16
Fuel science
and technology (fundamental
science, analysis, instrumentation)
Depolymerization of low-rank coal by extracellular 97104253 fungal enzyme systems. Ill. In vitro depolymerization of coal humic acids by a crude preparation of manganese peroxidase from the white-rot fungus Nematoloma frowardii b19 Hofrichter, M. and Fritsche, W. Appl. Microbial. Riotechnol., 1997, 47, (S), 566-571. A manganese peroxidase (I) preparation from the white-rot fungus, Nemntoloma frowardii b19 was used to study the in vitro depolymerization of humic acids derived from German lignite. The HzOz required was continuously generated by glucose oxidase. I depolymerized high-molecular weight humic acids by forming fulvic acid-like compounds. This process was accompanied by the decolorization of the dark-brown humic acid fraction soluble in alkali solutions and by the yellowish colouring of the fraction of acid-soluble fulvic-acid-like compounds. I was proved to be highly stable; even after an in vitro reaction time of 7 days in the presence of humic acids; < 10% loss in total oxidizing activity was detectable. Determination of kerogen type by using DSC and 97104254 TG analysis Skala, D. et al. J. Therm. Anal., 1997, 49, (2), 745-753. Eight different samples of oil shale kerogen cone (KC) were investigated with regard to their pyrolysis and oxidation rates. DSC analysis was the method used. Recently performed thermogravimetric studies (TG and DTG) with the same samples of KC indicated that the activation energy of the pyrolysis of specific KCs increases with increasing paraffinic structure. An opposite effect was determined in the case of KC oxidation. In this study, using the standard ASTM E-698 method based on the determined temperature at which the maximum heat effect could be observed, an activation energy for the pyrolysis, as well as for the oxidation process was determined. In addition it was successfully correlated with the content of paraffinic structure of KC. The higher content of paraffinic structure in KCs therefore indicates that higher values of the activation energy could be determined either in the case of pyrolysis or oxidation followed by DSC analysis. Development and economic analysis of Army coal 97104255 conversion program Lin, M. et al. Proc. Int. Tech. Conf. Coal Util, Fuel Syst., 1994, 19,365-376. Certain legal requirements compel the U.S. Department of Defense (DOD) to increase coal utilization at its facilities. The development of the Army coal conversion programme is reported. The first two phases of the programme developed computerized evaluation programmes and plant conversion strategies, and conducted economic analyses for converting large Army gas-/oil-fired plants to coal. The third phase, coal technology support, will create an intelligent computer program to assist coal plant operation and maintenance. The development of generic image processing 97104256 algorithms for froth characterization Sadr-Kazemi, N. and Cilliers, J. J. Jubilee Res. Event, Two-Day Symp., 1997, 2, 1137-1140. This research attempts to provide an understanding of the structure of a coal flotation froth and to relate this to the mechanism of selective adhesion of fine coal particles to bubbles. To this end, image processing was implemented to characterize the surface properties of a flowing froth. The algorithm developed consists of a robust pre-processing technique followed by a more conventional edge detection method. It has been found to successfully isolate bubble edges for a variety of flotation froths. Development of the quality assurance system and 97104257 accreditation of the chemical testing laboratory of the Austrian Dreukraftwerke Power Plant Works Schongrundner, W. and Rapp, K. VGB Tech. Ver. Grosskraftwerksbetr., [Tagungsber.] VGE-TB, 1996, (VGB-TB 432, VGB-Konferenz ‘Chemie im Kraftwerk 1996’) Paper V14, 30 pp. (In German) The Austrian Draukraftwerke Power Plant Works operates three heating installations, ten river power plants, two storage power plants as well as two smaller biomass boilers. These different primary energy sources place a high demand on chemical analysis. Topics discussed are the global concept for certification and testing, development and content of the EN 45001 norms, the quality concept in analysis chemistry, the quality assurance system of the chemical testing laboratory of the power plant works, and the advantages and disadvantages of accreditation. Economic comparisons of state of the art wet and 97104258 dry FGD systems Achenbach, D. A. Proc. Int. Tech. Conf. Coal Util. Fuel Syst., 1993, 18, 419-430. The amount of SOz removed from flue gas by lime in a coal-fired power plant exceeded 90%. Effects of jet momentum distribution on thermal 97104259 characteristics of co-swirling flames Marshall, A. W. Proc. Int. Tech. Conf. Coal Util. Fuel Syst., 1996, 21, 221232. This investigation studies the thermal characteristics of flames with various axial and angular inlet momentum distributions. These flames were stabilized with a co-annular swirl burner having two annular air jets and a central fuel pipe. The heat loading, the Reynolds number, and the overall
358
Fuel and Energy Abstracts
September
1997
equivalence ratio were held constant while the swirl and flow distribution were systematically varied between the two air jets. Seven strikingly different unconfined flames were created in this manner. A fine wire thermocouple measured temperatures. A digital compensation technique was used to decrease the thermocouple response time. Fluctuating temperature measurements were obtained in the recirculation zone, shear layer, and post combustion regions. The total swirl number and the total equivalence ratio were insufficient in characterizing thermal effects in these flames. Consequently, additional governing parameters are presented which more accurately describe behaviour in co-annular burners. These parameters account for the swirl number in each jet, the relative jet strength, and the local stoichiometry at the inlet of the burner. Energy test procedures for appliances 97104260 Meier, A. K. and Hill, J. E. Energy and Buildings, 1997, 26, (I), 23-33. An energy test procedure is the technical foundation for all energy efficiency standards. It provides manufacturers, regulatory authorities, and consumers a way of consistently evaluating energy use. The ideal test procedure reflects actual usage conditions without compromising reliability and cost-effectiveness. Unfortunately, because these goals are contradictory, every test procedure is a compromise. Energy test procedures exist for a wide range of appliances and often each country has its own unique test procedure. The procedures for refrigerators, furnaces, air conditioners, clothes washers, and other appliances are described and compared. The emergence of microprocessor controls complicates developing specifications for a single operating schedule and simple comparisons of energy performance. Energy test procedures will face unprecedented pressures in the next decade as a consequence of international economic integration and technical innovations. 97104261 Evaluation of wear distribution of a dismountable impeller in a model dredge-pump Wiedenroth, W. Proc. Int. Tech. Conf. Coal Util. Fuel Syst., 1993, 18. 483493. The deciding parameter for the economic success of a hydraulic transportation system can be wear. Facts about different types of wear are listed and several bench testing approaches are described. Results of the trials are presented and a dismountable construction was introduced to improve the measuring technique for the wear pattern of the impeller. Feeding method for coal and waste plastics to coke 97104262 ovens and apparatus for loading coal and waste plastics to coalcharge cars Ishiguro, H. et al. Jpn. Kokai Tokkyo Koho JP 09,132,780 [97,132,780] (Cl. ClOB31/02), 20 May 1997, Appl. 95/291,253, 9 Nov 1995, 6 pp. (In Japanese) The title method involves feeding waste plastics to charge hoppers of coal cars and then feeding coal to the hoppers, from the bottom of which the raw material loaded is withdrawn to the coke ovens. The coke oven comprises a lower layer mainly of waste plastics and an upper layer consisting mainly of coal. 97104263 Flue gas desulfuriration system capital and operating cost reductions based on improved thiosorbic scrubber system design and latest process innovations Smith, K. et al. Proc. Int. Tech. Conf. Coal Util. Fuel Syst.. 1994, 19, 239249. The Miami Fort wet scrubber flue gas desulfurization (FGD) pilot test unit has been in operation since late 1989 and has continued in-house R&D to improve the economics of the magnesium-enhanced scrubbing process. Various tests provided data then used to evaluate the capital and operating costs for the improved systems. These evaluations were made bearing in mind the choices electrical utilities will need to make in the near future to meet the Phase II emission limits mandated by the 1990 Clean Air Act. Some of the process modifications investigated apply to potential beneficial retrofit of existing FGD systems today. Fluidized bed granulation: gas flow, particle motion 97104264 and moisture distribution Becher, R.-D. and Schliinder, E.-U. Chemical Engineering and Processing, 1997, 36, (4), 261-269. A two-fluid-nozzle inside the bed is often used in fluidized bed granulation to distribute the liquid. Then the wetting process takes place in the jet that is formed by the atomizing air. A model has been derived for a free jet to calculate the particle and gas velocities, the void fraction and the crosssectional area of the jet. The results are compared with experimental data for the particle circulation time in the fluidized bed. Based on the particle and gas motion the liquid deposition is calculated, resulting in particle moisture distributions. The paper discusses the influence of different parameters on the moisture distribution and its possible consequences on the granulation process. 97104285 Fuels program for the Fellin, M. A. and Mahr, D. Proc. Int. 1996, 21, 193-200. The paper reports that the coal handling upgraded to help the plant operators to
Nucla AFBC plant Tech. Conf. Coal (itil. Fuel Syst.. system of the power plant is being reliably fuel the AFBC unit.