of promising technologies are currently being optimized for coal-based power generation, including the Integrated-Gasification Combined Cycle (IGCC) system. If IGCC is to be used successfully for power generation, an economic and efficient way must be found to remove the contaminants, particularly sulfur species, found in coal gas. Except for the hot gas desulfurization system, all major components of IGCC are commercially available or have been shown to meet system requirements. Over the last two decades, the U.S. Department of Energy/Morgantown Energy Technology Center (DOE/METC) has sponsored development of various configurations of high-temperature desulfurization systems including fixed-bed, moving-bed, transport-bed, and fluidized-bed systems. Because of their mode of operation and requirements for sorbent manufacturing, the fixed-bed systems can generally use the same materials as moving-bed configurations, i.e., pelletized or extruded sorbents, while fluidized-bed (circulating or bubbling configurations) and transport reactor configurations use materials generally described as agglomerated or granulated.The objective of this program is to remove hydrogen sulfides from coal gas using sorbent materials.
Date: December 1, 1995
Creator: Ayala, R.E.; Venkataramani, V.S.; Abbasian, J. & Hill, A.H.
Partner: UNT Libraries Government Documents Department

A method for measuring non-linear elastic properties of thermal barrier coatings

Description: Accurate characterization of the elastic properties of thermal barrier coatings (TBC`s) is important for failure prediction. Thermally sprayed coatings often exhibit anisotropic and nonlinear elastic properties due to the coating microstructure that results from the thermal spray process. A method was developed for determining the elastic behavior of TBC`s on substrates by measuring the in-plane modulus as a function of residual coating stress. The in-plane modulus was determined by resonant frequency measurement, and the residual stress was measured from the substrate curvature. The residual stress was varied both by increasing the temperature of the TBC and substrate and by applying compressive plastic strain to the metal substrate. The stress-strain behavior of the TBC was derived from the data for modulus versus residual stress, and significant nonlinear elastic behavior was observed.
Date: June 1, 1995
Creator: Johnson, C.A.; Ruud, J.A.; Kaya, A.C. & deLorenzi, H.G.
Partner: UNT Libraries Government Documents Department

General Electric ATS Program technical review Phase 2 activities

Description: The Advanced Turbine Systems (ATS) Program Phase 2 objectives are to select a cycle, and to identify and resolve technical issues required to realize the ATS Program goals of 60% net combined cycle efficiency, single digit NOx, and a 10% electric power cost reduction, compared to current technology. The Phase 2 efforts have showns that the ATS Program goals are achievable. The GE Power Generation advanced gas turbine will use closed-loop steam cooling in the first two turbine stages and advanced coatings, seals and cooling designs to meet ATS performance and cost of electricity goals.
Date: December 31, 1995
Creator: Chance, T. & Smith, D.
Partner: UNT Libraries Government Documents Department