Behavior of Fouling Deposits Formed on a Probe with Different Surface Temperatures

Zhou, Hao; Zhou, Bin; Zhang, Hailong; Li, Letian

doi:10.1021/ef502141x

Cited by 42 publications

(43 citation statements)

References 29 publications

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“…With the progression of deposition, the contact area between ash particles was enlarged and the deposits became dense. In consequence, the thermal conductivity was increased [24]. Thus, at the final depositing stage, the wall temperature rose slightly again and the temperature difference was diminished.…”

Section: Deposition Tendency At Different Wall Temperaturesmentioning

confidence: 95%

“…Thus, the presence of Al 2 O 3 in the granular slags indicates it served as a skeleton of slagging. Ca 2 Al 2 SiO 7 , a common fluxing material in the slags of Zhundong coal, tended to appear at high temperature [5,24]. Na 2 Al 2 Si 3 O 10 resulted from the reaction among Na-based compounds, SiO 2 and Al 2 O 3 .…”

Section: Deposition Tendency At Different Wall Temperaturesmentioning

confidence: 99%

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Effects of wall temperature on slagging and ash deposition of Zhundong coal during circulating fluidized bed gasification

Song

et al. 2016

Applied Thermal Engineering

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Section: Deposition Tendency At Different Wall Temperaturesmentioning

confidence: 95%

Section: Deposition Tendency At Different Wall Temperaturesmentioning

confidence: 99%

Effects of wall temperature on slagging and ash deposition of Zhundong coal during circulating fluidized bed gasification

Song

et al. 2016

Applied Thermal Engineering

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“…According to our previous work 21 and research of other scholars, 17,18 alkali vapor condensation and Na-and K-bearing aerosol particle deposition contribute significantly to the formation of the initial layer of ash deposits. This layer is thin but has a critical role in initiating and expediting the accumulation of subsequent ash particles.…”

Section: Introductionmentioning

confidence: 90%

Further Study on Ash Deposits in a Large-Scale Wastewater Incineration Plant: Ash Fusion Characteristics and Kinetics

Cai

Chen

et al. 2015

Energy Fuels

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Ash deposition and fusion during the incineration of high-concentration organic wastewater rich in salt is complicated by various issues, resulting in severe operational problems, such as fouling, slagging, and even unscheduled shutdown. The fusion characteristics and melting kinetics of ash samples collected from an industrial-scale wastewater incineration plant were determined by ash fusion temperature tests, simultaneous thermal analysis, and X-ray powder diffractometry. The results showed that the ash fusion characteristics depended upon not only ash compositions but also mineralogy transformation and evolution. The major melting process of ash sample 1 was within the range of 1158−1196 K. Because of the existence of the low-temperature eutectic compounds Na 3 Fe(SO 4 ) 3 and Na 2 Ni(SO 4 ) 2 ·4H 2 O, the temperature ranges of melting processes of ash samples 2−4 were 200−300 K lower than that of ash sample 1. Weight loss processes in ash sample 5 continued over the whole furnace temperature range. The Coats−Redfern equation was used to approximately evaluate the ash melting kinetics. Ash sample 1 had the highest activation energy for an ash melting process (3125.31 kJ mol −1 ). Ash samples 2 and 5 had relatively moderate activation energies (729.15−1338.93 kJ mol −1 ). Ash samples 3 and 4 had the lowest activation energies (374.00 and 375.68 kJ mol −1 ), which indicated that Na 2 SO 4 melting required more energy than the melting of low-temperature eutectic compounds. The most probable reaction model for all of the melting processes was f(α) = (1 − α) 2 . The most probable reaction model for the melting process at 1163.0−1284.9 K in ash sample 3 was f(α) = (1 − α) 4 .

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“…For example, Zhundong 3 coal, which is projected to be one of the most abundant coalmine reserves in China, contains a high concentration of sodium compounds [12]. During the combustion of Zhundong coal, severe fouling and slagging have been encountered arising from the release of sodium in the boiler [13]. Therefore, understanding the conversion and release dynamics of Na and K during coal-biomass combustion processes is essential to increase utilization of blended biomass and coal fuel mixtures.…”

Section: Introductionmentioning

confidence: 99%

Characteristics of alkali species release from a burning coal/biomass blend

Liu

Wang

et al. 2018

Applied Energy

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Solvent fractionation, Laser induced breakdown spectroscopy (LIBS), X-ray Diffraction (XRD) and chemical analysis were applied to binary fuel mixtures of Zhundong coal and cornstalk agricultural class to investigate the release characteristics of alkali species during co-firing of coal and biomass. As the biomass proportion increases, the water-soluble, NH4Ac-soluble and HCl-soluble alkali species interconvert; the extent of the conversion depends on the composition of the blend. From LIBS measurements, it was found that adding the biomass accelerates combustion and outgassing processes.The higher the proportion of the biomass in the blend, the earlier the peak concentrations of alkali appear, and the magnitude of peak concentrations of sodium and potassium decrease and increase, respectively. Furthermore, the interaction between coal and biomass can generate crystals causing the eutectic melting phenomenon (similar to feldspar in XRD results), which results in a sharp decline of the ash fusion temperatures (AFTs). The results not only provide the information of fundamental transformation but also guide industrial co-firing applications of lignite and agricultural class biomass to reduce the risk of ash deposition.

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Behavior of Fouling Deposits Formed on a Probe with Different Surface Temperatures

Cited by 42 publications

References 29 publications

Effects of wall temperature on slagging and ash deposition of Zhundong coal during circulating fluidized bed gasification

Effects of wall temperature on slagging and ash deposition of Zhundong coal during circulating fluidized bed gasification

Further Study on Ash Deposits in a Large-Scale Wastewater Incineration Plant: Ash Fusion Characteristics and Kinetics

Characteristics of alkali species release from a burning coal/biomass blend

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