Development of Key Technologies for White Lighting Based on Light-Emitting Diodes (LEDs) (open access)

Development of Key Technologies for White Lighting Based on Light-Emitting Diodes (LEDs)

This program was organized to focus on materials development issues critical to the acceleration of solid-state lighting, and was split into three major thrust areas: (1) study of dislocation density reduction for GaN grown on sapphire using 'cantilever epitaxy', and the impact of dislocation density on the performance of state-of-the-art high-power LEDs; (2) the evaluation of in situ techniques for monitoring gas phase chemistry and the properties of GaN-based layers during metal-organic vapor phase epitaxy (MOCVD), and (3) feasibility for using semiconductor nanoparticles ('quantum dots') for the down-conversion of blue or ultraviolet light to generate white light. The program included a partnership between Lumileds Lighting (epitaxy and device fabrication for high power LEDs) and Sandia National Laboratories (cantilever epitaxy, gas phase chemistry, and quantum dot synthesis). Key findings included: (1) cantilever epitaxy can provide dislocation density reduction comparable to that of more complicated approaches, but all in one epitaxial growth step; however, further improvements are required to realize significant gains in LED performance at high drive currents, (2) in situ tools can provide detailed knowledge about gas phase chemistry, and can be used to monitor and control epitaxial layer composition and temperature to provide improved yields (e.g., a fivefold increase …
Date: March 31, 2004
Creator: Goetz, Werner; Imler, Bill; Kim, James; Kobayashi, Junko; Kim, Andrew; Krames, Mike et al.
Object Type: Report
System: The UNT Digital Library
The Tiffany Unit N2 - ECBM Pilot: A Reservoir Modeling Study (open access)

The Tiffany Unit N2 - ECBM Pilot: A Reservoir Modeling Study

In October, 2000, the U.S. Department of Energy, through contractor Advanced Resources International, launched a multi-year government-industry R&D collaboration called the Coal-Seq project. The Coal-Seq project is investigating the feasibility of CO{sub 2} sequestration in deep, unmineable coalseams, by performing detailed reservoir studies of two enhanced coalbed methane recovery (ECBM) field projects in the San Juan basin. The two sites are the Allison Unit, operated by Burlington Resources, and into which CO{sub 2} is being injected, and the Tiffany Unit, operating by BP America, into which N{sub 2} is being injected (the interest in understanding the N{sub 2}-ECBM process has important implications for CO{sub 2} sequestration via flue-gas injection). The purposes of the field studies are to understand the reservoir mechanisms of CO{sub 2} and N{sub 2} injection into coalseams, demonstrate the practical effectiveness of the ECBM and sequestration processes, demonstrate an engineering capability to model them, and to evaluate sequestration economics. In support of these efforts, laboratory and theoretical studies are also being performed to understand and model multi-component isotherm behavior, and coal permeability changes due to swelling with CO{sub 2} injection. This report describes the results of an important component of the overall project, the Tiffany Unit reservoir …
Date: March 31, 2004
Creator: Reeves, Scott & Oudinot, Anne
Object Type: Report
System: The UNT Digital Library
CFD SIMULATIONS OF JOINT URBAN ATMOSPHERE DISPERSION FIELD STUDY 2003 (open access)

CFD SIMULATIONS OF JOINT URBAN ATMOSPHERE DISPERSION FIELD STUDY 2003

In the Spring of 2003, a series of dispersion field experiments (Joint Urban 2003) were conducted at Oklahoma City. These experiments were complimentary to the URBAN 2000 field studies at Salt Lake City (Allwine, et. al, 2002) in that they will provide a second set of comprehensive field data for evaluation of CFD as well as for other dispersion models. In contrast to the URBAN 2000 experiments that were conducted entirely at night, these new field studies took place during both daytime and nighttime thus including the possibility of convective as well as stable atmospheric conditions. Initially several CFD modeling studies were performed to provide guidance for the experimental team in the selection of release sites and in the deployment of wind and concentration sensors. Also, while meteorological and concentration measurements were taken over the greater Oklahoma City urban area, our CFD calculations were focused on the near field of the release point. The proximity of the source to a large commercial building and to the neighboring buildings several of which have multi-stories, present a significant challenge even for CFD calculations involving grid resolutions as fine as 1 meter. A total of 10 Intensive Observations Periods (IOP's) were conducted within …
Date: March 31, 2004
Creator: Lee, R L; Humphreys, T D & Chan, S T
Object Type: Article
System: The UNT Digital Library
Dilute Surfactant Methods for Carbonate Formations (open access)

Dilute Surfactant Methods for Carbonate Formations

There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. Anionic surfactants (Alfoterra 35, 38) recover more than 40% of the oil in about 50 days by imbibition driven by wettability alteration in the core-scale. Anionic surfactant, Alfoterra-68, recovers about 28% of the oil by lower tension aided gravity-driven imbibition in the core-scale. Residual oil saturation showed little capillary number dependence between 10{sup -5} and 10{sup -2}. Wettability alteration increases as the number of ethoxy groups increases in ethoxy sulfate surfactants. Plans for the next quarter include conducting mobilization, and imbibition studies.
Date: March 31, 2004
Creator: Mohanty, Kishore K.
Object Type: Report
System: The UNT Digital Library
Tampa Electric Neural Network Sootblowing (open access)

Tampa Electric Neural Network Sootblowing

Boiler combustion dynamics change continuously due to several factors including coal quality, boiler loading, ambient conditions, changes in slag/soot deposits and the condition of plant equipment. NOx formation, Particulate Matter (PM) emissions, and boiler thermal performance are directly affected by the sootblowing practices on a unit. As part of its Power Plant Improvement Initiative program, the US DOE is providing co-funding (DE-FC26-02NT41425) and NETL is the managing agency for this project at Tampa Electric's Big Bend Station. This program serves to co-fund projects that have the potential to increase thermal efficiency and reduce emissions from coal-fired utility boilers. A review of the Big Bend units helped identify intelligent sootblowing as a suitable application to achieve the desired objectives. The existing sootblower control philosophy uses sequential schemes, whose frequency is either dictated by the control room operator or is timed based. The intent of this project is to implement a neural network based intelligent sootblowing system, in conjunction with state-of-the-art controls and instrumentation, to optimize the operation of a utility boiler and systematically control boiler fouling. Utilizing unique, on-line, adaptive technology, operation of the sootblowers can be dynamically controlled based on real-time events and conditions within the boiler. This could be …
Date: March 31, 2004
Creator: Rhode, Mark A.
Object Type: Report
System: The UNT Digital Library
T-R Cycle Characterization and Imaging: Advanced Diagnostic Methodology for Petroleum Reservoir and Trap Detection and Delineation (open access)

T-R Cycle Characterization and Imaging: Advanced Diagnostic Methodology for Petroleum Reservoir and Trap Detection and Delineation

None
Date: March 31, 2004
Creator: Mancini, Ernest A.
Object Type: Report
System: The UNT Digital Library
Stimulation Technologies for Deep Well Completions: Technical Progress Report 3 (open access)

Stimulation Technologies for Deep Well Completions: Technical Progress Report 3

The Department of Energy (DOE) is sponsoring the Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies is conducting a study to evaluate the stimulation of deep wells. The objective of the project is to assess U.S. deep well drilling and stimulation activity, review rock mechanics and fracture growth in deep, high-pressure/temperature wells and evaluate stimulation technology in several key deep plays. An assessment of historical deep gas well drilling activity and forecast of future trends was completed during the first six months of the project; this segment of the project was covered in Technical Progress Report No. 1. During the next six months, efforts were primarily split between summarizing rock mechanics and fracture growth in deep reservoirs and contacting operators about case studies of deep gas well stimulation as documented in Technical Progress Report No. 2. This report details work done with Anadarko and ChevronTexaco in the Table Rock Field in Wyoming.
Date: March 31, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Ceramic Membrane Enabling Technology for Improved IGCC Efficiency, Quarterly Technical Progress Report: January 1 - March 31, 2004 (open access)

Ceramic Membrane Enabling Technology for Improved IGCC Efficiency, Quarterly Technical Progress Report: January 1 - March 31, 2004

This quarterly technical progress report will summarize work accomplished for Phase 2 Program during the quarter January to March 2004. In task 1 OTM development has led to improved strength and composite design for lower temperatures. In task 2, the measurement system of OTM element dimensions was improved. In task 3, a 10-cycle test of a three-tube submodule was reproduced successfully. In task 5, sizing of several potential heat recovery systems was initiated. In task 7, advanced OTM and cryogenic IGCC cases for near-term integration were developed.
Date: March 31, 2004
Creator: Prasad, Ravi
Object Type: Report
System: The UNT Digital Library
Southeast Regional Carbon Sequestration Partnership (SECARB) (open access)

Southeast Regional Carbon Sequestration Partnership (SECARB)

Work during the first six months of the project mainly concentrated on contracts execution and collection of data to characterize the region and input of that data into the geographical information system (GIS) system. Data was collected for source characterization, transportation options and terrestrial options. In addition, discussions were held to determine the extent of the geologic information that would be needed for the project. In addition, activities associated with the regulatory, permitting and safety issues were completed. Outreach activities are in the formative stages.
Date: March 31, 2004
Creator: Baskin, Kathryn A.
Object Type: Report
System: The UNT Digital Library
Ceramic Coatings for Corrosion Resistant Nuclear Waste Container Evaluated in Simulated Ground Water at 90?C (open access)

Ceramic Coatings for Corrosion Resistant Nuclear Waste Container Evaluated in Simulated Ground Water at 90?C

Ceramic materials have been considered as corrosion resistant coatings for nuclear waste containers. Their suitability can be derived from the fully oxidized state for selected metal oxides. Several types of ceramic coatings applied to plain carbon steel substrates by thermal spray techniques have been exposed to 90 C simulated ground water for nearly 6 years. In some cases no apparent macroscopic damage such as coating spallation was observed in coatings. Thermal spray processes examined in this work included plasma spray, High Velocity Oxy Fuel (HVOF), and Detonation Gun. Some thermal spray coatings have demonstrated superior corrosion protection for the plain carbon steel substrate. In particular the HVOF and Detonation Gun thermal spray processes produced coatings with low connected porosity, which limited the growth rate of corrosion products. It was also demonstrated that these coatings resisted spallation of the coating even when an intentional flaw (which allowed for corrosion of the carbon steel substrate underneath the ceramic coating) was placed in the coating. A model for prediction of the corrosion protection provided by ceramic coatings is presented. The model includes the effect of the morphology and amount of the porosity within the thermal spray coating and provides a prediction of the …
Date: March 31, 2004
Creator: Haslam, J J & Farmer, J C
Object Type: Article
System: The UNT Digital Library
Combustion Turbine (CT) Hot Section Coating Life Management (open access)

Combustion Turbine (CT) Hot Section Coating Life Management

The integrity of coatings used in hot section components of combustion turbines is crucial to the reliability of the buckets. This project was initiated in recognition of the need for predicting the life of coatings analytically, and non-destructively; correspondingly, three principal tasks were established. Task 1, with the objective of analytically developing stress, strain and temperature distributions in the bucket and thereby predicting thermal fatigue (TMF) damage for various operating conditions; Task 2 with the objective of developing eddy current techniques to measure both TMF damage and general degradation of coatings and, Task 3 with the objective of developing mechanism based algorithms. Task 4 would be aimed at verifying analytical predictions from Task 1 and the NDE predictions from Task 3 against field observations. Task 5 would develop a risk-based decision analysis model to make run/repair decisions. This report is a record of the progress to date on these four tasks.
Date: March 31, 2004
Creator: Viswanathan, R.; Gandy, D.; Krzywosz, K.; Cheruvu, S. & Wan, E.
Object Type: Report
System: The UNT Digital Library
IEMDC - In-Line Electric Motor Driven Compressor (open access)

IEMDC - In-Line Electric Motor Driven Compressor

This report covers the fifth quarter (01/01/04 to 03/31/04) of the In-Line Electric Motor Driven Compressor (IEMDC) project. Design efforts on the IEMDC continued with compressor efforts focused on performing aerodynamic analyses. These analyses were conducted using computational fluid dynamics. Compressor efforts also entailed developing mechanical designs of components through the use of solid models and working on project deliverables. Electric motor efforts focused on the design of the magnetic bearing system, motor pressure housing, and the motor-compressor interface. The mechanical evaluation of the main interface from both the perspective of the compressor manufacturer and electric motor manufacturer indicates that an acceptable design has been achieved. All mechanical and aerodynamic design efforts have resulted in considerable progress being made towards the completion of the compressor and electric motor design and towards the successful completion of the IEMDC unit.
Date: March 31, 2004
Creator: Crowley, Michael J.
Object Type: Report
System: The UNT Digital Library
Mercury Control With The Advanced Hybrid Particulate Collector (open access)

Mercury Control With The Advanced Hybrid Particulate Collector

This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4 - Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore and Associates, Inc., and is now marketed as the Advanced Hybrid{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears …
Date: March 31, 2004
Creator: Benson, Steven A.; Miller, Stanley J.; Crocker, Charlene R.; Galbreath, Kevin C.; Laumb, Jason D.; Zola, Jill M. et al.
Object Type: Report
System: The UNT Digital Library
Novel Binders and Methods for Agglomeration of Ore (open access)

Novel Binders and Methods for Agglomeration of Ore

Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. A primary example of this is copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process. As a result, operators of acidic heap-leach facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy …
Date: March 31, 2004
Creator: Kawatra, S. K.; Eisele, T. C. & Gurtler, J. A.
Object Type: Report
System: The UNT Digital Library
Investigation of Phase and Emulsion Behavior, Surfactant Retention and Condensate Recovery for Condensate/Water/Ethanol Mixtures (open access)

Investigation of Phase and Emulsion Behavior, Surfactant Retention and Condensate Recovery for Condensate/Water/Ethanol Mixtures

This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FG26-02NT15447 during the period October 01, 2003 to March 31, 2004 which covers the third six months of the project. Presently work is in progress to characterize phase and emulsion behavior for ethylbenzene/water/ethanol system. Ethylbenzene that has the equivalent carbon number is used as the model condensate. During this reporting period, temperature scans were performed mixing equal volumes of ethylbenzene and 10mM NaCl water with various concentrations of ethanol ranging from 2 to 70 vol%. For the range of temperatures tested (2 to 70 C), results indicate that temperature is invariant and produced a single phase for ethanol concentrations greater than 60 vol%. For ethanol concentrations less than 60 vol%, only two phases were obtained with aqueous rich bottom phase more in volume than that of the ethylbenzene rich top phase. Linear coreflooding experiments were completed by our industrial partner in this project, Surtek, CO, to measure the condensate recovery in flooding processes. It was found about 30% ethylbenzene recovery was obtained by the waterflooding, however, 2wt% ethanol flooding did not produce incremental recovery of the ethylbenzene. Radial coreflooding with ethanol injection prior to water …
Date: March 31, 2004
Creator: Sampath, Ramanathan
Object Type: Report
System: The UNT Digital Library
Ammonia-Free NOx Control System (open access)

Ammonia-Free NOx Control System

Research is being conducted under United States Department of Energy (DOE) Contract DEFC26-03NT41865 to develop a new technology to achieve very low levels of NOx emissions from pulverized coal fired boiler systems by employing a novel system level integration between the PC combustion process and the catalytic NOx reduction with CO present in the combustion flue gas. The combustor design and operating conditions will be optimized to achieve atypical flue gas conditions. This approach will not only suppress NOx generation during combustion but also further reduce NOx over a downstream catalytic reactor that does not require addition of an external reductant, such as ammonia. This report describes the work performed during the January 1 to March 31, 2004 time period.
Date: March 31, 2004
Creator: Wu, S.; Fan, Z. & Herman, R.
Object Type: Report
System: The UNT Digital Library
Total Ore Processing Integration and Management (open access)

Total Ore Processing Integration and Management

This report outlines the technical progress achieved for project DE-FC26-03NT41785 (Total Ore Processing Integration and Management) during the period 01 January through 31 March of 2004.
Date: March 31, 2004
Creator: Gertsch, Leslie & Gertsch, Richard
Object Type: Report
System: The UNT Digital Library
Nitrogen Control in Electric Arc Furnace Steelmaking by DRI (TRP 0009) (open access)

Nitrogen Control in Electric Arc Furnace Steelmaking by DRI (TRP 0009)

Nitrogen is difficult to remove in electric arc furnace (EAF) steelmaking, requiring the use of more energy in the oxygen steelmaking route to produce low-nitrogen steel. The objective of this work was to determine if the injection of directly reduced iron (DRI) fines into EAFs could reduce the nitrogen content by creating fine carbon monoxide bubbles that rinse nitrogen from the steel. The proposed work included physical and chemical characterization of DRI fines, pilot-scale injection into steel, and mathematical modeling to aid in scale-up of the process. Unfortunately, the pilot-scale injections were unsuccessful, but some full-scale data was obtained. Therefore, the original objectives were met, and presented in the form of recommendations to EAF steelmakers regarding: (1) The best composition and size of DRI fines to use; (2) The amount of DRI fines required to achieve a specific reduction in nitrogen content in the steel; and (3) The injection conditions. This information may be used by steelmakers in techno-economic assessments of the cost of reducing nitrogen with this technology.
Date: March 31, 2004
Creator: Irons, Gordon A.
Object Type: Report
System: The UNT Digital Library
Environmental Biosciences Program Third Quarter Report (open access)

Environmental Biosciences Program Third Quarter Report

In May 2002, the United States Department of Energy (DOE) signed Assistance Instrument Number DE-FC09-02CH11109 with the Medical University of South Carolina (MUSC) to support the Environmental Biosciences Program (EBP). This funding instrument replaces DOE Assistance Instrument Number DE-FC02-98CH10902. EBP is an integrated, multidisciplinary scientific research program, employing a range of research initiatives to identify, study and resolve environmental health risks. These initiatives are consistent with the MUSC role as a comprehensive state-supported health sciences institution and with the nation's need for new and better approaches to the solution of a complex and expansive array of environment-related health problems. The intrinsic capabilities of a comprehensive health sciences institution enable MUSC to be a national resource for the scientific investigation of environmental health issues. EBPs success as a nationally prominent research program is due, in part, to its ability to task-organize scientific expertise from multiple disciplines in addressing these complex problems Current research projects have focused EBP talent and resources on providing the scientific basis for risk-based standards, risk-based decision making and the accelerated clean-up of widespread environmental hazards. These hazards include trichloroethylene (TCE), polychlorinated biphenyls (PCBs), asbestos and low-dose ionizing radiation. A project is also being conducted in the use …
Date: March 31, 2004
Creator: Mohr, Lawrence C.
Object Type: Text
System: The UNT Digital Library
Impermeable Thin Al2O3 Overlay for TBC Protection From Sulfate and Vanadate Attack in Gas Turbines Quarterly Report (open access)

Impermeable Thin Al2O3 Overlay for TBC Protection From Sulfate and Vanadate Attack in Gas Turbines Quarterly Report

To improve the hot corrosion resistance of YSZ thermal barrier coatings, a 25 {micro}m thick Al{sub 2}O{sub 3} overlay were deposited by HVOF thermal spray, respectively, onto to the surface of YSZ coating. In the next reporting period, we will measure or calculate the residue stress within Al{sub 2}O{sub 3} overlay and YSZ coating to study the mechanism of effect of Al{sub 2}O{sub 3} overlay on spalling of YSZ coating. However, due to the thermal expansion mismatch between YSZ coating and Al{sub 2}O{sub 3} overlay, such surface modification using Al{sub 2}O{sub 3} overlay might deteriorate strain tolerance of the TBC. In the present work, in order to investigate the effect of Al{sub 2}O{sub 3} overlay on residual stress developed in the samples during cooling after hot corrosion at high temperature, Finite Element method (FEM) was employed to determine the detailed stress states in the test specimens after cooling. The results showed that there is no high stress concentration at the interface between the YSZ and the bond coat for TBCs system without Al{sub 2}O{sub 3} overlay. On the other hand, the maximum compressive stress with a value of approximately, -330 MPa occurred within the Al{sub 2}O{sub 3} overlay. The maximum …
Date: March 31, 2004
Creator: Mao, Scott X.
Object Type: Report
System: The UNT Digital Library
Porous Medium Analysis or Interstitial Liquid Removal from Tank 41 and Tank 3 (open access)

Porous Medium Analysis or Interstitial Liquid Removal from Tank 41 and Tank 3

During Tank 41 interstitial liquid removal in fall 2002 and early 2003, analytical analyses of capillary liquid retention and fluid flow in porous saltcake were performed to guide waste processing under the Low Curie Salt program. Tank drainage was completed in June 2003 with the interstitial level at about 68 in. In late June and early July, flush water was added to dissolve hard salt for later liquid retrieval. Data from these subsequent operations has been used to validate the earlier analytical models and assess model uncertainty. Data comparisons suggest the analytical drain model performs well when empirical data are available to calibrate the model. Subsequent model forecasts can be expected to be reasonably accurate, provided the pumping rate is steady.
Date: March 31, 2004
Creator: FLACH, GREGORY
Object Type: Report
System: The UNT Digital Library
Life-Cycle Cost and Payback Period Analysis for Commercial Unitary Air Conditioners (open access)

Life-Cycle Cost and Payback Period Analysis for Commercial Unitary Air Conditioners

This report describes an analysis of the economic impacts of possible energy efficiency standards for commercial unitary air conditioners and heat pumps on individual customers in terms of two metrics: life-cycle cost (LCC) and payback period (PBP). For each of the two equipment classes considered, the 11.5 EER provides the largest mean LCC savings. The results show how the savings vary among customers facing different electricity prices and other conditions. At 11.5 EER, at least 80% of the users achieve a positive LCC savings. At 12.0 EER, the maximum efficiency analyzed, mean LCC savings are lower but still positive. For the {ge} $65,000 Btu/h to <135,000 Btu/h equipment class, 59% of users achieve a positive LCC savings. For the $135,000 Btu/h to <240,000 Btu/h equipment class, 91% of users achieve a positive LCC savings.
Date: March 31, 2004
Creator: Rosenquist, Greg; Coughlin, Katie; Dale, Larry; McMahon, James & Meyers, Steve
Object Type: Report
System: The UNT Digital Library
Tracing Geothermal Fluids (open access)

Tracing Geothermal Fluids

Chemical compounds have been designed under this contract that can be used to trace water that has been injected into vapor-dominated and two-phase geothermal fields. Increased knowledge of the injection flow is provided by the tracers, and this augments the power that can be produced. Details on the stability and use of these tracers are included in this report.
Date: March 31, 2004
Creator: Nash, Michael C. Adams Greg
Object Type: Report
System: The UNT Digital Library
SYNTHESIS AND CHARACTERIZATION OF CO-AND H2S-TOLERANT ELECTROCATALYSTS FOR PEM FUEL CELL (open access)

SYNTHESIS AND CHARACTERIZATION OF CO-AND H2S-TOLERANT ELECTROCATALYSTS FOR PEM FUEL CELL

The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H{sub 2}-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO and H{sub 2}S in the H{sub 2}-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to reduce the Pt-loading and improve the PEMFC performance, we propose to synthesize a number of Pt-based binary, ternary, and quaternary electrocatalysts using Ru, Mo, Ir, Ni, and Co as a substitute for Pt. By fine-tuning the metal loadings and compositions of candidate electrocatalysts, we plan to minimize the cost and optimize the catalyst activity and performance in PEMFC. The feasibility of the novel electrocatalysts will be demonstrated in the proposed effort with gas phase CO and H{sub 2}S concentrations typical of those found in reformed fuel gas with coal/natural gas/methanol feedstocks. During this reporting period several bi-metallic electrocatalysts were synthesized and tested in MEAs. From Galvonstatic study the catalytic activity was found in the order of: Pt/Ru/C …
Date: March 31, 2004
Creator: Ilias, Shamsuddin
Object Type: Report
System: The UNT Digital Library