【作者】 谭娅；

【导师】 李彩亭；

【作者基本信息】 湖南大学 ， 环境工程， 2005， 硕士

【摘要】 燃煤引起的二氧化硫污染是严重的全球性问题。目前我国二氧化硫的排放量居世界第一位。燃烧中固硫技术是一种适合我国国情的脱硫技术之一。但是燃烧中固硫技术存在钙基固硫剂利用率低、固硫产物在高温下易分解等缺点,从而导致固硫率偏低。本文针对这一技术难点,开展了燃煤固硫添加剂的实验研究,并对其促进固硫的机理进行了分析。 本文重点考虑了影响固硫率的四个主要因素（燃烧温度、钙硫比、固硫剂和煤粉粒径）,针对所选煤种,研究了四种钙基固硫剂的固硫特性。实验表明,电石渣的固硫效果最好。 选用9种化合物进行了单组分固硫添加剂的实验研究。添加剂的促进作用受到不同因素的影响,其中温度的影响因素最大。实验结果表明,加入添加剂对电石渣固硫都有不同程度的促进作用,且其促进固硫的作用和机理各不相同。其中,MnO₂和Fe₂O₃在低温下对固硫剂固硫的促进作用比较大,但高温下则有所下降。而K₂CO₃在高温下对固硫剂固硫的催化作用比较稳定。稀土氧化物在不同温度下对固硫都有较好的催化作用,这个结果尚未见文献报导。 在单组分实验的基础上,进行了三组共13种双组分添加剂的实验研究。研究结果表明,在添加剂的添加量为1%,温度为900℃的条件下,K₂CO₃和MgO以摩尔比为0.1时固硫效果最好,达到77.99%;MnO₂和Fe₂O₃以摩尔比为0.2时固硫效果次之,达到74.21%。在此基础上进行了三组分复合添加剂的实验研究,研究得出,所研制成的复合添加剂KMM和MFK可使所选煤种固硫率达到84%以上。 采用TG和DTG热分析方法对加入添加剂前后煤样的燃烧过程进行了分析,采用XRD和SEM对煤渣进行了表征。结果表明,添加剂的加入一方面形成了热稳定性的物质,另一方面改变了煤渣的结构。根据TG和DTG曲线研究了固硫反应动力学参数。结果表明,频率因子A对于固硫反应的影响大于表面活化能E_a的影响。更多还原

【Abstract】 The sulfur dioxide pollutant derived from coal combustion was a serious worldwide problem. The total sulfur dioxide emission in China was foremost in the world. Sulfur capture in furnaces was competitive for controlling the SO₂ pollutants, due to the low capital and operating costs. But it had some shortcomings, such as the low using efficiency of Ca-based, sulfate product redecomposing easily during high temperature, leading to the low desulfurization efficiency. In this thesis, additives were researched to increase the sulfur capture efficiency, and effect and mechanism additives affecting sulfur capture efficiency were discussed.Put the importance on four mail factors, such as burning temperature, Ca/S mol ratio, sulfur capture sorbent and the size of coal particle, based on the representative coal, characteristic of four sulfur capture sorbents were investigated. It was found that calcium carbide residue showed the best activity.The additive effect of 12 kinds different single-composition was investigated. The promoting effect of additive was affected by different factors, and the temperature showed the most distinct influence. It was found that different additives produced different promoting effect on calcium carbide residue sulfur capture and the promoting effect and mechanism were dissimilar. For example, the promoting effect of MnO₂ and Fe₂O₃ were the more prominent at low temperature than at high temperature. By contraries, K₂CO₃ showed the more remarkable at high temperature than at low temperature. And rare earths oxide showed good catalyzing character. And this important result was not reported now.Based on the single-composition experiment, 13 kinds double-composition additives were researched. It were concluded that, on the condition of the additive total quality of 1.0% of coal and the temperature of 900℃, when K₂CO₃ and MgO mol ratio was 0.1 the sulfur capture ratio got 77.99% the best result, and the second was 74.21% when MnO₂ and Fe₂O₃ mol ratio was 0.1. At last, three compositions additive were studied, and the sulfur capture ratio of two composite additives, which were named KMM and MFK, was higher than 84%.The coal samples were analyzed through TG and DTG and the cinder was characterized through XRD and SEM. The result showed that the thermal stability更多还原