04103 Combustion characteristics of heavy oil-water emulsions

04103 Combustion characteristics of heavy oil-water emulsions

09 Combustion (burners, combustion systems) 96104100 Coal oxidation and calcium loadlng on oxldlzed coal Cho, E. H. and Luo, Q. Fuel Process Techn...

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09

Combustion

(burners, combustion

systems)

96104100 Coal oxidation and calcium loadlng on oxldlzed coal Cho, E. H. and Luo, Q. Fuel Process Technol., 1996, 46, (l), 25-39. Pittsburgh No. 8 coal and two IBC coals (Illinois Basin Coal, No. 101 and 112) were oxidized in a 2-L Parr stirred bench-top reactor at 150-225” and 100-600 psi 0, for up to 5 hours. The coal oxidation was evaluated by measuring total acidic groups formed on the coal surface as well as by measuring adsorption o‘i Ca2’ on the oxidized coal from a solution in g separate system. The value of Ca/S molar ratio may be high enough to capture sulphur during fluidized combustion and coal gasification. Thus, the present method has the potential to be used in a commercial process for preparation of a feedstock for fluidized-bed combustion and coal gasification.

96104101 envlronment

Coal

pyrolysls

with

methane

In

a

reducing

Voigtmann, M. F. et al., Coal Sci. Technol., 1995, 24, (2). 1399-1402. When Millmerran coal and CH, were reacted with 400“ for 64 h in the presence of Ni-Mo/Al,O, catalyst, conversion to liquid products and gasebus hydrocarbons was-higher than under N,, althoigh ii was signifi&tly lower than when H, was used. To achieve higher yields, CH, and H, mixtures were used.

96104102 Combustion accelerators for coal Li, C. Faming Zhuanli Shenqing Gongkai Shuorningshu, CN.1,109,096, Sep. 1995. (In Chinese) Combustion characteristics of heavy 96104103 emulsions Ballester, J. M. et al., Fuel, May 1996, 75, (6), 695-705.

oil-water

The combustion of heavy oil and its emulsions with water was investigated in experiments on a semi-industrial scale. Two comparisons between heavy oil and oil-water emulsion flames are presented that, due lo the different initial conditions of the spray, provide complementary information. Reporter results include spatial distributions in the flame of temperature and species concentrations (0,, CO, UHC, NO,) as well as gaseous and solid emissions in the flue gases. The measurements inside the emulsion flame display a remarkable improvement in the combustion process with respect lo that of the neat oil with poor atomization; differences are much less important if a fine spray is achieved with the heavy oil.

96104 104 Combustion Alberta coals

properties

of

macerals

from

four

Gentzis, T. and Chambers, A. Energy Sowces, 1995, 17, (6), 655-680. The combustibility of handpicked vitrinite and inertinite concentrations from four Alberta coals ranging in rank from subbituminous C to lowvolatile bituminous was measured and compared with the parent coal. The combustion properties of the concentrations were studied by routine analysis of the maceral concentrations, examination of low-temperature reactivity on a thermogravimetric analyzer, examinations of high-temperature burnout profiles on the entrained flow reactor, and measurement of char combustion reactivity on a single-particle combustor. The structure of partially cornbusted chars from two of the coals and their maceral concentrations were examined using SEM.

Computations of steady-state and transient premixed turbulent flames using pdf methods Hulek, T. and Lindstedt, R. P. Cornbusrion & Flame, Mar. 1996, 104, (4),

96104105

481-504. Describes how premixed propagating turbulent flames are modelled using a one-point, single time, joint velocity-composition probability density function (pdf) closure. The pdf evolution equation is solved using a Monte

Carlo method.

96104 106 Conservation of microporous structure of coal in the course of carbonization and its transition into products of heat treatment Weishauptova, 2. et al., Coal Sci. Techrlol., lYY5, 24, (l), 933-936. The aim of this work was lo studv the assumntion that the original microporosity of coal is modified during carbonizat;on. Emanation thkrmal analysis was used in the study.

96104106 tlon plant Rovaglio, Describes conditions subject to

Cycom

Plus - A supervlslon

system

for Inclnera-

M. er al., Termotecnica, Dec. 1995, (12), 67-73. (In Italian) how the Cycom Plus is designed to improve the plant operating in terms of thermal efficiency while maximising the waste load legal restrictions and user-defined bounds.

96104109 Demonstration of PromlSORB lnjectlon MWe tangentially-flred utlllty furnace Rodriguez, P. er al., Vision Tecnol., 1995, 3, (l), 9-14.

In a 75

Discusses how the injection of dry calcium based sorbent materials into the furnace space is an SO, control technique which has been thoroughly studied and well documented in recent years. Aoalication of the technique has however been limited by the rela&ely low’utilization of typical sorbent materials, and by a capacity lo achieve only moderate levels of SO, emission control. Describes a newly developed promoted Ca(OH), sorbent material, in which small quantities of chemical additives are introduced into the water of hydration.

Desulfurlratlon by limestone powder Injection Into furnace. Some conslderatlon by aerosol chemical reaction enalneerlna Kogayashi, 7. Funral Kogaku Krrishi, 1995, 32, (ll), 822-830. (In

96104110

Japanese) Discusses a theoretical explanation limestone aerosol injection.

of

desulphurization

techniques

by

96104 111 Determination of sulfur release from the rapid yrolysis of coals. Kinetic determination and Its application to Parge coal particles Garcia-Labiano, F. er al., Cool Sci. Technol., 1995, 24, (l), 857-860. Four coals of different rank were flash pyrolyzed at 700-1200°C inside a heated wire mesh reactor at atmospheric pressure. The yields of volatile sulphur products were determined as a function of the pyrolysis temperature and particle size.

96104112 Diffusion-flame burning of fuel-vapour pockets in oxidizer for general Lewis numbers Fendell, F. and Wu, F. Combustion & Flame, Apr. 1996, 105, (l), l-14. The authors formulate, and then solve via numercial intregration by the method lines, the unsteady, diffusively limited burnup of initially unmixed fuel vapour and gaseous oxidizer. They studied a simple geometry with spherical symmetry: an initially uniform fuel-vapour sphere is enveloped by a finite shell of gaseous oxidizer. The gaseous oxidizer, in turn, is confined by a concentric impervious noncatalytic spherical container, either adiabatic or isothermal. The contents of the container were treated as ideal gases, and accounts for the rise of pressure in time during the exothermic burn (which ends when the stoichiometrically deficient reactant is fully depleted).

Distributed 96/04113 ous coal ignition Chen, J. C. Chetn. Phys. The distributed activation tional ignition experiment sample to have a distribution

activation

energy

model of heterogene-

Processes Combusr., 1995, 345-348. energy model of ignition models the convenby allowing for the particles within the coal of reactivity. Although it was assumed in this study that pulverized-coal ignition occurs heterogeneously without influence from any volatile matter that may be present, and even though the results closely fit the experimental data, it cannot be said that the model confirms that ignition is purely a heterogeneous process.

96104 114

development

The effect of coal lithotype grindability on pulverized fuel combustion Coal Sci. Techrtol.. 1995. 24. (1). 631-634.

and char

Bailev, J. G. The paper describes laboratory scale comb&ion experiments which demonstrated the relevance of coal petrographic content, which usually differ from industrial scale combustion in using only a selected size fraction of the coal, which alters the natural milled size distribution of petrographic components, and in eliminating turbulence, which alters oxygen diffusion patterns lo and throughout porous particles.

Effect of confinement and thermal cycling on the initiation of LX-17 Urtiew, P. A. er al., Combusrion & Flame, Apr. 1996, 105, (l), 43-53. 96104115

shock

Conversion of fuel-nitrogen pulverized coal flames Niksa, S. and Cho, S. Energy Fuels, 1996.

96104107

in the primary

zones of

10, (2), 463-473. Reports on the complete distributions of all major products and nitrogen species for the oxidative pyrolysis and combustion of premixed suspensions of subbituminous, Pittsburgh No. 8 hvA bituminous, and a Iowvolatile bituminous coal after 150 ms. As Inlet OZ levels were progressively increased from 0 to 15% in successive tests, the process chemical moved through oxidative volatiles pyrolysis, volatiles combustion. soot combustion and char oxidation. However, the different fuel components were consumed sequentially only with the low-volatility coal.

266

Fuel and Energy

Abstracts

July

1996

The shock initialion of rhe insensitive high explosive LX-17, which contains 92.5% triaminotrinitrobenzene (TATB) and 7.5% Kel-F binder, was studied under two simulated accident conditions: initially confined charges were heated to 25O’C and shocked; and unconfined charges were thermally cycled between 25” and 250°C and shocked. Previous research on unconfined TATB-based explosives heated 10 250” revealed increased shock sensitivity. This increase was attributed to both the increased porosity caused by the unsymmetrical thermal expansion of TATB, which resulted in more hot spot ignition sites, and the faster growth of hot spot reactions due 10 the increased surrounding temperature. In this study, aluminum confinement was used 10 decrease the thermal expasion of LX-17.