Search Results

Physical and chemical characteristics of topographically affected airflow in an open borehole at Yucca Mountain, Nevada

Description: Borehole UZ6S, on the crest of Yucca Mountain, Nevada Test Site, has exhaled approximately 10{sup 6} m{sup 3} of gas annually during winter months for three successive years. The flow arises from thermal-topographic effects. The average composition of the exhausted gas is: N{sub 2} = 78%, O{sub 2} = 21%, Ar = 0.94%, CO{sub 2} = 0.125%, and CH{sub 4} = 0.2 ppMv. The CO{sub 2} has the following isotopic signature: {sup 14}C = 108.5 percent modern carbon (pmc), and {delta}{sup 13}C = 17.1 per mil. In the thirty-month observation period, there has been a net flux to the atmosphere of approximately 40 m{sup 3} of liquid water and 1150 kg of carbon. The gas flowing from UZ6S appears to originate in the soil and/or shallow unsaturated zone at Yucca Mountain crest. 25 refs., 6 figs., 4 tabs.
Date: December 31, 1989
Creator: Thorstenson, D.C.; Woodward, J.C.; Weeks, E.P. & Haas, H.
Item Type: Article
Partner: UNT Libraries Government Documents Department

Albany Interim Landfill gas extraction and mobile power system: Using landfill gas to produce electricity. Final report

Description: The Albany Interim Landfill Gas Extraction and Mobile Power System project served three research objectives: (1) determination of the general efficiency and radius of influence of horizontally placed landfill gas extraction conduits; (2) determination of cost and effectiveness of a hydrogen sulfide gas scrubber utilizing Enviro-Scrub{trademark} liquid reagent; and (3) construction and evaluation of a dual-fuel (landfill gas/diesel) 100 kW mobile power station. The horizontal gas extraction system was very successful; overall, gas recovery was high and the practical radius of influence of individual extractors was about 50 feet. The hydrogen sulfide scrubber was effective and its use appears feasible at typical hydrogen sulfide concentrations and gas flows. The dual-fuel mobile power station performed dependably and was able to deliver smooth power output under varying load and landfill gas fuel conditions.
Date: June 1, 1997
Item Type: Report
Partner: UNT Libraries Government Documents Department

Methane Capture: Options for Greenhouse Gas Emission Reduction

Description: This report discusses legislative alternatives for addressing methane capture, sources of methane, opportunities and challenges for methane capture, and current federal programs that support methane recovery.
Date: September 17, 2009
Creator: Bracmort, Kelsi; Ramseur, Jonathan L.; McCarthy, James E.; Folger, Peter & Marples, Donald J.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Development of monitoring and control technology based on trace gas monitoring. Final report

Description: Trace gases are generated by many biological reactions. During anaerobic decomposition, trace levels of hydrogen (H{sub 2}) and carbon monoxide (CO) gases are produced. It was shown previously that these trace gases are intrinsically related to the biochemical reactions occurring and, therefore, offer promise for on-line process monitoring and control. This work was designed to test how effectively hydrogen and CO could be to monitor high-rate anaerobic systems that has significant mass transfer and complex hydraulics. An experimental program was designed to examine the behavior of an upflow anaerobic sludge blanket (UASB) reactor system under steady state and in response to organic loading perturbations. The responses of trace gases CO and H{sub 2} were tracked using an on-line, real-time gas-monitoring system linked to a computer-controlled data acquisition package. Data on conventional process parameters such as pH, chemical oxygen demand (COD), volatile fatty acids (VFAs) were concurrently collected. Monitoring of conventional process indicators (i.e., pH, VFA, gas production) and trace gas (H{sub 2} and CO) indicators was conducted using a matrix of nine different steady-state OLRs (4-23 kg COD/m{sup 3} -d) and system HRTs (0.5 to 2.5 days) was performed to determine any correlation among the indicators. Of OLR, HRT, and influent COD, only OLR had any significant influence on the process indicators examined. All parameters except methane increased with increases in OLR; methane decreased with increased OLR. The OLR and gas production rate (GP) were observed to be linearly correlated.
Date: July 1, 1997
Creator: Liebowitz, B.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Methyl chloride via oxhydrochlorination of methane

Description: Dow Corning is developing a route from methane to methyl chloride via oxyhydrochlorination (OHC) chemistry with joint support from the Gas Research Institute and the Department of Energy Federal Energy Technology Center. Dow Corning is the world`s largest producer of methyl chloride and uses it as an intermediate in the production of silicone materials. Other uses include production of higher hydrocarbons, methyl cellulose, quaternary ammonium salts and herbicides. The objective of this project is to demonstrate and develop a route to methyl chloride with reduced variable cost by using methane instead of methanol raw materials. Methyl chloride is currently produced from methanol, but U.S. demand is typically higher than available domestic supply, resulting in fluctuating prices. OHC technology utilizes domestic natural gas as a feedstock, which allows a lower-cost source of methyl chloride which is independent of methanol. In addition to other uses of methyl chloride, OHC could be a key step in a gas-to-liquid fuels process. These uses could divert significant methanol demand to methane. A stable and selective catalyst has been developed in the laboratory and evaluated in a purpose-built demonstration unit. Materials of construction issues have been resolved and the unit has been run under a range of conditions to evaluate catalyst performance and stability. Many technological advances have been made, especially in the areas of catalyst development, online FTIR analysis of the product stream, and recovery of methyl chloride product via an absorber/stripper system. Significant technological hurdles still remain including heat transfer, catalysts scaleup, orthogonality in modeling, and scaleable absorption data. Economics of the oxyhydrochlorination process have been evaluated an found to be unfavorable due to high capital and utility costs. Future efforts will focus on improved methane conversion at high methyl chloride selectivity.
Date: December 31, 1997
Creator: Jarvis, R.F. Jr.
Item Type: Article
Partner: UNT Libraries Government Documents Department

Modeling of Carbon Migration During JET Injection Experiments

Description: JET has performed two dedicated carbon migration experiments on the final run day of separate campaigns (2001 and 2004) using {sup 13}CH{sub 4} methane injected into repeated discharges. The EDGE2D/NIMBUS code modelled the carbon migration in both experiments. This paper describes this modelling and identifies a number of important migration pathways: (1) deposition and erosion near the injection location, (2) migration through the main chamber SOL, (3) migration through the private flux region aided by E x B drifts, and (4) neutral migration originating near the strike points. In H-Mode, type I ELMs are calculated to influence the migration by enhancing erosion during the ELM peak and increasing the long-range migration immediately following the ELM. The erosion/re-deposition cycle along the outer target leads to a multistep migration of {sup 13}C towards the separatrix which is called 'walking'. This walking created carbon neutrals at the outer strike point and led to {sup 13}C deposition in the private flux region. Although several migration pathways have been identified, quantitative analyses are hindered by experimental uncertainty in divertor leakage, and the lack of measurements at locations such as gaps and shadowed regions.
Date: October 15, 2008
Creator: Strachan, J. D.; Likonen, J.; Coad, P.; Rubel, M.; Widdowson, A.; Airila, M. et al.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Analysis of Devonian Black Shales in Kentucky for Potential Carbon Dioxide Sequestration and Enhanced Natural Gas Production

Description: Carbonaceous (black) Devonian gas shales underlie approximately two-thirds of Kentucky. In these shales, natural gas occurs in the intergranular and fracture porosity and is adsorbed on clay and kerogen surfaces. This is analogous to methane storage in coal beds, where CO2 is preferentially adsorbed, displacing methane. Black shales may similarly desorb methane in the presence of CO2. Drill cuttings from the Kentucky Geological Survey Well Sample and Core Library were sampled to determine both CO2 and CH4 adsorption isotherms. Sidewall core samples were acquired to investigate CO2 displacement of methane. An elemental capture spectroscopy log was acquired to investigate possible correlations between adsorption capacity and mineralogy. Average random vitrinite reflectance data range from 0.78 to 1.59 (upper oil to wet gas and condensate hydrocarbon maturity range). Total organic content determined from acid-washed samples ranges from 0.69 to 14 percent. CO2 adsorption capacities at 400 psi range from a low of 14 scf/ton in less organic-rich zones to more than 136 scf/ton in the more organic-rich zones. There is a direct linear correlation between measured total organic carbon content and the adsorptive capacity of the shale; CO2 adsorption capacity increases with increasing organic carbon content. Initial volumetric estimates based on these data indicate a CO2 sequestration capacity of as much as 28 billion tons total in the deeper and thicker parts of the Devonian shales in Kentucky. In the Big Sandy Gas Field area of eastern Kentucky, calculations using the net thickness of shale with 4 percent or greater total organic carbon, indicate that 6.8 billion tonnes of CO2 could be sequestered in the five county area. Discounting the uncertainties in reservoir volume and injection efficiency, these results indicate that the black shales of Kentucky are a potentially large geologic sink for CO2. Moreover, the extensive occurrence of gas shales in ...
Date: September 30, 2005
Creator: Nuttall, Brandon C.; Eble, Cortland F.; Drahovzal, James A. & Bustin, R. Marc
Item Type: Report
Partner: UNT Libraries Government Documents Department

Analysis of Halogen-Mercury Reactions in Flue Gas

Description: Oxidized mercury species may be formed in combustion systems through gas-phase reactions between elemental mercury and halogens, such as chorine or bromine. This study examines how bromine species affect mercury oxidation in the gas phase and examines the effects of mixtures of bromine and chlorine on extents of oxidation. Experiments were conducted in a bench-scale, laminar flow, methane-fired (300 W), quartz-lined reactor in which gas composition (HCl, HBr, NO{sub x}, SO{sub 2}) and temperature profile were varied. In the experiments, the post-combustion gases were quenched from flame temperatures to about 350 C, and then speciated mercury was measured using a wet conditioning system and continuous emissions monitor (CEM). Supporting kinetic calculations were performed and compared with measured levels of oxidation. A significant portion of this report is devoted to sample conditioning as part of the mercury analysis system. In combustion systems with significant amounts of Br{sub 2} in the flue gas, the impinger solutions used to speciate mercury may be biased and care must be taken in interpreting mercury oxidation results. The stannous chloride solution used in the CEM conditioning system to convert all mercury to total mercury did not provide complete conversion of oxidized mercury to elemental, when bromine was added to the combustion system, resulting in a low bias for the total mercury measurement. The use of a hydroxylamine hydrochloride and sodium hydroxide solution instead of stannous chloride showed a significant improvement in the measurement of total mercury. Bromine was shown to be much more effective in the post-flame, homogeneous oxidation of mercury than chlorine, on an equivalent molar basis. Addition of NO to the flame (up to 400 ppmv) had no impact on mercury oxidation by chlorine or bromine. Addition of SO{sub 2} had no effect on mercury oxidation by chlorine at SO{sub 2} concentrations below about ...
Date: January 1, 2010
Creator: Buitrago, Paula; Silcox, Geoffrey; Senior, Constance & Otten, Brydger Van
Item Type: Report
Partner: UNT Libraries Government Documents Department

Capture and Use of Coal Mine Ventilation Air Methane

Description: CONSOL Energy Inc., in conjunction with MEGTEC Systems, Inc., and the U.S. Department of Energy with the U.S. Environmental Protection Agency, designed, built, and operated a commercial-size thermal flow reversal reactor (TFRR) to evaluate its suitability to oxidize coal mine ventilation air methane (VAM). Coal mining, and particularly coal mine ventilation air, is a major source of anthropogenic methane emissions, a greenhouse gas. Ventilation air volumes are large and the concentration of methane in the ventilation air is low; thus making it difficult to use or abate these emissions. This test program was conducted with simulated coal mine VAM in advance of deploying the technology on active coal mine ventilation fans. The demonstration project team installed and operated a 30,000 cfm MEGTEC VOCSIDIZER oxidation system on an inactive coal mine in West Liberty, WV. The performance of the unit was monitored and evaluated during months of unmanned operation at mostly constant conditions. The operating and maintenance history and how it impacts the implementation of the technology on mine fans were investigated. Emission tests showed very low levels of all criteria pollutants at the stack. Parametric studies showed that the equipment can successfully operate at the design specification limits. The results verified the ability of the TFRR to oxidize {ge}95% of the low and variable concentration of methane in the ventilation air. This technology provides new opportunities to reduce greenhouse gas emissions by the reduction of methane emissions from coal mine ventilation air. A large commercial-size installation (180,000 cfm) on a single typical mine ventilation bleeder fan would reduce methane emissions by 11,000 to 22,100 short tons per year (the equivalent of 183,000 to 366,000 metric tonnes carbon dioxide).
Date: October 31, 2008
Creator: Kosmack, Deborah
Item Type: Report
Partner: UNT Libraries Government Documents Department

Catalytic Process for the Conversion of Coal-derived Syngas to Ethanol

Description: The catalytic conversion of coal-derived syngas to C{sub 2+} alcohols and oxygenates has attracted great attention due to their potential as chemical intermediates and fuel components. This is particularly true of ethanol, which can serve as a transportation fuel blending agent, as well as a hydrogen carrier. A thermodynamic analysis of CO hydrogenation to ethanol that does not allow for byproducts such as methane or methanol shows that the reaction: 2 CO + 4 H{sub 2} {yields} C{sub 2}H{sub 5}OH + H{sub 2}O is thermodynamically favorable at conditions of practical interest (e.g,30 bar, {approx}< 250 C). However, when methane is included in the equilibrium analysis, no ethanol is formed at any conditions even approximating those that would be industrially practical. This means that undesired products (primarily methane and/or CO{sub 2}) must be kinetically limited. This is the job of a catalyst. The mechanism of CO hydrogenation leading to ethanol is complex. The key step is the formation of the initial C-C bond. Catalysts that are selective for EtOH can be divided into four classes: (a) Rh-based catalysts, (b) promoted Cu catalysts, (c) modified Fischer-Tropsch catalysts, or (d) Mo-sulfides and phosphides. This project focuses on Rh- and Cu-based catalysts. The logic was that (a) Rh-based catalysts are clearly the most selective for EtOH (but these catalysts can be costly), and (b) Cu-based catalysts appear to be the most selective of the non-Rh catalysts (and are less costly). In addition, Pd-based catalysts were studied since Pd is known for catalyzing CO hydrogenation to produce methanol, similar to copper. Approach. The overall approach of this project was based on (a) computational catalysis to identify optimum surfaces for the selective conversion of syngas to ethanol; (b) synthesis of surfaces approaching these ideal atomic structures, (c) specialized characterization to determine the extent to which the ...
Date: July 29, 2011
Creator: Spivery, James; Harrison, Doug; Earle, John; Goodwin, James; Bruce, David; Mo, Xunhau et al.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Ab Initio Studies of Coke Formation on Ni Catalysts During Methane Reforming

Description: The atomic-scale processes that control the formation of carbon deposits on Ni catalysts in reforming applications are poorly understood. Ab initio Density Functional Theory calculations have been used to examine several key elementary steps in the complex network of chemical reactions that precedes carbon formation on practical catalysts. Attention has been focused on the disproportionation of CO. A comparative study of this reaction on flat and stepped crystal planes of Ni has provided the first direct evidence that surface carbon formation is driven by elementary reactions occurring at defect sites on Ni catalysts. The adsorption and diffusion of atomic H on several flat and stepped Ni surfaces has also been characterized experimentally.
Date: March 5, 2006
Creator: Sholl, David S.
Item Type: Report
Partner: UNT Libraries Government Documents Department

An Ab Initio Approach Towards Engineering Fischer-Tropsch Surface Chemistry

Description: As the US seeks to develop an energy strategy that reduces the reliance on foreign oil, there is a renewed interest in the research and development of the Fischer Tropsch synthesis for converting syngas into long chain hydrocarbon products. This report investigates some of the basic elementary steps for Fischer-Tropsch synthesis over ideal Pt, Ru and carbon-covered Pt and Ru metal surfaces by using ab initio density functional theoretical calculations. We examine in detail the adsorption sites as well as the binding energies for C, CH, CH{sub 2}, CH3 and CH4 on Pt(111), Ru(0001), 2x2-C-Pt(111) and 2x2-C-Ru(0001). The results indicate that the binding energies increase with decreasing the hydrogen in the fragment molecule, i.e. CH{sub 4} < CH{sub 3} < CH{sub 2} < CH < C. More specifically the work analyzes the elementary steps involved in the activation of methane. This is simply the reverse set of steps necessary for the hydrogenation of C to CH{sub 4}. The results indicate that these hydrocarbon intermediates bind more strongly to Ru than Pt. The introduction of co-adsorbed carbon atoms onto both Ru(0001) as well as Pt(111) significantly increased the overall energies as well as the activation barriers for C-H bond activation. The results suggest that Ru may be so active that it initially can initially activate CH4 into CH or C but ultimately it dies because the CH and C intermediates poison the surface and thus kill its activity. Methane can dissociate on Pt but subsequent hydrocarbon coupling reactions act to remove the surface carbon.
Date: September 11, 2003
Creator: Neurock, Matthew & Chopra, Siddharth
Item Type: Report
Partner: UNT Libraries Government Documents Department

An Ab Initio Approach Towards Engineering Fischer-Tropsch Surface Chemistry

Description: One of the greatest societal challenges over the next decade is the production of cheap, renewable energy for the 10 billion people that inhabit the earth. This will require the development of various different energy sources potentially including fuels derived from methane, coal, and biomass and alternatives sources such as solar, wind and nuclear energy. One approach will be to synthesize gasoline and other fuels from simpler hydrocarbons such as CO derived from methane or other U.S. based sources such as coal. Syngas (CO and H{sub 2}) can be readily converted into higher molecular weight hydrocarbons through Fischer-Tropsch synthesis. Fischer-Tropsch synthesis involves the initiation or activation of CO and H{sub 2} bonds, the subsequent propagation steps including hydrogenation and carbon-carbon coupling, followed by chain termination reactions. Commercially viable catalysts include supported Co and Co-alloys. Over the first two years of this project we have used ab initio methods to determine the adsorption energies for all reactants, intermediates, and products along with the overall reaction energies and their corresponding activation barriers over the Co(0001) surface. Over the third year of the project we developed and advanced an ab initio-based kinetic Monte Carlo simulation code to simulate Fischer Tropsch synthesis. This report details our work over the last year which has focused on the derivation of kinetic parameters for the elementary steps involved in FT synthesis from ab initio density functional theoretical calculations and the application of the kinetic Monte Carlo algorithm to simulate the initial rates of reaction for FT over the ideal Co(0001) surface. The results from our simulations over Co(0001) indicate the importance of stepped surfaces for the activation of adsorbed CO. In addition, they demonstrate that the dominant CH{sub x}* surface intermediate under steady state conditions is CH*. This strongly suggests that hydrocarbon coupling occurs through reaction with ...
Date: May 7, 2006
Creator: Neurock, Matthew & Walthall, David A.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Addition of Tropospheric Chemistry and Aerosols to the NCAR Community Climate System Model

Description: Atmospheric chemistry and aerosols have several important roles in climate change. They affect the Earth's radiative balance directly: cooling the earth by scattering sunlight (aerosols) and warming the Earth by trapping the Earth's thermal radiation (methane, ozone, nitrous oxide, and CFCs are greenhouse gases). Atmospheric chemistry and aerosols also impact many other parts of the climate system: modifying cloud properties (aerosols can be cloud condensation nuclei), fertilizing the biosphere (nitrogen species and soil dust), and damaging the biosphere (acid rain and ozone damage). In order to understand and quantify the effects of atmospheric chemistry and aerosols on the climate and the biosphere in the future, it is necessary to incorporate atmospheric chemistry and aerosols into state-of-the-art climate system models. We have taken several important strides down that path. Working with the latest NCAR Community Climate System Model (CCSM), we have incorporated a state-of-the-art atmospheric chemistry model to simulate tropospheric ozone. Ozone is not just a greenhouse gas, it damages biological systems including lungs, tires, and crops. Ozone chemistry is also central to the oxidizing power of the atmosphere, which destroys a lot of pollutants in the atmosphere (which is a good thing). We have also implemented a fast chemical mechanism that has high fidelity with the full mechanism, for significantly reduced computational cost (to facilitate millennium scale simulations). Sulfate aerosols have a strong effect on climate by reflecting sunlight and modifying cloud properties. So in order to simulate the sulfur cycle more fully in CCSM simulations, we have linked the formation of sulfate aerosols to the oxidizing power of the atmosphere calculated by the ozone mechanisms, and to dimethyl sulfide emissions from the ocean ecosystem in the model. Since the impact of sulfate aerosols depends on the relative abundance of other aerosols in the atmosphere, we also implemented interactive simulation ...
Date: November 14, 2005
Creator: Cameron-Smith, P; Lamarque, J; Connell, P; Chuang, C; Rotman, D & Taylor, J
Item Type: Report
Partner: UNT Libraries Government Documents Department

Arctic Energy Technology Development Laboratory

Description: The Arctic Energy Technology Development Laboratory was created by the University of Alaska Fairbanks in response to a congressionally mandated funding opportunity through the U.S. Department of Energy (DOE), specifically to encourage research partnerships between the university, the Alaskan energy industry, and the DOE. The enabling legislation permitted research in a broad variety of topics particularly of interest to Alaska, including providing more efficient and economical electrical power generation in rural villages, as well as research in coal, oil, and gas. The contract was managed as a cooperative research agreement, with active project monitoring and management from the DOE. In the eight years of this partnership, approximately 30 projects were funded and completed. These projects, which were selected using an industry panel of Alaskan energy industry engineers and managers, cover a wide range of topics, such as diesel engine efficiency, fuel cells, coal combustion, methane gas hydrates, heavy oil recovery, and water issues associated with ice road construction in the oil fields of the North Slope. Each project was managed as a separate DOE contract, and the final technical report for each completed project is included with this final report. The intent of this process was to address the energy research needs of Alaska and to develop research capability at the university. As such, the intent from the beginning of this process was to encourage development of partnerships and skills that would permit a transition to direct competitive funding opportunities managed from funding sources. This project has succeeded at both the individual project level and at the institutional development level, as many of the researchers at the university are currently submitting proposals to funding agencies, with some success.
Date: December 31, 2008
Creator: Bandopadhyay, Sukumar; Chamberlin, Charles; Chaney, Robert; Chen, Gang; Chukwu, Godwin; Clough, James et al.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Arctic Energy Technology Development Laboratory (Part 2)

Description: Methane (CH{sub 4}) in natural gas is a major energy source in the U.S., and is used extensively on Alaska's North Slope, including the oilfields in Prudhoe Bay, the community of Barrow, and the National Petroleum Reserve, Alaska (NPRA). Smaller villages, however, are dependent on imported diesel fuel for both power and heating, resulting in some of the highest energy costs in the U.S. and crippling local economies. Numerous CH{sub 4} gas seeps have been observed on wetlands near Atqasuk, Alaska (in the NPRA), and initial measurements have indicated flow rates of 3,000-5,000 ft{sup 3} day{sup -1} (60-100 kg CH{sub 4} day{sup -1}). Gas samples collected in 1996 indicated biogenic origin, although more recent sampling indicated a mixture of biogenic and thermogenic gas. In this study, we (1) quantified the amount of CH{sub 4} generated by several seeps and evaluated their potential use as an unconventional gas source for the village of Atqasuk; (2) collected gas and analyzed its composition from multiple seeps several miles apart to see if the source is the same, or if gas is being generated locally from isolated biogenic sources; and (3) assessed the potential magnitude of natural CH{sub 4} gas seeps for future use in climate change modeling.
Date: December 31, 2008
Creator: 960443, See OSTI ID Number
Item Type: Report
Partner: UNT Libraries Government Documents Department

Assessment of CO2 Sequestration and ECBM Potential of U.S. Coalbeds

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, an engineering capability to simulate 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, applying the findings from the San Juan Basin to a national scale to develop a preliminary assessment of the CO{sub 2} sequestration and ECBM recovery potential of U.S. coalbeds. Importantly, this assessment improves upon previous investigations by (1) including a more comprehensive list of U.S. coal basins, (2) adopting technical rationale for setting upper-bound limits on the results, and (3) incorporating new information on CO{sub 2}/CH{sub 4} replacement ratios as a function of coal rank. Based on the results of the assessment, the following conclusions have been drawn: (1) The CO{sub 2} sequestration capacity of U.S. coalbeds is estimated to be about 90 Gt. Of ...
Date: March 31, 2003
Creator: Reeves, Scott R.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Development of a Hydrogasification Process for Co-Production of Substitute Natural Gas (SNG) and Electric Power from Western Coals-Phase I

Description: The Advanced Hydrogasification Process (AHP)--conversion of coal to methane--is being developed through NETL with a DOE Grant and has successfully completed its first phase of development. The results so far are encouraging and have led to commitment by DOE/NETL to begin a second phase--bench scale reactor vessel testing, expanded engineering analysis and economic perspective review. During the next decade new means of generating electricity, and other forms of energy, will be introduced. The members of the AHP Team envision a need for expanded sources of natural gas or substitutes for natural gas, to fuel power generating plants. The initial work the team has completed on a process to use hydrogen to convert coal to methane (pipeline ready gas) shows promising potential. The Team has intentionally slanted its efforts toward the needs of US electric utilities, particularly on fuels that can be used near urban centers where the greatest need for new electric generation is found. The process, as it has evolved, would produce methane from coal by adding hydrogen. The process appears to be efficient using western coals for conversion to a highly sought after fuel with significantly reduced CO{sub 2} emissions. Utilities have a natural interest in the preservation of their industry, which will require a dramatic reduction in stack emissions and an increase in sustainable technologies. Utilities tend to rank long-term stable supplies of fuel higher than most industries and are willing to trade some ratio of cost for stability. The need for sustainability, stability and environmentally compatible production are key drivers in the formation and progression of the AHP development. In Phase II, the team will add a focus on water conservation to determine how the basic gasification process can be best integrated with all the plant components to minimize water consumption during SNG production. The process ...
Date: May 31, 2007
Creator: Hobbs, Raymond
Item Type: Report
Partner: UNT Libraries Government Documents Department

Design and fabrication of a meso-scale stirling engine and combustor.

Description: Power sources capable of supplying tens of watts are needed for a wide variety of applications including portable electronics, sensors, micro aerial vehicles, and mini-robotics systems. The utility of these devices is often limited by the energy and power density capabilities of batteries. A small combustion engine using liquid hydrocarbon fuel could potentially increase both power and energy density by an order of magnitude or more. This report describes initial development work on a meso-scale external combustion engine based on the Stirling cycle. Although other engine designs perform better at macro-scales, we believe the Stirling engine cycle is better suited to small-scale applications. The ideal Stirling cycle requires efficient heat transfer. Consequently, unlike other thermodynamic cycles, the high heat transfer rates that are inherent with miniature devices are an advantage for the Stirling cycle. Furthermore, since the Stirling engine uses external combustion, the combustor and engine can be scaled and optimized semi-independently. Continuous combustion minimizes issues with flame initiation and propagation. It also allows consideration of a variety of techniques to promote combustion that would be difficult in a miniature internal combustion engine. The project included design and fabrication of both the engine and the combustor. Two engine designs were developed. The first used a cylindrical piston design fabricated with conventional machining processes. The second design, based on the Wankel rotor geometry, was fabricated by through-mold electroforming of nickel in SU8 and LIGA micromolds. These technologies provided the requisite precision and tight tolerances needed for efficient micro-engine operation. Electroformed nickel is ideal for micro-engine applications because of its high strength and ductility. A rotary geometry was chosen because its planar geometry was more compatible with the fabrication process. SU8 lithography provided rapid prototypes to verify the design. A final high precision engine was created via LIGA. The micro-combustor was based ...
Date: May 1, 2005
Creator: Echekki, Tarek (Sandia National Laboratories, Livermore, CA); Haroldsen, Brent L. (Sandia National Laboratories, Livermore, CA); Krafcik, Karen L. (Sandia National Laboratories, Livermore, CA); Morales, Alfredo Martin (Sandia National Laboratories, Livermore, CA); Mills, Bernice E. (Sandia National Laboratories, Livermore, CA); Liu, Shiling (Sandia National Laboratories, Livermore, CA) et al.
Item Type: Report
Partner: UNT Libraries Government Documents Department

DEVELOPMENT OF A CATALYST/SORBENT FOR METHANE REFORMING

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
Item Type: Report
Partner: UNT Libraries Government Documents Department

Development of a Catalyst/Sorbent for Methane Reforming

Description: This project led to the further development of a combined catalyst and sorbent for improving the process technology required for converting CH{sub 4} and/or CO into H{sub 2} while simultaneously separating the CO{sub 2} byproduct all in a single step. The new material is in the form of core-in-shell pellets such that each pellet consists of a CaO core surrounded by an alumina-based shell capable of supporting a Ni catalyst. The Ni is capable of catalyzing the reactions of steam with CH{sub 4} or CO to produce H{sub 2} and CO{sub 2}, whereas the CaO is capable of absorbing the CO{sub 2} as it is produced. The absorption of CO{sub 2} eliminates the reaction inhibiting effects of CO{sub 2} and provides a means for recovering the CO{sub 2} in a useful form. The present work showed that the lifecycle performance of the sorbent can be improved either by incorporating a specific amount of MgO in the material or by calcining CaO derived from limestone at 1100 C for an extended period. It also showed how to prepare a strong shell material with a large surface area required for supporting an active Ni catalyst. The method combines graded particles of {alpha}-alumina with noncrystalline alumina having a large specific surface area together with a strength promoting additive followed by controlled calcination. Two different additives produced good results: 3 {micro}m limestone and lanthanum nitrate which were converted to their respective oxides upon calcination. The oxides partially reacted with the alumina to form aluminates which probably accounted for the strength enhancing properties of the additives. The use of lanthanum made it possible to calcine the shell material at a lower temperature, which was less detrimental to the surface area, but still capable of producing a strong shell. Core-in-shell pellets made with the improved shell ...
Date: December 31, 2008
Creator: Shans, B.H.; Wheelock, T.D.; Satrio, Justinus; Albrecht, Karl; Keeley, Tanya Harris Janine; Silva, Ben et al.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Engineering Development of Ceramic Membrane Reactor System for Converting Natural Gas to Hydrogen and Synthesis Gas for Liquid Transportation Fuels

Description: An Air Products-led team successfully developed ITM Syngas technology from the concept stage to a stage where a small-scale engineering prototype was about to be built. This technology produces syngas, a gas containing carbon monoxide and hydrogen, by reacting feed gas, primarily methane and steam, with oxygen that is supplied through an ion transport membrane. An ion transport membrane operates at high temperature and oxygen ions are transported through the dense membrane's crystal lattice when an oxygen partial pressure driving force is applied. This development effort solved many significant technical challenges and successfully scaled-up key aspects of the technology to prototype scale. Throughout the project life, the technology showed significant economic benefits over conventional technologies. While there are still on-going technical challenges to overcome, the progress made under the DOE-funded development project proved that the technology was viable and continued development post the DOE agreement would be warranted.
Date: September 30, 2008
Creator: Chemicals, Air Products and
Item Type: Report
Partner: UNT Libraries Government Documents Department

An Evaluation of the Available Energy Potential of the Gulf Coast Geopressured Zones

Description: The geopressured zones presently under serious study in the U.S. are tertiary sediments in the Gulf Coastal basin which are water saturated and exhibit pressures significantly greater than hydrostatic. These sediments are primarily shale, interbedded with sandstone. The top of the geopressured zone is frequently near 10,000 ft. or so, and extends to indeterminate depths. The water contained in these zones is at a moderately elevated temperature and, more significantly, appears to contain dissolved methane at near-saturation values. Conceptually, wells drilled into the geopressured zone might be expected to produce water without pumping, due to the high pressures. The dissolved methane could then be separated at the surface and used conventionally as natural gas. The water may contain sufficient heat to provide a useful source of geothermal energy, and the hydraulic energy might also provide useful work. Development of the geopressured/geothermal resource is largely dependent upon production characteristics of geopressured reservoirs. These in turn are intimately related to properties of the formations, and can be defined within reasonable limits.
Date: December 1, 1980
Creator: Swanson, R.K.; Osoba, J. S. & Hankin, J.W.
Item Type: Article
Partner: UNT Libraries Government Documents Department