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Preliminary evaluation of an electromagnetic concept for simultaneous NO sub x /SO sub 2 removal

Description: Western Research Institute is developing concepts to use radio frequency (RF) energy to remove NO and SO{sub 2} from combustion flue gas. Char produced from the mild gasification of coal can be heated with RF energy to react with sulfur oxides and nitric oxide at low temperatures and pressures using RF energy to form carbon dioxide, carbon monoxide, elemental sulfur, and nitrogen.
Date: December 1, 1990
Creator: Grimes, R.W.
Partner: UNT Libraries Government Documents Department

Study of the combustion of low rank coal in a fluidized bed

Description: This report describes the results of preliminary combustion tests performed with Eagle Butte Coal in a bubbling, fluidized-bed combustion system. The system was designed for the combustion of low-rank coals and industrial wastes. The work, as proposed, was aimed at not only the evaluation of co-firing of waste material with coal, but also at developing modifications to first generation bubbling bed designs to improve the combustion performance during co-firing. However, the funding for the work was redirected and the combustion tests were suspended soon after the shakedown testing was completed. Consequently, this report describes the results of the tests completed prior to the redirection of the effort and funding. A total of 33 combustion tests were performed in a 6-inch diameter fluidized-bed combustor. Oxygen concentrations were measured at two points in the system; the vent line and at the interface between the fluid bed and the freeboard. These measurements provided a measure of the amount of conversion of coal within the fluidized bed compared to the conversion in the freeboard region. Typically, 75 to 80% of the conversion occurred within the bed. Several experiments were performed in which special bed internals were placed in the bed. The internals were designed to reduce bubble size in the bed thus increasing the surface area of the bubbles and hence promoting oxygen diffusion into the emulsion phase.
Date: September 1, 1991
Creator: Glaser, R. & Grimes, R.W.
Partner: UNT Libraries Government Documents Department

OPTIMIZATION OF CERAMICS FOR NUCLEAR FUEL AND WASTE FORM APPLICATIONS

Description: We have used atomistic computer simulations and ion beam irradiations to examine radiation damage accumulation in oxides and nitrides. We have developed contour energy maps for oxides via computer simulations, to predict the effects of structure and chemical composition on radiation-induced atomic disorder, defect migration, and swelling. Ion irradiation damage experiments have been performed on fluorite and pyrochlore-structured oxide ceramics, as well as alkali halide-structured nitrides, to examine trends and to test the predictions from computer models. This presentation will examine both theoretical predictions and experimental results regarding radiation damage behavior in ceramics intended for nuclear fuel and waste form applications.
Date: January 1, 2001
Creator: Sickafus, K. (Kurt E.) & Grimes, R. W. (Robin W.)
Partner: UNT Libraries Government Documents Department

Predicting the radiation tolerance of oxides

Description: We have used atomistic computer simulations and ion beam irradiations to examine radiation damage accumulation in multicomponent oxides, We have developed contour energy maps via computer simulations to predict the effects of oxide structure and chemical composition on radiation-induced atomic disorder, defect migration, and swelling. Ion irradiation damage experiments have been perfonned on, pyrochlore and fluorite-structured oxide ceramics to test the predictions from computer models.
Date: January 1, 2001
Creator: Sickafus, K. (Kurt E.) & Grimes, R. W. (Robin W.)
Partner: UNT Libraries Government Documents Department

Preparation for upgrading western subbituminous coal

Description: The objective of this project was to establish the physical and chemical characteristics of western coal and determine the best preparation technologies for upgrading this resource. Western coal was characterized as an abundant, easily mineable, clean, low-sulfur coal with low heating value, high moisture, susceptibility to spontaneous ignition, and considerable transit distances from major markets. Project support was provided by the Morgantown Energy Technology Center (METC) of the US Department of Energy (DOE). The research was conducted by the Western Research Institute, (WRI) in Laramie, Wyoming. The project scope of work required the completion of four tasks: (1) project planning, (2) literature searches and verbal contacts with consumers and producers of western coal, (3) selection of the best technologies to upgrade western coal, and (4) identification of research needed to develop the best technologies for upgrading western coals. The results of this research suggest that thermal drying is the best technology for upgrading western coals. There is a significant need for further research in areas involving physical and chemical stabilization of the dried coal product. Excessive particle-size degradation and resulting dustiness, moisture reabsorption, and high susceptibility to spontaneous combustion are key areas requiring further research. Improved testing methods for the determination of equilibrium moisture and susceptibility to spontaneous ignition under various ambient conditions are recommended.
Date: November 1, 1990
Creator: Grimes, R.W.; Cha, C.Y. & Sheesley, D.C.
Partner: UNT Libraries Government Documents Department

Western oil shale conversion using the ROPE copyright process

Description: Western Research Institute (WRI) is continuing to develop the Recycle Oil Pyrolysis and Extraction (ROPE) process to recover liquid hydrocarbon products from oil shale, tar sand, and other solid hydrocarbonaceous materials. The process consists of three major steps: (1) pyrolyzing the hydrocarbonaceous material at a low temperature (T {le} 400{degrees}C) with recycled product oil, (2) completing the pyrolysis of the residue at a higher temperature (T > 400{degrees}C) in the absence of product oil, and (3) combusting the solid residue and pyrolysis gas in an inclined fluidized-bed reactor to produce process heat. Many conventional processes, such as the Paraho and Union processes, do not use oil shale fines (particles smaller than 1.27 cm in diameter). The amount of shale discarded as fines from these processes can be as high as 20% of the total oil shale mined. Research conducted to date suggests that the ROPE process can significantly improve the overall oil recovery from western oil shale by processing the oil shale fines typically discarded by conventional processes. Also, if the oil shale fines are co-processed with shale oil used as the heavy recycle oil, a better quality oil will be produced that can be blended with the original shale oil to make an overall produce that is more acceptable to the refineries and easier to pipeline. Results from tests conducted in a 2-inch process development unit (PDU) and a 6-inch bench-scale unit (BSU) with western oil shale demonstrated a maximum oil yield at temperatures between 700 and 750{degrees}F (371 and 399{degrees}C). Test results also suggest that the ROPE process has a strong potential for recovering oil from oil shale fines, upgrading shale oil, and separating high-nitrogen-content oil for use as an asphalt additive. 6 refs., 10 figs., 11 tabs.
Date: December 1, 1989
Creator: Cha, C.Y.; Fahy, L.J. & Grimes, R.W.
Partner: UNT Libraries Government Documents Department

Defects in Ga, Cr, and In-doped CoO

Description: From simulation, trivalent cations, Ga(3+), Cr(3+), Co(3+) and In(3+), bind with Co vacancy to form singly pairs with binding energies of about 0.7 to 0.8 eV. These binding energies are in reasonable agreement with experimental measurement of about 0.5 eV. In ion prefers the second nearest neighbor position from a Co vacancy, while other cations prefer the third nearest neighbor sites. Two cations can also forma triplet with a Co vacancy with binding energies of about 1.2 to 1.5 eV. These valves are in fair agreement with the 0.8 to 1.1 eV measured from the tracer diffusion experiments.
Date: July 1, 1995
Creator: Chen, S.P.; Yan, M.; Grimes, R.W. & Vyas, S.
Partner: UNT Libraries Government Documents Department

Defects and metastable structures of MgAl{sub 2}O{sub 4}

Description: This paper presents calculated properties of normal and inverse spinel structures of MgAl{sub 2}O{sub 4} and of point defects in the spinel structure. These results provide information for further study of possible metastable states. Calculated properties of ``amorphous`` structure are also presented. Atomistic simulations show that in MgAl{sub 2}O{sub 4} spinel structure, the exchange of an Mg{sup 2+} ion with an Al{sup 3+} ion has the lowest energy increase, 0. 92eV/atom. The Schottky defect increases the energy by 3.71 eV/atom. Frenkel defects are difficult to form, increasing the energy at least 4.59eV/atom for the Mg{sup 2+} Frenkel defect. Proposed rock salt structure of MgAl{sub 2}O{sub 4} has smaller volume and larger Young modulus, and the amorphosu state has larger volume and smaller Young modulus than the MgAl{sub 2}O{sub 4} spinel.
Date: July 1, 1995
Creator: Chen, S.P.; Yan, M.; Grimes, R.W.; Vyas, S. & Gale, J.D.
Partner: UNT Libraries Government Documents Department