煤中形态硫在不同燃烧前预处理过程的脱除行为

The Removal Behavior of Sulfur Forms in Coal During Different Pretreatment Before Coal Combustion

利用ASTM形态硫分析法和X射线光电子能谱法(XPS)分析了田沟(TG)和胜利(SL)煤中不同形态硫组分及含量,在煤燃烧前通过过氧乙酸和NaOH/KOH溶液进行洗煤预处理以及不同温度和气氛下的温和热解预处理,分析煤中形态硫在不同的燃前预处理过程中的脱除行为.结果表明,酸/碱洗煤通过选择性氧化和亲核置换反应能有效脱除煤中黄铁矿硫、易分解的有机硫和部分难分解的苯并噻吩等有机硫;燃烧前温和热解预处理可使煤中含硫组分分解释放,微氧化性热解气氛能促进C-S键断裂,其对煤中黄铁矿硫和不稳定有机硫的脱除有明显促进,对稳定有机硫化物的脱除影响不大。

Different forms of sulfur in TianGou （TG） and ShengLi （SL） coals were identified by using X-ray photoelectron spectroscopy （XPS）, the two coals were pre-treated by two-step washing using peroxyacetic acid and NaOH/KOH solutions and also pyrolyzed in a fix-bed reactor under different atmospheres. Different pre-treatment methods were used to investigate the removal characteristics of different sulfur forms in coal. The results show that, via selective oxidation and nucleophilic displacement reaction, the coal-washing pretreatment could effectively remove pyrite, most unstable organic sulfur and sulfate and even part of hard decomposition organic sulfur. The mild thermal pyrolysis made the sulfur compounds release further. Oxygen can selectively break C-S bonds, which could promote to remove pyrite and unstable organic sulfur but have little effect on the stable thiophene.