Biological Kraft Chemical Recycle for Augmentation of Recovery Furnace Capacity (open access)

Biological Kraft Chemical Recycle for Augmentation of Recovery Furnace Capacity

The chemicals used in pulping of wood by the kraft process are recycled in the mill in the recovery furnace, which oxidizes organics while simultaneously reducing sulfate to sulfide. The recovery furnace is central to the economical operation of kraft pulp mills, but it also causes problems. The total pulp production of many mills is limited by the recovery furnace capacity, which cannot easily be increased. The furnace is one of the largest sources of air pollution (as reduced sulfur compounds) in the kraft pulp mill.
Date: December 6, 2001
Creator: Strand, Stuart E.
Object Type: Report
System: The UNT Digital Library
Biosphere Modeling and Analyses in Support of Total System Performance Assessment (open access)

Biosphere Modeling and Analyses in Support of Total System Performance Assessment

The Nuclear Waste Policy Act of 1982 established the obligations of and the relationship between the U.S. Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE) for the management and disposal of high-level radioactive wastes. In 1985, the EPA promulgated regulations that included a definition of performance assessment that did not consider potential dose to a member of the general public. This definition would influence the scope of activities conducted by DOE in support of the total system performance assessment program until 1995. The release of a National Academy of Sciences (NAS) report on the technical basis for a Yucca Mountain-specific standard provided the impetus for the DOE to initiate activities that would consider the attributes of the biosphere, i.e. that portion of the earth where living things, including man, exist and interact with the environment around them. The evolution of NRC and EPA Yucca Mountain-specific regulations, originally proposed in 1999, was critical to the development and integration of biosphere modeling and analyses into the total system performance assessment program. These proposed regulations initially differed in the conceptual representation of the receptor of interest to be considered in assessing performance. The publication …
Date: December 6, 2001
Creator: Tappen, Jeff; Wasiolek, M. A.; Wu, D. W. & Schmitt, J. F.
Object Type: Report
System: The UNT Digital Library
Effect of thin-film coating on wear in EGR-contaminated oil. (open access)

Effect of thin-film coating on wear in EGR-contaminated oil.

Increased use of higher-efficiency compression ignition direct injection (CIDI) diesel engines instead of today's gasoline engines will result in reduced fuel consumption and greenhouse gases emissions. However, NO{sub x} and particulate exhaust emissions from diesel engines must be significantly reduced due to their possible adverse health effects. Exhaust gas recirculation (EGR) is an effective way to reduce NO{sub x} emissions from diesel engines, but the particulates and acidic exhaust products in the recirculated gas will contaminate engine lubricant oil by increasing the soot content and total acid number (TAN). These factors will increase the wear rate in many critical engine components and seriously compromise engine durability. We have investigated the use of commercially available thin and hard coatings (TiN, TiCN, TiAlN, and CrN) to mitigate the negative effects of EGR on wear. In tests with the four-ball machine according to ASTM D4172, we found that all the four coatings deposited on M-50 steel significantly reduced wear in EGR-contaminated oils when compared with uncoated M50 steel balls.
Date: December 6, 2001
Creator: Ajayi, O. O.; Aldajah, S. H.; Erdemir, A. & Fenske, G. R.
Object Type: Article
System: The UNT Digital Library
EPAct Fleet Information and Regulations: State and Alternative Fuel Provider Program, Annual Report FY 2001 (open access)

EPAct Fleet Information and Regulations: State and Alternative Fuel Provider Program, Annual Report FY 2001

A detailed account of the activity and accomplishments made by fleets covered by the EPAct State and Alternative Fuel Provider Program.
Date: December 6, 2001
Creator: Melendez, M. & White, H.
Object Type: Book
System: The UNT Digital Library
Far-infrared absorption in Sb-doped Ge epilayers near the metal-insulator transition (open access)

Far-infrared absorption in Sb-doped Ge epilayers near the metal-insulator transition

None
Date: December 6, 2001
Creator: Bandaru, Jordana; Beeman, Jeffrey W. & Haller, Eugene E.
Object Type: Article
System: The UNT Digital Library
Geologic Repository Plan for Disposal of Pu-Containing and Other Radioactive Materials in Russia (open access)

Geologic Repository Plan for Disposal of Pu-Containing and Other Radioactive Materials in Russia

None
Date: December 6, 2001
Creator: Jardine, L
Object Type: Report
System: The UNT Digital Library
The history of LOCA embrittlement criteria. (open access)

The history of LOCA embrittlement criteria.

None
Date: December 6, 2001
Creator: Hache, G. & Chung, H.M.
Object Type: Article
System: The UNT Digital Library
Performance of amorphous carbon coating in turbocompressor air bearings. (open access)

Performance of amorphous carbon coating in turbocompressor air bearings.

None
Date: December 6, 2001
Creator: Ajayi, O. O.; Woodford, J. B.; Erdemir, A. & Fenske, G. R.
Object Type: Article
System: The UNT Digital Library
A Review of the IAEA Vulnerability Assessment Level Scheme: Applicabiliy to DTRA and DOE Programs in the FSU (open access)

A Review of the IAEA Vulnerability Assessment Level Scheme: Applicabiliy to DTRA and DOE Programs in the FSU

The International Atomic Energy Agency (IAEA) plans to use the Common Criteria, as the tool for developing graded and measurable evaluation criteria for information technology (IT) in safeguards systems in facilities subject to IAEA inspection. In their draft paper [ITSECSES] the IAEA defines a three-tiered Vulnerability Assessment Level (VAL) scheme. Each increased VAL level (1-3) defines additional and more stringent security and security-related requirements for the system developer, the system evaluator (assessor or authenticator), and for the IAEA. When all parties meet all requirements for a particular VAL level, IAEA has a measurable degree of confidence in the secure and proper operation of an IT system.
Date: December 6, 2001
Creator: Devaney, Mike M.; Hansen, Randy R.; Kouzes, Richard T. & Melton, Ronald B.
Object Type: Report
System: The UNT Digital Library
Structural basis of water specific transport through AQP1 water channel (open access)

Structural basis of water specific transport through AQP1 water channel

None
Date: December 6, 2001
Creator: Sui, Haixin; Han, Bong-Gyoon; Lee, John K.; Walian, Peter & Jap, Bing K.
Object Type: Article
System: The UNT Digital Library
Structure characteristics of ISD coated conductors. (open access)

Structure characteristics of ISD coated conductors.

None
Date: December 6, 2001
Creator: Tang, Y. L.; Miller, D. J.; Ma, B.; Koritala, R. E. & Balachandran, U.
Object Type: Article
System: The UNT Digital Library
Support Facility for a Mercury Target Neutrino Factory (open access)

Support Facility for a Mercury Target Neutrino Factory

A conceptual design for a neutrino-producing facility is presented, including the mercury-jet target system, beam absorber, and facility for the target/capture region. The mercury system is a closed loop that includes a containment structure in the high-magnetic field region, a mercury pool beam absorber, conventional equipment such as magnetic-coupled pumps, valves, a heat exchanger, and a special nozzle insert. The superconducting solenoids in the target region are protected from nuclear heating and radiation damage with water-cooled tungsten-carbide shielding; the decay channel solenoids are protected with water-cooled steel shielding. The target region and decay channel have high-neutron fluxes resulting in components that are highly activated. Therefore, the facility configuration is based on remotely maintaining the target system and the magnets, as well as providing sufficient shielding for personnel. Summaries of cost estimates for the target system, magnet shielding, maintenance equipment, and the facility are also presented.
Date: December 6, 2001
Creator: Spampinato, P. T.; Chesser, J. B.; Conner, D. L.; Gabriel, T. A.; Gallmeier, F. X.; Haines, J. R. et al.
Object Type: Report
System: The UNT Digital Library
Synchrotron radiation from electron beams in plasma focusing channels (open access)

Synchrotron radiation from electron beams in plasma focusing channels

Spontaneous radiation emitted from relativistic electrons undergoing betatron motion in a plasma focusing channel is analyzed and application to plasma wakefield accelerator experiments and to the ion channel laser (ICL) are discussed. Important similarities and differences between a free electron laser (FEL) and an ICL are delineated. It is shown that the frequency of spontaneous radiation is a strong function of the betatron strength parameter alpha-beta, which plays a similar role to that of the wiggler strength parameter in a conventional FEL. For alpha-beta > 1, radiation is emitted in numerous harmonics. Furthermore, alpha-beta is proportional to the amplitude of the betatron orbit, which varies for every electron in the beam. The radiation spectrum emitted from an electron beam is calculated by averaging the single electron spectrum over the electron distribution. This leads to a frequency broadening of the radiation spectrum, which places serious limits on the possibility of realizing an ICL.
Date: December 6, 2001
Creator: Esarey, E.; Shadwick, B. A.; Catravas, P. & Leemans, W. P.
Object Type: Article
System: The UNT Digital Library
ADVANCED STEAM GENERATORS (open access)

ADVANCED STEAM GENERATORS

Concerns about climate change have encouraged significant interest in concepts for ultra-low or ''zero''-emissions power generation systems. In some proposed concepts, nitrogen is removed from the combustion air and replaced with another diluent such as carbon dioxide or steam. In this way, formation of nitrogen oxides is prevented, and the exhaust stream can be separated into concentrated CO{sub 2} and steam or water streams. The concentrated CO{sub 2} stream could then serve as input to a CO{sub 2} sequestration process or utilized in some other way. Some of these concepts are illustrated in Figure 1. This project is an investigation of one approach to ''zero'' emission power generation. Oxy-fuel combustion is used with steam as diluent in a power cycle proposed by Clean Energy Systems, Inc. (CES) [1,2]. In oxy-fuel combustion, air separation is used to produce nearly pure oxygen for combustion. In this particular concept, the combustion temperatures are moderated by steam as a diluent. An advantage of this technique is that water in the product stream can be condensed with relative ease, leaving a pure CO{sub 2} stream suitable for sequestration. Because most of the atmospheric nitrogen has been separated from the oxidant, the potential to form any …
Date: November 6, 2001
Creator: Richards, George A.; Casleton, Kent H.; Lewis, Robie E.; Rogers, William A.; Woike, Mark R. & Willis, Brian P.
Object Type: Article
System: The UNT Digital Library
CHARACTERIZATION OF A RIGID BARRIER FILTER SYSTEM (open access)

CHARACTERIZATION OF A RIGID BARRIER FILTER SYSTEM

A mathematical model is formulated to describe the dynamics of a rigid barrier filter system. Complete with filtration, regeneration and particle re-deposition, this model provides sizing information for new filter systems and diagnostic information for operating filter systems. To turn this model into a practical and smart filter system predictive model, monitoring devices for variables such as real-time particle concentration and size distribution are currently under laboratory development. The program goal is to introduce a smart filter system to supervise its operation and to assure its system reliability. Primarily, a smart filter system will update operating information, sound up malfunction alarms, and provide self-activated measures such as adjusting the cleaning frequency, intensity and back-pulse duration.
Date: November 6, 2001
Creator: Chiang, Ta-Kuan
Object Type: Article
System: The UNT Digital Library
Circulating Fluid-Bed Technology for Advanced Power Systems (open access)

Circulating Fluid-Bed Technology for Advanced Power Systems

Circulating fluid bed technology offers the advantages of a plug flow, yet well-mixed, and high throughput reactor for power plant applications. The ability to effectively scale these systems in size, geometry, and operating conditions is limited because of the extensive deviation from ideal dilute gas-solids flow behavior (Monazam et al., 2001; Li, 1994). Two fluid computations show promise of accurately simulating the hydrodynamics in the riser circulating fluid bed; however, validation tests for large vessels with materials of interest to the power industry are lacking (Guenther et al., 2002). There is little available data in reactors large enough so that geometry (i.e. entrance, exit, and wall) effects do not dominate the hydrodynamics, yet with sufficiently large particle sizes to allow sufficiently large grid sizes to allow accurate and timely hydrodynamic simulations. To meet this need experimental tests were undertaken with relatively large particles of narrow size distribution in a large enough unit to reduce the contributions of wall effects and light enough to avoid geometry effects. While computational fluid dynamic calculations are capable of generating detailed velocity and density profiles, it is believed that the validation and model development begins with the ability to simulate the global flow regime transitions. …
Date: November 6, 2001
Creator: Shadle, Lawrence J.; Ludlow, J. Christopher; Mei, Joseph S. & Guenther, Christopher
Object Type: Article
System: The UNT Digital Library
COMPUTATIONAL FLUID DYNAMICS MODELING ANALYSIS OF COMBUSTORS (open access)

COMPUTATIONAL FLUID DYNAMICS MODELING ANALYSIS OF COMBUSTORS

In the current fiscal year FY01, several CFD simulations were conducted to investigate the effects of moisture in biomass/coal, particle injection locations, and flow parameters on carbon burnout and NO{sub x} inside a 150 MW GEEZER industrial boiler. Various simulations were designed to predict the suitability of biomass cofiring in coal combustors, and to explore the possibility of using biomass as a reburning fuel to reduce NO{sub x}. Some additional CFD simulations were also conducted on CERF combustor to examine the combustion characteristics of pulverized coal in enriched O{sub 2}/CO{sub 2} environments. Most of the CFD models available in the literature treat particles to be point masses with uniform temperature inside the particles. This isothermal condition may not be suitable for larger biomass particles. To this end, a stand alone program was developed from the first principles to account for heat conduction from the surface of the particle to its center. It is envisaged that the recently developed non-isothermal stand alone module will be integrated with the Fluent solver during next fiscal year to accurately predict the carbon burnout from larger biomass particles. Anisotropy in heat transfer in radial and axial will be explored using different conductivities in radial and …
Date: November 6, 2001
Creator: Mathur, M. P.; Freeman, Mark & Gera, Dinesh
Object Type: Article
System: The UNT Digital Library
A Computational Workbench Environment For Virtual Power Plant Simulation (open access)

A Computational Workbench Environment For Virtual Power Plant Simulation

In this paper we describe our progress toward creating a computational workbench for performing virtual simulations of Vision 21 power plants. The workbench provides a framework for incorporating a full complement of models, ranging from simple heat/mass balance reactor models that run in minutes to detailed models that can require several hours to execute. The workbench is being developed using the SCIRun software system. To leverage a broad range of visualization tools the OpenDX visualization package has been interfaced to the workbench. In Year One our efforts have focused on developing a prototype workbench for a conventional pulverized coal fired power plant. The prototype workbench uses a CFD model for the radiant furnace box and reactor models for downstream equipment. In Year Two and Year Three, the focus of the project will be on creating models for gasifier based systems and implementing these models into an improved workbench. In this paper we describe our work effort for Year One and outline our plans for future work. We discuss the models included in the prototype workbench and the software design issues that have been addressed to incorporate such a diverse range of models into a single software environment. In addition, we …
Date: November 6, 2001
Creator: Bockelie, Michael J.; Swensen, David A.; Denison, Martin K. & Sarofim, Adel F.
Object Type: Article
System: The UNT Digital Library
Development of Foster Wheeler's Vision 21 Partial Gasification Module (open access)

Development of Foster Wheeler's Vision 21 Partial Gasification Module

The US Department of Energy (DOE) has awarded Foster Wheeler Development Corporation a contract to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% while producing near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The unique aspect of the process is that it utilizes a pressurized circulating fluidized bed partial gasifier and does not attempt to consume the coal in a single step. To convert all the coal to syngas in a single step requires extremely high temperatures ({approx} 2500 to 2800F) that melt and vaporize the coal and essentially drive all coal ash contaminants into the syngas. …
Date: November 6, 2001
Creator: Robertson, A.
Object Type: Article
System: The UNT Digital Library
Durable Zinc Oxide-Based Regenerable Sorbents for Desulfurization of Syngas in a Fixed-Bed Reactor (open access)

Durable Zinc Oxide-Based Regenerable Sorbents for Desulfurization of Syngas in a Fixed-Bed Reactor

A fixed-bed regenerable desulfurization sorbent, identified as RVS-land developed by researchers at the U.S. Department of Energy's National Energy Technology Laboratory, was awarded the R&D 100 award in 2000 and is currently offered as a commercial product by Sued-Chemie Inc. An extensive testing program for this sorbent was undertaken which included tests at a wide range of temperatures, pressures and gas compositions both simulated and generated in an actual gasifier for sulfidation and regeneration. This testing has demonstrated that during these desulfurization tests, the RVS-1 sorbent maintained an effluent H2S concentration of <5 ppmv at temperatures from 260 to 600 C (500-1100 F) and pressures of 203-2026 kPa(2 to 20 atm) with a feed containing 1.2 vol% H{sub 2}S. The types of syngas tested ranged from an oxygen-blown Texaco gasifier to biomass-generated syngas. The RVS-1 sorbent has high crush strength and attrition resistance, which, unlike past sorbent formulations, does not decrease with extended testing at actual at operating conditions. The sulfur capacity of the sorbent is roughly 17 to 20 wt.% and also remains constant during extended testing (>25 cycles). In addition to H{sub 2}S, the RVS-1 sorbent has also demonstrated the ability to remove dimethyl sulfide and carbonyl sulfide …
Date: November 6, 2001
Creator: Siriwardane, Ranjani V.; Cicero, Daniel C. (U.S. Department of Energy, National Energy Technology Laboratory, Morgantown); Stiegel, Gary J.; Gupta, Raghubir P. (U.S. Department of Energy, National Energy Technology Laboratory, Pittsburgh) & Turk, Brian S. (Research Triangle Institute)
Object Type: Article
System: The UNT Digital Library
Electroproduction of Photons and of Pawns on the Proton in Quadrimoment of Transfer Q2=1.0GeV2. Measure Cross Sections and Extraction of Polarizabilities Generalities; Electroproduction de Photons et de Pions sur le Proton au Quadrimoment de Transfert Q2=1.0GeV2. Mesure des Sections Efficaces et Extraction des Polarisabilites Generalisees (open access)

Electroproduction of Photons and of Pawns on the Proton in Quadrimoment of Transfer Q2=1.0GeV2. Measure Cross Sections and Extraction of Polarizabilities Generalities; Electroproduction de Photons et de Pions sur le Proton au Quadrimoment de Transfert Q2=1.0GeV2. Mesure des Sections Efficaces et Extraction des Polarisabilites Generalisees

In hadronic physics, the nucleon structure and the quarks confinement are still topical issues. The neutral pion electroproduction and virtual Compton scattering (VCS) reactions allow us to access new observables that describe this structure. This work is focused on the VCS experiment performed at Jefferson Lab in 1998.
Date: November 6, 2001
Creator: Laveissiere, Geraud
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Final Report 94ER75989 [U.S. DOE-FCCSET-Summer Teaching Enhancement Program] (open access)

Final Report 94ER75989 [U.S. DOE-FCCSET-Summer Teaching Enhancement Program]

This is the final report for the interagency agreement between the Department of Energy and NASA, 94ER75989, titled U.S. DOE-FCCSET-Summer Teaching Enhancement Program. Our goal to enhance the classroom Instruction in the earth and environmental science programs in the secondary schools of the state of Maryland. The participation of 72 teachers of secondary school students were collaborative partners with the 24 local Maryland School System, the Maryland State Department of Education, the University of Maryland, and the Goddard Space Flight Center. The program enabled these teachers the opportunity to attend a four-week program to enhance the teaching of the earth and environmental sciences in the secondary schools of Maryland. Participants learned how earth systems are studied both from the ground station earth monitoring project and continued it during the school year with their students. Each teacher served as an ambassador for earth science teaching enhancement in their respective school and school system.
Date: November 6, 2001
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Fuel Cell/Turbine Ultra High Efficiency Power System (open access)

Fuel Cell/Turbine Ultra High Efficiency Power System

FuelCell Energy, INC. (FCE) is currently involved in the design of ultra high efficiency power plants under a cooperative agreement (DE-FC26-00NT40) managed by the National Energy Technology Laboratory (NETL) as part of the DOE's Vision 21 program. Under this project, FCE is developing a fuel cell/turbine hybrid system that integrates the atmospheric pressure Direct FuelCell{reg_sign} (DFC{reg_sign}) with an unfired Brayton cycle utilizing indirect heat recovery from the power plant. Features of the DFC/T{trademark} system include: high efficiency, minimal emissions, simplicity in design, direct reforming internal to the fuel cell, no pressurization of the fuel cell, independent operating pressure of the fuel cell and turbine, and potential cost competitiveness with existing combined cycle power plants at much smaller sizes. Objectives of the Vision 21 Program include developing power plants that will generate electricity with net efficiencies approaching 75 percent (with natural gas), while producing sulfur and nitrogen oxide emissions of less than 0.01 lb/million BTU. These goals are significant improvements over conventional power plants, which are 35-60 percent efficient and produce emissions of 0.07 to 0.3 lb/million BTU of sulfur and nitrogen oxides. The nitrogen oxide and sulfur emissions from the DFC/T system are anticipated to be better than the Vision …
Date: November 6, 2001
Creator: Hossein, Ghezel-Ayagh
Object Type: Article
System: The UNT Digital Library
Fuel Flexibility in Gasification (open access)

Fuel Flexibility in Gasification

In order to increase efficiencies of carbonizers, operation at high pressures is needed. In addition, waste biomass fuels of opportunity can be used to offset fossil fuel use. The National Energy Technology Laboratory (NETL) Fluidized Bed Gasifier/Combustor (FBG/C) was used to gasify coal and mixtures of coal and biomass (sawdust) at 425 psig. The purpose of the testing program was to generate steady state operating data for modeling efforts of carbonizers. A test program was completed with a matrix of parameters varied one at a time in order to avoid second order interactions. Variables were: coal feed rate, pressure, and varying mixtures of sawdust and coal types. Coal types were Montana Rosebud subbituminous and Pittsburgh No. 8 bituminous. The sawdust was sanding waste from a furniture manufacturer in upstate New York. Coal was sieved from -14 to +60 mesh and sawdust was sieved to -14 mesh. The FBG/C operates at a nominal 425 psig, but pressures can be lowered. For the tests reported it was operated as a jetting, fluidized bed, ash-agglomerating gasifier. Preheated air and steam are injected into the center of the bottom along with the solid feed that is conveyed with cool air. Fairly stable reactor internal …
Date: November 6, 2001
Creator: McLendon, T. Robert; Pineault, Richard L.; Richardson, Steven W.; Rockey, John M.; Beer, Stephen K. (U.S. DOE National Energy Technology Laboratory); Lui, Alain P. et al.
Object Type: Article
System: The UNT Digital Library