A kinetic description of vapor phase alkali transformations in combustion systems

Srinivasachar, S.; Helble, J.J.; Ham, D.; Domazetis, G.

doi:10.1016/0360-1285(90)90039-6

Cited by 75 publications

(20 citation statements)

References 9 publications

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“…The first two groups are found to be releasable during combustion [5,6] and, to a certain extent, decompose into atomic sodium [7]. Based on equilibrium calculations, atomic sodium is the favored form of sodium species within a flame environment except under high chlorine concentration conditions [8]. The final forms of sodium in post-flame gases can be modeled well using current mechanisms [7,9,10] and the calculation results suggest sodium chloride NaCl and sodium hydroxide NaOH are the major sodium species [7].…”

Section: Introductionmentioning

confidence: 94%

Measurement of atomic sodium release during pyrolysis and combustion of sodium-enriched Zhundong coal pellet

Wang

Liu

Whiddon

et al. 2017

Combustion and Flame

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Temporally resolved measurements of surface temperature, pellet diameter and proximal sodium concentration field are presented for the combustion of a high sodium coal (Zhundong) pellet. Non-resonant Planar laser-induced fluorescence (PLIF) was used to image the atomic sodium distribution around the coal pellet. The release profile of atomic sodium demonstrates three phases of combustion: (I) the devolatilization stage, (II) the char burnout stage, and (III) the ash reaction stage. Highest peak sodium concentration occurred in the char burnout stage, while the ash stage had the longest duration. The radial and axial sodium concentration decay during different phases of combustion was analyzed. During char burnout and ash stages, the maximum concentration of atomic sodium was near the pellet. In the devolatilization stage, burning of volatile-gases creates a high temperature region away from the surface of the coal pellet, which enhances the decomposition of sodium compounds in this region. Axial decay of atomic sodium concentration was governed by chemical reactions during all combustion stages. Calculation of atomic sodium flux (Na * flux) indicate that the smaller pellet releases atomic sodium more strongly in the devolatilization and char burnout stages than larger pellet. The mechanism of sodium release was inferred from the time derivatives of Na * flux , pellet-surface temperature (T) and pellet diameter (d). During the devolatilization stage, only Na * flux and T show variations, indicating that atomic sodium release is due to pyrolysis of the coal pellet. In the char burnout stage, time derivatives of the three parameters obey a common trend, indicating that the sodium release is associated with the burning of organic components in the pellet. In the ash reaction stage, T and d remain constant, indicating that the release of atomic sodium may be attributed to slow processes in the ash, likely vaporization of sodium from crystalline solids. A two-steps sodium release kinetics has been developed in this study and the simulation results agree well with measurements at three burning stages of coal pellet.

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Section: Introductionmentioning

confidence: 94%

Measurement of atomic sodium release during pyrolysis and combustion of sodium-enriched Zhundong coal pellet

Wang

Liu

Whiddon

et al. 2017

Combustion and Flame

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show abstract

“…If the Cl content is only about 0.05 wt%, the proportion of the hydroxides exceeds that of the chlorides from ca. 1200 C. Kinetic modelling for the NaeCl system [86] shows that the gas phase species NaOH and NaCl generally reach their equilibrium values on the millisecond timescale. In contrast, equilibrium between gas and condensed phase components is not normally reached.…”

Section: Alkali Chemistrymentioning

confidence: 99%

On-line spectroscopic and spectrometric methods for the determination of metal species in industrial processes☆

Monkhouse

2011

Progress in Energy and Combustion Science

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“…Total number of considering gaseous species are 33, and 182 of the elementary reactions are considered. The elementary reactions for H 2 -O 2 system refers the schemes presented by Miller and Bowman [42], and the reaction system for Na/O/H/S/Cl refers that by Srinivasachar et al [43] and Glarborg and Marshall [44].…”

Section: Kinetic Simulation By Elementary Reactionsmentioning

confidence: 99%

Emission control of sodium compounds and their formation mechanisms during coal combustion

Takuwa

Naruse

2007

Proceedings of the Combustion Institute

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A kinetic description of vapor phase alkali transformations in combustion systems

Cited by 75 publications

References 9 publications

Measurement of atomic sodium release during pyrolysis and combustion of sodium-enriched Zhundong coal pellet

Measurement of atomic sodium release during pyrolysis and combustion of sodium-enriched Zhundong coal pellet

On-line spectroscopic and spectrometric methods for the determination of metal species in industrial processes☆

Emission control of sodium compounds and their formation mechanisms during coal combustion

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