Transformations and affinities for sulfur of Chinese Shenmu coal ash in a pulverized coal-fired boiler

Journal Article · Wed Jul 01 04:00:00 EDT 2009 · Energy Sources, Part A: Recovery, Utilization, and Environmental Effects

DOI:https://doi.org/10.1080/15567030802572206· OSTI ID:21187159

Cheng, J; Zhou, J H; Liu, J Z; Cao, X Y; Cen, K F ^[1]

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1. Zhejiang University, Hangzhou (China)

The self-desulfurization efficiency of Shenmu coal with a high initial Ca/S molar ratio of 2.02 was measured in a 1,025 t/h pulverized coal-fired boiler. It increases from 29% to 32% when the power capacity decreases from 100% to 70%. About 60% of the mineral matter and calcium element fed into the furnace is retained in the fly ash, while less than 10% is retained in the bottom ash. About 70% of the sulfur element fed into the furnace is emitted as SO{sub 2} in the flue gas, while less than 10% is retained in the fly ash and less than 1% is retained in the bottom ash. The mineralogical compositions of feed coal, fly ash, and bottom ash were obtained by X-ray diffraction analysis. It is found that the initial amorphous phase content is 91.17% and the initial CaCO{sub 3} phase content is 2.07% in Shenmu coal. The vitreous phase and sulfation product CaSO{sub 4} contents are, respectively, 70.47% and 3.36% in the fly ash obtained at full capacity, while the retained CaCO{sub 3} and CaO contents are, respectively, 4.73% and 2.15%. However, the vitreous phase content is only 25.68% and no CaSO{sub 4} is detected in the bottom ash obtained at full capacity. When the power capacity decreases from 100% to 70%, the vitreous phase content in fly ash decreases from 70.47% to 67.41% and that in bottom ash increases from 25.68% to 28.10%.

• OSTI ID: 21187159
• Journal Information: Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, Journal Name: Energy Sources, Part A: Recovery, Utilization, and Environmental Effects Journal Issue: 1 Vol. 31; ISSN 1556-7036
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ASHES
BOILERS
CALCIUM
CALCIUM CARBONATES
CALCIUM OXIDES
CALCIUM SULFATES
CHINA
COAL
DESULFURIZATION
FLY ASH
MINERALOGY
MINERALS
X-RAY DIFFRACTION