为了适应当今我国的能源结构和降低煤炭发电等利用过程中产生的污染物排放问题，提出了煤炭纯化−燃烧的新型煤炭反应方式，将整个煤炭的燃烧途径分为纯化和柔和燃烧2个步骤，其中纯化包括中温活化过程(对煤进行性能活化)和高温还原过程(在高温下进行煤中杂质的去除)，从而实现煤的纯化和在后续反应中的N元素的定向转化和NO_x排放的降低。并在搭建好的200 kW纯化−燃烧试验台上，对宽负荷下系统的纯化−燃烧特性和N元素的转化机理进行了研究。结果表明，系统能够在53%～89%的负荷内实现稳定运行，纯化单元和柔和燃烧单元温度分布均匀，系统的温度随负荷的升高而增加，纯化单元的高温区位于高温还原单元底部，最高可达1378 ℃，而柔和燃烧单元的高温区则出现在距顶端3700 mm处。在纯化单元出口的煤气中， CO、H₂和CH₄的体积分数在89%负荷时最高可达23.28%、4.97%、1.52%，随着负荷的增加，燃料中C、H、N元素的转化率均有上升，且高温还原单元出口的元素转化率明显大于中温活化单元出口，达到了88.63%、96.83%和93.91%。大部分的N元素均生成了N₂，53%负荷下仅有1.27%的N转化生成了NO，NO_x排放最低可以达到47.38 mg/m³，此时燃烧效率可达99.01%。对氮的迁移路径转化的研究表明，系统在柔和燃烧单元沿程并没有检测到HCN的存在；而NH₃则广泛存在于三级三次风喷口前；NO_x首先以N₂O和NO₂的形式分布在柔和燃烧单元沿程，在四级三次风喷入后转化为NO。

A purification-combustion coal utilization method has been proposed in this study to align with China’s energy structure and reduce pollution emissions in coal power station. This method transforms the traditional coal combustion pathways into two steps: purification and mild combustion. Purification involves medium temperature activation (enhance coal activation) and high temperature reduction (remove impurities at high temperature), ultimately achieving coal purification, directional transformation of N and low NO_x emissions in subsequent reactions. Experimental tests are conducted on a 200 kW purification-combustion platform aimed to explore purification and combustion characteristics and transmutation of N under wide-load conditions. The results indicate that the stable operation of the platform at loads ranging from 53%-89%, with uniform distribution across the system that increases with load. The peak temperature of the purification unit which locates at the bottom of the high-temperature reduction unit reaches a maximum of 1378 ℃, while the mild combustion unit peaks at a distance of 3700 mm from the top. At the purification outlet, the proportion of CO, H₂ and CH₄ can reach 23.28%, 4.97% and 1.52% at 89% loads. The conversion rates of C, H and N at the high temperature reduction outlet increase with load and are significantly higher than those at medium temperature activation unit, with maximum values of 88.63%, 96.83% and 93.91%. The majority of N is transformed into N₂ during the process, with only 1.27% converts into NO_x at 53% loads. The minimum NO_x emissions are 47.38 mg/m³ with the combustion efficiency of 99.01%. Moreover, the research on the migration pathway of N transformation demonstrates the absence of HCN detection along the process, while NH₃ is found to be abundant above the third-stage tertiary air nozzle. NO_x is observed to distribute along the mild combustion unit initially in the form of N₂O and NO₂, and converts to NO after the injection of the fourth-stage tertiary air.