03425 Modeling laminar flames for domestic burners

03425 Modeling laminar flames for domestic burners

16 Fuel science and technology (fundamental science, analysis, instrumentation) 99lO3415 Ebara fluidired-bed gasification combustion system Takahas...

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16

Fuel science and technology (fundamental

science, analysis, instrumentation)

99lO3415 Ebara fluidired-bed gasification combustion system Takahashi, K. Kami Pa Gikyoshi, 1998, 52, (lo), 1348-1358. (In Japanese) A new environment-friendly waste treatment system has been designed combining the EBARA urban refuse incinerator and the sludge circular combustor technologies. The technology has a great potential amidst current moves from waste treatment toward waste recycling. 99103416 Fluidized bed coal gasification furnaces Yoshida, K. et al. Jpn. Kokai Tokkyo Koho JP 10 306,284 [98 306,284] (Cl. ClOJ3/46), 17 Nov 1998, Appl. 97/116,750,7 May 1997, 6 pp. (In Japanese) Included in the furnaces are a slag discharging opening at the bottom of a gasification chamber, a slag cooling chamber containing cooling water, a means monitoring the brightness distribution image of the slag falling on the water surface and an image processing the slag data from the monitoring means. Fluidired bed dry distillation furnaces 99103417 Kojima, K. Jpn. Kokai Tokkyo Koho JP 10 306,283 [98 306,283] (Cl. ClOB49/22), 17 Nov 1998, Appl. 97/117,898, 8 May 1997, 6 pp. (In Japanese) In order to generate a pyrolytic gas from a fuel mixed with a flowing material, the furnaces have a hearth tilted downward from below the fuel inlet of the furnace. Nozzles on the hearth blow a gas flow to bring the flowing material to the top part of the furnace and a cyclone at the top part of the furnace separates the flowing material from the pyrolytic gas. The separated material is recycled to the hearth. The furnaces can be used for treating coal, heavy oil and wastes. Gas and solids reducing slurry downcomer 99103418 W. C. and Mart, C. J. PCT Int. Appl. WO 98 50,494 (Cl. Behrmann, ClOG2/00), 12 Nov 1998, US Appl. 851,863, 6 May 1997, 22 pp. The remokal of particulate solids and gas from a three-phase hydrocarbon synthesis slurry of solid catalyst particles, gas and liquid is described. The slurry is passed successively from a slurry body through solids and gas disengaging zones in fluid communication, with the solids disengaging zone upstream of the gas disengaging zone. This is accomplished using a solids and gas disengaging downcomer immersed in the slurry wherein solids are disengaged in a quiescent zone adjacent the slurry body, from which the solids reduced slurry passes through an enclosed cup in which gas is disengaged and removed. The bottom of the cup terminates in a downwardly depending downcomer which hydraulically feeds the densified, solids and gas reduced slurry to the bottom of the reactor or to filtration. Global kinetic analysis of complex materials 99103419 Burnham, A. K. and Braun, R. L. Energy Fuels, 1999, 13, (I), l-22. First-order, nth-order, nucleation and sequential models are among a variety of global kinetic models reviewed here, as well as models having Gaussian, Weibull and discrete activation-energy distributions. The important characteristics of these various models are outlined, with guidance in how to select the correct model. Some of the models have similar characteristics and the parameter relationships among similar models are discussed. Additionally, a new method for deriving discrete activation-energy distribution parameters having In(A) = a + bE is presented. Data accuracy requirements are discussed briefly and kinetic analyses are given for a variety of materials. Hearth structure of coal gasification furnaces. 99103420 Murakami, K. and Morimoto, T. Jpn. Kokai Tokkyo Koho JP 10 306,285 (98 306,285] (Cl. ClOJ3/52), 17 Nov 1998, Appl. 97/116,733, 7 May 1997, 5 pp. (In Japanese) The hearth have taps for discharging melted slag to a slag cooling chamber and grooves guiding the slag to the taps, where the taps have cut off sections at areas connecting to the grooves.

shrinking core model was inadequate to describe the sulfation under the conditions studied. The expression of the product layer coefficient as an exponential function of the conversion led to a unreacted shrinking core model which described the sulfation more accurately.

reaction diffusion modified reaction

Hydroprocessing catalyst 99103423 Kresge, C. T. et al. US 5,837,639 (Cl. 502-64; BOlJ29/00), 17 Nov 1998, US Appl. 625,245, 10 Dee 1990, 22 pp. Comprising a metal hydrogenation-dehydrogenation component supported on a support material comprising an ultra-large pore crystallized material of high surface area and porosity, the catalytic composition is described. The crystallized material exhibits unusually large sorption capacity demonstrated by its benzene adsorption capacity of 215g benzene/lOOg at 50 torr and 25°C and has upiformly sized pores with a maximum perpendicular cross-section of 213A. 99103424 Investigative results of the research program ‘Auxiliary ventilation and monitoring’ Pollak, R. et al. Glueckauf-Forschungsh., 1998, 59, (4), 104-109. (In German) As part of the technology programme mining, DMT Gesellschaft fuer Forschune. und Pruefunr! mbH, Pro Tee Division, carried out an investigatl’re project entified Auxiliary ventilation and monitoring III between 1994 and 1996. Part-financed by the Ministry for Commerce and Trade in Germany, this project focused on auxiliary ventilation in roadway drivages in collieries and covered the following aspects: auxiliary ventilation in advanced headings, safe operation of combined fan systems in the presence of very high CH4 concentrations, flushing of CH4 accumulations after a shutdown of the auxiliary ventilation system and improved techniques and equipment for ventilation, monitoring and air conditioning in headings with auxiliary ventilation. The report presents a summary overview of the problems associated with each part of the project, the main results obtained and the level of technical development achieved. 99103425 Modeling laminar flames for domestic burners Brion, L. Gar d’aujourd’hui, 1999, 123, (3), 7-11. (In French) One research method for designing domestic natural gas burners is modelling; it involves complex chemical reactions inside laminar flames of a methane-air or natural gas-air mixture. This type of flame can be modelled using numeric tools which have been developed by Gaz de France’s Research and Development Division. This article shows the structure of a two-dimensional flame, calculated using the Phoenics algorithm and also improvements made to the physical model and the numerical method of the ESTET-CC algorithm. 99103426 A new method for adiabatic flame temperature estimations of hydrocarbon fuels Zhou, M. and Gauthier, J. E. D. Fuel, 1999, 78, (4), 471-478. The application of artificial neural networks to adiabatic flame temperature prediction of hydrocarbon fuels is presented here. The investigation was conducted over a wide range of operating conditions in terms of fuel composition, pressure and temperature of reactants, fuel-air equivalence ratio and fuel vapour fraction. Several neural network models for predicting the flame temperature for different applicable fuel ranges were built and examined. The proper preparation of network training data and the appropriate choice of network parameters for achieving better prediction accuracy are discussed. The neural network prediction results were compared with those calculated by a thermodynamic and chemical equilibrium-based computer code-the NASA program CET89. It was shown that trained neural network models can provide the adiabatic flame temperature prediction with a good level of accuracy over a wide range of operating conditions.

Heat transfer analysis in a coke oven chamber. 99103421 Aoki, H. Kagoku Kogaku, 1998, 62, (12), 726-729. (In Japanese) Heat transfer in a coke oven and related coke retorting phenomena, including the existence of coal, molten and coke layer, thermal expansion and shrinkage and occurrence of internal stress and cracks, form the subject of this review. Development of the next generation coke manufacturing technology, the SCOPE 21 (super coke oven for productivity and environment enhancement toward the 21st century), is also briefly discussed.

99193427 Oxidation of cyclohexene in liquid phase over hydrotalcite-like compounds containing transition metals Dinka, P. et al. Petroleum and Coal, 1999, 41, (l), 57-61. Tests were carried out on synthesized hydrotalcite-like compounds (HTLc) containing transition metals (cobalt, manganese, nickel, chromium, vanadium) incorporated in the hydrotalcite structure as catalysts for cyclohexene oxidation by oxygen in the liquid phase. The catalytic activity of these compounds was compared with corresponding transition metals in the form of organic salts. The main reaction products are 2-cyclohexene-lon and 2-cyclohexene-l-01.

High pressure thermogravimetric analysis of the 99103422 direct sulfation of Spanish calcium-based sorbents Alvarez, E. and Gonzalez, J. F. Fuel, 1999, 78, (3), 341-348. Typical pressurized fluidized bed combustion (PFBC) conditions thermodynamically inhibit the calcination reaction of limestones and causes the sorbent to react with SO1 by a direct mechanism. Direct sulfation reactivity of different Spanish sorbents was studied by high-pressure thermogravimetric analysis. The physical structure of the surface of the particles was found to influence the sulfation behaviour of the sorbents. Total pore volume and pore surface area correlated well with the reactivity of the sorbents. Temperatures between 800 and 925°C and pressures between 12 and 25 bar promoted an increase in reactivity. However, the gas composition had no effect when changed from 15% C02:3% Oz:O.5% SOz:balance Nz to 12% CO2:7% 02:0.5% SOz:balance Nz. The unreacted

99103428 Oxidative coupling of methane over alkaline earth oxides de osited on commercial support precoated with rare earth oxi 8 es Choudhary, V. R. er al. Fuel, 1999, 78, (4), 427437. Prepared by depositing alkaline earth oxides on a commercial support (SA5205) pre-coated with various rare earth oxides, a number of supported catalysts have been evaluated for their surface properties and activity/ selectivity in oxidative coupling of methane (OCM) at low contact time. The catalysts have been characterized for their basicity and acidity distributions by temperature programmed desorption (TPD) of COz and ammonia from 50°C to 95O”C, respectively and for their oxygen chemisorption sites by TPD of Oz. The OCM activity of the catalysts has been correlated with their basic sites measured in terms of the COz desorbed between 500°C and 950°C. The catalysts with LazOs and/or NdzOs, showing good OCM activity,

358

Fuel and Energy Abstracts

September

1999