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Steam pretreatment for coal liquefaction. Sixth quarterly report, 1 January 1992--31 March 1992

Description: Steam pretreatment is the reaction of coal with steam at temperatures well below those usually used for solubilization. The objective of the proposed work is to test the application of steam pretreatment to coal liquefaction. Conversion of the autoclave apparatus to rapid heating liquefaction was carried out this quarter following redesign of the coal slurry injection system. The modified equipment and procedure was tested in a simulated liquefaction run without coal. Initial tests of slurried {minus}20 mesh coal showed too rapid settling for successful operation. Coal ground to pass 200 mesh proved suitable, and a impact grinder was put into operation to grind the material under an inert atmosphere. A batch of Illinois No. 6 coal for the, first rapid heating liquefaction tests has been prepared and stored under inert gas. The steam pretreatment of {alpha}-benzylnaphthyl ether was carried out using stainless steel and glass lined reactors. A preparative scale procedure for product separation was developed. The major components were identified and the average product distribution determined for both types of reactors. Pretreatment of {alpha}-naphthylmethyl phenyl ether was also carried out using stainless steel and glass-lined reactors. Separation and analysis of the products has been started. The major components have been identified. Analyses and identification of the components will be continued next quarter.
Date: June 28, 1992
Creator: Graff, R.A. & Balogh-Nair, V.
Partner: UNT Libraries Government Documents Department

Methane coupling by membrane reactor. Quarterly technical progress report, December 25, 1995--March 24, 1996

Description: Methane oxidative coupling experiments were conducted in a packed-bed reactor using La/MgO catalyst. The results were in agreement with those reported in the literature. Oxygen permeability through an oxygen-conductive dense membrane was measured. The oxygen permeability was about 20% of the reported values and increased with the sweep flow rate of helium in the tube side. Blank runs under methane coupling conditions were carried out with no catalyst packed in the dense membrane tube. Nearly 100% CO{sub 2} selectivity was observed, suggesting that the membrane material is a facile total oxidation catalyst. After the experiment the membrane tube was analyzed by scanning electron microscopy.
Date: May 28, 1996
Partner: UNT Libraries Government Documents Department

Dielectron production in nucleus {plus} nucleus collisions at 1.05 GeV/nucleon

Description: Measurements of dielectron production in heavy-ion collisions are valuable probes into the dynamics of the collision process. While the hadronic participants of the collision are subject to strong final state interactions, the coupling of the electron-positron pair to the collision medium is electromagnetic. Dielectrons, therefore suffer little rescattering leaving the interaction and can retain information about their production origins, probing even the early stages in the evolution of the collision. The DiLepton Spectrometer (DLS) collaboration`s original measurements of dielectron production established the existence of the signal at Bevalac energies. The 1992- 93 DLS measurements in nucleus+Nucleus collisions at a kinetic beam energy of 1.05 {ital GeV/nucleon} are the subject of this presentation.
Date: June 28, 1996
Creator: Porter, R.J.; Beedoe, S.; Bougteb, M.; Hallman, T. & Wang, Z.F.
Partner: UNT Libraries Government Documents Department

Surface Inspection Machine Infrared (SIMIR). Final CRADA report

Description: This Cooperative Research and Development Agreement was a one year effort to make the surface inspection machine based on diffuse reflectance infrared spectroscopy (Surface Inspection Machine-Infrared, SIMIR), being developed by Surface Optics Corporation, perform to its highest potential as a practical, portable surface inspection machine. The design function of the SIMIR is to inspect metal surfaces for cleanliness (stains). The system is also capable of evaluating graphite-resin systems for cure and heat damage, and for measuring the effects of moisture exposure on lithium hydride, corrosion on uranium metal, and the constituents of and contamination on wood, paper, and fabrics. Over the period of the CRADA, extensive experience with the use of the SIMIR for surface cleanliness measurements have been achieved through collaborations with NASA and the Army. The SIMIR was made available to the AMTEX CRADA for Finish on Yarn where it made a very significant contribution. The SIMIR was the foundation of a Forest Products CRADA that was developed over the time interval of this CRADA. Surface Optics Corporation and the SIMIR have been introduced to the chemical spectroscopy on-line analysis market and have made staffing additions and arrangements for international marketing of the SIMIR as an on-line surface inspection device. LMES has been introduced to a wide range of aerospace applications, the research and fabrication skills of Surface Optics Corporation, has gained extensive experience in the areas of surface cleanliness from collaborations with NASA and the Army, and an extensive introduction to the textile and forest products industries. The SIMIR, marketed as the SOC-400, has filled an important new technology need in the DOE-DP Enhanced Surveillance Program with instruments delivered to or on order by LMES, LANL, LLNL, and Pantex, where extensive collaborations are underway to implement and improve this technology.
Date: February 28, 1997
Creator: Powell, G.L.; Neu, J.T. & Beecroft, M.
Partner: UNT Libraries Government Documents Department

Development of high temperature catalytic membrane reactors. Final report

Description: Early efforts in 1992 were focused on relocating the membrane reactor system from Alcoa Separation Technology, Inc.`s Warrendale, PA facility to laboratory space at the University of Pittsburgh Applied Research Center (UPARC) in Harmarville, PA following the divestiture of Alcoa Separations to US Filter, Inc. Reconstruction was completed in March, 1992, at which time the reactor was returned to ethylbenzene dehydrogenation service. Efforts on ethylbenzene dehydrogenation to styrene focused on optimizing hybrid reactor performance relative to packed bed operation. Following this, the reactor system was converted to isobutane dehydrogenation. Experimentation on isobutane dehydrogenation focused on design of an inert reactor, evaluation of commercial light alkane dehydrogenation catalysts, and modeling of membrane reactor performance relative to the performance of a packed bed reactor. This report summarizes the effort in 1992 on the development of ceramic membranes as dehydrogenation reactors. In addition, outside interactions on behalf of this investigation are discussed.
Date: February 28, 1992
Creator: Gallaher, G.; Gerdes, T. & Gregg, R.
Partner: UNT Libraries Government Documents Department

Two-dimensional synthesis: Ultrathin porous membranes. Final report, December 1, 1993--November 30, 1996

Description: The proposed proof of concept has been accomplished. We have synthesized an ultrathin (7 {angstrom}) covalent molecular grid of the proposed type, composed of 2.5 nm x 2.5 run squares with 1.5 nm x 1. 5 nm square openings, we have demonstrated that it is sturdy (boiling with alcoholic HCl and surface-to-surface transfer), and we have obtained its spectral and STM characterization. The synthesis was based on the originally proposed two-dimensional linear cross-coupling of oriented molecular connectors mounted on pedestals that were constrained to a two-dimensional liquid mercury surface, but the molecules actually used in the successful experiment were different from those intended originally. In this first attempt, only small sheets of the grid were made (up to 0.15 {mu} x 0.15 {mu}), and they did not have long-range order. Both of these problems were undoubtedly caused by the use of an irreversible coupling reaction in the polymerization process, and by the use of a coupler that was not strictly linear and thus permitted easy formation of defects (pentagons instead of squares, etc.). Neither of these limitations are inherent, and we have already submitted research proposals in which we outline how we propose to do the polymerization in a reversible way, yet produce a sturdy polymeric grid, and suggest chemical structures for linear couplers. Patent protection for these results has been applied for by the University of Colorado (following up on a previous conceptual patent already granted) and several publications have been written.
Date: May 28, 1997
Creator: Michl, J.
Partner: UNT Libraries Government Documents Department

Aqueous oxidation of trichloroethene (TCE): a kinetic and thermodynamic analysis

Description: An empirical kinetic rate law was determined for the aqueous oxidation of trichloroethene (TCE). By measuring both the rate of disappearance of TCE and the rate of appearance of carbon dioxide and chloride ion, mass balances were monitored to confirm that `mineralization` was the ultimate reaction. Dilute buffer solutions were used to fix pH and stoichiometrically sufficient amounts of dissolved oxygen were used to make the reactions zero-order in oxygen. Using standard chemical kinetic methods, two orders of magnitude were spanned in initial TCE concentration and used in the resulting double-log plot vs. initial rate (regressed using both linear and polynomial fits) to determine the rate constant and `true` reaction order (i.e., with respect to;concentration, not time). By determining rate constants over the temperature interval 343-373K, an Arrhenius activation energy was determined for the reaction. A study was made of the potential effect of buffer ligand concentration and type (phosphate, borate, acetate, carbonate, sulfate), ionic strength, specific electrolytes, and pH on the rate of TCE. The aqueous oxidation reaction rate was found to be pH dependent over the pH range pH 2 to pH 1O and strongly inhibited by high dissolved bromide concentration. The equilibrium aqueous solubilities of TCE was determined by making reversed measurements from 294-390K. Together with the kinetic rate law, the thermodynamic data are required to develop in situ thermal remedial techniques for TCE and to model the reactive transport behavior of TCE in the subsurface.
Date: February 28, 1998
Creator: Knauss, K. G., LLNL
Partner: UNT Libraries Government Documents Department

Multiphoton ionization of ions, neutrals, and clusters. Progress report

Description: Scientific results are summarized from a three year research program on multiphoton ionization in aromatic molecules, clusters, and their ions. As originally proposed, the studies elucidated a new cluster ionization mechanism, characterized properties of long range intermolecular interactions, and investigated electronic transitions of aromatic cations cooled in a supersonic beam. The studies indicate that the new cluster ionization mechanism is highly efficient and dominates conventional 1 + 1 resonant ionization. In the case of the dimer of the large aromatic molecule fluorene, the results suggest that excimer formation competes with a direct ionization process. Highly selective excitonic spectra have been identified for several cluster species.
Date: June 28, 1991
Creator: Wessel, J.
Partner: UNT Libraries Government Documents Department

Estimation of Total Error in DWPF Reported Radionuclide Inventories

Description: This report investigates the impact of random errors due to measurement and sampling on the reported concentrations of radionuclides in DWPF`s filled canister inventory resulting from each macro-batch. The objective of this investigation is to estimate the variance of the total error in reporting these radionuclide concentrations.
Date: February 28, 1995
Creator: Edwards, T.B.
Partner: UNT Libraries Government Documents Department

Multiphoton ionization of ions, neutrals, and clusters. Final report

Description: A multiyear research program investigating molecular detection methods based on multiphoton spectroscopy has been completed under DOE sponsorship. A number of new laser-based spectroscopic methods were developed and applied to a variety of aromatic hydrocarbons, including monomer and cluster species. The objectives of sensitivities approaching single molecule detection combined with high selectivity were achieved. This report references the status of the field at the beginning of this work and summarizes the significant progress during the period from 1987 onward. Detailed scientific findings from the studies are presented in the published literature referenced throughout this report.
Date: December 28, 1995
Creator: Wessel, J.
Partner: UNT Libraries Government Documents Department

Distributed measurements of tracer response on packed bed flows using a fiberoptic probe array. Final report

Description: Scale-up of packed bed processes, particularly those involving chromatographic separations, is made difficult by a seemingly inevitable increase in dispersion due to packing nonuniformity. To provide a suitable characterization, the authors measured the spatial distribution of dispersion and mixing in packed beds of uniform impervious spherical glass particles by a tracer impulse technique. The key feature in this work is the use of a fiberoptic array at the exit plane to obtain a time-resolved spatially distributed response. All experiments were in the creeping flow regime. The authors used a fluorescent dye with laser excitation through the fiber terminations in the bed. The fluoresced radiation was collected through the same fibers. They analyzed the data by the use of indices of the extent of micromixing based on Danckwerts`s original degree of segregation and an additional index of structural uniformity. The computations involve a moment analysis of the individual and average probe responses. A simple model gives expressions for the indices in terms of the Peclet number and is shown to provide a useful limiting case. The computed indices are also shown to be very sensitive to adsorption of dye on the surface of the glass. However, for some of the experiments with the largest spheres using Pyrex glass, the effects of adsorption are indiscernible. This technique successfully separates the contribution of micromixed fluid to overall bed dispersion from the contribution due to the transverse variation of the flow residence time.
Date: October 28, 1994
Creator: Jones, M.C.; Nassimbene, R.; Wolfe, J. & Frederick, N.
Partner: UNT Libraries Government Documents Department

Effect of Palladium Form on Tetraphenylborate Decomposition Rate

Description: Palladium catalyzes the decomposition of tetraphenylborate in alkaline solutions. Researchers postulate several decomposition mechanisms that differ in the form of the palladium catalyst. Potential forms include solid and soluble, different soluble species (such as aqueous or organic soluble), and different oxidation states (i.e., 0, II, and IV). Initial tests measured the reactivity and distribution of four Pd forms in tetraphenylborate slurries.
Date: April 28, 1998
Creator: Walker, D. D.
Partner: UNT Libraries Government Documents Department

Oxygenated octane enhancers: Syngas to isobutylene. Technical progress report No. 18, July 1, 1995--September 30, 1995

Description: The goals of this project are to develop a catalyst and process for the conversion of syngas to isobutanol. The research will identify and optimize key catalyst and process characteristics. In addition, the commercial potential of the new process will be evaluated by an economic analysis. The combination of the best conditions from independent process variable studies has afforded the best performance to date with the 2% Pt on Zn/Mn/Zr oxide catalyst. At 325{degrees}C, 300 psig, 7/1 MeOH/EtOH molar feed ratio and 1 hr{sup {minus}1} MEOH WH 22.20% selectivity to isobutanol is obtained with 55 and 97% conversions of methanol and ethanol, respectively. The results of this run will be used as a basis for the economic evaluation of a higher alcohols process. The ability of the Pt on Zn/Mn/Zr oxide catalyst to produce isobutanol in the presence of high partial pressures of H{sub 2} has been investigated. Such operation could allow the integration of a higher alcohol process with a conventional methanol synthesis plant by placing it within the methanol synthesis recycle loop. However, higher alcohol yields are severely suppressed by a large H{sub 2} cofeed, even at pressures as low as 50 psig. Elimination of the H{sub 2} co-feed did not restore the performance of the catalyst to expected levels, suggesting that the high H{sub 2} partial pressure has caused degradation of the catalyst. No further testing of high H{sub 2} conditions is planned. The commercial system has been modeled using the product slate obtained from the ``best case`` pilot plant conditions combined with the assumption of equilibrium CO, H{sub 2}O, CO{sub 2} and H{sub 2} makes. A stand-alone isobutanol plant processing 500 MT/D synthesis gas-derived methanol can yield 92 MT/D isobutanol and additional 20 MT/D assuming complete hydrogenation of isobutyraldehyde which accumulates in the liquid recycle loop. ...
Date: March 28, 1996
Creator: Barger, P.T. & Spehlmann, B.C.
Partner: UNT Libraries Government Documents Department

Direct catalytic conversion of methane and light hydrocarbon gases. Quarterly report No. 3, April 16--July 15, 1987

Description: The goal of this research is to develop catalysts that directly convert methane and light hydrocarbons to intermediates that can, as economics dictate, be subsequently converted either to liquid fuels or value-added chemicals. In this program we are exploring two approaches to developing such catalysts. The first approach consists of developing advanced catalysts for reforming methane. We will prepare the catalysts by reacting organometallic complexes of transition metals (Fe, Ru, Rh, and Re) with zeolitic and rare-earth-exchanged zeolitic supports to produce surface-confined metal complexes in the zeolite pores. Our second approach entails synthesizing the porphyrin and phthalocyanine complexes of Cr, Mn, Ru, Fe, and/or Co within the pores of zeolitic supports for use as selective oxidation catalysts for methane and light hydrocarbons. During this reporting period, we concentrated on synthesizing and testing methane oxidation catalysts using the automated GC sampling system. We modified our preparation method of zeolite-encapsulated phthalocyanines (PC). The catalysts have higher complex loading, and the uncomplexed metal ions were back-exchanged by sodium ions (to remove any uncomplexed metal ions). Four metal ions were used: cobalt, iron, ruthenium, and manganese. We also synthesized four zeolite-encapsulated tetraphenylporphyrin (TPP) complexes using the same metals. These catalysts were tested for methane oxidation in the temperature range from 300{degrees} to 500{degrees}C at 50 psig pressure. The RUPC, COTPP, and MNTPP showed activity toward the formation of methanol. The RUPC zeolite gave the best methanol yield. The methane conversion was 4.8%, and the selectivity to methanol is 11.3% at 375{degrees}C. Again, the major products are carbon dioxide and water in every catalyst we tested during this reporting period.
Date: August 28, 1987
Creator: Wilson, R.B. Jr. & Chan, Yee Wai
Partner: UNT Libraries Government Documents Department

A theoretical comparison of evolutionary algorithms and simulated annealing

Description: This paper theoretically compares the performance of simulated annealing and evolutionary algorithms. Our main result is that under mild conditions a wide variety of evolutionary algorithms can be shown to have greater performance than simulated annealing after a sufficiently large number of function evaluations. This class of EAs includes variants of evolutionary strategie and evolutionary programming, the canonical genetic algorithm, as well as a variety of genetic algorithms that have been applied to combinatorial optimization problems. The proof of this result is based on a performance analysis of a very general class of stochastic optimization algorithms, which has implications for the performance of a variety of other optimization algorithm.
Date: August 28, 1995
Creator: Hart, W.E.
Partner: UNT Libraries Government Documents Department

Selective transformation of carbonyl ligands to organic molecules. Final report, November 15, 1992--November 14, 1995

Description: The hydrosilation chemistry involving manganese acyl complexes (L)(CO){sub 4}MnC(O)R (L = CO, PPh{sub 3}; R = CH{sub 3}, Ph) as substrates and as precatalysts has been developed. Results of a kinetics study on the (CO){sub 5}Mn(p-toluoyl)-catalyzed SiH/SiD exchange between DSiMe{sub 2}Ph and HSiMe{sub 2}Et established that coordinatively unsaturated (CO){sub 4}MnSiR{sub 3}, the active catalyst, sequentially adds one substrate silane and then releases a product silane. Results of this mechanistic study afforded the working hypothesis for much of our current research: manganese acyl-hydrosilane mixtures generate unsaturated silyl complexes, which are active catalysts for the hydrosilation of a variety of substrates. These active catalysts, (CO){sub 4}MnSiR{sub 3}, also were generated through photolysis of (CO){sub 5}MnSiR{sub 3}.
Date: February 28, 1996
Creator: Cutler, A.R.
Partner: UNT Libraries Government Documents Department

Apparatus and method for two-stage oxidation of wastes

Description: An apparatus and method for oxidizing wastes in a two-stage process. The apparatus includes an oxidation device, a gas-liquid contacting column and an electrocell. In the first stage of the process, wastes are heated in the presence of air to partially oxidize the wastes. The heated wastes produce an off-gas stream containing oxidizable materials. In the second stage, the off-gas stream is cooled and flowed through the contacting column, where the off-gas stream is contacted with an aqueous acid stream containing an oxidizing agent having at least two positive valence states. At least a portion of the oxidizable materials are transferred to the acid stream and destroyed by the oxidizing agent. During oxidation, the valence of the oxidizing agent is decreased from its higher state to its lower state. The acid stream is flowed to the electrocell, where an electric current is applied to the stream to restore the oxidizing agent to its higher valence state. The regenerated acid stream is recycled to the contacting column.
Date: September 28, 1993
Creator: Fleischman, S. D.
Partner: UNT Libraries Government Documents Department