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Accounting for fuel price risk when comparing renewable togas-fired generation: the role of forward natural gas prices

Description: Unlike natural gas-fired generation, renewable generation (e.g., from wind, solar, and geothermal power) is largely immune to fuel price risk. If ratepayers are rational and value long-term price stability, then--contrary to common practice--any comparison of the levelized cost of renewable to gas-fired generation should be based on a hedged gas price input, rather than an uncertain gas price forecast. This paper compares natural gas prices that can be locked in through futures, swaps, and physical supply contracts to contemporaneous long-term forecasts of spot gas prices. We find that from 2000-2003, forward gas prices for terms of 2-10 years have been considerably higher than most contemporaneous long-term gas price forecasts. This difference is striking, and implies that comparisons between renewable and gas-fired generation based on these forecasts over this period have arguably yielded results that are biased in favor of gas-fired generation.
Date: July 17, 2004
Creator: Bolinger, Mark; Wiser, Ryan & Golove, William
Partner: UNT Libraries Government Documents Department

EOS7C Version 1.0: TOUGH2 Module for Carbon Dioxide or Nitrogen inNatural Gas (Methane) Reservoirs

Description: EOS7C is a TOUGH2 module for multicomponent gas mixtures in the systems methane carbon dioxide (CH4-CO2) or methane-nitrogen (CH4-N2) with or without an aqueous phase and H2O vapor. EOS7C uses a cubic equation of state and an accurate solubility formulation along with a multiphase Darcy s Law to model flow and transport of gas and aqueous phase mixtures over a wide range of pressures and temperatures appropriate to subsurface geologic carbon sequestration sites and natural gas reservoirs. EOS7C models supercritical CO2 and subcritical CO2 as a non-condensible gas, hence EOS7C does not model the transition to liquid or solid CO2 conditions. The components modeled in EOS7C are water, brine, non-condensible gas, gas tracer, methane, and optional heat. The non-condensible gas (NCG) can be selected by the user to be CO2 or N2. The real gas properties module has options for Peng-Robinson, Redlich-Kwong, or Soave-Redlich-Kwong equations of state to calculate gas mixture density, enthalpy departure, and viscosity. Partitioning of the NCG and CH4 between the aqueous and gas phases is calculated using a very accurate chemical equilibrium approach. Transport of the gaseous and dissolved components is by advection and Fickian molecular diffusion. We present instructions for use and example problems to demonstrate the accuracy and practical application of EOS7C.
Date: June 29, 2004
Creator: Oldenburg, Curtis M.; Moridis,George J.; Spycher, Nicholas & Pruess, Karsten
Partner: UNT Libraries Government Documents Department

Guidance on risk analysis and safety implications of a large liquefied natural gas (LNG) spill over water.

Description: While recognized standards exist for the systematic safety analysis of potential spills or releases from LNG (Liquefied Natural Gas) storage terminals and facilities on land, no equivalent set of standards or guidance exists for the evaluation of the safety or consequences from LNG spills over water. Heightened security awareness and energy surety issues have increased industry's and the public's attention to these activities. The report reviews several existing studies of LNG spills with respect to their assumptions, inputs, models, and experimental data. Based on this review and further analysis, the report provides guidance on the appropriateness of models, assumptions, and risk management to address public safety and property relative to a potential LNG spill over water.
Date: December 1, 2004
Creator: Wellman, Gerald William; Melof, Brian Matthew; Luketa-Hanlin, Anay Josephine; Hightower, Marion Michael; Covan, John Morgan; Gritzo, Louis Alan et al.
Partner: UNT Libraries Government Documents Department

In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

Description: The primary accomplishments of the JOI Cooperative Agreement with DOE/NETL in this quarter were that: (1) post-cruise evaluation of the data, tools and measurement systems that were used during ODP Leg 204 continued in the preparation of deliverables under this agreement. Work continued on analyzing data collected during ODP Leg 204 and preparing reports on the outcomes of Phase 1 projects as well as developing plans for Phase 2.
Date: June 30, 2004
Creator: Rack, Frank & Party, ODP Leg 204 Shipboard Scientific
Partner: UNT Libraries Government Documents Department

In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

Description: The primary accomplishments of the JOI Cooperative Agreement with DOE/NETL in this quarter were that: (1) postcruise evaluation of the data, tools and measurement systems that were used during ODP Leg 204 continued in the preparation of deliverables under this agreement. Work continued on analyzing data collected during ODP Leg 204 and preparing reports on the outcomes of Phase 1 projects as well as developing plans for Phase 2.
Date: September 30, 2004
Creator: Rack, Frank R. & Party, ODP Leg 204 Shipboard Scientific
Partner: UNT Libraries Government Documents Department

The Gas to Liquids Industry and Natural Gas Markets

Description: This report provides and analyzes basic information concerning the gas to liquids industry (GTL) industry to inform debate on broad energy legislation, as well as more specific natural gas legislation on supply issues including an Alaskan natural gas pipeline as well as LNG facility development.
Date: November 8, 2004
Creator: Pirog, Robert
Partner: UNT Libraries Government Documents Department

Advanced Membrane Filtration Technology for Cost Effective Recovery of Fresh Water from Oil & Gas Produced Brine

Description: Produced water is a major waste generated at the oil and natural gas wells in the state of Texas. This water could be a possible source of new fresh water to meet the growing demands of the state after treatment and purification. Treatment of brine generated in oil fields or produced water with an ultrafiltration membranes were the subject of this thesis. The characterization of ultrafiltration membranes for oil and suspended solids removal of produced water, coupled with the reverse osmosis (RO) desalination of brine were studied on lab size membrane testing equipment and a field size testing unit to test whether a viable membrane system could be used to treat produced water. Oil and suspended solids were evaluated using turbidity and oil in water measurements taken periodically. The research considered the effect of pressure and flow rate on membrane performance of produced water treatment of three commercially available membranes for oily water. The study also analyzed the flux through the membrane and any effect it had on membrane performance. The research showed that an ultrafiltration membrane provided turbidity removal of over 99% and oil removal of 78% for the produced water samples. The results indicated that the ultrafiltration membranes would be asset as one of the first steps in purifying the water. Further results on selected RO membranes showed that salt rejection of greater than 97% could be achieved with satisfactory flux and at reasonable operating cost.
Date: September 29, 2004
Creator: Burnett, David B.
Partner: UNT Libraries Government Documents Department


Description: This work has led to the initial development of a very promising material that has the potential to greatly simplify hydrocarbon reforming for the production of hydrogen and to improve the overall efficiency and economics of the process. This material, which was derived from an advanced calcium-based sorbent, was composed of core-in-shell pellets such that each pellet consisted of a CaO core and an alumina-based shell. By incorporating a nickel catalyst in the shell, a combined catalyst and sorbent was prepared to facilitate the reaction of hydrocarbons with steam. It was shown that this material not only catalyzes the reactions of methane and propane with steam, it also absorbs CO{sub 2} simultaneously, and thereby separates the principal reaction products, H{sub 2} and CO{sub 2}. Furthermore, the absorption of CO{sub 2} permits the water gas shift reaction to proceed much further towards completion at temperatures where otherwise it would be limited severely by thermodynamic equilibrium. Therefore, an additional water gas shift reaction step would not be required to achieve low concentrations of CO. In a laboratory test of methane reforming at 600 C and 1 atm it was possible to produce a gaseous product containing 96 mole% H{sub 2} (dry basis) while also achieving a H{sub 2} yield of 95%. Methane reforming under these conditions without CO{sub 2} absorption provided a H{sub 2} concentration of 75 mole% and yield of 82%. Similar results were achieved in a test of propane reforming at 560 C and 1 atm which produced a product containing 96 mole% H{sub 2} while CO{sub 2} was being absorbed but which contained only 69 mole% H{sub 2} while CO{sub 2} was not being absorbed. These results were achieved with an improved catalyst support that was developed by replacing a portion of the {alpha}-alumina in the original shell material ...
Date: September 27, 2004
Creator: Shanks, B.H.; Wheelock, T.D.; Satrio, Justinus A.; Diehl, Timothy & Vollmer, Brigitte
Partner: UNT Libraries Government Documents Department

Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

Description: The objectives of the study are: to perform resource assessment of the in-place deep (>15,000 ft) natural gas resource of the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling and to use the petroleum system based resource assessment to estimate the volume of the in-place deep gas resource that is potentially recoverable and to identify those areas in the interior salt basins with high potential to recover commercial quantities of the deep gas resource. The principal research effort for Year 1 of the project is data compilation and petroleum system identification. The research focus for the first nine (9) months of Year 1 is on data compilation and for the remainder of the year the emphasis is on petroleum system identification.
Date: October 28, 2004
Creator: Mancini, Ernest A. & Goddard, Donald A.
Partner: UNT Libraries Government Documents Department

Study of Reservoir Heterogencities and Structural Features Affecting Production in the Shallow Oil Zone, Eastern Elk Hills Area, California

Description: Late Neogene (Plio-Pleistocene) shallow marine strata of the western Bakersfield Arch and Elk Hills produce hydrocarbons from several different reservoirs. This project focuses on the shallow marine deposits of the Gusher and Calitroleum reservoirs in the Lower Shallow Oil Zone (LSOZ). In the eastern part of the study area on the Bakersfield Arch at North and South Coles Levee field and in two wells in easternmost Elk Hills, the LSOZ reservoirs produce dry (predominantly methane) gas. In structurally higher locations in western Elk Hills, the LSOZ produces oil and associated gas. Gas analyses show that gas from the eastern LSOZ is bacterial and formed in place in the reservoirs, whereas gas associated with oil in the western part of the study area is thermogenic and migrated into the sands from deeper in the basin. Regional mapping shows that the gas-bearing LSOZ sands in the Coles Levee and easternmost Elk Hills area are sourced from the Sierra Nevada to the east whereas the oil-bearing sands in western Elk Hills appear to be sourced from the west. The eastern Elk Hills area occupied the basin depocenter, farthest from either source area. As a result, it collected mainly low-permeability offshore shale deposits. This sand-poor depocenter provides an effective barrier to the updip migration of gases from east to west. The role of small, listric normal faults as migration barriers is more ambiguous. Because our gas analyses show that the gas in the eastern LSOZ reservoirs is bacterial, it likely formed in-place near the reservoirs and did not have to migrate far. Therefore, the gas could have been generated after faulting and accumulated within the fault blocks as localized pools. However, bacterial gas is present in both the eastern AND western parts of Elk Hills in the Dry Gas Zone (DGZ) near the top ...
Date: November 1, 2004
Creator: Gillespie, Janice
Partner: UNT Libraries Government Documents Department

Near-Zero NOx Combustion Technology for ATS Mercury 50 Gas Turbine

Description: A project to demonstrate a near-zero NOx, catalytic combustion technology for natural gas-fired, industrial gas turbines is described. In a cooperative effort between Solar Turbines Incorporated and Precision Combustion Incorporated (PCI), proof-of-concept rig testing of PCI's fuel-rich catalytic combustion technology has been completed successfully. The primary technical goal of the project was to demonstrate NOx and CO emissions below 5ppm and 10 ppm, respectively, (corrected to 15% O{sub 2}) at realistic gas turbine operating conditions. The program consisted of two tasks. In the first task, a single prototype RCL{trademark} (Rich Catalytic Lean Burn) module was demonstrated at Taurus 70 (7.5 Mw) operating conditions (1.6 MPa, 16 atm) in a test rig. For a Taurus 70 engine, eight to twelve RCL modules will be required, depending on the final system design. In the second task, four modules of a similar design were adapted to a Saturn engine (1 Mw) test rig (600 kPa, 6 atm) to demonstrate gas turbine light-off and operation with an RCL combustion system. This project was initially focused on combustion technology for the Mercury 50 engine. However, early in the program, the Taurus 70 replaced the Mercury. This substitution was motivated by the larger commercial market for an ultra-low NOx Taurus 70 in the near-term. Rig tests using a single prototype RCL module at Taurus 70 conditions achieved NOx emissions as low as 0.75 ppm. A combustor turndown of approximately 110C (200F) was achieved with NOx and CO emissions below 3 ppm and 10 ppm, respectively. Catalyst light-off occurred at an inlet temperature of 310C (590F). Once lit the module remained active at inlet air temperatures as low as 204C (400F). Combustor pressure oscillations were acceptably low during module testing. Single module rig tests were also conducted with the Taurus 70 module reconfigured with a central pilot ...
Date: December 31, 2004
Creator: Smith, Kenneth
Partner: UNT Libraries Government Documents Department

Natural gas production problems : solutions, methodologies, and modeling.

Description: Natural gas is a clean fuel that will be the most important domestic energy resource for the first half the 21st centtuy. Ensuring a stable supply is essential for our national energy security. The research we have undertaken will maximize the extractable volume of gas while minimizing the environmental impact of surface disturbances associated with drilling and production. This report describes a methodology for comprehensive evaluation and modeling of the total gas system within a basin focusing on problematic horizontal fluid flow variability. This has been accomplished through extensive use of geophysical, core (rock sample) and outcrop data to interpret and predict directional flow and production trends. Side benefits include reduced environmental impact of drilling due to reduced number of required wells for resource extraction. These results have been accomplished through a cooperative and integrated systems approach involving industry, government, academia and a multi-organizational team within Sandia National Laboratories. Industry has provided essential in-kind support to this project in the forms of extensive core data, production data, maps, seismic data, production analyses, engineering studies, plus equipment and staff for obtaining geophysical data. This approach provides innovative ideas and technologies to bring new resources to market and to reduce the overall environmental impact of drilling. More importantly, the products of this research are not be location specific but can be extended to other areas of gas production throughout the Rocky Mountain area. Thus this project is designed to solve problems associated with natural gas production at developing sites, or at old sites under redevelopment.
Date: October 1, 2004
Creator: Rautman, Christopher Arthur; Herrin, James M.; Cooper, Scott Patrick; Basinski, Paul M. (El Paso Production Company, Houston, TX); Olsson, William Arthur; Arnold, Bill Walter et al.
Partner: UNT Libraries Government Documents Department

Rapid Deployment of Rich Catalytic Combustion

Description: The overall objective of this research under the Turbines Program is the deployment of fuel flexible rich catalytic combustion technology into high-pressure ratio industrial gas turbines. The resulting combustion systems will provide fuel flexibility for gas turbines to burn coal derived synthesis gas or natural gas and achieve NO{sub x} emissions of 2 ppmvd or less (at 15 percent O{sub 2}), cost effectively. This advance will signify a major step towards environmentally friendly electric power generation and coal-based energy independence for the United States. Under Phase 1 of the Program, Pratt & Whitney (P&W) performed a system integration study of rich catalytic combustion in a small high-pressure ratio industrial gas turbine with a silo combustion system that is easily scalable to a larger multi-chamber gas turbine system. An implementation plan for this technology also was studied. The principal achievement of the Phase 1 effort was the sizing of the catalytic module in a manner which allowed a single reactor (rather than multiple reactors) to be used by the combustion system, a conclusion regarding the amount of air that should be allocated to the reaction zone to achieve low emissions, definition of a combustion staging strategy to achieve low emissions, and mechanical integration of a Ceramic Matrix Composite (CMC) combustor liner with the catalytic module.
Date: June 10, 2004
Creator: Tuthill, Richard S.
Partner: UNT Libraries Government Documents Department

Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation

Description: This report summarizes the work performed by Hybrid Power Generation Systems, LLC (HPGS) during the April to October 2004 reporting period in Task 2.3 (SOFC Scaleup for Hybrid and Fuel Cell Systems) under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL), entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. This study analyzes the performance and economics of power generation systems for central power generation application based on Solid Oxide Fuel Cell (SOFC) technology and fueled by natural gas. The main objective of this task is to develop credible scale up strategies for large solid oxide fuel cell-gas turbine systems. System concepts that integrate a SOFC with a gas turbine were developed and analyzed for plant sizes in excess of 20 MW. A 25 MW plant configuration was selected with projected system efficiency of over 65% and a factory cost of under $400/kW. The plant design is modular and can be scaled to both higher and lower plant power ratings. Technology gaps and required engineering development efforts were identified and evaluated.
Date: September 30, 2004
Creator: Deangelis, David; Depuy, Rich; Dey, Debashis; Karvountzi, Georgia; Minh, Nguyen; Peter, Max et al.
Partner: UNT Libraries Government Documents Department

Simulation Modeling of an Enhanced Low-Emission Swirl-Cascade Burner

Description: ''Cascade-burners'' is a passive technique to control the stoichiometry of the flame through changing the flow dynamics and rates of mixing in the combustion zone with a set of venturis surrounding the flame. Cascade-burners have shown advantages over other techniques; its reliability, flexibility, safety, and cost makes it more attractive and desirable. On the other hand, the application of ''Swirl-burners'' has shown superiority in producing a stable flame under a variety of operating conditions and fuel types. The basic idea is to impart swirl to the air or fuel stream, or both. This not only helps to stabilize the flame but also enhances mixing in the combustion zone. As a result, nonpremixed (diffusion) swirl burners have been increasingly used in industrial combustion systems such as gas turbines, boilers, and furnaces, due to their advantages of safety and stability. Despite the advantages of cascade and swirl burners, both are passive control techniques, which resulted in a moderate pollutant emissions reduction compared to SCR, SNCR and FGR (active) methods. The present investigation will study the prospects of combining both techniques in what to be named as ''an enhanced swirl-cascade burner''. Natural gas jet diffusion flames in baseline, cascade, swirl, and swirl-cascade burners were numerically modeled using CFDRC package. The thermal, composition, and flow (velocity) fields were simulated. The numerical results showed that swirl and cascade burners have a more efficient fuel/air mixing, a shorter flame, and a lower NOx emission levels, compared to the baseline case. The results also revealed that the optimal configurations of the cascaded and swirling flames have not produced an improved performance when combined together in a ''swirl-cascade burner''. The non-linearity and complexity of the system accounts for such a result, and therefore, all possible combinations, i.e. swirl numbers (SN) versus venturi diameter ratios (D/d), need to be ...
Date: September 1, 2004
Creator: Qubbaj, Ala
Partner: UNT Libraries Government Documents Department

RP-5 Renewable Energy Efficiency Project

Description: This is the sixth quarterly technical report for the RP-5 Renewable Energy Efficiency Project. The report summarizes the work progress, effort and activities that took place during the period from October 1, 2003 through December 31, 2003. The report has been prepared in accordance with the Department of Energy (DOE) Guidelines. In coordination with the DOE, IEUA has revised the original Cooperative Agreement to reflect the actual and current project scope of work. The original Agreement statement of work (SOW) included conceptual and preliminary equipment and systems, which were further evaluated for feasibility and suitability for the project. As a result, some of the equipment was taken out of the project scope. In response to questions from the DOE, IEUA has submitted a summary report on the Organic Rankine Cycle (ORC) secondary power generation units for availability and suitability for this project and associated safety concerns pointed out by the DOE. IEUA has awarded the consulting engineering contract to Parsons Water and Infrastructure, Inc. to provide the project's design and construction services. The project's pre-design kickoff meeting was held at IEUA's headquarters on December 11, 2003. IEUA has submitted a proposal for a grant offered by California Energy Commission (CEC) which if awarded to IEUA, will add value to this project. IEUA has finalized and signed the agreement with Stirling Energy Systems (SES) to host a 25 kW Stirling Engine at the RP-5 plant site for reliability and performance testing using digester and natural gas. As a result of further evaluation of the flexible microturbine system, IEUA has decided to take it out of the project's scope of work; however, it may be considered in future projects at other locations. IEUA has installed a 60 kW Photovoltaic (PV) power generation system on the roof of the new headquarters building. A ...
Date: January 29, 2004
Creator: Clifton, Neil; Whitman, Eliza Jane & Zughbi, Jamal A.
Partner: UNT Libraries Government Documents Department

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

Description: 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 modeling study. The Tiffany Unit is located in the northern portion of the prolific San Juan basin (in Southern Colorado). The study area consists of 34 methane production wells and 12 nitrogen injection wells. The field originally began production in 1983, and N{sub 2} injection operations for ECBM purposes commenced in 1998. Nitrogen injection was suspended in 2002, to evaluate the results of the pilot. In this study, a detailed reservoir characterization of the field was developed, the field history was matched using the COMET3 reservoir simulator, and future field performance was forecast under various operating conditions. Based on the ...
Date: March 31, 2004
Creator: Reeves, Scott & Oudinot, Anne
Partner: UNT Libraries Government Documents Department


Description: The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. ''green'') products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Previous testing of pepper extracts resulted in preliminary data indicating that some pepper extracts inhibit the growth of some corrosion-associated microorganisms. This quarter additional tests were performed to more specifically investigate the ability of three pepper extracts to inhibit the growth, and to influence the metal corrosion caused by two microbial species: Desulfovibrio vulgaris, and Comomonas denitrificans. All three pepper extracts rapidly killed Desulfovibrio vulgaris, but did not appear to inhibit Comomonas denitrificans. While corrosion rates were at control levels in experiments with Desulfovibrio vulgaris that received pepper extract, corrosion rates were increased in the presence of Comomonas denitrificans plus pepper extract. Further testing with a wider range of pure bacterial cultures, and more importantly, with mixed bacterial cultures should be performed to determine the potential effectiveness of pepper extracts to inhibit MIC.
Date: April 30, 2004
Creator: Bogan, Bill W.; Sullivan, Wendy R.; Cruz, Kristine M. H.; Lowe, Kristine L. & II, John J. Kilbane
Partner: UNT Libraries Government Documents Department

Integrated Fast Neutron Flux at the End of Phases I, II, III, and IV-1B of the MOX Zr-cladding Tube

Description: This report using the detailed ATR quarter core model calculated neutronic tallies, the MCWO-calculated Zr-cladding fast neutron fluence (E > 0.1 MeV and E > 1.0 MeV) distributions at the end of Phase-I, -II, -III, and -IV Irradiation are tabulated in Table 1, 2, 3, and 4. At the end of the Phase-I irradiation, the MCWO-calculated Zr-cladding fast neutron fluences of the removed MOX capsules 1 and 8 are 2.68 and 2.68 x 1020 n/cm2, respectively. At the end of Phase-II Irradiation are tabulated in Table 2. At the end of the Phase-II irradiation, the MCWO-calculated Zr-cladding fast neutron fluences of the removed MOX capsules 9 and 2 are 6.78 and 6.79 x 1020 n/cm2, respectively. At the end of the Phase-III irradiation, the MCWO-calculated Zr-cladding fast neutron fluences of the removed MOX capsules 10 and 3 are 9.82 and 9.70 x 1020 n/cm2, respectively. And, at the end of the Phase-IV part 1B irradiation, the MCWO-calculated Zr-cladding fast neutron fluences of the removed MOX capsules 4 and 13 are 1.41 and 1.39 x 1021 n/cm2, respectively.
Date: March 1, 2004
Creator: Chang, Gray
Partner: UNT Libraries Government Documents Department


Description: The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. ''green'') products that can be applied to maintain the structure and dependability of the natural gas infrastructure. The technical approach for this quarter included the fractionation of extracts prepared from several varieties of pepper plants, and using several solvents, by high performance liquid chromatography (HPLC). A preliminary determination of antimicrobial activities of the new extracts and fractions using a growth inhibition assay, and evaluation of the extracts ability to inhibit biofilm formation was also performed. The analysis of multiple extracts of pepper plants and fractions of extracts of pepper plants obtained by HPLC illustrated that these extracts and fractions are extremely complex mixtures of chemicals. Gas chromatography-mass spectrometry was used to identify the chemical constituents of these extracts and fractions to the greatest degree possible. Analysis of the chemical composition of various extracts of pepper plants has illustrated the complexity of the chemical mixtures present, and while additional work will be performed to further characterize the extracts to identify bioactive compounds the focus of efforts should now shift to an evaluation of the ability of extracts to inhibit corrosion in mixed culture biofilms, and in pure cultures of bacterial types which are known or believed to be important in corrosion.
Date: January 31, 2004
Creator: II, John J. Kilbane & Bogan, William
Partner: UNT Libraries Government Documents Department

The Hydrogen Futures Simulation Model (H[2]Sim) technical description.

Description: Hydrogen has the potential to become an integral part of our energy transportation and heat and power sectors in the coming decades and offers a possible solution to many of the problems associated with a heavy reliance on oil and other fossil fuels. The Hydrogen Futures Simulation Model (H2Sim) was developed to provide a high level, internally consistent, strategic tool for evaluating the economic and environmental trade offs of alternative hydrogen production, storage, transport and end use options in the year 2020. Based on the model's default assumptions, estimated hydrogen production costs range from 0.68 $/kg for coal gasification to as high as 5.64 $/kg for centralized electrolysis using solar PV. Coal gasification remains the least cost option if carbon capture and sequestration costs ($0.16/kg) are added. This result is fairly robust; for example, assumed coal prices would have to more than triple or the assumed capital cost would have to increase by more than 2.5 times for natural gas reformation to become the cheaper option. Alternatively, assumed natural gas prices would have to fall below $2/MBtu to compete with coal gasification. The electrolysis results are highly sensitive to electricity costs, but electrolysis only becomes cost competitive with other options when electricity drops below 1 cent/kWhr. Delivered 2020 hydrogen costs are likely to be double the estimated production costs due to the inherent difficulties associated with storing, transporting, and dispensing hydrogen due to its low volumetric density. H2Sim estimates distribution costs ranging from 1.37 $/kg (low distance, low production) to 3.23 $/kg (long distance, high production volumes, carbon sequestration). Distributed hydrogen production options, such as on site natural gas, would avoid some of these costs. H2Sim compares the expected 2020 per mile driving costs (fuel, capital, maintenance, license, and registration) of current technology internal combustion engine (ICE) vehicles (0.55$/mile), hybrids ...
Date: October 1, 2004
Creator: Jones, Scott A.; Kamery, William; Baker, Arnold Barry; Drennen, Thomas E.; Lutz, Andrew E. & Rosthal, Jennifer Elizabeth
Partner: UNT Libraries Government Documents Department

Monolithic supports with unique geometries and enhanced mass transfer.

Description: The catalytic combustion of natural gas has been the topic of much research over the past decade. Interest in this technology results from a desire to decrease or eliminate the emissions of harmful nitrogen oxides (NOX) from gas turbine power plants. A low-pressure drop catalyst support, such as a ceramic monolith, is ideal for this high-temperature, high-flow application. A drawback to the traditional honeycomb monoliths under these operating conditions is poor mass transfer to the catalyst surface in the straight-through channels. 'Robocasting' is a unique process developed at Sandia National Laboratories that can be used to manufacture ceramic monoliths with alternative 3-dimensional geometries, providing tortuous pathways to increase mass transfer while maintaining low pressure drops. This report details the mass transfer effects for novel 3-dimensional robocast monoliths, traditional honeycomb-type monoliths, and ceramic foams. The mass transfer limit is experimentally determined using the probe reaction of CO oxidation over a Pt / {gamma}-Al{sub 2}O{sub 3} catalyst, and the pressure drop is measured for each monolith sample. Conversion versus temperature data is analyzed quantitatively using well-known dimensionless mass transfer parameters. The results show that, relative to the honeycomb monolith support, considerable improvement in mass transfer efficiency is observed for robocast samples synthesized using an FCC-like geometry of alternating rods. Also, there is clearly a trade-off between enhanced mass transfer and increased pressure drop, which can be optimized depending on the particular demands of a given application.
Date: January 1, 2004
Creator: Stuecker, John Nicholas; Ferrizz, Robert Matthew; Cesarano, Joseph, III & Miller, James Edward
Partner: UNT Libraries Government Documents Department

Multi-Attribute Seismic/Rock Physics Approach to Characterizing Fractured Reservoirs

Description: Most current seismic methods to seismically characterize fractures in tight reservoirs depend on a few anisotropic wave propagation signatures that can arise from aligned fractures. While seismic anisotropy can be a powerful fracture diagnostic, a number of situations can lessen its usefulness or introduce interpretation ambiguities. Fortunately, laboratory and theoretical work in rock physics indicates that a much broader spectrum of fracture seismic signatures can occur, including a decrease in P- and S-wave velocities, a change in Poisson's ratio, an increase in velocity dispersion and wave attenuation, as well as well as indirect images of structural features that can control fracture occurrence. The goal of this project was to demonstrate a practical interpretation and integration strategy for detecting and characterizing natural fractures in rocks. The approach was to exploit as many sources of information as possible, and to use the principles of rock physics as the link among seismic, geologic, and log data. Since no single seismic attribute is a reliable fracture indicator in all situations, the focus was to develop a quantitative scheme for integrating the diverse sources of information. The integrated study incorporated three key elements: The first element was establishing prior constraints on fracture occurrence, based on laboratory data, previous field observations, and geologic patterns of fracturing. The geologic aspects include analysis of the stratigraphic, structural, and tectonic environments of the field sites. Field observations and geomechanical analysis indicates that fractures tend to occur in the more brittle facies, for example, in tight sands and carbonates. In contrast, strain in shale is more likely to be accommodated by ductile flow. Hence, prior knowledge of bed thickness and facies architecture, calibrated to outcrops, are powerful constraints on the interpreted fracture distribution. Another important constraint is that fracturing is likely to be more intense near faults--sometimes referred to as ...
Date: November 30, 2004
Creator: Mavko, Gary
Partner: UNT Libraries Government Documents Department