Interactions among Inherent Minerals during Coal Combustion and Their Impacts on the Emission of PM10. 2. Emission of Submicrometer-Sized Particles
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- 作者：Lian Zhang ; Qunying Wang ; Atsushi Sato ; Yoshihiko Ninomiya ; Toru Yamashita
- 刊名：Energy & Fuels
- 出版年：2007
- 出版时间：March 2007
- 年：2007
- 卷：21
- 期：2
- 页码：766 - 777
- 全文大小：928K
- 年卷期：v.21,no.2(March 2007)
- ISSN：1520-5029
文摘
Four bituminous coals, possessing similar organic properties, were combusted in a lab-scale drop tube furnace(DTF) to investigate the emission of particulates less than 1.0 
m in diameter (PM1). The combustion conditionsare as follows: 1450 
C, air as gas atmosphere, and a residence time of about 3 s. The results indicate thatPM1 is formed by two pathways: metallic vaporization and direct liberation of inherent submicrometer particles.Excluded minerals play no role in its formation. The amount of PM1 as well as the concentrations of individualelements within it vary with coal considerably. Regarding the refractory elements, the transformation of Siand Al is likely affected negatively by the amount of excluded (CaO+Fe2O3) in the parent coals. Ca and Mgin PM1 are entirely contributed from their organically bound fraction and the inherent submicrometer particlescontaining these two elements. A small amount of coarse particles containing Fe (>1 m) also possiblytransforms into PM1 via vaporization or fragmentation. Its extent is dependent on the mode of occurrence ofFe in raw coals. For the volatile elements in PM1, S, P, Na, and K are the most prevalent; they are mainly informs of sulfates, phosphates, and P2O5. The amount of S is determined by the presence of alkali elements andCa in PM1, due to their interactions. The other three are, however, affected by their original modes of occurrence.P in a complicated form containing Si, Al, Ca/Fe, and P likely vaporizes readily due to its melting propensity.The water-soluble species containing Na and K preferentially vaporizes too. The vaporized heavy metals, Mn,Ni, and Cr studied here, possibly bind with the refractory Si and Fe in PM1, which is proven by both thevariation of their concentrations with particulate size and a thermodynamic equilibrium consideration.
m in diameter (PM1). The combustion conditionsare as follows: 1450 C, air as gas atmosphere, and a residence time of about 3 s. The results indicate thatPM1 is formed by two pathways: metallic vaporization and direct liberation of inherent submicrometer particles.Excluded minerals play no role in its formation. The amount of PM1 as well as the concentrations of individualelements within it vary with coal considerably. Regarding the refractory elements, the transformation of Siand Al is likely affected negatively by the amount of excluded (CaO+Fe2O3) in the parent coals. Ca and Mgin PM1 are entirely contributed from their organically bound fraction and the inherent submicrometer particlescontaining these two elements. A small amount of coarse particles containing Fe (>1 m) also possiblytransforms into PM1 via vaporization or fragmentation. Its extent is dependent on the mode of occurrence ofFe in raw coals. For the volatile elements in PM1, S, P, Na, and K are the most prevalent; they are mainly informs of sulfates, phosphates, and P2O5. The amount of S is determined by the presence of alkali elements andCa in PM1, due to their interactions. The other three are, however, affected by their original modes of occurrence.P in a complicated form containing Si, Al, Ca/Fe, and P likely vaporizes readily due to its melting propensity.The water-soluble species containing Na and K preferentially vaporizes too. The vaporized heavy metals, Mn,Ni, and Cr studied here, possibly bind with the refractory Si and Fe in PM1, which is proven by both thevariation of their concentrations with particulate size and a thermodynamic equilibrium consideration.