富氧燃煤复合固硫剂固硫机理研究

Coal-combustion sulfur-fixation technology is a SO2 emission reduction technology fitted to the situation of our country，oxygen-enriched combustion is high effective combustion technology for coal，efficient and clean use of coal especially in combustion would be achievable after coal-combustion sulfur-fixation technology and oxygen-enriched combustion technology is combined organically。The key of oxygen-enriched coal-combustion sulfur-fixation technology is to develop the low cost，convenient to use，high sulfur fixing efficiency and no secondary pollution compound sulfur fixing agent，but now there are few reports to see about oxygen-enriched coal-combustion compound sulfur fixing agent。So，by trial production compound sulfur fixing agent，this study would explore sulfur fixing mechanism of oxygen-enriched coal-combustion compound sulfur fixing agent，and how to enhance combustion efficiency and sulfur fixing effect in order to obtain triple benefit of environmental protection，energy conservation and economy，these have fundamental significance to promote the comprehensive utilization of metallurgy secondary resources and efficient and clean use of coal especially in combustion。 On the basis of fully analyzing the kinds，composition and properties of metallurgy secondary resources，from them the raw materials were picked out to make coal-combustion compound sulfur fixing agents and additives。This item mainly study the sulfur fixing effect of compound sulfur fixing agent both in oxygen-enriched and atmosphere in air atmosphere by orthogonal experiments and at the same time analyze the sulfur fixing mechanism of compound sulfur fixing agent by building thermodynamics model and kinetics model of oxygen-enriched coal-combustion compound sulfur fixing agent。This study strives to achieve some breakthroughs in compound sulfur fixing agent preparation based on metallurgy secondary resources and sulfur fixing model building in order to establish the theoretical foundation for efficient and clean use of coal especially in combustion。

燃煤固硫是一项适合我国国情的减排SO2的技术，富氧燃烧又是煤的高效燃烧技术，燃煤固硫与富氧燃烧有机结合可实现煤的高效洁净燃烧。富氧燃煤固硫能取得理想效果的关键是研制开发价格低廉、使用方便、固硫率高、无二次污染的复合固硫剂，然而目前对富氧燃煤复合固硫剂的研究还少见报道。因此，本研究通过试制冶金二次资源复合固硫剂，探索煤在富氧燃烧时添加复合固硫剂后的固硫机理，提高煤的燃烧效率和固硫效果，以获得环保、节能、经济的三重效益，对促进冶金二次资源的综合利用和煤的高效洁净燃烧具有十分重要的意义。 在全面分析冶金二次资源种类、成分及性质的基础上，选择能作为燃煤固硫剂及助剂的原料。用正交实验法研究空气燃煤和富氧燃煤复合固硫剂的固硫效果，通过建立富氧燃煤复合固硫剂固硫的热力学与动力学模型，分析其固硫机理。本研究力求在冶金二次资源复合固硫剂的制备及固硫模型建立方面有所突破，为煤的高效洁净燃烧奠定理论基础。

以含硫量为0.8%、1.22%的重庆永川煤为研究对象，采用综合热分析仪、定硫仪等，研究了不同钙基固硫剂对固硫效率和固硫动力学的影响。研究结果表明，煤中硫的析出大致分为三个阶段，各阶段的析出率分别为：53.56%、16.52%、29.92%。低硫煤、高硫煤时四种不同钙基固硫剂的最佳钙硫摩尔比Ca/S有所差异，低硫煤最佳Ca/S时为3.0、3.0、2.5、2.5，高硫煤时为2.19、2.19、2.63和2.63；综合固硫率η(%)、失重率、活化能Ea及误差分析得出，在四种钙基固硫剂中，Ca(OH)2的固硫效果最佳。原煤在加入钙基固硫剂后，动力学参数表面反应活化能Ea有明显的减少，而 Ca(OH)2与CaO2的加入使得活化能减少的效果最明显。.通过研究MgO、Al2O3、MnO2等几种助剂对常见钙基固硫剂固硫效率的影响，研究结果发现：在Ca/S为2.0的基础上，随着MgO含量的增加，燃煤固硫效果有所改善，添加助剂后固硫率提高了15%~20%；添加MgO后，煤样燃烧失重百分比略升高，着火温度Te稍提前而燃烬温度Tc稍推迟。添加剂MnO2对固硫效果的影响是先促进后抑制，当MnO2加入量为15%左右时，MnO2对固硫剂的固硫促进作用最明显。Al2O3可以有效提高Ca(OH)2固硫效果，但是对CaO2的固硫效果提升不大。.选取Ca(OH)2为钙基，Ca/S比为2，分别加入高炉渣、转炉渣、布袋除尘灰、动力除尘灰作为催化固硫的添加剂。结果表明：转炉渣可以使固硫率明显上升，且在添加量为20%左右的固硫率最高：41.80%，是四种固废中最适合作为催化固硫的添加剂。同时对比了空冷与水淬钢渣对固硫效率的影响发现：原煤中加入转炉渣后具有一定的固硫效果，在加入25%转炉渣时固硫率最高，固硫率最高能达到27.8%；空冷渣的固硫效果比水淬渣的固硫效果好水淬使得钢渣中的CaO晶格结构发生改变，反应效果变差；在钢渣的基础上加入一定的添加剂Al2O3、MnO2后，转炉渣的固硫效果有提升，但幅度较小。.研究了富氧气氛下固硫剂对煤粉燃烧过程中硫迁移规律的影响，结果表明：煤样在炉内富氧燃烧时，硫的析出为单峰析出。在（O2/CO2=1:4）气氛下，相比于煤在空气中燃烧，硫的析出量降低，由于燃烧生成的CO2产物的扩散，燃烧时间将延长。