Abstract:

For the purpose of investigating desulfuration characteristics and mechanism of black liquor coal slurry, three combustion experiments were performed in thermobalance, test furnace and industrial boiler, respectively, and sulfur dioxide emission in the combustion fume was compared between black liquor coal slurry and the raw coal, qualitatively and quantitatively.The desulfuration mechanism of black liquor coal slurry was investigated by means of energy spectroscopy, electron probe microanalyzer and X-ray diffraction analysis of typical combustion ash samples from test furnace and industrial boiler.The result indicated that most of sulfur dioxide was absorbed by sodium hydroxide and fixed in fly ash and slag during the combustion of black liquor coal slurry, and the sulpharization process of sodium carbonate in the high temperature environment could also absorb part of sulfur dioxide.Sodium hydroxide and sodium carbonate are two principal desulfuration agents with the mechanism different from coal’s calcium-base desulfuration.The occurrence form of the desulfuration phase in fly ash and slag of black liquor coal slurry was mainly thenardite, sodium sulfate and aphthitalite.

Key words:

黑液水煤浆, Na, 固硫特性, 固硫机理

摘要：

为了解黑液水煤浆自身固硫特性及机理，采用热天平、试验炉和工业炉燃烧运行实验，定性定量比较了黑液浆与制浆原煤燃烧烟气SO₂排放特性，并通过对炉内典型燃烧灰样的能谱、电子探针和X射线衍射分析，对黑液浆燃烧固硫机理进行了深入研究。结果表明，与燃煤Ca基固硫机理不同的是，NaOH和Na₂CO₃是两种最主要的固硫剂，黑液浆燃烧产生的SO₂绝大部分被NaOH所吸收而固定在灰渣中，Na₂CO₃在炉内高温环境下经历的硫酸盐化过程也能吸收烟气中部分硫氧化物，固硫物相在灰渣中主要以无水芒硝、硫酸钠、钾芒硝的形态存在。

关键词:

黑液水煤浆, Na, 固硫特性, 固硫机理