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9 M.y. record of southern Nevada climate from Yucca Mountain secondary minerals (open access)

9 M.y. record of southern Nevada climate from Yucca Mountain secondary minerals

Yucca Mountain, Nevada, is presently the object of intense study as a potential permanent repository for the Nation`s high-level radioactive wastes. The mountain consists of a thick sequence of volcanic tuffs within which the depth to water table ranges from 500 to 700 meters below the land surface. This thick unsaturated zone (UZ), which would host the projected repository, coupled with the present day arid to semi-arid climate, is considered a favorable attribute of the site. Evaluation of the site includes defining the relation between climate variability, as the input function or driver of site- and regional-scale ground-water flow, and the possible future transport and release of radionuclides to the accessible environment. Secondary calcite and opal have been deposited in the UZ by meteoric waters that infiltrated through overlying soils and percolated through the tuffs. The oxygen isotopic composition ({delta}{sup 18}O values) of these minerals reflect contemporaneous meteoric waters and the {delta}{sup 13}C values reflect soil organic matter, and hence the resident plant community, at the time of infiltration. Recent U/Pb age determinations of opal in these occurrences, coupled with the {delta}{sup 13}C values of associated calcite, allow broadbrush reconstructions of climate patterns during the past 9 M.y.
Date: December 1998
Creator: Whelan, Joseph F. & Moscati, Richard J.
Object Type: Article
System: The UNT Digital Library
An 800-MeV proton radiography facility for dynamic experiments (open access)

An 800-MeV proton radiography facility for dynamic experiments

The capability has been successfully developed at the Los Alamos Nuclear Science Center (LANSCE) to utilize a spatially and temporally prepared 800-MeV proton beam to produce proton radiographs. A series of proton bursts are transmitted through a dynamically varying object and transported, via a unique magnetic lens system, to an image plane. The magnetic lens system permits correcting for the effects of multiple coulomb scattering which would otherwise completely blur the spatially transmitted information at the image plane. The proton radiographs are recorded on either a time integrating film plate or with a recently developed multi-frame electronic imaging camera system. The latter technique permits obtaining a time dependent series of proton radiographs with time intervals (modulo 358 ns) up to many microseconds and variable time intervals between images. One electronically shuttered, intensified, CCD camera is required per image. These cameras can detect single protons interacting with a scintillating fiber optic array in the image plane but also have a dynamic range which permits recording radiographs with better than 5% statistics for observation of detailed density variations in the object. A number of tests have been carried out to characterize the quality of the proton radiography system for absolute mass determination, …
Date: December 1, 1998
Creator: King, N.S.P.; Adams, K. & Ables, E.
Object Type: Article
System: The UNT Digital Library
129Iodine: a new tracer for surface water/groundwater interaction (open access)

129Iodine: a new tracer for surface water/groundwater interaction

We measured <sup>129</sup>I/<sup>127</sup>I ratios in about 30 major rivers and found a strong signal of anthropogenic <sup>129</sup>I in all of them (Moran et al., 1998). The effect of local point sources ,such as the Savannah River Facility and Hanford Facility are easily observed in the Savannah and Columbia Rivers, respectively. Likewise, the Rhine and Rhone rivers in Switzerland, have ratios well above �background� due to their proximity to the main global source in northwest Europe. Away from local point sources, one observes a mixing trend between atmospherically-delivered <sup>129</sup>I from European nuclear fuel reprocessing facilities, and low-ratio iodine derived from soil weathering (Moran et al., 1998). This anthropogenic <sup>129</sup>I should be easily observable in soil water and shallow groundwater anywhere in the northern hemisphere.
Date: December 1, 1998
Creator: Hoehn, E; Oktay, S & Santschi, P H
Object Type: Article
System: The UNT Digital Library
1998 Pacific Northwest Loads and Resources Study: The White Book. (open access)

1998 Pacific Northwest Loads and Resources Study: The White Book.

The Pacific Northwest Loads and Resources Study (White Book) is published annually by BPA and establishes the planning basis for supplying electricity to customers. It serves a dual purpose. First, the White Book presents projections of regional and Federal system load and resource capabilities, along with relevant definitions and explanations. Second, the White Book serves as a benchmark for annual BPA determinations made pursuant to the 1981 regional power sales contracts. Specifically, BPA uses the information in the White Book for determining the notice required when customers request to increase or decrease the amount of power purchased from BPA. The White Book compiles information obtained from several formalized resource planning reports and data submittals, including those from the Northwest Power Planning Council (Council) and the Pacific Northwest Utilities Conference Committee (PNUCC). The White Book is not an operational planning guide, nor is it used for inventory planning to determine BPA revenues. Operation of the Federal Columbia River Power System (FCRPS) is based on a set of criteria different from that used for resource planning decisions. Operational planning is dependent upon real-time or near-term knowledge of system conditions, including expectations of river flows and runoff, market opportunities, availability of reservoir storage, …
Date: December 1, 1998
Creator: United States. Bonneville Power Administration.
Object Type: Report
System: The UNT Digital Library
2D neural hardware versus 3D biological ones (open access)

2D neural hardware versus 3D biological ones

This paper will present important limitations of hardware neural nets as opposed to biological neural nets (i.e. the real ones). The author starts by discussing neural structures and their biological inspirations, while mentioning the simplifications leading to artificial neural nets. Going further, the focus will be on hardware constraints. The author will present recent results for three different alternatives of implementing neural networks: digital, threshold gate, and analog, while the area and the delay will be related to neurons' fan-in and weights' precision. Based on all of these, it will be shown why hardware implementations cannot cope with their biological inspiration with respect to their power of computation: the mapping onto silicon lacking the third dimension of biological nets. This translates into reduced fan-in, and leads to reduced precision. The main conclusion is that one is faced with the following alternatives: (1) try to cope with the limitations imposed by silicon, by speeding up the computation of the elementary silicon neurons; (2) investigate solutions which would allow one to use the third dimension, e.g. using optical interconnections.
Date: December 1998
Creator: Beiu, V.
Object Type: Article
System: The UNT Digital Library
Abilene Philharmonic Playbill: December 5-January 30, 1999 (open access)

Abilene Philharmonic Playbill: December 5-January 30, 1999

Program for an Abilene Philharmonic concert that ran from December 5th, 1998 to January 30th during the 49th season. It includes information about the pieces performed, artists and musicians, and advertising from local companies.
Date: December 1998
Creator: Abilene Philharmonic
Object Type: Pamphlet
System: The Portal to Texas History
Achieving 800kW CW Beam Power and Continuing Energy Improvements in CEBAF (open access)

Achieving 800kW CW Beam Power and Continuing Energy Improvements in CEBAF

During the past year, CEBAF at Jefferson Lab has demonstrated its full capacity of sustained 800 kW beam power. All systems performed as intended. The energy stability at the design parameters of 4.0 GeV, 200 muA CW beam was measured to be better than 3x10{sup -5} rms. During the fall of 1997, physics experiments were conducted using 4.4 GeV beam. Having demonstrated the benefits of in situ helium/rf processing of SRF cavities for increasing the energy reach of CEBAF, we began a program of processing all installed cryomodules. This processing has proven effective against the principal gradiation limitation of the SRF cavities in CEBAF: discharges at the cold rf waveguide window, induced by electron field emission in the cavities. Such effects limit approximately half of the cavities. Regular operation at 5.0 GeV is just beginning, and preparations are underway to support 5.5 GeV in early 1999.
Date: December 1, 1998
Creator: Reece, Charlie
Object Type: Article
System: The UNT Digital Library
Acousto-optically tuned isotopic CO{sub 2} lasers for long-range differential absorption LIDAR (open access)

Acousto-optically tuned isotopic CO{sub 2} lasers for long-range differential absorption LIDAR

The authors are developing 2--100 kHz repetition rate CO{sub 2} lasers with milliJoule pulse energies, rapid acousto-optic tuning and isotopic gas mixes, for Differential Absorption LIDAR (DIAL) applications. The authors explain the tuning method, which uses a pair of acousto-optic modulators and is capable of random access to CO{sub 2} laser lines at rates of 100 kHz or more. The laser system is also described, and they report on performance with both normal and isotopic gas mixes.
Date: December 1, 1998
Creator: Thompson, D. C.; Busch, G. E.; Hewitt, C. J.; Remelius, D. K.; Shimada, Tsutomu; Strauss, C. E. M. et al.
Object Type: Article
System: The UNT Digital Library
N-Acylethanolamines and Plant Phospholipase D (open access)

N-Acylethanolamines and Plant Phospholipase D

Recently, three distinct isoforms of phospholipase D (PLD) were identified in Arabidopsis thaliana. PLD α represents the well-known form found in plants, while PLD β and γ have been only recently discovered (Pappan et al., 1997b; Qin et al., 1997). These isoforms differ in substrate selectivity and cofactors required for activity. Here, I report that PLD β and γ isoforms were active toward N-acylphosphatidylethanolamine (NAPE), but PLD α was not. The ability of PLD β and γ to hydrolyze NAPE marks a key difference from PLD α. N-acylethanolamines (NAE), the hydrolytic products of NAPE by PLD β and γ, inhibited PLD α from castor bean and cabbage. Inhibition of PLD α by NAE was dose-dependent and inversely proportional to acyl chain length and degree of unsaturation. Enzyme kinetic analysis suggested non-competitive inhibition of PLD α by NAE 14:0. In addition, a 1.2-kb tobacco (Nicotiana tabacum L.) cDNA fragment was isolated that possessed a 74% amino acid identity to Arabidopsis PLD β indicating that this isoform is expressed in tobacco cells. Collectively, these results provide evidence for NAE producing PLD activities and suggest a possible regulatory role for NAE with respect to PLD α.
Date: December 1998
Creator: Brown, Shea Austin
Object Type: Thesis or Dissertation
System: The UNT Digital Library
An adaptive synchronization protocol for parallel discrete event simulation (open access)

An adaptive synchronization protocol for parallel discrete event simulation

Simulation, especially discrete event simulation (DES), is used in a variety of disciplines where numerical methods are difficult or impossible to apply. One problem with this method is that a sufficiently detailed simulation may take hours or days to execute, and multiple runs may be needed in order to generate the desired results. Parallel discrete event simulation (PDES) has been explored for many years as a method to decrease the time taken to execute a simulation. Many protocols have been developed which work well for particular types of simulations, but perform poorly when used for other types of simulations. Often it is difficult to know a priori whether a particular protocol is appropriate for a given problem. In this work, an adaptive synchronization method (ASM) is developed which works well on an entire spectrum of problems. The ASM determines, using an artificial neural network (ANN), the likelihood that a particular event is safe to process.
Date: December 1, 1998
Creator: Bisset, K.R.
Object Type: Article
System: The UNT Digital Library
[ADVANCE: America`s economic Development Venture for Area Neighborhoods, Communities, and Enterprises]. Quarterly progress report -- Year two (open access)

[ADVANCE: America`s economic Development Venture for Area Neighborhoods, Communities, and Enterprises]. Quarterly progress report -- Year two

The US Department of Energy (DOE) has a mission to foster a secure and reliable energy system that is environmentally and economically sustainable, to be a responsible steward of the Nation`s nuclear weapons, to clean up decommissioned facilities, and to support continued US leadership in science and technology. To effectively utilize and integrate its mission, DOE has created the Regional Environmental Technology and Business Development Office (RETBDO) serving as a Community Reuse Organization, a stakeholder organization, which represents interests and economic concerns of communities surrounding DOE sites that are being closed or reconfigured. RETBDO is a branch office of ADVANCE, a 501(c) (3) non-profit organization established in 1994. The mission of RETBDO is to diversify the economy by creating an environment conductive to improve the representation of minorities and small businesses in the region and to assure fair business participation in major environmental decision-making, technology based start-ups, expansion management, and the attractive of new ventures to the Southwest region, including, bu not limited to, California, Nevada, Utah, Colorado, Arizona, New Mexico, and Texas. This report describes the RETBDO program and its implementation.
Date: December 1, 1998
Creator: McDavid, R.A.
Object Type: Report
System: The UNT Digital Library
Advanced biomolecular materials based on membrane-protein/polymer complexation (open access)

Advanced biomolecular materials based on membrane-protein/polymer complexation

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project was to apply neutron reflectometry and atomic force microscopy to the study of lipid membranes containing proteins. Standard sample preparation techniques were used to produce thin films of these materials appropriate for these techniques. However, these films were not stable, and a new sample preparation technique was required. Toward this goal, the authors have developed a new capability to produce large, freely suspended films of lipid multi-bilayers appropriate for these studies. This system includes a controlled temperature/humidity oven in which the films 5-cm x 5-cm are remotely drawn. The first neutron scattering experiments were then performed using this oven.
Date: December 1, 1998
Creator: Smith, G. S.; Nowak, A. & Safinya, C.
Object Type: Report
System: The UNT Digital Library
Advanced fracture modeling in the Uinta Basin (Utah) for optimized primary and secondary recovery. Final report, September 1998 (open access)

Advanced fracture modeling in the Uinta Basin (Utah) for optimized primary and secondary recovery. Final report, September 1998

The completed study focused on an area fracture-controlled highly unpredictable, fracture-controlled production near the Duchesne Fault Zone, Uinta Basin, in northeastern Utah. Production is seriously influenced by numerous high-angle faults and associated fractures--represented at the surface by a set of parallel, N80{degree}W-trending lineaments, and intricate fracture patterns in outcrop. Specific production is erratic and secondary recovery design is difficult because well-specific structural characterization and local fracture patterns are poorly understood. Furthermore, numerical models to simulate fluid flow in fractured reservoirs were either overly simplistic (did not adequately account for mechanical contrasts between matrix and fractures) or were extremely complex, requiring volumes of data typically not available to the operator. The contractors proposed implementing advanced geological, geomechanical and reservoir engineering methods to recognize and model the complex fracture networks exhibited at the surface and suggested in the shallow subsurface in the Duchesne Fault Zone. The intended methodology was to be developed in a data-limited environment, recognizing that operators in the basin will not have the financial resources or motivation to perform sophisticated and expensive reservoir engineering programs. User-friendly models for permeability, stress, and production using key geological and geophysical data, developed in this study can then be used to determine: economic …
Date: December 1, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Advanced Recyclable Media System{reg_sign}. Innovative technology summary report (open access)

Advanced Recyclable Media System{reg_sign}. Innovative technology summary report

The objective of the Large-Scale Demonstration Project (LSDP) is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory East`s (ANL) Chicago Pile-5 (CP-5) Research Reactor. The purpose of the LSDP is to demonstrate that using innovative and improved deactivation and decommissioning (D and D) technologies from various sources can result in significant benefits, such as decreased cost and increased health and safety, as compared with baseline D and D technologies. This report describes a demonstration of the Advanced Recyclable Media System{reg_sign} technology which was employed by Surface Technology Systems, Inc. to remove coatings from a concrete floor. This demonstration is part of the CP-5 LSDP sponsored by the US Department of Energy (DOE) Office of Science and Technology Deactivation and Decommissioning Focus Area (DDFA). The Advanced Recyclable Media System{reg_sign} (ARMS) technology is an open blast technology which uses a soft recyclable media. The patented ARMS Engineered Blast Media consists of a fiber-reinforced polymer matrix which can be manufactured in various grades of abrasiveness. The fiber media can be remade and/or reused up to 20 times and can clean almost any surface (e.g., metal, wood, concrete, lead) and geometry including corners and the inside of air ducts.
Date: December 1, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Advanced research capabilities for neutron science and technology: Neutron polarizers for neutron scattering (open access)

Advanced research capabilities for neutron science and technology: Neutron polarizers for neutron scattering

The authors describe work on the development of polarized gaseous {sup 3}He cells, which are intended for use as neutron polarizers. Laser diode arrays polarize Rb vapor in a sample cell and the {sup 3}He is polarized via collisions. They describe development and tests of such a system at LANSCE.
Date: December 1998
Creator: Penttila, S. I.; Fitzsimmons, M. R. & Delheij, P. J.
Object Type: Report
System: The UNT Digital Library
Advanced tokamak physics experiments on DIII-D (open access)

Advanced tokamak physics experiments on DIII-D

Significant reductions in the size and cost of a fusion power plant core can be realized if simultaneous improvements in the energy confinement time ({tau}{sub E}) and the plasma pressure (or beta {beta}{sub T} = 2 {mu}{sub 0} < p > /B{sub T}{sup 2}) can be achieved in steady-state conditions with high self driven bootstrap current fraction. In addition, effective power exhaust and impurity and particle control is required. Significant progress has been made in experimentally achieving regimes having the required performance in all of these aspects as well as in developing a theoretical understanding of the underlying physics. The authors have extended the duration of high performance ELMing H-mode plasmas with {beta}{sub N} H{sub iop} {approximately} 10 for 5 {tau}{sub E} ({approximately}1 s) and have demonstrated that core transport barriers can be sustained for the entire 5-s neutral beam duration in L-mode plasmas. Recent DIII-D work has advanced the understanding of improved confinement and internal transport barriers in terms of E x B shear stabilization of micro turbulence. With the aim of current profile control in discharges with negative central magnetic shear, they have demonstrated off-axis electron cyclotron current drive for the first time in a tokamak, finding an …
Date: December 1998
Creator: Taylor, T. S.
Object Type: Article
System: The UNT Digital Library
Advanced Turbine Technology Applications Project (ATTAP) and Hybrid Vehicle Turbine Engine Technology Support project (HVTE-TS): Final summary report (open access)

Advanced Turbine Technology Applications Project (ATTAP) and Hybrid Vehicle Turbine Engine Technology Support project (HVTE-TS): Final summary report

This final technical report was prepared by Rolls-Royce Allison summarizing the multiyear activities of the Advanced Turbine Technology Applications Project (ATTAP) and the Hybrid Vehicle Turbine Engine Technology Support (HVTE-TS) project. The ATTAP program was initiated in October 1987 and continued through 1993 under sponsorship of the US Department of Energy (DOE), Energy Conservation and Renewable Energy, Office of Transportation Technologies, Propulsion Systems, Advanced Propulsion Division. ATTAP was intended to advance the technological readiness of the automotive ceramic gas turbine engine. The target application was the prime power unit coupled to conventional transmissions and powertrains. During the early 1990s, hybrid electric powered automotive propulsion systems became the focus of development and demonstration efforts by the US auto industry and the Department of energy. Thus in 1994, the original ATTAP technology focus was redirected to meet the needs of advanced gas turbine electric generator sets. As a result, the program was restructured to provide the required hybrid vehicle turbine engine technology support and the project renamed HVTE-TS. The overall objective of the combined ATTAP and HVTE-TS projects was to develop and demonstrate structural ceramic components that have the potential for competitive automotive engine life cycle cost and for operating 3,500 hr …
Date: December 1, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Advances in beryllium powder consolidation simulation (open access)

Advances in beryllium powder consolidation simulation

A fuzzy logic based multiobjective genetic algorithm (GA) is introduced and the algorithm is used to optimize micromechanical densification modeling parameters for warm isopressed beryllium powder, HIPed copper powder and CIPed/sintered and HIPed tantalum powder. In addition to optimizing the main model parameters using the experimental data points as objective functions, the GA provides a quantitative measure of the sensitivity of the model to each parameter, estimates the mean particle size of the powder, and determines the smoothing factors for the transition between stage 1 and stage 2 densification. While the GA does not provide a sensitivity analysis in the strictest sense, and is highly stochastic in nature, this method is reliable and reproducible in optimizing parameters given any size data set and determining the impact on the model of slight variations in each parameter.
Date: December 1, 1998
Creator: Reardon, B. J.
Object Type: Report
System: The UNT Digital Library
The Age, Volume 21, Number 12, December 1998 (open access)

The Age, Volume 21, Number 12, December 1998

Monthly publication containing information related to Chambers County, Texas, including current events of the Chambers County Historical Commission, the Wallisville Heritage Park, and the Chambers County historical and genealogical societies; reprinted newspaper articles about county events and citizens; and historical news and records.
Date: December 1998
Creator: Wallisville Heritage Park (Organization)
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Agent-based enterprise integration (open access)

Agent-based enterprise integration

The authors are developing and deploying software agents in an enterprise information architecture such that the agents manage enterprise resources and facilitate user interaction with these resources. The enterprise agents are built on top of a robust software architecture for data exchange and tool integration across heterogeneous hardware and software. The resulting distributed multi-agent system serves as a method of enhancing enterprises in the following ways: providing users with knowledge about enterprise resources and applications; accessing the dynamically changing enterprise; locating enterprise applications and services; and improving search capabilities for applications and data. Furthermore, agents can access non-agents (i.e., databases and tools) through the enterprise framework. The ultimate target of the effort is the user; they are attempting to increase user productivity in the enterprise. This paper describes their design and early implementation and discusses the planned future work.
Date: December 1, 1998
Creator: Berry, N. M. & Pancerella, C. M.
Object Type: Report
System: The UNT Digital Library
Los Alamos National Laboratory case studies on decommissioning of research reactors and a small nuclear facility (open access)

Los Alamos National Laboratory case studies on decommissioning of research reactors and a small nuclear facility

Approximately 200 contaminated surplus structures require decommissioning at Los Alamos National Laboratory. During the last 10 years, 50 of these structures have undergone decommissioning. These facilities vary from experimental research reactors to process/research facilities contaminated with plutonium-enriched uranium, tritium, and high explosives. Three case studies are presented: (1) a filter building contaminated with transuranic radionuclides; (2) a historical water boiler that operated with a uranyl-nitrate solution; and (3) the ultra-high-temperature reactor experiment, which used enriched uranium as fuel.
Date: December 1, 1998
Creator: Salazar, M. D.
Object Type: Article
System: The UNT Digital Library
Alkaline-Side Extraction of Cesium from Savannah River Tank Waste Using a Calixarene-Crown Ether Extractant (open access)

Alkaline-Side Extraction of Cesium from Savannah River Tank Waste Using a Calixarene-Crown Ether Extractant

Results are presented supporting the viability of the alkaline-side CSEX process as a potential replacement for the In-Tank Precipitation process for removal of cesium from aqueous high-level waste (HLW) at the Savannah River Site (SRS). Under funding from the USDOE Efficient Separations and Crosscutting program, a flowsheet was suggested in early June of 1998, and in the following four months, this flowsheet underwent extensive testing, both in batch tests at ORNL and ANL and in two centrifugal-contactor tests at ANL. To carry out these tests, the initial ESP funding was augmented by direct funds from Westinghouse Savannah River Corporation. The flowsheet employed a solvent containing a calixarene-crown hybrid compound called BoBCalixC6 that was invented at ORNL and can now be obtained commercially for government use from IBC Advanced Technologies. This special extractant is so powerful and selective that it can be used at only 0.01 M, compensating for its expense, but a modifier is required for use in an aliphatic diluent, primarily to increase the cesium distribution ratio D{sub Cs} in extraction. The modifier selected is a relatively economical fluorinated alcohol called Cs3, invented at ORNL and so far available. only from ORNL. For the flowsheet, the modifier is used …
Date: December 1, 1998
Creator: Bonnesen, P. V.; Delmau, L. H.; Haverlock, T. J. & Moyer, B. A.
Object Type: Report
System: The UNT Digital Library
Alpha detection on moving surfaces (open access)

Alpha detection on moving surfaces

Both environmental restoration (ER) and decontamination and decommissioning (D and D) require characterization of large surface areas (walls, floors, in situ soil, soil and rubble on a conveyor belt, etc.) for radioactive contamination. Many facilities which have processed alpha active material such as plutonium or uranium require effective and efficient characterization for alpha contamination. Traditional methods for alpha surface characterization are limited by the short range and poor penetration of alpha particles. These probes are only sensitive to contamination located directly under the probe. Furthermore, the probe must be held close to the surface to be monitored in order to avoid excessive losses in the ambient air. The combination of proximity and thin detector windows can easily cause instrument damage unless extreme care is taken. The long-range alpha detection (LRAD) system addresses these problems by detecting the ions generated by alpha particles interacting with ambient air rather than the alpha particle directly. Thus, detectors based on LRAD overcome the limitations due to alpha particle range (the ions can travel many meters as opposed to the several-centimeter alpha particle range) and penetrating ability (an LRAD-based detector has no window). Unfortunately, all LRAD-based detectors described previously are static devices, i.e., these detectors …
Date: December 1, 1998
Creator: MacArthur, D.; Orr, C. & Luff, C.
Object Type: Article
System: The UNT Digital Library
Alternative fuels and chemicals from synthesis gas (open access)

Alternative fuels and chemicals from synthesis gas

A DOE/PETC funded study was conducted to examine the use of a liquid phase mixed alcohol synthesis (LPMAS) plant to produce gasoline blending ethers. The LPMAS plant was integrated into three utilization scenarios: a coal fed IGCC power plant, a petroleum refinery using coke as a gasification feedstock, and a standalone natural gas fed partial oxidation plant. The objective of the study was to establish targets for the development of catalysts for the LPMAS reaction. In the IGCC scenario, syngas conversions need only be moderate because unconverted syngas is utilized by the combined cycle system. A once through LPMAS plant achieving syngas conversions in the range of 38--49% was found to be suitable. At a gas hourly space velocity of 5,000 sL/Kg-hr and a methanol:isobutanol selectivity ratio of 1.03, the target catalyst productivity ranges from 370 to 460 g iBuOH/Kg-hr. In the petroleum refinery scenario, high conversions ({approximately}95%) are required to avoid overloading the refinery fuel system with low Btu content unconverted syngas. To achieve these high conversions with the low H{sub 2}/CO ratio syngas, a recycle system was required (because of the limit imposed by methanol equilibrium), steam was injected into the LPMAS reactor, and CO{sub 2} was removed …
Date: December 1, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library